[Effect of GSK-3β inhibitor on the expression of RANK-RANKL in rats kidney tissue with diabetic nephropathy]

YAP1 Overexpression Is Associated with Kidney Dysfunction in Lupus Nephritis

OBJECTIVE

The goal of the present study was to determine the expression of yes-associated protein 1 (YAP1) in renal tissues of mice with lupus nephritis (LN) and elucidate its role in the progression of renal fibrosis.

METHODS

C57BL/6 mice and MRL/lpr mice were selected for experimental comparison. Mouse kidney tissues were removed and sectioned for hematoxylin and eosin staining, Masson's trichome staining, Sirius staining, and immunohistochemistry. The mRNA and protein levels of YAP1 in mouse kidney tissues were detected, and the correlation between YAP1 and fibronectin (FN) mRNA levels was analyzed. Mouse renal epithelial cells were used for in vitro experiments. After transfection and stimulation, the cells were divided into 4 groups, namely the C57BL/6 serum group (group 1), the MRL/lpr serum group (group 2), the MRL/lpr serum + siRNA-negative control group (group 3), and the MRL/lpr serum + siRNA-YAP1 group (group 4). Epithelial-mesenchymal transition (EMT) markers in each group were detected by Western blotting and immunofluorescence staining. Serum creatinine, blood urea nitrogen, and urinary protein levels were detected and assessed for their correlation with YAP1 mRNA levels by Spearman's analysis.

RESULTS

Compared to C57BL/6 mice, MRL/lpr mice exhibited obvious changes in fibrosis in renal tissues. In addition, YAP1 expression was significantly higher in the renal tissues of MRL/lpr mice than in those of C57BL/6 mice, and YAP1 mRNA levels were positively correlated with those of FN. YAP1 silencing in lupus serum-stimulated cells could effectively relieve serum-induced EMT. Finally, we observed that YAP1 mRNA levels in mouse kidney tissue were significantly and positively correlated with the degree of renal function injury.

CONCLUSION

YAP1 expression in the kidney tissues of LN mice was higher than that observed in normal mice, indicating that YAP1 may play an important role in the occurrence and development of LN.

Leonurine Regulates Treg/Th17 Balance to Attenuate Rheumatoid Arthritis Through Inhibition of TAZ Expression

Leonurine, an active alkaloid extracted from Herba leonuri, is reported to have potent anti-inflammatory activity against rheumatoid arthritis (RA). However, the molecular mechanism of action of leonurine in RA remains poorly understood. In this study, we detected 3,425 mRNAs differentially expressed between CD4⁺ T cells of RA patients and those of healthy individuals using microarray raw data mining. Kyoto Encyclopedia of Genes and Genomes enrichment analysis revealed that transcriptional coactivator with PDZ-binding motif (TAZ) regulates a variety of biological processes including T-helper (Th)-17 cell development, and was thus selected for functional verification. In a naïve CD4⁺ T cell differentiation assay, we found that TAZ overexpression was associated with impaired balance between T regulatory (Treg) and Th17 cells in vitro. TAZ overexpression increased the levels of the pro-inflammatory cytokines interleukin (IL)-17, IL-1β, and tumor necrosis factor (TNF)-α and decreased that of the anti-inflammatory cytokine IL-10. Leonurine treatment had a direct recovery effect on the impaired balance and reduced the expression of TAZ and led to normalization of IL-17, IL-1β, and TNF-α and IL-10. Furthermore, IL-6 was found to promote the expression of TAZ and receptor activator of nuclear factor kappa-B ligand (RANKL), and RANK. Leonurine significantly inhibited TAZ-mediated expression of RANKL, and RANK and IL-6 in synovial fibroblasts. We conclude that the therapeutic effect of leonurine was through suppression of TAZ led to restoration of Treg/Th17 balance and suppression of synovial fibroblast action.