Dysfunction of the key ferroptosis-surveilling systems hypersensitizes mice to tubular necrosis during acute kidney injury

Abstract

Acute kidney injury (AKI) is morphologically characterized by a synchronized plasma membrane rupture of cells in a specific section of a nephron, referred to as acute tubular necrosis (ATN). Whereas the involvement of necroptosis is well characterized, genetic evidence supporting the contribution of ferroptosis is lacking. Here, we demonstrate that the loss of ferroptosis suppressor protein 1 (Fsp1) or the targeted manipulation of the active center of the selenoprotein glutathione peroxidase 4 (Gpx4cys/-) sensitize kidneys to tubular ferroptosis, resulting in a unique morphological pattern of tubular necrosis. Given the unmet medical need to clinically inhibit AKI, we generated a combined small molecule inhibitor (Nec-1f) that simultaneously targets receptor interacting protein kinase 1 (RIPK1) and ferroptosis in cell lines, in freshly isolated primary kidney tubules and in mouse models of cardiac transplantation and of AKI and improved survival in models of ischemia-reperfusion injury. Based on genetic and pharmacological evidence, we conclude that GPX4 dysfunction hypersensitizes mice to ATN during AKI. Additionally, we introduce Nec-1f, a solid inhibitor of RIPK1 and weak inhibitor of ferroptosis.

A targetable LIFR−NF-κB−LCN2 axis controls liver tumorigenesis and vulnerability to ferroptosis

“…We treated cells with erastin, RSL3, FIN56, or FINO2, and performed flow cytometry analysis of 7-AAD (a DNA intercalator and an indicator of loss of cell membrane integrity) and annexin V (a marker of phosphatidylserine accessibility). Since 7-AAD and annexin V indicate cell death but do not serve as definitive markers of ferroptosis, apoptosis, or necroptosis, we used the percentage of 7-AAD and annexin V double-negative cells to gauge cell viability, as described previously 68 , 69 .…”

The multifaceted role of ferroptosis in liver disease

“…Importantly, necrostatin-1 (Nec-1), a widely used inhibitor of necroptosis, has been suggested to inhibit both necroptosis and ferroptosis. For example, Nec-1f, a highly selective inhibitor of RIPK1 (receptor interacting protein kinase 1) has been shown to simultaneously inhibit necroptosis and ferroptosis in primary kidney tubules and mouse cardiac transplantation models [ 114 ]. Future studies are warranted to identify the mechanism underlying this dual inhibition as well as potential targets for treating pathological conditions associated with both necroptosis and ferroptosis.…”

“…Future studies are warranted to identify the mechanism underlying this dual inhibition as well as potential targets for treating pathological conditions associated with both necroptosis and ferroptosis. It is also interesting to note that Nec-1 has a better pharmacokinetics profile than Fer-1, and the maximum concentration of Nec-1f in tissues is relatively well tolerated [ 114 – 116 ], suggesting that Nec-1f may have better translational potential than Fer-1.…”

Obacunone alleviates ferroptosis during lipopolysaccharide-induced acute lung injury by upregulating Nrf2-dependent antioxidant responses

“…It is different from apoptosis, autophagy, and other forms of cell death, and is mainly characterized by the production of large quantities of cellular ROS, iron-based lipid peroxidation, and oxide accumulation [ 7 – 9 ]. Its relationship with various diseases has been established [ 10 – 12 ]. In experimental neurodegenerative disease, liver injury, renal failure, and intestinal disease models [ 13 – 16 ], ferroptosis inhibition has been shown to reduce clinical symptoms.…”