Effect of curcumin on learning-memory ability and expression of HMGB1 and JNK in rat model of Alzheimer disease

AIM: To evaluate the effect of curcumin on impaired learning-memory ability and the expression of high mobility group box protein 1 (HMGB1) and c-Jun N-terminal kinase (JNK) in a rat model of Alzheimer disease (AD). METHODS: Male Sprague-Dawley rats, weighing 250~270 g, were randomly divided into 4 groups (n=9): blank control group (group A), model group (group B), curcumin treatment group (group C, curcumin injected intraperitoneally at 100 mg·kg-1·d-1 for 6 consecutive days) and solvent control group (group D). The rats of AD model were induced by injection of ibotenic acid into the nucleus basalis of Meynert (NBM) bilaterally. All rats were trained in Morris maze to assess the ability of learning and memory. The expression of HMGB1 and JNK in the hippocampus was detected by the methods of immunohistochemistry and Western blotting. RESULTS: Compared with group A, the average escape latency (AEL) in groups B and D were obviously longer (P<0.05), while AEL in group C in the 5th and 6th days were significantly shorter (P<0.05). The releases of HMGB1 in the CA1 and CA3 areas in groups B and D from the nucleus were abundant. Compared with groups B and D, HMGB1 in hippocampal CA1 and CA3 areas in group C secreted out of the nucleus decreased obviously (P<0.05). No significant difference of the release of HMGB1 between group A and group C was observed (P>0.05). No significant difference in the expression of HMGB1 in the hippocampus among the 4 groups was found (P>0.05). However, compared with groups B and D, the expression of JNK in group C was decreased obviously (P<0.05). CONCLUSION: Curcumin significantly improves the learning and memory ability of AD rats. The probable mechanisms may be related to inhibiting the release of HMGB1 from the nucleus of hippocampal neurons and decreasing the expression of JNK in the hippocampus.     

Effect of JNK/MCP-1 signaling pathway on anti-diabetic neuropathic pain by curcumin in type 2 diabetic rats

AIM:To investigate the effect of JNK/MCP-1 signaling pathway on anti-diabetic neuropathic pain by curcumin in type 2 diabetic rats. METHODS:The male Sprague-Dawley rats were induced as the model of the type 2 diabetic neuropathic pain rats, they were randomly divided into 6 groups (n=27): type 2 diabetic neuropathic pain (DNP) group, type 2 diabetic neuropathic pain and intraperitoneal injection of curcumin (Cur) group, type 2 diabetic neuropathic pain and solvent control (DSC) group, type 2 diabetic neuropathic pain and JNK inhibitor (DJ) group, type 2 diabetic neuropathic pain and JNK inhibitor solvent control (DJS) group, type 2 diabetic neuropathic pain and monocyte chemoattractant protein 1 (MCP-1) agonist (DM) group. Another 27 normal SD rats were selected as control group. Mechanical withdrawal threshod and thermal withdrawal latency were measured at 3rd d, 7th d and 14th d after dosing, then the lumbar segment 4~6 of the spinal cord and L4~6 DRG were removed at the same time. ELISA was used to measure MCP-1 level. The expression of p-JNK was determined by Western blotting. RESULTS:Compared with DNP group, p-JNK was significantly decreased at 7th d and 14th d in Cur group, DJ group and DM group after treatment (P<0.05). Compared with C group, the MCP-1 was significantly declined in other 6 group after streptozotocin injection (P<0.05). Compared with DNP group, MCP-1 were significantly increased at 7th d and 14th d in Cur group and DJ group after treatment (P<0.05), and that in DM group was greatly decreased (P<0.05). CONCLUSION: The expression of p-JNK and MCP-1 was increased in DNP rats with spinal cord and dorsal root ganglion. The mechanism of curcumin reducing the neuropathic pain in type 2 diabetic rats might be through regulating the JNK/MCP-1 pathway.     

Expression of p-p38 MAPK in partial cerebral tissues after hypoxic-ischemic brain damage in neonatal A2AR knockout mice

AIM： To study the expression of p-p38 MAPK in partial cerebral tissues after hypoxic-ischemic brain damage (HIBD) in the neonatal adenosine A2A receptor knockout (A2AR-/-) mice. METHODS：Base on the modified Rice method, the model of HIBD was established. The total 64 C57/BL6 neonatal mice (7 days old) of A2AR-/-(KO) and corresponding wild type (A2AR+/+, WT) were randomized into sham-operated group and model group. The mice in model group were divided into 3 subgroups： 1 d after HIBD, 3 d after HIBD and 7 d after HIBD (n=8 for each group). The cortex and hippocampal CA1 region were used as the study areas. The neuronal apoptosis was detected using TUNEL assay combined with Nissl staining. The expression of p-p38 MAPK and activated caspase-3 was determined by the method of immunohistochemistry. The KO mice and WT mice were also taken from sham-operated group (SKO and SWT, n=10) and model group (MKO and MWT, n=30) 1 d after HIBD to assess the early neurological behavior. RESULTS：The apoptotic neurons, activated caspase-3 and p-p38 MAPK increased after HIBD and peaked at 1 d after HIBD in the cortex and the hippocampal CA1 region. The apoptotic neurons and the expression of activated caspase-3 in KO mice were significantly higher than those in WT mice at the same time point after HIBD. The expression level of p-p38 MAPK in KO mice were significantly higher than that in WT mice at 1 d and 3 d after HIBD. The expression of activated caspase-3 was positively correlated with the expression of p-p38 MAPK in neonatal mice after HIBD (in the cortex：r=0.957, P<0.01; in the hippocampal CA1 region： r=0.939, P<0.01). CONCLUSION：p-p38 MAPK might be involved in the aggravated neuron apoptosis and brain damage induced by A2AR knockout after neonatal HIBO.     

Intervention of hydrogen on memory damage induced by chronic hypoxia-hypercapnia in rats

AIM: To investigate the effects of hydrogen on the memory damage caused by chronic hypoxia-hypercapnia in rats. METHODS: Twenty-four SD rats trained by eight-arm radial maze test were randomly divided into 3 groups:normal control group (NC), hypoxia-hypercapnia+saline group (MS) and hypoxia-hypercapnia+ hydrogen group (MH). The rats in the latter 2 groups were placed in a closed cabin for 8 h/day,6 days/week and lasted for 4 weeks, in which O₂ was 9％-11％ and CO₂ was 5％-6％. In every time after the animals were out of the cabin, the MS rats were intraperitoneally injected with saline (5 mL/kg) and the MH rats were intraperitoneally injected with hydrogen solution at the same dose. The learning and memory function, the activity of superoxide dismutase (SOD), the content of malondialdehyde (MDA) and 8-hydroxydeoxyguanosine (8-OHdG) were examined after the cabin training. The ultramicrostructures of hippocampus were also observed. RESULTS: (1) Compared with NC group, the number of working memory errors, the total errors, the content of hippocampus 8-OHdG and serum MDA in MS and MH groups were higher and the activity of serum SOD was lower (P<0.05). The hippocampus structure was destroyed and some degree of edema and more apoptosis in the neurons were obserued in MS group and MH group. (2) Compared with MS group, the number of working memory errors(WME), the total errors, the content of hippocampus 8-OHdG and serum MDA were lower and the activity of serum SOD was higher in MH group (P<0.05). In MH group, the morphology of hippocampus structures kept nearly normal arrangement and the only mild edema and fewer apoptosis in the neurons were found. CONCLUSION: Hydrogen may attenuate chronic hypoxia-hypercapnia-induced memory damage in rats by inhibiting apoptosis of the neurons and decreasing detrimental free radicals reaction.     

Chemical composition of the green alga Codium Divaricatum Holmes

A new sterol, 24-R-stigmasta-4,25-diene-3β,6β-diol (1), along with three known compounds (2–3), was isolated from the green alga Codium divaricatum Holmes, a traditional Chinese medicine, which is efficacious against cancer. All structures were determined by spectroscopic methods and comparison with related known compounds. Single-crystal X-ray crystallography allowed us to confirm the structure of 1. To our knowledge, the compound 1 is reported as the first from natural source, and compounds 2, 4 have not been isolated from green algae before.     

快速检测双芽巴贝斯虫LAMP方法的建立

为提高双芽巴贝斯虫(Babesia bigemina)检出率,本研究采用环介导等温扩增技术(LAMP)建立一种快速、灵敏、特异的B.bigemina检测方法。根据GenBank上公布的Babesia bigemina细胞色素b(Cytochrome b,cyt b)基因序列,设计4条特异地识别B.bigemina的cyt b基因6个特殊区域的LAMP引物,优化反应体系和条件,在Bst DNA聚合酶的作用下,65 ℃反应60 min,加入SYBR Green Ⅰ后观察。结果表明,该LAMP检测方法特异性强,与牛巴贝斯虫(Babesia bovis)等DNA不发生交叉反应;敏感性高,对B.bigemina的cyt b基因最小检测值为0.085 fg/μL,是一般PCR方法的1000倍。该方法具有简单、快速、低成本的特点,可用于B.bigemina的基层现场快速检测。     

牛副结核病PCR检测方法的建立

根据GenBank上公布的副结核分枝杆菌C-2染色体的ISMav2基因序列设计特异性引物,对牛副结核分枝杆菌进行PCR扩增并将产物克隆到pMD18-T载体后测序。结果表明,扩增的目的片段大小为246 bp,与预期扩增序列同源性为99.6%。该PCR检测体系的特异性强,不能在非副结核分枝杆菌 DNA中扩增出条带;敏感性高,最低检测的DNA含量为1 pg。该检测体系的成功构建为牛副结核病的检测、鉴定和流行病学调查提供了有力的技术支持。     

利用转基因番茄表达血管内皮生长因子的研究

【目的】应用基因工程技术,获得表达血管内皮生长因子（VEGF）的转基因番茄植株,为以番茄作为生物反应器生产药用蛋白奠定基础。【方法】利用植物偏好的密码子改造合成VEGF基因全长,构建植物表达载体p1390RVEGF,通过农杆菌菌株EHA105介导将其T-DNA区转入到番茄细胞中,再生后获得转基因番茄植株,对其进行分子和蛋白水平检测。【结果】成功构建了植物整株表达载体p1390R-VEGF,建立了高频的番茄再生培养体系;PCR检测、Southern blot和Western blot检测结果表明,VEGF基因已经转入番茄中,并成功得到了表达。【结论】得到了转基因番茄植株和果实,且VEGF蛋白有良好的抗原性。     

泥蚶与牡蛎净化工艺优化初探

应用臭氧与二氧化氯对活体泥蚶和牡蛎进行微生物净化处理。首先对泥蚶和牡蛎进行暂养吐泥,每5 h换水一次,收集排泄物经离心计算相对吐泥量;臭氧净化处理浓度分别为0.4、0.8、1.6 mg/L,二氧化氯浓度分别为5、10、20 mg/L。结果表明：经5 h暂养吐泥即基本完成;用臭氧浓度0.4～1.6 mg/L或二氧化氯浓度5～20 mg/L净化处理24 h,细菌总数减少90%左右,大肠菌群与致病菌则由净化前的超标变成净化后的全面达标;净化处理后的泥蚶与牡蛎在5 ℃的条件下保存,10 d以内存活率为100%,净化处理后的泥蚶保存10 d再进行微生物检测依然达标。得出简便可行的净化工艺流程为：暂养吐泥5 h,再用0.4 mg/L臭氧净化24 h,然后用尼龙袋密封在5 ℃条件下保存。     

牛副结核分枝杆菌实时荧光定量 PCR 检测方法的建立

根据GenBank上公布的牛副结核分枝杆菌C-2染色体的ISMav2基因保守区域序列设计合成1对特异性引物,建立了一套SYBR GreenⅠ荧光定量PCR检测牛副结核分枝杆菌(Mycobacterium paratuberculosis)的方法。以实验室构建的牛副结核分枝杆菌pMD-ISMav2阳性重组质粒为标准品,通过优化反应条件,建立了标准曲线,其相关系数为0.999。以构建的标准品为模板,进行了特异性和敏感性试验。结果显示,该方法检测布氏杆菌、大肠杆菌、沙门氏菌、链球菌DNA均为阴性;最低可检测到相当于每微升1.96×10¹拷贝数的标准品阳性质粒。本研究建立的实时荧光定量PCR具有特异、敏感和快速等优点,可用于牛副结核杆菌病的监测。