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Title: Mutant NURR1 gene in
Parkinson's disease
United States Patent: 7,037,657
Issued: May 2, 2006
Inventors: Le; Wei-Dong
(Houston, TX); Vassilatis; Demetrios K. (Seattle, WA)
Assignee: Baylor College of
Medicine (Houston, TX)
Appl. No.: 205951
Filed: July 26, 2002
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Patheon
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Abstract
The identification of mutations in NURR1
provides molecular tools for the development of diagnostic, prophylactic
and therapeutic agents for Parkinson's Disease. In specific embodiments,
two point mutations are identified in exon 1 of the NURR1 gene in 10/107
(9.3%) cases of familial Parkinson's disease (PD). The mutations reduce
NURR1 gene expression (mRNA and protein levels) by 87-95% and decrease
tyrosine hydroxylase (a rate-limited dopamine synthesis enzyme) gene
expression in vitro. It is also demonstrated that in vivo NURR1 mRNA
levels in the lymphocytes from the PD patients with the exon 1 mutation
are reduced by 68-84%, and in over 50% sporadic PD patients the NURR1 mRNA
levels in lymphocytes are significantly reduced. A homozygous polymorphism
is identified in intron 6 of NURR1 that correlates with the presence of
Parkinson's disease. A splicing variant in NURR1 exon 5 is identified.
DETAILED DESCRIPTION
OF THE INVENTION
NURR1, a member of nuclear receptor
superfamily, essential for phenotype of the nigral dopaminergic neurons (Zetterstrom
et al., 1997; Saucedo-Cardenas et al., 1998; Caastillo et al., 1998), is
considered relevant to Parkinson's disease. To determine whether NURR1 is
a susceptibility gene for PD, genetic analysis of NURR1 gene was performed
in 201 PD patients and 221 age-matched normal controls (NC). Two
PD-related mutations (-291T deletion and -245 T to G substitution) were
identified in the first exon of NURR1 gene. These mutations affect one of
the NURR1 alleles in 9.3% (10/107) of familial PD but not in sporadic PD
(n=94) or in NC (n=221). Genotype-phenotype analysis in the ten families
of these PD patients with the identified mutations clearly showed a
segregation between PD and non-PD. Haplotype analysis in four complete fPD
pedigrees suggested that at least two distinct founders may exist in fPD
patients. The age at onset of disease and clinical features of these
patients were not different from typical PD. The mutations resulted in a
dramatically decreased NURR1 mRNA in vitro and in vivo and affected the
tyrosine hydroxylase expression. In addition, NURR1 mRNA levels from
lymphocytes of PD patients with the -291T-del showed a significant
reduction. Together these data indicate that mutations in the exon 1 of
NURR1 can cause dopaminergic dysfunction, which in specific embodiments
leads to the phenotype of PD.
A skilled artisan recognizes that NURR1 sequences may be obtained from
publicaly available databases, including the National Center for
Biotechnology Information's GenBank database, or from the database of
Celera Genomics, Inc. (Rockville, Md.). Examples of nucleic acid NURR1
sequences, followed by the Genbank accession number, include SEQ ID NO:43
(AB017586), SEQ ID NO:44 (AJ278700), SEQ ID NO:45 (NM—013613),
SEQ ID NO:46 (NM—006186), SEQ ID NO:47 (BB539587), SEQ ID NO:48
(BB536225), SEQ ID NO:49 (BB432168), SEQ ID NO:50 (BB424269), SEQ ID NO:51
(BB345745), SEQ ID NO:52 (BB322941), SEQ ID NO:53 (BB023391), SEQ ID NO:54
(BB023355), SEQ ID NO:55 (AB019433), SEQ ID NO:56 (XM—002441),
SEQ ID NO:57 (AV356519), SEQ ID NO:58 (AV356512), SEQ ID NO:59 (AV382234),
SEQ ID NO:60 (AV368035), SEQ ID NO:61 (AV352127), SEQ ID NO:62 (AV341553),
SEQ ID NO:63 (AV245724), SEQ ID NO:64 (AV221665), SEQ ID NO:65 (AB014889),
SEQ ID NO:66 (U72345), SEQ ID NO:67 (U86783), SEQ ID NO:68 (U67738), SEQ
ID NO:69 (U93471), SEQ ID NO:70 (U93429), SEQ ID NO:71 (S53744), SEQ ID
NO:72 (R35928), and SEQ ID NO:73 (R25908). Examples of amino acid NURR1
sequence include SEQ ID NO:74 (548390), SEQ ID NO:75 (XP—002441),
SEQ ID NO:76 (CAC27783), SEQ ID NO:77 (A46225), SEQ ID NO:78 (NP—038641),
SEQ ID NO:79 (NP—006177), SEQ ID NO:80 (BAA77328), SEQ ID NO:81
(BAA75666), SEQ ID NO:82 (Q07917), SEQ ID NO:83 (P43354), SEQ ID NO:84
(Q04913), SEQ ID NO:85 (AAB68748), SEQ ID NO:86 (AAB68706), and SEQ ID
NO:87 (AAB25138). In specific embodiments of the present invention, a
NURR1 nucleic acid sequence of SEQ ID NO:1 and/or a NURR1 amino acid
sequence of SEQ ID NO:2 is utilized.
III. Nucleic Acid-Based Expression Systems
A. Vectors
In specific methods of the present invention, a vector is utilized to
transport an exogenous nucleic acid sequence. A nucleic acid sequence is
"exogenous," if it is foreign to the cell into which the vector is being
introduced or if the sequence is homologous to a sequence in the cell but
in a position within the host cell nucleic acid in which the sequence is
ordinarily not found. Vectors include plasmids, cosmids, viruses (bacteriophage,
animal viruses, and plant viruses), and artificial chromosomes (e.g.,
yeast artificial chromosomes (YACS) or bacterial artificial chromosomes (BACs)).
One of skill in the art would be well equipped to construct a vector
through standard recombinant techniques, which are described in Maniatis
et al., 1988 and Ausubel et al., 1994, both incorporated herein by
reference.
The term "expression vector" refers to a vector containing a nucleic acid
sequence coding for at least part of a gene product capable of being
transcribed. In some cases, RNA molecules are then translated into a
protein, polypeptide, or peptide. In other cases, these sequences are not
translated, for example, in the production of antisense molecules or
ribozymes. Expression vectors can contain a variety of "control
sequences," which refer to nucleic acid sequences necessary for the
transcription and possibly translation of an operably linked coding
sequence in a particular host organism. In addition to control sequences
that govern transcription and translation, vectors and expression vectors
may contain nucleic acid sequences that serve other functions as well and
are described infra.
1. Promoters and Enhancers
A "promoter" is a control sequence that is a region of a nucleic acid
sequence at which initiation and rate of transcription are controlled. It
may contain genetic elements at which regulatory proteins and molecules
may bind such as RNA polymerase and other transcription factors. The
phrases "operatively positioned," "operatively linked," "under control,"
and "under transcriptional control" mean that a promoter is in a correct
functional location and/or orientation in relation to a nucleic acid
sequence to control transcriptional initiation and/or expression of that
sequence. A promoter may or may not be used in conjunction with an
"enhancer," which refers to a cis-acting regulatory sequence involved in
the transcriptional activation of a nucleic acid sequence.
A promoter may be one naturally associated with a gene or sequence, as may
be obtained by isolating the 5′ non-coding sequences located upstream of
the coding segment and/or exon. Such a promoter can be referred to as
"endogenous." Similarly, an enhancer may be one naturally associated with
a nucleic acid sequence, located either downstream or upstream of that
sequence. Alternatively, certain advantages will be gained by positioning
the coding nucleic acid segment under the control of a recombinant or
heterologous promoter, which refers to a promoter that is not normally
associated with a nucleic acid sequence in its natural environment. A
recombinant or heterologous enhancer refers also to an enhancer not
normally associated with a nucleic acid sequence in its natural
environment. Such promoters or enhancers may include promoters or
enhancers of other genes, and promoters or enhancers isolated from any
other prokaryotic, viral, or eukaryotic cell, and promoters or enhancers
not "naturally occurring," i.e., containing different elements of
different transcriptional regulatory regions, and/or mutations that alter
expression. In addition to producing nucleic acid sequences of promoters
and enhancers synthetically, sequences may be produced using recombinant
cloning and/or nucleic acid amplification technology, including PCR™, in
connection with the compositions disclosed herein (see U.S. Pat. No.
4,683,202, U.S. Pat. No. 5,928,906, each incorporated herein by
reference). Furthermore, it is contemplated the control sequences that
direct transcription and/or expression of sequences within non-nuclear
organelles such as mitochondria, chloroplasts, and the like, can be
employed as well.
Naturally, it will be important to employ a promoter and/or enhancer that
effectively directs the expression of the DNA segment in the cell type,
organelle, and organism chosen for expression. Those of skill in the art
of molecular biology generally know the use of promoters, enhancers, and
cell type combinations for protein expression, for example, see Sambrook
et al. (1989), incorporated herein by reference. The promoters employed
may be constitutive, tissue-specific, inducible, and/or useful under the
appropriate conditions to direct high level expression of the introduced
DNA segment, such as is advantageous in the large-scale production of
recombinant proteins and/or peptides. The promoter may be heterologous or
endogenous.
The identity of tissue-specific promoters or elements, as well as assays
to characterize their activity, is well known to those of skill in the
art. Examples of such regions include the human LIMK2 gene (Nomoto et al.,
1999), the somatostatin receptor 2 gene (Kraus et al., 1998), murine
epididymal retinoic acid-binding gene (Lareyre et al., 1999), human CD4
(Zhao-Emonet et al., 1998), mouse alpha2 (XI) collagen (Tsumaki, et al.,
1998), D1A dopamine receptor gene (Lee, et al., 1997), insulin-like growth
factor II (Wu et al., 1997), human platelet endothelial cell adhesion
molecule-1 (Almendro et al., 1996).
2. Initiation Signals and Internal Ribosome Binding Sites
A specific initiation signal also may be required for efficient
translation of coding sequences. These signals include the ATG initiation
codon or adjacent sequences. Exogenous translational control signals,
including the ATG initiation codon, may need to be provided. One of
ordinary skill in the art would readily be capable of determining this and
providing the necessary signals. It is well known that the initiation
codon must be "in-frame" with the reading frame of the desired coding
sequence to ensure translation of the entire insert. The exogenous
translational control signals and initiation codons can be either natural
or synthetic. The efficiency of expression may be enhanced by the
inclusion of appropriate transcription enhancer elements.
In certain embodiments of the invention, the use of internal ribosome
entry sites (IRES) elements are used to create multigene, or polycistronic,
messages. IRES elements are able to bypass the ribosome scanning model of
5′ methylated Cap dependent translation and begin translation at internal
sites (Pelletier and Sonenberg, 1988). IRES elements from two members of
the picornavirus family (polio and encephalomyocarditis) have been
described (Pelletier and Sonenberg, 1988), as well an IRES from a
mammalian message (Macejak and Samow, 1991). IRES elements can be linked
to heterologous open reading frames. Multiple open reading frames can be
transcribed together, each separated by an IRES, creating polycistronic
messages. By virtue of the IRES element, each open reading frame is
accessible to ribosomes for efficient translation. Multiple genes can be
efficiently expressed using a single promoter/enhancer to transcribe a
single message (see U.S. Pat. Nos. 5,925,565 and 5,935,819, herein
incorporated by reference).
3. Multiple Cloning Sites
Vectors can include a multiple cloning site (MCS), which is a nucleic acid
region that contains multiple restriction enzyme sites, any of which can
be used in conjunction with standard recombinant technology to digest the
vector. (See Carbonelli et al., 1999, Levenson et al., 1998, and Cocea,
1997, incorporated herein by reference.) "Restriction enzyme digestion"
refers to catalytic cleavage of a nucleic acid molecule with an enzyme
that functions only at specific locations in a nucleic acid molecule. Many
of these restriction enzymes are commercially available. Use of such
enzymes is widely understood by those of skill in the art. Frequently, a
vector is linearized or fragmented using a restriction enzyme that cuts
within the MCS to enable exogenous sequences to be ligated to the vector.
"Ligation" refers to the process of forming phosphodiester bonds between
two nucleic acid fragments, which may or may not be contiguous with each
other. Techniques involving restriction enzymes and ligation reactions are
well known to those of skill in the art of recombinant technology.
4. Splicing Sites
Most transcribed eukaryotic RNA molecules will undergo RNA splicing to
remove introns from the primary transcripts. Vectors containing genomic
eukaryotic sequences may require donor and/or acceptor splicing sites to
ensure proper processing of the transcript for protein expression. (See
Chandler et al., 1997, herein incorporated by reference.)
5. Polyadenylation Signals
In expression, one will typically include a polyadenylation signal to
effect proper polyadenylation of the transcript. The nature of the
polyadenylation signal is not believed to be crucial to the successful
practice of the invention, and/or any such sequence may be employed.
Preferred embodiments include the SV40 polyadenylation signal and/or the
bovine growth hormone polyadenylation signal, convenient and/or known to
function well in various target cells. Also contemplated as an element of
the expression cassette is a transcriptional termination site. These
elements can serve to enhance message levels and/or to minimize read
through from the cassette into other sequences.
6. Origins of Replication
In order to propagate a vector in a host cell, it may contain one or more
origins of replication sites (often termed "ori"), which is a specific
nucleic acid sequence at which replication is initiated. Alternatively an
autonomously replicating sequence (ARS) can be employed if the host cell
is yeast.
7. Selectable and Screenable Markers
In certain embodiments of the invention, the cells contain nucleic acid
construct of the present invention, a cell may be identified in vitro or
in vivo by including a marker in the expression vector. Such markers would
confer an identifiable change to the cell permitting easy identification
of cells containing the recombinant vector. Generally, a selectable marker
is one that confers a property that allows for selection. A positive
selectable marker is one in which the presence of the marker allows for
its selection, while a negative selectable marker is one in which its
presence prevents its selection. An example of a positive selectable
marker is a drug resistance marker.
Usually the inclusion of a drug selection marker aids in the cloning and
identification of transformants, for example, genes that confer resistance
to neomycin, puromycin, hygromycin, DHFR, GPT, zeocin and histidinol are
useful selectable markers. In addition to markers conferring a phenotype
that allows for the discrimination of transformants based on the
implementation of conditions, other types of markers including screenable
markers such as GFP, whose basis is colorimetric analysis, are also
contemplated. Alternatively, screenable enzymes such as herpes simplex
virus thymidine kinase (tk) or chloramphenicol acetyltransferase (CAT) may
be utilized. One of skill in the art would also know how to employ
immunologic markers, possibly in conjunction with FACS analysis. The
marker used is not believed to be important, so long as it is capable of
being expressed simultaneously with the nucleic acid of the present
application encoding a gene product or a portion thereof. Further examples
of selectable and screenable markers are well known to one of skill in the
art.
B. Host Cells
As used herein, the terms "cell," "cell line," and "cell culture" may be
used interchangeably. All of these term also include their progeny, which
is any and all subsequent generations. It is understood that all progeny
may not be identical due to deliberate or inadvertent mutations. In the
context of expressing a heterologous nucleic acid sequence, "host cell"
refers to a prokaryotic or eukaryotic cell, and it includes any
transformable organisms that is capable of replicating a vector and/or
expressing a heterologous gene encoded by a vector. A host cell can, and
has been, used as a recipient for vectors. A host cell may be "transfected"
or "transformed," which refers to a process by which exogenous nucleic
acid is transferred or introduced into the host cell. A transformed cell
includes the primary subject cell and its progeny.
Host cells may be derived from prokaryotes or eukaryotes, depending upon
whether the desired result is replication of the vector or expression of
part or all of the vector-encoded nucleic acid sequences. Numerous cell
lines and cultures are available for use as a host cell, and they can be
obtained through the American Type Culture Collection (ATCC), which is an
organization that serves as an archive for living cultures and genetic
materials (www.atcc.org). An appropriate host can be determined by one of
skill in the art based on the vector backbone and the desired result. A
plasmid or cosmid, for example, can be introduced into a prokaryotic host
cell for replication of many vectors. Bacterial cells used as host cells
for vector replication and/or expression include E. coli K12, DH5a,
JM109, and KC8 strains, as well as a number of commercially available
bacterial hosts such as SURE® Competent Cells and SOLOPACKä Gold Cells (STRATAGENE®,
La Jolla). Alternatively, bacterial cells such as E. coli K12 or
LE392 strains could be used as host cells for phage viruses.
Examples of eukaryotic host cells for replication and/or expression of a
vector include HeLa, NIH3T3, Jurkat, 293, Cos, CHO, Saos, and PC12. Many
host cells from various cell types and organisms are available and would
be known to one of skill in the art. Similarly, a viral vector may be used
in conjunction with either a eukaryotic or prokaryotic host cell,
particularly one that is permissive for replication or expression of the
vector.
Some vectors may employ control sequences that allow it to be replicated
and/or expressed in both prokaryotic and eukaryotic cells. One of skill in
the art would further understand the conditions under which to incubate
all of the above described host cells to maintain them and to permit
replication of a vector. Also understood and known are techniques and
conditions that would allow large-scale production of vectors, as well as
production of the nucleic acids encoded by vectors and their cognate
polypeptides, proteins, or peptides.
C. Expression Systems
Numerous expression systems exist that comprise at least a part or all of
the compositions discussed above. Prokaryote- and/or eukaryote-based
systems can be employed for use with the present invention to produce
nucleic acid sequences, or their cognate polypeptides, proteins and
peptides. Many such systems are commercially and widely available.
The insect cell/baculovirus system can produce a high level of protein
expression of a heterologous nucleic acid segment, such as described in
U.S. Pat. No. 5,871,986, 4,879,236, both herein incorporated by reference,
and which can be bought, for example, under the name MAXBAC® 2.0 from
INVITROGEN® and BACPACK™ BACULOVIRUS EXPRESSION SYSTEM FROM CLONTECH®.
Other examples of expression systems include STRATAGENE®'s COMPLETE
CONTROLä Inducible Mammalian Expression System, which involves a synthetic
ecdysone-inducible receptor, or its pET Expression System, an E. coli
expression system. Another example of an inducible expression system
is available from INVITROGEN®, which carries the T-REX™
(tetracycline-regulated expression) System, an inducible mammalian
expression system that uses the full-length CMV promoter. INVITROGEN® also
provides a yeast expression system called the Pichia methanolica
Expression System, which is designed for high-level production of
recombinant proteins in the methylotrophic yeast Pichia methanolica.
One of skill in the art would know how to express a vector, such as an
expression construct, to produce a nucleic acid sequence or its cognate
polypeptide, protein, or peptide.
IV. Nucleic Acid Detection
In addition to their use in directing the expression of NURR1 proteins,
polypeptides and/or peptides, the nucleic acid sequences disclosed herein
have a variety of other uses. For example, they have utility as probes or
primers for embodiments involving nucleic acid hybridization.
A. Hybridization
The use of a probe or primer of between 13 and 100 nucleotides, preferably
between 17 and 100 nucleotides in length, or in some aspects of the
invention up to 1-2 kilobases or more in length, allows the formation of a
duplex molecule that is both stable and selective. Molecules having
complementary sequences over contiguous stretches greater than 20 bases in
length are generally preferred, to increase stability and/or selectivity
of the hybrid molecules obtained. One will generally prefer to design
nucleic acid molecules for hybridization having one or more complementary
sequences of 20 to 30 nucleotides, or even longer where desired. Such
fragments may be readily prepared, for example, by directly synthesizing
the fragment by chemical means or by introducing selected sequences into
recombinant vectors for recombinant production.
Accordingly, the nucleotide sequences of the invention may be used for
their ability to selectively form duplex molecules with complementary
stretches of DNAs and/or RNAs or to provide primers for amplification of
DNA or RNA from samples. Depending on the application envisioned, one
would desire to employ varying conditions of hybridization to achieve
varying degrees of selectivity of the probe or primers for the target
sequence.
For applications requiring high selectivity, one will typically desire to
employ relatively high stringency conditions to form the hybrids. For
example, relatively low salt and/or high temperature conditions, such as
provided by about 0.02 M to about 0.10 M NaCl at temperatures of about 50°
C. to about 70° C. Such high stringency conditions tolerate little, if
any, mismatch between the probe or primers and the template or target
strand and would be particularly suitable for isolating specific genes or
for detecting specific mRNA transcripts. It is generally appreciated that
conditions can be rendered more stringent by the addition of increasing
amounts of formamide.
For certain applications, for example, site-directed mutagenesis, it is
appreciated that lower stringency conditions are preferred. Under these
conditions, hybridization may occur even though the sequences of the
hybridizing strands are not perfectly complementary, but are mismatched at
one or more positions. Conditions may be rendered less stringent by
increasing salt concentration and/or decreasing temperature. For example,
a medium stringency condition could be provided by about 0.1 to 0.25 M
NaCl at temperatures of about 37° C. to about 55° C., while a low
stringency condition could be provided by about 0.15 M to about 0.9 M
salt, at temperatures ranging from about 20° C. to about 55° C.
Hybridization conditions can be readily manipulated depending on the
desired results.
In other embodiments, hybridization may be achieved under conditions of,
for example, 50 mM Tris-HCl (pH 8.3), 75 mM KCl, 3 mM MgCl2,
1.0 mM dithiothreitol, at temperatures between approximately 20° C. to
about 37° C. Other hybridization conditions utilized could include
approximately 10 mM Tris-HCl (pH 8.3), 50 mM KCl, 1.5 mM MgCl2,
at temperatures ranging from approximately 40° C. to about 72° C.
In certain embodiments, it will be advantageous to employ nucleic acids of
defined sequences of the present invention in combination with an
appropriate means, such as a label, for determining hybridization. A wide
variety of appropriate indicator means are known in the art, including
fluorescent, radioactive, enzymatic or other ligands, such as avidin/biotin,
which are capable of being detected. In preferred embodiments, one may
desire to employ a fluorescent label or an enzyme tag such as urease,
alkaline phosphatase or peroxidase, instead of radioactive or other
environmentally undesirable reagents. In the case of enzyme tags,
colorimetric indicator substrates are known that can be employed to
provide a detection means that is visibly or spectrophotometrically
detectable, to identify specific hybridization with complementary nucleic
acid containing samples.
In general, it is envisioned that the probes or primers described herein
will be useful as reagents in solution hybridization, as in PCR™, for
detection of expression of corresponding genes, as well as in embodiments
employing a solid phase. In embodiments involving a solid phase, the test
DNA (or RNA) is adsorbed or otherwise affixed to a selected matrix or
surface. This fixed, single-stranded nucleic acid is then subjected to
hybridization with selected probes under desired conditions. The
conditions selected will depend on the particular circumstances
(depending, for example, on the G+C content, type of target nucleic acid,
source of nucleic acid, size of hybridization probe, etc.). Optimization
of hybridization conditions for the particular application of interest is
well known to those of skill in the art. After washing of the hybridized
molecules to remove non-specifically bound probe molecules, hybridization
is detected, and/or quantified, by determining the amount of bound label.
Representative solid phase hybridization methods are disclosed in U.S.
Pat. Nos. 5,843,663, 5,900,481 and 5,919,626. Other methods of
hybridization that may be used in the practice of the present invention
are disclosed in U.S. Pat. Nos. 5,849,481, 5,849,486 and 5,851,772. The
relevant portions of these and other references identified in this section
of the Specification are incorporated herein by reference.
B. Amplification of Nucleic Acids
Nucleic acids used as a template for amplification may be isolated from
cells, tissues or other samples according to standard methodologies (Sambrook
et al., 1989). In certain embodiments, analysis is performed on whole cell
or tissue homogenates or biological fluid samples without substantial
purification of the template nucleic acid. The nucleic acid may be genomic
DNA or fractionated or whole cell RNA. Where RNA is used, it may be
desired to first convert the RNA to a complementary DNA.
The term "primer," as used herein, is meant to encompass any nucleic acid
that is capable of priming the synthesis of a nascent nucleic acid in a
template-dependent process. Typically, primers are oligonucleotides from
ten to twenty and/or thirty base pairs in length, but longer sequences can
be employed. Primers may be provided in double-stranded and/or
single-stranded form, although the single-stranded form is preferred.
Pairs of primers designed to selectively hybridize to nucleic acids
corresponding to at least one of SEQ ID NO:43 through SEQ ID NO:73 or to
SEQ ID NO:94 are contacted with the template nucleic acid under conditions
that permit selective hybridization. Depending upon the desired
application, high stringency hybridization conditions may be selected that
will only allow hybridization to sequences that are completely
complementary to the primers. In other embodiments, hybridization may
occur under reduced stringency to allow for amplification of nucleic acids
that contain one or more mismatches with the primer sequences. Once
hybridized, the template-primer complex is contacted with one or more
enzymes that facilitate template-dependent nucleic acid synthesis.
Multiple rounds of amplification, also referred to as "cycles," are
conducted until a sufficient amount of amplification product is produced.
The amplification product may be detected or quantified. In certain
applications, the detection may be performed by visual means.
Alternatively, the detection may involve indirect identification of the
product via chemiluminescence, radioactive scintigraphy of incorporated
radiolabel or fluorescent label or even via a system using electrical
and/or thermal impulse signals (Bellus, 1994).
A number of template dependent processes are available to amplify the
oligonucleotide sequences present in a given template sample. One of the
best known amplification methods is the polymerase chain reaction
(referred to as PCR™) which is described in detail in U.S. Pat. Nos.
4,683,195, 4,683,202 and 4,800,159, and in Innis et al., 1990, each of
which is incorporated herein by reference in their entirety.
A reverse transcriptase PCR™ (RT-PCR) amplification procedure may be
performed to quantify the amount of mRNA amplified. Methods of reverse
transcribing RNA into cDNA are well known and described in Sambrook et
al., 1989. Alternative methods for reverse transcription utilize
thermostable DNA polymerases. These methods are described in WO 90/07641.
Polymerase chain reaction methodologies are well known in the art.
Representative methods of RT-PCR are described in U.S. Pat. No. 5,882,864.
Another method for amplification is ligase chain reaction ("LCR"),
disclosed in European Application No. 320 308, incorporated herein by
reference in its entirety. U.S. Pat. No. 4,883,750 describes a method
similar to LCR for binding probe pairs to a target sequence. A method
based on PCR™ and oligonucleotide ligase assay (OLA), disclosed in U.S.
Pat. No. 5,912,148, may also be used.
Alternative methods for amplification of target nucleic acid sequences
that may be used in the practice of the present invention are disclosed in
U.S. Pat. Nos. 5,843,650, 5,846,709, 5,846,783, 5,849,546, 5,849,497,
5,849,547, 5,858,652, 5,866,366, 5,916,776, 5,922,574, 5,928,905,
5,928,906, 5,932,451, 5,935,825, 5,939,291 and 5,942,391, GB Application
No. 2 202 328, and in PCT Application No. PCT/US89/01025, each of which is
incorporated herein by reference in its entirety.
Qbeta Replicase, described in PCT Application No. PCT/US87/00880, may also
be used as an amplification method in the present invention. In this
method, a replicative sequence of RNA that has a region complementary to
that of a target is added to a sample in the presence of an RNA
polymerase. The polymerase will copy the replicative sequence which may
then be detected.
An isothermal amplification method, in which restriction endonucleases and
ligases are used to achieve the amplification of target molecules that
contain nucleotide 5′-[alpha-thio]-triphosphates in one strand of a
restriction site may also be useful in the amplification of nucleic acids
in the present invention (Walker et al., 1992). Strand Displacement
Amplification (SDA), disclosed in U.S. Pat. No. 5,916,779, is another
method of carrying out isothermal amplification of nucleic acids which
involves multiple rounds of strand displacement and synthesis, i.e., nick
translation.
Other nucleic acid amplification procedures include transcription-based
amplification systems (TAS), including nucleic acid sequence based
amplification (NASBA) and 3SR (Kwoh et al., 1989; Gingeras et al., PCT
Application WO 88/10315, incorporated herein by reference in their
entirety). Davey et al., European Application No. 329 822 disclose a
nucleic acid amplification process involving cyclically synthesizing
single-stranded RNA ("ssRNA"), ssDNA, and double-stranded DNA (dsDNA),
which may be used in accordance with the present invention.
Miller et al., PCT Application WO 89/06700 (incorporated herein by
reference in its entirety) disclose a nucleic acid sequence amplification
scheme based on the hybridization of a promoter region/primer sequence to
a target single-stranded DNA ("ssDNA") followed by transcription of many
RNA copies of the sequence. This scheme is not cyclic, i.e., new templates
are not produced from the resultant RNA transcripts. Other amplification
methods include "race" and "one-sided PCR" (Frohman, 1990; Ohara et al.,
1989).
C. Detection of Nucleic Acids
Following any amplification, it may be desirable to separate the
amplification product from the template and/or the excess primer. In one
embodiment, amplification products are separated by agarose,
agarose-acrylamide or polyacrylamide gel electrophoresis using standard
methods (Sambrook et al., 1989). Separated amplification products may be
cut out and eluted from the gel for further manipulation. Using low
melting point agarose gels, the separated band may be removed by heating
the gel, followed by extraction of the nucleic acid.
Separation of nucleic acids may also be effected by chromatographic
techniques known in art. There are many kinds of chromatography which may
be used in the practice of the present invention, including adsorption,
partition, ion-exchange, hydroxylapatite, molecular sieve, reverse-phase,
column, paper, thin-layer, and gas chromatography as well as HPLC.
In certain embodiments, the amplification products are visualized. A
typical visualization method involves staining of a gel with ethidium
bromide and visualization of bands under UV light. Alternatively, if the
amplification products are integrally labeled with radio- or
fluorometrically-labeled nucleotides, the separated amplification products
can be exposed to x-ray film or visualized under the appropriate
excitatory spectra.
In one embodiment, following separation of amplification products, a
labeled nucleic acid probe is brought into contact with the amplified
marker sequence. The probe preferably is conjugated to a chromophore but
may be radiolabeled. In another embodiment, the probe is conjugated to a
binding partner, such as an antibody or biotin, or another binding partner
carrying a detectable moiety.
In particular embodiments, detection is by Southern blotting and
hybridization with a labeled probe. The techniques involved in Southern
blotting are well known to those of skill in the art. See Sambrook et al.,
1989. One example of the foregoing is described in U.S. Pat. No.
5,279,721, incorporated by reference herein, which discloses an apparatus
and method for the automated electrophoresis and transfer of nucleic
acids. The apparatus permits electrophoresis and blotting without external
manipulation of the gel and is ideally suited to carrying out methods
according to the present invention.
Other methods of nucleic acid detection that may be used in the practice
of the instant invention are disclosed in U.S. Pat. Nos. 5,840,873,
5,843,640, 5,843,651, 5,846,708, 5,846,717, 5,846,726, 5,846,729,
5,849,487, 5,853,990, 5,853,992, 5,853,993, 5,856,092, 5,861,244,
5,863,732, 5,863,753, 5,866,331, 5,905,024, 5,910,407, 5,912,124,
5,912,145, 5,919,630, 5,925,517, 5,928,862, 5,928,869, 5,929,227,
5,932,413 and 5,935,791, each of which is incorporated herein by
reference.
D. Other Assays
Other methods for genetic screening may be used within the scope of the
present invention, for example, to detect mutations in genomic DNA, cDNA
and/or RNA samples. Methods used to detect point mutations include
denaturing gradient gel electrophoresis ("DGGE"), restriction fragment
length polymorphism analysis ("RFLP"), chemical or enzymatic cleavage
methods, direct sequencing of target regions amplified by PCRTM(see
above), single-strand conformation polymorphism analysis ("SSCP"),
denaturing high pressure liquid chromatography (DHPLC) and other methods
well known in the art.
One method of screening for point mutations is based on RNase cleavage of
base pair mismatches in RNA/DNA or RNA/RNA heteroduplexes. As used herein,
the term "mismatch" is defined as a region of one or more unpaired or
mispaired nucleotides in a double-stranded RNA/RNA, RNA/DNA or DNA/DNA
molecule. This definition thus includes mismatches due to
insertion/deletion mutations, as well as single or multiple base point
mutations.
U.S. Pat. No. 4,946,773 describes an RNase A mismatch cleavage assay that
involves annealing single-stranded DNA or RNA test samples to an RNA
probe, and subsequent treatment of the nucleic acid duplexes with RNase A.
For the detection of mismatches, the single-stranded products of the RNase
A treatment, electrophoretically separated according to size, are compared
to similarly treated control duplexes. Samples containing smaller
fragments (cleavage products) not seen in the control duplex are scored as
positive.
Other investigators have described the use of RNase I in mismatch assays.
The use of RNase I for mismatch detection is described in literature from
Promega Biotech. Promega markets a kit containing RNase I that is reported
to cleave three out of four known mismatches. Others have described using
the MutS protein or other DNA-repair enzymes for detection of single-base
mismatches.
Alternative methods for detection of deletion, insertion or substitution
mutations that may be used in the practice of the present invention are
disclosed in U.S. Pat. Nos. 5,849,483, 5,851,770, 5,866,337, 5,925,525 and
5,928,870, each of which is incorporated herein by reference in its
entirety.
E. Kits
All the essential materials and/or reagents required for detecting a NURR1
nucleic acid sequence in a sample may be assembled together in a kit. This
generally will comprise at least one probe or primer designed to hybridize
specifically to individual nucleic acids of interest in the practice of
the present invention, including any one of SEQ ID NOS:43 through SEQ ID
NO:73, or SEQ ID NO:94. Examples of such primers include SEQ ID NOS:3
through SEQ ID NO:30, SEQ ID NOS:37 through SEQ ID NO:42, SEQ ID NOS:88
through SEQ ID NO:93, and/or SEQ ID NOS:95 through SEQ ID NO:123. Also
included may be enzymes suitable for amplifying nucleic acids, including
various polymerases (reverse transcriptase, Taq, etc.), deoxynucleotides
and buffers to provide the necessary reaction mixture for amplification.
Such kits may also include enzymes and other reagents suitable for
detection of specific nucleic acids or amplification products. Such kits
generally will comprise, in suitable means, distinct containers for each
individual reagent or enzyme as well as for each probe or pnmer pair.
V. NURR1 Nucleic Acids
A. Nucleic Acids and Uses Thereof
Certain aspects of the present invention concern at least one NURR1
nucleic acid. In certain aspects, the at least one NURR1 nucleic acid
comprises a wild-type or mutant NURR1 nucleic acid. In particular aspects,
the NURR1 nucleic acid encodes for at least one transcribed nucleic acid.
In particular aspects, the NURR1 nucleic acid encodes at least one NURR1
protein, polypeptide or peptide, or biologically functional equivalent
thereof. In other aspects, the NURR1 nucleic acid comprises at least one
nucleic acid segment of SEQ ID NO:43 through SEQ ID NO:73 or SEQ ID NO:94,
or at least one biologically functional equivalent thereof.
The present invention also concerns the isolation or creation of at least
one recombinant construct or at least one recombinant host cell through
the application of recombinant nucleic acid technology known to those of
skill in the art or as described herein. The recombinant construct or host
cell may comprise at least one NURR1 nucleic acid, and may express at
least one NURR1 protein, polypeptide or peptide, or at least one
biologically functional equivalent thereof.
As used herein "wild-type" refers to the naturally occurring sequence of a
nucleic acid at a genetic locus in the genome of an organism, and
sequences transcribed or translated from such a nucleic acid. Thus, the
term "wild-type" also may refer to the amino acid sequence encoded by the
nucleic acid. As a genetic locus may have more than one sequence or
alleles in a population of individuals, the term "wild-type" encompasses
all such naturally occurring alleles. As used herein the term
"polymorphic" means that variation exists (i.e. two or more alleles exist)
at a genetic locus in the individuals of a population. As used herein
"mutant" refers to a change in the sequence of a nucleic acid or its
encoded protein, polypeptide or peptide that is the result of the hand of
man.
A nucleic acid may be made by any technique known to one of ordinary skill
in the art. Non-limiting examples of synthetic nucleic acid, particularly
a synthetic oligonucleotide, include a nucleic acid made by in vitro
chemical synthesis using phosphotriester, phosphite or phosphoramidite
chemistry and solid phase techniques such as described in EP 266,032,
incorporated herein by reference, or via deoxynucleoside H-phosphonate
intermediates as described by Froehler et al., 1986, and U.S. Pat. No.
5,705,629, each incorporated herein by reference. A non-limiting example
of enzymatically produced nucleic acid include one produced by enzymes in
amplification reactions such as PCR™ (see for example, U.S. Pat. No.
4,683,202 and U.S. Pat. No. 4,682,195, each incorporated herein by
reference), or the synthesis of oligonucleotides described in U.S. Pat.
No. 5,645,897, incorporated herein by reference. A non-limiting example of
a biologically produced nucleic acid includes recombinant nucleic acid
production in living cells, such as recombinant DNA vector production in
bacteria (see for example, Sambrook et al. 1989, incorporated herein by
reference).
A nucleic acid may be purified on polyacrylamide gels, cesium chloride
centrifugation gradients, or by any other means known to one of ordinary
skill in the art (see for example, Sambrook et al. 1989, incorporated
herein by reference).
The term "nucleic acid" will generally refer to at least one molecule or
strand of DNA, RNA or a derivative or mimic thereof, comprising at least
one nucleobase, such as, for example, a naturally occurring purine or
pyrimidine base found in DNA (e.g. adenine "A," guanine "G," thymine "T"
and cytosine "C") or RNA (e.g. A, G, uracil "U" and C). The term "nucleic
acid" encompass the terms "oligonucleotide" and "polynucleotide." The term
"oligonucleotide" refers to at least one molecule of between about 3 and
about 100 nucleobases in length. The term "polynucleotide" refers to at
least one molecule of at least about 40 nucleobases in length. These
definitions generally refer to at least one single-stranded molecule, but
in specific embodiments will also encompass at least one additional strand
that is partially, substantially or fully complementary to the at least
one single-stranded molecule. Thus, a nucleic acid may encompass at least
one double-stranded molecule or at least one triple-stranded molecule that
comprises one or more complementary strand(s) or "complement(s)" of a
particular sequence comprising a strand of the molecule. As used herein, a
single stranded nucleic acid may be denoted by the prefix "ss", a double
stranded nucleic acid by the prefix "ds", and a triple stranded nucleic
acid by the prefix "ts."
Thus, the present invention also encompasses at least one nucleic acid
that is complementary to a NURR1 nucleic acid. In particular embodiments,
the invention encompasses at least one nucleic acid or nucleic acid
segment complementary to the sequence set forth in at least one of SEQ ID
NO:43 through SEQ ID NO:73 or SEQ ID NO:94. Nucleic acid(s) that are
"complementary" or "complement(s)" are those that are capable of
base-pairing according to the standard Watson-Crick, Hoogsteen or reverse
Hoogsteen binding complementarity rules. As used herein, the term
"complementary" or "complement(s)" also refers to nucleic acid(s) that are
substantially complementary, as may be assessed by the same nucleotide
comparison set forth above. The term "substantially complementary" refers
to a nucleic acid comprising at least one sequence of consecutive
nucleobases, or semiconsecutive nucleobases if one or more nucleobase
moieties are not present in the molecule, are capable of hybridizing to at
least one nucleic acid strand or duplex even if less than all nucleobases
do not base pair with a counterpart nucleobase. In certain embodiments, a
"substantially complementary" nucleic acid contains at least one sequence
in which about 70%, about 75%, about 80%, about 85%, about 90%, about 95%,
to about 100%, and any range therein, of the nucleobase sequence is
capable of base-pairing with at least one single or double stranded
nucleic acid molecule during hybridization. In certain embodiments, the
term "substantially complementary" refers to at least one nucleic acid
that may hybridize to at least one nucleic acid strand or duplex in
stringent conditions. In certain embodiments, a "partly complementary"
nucleic acid comprises at least one sequence that may hybridize in low
stringency conditions to at least one single or double stranded nucleic
acid, or contains at least one sequence in which less than about 70% of
the nucleobase sequence is capable of base-pairing with at least one
single or double stranded nucleic acid molecule during hybridization.
As used herein, "hybridization", "hybridizes" or "capable of hybridizing"
is understood to mean the forming of a double or triple stranded molecule
or a molecule with partial double or triple stranded nature. The term
"hybridization", "hybridize(s)" or "capable of hybridizing" encompasses
the terms "stringent condition(s)" or "high stringency" and the terms "low
stringency" or "low stringency condition(s)."
As used herein "stringent condition(s)" or "high stringency" are those
that allow hybridization between or within one or more nucleic acid
strand(s) containing complementary sequence(s), but precludes
hybridization of random sequences. Stringent conditions tolerate little,
if any, mismatch between a nucleic acid and a target strand. Such
conditions are well known to those of ordinary skill in the art, and are
preferred for applications requiring high selectivity. Non-limiting
applications include isolating at least one nucleic acid, such as a gene
or nucleic acid segment thereof, or detecting at least one specific mRNA
transcript or nucleic acid segment thereof, and the like.
Stringent conditions may comprise low salt and/or high temperature
conditions, such as provided by about 0.02 M to about 0.15 M NaCl at
temperatures of about 50° C. to about 70° C. It is understood that the
temperature and ionic strength of a desired stringency are determined in
part by the length of the particular nucleic acid(s), the length and
nucleobase content of the target sequence(s), the charge composition of
the nucleic acid(s), and to the presence of formamide, tetramethylammonium
chloride or other solvent(s) in the hybridization mixture. It is generally
appreciated that conditions may be rendered more stringent, such as, for
example, the addition of increasing amounts of formamide.
It is also understood that these ranges, compositions and conditions for
hybridization are mentioned by way of non-limiting example only, and that
the desired stringency for a particular hybridization reaction is often
determined empirically by comparison to one or more positive or negative
controls. Depending on the application envisioned it is preferred to
employ varying conditions of hybridization to achieve varying degrees of
selectivity of the nucleic acid(s) towards target sequence(s). In a
non-limiting example, identification or isolation of related target
nucleic acid(s) that do not hybridize to a nucleic acid under stringent
conditions may be achieved by hybridization at low temperature and/or high
ionic strength. Such conditions are termed "low stringency" or "low
stringency conditions", and non-limiting examples of low stringency
include hybridization performed at about 0.15 M to about 0.9 M NaCl at a
temperature range of about 20° C. to about 50° C. Of course, it is within
the skill of one in the art to further modify the low or high stringency
conditions to suite a particular application.
One or more nucleic acid(s) may comprise, or be composed entirely of, at
least one derivative or mimic of at least one nucleobase, a nucleobase
linker moiety and/or backbone moiety that may be present in a naturally
occurring nucleic acid. As used herein a "derivative" refers to a
chemically modified or altered form of a naturally occurring molecule,
while the terms "mimic" or "analog" refers to a molecule that may or may
not structurally resemble a naturally occurring molecule, but functions
similarly to the naturally occurring molecule. As used herein, a "moiety"
generally refers to a smaller chemical or molecular component of a larger
chemical or molecular structure, and is encompassed by the term
"molecule."
As used herein a "nucleobase" refers to a naturally occurring heterocyclic
base, such as A, T, G, C or U ("naturally occurring nucleobase(s)"), found
in at least one naturally occurring nucleic acid (i.e. DNA and RNA), and
their naturally or non-naturally occurring derivatives and mimics.
Non-limiting examples of nucleobases include purines and pyrimidines, as
well as derivatives and mimics thereof, which generally can form one or
more hydrogen bonds ("anneal" or "hybridize") with at least one naturally
occurring nucleobase in manner that may substitute for naturally occurring
nucleobase pairing (e.g. the hydrogen bonding between A and T, G and C,
and A and U).
Nucleobase, nucleoside and nucleotide mimics or derivatives are well known
in the art, and have been described in exemplary references such as, for
example, Scheit, Nucleotide Analogs (John Wiley, New York, 1980),
incorporated herein by reference. "Purine" and "pyrimidine" nucleobases
encompass naturally occurring purine and pyrimidine nucleobases and also
derivatives and mimics thereof, including but not limited to, those
purines and pyrimidines substituted by one or more of alkyl, carboxyalkyl,
amino, hydroxyl, halogen (i.e. fluoro, chloro, bromo, or iodo), thiol, or
alkylthiol wherein the alkyl group comprises of from about 1, about 2,
about 3, about 4, about 5, to about 6 carbon atoms. Non-limiting examples
of purines and pyrimidines include deazapurines, 2,6-diaminopurine,
5-fluorouracil, xanthine, hypoxanthine, 8-bromoguanine, 8-chloroguanine,
bromothymine, 8-aminoguanine, 8-hydroxyguanine, 8-methylguanine,
8-thioguanine, azaguanines, 2-aminopurine, 5-ethylcytosine,
5-methylcyosine, 5-bromouracil, 5-ethyluracil, 5-iodouracil,
5-chlorouracil, 5-propyluracil, thiouracil, 2-methyladenine,
methylthioadenine, N,N-diemethyladenine, azaadenines, 8-bromoadenine,
8-hydroxyadenine, 6-hydroxyaminopurine, 6-thiopurine,
4-(6-aminohexyl/cytosine), and the like. A table of exemplary, but not
limiting, purine and pyrimidine derivatives and mimics is also provided
herein below.
As used herein, "nucleoside" refers to an individual chemical unit
comprising a nucleobase covalently attached to a nucleobase linker moiety.
A non-limiting example of a "nucleobase linker moiety" is a sugar
comprising 5-carbon atoms (a "5-carbon sugar"), including but not limited
to deoxyribose, ribose or arabinose, and derivatives or mimics of 5-carbon
sugars. Non-limiting examples of derivatives or mimics of 5-carbon sugars
include 2′-fluoro-2′-deoxyribose or carbocyclic sugars where a carbon is
substituted for the oxygen atom in the sugar ring. By way of non-limiting
example, nucleosides comprising purine (i.e. A and G) or 7-deazapurine
nucleobases typically covalently attach the 9 position of the purine or
7-deazapurine to the 1′-position of a 5-carbon sugar. In another
non-limiting example, nucleosides comprising pyrimidine nucleobases (i.e.
C, T or U) typically covalently attach the 1 position of the pyrimidine to
1′-position of a 5-carbon sugar (Kornberg and Baker, DNA Replication, 2nd
Ed. (Freeman, San Francisco, 1992). However, other types of covalent
attachments of a nucleobase to a nucleobase linker moiety are known in the
art, and non-limiting examples are described herein.
As used herein, a "nucleotide" refers to a nucleoside further comprising a
"backbone moiety" generally used for the covalent attachment of one or
more nucleotides to another molecule or to each other to form one or more
nucleic acids. The "backbone moiety" in naturally occurring nucleotides
typically comprises a phosphorus moiety, which is covalently attached to a
5-carbon sugar. The attachment of the backbone moiety typically occurs at
either the 3′- or 5′-position of the 5-carbon sugar. However, other types
of attachments are known in the art, particularly when the nucleotide
comprises derivatives or mimics of a naturally occurring 5-carbon sugar or
phosphorus moiety, and non-limiting examples are described herein.
A non-limiting example of a nucleic acid comprising such nucleoside or
nucleotide derivatives and mimics is a "polyether nucleic acid", described
in U.S. Pat. No. 5,908,845, incorporated herein by reference, wherein one
or more nucleobases are linked to chiral carbon atoms in a polyether
backbone. Another example of a nucleic acid comprising nucleoside or
nucleotide derivatives or mimics is a "peptide nucleic acid", also known
as a "PNA", "peptide-based nucleic acid mimics" or "PENAMs", described in
U.S. Pat. Nos. 5,786,461, 5891,625, 5,773,571, 5,766,855, 5,736,336,
5,719,262, 5,714,331, 5,539,082, and WO 92/20702, each of which is
incorporated herein by reference. A peptide nucleic acid generally
comprises at least one nucleobase and at least one nucleobase linker
moiety that is either not a 5-carbon sugar and/or at least one backbone
moiety that is not a phosphate backbone moiety. Examples of nucleobase
linker moieties described for PNAs include aza nitrogen atoms, amido
and/or ureido tethers (see for example, U.S. Pat. No. 5,539,082). Examples
of backbone moieties described for PNAs include an aminoethylglycine,
polyamide, polyethyl, polythioamide, polysulfinamide or polysulfonamide
backbone moiety.
Peptide nucleic acids generally have enhanced sequence specificity,
binding properties, and resistance to enzymatic degradation in comparison
to molecules such as DNA and RNA (Egholm et al., Nature 1993, 365, 566;
PCT/EP/01219). In addition, U.S. Pat. Nos. 5,766,855, 5,719,262, 5,714,331
and 5,736,336 describe PNAs comprising naturally and non-naturally
occurring nucleobases and alkylamine side chains with further improvements
in sequence specificity, solubility and binding affinity. These properties
promote double or triple helix formation between a target nucleic acid and
the PNA.
U.S. Pat. No. 5,641,625 describes that the binding of a PNA to a target
sequence has applications including the creation of PNA probes to
nucleotide sequences, modulating (i.e. enhancing or reducing) gene
expression by binding of a PNA to an expressed nucleotide sequence, and
cleavage of specific dsDNA molecules. In certain embodiments, nucleic acid
analogues such as one or more peptide nucleic acids may be used to inhibit
nucleic acid amplification, such as in PCR, to reduce false positives and
discriminate between single base mutants, as described in U.S. Pat. No.
5,891,625.
U.S. Pat. No. 5,786,461 describes PNAs with amino acid side chains
attached to the PNA backbone to enhance solubility. The neutrality of the
PNA backbone may contribute to the thermal stability of PNA/DNA and PNA/RNA
duplexes by reducing charge repulsion. The melting temperature of PNA
containing duplexes, or temperature at which the strands of the duplex
release into single stranded molecules, has been described as less
dependent upon salt concentration.
One method for increasing amount of cellular uptake property of PNAs is to
attach a lipophilic group. U.S. application Ser. No. 117,363, filed Sep.
3, 1993, describes several alkylamino functionalities and their use in the
attachment of such pendant groups to oligonucleotides. U.S. application
Ser. No. 07/943,516, filed Sep. 11, 1992, and its corresponding published
PCT application WO 94/06815, describe other novel amine-containing
compounds and their incorporation into oligonucleotides for, inter alia,
the purposes of enhancing cellular uptake, increasing lipophilicity,
causing greater cellular retention and increasing the distribution of the
compound within the cell.
Additional non-limiting examples of nucleosides, nucleotides or nucleic
acids comprising 5-carbon sugar and/or backbone moiety derivatives or
mimics are well known in the art.
In a certain aspect, the present invention concerns at least one nucleic
acid that is an isolated nucleic acid. As used herein, the term "isolated
nucleic acid" refers to at least one nucleic acid molecule that has been
isolated free of, or is otherwise free of, the bulk of the total genomic
and transcribed nucleic acids of one or more cells, particularly mammalian
cells, and more particularly human and/or mouse and/or rat cells. In
certain embodiments, "isolated nucleic acid" refers to a nucleic acid that
has been isolated free of, or is otherwise free of, bulk of cellular
components and macromolecules such as lipids, proteins, small biological
molecules, and the like. As different species may have a RNA or a DNA
containing genome, the term "isolated nucleic acid" encompasses both the
terms "isolated DNA" and "isolated RNA". Thus, the isolated nucleic acid
may comprise a RNA or DNA molecule isolated from, or otherwise free of,
the bulk of total RNA, DNA or other nucleic acids of a particular species.
As used herein, an isolated nucleic acid isolated from a particular
species is referred to as a "species specific nucleic acid." When
designating a nucleic acid isolated from a particular species, such as
human, such a type of nucleic acid may be identified by the name of the
species. For example, a nucleic acid isolated from one or more humans
would be an "isolated human nucleic acid", a nucleic acid isolated from
human would be an "isolated human nucleic acid", and so forth.
Of course, more than one copy of an isolated nucleic acid may be isolated
from biological material, or produced in vitro, using standard techniques
that are known to those of skill in the art. In particular embodiments,
the isolated nucleic acid is capable of expressing a protein, polypeptide
or peptide that has NURR1 activity. In other embodiments, the isolated
nucleic acid comprises an isolated NURR1 gene.
In certain embodiments, a "gene" refers to a nucleic acid that is
transcribed. As used herein, a "gene segment" is a nucleic acid segment of
a gene. In certain aspects, the gene includes regulatory sequences
involved in transcription, or message production or composition. In
particular embodiments, the gene comprises transcribed sequences that
encode for a protein, polypeptide or peptide. In other particular aspects,
the gene comprises a NURR1 nucleic acid, and/or encodes a NURR1
polypeptide or peptide coding sequences. The term "an amino acid sequence"
as used herein may be used interchangeably with the terms protein,
polypeptide, or peptide, and the like. In keeping with the terminology
described herein, an "isolated gene" may comprise transcribed nucleic
acid(s), regulatory sequences, coding sequences, or the like, isolated
substantially away from other such sequences, such as other naturally
occurring genes, regulatory sequences, polypeptide or peptide encoding
sequences, and so forth. In this respect, the term "gene" is used for
simplicity to refer to a nucleic acid comprising a nucleotide sequence
that is transcribed, and the complement thereof. In particular aspects,
the transcribed nucleotide sequence comprises at least one functional
protein, polypeptide and/or peptide encoding unit. As will be understood
by those in the art, this function term "gene" includes both genomic
sequences, RNA or cDNA sequences or smaller engineered nucleic acid
segments, including nucleic acid segments of a non-transcribed part of a
gene, including but not limited to the non-transcribed promoter or
enhancer regions of a gene. Smaller engineered gene nucleic acid segments
may express, or may be adapted to express using nucleic acid manipulation
technology, proteins, polypeptides, domains, peptides, fusion proteins,
mutants and/or such like.
"Isolated substantially away from other coding sequences" means that the
gene of interest, in this case the NURR1 gene(s), forms the significant
part of the coding region of the nucleic acid, or that the nucleic acid
does not contain large portions of naturally-occurring coding nucleic
acids, such as large chromosomal fragments, other functional genes, RNA or
cDNA coding regions. Of course, this refers to the nucleic acid as
originally isolated, and does not exclude genes or coding regions later
added to the nucleic acid by the hand of man.
In certain embodiments, the nucleic acid is a nucleic acid segment. As
used herein, the term "nucleic acid segment", is a smaller fragment of a
nucleic acid, such as for non-limiting example, one that encodes only part
of the NURR1 peptide or polypeptide sequence. Thus, a "nucleic acid
segment" may comprise any part of the NURR1 gene sequence(s), of from
about 2 nucleotides to the full length of the NURR1 peptide or polypeptide
encoding region. In certain embodiments, the "nucleic acid segment"
encompasses the full length NURR1 gene(s) sequence. In particular
embodiments, the nucleic acid comprises any part of at least one of SEQ ID
NO:43 through SEQ ID NO:73 or SEQ ID NO:94 sequence(s), of from about 2
nucleotides to the full length of the sequence disclosed in at least one
of SEQ ID NO:43 through SEQ ID NO:73 or SEQ ID NO:94.
Various nucleic acid segments may be designed based on a particular
nucleic acid sequence, and may be of any length. In certain embodiments,
the nucleic acid segment may be a probe or primer. As used herein, a
"probe" is a relatively short nucleic acid sequence, such as an
oligonucleotide, used to identify other nucleic acid sequences to which it
hybridizes. As used herein, a "primer" is a relatively short nucleic acid
sequence used as a starting molecule for polymerization to extend from,
such as in polymerase chain reaction, which is a method well known in the
art. A non-limiting example of this would be the creation of nucleic acid
segments of various lengths and sequence composition for probes and
primers based on the sequences disclosed in at least one of SEQ ID NO:43
through SEQ ID NO:73 or SEQ ID NO:94.
The nucleic acid(s) of the present invention, regardless of the length of
the sequence itself, may be combined with other nucleic acid sequences,
including but not limited to, promoters, enhancers, polyadenylation
signals, restriction enzyme sites, multiple cloning sites, coding
segments, and the like, to create one or more nucleic acid construct(s).
The overall length may vary considerably between nucleic acid constructs.
Thus, a nucleic acid segment of almost any length may be employed, with
the total length preferably being limited by the ease of preparation or
use in the intended recombinant nucleic acid protocol.
In a non-limiting example, one or more nucleic acid constructs may be
prepared that include a contiguous stretch of nucleotides identical to or
complementary to at least one of SEQ ID NO:43 through SEQ ID NO:73 or SEQ
ID NO:94. A nucleic acid construct may be about 3, about 5, about 8, about
10 to about 14, or about 15, about 20, about 30, about 40 about 50, about
100, about 200, about 500, about 1,000, about 2,000, about 3,000, about
5,000, about 10,000, about 15,000, about 20,000, about 30,000, about
50,000, about 100,000, about 250,000, about 500,000, about 750,000, to
about 1,000,000 nucleotides in length, as well as constructs of greater
size, up to and including chromosomal sizes (including all intermediate
lengths and intermediate ranges), given the advent of nucleic acids
constructs such as a yeast artificial chromosome are known to those of
ordinary skill in the art. It will be readily understood that
"intermediate lengths" and "intermediate ranges", as used herein, means
any length or range including or between the quoted values (i.e. all
integers including and between such values).
In particular embodiments, the invention concerns one or more recombinant
vector(s) comprising nucleic acid sequences that encode a NURR1 protein,
polypeptide or peptide that includes within its amino acid sequence a
contiguous amino acid sequence in accordance with, or essentially as set
forth in one of SEQ ID NO:74 through SEQ ID NO:87, particularly one
corresponding to human Nurr1. In other embodiments, the invention concerns
recombinant vector(s) comprising nucleic acid sequences that encode a
mouse NURR1 protein, polypeptide or peptide that includes within its amino
acid sequence a contiguous amino acid sequence. In particular aspects, the
recombinant vectors are DNA vectors.
For example, the term "a sequence essentially as set forth in SEQ ID NO:74
means that the sequence substantially corresponds to a portion of SEQ ID
NO:74 and has relatively few amino acids that are not identical to, or a
biologically functional equivalent of, the amino acids of SEQ ID NO:74.
The term "biologically functional equivalent" is well understood in the
art and is further defined in detail herein. Accordingly, a sequence that
has between about 70% and about 80%; or more preferably, between about 81%
and about 90%; or even more preferably, between about 91% and about 99%;
of amino acids that are identical or functionally equivalent to the amino
acids of at least one of SEQ ID NO:74 through SEQ ID NO:87 will be a
sequence that is "essentially as set forth in at least one of SEQ ID NO:74
through SEQ ID NO:87", provided the biological activity of the protein,
polypeptide or peptide is maintained.
In certain other embodiments, the invention concerns at least one
recombinant vector that includes within its sequence a nucleic acid
sequence essentially as set forth in at least one of SEQ ID NO:43 through
SEQ ID NO:73 or SEQ ID NO:94. In particular embodiments, the recombinant
vector comprises DNA sequences that encode protein(s), polypeptide(s) or
peptide(s) exhibiting NURR1 activity.
The term "functionally equivalent codon" is used herein to refer to codons
that encode the same amino acid, such as the six codons for arginine and
serine, and also refers to codons that encode biologically equivalent
amino acids. Information on codon usage in a variety of non-human
organisms is known in the art (see for example, Bennetzen and Hall, 1982;
Ikemura, 1981a, 1981b, 1982; Grantham et al., 1980, 1981; Wada et al.,
1990; each of these references are incorporated herein by reference in
their entirety). Thus, it is contemplated that codon usage may be
optimized for other animals, as well as other organisms such as fungi,
plants, prokaryotes, virus and the like, as well as organelles that
contain nucleic acids, such as mitochondria, chloroplasts and the like,
based on the preferred codon usage as would be known to those of ordinary
skill in the art.
It will also be understood that amino acid sequences or nucleic acid
sequences may include additional residues, such as additional N- or
C-terminal amino acids or 5′ or 3′ sequences, or various combinations
thereof, and yet still be essentially as set forth in one of the sequences
disclosed herein, so long as the sequence meets the criteria set forth
above, including the maintenance of biological protein, polypeptide or
peptide activity where expression of a proteinaceous composition is
concerned. The addition of terminal sequences particularly applies to
nucleic acid sequences that may, for example, include various non-coding
sequences flanking either of the 5′ and/or 3′ portions of the coding
region or may include various internal sequences, i.e., introns, which are
known to occur within genes.
Excepting intronic and flanking regions, and allowing for the degeneracy
of the genetic code, nucleic acid sequences that have between about 70%
and about 79%; or more preferably, between about 80% and about 89%; or
even more particularly, between about 90% and about 99%; of nucleotides
that are identical to the nucleotides of at least one of SEQ ID NO:43
through SEQ ID NO:73 or SEQ ID NO:94 will be nucleic acid sequences that
are "essentially as set forth in at least one of SEQ ID NO:43 through SEQ
ID NO:73 or SEQ ID NO:94".
It will also be understood that this invention is not limited to the
particular nucleic acid or amino acid sequences of NURR1 Recombinant
vectors and isolated nucleic acid segments may therefore variously include
these coding regions themselves, coding regions bearing selected
alterations or modifications in the basic coding region, and they may
encode larger polypeptides or peptides that nevertheless include such
coding regions or may encode biologically functional equivalent proteins,
polypeptide or peptides that have variant amino acids sequences.
The nucleic acids of the present invention encompass biologically
functional equivalent NURR1 proteins, polypeptides, or peptides. Such
sequences may arise as a consequence of codon redundancy or functional
equivalency that are known to occur naturally within nucleic acid
sequences or the proteins, polypeptides or peptides thus encoded.
Alternatively, functionally equivalent proteins, polypeptides or peptides
may be created via the application of recombinant DNA technology, in which
changes in the protein, polypeptide or peptide structure may be
engineered, based on considerations of the properties of the amino acids
being exchanged. Changes designed by man may be introduced, for example,
through the application of site-directed mutagenesis techniques as
discussed herein below, e.g., to introduce improvements or alterations to
the antigenicity of the protein, polypeptide or peptide, or to test
mutants in order to examine NURR1 protein, polypeptide or peptide activity
at the molecular level.
Fusion proteins, polypeptides or peptides may be prepared, e.g., where the
NURR1 coding regions are aligned within the same expression unit with
other proteins, polypeptides or peptides having desired functions.
Non-limiting examples of such desired functions of expression sequences
include purification or immunodetection purposes for the added expression
sequences, e.g., proteinaceous compositions that may be purified by
affinity chromatography or the enzyme labeling of coding regions,
respectively.
As used herein the term "sequence" encompasses both the terms "nucleic
acid" and "proteinaceous" or "proteinaceous composition." As used herein,
the term "proteinaceous composition" encompasses the terms "protein",
"polypeptide" and "peptide." As used herein "artificial sequence" refers
to a sequence of a nucleic acid not derived from sequence naturally
occurring at a genetic locus, as well as the sequence of any proteins,
polypeptides or peptides encoded by such a nucleic acid. A "synthetic
sequence", refers to a nucleic acid or proteinaceous composition produced
by chemical synthesis in vitro, rather than enzymatic production in vitro
(i.e. an "enzymatically produced" sequence) or biological production in
vivo (i.e. a "biologically produced" sequence).
VI. Pharmaceutical Compositions
Aqueous compositions of the present invention comprise an effective amount
of a chemical compound or pharmaceutically acceptable salts thereof or the
NURR1 protein, polypeptide, peptide, epitopic core region, inhibitor,
and/or such like, and a NURR1 agonist or antagonist dissolved and/or
dispersed in a pharmaceutically acceptable carrier and/or aqueous medium.
Aqueous compositions of gene therapy vectors expressing any of the
foregoing are also contemplated.
The phrases "pharmaceutically and/or pharmacologically acceptable" refer
to molecular entities and/or compositions that do not produce an adverse,
allergic and/or other untoward reaction when administered to an animal,
such as a human, as appropriate.
As used herein, "pharmaceutically acceptable carrier" includes any and/or
all solvents, dispersion media, coatings, antibacterial and/or antifungal
agents, isotonic and/or absorption delaying agents and/or the like. The
use of such media and/or agents for pharmaceutical active substances is
well known in the art. Except insofar as any conventional media and/or
agent is incompatible with the active ingredient, its use in the
therapeutic compositions is contemplated. Supplementary active ingredients
can also be incorporated into the compositions. For human administration,
preparations should meet sterility, pyrogenicity, general safety and/or
purity standards as required by FDA Office of Biologics standards.
The biological material should be extensively dialyzed to remove undesired
small molecular weight molecules and/or lyophilized for more ready
formulation into a desired vehicle, where appropriate. The active
compounds may generally be formulated for parenteral administration, e.g.,
formulated for injection via the intravenous, intramuscular, sub-cutaneous,
intralesional, and/or even intraperitoneal routes. The preparation of an
aqueous compositions that contain an effective amount of chemical compound
or pharmaceutically acceptable salts thereof or a NURR1 agent as an active
component and/or ingredient will be known to those of skill in the art in
light of the present disclosure. Typically, such compositions can be
prepared as injectables, either as liquid solutions and/or suspensions;
solid forms suitable for using to prepare solutions and/or suspensions
upon the addition of a liquid prior to injection can also be prepared;
and/or the preparations can also be emulsified.
The pharmaceutical forms suitable for injectable use include sterile
aqueous solutions and/or dispersions; formulations including sesame oil,
peanut oil and/or aqueous propylene glycol; and/or sterile powders for the
extemporaneous preparation of sterile injectable solutions and/or
dispersions. In all cases the form must be sterile and/or must be fluid to
the extent that easy syringability exists. It must be stable under the
conditions of manufacture and/or storage and/or must be preserved against
the contaminating action of microorganisms, such as bacteria and/or fungi.
Solutions of the active compounds as free base and/or pharmacologically
acceptable salts can be prepared in water suitably mixed with a
surfactant, such as hydroxypropylcellulose. Dispersions can also be
prepared in glycerol, liquid polyethylene glycols, and/or mixtures thereof
and/or in oils. Under ordinary conditions of storage and/or use, these
preparations contain a preservative to prevent the growth of
microorganisms.
A chemical compound or NURR1 protein, polypeptide, peptide, agonist and/or
antagonist of the present invention can be formulated into a composition
in a neutral and/or salt form. Pharmaceutically acceptable salts, include
the acid addition salts (formed with the free amino groups of the protein)
and/or which are formed with inorganic acids such as, for example,
hydrochloric and/or phosphoric acids, and/or such organic acids as acetic,
oxalic, tartaric, mandelic, and/or the like. Salts formed with the free
carboxyl groups can also be derived from inorganic bases such as, for
example, sodium, potassium, ammonium, calcium, and/or ferric hydroxides,
and/or such organic bases as isopropylamine, trimethylamine, histidine,
procaine and/or the like. In terms of using peptide therapeutics as active
ingredients, the technology of U.S. Pat. Nos. 4,608,251; 4,601,903;
4,599,231; 4,599,230; 4,596,792; and/or 4,578,770, each incorporated
herein by reference, may be used.
The carrier can also be a solvent and/or dispersion medium containing, for
example, water, ethanol, polyol (for example, glycerol, propylene glycol,
and/or liquid polyethylene glycol, and/or the like), suitable mixtures
thereof, and/or vegetable oils. The proper fluidity can be maintained, for
example, by the use of a coating, such as lecithin, by the maintenance of
the required particle size in the case of dispersion and/or by the use of
surfactants. The prevention of the action of microorganisms can be brought
about by various antibacterial and/or antifungal agents, for example,
parabens, chlorobutanol, phenol, sorbic acid, thimerosal, and/or the like.
In many cases, it will be preferable to include isotonic agents, for
example, sugars and/or sodium chloride. Prolonged absorption of the
injectable compositions can be brought about by the use in the
compositions of agents delaying absorption, for example, aluminum
monostearate and/or gelatin.
Sterile injectable solutions are prepared by incorporating the active
compounds in the required amount in the appropriate solvent with various
of the other ingredients enumerated above, as required, followed by
filtered sterilization. Generally, dispersions are prepared by
incorporating the various sterilized active ingredients into a sterile
vehicle which contains the basic dispersion medium and/or the required
other ingredients from those enumerated above. In the case of sterile
powders for the preparation of sterile injectable solutions, the preferred
methods of preparation are vacuum-drying and/or freeze-drying techniques
which yield a powder of the active ingredient plus any additional desired
ingredient from a previously sterile-filtered solution thereof. The
preparation of more, and/or highly, concentrated solutions for direct
injection is also contemplated, where the use of DMSO as solvent is
envisioned to result in extremely rapid penetration, delivering high
concentrations of the active agents to the desired area.
Upon formulation, solutions will be administered in a manner compatible
with the dosage formulation and/or in such amount as is therapeutically
effective. The formulations are easily administered in a variety of dosage
forms, such as the type of injectable solutions described above, but drug
release capsules and/or the like can also be employed.
For parenteral administration in an aqueous solution, for example, the
solution should be suitably buffered if necessary and/or the liquid
diluent first rendered isotonic with sufficient saline and/or glucose.
These particular aqueous solutions are especially suitable for
intravenous, intramuscular, subcutaneous and/or intraperitoneal
administration. In this connection, sterile aqueous media which can be
employed will be known to those of skill in the are in light of the
present disclosure. For example, one dosage could be dissolved in 1 ml of
isotonic NaCl solution and/or either added to 1000 ml of hypodermoclysis
fluid and/or injected at the proposed rate of infusion, (see for example,
"Remington's Pharmaceutical Sciences" 15th Edition, pages 1035-1038 and/or
1570-1580). Some variation in dosage will necessarily occur depending on
the condition of the subject being treated. The person responsible for
administration will, in any event, determine the appropriate dose for the
individual subject.
The chemical compound or pharmaceutically acceptable salts thereof or the
active NURR1 protein-derived peptides and/or agents may be formulated
within a therapeutic mixture to comprise about 0.0001 to 1.0 milligrams,
and/or about 0.001 to 0.1 milligrams, and/or about 0.1 to 1.0 and/or even
about 10milligrams per dose and/or so on. Multiple doses can also be
administered.
In addition to the compounds formulated for parenteral administration,
such as intravenous and/or intramuscular injection, other pharmaceutically
acceptable forms include, e.g., tablets and/or other solids for oral
administration; liposomal formulations; time release capsules; and/or any
other form currently used, including cremes.
One may also use nasal solutions and/or sprays, aerosols and/or inhalants
in the present invention. Nasal solutions are usually aqueous solutions
designed to be administered to the nasal passages in drops and/or sprays.
Nasal solutions are prepared so that they are similar in many respects to
nasal secretions, so that normal ciliary action is maintained. Thus, the
aqueous nasal solutions usually are isotonic and/or slightly buffered to
maintain a pH of 5.5 to 6.5. In addition, antimicrobial preservatives,
similar to those used in ophthalmic preparations, and/or appropriate drug
stabilizers, if required, may be included in the formulation.
Additional formulations which are suitable for other modes of
administration include vaginal suppositories and/or pessaries. A rectal
pessary and/or suppository may also be used. Suppositories are solid
dosage forms of various weights and/or shapes, usually medicated, for
insertion into the rectum, vagina and/or the urethra. After insertion,
suppositories soften, melt and/or dissolve in the cavity fluids. In
general, for suppositories, traditional binders and/or carriers may
include, for example, polyalkylene glycols and/or triglycerides; such
suppositories may be formed from mixtures containing the active ingredient
in the range of 0.5% to 10%, preferably 1%-2%.
Oral formulations include such normally employed excipients as, for
example, pharmaceutical grades of mannitol, lactose, starch, magnesium
stearate, sodium saccharine, cellulose, magnesium carbonate and/or the
like. These compositions take the form of solutions, suspensions, tablets,
pills, capsules, sustained release formulations and/or powders. In certain
defined embodiments, oral pharmaceutical compositions will comprise an
inert diluent and/or assimilable edible carrier, and/or they may be
enclosed in hard and/or soft shell gelatin capsule, and/or they may be
compressed into tablets, and/or they may be incorporated directly with the
food of the diet. For oral therapeutic administration, the active
compounds may be incorporated with excipients and/or used in the form of
ingestible tablets, buccal tables, troches, capsules, elixirs,
suspensions, syrups, wafers, and/or the like. Such compositions and/or
preparations should contain at least 0.1% of active compound. The
percentage of the compositions and/or preparations may, of course, be
varied and/or may conveniently be between about 2 to about 75% of the
weight of the unit, and/or preferably between 25-60%. The amount of active
compounds in such therapeutically useful compositions is such that a
suitable dosage will be obtained.
The tablets, troches, pills, capsules and/or the like may also contain the
following: a binder, as gum tragacanth, acacia, cornstarch, and/or
gelatin; excipients, such as dicalcium phosphate; a disintegrating agent,
such as corn starch, potato starch, alginic acid and/or the like; a
lubricant, such as magnesium stearate; and/or a sweetening agent, such as
sucrose, lactose and/or saccharin may be added and/or a flavoring agent,
such as peppermint, oil of wintergreen, and/or cherry flavoring. When the
dosage unit form is a capsule, it may contain, in addition to materials of
the above type, a liquid carrier. Various other materials may be present
as coatings and/or to otherwise modify the physical form of the dosage
unit. For instance, tablets, pills, and/or capsules may be coated with
shellac, sugar and/or both. A syrup of elixir may contain the active
compounds sucrose as a sweetening agent methyl and/or propylparabens as
preservatives, a dye and/or flavoring, such as cherry and/or orange
flavor.
A. Lipid Formulations and/or Nanocapsules
In certain embodiments, the use of lipid formulations and/or nanocapsules
is contemplated for the introduction of a chemical compound or
pharmaceutically acceptable salts thereof or NURR1 protein, polypeptides,
peptides and/or agents, and/or gene therapy vectors, including both
wild-type and/or antisense vectors, into host cells.
Nanocapsules can generally entrap compounds in a stable and/or
reproducible way. To avoid side effects due to intracellular polymeric
overloading, such ultrafine particles (sized around 0.1 mm) should be
designed using polymers able to be degraded in vivo. Biodegradable
polyalkyl-cyanoacrylate nanoparticles that meet these requirements are
contemplated for use in the present invention, and/or such particles may
be easily made.
In a preferred embodiment of the invention, the pharmaceutical may be
associated with a lipid. The pharmaceutical associated with a lipid may be
encapsulated in the aqueous interior of a liposome, interspersed within
the lipid bilayer of a liposome, attached to a liposome via a linking
molecule that is associated with both the liposome and the oligonucleotide,
entrapped in a liposome, complexed with a liposome, dispersed in a
solution containing a lipid, mixed with a lipid, combined with a lipid,
contained as a suspension in a lipid, contained or complexed with a
micelle, or otherwise associated with a lipid. The lipid or
lipid/pharmaceutical-associated compositions of the present invention are
not limited to any particular structure in solution. For example, they may
be present in a bilayer structure, as micelles, or with a "collapsed"
structure. They may also simply be interspersed in a solution, possibly
forming aggregates which are not uniform in either size or shape.
Lipids are fatty substances which may be naturally occurring or synthetic
lipids. For example, lipids include the fatty droplets that naturally
occur in the cytoplasm as well as the class of compounds which are well
known to those of skill in the art which contain long-chain aliphatic
hydrocarbons and their derivatives, such as fatty acids, alcohols, amines,
amino alcohols, and aldehydes.
Phospholipids may be used for preparing the liposomes according to the
present invention and may carry a net positive, negative, or neutral
charge. Diacetyl phosphate can be employed to confer a negative charge on
the liposomes, and stearylamine can be used to confer a positive charge on
the liposomes. The liposomes can be made of one or more phospholipids.
A neutrally charged lipid can comprise a lipid with no charge, a
substantially uncharged lipid, or a lipid mixture with equal number of
positive and negative charges. Suitable phospholipids include phosphatidyl
cholines and others that are well known to those of skill in the art.
Lipids suitable for use according to the present invention can be obtained
from commercial sources. For example, dimyristyl phosphatidylcholine ("DMPC")
can be obtained from Sigma Chemical Co., diacetyl phosphate ("DCP") is
obtained from K & K Laboratories (Plainview, N.Y.); cholesterol ("Chol")
is obtained from Calbiochem□Behring; dimyristyl phosphatidylglycerol ("DMPG")
and other lipids may be obtained from Avanti Polar Lipids, Inc.
(Birmingham, Ala.). Stock solutions of lipids in chloroform or
chloroform/methanol can be stored at about -20° C. Preferably, chloroform
is used as the only solvent since it is more readily evaporated than
methanol.
Phospholipids from natural sources, such as egg or soybean
phosphatidylcholine, brain phosphatidic acid, brain or plant
phosphatidylinositol, heart cardiolipin and plant or bacterial
phosphatidylethanolamine are preferably not used as the primary
phosphatide, i.e., constituting 50% or more of the total phosphatide
composition, because of the instability and leakiness of the resulting
liposomes.
"Liposome" is a generic term encompassing a variety of single and
multilamellar lipid vehicles formed by the generation of enclosed lipid
bilayers or aggregates. Liposomes may be characterized as having vesicular
structures with a phospholipid bilayer membrane and an inner aqueous
medium. Multilamellar liposomes have multiple lipid layers separated by
aqueous medium. They form spontaneously when phospholipids are suspended
in an excess of aqueous solution. The lipid components undergo
self-rearrangement before the formation of closed structures and entrap
water and dissolved solutes between the lipid bilayers (Ghosh and
Bachhawat, 1991). However, the present invention also encompasses
compositions that have different structures in solution than the normal
vesicular structure. For example, the lipids may assume a micellar
structure or merely exist as nonuniform aggregates of lipid molecules.
Also contemplated are lipofectamine-nucleic acid complexes.
Phospholipids can form a variety of structures other than liposomes when
dispersed in water, depending on the molar ratio of lipid to water. At low
ratios the liposome is the preferred structure. The physical
characteristics of liposomes depend on pH, ionic strength and/or the
presence of divalent cations. Liposomes can show low permeability to ionic
and/or polar substances, but at elevated temperatures undergo a phase
transition which markedly alters their permeability. The phase transition
involves a change from a closely packed, ordered structure, known as the
gel state, to a loosely packed, less-ordered structure, known as the fluid
state. This occurs at a characteristic phase-transition temperature and/or
results in an increase in permeability to ions, sugars and/or drugs.
Liposomes interact with cells via four different mechanisms: Endocytosis
by phagocytic cells of the reticuloendothelial system such as macrophages
and/or neutrophils; adsorption to the cell surface, either by nonspecific
weak hydrophobic and/or electrostatic forces, and/or by specific
interactions with cell-surface components; fusion with the plasma cell
membrane by insertion of the lipid bilayer of the liposome into the plasma
membrane, with simultaneous release of liposomal contents into the
cytoplasm; and/or by transfer of liposomal lipids to cellular and/or
subcellular membranes, and/or vice versa, without any association of the
liposome contents. Varying the liposome formulation can alter which
mechanism is operative, although more than one may operate at the same
time.
Liposome-mediated oligonucleotide delivery and expression of foreign DNA
in vitro has been very successful. Wong et al. (1980) demonstrated the
feasibility of liposome-mediated delivery and expression of foreign DNA in
cultured chick embryo, HeLa and hepatoma cells. Nicolau et al. (1987)
accomplished successful liposome-mediated gene transfer in rats after
intravenous injection.
In certain embodiments of the invention, the lipid may be associated with
a hemagglutinating virus (HVJ). This has been shown to facilitate fusion
with the cell membrane and promote cell entry of liposome-encapsulated DNA
(Kaneda et al., 1989). In other embodiments, the lipid may be complexed or
employed in conjunction with nuclear non-histone chromosomal proteins
(HMG-1) (Kato et al., 1991). In yet further embodiments, the lipid may be
complexed or employed in conjunction with both HVJ and HMG-1. In that such
expression vectors have been successfully employed in transfer and
expression of an oligonucleotide in vitro and in vivo, then they are
applicable for the present invention. Where a bacterial promoter is
employed in the DNA construct, it also will be desirable to include within
the liposome an appropriate bacterial polymerase.
Liposomes used according to the present invention can be made by different
methods. The size of the liposomes varies depending on the method of
synthesis. A liposome suspended in an aqueous solution is generally in the
shape of a spherical vesicle, having one or more concentric layers of
lipid bilayer molecules. Each layer consists of a parallel array of
molecules represented by the formula XY, wherein X is a hydrophilic moiety
and Y is a hydrophobic moiety. In aqueous suspension, the concentric
layers are arranged such that the hydrophilic moieties tend to remain in
contact with an aqueous phase and the hydrophobic regions tend to
self-associate. For example, when aqueous phases are present both within
and without the liposome, the lipid molecules may form a bilayer, known as
a lamella, of the arrangement XY-YX. Aggregates of lipids may form when
the hydrophilic and hydrophobic parts of more than one lipid molecule
become associated with each other. The size and shape of these aggregates
will depend upon many different variables, such as the nature of the
solvent and the presence of other compounds in the solution.
Liposomes within the scope of the present invention can be prepared in
accordance with known laboratory techniques. In one preferred embodiment,
liposomes are prepared by mixing liposomal lipids, in a solvent in a
container, e.g., a glass, pear-shaped flask. The container should have a
volume ten-times greater than the volume of the expected suspension of
liposomes. Using a rotary evaporator, the solvent is removed at
approximately 40° C. under negative pressure. The solvent normally is
removed within about 5 min. to 2 hours, depending on the desired volume of
the liposomes. The composition can be dried further in a desiccator under
vacuum. The dried lipids generally are discarded after about 1 week
because of a tendency to deteriorate with time.
Dried lipids can be hydrated at approximately 25-50 mM phospholipid in
sterile, pyrogen-free water by shaking until all the lipid film is
resuspended. The aqueous liposomes can be then separated into aliquots,
each placed in a vial, lyophilized and sealed under vacuum.
In the alternative, liposomes can be prepared in accordance with other
known laboratory procedures: the method of Bangham et al. (1965), the
contents of which are incorporated herein by reference; the method of
Gregoriadis, as described in DRUG CARRIERS IN BIOLOGY AND MEDICINE, G.
Gregoriadis ed. (1979) pp. 287-341, the contents of which are incorporated
herein by reference; the method of Deamer and Uster (1983), the contents
of which are incorporated by reference; and the reverse-phase evaporation
method as described by Szoka and Papahadjopoulos (1978). The
aforementioned methods differ in their respective abilities to entrap
aqueous material and their respective aqueous space-to-lipid ratios.
The dried lipids or lyophilized liposomes prepared as described above may
be dehydrated and reconstituted in a solution of inhibitory peptide and
diluted to an appropriate concentration with an suitable solvent, e.g.,
DPBS. The mixture is then vigorously shaken in a vortex mixer.
Unencapsulated nucleic acid is removed by centrifugation at 29,000 g and
the liposomal pellets washed. The washed liposomes are resuspended at an
appropriate total phospholipid concentration, e.g., about 50-200 mM. The
amount of nucleic acid encapsulated can be determined in accordance with
standard methods. After determination of the amount of nucleic acid
encapsulated in the liposome preparation, the liposomes may be diluted to
appropriate concentrations and stored at 4° C. until use.
A pharmaceutical composition comprising the liposomes will usually include
a sterile, pharmaceutically acceptable carrier or diluent, such as water
or saline solution.
B. Kits
Therapeutic kits of the present invention are kits comprising a chemical
compound or pharmaceutically acceptable salts thereof or a NURR1 protein,
polypeptide, peptide, inhibitor, gene, vector and/or other NURR1 effector.
Such kits will generally contain, in suitable container means, a
pharmaceutically acceptable formulation of a chemical compound or
pharmaceutically acceptable salts thereof or a NURR1 protein, polypeptide,
peptide, domain, inhibitor, and/or a gene and/or vector expressing any of
the foregoing in a pharmaceutically acceptable formulation. The kit may
have a single container means, and/or it may have distinct container means
for each compound.
When the components of the kit are provided in one and/or more liquid
solutions, the liquid solution is an aqueous solution, with a sterile
aqueous solution being particularly preferred. The chemical compound or
pharmaceutically acceptable salts thereof or NURR1 compositions may also
be formulated into a syringeable composition. In which case, the container
means may itself be a syringe, pipette, and/or other such like apparatus,
from which the formulation may be applied to an infected area of the body,
injected into an animal, and/or even applied to and/or mixed with the
other components of the kit.
However, the components of the kit may be provided as dried powder(s).
When reagents and/or components are provided as a dry powder, the powder
can be reconstituted by the addition of a suitable solvent. It is
envisioned that the solvent may also be provided in another container
means.
The container means will generally include at least one vial, test tube,
flask, bottle, syringe and/or other container means, into which the
chemical compound or pharmaceutically acceptable salts thereof or NURR1
protein, gene and/or inhibitory formulation are placed, preferably,
suitably allocated. The kits may also comprise a second container means
for containing a sterile, pharmaceutically acceptable buffer and/or other
diluent.
The kits of the present invention will also typically include a means for
containing the vials in close confinement for commercial sale, such as,
e.g., injection and/or blow-molded plastic containers into which the
desired vials are retained.
Irrespective of the number and/or type of containers, the kits of the
invention may also comprise, and/or be packaged with, an instrument for
assisting with the injection/administration and/or placement of the
ultimate chemical compound or pharmaceutically acceptable salts thereof or
a NURR1 protein and/or gene composition within the body of an animal. Such
an instrument may be a syringe, pipette, forceps, and/or any such
medically approved delivery vehicle.
VII. Methods of Making Transgenic Mice
A particular embodiment of the present invention provides transgenic
animals that contain the transgenic constructs of interest. In a specific
embodiment, there is a transgenic non-human animal whose genome comprises
a transgene encoding a NURR1 amino acid sequence, wherein said transgene
is under the control of an operably linked promoter active in eukaryotic
cells. In another specific embodiment the promoter is constitutive,
tissue-specific, and/or inducible. In an additional specific embodiment,
the animal is a mouse. In a preferred embodiment, a transgenic mouse is
generated wherein the mouse harbors a NURR1 mutation, such as the
-291T-del or the -245T-G-sub mutations. In specific embodiments, the
transgenic mouse is then utilized to screen for drug candidates for a
disease related to defective NURR1, such as Parkinson's disease.
In a general aspect, a transgenic animal is produced by the integration of
a given transgene into the genome in a manner that permits the expression
of the transgene. Methods for producing transgenic animals are generally
described by Wagner and Hoppe (U.S. Pat. No. 4,873,191; which is
incorporated herein by reference), Brinster et al. 1985; which is
incorporated herein by reference in its entirety) and in "Manipulating the
Mouse Embryo; A Laboratory Manual" 2nd edition (eds., Hogan, Beddington,
Costantimi and Long, Cold Spring Harbor Laboratory Press, 1994; which is
incorporated herein by reference in its entirety).
Typically, a gene flanked by genomic sequences is transferred by
microinjection into a fertilized egg. The microinjected eggs are implanted
into a host female, and the progeny are screened for the expression of the
transgene. Transgenic animals may be produced from the fertilized eggs
from a number of animals including, but not limited to reptiles,
amphibians, birds, mammals, and fish.
DNA clones for microinjection can be prepared by any means known in the
art. For example, DNA clones for microinjection can be cleaved with
enzymes appropriate for removing the bacterial plasmid sequences, and the
DNA fragments electrophoresed on 1% agarose gels in TBE buffer, with
standard techniques. The DNA bands are visualized by staining with
ethidium bromide, and the band containing the expression sequences is
excised. The excised band is then placed in dialysis bags containing 0.3 M
sodium acetate, pH 7.0. DNA is electroeluted into the dialysis bags,
extracted with a 1:1 phenol:chloroform solution and precipitated by two
volumes of ethanol. The DNA is redissolved in 1 ml of low salt buffer (0.2
M NaCl, 20 mM Tris, pH 7.4, and 1 mM EDTA) and purified on an Elutip-D™column.
The column is first primed with 3 ml of high salt buffer (1 M NaCl, 20 mM
Tris, pH 7.4, and 1 mM EDTA) followed by washing with 5 ml of low salt
buffer. The DNA solutions are passed through the column three times to
bind DNA to the column matrix. After one wash with 3 ml of low salt
buffer, the DNA is eluted with 0.4 ml high salt buffer and precipitated by
two volumes of ethanol. DNA concentrations are measured by absorption at
260 nm in a UV spectrophotometer. For microinjection, DNA concentrations
are adjusted to 3 mg/ml in 5 mM Tris, pH 7.4 and 0.1 mM EDTA.
Other methods for purification of DNA for microinjection are described in
Hogan et al. Manipulating the Mouse Embryo (Cold Spring Harbor Laboratory,
Cold Spring Harbor, N.Y., 1986), in Palmiter et al. Nature 300:611 (1982);
in The Qiagenologist, Application Protocols, 3rd edition, published by
Qiagen, Inc., Chatsworth, Calif.; and in Sambrook et al. Molecular
Cloning: A Laboratory Manual (Cold Spring Harbor Laboratory, Cold Spring
Harbor, N.Y., 1989).
In an exemplary microinjection procedure, female mice six weeks of age are
induced to superovulate with a 5 IU injection (0.1 cc, ip) of pregnant
mare serum gonadotropin (PMSG; Sigma) followed 48 hours later by a 5 IU
injection (0.1 cc, ip) of human chorionic gonadotropin (hCG; Sigma).
Females are placed with males immediately after hCG injection. Twenty-one
hours after hCG injection, the mated females are sacrificed by CO2
asphyxiation or cervical dislocation and embryos are recovered from
excised oviducts and placed in Dulbecco's phosphate buffered saline with
0.5% bovine serum albumin (BSA; Sigma). Surrounding cumulus cells are
removed with hyaluronidase (1 mg/ml). Pronuclear embryos are then washed
and placed in Earle's balanced salt solution containing 0.5% BSA (EBSS) in
a 37.5° C. incubator with a humidified atmosphere at 5% CO2, 95% air until
the time of injection. Embryos can be implanted at the two-cell stage.
Randomly cycling adult female mice are paired with vasectomized males.
C57BL/6 or Swiss mice or other comparable strains can be used for this
purpose. Recipient females are mated at the same time as donor females. At
the time of embryo transfer, the recipient females are anesthetized with
an intraperitoneal injection of 0.015 ml of 2.5% avertin per gram of body
weight. The oviducts are exposed by a single midline dorsal incision. An
incision is then made through the body wall directly over the oviduct. The
ovarian bursa is then torn with watchmakers forceps. Embryos to be
transferred are placed in DPBS (Dulbecco's phosphate buffered saline) and
in the tip of a transfer pipet (about 10 to 12 embryos). The pipet tip is
inserted into the infundibulum and the embryos transferred. After the
transfer, the incision is closed by two sutures.
VIII. Gene Therapy Administration
Where appropriate, gene therapy vectors can be formulated into
preparations in solid, semisolid, liquid, or gaseous forms in the ways
known in the art for their respective route of administration. Means known
in the art can be utilized to prevent release and absorption of the
composition until it reaches the target organ or to ensure timed-release
of the composition. A pharmaceutically acceptable form should be employed
which does not ineffectuate the compositions of the present invention. In
pharmaceutical dosage forms, the compositions can be used alone or in
appropriate association, as well as in combination, with other
pharmaceutically active compounds.
Accordingly, the pharmaceutical composition of the present invention may
be delivered via various routes and to various sites in an animal body to
achieve a particular effect (see, e.g., Rosenfeld et al., 1991; Rosenfeld
et al., 1991a; Jaffe et al., 1992). One skilled in the art will recognize
that although more than one route can be used for administration, a
particular route can provide a more immediate and more effective reaction
than another route. Local or systemic delivery can be accomplished by
administration comprising application or instillation of the formulation
into body cavities, inhalation or insufflation of an aerosol, or by
parenteral introduction, comprising intramuscular, intravenous,
peritoneal, subcutaneous, intradermal, and topical administration.
One skilled in the art recognizes that different methods of delivery may
be utilized to administer a vector into a cell. Examples include: (1)
methods utilizing physical means, such as electroporation (electricity), a
gene gun (physical force), or applying large volumes of a liquid
(pressure); and (2) methods wherein said vector is complexed to another
entity, such as a liposome or transporter molecule.
Accordingly, the present invention provides a method of transferring a
therapeutic gene to a host, which comprises administering the vector of
the present invention, preferably as part of a composition, with any of
the aforementioned routes of administration or alternative routes known to
those skilled in the art and appropriate for a particular application.
Effective gene transfer of a vector to a host cell in accordance with the
present invention can be monitored in terms of a therapeutic effect (e.g.,
alleviation of some symptom or sign associated with the particular disease
being treated) or, further, by evidence of the transferred gene or
expression of the gene within the host (e.g., with the polymerase chain
reaction in conjunction with sequencing, Northern or Southern
hybridizations, or transcription assays to detect the nucleic acid in host
cells, or with immunoblot analysis, antibody-mediated detection, mRNA, or
protein half-life studies, or particularized assays to detect protein or
polypeptide encoded by the transferred nucleic acid, or impacted in level
or function due to such transfer).
These methods described herein are by no means all-inclusive, and further
methods to suit the specific application will be apparent to the ordinary
skilled artisan. Moreover, the effective amount of the compositions can be
approximated further through analogy to compounds known to exert the
desired effect.
Furthermore, the actual dose and schedule can vary depending on whether
the compositions are administered in combination with other pharmaceutical
compositions, or depending on interindividual differences in
pharmacokinetics, drug disposition, and metabolism. Similarly, amounts can
vary in in vitro applications depending on the particular cell line
utilized (e.g., based on the number of vector receptors present on the
cell surface, or the ability of the particular vector employed for gene
transfer to replicate in that cell line). Furthermore, the amount of
vector to be added per cell will likely vary with the length and stability
of the therapeutic gene inserted in the vector, as well as the nature of
the sequence, and is particularly a parameter which needs to be determined
empirically, and can be altered due to factors not inherent to the methods
of the present invention (for instance, the cost associated with
synthesis). One skilled in the art can easily make any necessary
adjustments in accordance with the exigencies of the particular situation.
Claim 1 of 14 Claims
1. A method of diagnosing
Parkinson's disease in an individual comprising the steps of:
obtaining a peripheral blood lymphocyte (PBL) sample from said individual;
and
assaying said sample for a decrease in NURR1 mRNA level, wherein said
decrease indicates said individual has said Parkinson's disease and wherein
the mRNA level is decreased relative to the mRNA level in a PBL normal
control.
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