Damm Morten Matthiesen Bach, Jensen Thorbjørn Søren Rønn, Mahmood Badar, Lundh Morten, Poulsen Steen Seier, Bindslev Niels, Hansen Mark Berner
Digestive Disease Center K, Bispebjerg Hospital, Copenhagen, Denmark.
The Novo Nordisk Foundation Center for Basic Metabolic Research, Integrative Physiology, University of Copenhagen, Copenhagen, Denmark.
Mol Carcinog. 2017 Oct;56(10):2223-2233. doi: 10.1002/mc.22675. Epub 2017 Jun 15.
The pathogenesis of colorectal neoplasia (CRN) has been associated with altered non-neuronal acetylcholine (ACh) metabolism. The aim of this study was to characterize expression, function, and cellular location of ACh-related proteins in biopsies obtained from endoscopic normal-appearing sigmoid colon in patients with and without CRN. Messenger-RNA (mRNA) levels of 17 ACh-related proteins were quantified by rt-qPCR. Functional responses to ACh, measured as electrogenic transepithelial short circuit current (SCC), were recorded using the Ussing chamber technique. Finally, cellular localization of choline transporter-like proteins (CTLs) and butyryl-cholinesterase enzyme (BChE) was determined by immunohistochemistry. mRNA expression of CTL1 and CTL4 was increased in patients with CRN (P = 0.002 and P = 0.04, respectively). In functional experiments, baseline SCC was increased in CRN patients. ACh induced rapid biphasic changes in SCC. An initial decreasing phase was observed in the minority of CRN patients versus the majority of controls (25% vs 69%, respectively, P = 0.031). For the second increasing phase of SCC, data indicated ACh-activation of two receptors. For both parts of the biphasic response, the half maximal effective concentration and maximal responses showed no difference between patient groups. Immunohistochemistry demonstrated CTL1, 3 and 4 and BChE to be localized to colonic crypt cells. We conclude that CRN is associated with increased expression of CTL1 and CTL4, augmented basal prostaglandin-dependent secretion, and altered functional channel response to ACh in human endoscopic normal-appearing colonic mucosa. The immunohistochemical findings support CTL1, CTL3, CTL4, and BChE to be involved in non-neuronal mucosal ACh metabolism.
结直肠肿瘤（CRN）的发病机制与非神经元乙酰胆碱（ACh）代谢改变有关。本研究的目的是在有和没有CRN的患者中，对从内镜检查外观正常的乙状结肠活检组织中ACh相关蛋白的表达、功能和细胞定位进行表征。通过逆转录定量聚合酶链反应（rt-qPCR）对17种ACh相关蛋白的信使核糖核酸（mRNA）水平进行定量。使用尤斯灌流小室技术记录以电生性跨上皮短路电流（SCC）衡量的对ACh的功能反应。最后，通过免疫组织化学确定胆碱转运体样蛋白（CTLs）和丁酰胆碱酯酶（BChE）的细胞定位。CRN患者中CTL1和CTL4的mRNA表达增加（分别为P = 0.002和P = 0.04）。在功能实验中，CRN患者的基线SCC增加。ACh诱导SCC快速双相变化。在少数CRN患者中观察到初始下降期，而多数对照组中则未观察到（分别为25%对69%，P = 0.031）。对于SCC的第二个上升期，数据表明ACh激活了两种受体。对于双相反应的两个部分，患者组之间的半数最大效应浓度和最大反应均无差异。免疫组织化学显示CTL1、3和4以及BChE定位于结肠隐窝细胞。我们得出结论，CRN与CTL1和CTL4表达增加、基础前列腺素依赖性分泌增加以及人类内镜检查外观正常的结肠黏膜对ACh的功能性通道反应改变有关。免疫组织化学结果支持CTL1、CTL3、CTL4和BChE参与非神经元黏膜ACh代谢。
