The Protective Effect Of Oligopeptide FLPNF On FK506-induced Apoptosis Of INS-1Cell

Objective: To investigate the protective effect of oligopeptide FLPNF and the improvement of insulin secretion against tacrolimus-induced apoptosis of INS-1.Methods: The rat islet beta cell line INS-1 strain was studied as research object.The research groups included group control,group FLPNF,group Ghrelin,group NFGAIL,group FK506,group FLPNF + FK506,group FLPNF + FK506,and group NFGAIL +FK506.The cell proliferation activity was assessed with CCK-8 assay.The apoptosis rate of each group was measured by flow cytometry.The glucose stimulated insulin secreation function of INS-1 cells was measured by Elisa.And the expression of apoptosis related proteins(bax,bcl-2,caspase-3)were measured by western blotting.Software Graph Pad Prism 5.0 was used to process the data obtained from the experiments,with p<0.05 as statistically significant difference.Result: The results showed that when INS-1 cells were treated by FK506 alone,INS-1cell proliferation activity appeared significantly reduced,at the same time in the apoptosis rate,apoptosis related proteins decreased the bcl-2 expression,bax and caspase3 expression quantity to increase,decrease of glucose stimulated insulin secretion,explain FK506 can induce cells apoptosis and can make glucose stimulated insulin secretion decline.Compared with the control group,the proliferation activity and apoptosis rate of INS-1 cells were not significantly changed when the oligopeptide FLPNF was used alone.The expression level of apoptosis-related proteins was not significantly changed,and glucose stimulated insulin secretion was not significantly changed.Use oligopeptide FLPNF pretreatment INS-1 cells and reuse FK506 stimulation,compared with the single use FK506,found that INS-1 cell proliferation activity and apoptosis percentage decreased,the expression of apoptosis related proteins bal-2quantity to increase,while the expression of bax and caspase3 quantity,INS-1 cell glucose stimulated insulin secretion function improved.Compared with the positive control group(Ghrelin),there was no significant difference in the results of each index when cells were treated with FLPNF alone.Compared with the negative control group(NFGAIL),the INS-1 cells were pretreated with FLPNF and then stimulated with FK506,the proliferation activity of INS-1 cells was increased,the percentage of apoptosis was decreased,the expression of apoptosis-related protein bcl-2 was increased,and the expression of bax and caspase3 was decreased.Conclusion:1.The oligopeptide FLPNF significantly increases the proliferation activity of INS-1 cells and improve the glucose-stimulated insulin secretion function of INS-1cells under the toxic effect of FK506.2.The oligopeptide FLPNF significantly reduced the apoptosis of INS-1 cells induced by FK506,up-regulated the expression of bcl-2protein,and down-regulated the expression of bax and caspase-3 protein.