Methods and compositions for treating obesity
The present invention relates to therapeutic compositions for treating or preventing obesity and obesity-related disorders in a subject. The present invention also relates to the use of PGC-1 expression levels to determine the safe dosage range for known or putative respiration uncoupling agents for use as anti-obesity therapeutics. The present invention further relates to methods for identifying new compounds that have respiration uncoupling activity.
1. A method of identifying the upper limit of a safe dosage range for a respiration uncoupling agent comprising:
a) contacting a cell expressing PGC-1 with varying amounts of the respiration uncoupling agent;
b) determining the maximum PGC-1 expression level and the corresponding amount of the respiration uncoupling agent to thereby identify the upper limit of the safe dosage range for the respiration uncoupling agent.
2. The method of claim 1 , wherein the respiration uncoupling agent is FCCP.
3. The method of claim 1 , wherein the respiration uncoupling agent is selected from the group consisting of FCCP, DNP, and CCCP.
4. The method of claim 1 , wherein the PGC-1 expression level is detected by an anti -PGC-1 antibody.
5. The method of claim 1 , wherein the PGC- 1 expression level is detected by the PGC-1 mRNA level.
6. The method of claim 1 , wherein said method further comprises determining the level of ATP.
7. The method of claim 1 , wherein said method further comprises determining the level of lactic acid.
8. The method of claim 1 , wherein said method further comprises determining the metabolic rate of the cell.
9. The method of claim 1 , wherein said method further comprises determining the level of AMP kinase.
10. The method of claim 1 , further comprising determining whether said safe dosage is effective to increase metabolic activity by increasing the uncoupling of mitochondrial oxidative phosphorylation.
11. The method of claim 10 , wherein said determining is carried out by identifying whether said safe dosage is capable of decreasing fat mass, decreasing adipocity, or increasing weight loss in a subject.
12. The method of claim 1 , further comprising administering to the subject a safe dosage of a respiration uncoupling agent such that obesity or the obesity-related disorder is treated.
13. The method of claim 12 , wherein the obesity related disorder is selected from the group consisting of obesity, diabetes, hyperphagia, endocrine abnormalities, triglyceride storage disease, Bardet-Biedl syndrome, Lawrence-Moon syndrome, Prader- Labhart-Willi syndrome, anorexia, and cachexia.
14. The method of claim 12 , wherein the respiration uncoupling agent is FCCP.
15. The method of claim 12 , wherein the respiration uncoupling agent is selected from the group consisting of FCCP, DNP, and CCCP.
16. The method of claim 12 , wherein the PGC-1 expression level is detected by an anti -PGC- 1 antibody.
17. The method of claim 12 , wherein PGC-1 expression is detected by the PGC-1 mRNA level.
18. The method of claim 12 , wherein the respiration uncoupling agent is administered intravenously.
19. The method of claim 12 , wherein the respiration uncoupling agent is administered intraperitoneally.
20. The method of claim 12 , wherein the respiration uncoupling agent is administered orally.
21. The method of claim 12 , wherein said method further comprises determining the level of ATP.
22. The method of claim 12 , wherein said method further comprises determining the level of lactic acid.
23. The method of claim 12 , wherein said method further comprises determining the metabolic rate of the cell.
24. The method of claim 12 , wherein said method further comprises determining the level of AMP kinase.
25. A method for increasing metabolic activity of a cell comprising contacting the cell with a safe dose of a respiration uncoupling agent, wherein the safe dose of the respiration uncoupling agent is identified by:
a) contacting a cell expressing PGC-1 with varying amounts of the respiration uncoupling agent;
b) determining the maximum PGC-1 expression level and the corresponding amount of the respiration uncoupling agent to thereby identify the upper limit of the safe dosage range for the respiration uncoupling agent.
26. The method of claim 25 , wherein the respiration uncoupling agent is FCCP.
27. The method of claim 25 , wherein the respiration uncoupling agent is selected from the group consisting of FCCP, DNP, and CCCP.
28. The method of claim 25 , wherein the PGC-1 expression level is detected by an anti-PGC- 1 antibody.
29. The method of claim 25 , wherein the PGC-1 expression level is detected by determining the PGC-1 mRNA level.
30. The method of claim 25 , wherein the cell is an adipocyte.
31. The method of claim 25 , wherein the cell is selected from the group consisting of adipose cells, muscle cells and neural cells.
32. The method of claim 25 , wherein said method further comprises determining the level of ATP.
33. The method of claim 25 , wherein said method further comprises determining the level of lactic acid.
34. The method of claim 25 , wherein said method further comprises determining the metabolic rate of the cell.
35. The method of claim 25 , wherein said method further comprises determining the level of AMP kinase.
36. A method for identifying a compound capable of respiration uncoupling activity comprising:
a) contacting a cell expressing PGC-1 with a test compound;
b) assaying the ability of the test compound to stimulate the expression of PGC-1, thereby identifying a compound capable of respiration uncoupling activity; and
c) identifying a safe dosage range of the respiration uncoupling agent.
37. The method of claim 36 , wherein the safe dosage range of a respiration uncoupling agent is identified by:
a) contacting a cell expressing PGC-1 with varying amounts of the respiration uncoupling agent;
b) determining the maximum PGC-1 expression level and the corresponding amount of the respiration uncoupling agent to thereby identify the upper limit of the safe dosage range for the respiration uncoupling agent.
38. The method of claim 36 , wherein said method further comprises determining the level of ATP.
39. The method of claim 36 , wherein said method further comprises determining the level of lactic acid.
40. The method of claim 36 , wherein said method further comprises determining the metabolic rate of the cell.
41. The method of claim 36 , wherein said method further comprises determining the level of AMP kinase.