BACKGROUND Tacrolimus(FK506)is a key calcineurin inhibitor used to prevent organ transplant rejection and is effective in improving graft survival.However,it is linked to hyperglycemia and insulin resistance,contribut...BACKGROUND Tacrolimus(FK506)is a key calcineurin inhibitor used to prevent organ transplant rejection and is effective in improving graft survival.However,it is linked to hyperglycemia and insulin resistance,contributing to new-onset diabetes after transplantation and negatively affecting islet function.AIM To study the effects of tacrolimus on the insulin signaling pathway of hepatocytes.METHODS HL7702 cells were treated with different concentrations of tacrolimus(0.1 mg/L,1 mg/L,5 mg/L)for 24 hours.The proteins involved in insulin signaling were detected by Western blotting.RESULTS Compared with the control group,phosphorylation of insulin receptor substrate(IRS)1 at Ser 307 and Ser 323 were increased significantly when the tacrolimus concentration reached 1 and 5 mg/L.Phosphorylation of IRS1 at Ser 1101 was also increased,although not significantly.However,phosphorylation of Ribosomal protein S6 kinase beta-1 at Thr 389 was decreased significantly.The levels of phosphorylated glycogen synthase kinase 3αSer 21 and Ser 9 were increased.Surprisingly,phosphorylation of glycogen synthase at Ser 641 was increased.There was no significant change in the activity of glycogen phosphorylase.CONCLUSION Tacrolimus has no direct effect on hepatic glucose metabolism,but inhibits IRS1-mediated insulin signaling.This may be one of the underlying mechanisms by which tacrolimus induces insulin resistance.展开更多
Objective To investigate the effects of electroacupuncture(EA)on the expression and phosphorylation of insulin signal transduction-related proteins in the hypothalamus of insulin resistance(IR)rats.Methods There were ...Objective To investigate the effects of electroacupuncture(EA)on the expression and phosphorylation of insulin signal transduction-related proteins in the hypothalamus of insulin resistance(IR)rats.Methods There were totally seventy-five Wistar rats.Ten rats were randomly assigned to the Normal group(N).The remaining 65 rats were fed a high-fat diet,fifty successfully modeled rats were randomly divided into the Model(M),EA,Sham EA(S+EA),l-leucine(L),and l-leucine+EA(L+EA)groups,with 10 rats in each group.EA was applied at acupoints“Guanyuan(CV 4)”,“Zhongwan(CV 12)”,“Zusanli(ST 36)”,and“Fenglong(ST 40)”,with each session lasting 10 min,three times per week for 8 weeks.The S+EA group received needle insertion to a depth of≤2 mm without electrical stimulation,with the same treatment duration and same acupoint selection.Body weight,fasting blood glucose(FBG),and insulin sensitivity(glucose infusion rate,GIR)were measured.Western blot analysis was used to assess insulin receptor substrate-1(IRS-1),(Protein kinase B)Akt,glycogen synthase kinase-3β(GSK-3β),mechanistic target of rapamycin complex 1(mTORC1),and Ribosomal S6 kinase 1(S6K1),along with their phosphorylated forms.PCR was used to evaluate mRNA expression of IRS-1,Akt,and GSK-3β.Immunofluorescence was used to detect hypothalamic Akt localization.Results(1)Compared to the N group,the M group exhibited increased body weight,FBG,and phosphorylation of GSK-3β,mTORC1,and S6K1,with decreased GIR,IRS-1,Akt phosphorylation,and mRNA expression(P<0.05,P<0.01).(2)Compared to the M group,the EA and S+EA groups showed reduced body weight,FBG,GSK-3β,mTORC1,and S6K1 phosphorylation,with increased GIR,IRS-1,Akt phosphorylation,and mRNA expression(P<0.05,P<0.01).(3)Compared to the EA group,the S+EA group had higher body weight,GSK-3βphosphorylation,and mRNA expression,with reduced p-IRS-1 and p-Akt expression(P<0.05);the L and L+EA groups showed increased GSK-3β,mTORC1,and S6K1 phosphorylation,with decreased GIR,IRS-1,and Akt mRNA expression(P<0.05).(4)Compared to the L+EA group,the L group exhibited higher GSK-3β,mTORC1,and S6K1 phosphorylation,with lower GIR,Akt mRNA,and p-Akt expression(P<0.05,P<0.01).Conclusion EA positively influences body weight,glucose-lipid metabolism,and insulin sensitivity in IR rats,with regulatory effects on central insulin signal transduction-related proteins,potentially linked to its suppression of hypothalamic mTORC1/S6K1 pathway activity.展开更多
文摘BACKGROUND Tacrolimus(FK506)is a key calcineurin inhibitor used to prevent organ transplant rejection and is effective in improving graft survival.However,it is linked to hyperglycemia and insulin resistance,contributing to new-onset diabetes after transplantation and negatively affecting islet function.AIM To study the effects of tacrolimus on the insulin signaling pathway of hepatocytes.METHODS HL7702 cells were treated with different concentrations of tacrolimus(0.1 mg/L,1 mg/L,5 mg/L)for 24 hours.The proteins involved in insulin signaling were detected by Western blotting.RESULTS Compared with the control group,phosphorylation of insulin receptor substrate(IRS)1 at Ser 307 and Ser 323 were increased significantly when the tacrolimus concentration reached 1 and 5 mg/L.Phosphorylation of IRS1 at Ser 1101 was also increased,although not significantly.However,phosphorylation of Ribosomal protein S6 kinase beta-1 at Thr 389 was decreased significantly.The levels of phosphorylated glycogen synthase kinase 3αSer 21 and Ser 9 were increased.Surprisingly,phosphorylation of glycogen synthase at Ser 641 was increased.There was no significant change in the activity of glycogen phosphorylase.CONCLUSION Tacrolimus has no direct effect on hepatic glucose metabolism,but inhibits IRS1-mediated insulin signaling.This may be one of the underlying mechanisms by which tacrolimus induces insulin resistance.
基金Supported by the Hubei Natural Science Foundation Joint Fund Project:2023AFD139,2023AFD140the "Shizhen Young Talent" Training Program of the College of Acupuncture and Orthopedics,Hubei University of Chinese Medicinethe National Famous Traditional Chinese Medicine Expert Inheritance Studio Construction Project。
文摘Objective To investigate the effects of electroacupuncture(EA)on the expression and phosphorylation of insulin signal transduction-related proteins in the hypothalamus of insulin resistance(IR)rats.Methods There were totally seventy-five Wistar rats.Ten rats were randomly assigned to the Normal group(N).The remaining 65 rats were fed a high-fat diet,fifty successfully modeled rats were randomly divided into the Model(M),EA,Sham EA(S+EA),l-leucine(L),and l-leucine+EA(L+EA)groups,with 10 rats in each group.EA was applied at acupoints“Guanyuan(CV 4)”,“Zhongwan(CV 12)”,“Zusanli(ST 36)”,and“Fenglong(ST 40)”,with each session lasting 10 min,three times per week for 8 weeks.The S+EA group received needle insertion to a depth of≤2 mm without electrical stimulation,with the same treatment duration and same acupoint selection.Body weight,fasting blood glucose(FBG),and insulin sensitivity(glucose infusion rate,GIR)were measured.Western blot analysis was used to assess insulin receptor substrate-1(IRS-1),(Protein kinase B)Akt,glycogen synthase kinase-3β(GSK-3β),mechanistic target of rapamycin complex 1(mTORC1),and Ribosomal S6 kinase 1(S6K1),along with their phosphorylated forms.PCR was used to evaluate mRNA expression of IRS-1,Akt,and GSK-3β.Immunofluorescence was used to detect hypothalamic Akt localization.Results(1)Compared to the N group,the M group exhibited increased body weight,FBG,and phosphorylation of GSK-3β,mTORC1,and S6K1,with decreased GIR,IRS-1,Akt phosphorylation,and mRNA expression(P<0.05,P<0.01).(2)Compared to the M group,the EA and S+EA groups showed reduced body weight,FBG,GSK-3β,mTORC1,and S6K1 phosphorylation,with increased GIR,IRS-1,Akt phosphorylation,and mRNA expression(P<0.05,P<0.01).(3)Compared to the EA group,the S+EA group had higher body weight,GSK-3βphosphorylation,and mRNA expression,with reduced p-IRS-1 and p-Akt expression(P<0.05);the L and L+EA groups showed increased GSK-3β,mTORC1,and S6K1 phosphorylation,with decreased GIR,IRS-1,and Akt mRNA expression(P<0.05).(4)Compared to the L+EA group,the L group exhibited higher GSK-3β,mTORC1,and S6K1 phosphorylation,with lower GIR,Akt mRNA,and p-Akt expression(P<0.05,P<0.01).Conclusion EA positively influences body weight,glucose-lipid metabolism,and insulin sensitivity in IR rats,with regulatory effects on central insulin signal transduction-related proteins,potentially linked to its suppression of hypothalamic mTORC1/S6K1 pathway activity.
