Matrine-induced nephrotoxicity via GSK-3β/nrf2-mediated mitochondria-dependent apoptosis

Integrative analysis of metabolomics and proteomics reveals mechanism of berberrubine-induced nephrotoxicity

Berberrubine (BRB), a main metabolite of berberine, has stronger hypoglycemic and lipid-lowering activity than its parent form. We previously found that BRB could cause obvious nephrotoxicity, but the molecular mechanism involved remains unknown. In this study, we systematically integrated metabolomics and quantitative proteomics to reveal the potential mechanism of nephrotoxicity caused by BRB. Metabolomic analysis revealed that 103 significant- differentially metabolites were changed. Among the mentioned compounds, significantly upregulated metabolites were observed for phosphorylcholine, sn-glycerol-3-phosphoethanolamine, and phosphatidylcholine. The top three enriched KEGG pathways were the mTOR signaling pathway, central carbon metabolism in cancer, and choline metabolism in cancer. ERK1/2 plays key roles in all three metabolic pathways. To further confirm the main signaling pathways involved, a proteomic analysis was conducted to screen for key proteins (such as Mapk1, Mapk14, and Caspase), indicating the potential involvement of cellular growth and apoptosis. Moreover, combined metabolomics and proteomics analyses revealed the participation of ERK1/2 in multiple metabolic pathways. These findings indicated that ERK1/2 regulated the significant- differentially abundant metabolites determined via metabolomics analysis. Notably, through a cellular thermal shift assay (CETSA) and molecular docking, ERK1/2 were revealed to be the direct binding target involved in BRB-induced nephrotoxicity. To summarize, this study sheds light on the understanding of severe nephrotoxicity caused by BRB and provides scientific basis for its safe use and rational development.

Sodium aescinate induces renal toxicity by promoting Nrf2/GPX4-mediated ferroptosis

Sodium aescinate (SA) is extracted from Aesculus wilsonii Rehd seeds and was first marketed as a medicament in German. With the wide application of SA in clinical practice, reports of adverse drug reactions and adverse events have gradually increased, including renal impairment. However, the pathogenic mechanisms of SA have not yet been fully elucidated. The toxic effects and underlying mechanisms of SA were explored in this study. Our data showed that SA significantly elevated the levels of blood urea nitrogen (BUN), serum creatinine (Scr) and Kidney injury molecule 1 (Kim-1), accompanied by pathologically significant changes in renal tissue. SA induced NRK-52E cell death and disrupted the integrity of the cell membrane. Moreover, SA caused significant reductions in FTH, Nrf2, xCT, GPX4, and FSP1 levels, but increased TFR1 and ACSL4 levels. SA decreased glutathione peroxidase (GPx), glutathione (GSH) and cysteine (Cys) levels, but improved Fe2+, malondialdehyde (MDA), reactive oxygen species (ROS) and lipid peroxidation levels, ultimately leading to the induction of ferroptosis. Importantly, inhibition of ferroptosis or activation of the Nrf2/GPX4 pathway prevented SA-induced nephrotoxicity. These findings indicated that SA induced oxidative damage and ferroptosis-mediated kidney injury by suppressing the Nrf2/GPX4 axis activity.

Sodium Selenite Prevents Matrine-Induced Nephrotoxicity by Suppressing Ferroptosis via the GSH-GPX4 Antioxidant System

Matrine (MT), an active ingredient derived from Sophor flavescens Ait, is used as a therapeutic agent to treat liver disease and cancer. However, the serious toxic effects of MT, including nephrotoxicity, have limited its clinical application. Here, we explored the involvement of ferroptosis in MT-induced kidney injury and evaluated the potential efficacy and underlying mechanism of sodium selenite (SS) in attenuating MT-induced nephrotoxicity. We found that MT not only disrupts renal structure in mice but also induces the death of NRK-52E cells. Additionally, MT treatment resulted in significant elevations in ferrous iron, reactive oxygen species (ROS) and lipid peroxidation levels, accompanied by decreases in glutathione (GSH) and glutathione peroxidase (GPx) levels. SS effectively mitigated the alterations in ferroptosis-related indicators caused by MT and prevented MT-induced nephrotoxicity as effectively as Fer-1 in vivo and in vitro. SS also reversed the MT-induced reduction in GPX4, CTH and xCT protein levels. However, the glutathione peroxidase 4 (GPX4) inhibitor RSL3 and knockdown of GPX4, CTH, or xCT via siRNA abolished the protective effect of SS against MT-induced nephrotoxicity, indicating that SS exhibited antiferroptotic effects via the GSH-GPX4 antioxidant system. Overall, MT-induced ferroptosis triggers nephrotoxicity, and SS is a promising therapeutic drug for alleviating MT-induced renal injury by activating the GSH-GPX4 axis.

Quercetin alleviates zearalenone-induced apoptosis and necroptosis of porcine renal epithelial cells by inhibiting CaSR/CaMKII signaling pathway

Zearalenone (ZEA) is a mycotoxin that is highly contaminated in feed and can cause severe toxic effects on the kidneys and other organs of animals. Quercetin (QUE) is a plant-derived flavonoid with a variety of detoxification properties, but the mechanism by which QUE detoxifies the toxic effects induced by ZEA has not yet been fully elucidated. We treated porcine kidney cells (PK15) with 80 μM ZEA and/or 30 μM QUE. The results showed that ROS and MDA levels were increased, antioxidant system levels were down-regulated, anti-apoptotic factor expression levels were decreased, and apoptotic and necroptosis-related factors were up-regulated after ZAE exposure. In addition, the results of Ca2+ staining, mitochondrial membrane potential, and mitochondrial dynamics-related indicators showed that ZEA induced Ca2+ overload in PK15 cells and increased mitochondrial Ca2+ uptake (MCU expression increased). The accumulated ROS and free Ca2+ further aggravate mitochondrial damage and eventually lead to mitochondrial pathway apoptosis and necroptosis. Nevertheless, QUE targets CaSR to inhibit the CaSR/CaMKII pathway and regulate calcium homeostasis, thereby alleviating apoptosis and necroptosis mediated by mitochondrial dynamic disorder and dysfunction. The present study demonstrated the mechanism by which ZEA induces apoptosis and necroptosis in PK15 and the protective role of QUE in this process.

Matrine disrupts Nrf2/GPX4 antioxidant system and promotes hepatocyte ferroptosis

Matrine (MT) is an alkaloid isolated from Sophora flavescens with various bioactivities and is widely used clinically. However, the broader its clinical use, the greater its toxicity concerns. We investigate the role of ferroptosis in MT-induced liver injury caused by an imbalance in the antioxidant pathway. Our results showed that MT could cause pathological changes in liver tissues and lead to a significant reduction in L02 cell viability. MT also reduced superoxide dismutase (SOD) and glutathione (GSH), increased malondialdehyde (MDA), reactive oxygen species (ROS), and lipid peroxidation levels, and disrupted iron homeostasis, leading to ferroptosis. In addition, MT decreased the protein levels of FTH, Nrf2, xCT, GPX4, HO-1 and ferroptosis suppressor protein 1 (FSP1) and increased the protein levels of TRF1 and DMT1, characteristic indicators of ferroptosis. Interestingly, the cytotoxic effects of MT were alleviated by ferroptosis inhibitor, Nrf2 agonist, or selenium supplementation. These results revealed that MT triggers hepatocyte ferroptosis by inhibiting the Nrf2/GPX4 antioxidant system.

Oxymatrine Alleviates Collagen-Induced Arthritis in Mice by Regulating the Immune Balance of T Cells

Rheumatoid arthritis (RA) is a chronic autoimmune disease characterized by systemic immunity and autoimmune disorders. We have previously found that oxymatrine (OMT), a natural alkaloid, can alleviate rheumatoid arthritis without knowing whether OMT can alleviate rheumatoid arthritis through gut microbiota. In this study, we found that OMT can alleviate collagen-induced arthritis in mice and reconstruct the immune balance of Th1/Th2, Treg/Th17, and Tfr/Tfh cells. Colon transcriptome gene enrichment analysis indicated that oxymatrine may alleviate collagen induced arthritis in mice through immune system process pathway. Furthermore, OMT significantly altered the gut microbiota variety, changed the composition of microbial colonies, and reshaped the gut microbiota of collagen-induced arthritis (CIA) mice, which may participate in the regulation of the balance of Th1/Th2, Treg/Th17, and Tfr/Tfh cells to alleviate collagen-induced arthritis in mice.