Betaine Downregulates RARRES1 to Alleviate Cartilage Fibrosis and Promote Hyaline Cartilage Repair

Wang S, Xue Y, Zhuang J, Xu N, Zhang Z, Tan G, Jiang H, Wu R, Shi D · International Journal of Molecular Sciences

Betaine bound and downregulated RARRES1, a fibrosis marker raised in damaged human OA cartilage, and upregulated RGS2 to clear reactive oxygen species; treated rat defects showed less fibrotic and more hyaline repair tissue.

Population

Human OA cartilage datasets, a CTGF-induced chondrocyte fibrosis model, and Sprague-Dawley rats with a femoral trochlear cartilage defect (4 groups of 6)

Intervention

Betaine, applied to chondrocytes in culture and by weekly intra-articular injection in rats from two weeks after surgery

Comparator

PBS injection, untreated defect, and sham surgery

Limitations

Full text read: the rat arm delivered betaine by weekly intra-articular injection, not by mouth, in a surgical cartilage-defect model rather than osteoarthritis, with 6 animals per group; the methods section names the injected agent as betamethasone at one point, which is inconsistent with the rest of the paper.