The Proosteogenic and Proangiogenic Effects of Small Extracellular Vesicles Derived from Bone Marrow Mesenchymal Stem Cells Are Attenuated in Steroid-Induced Osteonecrosis of the Femoral Head.

Jia Li,Kunzheng Wang,Zhaogang Ge,Na Yuan,Wenchen Ji

doi:10.1155/2020/4176926

Abstract

Small extracellular vesicles (sEVs) derived from bone marrow mesenchymal stem cells (BMMSCs) from individuals with steroid-induced osteonecrosis of the femoral head (ONFH) have not been studied. The objective of the present study was to compare the proosteogenic and proangiogenic effects of sEVs derived from BMMSCs from rats with steroid-induced ONFH (oBMMSCs-sEVs) and sEVs derived from BMMSCs from normal rats (nBMMSCs-sEVs). BMMSCs were isolated from steroid-induced ONFH rats and healthy rats. sEVs were isolated and characterized by Western blotting analysis of exosomal surface biomarkers and by transmission electron microscopy. The impacts of nBMMSCs-sEVs and oBMMSCs-sEVs on the proliferation and osteogenic differentiation of BMMSCs were determined via cell proliferation assay, alizarin red staining, and alkaline phosphatase activity assay. Enzyme-linked immunosorbent assay and tube formation assay were conducted to investigate the effect of nBMMSCs-sEVs and oBMMSCs-sEVs on the angiogenic potential of human umbilical vein endothelial cells (HUVECs). The expression of relevant genes was detected by quantitative real-time polymerase chain reaction analysis, and the expression of β-catenin was detected by immunofluorescence. Both nBMMSCs-sEVs and oBMMSCs-sEVs promoted proliferation, osteogenic differentiation, and β-catenin expression of BMMSCs and enhanced angiogenesis of HUVECs. However, compared with nBMMSCs-sEVs, oBMMSCs-sEVs exhibited attenuated effects. Our findings indicated that the proosteogenic and proangiogenic effects of sEVs were partially attenuated in steroid-induced ONFH. Therefore, this study might offer guidance for the selection of source cells for sEV therapy in the future.

Highlights

Steroid-induced osteonecrosis of the femoral head (ONFH) is a refractory and progressive disease caused by glucocorticoid administration
We found that the proosteogenic and proangiogenic ability of small EVs (sEVs) derived from bone marrow mesenchymal stem cells (BMMSCs) from rats with steroid-induced ONFH was partially attenuated
Our results showed that both sEVs secreted by normal BMMSCs and sEVs secreted by ONFH BMMSCs promoted the proliferation and osteogenic differentiation of BMMSCs and enhanced the angiogenesis of human umbilical vein endothelial cells (HUVECs) in vitro

Summary

Introduction

Steroid-induced osteonecrosis of the femoral head (ONFH) is a refractory and progressive disease caused by glucocorticoid administration. If treatment is not properly administered in a timely manner, it will lead to articular cartilage collapse and secondary osteoarthritis, necessitating artificial joint replacement. These conditions cause a heavy burden on society and families. To date, the detailed pathological mechanism of steroid-induced ONFH is not clear. Hypotheses about ONFH pathogenesis indicate that lipid metabolism disorders, hypercoagulable conditions, intraosseous hypertension, bone cell apoptosis, immune factors, and enhanced vasoconstriction are involved in the mechanisms of steroid-induced ONFH [1]. Dysfunction of the vascular endothelium and altered characteristics of mesenchymal stem cells have been suggested to contribute

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