Applying vibration in early postmenopausal osteoporosis promotes osteogenic differentiation of bone marrow-derived mesenchymal stem cells and suppresses postmenopausal osteoporosis progression.

Huiming Li,Liang Li,Chengjian Cao,Xueling He,Xiaoqin Yu,Wenchao Wu,Ye Zeng

doi:10.1042/bsr20191011

Abstract

We aimed to evaluate whether applying low magnitude vibration (LMV) in early postmenopausal osteoporosis (PMO) suppresses its progression, and to investigate underlying mechanisms. Rats were randomly divided into Sham (Sham-operated), Sham+V, OVX (ovariectomized), OVX+E2 (estradiol benzoate), OVX+V (LMV at 12–20 weeks postoperatively), and OVX+Vi (LMV at 1–20 weeks postoperatively) groups. LMV was applied for 20 min once daily for 5 days weekly. V rats were loaded with LMV at 12–20 weeks postoperatively. Vi rats were loaded with LMV at 1–20 weeks postoperatively. Estradiol (E2) rats were intramuscularly injected at 12–20 weeks postoperatively once daily for 3 days. The bone mineral densities (BMDs), biomechanical properties, and histomorphological parameters of tibiae were analyzed. In vitro, rat bone marrow-derived mesenchymal stem cells (rBMSCs) were subjected to LMV for 30 min daily for 5 days, or 17β-E2 with or without 1-day pretreatment of estrogen receptor (ER) inhibitor ICI 182,780 (ICI). The mRNA and protein expresion were performed. Data showed that LMV increased BMD, bone strength, and bone mass of rats, and the effects of Vi were stronger than those of E2. In vitro, LMV up-regulated the mRNA and protein expressions of Runx2, Osx, Col I, and OCN and down-regulated PPARγ, compared with E2. The effects of both LMV and E2 on rBMSCs were inhibited by ICI. Altogether, LMV in early PMO suppresses its progression, which is associated with osteogenic differentiation of rBMSCs via up-regulation of ERα and activation of the canonical Wnt pathway. LMV may therefore be superior to E2 for the suppression of PMO progression.

Highlights

Postmenopausal osteoporosis (PMO) usually occurs 5–10 years after menopause, and is mainly caused by a decrease in estrogen
We evaluated the effects of low magnitude vibration (LMV) (0.9×g and 45 Hz) on ovariectomized rats at 1 or 12 weeks postoperatively, and investigated the effects of LMV on osteogenic differentiation of rat bone marrow-derived mesenchymal stem cells (rBMSCs) and ERα signaling in rats
When loading the vibration after operation immediately, the bone mineral density (BMD) was significantly more than the V and E2 groups at the end time points (20 weeks, Figure 1), suggesting strong protection from bone loss by vibration, which was more effective during the early stage of osteoporosis

Summary

Introduction

Postmenopausal osteoporosis (PMO) usually occurs 5–10 years after menopause, and is mainly caused by a decrease in estrogen. It is a type of systemic skeletal disease characterized by osteopenia, deterioration of bone microarchitecture, increased bone fragility, and susceptibility to fracture [1]. With the aging global population, the incidence of PMO is rapidly rising. PMO seriously influences patients’ health and quality of life, placing a heavy burden on patients’ families and the national economy [2]. Osteoporotic fractures have become a public health problem. It is estimated that 84% of patients with osteoporotic fractures did License 4.0 (CC BY)

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