Department of Gastroenterology, First Affiliated Hospital, Jinzhou Medical University, Jinzhou City, Liaoning Province, China.
Department of Gastroenterology, First Hospital of China Medical University, Shenyang City, Liaoning Province, China.
mBio. 2024 Aug 14;15(8):e0153324. doi: 10.1128/mbio.01533-24. Epub 2024 Jul 2.
Emerging evidence indicates that gut dysbiosis is involved in the pathogenesis of visceral hypersensitivity (VH). However, how gut microbiota contributes to the development of VH is unknown. Here, we sought to examine the signal transduction pathways from gut to dorsal root ganglion (DRG) responsible for this. Therefore, abdominal withdrawal reflex (AWR) scores, fecal output, fecal water content, and total gastrointestinal transit time (TGITT) were assessed in Con rats, VH rats, rats treated with NaB, and VH rats treated with VSL#3. Fecal microbiota and its metabolite (short-chain fatty acids, SCFAs), mast cell degranulation in colon, lincRNA-01028, miR-143, and protease kinase C (PKC) and TRPV1 expression in DRGs were further detected. VH rats showed an increased fecal water content, a shortened TGITT, an increased abundance of Clostridium 1 and increased butyrate in fecal samples, an increased mast cell degranulation, an increased expression of lincRNA-01028, PKC, and TRPV1, and a decreased expression of miR-143 in DRGs compared with control rats, which could be restored by the application of probiotic VSL#3. The above-mentioned detection in rats treated with butyrate was similar to that of VH rats. We further confirm whether butyrate sensitized DRG neurons by a lincRNA-01028, miR-143, and PKC-dependent mechanism via mast cell . In co-cultures, MCs treated with butyrate elicited a higher TRPV1 current, a higher expression of lincRNA-01028, PKC, and a lower expression of miR-143 in DRG neurons, which could be inhibited by a lincRNA-01028 inhibitor. These findings indicate that butyrate promotes visceral hypersensitivity via mast cell-derived DRG neuron lincRNA-01028-PKC-TRPV1 pathway.IMPORTANCEIrritable bowel syndrome (IBS), characterized by visceral hypersensitivity, is a common gastrointestinal dysfunction syndrome. Although the gut microbiota plays a role in the pathogenesis and treatment of irritable bowel syndrome (IBS), the possible underlying mechanisms are unclear. Therefore, it is of critical importance to determine the signal transduction pathways from gut to DRG responsible for this and assay. This study demonstrated that butyrate sensitized TRPV1 in DRG neurons via mast cells and by a lincRNA-01028, miR-143, and PKC-dependent mechanism. VH rats similarly showed an increased abundance of Clostridium 1, an increased fecal butyrate, an increased mast cell degranulation, and increased expression of TRPV1 compared with control rats, which could be restored by the application of VSL#3. In conclusion, butyrate produced by the altered intestinal microbiota is associated with increased VH.
新兴证据表明,肠道菌群失调与内脏高敏感(VH)的发病机制有关。然而,肠道微生物群如何导致 VH 的发展尚不清楚。在这里,我们试图研究负责这一现象的从肠道到背根神经节(DRG)的信号转导途径。因此,我们评估了 Con 大鼠、VH 大鼠、用 NaB 治疗的大鼠和用 VSL#3 治疗的 VH 大鼠的腹部退缩反射(AWR)评分、粪便排出量、粪便含水量和总胃肠道转运时间(TGITT)。进一步检测了结肠肥大细胞脱颗粒、DRG 中的 lincRNA-01028、miR-143、蛋白激酶 C(PKC)和 TRPV1 的表达以及粪便微生物群及其代谢产物(短链脂肪酸,SCFAs)。与对照大鼠相比,VH 大鼠的粪便含水量增加,TGITT 缩短,粪便中梭状芽胞杆菌 1 的丰度增加,粪便中丁酸盐增加,肥大细胞脱颗粒增加,DRG 中的 lincRNA-01028、PKC 和 TRPV1 表达增加,miR-143 表达减少,而应用益生菌 VSL#3 可恢复上述变化。用丁酸处理的大鼠的上述检测结果与 VH 大鼠相似。我们进一步通过肥大细胞证实丁酸是否通过 lincRNA-01028、miR-143 和 PKC 依赖性机制使 DRG 神经元敏感。在共培养物中,用丁酸处理的 MC 可引起 DRG 神经元中 TRPV1 电流升高、lincRNA-01028、PKC 表达升高和 miR-143 表达降低,这可被 lincRNA-01028 抑制剂抑制。这些发现表明,丁酸通过肥大细胞衍生的 DRG 神经元 lincRNA-01028-PKC-TRPV1 途径促进内脏高敏感。
肠易激综合征(IBS)的特征是内脏高敏感,是一种常见的胃肠道功能障碍综合征。尽管肠道微生物群在肠易激综合征(IBS)的发病机制和治疗中起作用,但潜在的机制尚不清楚。因此,确定负责这一点的从肠道到 DRG 的信号转导途径至关重要。本研究表明,丁酸通过肥大细胞和 lincRNA-01028、miR-143 和 PKC 依赖性机制使 DRG 神经元中的 TRPV1 敏感。VH 大鼠与对照大鼠相比,同样表现出梭状芽胞杆菌 1 的丰度增加、粪便丁酸增加、肥大细胞脱颗粒增加和 TRPV1 表达增加,而 VSL#3 的应用可恢复这些变化。总之,改变的肠道微生物群产生的丁酸与 VH 的增加有关。