Connexin 43 (Cx43) plays an essential role in osteocyte mechanotransduction. Although estrogen involves in the adaptive responses of bone cells to mechanical loadings, its effects on osteocytic Cx43-based gap junction intercellular communication (GJIC) remain obscure. We found that 17β estradiol (E2) up-regulated Cx43, and enhanced GJIC in osteocyte-like MLO-Y4 cells in fluorescence recovery after photobleaching (FRAP) assay. Combination of E2 pre-treatment and oscillating fluid flow (OFF) further enhanced Cx43 expression and mitogen-activated protein kinase (MAPK) phosphorylation, comparing to E2 or OFF treatment alone. Both blocking of classical estrogen receptors (ERα/β) by fulvestrant and ERα knockdown by small interfering RNA inhibited E2-mediated Cx43 increase, while a GPR30-specific agonist G-1 failed to promote Cx43 expression. Our results suggest that the presence of E2 enhanced Cx43-based GJIC mainly via ERα/β pathway, and sensitized osteocytes to mechanical loading. © 2012 Elsevier Inc. All rights reserved.
|Original language||English (US)|
|Number of pages||10|
|State||Published - Apr 2013|
Bibliographical noteKAUST Repository Item: Exported on 2020-10-01
Acknowledgements: We thank Dr. Lynda Bonewald for her kind gift of MLO-Y4 cells. This work was supported by the Nature Science Foundation of Shanghai, China (grant no. 11ZR1440700) and Scientific research Funds for distinguished Young Scholar of Shanghai colleges and universities (grant no. 1504144003 & 1504144502).