Compositions and methods for identifying metabolically active agents

Abstract

The present invention relates to cells with altered cell cycle control. In particular, the present invention provides cells with altered cell cycle control and uses of such cells to identify metabolically active agents.

We claim: 
     
         1 . A plurality of immortalized or primary beta cells, wherein said beta cells lack a functional Bmal1 gene. 
     
     
         2 . The beta cells of  claim 1 , wherein said Bmal1 gene comprises a deletion of at least a portion of said gene. 
     
     
         3 . The beta cells of  claim 1  or  2 , wherein said cells further comprise a reporter gene that reports the level of insulin secretion. 
     
     
         4 . The beta cells of  claim 3 , wherein said reporter gene expresses a fluorescent marker in response to cleavage of proinsulin. 
     
     
         5 . The beta cells of  claim 4 , wherein said fluorescent marker is luciferase. 
     
     
         6 . The beta cells of any one of  claims 3  to  5 , wherein said reporter gene is present on a plasmid. 
     
     
         7 . The beta cells of any one of  claims 1  to  6 , wherein said cells lack glucose-stimulated insulin secretion or exhibit impaired glucose-stimulated insulin secretion. 
     
     
         8 . The beta cells of any one of  claims 1  to  7 , wherein said beta cells are in vitro, ex vivo, or in vivo in a non-human mammal. 
     
     
         9 . A kit or system, comprising:
 a) the beta cells of any one of  claims 1  to  8 ; and   b) glucose.   
     
     
         10 . A method of screening for compounds that alter insulin secretion, comprising:
 a) contacting the beta cells of any one of  claims 1  to  8  with a test compound and glucose; and   b) measuring the level of insulin secretion in said beta cells in the presence and absence of said test compound.   
     
     
         11 . The method of  claim 10 , wherein test compounds that restore said insulin secretion are identified. 
     
     
         12 . A compound identified by the method of  claim 10  or  11 . 
     
     
         13 . A plurality of immortalized or primary myoblasts, wherein said myoblasts lack a functional Bmal1 gene. 
     
     
         14 . The myoblasts of  claim 1 , wherein said Bmal1 gene comprises a deletion of at least a portion of said gene. 
     
     
         15 . The myoblasts of  claim 13  or  14 , wherein said myoblasts are in vitro, ex vivo, or in vivo in a non-human mammal. 
     
     
         16 . The myoblasts of any one of  claims 13  to  15 , wherein said myoblasts exhibit impairs oxygen consumption and/or extracellular lactate production. 
     
     
         16 . The myoblasts of any one of  claims 13  to  15 , wherein said myoblasts exhibit reduced hypoxia induced HIF1α accumulation. 
     
     
         17 . A composition, kit or system, comprising the myoblasts of any one of  claims 13  to  16 . 
     
     
         18 . A method of screening for compounds that alter oxygen consumption, comprising:
 a) contacting the myoblasts of any one of  claims 13  to  16  with a test compound; and   b) measuring the level of oxygen consumption said myoblasts in the presence and absence of said test compound.   
     
     
         19 . The method of  claim 18 , wherein test compounds that restore oxygen consumption are identified. 
     
     
         20 . The method of  claim 18  or  19 , further comprising contacting said myoblasts with glucose. 
     
     
         21 . A compound identified by the method of any one of  claims 18  to  20 .