How Tongxie-Yaofang Regulates Intestinal Synaptic Plasticity by Activating Enteric Glial Cells and NGF/TrkA Pathway in Diarrhea-Predominant Irritable Bowel Syndrome Rats.
How Tongxie-Yaofang Regulates Intestinal Synaptic Plasticity by Activating Enteric Glial Cells and NGF/TrkA Pathway in Diarrhea-Predominant Irritable Bowel Syndrome Rats.
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DOI：
10.2147/dddt.s423333
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发表时间：
2023
影响因子：
4.8
通讯作者：
Zhang, Shengsheng
中科院分区：
文献类型：
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作者：
Lu, Xiaofang;Zhang, Shengsheng
关键词：
腹泻型肠易激综合征（Diarrhea-predominantirritablebowelsyndrome，D-IBS）是一种常见的功能性胃肠道疾病，发病率高，复发率高，严重影响患者的健康和生活质量。痛泻要方是治疗腹泻型肠易激综合征的传统中药。然而，TXYF的治疗机制尚未完全阐明。本研究旨在探讨通心益肺方对应激诱导的D-IBS大鼠内脏高敏感性的影响及其机制。采用外斜肌肌电图（EMG）活动和腹回缩反射（AWR）评分来量化TXYF对内脏敏感性的影响。透射电镜观察肠神经系统的超微结构。在分子水平上，结肠表达肠神经胶质细胞（EGC）的活化标志物，胶质细胞酸性蛋白（GFAP）和钙结合蛋白S100β，神经生长因子，TrkA，突触可塑性相关因子，突触素（SYN）和突触后密度-95（PSD-95），谷氨酸，谷氨酸受体α-氨基-3-羟基-5-甲基-4-异恶唑丙酸受体（AMPAR），采用免疫组化、酶联免疫吸附试验和实时荧光定量PCR检测脑组织中N-甲基-D-天冬氨酸受体（NMDAR）的表达。进行离体实验以测量EGC诱导的NGF释放。TXYF能降低D-IBS大鼠的肌电活动和AWR评分。透射电镜下，通心泄肺方可改善D-IBS大鼠神经排列的致密性和不规则性，缩小突触间隙，减少突触囊泡数量。此外，通心益气方还能降低GFAP、S100β、SYN和PSD-95的表达，下调NGF、TrkA和谷氨酸的水平，降低AMPAR 1、NMDAR 1和NMDAR 2B的mRNA表达。在离体实验中，TXYF减少D-IBS大鼠的NGF释放，并且这种趋势在EGC抑制下消失。TXYF可能通过抑制结肠EGCs活性和NGF/TrkA信号通路，改善突触可塑性，从而减轻D-IBS大鼠内脏高敏感性。
Diarrhea-predominant irritable bowel syndrome (D-IBS) is a frequent functional gastrointestinal disease that affects health and quality of life owing to its high incidence and recurrence rate. Tongxie-Yaofang (TXYF) is a traditional Chinese medicine prescribed for D-IBS. However, the therapeutic mechanism of TXYF has not been fully elucidated. This study aimed to investigate the effects of TXYF on visceral hypersensitivity in stress-induced D-IBS rats and the underlying mechanisms. Electromyographic (EMG) activity of the external oblique muscles and the abdominal withdrawal reflex (AWR) score captured by Barostat were used to quantify the effect of TXYF on visceral sensitivity. Transmission electron microscopy (TEM) was used to observe the ultrastructure of the enteric nervous system (ENS). For molecular detection, the colonic expression of enteric glial cell’s (EGC’s) activation markers, glial fibrillary acidic protein (GFAP) and calcium-binding protein S100β, NGF, TrkA, synaptic plasticity-related factors, synaptophysin (SYN) and postsynaptic density-95 (PSD-95), glutamate, glutamate receptors α-amino-3-hydroxy-5-methyl-4-isoxazole-propionic acid receptor (AMPAR), and N-methyl-D-aspartate receptor (NMDAR) were detected by immunohistochemistry, enzyme-linked immunosorbent assay, and real-time PCR. An ex vivo experiment was conducted to measure the EGC-induced NGF release. TXYF decreased the EMG activity and AWR scores in rats with D-IBS. Under TEM, TXYF improved the dense and irregular nerve arrangement, narrowed the synaptic cleft, and decreased the number of synaptic vesicles in D-IBS rats. In addition, TXYF decreased the expression of GFAP, S100β, SYN, and PSD-95; down-regulated the levels of NGF, TrkA, and glutamate; and reduced the mRNA expression of AMPAR1, NMDAR1, and NMDAR2B. In an ex vivo experiment, TXYF decreased NGF release in D-IBS rats, and this trend disappeared under EGC inhibition. TXYF alleviated visceral hypersensitivity in D-IBS rats possibly by improving synaptic plasticity through inhibiting the activity of EGCs and the NGF/TrkA signaling pathway in the colon.