Collins Michelle L, Sondel Nicole, Cesar Denise, Hellerstein Marc K
Department of Nutritional Sciences and Toxicology, University of California at Berkeley, CA 94720-3104, USA.
J Acquir Immune Defic Syndr. 2004 Sep 1;37(1):1132-9. doi: 10.1097/01.qai.0000131585.77530.64.
Nucleoside reverse transcriptase inhibitors (NRTIs) have been hypothesized to inhibit mitochondrial DNA polymerase gamma, resulting in decreased mtDNA synthesis and mitochondrial insufficiency in HIV-1-infected patients. mtDNA synthesis was measured directly using a stable isotope mass spectrometric method following NRTI treatment in rodents. 3'-Azido-3'-deoxythymidine (AZT) was added to water (1 mg/mL) and administered ad libitum to female Sprague-Dawley rats for 1-8 weeks (n = 4 or 5 animals/timepoint). Neither body weight nor food intake was affected by AZT intake. Untreated controls and AZT-treated rats were given 4% H2O as drinking water for 2 weeks. AZT (approximately 100 mg/kg/d) produced a significant (P < 0.05) decrease in cardiac and hindlimb muscle mtDNA fractional synthesis compared with control groups (from 13.8 +/- 4.2% to 7.0 +/- 4.8% and from 7.6 +/- 1.8% to 4.5 +/- 0.4%, respectively) after 4 weeks. Cytochrome c oxidase content in hindlimb muscle was also decreased by 50% compared with controls after 4 weeks of AZT treatment (P < 0.07) and a calculated index of absolute mitochondrial biogenesis rate was significantly reduced by week 2 of AZT (P < 0.05) in hindlimb muscle. In preliminary studies, platelet mtDNA enrichments were compared to monocyte nDNA enrichments (used as a marker of a fully turned over tissue) in healthy human subjects. Fractional synthesis of mtDNA in platelets reached 98 +/- 3% after 5 weeks of H2O labeling. It is concluded that NRTIs decrease mtDNA synthesis and oxidative enzyme content and thus mitochondrial biogenesis in rodents and that the effects of NRTIs on mitochondrial biogenesis in tissues of HIV-1- infected humans can in principle be measured using this approach.
核苷类逆转录酶抑制剂（NRTIs）被认为可抑制线粒体DNA聚合酶γ，导致HIV-1感染患者的线粒体DNA合成减少和线粒体功能不全。在啮齿动物中，采用稳定同位素质谱法在NRTI治疗后直接测量线粒体DNA合成。将3'-叠氮-3'-脱氧胸苷（AZT）添加到水中（1mg/mL），随意给予雌性Sprague-Dawley大鼠，持续1至8周（每个时间点n = 4或5只动物）。AZT摄入对体重和食物摄入量均无影响。未治疗的对照组和接受AZT治疗的大鼠饮用4%的H2O作为饮用水，持续2周。4周后，与对照组相比，AZT（约100mg/kg/d）使心脏和后肢肌肉线粒体DNA的分数合成显著降低（P < 0.05）（分别从13.8±4.2%降至7.0±4.8%，从7.6±1.8%降至4.5±0.4%）。AZT治疗4周后，后肢肌肉中的细胞色素c氧化酶含量也比对照组降低了50%（P < 0.07），并且在AZT治疗第2周时，后肢肌肉中计算得出的绝对线粒体生物合成率指数显著降低（P < 0.05）。在初步研究中，对健康人类受试者的血小板线粒体DNA富集与单核细胞核DNA富集（用作完全更新组织的标志物）进行了比较。H2O标记5周后，血小板中线粒体DNA的分数合成达到98±3%。得出的结论是，NRTIs可降低啮齿动物的线粒体DNA合成和氧化酶含量，从而减少线粒体生物合成，并且原则上可以使用这种方法来测量NRTIs对HIV-1感染人类组织中线粒体生物合成的影响。
