Exosomal miR-9-5p secreted by bone marrow –derived mesenchymal stem cells alleviates osteoarthritis by inhibiting syndecan-1

This study aims to investigate the regulatory role of exosomal microRNA-9-5p (miR-9-5p) secreted by bone marrow –derived MSCs (BM-MSCs) on OA in a rat model induced by anterior cruciate ligament/medial collateral ligament transection. Luciferase reporter assay was conducted to verify the putative miR-9-5p binding sites to 3′UTR of syndecan-1 (SDC1). Additionally, an intra-articular injection of miR-9-5p c arried by BM-MSC–derived exosomes or liposomes into rats with OA-like damage was performed to ascertain the role of exosomal miR-9-5p and a gain-of-function study of SDC1 was carried out to explore the potential mechanism in relation to SDC1. Subsequently, the expression of SDC1 was determined and the levels of inflammatory factors (IL-1, IL-6, TNF-α and CRP) and oxidative stress injury indicators (NO, MDA, iNOS, COX2 and SOD), the contents of AKP as well as the levels of OA-related factors (MMP-13, COMP and OCN) were measured. Injection of miR-9-5p-contained exosomes resulted in an allevia tion of inflammation and OA-like damage, which was evidenced by downregulated levels of inflammatory factors, reduced oxidative stress injury and decreased OCN, MMP-13, COMP and AKP levels. As a target gene of miR-9-5p, the upregulation of SDC1 led to aggravation of inflammation and OA-like damage, which is opposite to exosomal miR-9-5p. To conclude, these findings suggest the anti-inflammatory and chondroprotective effects of BM-MSC–derived exosomal miR-9-5p on OA via regulation...
Source: Cell and Tissue Research - Category: Cytology Source Type: research