R Mancarella

Effects of exendin-4 on islets from type 2 diabetes patients

Exendin‐4 is a dipeptidyl peptidase IV (DPP‐IV)‐resistant glucagon‐like peptide1 (GLP‐1) mimetic and its synthetic counterpart, exenatide, is being used in the therapy of type 2 diabetes (T2DM). No information, however, is currently available as for the direct action of exendin‐4 on human T2DM islets. In the present study, we exposed pancreatic islets prepared from non‐diabetic and T2DM subjects to exendin‐4 for 48 h and found that the compound had several, direct beneficial actions on insulin secretion and the expression of genes involved in beta‐cell function and differentiation.

Beneficial effect of the nonpeptidyl low molecular weight radical scavenger IAC on cultured human islet function.

We examined a possible protective effect of the nonpeptidyl low molecular weight radical scavenger IAC [bis(1-hydroxy-2,2,6,6-tetramethyl-4-piperidinyl)decanedioate di-hydrochloride] on isolated human islet cells against isolation and culture oxidative stress. Islets isolated from pancreases of nondiabetic multiorgan donors by collagenase digestion were purified by density gradient centrifugation. After the isolation, islets were either exposed or not exposed for 7 days to 10 μmol/L IAC. We found that IAC markedly reduced oxidative stress and ameliorated islets function. These results suggest that the use of IAC could be an interesting pharmacological approach for the treatment of the islets before transplantation.