Synchronized renal tubular cell death involves ferroptosis

Abstract

Receptor-interacting protein kinase 3 (RIPK3)-mediated necroptosis is thought to be the pathophysiologically predominant pathway that leads to regulated necrosis of parenchymal cells in ischemia-reperfusion injury (IRI), and loss of either Fas-associated protein with death domain (FADD) or caspase-8 is known to sensitize tissues to undergo spontaneous necroptosis. Here, we demonstrate that renal tubules do not undergo sensitization to necroptosis upon genetic ablation of either FADD or caspase-8 and that the RIPK1 inhibitor necrostatin-1 (Nec-1) does not protect freshly isolated tubules from hypoxic injury. In contrast, irondependent ferroptosis directly causes synchronized necrosis of renal tubules, as demonstrated by intravital microscopy in models of IRI and oxalate crystal-induced acute kidney injury. To suppress ferroptosis in vivo, we generated a novel third-generation ferrostatin (termed 16-86), which we demonstrate to be more stable, to metabolism and plasma, and more potent, compared with the firstin-class compound ferrostatin-1 (Fer-1). Even in conditions with extraordinarily severe IRI, 16-86 exerts strong protection to an extent which has not previously allowed survival in any murine setting. In addition, 16-86 further potentiates the strong protective effect on IRI mediated by combination therapy with necrostatins and compounds that inhibit mitochondrial permeability transition. Renal tubules thus represent a tissue that is not sensitized to necroptosis by loss of FADD or caspase-8. Finally, ferroptosis mediates postischemic and toxic renal necrosis, which may be therapeutically targeted by ferrostatins and by combination therapy.

Peroxidation of polyunsaturated fatty acids by lipoxygenases drives ferroptosis

“…Cells undergoing ferroptosis cannot be rescued by chemical or genetic inhibitors of apoptosis (such as zVAD-fmk or Bax/Bak double knockout) (3)(4)(5)(6) or inhibitors of necroptosis (such as Nec-1 or RIPK1/3 knockdown) (1,7), which indicates that ferroptosis is a distinct cell death modality. Inhibition of ferroptosis is protective in models of Huntington's disease (8), periventricular leukomalacia (8)(9)(10), and kidney dysfunction (8,11,12). These results suggest that ferroptosis may play a detrimental role in pathological conditions.…”

Ferroptosis: process and function

“…23 Indeed, several normal Ras wild-type cells such as kidney tubule cells, T cells, and fibroblasts are sensitive to erastin. 5,22,[26][27][28] Even in some cases, overexpression of mutant Ras in rhabdomyosarcoma cells (e.g., RMS13 cells) promotes ferroptosis resistance to erastin and RLS3. 29 TFR1: Compared with ferroptosis-resistant cells (e.g., BJ cells), the expression of TFR1 is upregulated in ferroptosissensitive cells (e.g., BJeLR cells).…”

“…1 Compared with ferrostatin-1, second-(termed SRS 11-92) and third-generation ferrostatins (termed SRS 16-86) have increased plasma and metabolic stability and significantly protect against tissue injury (e.g., acute kidney injury and ischemia-reperfusion injury) in vivo (Figure 1a). 22,28 Liproxstatin-1. Liproxstatin-1 prevents ROS accumulation and cell death in GPX4 − / − cells (Figure 1a).…”

“…Inhibition of ferroptosis by third-generation ferrostatins (SRS 16-86) limits acute ischemia-reperfusion injury and oxalate nephropathyrelated AKF. 28 Similarity, inducible knockout of GPX4 in the kidney leads to ferroptosis, which contributes to AKF in mice. 5 Liver injury.…”

Ferroptosis is an autophagic cell death process

“…For example, ferroptosis is involved in ischemia-induced organ injury, and inhibition of ferroptosis has been shown to be effective in treating ischemia/reperfusion-induced organ damage in multiple experimental models [14,16,17]. Ferroptosis has also been investigated in cancer and cancer treatment [11,13].…”