小非编码穹窿 RNA (vtRNA) 参与许多对健康和疾病很重要的细胞过程，但它们在肠上皮细胞中的病理生物学功能尚未得到充分研究。在这里，我们研究了人类 vtRNA1-1 在调节肠上皮更新和屏障功能中的作用。研究在 vtRNA1-1 转基因 (vtRNA1-1Tg) 小鼠、原代肠上皮细胞和 Caco-2 细胞中进行。从休克患者和脓毒症小鼠的血清中分离出细胞外囊泡（EV）。从 vtRNA1-1Tg 和同窝小鼠中制备肠类器官（肠类器官）。通过 Ki67 免疫染色或 BrdU 掺入测量粘膜生长，并使用 FITC-葡聚糖测定评估肠道通透性。从休克患者和脓毒症小鼠中回收的肠道组织显示粘膜损伤和肠道屏障功能障碍；从其血清中分离出的 EV 中 vtRNA 水平升高。在小鼠中，vtRNA1-1的肠上皮特异性转基因表达抑制粘膜生长，减少潘氏细胞数量和细胞间连接（IJ）蛋白表达，并增加肠道屏障对脂多糖暴露的脆弱性。相反，体外沉默 vtRNA1-1 会增加 IJ 蛋白水平并增强上皮屏障功能。将肠类暴露于富含 vtRNA1-1 的 EV 会增强细胞旁通透性。从机制上讲，vtRNA1-1与CUG结合蛋白1（CUGBP1）相互作用，增加CUGBP1与claudin-1和occludin mRNA的关联，从而抑制它们的表达。这些发现表明，EV和粘膜组织中vtRNA1-1水平升高会抑制肠上皮细胞更新和屏障功能。值得注意的是，这项工作揭示了 vtRNA1-1/CUGBP1 轴失调在危重疾病肠粘膜破坏发病机制中的新作用。版权所有 © 2024 作者。由爱思唯尔公司出版。保留所有权利。

Small noncoding vault RNAs (vtRNAs) are involved in many cell processes important for health and disease, but their pathobiological functions in the intestinal epithelium are underexplored. Here, we investigated the role of human vtRNA1-1 in regulating intestinal epithelial renewal and barrier function.Studies were conducted in vtRNA1-1 transgenic (vtRNA1-1Tg) mice, primary enterocytes, and Caco-2 cells. Extracellular vesicles (EVs) were isolated from the serum of shock patients and septic mice. Intestinal organoids (enteroids) were prepared from vtRNA1-1Tg and littermate mice. Mucosal growth was measured by Ki67 immunostaining or BrdU incorporation, and gut permeability assessed using the FITC-dextran assay.Intestinal tissues recovered from shock patients and septic mice evidenced mucosal injury and gut barrier dysfunction; vtRNA levels were elevated in EVs isolated from their sera. In mice, intestinal epithelial-specific transgenic expression of vtRNA1-1 inhibited mucosal growth, reduced Paneth cell numbers and intercellular junction (IJ) protein expression, and increased gut barrier vulnerability to lipopolysaccharide exposure. Conversely, in vitro silencing of vtRNA1-1 increased IJ protein levels and enhanced epithelial barrier function. Exposing enteroids to vtRNA1-1-rich EVs augmented paracellular permeability. Mechanistically, vtRNA1-1 interacted with CUG-binding protein 1 (CUGBP1) and increased CUGBP1 association with claudin-1 and occludin mRNAs, thereby inhibiting their expression.These findings indicate that elevated levels of vtRNA1-1 in EVs and mucosal tissues repress intestinal epithelial renewal and barrier function. Notably, this work reveals a novel role for dysregulation of the vtRNA1-1/CUGBP1 axis in the pathogenesis of gut mucosal disruption in critical illness.Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.