Protective effect of necrostatin-1 on the damage of pancreas islet cells induced by TNF-α.

Abstract

To investigate whether necrostatin-1 (Nec-1) can protect islet cells from the damage induced by TNF-α. After isolation and purification, the neonatal porcine islet cell clusters (NICCs) were divided into 3 groups (islets 10 000 IEQ/group): a Nec-1 group (Nec-1+TNF-α was added to the culture medium), a TNF-α group (TNF-α was added to the culture medium), and a control group (pure medium). The number of cells was observed after 48 h of co-culture. The cell death was evaluated by AO/EB staining. Insulin secretion and DNA of islets were detected by chemiluminescence and nucleic acid quantitative analysis. RT-PCR assay was used to examine the mRNA expressions of insulin gene, glueogan gene and somatostatin gene. Flow cytometry analysis was used to detect the viability of B cells. The number of islets in Nec-1 group, TNF-α group and the control group were (8 425±2 187), (4 325±778), and (7 122±1 558) IEQ, respectively. Compared to the other two groups, the number of dead cells in TNF-α group was greatly increased. The insulin/DNA values in the Nec-1 group, TNF-α group and blank control group were (13.21±3.15), (2.47±0.45), and (7.44±0.97) mIU/mg, respectively. Compared to the TNF-α group and the control group, the mRNA relative expression levels of insulin gene (6.73±1.07), glucagon gene (10.13±1.98), somatostatin gene (8.57±1.11) were significantly increased in the Nec-1 group (all P<0.05), the rate of live cells (97.32±1.87)% and live B cells (90.86±3.68)% were increased significantly in the Nec-1 group (all P<0.05). TNF-α can induce neonatal porcine islet cells damage, which is attenuated in the presence of Nec-1. Nec-1 can increase the content of endocrine cells in NICCs.