Truncated actriib-fc fusion proteins

Abstract

In certain aspects, the present invention provides compositions and methods for modulating (promoting or inhibiting) growth of a tissue, such as bone, cartilage, muscle, fat, brown fat and/or neuronal tissue and for treating metabolic disorders such as diabetes and obesity, as well as disorders associated with any of the foregoing tissue.

1 - 29 . (canceled) 
     
     
         30 . A method for treating a metabolic disorder in a subject, comprising administering to a subject an effective amount of a polypeptide selected from the group consisting of:
 a. a polypeptide that consists of the amino acid sequence of SEQ ID NO: 8;   b. a polypeptide produced by expressing in a mammalian cell the nucleic acid of SEQ ID NO: 4; and   c. a polypeptide produced by expressing in a mammalian cell the nucleic acid of SEQ ID NO: 6.   
     
     
         31 . The method of  claim 30 , wherein the subject has one or more of the following characteristics:
 a. elevated serum triglyceride levels;   b. elevated free fatty acid levels; or   c. elevated serum insulin levels.   
     
     
         32 . The method of  claim 30 , wherein the metabolic disorder is selected from the group consisting of: type 2 diabetes, metabolic syndrome, insulin resistance and obesity. 
     
     
         33 . The method of  claim 30 , wherein the polypeptide is a polypeptide of part (a). 
     
     
         34 . The method of  claim 30 , wherein the polypeptide is a polypeptide of part (b). 
     
     
         35 . The method of  claim 30 , wherein the polypeptide is a polypeptide of part (c). 
     
     
         36 . The method of  claim 30 , wherein the polypeptide is capable of causing a statistically significant decrease in serum triglyceride levels in a mouse fed a high fat diet after four weeks of treatment twice per week at a dose level of 10 mg/kg. 
     
     
         37 . The method of  claim 36 , wherein the mean decrease is at least 50 mg/dl triglycerides. 
     
     
         38 . The method of  claim 30 , wherein the polypeptide is capable of causing a statistically significant decrease in serum free fatty acid levels in a mouse fed a high fat diet after four weeks of treatment twice per week at a dose level of 10 mg/kg. 
     
     
         39 . The method of  claim 38 , wherein the mean decrease is at least 500 micromoles/dl free fatty acids. 
     
     
         40 . The method of  claim 30 , wherein the polypeptide is covalently associated with a second polypeptide to form a homodimer.