Mediation of Cartilage Matrix Degeneration and Fibrillation by Decorin in Post-traumatic Osteoarthritis.

Qing Li, Biao Han, Chao Wang, Wei Tong, Yulong Wei, Wei-Ju Tseng, Li-Hsin Han, X Sherry Liu, Motomi Enomoto-Iwamoto, Robert L Mauck, Ling Qin, Renato V Iozzo, David E Birk, Lin Han

Arthritis & rheumatology (Hoboken, N.J.) 2020 Aug

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To elucidate the role of decorin, a small leucine-rich proteoglycan, in the degradation of cartilage matrix during the progression of post-traumatic osteoarthritis (OA). Three-month-old decorin-null (Dcn-/- ) and inducible decorin-knockout (Dcni KO ) mice were subjected to surgical destabilization of the medial meniscus (DMM) to induce post-traumatic OA. The OA phenotype that resulted was evaluated by assessing joint morphology and sulfated glycosaminoglycan (sGAG) staining via histological analysis (n = 6 mice per group), surface collagen fibril nanostructure via scanning electron microscopy (n = 4 mice per group), tissue modulus via atomic force microscopy-nanoindentation (n = 5 or more mice per group) and subchondral bone structure via micro-computed tomography (n = 5 mice per group). Femoral head cartilage explants from wild-type and Dcn-/- mice were stimulated with the inflammatory cytokine interleukin-1β (IL-1β) in vitro (n = 6 mice per group). The resulting chondrocyte response to IL-1β and release of sGAGs were quantified. In both Dcn-/- and Dcni KO mice, the absence of decorin resulted in accelerated sGAG loss and formation of highly aligned collagen fibrils on the cartilage surface relative to the control (P < 0.05). Also, Dcn-/- mice developed more salient osteophytes, illustrating more severe OA. In cartilage explants treated with IL-1β, loss of decorin did not alter the expression of either anabolic or catabolic genes. However, a greater proportion of sGAGs was released to the media from Dcn-/- mouse explants, in both live and devitalized conditions (P < 0.05). In post-traumatic OA, decorin delays the loss of fragmented aggrecan and fibrillation of cartilage surface, and thus, plays a protective role in ameliorating cartilage degeneration. © 2020, American College of Rheumatology.

Citation

Qing Li, Biao Han, Chao Wang, Wei Tong, Yulong Wei, Wei-Ju Tseng, Li-Hsin Han, X Sherry Liu, Motomi Enomoto-Iwamoto, Robert L Mauck, Ling Qin, Renato V Iozzo, David E Birk, Lin Han. Mediation of Cartilage Matrix Degeneration and Fibrillation by Decorin in Post-traumatic Osteoarthritis. Arthritis & rheumatology (Hoboken, N.J.). 2020 Aug;72(8):1266-1277