Format

Send to

Choose Destination
J Cell Biochem. 2019 Mar;120(3):4009-4020. doi: 10.1002/jcb.27685. Epub 2018 Sep 27.

Simulated microgravity reduces intracellular-free calcium concentration by inhibiting calcium channels in primary mouse osteoblasts.

Author information

1
Department of Orthopedics, Jinling Hospital, Medical School of Nanjing University, Nanjing, China.
2
Department of Orthopedics, No. 454 Hospital of PLA, Anhui Medical University, Nanjing, China.
3
The Key Laboratory of Aerospace Medicine, Chinese Ministry of Education, Fourth Military Medical University, Xi'an, China.
4
Department of Emergency, First Affiliated Hospital, Xi'an Medical University, Xi'an, China.
5
Medical Services Section, No. 454 Hospital of PLA, Anhui Medical University, Nanjing, China.
6
Department of Pharmacy, No. 454 Hospital of PLA, Anhui Medical University, Nanjing, China.

Abstract

Calcium homeostasis in osteoblasts plays fundamental roles in the physiology and pathology of bone tissue. Various types of mechanical stimuli promote osteogenesis and increase bone formation elicit increases in intracellular-free calcium concentration in osteoblasts. However, whether microgravity, a condition of mechanical unloading, exerts an influence on intracellular-free calcium concentration in osteoblasts or what mechanisms may underlie such an effect are unclear. Herein, we show that simulated microgravity reduces intracellular-free calcium concentration in primary mouse osteoblasts. In addition, simulated microgravity substantially suppresses the activities of L-type voltage-sensitive calcium channels, which selectively allow calcium to cross the plasma membrane from the extracellular space. Moreover, the functional expression of ryanodine receptors and inositol 1,4,5-trisphosphate receptors, which mediate the release of calcium from intracellular storage, decreased under simulated microgravity conditions. These results suggest that simulated microgravity substantially reduces intracellular-free calcium concentration through inhibition of calcium channels in primary mouse osteoblasts. Our study may provide a novel mechanism for microgravity-induced detrimental effects in osteoblasts, offering a new avenue to further investigate bone loss induced by mechanical unloading.

KEYWORDS:

L-type voltage-sensitive calcium channels; inositol 1,4,5-trisphosphate receptors; intracellular-free calcium concentration; osteoblasts; ryanodine receptors; simulated microgravity

PMID:
30260002
DOI:
10.1002/jcb.27685

Supplemental Content

Full text links

Icon for Wiley
Loading ...
Support Center