Tenascin-C knockdown suppresses osteoblast differentiation and promotes osteoporosis in mice by inhibiting Wnt signaling.
- Author:
Yu CHEN
1
;
Zi-Feng CHEN
;
Fan HE
Author Information
- Publication Type:Journal Article
- MeSH: Animals; Cell Differentiation; Gene Knockdown Techniques; Mice; Osteoblasts; cytology; Osteogenesis; Osteoporosis; physiopathology; RNA, Small Interfering; genetics; Tenascin; genetics; metabolism; Up-Regulation; Wnt Signaling Pathway; beta Catenin; metabolism
- From: Journal of Southern Medical University 2016;36(8):1117-1122
- CountryChina
- Language:Chinese
-
Abstract:
OBJECTIVETo understand the mechanism by which tenascin-C regulates osteoblast differentiation and the role of tenascin-C in osteoporosis.
METHODSTenascin-C protein expression in femoral spongy bone of mice with or without osteoporosis was analyzed using Western blotting. In MC3T3-E1 osteoblasts with or without tenascin-C depletion by a specific siRNA targeting tenascin-C, alkaline phosphatase activity and Dickkopf-1 (DKK-1) expression were determined using quantitative RT-PCR and Western blotting, and the transcriptional activity of Wnt signaling pathway was analyzed using a luciferase reporter assay. The possible interaction of tenascin-C with DKK-1 predicted by STRING software was verified by immunoprecipitation.
RESULTSs Tenascin-C was markedly down-regulated in hemoral spongy bone of mice with osteoporosis as compared with the control mice. Osteoblastic differentiation was markedly suppressed in MC3T3-E1 osteoblast after tenascin-C depletion, and was significantly reversed by simultaneous β-catenin over-expression. siRNA-mediated knockdown of tenascin-C, which bound DKK-1, up-regulated the expression of DKK-1 and consequently lowered the transcriptional activity of Wnt pathway.
CONCLUSIONTenascin-C knockdown attenuates its negative control on DKK-1 to suppress the transcriptional activity of Wnt pathway, which in turn suppresses osteoblastic differentiation and promotes osteoporosis.