Abstract
MicroRNAs (miRNAs) play a pivotal role in cartilage development and homeostasis in osteoarthritis (OA). While the fundamental roles of miRNAs in cartilage degeneration have been extensively studied, their effects on chondrogenic differentiation induced by human adipose-derived stem cells (hADSCs) and the underlying mechanisms remain largely elusive. Here, we investigated the roles and mechanisms of miRNAs in hADSC chondrogenic differentiation and chondrocyte homeostasis. Using microarray analysis, we screened miRNAs expressed in the chondrogenic differentiated hADSCs and identified miR-490-5p as the most significantly down-regulated miRNA. We analyzed its expression patterns during chondrogenesis in vivo and in vitro. Our study showed that miR-490-5p overexpression promoted the transition of hADSCs from chondrogenesis to osteogenesis. In addition, based on miRNA–mRNA prediction analysis and dual-luciferase reporter assay, we proposed and proved that miR-490-5p targeted PITPNM1 by binding to its 3′-UTR and inhibiting its translation. Moreover, loss- and gain-of-function experiments identified the involvement of the PI3K/AKT signaling pathway, and a rescue experiment determined the effect and specific mechanism of the miR-490-5p/PITPNM1/PI3K/AKT axis in hADSC chondrogenic differentiation and chondrocyte homeostasis. Inhibition of miR-490-5p alleviated cartilage injury in vivo as demonstrated using the destabilization of the medial meniscus (DMM) OA model. We identified miR-490-5p as a novel modulator of hADSC-mediated chondrogenesis and chondrocyte phenotype. This study highlighted that miR-490-5p attenuated hADSC chondrogenesis and accelerated cartilage degradation through activation of the PI3K/AKT signaling pathway by targeting PITPNM1. Inhibition of miR-490-5p facilitated hADSC chondrogenic differentiation and protected chondrocyte phenotype via the PITPNM1/PI3K/AKT axis, thus providing a novel stem cell potential therapeutic target for OA treatment.
Highlights
MATERIALS AND METHODSThe prevalence of osteoarthritis (OA), a degenerative disease, is increasing because of aging and increasing obesity in the global population (Hunter and Bierma-Zeinstra, 2019)
To examine the expression pattern of the miR490-5p in vitro OA model, primary human chondrocytes (PHCs) were subjected to 5 ng/ml interleukin (IL)-1β and 10 ng/ml tumor necrosis factor (TNF)-α; qRT-PCR analyses showed up-regulated expression of miR-490-5p (Figure 1D). miR-490-5p expression was further validated in the whole process of chondrogenesis
RNA Fluorescence in situ Hybridization (FISH) showed that the expression of miR-490-5p in cytoplasm was more than that in nucleus of PHCs; that is, miR-490-5p was mainly localized in the cytoplasm (Figure 1I)
Summary
MATERIALS AND METHODSThe prevalence of osteoarthritis (OA), a degenerative disease, is increasing because of aging and increasing obesity in the global population (Hunter and Bierma-Zeinstra, 2019). Overwhelming evidence indicates that chondrogenesis induced by bone mesenchymal stem cells (MSCs) could be a promising therapeutic target for the treatment of OA (De Bari and Roelofs, 2018). Several studies have suggested that compared with MSCs, human adipose-derived stem cells (hADSCs) are more accessible as well as have great multilineage potential, promoting hADSCs as an ideal seeding cell type for tissue engineering and regenerative therapies (Naderi et al, 2017; Liu et al, 2019). MicroRNAs (miRNAs, < 22 bp) are considered to play vital roles in post-translational regulation of gene expression by sponging messenger RNAs (mRNAs); their impaired function is closely related to many complex diseases including OA (Coutinho de Almeida et al, 2019). MiRNA-regulated chondrogenesis in hADSCs opens promising avenues for the development of targeted therapies for OA
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
