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International Journal of Endocrinology
Volume 2013 (2013), Article ID 368970, 6 pages
http://dx.doi.org/10.1155/2013/368970
Research Article

Omentin-1 Stimulates Human Osteoblast Proliferation through PI3K/Akt Signal Pathway

Institute of Metabolism and Endocrinology, Second Xiang-Ya Hospital, Central South University, Changsha 410011, Hunan, China

Received 3 January 2013; Accepted 8 March 2013

Academic Editor: Guang-Da Xiang

Copyright © 2013 Shan-Shan Wu et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

It has been presumed that adipokines deriving from adipose tissue may play important roles in bone metabolism. Omentin-1, a novel adipokine, which is selectively expressed in visceral adipose tissue, has been reported to stimulate proliferation and inhibit differentiation of mouse osteoblast. However, little information refers to the effect of omentin-1 on human osteoblast (hOB) proliferation. The current study examined the potential effects of omentin-1 on proliferation in hOB and the signal pathway involved. Omentin-1 promoted hOB proliferation in a dose-dependent manner as determined by [3H]thymidine incorporation. Western blot analysis revealed that omentin-1 induced activation of Akt (phosphatidylinositol-3 kinase downstream effector) and such effect was impeded by transfection of hOB with Akt-siRNA. Furthermore, LY294002 (a selective PI3K inhibitor) and HIMO (a selective Akt inhibitor) abolished the omentin-1-induced hOB proliferation. These findings indicate that omentin-1 induces hOB proliferation via the PI3K/Akt signaling pathway and suggest that osteoblast is a direct target of omentin-1.