Human G protein-coupled receptor and modulators thereof for the treatment of ischemic heart disease and congestive heart failure

Abstract

The present invention relates to methods of identifying whether a candidate compound is a modulator of an orphan G protein-coupled receptor (GPCR). Preferably the GPCR is human. In some embodiments, the GPCR is expressed endogenously by cardiomyocytes. In some embodiments, the GPCR is coupled to Gi and lowers the level of intracellular cAMP. In some embodiments, overexpression of the GPCR promotes survival of cardiomyocytes. In some embodiments, overexpression of the GPCR rescues cardiomyoctes from hypoxia/reoxygenation induced apoptosis. In some embodiments, the GPCR is down-regulated in individuals with congestive heart failure. Agonists of the invention are envisioned to be useful as therapeutic agents for the treatment of ischemic heart disease, including myocardial infarction, post-myocardial infarction remodeling, and congestive heart failure.

1 - 60 . (canceled)  
     
     
         61 . A method comprising: 
 (a) contacting a candidate compound with a G protein-coupled receptor comprising an amino acid sequence having at least 90% identity to SEQ ID NO:3, wherein said GPCR is present on a cell or isolated membrane thereof;    (b) determining the ability of the compound to modulate the G protein-coupled receptor; and    (c) determining if said compound has cardioprotective activity.    
     
     
         62 . The method of  claim 61 , wherein said cell is a mammalian cell, a yeast cell or a melanophore cell.  
     
     
         63 . The method of  claim 61 , wherein said G protein-coupled receptor is constitutively active.  
     
     
         64 . The method of  claim 61 , wherein said G protein-coupled receptor comprises the amino acid sequence of an endogenous receptor comprising the amino acid sequence of SEQ ID NO:2, SEQ ID NO:3 or SEQ ID NO:5.  
     
     
         65 . The method of  claim 61 , wherein the method comprises detecting a second messenger.  
     
     
         66 . The method of  claim 65 , wherein the second messenger is cAMP or IP 3 .  
     
     
         67 . The method of  claim 61 , wherein the method comprises measuring pigment distribution in melanophore assay.  
     
     
         68 . The method of  claim 61 , wherein the method comprises measuring GTPγS binding to membrane.  
     
     
         69 . The method of  claim 61 , wherein element (c) comprises: 
 (i) contacting a compound which modulates the G protein-coupled receptor in (b) in vitro with a cardiomyocyte cell; and    (ii) determining whether the compound modulates survival of the cardiomyocyte cell.    
     
     
         70 . The method of  claim 69 , wherein the method comprises measuring apoptosis of the cardiomyocyte cell.  
     
     
         71 . The method of  claim 61 , wherein element (c) comprises: 
 (i) administering a compound which modulates the G protein-coupled receptor in (b) to a mammal; and    (ii) determining whether the compound modulates cardiac function in the mammal.    
     
     
         72 . The method of  claim 71 , wherein the mammal is a rat or mouse model of heart disease.  
     
     
         73 . The method of  claim 71 , wherein element (ii) comprises evaluating a cardiovascular disorder, an ischemic heart disease, or a cardiovascular function in said mammal.  
     
     
         74 . The method of  claim 61 , wherein the candidate compounds are screened as pharmaceutical agents for congestive heart failure.  
     
     
         75 . The method of  claim 74 , wherein the screen is for an agonist of the GPCR.  
     
     
         76 . The method of  claim 75 , wherein the agonist is a partial agonist.  
     
     
         77 . A method comprising: 
 (a) administering a candidate compound to a non-human mammal having a genome comprising an inactivated mammalian RUP41 gene; and    (b) determining if said compound provides cardioprotection.    
     
     
         78 . The method of  claim 77 , wherein the non-human mammal is a rat, a mouse or a pig.  
     
     
         79 . A cultured cardiomyocyte cell comprising a recombinant nucleic acid encoding a G protein-coupled receptor comprising an amino acid sequence having at least 90% identity to SEQ ID NO:3.  
     
     
         80 . A non-human mammal having a genome that is modified to provide for selective expression of a G protein-coupled receptor comprising an amino acid sequence having at least 90% identity to SEQ ID NO:3 in cardiomyocytes.  
     
     
         81 . A non-human mammal having a genome that is modified to provide for selective inactivation of a mammalian RUP41 gene in cardiomyocytes.