COMP-Ang1 promotes long-term survival of allogeneic islet grafts in a bioinert perforated chamber by inhibiting inflammation via inhibition of the TLR4 signaling pathway.

Abstract

To evaluate the effects of cartilage oligomeric matrix protein (COMP)- angiopoietin-1 (Ang1) on allogeneic islet graft survival in a bioinert perforated chamber. COMP-Ang1 treatment significantly decreased lipopolysaccharide-induced cell apoptosis and islet-related lymph node cell proliferation (both P<0.01). Tumor necrosis factor (TNF)-α, interleukin (IL)-1β, and IL-6 levels in the chamber exudate were significantly lower in the COMP-Ang1+chamber group than in the chamber group (all P<0.05), as were the protein expression levels. COMP-Ang1 significantly inhibited the expression of Toll-like receptor 4 (TLR4) in cultured islets. Finally, full COMP-Ang1 treatment resulted in the longest survival time among the treatment groups. Combined use of the bioinert perforated chamber with COMP-Ang1 is an effective strategy for improving islet allograft survival.