紫草素对人绒毛膜滋养层细胞HTR-8/Svneo线粒体自噬和功能的影响

目的 研究紫草素对HTR-8/Svneo细胞线粒体自噬和线粒体功能的影响。方法 将人绒毛膜滋养层细胞分为4组：对照组、Mdivi-1组、紫草素组和紫草素+Mdivi-1组。对照组正常培养;Mdivi-1组以5μmol·L^-1 Mdivi-1处理;紫草素组用0.8μmol·L^-1紫草素干预;紫草素+Mdivi-1组以0.8μmol·L^-1紫草素+5μmol·L^-1 Mdivi-1干预处理。用流式细胞术检测细胞凋亡率;用ATP检测试剂盒测定细胞ATP含量;用Dihydroethidium(DHE)荧光检测探针测定细胞内超氧化物水平;用蛋白质印迹法测定线粒体自噬相关蛋白表达水平。结果 细胞分组处理24 h后,对照组、Mdivi-1组、紫草素组、紫草素+Mdivi-1组的凋亡率分别为(6.86±0.37)%,(7.14±0.23)%,(39.97±1.52)%和(14.63±1.19)%;这4组的ATP含量为100%,(89.13±6.23)%,(52.03±9.12)%和(67.84±10.03)%;这4...     

重建线粒体动态平衡对NK细胞NK2型活化影响

目的立于“线粒体功能紊乱-细胞异常活化”视角,探讨NK细胞NK2型活化机制。方法将NK-92MI细胞分为空白组、TSLP组、1、5、10μmol·L^-1 Mdivi-1组。ELISA法测定各组IL-4、IL-5、IFN-γ水平;蛋白印迹法分析各组p-Drp1、MnSOD蛋白表达;DHE染色及流式检测各组ROS水平;激光共聚焦观察各组线粒体形态。结果ELISA显示,与对照组比较,TSLP组IL-4、IL-5水平明显升高,IFN-γ水平下调(P<0.05);与TSLP组比较,5、10μmol·L^-1 Mdivi-1组IL-4、IL-5水平降低,10μmol·L^-1 Mdivi-1组IFN-γ浓度有所回升(P<0.05)。DHE染色及流式显示,TSLP组ROS水平较对照组升高;而5、10μmol·L^-1 Mdivi-1组ROS水平较TSLP组降低(P<0.05)。共聚焦显示,TSLP刺激后,细胞内大量圆球状线粒体生成,5、10μmol·L^-1 Mdivi-1干预后该现象得到改善。蛋白印迹显示,TSLP组p-Drp1水平明显上调,MnSOD表达下降,Mdivi-1干预则有效逆转了上述变化。结论线粒体动态失衡可能是NK细胞异常活化内在机制之一,其或是调控NK细胞NK2型活化介导的变应性炎症反应的重要靶点。     

5-单硝酸异山梨酯缓释胶囊的人体生物等效性

采用GC法测定 5 单硝酸异山梨酯血浆药物浓度 ,研究 5 单硝酸异山梨酯缓释胶囊相对生物利用度和生物等效性。 18名健康志愿者随机交叉单剂量口服试验药 (T)与对照药 (R) 4 0mg ,测得Cmax分别为 (348 3± 146 8)ng/mL和 (347 9± 2 0 2 4)ng/mL ;Tmax 分别为 (4 7± 1 8)h和(4 6± 1 7)h ;AUC( 0 -n) 分别为 (3 933 2± 142 5 0 )ng h/mL和 (3 6 93 0± 12 39 5 )ng h/mL ;相对生物利用度为 (10 6 6± 16 9) %。 18名志愿者随机交叉多剂量口服T与R ,测得达稳态的Cmax分别为 (2 30 9± 72 4)ng/mL和 (190 9± 6 6 9)ng/mL ;Cmin分别为 (4 2 6± 2 3 5 )ng/mL和 (4 7 4±2 2 1)ng/mL ;AUCSS分别为 (2 939 4± 92 2 1)ng h /mL和 (2 6 6 7 4± 832 9)ng·h /mL ;DF分别为1 6± 0 4和 1 3± 0 3 ;相对生物利用度为 (111 0 2± 2 1 0 5 ) %。经生物等效性分析 ,两制剂在单剂量与多剂量条件下生物等效     

灯盏花乙素通过调节线粒体融合-分裂平衡抑制氧糖剥夺/复糖复氧诱导的N2a细胞焦亡

目的: 探讨灯盏花乙素对氧糖剥夺/复氧复糖(OGD/R)诱导的N2a细胞焦亡的影响及作用机制。方法: 建立N2a细胞OGD/R损伤模型,设立对照组、模型组、灯盏花乙素给药组和线粒体分裂抑制剂Mdivi-1组。通过CCK-8检测N2a细胞增殖能力,检测各组细胞培养基中LDH和IL-1β水平,通过JC-1探针检测线粒体膜电位,Western blot检测线粒体融合分裂关键蛋白(Drp-1、Mfn-1、Mfn-2、OPA-1)和细胞焦亡标志蛋白(Caspase-1、NLRP-3和GSDMD)表达。结果: 与对照组相比,OGD/R可显著降低N2a细胞活力,灯盏花乙素可明显提高N2a细胞活力。与模型组相比,灯盏花乙素可减少LDH的释放,降低Caspase-1和IL-1β水平,提高线粒体膜势能,降低Drp-1的表达水平,上调Mfn-1、Mfn-2和OPA-1的表达,并减少细胞焦亡关键蛋白NLRP-3和GSDMD的表达。进一步给予Drp-1抑制剂Mdivi-1,与模型组相比,Mdivi-1可明显提高线粒体膜势能,减少Caspase-1、NLRP-3和GSDMD的表达。结论: 灯盏花乙素可通过抑制线粒体过度分裂,改善线粒体融合-分裂失衡与功能异常,进而缓解OGD/R所致N2a细胞焦亡。     

大黄中游离蒽醌对HK-2细胞系的毒性作用研究*

目的:观察大黄中大黄素等游离蒽醌对人近曲小管上皮细胞(HK-2)的细胞毒性作用及毒性作用机制。方法:体外培养HK-2细胞,利用MTT法评价大黄素等对HK-2细胞的增殖抑制作用,观察不同浓度药物对细胞形态和LDH释放率的影响,利用TUNEL染色检测大黄素等对HK-2细胞凋亡的影响,细胞线粒体膜电位和活性氧(ROS)生成的检测采用流式细胞技术,分别以DCFH-DA和罗丹明-123为荧光探针。结果:大黄素、大黄酸和大黄素甲醚作用HK-2细胞48 h后,明显抑制细胞增殖,其IC50值分别为130.65,82.97和76.02μmol.L-1,芦荟大黄素轻微抑制HK-2细胞增殖,大黄酚作用不明显。大黄素、大黄酸和大黄素甲醚能够导致细胞皱缩和空泡化,LDH漏出率增加以及促使细胞凋亡,3种蒽醌均使细胞的线粒体膜电位降低,而ROS生成减少,80μmol.L-1大黄素预处理细胞能够明显降低H2O2引起的ROS升高。结论:大黄素、大黄酸和大黄素甲醚可能是大黄中主要的肾毒性物质,能够引起HK-2细胞的凋亡,其机制可能涉及线粒体膜电位途径,但是不包括ROS生成途径。     

土木香乙酸乙酯提取物对人胰腺癌Capan-2细胞增殖的抑制作用及机制研究

目的:研究土木香乙酸乙酯提取物(IHE)对人胰腺癌Capan-2细胞增殖的抑制作用及机制。方法:采用MTT法测定0、0.5、1、2、4、8μg/mL的IHE作用48 h后细胞的增殖抑制率,克隆形成试验观察0、1、2μg/mL的IHE作用1周后对细胞克隆形成的影响,Hoechst 33342染色法观察0、2、4μg/mL的IHE作用48 h后细胞核形态的变化,流式细胞术检测0、4、8、16μg/mL的IHE作用48 h后细胞的凋亡率,JC-1染色法观察0、4、8、16μg/mL的IHE作用24 h后细胞线粒体膜电位变化,Western blot法检测0、4、8、16μg/mL的IHE作用48 h后细胞线粒体凋亡相关蛋白Bcl-2、Bax、Mcl-1和p53上调凋亡因子(PUMA)、多聚二磷酸腺苷核糖聚合酶(PARP)蛋白的表达。结果:2、4、8μg/mL的IHE对细胞的增殖有明显抑制作用,且呈浓度依赖性,半数抑制浓度为6.6μg/mL;1、2μg/mL的IHE可明显抑制细胞的克隆形成;4μg/mL的IHE可明显造成细胞核固缩;8、16μg/mL的IHE可明显促进细胞凋亡,16μg/mL的IHE作用48 h后细胞凋亡率达到45.53%;16μg/mL的IHE作用24 h后可引起82.47%的细胞线粒体膜电位下降;8μg/mL的IHE可明显下调细胞中Bcl-2、Mcl-1、PUMA、PARP蛋白表达,16μg/mL的IHE可明显下调细胞中Mcl-1、PUMA表达。结论:IHE可能通过引起细胞线粒体膜电位的下降,下调细胞中PUMA、Mcl-1蛋白的表达,引起细胞的凋亡,从而发挥其抑制人胰腺癌Capan-2细胞增殖的作用。     

去氢骆驼蓬碱诱发PC12细胞凋亡时对线粒体融合分裂的影响

目的 探讨去氢骆驼蓬碱(HM)对PC12细胞线粒体功能损伤和线粒体融合分裂相关蛋白表达水平的影响。方法 PC12细胞分为细胞对照组、HM组、线粒体分裂抑制剂Mdivi-1组、HM+Mdivi-1组、线粒体裂变激动剂WY14643组、HM+WY14643组,药物浓度均为1、10、25、50、100μmol·L^-1,处理24 h,噻唑蓝(MTT)法检测细胞存活率,显微镜观察细胞形态;MitoTracker Red探针染色观察线粒体形态和纵横轴长度比值,JC-1染色检测线粒体膜电位,试剂盒检测ROS、ATP水平和乳酸脱氢酶(LDH)活性,免疫荧光染色法和Western blotting检测胱天蛋白酶3(caspase-3)、促凋亡蛋白(Bax)、细胞色素C(cyt-c)和线粒体融合蛋白(Mfn2)、线粒体分裂蛋白(Drp-1)的表达水平;电穿孔法转染Drp1的干扰序列,筛选转染效果好的siRNA序列,协同药物干预,通过荧光法、MTT法、免疫印迹法检测相关指标。结果 MTT结果显示,与细胞对照组比较,HM组、Mdivi-1组、HM+Mdivi-1组、WY14643组和HM...     

大黄素诱导HK-2细胞凋亡的机制探讨

 目的：探讨大黄中游离蒽醌大黄素诱导人近曲小管上皮细胞（HK-2）的细胞凋亡作用机制。方法：体外 培养HK-2细胞,利用MTT法评价大黄素对HK-2细胞的增殖抑制作用,利用TUNEL染色检测大黄素对HK-2细胞凋亡的影响, 流式细胞技术检测大黄素对HK-2细胞线粒体膜电位的影响,凋亡相关蛋白检测采用Western Blot分析;结果：大黄素作 用HK-2细胞48 h后,明显抑制细胞的增殖,IC50值为130.65 μmol•L-1。大黄素浓度为80 μmol•L-1时促使细胞凋亡, 线粒体膜电位降低,Western Blot分析凋亡相关蛋白显示,大黄素作用HK-2细胞后,抑制细胞外信号调节激酶1/2 （extracelluar signal regulated kinase 1/2,ERK1/2）的磷酸化,并且呈现明显的剂量和时间效应关系,细胞内 Bcl-2表达降低,Bax没有明显的变化,致使促凋亡基因蛋白占优势,细胞向促调亡的方向发展,细胞色素c释放增加, 从而使Caspase-8活化,激活下游Caspase-3,引起细胞的凋亡;大黄素对HK-2细胞的损伤效应可能是通过MAPK/ERK信号 转导通路抑制ERK磷酸化,而导致了细胞凋亡。结论：大黄素能够引起HK-2细胞的凋亡,其机制可能涉及MAPK/ERK信号 转导通路抑制途径。     

线粒体DNA缺失A549细胞与其母本细胞核蛋白质组差异分析(英文)

目的比较线粒体DNA(mtDNA)缺失A549细胞(Rho0细胞)与其母本细胞(Rho+细胞)核蛋白表达谱,并探讨细胞核对线粒体功能缺陷的应答反应。方法二维凝胶电泳(2-DE)和表面增强激光法解吸电离-飞行时间(SELDI-TOF)蛋白芯片测定Rho0细胞和Rho+细胞核蛋白表达谱,基质辅助激光解吸电离-飞行时间(MALDI-TOF)质谱结合数据库检索鉴定差异表达的蛋白点,Western印迹法测定核磷蛋白和P53表达,激光共聚焦显微镜测定线粒体膜电位。结果 2-DE显示Rho0细胞核中11个蛋白点表达下调,21个蛋白点表达上调。基于NP20蛋白质芯片的SELDI-TOF质谱分析发现4个蛋白质峰在Rho0细胞核中明显下降。其中1个表达下调的蛋白点被鉴定为eIF-6,4个表达上调的蛋白点被鉴定为核磷蛋白,SFRS1,SFRS3和hnRNP G。Western印迹实验结果显示,Rho0细胞中核磷蛋白表达增加。P53和线粒体膜电位(MMP)测定结果显示,Rho0细胞中P53表达高于Rho+细胞,两种细胞MMP基本一致。结论 mtDNA缺失诱导了细胞核蛋白质组改变。Rho0细胞可以作为研究线粒体与核交互作用的模型。     

四嗪二甲酰胺对白血病细胞株HL-60体外作用的研究

目的:观察四嗪二甲酰胺(ZGDHu-1)体外抑制白血病细胞株HL-60增殖,诱导细胞分化和凋亡作用,并对其作用机制进行初步探讨。方法:将不同浓度的ZGDHu-1与HL-60细胞在体外培养,台盼蓝染色、MTT比色法观察对HL-60细胞增殖的抑制作用;用细胞形态学、DNA凝胶电泳、DNA含量及细胞周期分析、Annexin-V/PI双标记和DNA片段原位末端标记法等分析细胞凋亡。通过NBT试验、细胞表面抗原CD11b、CD13、CD14、CD64和细胞形态学检测ZGDHu-1对HL-60细胞的分化作用。用Rh123/PI测定线粒体跨膜电位(ΔΨm),用流式细胞术检测Bcl-2、Bax、P53、Fas和线粒体膜蛋白的表达变化。结果:ZGDHu-1呈现作用时间和剂量的量效性抑制HL-60细胞增殖和活力,10 ng.ml-1ZGDHu-1作用HL-60细胞24~72 h后,MTT法检测细胞增殖抑制率分别为(7.3±0.3)%、(15.8±1.0)%和(21.3±1.2)%,均显著高于对照组(P<0.01);48 h、72 h的IC50分别为180、180 ng.ml-1。HL-60细胞经ZGDHu-1作用后,大部分细胞阻滞于G2-M期,G0/1期细胞减少;出现典型的细胞形态改变,DNA片端化,经50~1 000 ng.ml-1的ZGDHu-1作用后,SubG1由(3.2±1.6)%上升至(67.7±5.9)%,与对照组(0.7±0.5)%比较,具有显著性差异(P<0.05),Annexin-V/PI标记升高,TUNEL染色后的凋亡细胞的特征性改变等均证实ZGDHu-1能诱导HL-60细胞凋亡。HL-60细胞经10~100 ng.ml-1ZGDHu-1作用3 d后,细胞发生部分分化,NBT阳性率增加,细胞表面CD11b、CD13、CD14、CD64表达增加。ZGDHu-1诱导HL-60细胞凋亡和分化过程中,Bcl-2表达无变化,但Bax表达显著增加,Bax/Bcl-2的比值升高,Fas表达增强,而P53表达无变化。随ZGDHu-1作用的浓度增加,ΔΨm下降、而线粒体膜蛋白表达显著升高。结论:ZGDHu-1能抑制HL-60细胞增殖和细胞活力,低浓度时诱导HL-60细胞向粒单系分化,高浓度时促进细胞凋亡,其机制可能与Bax表达上调,线粒体膜电位下降等有关。     

选择性线粒体分裂抑制剂对大鼠急性脊髓损伤后神经细胞的保护作用及其机制

【摘要】目的 检测选择性线粒体分裂抑制剂-1（Mdivi-1）对大鼠急性脊髓损伤（ASCI）后神经细胞线粒体中丙二醛（MDA）、谷胱甘肽（GSH）、细胞色素C（Cyt-C）及神经细胞凋亡的影响。方法成年雌性SD大鼠36只,体质量 250~300g,随机分为假手术组（Sham组）、单纯脊髓损伤组（SCI组）、Mdivi-1预处理组（1.20mg/kg,Mdivi-1组）,各12 只。Sham组只暴露脊髓,不打击。SCI组和Mdivi-1组采用Allen’s方法制备脊髓损伤模型。Mdivi-1组在脊髓打击之前15min尾静脉给予Mdivi-1,而SCI组给予等量二甲基亚砜（DMSO）。Sham组在暴露脊髓8h后立即处死,SCI组和Mdivi-1组均于脊髓损伤后8h处死;然后取出脊髓节段T9~T11,用分光光度计检测各组脊髓组织线粒体中MDA 和GSH的含量,Western Blot法检测线粒体及胞浆内Cyt-C表达情况,荧光TUNEL法观察神经细胞凋亡情况。结果与Sham组相比,SCI组线粒体中Cyt-C和GSH明显减少,但线粒体中的MDA,胞浆中Cyt-C及神经细胞凋亡数目明显增多（P<0.01）;与SCI组相比,Mdivi-1组线粒体中Cyt-C和GSH明显增多,但线粒体中MDA,胞浆中Cyt-C以及神经细胞凋亡数目明显减少（P<0.01）。结论Mdivi-1具有减轻ASCI后神经细胞线粒体氧化损伤,抑制线粒体中Cyt-C 的释放及神经细胞凋亡的作用,促进了脊髓功能恢复。     

线粒体动力学蛋白异常表达参与阿德福韦酯致大鼠肾小管上皮细胞的损伤

目的：探讨线粒体动力学相关蛋白drp1和mfn1对阿德福韦酯引起的大鼠肾小管上皮细胞损伤的机制。方法：根据阿德福韦酯给药剂量差异,对大鼠随机分为对照组和低、中、高剂量组;对照组给予生理盐水,其余3组分别给予0.2、0.4、0.8 mg·kg-1·d-1阿德福韦酯灌胃。给药60 d后取出大鼠肾脏,常规石蜡包埋,切片,HE染色观察肾小管上皮的形态学改变;免疫组化检测肾小管上皮中drp1和mfn1蛋白的表达。结果：阿德福韦酯干预的可见嗜酸性凝固坏死物和空泡样变性,近曲小管上皮细胞游离面的刷状缘结构不清,上皮细胞排列较紊乱。在drp1及mfn1的免疫组化中,高、中剂量组与对照组之间蛋白表达的平均光密度值差异有统计学意义（P<0.05）。结论：线粒体动力学蛋白drp1/mfn1可能介导了阿德福韦酯对人肾小管上皮细胞（HK-2）的损伤。     

Evaluation of mitochondrial DNA content and enzyme levels in tenofovir DF-treated rats,rhesus monkeys and woodchucks

The antiviral compound tenofovir DF (Gilead Sciences) was evaluated for possible mitochondrial toxicity in rats, rhesus monkeys and woodchucks. Animals were treated by oral gavage with tenofovir DF, and the levels of mitochondrial enzymes cytochrome c oxidase and citrate synthase were assayed. In rats (6/group) treated daily for 28 days with 300 mg/kg tenofovir DF the enzyme levels were unchanged versus control in liver, kidney, and skeletal muscle. In a parallel study, rats (6/group) were treated with 40 mg/kg of the antiviral adefovir dipivoxil (Gilead Sciences) and enzyme levels were also unchanged versus control. In rhesus monkeys (6/group) treated daily with 30 mg/kg or 250 mg/kg tenofovir DF for 56 days, and in woodchucks (6/group) treated daily with 15 mg/kg or 50mg/kg tenofovir DF for 90 days, the enzyme levels were unchanged in liver, kidney, skeletal muscle and cardiac muscle. Mitochondrial DNA (mtDNA) content was determined in tissue from treated versus control animals by utilizing a quantitative real-time PCR (QPCR) technique, where the relative ratios of mitochondrial cytochrome b gene to the genomic actin gene were measured. The relative mtDNA content from rats, rhesus monkeys and woodchucks were unchanged in the various treatment groups. Variations in mtDNA content between animals in the same treatment group were noted. The actual species-dependent mitochondria/genomic ratios were estimated from the QPCR assay. In summary, treatment with tenofovir DF, or with adefovir dipivoxil, did not affect mtDNA content or level of mitochondrial enzymes, and no liver, muscle or renal microscopic abnormalities were observed in tenofovir-treated animals.     

Extracellular Mitochondria and Mitochondrial Components Act as Damage-Associated Molecular Pattern Molecules in the Mouse Brain

Mitochondria and mitochondrial debris are found in the brain’s extracellular space, and extracellular mitochondrial components can act as damage associated molecular pattern (DAMP) molecules. To characterize the effects of potential mitochondrial DAMP molecules on neuroinflammation, we injected either isolated mitochondria or mitochondrial DNA (mtDNA) into hippocampi of C57BL/6 mice and seven days later measured markers of inflammation. Brains injected with whole mitochondria showed increased Tnfα and decreased Trem2 mRNA, increased GFAP protein, and increased NFκB phosphorylation. Some of these effects were also observed in brains injected with mtDNA (decreased Trem2 mRNA, increased GFAP protein, and increased NFκB phosphorylation), and mtDNA injection also caused several unique changes including increased CSF1R protein and AKT phosphorylation. To further establish the potential relevance of this response to Alzheimer’s disease (AD), a brain disorder characterized by neurodegeneration, mitochondrial dysfunction, and neuroinflammation we also measured App mRNA, APP protein, and Aβ_1–42 levels. We found mitochondria (but not mtDNA) injections increased these parameters. Our data show that in the mouse brain extracellular mitochondria and its components can induce neuroinflammation, extracellular mtDNA or mtDNA-associated proteins can contribute to this effect, and mitochondria derived-DAMP molecules can influence AD-associated biomarkers.     

Mediating effect of ROS on mtDNA damage and low ATP content induced by arsenic trioxide in mouse oocytes

Mitochondria provide most of the adenosine triphosphates (ATP) necessary for the maturation of oocytes. Various environmental toxicants would lead damage to mitochondrial DNA (mtDNA) and hence interfere with oocytes development. In the current study, the effect of arsenic trioxide (As₂O₃) on the common 3867 bp deletion and the copy number of mtDNA in mitochondria of mouse oocytes in vivo or in vitro, as well as the molecular pathway leading to the damage were investigated. PCR strategy was used to detect the damage of mtDNA. Reactive oxygen species (ROS) and ATP content in oocytes were checked to determine the influence of As₂O₃ on oxidative stress and activity of mitochondria. The results showed that As₂O₃ could obviously decrease the copy number of mtDNA and cause severe 3867 bp deletion in mitochondria together with elevated ROS level, while ATP content was decreased. Co-treatment with N-Acetyl-Cysteine (NAC) efficiently eliminated ROS induced by As₂O₃, lessened the mtDNA damage and enhanced ATP content in mouse oocytes both in vivo and in vitro. Taken together, the present study revealed that As₂O₃ could cause severe mtDNA damage and decrease ATP content by inducing excessive ROS, and this damage would then probably restrain the further development of mouse oocytes.     

Melatonin attenuates brain mitochondria DNA damage induced by potassium cyanide in vivo and in vitro

The effect of potassium cyanide on mitochondria DNA (mtDNA) in mouse brain was investigated in vivo and in vitro. When potassium cyanide (0, 0.1, 1.0 or 2.0 mM) was incubated with a crude mitochondria fraction prepared from mouse brain at 37 degrees C for 60 min, the damage of mtDNA was observed in a concentration-dependent manner. However, the mtDNA damage was prevented by a co-treatment with melatonin (1.5 mM), a scavenger of hydroxyl radicals (*OH). Furthermore, a subcutaneous injection of potassium cyanide (7mg/kg) caused both brain mtDNA damage and severe seizures in mouse. The damage of mtDNA and seizures induced by potassium cyanide were abolished by the pre-injection of melatonin (20 mg/kg). Hydrogen peroxide (1.5 mM) inflicted damage to brain mtDNA in the presence of Fe(2+) (3.0 microM). The damage was abolished by the co-treatment with melatonin. Furthermore, when cyanide (0, 0.1 or 1.0 mM) was incubated with the crude mitochondria fraction prepared from mouse brain, the lipid peroxidation was significantly increased in a concentration-dependent manner. The increased lipid peroxidation was completely inhibited by the co-treatment with melatonin (1.0 mM). These results suggest that reactive oxygen species including the *OH may play a cardinal role for mtDNA damage induced by potassium cyanide. Hence, the present study concluded that melatonin protects against DNA damage induced by the *OH produced by cyanide or hydrogen peroxide.     

An OGG1 polymorphism is associated with mitochondrial DNA content in pesticide-exposed fruit growers

Exposure to pesticides has the capacity to cause mitochondrial dysfunction. An increase mitochondrial DNA (mtDNA) content has also been suggested to relate with DNA damaging agent. In mitochondria, the manganese superoxide dismutase (MnSOD) is a scavenger of reactive oxygen species, and the 8-oxoguanine DNA glycosylase (OGG1) is the major DNA glycosylase for the repair of 8-oxoG lesions. However, the alteration of mtDNA content elicited by pesticide exposure in people with genetic variations in MnSOD or OGG1 has not been investigated. In this study, the mitochondrial to nuclear DNA ratio was quantified in the peripheral blood of 120 fruit growers who experienced pesticide exposure and 106 unexposed controls by real-time quantitative polymerase chain reaction (real-time qPCR). Questionnaires were administered to obtain demographic data and occupational history. The MnSOD and OGG1 genotypes were identified by the PCR based restriction fragment length polymorphism analysis. After adjusting for confounding effects, multiple regression model revealed that subjects experiencing high or low pesticide exposure had a greater mtDNA content than that of controls. The OGG1 Ser-Ser genotype was also associated with an increased mtDNA content. No association between MnSOD genotype and mtDNA content was revealed. Thus, subjects experiencing pesticide exposure had greater mtDNA content and the OGG1 genotype may modulate mtDNA content in pesticide-exposed fruit growers.     

Drp1介导线粒体能量代谢拮抗大鼠缺血再灌注肾损伤

目的　探讨线粒体动力相关蛋白1（Drp1）介导线粒体能量代谢参与缺血再灌注肾损伤的分子机制。方法　实验时间2020年10月14日。8～10周龄雄性Wistar大鼠随机分为正常对照组、假手术组、模型组和Drp1抑制剂组,每组5只,每只体质量为0.25～0.30 kg。通过手术建立大鼠肾脏缺血再灌注急性肾损伤模型,Drp1抑制剂组大鼠腹腔注射线粒体分裂抑制剂（mitochondrial division inhibitor 1,Mdivi-1）20 mg/kg体质量,其余各组大鼠注射等体积生理盐水,造模24 h留取血清及肾脏组织。比较组间大鼠血肌酐水平、肾组织病理学改变、肾组织细胞凋亡情况、线粒体超微结构、线粒体ATP酶活力,并建立体外HK-2细胞缺氧复氧模型,经处理后JC-1染色法检测细胞线粒体膜电位变化。采用方差分析。结果　与假手术组比较,模型组大鼠血肌酐明显升高［（41.12±1.895）µmol/L比（48.68±2.065）µmol/L］,肾小管损伤评分升高［（1.29±0.426）分比（6.50±0.577）分］,每高倍镜视野下大鼠肾组织细胞凋亡数量增加［（2.40±0.547）个比（10.20±1.095）个］,电镜下线粒体损伤更明显,线粒体ATP酶活力降低［（6.38±0.321）U/mg prot比（4.18±0.198）U/mg prot］,HK-2细胞缺氧复氧模型中,模型组较假手术组线粒体膜电位降低的细胞比例增多［（9.81±0.251）%比（4.24±0.598）%］,差异均有统计学意义（均P<0.05）。与模型组相比,Drp1抑制剂组大鼠血肌酐下降［（48.68±2.065）µmol/L比（43.28±0.895）µmol/L］,肾小管损伤评分降低［（6.50±0.577）分比（4.50±0.578）分］,每高倍镜视野下大鼠肾组织细胞凋亡数量减少［（10.20±1.095）个比（6.60±1.140）个］,线粒体结构损伤减轻,细胞线粒体ATP酶活力增加［（4.18±0.198）U/mg prot比（5.16±0.628）U/mg prot］,HK-2细胞缺氧复氧模型中,Drp1抑制剂组较模型组线粒体膜电位降低的细胞比例减少［（5.90±0.360）%比（9.81±0.251）%］,差异均有统计学意义（均P<0.05）。结论　选择性抑制Drp1可通过抑制线粒体分裂,有效改善能量代谢障碍,减少细胞凋亡,减轻肾缺血再灌注损伤。