MiR-218 affects hypertrophic differentiation of human mesenchymal stromal cells during chondrogenesis via targeting RUNX2, MEF2C, and COL10A1

作者：Svitlana Melnik, Jessica Gabler, Simon I. Dreher, Nicole Hecht, Nina Hofmann, Tobias Großner, Wiltrud Richter · 发表于：Stem Cell Research & Therapy · 年份：2020 · DOI：10.1186/s13287-020-02026-6 · 被引用次数：24 · 研究领域：Osteoarthritis Treatment and Mechanisms、MicroRNA in disease regulation、Mesenchymal stem cell research

BACKGROUND: Human mesenchymal stromal cells (MSC) hold hopes for cartilage regenerative therapy due to their chondrogenic differentiation potential. However, undesirable occurrence of calcification after ectopic transplantation, known as hypertrophic degeneration, remains the major obstacle limiting application of MSC in cartilage tissue regeneration approaches. There is growing evidence that microRNAs (miRs) play essential roles in post-transcriptional regulation of hypertrophic differentiation during chondrogenesis. Aim of the study was to identify new miR candidates involved in repression of hypertrophy-related targets. METHODS: The miR expression profile in human articular chondrocytes (AC) was compared to that in hypertrophic chondrocytes derived from human MSC by microarray analysis, and miR expression was validated by qPCR. Putative targets were searched by in silico analysis and validated by miR reporter assay in HEK293T, by functional assays (western blotting and ALP-activity) in transiently transfected SaOS-2 cells, and by a miR pulldown assay in human MSC. The expression profile of miR-218 was assessed by qPCR during in vitro chondrogenesis of MSC and re-differentiation of AC. MSC were transfected with miR-218 mimic, and differentiation outcome was assessed over 28 days. MiR-218 expression was quantified in healthy and osteoarthritic cartilage of patients. RESULTS: Within the top 15 miRs differentially expressed between chondral AC versus endochondral MSC different...