Based On Notch Signaling Pathway, The Mechanism Of Qignao Jieyu Recipe On Hippocampal Neuroremodeling In Post-stroke Depression Rats Was Explored

ObjectivePost-stroke Depression(PSD)is a common affective disorder of stroke.PSD plays a negative role in the rehabilitation of neural and cognitive function,and related to the social function impairment after stroke,and increased mortality,adding to the financial burden of the family,the psychological burden caused by stroke,the same time led to the increase of social costs.Although the understanding of the clinical importance of PSD is increasing gradually,its pathogenesis is still unclear.According to the primary neural plasticity mechanism of depression disorders,the PSD are presented with the team’s own research results "theory of hippocampal neural plasticity barrier" of the disease,and stroke of neural plasticity is associated with Notch signal transduction pathway.Therefore,this project will focus on the hippocampal nerve plasticity,and the influence of the Notch signaling pathway on the development of PSD,and explore the pathogenesis of PSD and the mechanism of the effect of YinaoJieyu Prescription(YNJYP).Methods180 SPF SD male rats were randomly divided into sham operation group,stroke group,PSD group,fluoxetine group(FXT group),and YNJYP group,each group of 36 rats.This study investigated the effects of YNJYP on adult neurogenesis,and explored its mechanism at the molecular level,in a rat model of PSD,established by middle cerebral artery occlusion(MCAO)accompanied by chronic immobilization stress for 1 week.Sham,stroke,and PSD groups were gavaged with saline,while treatment groups received Fluoxetine hydrochloride capsules(FXT)or YNJYP.At 2,4 and 8 weeks,the following experiment was conducted:1.Behavioral tests(including open field test,forced swimming test and sucrose water preference test)were applied to evaluate the rats in each group.2.HE staining was used to observe the pathological changes of the hippocampal dentate gyrus,and the expression of 5-HT in the hippocampal dentate gyrus was detected by immunohistochemistry.3.The proliferation and differentiation of hippocampal dentate neural stem cells were observed with 3 rats in each group.4.Real-time fluorescence quantitative PCR(rt-pcr)was used to detect the expression of receptor Notch1,ligand Jagged1,transcription factor Hesl and Hes5 gene in Notch pathway of the left hippocampus of rats.Results2 weeks,the horizontal,vertical activity times of PSD rats were less than that in the stroke group,despair time in forced swimming test increased,sucrose water preference decreased(P<0.05,P>0.05,P<0.05,P>0.05);Compared with the PSD group,the horizontal,vertical activity times of YNJYP rats increased than that in the PSD group,despair time in forced swimming test decreased,sucrose water preference increased(P<0.01,P>0.05,P>0.05,P>0.05).4 weeks,the horizontal,vertical activity times of PSD rats were less than that in the stroke group,despair time in forced swimming test increased,sucrose water preference decreased(P<0.01,P<0.05,P<0.01,P<0.01)and the differences were statistically significant(P<0.01,P<0.05,P<0.05,P<0.01).Compared with the PSD group,the horizontal,vertical activity times of YNJYP rats increased than that in the PSD group,despair time in forced swimming test decreased,sucrose water preference increased.8 weeks,the horizontal,vertical activity times of PSD rats were less than that in the stroke group,despair time in forced swimming test increased,sucrose water preference decreased(P<0.05,P<0.05,P<0.01,P<0.01);Compared with the PSD group,the horizontal,vertical activity times of YNJYP rats increased than that in the PSD group,despair time in forced swimming test decreased,sucrose water preference increased(P>0.05,P>0.05,P>0.05,P<0.01).The changes of hippocampal dentate gyrus of each rat were observed by HE staining at 2,4,8 weeks.The cells in hippocampal dentate gyrus of PSD rats loosely arranged,and less nuclei was hyperchromatic in granulosa cells.The cells in hippocampal dentate gyrus of rats in YNJYP group were arranged neatly and in normal morphology.At 2 weeks,the expression of 5-HT in the hippocampal dentate gyrus in PSD rats was lower than that in the stroke group(P>0.05),and the expression of 5-HT of rats in YNJYP group was higher than that in the PSD group(P<0.01).At 4 weeks,8 weeks,the 5-HT expression of rats in PSD group was lower than that in stroke group(P<0.01,P<0.05),the expression of 5-HT of rats in YNJYP group was much higher than that in the PSD group(P<0.01,P<0.01).Rats in the stroke group showed an increase in the number of BrdU labeled newly born cells and nestin labeled progenitor cells in the DG,compared to the sham group.At 2,4,and 8 weeks,nestin-positive or BrdU-positive cells could be observed in the PSD,FXT and YNJYP groups,but few cells were positive for both nestin and BrdU.Less BrdU and NeuN were observed in overlapping cell populations of rats in the sham,stroke,and PSD groups,but after treatment with FXT or YNJYP more newly formed cells appeared near the DG,and were incorporated as mature neurons at 2,4,and 8 weeks.At 2 and 4 weeks,newly formed neurons appeared outside the granule cell layer,and had migrated into the granule cell layer at 8 weeks.The PSD rats showed an obvious increase in the number of BrdU labeled newly born cells and GFAP labeled astrocytes in the granule cell layer at 4 weeks.FXT and YNJYP decreased the number of astrocytes and newly born astrocytes at 2,4 and 8 weeks.At 8 weeks,neurogenesis was reduced compared to the other time points.At 4 weeks the expression of Notch 1 mRNA transcripts in the stroke group was higher than that in sham group(P<0.01).The expression of Notchl mRNA transcripts for rats in the PSD group was lower than that in the stroke group(P<0.01),but significantly increased after treatment with FXT or YNJYP(P<0.01).There were no significant differences between the YNJYP and FXT groups(P>0.05).At 2 or 8 weeks,levels of Notchl mRNA transcripts of rats in the five groups were similar(P>0.05).At 2 weeks the levels of Jagged1 mRNA transcripts of rats in the five groups were similar(P>0.05).At 4 weeks,Jagged1 mRNA transcript levels in the YNJYP group were higher than those in the FXT groups(P<0.05).At 8 weeks,the expression of Jaggedl mRNA transcripts in the PSD group was higher than that in the stroke group(P<0.01).There were no significant differences detected between the YNJYP and PSD groups(P>0.05).These data show that YNJYP was unable to reduce the expression of Jagged1 mRNA transcripts in the PSD group at 8 weeks.At 4 weeks the expression levels of Hesl mRNA transcripts of rats in the stroke and PSD groups were similar(P>0.05).After treatment by YNJYP,levels of Hesl mRNA transcript expression in the PSD rats increased(P<0.01).At 2 or 8 weeks,levels of Hesl mRNA transcripts in rats in the five groups were similar and showed no significant differences(P>0.05).At 2 weeks levels of Hes5 mRNA transcripts of rats in the PSD group was significantly lower than those in the stroke group(P<0.01).After treatment by FXT or YNJYP,the expression levels of Hes5 mRNA transcript of rats in the PSD group increased significantly(P<0.01).At 4 weeks,Hes5 mRNA transcript levels in the YNJYP group were lower than those of the FXT group(P<0.05).At 8 weeks,levels of Hes5 mRNA transcripts of rats in the five groups were similar(P>0.05).ConclusionsThis current investigation indicates that YNJYP can alleviate depressive behavior,and has a positive effect on neurogenesis through increasing neurogenesis,promoting differentiation toward neurons,and inhibiting differentiation toward astrocytes.At 4 weeks the effect of YNJYP on neurogenesis was the most significant.The beneficial effects of YNJYP treatment may be mediated by the activation of the Notch signaling pathway.