Protein kinase C epsilon as modulator of anxiety, alcohol consumption and self-administration of drugs of abuse

Abstract

The present invention is directed to the production of PKC isozyme ε (PKCε)-deficient cells and non-human animals. The present invention is further directed to the identification of PKCε as a target for drugs that reduce anxiety. According to the present invention, PKCε-inhibiting compounds act in synergy with drugs acting at the GABA A receptor. The present invention is also directed to the use of modulators of PKCε to modulate alcohol consumption, self-administration of other drugs of abuse, and the effects of alcohol consumption as well as the use of inhibitors of PKCε, either alone or in conjunction with allosteric agonists of GABA A receptors, to treat conditions, such as addiction, withdrawal syndrome, skeletal muscle spasms, convulsive seizures, and epilepsy, that are amenable to treatment by allosteric agonists of GABA A receptors. Additional aspects of the present invention are diagnostic methods for identifying individuals at risk for becoming alcoholics or abusers of other drugs and kits for performing such diagnostic methods. The present invention relates to: cells and non-human animals deficient for the PKC isozyme ε (PKCε); the use of PKCε as a target for drugs; the use of inhibitors of PKCε in methods of reducing anxiety and treating conditions associated with insufficient activity of the GABA A receptor; the use of modulators of PKCε in methods of modulating alcohol consumption, modulating self-administration of other drugs of abuse, and altering the effects of alcohol; pharmaceutical compositions comprising inhibitors of PKCε and allosteric agonists of GABA A receptors; and the identification of individuals with enhanced susceptibility to alcoholism or other forms of addiction.

What is claimed is:  
     
         1 . A diploid animal cell containing an engineered mutation in at least one allele of the gene encoding the ε isozyme of protein kinase C (PKCε).  
     
     
         2 . The cell of  claim 1  wherein said cell is a mouse cell.  
     
     
         3 . The cell of  claim 2 , wherein, due to said engineered mutation, the cell's levels of PKCε activity are less than the levels of PKCε activity in wild-type cells.  
     
     
         4 . The cell of  claim 3 , wherein said mutation is a deletion mutation.  
     
     
         5 . The cell of  claim 1 , wherein the cell is homozygous for the mutation.  
     
     
         6 . A non-human transgenic animal comprising the cell of  claim 1 .  
     
     
         7 . An animal that is a descendent of the non-human transgenic animal of  claim 6  and comprises said engineered mutation.  
     
     
         8 . The animal of  claim 7 , wherein, due to said engineered mutation, the animal's levels of PKCε activity are less than the levels of PKCε activity in wild-type animals.  
     
     
         9 . The animal of  claim 8 , wherein the cells of said animal are homozygous for said engineered mutation.  
     
     
         10 . A method of identifying a compound that modulates anxiety, said method comprising: 
 selecting, as a test compound, a compound that modulates the activity of PKCε, and    administering said test compound to a subject to determine whether the symptoms of anxiety are modulated.    
     
     
         11 . A method of modulating consumption of a drug of abuse, said method comprising: administering an effective amount of a modulator of PKCε.  
     
     
         12 . The method of  claim 11 , wherein said drug of abuse is selected from the group consisting of: alcohol, psychostimulants, opiates and sedative-hypnotic drugs.  
     
     
         13 . The method of  claim 11 , wherein said modulator is an inhibitor of PKCε.  
     
     
         14 . The method of  claim 13 , wherein said inhibitor is a selective inhibitor of PKCε.  
     
     
         15 . The method of  claim 13 , wherein said inhibitor is a peptide selected from the group consisting of: εV1-1, εV1-2, εV1-3, εV1-4, εV1-5, εV1-6 and εV1-7.  
     
     
         16 . A method of modulating the effects of a drug of abuse, said method comprising: administering to a person, an effective amount of a modulator of PKC6.  
     
     
         17 . The method of  claim 16 , wherein said modulator is an inhibitor of PKCε and said effects of the drug of abuse are enhanced.  
     
     
         18 . The method of  claim 16 , wherein said modulator is an activator of PKCε and said effects of the drug of abuse are reduced.  
     
     
         19 . A method of treating a condition amenable to treatment by an allosteric modulator of a GABA A  receptor, said method comprising: administering to a subject having such condition, an effective amount of an inhibitor of PKCε.  
     
     
         20 . The method of  claim 19 , wherein said condition is selected from the group consisting of: anxiety, addiction, withdrawal syndrome, skeletal muscle spasms, convulsive seizures, and epilepsy.  
     
     
         21 . The method of  claim 19 , further comprising administering to said person, an effective amount of an allosteric agonist of a GABA A  receptor.  
     
     
         22 . A method of determining the likelihood that a person will become dependent upon or an abuser of a drug of abuse, said method comprising: 
 analyzing a sample containing PKCε or nucleic acid encoding PKCε from a person to determine PKCε activity or concentration in said person;    comparing said activity or concentration with a standard value selected from a range of PKCε activities or concentrations, respectively, for similar samples obtained from a population of persons having a known characteristic with respect to dependence on a drug of abuse; and    relating said activity or concentration of PKCε to said standard value, wherein a statistically different activity or concentration is predictive of the degree of likelihood of said person becoming dependent upon or an abuser of said drug of abuse.    
     
     
         23 . A composition comprising an inhibitor of PKCε and an agonist of a GABA A  receptor.  
     
     
         24 . The composition of  claim 23 , wherein said agonist is an allosteric agonist.  
     
     
         25 . The composition of  claim 24 , wherein said allosteric agonist is a benzodiazepine.  
     
     
         26 . The composition of  claim 25 , wherein said benzodiazepine is selected from the group consisting of: alprazolam, chlordiazepoxide, chlordiazepoxide hydrochloride, chlormezanone, clobazam, clonazepam, clorazepate dipotassium, diazepam, droperidol, estazolam, fentanyl citrate, flurazepam hydrochloride, halazepam, lorazepam, midazolam hydrochloride, oxazepam, prazepam, quazepam, temazepam, and traizolam.  
     
     
         27 . The composition of  claim 24 , wherein said allosteric agonist is a barbituate.  
     
     
         28 . The composition of  claim 27 , wherein said barbituate is selected from the group consisting of: amobarbital, amobarbital sodium, aprobarbital, butabarbital sodium, hexobarbital sodium, mephobarbital, metharbital, methohexital sodium, pentobarbital, pentoberbital sodium, phenobarbital, phenobarbital sodium, secobarbital, secobarbital sodium, talbutal, thiamylal sodium, and thiopental sodium.