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.

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.

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.

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 sessions 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 immunohistochemistry 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.

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.

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.

CUMS诱导的抑郁症对小鼠海马神经元及炎症相关通路的影响

为探讨慢性不可预知应激(CUMS)诱导的抑郁症对小鼠海马神经元及炎症相关通路的影响。试验选取12只8周龄C57BL/6雄性小鼠,平均分为2组(n=6):对照组、CUMS组,建立慢性不可预知应激模型。试验对2组小鼠进行糖水偏好试验、强迫游泳试验;采用尼氏染色观察小鼠脑组织海马区神经元变化;采用Western blot、qRT-PCR对小鼠海马区相关炎症因子(TNF-α、IL-1β、iNOS、IL-6)表达量进行检测。与对照组相比,CUMS组小鼠糖水偏好指数降低,但在水中静止时间增加;CUMS组小鼠海马区CA1、CA3及DG区尼氏染色阳性细胞数量显著下降,海马区炎症因子(TNF-α、IL-1β、iNOS、IL-6)蛋白表达量及m RNA表达量显著增加。CUMS诱导的抑郁症会导致小鼠海马神经元数量减少,并促进神经炎症的发生。

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GABA能神经系统探究淫羊藿次苷Ⅱ的抗抑郁作用及机制

目的基于γ氨基丁酸(GABA)能神经系统研究淫羊藿次苷Ⅱ(ICSⅡ)的抗抑郁作用及潜在机制。方法将雄性昆明小鼠分为对照组(C组,10只)和造模组(50只),造模组小鼠以慢性不可预知温和应激法复制抑郁模型。刺激21 d后,将造模组小鼠随机分为抑郁模型组(NS组)、阳性对照药组[ECS组,草酸艾司西酞普兰15 mg/(kg·d)]和ICSⅡ低、中、高剂量组[ICSⅡ-L、ICSⅡ-M、ICSⅡ-H组,ICSⅡ10、20、30 mg/(kg·d)],每组10只。各药物组小鼠灌胃相应药物,每天1次,连续14 d。检测各组小鼠的糖水偏爱率、运动总距离、悬尾实验和强迫游泳实验的静止不动时间,观察其海马CA3区神经元及尼氏体形态,检测海马组织中GABA、谷氨酸(Glu)含量、GABA/Glu比值及GABA能神经系统相关蛋白(GABA A受体α1、GABA B受体1、GABA囊泡转运体、谷氨酸脱羧酶67、GABA膜转运体3)的表达情况。结果与C组比较,NS组小鼠糖水偏爱率显著降低,运动总距离显著缩短,悬尾实验和强迫游泳实验的静止不动时间均显著延长(P<0.05);海马CA3区的神经元形态不规则且尼氏体减少,结构完整的神经元数量显著减少(P<0.05);海马组织中Glu含量显著升高,GABA含量、GABA/Glu比值和GABA能神经系统相关蛋白表达水平均显著降低(P<0.05)。与NS组比较,各药物组大鼠的抑郁样行为均有所改善,上述指标普遍逆转(P<0.05)。结论ICSⅡ能够改善抑郁模型小鼠的抑郁样行为,其机制可能与调节GABA、Glu平衡,增加GABA的合成、转运、释放以及调节相关受体的表达进而改善GABA能神经系统功能有关。

Quercetin regulates depression-like behavior in CUMS rat models via TLR4/NF-κB signaling

Background:Depression is becoming increasingly prevalent around the world,imposing a substantial burden on individuals,families,as well as society.Quercetin is known to be highly effective in treating depression.However,additional research is needed to dissect the mechanisms of its anti-depressive effects.Methods:For this study,Sprague-Dawley(SD)rats were randomized into the control,model,quercetin,or fluoxetine group.The latter three groups were exposed to chronic unpredictable mild stress(CUMS)for 42 d.The first two groups received saline solution daily via oral gavage.Meanwhile,the quercetin group was orally administered a quercetin suspension(52.08 mg/kg)every day,while the fluoxetine group was orally administered a fluoxetine solution(2.08 mg/kg).Here,fluoxetine served as the positive control drug to compare the therapeutic effects of quercetin.The experimental period was 6 weeks.Depressive behaviors in rats were assessed through various physiological and behavioral measures.Additionally,pathological changes in hippocampal tissues were examined using Nissl staining.Serum cytokines were detected using an enzymelinked immunosorbent assay(ELISA),and immunohistochemistry was employed to quantify the levels and integral optical density(IOD)values of ionized calcium binding adaptor molecule-1(Iba-1)expression in the brain.Real-time fluorescence quantitative PCR(RT-qPCR)was utilized to evaluate the mRNA levels of inflammatory indicators as well as toll-like receptor 4(TLR4),and nuclear factor-κappa B P65(NF-κB P65)in hippocampus.Western blot(WB)technique was employed to observe the protein levels of TLR4,NF-κB P65,and phospho-NF-κB P65(p-NF-κB P65).Results:After 42 d of exposure to CUMS,rats exhibited a slow increase in body weight,a reduction in food intake,an abnormal preference for sugar water,and aberrant open-field behaviors.Pathological analysis revealed the disintegration,rupture,interruption,and disorganization of hippocampal neuronal cells after CUMS exposure,along with a decrease in Nissl bodies in the CA1 region.This was accompanied by the elevated expression of interleukin-1β(IL-1β),tumor necrosis factor-α(TNF-α),and interleukin-6(IL-6)in the serum and the upregulation of IL-1β,IL-6,and TNF-αmRNA expression in the hippocampus.Increases in Iba-1-positive cells and the IOD values of Iba-1 were detected in hippocampal microglia.Furthermore,TLR4 and NF-κB P65 mRNA and protein levels were upregulated in hippocampal tissues.Quercetin,an antidepressant,could alleviate depression-like symptoms in rats and downregulate inflammatory factors associated with the TLR4/NF-κB signaling pathway in hippocampal microglia,and its therapeutic effect was comparable to fluoxetine.Conclusion:In rat models of CUMS,quercetin may act as an antidepressant by inhibiting inflammation in hippocampal microglia via TLR4/NF-κB signaling pathway.These results offer experimental and theoretical support for applying quercetin in the clinical management of depression.

柴胡皂苷A抗抑郁的靶点识别及作用研究

中药柴胡具有改善抑郁患者临床治疗效果的作用,柴胡皂苷A(saikosaponin A,SSA)是柴胡主要药效成分,本研究以SSA为研究对象,利用慢性不可预知性温和应激(chronic unpredictable mild stress,CUMS)模型小鼠悬尾(tail suspension test,TST)和强迫游泳实验(forced swimming test,FST)明确SSA的抗抑郁作用。利用计算机分子对接技术分析并验证SSA的作用靶点,并利用细胞热转移测定实验(cellular thermal shift assay,CETSA)和药物亲和力靶稳定性实验(drug affinity responsive target stability,DARTS)验证SSA的靶标;采用Western blotting等技术研究SSA的抗抑郁作用机制。CUMS模型TST和FST结果表明,与模型组相比,SSA能够显著缩短小鼠的不动时间,表明SSA具有显著的抗抑郁作用。计算机分子对接证明了SSA与催产素受体(oxytocin receptor,OXTR)结合效果较好,表明SSA抗抑郁的作用靶点可能是OXTR。CETSA结果表明在一系列温度梯度处理下,SSA能够明显延缓OXTR的热变性;DARTS实验结果表明,在一系列酶浓度梯度处理下,SSA能够显著降低OXTR对蛋白质水解的敏感性,表明SSA抗抑郁的作用靶点是OXTR。此外,SSA对OXTR下游的ERK通路没有激活作用。本研究表明SSA发挥抗抑郁作用的靶点可能为OXTR,为抑郁症等精神疾病的临床研究治疗和新药开发提供必要的理论与参考依据。

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。

腧穴“解郁方”对慢性不可预测轻度应激抑郁大鼠下丘脑-垂体-肾上腺轴及BDNF/TrkB/CREB通路的影响

目的:观察腧穴“解郁方”对慢性不可预测轻度应激(CUMS)抑郁大鼠下丘脑-垂体-肾上腺(HPA)轴和脑源性神经营养因子(BDNF)/酪氨酸激酶B受体(TrkB)/环磷酸腺苷反应元件结合蛋白(CREB)信号通路的影响。方法:40只无特定病原体(SPF)级Sprague Danley(SD)雄性大鼠随机分为空白组(10只)、模型组(10只)、西药组(10只)、针刺组(10只),除空白组外,其余3组连续28 d构建CUMS抑郁大鼠模型,造模成功后,西药组连续14 d灌胃盐酸帕罗西汀混悬液,每日1次;针刺组针刺百会、太冲、神门,每日1次,每次20 min,连续针刺14 d。苏木素-伊红(HE)染色观察大鼠海马病理变化,酶联免疫吸附法(ELISA)测定血清促肾上腺皮质激素释放激素(CRH)、促肾上腺皮质激素(ACTH)、皮质醇(CORT)水平;免疫组化(IHC)检测海马BDNF、TrkB表达情况,蛋白质免疫印迹法(Western Blot)及实时荧光定量-聚合酶链式反应(PCR)测定海马BDNF、TrkB、CREB蛋白及mRNA的表达。结果:与空白组比较,模型组血清CRH、ACTH和CORT含量上升(P<0.01),海马病理损伤严重,海马BDNF、TrkB平均光密度降低(P<0.01),BDNF、TrkB、CREB蛋白及mRNA明显下降(P<0.05或P<0.01)。与模型组比较,针刺组血清CRH、ACTH、CORT含量下降(P<0.05),海马病理损害明显减轻,BDNF、TrkB平均光密度明显增加(P<0.05),BDNF、CREB、TrkB蛋白及mRNA表达水平上升(P<0.05)。结论:腧穴“解郁方”可能通过调节HPA轴和调控BDNF/TrkB/CREB信号通路,改善CUMS诱导的大鼠抑郁样行为。

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 anhedonia 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 microinjection 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 individuals 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.

跑台运动对慢性应激大鼠抑郁行为及内质网应激介导的细胞凋亡和BDNF/TrkB表达的影响

目的:通过检测前额叶皮质内质网应激蛋白及凋亡蛋白和BDNF、TrkB蛋白的表达,探讨跑台运动改善慢性不可预知温和应激(CUMS)大鼠抑郁样行为的可能机制。方法:30只SD大鼠随机分为对照组(control group,n=10)、应激模型组(CUMS group,n=10)及应激运动组(CUMS+E group,n=10)。随后,CUMS组及CUMS+E组大鼠建立CUMS抑郁模型,同时,CUMS+E组大鼠进行4周中等强度跑台运动(速度为18~20 m/min)。运动及应激结束后采用开场实验、糖水偏爱实验、强迫游泳实验及新奇抑制摄食实验评估大鼠抑郁样行为,并于实验前及实验期间每周测量大鼠体重,westernblot实验测定前额叶皮质PERK/eIF2α/CHOP、Bcl2/Bax及BDNF/TrkB蛋白表达。结果:(1)与对照组比较,蔗糖偏爱实验中CUMS组大鼠蔗糖摄入量及蔗糖偏爱率显著减少;强迫游泳实验中静止时间增加、静止潜伏期及攀爬时间均显著缩短;开场实验中大鼠中央格时间显著缩短、水平穿格次数及直立次数均显著下降;新奇抑制摄食实验中新环境中大鼠摄食潜伏期延长,并且大鼠体重增长缓慢。CUMS组大鼠前额叶皮质PERK、eIF2α、CHOP及Bax蛋白表达明显增加,Bcl-2及BDNF、TrkB表达明显下降。(2)4周跑台运动可显著改善CUMS大鼠的抑郁样行为,与CUMS组比较,CUMS+E组大鼠前额叶皮质PERK、eIF2α及CHOP蛋白表达显著下降,Bcl-2及BDNF、TrkB蛋白表达明显增加,Bax蛋白表达两组无显著差异。结论:跑台运动改善CUMS大鼠抑郁样行为可能与此运动激活前额叶皮质BDNF-TrkB信号通路及降低内质网应激PERK/eIF2α/CHOP通路诱导的凋亡有关,提示跑台运动可能通过BDNF/TrkB信号通路调节的内质网应激PERK/eIF2α/CHOP通路介导的细胞凋亡发挥抗抑郁作用。

运动对慢性不可预测轻度应激模型鼠抑郁样行为的干预作用:系统综述和Meta分析

目的:抑郁症是全球疾病负担的五大主要原因之一,目前可用的抗抑郁药物疗效低、起效慢、不良反应严重,而运动是治疗抑郁症的一种较好的方式。文章系统评价了运动对慢性不可预知轻度应激(CUMS)模型鼠抑郁相关行为的干预效果。方法:检索万方、中国知网、PubMed、Embase和Web of Science数据库,检索文献时限为2000-01-01/2022-02-28,收集跑台、游泳、转轮等运动对慢性不可预知轻度应激(CUMS)抑郁动物模型强迫游泳、悬尾、糖水偏好行为学影响的研究。由2位研究者按照纳入标准独立完成文献筛选、资料提取及SYRCLE动物实验偏倚风险评估工具进行方法学质量评价,运用RevMan 5.3和Stata 13.0分析软件进行统计分析。结果:共纳入23篇对照动物实验文献,运动组实验动物301只,对照组302只。Meta分析结果显示:①运动能够显著降低抑郁模型鼠强迫游泳测试潜伏期[SMD=-3.93,95%CI:(-4.88,-2.98),P<0.00001]及悬尾测试潜伏期[SMD=-4.42,95%CI:(-5.62,-3.23),P<0.00001];②运动同样可以提高糖水偏好指数[SMD=2.37,95%CI:(1.62,3.11),P<0.00001];③悬尾测试中对运动方式进行亚组分析可以降低异质性[SMD=-3.68,95%CI:(-4.16,-3.21),P<0.00001],但并不影响运动效果。结论:运动能有效改善慢性不可预知轻度应激(CUMS)模型鼠强迫游泳、悬尾、糖水偏好的抑郁样行为。运动方式可能是影响悬尾测试行为的异质性来源;造模时间、干预阶段、运动方式及运动时间不是影响运动改善抑郁效果的主要因素。

肝X受体激动剂对抑郁模型小鼠海马树突棘数目的影响

目的:探讨肝X受体(LXRs)激动剂GW3965对慢性不可预知性应激(CUS)诱导的抑郁症模型小鼠海马结构各亚区CA1、CA3和DG内树突棘数目变化的影响。方法:选取雄性C57BL/6J小鼠,经过适应性喂养和糖水基线调整后,被随机分为对照组(control)、对照+GW3965组(GW)、抑郁模型组(CUS)以及抑郁模型+GW3965组(CUS/GW)。CUS组和CUS/GW组小鼠接受连续10周的CUS干预,GW组和CUS/GW组小鼠在CUS干预的第7周开始接受4周的GW3965给药。第10周末进行行为学测试,之后应用免疫组化及现代体视学技术精准定量小鼠海马结构各亚区树突棘密度和总数目改变。结果:持续数周的应激使小鼠的体质量及糖水偏好百分比明显下降,强迫游泳不动时间显著增加。体视学结果显示CUS干预使小鼠CA1、CA3和DG区树突棘密度和数量明显减少。4周GW3965治疗改善了小鼠的抑郁样行为及逆转了DG区树突棘密度和总数目的下降。结论:LXRs激动剂GW3965对CUS模型小鼠DG区树突棘总数目的影响可能是其发挥抗抑郁作用的神经生物学基础之一。

Splenectomy does not affect mouse behaviors

The spleen is critical for immunity.It is the largest immune organ and immune center in the peripheral system.While the relationship between behavior and immunity has been demonstrated in physiology and diseases,the role of the spleen in behavior is not clear.To investigate the effects of the spleen on behaviors,we performed a refined splenectomy procedure on C57BL/6J mice and performed an open field test,circadian rhythm test,elevated plus maze,sucrose preference test,and Barnes maze test.Splenectomy did not induce changes in general locomotion,circadian rhythms,learning and memory,or depression/anxiety-related behaviors.To further investigate the effects of spleen on stress susceptibility,we established mouse models of depression through chronic unpredictable mild stress.The behavioral performances of mice subjected to splenectomy showed no differences from control animals.These findings suggest that splenectomy does not cause changes in baseline behavioral performance in mice.