Wang H, Xie H, Xu W, Li M
Department of Pediatrics, Affiliated Hospital of Inner Mongolia University for Nationalities, Tongliao 028000, China.
Department of Pediatrics, Fourth People's Hospital of Horqin District, Tongliao 028000, China.
Nan Fang Yi Ke Da Xue Xue Bao. 2024 Jul 20;44(7):1370-1381. doi: 10.12122/j.issn.1673-4254.2024.07.17.
To observe the therapeutic effects of urolithin A (UA) on respiratory syncytial virus (RSV)-induced lung infection in neonatal mice and explore the underlying mechanisms.
Babl/c mice (5-7 days old) were subjected to nasal instillation of RSV and received intraperitoneal injection of saline or 2.5, 5 and 10 mg/kg UA 2 h after the infection and then once daily for 2 weeks. Bronchoalveolar lavage fluid (BALF) was then collected for detection of inflammatory cells and mediators, and lung pathology was evaluated with HE staining. RSV-infected BEAS-2B cells were treated with 2.5, 5 or 10 µmol/ L UA. Inflammatory factors, cell viability, apoptosis and autophagy were analyzed using ELISA, CCK-8 assay, TUNEL staining, flow cytometry, Western blotting and immunofluorescence staining. The cellular expressions of miR-136 and Sirt1 mRNAs were detected using qRT-PCR. A dual-luciferase reporter system was used to verify the binding between miR-136 and Sirt1.
In neonatal Babl/c mice, RSV infection caused obvious lung pathologies, promoted pulmonary cell apoptosis and LC3-Ⅱ/Ⅰ, Beclin-1 and miR-136 expressions, and increased the total cell number, inflammatory cells and factors in the BALF and decreased p62 and Sirt1 expressions. All these changes were alleviated dose-dependently by UA. In BEAS-2B cells, RSV infection significantly increased cell apoptosis, LC3B-positive cells and miR-136 expression and reduced Sirt1 expression (<0.01), which were dose-dependently attenuated by UA. Dual-luciferase reporter assay confirmed the binding between miR-136 and Sirt1. In RSV-infected BEAS-2B cells with UA treatment, overexpression of miR-136 and Ex527 treatment both significantly increased the inflammatory factors and cell apoptosis but decreased LC3B expression, and these changes were further enhanced by their combined treatment.
UA ameliorates RSV-induced lung infection in neonatal mice by activating miR-136-mediated Sirt1 signaling pathway.
观察尿石素A（UA）对呼吸道合胞病毒（RSV）诱导的新生小鼠肺部感染的治疗效果，并探讨其潜在机制。
将5-7日龄的Babl/c小鼠经鼻腔滴注RSV，并在感染后2小时腹腔注射生理盐水或2.5、5和10mg/kg的UA，然后每天注射一次，持续2周。随后收集支气管肺泡灌洗液（BALF）以检测炎症细胞和介质，并通过HE染色评估肺组织病理学。用2.5、5或10μmol/L的UA处理RSV感染的BEAS-2B细胞。使用ELISA、CCK-8法、TUNEL染色、流式细胞术、蛋白质免疫印迹法和免疫荧光染色分析炎症因子、细胞活力、细胞凋亡和自噬。使用qRT-PCR检测miR-136和Sirt1 mRNA的细胞表达。使用双荧光素酶报告系统验证miR-136与Sirt1之间的结合。
在新生Babl/c小鼠中，RSV感染导致明显的肺部病变，促进肺细胞凋亡以及LC3-Ⅱ/Ⅰ、Beclin-1和miR-136的表达，并增加BALF中的细胞总数、炎症细胞和炎症因子，降低p62和Sirt1的表达。UA可剂量依赖性地减轻所有这些变化。在BEAS-2B细胞中，RSV感染显著增加细胞凋亡、LC3B阳性细胞和miR-136表达，并降低Sirt1表达（<0.01），而UA可剂量依赖性地减弱这些变化。双荧光素酶报告基因检测证实了miR-136与Sirt1之间的结合。在UA处理的RSV感染的BEAS-2B细胞中，miR-136过表达和Ex527处理均显著增加炎症因子和细胞凋亡，但降低LC3B表达，联合处理可进一步增强这些变化。
UA通过激活miR-136介导的Sirt1信号通路改善RSV诱导的新生小鼠肺部感染。
