短暂前脑缺血再灌注对大鼠海马脑区脑源性神经营养因子蛋白及mRNA表达的影响

目的探讨短暂前脑缺血再灌注(transient forebrain ischemia-reperfusion,I/R)对脑源性神经营养因子(brainderived neurotrophic factor,BDNF)蛋白及mRNA表达的影响,为进一步探索大鼠海马CA1区神经元损伤机制提供新的思路。方法将雄性SD大鼠随机分为control组、sham组和I/R组,利用Western blot和荧光定量PCR分析I/R后大鼠BDNF蛋白及mRNA表达的变化;染色质免疫共沉淀(chromatin immunoprecipitation,ChIP)试验检测I/R后大鼠BDNF基因启动子上H3K27的乙酰化水平。结果与control组相比,sham组大鼠CA1和CA3区BDNF蛋白和mRNA表达差异无统计学意义(P>0.05)。与sham组相比,I/R组大鼠CA1区BDNF蛋白表达显著下降(P<0.001),而CA3区BDNF蛋白表达增高(P<0.05);I/R组大鼠CA1区BDNF mRNAⅠ、Ⅱ和Ⅵ的表达均显著增高(P<0.01),而mRNAⅣ的表达显著下降(P<0.01),在CA3区4种mRNA均显著增高(P<0.01)。与sham组相比,I/R组大鼠CA1区BDNF启动子4的H3K27乙酰化水平显著下降(P<0.001),而CA3区BDNF启动子区域H3K27乙酰化水平增高(P<0.01)。结论I/R诱导大鼠海马CA1区BDNF蛋白及mRNA表达降低,并改变了BDNF基因启动子区乙酰化水平,为进一步研究BDNF表达降低引起神经元死亡的机制提供了新的方向。     

大鼠脑缺血再灌注后NF-κB的表达及低分子肝素的保护作用

目的探讨低分子肝素在大鼠脑局灶性缺血再灌注损伤后核转录因子NF-κB的表达及其保护作用。方法选择健康雄性SD大鼠,随机分为假手术组、缺血再灌注组、低分子肝素组,采用改良Longa[1]法制作大鼠右侧大脑中动脉闭塞局灶性脑缺血再灌注模型,观察海马CA1区NF-κB的表达情况。结果再灌注后各时间点NF-κB的表达随再灌注时间延长逐渐增加,低分子肝素组核NF-κB的表达量低于脑缺血再灌注组。结论低分子肝素能抑制模型大鼠的核转录因子NF-κB的释放,减少梗死范围,具有脑保护作用。     

雌激素对大鼠脑缺血再灌注后的神经保护作用

目的探讨雌激素对大鼠脑缺血再灌注的保护作用。方法建立大鼠脑缺血再灌注模型,按照Zea-longa评分法测定脑缺血再灌注后神经功能评分及观察免疫组化染色标本。结果雌激素治疗组的神经功能评分及神经元损伤明显低于缺血再灌注组。结论雌激素对大鼠脑缺血再灌注损伤有一定的神经保护作用。     

短暂前脑缺血再灌注对大鼠海马中脑源性神经营养因子启动子与组蛋白去乙酰化酶3结合的影响及其作用机制

目的 评价短暂前脑缺血再灌注(ischemia-reperfusion,I/R)对大鼠海马中脑源性神经营养因子(brain-derived neurotrophic factor,BDNF)启动子与组蛋白去乙酰化酶3(histone deacetylase 3,HDAC3)结合的影响，并探讨其作用机制。方法 采用Pulsinelli四血管夹闭法建立SD大鼠的I/R模型(I/R组)，同时设假手术组(Sham组)。尼氏染色法观察大鼠海马中神经元存活情况；染色质免疫共沉淀(chromatin immunoprecipitation,ChIP)法检测大鼠海马中BDNF启动子(Bdnf-p1、Bdnf-p2、Bdnf-p4和Bdnf-p6)与HDAC3的结合情况；qPCR法检测大鼠海马中反义脑源性神经营养因子(brain derived neurotrophic factor antisense,BDNF-AS)的表达情况。结果 与Sham组比较，I/R组大鼠海马CA1区神经元数目大幅减少，CA3和DG区神经元数目变化较小。I/R组大鼠海马CA1区中Bdnf-p1和Bdnf-p2与HDAC3结合...     

大鼠脑缺血再灌注后NF-кB的表达及低分子肝素的保护作用

目的 探讨低分子肝素在大鼠脑局灶性缺血再灌注损伤后核转录因子NF-кB的表达及其保护作用.方法 选择健康雄性SD大鼠,随机分为假手术组,缺血再灌注组,低分子肝素组,采用改良Longa 法制作大鼠右侧大脑中动脉闭塞局灶性脑缺血再灌注模型,观察海马CAI区NF-кB的表达情况.结果 再灌注后各时间点NF-кB的表达随再灌注时间延长逐渐增加,低分子肝素组核NF-кB的表达量低于脑缺血再灌注组.结论 低分子肝素能押制模型大鼠的核转录因子NF-kB的释放,减少梗死范围,具有脑保护作用.     

大鼠颅脑外伤后生长相关蛋白在中枢神经系统的表达

目的观察大鼠颅脑外伤后生长相关蛋白(GAP-43)在中枢神经系统表达的变化,为探讨颅脑外伤后神经元再生和修复机制及临床应用药物治疗颅脑外伤提供理论依据。方法采用液压冲击法建立大鼠脑外伤模型,同时设正常对照组和假手术对照组。成模后取额皮质及海马部位,应用HE染色法观察额皮质区和海马CA1区的病理学改变,免疫组化法检测GAP-43的表达。结果轻、中、重度损伤组大鼠脑组织均出现明显的病理学改变,各损伤组大鼠创伤性颅脑外伤(TBI)后,额皮质区及海马CA1区均于12 h开始出现GAP-43表达增强,3 d后明显增强,1周达高峰,2周时开始降低。GAP-43的免疫反应产物的实际累积光密度值(CIOD)值在TBI 12 h后各时间点均明显高于同期的正常对照组和假手术对照组,中、重度损伤组CIOD值在TBI12 h后明显高于同期轻度损伤组。结论大鼠TBI后,GAP-43的表达增强;TBI损伤越重,其GAP-43的表达越强。     

白藜芦醇对大鼠脑缺血再灌注氧化应激损伤的影响

目的探讨白藜芦醇(Resveratrol,Res)对大鼠脑缺血再灌注氧化应激损伤的影响。方法将SD大鼠随机分为假手术组(S组)、缺血再灌注组(I/R组,线栓法复制大鼠右侧大脑中动脉栓塞模型)、Res低剂量组(15 mg/kg,I/R+R1组)和Res高剂量组(30 mg/kg,I/R+R2组),于缺血2 h再灌注24 h进行神经功能缺损评分;化学比色法测定大鼠血清和脑组织中丙二醛(Malondialdehyde,MDA)含量及超氧化物歧化酶(Superoxide dismutase,SOD)活性;TTC法测定脑梗死体积;干湿重法测定脑含水量,HE染色观察脑组织的病理改变。结果与I/R组相比,Res能改善大鼠脑缺血再灌注损伤后的神经功能缺失(P<0.01),降低血清及脑组织中MDA的含量(P<0.01),提高SOD活性(P<0.01),缩小脑梗死体积(P<0.01),降低损伤侧脑含水量(P<0.01),改善脑组织的病理变化,且呈剂量依赖性。结论 Res对大鼠局灶性脑缺血再灌注氧化应激损伤具有良好的保护作用,其机制可能与清除自由基,减轻氧化性损伤有关。     

扶芳藤提取物对局灶性脑缺血大鼠脑组织IL-6含量的影响

目的探讨扶芳藤提取物对大鼠急性脑缺血再灌注损伤过程IL-6表达的影响。方法取Wistar大鼠随机分为假手术组、模型组和用药组,Longa法制作大鼠急性脑缺血再灌注损伤模型,用酶联免疫标记法测定脑组织与血清中IL-6的浓度。结果扶芳藤提取物能降低再灌注3h、6h、12h、24h后大鼠脑组织与血清中IL-6的表达。结论扶芳藤提取物对大鼠急性脑缺血再灌注损伤的保护作用可能与其抑制脑组织与血清中IL-6的过度表达有关。     

大鼠脑缺血再灌注后层粘连蛋白表达的研究

目的探讨层粘连蛋白(Laminin,LN)在脑缺血再灌注损伤后的表达及其意义,为有效治疗缺血性脑病提供实验依据。方法以线栓法制作大鼠大脑中动脉阻塞的局灶性脑缺血再灌注模型,采用免疫组化、2,3,5-氯化三苯四氮唑(TTC)、H-E染色和神经行为相结合的方法,观测缺血再灌注侧大脑皮质内LN的表达、脑组织结构的变化。结果脑缺血再灌3h后,LN的表达较正常对照组明显下降,至再灌注24h降至最低点,于再灌注3d后开始回升。结论脑缺血再灌注后LN的表达先减低后回升,早期参与了血脑屏障的病理性改变,导致了继发性脑水肿损伤;稍后又参与了促使新生血管生成的过程。     

大鼠颅脑损伤后神经细胞的凋亡

目的观察大鼠颅脑损伤后不同时间损伤周边区额皮质及海马CA1区神经细胞的凋亡现象,为颅脑外伤的临床治疗提供理论依据。方法将SD大鼠分为正常对照组(30只)、假手术对照组(30只)和损伤组(80只),采用侧位液压冲击法制成颅脑损伤动物模型,损伤组按冲击时脑组织所承受力量大小,进一步分为轻、中、重度3组,采用免疫组织化学技术和原位末端标记法(TUNEL)检测各组大鼠损伤后4、8、24、72、96h和7d大鼠伤灶周边额皮质及海马CA1区的凋亡细胞。结果轻、中、重度损伤组大鼠损伤区周边额皮质和海马CA1区各时间点凋亡阳性细胞数均高于正常对照组和假手术对照组,重度损伤组高于轻度和中度损伤组,且差异均有统计学意义。损伤4h后,各损伤组伤灶边缘额皮质和海马CA1区开始出现凋亡细胞,随后逐渐增加,分别于72和24h达高峰,之后开始下降。结论颅脑损伤可导致损伤周边区大脑额皮质及海马CA1区神经细胞凋亡,凋亡高峰时间分别为损伤后72和24h。     

Therapeutic Effects of Aripiprazole in the 5xFAD Alzheimer’s Disease Mouse Model

Global aging has led to growing health concerns posed by Alzheimer’s disease (AD), the most common type of dementia. Aripiprazole is an atypical FDA-approved anti-psychotic drug with potential against AD. To investigate its therapeutic effects on AD pathology, we administered aripiprazole to 5xFAD AD model mice and examined beta-amyloid (βA)-induced AD-like phenotypes, including βA production, neuroinflammation, and cerebral glucose metabolism. Aripiprazole administration significantly decreased βA accumulation in the brains of 5xFAD AD mice. Aripiprazole significantly modified amyloid precursor protein processing, including carboxyl-terminal fragment β and βA, a disintegrin and metalloproteinase domain-containing protein 10, and beta-site APP cleaving enzyme 1, as determined by Western blotting. Neuroinflammation, as evidenced by ionized calcium binding adapter molecule 1 and glial fibrillary acidic protein upregulation was dramatically inhibited, and the neuron cell layer of the hippocampal CA1 region was preserved following aripiprazole administration. In 18F-fluorodeoxyglucose positron emission tomography, after receiving aripiprazole, 5xFAD mice showed a significant increase in glucose uptake in the striatum, thalamus, and hippocampus compared to vehicle-treated AD mice. Thus, aripiprazole effectively alleviated βA lesions and prevented the decline of cerebral glucose metabolism in 5xFAD AD mice, suggesting its potential for βA metabolic modification and highlighting its therapeutic effect over AD progression.     

氟伐他汀对糖尿病大鼠肾脏CTGF表达的影响

目的观察氟伐他汀对糖尿病大鼠肾脏结缔组织生长因子(CTGF)表达的影响。方法用链脲佐菌素复制糖尿病大鼠模型,成模后给予氟伐他汀治疗。采用ELISA法检测尿微量白蛋白浓度;Western blot和RT-PCR法检测大鼠肾皮质CT-GF蛋白及mRNA的表达水平;免疫组化法检测肾小球内CTGF和FN的表达。结果氟伐他汀治疗组大鼠尿白蛋白排泄率、肾脏肥大指数(KHI)、肾皮质中CTGF的mRNA及蛋白表达、肾小球内CTGF和FN的表达较糖尿病组大鼠均明显降低。结论氟伐他汀能降低肾小球内CTGF及FN的表达,减轻肾小球肥大,起到抑制和延缓糖尿病肾病进展的作用。     

长春新碱治疗糖尿病肾病大鼠的实验研究

目的验证长春新碱对糖尿病肾病大鼠的治疗作用。方法用链脲佐菌素(STZ)诱导大鼠糖尿病模型。将模型大鼠分为治疗组与非治疗组,治疗组给予长春新碱(VCR)0.2 mg/kg,尾静脉注射,每周2次,观察给药后大鼠血糖、尿蛋白、肾功能、肾重,体重等值的改变以及肾脏病理的改善情况。结果 治疗组大鼠尿蛋白明显减少,肾重/体重低于非治疗组。光镜下观察治疗组肾脏病理学变化情况有明显改善。结论长春新碱可降低糖尿病肾病大鼠的尿蛋白并改善糖尿病肾病早期病理损害。     

Ischemia-Reperfusion under Hyperthermia Increases Heme Oxygenase-1 in Pyramidal Neurons and Astrocytes with Accelerating Neuronal Loss in Gerbil Hippocampus

It has been studied that the damage or death of neurons in the hippocampus is different according to hippocampal subregions, cornu ammonis 1–3 (CA1–3), after transient ischemia in the forebrain, showing that pyramidal neurons located in the subfield CA1 (CA1) are most vulnerable to this ischemia. Hyperthermia is a proven risk factor for brain ischemia and can develop more severe and extensive brain damage related with mortality rate. It is well known that heme oxygenase-1 (HO-1) activity and expression is increased by various stimuli in the brain, including hyperthermia. HO-1 can be either protective or deleterious in the central nervous system, and its roles depend on the expression levels of enzymes. In this study, we investigated the effects of hyperthermia during ischemia on HO-1 expression and neuronal damage/death in the hippocampus to examine the relationship between HO-1 and neuronal damage/death following 5-min transient ischemia in the forebrain using gerbils. Gerbils were assigned to four groups: (1) sham-operated gerbils with normothermia (Normo + sham group); (2) ischemia-operated gerbils with normothermia (Normo + ischemia group); (3) sham-operated gerbils with hyperthermia (39.5 ± 0.2 °C) during ischemia (Hyper + sham group); and (4) ischemia-operated gerbils with hyperthermia during ischemia (Hyper + ischemia group). HO-1 expression levels in CA1–3 of the Hyper + ischemia group were significantly higher than those in the Normo + ischemia group. HO-1 immunoreactivity in the Hyper + ischemia group was significantly increased in pyramidal neurons and astrocytes with time after ischemia, and the immunoreactivity was significantly higher than that in the Normo + ischemia group. In the Normo + Ischemia group, neuronal death was shown in pyramidal neurons located only in CA1 at 5 days after ischemia. However, in the Hyper + ischemia group, pyramidal neuronal death occurred in CA1–3 at 2 days after ischemia. Taken together, our findings showed that brain ischemic insult during hyperthermic condition brings up earlier and severer neuronal damage/death in the hippocampus, showing that HO-1 expression in neurons and astrocytes is different according to brain subregions and temperature condition. Based on these findings, we suggest that hyperthermia in patients with ischemic stroke must be taken into the consideration in the therapy.     

Ischemic Postconditioning Alleviates Neuronal Injury Caused by Relief of Carotid Stenosis in a Rat Model of Cerebral Hypoperfusion

The effects of early relief of heavy bilateral carotid stenosis and ischemic postconditioning on hippocampus CA1 neurons are still unclear. In this study, we used a rat model to imitate severe bilateral carotid stenosis in humans. The rats were divided into sham group, carotid stenosis group, stenosis relief group and ischemic postconditioning group. Ischemic postconditioning consisted of three cycles of 30 s ischemia and 30 s reperfusion. The cerebral blood flow was measured with a laser Doppler flowmeter. Neuronal death in the CA1 region was observed by hematoxylin-eosin staining, and the number of live neurons was assessed by cell counting under a light microscope. The levels of oxidative products MDA and 8-iso-PGF2α, inflammatory factors IL-1β and TNF-α, and the activities of anti-oxidative enzymes SOD and CAT were assayed by specific enzyme-linked immunosorbent assay (ELISA) kits, respectively. We found that relief of carotid stenosis and ischemic postconditioning could increase cerebral blood flow. When stenosis was relieved, the percentage of live neurons was 66.6% ± 6.2% on day 3 and 62.3% ± 9.8% on day 27, which was significantly higher than 55.5% ± 4.8% in stenosis group. Ischemic postconditioning markedly improved the live neurons to 92.5% ± 6.7% on day 3 and 88.6% ± 9.1% on day 27. Further study showed that, neuronal death caused by relief of stenosis is associated with increased oxidative stress and enhanced inflammatory response, and the protection of ischemic postconditioning is related to inhibition of oxidative stress and suppression of inflammatory response.     

CpG-ODN对肾小球肾炎进展的影响

目的观察CpG-ODN对肾小球肾炎进展的影响。方法将Wistar雄性大鼠随机分为N组(正常对照)、M组(模型对照)、CpG组和GpC组。N组大鼠经尾静脉注射生理盐水2.5ml/(kg·d),其余3组大鼠经尾静脉注射抗-thy1.1单克隆抗体2.5ml/(kg·d),隔日1次,共3次。注射抗-thy1.1单克隆抗体后,隔天,CpG组经尾静脉注射CpG-ODN,300μg/只,GpC组经尾静脉注射GpC-ODN,300μg/只,隔日注射,共3次。各组大鼠分别于用药前和第1针注射后1周测定尿蛋白;用药后第8周留取大鼠24h尿、血清及肾脏组织,检测24h尿蛋白定量、血清白蛋白和肾功;肾脏组织用于肾脏病理检查以及RT-PCR法检测TLR-9mRNA的表达。结果CpG组与M组和GpC组相比,血清白蛋白含量明显降低,且差异有显著意义;M组、CpG组和GpC组在给药后1周均出现尿蛋白,在给药后8周,24h尿蛋白含量明显增多;CpG组与M组相比,TLR-9mRNA在肾脏的表达水平明显增加,且差异有显著意义;GpC组与M组相比,差异无显著意义;光镜下可见CpG组肾组织病理改变明显加重。结论天然CpG-ODN可促进肾小球肾炎病情加重,TLR-9可能在其发生机理中起重要作用。