Objective To investigate the role of vitamin D in the synthesis and degradation of aggrecan in rat articular chondrocytes at cellular level. Methods Rat articular chondrocytes were stimulated by IL-1α, IL-1β and TNF-α, respectively. Normal and inflammatory chondrocytes were treated with different doses of vitamin D, respectively. CCK8, Flow cytometry, real time-PCR and western blot analysis were used to examine the proliferation activity and apoptosis level of chondrocytes, and the expression of aggrecan, ADAMTS-4 and ADAMTS-5 at both mRNA and protein levels. Results IL-1α,IL-1β and TNF-α significantly decreased the proliferation activity and increased the apoptosis level of the chondrocytes. Furthermore, IL-1α, IL-1β and TNF-α significantly decreased the expression of aggrecan, and increased the expressions of ADAMTS-4 and ADAMTS-5 at both mRNA and protein levels in the chondrocytes. 1α,25 (OH)2D3supplementation significantly increased the proliferation activity and decreased the apoptosis level of chondrocytes stimulated by IL-1α, IL-1β and TNF-α in a dose-dependent manner, but not affected the normal chondrocytes. Meanwhile, 1α,25(OH)2D3also significantly increased the expression of aggrecan, and decreased the expressions of ADAMTS-4 and ADAMTS-5 at both mRNA and protein levels in the chondrocytes under inflammatory conditions. Conclusions Vitamin D may promote the anabolism of aggrecan and inhibit aggrecanase activity in chondrocytes under inflammatory conditions, which may impact overall protection for articular cartilage.

Objective:To investigate changes in mRNA and protein expression of interleukin-27(IL-27)in glomerular podocyte injury caused by Puromycinonucleoside(PAN), and to explore the mechanism of the protective effect of Tacrolimus(FK506)on glomerular podocyte injury.Methods:Glomerular foot cells from mice were cultured in vitro and divided into 3 groups, which were the control group, PAN group and FK506 group.The morphology of 3 groups of foot cells was observed under a microscope after 8 h, 24 h, and 48 h treatment.The changes in IL-27 concentrations were detected by analyzing the enzyme-linked immunosorbent assay(ELISA)method.The cultured foot cells were then collected.The changes of IL-27 mRNA expression were measured by real-time fluorescence quantitative PCR(qPCR), and the changes of IL-27 protein expression were detected by Western blot. Results:(1)At each time point(8 h, 24 h, 48 h), the cells of the PAN group had smaller volume and different morphology than the cells of the control group, and the cells of the FK506 group was larger and fuller than the cells of the PAN group.(2)The concentrations of IL-27 in the PAN group [(110.00±3.52) ng/L, (302.00±6.23) ng/L, (397.00±8.92) ng/L] were significantly higher than those in the control group [(90.00±5.12) ng/L, (85.00±4.21) ng/L, (88.00±4.20) ng/L] and those in the FK506 group [(96.00±4.17) ng/L, (107.00±4.86) ng/L, (112.00±6.24) ng/L] at 8 h, 24 h and 48 h(all P<0.05). (3)At each time point(8 h, 24 h, 48 h), the IL-27 mRNA expression of the PAN group(1.25±0.11, 1.57±0.08, 1.73±0.13)was significantly higher than that of the control group(1.02±0.02, 1.10±0.04, 0.96±0.02)(all P<0.05). Compared with the control group, the IL-27 mRNA expression of the FK506 group did not significantly increase at 8 h (1.10±0.06), and showed a slight increase at 24 h and 48 h(1.21±0.04, 1.30±0.09). Compared with PAN group, HC506 group were all lower (all P<0.05). (4)At each time point(8 h, 24 h, 48 h), the expression of IL-27 protein in the PAN group(0.94±0.04, 1.56±0.07, 1.63±0.04) was significantly higher than that in the control group(0.83±0.04, 0.85±0.03, 0.83±0.05), there was significant difference(all P<0.05). Compared with the PAN group, the expression of IL-27 protein in the FK506 group(0.84±0.05, 0.89±0.04, 0.91±0.06)was not significantly different at 8 h, but decreased significantly at 24 h and 48 h, there was significant difference ( P<0.05). Conclusions:IL-27 is involved in the pathogenesis of kidney diseases.FK506 can prevent the glomerular podocyte injury by reducing the expression of IL-27.This study provides experimental basis for clinical application of FK506 in the treatment of kidney diseases.