Misa Hayashi1, Kumi Futawaka1, Midori Matsushita1, Rie Koyama1, Yue Fun1, Yuki Fukuda1, Ayaka Nushida1, Syoko Nezu1, Tetsuya Tagami2, Kenji Moriyama3. 1. Medicine & Clinical Science, Faculty of Pharmaceutical Sciences, Mukogawa Women's University, Hyogo 663-8179, Japan. 2. Clinical Research Institute for Endocrine and Metabolic Diseases, National Hospital Organization Kyoto Medical Center, Kyoto 612-8555, Japan. 3. Medicine & Clinical Science, Faculty of Pharmaceutical Sciences, Mukogawa Women's University, Hyogo 663-8179, Japan; Clinical Research Institute for Endocrine and Metabolic Diseases, National Hospital Organization Kyoto Medical Center, Kyoto 612-8555, Japan. Electronic address: kemori@mukogawa-u.ac.jp.
Abstract
OBJECTIVE: We evaluated the direct action of GH signaling in energy homeostasis in myocytes. DESIGN: We investigated the GH-induced expression of UCP3 in human embryonic kidney 293 cells, human H-EMC-SS chondrosarcoma cells, murine C2C12 skeletal muscle myoblasts, and rat L6 skeletal muscle cells, as well as its direct effect on the GHR/JAK/STAT5 pathway using a combination of a reporter assay, real-time quantitative polymerase chain reaction, and western blotting. RESULTS: We demonstrated that the regulation of energy metabolism by GH involves UCP3 via activated STAT5, a signal transducer downstream of GH. UCP3 expression increased with STAT5 in a dose-dependent manner and was higher than that of UCP2. We confirmed the functional STAT5 binding site consensus sequences at -861 and -507 bp in the UCP3 promoter region. CONCLUSION: The results suggest that GH stimulates UCP3 directly and that UCP2 and that UCP3 participate in the signal transduction pathway that functions downstream of the GHR/JAK/STAT.
OBJECTIVE: We evaluated the direct action of GH signaling in energy homeostasis in myocytes. DESIGN: We investigated the GH-induced expression of UCP3 in humanembryonic kidney 293 cells, humanH-EMC-SS chondrosarcoma cells, murine C2C12 skeletal muscle myoblasts, and rat L6 skeletal muscle cells, as well as its direct effect on the GHR/JAK/STAT5 pathway using a combination of a reporter assay, real-time quantitative polymerase chain reaction, and western blotting. RESULTS: We demonstrated that the regulation of energy metabolism by GH involves UCP3 via activated STAT5, a signal transducer downstream of GH. UCP3 expression increased with STAT5 in a dose-dependent manner and was higher than that of UCP2. We confirmed the functional STAT5 binding site consensus sequences at -861 and -507 bp in the UCP3 promoter region. CONCLUSION: The results suggest that GH stimulates UCP3 directly and that UCP2 and that UCP3 participate in the signal transduction pathway that functions downstream of the GHR/JAK/STAT.