Jiao-tai-wan And Its Effective Component-berberine Improve Diabetes And Depressive Disorder Through CAMP/PKA/CREB Signaling Pathway

Objective:(1)To investigate the effects and potential mechanisms of Jiao-tai-wan(JTW)on mice with diabetes mellitus(DM)and depressive disorder.(2)To investigate the effects and potential mechanisms of berberine(Ber),the effective component of JTW,on hippocampal neuronal cells and islet β cells damage induced by high glucose(Glu)combined with corticosterone(CORT).Methods:(1)Chronic restraint stress(CRS)was used in C57BL/6 mice to preliminarily verify the effects of JTW on improving depression-like behavior.A mouse model of DM combined with depressive disorder was constructed by CRS for db/db mice.Then the mice were divided into 6 groups randomly: db/db group,DM and depressive disorder group(DD),low-dose JTW group,high-dose JTW group,fluoxetine group and metformin group,while db/m mice were assigned as normal control.After three-week of interventions of corresponding drugs,the therapeutic effects of JTW were evaluated by glucolipid metabolic indexes,behavioral tests,and depression-related neurotransmitter levels.Subsequently,the effects of JTW on the inflammatory status,cell damage and apoptosis,and maintenance of pancreatic cells identity were investigated by various methods such as detection of inflammatory factors levels,immunofluorescence(IF),NISSL staining,H&E staining,TUNEL staining,Western Blot and RT-q PCR.Finally,the changes of protein and m RNA expression of cAMP/PKA/CREB signaling pathway were detected in order to elucidate the molecular mechanism.(2)Combining the results of HPLC fingerprinting with molecular docking,the active components that may play a role in JTW were obtained.A cellular model was constructed by intervention of Glu combined with CORT.The appropriate concentration of modeling and drug intervention were screened by CCK-8 assay.The morphological changes of cells were observed under microscope and the apoptosis of different groups of cells were detected by IF.The levels of depression-related neurotransmitters in HT22 cells were examined by ELISA,and the proteins and m RNA expression levels of synaptic plasticity-related genes in HT22 cells and key genes for maintaining pancreatic identity in MIN6 cells were tested by Western Blot and RT-q PCR.Finally,changes of the cAMP/PKA/CREB signaling pathway were detected,and the activator and inhibitor of PKA protein were used successively for reverse validation experiments to clarify the molecular mechanism.Results:(1)Compared with DD group,JTW could reduce fasting glucose levels,fasting insulin levels and insulin resistance index,indicating that JTW could improve the impaired glucose tolerance.JTW could improve lipid metabolism disorders by reversing the serum levels of TG,TC,LDL-C and HDL-C.Meanwhile,JTW significantly improved the depression-like behaviors and increased the serum levels of 5-HT,DA,NE and GABA,thus improving depression-like symptoms in DD mice.In addition,JTW could reduce the serum levels of inflammatory factors,and suppress the microglia activation in the hippocampus.JTW also improved hippocampal neurons damage and apoptosis in DD mice and maintained the identity of pancreatic cells.Finally,the dual effects of JTW might be related to the activation of cAMP/PKA/CREB signaling pathway.(2)A total of nine active components were determined by HPLC fingerprinting analysis of JTW,and the molecular docking results demonstrated that Ber showed the maximum binding energy to PKA,so that Ber was identified for subsequent experiments.Ber could reverse the morphological changes and apoptosis of HT22 cells and MIN6 cells induced by Glu and CORT,and could up-regulate the levels of depression-related neurotransmitters and the proteins and m RNA expression levels of synaptic plasticity-related genes in HT22 cells.What’s more,Ber could increase the expression of key proteins for maintaining the identity of pancreatic cells.Finally,the effects of Ber were associated with the activation of the cAMP/PKA/CREB signaling pathway as well.Conclusions:(1)JTW could exert both hypoglycemic and antidepressant effects through activating the cAMP/PKA/CREB signaling pathway.(2)Ber could improve the damage to HT22 cells and MIN6 cells induced by Glu combined with CORT via activating the cAMP/PKA/CREB signaling pathway.Ber may be an effective component of the dual effects of JTW.