Vallés A S, Tenconi P E, Luquez J M, Furland N E
Instituto de Investigaciones Bioquıímicas de Bahía Blanca, Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Universidad Nacional del Sur (UNS), Bahía Blanca, Argentina.
Instituto de Investigaciones Bioquıímicas de Bahía Blanca, Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Universidad Nacional del Sur (UNS), Bahía Blanca, Argentina.
Toxicol Appl Pharmacol. 2021 Sep 1;426:115607. doi: 10.1016/j.taap.2021.115607. Epub 2021 Jun 2.
Sertoli cells (SC) structurally support and transport nutrients to germ cells during spermatogenesis facilitated by an active cytoskeleton. Chemical perturbation of SC microtubule (MT) dynamics instability leads to premature germ cell exfoliation demonstrating that this process is essential for male fertility, yet the effects of MT damaging drugs on SC lipid metabolism have been less explored. The aim of this study was to advance our understanding of how adequate SC MT dynamicity is needed to finely tune lipid homeostasis. To elucidate the role of MT dynamics instability on the latter, we suppressed MT dynamicity by long-term exposures to 10 nM of nocodazole (NCZ) on TM4-SC cultures. Inhibition of MT dynamics instability affected the distribution of [H] arachidonate on TM4-SC. Triacylglycerols (TAG) exhibited a higher proportion of the [H] label, with significantly lower percentages in the mitochondrial phospholipid cardiolipin, and notably, also in phosphatidylethanolamine. A noteworthy and progressive accumulation of lipid droplets during the period of exposure to NCZ was accompanied by increased TAG levels but not cholesterol levels in TM4-SC. NCZ-exposed cells reduced their mitochondrial membrane potential and increased ROS production without triggering apoptosis, had a compromised autophagic flux, and lost their transferrin expression. Although SC morphology was preserved, the NCZ-exposed cells displayed alteration of the normal organization of microfilaments (f-actin) and intermediate filaments (vimentin). Our findings suggest that a preserved MT dynamicity is essential in the maintenance of lipid and fatty acids homeostasis in SC, and thus highlights a novel target in these cells for drugs that impair MT dynamicity.
在精子发生过程中，支持细胞（SC）通过活跃的细胞骨架在结构上支持生殖细胞并为其运输营养物质。支持细胞微管（MT）动力学不稳定性的化学扰动会导致生殖细胞过早脱落，这表明该过程对男性生育能力至关重要，然而MT损伤药物对支持细胞脂质代谢的影响尚未得到充分研究。本研究的目的是加深我们对维持支持细胞脂质稳态所需的适当MT动力学的理解。为了阐明MT动力学不稳定性对后者的作用，我们通过在TM4 - SC培养物中长期暴露于10 nM的诺考达唑（NCZ）来抑制MT动力学。MT动力学不稳定性的抑制影响了[H]花生四烯酸在TM4 - SC上的分布。三酰甘油（TAG）显示出较高比例的[H]标记，而线粒体磷脂心磷脂以及磷脂酰乙醇胺中的比例则显著降低。在暴露于NCZ期间，脂质滴出现了显著且逐渐的积累，同时TM4 - SC中的TAG水平升高，但胆固醇水平未升高。暴露于NCZ的细胞线粒体膜电位降低，活性氧生成增加，但未引发细胞凋亡，自噬通量受损，转铁蛋白表达丧失。尽管支持细胞形态得以保留，但暴露于NCZ的细胞显示微丝（f - 肌动蛋白）和中间丝（波形蛋白）的正常组织发生了改变。我们的研究结果表明，维持支持细胞中MT的动态性对于维持脂质和脂肪酸稳态至关重要，因此突出了这些细胞中一个针对损害MT动态性药物的新靶点。
