Gene expression profiling of human pancreatic islets undergoing a simulated process of instant blood-mediated inflammatory reaction.

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 degrees 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.