Mechanistic Insights into Ferroptotic Cell Death in Pancreatic Islets

Abstract

Ferroptosis was recently identified as a non-apoptotic, iron-dependent cell death mechanism that is involved in various pathologic conditions. There is first evidence for its significance also in the context of islet isolation and transplantation. Transplantation of pancreatic human islets is a viable treatment strategy for patients with complicated diabetes mellitus type 1 (T1D) that suffer from severe hypoglycemia. A major determinant for functional outcome is the initial islet mass transplanted. Efficient islet isolation procedures and measures to minimize islet loss are therefore of high relevance. To this end, better understanding and subsequent targeted inhibition of cell death during islet isolation and transplantation is an effective approach. In this study, we aimed to elucidate the mechanism of ferroptosis in pancreatic islets. Using a rodent model, isolated islets were characterized relating to the effects of experimental induction (RSL3) and inhibition (Fer1) of ferroptotic pathways. Besides viability, survival, and function, the study focused on characteristic ferroptosis-associated intracellular changes such as MDA level, iron concentration and the expression of ACSL4. The study demonstrates that pharmaceutical induction of ferroptosis by RSL3 causes enhancement of oxidative stress and leads to an increase of intracellular iron, zinc and MDA concentration, as well as the expression of ACSL4 protein. Consequently, a massive reduction of islet function, viability, and survival was found. Fer1 has the potential to inhibit and attenuate these cellular changes and thereby protect the islets from cell death.

Key words

ferroptosis - islets - insulin secretion - diabetes - cell death - iron - ROS

• References

• 1 Yang WS, Stockwell BR. Ferroptosis: death by lipid peroxidation. Trends Cell Biol 2016; 26: 165-176
• 2 Yang WS, Kim KJ, Gaschler MM. et al. Peroxidation of polyunsaturated fatty acids by lipoxygenases drives ferroptosis. Proc Natl Acad Sci U S A 2016; 113: E4966-E4975
• 3 Stockwell BR, Friedmann Angeli JP, Bayir H. et al. Ferroptosis: a regulated cell death nexus linking metabolism, redox biology, and disease. Cell 2017; 171: 273-285
• 4 Dixon SJ, Lemberg KM, Lamprecht MR. et al. Ferroptosis: an iron-dependent form of nonapoptotic cell death. Cell 2012; 149: 1060-1072
• 5 Miotto G, Rossetto M, Di Paolo ML. et al. Insight into the mechanism of ferroptosis inhibition by ferrostatin-1. Redox Biol 2020; 28: 101328
• 6 Bruni A, Pepper AR, Pawlick RL. et al Ferroptosis-inducing agents compromise in vitro human islet viability and function article. Cell Death Dis 2018; 9 Article number 595
• 7 Pathak V, Pathak NM, O’Neill CL. et al. Therapies for type 1 diabetes: current scenario and future perspectives. Clin Med Insights Endocrinol Diabetes 2019; 12: 1179551419844521
• 8 Ludwig B. Islet Transplantation as a treatment option for patients with type-1 diabetes mellitus: indication, intention, and outcome. Gastroenterol Hepatol Erkrank 2014; 12: 5-9
• 9 Warnock GL, Thompson DM, Meloche RM. et al. A multi-year analysis of islet transplantation compared with intensive medical therapy on progression of complications in type 1 diabetes. Transplantation 2008; 86: 1762-1766
• 10 McCall MD, Maciver AM, Kin T. et al. Caspase inhibitor IDN6556 facilitates marginal mass islet engraftment in a porcine islet autotransplant model. Transplantation 2012; 94: 30-35
• 11 Ricordi C, Gray DWR, Hering BJ. et al. Islet isolation assessment in man and large animals. Acta Diabetol Lat 1990; 27: 185-195
• 12 Palmer LD, Jordan AT, Maloney KN. et al. Zinc intoxication induces ferroptosis in A549 human lung cells. Metallomics 2019; 11: 982-993
• 13 Zhang C, Liu Z, Zhang Y. et al “Iron free” zinc oxide nanoparticles with ion-leaking properties disrupt intracellular ROS and iron homeostasis to induce ferroptosis. Cell Death Dis 2020; 11 Article number 183
• 14 Doll S, Proneth B, Tyurina YY. et al. ACSL4 dictates ferroptosis sensitivity by shaping cellular lipid composition. Nat Chem Biol 2017; 13: 91-98
• 15 Bruni A, Bornstein S, Linkermann A. et al. Regulated cell death seen through the lens of islet transplantation. Cell Transplant 2018; 27: 890-901
• 16 Bottino R, Balamurugan AN, Tse H. et al. Response of human islets to isolation stress and the effect of antioxidant treatment. Diabetes 2004; 53: 2559-2568
• 17 Paraskevas S, Maysinger D, Wang R. et al. Cell loss in isolated human islets occurs by apoptosis. Pancreas 2000; 20: 270-276
• 18 Seibt TM, Proneth B, Conrad M. Role of GPX4 in ferroptosis and its pharmacological implication. Free Radic Biol Med 2019; 133: 144-152
• 19 Gaschler MM, Hu F, Feng H. et al. Determination of the subcellular localization and mechanism of action of ferrostatins in suppressing ferroptosis. ACS Chem Biol 2018; 13: 1013-1020
• 20 Kanak MA, Takita M, Kunnathodi F. et al. Inflammatory response in islet transplantation. Int J Endocrinol 2014; 2014: 1-13
• 21 Anderson GJ, Frazer DM. Hepatic iron metabolism. Semin Liver Dis 2005; 25: 420-432