Activation of the neurokinin-1 receptor in rat spinal astrocytes induces Ca2+ release from IP3-sensitive Ca2+ stores and extracellular Ca2+ influx through TRPC3
Activation of the neurokinin-1 receptor in rat spinal astrocytes induces Ca2+ release from IP3-sensitive Ca2+ stores and extracellular Ca2+ influx through TRPC3
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DOI：
10.1016/j.neuint.2010.09.012
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发表时间：
2010-12-01
影响因子：
4.2
通讯作者：
Nakata, Yoshihiro
中科院分区：
文献类型：
--
作者：
Miyano, Kanako;Morioka, Norimitsu;Nakata, Yoshihiro
P物质（SP）通过刺激脊髓神经元中表达的神经激肽（NK）受体，以及随后细胞内Ca2+浓度（[Ca2+](i)）的增加，在疼痛传递中起着重要作用。由于这种刺激，研究表明，脊髓星形胶质细胞也通过激活NK受体参与SP相关的疼痛传递。然而，SP刺激的[Ca2+](i)的机制通过脊髓星形胶质细胞增加因此，我们研究了NK受体的激活是否（以及如何）在大鼠培养的脊髓星形胶质细胞中引起[Ca2+](i)的增加，使用Ca2+成像试验，SP和GR73632 （NK1受体的选择性激动剂）以剂量依赖的方式诱导[Ca2+](i)的短暂和持续增加。SP诱导的[Ca2+](i)的增加被CP-96345 （NK1受体拮抗剂）显著减弱，GR73632诱导的[Ca2+](i)的增加被完全抑制在缺乏细胞外Ca2+的情况下，用U73122（磷脂酶C抑制剂）或xestospongin C（肌醇1 4 5-三磷酸（IP3）受体抑制剂）预处理GR73632只诱导了[Ca2+]的短暂增加(i)此外，蛋白激酶a （PICA）抑制剂H89降低了gr73682介导的Ca2+从细胞内Ca2+储存中释放，而蛋白激酶C （PKC）抑制剂双吲酞丙烯酰亚胺i增强了GR73632诱导的细胞外Ca2+内流RT-PCR检测此外，BTP2（一种通用的TRPC通道抑制剂）或Pyr3（一种TRPC3抑制剂）显著阻断了gr73632诱导的[Ca2+]的持续增加(i)。这些发现表明，脊髓星形胶质细胞中NK-1受体的刺激诱导Ca2+从IP3敏感的细胞内Ca2+储存中释放，这是由PICA正调节的。随后Ca2+内流通过TRPC3，由PKC负调控(C) 2010 Elsevier Ltd版权所有
Substance P (SP) plays an important role in pain transmission through the stimulation of the neurokinin (NK) receptors expressed in neurons of the spinal cord and the subsequent increase in the intracellular Ca2+ concentration ([Ca2+](i)) as a result of this stimulation RI cent studies suggest that spinal astrocytes also contribute to SP-related pain transmission through the activation of NK receptors However the mechanisms involved in the SP-stimulated [Ca2+](i) increase by spinal astrocytes are unclear We therefore examined whether (and how) the activation of NK receptors evoked Increase in [Ca2+](i) in rat cultured spinal astrocytes using a Ca2+ imaging assay Both SP and GR73632 (a selective agonist of the NK1 receptor) induced both transient and sustained increases in [Ca2+](i) in a dose-dependent manner The SP-induced increase in [Ca2+](i) was significantly attenuated by CP-96345 (an NK1 receptor antagonist) The GR73632-induced increase in [Ca2+](i) was completely inhibited by pretreatment with U73122 (a phospholipase C inhibitor) or xestospongin C (an inositol 1 4 5-triphosphate (IP3) receptor inhibitor) In the absence of extracellular Ca2+ GR73632 Induced only a transient increase in [Ca2+](i) In addition H89 an inhibitor of protein kinase A (PICA) decreased the GR73682-mediated Ca2+ release from intracellular Ca2+ stores while bisindolylmaleimide I an inhibitor of protein kinase C (PKC) enhanced the GR73632-induced influx of extracellular Ca2+ RT-PCR assays revealed that canonical transient receptor potential (TRPC) 1 2 3 4 and 6 mRNA were expressed in spinal astrocytes Moreover BTP2 (a general TRPC channel inhibitor) or Pyr3 (a TRPC3 inhibitor) markedly blocked the GR73632-induced sustained increase in [Ca2+](i) These findings suggest that the stimulation of the NK-1 receptor in spinal astrocytes induces Ca2+ release from IP3 sensitive intracellular Ca2+ stores which is positively modulated by PICA, and subsequent Ca2+ influx through TRPC3 which is negatively regulated by PKC (C) 2010 Elsevier Ltd All rights reserved