| Objective:Use lipopolysaccharide(LPS)to induce neuroinflammation model,steroid receptor coactivator-1(SRC-1)inhibitor(Dasatinib)inhibits SRC-1 expression,SRC-1 agonist(MCB)-613)Stimulate the expression of SRC-1 to detect the latency of the mice with neuroinflammatory cognitive impairment in the water maze,the changes in the number of crossing platforms,the changes in the concentration of inflammatory factors in the hippocampus brain tissue,and the changes in hippocampal nerve damage.The relationship between glial cells and SRC-1 co-expression,AKT protein and synaptophysin in the phosphatidylinositol 3-kinase/protein kinase B(phosphatidylinositol 3-kinase/protein kinase B,PI3K/AKT)signaling pathway in brain tissue(Synaptophysin,SYN)protein expression changes,to explore the role and mechanism of SRC-1 mediated synaptic plasticity through PI3K/AKT signaling pathway in neuroinflammation-induced cognitive impairment mice.Knowing the pathogenesis of dysfunction provides a richer theoretical basis.Methods:64 adult male C57BL/6 mice were randomly divided into 4 groups:blank control group(n=16),inflammation model group(n=16),SRC-1 inhibition group(n=16),SRC-1 agonistic group(N=16).All groups except the blank control group were injected with LPS(5mg/kg)through stereotactic brain technology,and the blank control group was injected with equal volume of normal saline.Intervention drugs were given by intragastric administration on the first 1-4 days after surgery.The SRC-1 inhibitor group was given the SRC-1 inhibitor Dasatinib(20mg/kg)to inhibit the expression of SRC-1,and the SRC-1 agonist group was given MCB-613(20mg/kg).)Stimulate SRC-1 expression.Four mice in each group were randomly selected to perform Morris water maze behavioral experiments from day 4 to day 9.The brain tissues of the remaining mice were sacrificed and subjected to related laboratory tests:Enzyme-linked immunosorbent assay(Enzyme-linked immunosorbent assay).linked immunosorbent assay,ELISA)to detect the inflammatory factors Tumor necrosis factor-α(Tumor necrosis factor-α,TNF-α),interleukin 1β(Interleukin 1β,IL-1β)content;Hematoxylin-eosin(HE)Staining to observe the damage of neuronal cells;Western blot(WB)to detect SRC-1,protein kinase B(AKT),phosphorylated protein kinase B(p-AKT),SYN protein content;immunofluorescence staining to observe the co-expression of SRC-1 and ionized calcium-binding adaptor molecule 1(Iba-1),a selective marker for microglia.Data analysis was performed using SPSS25.0,and P<0.05 was statistically significant.Results:1.The effect of regulating SRC-1 on the space escape lat ency of mice:①The escape latency of different groups of mice in the Morris water maze cruise experiment gradually shortened with the traini ng time.②On the 4th day of the cruise experiment,compared with the blank control group,the escape latency of the neuroinflammation grou p was significantly prolonged(P<0.05),and the escape latency of the S RC-1 inhibition group was significantly prolonged(P<0.01).③The esca pe latency of SRC-1 excited group was significantly longer than that of SRC-1 inhibited group(P<0.01).④On the 5th day of the cruise ex periment,compared with the neuroinflammation group,the escape latenc y of the SRC-1 excited group was significantly shorter(P<0.01).2.Regulation of the influence of SRC-1 on the number of crossin g platforms in mice:①Compared with the neuroinflammation group,th e number of crossing platforms in the SRC-1 excited group was signifi cantly increased(P<0.01).②Compared with the SRC-1 inhibition group,the number of platform crossings in the SRC-1 activation group was s ignificantly reduced(P<0.01).3.The effect of regulating SRC-1 on the retention time in the targ et quadrant of mice:The results showed that compared with the blank control group,the retention time in the target quadrant of the neuroinfl ammation group was significantly shorter(P<0.05),and the difference w as statistically significant.The results of the analysis of variance indicat ed that there was no significant difference between the groups(F=1.364,P>0.05),and the difference between the groups was not statistically si gnificant.4.The effect of regulating SRC-1 on the pathological changes in t he hippocampus of mice:①The cell membrane of neurons in the CA1(Cornu Ammonis 1 Filed)area of the blank control group mouse was intact,arranged neatly,and the structure was clear.②In the hippocam pal tissue sections of the neuroinflammation group,SRC-1 inhibition gr oup,and SRC-1 agonism group,different degrees of neuronal degenerati on,necrosis,structural disorder,inflammatory cell infiltration,vacuolar c ells and nucleolus dissolution were seen in the hippocampal tissue secti ons.③Compared with the neuroinflammation group,the neuronal cells in the CA1 area of the SRC-1 inhibition group are arranged chaotically,the structure is incomplete,the inflammatory cell infiltration is signific antly increased,and the nucleolus is significantly dissolved.④Compare d with the neuroinflammatory group,the degeneration,necrosis,and infl ammatory cell infiltration of nerve cells in the SRC-1 activation group were reduced,and the structural disorder was reduced.5.The effect of regulating SRC-1 on the expression of IL-1β in mice:①Compared with the blank control group,the expression of IL-1β in the hippocampus of mice in the neuroinflammation group was sig nificantly increased(P<0.01).②Compared with the neuroinflammation g roup,the IL-1β of the SRC-1 inhibition group was significantly increa sed(P<0.05).③Compared with the neuroinflammation group,the IL-1β of the SRC-1 agonist group was significantly reduced(P<0.05).6.The effect of regulating SRC-1 on the expression of TNF-α in mice:①Compared with the blank control group,the expression of TN F-α in the hippocampus of mice in the neuroinflammation group was significantly increased(P<0.05).②Compared with the neuroinflammatio n group,TNF-α in the SRC-1 inhibition group was significantly increa sed(P<0.05).③The TNF-α in the SRC-1 agonist group was significan tly reduced(P<0.05).7.Regulate the changes of AKT,p-AKT,and SYN protein expression in the hippocampus of each group of SRC-1 mice:①Compared with the blank control group,the level of SRC-1 and p-AKT protein in the hippocampus of the neuroinflammation group Significantly reduced(P<0.05),and the expression of SYN protein was significantly reduced(P<0.01).②Compared with the neuroinflammation group,the protein levels of SRC-1,p-AKT and SYN in the SRC-1 inhibition group were significantly reduced(P<0.05).③Compared with the neuroinflammation group,the SRC-1,p-AKT and SYN protein levels in the SRC-1 agonist group were significantly increased(P<0.05).④There was no significant difference in AKT protein expression(P>0.05).Conclusion:SRC-1 may inhibit inflammation,protect nerve damage,up-regulate the phosphorylation level of AKT protein in the PI3K/AKT pathway,stimulate the expression of SYN,improve synaptic plasticity,and improve cognitive dysfunction. |
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