Fluoride exposure decreased neurite formation on cerebral cortical neurons of SD rats in vitro
Fluoride exposure decreased neurite formation on cerebral cortical neurons of SD rats in vitro
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DOI：
10.1007/s11356-021-13950-2
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发表时间：
2021-05-11
影响因子：
5.8
通讯作者：
Chen, Lingli
中科院分区：
文献类型：
--
作者：
Ning, Hongmei;Li, Chong;Chen, Lingli
氟化物是一种地球化学元素，会损害大脑，导致中枢神经系统功能障碍。近年来，氟致神经毒性已成为环境毒理学的研究热点之一。我们先前的研究表明，氟可导致大脑皮层结构损伤，降低子代小鼠的学习记忆能力。然而，这些效应的潜在机制仍不清楚。本研究从出生后1天的SD大鼠大脑皮质分离出原代神经元。原代培养的大脑皮层神经元贴壁，细胞网络明显。尼氏染色鉴定神经元并用于实验。选用不同浓度的氟化钠(0.5、1.0、1.5、2.0和2.5 mM)，观察其对体外培养的SD大鼠神经元的毒性作用。结果显示，2.0 mm和2.5 mm损伤明显，0.5 mm和1 mm损伤不明显。进一步的研究发现，随着NaF剂量的增加，神经元突起缩小，甚至断裂，扫描电子显微镜(SEM)观察到了这一点。1.5、2、2.5 mm组同时可见染色质边际化、核间隙增宽、核损伤、线粒体肿胀甚至缺失。细胞骨架染色结果与上述结果一致。免疫荧光检测显示染氟后大鼠大脑皮层神经元突起数量明显减少。综上所述，高浓度氟(1.5、2和2.5 mM)对原代培养的大脑皮层神经元的细胞形态和神经形成有明显的毒性作用。这些发现为NaF在神经元损伤中的作用提供了新的见解，并有助于更好地理解氟化物诱导的神经毒性。
Fluoride, a geochemical element, can damage the brain and result in dysfunction of the central nervous system. In recent years, fluoride-induced neurotoxicity has become one of research focuses of environmental toxicology. Our previous study showed that fluoride could induce the structural damages of the cerebral cortex and reduce the learning and memory abilities of mice offspring. However, the underlying mechanisms of these effects remain unclear. In this study, primary neurons were isolated from the cerebral cortices of postnatal 1-day SD rats. The primary cultured cerebral cortical neurons were adherent and the cellular network was obvious. Neurons were identified by Nissl's staining and were used for experiments. Different concentrations of sodium fluoride (0.5, 1.0, 1.5, 2.0 and 2.5 mM) were chosen to explore its toxic effects on neuron of SD rats in vitro. Results showed that neuronal morphology was obviously damaged in 2.0 and 2.5 mM, but was not adversely affected in 0.5 and 1 mM. Further studies revealed that the neurites of neuron were shrunken and even became fractured with the increase in NaF dose, which have been detected by scanning electron microscopy (SEM). Meanwhile, TEM showed marginated chromatin, widened nuclear gaps, damaged nuclei and swollen or even absent mitochondria in 1.5, 2 and 2.5 mM group. The cytoskeletal staining was consistent with the above results. The number of neurites of cerebral cortical neuron significantly decreased after fluoride exposure by immunofluorescent assay. In summary, high fluoride (1.5, 2 and 2.5 mM) concentrations exerted a significant toxic effect on the cellular morphologies and neural formation of primary cultured cortical neurons. These findings provide new insights into the roles of NaF in neuronal damage and can contribute to an improved understanding of fluoride-induced neurotoxicity.