Both hemoglobin and hemin cause damage to retinal pigment epithelium through the iron ion accumulation.

Subretinal hemorrhages result in poor vision and visual field defects. During hemorrhage, several potentially toxic substances are released from iron-based hemoglobin and hemin, inducing cellular damage, the detailed mechanisms of which remain unknown. We examined the effects of excess intracellular iron on retinal pigment epithelial (RPE) cells. A Fe2+ probe, SiRhoNox-1 was used to investigate Fe2+ accumulation after treatment with hemoglobin or hemin in the human RPE cell line ARPE-19. We also evaluated the production of reactive oxygen species (ROS) and lipid peroxidation. Furthermore, the protective effect of-an iron chelator, 2,2'-bipyridyl (BP), and ferrostatin-1 (Fer-1) on the cell damage, was evaluated. Fe2+ accumulation increased in the hemoglobin- or hemin-treated groups, as well as intracellular ROS production and lipid peroxidation. In contrast, BP treatment suppressed RPE cell death, ROS production, and lipid peroxidation. Pretreatment with Fer-1 ameliorated cell death in a concentration-dependent manner and suppressed ROS production and lipid peroxidation. Taken together, these findings indicate that hemoglobin and hemin, as well as subretinal hemorrhage, may induce RPE cell damage and visual dysfunction via intracellular iron accumulation.

LOXL3 Silencing Hampers the Metastasis and Angiogenesis of Gastric Cancer Cells Dependent on Ferroptosis Activation.

Gastric cancer (GC) remains a major unmet clinical problem accountable for considerable incidence and fatality rate. Lysyl oxidase-like 3 (LOXL3) has been recognized to be overexpressed in GC. Our work was meant to disclose the significance of LOXL3 in the advancement of GC and the likely action mechanism. LOXL3 expression in GC tissues and its correlation with the outcome of GC patients were investigated through bioinformatics tools. RT-qPCR and western blotting inspected LOXL3 expression in GC cells. CCK-8 method, EDU, as well as colony formation assays assayed cell proliferation. The capacities of cells to migrate and invade were appraised by wound healing and transwell assays, severally. Tube formation assay and ELISA measured angiogenesis. TBARS, C11 BODIPY staining, and FerroOrange estimated ferroptosis. Western blotting examined the expression of proteins implicated in metastasis and ferroptosis. The up-regulation of LOXL3 expression was noticed in GC tissues and cells, which was also associated with the poor outcome of GC patients. When LOXL3 was underexpressed, the proliferation, migration, invasion, epithelial-mesenchymal transition, and angiogenesis of GC cells were all halted. In addition, LOXL3 deletion resulted in the activation of ferroptosis in GC cells, and ferrostatin-1 (Fer-1), the specific ferroptosis inhibitor, compensated the suppressive role of LOXL3 down-regulation in the proliferation, metastasis, and angiogenesis of GC cells in vitro. All in all, knockdown of LOXL3 may serve an activator of ferroptosis to obstruct the aggressive process of GC.