Protective role of Astragaloside IV in chronic glomerulonephritis by activating autophagy through PI3K/AKT/AS160 pathway.

Astragaloside IV(AS-IV), a saponin purified from Astragalus membranaceus (Fisch.) Bge.var.mongholicus (Bge.) Hsiao, has been widely used in traditional Chinese medicine. However, the underlying mechanisms in treating chronic glomerular nephritis (CGN) have not been fully understood. The aim of the present study was to evaluate the potential mechanism of AS-IV on CGN. CGN rats were administrated with AS-IV at 10 mg·kg-1 ·d-1 (ASL) and 20 mg·kg-1 ·d-1 (ASH). Twenty four hour proteinuria, blood urea nitrogen (BUN), and serum creatinine (SCr) were detected. Hematoxylin-eosin (HE) and periodic acid-Schiff (PAS) staining were performed to evaluate the kidney lesion. Transmission electron microscope and GFP-RFP-LC3 transfection assay were used to monitor the effect of AS-IV on autophagy. IL-6 and IL-1ß were detected. The expression of CyclinD1, PI3K/AKT/AS160 pathway and autophagy related proteins were detected by Western Blot. The results demonstrated that AS-IV improved kidney function, ameliorated kidney lesion, and diminished inflammatory in CGN rats. Further, both in vivo and vitro study demonstrated that AS-IV inhibited the proliferation of mesangial cells. AS-IV further displayed a remarkable effect on inhibiting the activation of PI3K/AKT/AS160 pathway and improved the activation of autophagy in vivo and vitro. These results suggested that AS-IV is a potential therapeutic agent for CGN and merits further investigation.

Renoprotective effects of artemisinin and hydroxychloroquine combination therapy on IgA nephropathy via suppressing NF-κB signaling and NLRP3 inflammasome activation by exosomes in rats.

Immunoglobulin A nephropathy (IgAN) is an autoimmune kidney disease with complex pathogenesis leading to end-stage renal damage. The prime pathological characteristics of IgAN are IgA immune complexes deposition accompany with mesangial cell proliferation and urine protein elevation. Artemisinin (ART) is extracted from traditional Chinese medicine Artemisia annua L. Hydroxychloroquine (HCQ) is a classical antimalarial drug applied in the treatment of autoimmune diseases. Both of them possess anti-inflammatory and immunomodulatory properties. The purpose of this research was to investigate the pharmacological effects of ART combined with HCQ (AH) and discuss thoroughly the potential molecular mechanisms in IgAN. In vivo, our results demonstrated that AH could efficiently ameliorate kidney damage by improving kidney dysfunction and reducing the levels of 24 h urine protein, IgA and IgG immune complexes deposition in glomerulus of IgAN rats. Interestingly, AH obviously promoted the secretion of exosomes in renal tissues, inhibited the expressions of nuclear factor-κB (NF-κB) signaling and NLRP3 inflammasome-related proteins, including IκB-α, p-p65, NLRP3, ASC, IL-1ß and caspase-1 in IgAN rats. In vitro, further mechanistic study illustrated that exosomes derived from human renal tubular epithelial cells (HK-2) were significantly enhanced by AH, which could be utterly taken up in human mesangial cells (HMCs) and inhibited the activation of NF-κB pathway and NLRP3 inflammasome after AH intervention. However, GW4869 interdicted the promotive effect of AH on exosomes from HK-2 cells and the suppression of exosomes on NF-κB/NLRP3 activation in HMCs. Taken together, this study demonstrated that there was an inhibitory effect of AH therapy on NF-κB/NLRP3 signaling via mediating exosomes release in IgAN rats, which provided an alternative approach for IgAN treatment.

Zhen-wu-tang ameliorates membranous nephropathy rats through inhibiting NF-κB pathway and NLRP3 inflammasome.

BACKGROUND: Zhen-wu-tang (ZWT), a traditional herbal formula, has been widely used for the treatment of kidney diseases in clinics, but the underlying molecular mechanisms have not been fully understood. PURPOSE: Inflammation mediated podocyte injury has been reported to constitute a crucial part in the pathogenesis of membranous nephropathy (MN). The current study was designed to evaluate the effect of ZWT on MN related to nuclear factor-κB (NF-κB) pathway and NLRP3 inflammasome. METHODS: The main components of ZWT were identified by 3D-ultra performance liquid chromatography (3D-UPLC) assay. A MN rat model induced by cationic-bovine serum albumin (C-BSA) and podocytes stimulated by TNF-α were used in this study. The 24 h urine protein, serum total cholesterol (TC) and triglyceride (TG), as well as kidney histology were measured to evaluate kidney damage. The expressions of IgG and complement 3 (C3), and the co-localization of NLRP3 and ASC were detected by immunofluorescence. The expressions of podocyte injury related protein desmin, podocin were measured by immunohistochemistry and western blot. Cell vitality of cultured podocytes was detected by MTT assay, as apoptosis assay was measured via flow cytometry. The protein expressions of p-p65, p-IκBα, NLRP3, Caspase-1, IL-1ß were detected by western blot. RESULTS: Our results showed that ZWT significantly ameliorated kidney damage in MN model rats by decreasing the levels of 24 h urine protein, TC and TG. ZWT also improved renal histology and reduced the expressions of IgG and C3 in glomerulus. In addition, ZWT lessened the expressions of desmin, but increased podocin expression in vivo and vitro. ZWT protected cultured podocytes by maintaining cell vitality and inhibiting apoptosis. Moreover, we found that ZWT suppressed the expressions of NLRP3, Caspase-1, IL-1ß and the co-localization of NLRP3 and ASC. Furthermore, the inhibition of NLRP3 inflammasome under ZWT treatment were accompanied by down-regulation of NF-κB pathway, as the p-p65 and p-IκBα protein expression were reduced. CONCLUSIONS: Our present study indicates that the inhibition of NF-κB pathway and NLRP3 inflammasome might be the potential mechanisms for the therapeutic effects of ZWT against MN.

Immunosuppressive effect of artemisinin and hydroxychloroquine combination therapy on IgA nephropathy via regulating the differentiation of CD4+ T cell subsets in rats.

Immunoglobulin A nephropathy (IgAN) is an autoimmune kidney disease with complex pathogenesis leading to end-stage renal damage. The crucial pathological characteristic in IgAN is IgA immune complexes deposition accompany with mesangial cell proliferation and mesangial matrix expansion. Artemisinin (ART) is isolated from traditional Chinese medicine Artemisia annua L. Hydroxychloroquine (HCQ) is a classical antimalarial drug used to treat autoimmune diseases. Both of them possess immunosuppressive, immunomodulatory and anti-inflammatory features. The aim of this study was to investigate the pharmacological effects of ART combined with HCQ (AH) and explore the underlying mechanisms in IgAN. In vivo, our results showed that AH could significantly improve kidney dysfunction, decrease mesangial matrix expansion as well as immune complexes in mesangial area visualized by H&E and PAS staining. The depositions of IgA immune complexes and complement 3 (C3) were obviously reduced after AH treatment by immunofluorescence. Interestingly, the morphology of kidney and spleen was significantly swelled but reverted by AH in IgAN rats. Further mechanistic study showed that the higher proportions of the Th2 and Th17 cells were reduced but the lower differentiation of Th1 and Treg cells subsets were promoted by AH. Taken together, this study demonstrated that there was an immunosuppressive effect of AH therapy on IgAN rats via regulating the differentiation of CD4+ T cell subsets, which provided an alternative approach for IgAN treatment.

Zhen-wu-tang protects against podocyte injury in rats with IgA nephropathy via PPARγ/NF-κB pathway.

Zhen-wu-tang (ZWT) has been widely applied in chronic kidney diseases. However, the mechanism of ZWT remains unclear. Peroxisome proliferator-activated receptors-γ (PPARγ) is known as a protective factor for podocyte and kidney function. This study is aimed to investigate the protective effects of ZWT on IgA nephropathy (IgAN) in rats against podocyte injury and the underlying mechanism related to PPARγ. IgAN model rats were induced by administering bovine serum albumin, lipopolysaccharide, and carbon tetrachloride. ZWT at two doses and GW9662 (PPARγ antagonist) was administered once daily for 4 weeks respectively. Cultured podocyte induced by LPS were used to evaluate the podocyte-protective effect and related mechanism of ZWT in vitro. Results showed that ZWT observably reduced proteinuria and hematuria excretion, as well as the levels of blood urea nitrogen, serum creatinine, serum uric acid, low-density lipoprotein cholesterol, total cholesterol and triglycerides, but increased the contents of high-density lipoprotein cholesterol, ameliorating renal function and hyperlipidemia state in IgAN rats. Besides, both ZWT administration groups alleviated kidney pathological lesion, macrophage infiltration, IgA and C3 deposition in glomeruli. To further demonstrate the protective effects of ZWT, we found that podocyte damage was markedly ameliorated with ZWT treatments in IgAN rats and LPS-induced podocyte injury model by suppressing the expressions of desmin, reducing podocyte apoptosis and augmenting nephrin and podocin levels. Moreover, ZWT inhibited the phosphorylation of NF-κB and IκBα, simultaneously upregulated PPARγ. However, GW9662 made no difference in all the above effects compared to the model group, and was reversed by ZWT in vitro study. In conclusion, these results demonstrated that ZWT ameliorated IgAN-induced podocyte injury via upregulation PPARγ and the underlying mechanism might involve the inhibition of NF-κB pathway.

Paeoniflorin ameliorates Adriamycin-induced nephrotic syndrome through the PPARγ/ANGPTL4 pathway in vivo and vitro.

Paeoniflorin (PF), an effective composition that is extracted from Radix Paeoniae Alba, plays a role in protecting against various kidney diseases. However, the mechanism of PF on nephrotic syndrome (NS) remains unclear. The aim of this study was to investigate the protective role of PF on Adriamycin (ADR)-induced NS in vivo and vitro as well as its potential mechanism. In animal study, PF significantly decreased the levels of 24-h urine protein, blood urea nitrogen, serum creatinine, total cholesterol and triglycerides in NS rats, but increased the total protein and albumin levels. Hematoxylin-eosin (HE) staining revealed that the kidney lesion was resolved upon PF treatment. After treatment with PF, the morphology and number of podocytes in renal tissue were restored to normal. PF increased expression of synaptopodin and decreased expression of desmin, demonstrating a protective effect in podocyte injury. Further studies revealed that PF upregulated Peroxisome proliferator-activated receptor gamma (PPARγ) and restrained Angiopointin-like 4 (ANGPTL4) in kidney tissue. In vitro study, PF reduced Caspase3 and Bax and increased Bcl-2, indicating that the apoptosis rate of podocytes induced by ADR was reduced by PF. Furthermore, PF ameliorated podocyte injury by upregulating synaptopodin and reducing desmin. In accordance with animal study, PF downregulated ANGPTL4 by activating PPARγ. However, the therapeutic effects of PF were reversed by GW9662 (PPARγ inhibitor), likely by suppressing ANGPTL4 degradation. In general, these results demonstrate that PF has a good therapeutic effect on NS by activating PPARγ and subsequently inhibiting ANGPTL4.