Insulinoma INS 832/13 cells were transduced with adenovirus expressing GFP, prepro-rIAPP or prepro-hIAPP fused with a GFP tag at an MOI = 100. To the medias was added 4, 40 nmol/l or 400 nmol/l recombinant NEP or NEPx or 400 nmol/l of transferrin (TF).
a. After 48 h cell viability was determined using the MTT assay.
b. Cell apoptosis was evaluated by following the cleavage and activation of caspase-3 by Western blot analysis 48 h after adenovirus transduction. hIAPP, but not rIAPP or GFP, overexpression induced cleavage and activation of caspase-3 in INS 832/13 cells.
c. Exogenously added NEP reduces cleaved caspase-3 levels induced by hIAPP overexpression. In contrast, only 400 nmol/l NEPx but not 40 and 4 nmol/l NEPx reduces cleaved caspase-3 levels induced by hIAPP overexpression.