气体信号分子硫化氢在油酸致大鼠急性肺损伤中的作用

目的:探讨胱硫脒-γ-裂解酶(cystathionine-γ-lyase,CSE)/硫化氢(hydrogen sulfide,H2S)系统在急性肺损伤(acute lunginjury,ALI)中的作用。方法:尾静脉注射油酸(oleic acid,OA)制备大鼠ALI模型为OA组,对照组注射等量生理盐水,注射OA前给予硫氢化钠(NaHS)(14μmol/kg)作为NaHS+OA组,单纯给予NaHS(14μmol/kg)作为NaHS组,分别测定血浆及肺组织H2S生成量、CSE活性、3-巯基丙酮酸转硫酶(3-mercaptopyruvate sulfurtransferase,MPST)活性、肺组织及血浆中丙二醛(MDA)、共轭二烯(Diene)键含量;并对肺部病变进行评定。结果:与对照组比较,OA组肺组织CSE、MPST活性及H2S浓度呈现下降趋势(P<0.01),血浆H2S浓度升高(P<0.01),血浆及肺组织MDA及Diene键含量升高(P<0.01);与OA组比较,NaHS+OA组血浆及肺组织MDA和Diene键含量明显下降(P<0.01)。结论:内源性CSE/H2S系统参与了OA致大鼠ALI的病理生理过程;给予外源性H2S可以减轻ALI时肺脏脂质过氧化损害。     

硫化氢对大鼠实验性肝硬化门静脉压力的影响

目的应用内源性硫化氢（H2S）供体硫氢化钠（NaHS）探讨内源性H2S/胱硫醚-γ-裂解酶（CSE）体系对大鼠肝硬化门静脉压力的影响。方法将32只健康雌性SD大鼠随机分为4组：C组和C＋S组采用复合因素法复制肝硬化模型。模型制备52 d后,N＋S组和C＋S组大鼠腹腔注射NaHS 56μmol/（kg.d）,N组和C组腹腔注射同等剂量的生理盐水。1周后分别测定各组大鼠门静脉压力（PVP）及门静脉血浆中H2S含量;采用免疫组织化学方法检测大鼠肝门区门静脉平滑肌细胞中CSE蛋白表达。结果与N组和N＋S组相比,C组和C＋S组PVP均升高,H2S含量及CSE蛋白表达均降低;与C组相比,C＋S组PVP降低,H2S含量及CSE蛋白表达均升高。结论 NaHS作为H2S供体可能具有改善肝硬化大鼠门脉高压的作用,其机制可能与H2S含量及CSE蛋白表达升高有关。     

Hydrogen sulfide is a novel prosecretory neuromodulator in the Guinea-pig and human colon

BACKGROUND & AIMS: Hydrogen sulfide (H(2)S) has been suggested as a novel gasomediator. We explored its unknown neuromodulatory role in human and guinea-pig colon. METHODS: We used immunohistochemistry to detect H(2)S-producing enzymes cystathionine gamma-lyase (CSE) and cystathionine beta-synthase (CBS) in enteric neurons, Ussing chambers to measure mucosal ion secretion, and neuroimaging with voltage- and Ca(++)-sensitive dyes to record H(2)S effects on guinea-pig and human enteric neurons. RESULTS: More than 90% of guinea-pig and human submucous and myenteric neurons were colabeled for CSE and CBS. Myenteric interstitial cells of Cajal were CSE-immunoreactive. The exogenous H(2)S donor NaHS (0.2-2.5 mmol/L) concentration-dependently increased chloride secretion in human and guinea-pig submucosa/mucosa preparations, but not in the colonic epithelial cell line T84. The secretory response was reduced significantly by tetrodotoxin (0.5 micromol/L), capsaicin desensitization (10 micromol/L), and the transient receptor potentials vanilloid receptor 1 antagonist capsazepine (10 micromol/L). The endogenous H(2)S donor L-cysteine also induced secretion that was diminished significantly by capsaicin desensitization, the CBS inhibitor amino-oxyacetic acid, and the CSE inhibitor propargylglycine. NaHS increased spike discharge in 23% of guinea-pig and 36% of human submucous neurons, but had no effect on Ca(++) mobilization in cultured guinea-pig enteric neurons. This excitatory response was reduced significantly by capsaicin desensitization and capsazepine, but not by glibenclamide (10 micromol/L). CONCLUSIONS: The presence of H(2)S-producing enzymes in human and guinea-pig enteric neurons, the excitatory action on enteric neurons, and the prosecretory effects of NaHS suggest H(2)S as a novel gut-signaling molecule. Its action mainly involves transient receptor potentials vanilloid receptor 1 receptors on extrinsic afferent terminals, which in turn activate enteric neurons.     

硫化氢与microRNA的调节作用及其对心血管疾病的影响

心血管疾病(cardiovascular disease,CVD)为世界头号死因.硫化氢(hydrogen sulfide,H2S)作为一种气体信号分子,通过促血管生成、血管舒张、抗血管内皮细胞衰老等机制,在CVD发生发展过程中发挥着重要作用.近年来的研究表明H2S可通过调节某些microRNA(miRNA)来改善心脏功能.miRNA是真核细胞中发现的一类高度保守的非编码小RNA分子,通过抑制蛋白质翻译和加速mRNA的降解从而调节基因表达.miRNA有望成为CVD的干预靶点.某些miRNA也可调节H2S的生物合成,这两者之间的调节作用开辟了CVD发生发展机制与干预研究的新途径.     

Time‐ and concentration‐dependent genomic responses of the rat airway to inhaled nickel sulfate

While insoluble nickel subsulfide (Ni₃S₂) was carcinogenic in the lung in a 2‐year rat bioassay, soluble nickel sulfate hexahydrate (NiSO_4*6H₂O) was not. To investigate whether differences in the cellular responses to these two nickel compounds could underlie their differential activities, we conducted parallel studies to determine the gene expression changes in micro‐dissected lung distal airway cells from Fischer 344 rats following inhalation of the two compounds for one and four weeks (6 hr per day, 5 days per week). The results of the Ni₃S₂ study have been reported previously; this paper reports the results for NiSO₄ and provides a comparative analysis. The cellular responses to NiSO₄ were highly similar to those previously reported for Ni₃S₂, and a set of genes was identified whose expression could be used as biomarkers for comparing cellular nickel effects from in vitro or in vivo studies with soluble NiSO₄ and particulate Ni₃S₂. Evaluation of the genomic concentration‐responses for the two compounds suggests that the highest inhaled concentration in the tumor bioassay for NiSO₄, which was limited by toxicity, may not have achieved the Ni concentrations at which tumors were observed in the Ni₃S₂ bioassay. However, several key differences in the immune responses to NiSO₄ and Ni₃S₂ were identified that may result from the differential intracellular disposition of Ni from NiSO₄ entering the cell as an ion rather than as a slowly soluble Ni₃S₂ particle. These differences may also contribute to the observation of tumors in the bioassay for Ni₃S₂ but not NiSO₄. Environ. Mol. Mutagen. 58:607–618, 2017. © 2017 The Authors Environmental and Molecular Mutagenesis published by Wiley Periodicals, Inc. on behalf of Environmental Mutagen Society     

四硫代钼酸铵作为新型硫化氢供体的鉴定及其对皮肤细胞的保护作用

 目的: 本研究旨在检测金属络合物四硫代钼酸铵(ATTM)的硫化氢(H₂S)释放能力并进一步观察其减轻氧化应激诱导的皮肤细胞损伤的作用。方法:反应瓶法检测ATTM在细胞培养基中释放的H₂S,二氯二氢荧光素二乙酸酯或罗丹明123染色结合荧光显微镜照相术分别检测细胞内活性氧簇(ROS)的含量和线粒体膜电位(ΔΨ_m),用试剂盒检测细胞存活率和乳酸脱氢酶(LDH)的释放。结果:与H₂S供体GYY4137类似,ATTM在细胞培养基中可剂量依赖性地释放H₂S。在25~400 μmol/L 的浓度范围内,ATTM处理对人皮肤细胞(HaCaT细胞)的存活率无明显影响(P>0.05)。紫外线照射或外源性给予ROS供体(过氧化氢,H₂O₂)处理均可增加HaCaT细胞内ROS的含量。400 μmol/L H₂O₂处理可明显降低HaCaT细胞的存活率(P<0.01),而在H₂O₂处理前给予ATTM预处理,细胞存活率明显提高,其中在100和200 μmol/L浓度时ATTM具有最好的细胞保护作用(P<0.01)。400 μmol/L H₂O₂处理还可损害细胞的ΔΨ_m和细胞膜并使LDH释放增加(P<0.01)。而在细胞遭受损伤前给予200 μmol/L ATTM预处理可明显改善ΔΨ_m的水平(P<0.05)并抑制LDH从细胞内释放(P<0.01)。结论:ATTM具有释放H₂S的能力并可保护人皮肤细胞对抗氧化应激诱导的损伤效应。     

内源性H2S在CCK-8减轻脂多糖所致急性肺损伤中的作用

目的：探讨内源性硫化氢(H₂S)在八肽胆囊收缩素(CCK-8)减轻脂多糖（LPS）所致急性肺损伤(ALI)中的作用。方法: 将84只SD大鼠随机分为正常对照组、LPS组（经气管内滴注LPS复制ALI）、NaHS(H₂S供体)+LPS组、炔丙基甘氨酸［胱硫醚-γ-裂解酶（CSE）抑制剂，PPG］+LPS组、CCK-8+LPS组、PPG+CCK-8+LPS组和CCK- 8组。给药后分别于4 h和8 h处死动物，测定肺湿/干比值；光镜观察肺组织形态学改变；化学法检测血浆H₂S含量，肺组织MDA含量、MPO活性和CSE活性；放免法检测肺组织P-selectin含量；RT-PCR检测肺组织CSE mRNA的表达；并行支气管肺泡灌洗，检测支气管肺泡灌洗液(BALF)中蛋白含量。结果: 气管内滴注LPS可引起肺组织明显的形态学改变；肺湿/干比值、BALF中蛋白含量及肺组织MDA、MPO活性和P-selectin水平增高；血浆H2S含量、肺组织CSE活性及CSE mRNA表达下降。预先给予NaHS或CCK-8可显著减轻LPS所致的上述改变，且血浆H₂S含量、肺组织CSE活性及CSE mRNA表达高于相应的LPS组；预先给予PPG可加重LPS所致的肺损伤，而血浆H₂S含量、肺组织CSE活性及CSE mRNA表达分别低于相应的LPS组和CCK-8+LPS组。结论: CCK-8可通过内源性H₂S介导的抗氧化、抑制PMN黏附聚集等效应发挥减轻LPS所致肺损伤的作用。     

CFTR氯通道在硫化氢诱导的心肌保护及细胞增殖中的作用

目的： 探讨囊性纤维化跨膜传导调节因子（CFTR）氯通道在硫化氢（H2S）诱导的心肌保护及细胞增殖中的作用。方法：应用氯化钴（CoCl2）在大鼠H9c2心肌细胞建立化学性缺氧损伤心肌细胞实验模型;CCK-8试剂盒检测心肌细胞存活率;Hoechst 33342核染色法检测心肌细胞凋亡。结果：在400-2 000 μmol/L浓度范围内,CoCl2呈剂量依赖性地抑制H9c2心肌细胞的存活率,600 μmol/L CoCl2 能诱导H9c2心肌细胞产生明显的凋亡;在100-800 μmol/L浓度范围内,硫氢化钠（NaHS）呈剂量依赖性地促进H9c2心肌细胞增殖;NaHS能保护H9c2心肌细胞对抗CoCl2引起的细胞损伤作用,使细胞存活率升高,凋亡率降低;100 μmol/L CFTR氯通道拮抗剂5-硝基-2-（3-苯丙胺）-苯甲酸（NPPB)能明显地阻断NaHS对CoCl2的细胞毒性的抑制作用,但不能阻断NaHS抗心肌细胞凋亡作用及促进心肌细胞增殖作用。结论：CFTR氯通道可能参与H2S的抗CoCl2引起的心肌细胞毒性作用。     

Role of cytochrome P4502E1 in alcoholic liver disease pathogenesis

The intragastric tube feeding model is ideal for the study of the role of dietary factors and the effect of drugs on experimental alcoholic liver disease (ALD), since the model allows us to study the effect of a single variable in the diet on the pathology of liver where the blood alcohol level (BAL) is maintained over 150 mg%. By varying the dietary fatty acid composition we showed that the pathology was worsened by increasing linoleic acid or polyunsaturated fatty acids (PUFAs) in the diet where cytochrome P4502E1 (CYP2E1) was increased posttranslationally by high BAL. Concomitant with the increase in CYP2E1 there was evidence for an increase in lipid peroxidation (LP) by microsomes. Protein adducts of the products of LP were increased in the blood. Isoniazid (INH) enhanced this process and the pathology of ALD when INH was fed at therapeutic levels with ethanol. Preliminary studies show that diallyl sulfide, which inhibits and destroys liver CYP2E1 selectively, also modified the pathologic effects of ethanol. Thus we postulate that CYP2E1 induction plays a central role in the pathogenesis of ALD.