Department of Physiological Sciences and Center for Environmental and Human Toxicology, University of Florida Genetics Institute, Interdisciplinary Program in Biomedical Sciences Neuroscience, College of Veterinary Medicine, University of Florida, Gainesville, FL 32611, USA.
Department of Physiological Sciences and Center for Environmental and Human Toxicology, University of Florida Genetics Institute, Interdisciplinary Program in Biomedical Sciences Neuroscience, College of Veterinary Medicine, University of Florida, Gainesville, FL 32611, USA; College of Fisheries, Huazhong Agricultural University, Wuhan, Hubei 430070, China.
Comp Biochem Physiol C Toxicol Pharmacol. 2021 May;243:108995. doi: 10.1016/j.cbpc.2021.108995. Epub 2021 Feb 2.
In teleost fish, radial glial cells (RGCs) are progenitor cells for neurons and the major cell type synthesizing neuroestrogens. We hypothesized that chemical exposure impairs mitochondrial bioenergetics of RGCs, which then may lead to downstream consequences for neuroestrogen production. Here we provide proof of concept that mitochondria of RGCs can be perturbed by fungicides. We isolated RGCs from a mixed sex population of goldfish (Carassius auratus) and measured metabolic capacity of primary cells to a model mitotoxin fluazinam, a broad-spectrum fungicide that inhibits mitochondria electron transport chain (or ETC) Complex I. Using immunocytochemistry and real-time PCR, we demonstrate that the goldfish primary cell cultures are highly enriched for glia after multiple passages. Cytotoxicity assays revealed that glia treated with >25 μM fluazinam for 24 and 48-h showed reduced viability. As such, metabolic assays were conducted with non-cytotoxic concentrations (0.25-12.5 μM). Fluazinam did not affect oxygen consumption rates of RGCs at 24 h, but after 48 h, oligomycin induced ATP-linked respiration was decreased by both 6.25 and 12.5 μM fluazinam. Moreover, concentrations as low as 0.25 μM disrupted the mitochondrial membrane potential of RGCs, reflecting strong uncoupling effects of the fungicide on mitochondria. Here we provide proof of concept that mitochondrial bioenergetics of teleostean RGCs can be responsive to agrochemicals. Additional studies are required to address low-dose exposures in vivo and to determine if metabolic disruption impairs neuroendocrine functions of RGCs. We propose this mechanism constitutes a novel aspect of neuroendocrine disruption, significant because dysregulation of neuron-glia communication is expected to contribute to neuroendocrine disruption.
在硬骨鱼类中，放射状胶质细胞（RGCs）是神经元的祖细胞，也是合成神经雌激素的主要细胞类型。我们假设化学物质暴露会损害 RGCs 的线粒体生物能学，从而导致神经雌激素产生的下游后果。在这里，我们提供了证据表明真菌杀菌剂可以干扰 RGCs 的线粒体。我们从金鱼（Carassius auratus）的混合性别群体中分离出 RGCs，并测量了原代细胞对模型线粒体毒素氟嗪胺的代谢能力，氟嗪胺是一种广谱杀菌剂，可抑制线粒体电子传递链（ETC）复合物 I。通过免疫细胞化学和实时 PCR，我们证明金鱼原代细胞培养物在多次传代后高度富含神经胶质。细胞毒性测定表明，用 >25 μM 氟嗪胺处理 24 和 48 小时的神经胶质细胞活力降低。因此，在非细胞毒性浓度（0.25-12.5 μM）下进行代谢测定。氟嗪胺在 24 小时内不影响 RGCs 的耗氧量，但在 48 小时后，寡霉素诱导的 ATP 连接呼吸在 6.25 和 12.5 μM 氟嗪胺下均降低。此外，浓度低至 0.25 μM 即可破坏 RGCs 的线粒体膜电位，反映出杀菌剂对线粒体的强烈解偶联作用。在这里，我们提供了证据表明硬骨鱼类 RGCs 的线粒体生物能学可以对农用化学品产生反应。需要进一步的研究来解决体内低剂量暴露的问题，并确定代谢紊乱是否会损害 RGCs 的神经内分泌功能。我们提出这种机制构成了神经内分泌干扰的一个新方面，因为神经元-神经胶质细胞通讯的失调预计会导致神经内分泌干扰，这一点非常重要。
