Celastrol is an active ingredient of Chinese medicine Tripterygium wilfordii which is clinically used to treat the immune diseases. Currently, celastrol is documented as a potent agent for treating cancer and inflammatory disorders. This study was to investigate the effect of celastrol on cisplatin nephrotoxicity and the underlying mechanism. Male C57BL/6 mice were treated with cisplatin (20 mg/kg) with or without celastrol treatment (1 and 2 mg/kg/day). In vitro, human proximal tubule epithelial cell line (HK-2) and mouse renal tubule epithelial cells (RTECs) were treated with cisplatin (5 μg/mL) with or without celastrol administration. Then renal injury and cell damage were evaluated. In vivo, after celastrol treatment, cisplatin-induced kidney injury was significantly ameliorated as shown by the improvement of renal function (BUN, serum creatinine, and cystatin C), kidney morphology (PAS staining) and oxidative stress (MDA) and the suppression of renal tubular injury markers of KIM-1 and NGAL. Meanwhile, the renal apoptosis and inflammation induced by cisplatin were also strikingly attenuated in celastrol-treated mice. In vitro, celastrol treatment markedly inhibited cisplatin-induced renal tubular cell apoptosis, suppressed NF-κB activation, and improved mitochondrial function evidenced by the restored mtDNA copy number, mitochondrial membrane potential, and OXPHOS activity in cisplatin-treated renal tubular epithelial cells. This work suggested that celastrol could protect against cisplatin-induced acute kidney injury possibly through suppressing NF-κB and improving mitochondrial function. FUND: The National Natural Science Foundation of China, National Key Research and Development Program, and Natural Science Foundation of Jiangsu Province.

Acetaminophen (APAP) overdose causes acute liver injury and leads to fatal liver damage. However, the therapies are quite limited. Shikonin is a natural product with antioxidant and anti-inflammatory activities. In the present study, the hepatoprotective effects and the underlying mechanisms of shikonin in APAP-induced hepatotoxicity in vivo and in vitro were investigated. APAP-induced acute liver injury and shikonin pretreatment models were established in vivo and in vitro, as evidenced by serum hepatic enzymes, histological changes, oxidative stress indicators and proinflammatory cytokines. The results revealed that shikonin pretreatment prevented the elevation of serum alanine transaminase (ALT), aspartate transaminase (AST) and lactate dehydrogenase (LDH) levels and markedly reduced APAP-induced histological alterations in liver tissues. Additionally, shikonin restored superoxide dismutase (SOD) expression and glutathione (GSH) content in line with the blockade of oxidative stress. The changes in gene expression involved in oxidative stress including methionine sulfoxide reductase (such as MsrA and MsrB1), heme oxygenase-1 (HO-1), SOD2 and cytochrome P450 2E1 (CYP2E1), were markedly reversed after shikonin therapy. Furthermore, shikonin markedly attenuated the APAP-induced production of tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), and interleukin-1β (IL-1β) and suppressed the expression of genes related to inflammation. In AML-12 cells, shikonin pretreatment decreased APAP-induced cytotoxicity as measured by CCK-8 assay and LDH release. The changes in gene expression involved in oxidative stress and the inflammatory response were consistent with those in mouse livers. This study indicated that shikonin attenuated APAP-induced acute liver injury via inhibiting oxidative stress and inflammatory responses in vivo and in vitro. These findings offer new insights into the potential therapy for APAP hepatotoxicity.

Pyroptosis, one kind of inflammatory regulated cell death, is involved in various inflammatory diseases, including acute kidney injury (AKI). Besides Gasdermin D (GSDMD), GSDME is a newly identified mediator of pyroptosis via the cleavage of caspase-3 generating pyroptotic GSDME-N. Here, we investigated the role of GSDME in renal cellular pyroptosis and AKI pathogenesis employing GSDME-deficient mice and human tubular epithelial cells (TECs) with the interventions of pharmacological and genetic approaches. After cisplatin treatment, GSDME-mediated pyroptosis was induced as shown by the characteristic pyroptotic morphology in TECs, upregulated GSDME-N expression and enhanced release of IL-1β and LDH, and decreased cell viability. Strikingly, silencing GSDME in mice attenuated acute kidney injury and inflammation. The pyroptotic role of GSDME was also verified in human TECs in vitro. Further investigation showed that inhibition of caspase-3 blocked GSDME-N cleavage and attenuated cisplatin-induced pyroptosis and kidney dysfunction. Moreover, deletion of GSDME also protected against kidney injury induced by ischemia-reperfusion. Taken together, the findings from current study demonstrated that caspase-3/GSDME-triggered pyroptosis and inflammation contributes to AKI, providing new insights into the understanding and treatment of this disease.

Renal hypoxia occurs in acute kidney injury (AKI) of various etiologies. Activation of hypoxia-inducible transcription factor (HIF) has been identified as an important mechanism of cellular adaptation to low oxygen. Preconditional HIF activation protects against AKI, suggesting a new approach in AKI treatment. HIF is degraded under normoxic conditions mediated by oxygen-dependent hydroxylation of specific prolyl residues of the regulative α-subunits by HIF prolyl hydroxylases (PHD). FG-4592 is a novel, orally active, small-molecule HIF PHD inhibitor for the treatment of anemia in patients with chronic kidney disease (CKD). The current study aimed to evaluate the effect of FG-4592 (Roxadustat) on cis-diamminedichloroplatinum (cisplatin)-induced kidney injury. In mice, pretreatment with FG-4592 markedly ameliorated cisplatin-induced kidney injury as shown by the improved renal function (blood urea nitrogen (BUN), serum creatinine (Scr), and cystatin C) and kidney morphology (periodic acid-Schiff (PAS) staining) in line with a robust blockade of renal tubular injury markers of kidney injury molecule 1 (KIM-1) and neutrophil gelatinase-associated lipocalin (NGAL). Meanwhile, the renal apoptosis and inflammation induced by cisplatin were also strikingly attenuated in FG-4592-treated mice. Along with the protective effects shown above, FG-4592 pretreatment strongly enhanced HIF-1α in tubular cells, as well as the expressions of HIF target genes. FG-4592 alone did not affect the renal function and morphology in mice. In vitro, FG-4592 treatment significantly up-regulated HIF-1α and protected the tubular cells against cisplatin-induced apoptosis. In summary, FG-4592 treatment remarkably ameliorated the cisplatin-induced kidney injury possibly through the stabilization of HIF. Thus, besides the role in treating CKD anemia, the clinical use of FG-4592 also could be extended to AKI.

Although various stimulator of interferon genes (STING) inhibitors have been identified, no research was performed to investigate the role of human STING inhibitors in AKI. Here, we evaluated the effect of H151 targeting both human and murine STING on cisplatin-induced AKI and observed a protection against renal injury possibly through ameliorating inflammation and mitochondrial dysfunction.