Effects and mechanisms of ferroptosis on high glucose-induced retinal pigment epithelial cells injury / 国际眼科杂志(Guoji Yanke Zazhi)

AIM: To observe the effects and mechanisms of ferroptosis on high glucose(HG)-induced retinal pigment epithelium(RPE)cells injury, and to provide new ideas for the treatment of diabetic retinopathy(DR).METHODS: The ARPE-19 cell lines cultured in vitro were divided into normal control group(NC group), high glucose group(HG group), and high glucose+Ferrostatin-1 group(Fer-1 group). The cell viability of each group was detected by CCK-8 assay. The expressions of interleukin 6(IL-6), IL-1β and monocyte chemotactic protein-1(MCP-1)were detected using ELISA kits. The levels of malondialdehyde(MDA), glutathione(GSH), glutathione peroxidase 4(GPX4)and iron content were detected using the corresponding assay kits. The mitochondrial changes in ARPE-19 cells were observed by transmission electron microscopy. The expressions of ferroptosis-related proteins including long-chain lipoyl CoA synthase 4(ACSL4)and GPX4, as well as vascular endothelial growth factor(VEGF)were detected by Western blotting and immunofluorescence staining.RESULTS: Compared with NC group, the cell viability of HG group decreased significantly, the expression levels of inflammatory factors in cell supernatant increased, the contents of MDA and iron significantly increased, GSH and GPX4 significantly decreased(all P<0.01), the mitochondria of ARPE-19 cells shrunk, the expression of proteins ACSL4 and VEGF increased, while the expression of GPX4 decreased(all P<0.01). Compared with HG group, the cell viability of Fer-1 group significantly increased, the expression levels of inflammatory factors in cell supernatant decreased, MDA and iron contents significantly decreased, GSH contents and GPX4 viability significantly increased(all P<0.05), the morphology of mitochondria in ARPE-19 cells improved, the expression of ACSL4 and VEGF decreased, while the expression of GPX4 increased(all P<0.05).CONCLUSION: Ferroptosis is involved in the injury of RPE induced by HG. Inhibiting ferroptosis can improve cell viability, reduce inflammation and oxidative stress, and alleviate HG-induced RPE cells injury.

Inhibiting ferroptosis attenuates myocardial injury in septic mice: the role of lipocalin-2 / 南方医科大学学报

OBJECTIVE@#To explore the contribution of ferroptosis to myocardial injury in mouse models of sepsis and the role lipocalin-2 (Lcn2) in ferroptosis.@*METHODS@#Adult male C57BL/6 mice were randomized equally into sham-operated group, cecal ligation and puncture (CLP)-induced sepsis group, and CLP + Fer-1 group where the mice received intraperitoneal injection of 5 mg/mL Fer-1 (5 mg/kg) 1 h before CLP. The left ventricular functions (including LVEF%, LVFS%, LVIDd and LVIDs) of the mice were assessed by echocardiography at 24 h after CLP. Myocardial injury in the mice was observed with HE staining, and the changes of myocardial ultrastructure and mitochondria were observed using transmission electron microscopy (TEM). Serum TNF-α level was measured with ELISA, and the changes of myocardial iron content were detected using tissue iron kit. The protein expressions of myocardial Lcn2, glutathione peroxidase 4 (GPX4) and ferroptosis suppressor protein 1 (FSP1) were determined with Western blotting.@*RESULTS@#The septic mice showed significantly decreased LVEF%, LVFS% and LVIDd and increased LVIDs at 24 h after CLP (P < 0.05), and these changes were significantly improved by Fer-1 treatment. Sepsis caused obvious myocardial pathologies and changes in myocardial ultrastructure and mitochondria, which were significantly improved by Fer-1 treatment. Fer-1 treatment also significantly ameliorated sepsis-induced elevations of serum TNF-α level, myocardial tissue iron content, and Lcn2 protein expression and the reduction of GPX4 and FSP1 protein expression levels (P < 0.05).@*CONCLUSION@#GPX4- and FSP1-mediated ferroptosis are involved in myocardial injury in mice with CLP-induced sepsis, and inhibition of ferroptosis can attenuate septic myocardial injury, in which Lcn2 may play a role.

Effect of ionizing radiation on ferroptosis of skin cells and the radioprotective role of ferroptosis inhibitor Ferrostatin-1 / 中华放射医学与防护杂志

Objective:To investigate the effect of ionizing radiation on the ferroptosis of skin cells and the potential therapeutic strategy of ferroptosis inhibitor Ferrostatin-1 (Fer-1) on irradiated skin cells.Methods:HaCaT cells were pre-treated with Fer-1 before X-ray irradiation. After irradiation, CCK-8 assay and LDH release assay were used to detect cell viability and cell death, flow cytometry was used to detect the lipid peroxidation levels, crystal violet staining assay was used to detect colony forming ability, and the expressions of ferroptosis related proteins ACSL4 and GPX4 were detected by Western blot.Results:The cell viability of HaCaT cells was significantly decreased ( t=5.63, 8.74, P<0.05) and the release of LDH was significantly increased ( t=3.98, 5.08, 9.27, P<0.05) after different doses of X-ray irradiation. The cell viability was improved ( t=5.79, P<0.05) and the release of LDH was reduced ( t=12.36, 11.96, 18.13, 9.96, P<0.05) after the pre-treatment with Fer-1. The lipid peroxidation levels of HaCaT cells were significantly increased ( t=9.59, P<0.05) and the clonogenic survival ability were reduced ( t=4.26, P<0.05) after 10 Gy X-ray irradiation, while Fer-1 pre-treatment reduced ( t=6.48, 17.04, P<0.05) the increase of lipid peroxidation level induced by X-ray irradiation and also effectively restore ( t=3.96, P<0.05) the clonogenic survival ability. The expressions of ACSL4 and GPX4 were decreased after 10 Gy X-ray irradiation, while they recovered to normal level ( t=5.23, 7.16, 4.78, 8.29, 6.43, P<0.05) after the pre-treatment with Fer-1. Conclusions:Ferroptosis inhibitor Fer-1 alleviates the progress of radiation-induced skin injury by inhibiting ferroptosis after ionizing radiation at the cellular level, which provides a potential strategy for the protection of radiation injury.