Departamento de Farmacología y Fisiología, Facultad de Veterinaria, Universidad de Zaragoza, Zaragoza, Spain.
Instituto de Investigación Sanitaria de Aragón (IIS Aragón), Zaragoza, Spain.
Neurogastroenterol Motil. 2019 Sep;31(9):e13648. doi: 10.1111/nmo.13648. Epub 2019 May 22.
H S is a neuromodulator that may inhibit intestinal motility. H S production in colon is yielded by cystathionine β-synthase (CBS) and cystathionine γ-lyase (CSE) enzymes and sulfate-reducing bacteria (SRB). Toll-like receptors (TLRs) recognize intestinal microbiota. The aim of this work was to evaluate the influence of TLR2 and TLR4 on the endogenous and SRB-mediated synthesis of H S and its consequences on the colonic motility of mouse.
Muscle contractility studies were performed in colon from WT, Tlr2 , and Tlr4 mice. The mRNA levels of TLR2, TLR4, CBS, CSE, and SRB were measured by real-time PCR. Free sulfide levels in colon and feces were determined by colorimetric assays.
NaHS and GYY4137, donors of H S, reduced the contractility of colon. Aminooxyacetic acid (AOAA), inhibitor of CBS, and D-L propargylglycine (PAG), inhibitor of CSE, increased the contractility of colon. In vivo treatment with NaHS or GYY4137 inhibited the spontaneous contractions and upregulated TLR2 expression. The in vivo activation of TLR4 with lipopolysaccharide increased the contractile response to PAG, mRNA levels of CSE, and the free sulfide levels of H S in colon. In Tlr2 and Tlr4 mice, the contractions induced by AOAA and PAG and mRNA levels of CBS and CSE were lower with respect to WT mice. Deficiency of TLR2 or TLR4 provokes alterations in free sulfide levels and SRB of colon.
Our study demonstrates interaction between TLR2 and TLR4 and the sulfide system in the regulation of colonic motility and contributes to the pathophysiology knowledge of intestinal motility disorders.
HS 是一种可能抑制肠道蠕动的神经调节剂。结肠中 HS 的产生由半胱氨酸 β-合酶（CBS）和半胱氨酸 γ-裂解酶（CSE）酶和硫酸盐还原菌（SRB）产生。Toll 样受体（TLR）识别肠道微生物群。本工作旨在评估 TLR2 和 TLR4 对内源性和 SRB 介导的 HS 合成的影响及其对小鼠结肠蠕动的影响。
在 WT、Tlr2 和 Tlr4 小鼠的结肠中进行肌肉收缩研究。通过实时 PCR 测量 TLR2、TLR4、CBS、CSE 和 SRB 的 mRNA 水平。通过比色测定法测定结肠和粪便中的游离硫化物水平。
HS 的供体 NaHS 和 GYY4137 降低了结肠的收缩性。CBS 抑制剂氨基氧乙酸（AOAA）和 CSE 抑制剂 D-L 炔丙基甘氨酸（PAG）增加了结肠的收缩性。体内给予 NaHS 或 GYY4137 抑制自发收缩并上调 TLR2 表达。用脂多糖体内激活 TLR4 增加了对 PAG 的收缩反应、CSE 的 mRNA 水平和结肠 HS 的游离硫化物水平。与 WT 小鼠相比，Tlr2 和 Tlr4 小鼠中由 AOAA 和 PAG 诱导的收缩以及 CBS 和 CSE 的 mRNA 水平较低。TLR2 或 TLR4 的缺失会引起结肠游离硫化物水平和 SRB 的改变。
本研究证明了 TLR2 和 TLR4 与调节结肠蠕动的硫化物系统之间的相互作用，并为肠道动力障碍的病理生理学知识做出了贡献。
