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
Background: LDL receptor-related protein-1(LRP1) is a cell-surface receptor that functions in diverse physiological pathways. We previously demonstrated that hepatocyte-specific LRP1 deficiency(hLRP1KO) promotes diet-...Background: LDL receptor-related protein-1(LRP1) is a cell-surface receptor that functions in diverse physiological pathways. We previously demonstrated that hepatocyte-specific LRP1 deficiency(hLRP1KO) promotes diet-induced insulin resistance and increases hepatic gluconeogenesis in mice. However, it remains unclear whether LRP1 regulates hepatic glycogenesis.Methods: Insulin signaling, glycogenic gene expression, and glycogen content were assessed in mice and HepG2 cells. The pcDNA 3.1 plasmid and adeno-associated virus serotype 8 vector(AAV8) were used to overexpress the truncated β-chain(βΔ) of LRP1 both in vitro and in vivo.Results: On a normal chow diet, hLRP1KO mice exhibited impaired insulin signaling and decreased glycogen content. Moreover, LRP1 expression in HepG2 cells was significantly repressed by palmitate in a dose-and time-dependent manner. Both LRP1 knockdown and palmitate treatment led to reduced phosphorylation of Akt and GSK3β, increased levels of phosphorylated glycogen synthase(GYS), and diminished glycogen synthesis in insulin-stimulated HepG2 cells, which was restored by exogenous expression of the βΔ-chain. By contrast, AAV8-mediated hepatic βΔ-chain overexpression significantly improved the insulin signaling pathway, thus activating glycogenesis and enhancing glycogen storage in the livers of high-fat diet(HFD)-fed mice.Conclusion: Our data revealed that LRP1, especially its β-chain, facilitates hepatic glycogenesis by improving the insulin signaling pathway, suggesting a new therapeutic strategy for hepatic insulin resistance-related diseases.展开更多
The present study evaluated the inhibitory effect of Ethiopian coffee(Coffea arabica)on carbohydrate digestive enzymes and its protective effect against glucose-induced testicular dysfunction using in vitro and in sil...The present study evaluated the inhibitory effect of Ethiopian coffee(Coffea arabica)on carbohydrate digestive enzymes and its protective effect against glucose-induced testicular dysfunction using in vitro and in silico study models.Testicular oxidative stress was initiated by co-incubating testocular tissue collected from male Sprague-Dawley rats in glucose solution with different concentrations of Ethiopian coffee aqueous extracts(hot and cold)for 2 h at 37℃.Glucose-mediated oxidative stress significantly(p<0.05)depleted reduced glutathione and total glycogen levels while it lowered catalase and superoxide dismutase(SOD)activities in the testicular tissue.Concomitantly,this led to elevated malondialdehyde and nitric oxide levels while it also increased glycogen phosphorylase,fructose-1,6-bisphosphatase,ATPase,and acetylcholinesterase activities.Treatment with different concentrations of coffee aqueous extracts restored the enzymes’and markers’levels and activities.Although both the cold and hot coffee extracts strongly inhibitedα-glucosidase and α-amylase enzymes,the former showed better activities.The subjection of the coffee extracts to LC-MS analysis indicated the presence of several compounds,including chlorogenic acid,caffeic acid,cafestol,kahweol,caffeine,quinic acid,ferulic acid,and catechol which were further docked with the carbohydrate digestive enzymes.The in silico results displayed that among the various metabolites,chlorogenic acid strongly interacted and had the best binding affinity withα-glucosidase andα-amylase.Our findings implied that Ethiopian coffee may have a preventive effect against glucose-induced testicular damage.These are evidenced by the capacity of the plant product to decrease oxidative stress and protect against testicular dysfunction.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.
基金financially supported by the National Natural Science Foundation of China (Grant No. 82270854)the Natural Science Foundation of Chongqing+2 种基金China (No. cstc2020jcyj-msxm X0408)the Program for Youth Innovation in Future MedicineChongqing Medical University (No. W0162) to Yinyuan Ding。
文摘Background: LDL receptor-related protein-1(LRP1) is a cell-surface receptor that functions in diverse physiological pathways. We previously demonstrated that hepatocyte-specific LRP1 deficiency(hLRP1KO) promotes diet-induced insulin resistance and increases hepatic gluconeogenesis in mice. However, it remains unclear whether LRP1 regulates hepatic glycogenesis.Methods: Insulin signaling, glycogenic gene expression, and glycogen content were assessed in mice and HepG2 cells. The pcDNA 3.1 plasmid and adeno-associated virus serotype 8 vector(AAV8) were used to overexpress the truncated β-chain(βΔ) of LRP1 both in vitro and in vivo.Results: On a normal chow diet, hLRP1KO mice exhibited impaired insulin signaling and decreased glycogen content. Moreover, LRP1 expression in HepG2 cells was significantly repressed by palmitate in a dose-and time-dependent manner. Both LRP1 knockdown and palmitate treatment led to reduced phosphorylation of Akt and GSK3β, increased levels of phosphorylated glycogen synthase(GYS), and diminished glycogen synthesis in insulin-stimulated HepG2 cells, which was restored by exogenous expression of the βΔ-chain. By contrast, AAV8-mediated hepatic βΔ-chain overexpression significantly improved the insulin signaling pathway, thus activating glycogenesis and enhancing glycogen storage in the livers of high-fat diet(HFD)-fed mice.Conclusion: Our data revealed that LRP1, especially its β-chain, facilitates hepatic glycogenesis by improving the insulin signaling pathway, suggesting a new therapeutic strategy for hepatic insulin resistance-related diseases.
基金funded by the Research Office,University of KwaZulu-Natal,DurbanIncentive Funding for Rated Researchers from National Research Foundation(NRF),Pretoria,South Africa.
文摘The present study evaluated the inhibitory effect of Ethiopian coffee(Coffea arabica)on carbohydrate digestive enzymes and its protective effect against glucose-induced testicular dysfunction using in vitro and in silico study models.Testicular oxidative stress was initiated by co-incubating testocular tissue collected from male Sprague-Dawley rats in glucose solution with different concentrations of Ethiopian coffee aqueous extracts(hot and cold)for 2 h at 37℃.Glucose-mediated oxidative stress significantly(p<0.05)depleted reduced glutathione and total glycogen levels while it lowered catalase and superoxide dismutase(SOD)activities in the testicular tissue.Concomitantly,this led to elevated malondialdehyde and nitric oxide levels while it also increased glycogen phosphorylase,fructose-1,6-bisphosphatase,ATPase,and acetylcholinesterase activities.Treatment with different concentrations of coffee aqueous extracts restored the enzymes’and markers’levels and activities.Although both the cold and hot coffee extracts strongly inhibitedα-glucosidase and α-amylase enzymes,the former showed better activities.The subjection of the coffee extracts to LC-MS analysis indicated the presence of several compounds,including chlorogenic acid,caffeic acid,cafestol,kahweol,caffeine,quinic acid,ferulic acid,and catechol which were further docked with the carbohydrate digestive enzymes.The in silico results displayed that among the various metabolites,chlorogenic acid strongly interacted and had the best binding affinity withα-glucosidase andα-amylase.Our findings implied that Ethiopian coffee may have a preventive effect against glucose-induced testicular damage.These are evidenced by the capacity of the plant product to decrease oxidative stress and protect against testicular dysfunction.
