Ma Xuena, Tian Dan, Lv Weina, Gao Baoyu, Ma Zhiyong, Zheng Xiaotuo
Department of Critical Medicine, The Fourth Central Hospital of Baoding City, Baoding, Hebei 072350, P.R. China.
Department of Otorhinolaryngology, The Fourth Central Hospital of Baoding City, Baoding, Hebei 072350, P.R. China.
Exp Ther Med. 2021 Sep;22(3):964. doi: 10.3892/etm.2021.10396. Epub 2021 Jul 7.
The aim of the present study was to investigate the mediation of micro RNA (miR)-223 on the anti-inflammatory effect of the Toll-like receptor (TLR) signaling pathway on sepsis-induced lung injury in rats via negatively regulating the expression of interleukin (IL)-6. Sprague-Dawley rats were used in the present study. It was determined whether miR-223 is differentially expressed in the lung using reverse transcription-quantitative PCR techniques and the content of cytokines in bronchoalveolar lavage (BAL) fluid was detected. The protein expression levels of TLR4 and nuclear factor (NF)-κB p65 were examined by western blotting and the pathological changes in the lung tissues of the sepsis group were observed. Hematoxylin and eosin was used to stain the lung tissues. The alveoli in the sham group exhibited a normal structure and morphology. In the sepsis group, the alveoli of the lung tissues were surrounded by numerous neutrophils, the mesenchyme was swollen, regions of the alveolar wall exhibited fibrosis and the alveolar wall was thickened. Furthermore, in the sepsis group, miR-223 expression was increased in the lung tissues when compared with that in the sham group. The content of cytokines, IL-6 and IL-1β in the BAL fluid was significantly increased when compared with that of the sham group and TLR4 and NF-κB were also highly expressed. In addition, when compared with RAW264.7 cells that were overexpressing miR-223, the content of IL-6 and IL-1β in the supernatant and protein expression of TLR and NF-κB in cells were markedly decreased. Thus, it was demonstrated that miR-223 negatively regulated the expression of IL-6, mediating the TLR4/NF-κB signaling pathway and exerting an anti-inflammatory effect in sepsis-induced lung injury.
本研究旨在探讨微小RNA（miR）-223通过负向调节白细胞介素（IL）-6的表达，对脓毒症诱导的大鼠肺损伤中Toll样受体（TLR）信号通路的抗炎作用的介导机制。本研究使用了Sprague-Dawley大鼠。采用逆转录定量PCR技术测定肺组织中miR-223是否差异表达，并检测支气管肺泡灌洗（BAL）液中细胞因子的含量。通过蛋白质印迹法检测TLR4和核因子（NF）-κB p65的蛋白表达水平，并观察脓毒症组肺组织的病理变化。苏木精-伊红染色法用于肺组织染色。假手术组肺泡结构和形态正常。脓毒症组肺组织肺泡周围有大量中性粒细胞，间质肿胀，肺泡壁区域出现纤维化，肺泡壁增厚。此外，与假手术组相比，脓毒症组肺组织中miR-223表达增加。与假手术组相比，BAL液中细胞因子IL-6和IL-1β的含量显著增加，TLR4和NF-κB也高表达。此外，与过表达miR-223的RAW264.7细胞相比，上清液中IL-6和IL-1β的含量以及细胞中TLR和NF-κB的蛋白表达明显降低。因此，证明miR-223负向调节IL-6的表达，介导TLR4/NF-κB信号通路，并在脓毒症诱导的肺损伤中发挥抗炎作用。
