Jafarzadeh Emad, Soodi Maliheh, Tiraihi Taki, Zarei Mohammadhadi, Qasemian-Lemraski Mehdi
Department of Toxicology, Faculty of Medical Sciences, 48503Tarbiat Modares University, Tehran, Iran.
Department of Anatomical Sciences, Faculty of Medical Sciences, 41616Tarbiat Modares University, Tehran, Iran.
Toxicol Ind Health. 2022 Oct;38(10):655-664. doi: 10.1177/07482337221115514. Epub 2022 Jul 15.
The developing brain is susceptible to the neurotoxic effects of lead. Exposure to lead has main effects on the cholinergic system and causes reduction of cholinergic neuron function during brain development. Disruption of the cholinergic system by chemicals, which play important roles during brain development, causes of neurodevelopmental toxicity. Differentiation of stem cells to neural cells is recently considered a promising tool for neurodevelopmental toxicity studies. This study evaluated the toxicity of lead acetate exposure during the differentiation of bone marrow-derived mesenchyme stem cells (bone marrow stem cells, BMSCs) to CCholinergic neurons. Following institutional animal care review board approval, BMSCs were obtained from adult rats. The differentiating protocol included two stages that were pre-induction with β-mercaptoethanol (BME) for 24 h and differentiation to cholinergic neurons with nerve growth factor (NGF) over 5 days. The cells were exposed to different lead acetate concentrations (0.1-100 μm) during three stages, including undifferentiated, pre-induction, and neuronal differentiation stages; cell viability was measured by MTT assay. Lead exposure (0.01-100 μg/ml) had no cytotoxic effect on BMSCs but could significantly reduce cell viability at 50 and 100 μm concentrations during pre-induction and neuronal differentiation stages. MAP2 and choline acetyltransferase (ChAT) protein expression were investigated by immunocytochemistry. Although cells treated with 100 μm lead concentration expressed MAP2 protein in the differentiation stages, they had no neuronal cell morphology. The ChAT expression was negative in cells treated with lead. The present study showed that differentiated neuronal BMSCs are sensitive to lead toxicity during differentiation, and it is suggested that these cells be used to study neurodevelopmental toxicity.
发育中的大脑易受铅的神经毒性影响。铅暴露主要影响胆碱能系统，并导致大脑发育过程中胆碱能神经元功能降低。化学物质对胆碱能系统的破坏在大脑发育过程中起重要作用，会导致神经发育毒性。干细胞向神经细胞的分化最近被认为是神经发育毒性研究的一种有前途的工具。本研究评估了醋酸铅暴露对骨髓间充质干细胞（骨髓干细胞，BMSCs）分化为胆碱能神经元过程的毒性。经机构动物护理审查委员会批准后，从成年大鼠获取BMSCs。分化方案包括两个阶段，先用β-巯基乙醇（BME）预诱导24小时，然后用神经生长因子（NGF）在5天内分化为胆碱能神经元。在三个阶段，即未分化、预诱导和神经元分化阶段，将细胞暴露于不同浓度的醋酸铅（0.1 - 100μm）；通过MTT法测量细胞活力。铅暴露（0.01 - 100μg/ml）对BMSCs没有细胞毒性作用，但在预诱导和神经元分化阶段，50和100μm浓度的铅可显著降低细胞活力。通过免疫细胞化学研究微管相关蛋白2（MAP2）和胆碱乙酰转移酶（ChAT）蛋白表达。尽管用100μm铅浓度处理的细胞在分化阶段表达MAP2蛋白，但它们没有神经元细胞形态。铅处理的细胞中ChAT表达为阴性。本研究表明，分化的神经元BMSCs在分化过程中对铅毒性敏感，建议用这些细胞来研究神经发育毒性。
