Gene Expression Profiling of Human Pancreatic Islets Undergoing a Simulated Process of Instant Blood-Mediated Inflammatory Reaction

Abstract

Objective Islet cell transplantation, as a treatment for type 1 diabetes mellitus, has historically required islet infusions from more than one donor organ to achieve insulin independence. Significant islet mass may be destroyed upon infusion due to a yet undefined process known as instant blood-mediated inflammatory reaction (IBMIR). Our objective was to identify gene expression changes in islets undergoing a simulated process of IBMIR. Materials and Methods Human pancreatic islets were isolated from 2 cadaveric donors and divided into 3 groups each for a total of 18 samples. Group one (n = 3) was treated with autologous sera, group two (n = 3) with allogeneic sera, and group three (n = 3) with type 1 diabetic sera (T1DM). Each group was treated for 3 hours at 37°C. Islets were washed, lysed using TRI reagent, and mRNA was isolated using the Total Prep mRNA isolation kit. Isolated cRNA was used for microarray analysis using Illumina Gene Chips Hu6_v2. GeneSpring GX software was used for statistical analysis. Results were significant at P < .05. Results One-way ANOVA statistical analysis of the microarray data revealed that interleukin-11 (IL-11), interleukin-12A (IL-12A), and Ras related associated with diabetes (RRAD) were overexpressed in islets exposed to diabetic sera when normalized to autologous control ( P < .01). Under the same conditions, islet cells exposed to T1DM serum had down-regulation of IL-1 receptor antagonist (IL-1RN). Conclusion These findings suggested that T1DM serum elicited an adaptive and innate immune response to the transplanted islet mass making them more susceptible to cytokine-mediated destruction.