Oxidative stress generated during islet isolation, culture, and transplantation causes islet cell damage mediated by hypoxia, reactive oxygen species (ROS) and inflammatory responses. We investigated the protective effects of NecroX-7, a novel ROS scavenger, during isolation and/or culture of islets. For ex vivo studies, islets from heterozygote human islet amyloid polypeptide (hIAPP+/-) mice and C57BL/6J mice were isolated by collagenase with and without supplementation with 20 uM of NecroX-7. Supplementation with NecroX-7 provided markedly increased islet viability and ATP contents, and attenuated ROS, transcription of c-Jun N-terminal kinases, high mobility group box-1 (HMGB1) and proinflammatory cytokines including interleukin-1beta (IL-1b), interleukin-6 (IL-6), and tumor necrosis factor-alpha (TNF-a). Transplantation of islets, which is derived from islet isolation method using supplementation with NecroX-7, into syngeneic subrenal subcapsular of hIAPP+/- mice also improved post-transplant blood glucose levels. Also, NecroX-7 protected RINm5F cells from t-BHP-induced and serum deprivation induced toxicity in in vitro culture by dose-dependent manner from 0.1 uM to 20 uM. Supplementation of medium with NecroX-7 during serum-deprived culture condition also improved impaired viability and serum deprivation-induced ROS in islets from hIAPP+/- mice by dose-dependent manner from 0.1 uM to 20 uM. These findings suggest that NecroX-7 supplementation during the islet isolation and/or culture process suppressed inflammatory responses and ROS induced by serum deprivation and provides a potential benefit to improve post-transplantation outcomes.
Y. Kwon: None. H. Lee: None. H. Kim: None. G. Kim: None. S. Jin: None. M. Lee: None. J. Kim: None.