Inhibition of miR-155 alleviates sepsis-induced inflammation and intestinal barrier dysfunction by inactivating NF-κB signaling
Inhibition of miR-155 alleviates sepsis-induced inflammation and intestinal barrier dysfunction by inactivating NF-κB signaling
复制标题
DOI：
10.1016/j.intimp.2020.107218
复制
发表时间：
2021-01-01
影响因子：
5.6
通讯作者：
Lu, Wei-Hua
中科院分区：
文献类型：
--
作者：
Cao, Ying-Ya;Wang, Zhen;Lu, Wei-Hua
microRNA-155（miR-155）参与脓毒症的病理过程。然而，miR-155在脓毒症诱导的炎症和肠屏障功能障碍中的功能和调控机制尚不清楚。本研究采用盲肠结扎穿孔法（CLP）建立小鼠脓毒症模型。为了减少miR-155表达，在CLP之前连续三天给小鼠注射miR-155抑制剂（80 mg/kg）。CLP后24 h用ELISA法测定血清DAO浓度，用H&E染色法观察小肠组织学变化。FITC-葡聚糖测定用于评价肠通透性。采用RT-PCR检测miR-155基因表达，Western blotting检测miR-155蛋白表达。分别用miR-155模拟物/miR-155抑制剂转染或NF-κ B B抑制剂预处理NCM 460细胞，检测细胞因子水平、miR-155基因表达及相关蛋白表达。脓毒症增加了miR-155、DAO和FITC-葡聚糖水平，降低了Occludin和ZO-1表达。注射miR-155抑制剂的小鼠从损伤中恢复。用miR-155模拟物转染NCM 460细胞可提高NF-κ B（P65）和p-NF-κ B（p-P65）在细胞核中的定位和表达，这可被miR-155抑制剂逆转。用NF-κ B抑制剂预处理抑制炎症，改善细胞对FITC-葡聚糖的渗透性，并增加Occludin和ZO-1水平。用miR-155抑制剂转染降低了TNF-α和IL-6水平，降低了细胞对FITC-葡聚糖的渗透性，并增加了ZO-1和Occludin表达。通过用NF-κ B抑制剂预处理，部分挽救了用miR-155模拟物转染诱导的效应，包括TNF-α和IL-6水平升高、对FITC-葡聚糖的高渗透性以及ZO-1和Occludin表达降低。这些发现揭示了miR-155抑制剂通过在脓毒症期间灭活NF-κ B信号传导来减轻炎症和肠屏障功能障碍。
MicroRNA-155 (miR-155) is implicated in the pathological processes of sepsis. However, the function and regulatory mechanism of miR-155 in sepsis-induced inflammation and intestinal barrier dysfunction remain unknown. In this study, mouse models of sepsis were established by caecal ligation and puncture (CLP). To reduce miR-155 expression, the mice were injected for three consecutive days with an miR-155 inhibitor (80 mg/kg) before CLP. The serum DAO concentration was measured by ELISA, and histological changes in the intestine were identified by H&E staining 24 h after CLP. FITC-dextran assays were used to evaluate intestinal permeability. MiR-155 gene expression was evaluated with RT-PCR, and relative protein expression was assessed by Western blotting. NCM460 cells were transfected with an miR-155 mimic/miR-155 inhibitor or pretreated with an NF-kappa B inhibitor before LPS treatment, and the cytokines levels, miR-155 gene expression and relative protein expression were measured. Sepsis increased miR-155, DAO and FITC-dextran levels and reduced Occludin and ZO-1 expression. Mice injected with the miR-155 inhibitor recovered from the damages. Transfection of NCM460 cells with the miR-155 mimic elevated the NF-kappa B (P65) and p-NF-kappa B (p-P65) localization and expression in the nucleus, which was reversed by the miR-155 inhibitor. Pretreatment with an NF-kappa B inhibitor suppressed inflammation, improved cell permeability to FITC-dextran and increased Occludin and ZO-1 levels. Transfection with the miR-155 inhibitor decreased TNF-alpha and IL-6 levels, reduced cell permeability to FITC-dextran and increased ZO-1 and Occludin expression. The effects induced by transfection with the miR-155 mimic, including elevated TNF-alpha and IL-6 levels, hyperpermeability to FITC-dextran and reduced ZO-1 and Occludin expression, were partly rescued by pretreatment with the NF-kappa B inhibitor. These findings reveal that the miR-155 inhibitor alleviates inflammation and intestinal barrier dysfunction by inactivating NF-kappa B signaling during sepsis.