Xu S U, Zhai Jinhai, Xu K E, Zuo Xingguo, Wu Chenghua, Lin Tao, Zeng L I
Department of Anorectal Surgery, Yancheng Hospital of Traditional Chinese Medicine Affiliated to Nanjing University of Chinese Medicine, Yancheng 224001, Jiangsu, China.
J Biosci. 2021;46.
Slow transit constipation (STC) is a gastrointestinal disorder characterized by abnormal prolonged colonic transit time, which affects the life quality of many people. The decrease number of interstitial cells of Cajal (ICCs) is involved in the pathogenesis of STC. However, the molecular mechanism of loss of ICCs in STC remains unclear, making it difficult to develop new agents for the disease. In this study, we investigated the mechanism of decreasing ICCs in the pathogenesis of STC. We constructed the STC model rats by using atropine and diphenoxylate. A series of methods were used including immunofluorescence and immunochemistry staining, western blot, qRT-PCR, exosomes extraction and exosomes labeling. The results indicate that ICCs decreased in the STC rats accompanied with the macrophages activation. Further studies suggested that macrophages decreased the cell viability of ICCs by secretion exosomes containing miR-34c-5p. miR-34c5p targeted the 3Ꞌ -UTR of stem cell factor(SCF) mRNA and regulated the expression of SCF negatively. In conclusion, we demonstrated a novel regulatory mechanism of ICCs cell viability in STC. We found that exosome miR-34c-5p mediate macrophage-ICCs cross-talk. M1 macrophages derived exosomes miR-34c-5p decreased ICCs cell viability by directly targeting SCF.
慢传输型便秘（STC）是一种胃肠道疾病，其特征为结肠传输时间异常延长，影响着许多人的生活质量。 Cajal间质细胞（ICCs）数量减少参与了STC的发病机制。然而，STC中ICCs丢失的分子机制仍不清楚，这使得开发针对该疾病的新药物变得困难。在本研究中，我们调查了STC发病机制中ICCs减少的机制。我们使用阿托品和地芬诺酯构建了STC模型大鼠。采用了一系列方法，包括免疫荧光和免疫化学染色、蛋白质免疫印迹法、定量逆转录-聚合酶链反应、外泌体提取和外泌体标记。结果表明，STC大鼠中ICCs减少，同时伴有巨噬细胞激活。进一步研究表明，巨噬细胞通过分泌含有miR-34c-5p的外泌体降低ICCs的细胞活力。miR-34c5p靶向干细胞因子（SCF）mRNA的3Ꞌ-非翻译区并负向调节SCF的表达。总之，我们证明了STC中ICCs细胞活力的一种新的调节机制。我们发现外泌体miR-34c-5p介导巨噬细胞与ICCs之间的相互作用。M1巨噬细胞衍生的外泌体miR-34c-5p通过直接靶向SCF降低ICCs的细胞活力。
