Background: Alcohol abuse triggers neuroinflammation, leading to neuronal damage and further memory and cognitive impairment. Few satisfactory advances have been made in the management of alcoholic central ner-vous impairment. Therefore, novel and more practical treatment options are urgently needed. Butyrate, a crucial metabolite of short-chain fatty acids (SCFAs), has been increasingly demonstrated to protect against numerous metabolic diseases. However, the impact of butyrate on chronic alcohol consumption-induced central nervous system (CNS) lesions remains unknown. Methods: In this study, we assessed the possible effects and underlying mechanisms of butyrate on the attenuation of alcohol-induced CNS injury in mice. Firstly, sixty female C57BL/6 J mice were randomly divided into 4 groups: pair-fed (PF) group (PF/CON), alcohol-fed (AF) group (AF/CON), PF with sodium butyrate (NaB) group (PF/NaB) and AF with NaB group (AF/NaB). Each group was fed a modified Lieber-DeCarli liquid diet with or without alcohol. After six weeks of feeding, the mice were euthanized and the associated indicators were investigated.Results: As indicated by the behavioral tests and brain morphology, dietary NaB administration significantly ameliorated aberrant behaviors, including locomotor hypoactivity, anxiety disorder, depressive behavior, impaired learning, spatial recognition memory, and effectively reduced chronic alcoholic central nervous system damage. To further understand the underlying mechanisms, microglia-mediated inflammation and the associated M1/M2 polarization were measured separately. Firstly, pro-inflammatory TNF-alpha, IL-1 beta, and IL-6 in brain and peripheral blood circulation were decreased, but IL-10 were increased in the AF/NaB group compared with the AF/CON group. Consistently, the abnormal proportions of activated and resting microglial cells in the hippo -campus and cortex regions after excessive alcohol consumption were significantly reduced with NaB treatment. Moreover, the rectification of microglia polarization (M1/M2) imbalance was found after NaB administration via binding GPR109A, up-regulating the expression of PPAR-gamma and down-regulating TLR4/NF-Kappa B activation. In addition to the direct suppression of neuroinflammation, intriguingly, dietary NaB intervention remarkably increased the levels of intestinal tight junction protein occludin and gut morphological barrier, attenuated thelevels of serum lipopolysaccharide (LPS) and dysbiosis of gut microbiota, suggesting that NaB supplementation effectively improved the integrity and permeability of gut microecology. Finally, the neurotransmitters including differential Tryptophan (Trp) and Kynurenine (Kyn) were found with dietary NaB administration, which showed significantly altered and closely correlated with the gut microbiota composition, demonstrating the complex interactions in the microbiome-gut-brain axis involved in the efficacy of dietary NaB therapy for alcoholic CNS lesions.Conclusion: Dietary microbial metabolite butyrate supplementation ameliorates chronic alcoholic central nervous damage and improves related memory and cognitive functions through suppressing microglia-mediated neuro-inflammation by GPR109A/PPAR-gamma/TLR4-NF-Kappa B signaling pathway and modulating microbiota-gut-brain axis.

目的 探讨黄芪甲苷(astragaloside Ⅳ,AS-Ⅳ)对小鼠小胶质细胞焦亡通路相关蛋白的影响及机制.方法 体外培养小鼠小胶质细胞(BV2),设置Control组(正常对照组),以20 U·mL-1凝血酶激活小胶质细胞作为凝血酶组,20 U·mL-1凝血酶+不同浓度的AS-Ⅳ(1、5和10 μmol·L-1)作为实验组.采用免疫印迹及免疫荧光法检测BV2细胞中焦亡相关因子NOD样受体热蛋白结构域相关蛋白3(NLRP3)、凋亡相关斑点样蛋白(ASC)、含半胱氨酸的天冬氨酸蛋白酶水解1(Caspase-1)、胞膜穿孔蛋白D-N端(GSDMD-N)表达量变化,ELISA法检测细胞培养液中焦亡下游分泌物[白细胞介素(IL)-18、IL-1β]的含量.结果 免疫印迹及免疫荧光结果显示,与Control组比较,凝血酶组BV2细胞内焦亡相关因子(ASC、NLRP3、Caspase-1、GSDMD-N)蛋白表达量均升高(P均＜0.05);与凝血酶组比较,不同浓度AS-&实验组BV2细胞内焦亡相关因子(ASC、NL-RP3、Caspase-1、GSDMD-N)表达量均降低(P均＜0.05),并且 5、10 μmol·L-1 AS-Ⅳ组较1 μmol·L-1 AS-Ⅳ组均降低(P均＜0.05).ELISA结果显示,凝血酶组IL-18 与IL-1β含量相较于Control组增加(P均＜0.05),而不同浓度AS-Ⅳ实验组IL-18与IL-1β含量相较于凝血酶组均减少(P均＜0.05),并且 5、10 μmol·L-1 AS-Ⅳ组较1 μmol·L-1 AS-Ⅳ组均降低(P均＜0.05).结论 AS-Ⅳ可能通过抑制活化的小胶质细胞内焦亡通路相关蛋白的表达来发挥其抗炎作用.

目的 探究P75 神经营养素受体(neurotrophin receptor P75,P75NTR)裂解抑制剂对双环己酮草酰二腙(cuprizone,CPZ)诱导脱髓鞘小鼠认知功能及海马髓鞘的改善作用.方法 采用连续喂食 0.2%CPZ的方法构建急性脱髓鞘模型(CPZ小鼠),同时设立对照组;5 周后,在CPZ小鼠海马区注射P75NTR裂解抑制剂或生理盐水.在第 6 周,通过水迷宫、高架十字迷宫实验检测小鼠行为学的改变;通过快蓝染色检测髓鞘脱失情况;通过Western blot检测海马组织中P75NTR及髓鞘碱性蛋白(myelin basic protein,MBP)的表达变化;通过免疫组织化学检测海马组织中MBP阳性表达量的变化.结果 与对照组相比,CPZ小鼠逃避潜伏期增加,跨台次数、进入开臂及在开臂中活动时间减少(P均＜0.05);快蓝染色结果显示,CPZ小鼠胼胝体区髓鞘结构疏松,着色明显变浅;CPZ小鼠海马区P75NTR表达增加(P＜0.05);CPZ小鼠海马区MBP表达减少(P＜0.05).相比于生理盐水的干预,P75NTR裂解抑制剂干预后,小鼠逃避潜伏期降低,进入开臂及在开臂中活动时间增加(P均＜0.05);P75NTR裂解抑制剂干预后,小鼠海马区MBP表达上升(P＜0.05).结论 抑制P75NTR的裂解可以改善CPZ模型小鼠的认知功能障碍,其作用机制与减轻海马中髓鞘脱失有关.

Objective: This study aimed to confirm that G protein-coupled estrogen receptor 1 (GPER1) deficiency affects cognitive function by reducing hippocampal neurogenesis via the PKA/ERK/IGF-I signaling pathway in mice with schizophrenia (SZ). Methods: Mice were divided into four groups, namely, KO Con, WT Con, KO Con, and WT SZ (n = 12 in each group). All mice were accustomed to the behavioral equipment overnight in the testing service room. The experimental conditions were consistent with those in the animal house. Forced swimming test and Y-maze test were conducted. Neuronal differentiation and maturation were detected using immunofluorescence and confocal imaging. The protein in the PKA/ERK/IGF-I signaling pathway was tested using Western blot analysis. Results: GPER1 KO aggravated depression during forced swimming test and decreased cognitive ability during Y-maze test in the mouse model of dizocilpine maleate (MK-801)-induced SZ. Immunofluorescence and confocal imaging results demonstrated that GPER1 knockout reduced adult hippocampal dentate gyrus neurogenesis. Furthermore, GPER1-KO aggravated the hippocampal damage induced by MK-801 in mice through the PKA/ ERK/IGF-I signaling pathway. Conclusions: GPER1 deficiency reduced adult hippocampal neurogenesis and neuron survival by regulating the PKA/ERK/IGF-I signaling pathway in the MK-801-induced mouse model of SZ.

Abstract Introduction: Oligodendrocyte precursor cells (OPCs) differentiation dysfunction is closely related to demyelinating diseases and cognitive dysfunction. P75 neurotrophin receptor (P75NTR) is a prototypical co-receptor that induces Schwann cell death via γ-secretase-dependent regulated intramembrane proteolysis. This study hypothesizes that P75NTR may also assists in inhibiting OPCs differentiation.Methods Male C57BL/6 mice were fed 0.2% cuprizone (CPZ) continuously for 6 weeks to establish the acute demyelinating model (CPZ mice). Morris Water Maze and Elevated Plus Maze tests were used to assess the behavioral changes of these mice. Immunohistochemistry and Western blot were used to detect the OPCs and oligodendrocytes (OLs) protein markers. Furthermore, γ-secretase inhibitor DAPT (GSI-IX) was injected into the hippocampus at the fifth week of establishing the demyelinating model to investigate the effects of DAPT on OPCs differentiation and the mice’s behavioral changes.Results CPZ mice performed abnormal behavioral changes, and the protein expression of the OLs marker 2',3'-cyclic-nucleotide 3'-phosphodiesterase (CNPase) decreased. However, the OPCs marker neural/glial antigen 2 (NG2) protein expression increased. After DAPT treatment, the abnormal behavior improved, CNPase increased, and NG2 decreased.Conclusions P75 cleavage plays an inhibitory role during the OPCs differentiation resulting in inefficient OPCs differentiation and recurrent demyelinating diseases.

Abstract Introduction: Oligodendrocyte precursor cells (OPCs) differentiation dysfunction is closely related to demyelinating diseases and cognitive dysfunction. P75 neurotrophin receptor (P75NTR) is a prototypical co-receptor that induces Schwann cell death via γ-secretase-dependent regulated intramembrane proteolysis. This study hypothesizes that P75NTR may also assists in inhibiting OPCs differentiation. Methods Male C57BL/6 mice were fed 0.2% cuprizone (CPZ) continuously for 6 weeks to establish the acute demyelinating model (CPZ mice). Morris Water Maze and Elevated Plus Maze tests were used to assess the behavioral changes of these mice. Immunohistochemistry and Western blot were used to detect the OPCs and oligodendrocytes (OLs) protein markers. Furthermore, γ-secretase inhibitor DAPT (GSI-IX) was injected into the hippocampus at the fifth week of establishing the demyelinating model to investigate the effects of DAPT on OPCs differentiation and the mice’s behavioral changes. Results CPZ mice performed abnormal behavioral changes, and the protein expression of the OLs marker 2',3'-cyclic-nucleotide 3'-phosphodiesterase (CNPase) decreased. However, the OPCs marker neural/glial antigen 2 (NG2) protein expression increased. After DAPT treatment, the abnormal behavior improved, CNPase increased, and NG2 decreased. Conclusions P75 cleavage plays an inhibitory role during the OPCs differentiation resulting in inefficient OPCs differentiation and recurrent demyelinating diseases.

Abstract Background Alcohol can cause neuroinflammation, leading to neuron damage and further memory and cognitive impairment. Recent animal studies have shown that the exposure to chronic alcohol consumption induces robust inflammatory microglial activation in the brain. However, as a novel anti-inflammation approach, the impact of sodium butyrate on chronic alcohol-induced neuroinflammation still remains unclear. Methods Sixty female C57BL/6J mice were randomly divided into 4 groups: pair-fed (PF) group (PF/CON), alcohol-fed (AF) group (AF/CON), PF with sodium butyrate (NaB) group (PF/NaB) and AF with NaB group (AF/NaB). Each group was fed a modified Lieber-DeCarli liquid diet with or without alcohol. Mice were subjected to different behavioral tests to assess aberrant behaviours (deficits in cognitive functions, depression and anxiety). Pathological changes were further investigated by Hematoxylin and eosin staining (HE) and Nissl staining. The microglial activation and microglial polarization were observed by immunohistochemistry (IHC), immunofluorescence (IF) and flow cytometry. Enzyme-linked immunosorbent assay (ELISA) was used to determine the levels of inflammatory factors. G-protein coupled receptor 109A (GPR109A), peroxisome proliferator-activated receptor γ (PPAR-γ) and nuclear factor-κB (NF-κB) mRNA and protein levels were evaluated by reverse transcription‑quantitative (RT‑q) PCR and western blot (WB). Results As indicated by the behavioural tests, inflammatory indicators, microglial activation (M1/M2 microglia polarization) and brain morphology, sodium butyrate administration ameliorated aberrant behaviours (locomotor hypoactivity, anxiety disorders and depressive behaviours, impaired learning and spatial recognition memory), effectively reduced neuroinflammation and neuronal damage. The effectiveness of sodium butyrate may attribute to the GPR109A receptor in microglia by up-regulating the expression of PPAR-γ and inhibiting the activation of NF-κB. Conclusion Sodium butyrate ameliorates neuroinflammation induced by chronic alcohol exposure and improves memory and cognitive functions in mice via modulating microglia-mediated GPR109A / PPAR-γ / NF-κB signaling pathway.

目的 探讨不同浓度胡椒碱(piperine,PIP)对缺血性脑卒中大鼠皮质和海马自噬相关基因(autophagy-related gene)Atg5、Atg14自噬蛋白以及神经功能的影响.方法 建立永久性大脑中动脉闭塞(permanent middle cerebral artery occlusion,pMCAO)体内模型,通过每天灌胃一次的干预方式证实PIP对缺血性脑卒中大鼠皮质和海马Atg5、Atg14自噬蛋白以及神经功能的影响.实验分为假手术组、模型组、10、20、30 mg·kg-1 PIP干预组,共五组.TTC染色法检测大鼠大脑梗死面积;Zea Longa神经功能评分检测大鼠神经功能;Western blot法检测皮质和海马Atg5、Atg14蛋白的表达水平.结果 与假手术组相比,模型组14 d后大鼠神经功能评分及大脑梗死面积升高(P<0.05).与模型组相比,10、20、30 mg·kg-1 PIP干预组14 d后大鼠神经功能评分及大脑梗死面积均下降(P均<0.05).与假手术组相比,模型组大鼠海马及皮质Atg5和Atg14蛋白表达水平均升高(P均<0.05).与模型组相比,大鼠海马中20、30 mg·kg-1 PIP干预组Atg5、Atg14蛋白表达水平均下调(P均<0.05);大鼠皮质中30 mg·kg-1 PIP干预组Atg5和Atg14蛋白表达水平均下调(P均<0.05).结论 PIP可降低缺血性脑卒中大鼠海马和皮质Atg5、Atg14自噬蛋白表达水平并对神经功能具有保护作用.