<b>Results:</b> The results of ELISA (IL-1β and tumor necrosis factor-α), the histological evaluation (Mankin and OARSI score), western blotting [COL2A1, matrix metalloproteinase (MMP)-3, MMP-13, IL-1β, and nuclear factor-kappaB (NF-κB) p65], and immunohistochemistry (COL2A1, MMP-3, and MMP-13) indicated that oral CAR attenuated the development of T2DM-induced OA and suppressed the inflammatory response.
A significant correlation was, however, observed for H19, COL2A1, and miR-675 expression levels in OA tissue, and functional regulation of these candidate molecules was assessed under anabolic and catabolic conditions.
Cartilage degeneration in OA is a gradual progress accompanied with gradual loss of collagen type II and a gradual decrease in mRNA expression of SOX9, ACAN and COL2A1.
Compared to control group, increasing levels of β-catenin and MMP-13 expression with reduction of miR-320 and COL2A1 expressions were observed in OA chondrocytes.
Compared with the normal group, the expression of ALK1, SMAD1, COL10A1 and MMP3 was higher in the OA groups, whereas the expression of COL2A1 was lower in the OA groups.
Despite studies suggesting associations of OA with both COL2A1 and VDR loci, our results suggest that mutations at the COL2A1/VDR locus do not play an important role as a cause of common OA in the population at large.
Follow-up with whole-exome sequencing analysis revealed a mutation c.2032G>A (p.Gly678Arg) in the COL2A1 gene (NCBI Reference Sequence: NM_001844.4), which co-segregated with the disease phenotype in this family, manifested by severe hip dysplasia and osteoarthritis.
Following transfection with ds-miRNA-4784, Col2a1 mRNA expression levels increased by 63 and 126% compared with the levels prior to treatment in groups OA at week 4 and 8, respectively (P<0.01).
Further, Wogonin exhibits potent chondroprotective potential by switching the signaling axis of matrix degradation from catabolic towards anabolic ends and inhibited the expression, production and activities of matrix degrading proteases including MMP-13, MMP-3, MMP-9, and ADAMTS-4 in OA chondrocytes, and blocked the release of s-GAG and COL2A1 in IL-1β-stimulated OA cartilage explants.
Furthermore, expression of several key mRNAs associated with OA, including those for matrix metalloproteinase (MMP)-9, MMP-13, bone morphogenetic protein (BMP)-2, COL2A1 and ADAMTS5, was investigated by RT-PCR in OA and normal cartilage.
IL-1β stimulus determined a significant regulation of survival, apoptotic ratio, as well as of gene expression and serum levels of MMP-1,-3,-13 and Col2a1 in OA chondrocytes compared to baseline.
In contrast, COL2A1, other collagen genes, and factors associated with skeletal development were up-regulated in late OA, compared with early OA or normal cartilage.
In grades II and III OA cartilage, the expression of miR-146a and COL2A1 was decreased, whereas the expression of matrix metalloproteinase 13 (MMP-13) was elevated in grade II OA cartilage.