Effects of Vitamin D Supplementation during the Induction and Progression of Osteoarthritis in a Rat Model

Abstract

Epidemiological studies correlate low levels of vitamin D with the osteoarthritis (OA) progression. Cytokines and metalloproteases play a major role in OA promoting the inflammation and degradation of the cartilage and can be induced through the Toll-like receptor (TLR) pathway. The aim of this study was to evaluate the protective effect of vitamin D supplementation on the development of osteoarthritis (OA) through examining the genetic regulation of TLRs, cytokines, and metalloproteases in chondrocytes as well as the wideness of cartilage in rats with OA. Our results demonstrate that the signaling through TLR-4 is a proinflammatory mechanism in osteoarthritis that drives the upregulation of MMP-3, IL-1β, and TNF-α gene expression, leading to cartilage degradation and inflammation. Vitamin D supplementation had a protective effect during the onset but not during the chronic stage of OA in the rat model.

The Paracrine Feedback Loop Between Vitamin D3 (1,25(OH)2D3) and PTHrP in Prehypertrophic Chondrocytes

“…and C,D). This is by no means a new finding, since 1,25(OH) 2 D 3 has been shown to inhibit terminal chondrocyte differentiation both in vitro and in vivo (Kato et al, ; Drissi et al, ; Idelevich et al, ; Castillo et al, ). In addition, VDR silencing in 1,25(OH) 2 D 3 ‐treated ATDC5 cells only partially reversed the anti‐hypertrophic effects of 1,25(OH) 2 D 3 : it prevented the inhibitory effect of 1,25(OH) 2 D 3 on Pthr1 gene expression, but it did not affect collagen type X expression (Fig.…”

Vitamin D prevents articular cartilage erosion by regulating collagen II turnover through TGF-β1 in ovariectomized rats

“…Vitamin D supplementation under conditions of VDD could significantly decrease collagenase activity in rat growth plate chondrocytes, which might reduce extracellular matrix (ECM) degradation 14 . Vitamin D supplementation under normal vitamin D conditions could also protect cartilage during the onset of OA induced by transecting the medial collateral ligament (MCL) of rats 15 , and it could even prevent and halt the progression of rheumatoid arthritis induced by Borrelia burgdorferi injection and by collagen injection 16 . In vivo, 1a,25(OH) 2 D 3 suppresses the phorbol-12-myristate-13-acetate (PMA)-induced production of matrix metalloproteinases (MMP)-9 and increases the tumor necrosis factor-a (TNF-a)-induced production of MMP-3 12 .…”

The role of Mincle in innate immune to fungal keratitis

“…P < 0.05 was considered to be statistically significant. The correlation analysis was performed using Pearson's correlation between gene expression and protein of Mincle and eight cytokines [9]. …”

“…Aspergillus is widely presented in the environment and it is one of the main pathogens of fungal keratitis in China [9]. Fungal keratitis comprises a dynamic interaction between host and microorganisms [10].…”