Adiponectin increases BMP-2 expression in osteoblasts via AdipoR receptor signaling pathway.
Adiponectin is a protein hormone secreted predominantly by differentiated adipocytes and involved in energy homeostasis. Bone morphogenetic protein (BMP) plays important roles in osteoblastic differentiation and bone formation. However, the effects of adiponectin on BMPs expression in cultured osteoblasts are largely unknown. Here we found that adiponectin increased mRNA expression of BMP-2 but not other BMPs in cultured osteoblastic cells. Stimulation of osteoblasts with adiponectin also increased protein levels of BMP-2 by Western blot and ELISA assay. Adiponectin-mediated BMP-2 expression was attenuated by 5'-AMP-activated protein kinase (AMPK) small interference RNA and AMPK inhibitor (araA and compound C). Activations of p38 and NF-kappaB pathways after adiponectin treatment were demonstrated, and adiponectin-induced expression of BMP-2 was inhibited by the specific inhibitor and mutant of p38 and NF-kappaB cascades. Taken together, our results provide evidence that adiponectin enhances BMP-2 expression in osteoblastic cells, and AdipoR1 receptor, AMPK, p38 and NF-kappaB signaling pathways may be involved in increasing BMP-2 expression by adiponectin.
Huang
Chun-Yin
CY
Department of Orthopaedic Surgery, China Medical University Beigang Hospital, Yun-Lin County, Taiwan.
Lee
Chun-Yi
CY
Chen
Meng-Yi
MY
Tsai
Hsiao-Chi
HC
Hsu
Horng-Chaung
HC
Tang
Chih-Hsin
CH
D055372:AMP-Activated Protein Kinases / Q000378:metabolism; D052242:Adiponectin / Q000494:pharmacology*; D000818:Animals; D055396:Bone Morphogenetic Protein 2 / Q000235:genetics / Q000378:metabolism*; D002460:Cell Line; D005786:Gene Expression Regulation / Q000187:drug effects; D006801:Humans; D051379:Mice; D016328:NF-kappa B / Q000378:metabolism; D010006:Osteoblasts / Q000187:drug effects* / Q000201:enzymology / Q000378:metabolism*; D054419:Receptors, Adiponectin / Q000378:metabolism*; D015398:Signal Transduction / Q000187:drug effects*; D048051:p38 Mitogen-Activated Protein Kinases / Q000378:metabolism
D052242:Adiponectin; C525718:BMP2 protein, human; D055396:Bone Morphogenetic Protein 2; D016328:NF-kappa B; D054419:Receptors, Adiponectin; D048051:p38 Mitogen-Activated Protein Kinases; D055372:AMP-Activated Protein Kinases