RIP kinase inhibition with Necrostatin-1 improves human marginal mass islet graft survival and function for the management of type 1 diabetes.

Islet transplantation (ITx) has demonstrated that cellular therapies can improve glycemic control in patients with type 1 diabetes. However, cell death in the acute post-transplant period accounts for the loss of up to 70% of the islets, resulting in the requirement of multiple donors per recipient to achieve normoglycemia. Several studies have targeted apoptosis prevention after ITx; herein, our study explores a novel approach by modulating RIPK1-associated stress pathways using Necrostatin-1 (Nec-1) to enhance human islet survival, engraftment, and function post-transplant. Nec-1 treatment for 24 h prior to transplant significantly reduced the expression of RIPK1 (p = 0.0021) and RIPK3 (p = 0.0042), resulting in decreased cell death (p < 0.0001) and necroptosis (p < 0.0001), measured as TUNEL+ and pMLKL+ cells, respectively, without affecting basal respiration or insulin secretion in human islets. Nec-1 treatment pre-transplant drastically reduced cytokine (p = 0.0083), NFκB (p = 0.0179), TGFβ (p = 0.0015) and TNF family (p = 0.0010) signaling pathways at the transcriptional level compared to control. These results correlated with increased diabetes reversal (p = 0.0200) and decreased reversal time (p = 0.0011) in the Nec-1-treated group compared to untreated controls. The success of Nec-1 treatment in this study showcases that short-term modulation of RIPK1-associated stress pathways promotes early human marginal mass engraftment post-ITx. In the clinical context, improvement of marginal mass islet function could enable single-donor islet infusion and could aid in future ß-cell replacement therapies, making ITx available to a broader population of individuals living with diabetes.