Transcriptome sequencing for exploring the mechanism of islet cell protection by anthocyanin.

We applied GSIS, immunofluorescence staining, WB, and flow cytometry to observe the protective effects of C3G on palmitate-induced beta cell apoptosis and insulin deficiency, after which we explored the mechanism using RNA sequencing (RNA-seq) and quantitative real-time PCR (qPCR), and finally validated the mechanism using Western Blot (WB) and small interfering RNA (siRNA).The results of GSIS on both INS-1E cells and mouse primary islets plus a series of experiments related to cell apoptosis showed that C3G could restore the damage caused by lipotoxicity through promoting insulin secretion and alleviating cell apoptosis. RNA-seq and qPCR results indicated that the protective effect of C3G was most likely mediated by repressing ER stress pathways, especially the PERK pathway, while partly due to elevated expression of insulin secretion-related genes. Finally, the results of knockdown of the pro-apoptotic marker CHOP in PERK pathway further confirmed the above findings.Conclusion: C3G may act though reducing ER stress to exert its protective impact on pancreatic beta cells under lipotoxicity. This research provides favorable evidence for the therapeutic application of C3G in T2DM. Overall design: Examination of the transcriptome of INS-1E cell lines in the presence of palmitic acid, palmitic acid and anthocyanin mixtures, and controls, with three replicates of each of the three groups.