MicroRNA-193b-3p regulates chondrogenesis and chondrocyte metabolism by targeting HDAC3

• Published in: Theranostics Vol. 8; no. 10; pp. 2862 - 2883
• Main Authors: Meng, Fangang, Li, Zhiwen, Zhang, Zhiqi, Yang, Zibo, Kang, Yan, Zhao, Xiaoyi, Long, Dianbo, Hu, Shu, Gu, Minghui, He, Suiwen, Wu, Peihui, Chang, Zongkun, He, Aishan, Liao, Weiming
• Format: Journal Article
• Language: English
• Published: Australia Ivyspring International Publisher 01-01-2018
• Subjects: 3' Untranslated Regions; Adult; Aged; Animals; Cells, Cultured; Chondrocytes - cytology; Chondrocytes - drug effects; Chondrocytes - metabolism; Chondrocytes - transplantation; Chondrogenesis; Exosomes - metabolism; Female; Histone Deacetylase Inhibitors - pharmacology; Histone Deacetylases - genetics; Histone Deacetylases - metabolism; Humans; Male; Mice; Mice, Inbred BALB C; Mice, Nude; MicroRNAs - genetics; MicroRNAs - metabolism; Middle Aged; Regeneration; Research Paper; microRNA-193b-3p; HDAC3; chondrogenesis; histone acetylation; cartilage
• ISSN: 1838-7640; 1838-7640
• DOI: 10.7150/thno.23547

Histone deacetylase 3 (HDAC3) plays a pivotal role in the repression of cartilage-specific gene expression in human chondrocytes. The aim of this study was to determine whether microRNA-193b-3p (miR-193b-3p) regulates the expression of HDAC3 during chondrogenesis and chondrocyte metabolism.
miR-193b-3p expression was assessed in a human mesenchymal stem cell (hMSC) model of chondrogenesis, in interleukin-1β (IL-1β)-treated primary human chondrocytes (PHCs), and in non-degraded and degraded cartilage. hMSCs and PHCs were transfected with miR-193b-3p or its antisense inhibitor. A direct interaction between miR-193b-3p and its putative binding site in the 3'-untranslated region (3'-UTR) of HDAC3 mRNA was confirmed by performing luciferase reporter assays. Chondrocytes were transfected with miR-193b-3p before performing a chromatin immunoprecipitation assay with an anti-acetylated histone H3 antibody. To investigate miR-193b-3p-transfected PHCs
, they were seeded in tricalcium phosphate-collagen-hyaluronate (TCP-COL-HA) scaffolds, which were then implanted in nude mice. In addition, plasma exosomal miR-193b-3p in samples from normal controls and patients with osteoarthritis (OA) were measured.
miR-193b-3p expression was elevated in chondrogenic and hypertrophic hMSCs, while expression was significantly reduced in degraded cartilage compared to non-degraded cartilage. In addition, miR-193b-3p suppressed the activity of reporter constructs containing the 3'-UTR of HDAC3, inhibited HDAC3 expression, and promoted histone H3 acetylation in the
,
,
, and
promoters. Treatment with the HDAC inhibitor trichostatin A (TSA) increased cartilage-specific gene expression and enhanced hMSCs chondrogenesis. TSA also increased AGGRECAN expression and decreased MMP13 expression in IL-1β-treated PHCs. Further, 8 weeks after implanting PHC-seeded TCP-COL-HA scaffolds subcutaneously in nude mice, we found that miR-193b overexpression strongly enhanced
cartilage formation compared to that found under control conditions. We also found that patients with OA had lower plasma exosomal miR-193b levels than control subjects.
These findings indicate that miR-193b-3p directly targets HDAC3, promotes H3 acetylation, and regulates hMSC chondrogenesis and metabolism in PHCs.