Strontium gluconate potently promotes osteoblast development and restores bone formation in glucocorticoid-induced osteoporosis rats

Glucocorticoid-induced osteoporosis (GIOP) has emerged as a challenge after long-term glucocorticoid administration during the clinical therapy of diverse diseases. Although some candidates for GIOP treatment have been explored, there is still a lack of reliable drugs for GIOP prevention. In this study, rat bone marrow stem cells (rBMSCs) were utilized to investigate the feasibility of applying strontium gluconate (GluSr), which displays mild activity, easy absorption and good biocompatibility, for GIOP prevention. Thirty-two SD rats were divided into 4 groups to explore the effects of GluSr on osteoporosis rescue in vivo. Our results suggested that GluSr markedly alleviated dexamethasone (DEX)-induced apoptosis of osteoblast precursor cells and rBMSCs and enhanced rBMSC osteogenesis differentiation in vitro. GluSr also effectively promoted osteoblast survival, inhibited osteoclast differentiation and restored bone formation in GIOP rat models. Microarray analysis of the femora from GIOP rats treated with GluSr revealed that the signalling pathways of the glucocorticoid receptor (GR), oestrogen receptor gene (ESR) and vitamin D receptor (VDR) were involved in bone restoration by GluSr. In summary, our study proved that GluSr enhanced osteoblast differentiation and suppressed osteoclast activity both in vitro and in vivo. GluSr might function as a novel strontium reagent for GIOP prevention. •GluSr could alleviate DEX-induced apoptosis and enhance osteogenesis differentiation.•GluSr could promote osteoblast survival and restore bone formation in GIOP rat models.•GluSr might function as a novel strontium reagent for GIOP prevention.