Neonatal colonic inflammation sensitizes voltage-gated Na+ channels via upregulation of cystathionine β-synthetase expression in rat primary sensory neurons
Neonatal colonic inflammation sensitizes voltage-gated Na+ channels via upregulation of cystathionine β-synthetase expression in rat primary sensory neurons
复制标题
新生儿结肠炎症通过大鼠初级感觉神经元中胱硫醚β-合成酶表达的上调使电压门控Na通道敏感
DOI：
10.1152/ajpgi.00466.2012
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发表时间：
2013-05-01
影响因子：
4.5
通讯作者：
Xu, Guang-Yin
中科院分区：
文献类型：
--
作者：
Qu, Ruobing;Tao, Jingde;Xu, Guang-Yin
肠易激综合征（IBS）疼痛的发病机制尚不清楚，治疗也很困难。我们之前曾报道，在新生儿结肠炎症（NCI）诱导的 IBS 大鼠模型中，结肠特异性背根神经节（DRG）神经元过度活跃。本研究旨在检查电压门控 Na+ 通道活性的可塑性以及内源性硫化氢产生酶胱硫醚β-合成酶 (CBS) 在慢性内脏痛觉过敏中的作用。记录成年雄性大鼠对分级结直肠扩张的腹部撤回反射（AWR）评分，作为内脏过敏的衡量标准。结肠特异性 DRG 神经元用 1,1'-二油基-3,3,3', 3-四甲基吲哚羰花青甲磺酸盐标记，并急剧解离以测量 Na+ 通道电流。采用蛋白质印迹分析检测电压门控 Na+ (Na-V) 通道亚型 1.7、Na(V)1.8 和 CBS 表达的变化。与年龄匹配的对照组相比，NCI 显着提高了 AWR 评分。 NCI 还导致结肠特异性 DRG 神经元中 Na+ 电流密度增加了 2.5 倍。此外，NCI 显着增强了结肠相关 DRG 中 Na(V)1.7、Na(V)1.8 和 CBS 的表达。 CBS 与 Na(V)1.7 或 -1.8 共定位于结肠特异性 DRG 神经元中。施用 CBS 抑制剂 O-(羧甲基)-羟胺半盐酸盐 (AOAA) 显着抑制 Na+ 电流密度并减少 Na(V)1.7 和 Na(V)1.8 的表达。更重要的是，腹膜内或鞘内应用AOAA以剂量依赖性方式减弱NCI大鼠的AWR评分。这些数据表明，NCI 增强了结肠 DRG 神经元的 Na+ 通道活性，这很可能是由 CBS 表达上调介导的，从而确定了治疗 IBS 患者慢性内脏疼痛的潜在靶点。
The pathogenesis of pain in irritable bowel syndrome (IBS) is poorly understood, and treatment remains difficult. We have previously reported that colon-specific dorsal root ganglion (DRG) neurons were hyperactive in a rat model of IBS induced by neonatal colonic inflammation (NCI). This study was designed to examine plasticity of voltage-gated Na+ channel activities and roles for the endogenous hydrogen sulfide-producing enzyme cystathionine beta-synthetase (CBS) in chronic visceral hyperalgesia. Abdominal withdrawal reflex (AWR) scores were recorded in response to graded colorectal distention in adult male rats as a measure of visceral hypersensitivity. Colon-specific DRG neurons were labeled with 1,1'-dioleyl-3,3,3', 3-tetramethylindocarbocyanine methanesulfonate and acutely dissociated for measuring Na+ channel currents. Western blot analysis was employed to detect changes in expressions of voltage-gated Na+ (Na-V) channel subtype 1.7, Na(V)1.8, and CBS. NCI significantly increased AWR scores when compared with age-matched controls. NCI also led to an similar to 2.5-fold increase in Na+ current density in colon-specific DRG neurons. Furthermore, NCI dramatically enhanced expression of Na(V)1.7, Na(V)1.8, and CBS in colon-related DRGs. CBS was colocalized with Na(V)1.7 or -1.8 in colon-specific DRG neurons. Administration of O-(carboxymethyl)-hydroxylamine hemihydrochloride (AOAA), an inhibitor for CBS, remarkably suppressed Na+ current density and reduced expression of Na(V)1.7 and Na(V)1.8. More importantly, intraperitoneal or intrathecal application of AOAA attenuated AWR scores in NCI rats in a dose-dependent manner. These data suggest that NCI enhances Na+ channel activity of colon DRG neurons, which is most likely mediated by upregulation of CBS expression, thus identifying a potential target for treatment for chronic visceral pain in patients with IBS.