Necroptosis is a key mediator of enterocytes loss in intestinal ischaemia/reperfusion injury

Abstract

Cell death is an important biological process that is believed to have a central role in intestinal ischaemia/reperfusion (I/R) injury. While the apoptosis inhibition is pivotal in preventing intestinal I/R, how necrotic cell death is regulated remains unknown. Necroptosis represents a newly discovered form of programmed cell death that combines the features of both apoptosis and necrosis, and it has been implicated in the development of a range of inflammatory diseases. Here, we show that receptor‐interacting protein 1/3 (RIP1/3) kinase and mixed lineage kinase domain‐like protein recruitment mediates necroptosis in a rat model of ischaemic intestinal injury in vivo. Furthermore, necroptosis was specifically blocked by the RIP1 kinase inhibitor necrostatin‐1. In addition, the combined treatment of necrostatin‐1 and the pan‐caspase inhibitor Z‐VAD acted synergistically to protect against intestinal I/R injury, and these two pathways can be converted to one another when one is inhibited. In vitro, necrostatin‐1 pre‐treatment reduced the necroptotic death of oxygen‐glucose deprivation challenged intestinal epithelial cell‐6 cells, which in turn dampened the production of pro‐inflammatory cytokines (tumour necrosis factor‐α and interleukin‐1β), and suppressed high‐mobility group box‐1 (HMGB1) translocation from the nucleus to the cytoplasm and the subsequent release of HMGB1 into the supernatant, thus decreasing the activation of Toll‐like receptor 4 and the receptor for advanced glycation end products. Collectively, our study reveals a robust RIP1/RIP3‐dependent necroptosis pathway in intestinal I/R‐induced intestinal injury in vivo and in vitro and suggests that the HMGB1 signalling is highly involved in this process, making it a novel therapeutic target for acute ischaemic intestinal injury.

HMGB1‐associated necroptosis and Kupffer cells M1 polarization underlies remote liver injury induced by intestinal ischemia/reperfusion in rats

“…Growing evidence suggests that instead of blocking the inflammatory cascade directly, novel strategies focusing on cell necroptosis may hold greater promise for improving outcomes in organ injury . We and others previously reported that necroptosis can promote inflammatory injury and acts as a key modulator in the pathogenesis of intestinal I/R injury and transplant survival in donor kidney, lung, and heart . In addition, RIP1‐dependent necrosis is involved in the pathological manifestation of acetaminophen‐induced hepatotoxicity.…”

“…Adult male Sprague‐Dawley rats (weighing 220‐250 g ) were obtained from the Animal Center of Sun Yat‐sen University (Guangzhou, China). The rats were anesthetized with pentobarbital (30 mg/kg, intraperitoneally) and the intestinal I/R model was established according to our previous research . Briefly, the small intestine was exteriorized with a 2‐cm midline laparotomy, and the superior mesenteric artery (SMA) was identified.…”

“…The rats were anesthetized with pentobarbital (30 mg/kg, intraperitoneally) and the intestinal I/R model was established according to our previous research. 18 Briefly, the small intestine was exteriorized with a 2-cm midline laparotomy, and the superior mesenteric artery (SMA) was identified. The SMA was occluded by a noncrushing microvascular clip for 90 minutes.…”

“…Moreover, HMGB1 reportedly acts as an endogenous DAMP after being released by necrotic cells or actively secreted by macrophage/monocytes into the extracellular environment, thereby triggering and amplifying inflammatory processes . In particular, we previously reported that HMGB1 is the major DAMP released from necroptotic enterocytes during intestinal I/R to induce an inflammatory response and subsequent intestinal damage …”

“…17 In particular, we previously reported that HMGB1 is the major DAMP released from necroptotic enterocytes during intestinal I/R to induce an inflammatory response and subsequent intestinal damage. 18 Recent advances have revealed the intimate interplay between SIRS or sepsis-induced organ failure and cell death or cell dysfunction resulting from necrosis/necroptosis, 19,20 apoptosis, 21,22 and autophagy. 23 Necroptosis is a newly defined lytic type of cell death and a form of regulated necrosis that is inherently associated with inflammation and distinguished from other forms of cell death by the associated activation of the receptor-interacting protein kinase 1 and 3 (RIP1/3) necrosome complex and phosphorylation of mixed lineage kinase domain-like (MLKL).…”