Title:  Method for screening for drugs useful in inhibition of polymerization of a.beta. and tau peptides

United States Patent:  6,458,847

Issued:  October 1, 2002

Inventors:  Wilson; David M. (West Roxbury, MA); Binder; Lester T. (Grayslake, IL)

Assignee:  University of Alabama at Birmingham Research Foundation (Birmingham, AL)

Appl. No.:  569729

Filed:  May 10, 2000

A method of stimulating polymerization of a tau protein, comprising the step of contacting said protein with a fatty acid. In another embodiment of the present invention, there is provided a method of stimulating polymerization of a amyloid peptide, comprising the step of contacting said peptide with a fatty acid.

DETAILED DESCRIPTION OF THE INVENTION

The present invention is directed to a method of regulating the assembly of the protein tau in the brain of a mammal in need of such treatment comprising the step of administering to said mammal a pharmacologically effective amount of an inhibitor of fatty acid liberation or release. Representative examples of such fatty acids include those fatty acids listed in FIG. 12 Representative examples of such fatty acids liberation or release inhibitors include at least two types of drugs. Both of these drugs are inhibitors of lecithin cholesterol acyl transferase (LCAT). In addition to being present in the cerebrospinal fluid (CSF), this enzyme is also present in the serum, and most of the available data on inhibition of this enzyme are based on assays of serum activity. Since serum concentrations of LCAT, lipids, and cholesterol are much higher than those observed in the CSF (100- IOOOX), however, drug concentrations required for serum effects may be much higher than those required for CSF effects. The first drug is propranolol. Dosage would be in the range of 2.5-250 mg/day. This drug besides inhibiting LCAF, also inhibits lysosomal phosholipases, which are potentially involved in the intra-lysosomal nucleation of amyloid filaments. Because d-propranolol and I-propranolol have somewhat different pharmacological properties, one might want to use them separately. The second type of drug belong to the general class of terpenes, and include menthol, menthone, and camphor. Dosage for therapeutic purposes would be in concentration range of 0.2-20 mg/kg.

The present invention is also directed to a method of inhibiting production of Alzheimer-type amyloidosis in a mammal comprising the step of administering to said mammal in need of such treatment an effective amount of at least one modulator of fatty acid liberation or release, said modulator capable of controlling the rate of assembly of proteins found in extracellular amyloid plaques. Representative examples of such fatty acids liberation or release inhibitors are described above.

The present invention is also directed to a method of treating amyloidosis associated with Alzheimer's disease in a mammalian patient comprising the step of administering to said patient in need of such treatment an effective amount of at least one modulator of fatty acid liberation or release, said modulator capable of controlling the rate of assembly of proteins found in intracellular neurofibrillary tangles and extracellular amyloid plaques.

The present invention also provides a method of stimulating polymerization of a tau protein, comprising the step of contacting said protein with an unesterified fatty acids. Representative fatty acids include those listed in FIG. 12 and include arachadonic acid, palmitoleic acid, oleic acid, linoleic acid and stearic acid. This method can also be used to screen for compounds which prevent tau polymer formation in the brains of patients with AD and other related neurodegenerative diseases characterized in part by in vivo tau polymer formation.

The present invention also provides a method of stimulating polymerization of a amyloid peptide, comprising the step of contacting said peptide with a fatty acid. Representative examples of such fatty acids include arachadonic acid, palmitoleic acid, oleic acid, linoleic acid and stearic acid.

The present invention also provides a method of stimulating the polymerization of the tau polymer, comprising the step of contacting the tau polymer with a reducing agent. Representative reducing agents include dithiothreitol, dithioerythreitol, 2-mercaptothanol and reduced gluthathione. This method can be used in a screening assay to discover drugs which prevent tau polymer formation in the brains of AD patients or patients with a neurodegenerative disease characterized at least in part by increased tau polymer formation in vivo.

In another embodiment of the present invention, there is provided a method of reducing the polymerization of imyloid and/or tau proteins in the brain of an animal in need of such treatment, comprising the step of introducing into the cerebrospinal fluid of the animal, an amount of a compound effective in absorbing unesterified fatty acids in the cerebrospinal fluid.

It is specifically contemplated that pharmaceutical compositions may be prepared using the novel fatty acid liberation or release inhibitors in the methods of the present invention. In such a case, the pharmaceutical composition comprises the novel fatty acid liberation or release inhibitors and a pharmaceutically acceptable carrier. A person having ordinary skill in this art would readily be able to determine, without undue experimentation, the appropriate dosages and routes of administration of such novel fatty acid liberation or release inhibitors in the methods of the present invention.

A method of screening for a drug useful in the treatment of Alzheimer's Disease, comprising the steps of: increasing the polymerization of A.beta. peptides in a medium by contacting said culture with an effective amount of at least one unesterified fatty acid or a compound that induces fatty acid liberation and release; and testing a drug of interest to determine whether the drug inhibits the polymerization of A.beta. peptides induced by the unesterified fatty acid. Representative examples of useful fatty acids include arachadonic acid, palmitoleic acid, oleic acid, linoleic acid and stearic acid. Preferably, the unesterified fatty acid is found in an amount from about 1 micromolar to about 100 micromolar. A represenative example of a compound that induces fatty acid liberation and release is melittin. Preferably, the melittin is found in amount of from about 0.1 micromolar to about 1.0 micromolar. Preferably, the medium is selected from the group consisting of cell culture or a test tube.

A method of screening for a drug useful in the treatment of Alzheimer's Disease, comprising the steps of: increasing the polymerization of tau peptides in a medium by contacting said culture with an effective amount of at least one unesterified fatty acid or a compound that induces fatty acid liberation and release; and testing a drug of interest to determine whether the drug inhibits the polymerization of tau peptides induced by the unesterified fatty acid. Representative examples of useful fatty acids include arachadonic acid, palmitoleic acid, oleic acid, linoleic acid and stearic acid. Preferably, the unesterified fatty acid is found in an amount from about 1 micromolar to about 100 micromolar. A represenative example of a compound that induces fatty acid liberation and release is melittin. Preferably, the melittin is found in amount of from about 0.1 micromolar to about 1.0 micromolar. Preferably, the medium is selected from the group consisting of cell culture or a test tube.

Claim 1 of 12 Claims

What is claimed is:

1. A method of screening for a drug useful in the treatment of Alzheimer's Disease, said method comprising the steps of:

increasing the polymerization of A.beta. peptides by contacting said A.beta. peptides with an effective amount of at least one unesterified fatty acid or a compound that induces fatty acid liberation and release; and

adding a drug of interest to said A.beta. peptides contacted with the unesterified fatty acid or the compound to determine whether the drug inhibits the polymerization of A.beta. peptides induced by the unesterified fatty acid or the compound.

 

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