Raji Baidya1,2, Jérémie Gautheron3,4, Darrell H G Crawford1,2, Haolu Wang2,5, Kim R Bridle1,2. 1. Faculty of Medicine, The University of Queensland, Brisbane, Queensland 40006, Australia. 2. Gallipoli Medical Research Institute, Brisbane, Queensland 4120, Australia. 3. Centre de Recherche Saint-Antoine (CRSA), Inserm, Sorbonne University, 75012 Paris, France. 4. Institute of Cardiometabolism and Nutrition (ICAN), 75013 Paris, France. 5. Diamantina Institute, The University of Queensland, Brisbane, Queensland 4102, Australia.
Abstract
BACKGROUND: Steatosis in donor livers poses a major risk of organ dysfunction due to their susceptibility to ischaemia-reperfusion (I/R) injury during transplant. Necroptosis, a novel form of programmed cell death, is orchestrated by receptor-interacting protein kinase 1 (RIPK1), receptor-interacting protein kinase 3 (RIPK3) and mixed-lineage kinase domain-like pseudokinase (MLKL), has been implicated in I/R injury. Here we investigated the mechanisms of cell death pathways in an in vitro model of hepato-steatotic ischaemia. METHODS: Free fatty acid (FFA) treated alpha mouse liver 12 (AML-12) cells were incubated in oxygen-glucose-deprivation (OGD) conditions as seen during ischaemia. RESULTS: We found that OGD triggered upregulation of insoluble fraction of RIPK3 and MLKL in FFA + OGD cells compared to FFA control cells. We report that intervention with small interfering (si) MLKL and siRIPK3 significantly attenuated cell death in FFA + OGD cells. Absence of activated CASPASE8 and cleaved-CASPASE3, no change in the expression of CASPASE1 and prostaglandin-endoperoxide synthase 2 (Ptgs2) in FFA + OGD treated cells compared to FFA control cells indicated that apoptosis, pyroptosis and ferroptosis, respectively, are unlikely to be active in this model. CONCLUSION: Our findings indicate that RIPK3-MLKL dependent necroptosis contributed to cell death in our in vitro model. Both MLKL and RIPK3 are promising therapeutic targets to inhibit necroptosis during ischaemic injury in fatty liver.
BACKGROUND:Steatosis in donor livers poses a major risk of organ dysfunction due to their susceptibility to ischaemia-reperfusion (I/R) injury during transplant. Necroptosis, a novel form of programmed cell death, is orchestrated by receptor-interacting protein kinase 1 (RIPK1), receptor-interacting protein kinase 3 (RIPK3) and mixed-lineage kinase domain-like pseudokinase (MLKL), has been implicated in I/R injury. Here we investigated the mechanisms of cell death pathways in an in vitro model of hepato-steatotic ischaemia. METHODS:Free fatty acid (FFA) treated alpha mouse liver 12 (AML-12) cells were incubated in oxygen-glucose-deprivation (OGD) conditions as seen during ischaemia. RESULTS: We found that OGD triggered upregulation of insoluble fraction of RIPK3 and MLKL in FFA + OGD cells compared to FFA control cells. We report that intervention with small interfering (si) MLKL and siRIPK3 significantly attenuated cell death in FFA + OGD cells. Absence of activated CASPASE8 and cleaved-CASPASE3, no change in the expression of CASPASE1 and prostaglandin-endoperoxide synthase 2 (Ptgs2) in FFA + OGD treated cells compared to FFA control cells indicated that apoptosis, pyroptosis and ferroptosis, respectively, are unlikely to be active in this model. CONCLUSION: Our findings indicate that RIPK3-MLKL dependent necroptosis contributed to cell death in our in vitro model. Both MLKL and RIPK3 are promising therapeutic targets to inhibit necroptosis during ischaemic injury in fatty liver.
Entities:
Keywords:
apoptosis; in vitro; ischaemia-reperfusion injury; liver transplantation; necroptosis; steatosis
Authors: Shaojun Shi; Eliano Bonaccorsi-Riani; Ivo Schurink; Thierry van den Bosch; Michael Doukas; Karishma A Lila; Henk P Roest; Daela Xhema; Pierre Gianello; Jeroen de Jonge; Monique M A Verstegen; Luc J W van der Laan Journal: Front Immunol Date: 2022-05-17 Impact factor: 8.786