TY - JOUR
T1 - 17β-estradiol rapidly activates calcium release from intracellular stores via the GPR30 pathway and MAPK phosphorylation in osteocyte-like MLO-Y4 cells
AU - Ren, Jian
AU - Wu, Junhua
N1 - KAUST Repository Item: Exported on 2020-10-01
Acknowledgements: We are indebted to Dr. Lynda Bonewald for her kind gift of MLO Y4 cells and thank Ms. Jennifer Rosser for help in arranging the transportation and logistics. This work was supported by the Nature Science Foundation of Shanghai, China (Grant 11ZR1440700).
PY - 2012/3/6
Y1 - 2012/3/6
N2 - Estrogen regulates critical cellular functions, and its deficiency initiates bone turnover and the development of bone mass loss in menopausal females. Recent studies have demonstrated that 17β-estradiol (E 2) induces rapid non-genomic responses that activate downstream signaling molecules, thus providing a new perspective to understand the relationship between estrogen and bone metabolism. In this study, we investigated rapid estrogen responses, including calcium release and MAPK phosphorylation, in osteocyte-like MLO-Y4 cells. E 2 elevated [Ca 2+] i and increased Ca 2+ oscillation frequency in a dose-dependent manner. Immunolabeling confirmed the expression of three estrogen receptors (ERα, ERβ, and G protein-coupled receptor 30 [GPR30]) in MLO-Y4 cells and localized GPR30 predominantly to the plasma membrane. E 2 mobilized calcium from intracellular stores, and the use of selective agonist(s) for each ER showed that this was mediated mainly through the GPR30 pathway. MAPK phosphorylation increased in a biphasic manner, with peaks occurring after 7 and 60 min. GPR30 and classical ERs showed different temporal effects on MAPK phosphorylation and contributed to MAPK phosphorylation sequentially. ICI182,780 inhibited E 2 activation of MAPK at 7 min, while the GPR30 agonist G-1 and antagonist G-15 failed to affect MAPK phosphorylation levels. G-1-mediated MAPK phosphorylation at 60 min was prevented by prior depletion of calcium stores. Our data suggest that E 2 induces the non-genomic responses Ca 2+ release and MAPK phosphorylation to regulate osteocyte function and indicate that multiple receptors mediate rapid E 2 responses. © 2012 Springer Science+Business Media, LLC.
AB - Estrogen regulates critical cellular functions, and its deficiency initiates bone turnover and the development of bone mass loss in menopausal females. Recent studies have demonstrated that 17β-estradiol (E 2) induces rapid non-genomic responses that activate downstream signaling molecules, thus providing a new perspective to understand the relationship between estrogen and bone metabolism. In this study, we investigated rapid estrogen responses, including calcium release and MAPK phosphorylation, in osteocyte-like MLO-Y4 cells. E 2 elevated [Ca 2+] i and increased Ca 2+ oscillation frequency in a dose-dependent manner. Immunolabeling confirmed the expression of three estrogen receptors (ERα, ERβ, and G protein-coupled receptor 30 [GPR30]) in MLO-Y4 cells and localized GPR30 predominantly to the plasma membrane. E 2 mobilized calcium from intracellular stores, and the use of selective agonist(s) for each ER showed that this was mediated mainly through the GPR30 pathway. MAPK phosphorylation increased in a biphasic manner, with peaks occurring after 7 and 60 min. GPR30 and classical ERs showed different temporal effects on MAPK phosphorylation and contributed to MAPK phosphorylation sequentially. ICI182,780 inhibited E 2 activation of MAPK at 7 min, while the GPR30 agonist G-1 and antagonist G-15 failed to affect MAPK phosphorylation levels. G-1-mediated MAPK phosphorylation at 60 min was prevented by prior depletion of calcium stores. Our data suggest that E 2 induces the non-genomic responses Ca 2+ release and MAPK phosphorylation to regulate osteocyte function and indicate that multiple receptors mediate rapid E 2 responses. © 2012 Springer Science+Business Media, LLC.
UR - http://hdl.handle.net/10754/562124
UR - http://link.springer.com/10.1007/s00223-012-9581-x
UR - http://www.scopus.com/inward/record.url?scp=84862781225&partnerID=8YFLogxK
U2 - 10.1007/s00223-012-9581-x
DO - 10.1007/s00223-012-9581-x
M3 - Article
C2 - 22392527
SN - 0171-967X
VL - 90
SP - 411
EP - 419
JO - Calcified Tissue International
JF - Calcified Tissue International
IS - 5
ER -