Histamine-induced Ca2+ Entry in Human Astrocytoma U373 MG Cells: Evidence for Involvement of Store-operated Channels
Histamine-induced Ca2+ Entry in Human Astrocytoma U373 MG Cells: Evidence for Involvement of Store-operated Channels
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DOI：
10.1002/jnr.21784
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发表时间：
2008-11-15
影响因子：
4.2
通讯作者：
Arias-Montano, Jose-Antonio
中科院分区：
文献类型：
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作者：
Barajas, Margarita;Andrade, Arturo;Arias-Montano, Jose-Antonio
神经胶质和神经胶质衍生细胞表达多种神经递质和激素的受体，其中大多数引起细胞内储存的Ca 2+释放和Ca 2+穿过质膜进入。我们研究了组胺H，受体激活，从细胞内钙库释放和钙离子内流在人星形细胞瘤U373 MG细胞之间的联系。组胺，通过H-1受体介导的作用，引起细胞质游离钙浓度（[Ca 2 +]（i））的增加，发生在两个阶段：初始，短暂，增加由于Ca 2+动员从细胞内池，第二，持续增加依赖于Ca 2+流入和连续受体占用。组胺诱导的[Ca 2 +]（i）增加的特征类似于用毒胡萝卜素排空Ca 2+储存所诱发的容量进入，而不同于用OAG（1-油酰基-2-乙酰基-sn-甘油）（一种二酰基甘油（DAG）类似物）激活Ca 2+内流时观察到的特征。OAG应用或增加内源性DAG，导致DAG激酶抑制，减少组胺诱导的反应。此外，TPA（12-O-十四烷酰基4 β-佛波醇13 α-乙酸酯）激活DAG靶点蛋白激酶C（PKC）导致组胺诱导的Ca 2+反应抑制，PKC抑制剂可阻止该作用。通过使用逆转录-聚合酶链反应分析，瞬时受体电位通道（TRPC）1，4和6以及STIM 1（基质相互作用分子）和Orai 1的mRNA被发现在U373 MG细胞中表达，使用特异性抗体的共聚焦显微镜显示了相应蛋白质的存在。因此，TRPC可能是U373 MG细胞中形成储存操纵通道的候选蛋白。此外，我们的研究结果证实了PKC参与调节H-1受体诱导的反应，并指出存在一种反馈机制，通过PKC发挥作用，以限制[Ca 2 +]（i）的增加。(C)2008 Wiley-Liss，Inc.
Glial and glia-derived cells express a variety of receptors for neurotransmitters and hormones, the majority of which evoke both Ca2+ release from intracellular stores and Ca2+ entry across the plasma membrane. We investigated the links between histamine H, receptor activation, Ca2+ release from intracellular stores and Ca2+ influx in human astrocytoma U373 MG cells. Histamine, through a H-1 receptor-mediated effect, evoked an increase in cytoplasmic free calcium concentration ([Ca2+](i)) that occurred in two phases: an initial, transient, increase owing to Ca2+ mobilization from intracellular pools, and a second, sustained increase dependent on both Ca2+ influx and continuous receptor occupancy. The characteristics of histamine-induced increases in [Ca2+](i) were similar to the capacitative entry evoked by emptying of the Ca2+ stores with thapsigargine, and different from that observed when Ca2+ influx was activated with OAG (1-oleoyl-2-acetyl-sn-glycerol), a diacylglycerol (DAG) analog. OAG application or increased endogenous DAG, resulting from DAG kinase inhibition, reduced the histamine-induced response. Furthermore, activation of the DAG target, protein kinase C (PKC), by TPA (12-O-tetradecanoyl 4 beta-phorbol 13 alpha-acetate) resulted in inhibition of the histamine-induced Ca2+ response, an action prevented by PKC inhibitors. By using reverse transcriptase-polymerase chain reaction analysis, mRNAs for transient receptor potential channels (TRPCs) 1, 4, and 6 as well as for STIM1 (stromal-interacting molecule) and Orai1 were found to be expressed in the U373 MG cells, and confocal microscopy using specific antibodies revealed the presence of the corresponding proteins. Therefore, TRPCs may be candidate proteins forming store-operated channels in the U373 MG cell line. Further, our results confirm the involvement of PKC in the regulation of H-1 receptor-induced responses and point out to the existence of a feedback mechanism acting via PKC to limit the increase in [Ca2+](i). (C) 2008 Wiley-Liss, Inc.