PFOS-induced excitotoxicity is dependent on Ca2+ influx via NMDA receptors in rat cerebellar granule neurons
PFOS-induced excitotoxicity is dependent on Ca2+ influx via NMDA receptors in rat cerebellar granule neurons
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DOI：
10.1016/j.taap.2018.08.015
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发表时间：
2018-10-15
影响因子：
3.8
通讯作者：
Ropstad, Erik
中科院分区：
文献类型：
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作者：
Berntsen, Hanne Friis;Bjorklund, Cesilie Granum;Ropstad, Erik
全氟烷基酸（PFAAs）是许多工业和消费品中使用的持久性化合物。尽管有限制，但在人类和动物来源的样品中发现了可测量浓度的这些化合物。在本研究中，我们研究了两种磺化和四种羧化PFAAs对小脑颗粒神经元（CGNs）细胞活力的影响是否与n -甲基- d -天冬氨酸受体（NMDA-R）的有害激活有关。采用MTT法检测pfa对大鼠CGNs和未刺激PC12细胞活力的影响。来自PC12大鼠嗜铬细胞瘤细胞系的细胞缺乏功能性NMDA-Rs的表达，并用于验证全氟辛烷磺酸（PFOS）对不表达NMDA-Rs的细胞的毒性较低。研究了NMDA-R拮抗剂、细胞外和细胞内Ca2+螯合剂的保护作用。用Fura-2测定胞质Ca2+ ([Ca2+](i))。在大鼠CGNs中，NMDA-R拮抗剂MK-801、美金刚和CPP的作用表明，NMDA-R参与了全氟辛烷磺酸和全氟己磺酸（PFHxS）诱导的生存能力下降。所研究的四种羧化PFAAs没有影响。此外，EGTA和CPP对pfos诱导的细胞活力下降有保护作用，而BAPTA-AM则没有保护作用。[Ca2+](i)在暴露于全氟辛烷磺酸后显著增加，MK-801完全阻断了这种增加。在PC12细胞中，与大鼠cgn相比，需要更高浓度的全氟辛烷磺酸才能诱导同等水平的毒性。CPP对pfos诱导的PC12细胞毒性无影响。综上所述，测试浓度的全氟辛烷磺酸在大鼠CGNs中诱导兴奋性毒性，这可能涉及通过NMDA-R流入细胞外Ca2+。这种作用可被特异性NMDA-R拮抗剂阻断。
Perfluoroalkyl acids (PFAAs) are persistent compounds used in many industrial as well as consumer products. Despite restrictions, these compounds are found at measurable concentrations in samples of human and animal origin. In the present study we examined whether the effects on cell viability of two sulfonated and four carboxylated PFAAs in cultures of cerebellar granule neurons (CGNs), could be associated with deleterious activation of the N-methyl-D-aspartate receptor (NMDA-R).PFAA-induced effects on viability in rat CGNs and unstimulated PC12 cells were examined using the MTT assay. Cells from the PC12 rat pheochromocytoma cell line lack the expression of functional NMDA-Rs and were used to verify lower toxicity of perfluorooctanesulfonic acid (PFOS) in cells not expressing NMDA-Rs. Protective effects of NMDA-R antagonists, and extracellular as well as intracellular Ca2+ chelators were investigated. Cytosolic Ca2+ ([Ca2+](i)) was measured using Fura-2.In rat CGNs the effects of the NMDA-R antagonists MK-801, memantine and CPP indicated involvement of the NMDA-R in the decreased viability induced by PFOS and perfluorohexanesulfonic acid (PFHxS). No effects were associated with the four carboxylated PFAAs studied. Further, EGTA and CPP protected against PFOS-induced decreases in cell viability, whereas no protection was afforded by BAPTA-AM. [Ca2+](i) significantly increased after exposure to PFOS, and this increase was completely blocked by MK-801. In PC12 cells a higher concentration of PFOS was required to induce equivalent levels of toxicity as compared to in rat CGNs. PFOS-induced toxicity in PC12 cells was not affected by CPP.In conclusion, PFOS at the tested concentrations induces excitotoxicity in rat CGNs, which likely involves influx of extracellular Ca2+ via the NMDA-R. This effect can be blocked by specific NMDA-R antagonists.