2009 Fiscal Year Final Research Report

Roles of AMPK in Osteogenic Differentiation

Research Project

Project/Area Number	20791434
Research Category	Grant-in-Aid for Young Scientists (B)
Allocation Type	Single-year Grants
Research Field	Prosthetic dentistry
Research Institution	Kagoshima University
Principal Investigator	KASAI Takayuki Kagoshima University, 医学部・歯学部附属病院, 医員 (30457650)
Project Period (FY)	2008 – 2009
Keywords	AMPK / 骨芽細胞 / メカニカルストレス / シグナル伝達 / エネルギー代謝
Research Abstract	AMP-activated protein kinase(AMPK) is a kinase responds to mechanical stress. Phosphorylation of AMPKα was significantly decreased during osteoblastic differentiation in both primary osteoblasts and MC3T3-E1, a mouse osteoblastic cell line. Conversely, the terminal differentiation of primary osteoblasts and MC3T3-E1 cells, represented by matrix mineralization, was significantly inhibited by stimulation with metformin, an activator of AMPK. Matrix mineralization of MC3T3-E1 cells was also inhibited by the forced expression of a constitutively active form of AMPKα Metformin significantly inhibited gene expression of Runx2 along with osteoblast differentiation markers including osteocalcin (Ocn), bone sialo protein (Bsp), and osteopontin (Opn). Thus, our present data indicate that differentiation of osteoblasts is functionally associated with decreased AMPK activity.