Growth hormone regulates the expression of UCP2 in myocytes

Abstract Objective To determine if and how growth hormone (GH) signaling is involved in energy metabolism. Design We used human embryonic kidney TSA201 cells, human H-EMC-SS chondrosarcoma cells, rat L6 skeletal muscle cells, and murine C2C12 skeletal muscle myoblasts to investigate GH-induced expression of uncoupling protein2 (UCP2) to the GHR/JAK/STAT5 pathway by a combination of a reporter assay, electrophoretic mobility shift assay (EMSA), real-time quantitative PCR, Western blotting. Results We demonstrated that the regulation energy metabolism, which was hypothesized to be directly acted on by GH, involves UCP2 via activated STAT5B, a signal transducer downstream of GH. We also showed that the sequence at the −586 ‘TTCnGA' may function as a novel putative consensus sequence of STAT5s. Conclusion The results suggest that GH regulates energy metabolism directly in myocytes and that UCP2 participates in the signal transduction pathway that functions downstream of the GHR/JAK/STAT.