The Expression of Relaxin-3 in Adipose Tissue and its Effects on Adipogenesis
Hiroyuki Yamamoto, Hiromi Shimokawa, Tatsuomi Haga, Yuki Fukui, Kazuaki Iguchi, Keiko Unno, Minoru Hoshino and Atsushi Takeda
Pages 517-522 (6)
Energy homeostasis is regulated by endocrine factors. The concentration of relaxin-3 in serum is related to
body mass index. However, relaxin-3 is found only in the brain and testis. In this study, we examined the expression of relaxin-
3 in adipose tissue and its effects on adipogenesis. The expression of relaxin-3 was determined using RT-PCR, a relaxin-
3 C-peptide-specific radioimmunoassay, specifically in the stromal-vascular fraction (SVF) cells rather than adipocytes.
The release of C-peptide was regulated by glucose concentration in the SVF cells. However, the differentiated adipocytes
did not express relaxin-3. In glucose perfusion experiments, C-peptide was released in response to high glucose
concentrations in the mesenteric perfusate, opposite to insulin release. Additionally, GPCR135 mRNA was expressed in
adipocytes. Relaxin-3 increased triglycerides in adipocytes and decreased lipase activity. The present study showed that
relaxin-3 is secreted from SVF cells and that it regulates lipid accumulation in adipocytes.
Adipocyte, GPCR135, lipid accumulation, mesentery adipose tissue, relaxin-3, .
Laboratory of Bioorganic Chemistry, School of Pharmaceutical Sciences, University of Shizuoka, 52- 1 Yada, Shizuoka 422-8526, Japan.