益气活血中药复方对CVB3大鼠心肌细胞感染模型ATP6基因表达的影响

目的：研究益气活血中药复方对CVB3大鼠心肌细胞感染模型ATP6（ATP synthase F0 subunit 6）基因表达的作用机制。方法：本实验用新生2-3dWistar大鼠心肌细胞,建立CVB,病毒感染模型,通过改良的抑制性消减杂交技术（SSH）,克隆了受CVB,攻击的心肌细胞中被中药（益气活血中药复方）调控的基因。结果：ATP6基因,在中药组中高表达,而病毒组中表达减弱或抑制。结论：益气活血中药复方能影响受CVB,病毒攻击的宿主细胞ATP6基因的表达,有效保护心肌、阻断病程进度,从而实现治疗病毒性心肌炎的目的。     

淫羊藿苷对CVB3诱导的幼龄大鼠心肌炎的作用

目的探究淫羊藿苷(Icariin)对柯萨奇B3病毒(coxsackievirus B3,CVB3)诱导的幼龄大鼠心肌炎的作用及作用机制。方法将幼龄SD大鼠随机分为对照组(Ctrl组)、Icariin组、CVB3组和CVB3+Icariin组,CVB3组和CVB3+Icariin组大鼠腹腔注射CVB3复制心肌炎模型。HE染色检测心肌组织病理改变,Western blot检测Caspase-3和Caspase-9的表达,试剂盒检测心脏功能指标肌红蛋白(myoglobin,Mb)、肌酸激酶同工酶(Creatine kinase MB,CK-MB)、肌钙蛋白I(Cardiac troponin I,c Tn I)、氧化应激指标超氧化物歧化酶(superoxide dismutase,SOD)和丙二醛(malondialdehyde,MDA)的浓度,ELISA检测炎症因子白介素-6(Interleukin-6,IL-6)和IL-1β的浓度。结果与Ctrl组相比,CVB3组大鼠心肌组织病理损伤加重;与CVB3组相比,CVB3+Icariin组大鼠心肌组织病理损伤明显减轻;同时,CVB3组Caspase-3和Caspase-9的表达水平明显高于Ctrl组,差异有统计学意义(P0.01),CVB3+Icariin组大鼠Caspase-3和Caspase-9表达水平均低于CVB3组,差异有统计学意义(P0.01); CVB3能明显升高大鼠血清Mb、CK-MB和c Tn I的浓度(P0.01),Icariin能降低模型大鼠Mb、CK-MB和c Tn I的浓度,差异有统计学意义(P0.01);与Ctrl组相比,CVB3组大鼠血清SOD浓度明显降低(P0.01),MDA浓度明显升高(P0.01),而Icariin能减弱CVB3对SOD和MDA的调控作用,差异有统计学意义(P0.01);此外,CVB3能升高模型大鼠血清中IL-6和IL-1β的浓度(P0.01),Icariin能降低IL-6和IL-1β的浓度(P0.01)。结论 Icariin能通过抑制氧化应激和炎症反应减轻CVB3诱导的幼龄大鼠心肌炎。     

小檗碱通过JNK通路调控柯萨奇病毒B3感染心肌细胞凋亡的作用

小檗碱是具有细胞保护作用的生物碱,能够在柯萨奇病毒B3(CVB3)感染引起的病毒性心肌炎小鼠中发挥心肌保护作用,但具体的机制未阐明。在内皮细胞中,小檗碱通过c-Jun氨基末端激酶(JNK)通路抑制细胞凋亡,因此本研究将分析小檗碱通过JNK通路调控CVB3感染心肌细胞凋亡的作用。H9c2心肌细胞分为对照组(不含药物的DMEM处理)、模型组(含CVB3的DMEM处理)、小檗碱组(含CVB3及小檗碱的DMEM处理)、小檗碱+JNK质粒组(含CVB3、小檗碱、JNK质粒的DMEM处理),检测细胞凋亡率、肿瘤坏死因子-α(TNF-α)、白介素-6(IL-6)、活性氧(ROS)、丙二醛(MDA)的含量、p-JNK、cleaved caspase-3、bax、bcl-2的表达量。结果显示,模型组的细胞凋亡率、TNF-α、IL-6、ROS、MDA的含量、p-JNK、cleaved caspase-3、bax的表达量高于对照组,bcl-2的表达量低于对照组(P<0.05);小檗碱组的细胞凋亡率、TNF-α、IL-6、ROS、MDA的含量、p-JNK、cleaved caspase-3、bax的表达量低于模型组,bcl-2的表达量高于模型组(P<0.05);小檗碱+JNK质粒组的细胞凋亡率、TNF-α、IL-6、ROS、MDA的含量、p-JNK、cleaved caspase-3、bax的表达量高于小檗碱组,bcl-2的表达量低于小檗碱组(P<0.05)。以上结果表明小檗碱对CVB3感染心肌细胞的凋亡具有抑制作用,抑制JNK通路是介导这一作用可能的分子机制。     

基于PI3K/AKT通路研究槲皮素对柯萨奇病毒B3诱导心肌细胞损伤的保护作用

柯萨奇病毒B3(Coxsackievirus B3,CVB3)是引起病毒性心肌炎的主要病毒株,能够通过激活氧化应激及细胞凋亡来引起心肌细胞损伤。槲皮素是具有抗氧化、抗凋亡作用的黄酮类化合物,已经在CVB3感染小鼠中被证实能够减轻心肌损伤,但槲皮素是否直接在心肌细胞中抑制CVB3引起的氧化应激及凋亡尚未明确。本研究的目的是基于PI3K/AKT通路研究槲皮素对CVB3诱导心肌细胞损伤及氧化应激、凋亡的调节作用。本研究将原代培养新生SD大鼠的心肌细胞,分为不感染CVB3的对照组、感染CVB3的CVB3组、感染CVB3并用槲皮素处理的槲皮素组、感染CVB3并用槲皮素及PI3K抑制剂LY294002处理的槲皮素+LY组。检测CVB3基因组RNA、细胞活力OD_(490nm)值及凋亡率、培养基中天冬氨酸氨基转移酶(AST)、乳酸脱氢酶(LDH)、丙二醛(MDA)、超氧化物歧化酶(SOD)的含量、细胞中bcl-2、bax、裂解型caspase-3、磷酸化PI3K、磷酸化AKT的表达量。结果显示,槲皮素组中CVB3的基因组RNA与CVB3组比较无差异(P0.05),凋亡率、培养基中AST、LDH、MDA的含量、细胞中bax、裂解型caspase-3的表达量均明显低于CVB3组(P0.05),OD_(490nm)值、培养基中SOD的含量、细胞中bcl-2、磷酸化PI3K、磷酸化AKT的表达量明显高于CVB3组(P0.05);槲皮素+LY组中CVB3的基因组RNA与槲皮素组比较无差异(P0.05),凋亡率、培养基中AST、LDH、MDA的含量、细胞中bax、裂解型caspase-3的表达量均明显高于槲皮素组(P0.05),OD_(490nm)值、培养基中SOD的含量、细胞中bcl-2、磷酸化PI3K、磷酸化AKT的表达量明显低于槲皮素组(P0.05)。本研究揭示,槲皮素能够减轻CVB3诱导的心肌细胞损伤、氧化应激及凋亡,且该作用与激活PI3K/AKT通路有关。     

卡托普利对心力衰竭大鼠心肌细胞Bax、Bcl-2蛋白表达的影响

目的:探讨卡托普利对慢性压力负荷性心力衰竭大鼠心肌细胞凋亡相关基因Bax、Bcl-2蛋白表达的影响。方法:90只SD大鼠随机分为3组(n=30):假手术组(SH)、腹主动脉缩窄组(CAA)、卡托普利治疗组(CAP)。采用腹主动脉缩窄法复制模型,于第6、10周,检测各组心衰大鼠心肌细胞凋亡相关基因Bax,Bcl-2蛋白的表达。结果:造模后6周、10周结果均显示,CAA组较SH组心肌细胞凋亡基因Bcl-2蛋白及Bcl-2/Bax比例表达显著下降(P<0.01),Bax蛋白表达显著升高(P<0.01)。CAP组较CAA组Bcl-2蛋白及Bcl-2/Bax比例表达显著升高(P<0.01),Bax蛋白表达显著降低(P<0.01)。CAP组10周时较6周Bcl-2蛋白表达明显升高(P<0.05),Bax蛋白表达显著降低(P<0.01),Bcl-2/Bax比例显著升高(P<0.01)。结论:卡托普利能增加Bcl-2、降低Bax蛋白的表达,上调Bcl-2/Bax比率,从而抑制心肌细胞凋亡改善心功能。     

miR-27a-3p通过靶向Sema7A调控病毒性心肌炎心肌细胞损伤的机制研究

目的探讨微小RNA-27a-3p(miR-27a-3p)过表达对病毒性心肌炎(VMC)细胞损伤的影响及其可能的作用机制。方法原代培养大鼠心肌细胞,柯萨奇B3病毒(CVB3)感染心肌细胞建立VMC模型(CVB3组)。正常心肌细胞作为对照组,分别将miR-NC、miR-27a-3p mimics、si-NC,si-Sema7A分别转染至CVB3感染的心肌细胞,记为CVB3+miR-NC组、CVB3+miR-27a-3p组、CVB3+si-NC组、CVB3+si-Sema7A组。分别将miR-27a-3p mimics与pcDNA,miR-27a-3p mimics与pcDNA-Sema7A共转染至CVB3感染的心肌细胞,记为CVB3+miR-27a-3p+pcDNA组、CVB3+miR-27a-3p+pcDNA-Sema7A组。采用实时荧光定量聚合酶链反应(qRT-PCR)与Western blot法分别检测细胞中miR-27a-3p、信号蛋白7A(Sema7A)的表达水平;流式细胞术检测miR-27a-3p过表达或干扰Sema7A表达后心肌细胞的凋亡率;酶联免疫吸附(ELISA)法检测细胞中肿瘤坏死因子-α(TNF-α)、白细胞介素-1(IL-1)的含量;双荧光素酶报告基因验证miR-27a-3p与Sema7A的靶向关系;Western blot检测B淋巴细胞瘤-2相关蛋白(Bax)、活化的含半胱氨酸的天冬氨酸蛋白水解酶3(cleaved caspase-3)、B淋巴细胞瘤-2(Bcl-2)蛋白表达。两组间比较采用独立样本t检验。结果与对照组比较,CVB3组miR-27a-3p的表达水平(1.01±0.09比0.42±0.04)降低,Sema7A的mRNA和蛋白表达水平(1.02±0.09比2.15±0.21、0.43±0.04比0.94±0.09)升高,TNF-α、IL-1水平[(403.56±38.16)pg/mL比(1156.48±63.59)pg/mL>(29.45±3.54)pg/mL比(136.57±12.47)pg/mL]升高,细胞凋亡率[(5.36±0.54)%比(24.58±2.14)%]升高,Bax、cleaved caspase-3的表达水平升高,Bcl-2的表达水平降低(P均<0.05);与CVB3+miR-NC组比较,CVB3+miR-27a-3p组TNF-α,IL-1水平[(1187.69±71.42)pg/mL比(516.28±48.31)pg/mL、(147.25±14.05)pg/mL比(43.68±5.02)pg/mL]和细胞凋亡率[(26.38±2.55)%比(10.24±1.15)%]降低,Bax、cleaved caspase-3表达水平降低,Bcl-2表达水平升高(P均<0.05);双荧光素酶报告实验证实miR-27a-3p可靶向调控Sema7A的表达;Sema7A过表达可逆转miR-27a-3p过表达对CVB3诱导的VMC细胞损伤的作用。结论miR-27a-3p过表达可降低VMC细胞中炎症因子的表达及抑制细胞凋亡从而减轻心肌损伤,其作用机制可能与靶向调控Sema7A的表达有关。     

白藜芦醇通过Nrf2/ARE通路减轻柯萨奇病毒B3感染的乳鼠心肌细胞炎症和氧化应激反应

柯萨奇病毒B3(Coxsackievirus B3,CVB3)是引起病毒性心肌炎的主要病毒株,CVB3感染能够通过激活炎症反应及氧化应激反应来造成心肌细胞损伤。白藜芦醇(Resveratrol,RES)是具有抗炎、抗氧化作用的多酚化合物,已经被证实能够减轻缺血缺氧、缺氧复氧、脂多糖、过氧化氢等病理因素引起的心肌细胞损伤,但RES对CVB3感染引起心肌细胞损伤的保护作用尚未明确。为了研究RES通过核因子-E2相关因子2(Nuclear factor E2-related factor 2,Nrf2)/抗氧化反应元件(Antioxidant response element,ARE)通路减轻CVB3感染乳鼠心肌细胞的炎症和氧化应激反应,本研究采用原代培养大鼠乳鼠心肌细胞,分为DMEM处理的对照组、CVB3感染的CVB3组、CVB3感染及RES处理的RES组、CVB3感染及RES、Nrf2抑制剂鸦胆苦醇处理的RES+鸦胆苦醇组、CVB3感染及RES、血红素加氧酶-1(Heme oxygenase-1,HO-1)抑制剂锌原卟啉-9(Zinc protoporphyrin-9,ZnPP9)处理的RES+ZnPP9组,比较5组间心肌酶、CVB3拷贝数、炎症因子、氧化应激指标、Nrf2/ARE通路分子的差异。结果显示:与对照组比较,CVB3组培养基中乳酸脱氢酶(Lactate dehydrogenase,LDH)、肌酸激酶同工酶-MB(Creatine kinase isoenzyme-MB,CK-MB)、白介素(Interleukin,IL)-1β、IL-6、IL-8、肿瘤坏死因子-α(Tumor necrosis factor-α,TNF-α)、活性氧簇(Reactive oxygen species,ROS)、丙二醛(Malondialdehyde,MDA)的含量及细胞中CVB3拷贝数、Nrf2、NADH依赖的醌氧化还原酶1(NAD(P)H:quinone oxidoreductase-1,NQO-1)、HO-1的表达量明显增多(P0.05),培养基中超氧化物歧化酶(Superoxide dismutase,SOD)、谷胱甘肽过氧化物酶(Glutathione peroxidase,GPx)的含量明显减少(P0.05);与CVB3组比较,RES组培养基中LDH、CK-MB、IL-1β、IL-6、IL-8、TNF-α、ROS、MDA的含量明显减少(P0.05),培养基中SOD、GPx的含量及Nrf2、NQO-1、HO-1的表达量明显增多(P0.05),CVB3拷贝数无明显变化(P0.05);与RES组比较,RES+鸦胆苦醇组、RES+ZnPP9组培养基中LDH、CK-MB、IL-1β、IL-6、IL-8、TNF-α、ROS、MDA的含量明显增多(P0.05),培养基中SOD、GPx的含量明显减少(P0.05),CVB3拷贝数无明显变化(P0.05)。本研究揭示RES能够减轻CVB3感染引起的乳鼠心肌细胞炎症和氧化应激反应,激活Nrf2/ARE通路可能是其分子机制。     

肺虚痰阻证模型大鼠肺组织水通道蛋白1 和5 分子表达与补肺化痰方对 其影响*

目的:1)从肺泡上皮水主动转运功能的角度探讨肺虚痰阻证的发生机理。2)通过观察肺虚痰阻证模型的AQP的活性及其相关基因、蛋白的表达和补肺化痰中药复方治疗前、后的对比,观察这一过程中上述指标的变化情况。方法:将雄性SD大鼠随机分为正常组、模型组、中药治疗组。模型组和治疗组造模40天,治疗组在造模26天后,药物灌胃治疗2周。采用组织化学染色法,对大鼠肺进行病理分析;RT-PCR的方法检测大鼠肺组织中AQP1、AQP5基因表达;western blot法检测大鼠肺组织中AQP1、AQP5蛋白水平。结果:1)与正常组相比,模型组局部出现明显炎症反应(P<0.01),治疗组局部炎症反应减轻(P<0.05)。2)mRNA结果显示,AQP1在正常组有表达,在模型组和治疗组未见表达。AQP5模型组与正常组相比,表达量显著增高(P<0.01);治疗组与模型组比较,表达量显著降低(P<0.01),但与正常组无显著差异。3)蛋白水平上,AQP1在模型组和治疗组与正常组相比差异显著(P<0.05),表达下降。AQP5模型组与正常组相比,显著升高(P<0.01);治疗组与模型组比较,显著下调(P<0.05);正常组表达低于治疗组,差异显著(P<0.05)。结论:1)AQP1和5基因及蛋白表达量变化是肺虚痰阻证的病理机制之一。2)补肺化痰中药复方可调节肺虚痰阻证模型大鼠肺组织AQP 5基因及蛋白表达。提示补肺化痰中药复方治疗肺虚痰阻证其作用机制与调节AQP5有关。     

过表达β 2-AR对心衰大鼠心肌细胞的保护作用及相关信号转导通路

目的:检测过表达β 2-AR蛋白的慢性心衰大鼠心肌细胞内与细胞存活相关蛋白的表达变化,探讨过表达的β 2-AR对心衰大鼠心肌细胞的保护作用的分子信号机制.方法:通过腹主动脉缩窄术建立大鼠慢性心力衰竭(HF)模型并采用胶原酶消化法分离心衰大鼠心肌细胞,转染携带β 2-AR目的基因的重组腺病毒,通过免疫印迹方法检测正常细胞和心衰细胞内Gi-PI3K-Akt信号通路上关键蛋白的表达变化.结果:与正常大鼠心肌细胞相比,β 2-AR过表达促进了胞内Akt磷酸化水平的增加,而使得凋亡效应因子Caspase-3的激活减少(p＜0.05).结论:心衰大鼠心肌细胞过表达β 2-AR后,增加的B 2-AR通过Gi-PI3K-Akt信号对心肌细胞产生了保护作用.     

Identification of subunit g of yeast mitochondrial F1F0-ATP synthase, a protein required for maximal activity of cytochrome c oxidase.

By means of a yeast genome database search, we have identified an open reading frame located on chromosome XVI of Saccharomyces cerevisiae that encodes a protein with 53% amino acid similarity to the 11.3-kDa subunit g of bovine mitochondrial F1F0-ATP synthase. We have designated this ORF ATP20, and its product subunit g. A null mutant strain, constructed by insertion of the HIS3 gene into the coding region of ATP20, retained oxidative phosphorylation function. Assembly of F1F0-ATP synthase in the atp20-null strain was not affected in the absence of subunit g and levels of oligomycin-sensitive ATP hydrolase activity in mitochondria were normal. Immunoprecipitation of F1F0-ATP synthase from mitochondrial lysates prepared from atp20-null cells expressing a variant of subunit g with a hexahistidine motif indicated that this polypeptide was associated with other well-characterized subunits of the yeast complex. Whilst mitochondria isolated from the atp20-null strain had the same oxidative phosphorylation efficiency (ATP : O) as that of the control strain, the atp20-null strain displayed approximately a 30% reduction in both respiratory capacity and ATP synthetic rate. The absence of subunit g also reduced the activity of cytochrome c oxidase, and altered the kinetic control of this complex as demonstrated by experiments titrating ATP synthetic activity with cyanide. These results indicate that subunit g is associated with F1F0-ATP synthase and is required for maximal levels of respiration, ATP synthesis and cytochrome c oxidase activity in yeast.     

Altered profile of gene expression in rat hearts induced by chronic nicotine consumption

Using a cDNA microarray technique, we analyzed the expression profile of 1081 genes in the whole heart tissue of rats. The expressions of three classes of genes encoding cellular energy metabolism enzymes, transmembrane receptors, and intracellular kinase network members were reduced by more than 2.5-fold in cardiac tissues from the rats fed with nicotine (3mg/kg/day) for 3 months. The down-regulated 11 genes included mitochondrial ATP synthase beta subunit, mitochondrial H(+) transporting ATP synthase F1 complex alpha subunit isoform 1, liver mitochondrial aldehyde dehydrogenase 2, glutathione-S-transferase mu type 2, corticotropin-releasing factor receptor 2, metabotropic glutamate receptor 2, N-methyl-D-aspartate receptor subtype 2B, muscarinic acetylcholine receptor M3, transmembrane receptor Unc5H1, glycogen synthase kinase 3alpha, and Ca(2+)/calmodulin-dependent protein kinase II beta subunit. It appears that chronic nicotine treatment affects cardiac function by modulating the expressions of genes involved in energy metabolism and signal transduction.     

Isolated epsilon subunit of thermophilic F1-ATPase binds ATP

F1-ATPase, a soluble part of the F0F1-ATP synthase, has subunit structure alpha3beta3gammadeltaepsilon in which nucleotide-binding sites are located in the alpha and beta subunits and, as believed, in none of the other subunits. However, we report here that the isolated epsilon subunit of F1-ATPase from thermophilic Bacillus strain PS3 can bind ATP. The binding was directly demonstrated by isolating the epsilon subunit-ATP complex with gel filtration chromatography. The binding was not dependent on Mg2+ but was highly specific for ATP; however, ADP, GTP, UTP, and CTP failed to bind. The epsilon subunit lacking the C-terminal helical hairpin was unable to bind ATP. Although ATP binding to the isolated epsilon subunits from other organisms has not been detected under the same conditions, a possibility emerges that the epsilon subunit acts as a built in cellular ATP level sensor of F0F1-ATP synthase.     

The typically mitochondrial DNA-encoded ATP6 subunit of the F1F0-ATPase is encoded by a nuclear gene in Chlamydomonas reinhardtii.

The atp6 gene, encoding the ATP6 subunit of F(1)F(0)-ATP synthase, has thus far been found only as an mtDNA-encoded gene. However, atp6 is absent from mtDNAs of some species, including that of Chlamydomonas reinhardtii. Analysis of C. reinhardtii expressed sequence tags revealed three overlapping sequences that encoded a protein with similarity to ATP6 proteins. PCR and 5'- and 3'-RACE were used to obtain the complete cDNA and genomic sequences of C. reinhardtii atp6. The atp6 gene exhibited characteristics of a nucleus-encoded gene: Southern hybridization signals consistent with nuclear localization, the presence of introns, and a codon usage and a polyadenylation signal typical of nuclear genes. The corresponding ATP6 protein was confirmed as a subunit of the mitochondrial F(1)F(0)-ATP synthase from C. reinhardtii by N-terminal sequencing. The predicted ATP6 polypeptide has a 107-amino acid cleavable mitochondrial targeting sequence. The mean hydrophobicity of the protein is decreased in those transmembrane regions that are predicted not to participate directly in proton translocation or in intersubunit contacts with the multimeric ring of c subunits. This is the first example of a mitochondrial protein with more than two transmembrane stretches, directly involved in proton translocation, that is nucleus-encoded.     

Turnover of ATP synthase subunits in F1-depleted HeLa and yeast cells

Mitochondrial translation of the Saccharomyces cerevisiae Atp6p subunit of F(1)-F(0) ATP synthase is regulated by the F(1) ATPase. Here we show normal expression of Atp6p in HeLa cells depleted of the F(1) β subunit. Instead of being translationally down-regulated, HeLa cells lacking F(1) degrade Atp6p, thereby preventing proton leakage across the inner membrane. Mammalian mitochondria also differ in the way they minimize the harmful effect of unassembled F(1) α subunit. While yeast mutants lacking β subunit have stable aggregated F(1) α subunit in the mitochondrial matrix, the human α subunit is completely degraded in cells deficient in F(1) β subunit. These results are discussed in light of the different properties of the proteins and environments in which yeast and human mitochondria exist.