MicroRNA-92a-3p Regulates Aggrecanase-1 and Aggrecanase-2 Expression in Chondrogenesis and IL-1β-Induced Catabolism in Human Articular Chondrocytes.

Aggrecanase-1 (ADAMTS-4) and aggrecanase-2 (ADAMTS-5) are secreted enzymes belonging to the ADAMTS (a disintegrin and metalloproteinase with thrombospondin motifs) family that play significant roles in the progression of osteoarthritis (OA). Here, we aimed to determine whether the expression of ADAMTS-4/5 in chondrogenesis and inflammation is regulated by microRNA-92a-3p (miR-92a-3p). MiR-92a-3p and ADAMTS-4/5 expressions were determined by quantitative polymerase chain reaction (qPCR). To investigate the repressive effect of miR-92a-3p on ADAMTS-4/5 expression, chondrogenic human mesenchymal stem cells (hMSCs) and human chondrocytes were transfected with mature miR-92a-3p or an antisense inhibitor (anti-miR-92a-3p), respectively. ADAMTS-4/5 protein production was quantified by enzyme-linked immunosorbent assay (ELISA), and miR-92a-3p involvement in IL-1β-mediated catabolic effects was examined by immunoblotting. The roles of activated MAP kinases (MAPK) and nuclear factor (NF)-κB were evaluated by using specific inhibitors. Interaction between miR-92a-3p and its putative binding site in the 3'-untranslated region (3'-UTR) of ADAMTS-4/5 mRNA was confirmed by luciferase reporter assay. miR-92a-3p expression was elevated in chondrogenic hMSCs, with significantly lower expression in OA cartilage than in normal cartilage. Stimulation with IL-1β significantly reduced miR-92a-3p expression in primary human chondrocytes (PHCs). Transfection of chondrocytes with miR-92a-3p downregulated IL-1β-induced ADAMTS-4/5 expression, and the activity of a reporter construct containing the 3'-UTR of human ADAMTS-4/5 mRNA. MiR-92a-3p expression was suppressed upon IL-1β-induced activation of MAPK and NF-κB in chondrocytes. MiR-92a-3p is an important regulator of ADAMTS-4/5 in human chondrocytes and may contribute to the development of OA.

Mao G ，Wu P ，Zhang Z ，Zhang Z ，Liao W ，Li Y ，Kang Y ... -  《-》

MicroRNA-558 regulates the expression of cyclooxygenase-2 and IL-1β-induced catabolic effects in human articular chondrocytes.

Cyclooxygenase-2 (COX-2) is a major prostaglandin E2 (PGE2) synthetic enzyme and is involved in the pathogenesis of chronic inflammation and pain in osteoarthritis (OA). The objective of this study was to directly address whether microRNA (miR)-558 can control the interleukin (IL)-1β-mediated induction of COX-2 and catabolic effects in human articular chondrocytes. Total RNA was extracted from the cartilage tissues of normal and OA donors or cultured human articular chondrocytes. The expression of miR-558 was quantified by TaqMan assay. To investigate the repressive effect of miR-558 on COX-2 expression, human chondrocytes and chondrogenic SW1353 cells were transfected with mature miR-558 or an antisense inhibitor (anti-miR-558). The expression of COX-2 protein was determined by Western blot analysis and the involvement of miR-558 in IL-1β-induced catabolic effects was examined by Western blot analysis and enzyme-linked immunosorbent assay (ELISA). Direct interaction between miR-558 and the putative site in the 3'-untranslated region (UTR) of COX-2 messenger RNA (mRNA) was validated by luciferase reporter assay. Normal human articular cartilage expressed miR-558, and its expression was significantly lower in OA cartilage. Stimulation with IL-1β led to a significant reduction in miR-558 expression in normal and OA chondrocytes. IL-1β-induced activation of MAP kinase (MAPK) and nuclear factor-κB (NF-κB) decreased miR-558 expression and induced COX-2 expression in chondrocytes. The overexpression of miR-558 directly suppressed the luciferase activity of a reporter construct containing the 3'-UTR of human COX-2 mRNA and significantly inhibited IL-1β-induced upregulation of COX-2, while treatment with anti-miR-558 enhanced IL-1β-induced COX-2 expression and reporter activity in chondrocytes. Interestingly, IL-1β-induced activation of NF-κB and expression of matrix metalloproteinase (MMP)-1 and MMP-13 was significantly inhibited by miR-558 overexpression. These findings demonstrated that cartilage homeostasis is influenced by miR-558, which directly targets COX-2 and regulates IL-1β-stimulated catabolic effects in human chondrocytes.

Park SJ ，Cheon EJ ，Kim HA 《-》

MicroRNA-92a-3p regulates the expression of cartilage-specific genes by directly targeting histone deacetylase 2 in chondrogenesis and degradation.

Increased activity of histone deacetylase 2 (HDAC2) has been found in patients with osteoarthritis (OA) and cartilage matrix degradation and has been shown to mediate the repression of cartilage-specific gene expression in human chondrocytes. We aimed to determine whether microRNA-92a-3p (miR-92a-3p) regulates cartilage-specific gene expression via targeted HDAC2 in chondrogenesis and degradation. miR-92a-3p expression was assessed in vitro in a human mesenchymal stem cells (hMSCs) model of chondrogenesis and in normal and OA primary human chondrocytes (PHCs), and in normal and OA human cartilage by in situ hybridization. hMSCs and PHCs were transfected with miR-92a-3p or its antisense inhibitor (anti-miR-92a-3p), respectively. PHCs were transfected with miR-92a-3p or anti-miR-92a-3p for 24 h before chromatin immunoprecipitation (ChIP) assay was performed with anti-ac-H3 antibody. Direct interaction between miR-92a-3p and its putative binding site in the 3'-untranslated region (3'-UTR) of HDAC2 mRNA was confirmed by luciferase reporter assay. miR-92a-3p expression was elevated in chondrogenic and hypertrophic hMSC, while reduced in OA cartilage compared with normal cartilage. The overexpression of miR-92a-3p suppressed the activity of a reporter construct containing the 3'-UTR and inhibited HDAC2 expression in both hMSCs and PHCs, while treatment with anti-miR-92a-3p enhanced HDAC2 expression. ChIP assays showed that miR-92a-3p enhances H3 acetylation on aggrecan (ACAN), cartilage oligomeric protein (COMP) and Col2a1 promoter, and also promotes relative cartilage matrix expression. Our results suggest that miR-92a-3p regulates cartilage development and homeostasis, which directly targets HDAC2, indicating histone hyperacetylation plays an important role in increased expression of cartilage matrix.

Mao G ，Zhang Z ，Huang Z ，Chen W ，Huang G ，Meng F ，Zhang Z ，Kang Y ... -  《-》

[Effect of chondrogenesis related miR-4287 on expression of aggrecanase-1 in human chondrocytes].

Sun H ，Zhang Z ，Huang Z ，Mao G ，Yu B ，Zhang C ，Fu M ... -  《-》

MicroRNA-320 regulates matrix metalloproteinase-13 expression in chondrogenesis and interleukin-1β-induced chondrocyte responses.

Meng F ，Zhang Z ，Chen W ，Huang G ，He A ，Hou C ，Long Y ，Yang Z ，Zhang Z ，Liao W ... -  《-》