BACKGROUND Glucotoxic pancreaticβcells impair glycogenesis of hepatocytes,with exosomes serving as novel mediators.miR-375-3p is the most abundant miRNA in the pancreas and critical forβ-cell function,but whether it...BACKGROUND Glucotoxic pancreaticβcells impair glycogenesis of hepatocytes,with exosomes serving as novel mediators.miR-375-3p is the most abundant miRNA in the pancreas and critical forβ-cell function,but whether it plays a role in pancreasliver crosstalk remains unclear.AIM To investigate the role of miR-375-3p,a key regulator of pancreaticβcells,in remotely regulating hepatocyte glycogenesis via exosomes.METHODS Mice fed a high-fat diet(HFD)served as animal models,and mouse primary pancreatic islet cells and theβ-cell line MIN-6 were used as cellular models.miR-375-3p expression in pancreatic cells,hepatocytes and exosomes was detected in both animal and cellular models.Transwell assays,exosome treatment,and exosome-depleted supernatant culture were used to investigate the role of exosomal miR-375-3p in pancreatic-hepatocyte crosstalk.The AKT/GSK signaling pathway and hepatic glycogen content were used as indicators to evaluate hepatocyte glycogenesis.Luciferase reporter assays were used to evaluate the downstream targets of miR-375-3p.RESULTS Increased levels of miR-375-3p were observed in both the pancreas and liver of HFD-fed mice.In contrast to the in vivo results,high-glucose treatment exclusively increased the expression of miR-375-3p in pancreatic cells but had no effect on hepatocytes.Furthermore,hepatocytes treated with the supernatant and exosomes from glucotoxic pancreatic cells presented elevated expression of miR-375-3p.Additionally,exosomal transfer of miR-375-3p from pancreatic cells to hepatocytes suppressed the AKT/GSK signaling pathway,thereby reducing the hepatic glycogen content.Luciferase analysis indicated that the recombination signal binding protein for the immunoglobulin kappa J region(Rbpj)is a target gene of miR-375-3p.Rbpj inhibition impaired hepatic glycogenesis,and Rbpj overexpression reversed the effect on glycogenesis induced by miR-375-3p.CONCLUSION Pancreatic cell-derived miR-375-3p can be delivered to hepatocytes via exosomes and inhibits hepatocyte glycogenesis by targeting Rbpj.展开更多
基金Supported by Beijing Natural Science Foundation,No.7252124National High Level Hospital Clinical Research Funding,No.BJ-2024-219,No.BJ-2025-125 and No.BJ-2023-236+1 种基金National Natural Science Foundation of China,No.82370584,No.82470395 and No.81600618National Key R&D Program of China,No.2021YFE0114200.
文摘BACKGROUND Glucotoxic pancreaticβcells impair glycogenesis of hepatocytes,with exosomes serving as novel mediators.miR-375-3p is the most abundant miRNA in the pancreas and critical forβ-cell function,but whether it plays a role in pancreasliver crosstalk remains unclear.AIM To investigate the role of miR-375-3p,a key regulator of pancreaticβcells,in remotely regulating hepatocyte glycogenesis via exosomes.METHODS Mice fed a high-fat diet(HFD)served as animal models,and mouse primary pancreatic islet cells and theβ-cell line MIN-6 were used as cellular models.miR-375-3p expression in pancreatic cells,hepatocytes and exosomes was detected in both animal and cellular models.Transwell assays,exosome treatment,and exosome-depleted supernatant culture were used to investigate the role of exosomal miR-375-3p in pancreatic-hepatocyte crosstalk.The AKT/GSK signaling pathway and hepatic glycogen content were used as indicators to evaluate hepatocyte glycogenesis.Luciferase reporter assays were used to evaluate the downstream targets of miR-375-3p.RESULTS Increased levels of miR-375-3p were observed in both the pancreas and liver of HFD-fed mice.In contrast to the in vivo results,high-glucose treatment exclusively increased the expression of miR-375-3p in pancreatic cells but had no effect on hepatocytes.Furthermore,hepatocytes treated with the supernatant and exosomes from glucotoxic pancreatic cells presented elevated expression of miR-375-3p.Additionally,exosomal transfer of miR-375-3p from pancreatic cells to hepatocytes suppressed the AKT/GSK signaling pathway,thereby reducing the hepatic glycogen content.Luciferase analysis indicated that the recombination signal binding protein for the immunoglobulin kappa J region(Rbpj)is a target gene of miR-375-3p.Rbpj inhibition impaired hepatic glycogenesis,and Rbpj overexpression reversed the effect on glycogenesis induced by miR-375-3p.CONCLUSION Pancreatic cell-derived miR-375-3p can be delivered to hepatocytes via exosomes and inhibits hepatocyte glycogenesis by targeting Rbpj.
