Celastrol attenuates renal injury in 5/6 nephrectomized rats via inhibiting epithelial-mesenchymal transition and transforming growth factor-ß1/Smad3 pathway.

Renal injury is an important factor in the development of chronic kidney diseases that pathologically manifested as renal fibrosis and podocyte damage. In the disease state, renal fibroblasts lead to high expression levels of α-smooth muscle actin (α-SMA), while podocytes undergo epithelial-mesenchymal transition, leading to proteinuria. Celastrol, a bioactive compound in the medicinal plant Tripterygium wilfordii, was found to delay the progression of early diabetic nephropathy and attenuate renal fibrosis in mice with unilateral ureteral obstruction. However, its effect on the renal system in 5/6 nephrectomized (Nx) rats remains unknown. The aim of this study was to explore the protective effects of celastrol and its underlying mechanisms in 5/6 Nx rats. We found that 24 h proteinuria and levels of blood urea nitrogen, serum creatinine, triglycerides, serum P, renal index and cholesterol significantly increased (P < 0.05), while that of serum albumin decreased significantly in 5/6 Nx rats. After intervention with celastrol, 24 h proteinuria and levels of blood urea nitrogen, serum creatinine, triglycerides, serum P, renal index, and cholesterol significantly decreased, while that of serum albumin significantly increased. Renal tissue pathological staining and transmission electron microscopy showed that celastrol ameliorated kidney injury and glomerular podocyte foot injury and induced significant anti-inflammatory effects. Quantitative polymerase chain reaction (PCR) and western blotting results revealed that nephrin and NEPH1 expression levels were upregulated, whereas α-SMA and Col4a1 expression levels were downregulated in the celastrol group. Celastrol inhibited the expression of transforming growth factor (TGF)-ß1/Smad3 signaling pathway-related molecules such as TGF-ß1 and P-Smad3. In summary, celastrol contributes to renal protection by inhibiting the epithelial-mesenchymal transdifferentiation and TGF-ß1/Smad3 pathways.

[Clinical Significance of IgG4 Level in Predicting the Activity and Outcome of Phospholipase A2 Receptor-associated Membranous Nephropathy].

Objective To investigate the feasibility of IgG4 as a biomarker of the activity and outcome of phospholipase A2 receptor (PLA2R)-associated membranous nephropathy (PLA2R-MN). Methods Serum and urine samples were collected from 56 patients with PLA2R-MN,13 patients with secondary membranous nephropathy (SMN),and 10 patients with primary IgA nephropathy (IgAN) when kidney biopsy was performed in the Department of Nephrology,Hangzhou Hospital of Traditional Chinese Medicine from April 2017 to January 2018.Sandwich enzyme-linked immunosorbent assay was employed to measure the serum and urinary IgG4 levels. Results The PLA2R-MN group had higher median serum IgG4/IgG ratio than the SMN group (P=0.009) and the IgAN group (P<0.001) and higher median urinary IgG4/creatinine ratio than the SMN group (P=0.008).In the patients with PLA2R-MN,the median serum IgG4/IgG ratio and urinary IgG4/creatinine ratio were significantly higher in the renal insufficiency group than in the normal renal function group (P=0.049,P=0.015).Moreover,the median serum IgG4/IgG ratio was higher in those with a serum albumin level<30 g/L than in those with a serum albumin level ≥30 g/L (P=0.005).Fifty-three patients with PLA2R-MN were followed up for at least 1 year,and the serum IgG4/IgG ratios of the patients in remission were lower than those of the patients without remission (P=0.005).The median serum IgG4/IgG ratio of 23 patients in remission decreased from 5.82% (4.54%,10.20%)(at initial enrollment) to 2.91% (2.11%,5.37%)(after 1-year follow up) in remission patients (P<0.001).The receiver operating characteristic curve showed that the patients with a serum IgG4/IgG ratio<10.24% had a higher possibility of remission (P=0.005). Conclusion Serum and urinary IgG4 levels may be an indicator of the activity in PLA2R-MN patients and thus may be a predictive biomarker of the outcomes.

The protective effect of Phellinus linteus decoction on podocyte injury in the kidney of FSGS rats.

BACKGROUND: This study aimed to investigate the effect of the Phellinus linteus (Mesima) decoction on podocyte injury in a rat model of focal and segmental glomerulosclerosis (FSGS) and evaluate the potential mechanisms. METHODS: FSGS resembling primary FSGS in humans was established in rats by uninephrectomy and the repeated injection of doxorubicin. The FSGS rats were randomly divided into the model group, low-dose group of P. linteus decoction (PLD-LD), medium-dose group of P. linteus decoction (PLD-MD), and high-dose group of P. linteus decoction (PLD-HD). Blood and urine analysis were performed after 12 weeks and the molecular indicators of renal function and the renal pathological changes were examined. RESULTS: FSGS developed within 12 weeks in the test group and showed progressive proteinuria and segmental glomerular scarring. Urinary protein, serum creatinine, urea nitrogen, triglycerides and cholesterol were significantly reduced following the 12-week intervention with P.linteus decoction, especially in the PLD-LD group. Renal nephrin and podocin were markedly increased. Moreover, the pathological damage in the renal tissue was alleviated by the PLD-LD intervention. CONCLUSION: The P. linteus decoction alleviated the podocyte injury in the FSGS rat model, thus minimizing the progression of glomerular sclerosis and improving renal function.