Effects of 1,25-Dihydroxy vitamin D 3 on TNF-α induced inflammation in human chondrocytes and SW1353 cells: a possible role for toll-like receptors

The purpose of this study is to evaluate anti-inflammatory and chondro-protective effects of 1,25(OH) D in human chondrocytes and SW1353 cells via investigating expressions of MMPs, TIMPs, VDR, and intracellular signalling pathway mediators such as TLR-2 and -4. The HC and SW1353 cells were treated with 1,25(OH) D at 10, 100, and 1000 nM concentrations in the absence/presence of TNF-α (20 ng/mL) for 48 h. The mRNA expressions of MMP-1, -2, -3, -9, and -13, TIMP-1 and -2, VDR, TLR-2 and -4 in HC and SW1353 cells were detected by qPCR after treatments. The cytotoxicity and cell proliferation analyses were assessed by LDH and WST-1 assay, respectively. Protein levels of MMPs, TIMPs, and VDR were analysed by immunocytochemistry and ELISA methods. TNF-α markedly increased cytotoxicity for 24, 48, 72 h (p