Department of Surgery, Kaohsiung Veterans General Hospital, Kaohsiung 81362, Taiwan; Department of Surgery, National Defense Medical Center, Taipei 11490, Taiwan; Department of Nursing, Meiho University, Pingtung 91202, Taiwan.
Department of Medical Education and Research, Kaohsiung Veterans General Hospital, Kaohsiung 81362, Taiwan.
Pestic Biochem Physiol. 2019 Jun;157:152-160. doi: 10.1016/j.pestbp.2019.03.015. Epub 2019 Mar 28.
Malathion, one of commonly used organophosphate insecticides, has a wide range of toxic actions in different models. However, the effect of this compound on Ca homeostasis and its related cytotoxicity in glial cells is elusive. This study examined whether malathion evoked intracellular Ca concentration ([Ca]) rises and established the relationship between Ca signaling and cytotoxicity in normal human astrocytes, rat astrocytes and human glioblastoma cells. The data show that malathion induced concentration-dependent [Ca] rises in Gibco Human Astrocytes (GHA cells), but not in DI TNC1 normal rat astrocytes and DBTRG-05MG human glioblastoma cells. In GHA cells, this Ca signal response was reduced by removing extracellular Ca. In Ca-free medium, pretreatment with the endoplasmic reticulum Ca pump inhibitor thapsigargin abolished malathion-induced [Ca] rises. Conversely, incubation with malathion abolished thapsigargin-induced [Ca] rises. Inhibition of phospholipase C (PLC) with U73122 also blocked malathion-induced [Ca] rises. In Ca-containing medium, malathion-induced [Ca] rises was inhibited by store-operated Ca channel blockers (2-APB, econazole or SKF96365) and the protein kinase C (PKC) inhibitor GF109203X. Malathion (5-25 μM) concentration-dependently caused cytotoxicity in GHA, DI TNC1 and DBTRG-05MG cells. This cytotoxic effect was partially prevented by prechelating cytosolic Ca with BAPTA-AM (a selective Ca chelator) only in GHA cells. Together, in GHA but not in DI TNC1 and DBTRG-05MG cells, malathion induced [Ca] rises by inducing PLC-dependent Ca release from the endoplasmic reticulum and Ca entry via PKC-sensitive store-operated Ca channels. Furthermore, malathion induced Ca-associated cytotoxicity, suggesting that Ca chelating may have a protective effect on malathion-induced cytotoxicity in normal human astrocytes.
马拉硫磷是一种常用的有机磷杀虫剂，在不同模型中具有广泛的毒性作用。然而，这种化合物对胶质细胞中钙稳态及其相关细胞毒性的影响尚不清楚。本研究旨在探讨马拉硫磷是否会引起细胞内钙浓度([Ca])升高，并确定钙信号与正常人类星形胶质细胞、大鼠星形胶质细胞和人神经胶质瘤细胞中细胞毒性之间的关系。研究数据表明，马拉硫磷诱导 Gibco 人星形胶质细胞（GHA 细胞）中浓度依赖性的[Ca]升高，但在正常大鼠星形胶质细胞（DI TNC1 细胞）和人神经胶质瘤细胞（DBTRG-05MG 细胞）中则没有。在 GHA 细胞中，去除细胞外 Ca 可减少这种 Ca 信号反应。在无 Ca 培养基中，内质网 Ca 泵抑制剂 thapsigargin 预处理可消除马拉硫磷诱导的[Ca]升高。相反，用马拉硫磷孵育可消除 thapsigargin 诱导的[Ca]升高。用 U73122 抑制磷酯酶 C (PLC) 也可阻断马拉硫磷诱导的[Ca]升高。在含有 Ca 的培养基中，用储存操作型 Ca 通道抑制剂（2-APB、 econazole 或 SKF96365）和蛋白激酶 C (PKC) 抑制剂 GF109203X 可抑制马拉硫磷诱导的[Ca]升高。浓度为 5-25 μM 的马拉硫磷可引起 GHA、DI TNC1 和 DBTRG-05MG 细胞的浓度依赖性细胞毒性。这种细胞毒性效应仅在 GHA 细胞中用 BAPTA-AM（一种选择性 Ca 螯合剂）预先螯合细胞溶质 Ca 时可部分预防。总之，马拉硫磷在 GHA 细胞中通过诱导 PLC 依赖性内质网 Ca 释放和 PKC 敏感储存操作型 Ca 通道的 Ca 内流来诱导[Ca]升高，而在 DI TNC1 和 DBTRG-05MG 细胞中则没有。此外，马拉硫磷诱导 Ca 相关的细胞毒性表明，Ca 螯合可能对正常人类星形胶质细胞中马拉硫磷诱导的细胞毒性具有保护作用。
