Open AccessCapacitative calcium entry and proliferation of human osteoblast‐like MG‐63 cells
Author(s) -
Labelle D.,
Jumarie C.,
Moreau R.
Publication year - 2007
Publication title -
cell proliferation
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.647
H-Index - 74
eISSN - 1365-2184
pISSN - 0960-7722
DOI - 10.1111/j.1365-2184.2007.00477.x
Subject(s) - trpc , thapsigargin , osteoblast , cell growth , intracellular , chemistry , microbiology and biotechnology , calcium in biology , endocrinology , calcium , transient receptor potential channel , medicine , bone cell , receptor , biology , biochemistry , in vitro
. Adult bone tissue is continuously being remodelled and bone mass is maintained by a balance between osteoclastic bone resorption and osteoblastic bone formation. Alteration of osteoblastic cell proliferation may account in part for lack of balance between these two processes in bone loss of osteoporosis. There is calcium (Ca 2+ ) control in numerous cellular functions; however, involvement of capacitative Ca 2+ entry (CCE) in proliferation of bone cells is less well investigated. Objectives : The study described here was aimed to investigate roles of CCE in the proliferation of osteoblast‐like MG‐63 cells. Meterials and Methods : Pharmacological characterizations of CCE were undertaken in parallel, with evaluation of the expression of transient receptor potential canonical (TRPC) channels and of cell proliferation. Results : Intracellular Ca 2+ store depletion by thapsigargin induced CCE in MG‐63 cells; this was characterized by a rapid transient increase of intracellular Ca 2+ followed by significant CCE, induced by conditions that stimulated cell proliferation, namely serum and platelet‐derived growth factor. Inhibitors of store‐operated Ca 2+ channels (2‐APB and SKF‐96365) prevented CCE, while voltage‐dependent Ca 2+ channel blockers had no effect. Expression of various TRPC channels was shown in the cells, some having been shown to be responsible for CCE. Voltage‐dependent Ca 2+ channel blockers had no effect on osteoblast proliferation while thapsigargin, 2‐APB and SKF‐96395, inhibited it. Cell cycle analysis showed that 2‐APB and SKF‐96395 lengthen the S and G 2 /M phases, which would account for the reduction in cell proliferation. Conclusions : Our results indicate that CCE, likely attributed to the activation of TRPCs, might be the main route for Ca 2+ influx involved in osteoblast proliferation.