CHAC1 exacerbates LPS-induced ferroptosis and apoptosis in HK-2 cells by promoting oxidative stress

Abstract

Background: Sepsis-induced acute kidney injury (AKI) is a singularly grievous and life-threatening syndrome. Its pathogenesis is closely related to inflammatory response, apoptosis, oxidative stress, and ferroptosis. Cation transport regulator-like protein 1 (CHAC1), as a proapoptic factor, may be involved in apoptosis, oxidative stress, and ferroptosis. This study aimed to explore the role of CHAC1 in the lipopolysaccharide (LPS)-induced the human renal proximal tubular epithelial (HK-2) cells. Methods: HK-2 cells were challenged with LPS to construct a model of sepsis-induced AKI in vitro. The role of CHAC1 in the LPS-induced HK-2 cells was explored using Western blot assay, cell counting kit-8 (CCK-8), flow cytometry, and colorimetric assays. Additionally, N-acetyl cysteine (NAC) was incubated with HK-2 cells to define deeply the relation between oxidative stress and apoptosis or ferroptosis. Results: The expression of CHAC1 was enhanced in the kidney tissues of mice with sepsis--induced multiple organ dysfunction syndrome (MODS), through the Gene Expression Omnibus database (GSE60088 microarray dataset), and in the LPS-induced HK-2 cells. The cell viability was significantly reduced by LPS treatment, which was at least partly restored by the transfection of siCHAC1#1 and siCHAC1#2 but not siNC. In addition, down-regulation of CHAC1 counteracted the LPS-induced reactive oxygen species level and malonaldehyde concentrations while restored the LPS-induced glutathione concentrations. Meanwhile, interference of CHAC1 neutralized LPS-induced apoptosis rate, and the relative level of cleaved poly(ADP-ribose) polymerase (PARP)/PARP, and cleaved caspase-3/caspase-3. In addition, silencing of CHAC1 recovered the LPS-induced enhanced protein level of glutathione peroxidase 4 (GPx4) whereas antagonized the LPS-induced relative protein level of ACSL4 and that of iron. Moreover, application of NAC inverted the effect of CHAC1 on apoptosis and ferroptosis in HK-2 cells. Conclusion: CHAC1 exacerbated ferroptosis and apoptosis by enhancing oxidative stress in LPS-induced HK-2 cells.

Lineage tracing reveals transient phenotypic adaptation of tubular cells during acute kidney injury

“… 35 identified a specific maladaptive/profibrotic PT cluster that expressed proinflammatory and profibrotic cytokines and was associated with the activation of inflammatory cell death pathways (pyroptosis and ferroptosis). In our STC transcriptomic data, we could identify genes that are associated with ferroptosis (e.g., Chac1, Acsl4, Hmox1 ), 40 , 41 , 42 particularly in the STC-S3 fraction ( Data S3 ). Balzer et al.…”

Molecular Mechanisms of Ferroptosis and Their Involvement in Acute Kidney Injury

“…EHT 1864 and phospholipase inhibitor (salubrinal) were effective in targeted treatment of cell ferroptosis and patients with SA-AKI. Zhou et al 81 also verified the existence of ferroptosis in the pathogenesis of SA-AKI after establishing the mouse model of SA-AKI. It was found that cationic transport regulator-like protein 1 could promote the ferroptosis of HK-2 cells by enhancing the oxidative stress induced by lipopolysaccharide.…”

Advance in Iron Metabolism, Oxidative Stress and Cellular Dysfunction in Experimental and Human Kidney Diseases

“…In addition, treatment with ferroptosis inhibitors has been shown to effectively alleviate IRI-AKI in mice model [ 327 , 330 ]. Ferroptosis is also increased in sepsis-induced AKI mouse models [ 331 ]. Recent studies have demonstrated that treatment with melatonin prevents ferroptosis and ameliorates sepsis-associated AKI by upregulating Nrf2/HO-1 cytoprotective pathway [ 332 ].…”