School of Basic Medical Sciences, Binzhou Medical University, Yantai Affiliated Hospital of Binzhou Medical University, Yantai, Shandong 264003, P.R. China.
Department of Gastrointestinal Surgery, Yantai Mountain Hospital, Yantai, Shandong 264003, P.R. China.
Mol Med Rep. 2024 Jun;29(6). doi: 10.3892/mmr.2024.13214. Epub 2024 Apr 5.
The intestinal mucosal barrier is of great importance for maintaining the stability of the internal environment, which is closely related to the occurrence and development of intestinal inflammation. Octreotide (OCT) has potential applicable clinical value for treating intestinal injury according to previous studies, but the underlying molecular mechanisms have remained elusive. This article is based on a cell model of inflammation induced by lipopolysaccharide (LPS), aiming to explore the effects of OCT in protecting intestinal mucosal barrier function. A Cell Counting Kit‑8 assay was used to determine cell viability and evaluate the effectiveness of OCT. Gene silencing technology was used to reveal the mediated effect of somatostatin receptor 2 (SSTR2). The changes in intestinal permeability were detected through trans‑epithelial electrical resistance and fluorescein isothiocyanate‑dextran 4 experiments, and the alterations in tight junction proteins were detected using immunoblotting and reverse transcription fluorescence‑quantitative PCR technology. Autophagosomes were observed by electron microscopy and the dynamic changes of the autophagy process were characterized by light chain (LC)3‑II/LC3‑I conversion and autophagic flow. The results indicated that SSTR2‑dependent OCT can prevent the decrease in cell activity. After LPS treatment, the permeability of monolayer cells decreased and intercellular tight junctions were disrupted, resulting in a decrease in tight junction protein zona occludens 1 in cells. The level of autophagy‑related protein LC3 was altered to varying degrees at different times. These abnormal changes gradually returned to normal levels after the combined application of LPS and SSTR2‑dependent OCT, confirming the role of OCT in protecting intestinal barrier function. These experimental results suggest that OCT maintains basal autophagy and cell activity mediated by SSTR2 in intestinal epithelial cells, thereby preventing the intestinal barrier dysfunction in inflammation injury.
肠黏膜屏障对于维持内环境的稳定性非常重要,其与肠道炎症的发生和发展密切相关。先前的研究表明,奥曲肽(OCT)在治疗肠道损伤方面具有潜在的临床应用价值,但潜在的分子机制仍不清楚。本文基于脂多糖(LPS)诱导的炎症细胞模型,旨在探讨 OCT 保护肠黏膜屏障功能的作用机制。通过细胞计数试剂盒-8 法(Cell Counting Kit-8 assay)检测细胞活力,评估 OCT 的有效性。采用基因沉默技术揭示生长抑素受体 2(SSTR2)的介导作用。通过跨上皮电阻和荧光素异硫氰酸酯-葡聚糖 4 实验检测肠上皮细胞通透性的变化,通过免疫印迹和逆转录荧光定量 PCR 技术检测紧密连接蛋白的变化。电子显微镜观察自噬体,通过 LC3-Ⅱ/LC3-I 转换和自噬流特征化自噬过程的动态变化。结果表明,SSTR2 依赖性 OCT 可防止细胞活性下降。LPS 处理后,单层细胞的通透性降低,细胞间紧密连接破坏,导致细胞中紧密连接蛋白 ZO-1 减少。自噬相关蛋白 LC3 的水平在不同时间发生不同程度的改变。LPS 和 SSTR2 依赖性 OCT 联合应用后,这些异常变化逐渐恢复正常水平,证实了 OCT 保护肠道屏障功能的作用。这些实验结果表明,OCT 通过 SSTR2 介导维持肠上皮细胞基础自噬和细胞活性,从而防止炎症损伤导致的肠道屏障功能障碍。