气体信号分子硫化氢在热性惊厥脑损伤形成机制中的作用

目的:探讨硫化氢(H2S)对反复热性惊厥(febrile seizures,FS)脑损伤的影响。方法:大鼠随机分为对照组、FS组、FS+NaHS组、FS+HA(hydroxylamine)组。采用热水浴诱导大鼠FS,隔日诱导1次,共10次。记录大鼠惊厥潜伏期、持续时间及强度;分光光度计法测定大鼠血浆中H~2|S含量;电镜观察海马神经元超微结构的改变;Timm染色观察海马发芽情况;原位杂交和免疫组化分别观察c-fos基因和Fos蛋白表达情况。结果:FS+NaHS组和FS+HA组大鼠惊厥潜伏期、持续时间及强度的改变与FS组相比无明显差异;FS+NaHS组大鼠海马神经元超微结构损伤性改变较FS组明显减轻,而FS+HA组则明显加重;NaHS干预后海马苔藓纤维发芽减轻,而HA干预后海马发芽加重;NaHS的干预使c-fos基因和Fos蛋白表达降低,而HA的干预使其表达增强。结论:应用H~2|S外源性供体NaHS和胱硫醚-β-合成酶抑制剂HA的干预研究表明,气体信号分子硫化氢参与了热性惊厥脑损伤的发生与发展过程。     

胱硫醚β-合成酶G919A基因多态性与原发性高血压关系的meta分析

目的综合评估胱硫醚β-合成酶(CBS)基因G919A多态性与原发性高血压(EH)发生风险的关系。方法全面检索Pub Med、Embase、Medline、万方数据库、中国知网(CNKI)、维普资讯,收集CBS基因G919A多态性与EH发生关系的病例对照研究,优势比(OR)及95%可信区间(CI)评估关联强度,应用Rev Man5.3软件对纳入研究进行异质性检验和效应值OR合并,漏斗图评价发表性偏倚;敏感度分析过程,分别以固定效应模型和随机效应模型合并OR值,以评估结果的稳定性。结果共纳入4篇文献6组病例-对照研究,共累计EH组患者1147例,健康对照组1138例,根据异质性检验结果选取固定效应模型或随机效应模型合并数据。Meta分析结果显示:CBS基因919纯合子模型(AA vs GG)、杂合子模型(GA vs GG)、显性模型(AA+GA vs GG)、隐性模型(AA vs GG+GA)和基因频率(A vs G)与EH关系的合并OR(95%CI)分别为3.03(1.95~4.72)、1.49(1.10~2.02)、1.61(1.23~2.10)、2.65(1.26~5.57)和1.55(1.35~1.79),均P0.01。漏斗图未检测出显著的发表性偏倚。结论目前Meta分析表明CBS基因G919A多态性与EH发病相关联,尤其是在中国人群。     

The selective effect of cystathionine on doxorubicin hepatotoxicity in tumor-bearing mice

The aim of the present study was to examine the protective effect of cystathionine as a cysteine precursor on doxorubicin toxicity in the liver of Ehrlich ascites tumor (EAT)-bearing mice and in the EAT cells. Both compounds were injected intraperitoneally alone or in combination at the following doses: cystathionine at 10 mg and doxorubicin at 5 mg per kg of body weight. In the liver of EAT-bearing mice, glutathione (GSH), cysteine and sulfane sulfur levels as well as the activities of: glutathione S-transferase, gamma-glutamyl transpeptidase, rhodanese and gamma-cystathionase significantly dropped in comparison with healthy animals. Administration of cystathionine elevated GSH and cysteine levels in the livers of EAT-bearing mice and reduced lipid peroxidation. Furthermore, cystathionine increased gamma-glutamyl transpeptidase activity, thereby activating gamma-glutamyl cycle, responsible for proper glutathione metabolism in the cells. Cystationine did not influence sulfane sulfur level and rhodanese and gamma-cystathionase activity in the livers of EAT-bearing mice. It was next shown that cystathionine administered in combination with doxorubicin protected against the drug toxicity since it elevated thiol level, lowering reactive oxygen species content and suppressing lipid peroxidation. This means that, cystathionine in the liver of EAT-bearing mice can both correct harmful effects of carcinogenesis, and protect the liver from doxorubicin cytotoxicity. In contrast, in EAT cells, cystathionine lowered GSH and cysteine levels and did not alter reactive oxygen species level, lipid peroxidation, and gamma-glutamyl transpeptidase activity. All these data indicate that cystathionine action is selectively beneficial for normal cells because it corrects harmful effects induced by EAT development and protects the organism against doxorubicin cytotoxicity without impairing cytotoxicity of this drug to tumor cells.     

七氟醚预先给药对大鼠心肌缺血再灌注损伤时胱硫醚β-合酶和血红素氧合酶-1表达的影响

目的 评价七氟醚预先给药对大鼠心肌缺血再灌注损伤时胱硫醚β-合酶(CBS)和血红素氧合酶-1(HO-1)表达的影响.方法 健康成年雄性SD大鼠30只,体重180～220 g,采用随机数字表法,将大鼠随机分为3组(n=10):假手术组(S组)、缺血再灌注损伤组(I/R组)和七氟醚组(Sev组).结扎左冠状动脉前降支,缺血30 min,再灌注2h,制备心肌缺血再灌注损伤模型.Sev组于缺血前吸入七氟醚,呼气末浓度1.5％～1.7％,60 min后制备心肌缺血再灌注损伤模型.于再灌注2h时处死大鼠,取心肌组织,测定MDA含量(硫代巴比妥酸法)、SOD活性(黄嘌呤氧化酶法)、GSH含量(荧光法)、H2S含量(分光光度法)、CO含量(分光光度法)、CBS mRNA和HO-1 mRNA表达(RT-PCR法),电镜下观察心肌细胞超微结构.结果 与S组比较,I/R组和Sev组CO、H2S、MDA含量和心肌细胞线粒体变性率升高,CBS mRNA和HO-1 mRNA表达上调,SOD活性及GSH含量降低(P＜0.05);与I/R组比较,Sev组CO、H2S、MDA含量和心肌细胞线粒体变性率降低,CBS mRNA和HO-1 mRNA表达下调,SOD活性和GSH含量升高(P＜0.05).结论 七氟醚预先给药减轻心肌缺血再灌注损伤的机制与下调CBS和HO-1的表达有关.     

内源性硫化氢及其合成酶在膀胱癌恶性进展中的表达

目的探讨内源性硫化氢(H2S)及其合成酶胱硫醚-β-合成酶(CBS)、胱硫醚-γ-裂解酶(CSE)和3-巯基丙酮酸硫转移酶(MPST)在正常膀胱组织以及膀胱癌中的表达。方法选取因膀胱癌而行膀胱肿瘤电切术或膀胱癌根治术的肿瘤组织标本76例,同时收集15例正常膀胱组织作对照组。通过免疫组化和Western blot研究CBS、CSE和MPST在正常膀胱组织以及不同病理分期/分级膀胱癌组织中的表达情况;通过敏感硫电极法检测H2S在正常膀胱组织和膀胱癌中的含量。分别比较H2S及其合成酶在各组之间的差异,初步探讨H2S及其合成酶与膀胱癌恶性进展之间的关系。结果免疫组化结果显示CBS(79.1%)、CSE(81.3%)和MPST(84.6%)在膀胱癌黏膜和肌层组织中均有表达。CBS(P=0.021和P<0.001)和MPST(P=0.015和P=0.045)的表达在膀胱癌不同分期和分级之间有统计学差异。在所有检测的标本中,肌层浸润性膀胱癌中的H2S含量最高[(52.6±2.91)nmol·mg-1·min-1],各组之间有统计学差异。结论内源性H2S及其合成酶CBS、CSE和MPST在膀胱癌组织中的表达明显高于正常膀胱组织,且其表达在膀胱癌不同分期和分级之间有统计学差异。