MicroRNAs regulate viability, longevity and extracellular matrix secretions of mesenchymal stem cell-derived chondrocytes in vitro.

BACKGROUND: Chondrogenic differentiation of human adipose tissue-derived mesenchymal stem cells (ADMSCs) is a promising strategy for cartilage regeneration, but its regulatory mechanisms remain incompletely understood. MicroRNAs (miRNAs) play critical roles in post-transcriptional control of lineage commitment and tissue development. This study aimed to identify miRNAs differentially expressed during ADMSCs chondrogenesis and explore their functional roles in chondrogenic gene regulation. METHODS: ADMSCs were induced to undergo chondrogenic differentiation under defined conditions. miRNA expression profiles were analyzed, and significantly dysregulated miRNAs were identified. Bioinformatic and literature-based analyses were used to associate these miRNAs with chondrogenic transcription factors, signaling pathways, and cellular processes. RESULTS: Chondrogenesis was associated with distinct patterns of miRNA regulation. miR-140-5p, miR-520d-5p, miR-127-5p, and miR-218-5p were upregulated and correlated with increased expression of cartilage markers (SOX9, COL2A1, ACAN) and suppression of hypertrophy. These miRNAs were linked to TGF-β signaling, epigenetic regulation, and inhibition of terminal differentiation. Conversely, miR-145-5p, miR-101-3p, miR-194-5p, miR-199a-5p, miR-182-5p, miR-29a-5p, miR-20a-5p, miR-193b-5p, and miR-574-3p were downregulated, potentially relieving repression of transcription factors, signaling components, autophagy-related genes, and extracellular matrix regulators. CONCLUSION: Chondrogenic differentiation of ADMSCs is governed by coordinated miRNA regulation, involving activation of pro-chondrogenic miRNAs and suppression of inhibitory ones. This regulatory network integrates key molecular pathways required for stable cartilage formation and highlights potential targets for improving ADMSCs-based regenerative therapies.