Depression is one of the most common mental disorders.Since 1960s,researchers have proposed a number of etiological hypotheses from the aspects of genetics,biochemistry,neuroendocrine and immune,but so far it has not been fully under-stood.Toll like receptor 4(TLR4),as a bridge between innate immunity and adaptive immunity,could induce inflammatory by activating related signal transduction pathways and promoting the expression of inflammatory factors in c-ells.More and more studies showed that the occurrence of depression was related to inflammation.Reviewing relationship of TLR4 and depressive disorder and exploring the effects of some interventions for depression on TLR4.Research on TLR4 shed light on pathological mechanism of depressive order.TLR4 could play an important role in inhibiting the production of 5-serotonin,the disorders of HPA axis,interfering with the hippocampus and cortical nerve regeneration,the autophagy of hippocampus.

Objective:To investigate the effect of salvianolic acid on depressive behavior in depression model rats induced by chronic mild stress (CMS) and its mechanism.Methods:Fifty healthy male clean grade Sprague-Dawley(SD) rats were divided into five groups according to a random number table with 10 in each group: control group (nCMS+ Nal group), CMS+ normal saline group (CMS+ Nal group), CMS+ fluoxetine group (CMS+ Flu group), CMS+ salvia acid group (CMS+ Sal group), CMS+ fluoxetine+ Salvia acid group (CMS+ Flu+ Sal group). Except the control group, the rats in the other four groups were all received CMS modeling for 21 days. Twenty-one days after CMS modeling, rats were intraperitoneally injected with 0.9% normal saline (10 mg·kg -1·d -1), fluoxetine (20 mg·kg -1·d -1), salvia acid(40 mg·kg -1·d -1), fluoxetine(20 mg·kg -1·d -1)+ salvia acid(40 mg·kg -1·d -1)for 21 days. During the administration period, rats in the other four groups continued to receive CMS intervention for 21 days. Forced swimming test and sucrose preference test were conducted at baseline (day 0), after modeling (day 21) and after intervention (day 42) so as to evaluate depression like behavior. Then the rats were sacrificed and the hippocampus and prefrontal cortex were taken. The mRNA levels of Toll like receptor 4 (TLR4) and myeloid differentiation primary response 88 (MyD88) were detected by RT-qPCR. The cytokines including interleukin-1β(IL-1β), interleukin-2(IL-2), interferon-γ (IFN-γ) and tumor necrosis factor-α (TNF-α) were detected by Luminex technique.SPSS 21.0 was used for statistical analysis.Repeated measurement ANOVA was used for behavioral data analysis, one-way ANOVA was used for molecular index data analysis, and Spearman was used for correlation analysis. Results:The results of repeated measurement ANOVA showed that the interaction effects between group and time of body mass, sucrose preference, forced swimming immobility time were significant at baseline, after modeling and after intervention ( F=18.238, 6.921, 7.591, all P<0.05). After modeling, compared with nCMS+ Nal group, the rats in CMS+ Flu group, CMS+ Sal group, CMS+ Flu+ Sal group and CMS+ Nal group had lower body weight, lower sucrose preference rate and longer forced swimming immobility time (all P<0.05). After intervention, compared with CMS+ Nal group(body weight (350.15±41.65)g, sucrose preference(52.95±11.13)%, static time(91.40±15.22)s), the body weight((378.21±30.78)g, (385.12±43.19)g, (391.41±31.21)g, (402.33±18.67)g, all P<0.05) and sucrose preference((69.30±15.56)%, (68.12±10.99)%, (71.18±9.51)%, (75.47±11.55)%, all P<0.05) of CMS+ Flu group, CMS+ Sal group, CMS+ Flu+ Sal group and nCMS+ Nal group were all increased, while the forced swimming immobility time ((68.81±21.74)s, (66.10±25.51)s, (63.53±22.32)s, (71.21±21.41)s, all P<0.05) were shorter (all P<0.05). After intervention, among the body weight, sucrose preference and the immobility time of CMS+ Flu group、CMS+ Sal group and CMS+ Flu+ Sal group, there were no differences between each two groups(all P>0.05). After intervention, the levels of TLR4 mRNA and MyD88 mRNA in prefrontal cortex and hippocampus of CMS+ Flu group, CMS+ Sal group, CMS+ Flu+ Sal group and nCMS+ Nal group were all lower than those in CMS+ Nal group (all P<0.05). In prefrontal cortex, the levels of TLR4 mRNA (0.715±0.358) and MyD88 mRNA (0.739±0.233) in CMS+ Flu+ Sal group were lower than those in CMS+ Sal group (1.943±0.606, 1.815±0.897) (both P<0.05). The level of TLR4 mRNA in prefrontal cortex and hippocampus of rats were positively correlated with the level of MyD88 mRNA and TNF-α level and forced swimming immobility time and negatively correlated with sucrose preference rate (prefrontal cortex r=0.915, 0.041, 0.027, -0.178, all P<0.05; hippocampus r=0.810, 0.070, 0.011, -0.153, all P<0.05). Conclusion:The antidepressant effect of salvianolic acid is presumedly achieved by inhibiting the immunoinflammatory response mediated by the TLR4/Myd88 signaling pathway in CMS rats.

Objective:To investigate whether short chain fatty acid(SCFAs) intervention has an antidepressant effect by improving gut microbiota dysregulation and regulating the TLR4/MyD88/NF-κB inflammatory pathway in depression model mice.Methods:Totally 60 SPF grade male C57BL/6 J mice aged 6-8 weeks were randomly divided into three groups: control group, depression model group, and SCFAs group, with 20 mice in each group.The mice in depression model group and SCFAs group were given the chronic unpredictable mild stress (CUMS) stimulations for 8 weeks to establish the depression model.From the 6th week, SCFAs group mice were given a mixed solution of short chain fatty acid salts for drinking, until modeling was completed, meanwhile mice in the model group were given 0.78% NaCl solution for drinking.The depression-like behavior was assessed using the sucrose preference test (SPT) and forced swimming test (FST) following modeling, and the open field test (OFT) was employed to evaluate the anxiety-like behavior of mice.16S rRNA gene sequence was used to analyze the gut microbiota of mice.The activation of astrocytes and TLR4/MyD88/NF-κB inflammatory pathway in hippocampus was determined by immunofluorescence staining and Western blot.SPSS 26.0 was used for statistical analysis, one-way ANOVA was used for comparison among the three groups, and LSD- t test was used for further pairwise comparisons. Results:There were statistically significant differences in the sugar water preference rate, the immobility time in FST, and the percentage of activity time in OFT among the three groups ( F=10.554, 10.912, 12.599, all P<0.05).The the sugar water preference rate and the percentage of activity time in OFT of the depression model group were both lower than those of the control group (both P<0.05), and the immobility time in FST was higher than that of the control group ( P<0.05).The sugar water preference rate in SCFAs group((84.7±3.5)%, (75.3±6.0)%)and the percentage of activity time in OFT((7.4±1.4)%, (3.2±0.9)%) were both higher than those in the depression model group(both P<0.05 ), while the immobility time in FST was shorter than that in the depression model group((110.5±21.5) s, (148.0±20.1) s, P<0.05).There was a statistical difference in the β diversity of gut microbiota among three groups ( P=0.001).At the family level, compared with the depression model group, the relative abundance of Rikenellaceaee and Bacteroidaceae increased in the SCFAs group, while the relative abundance of Clostridia_UCG-014 decreased.At the genus level, the relative abundance of Clostridia_UCG-014 and Prevotella decreased, while the relative abundance of Alistipes increased (all P<0.05).The immunofluorescence results showed that there was a statistically significant difference in GFAP expression levels among the three groups of mice ( F=16.565, P=0.004).The GFAP expression in the depression model group was higher than that in the control group and SCFAs group (both P<0.05).The Western blot results showed that there were statistically significant differences in the expression levels of TLR4, MYD88, and NF-κB ptoteins in the hippocampal tissue of the three groups ( F=70.59, 174.39, 14.40, all P<0.05).The protein levels of TLR4, MyD88, and NF-κB in the depression model group were all higher than those in the control group and SCFAs group (all P<0.05). Conclusion:SCFAs can ameliorate the depressive-like behavior in depression model mice and reduce the activation of astrocytes in the hippocampus, which may be associated with the improvement of dysregulated gut microbiota and down-regulation of the TLR4/MyD88/NF-κB pathway protein.

Objective:To explore the relationship between marital status and mild cognitive impairment in older adults.Methods:This study is a cluster random sampling.From January to December 2020, a questionnaire survey was conducted among older adults aged 60 years and over in four cities of Hebei Province.Finally, 2690 older adults with mild cognitive impairment and normal cognitive function were enrolled.The older adults were divided into 2 groups according to their marital status: married and living with their spouses(group E1), divorced or living alone(group E2). The mini-mental state examination(MMSE)scores of older adults in the two groups were compared.Moreover, the cognitive differences of older adults between the two groups and the interaction of marital status, social activities and life events on cognitive outcomes were analyzed.Results:The married older adults with partners had better cognitive preservation( P<0.01). The more life events were more likely to cause cognitive impairment( P<0.01), and the interaction of marital status, social activities and life events had a significant impact on cognition( P<0.01). Older men who were married and lived with spouse had better cognition than older women who were married and lived with spouse( P<0.05 in Model 3). The cognition of widowed elderly women was better than those of widowed elderly men( P<0.1 in Model 1; P<0.1 in Model 2). Among elderly men, the cognition of those married and living with spouse was better than that those of widowed( P<0.01 in models 1 and 2, P<0.1 in model 3). Among elderly women, those married and living with spouse had better cognitive outcomes than those widowed( P<0.01 in Model 1, P<0.01 in Model 2). Conclusions:Marital companionship is a protective factor for the cognition of older adults, and there are gender differences in the impact of marital status on cognition in late life.

Objective To investigate the effect of prenatal stress (PS) at different pregnant time on emotion and cognition of adult offspring rats.Methods Twelve healthy female Sprague Dawley (SD) rats were randomly divided into control group(CON,n=4),the early pregnancy group(PS1,the 1～ 7 days of pregnancy,n=4) and the late pregnancy group(PS3,the 15 ～ 21 days of pregnancy,n=4).The pregnant rats were exposed to single-prolonged stress(SPS) on gestational day 7 or 15 respectively,except control group.The offspring were measured every weekend from 1-7 week after birth.At the eighth weekend,the sucrose intake (anhedonia) and Morris water maze (MWM) were performed to assess depression-like behavior and spatial learning and memory.Results The body weight of the first to seventh weeks after birth showed that there was a statistically significant difference among the three groups (F=28.207,P＜0.01),and there was a significant difference in time effect (F=1 041.546,P＜0.01).The body weight of two PS groups was significantly lower than those of control group(P＜0.05).The body weight of PS3 was lower than that of PS1 significantly(P＜0.05).Sucrose preference:PS3((27.70± 19.31) ％) were reductive on sucrose consumption than CON significantly((66.93±19.67) ％)(P＜0.05)while PS1 ((89.80±6.79) ％) increased in sucrose consumption compared with the CON significantly(P＜0.05).MWM:in training stage the difference of average avoid latency was existed in the three groups of the first 5 days(F=11.121,P＜0.01).Similarly,there was a significant difference in measure time(F=91.327,P＜0.01),the escape latency of the PS3 was decreased,while PS1 was significantly increased compared with CON;in testing stage,PS3 ((54.50±4.64) s,(53.21±4.45)) showed a significant increase in the duration in target site and numbers of times across the target site compared with CON((32.24±.4.17) s,(31.68±4.00)) (P＜0.05).Conclusion The acceptance of stress in the late pregnancy may lead to depression like behavior in the adult offspring and also enhance the learning and memory ability.And acceptance of stress in early pregnancy can cause impairment of learning and memory ability in adult offspring rats.