Antidepressant effects of Yuanzhi (Polygalae Radix) extract on chronic unpredictable mild stress-induced depression in rats: modulation of the NLRP3 inflammasome and NF-κB pathway

Objective To investigate the antidepressant effects of Yuanzhi(Polygalae Radix;PR)aqueous extract on chronic unpredictable mild stress(CUMS)-induced depression rat models and the underlying mechanisms.Methods A total of 40 male Sprague Dawley(SD)rats were randomly divided into control;model;low dose of PR(PR-L;0.5 g/kg);high dose of PR(PR-H;1 g/kg);and fluoxetine(10 mg/kg)groups;with 8 rats in each group.Except for the rats in control group;those in the other four groups underwent CUMS-induced depression modeling.PR and fluoxetine were administered intragastrically once daily;30 min prior to the CUMS procedure;for 14 consecu-tive days until the behavioral tests were performed.After CUMS modeling;the sucrose prefer-ence test(SPT);open field test(OFT);novelty-suppressed feeding test(NSFT);forced swim test(FST);and tail suspension test(TST)were employed to assess the pharmacological ef-fects of PR on the mitigation of depressive-like behaviors in rat models.Additionally;the en-zyme-linked immunosorbent assay(ELISA)was utilized to quantify the serum levels of tumor necrosis factor(TNF)-α;interleukin(IL)-6;and IL-1βin the rats.Western blot analysis was al-so conducted to evaluate the protein expression levels of nuclear factor kappa-B(NF-κB);in-ducible nitric oxide synthase(iNOS);cyclooxygenase-2(COX-2);nucleotide-binding oligomerization domain(NOD)-like receptor family pyrin domain containing 3(NLRP3);apoptosis-associated speck-like protein containing caspase recruitment domain(ASC);and caspase-1 in the hippocampal tissues of the rats.Immunofluorescence staining was per-formed to observe the morphological changes in ionized calcium-binding adapter molecule 1 positive(Iba-1+)cells in the dentate gyrus(DG)of rats with CUMS-induced depression.Results(i)Treatment with PR-H and fluoxetine resulted in significant enhancements in both the total distance and time the rats moved during tests(P<0.01 and P<0.05;respectively).Post-administration of PR-H and fluoxetine also led to statistically significant increase in su-crose preference among rats(P<0.05).Besides;PR-L;PR-H;and fluoxetine treatment markedly decreased the latency of ingestion(P<0.05;P<0.05;and P<0.01;respectively).As observed from the FST;PR-L;PR-H;and fluoxetine presented antidepressant effects on rats with CUMS-induced depression;leading to the reduction in time of their immobility(P<0.05;P<0.01;and P<0.01;respectively).The results of TST indicated reduced immobility time in rats receiving PR-H and fluoxetine treatment as well(P<0.01).(ii)Rats in model group showed an increase in the levels of Iba-1+microglia in their left and right brains in compari-son with control group(P<0.01).However;such increase was negated post PR treatment(P<0.01).Treatment with PR-L;PR-H;and fluoxetine considerably reduced the levels of inflam-matory factors(TNF-α;IL-1β;and IL-6;P<0.01).In addition;treatment of PR-L and PR-H ef-fectively counteracted the elevated levels of NLRP3;ASC;and caspase-1;and markedly down-regulated the expression levels of phosphorylated p65(p-p65);COX-2;and iNOS in rats’hip-pocampus(P<0.01).Conclusion Collectively;these findings indicate that PR exerts an antidepressant effect on rats with CUMS-induced depression partially through the modulation of the NLRP3 and NF-κB signaling pathways.

Dynamic changes of behaviors, dentate gyrus neurogenesis and hippocampal miR-124 expression in rats with depression induced by chronic unpredictable mild stress

The depression-like behavior phenotype,neurogenesis in the dentate gyrus and miR-124 expression in the hippocampus are the focus of current research on the pathogenesis of depression and antidepressant therapy.The present study aimed to clarify the dynamic changes of depression-like behavior,dentate gyrus neurogenesis and hippocampal miR-124 expression during depression induced by chronic stress to reveal pathological features at different stages of depression and to further provide insight into depression treatment.Chronic unpredictable mild stress depression models were established by exposing Sprague-Dawley rats to various mild stressors,including white noise,thermal swimming,stroboscopic illumination,soiled cages,pairing with three other stressed animals,cold swimming,tail pinch,restraint and water and food deprivation.Chronic unpredictable mild stress model rats underwent dynamic observation from 1 to 8 weeks and were compared with a control group(normal feeding without any stressors).To observe changes in the depression-like behavior phenotype during chronic unpredictable mild stress-induced depression,a sucrose preference test was used to evaluate the degree of anhedonia.An open-field test was used to evaluate locomotor activity and anxiety status.Compared with the control group,chronic unpredictable mild stress rats lost weight but did not have a depression-like behavioral phenotype at 1-4 weeks.Chronic unpredictable mild stress rats presented decreased sucrose preference and locomotor activity at 5-8 weeks.In addition,chronic unpredictable mild stress rats did not have significant anxiety-like behavior during 1-8 weeks of modeling.To observe neurogenesis dysfunctions and changes in neuronal number in the dentate gyrus during chronic unpredictable mild stress-induced depression,markers(DCX and DCX/BrdU)of neural proliferation and differentiation and the neuronal marker NeuN were assessed by immunofluorescence.Compared with the control group,neurogenesis and the neuronal number in the dentate gyrus did not change from 2 to 6 weeks;however,neural proliferation and differentiation in the dentate gyrus decreased,and the number of neurons decreased until the eighth week in the chronic unpredictable mild stress group.Real-time quantitative reverse transcription polymerase chain reaction assays and fluorescence in situ hybridization were used to measure the expression of hippocampal miR-124 during chronic unpredictable mild stress-induced depression.The results showed that the expression of hippocampal miR-124 was unchanged during the first 4 weeks but increased from 5 to 6 weeks and decreased from 7 to 8 weeks compared with the control group.These findings indicate that during chronic unpredictable mild stress-induced depression,the behavioral phenotype,miR-124 expression in the hippocampus,neurogenesis in the dentate gyrus and neuronal numbers showed dynamic changes,which suggested that various pathological changes occur at different stages of depression.All experimental procedures and protocols were approved by the Experimental Animal Ethics Committee of Guangzhou University of Chinese Medicine of China in March 2015.

Glutamate Transporter 1-mediated Antidepressant-like Effect in a Rat Model of Chronic Unpredictable Stress

In recent years, more attention has been paid to the role of the glutamate transporter 1 （GLT-1, EAAT2） in major depressive disorder （MDD）. However, experimental data on brain GLT-1 levels are, to some extent, inconsistent in human postmortem and animal studies, These discrepancies imply that the role of GLT-1 in the pathophysiology of MDD and the action of antidepressants remain obscure. This work was designed to study the impact of chronic unpredictable stress （CUS） for 2 ses- sions per day for 35 days and four weeks of fluoxetine （FLX） on depressive-like behaviors in rats, as well as the concomitant expression of the GLT-1 protein in the hippocampus. Behavioral changes were assessed by the sucrose preference and open field tests. GLT-1 levels were detected by immunohisto- chemistry and Western blot analysis. Our study demonstrated that the animals exposed to CUS showed depressive-like behaviors and exhibited a significant decrease in GLT-1 expression in the hippocampus. Chronic FLX treatment reversed the behavioral deficits and the CUS-induced decrease in GLT-1 levels. Taken together, our results support the reduction of GLT-1 in human postmortem studies in MDD and suggest that GLT-1 may be involved in the antidepressant activity of FLX. Our studies further support the notion that GLT-1 is an attractive candidate molecule associated with the fundamental processes of MDD and may be a potential, and novel pharmacological target for the treatment of MDD.

Optimization of food deprivation and sucrose preference test in SD rat model undergoing chronic unpredictable mild stress

Background:The chronic unpredictable mild stress(CUMS)model has long been considered the best model for exploring the pathophysiological mechanisms underlying depression.However,there are no widely recognised standards for strategies for modeling and for behavioral testing.The present study aimed to optimize the protocols for food deprivation and the sucrose preference test(SPT)for the CUMS model.Methods:We first evaluated the effects of different long periods of food deprivation on the body weight of Sprague Dawley(SD)rats by testing food deprivation for 24 hours(8:00-8:00^+),food deprivation for 12 hours during the daytime(8:00-20:00)and food deprivation for 12 hours at night(20:00-8:00^+).Next,we established a SD rat CUMS model with 15 different stimulations,and used body weight measurement,SPT,forced swim test(FST),open field test(OFT)and Morris water maze(MWM)test to verify the success of the modeling.In the SPT,consumption of sucrose and pure water within 1 and 12 hours was measured.Results:Twelve hours of food deprivation during the daytime(8:00-20:00)had no effect on body weight,while 12 hours of food deprivation at night(20:00-8:00^+)and 24 hours of food deprivation(8:00-8:00^+)significantly reduced the mean body weight of the SD rats.When SPT was used to verify the successful establishment of the CUMS rat model,sucrose consumption measured within 12 hours was less variable than that measured within 1 hour.Conclusions:Twelve hours of food deprivation in the daytime(8:00-20:00)may be considered a mild stimulus for the establishment of a CUMS rat model.Measuring sucrose consumption over 12 hours is recommended for SPT.

Effect and mechanism of LW-AFC on chronic unpredictable mild stress-induced mood and cognition impairment of mice

OBJECTIVE To explore the effect and mechanisms of LW-AFC,a new formula derived fromLiuwei Dihuang decoction,on chronic unpredictable mild stress(CUMS)-induced mood and cogni.tion impairment in mice.METHODS C57 BL/6 J mice were randomly placed into seven groups(n=10):normal control group,CUMS group,Fluoxetine(10 mg·kg^(-1),once per day) group,Liuwei Dihuang decoction group(LW,10 g·kg^(-1),once per day),and LW-AFC(0.8 g·kg^(-1),1.6 g·kg^(-1),3.2 g·kg^(-1),once per day) group.The stressed group was given CUMS for 4 weeks to set up a chronic multiple-stressed model.LW and LW-AFC was oral administered a week prior to CUMS and until the end of the study(a total of 35 d),while fluoxetine was administrated orally for 4 weeks.The anxiety behavior was analyzed using the open field test(OFT) and elevated plus maze test(EPM).The depression behavior was ana.lyzed using the sucrose preference test(SPT) and forced swimming test(FST).Spatial cognition was evaluated using Morris water maze(MWM) test and working memory was evaluated using new object recognition test(NORT).RESULTS CUMS for 28 d increased depressive-and anxiety-like behaviors.LW-AFC(1.6 g·kg^(-1)) significantly increased the numbers of entries into the open arm and time in the open arm of CUMS mice(P<0.05).LW-AFC(3.2 g·kg^(-1)) increased sucrose consumption and de.creased the immobility time of FST(P<0.01) of CUMS mice.The MWM test showed that spatial learning andmemory in CUMS mice were remarkably affected relative to controls,whereas LW-AFC(3.2 g·kg^(-1)) im.proves cognitive functions(P<0.05).CONCLUSION The mood and theability of learning and memory of thestressed group can be affected after exposure to CUS.Oral administration of LW-AFC significant.ly improved CUMS-induced impairments of mood and cognition in mice.

Shuganheweitang Ameliorates Chronic Unpredictable Mild Stress-Induced Depression-Like Behaviors in Rats through the PI3K/AKT/mTOR Pathway: Involvement of Amino Acids, Glycerophospholipids, and Energy Metabolism

Background: Depression is a typical psychosomatic disease. Shuganheweitang (SGHWT) is a clinical formula that effectively treats depression. However, the potential mechanism used by SGHWT to ameliorate depression-like behaviors is still unclear. This study investigated the effects of SGHWT on metabolic change in the liver and hypothalamus with signaling pathways involved in chronic unpredictable mild stress (CUMS)-induced depression in rats to explore the mechanism of the anti-depressive effect. Methods: A total of 52 rats were used to create a model of depression by CUMS combined with solitary rearing for 6 weeks. Open field test (OFT), sucrose preference test (SPT), forced swim test (FST), and body weight (BW) were performed to analyze the pharmacodynamic effects of SGHWT. H&E staining, Nissl staining, immunofluorescence, immunohistochemistry, and western blot were used to evaluate the mechanism of action. Untargeted metabolomics techniques by ultra-performance liquid chromatography-quantitative time-of-flight tandem mass spectrometry (UPLC-Q-TOF-MS/MS) were used to analyze all the metabolic differences in the liver and hypothalamus. Results: SGHWT improved CUMS-induced depression-like behaviors in vivo. SGHWT reduced hepatic c-Fos protein expression and increased hypothalamic c-Fos protein expression. Moreover, p-PI3K, p-AKT473, p-AKT308, and p-mTOR protein expressions were significantly downregulated in the liver and hypothalamus of CUMS rats. Notably, these alterations were reversed by the SGHWT administration. Furthermore, the metabolomic analysis identified 15 and 5 key differential SPT-associated metabolites in the liver and hypothalamus, respectively. Conclusion: This study suggests that SGHWT ameliorates chronic unpredictable mild stress-induced depression-like behaviors, by the involvement of amino acids, glycerophospholipids, energy metabolism, and the PI3K/AKT/mTOR pathway. Highlights: 1) Shuganheweitang was derived from the TCM herbal formula Sinisan. 2) SGHWT treatment reverses depression-like behaviors in CUMS-induced rats. 3) The mechanism of SGHWT on depression by the liver and hypothalamus metabolomics. 4) SGHWT regulates amino acids, glycerophospholipids, and energy metabolism. 5) SGHWT exerts antidepressant effects through the PI3K/AKT/mTOR pathway.

Jobelyn^(■), a Sorghum-Based Nutritional Supplement Attenuates Unpredictable Chronic Mild Stress-Induced Memory Deficits in Mice

The ability of an organism to adapt to aversive stressful situations or life challenging circumstances is very crucial to its state of health and survival. However, breakdown in adaptation due to persistent uncontrollable stress, leads to impairment of bodily functions and onset of a variety of pathological disorders especially memory decline. This study was designed to evaluate the effect of Jobelyn&reg;(JB), a potent antioxidant sorghum-based food supplement on unpredictable chronic mild stress (UCMS)-induced memory impairment in mice. Male Swiss mice were given JB (5 - 50 mg/kg, p.o) 30 min prior to exposure to UCMS for 14 consecutive days before testing for memory. Thereafter, the serum corticosterone level was estimated by using ELISA kits. The levels of malondialdehyde (MDA) and glutathione (GSH) as well as acetylcholinesterase activity were estimated in the brain homogenate using spectrophotometer. Histology of the brain tissues and estimation of the populations of viable neurons in the hippocampal region were done after staining with hematoxyline and eosin. Our results showed that JB reversed memory impairment and suppressed corticosterone concentrations induced by UCMS. Moreover, JB reduced oxidative stress in the brain of UCMS-mice as shown by decreased MDA levels and elevated GSH concentrations. It also decreased brain acetylcholinesterase activity when compared with chronic stress group (p < 0.05). Furthermore, JB (5 - 10 mg/kg, p.o) offered significant protection against UCMS-induced degeneration and death of neuronal cells of the cornu ammonis 3 (CA3) of the hippocampal region of the brain indicating neuroprotection. Taken together, these findings suggest that JB attenuates memory deficits induced by UCMS in mice and may be useful therapeutically for stress-related cognitive dysfunctions. The reduction in the levels of serum corticosterone, antioxidation, neuroprotection and inhibition of cholinesterase enzyme might be contributing significantly to the positive effect of JB on memory in mice exposed to unpredictable chronic mild stress.

L-tyrosine improves neuroendocrine function in a mouse model of chronic stress

Adult BALB/c mice, individually housed, were stimulated with nine different stressors, arranged randomly, for 4 continuous weeks to generate an animal model of chronic stress. In chronically stressed mice, spontaneous locomotor activity was significantly decreased, escape latency in the Morris water maze test was prolonged, serum levels of total thyrotropin and total triiodothyronine were significantly decreased, and dopamine and norepinephrine content in the pallium, hippocampus and hypothalamus were significantly reduced. All of these changes were suppressed, to varying degrees, by L-tyrosine supplementation. These findings indicate that the neuroendocrine network plays an important role in chronic stress, and that L-tyrosine supplementation has therapeutic effects.

Vitamin D_(3) attenuates anxiety-like behavior in long-term ovariectomized rats with unpredictable mild stress

The impact of various vitamin D3(VD3)doses(1.0,2.5,or 5 mg/kg,s.c.)in mitigating the negative consequences of chronic unpredictable mild stress(CUMS)was investigated.Adult female rats with long-term estrogen deficiency were assessed using the sucrose preference test(SPT),the elevated plus-maze(EPM),the light/dark test(LDT),and the open-field test(OFT)to measure anhedonia-like and anxiety-like behavior.The corticosterone(CS)and adrenocorticotrophic hormone(ACTH)concentrations in blood serum and the brain-derived neurotrophic factor(BDNF)expression in the hippocampus of long-term ovariectomized(OVX)rats were measured by ELISA kits and/or western blotting.Treatment with VD3(5.0 mg/kg),similarly to fluoxetine(10.0 mg/kg),significantly reduced the anhedonia profile in the SPT and anxiety-like behavior in the EPM and LDT,and CS and ACTH levels in blood serum.It also elevated BDNF levels in the hippocampus of long-term OVX/CUMS compared to OVX/CUMS/solvent rats.Thus,these findings suggest that VD3(5.0 mg/kg)administration might attenuate the anxiety-like profile in long-term OVX adult rats subjected to the CUMS.This might occur via activation of the BDNF signaling pathway in the hippocampus and via restoration of CS and ACTH levels in blood serum.

抑郁症CUS模型大鼠海马CA1区及CA3区内树突棘数目减少

目的采用慢性不可预知性应激(chronic unpredictable stress,CUS)模型建立抑郁症大鼠模型,对抑郁症CUS模型大鼠海马CA1及CA3区体积及其内树突棘素阳性(spinophilin^+)树突棘的密度、数目进行精确定量研究,探讨海马CA1及CA3区内树突棘的改变在抑郁症中的作用。方法雄性Sprague-Dawley(SD)大鼠,糖水适应性训练后剔除糖水偏好不稳定的大鼠,将剩余大鼠随机分为空白对照组和抑郁模型组,采用孤养结合CUS的模式建立抑郁症大鼠模型,为期4周。筛选出成模大鼠后每组随机选取5只大鼠,利用免疫组织化学方法结合体视学方法进行定量分析。结果应激第4周末,抑郁模型组大鼠的体质量、糖水偏好百分比以及旷场总评分均显著低于空白对照组;抑郁模型组大鼠海马CA1及CA3区体积无明显改变;抑郁模型组大鼠海马CA1和CA3区内树突棘的密度及总数目显著少于空白对照组。结论抑郁症CUS模型大鼠海马CA1和CA3区内树突棘的密度、总数目显著减少,提示抑郁模型组大鼠海马CA1和CA3区内树突棘数量上的改变可能是抑郁症病理改变的重要的神经生物学基础之一,由此为将来寻找治疗抑郁症的新靶点提供了理论依据。

基于肝脏代谢组学的酸枣仁汤抗抑郁作用机制研究

采用LC-MS代谢组学技术,分析酸枣仁汤对慢性不可预知温和应激(CUMS)抑郁大鼠肝脏内源性代谢物调控作用,探索酸枣仁汤抗抑郁的作用机制。将大鼠随机分为正常组、模型组、酸枣仁汤低剂量组、酸枣仁汤高剂量组和阳性药组,采用禁食、禁水、冰水游泳、热水游泳、昼夜颠倒、夹尾、束缚等刺激,复制CUMS大鼠抑郁模型,造模与给药持续56d。观察各组大鼠行为学指标(大鼠体质量、旷场实验、糖水偏好实验和悬尾实验),收集大鼠血浆和肝脏组织,采用酶联免疫吸附测定(ELISA)检测血浆中5-羟色胺(5-HT)、多巴胺(DA)、去甲肾上腺素(NE)的含量,采用LC-MS代谢组学方法分析酸枣仁汤对CUMS模型大鼠肝脏代谢轮廓的调节作用。结果显示酸枣仁汤能显著改善CUMS模型大鼠的抑郁样行为,升高血浆中5-HT、DA、NE的神经递质水平;通过LC-MS代谢组学技术在肝脏中鉴定出24种差异代谢物,酸枣仁汤能回调其中的13种;代谢通路分析共筛选得到9条与抑郁显著相关的代谢通路,酸枣仁汤低剂量组能调节其中的4条,包括戊糖磷酸途径、嘌呤代谢、磷酸肌醇代谢、鞘脂代谢;酸枣仁汤高剂量组能调节其中的2条,包括鞘脂代谢和甘油磷脂代谢。鞘脂代谢是酸枣仁汤在不同剂量下均可调节的代谢通路,推测可能是其改善CUMS模型大鼠肝脏代谢紊乱的主要途径。

慢性应激对小鼠下丘脑食欲调节因子的影响

目的观察小鼠在慢性应激时及应激停止后下丘脑食欲调节因子的变化,并初步探索应激依赖性的食欲变化机制。方法将32只雄性C57BL/6小鼠随机分为对照(Ctrl)组及慢性不可预知温和应激(CUMS)组,每组16只。CUMS组小鼠予以CUMS(持续11周)建立应激模型,Ctrl组正常饲养。记录小鼠摄食量和体重。通过悬尾实验和强迫游泳实验验证CUMS模型是否构建成功。第12周时从两组各随机取8只小鼠收集全脑、下丘脑组织待测;两组各剩余的8只小鼠重新编组为应激停止(C-CUMS)组和应激停止对照(C-Ctrl)组,继续观察3周后,取全脑、下丘脑组织待测。通过qPCR和免疫组织化学染色方法检测小鼠下丘脑中食欲调节因子食欲素1型受体(OX1R)、瘦素受体(LEPR)和刺鼠相关蛋白(AgRP)的表达情况。结果应激第2~11周,CUMS组小鼠累积摄食量高于Ctrl组(均P<0.05),11周内两组小鼠体重差异无统计学意义(均P>0.05)。11周后CUMS组小鼠悬尾不动时间和水中漂浮时间均长于Ctrl组小鼠(均P<0.01),提示造模成功。造模成功后,CUMS组小鼠下丘脑组织中促食欲因子AgRP mRNA、OX1R mRNA表达量高于Ctrl组(均P<0.01),抑食欲因子LEPR mRNA表达量低于Ctrl组(P<0.01);CUMS组小鼠下丘脑弓状核中AgRP蛋白表达水平高于Ctrl组(P<0.05),LEPR蛋白表达水平低于Ctrl组(P<0.01)。应激停止3周后,C-CUMS组小鼠累积摄食量少于C-Ctrl组(P<0.05),体重低于C-Ctrl组(P<0.05)。C-CUMS组小鼠LEPR mRNA表达量高于C-Ctrl组(P<0.01),AgRP mRNA、OX1R mRNA表达量与C-Ctrl组相比差异无统计学意义(均P>0.05);C-CUMS组小鼠AgRP蛋白表达水平与C-Ctrl组比较差异无统计学意义(P>0.05),LEPR蛋白表达水平高于C-Ctrl组(P<0.01)。结论CUMS导致小鼠食欲增加,其机制可能与LEPR和AgRP的功能调节有关;应激停止后其食欲下降,机制可能涉及LEPR的功能调节。

心理应激相关非酒精性脂肪性肝病小鼠模型的建立及四逆散的治疗效应研究

目的建立心理应激相关非酒精性脂肪性肝病小鼠模型并探讨四逆散的治疗效应。方法40只雄性C57 BL/6J小鼠随机区分为空白组(CON)、高蔗糖富含胆固醇饮食组(CHR)、复合模型组(CS+CHR)、百洛特组(BLT)、四逆散组(SNS)。除CON组外,其余各组小鼠均给予CHR饮食,且CS+CHR组、BLT组、SNS组每天随机给予2种不同应激,共60 d。BLT组、SNS组于造模后30 d进行灌胃给药。观察小鼠行为学变化,计算肝指数、胸腺指数、脂肪指数,检测肝组织TC、TG含量,油红O、HE染色观察肝组织病理改变,检测血清皮质酮(CORT)、醛固酮(ALD)、胰岛素(INS)、胰高血糖素(GCG)含量。结果与CON组相比,CHR组脂肪指数、TC含量升高(P<0.05),CS+CHR组直立次数下降(P<0.05),脂肪指数及TC、TG、CORT、ALD、GCG含量显著增高(P<0.01);与CHR组相比,CS+CHR组直立次数下降(P<0.05),TC、TG、ALD、INS、GCG含量显著增高(P<0.01);与CS+CHR组相比,SNS散组直立次数回升(P<0.05),TG、ALD含量显著降低(P<0.01),BLT组脂肪指数、TC含量降低(P<0.05),ALD含量显著降低(P<0.01)。油红O染色结果显示,CS+CHR组可见少量脂滴,BLT组与SNS组均有减轻;而HE石蜡染色结果显示,CHR组可见少量大小不等、数量不一的圆形空泡,部分肝细胞核被挤压向肝细胞一侧,CS+CHR组可见大量大小不等、数量不一的圆形空泡,脂滴数量较多,部分肝细胞核被挤压向肝细胞一侧,而BLT组与SNS组均有减轻。结论CUMS联合CHR饮食可以更好地构建心理应激相关NAFLD小鼠模型,四逆散改善此疾病可能与其降低血清醛固酮含量相关。

红笛鲷粗蛋白寡糖复合粉预防小鼠抑郁样行为及相关损伤的作用

该研究选用红笛鲷粗蛋白与低聚麦芽糖、低聚果糖和半乳低聚木糖组成的复合粉(PRSP)饲喂慢性不可预知温和应激(chronic unpredictable mild stress,CUMS)模型小鼠,探究其预防抑郁样行为及机体相关损伤的作用。将80只小鼠平均分为空白对照组(CON)、模型组(CUMS)、氟西汀对照组(FLU)、复合粉干预组(PRSP)。模型组小鼠以CUMS进行42 d造模,造模同时给予部分小鼠灌胃1.8 g/(kg·d)PRSP,以10 mg/(kg·d)氟西汀为阳性对照。饲喂结束后对各组小鼠进行行为学测试、结肠切片苏木精-伊红染色和免疫组化染色观察、血清中内毒素(lipopolysaccharides,LPS)、D-乳酸(D-lactic acid,D-LA)、肿瘤坏死因子(tumor necrosis factor-α,TNF-α)、白细胞介素6(interleukin-6,IL-6)、IL-1β和IL-10含量测定、结肠内容物样本菌群高通量测序和生物信息学分析。CUMS造模引起了小鼠行为指标异常,结肠损伤评分升高,肠上皮黏液蛋白2表达显著降低,血清中D-LA、LPS、TNF-α、IL-1β和IL-6水平显著上升,CUMS组小鼠结肠内容物特有分类单元数目显著下降,厚壁菌门(Firmicutes)与拟杆菌门(Bacteroidetes)丰度之比显著升高,CUMS小鼠结肠中毛螺菌属(Lachnospiraceae)与罗氏菌属(Oscillibacter)丰度显著下降、另枝菌属(Alistipes)丰度显著上升,菌群谷氨酸、谷氨酰胺、酪氨酸、苏氨酸、半乳糖、果糖、蔗糖、麦芽糖代谢通路基因丰度显著升高,PRSP干预后上述指标均恢复到空白对照组水平。该复合粉可以抑制慢性应激诱发的小鼠结肠菌群结构紊乱及其特定的氨基酸和糖代谢异常升高,并阻止机体系统炎症及结肠损伤的发生,对抑郁样行为起到很好的预防作用,研究结果可为高效安全预防抑郁症的食物源产品的开发提供理论支撑。

电针干预对CUS大鼠抑郁样行为及海马内源性大麻素相关基因表达的影响

目的:探讨电针刺激对慢性不可预见性应激(CUS)大鼠抑郁行为的改善作用及内源性大麻素受体1(CB1)、二酰基甘油脂肪酶(DAGLα)、脂肪酰胺水解酶(FAAH)和单酰基甘油脂肪酶(MAGL)基因表达的影响。方法:24只SD大鼠随机分为对照组(Sham),模型组(CUS),模型+电针治疗组(CUS+EA),每组8只。CUS组以及EA+CUS组大鼠接受慢性不可预见性刺激处理(CUS)造模; EA+CUS组在造模第14 d开始给予电针干预,每天给予百会穴电针刺激30 min,电流1 m A,频率2/15 Hz疎密波,连续7 d; Sham组和CUS组给予假刺激;静养两周后,通过旷场,强迫游泳以及糖水偏好实验检测各组大鼠的抑郁样行为。行为学检测结束后处死大鼠,通过real time RT-PCR检测海马CB1受体、DAGLα、FAAH及MAGL的mRNA表达情况。结果:(1) CUS处理可以导致大鼠明显的抑郁样行为,包括进入旷场中心区次数和时间减少(P <0. 05),强迫游泳不动时间增加(P <0. 01),糖水摄取量下降(P <0. 05)。CUS组大鼠海马的CB1、DAGLα的mRNA表达下调(P <0. 05),而FAAH和MAGL表达上调(P <0. 05)。(2)电针刺激可以缓解CUS大鼠的抑郁样行为,CUS组与EA+CUS组之间存在显著性差异(P <0. 05)。(3)电针刺激可以恢复CUS大鼠海马的内源性大麻素相关基因表达水平。结论:电针刺激可以缓解CUS模型大鼠的抑郁样行为,调节抑郁模型大鼠海马的CB1受体和内源性大麻素代谢酶基因表达。

Integration of animal behaviors under stresses with different time courses

We used animal models of ＂forced swim stress＂ and ＂chronic unpredictable stress＂, and tried to reveal whether a passive coping style of high flotation behavior in forced swim stress predicts an- hedonia behavior after chronic unpredictable stress, and whether the dopamine system regulates floating and anhedonia behaviors. Our results confirmed that depression-prone rats use ＂floating behavior＂ as a coping strategy in forced swim stress and more readily suffer from anhedonia during chronic unpredictable stress. Intraperitoneal injection or nucleus accumbens microin- jection of the dopamine 2/3 receptor subtype agonist ropinirole reduced floating behaviors in depression-prone animals, but increased sucrose preference in rats showing anhedonia. These data indicate that floating behavior is a defensive mode that is preferred by susceptible individ- uals under conditions of acute stress. Simultaneously, these animals more readily experienced anhedonia under long-term stress; that is, they were more readily affected by depression. Our results suggest that dopamine 2/3 receptor subtypes in the nucleus accumbens play an important role in floating behaviors and anhedonia.

Increased expression level of corticotropin-releasing hormone in the amygdala and in the hypothalamus in rats exposed to chronic unpredictable mild stress

Objective Corticotropin-releasing hormone（CRH）plays an important role in neuroendocrine,autonomic and behavioral responses to stressors.In the present study,the effect of chronic unpredictable mild stress（CUMS）on CRH neurons was investigated in rat brain.Methods The rats were exposed to one of the stressors each day for 21 d.Immunostaining was performed to detect the CRH-positive neurons in the paraventricular nucleus（PVN）of the hypothalamus and in amygdala.Results After the stress protocol,the animals showed a reduction in body weight gain as well as reduced sucrose preference and locomotor activity.Interestingly,the CRH neurons in both PVN and central nucleus of the amygdala（CeA）were stimulated by CUMS.The densities of CRH-containing neurons in both PVN and CeA were significantly higher than those in control group.Conclusion The CRH systems in PVN and CeA may both contribute to depression-like behaviors during CUMS.

7.0 T MR GluCEST成像评估抑郁症模型鼠疗效的应用价值

目的探讨7.0 T磁共振谷氨酸化学交换饱和转移(glutamate chemical exchange saturation transfer,GluCEST)成像技术定量评估抑郁症模型大鼠治疗前后海马谷氨酸(glutamate,Glu)浓度变化的应用价值。材料与方法雄性SD大鼠36只,通过慢性不可预知轻度应激模型(chronic unpredictable mild stress,CUMS)诱导抑郁样行为,并随机分为3组:正常对照组、CUMS组、氟西汀(fluoxetine)给药组(CUMS-fluoxetine)。每组12只大鼠。采用糖水偏爱测试(sucrose preference test,SPT)、强迫游泳测试(forced swimming test,FST)及旷场测试(open field test,OPT)评价大鼠抑郁样行为。使用7.0 T小动物核磁共振扫描仪采集T2WI及GluCEST序列,用Matlab软件测定海马区Glu相对浓度值。将CUMS组与正常对照组、CUMS-fluoxetine组与CUMS组分别比较,三组大鼠双侧海马区分别进行组内比较,评估给药组的治疗效果。结果(1)行为学结果显示,CUMS组大鼠糖水偏爱率降低、强迫游泳测试不动时间延长及旷场测试运动距离减少,CUMS-fluoxetine组糖水偏爱率提高、强迫游泳测试不动时间减少及旷场测试运动距离增加。(2)GluCEST测定值结果显示,与正常对照组相比,CUMS组双侧海马区Glu浓度明显升高(左侧P<0.001,右侧P=0.014);与CUMS组相比,CUMS-fluoxetine组双侧海马区Glu浓度明显减低(左侧P=0.002,右侧P=0.025);三组大鼠双侧海马区分别进行组内比较,左、右侧海马区Glu浓度差异不具有统计学意义(P>0.05);CUMS-fluoxetine组海马区Glu浓度接近正常对照组。结论7.0 T MR GluCEST成像技术能够无创性定量反映抑郁症模型鼠治疗前后双侧海马区Glu浓度变化,为临床评估抑郁症疗效提供理论依据。

基于血清代谢组学和网络药理学整合策略探讨疏肝和胃汤抗抑郁作用机制

目的运用血清代谢组学与网络药理学技术挖掘疏肝和胃汤(Shuganheweitang,SGHWT)治疗抑郁症的相关代谢通路和作用靶点,探究疏肝和胃汤抗抑郁的作用机制。方法将40只SD雄性大鼠随机选择10只为正常对照组,剩余30只大鼠利用慢性不可预知温和刺激(Chronic unpredictable mild stress,CUMS)复刻抑郁大鼠模型,分为模型组、疏肝和胃汤组(7.34 g·kg^(-1)·d^(-1))和氟西汀组(1.58 mg·kg^(-1)·d^(-1)),每组10只,连续造模和灌胃共6周。采用超高效液相色谱-四级杆-飞行时间质谱法(Ultra-performance liquid chromatography-quantitative time-of-flight tandem mass spectrometry,UPLC-Q-TOF-MS/MS)对大鼠血清中内源性差异代谢物进行检测。利用网络药理学方法筛选疏肝和胃汤中的核心成分和关键靶点信息。最后借助Cytoscape软件对差异代谢物及蛋白靶点进行联合分析,运用ELISA实验检测各组大鼠血清中花生四烯酸(Arachidonic acid,AA)、肿瘤坏死因子-α(Tumor necrosis factor-α,TNF-α)、白细胞介素-6(Interleukin-6,IL-6)和环氧合酶(Cyclooxygenase,COX-2)的含量。结果从血清代谢组中共鉴定得到47个差异代谢物,疏肝和胃汤可回调其中18个差异代谢物,通路富集分析发现主要涉及初级胆汁酸的生物合成、花生四烯酸代谢(impact>0.1)。利用网络药理学手段筛选出疏肝和胃汤71种活性成分和47个关键靶点蛋白,联合分析中花生四烯酸及相关靶点所占比重最大。经过验证发现,与对照组相比,模型组血清中AA(P<0.05)、IL-6(P<0.01)和TNF-α(P<0.01)的含量均显著升高。与模型组相比,疏肝和胃汤组血清中IL-6和TNF-α的含量均显著降低(P<0.01)。结论疏肝和胃汤有效组分治疗抑郁症具有多靶点和多通路的特性,其作用机制可能与疏肝和胃汤参与调控花生四烯酸代谢途径,抑制炎症因子水平,进而改善慢性应激诱导的抑郁样症状相关。

枣仁安神方对抑郁大鼠脑内单胺神经递质、HPA轴及CREB/BDNF信号通路的影响

目的:研究枣仁安神方(Zaoren Anshen Prescription,ZAP)对慢性不可预知温和应激(chronic mild unpredictable stress,CUMS)抑郁模型大鼠脑内单胺类神经递质、HPA轴功能及CREB/BDNF信号通路的影响,探讨其抗抑郁作用机制。方法:成年雄性SD大鼠随机分为正常对照组10只和模型组30只;正常对照组(CUMS-/Vehicle组)不给予任何处理,模型组给予孤养联合慢性不可预知温和应激,4周后再根据糖水偏好实验基线值评分将模型组大鼠分为3个亚组,分别为抑郁模型组(CUMS+/Vehicle组)、氟西汀阳性对照组(CUMS+/FLU组)和枣仁安神方治疗组(CUMS+/ZAP组)。各组均在造模时灌胃给药,给药时间为4周,CUMS-/Vehicle组大鼠给予0.9%生理盐水10 mL/(kg·d),CUMS+/ZAP组给予枣仁安神方15 g/(kg·d),CUMS+/FLU组给予FLU 10 mg/(kg·d)。实验结束后进行旷场实验、糖水偏好实验、强迫游泳实验和新环境进食抑制实验观察。应用高效液相色谱法检测大鼠海马组织单胺类神经递质及其代谢产物的浓度;采用酶联免疫吸附测定法检测各组大鼠血清促肾上腺皮质激素(adrenocorticotropic hormone,ACTH)、皮质酮(corticosterone,CORT)含量;采用Western blot检测大鼠海马组织中p-CREB、BDNF蛋白表达含量。结果:造模8周(ZAP治疗4周)后,与CUMS-/Vehicle组相比,CUMS+/Vehicle组大鼠体质量增量明显降低(P<0.01),糖水偏好显著降低(P<0.01),中心区域停留时间以及中心区域停留次数均减少(P<0.01),强迫游泳中不动时间显著增加(P<0.01),在新环境下的摄食潜伏期显著延长(P<0.01),血清ACTH、CORT的含量明显升高(P<0.01),海马组织单胺类神经递质水平显著降低(P<0.01),海马组织BDNF、p-CREB蛋白表达降低(P<0.01)。在应激持续存在的情况下,给予枣仁安神方治疗,上述异常的指标均得到明显改善,差异均有统计学意义(P<0.05,P<0.01)。结论:枣仁安神方可有效改善抑郁模型大鼠的行为学指标,可通过提高海马单胺类神经递质的水平、抑制HPA轴活性及增强海马p-CREB、BDNF表达,从而发挥其抗抑郁的作用。