Quantification and Potential Functions of Endogenous Agonists of Transient Receptor Potential Channels in Patients With Irritable Bowel Syndrome
Quantification and Potential Functions of Endogenous Agonists of Transient Receptor Potential Channels in Patients With Irritable Bowel Syndrome
复制标题
DOI：
10.1053/j.gastro.2015.04.011
复制
发表时间：
2015-08-01
期刊：
影响因子：
29.4
通讯作者：
Vergnolle, Nathalie
中科院分区：
文献类型：
--
作者：
Cenac, Nicolas;Bautzova, Tereza;Vergnolle, Nathalie
背景与目的：在小鼠中，瞬时受体电位阳离子通道（TRP）TRPV 1、TRPV 4和TRPA 1的激活引起内脏高敏感性。这些受体及其激动剂可能参与肠易激综合征（IBS）的发生发展。我们研究了激活TRP的多不饱和脂肪酸（PUFA）代谢产物是否存在于IBS患者的结肠组织中，并作为内源性激动剂诱导超敏反应。方法：我们分析了40例IBS患者（IBS活检）和11例接受结直肠癌筛查的健康个体（对照）的结肠活检样本，这些样本是在意大利博洛尼亚大学结肠镜检查期间收集的。激活TRPV 1的PUFA代谢物水平（12-氢过氧二十碳四烯酸、15-羟基二十碳四烯酸、5-羟基二十碳四烯酸和白三烯B4），TRPV 4（5，6-环氧二十碳三烯酸[EET]和8，9-EET）和TRPA 1（PGA 1，8-异前列腺素A2，和15-脱氧-δ-前列腺素J（2））在活组织检查和它们的上清液中使用液相色谱和串联质谱进行测量;我们还测量了PUFA代谢产物前列腺素E-2（PGE（2））和消退素的水平。给予C57 B16小鼠鞘内注射小干扰RNA以降低TRPV 4的水平，或对照小干扰RNA，沿着结肠注射活检上清液;基于对结肠直肠扩张的反应测量内脏高敏感性。培养小鼠感觉神经元，并与活检上清液和从小鼠活检或结肠提取的脂质一起孵育。免疫组织化学用于检测人背根神经节样品中的TRPV 4（来自国家疾病研究交换中心）。研究结果：与对照组相比，IBS活检组织中TRPV 4激动剂5，6-EET水平升高，而TRPV 1或TRPA 1激动剂水平未升高;升高与疼痛和腹胀评分相关。IBS活检的上清液，而不是对照组，诱导小鼠内脏高敏感性。小干扰RNA敲低小鼠初级传入神经元中TRPV 4可抑制IBS活检上清液引起的超敏反应。内脏高敏感性小鼠结肠中5，6-EET和15-HETE水平升高，但非无内脏高敏感性。从具有内脏高敏感性的小鼠的IBS活检组织或结肠中提取的PUFA代谢物通过激活TRPV 4在体外激活小鼠感觉神经元。暴露于IBS活检上清液的小鼠感觉神经元通过涉及蛋白酶激活受体2和细胞色素环氧合酶的机制产生5，6-EET。在人背根神经节中，35%的神经元表达TPV 4。结论：肠易激综合征患者的结肠组织中特异性PUFA代谢物水平升高。这些刺激来自小鼠的感觉神经元，并通过激活TRPV 4产生内脏超敏反应。
BACKGROUND & AIMS: In mice, activation of the transient receptor potential cation channels (TRP) TRPV1, TRPV4, and TRPA1 causes visceral hypersensitivity. These receptors and their agonists might be involved in development of irritable bowel syndrome (IBS). We investigated whether polyunsaturated fatty acid (PUFA) metabolites, which activate TRPs, are present in colon tissues from patients with IBS and act as endogenous agonists to induce hypersensitivity. METHODS: We analyzed colon biopsy samples from 40 patients with IBS (IBS biopsies) and 11 healthy individuals undergoing colorectal cancer screening (controls), collected during colonoscopy at the University of Bologna, Italy. Levels of the PUFA metabolites that activate TRPV1 (12-hydroperoxyeicosatetraenoic acid, 15-hydroxyeicosatetraenoic acid, 5-hydroxyeicosatetraenoic acid, and leukotriene B4), TRPV4 (5,6-epoxyeicosatrienoic acid [EET] and 8,9-EET), and TRPA1 (PGA1, 8-iso-prostaglandin A2, and 15-deoxy-Delta-prostaglandin J(2)) were measured in biopsies and their supernatants using liquid chromatography and tandem mass spectrometry; we also measured levels of the PUFA metabolites prostaglandin E-2 (PGE(2)) and resolvins. C57Bl6 mice were given intrathecal injections of small interfering RNAs to reduce levels of TRPV4, or control small interfering RNAs, along with colonic injections of biopsy supernatants; visceral hypersensitivity was measured based on response to colorectal distension. Mouse sensory neurons were cultured and incubated with biopsy supernatants and lipids extracted from biopsies or colons of mice. Immunohistochemistry was used to detect TRPV4 in human dorsal root ganglia samples (from the National Disease Research Interchange). RESULTS: Levels of the TRPV4 agonist 5,6-EET, but not levels of TRPV1 or TRPA1 agonists, were increased in IBS biopsies compared with controls; increases correlated with pain and bloating scores. Supernatants from IBS biopsies, but not from controls, induced visceral hypersensitivity in mice. Small interfering RNA knockdown of TRPV4 in mouse primary afferent neurons inhibited the hypersensitivity caused by supernatants from IBS biopsies. Levels of 5,6-EET and 15-HETE were increased in colons of mice with, but not without, visceral hypersensitivity. PUFA metabolites extracted from IBS biopsies or colons of mice with visceral hypersensitivity activated mouse sensory neurons in vitro, by activating TRPV4. Mouse sensory neurons exposed to supernatants from IBS biopsies produced 5,6-EET via a mechanism that involved the proteinase-activated receptor-2 and cytochrome epoxygenase. In human dorsal root ganglia, TPV4 was expressed by 35% of neurons. CONCLUSIONS: Colon tissues from patients with IBS have increased levels of specific PUFA metabolites. These stimulate sensory neurons from mice and generate visceral hypersensitivity via activation of TRPV4.