Thymidine Analogues Suppress Autophagy and Adipogenesis in Cultured Adipocytes
Thymidine Analogues Suppress Autophagy and Adipogenesis in Cultured Adipocytes
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DOI：
10.1128/aac.01560-12
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发表时间：
2013-01-01
影响因子：
4.9
通讯作者：
Behrens, Georg M. N.
中科院分区：
文献类型：
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作者：
Stankov, Metodi V.;Panayotova-Dimitrova, Diana;Behrens, Georg M. N.
HIV患者的脂肪萎缩可能是由于长期暴露于胸苷类似物造成的。线粒体毒性导致脂肪生成失调和细胞死亡增加，已被认为是外周脂肪减少的病因学的主要因素。我们假设胸腺嘧啶类似物干扰自噬，一种溶酶体降解途径，这对线粒体质量控制、细胞存活和脂肪形成很重要。我们通过荧光显微镜和流式细胞术评估齐多夫定（AZT）、司他夫定（d4T）和拉米夫定（3TC）对真核细胞和脂肪细胞（3T3-F442A）自噬的影响。将其效果与已建立的基因和药理学自噬抑制剂的干预进行比较，并与细胞活力、增殖和分化的评估相关。AZT和d4T抑制脂肪细胞的组成性和诱导性自噬活性，而3TC没有。这种抑制与功能失调线粒体的积累、活性氧（ROS）产生的增加、细胞凋亡的增加、增殖的减少和成脂转化的受损有关。自噬抑制是剂量和时间依赖性的，并且在治疗药物浓度下可检测到。当采用遗传或药物抑制自噬时，获得了类似的表型变化。我们的数据表明胸苷类似物通过抑制自噬来干扰脂肪细胞功能。这种新机制可能有助于hiv感染患者的外周脂肪减少。
Lipoatrophy in HIV patients can result from prolonged exposure to thymidine analogues. Mitochondrial toxicity leading to dys-regulated adipogenesis and increased cell death has been proposed as a leading factor in the etiology of peripheral fat loss. We hypothesized that thymidine analogues interfere with autophagy, a lysosomal degradation pathway, which is important for mitochondrial quality control, cellular survival, and adipogenesis. We assessed the effects of zidovudine (AZT), stavudine (d4T), and lamivudine (3TC) on autophagy in eukaryotic cells and adipocytes (3T3-F442A) by fluorescence microscopy and flow cytometry. The effects were compared to interventions with established genetic and pharmacological inhibitors of autophagy and correlated to assessments of cell viability, proliferation, and differentiation. AZT and d4T, but not 3TC, inhibited both constitutive and induced autophagic activity in adipocytes. This inhibition was associated with accumulation of dysfunctional mitochondria, increased reactive oxygen species (ROS) production, increased apoptosis, decreased proliferation, and impaired adipogenic conversion. Autophagy inhibition was dose and time dependent and detectable at therapeutic drug concentrations. Similar phenotypic changes were obtained when genetic or pharmacological inhibition of autophagy was employed. Our data suggest that thymidine analogues disturb adipocyte function through inhibition of autophagy. This novel mechanism potentially contributes to peripheral fat loss in HIV-infected patients.