Transgenic animals expressing human p25

Abstract

The invention provides transgenic, non-human animals and transgenic non-human mammalian cells harboring a transgene encoding a p25 (activator of the protein kinase cdk 5) polypeptide. The two neuropathological lesions associated with Alzheimer's disease (AD) are amyloid plaques and neurofibrillary tangles (NFTs), composed predominantly of amyloid β peptides and hyperphosphorylated tau, respectively. While animal models for plaque formation exist, there is no animal model that recapitulates the formation of NFTs. This invention provides transgenic mice that overexpress human p25, an activator of cdk5, resulting in tau that is hyperphosphorylated at AD-relevant epitopes. Deposition of tau is detected in the amygdala, thalamus and cortex. Increased phosphorylated neurofilament, silver-positive neurons and neuronal death are also observed in these regions. We conclude that the overexpression of p25, an activator of cdk5, is sufficient to produce hyperphosphorylation of tau and neuronal death. The p25 transgenic mouse represents the first model for tau pathology in AD.

1 . Recombinant DNA comprising a rat neuron specific enolase promoter operably linked to a p25 encoding sequence of the human cdk5 gene encoding sequence.  
     
     
         2 . Recombinant DNA according to  claim 1  wherein said sequence encoding said p25 fragment has the characteristics of genomic DNA.  
     
     
         3 . Recombinant DNA according to  claim 1  wherein said sequence encoding said p25 fragment has the characteristics of cDNA.  
     
     
         4 . Recombinant DNA according to  claim 1  wherein said sequence is that of SEQ ID NO: 4  
     
     
         5 . A vector comprising recombinant DNA according to  claim 1 .  
     
     
         6 . A vector comprising recombinant DNA according to  claim 2 .  
     
     
         7 . A vector comprising recombinant DNA according to  claim 3 .  
     
     
         8 . An eukaryotic cell line comprising recombinant DNA according to  claim 1 .  
     
     
         9 . An eukaryotic cell line comprising recombinant DNA according to  claim 2 .  
     
     
         10 . An eukaryotic cell line comprising recombinant DNA according to  claim 3 .  
     
     
         11 . A transgenic non-human mammal, and progeny thereof whose germ cells and somatic cell express recombinant DNA according to  claim 1 .  
     
     
         12 . A transgenic non-human animal, or progeny, thereof, whose germ cells and somatic cells express recombinant DNA according to  claim 2 .  
     
     
         13 . A transgenic non-human animal, or progeny thereof, whose germ cells and somatic cells express recombinant DNA according to  claim 3 .  
     
     
         14 . A transgenic non-human animal, or a progeny thereof, according to  claim 12  which is a mouse.  
     
     
         15 . A transgenic non-human animal, or a progeny thereof, according to  claim 13  which is a mouse.  
     
     
         16 . A transgenic non-human animal, or a progeny thereof, according to  claim 14  which is a mouse.  
     
     
         17 . A method for treating an animal having a disease characterized by the expression of a p25 fragment of a human cdK5 gene comprising administering a therapeutically effective amount of an inhibitor of said p25 fragment.  
     
     
         18 . A method for determining the ability of a compound to inhibit the expression of a p25 fragment of a human cdk5 gene comprising the steps of: 
 a. creating a transgenic non-human animal by stably incorporating into the embryonic stem cells of said animal the recombinant DNA of  claim 1;     b. growing said embryonic stem cells into a mature transgenic non human animal;    c. administering to said transgenic non-human animal the compound of interest;    d. measuring the inhibition of said p25 fragment by said compound.    
     
     
         19 . A method for generating data to determing the ability of a compound to inhibit the expression of a p25 fragment of a human cdk5 gene comprising the steps of: 
 a. creating a transgenic non-human animal by stably incorporating into the embryonic stem cells of said animal the recombinant DNA of  claim 1;     b. growing said embryonic stem cells into a mature transgenic non human animal;    c. administering to said transgenic non-human animal the compound of interest;    d. measuring the inhibition of said p25 fragment by said compound.    e. using the data derived from said inhibition to synthesize compounds capable of inhibiting said p25 fragment.