Andrade-Oliveira Salvianolic Acid B Modulates Caspase-1-Mediated Pyroptosis in Renal Ischemia-Reperfusion Injury via Nrf2 Pathway.

Acute kidney injury (AKI) is a serious disease characterized by a rapid decline in kidney function. Oxidative stress is the primary pathogenesis of AKI. Salvianolic acid B (SalB), a water-soluble compound extracted from Salvia miltiorrhiza, possesses a potent antioxidant activity. Here, we investigated the protective effect of SalB against renal ischemia-reperfusion injury (I/R) in mice. Briefly, by analyzing renal function, oxidative stress markers and inflammatory biomarkers, we found that SalB could improve kidney damage, reduce oxidative stress and inflammatory factor levels. Interestingly, the expression of the NLR family pyrin domain-containing 3 (NLRP3), caspase-1, pyroptosis related proteins gasdermin D (GSDMD) and interleukin (IL)-1ß, which were significantly upregulated in the kidney tissues of I/R group, was effectively reversed by SalB. Meanwhile, renal tubular epithelial cells hypoxia and reoxygenation model was used to explore pyroptosis of caspase-1-dependent. Further mechanism study showed that the SalB pretreatment could promote the increase of nuclear factor erythroid-2 related factor 2 (Nrf2) nuclear accumulation, which significantly suppressed oxidative stress, proinflammatory cytokines, NLRP3 inflammasome activation and pyroptosis. These results indicate that SalB can inhibit caspase-1/GSDMD-mediated pyroptosis by activating Nrf2/NLRP3 signaling pathway, resulting in alleviating I/R injury in mice.

Cordyceps militaris polysaccharides exerted protective effects on diabetic nephropathy in mice via regulation of autophagy.

The present study was designed to investigate the protective effects of Cordyceps militaris polysaccharides (CMP) on STZ-treated DN mice. CMP were identified by FT-IR and HPLC. Diabetic nephropathy (DN) was induced in male C57BL/6 mice by the injection of streptozotocin (STZ, 50 mg kg-1) in citrate buffer on 5 consecutive days. Administration of CMP at 200 and 400 mg kg-1 or irbesartan at 60 mg kg-1 in the STZ-treated mice could prevent the damage caused by STZ. CMP significantly reduced the STZ-induced higher expression of the kidney index, TC, TG, MDA, urinary protein, Scr, and BUN, while it markedly increased the STZ-induced decrease in GSH levels compared with the DN group. Histopathology analysis of the kidney by PAS, Masson, and HE staining confirmed the renal injury induced by STZ and the protective effects of CMP. Transmission electron microscopy (TEM) results confirmed the severe foot process effacement induced by STZ, but CMP treatment inhibited the podocytes' structure defects and ameliorated the function of podocytes. Desmin was measured by immunofluorescence and was related to podocyte injury. The results showed that CMP lessened the expression of desmin induced by STZ. CD68 expression was measured by immunohistochemistry analysis, and the expressions of IL-1ß, IL-6, and MCP-1 mRNA were measured by qRT-PCR. The results showed that CMP suppressed the expressions of CD68, IL-1ß, IL-6, and MCP-1 mRNA induced by STZ. The role of autophagy in the treatment of DN mice with CMP was detected by TEM and western blotting. The results showed that the administration of CMP was able to overcome the STZ-treated autophagy deficiency, significantly increase the rate of autophagy in the kidney, promote the expression of Atg5, beclin1 and LC3 protein, and reduce the expression of p62 protein. In conclusion, the present study demonstrates that CMP exert a protective effect on DN in STZ-treated mice possibly via activation of autophagy.

Zhen-wu-tang attenuates Adriamycin-induced nephropathy via regulating AQP2 and miR-92b.

Nephrotic syndrome (NS) is characterized by proteinuria, hypoalbuminemia and edema. The disorder of sodium and water metabolism is a critical mechanism regulating the origination and progression of NS. Zhen-wu-tang (ZWT) has been traditionally used to treat edema disease in China and Japan. The present study was carried out to assess the protective effect of ZWT in Adriamycin-induced (ADR) NS rats and investigate the potential anti-NS mechanisms of ZWT. We found that ZWT treatment ameliorate impaired kidney function and regulate water balance of kidney. Importantly, ZWT increased the expression of Aquaporin-2 (AQP2) which play key roles in maintaining body water homeostasis. Additionally, we determined miRNAs expression patterns in NS rats. Using bioinformatics prediction and miR-92b mimic or inhibitor in vitro, we identified miR-92b as a possible modulator of AQP2. Also we found that ZWT can decrease the expression of miR-92b and reverse the effect of miR-92b on AQP2 in vitro. We further demonstrated that miR-92b directly regulated AQP2 expression by targeting 3'-UTR of AQP2. These finding suggest that ZWT may reduce renal edema in Adriamycin-induced nephropathy via regulating AQP2 and miR-92b.