Huang Dong, Fang Fang, Xu Feng
Department of Pediatrics Intensive Care Unit, Chongqing Children's Hospital, Chongqing Medical University, Chongqing 400014, China.
Zhongguo Wei Zhong Bing Ji Jiu Yi Xue. 2009 Nov;21(11):644-7.
To investigate the role of Toll-like receptors (TLRs) in pathogenesis of hyperoxia- induced acute lung injury (ALI).
Thirty-two Sprague-Dawley (SD) rats were randomly divided into air control group, hyperoxia for 24 hours group, hyperoxia for 48 hours group, and hyperoxia for 72 hours group, with 8 rats in each group. At corresponding exposure time points the animals were sacrificed, then the left lung was removed and measured the wet/dry weight (W/D) ratio. The severity of lung injury was assessed by lung histopathology scores, the expression of TLR2 mRNA and TLR4 mRNA in lung tissue was assessed by real-time reverse transcription-polymerase chain reaction (RT-PCR), the expression of TLR2 and TLR4 protein in lung tissue was measured by Western blotting, the amount of interleukin-6 (IL-6) in lung tissue was measured by enzyme linked immunosorbent assay (ELISA).
After hyperoxia exposure, an increase in lung W/D ratio was noted compared with that of the air control group (all P<0.01). Lung injury scores in hyperoxia for 48 hours (2.69+/-0.52) and 72 hours group (3.94+/-0.62) were significantly higher than that of the air control group (0.41+/-0.38, both P<0.01). Real-time RT-PCR results showed that TLR2 mRNA and TLR4 mRNA expression in lung tissue in hyperoxia exposure groups was significantly higher than that of the air control group (0.67+/-0.15, 0.63+/-0.19), and it reached the peak at 24 hours (1.82+/-0.33, 1.35+/-0.26, both P<0.05). Western blotting study showed increased protein expression of TLR2 and TLR4 in lung tissues of the hyperoxia groups compared with the air control group [(7.20+/-0.51)%, (14.26+/-0.19)%], and it peaked at 48 hours and 72 hours [(28.12+/-0.24)%, (81.35+/-0.82)%, both P<0.05]. ELISA assay also demonstrated upregulation of IL-6 levels in lung tissue of hyperoxia groups compared with the air control group [(639.38+/-95.24) pg/L], and it reached the peak at 72 hours [(1 300.58+/-442.24) pg/L, P<0.05].
The prolonged exposure to hyperoxia may cause ALI in rat, and TLR2 and TLR4 plays an important role in the development of hyperoxia-induced ALI in rat.
探讨Toll样受体（TLRs）在高氧诱导的急性肺损伤（ALI）发病机制中的作用。
将32只Sprague-Dawley（SD）大鼠随机分为空气对照组、高氧24小时组、高氧48小时组和高氧72小时组，每组8只。在相应的暴露时间点处死动物，然后取出左肺并测量湿/干重（W/D）比值。通过肺组织病理学评分评估肺损伤的严重程度，通过实时逆转录-聚合酶链反应（RT-PCR）评估肺组织中TLR2 mRNA和TLR4 mRNA的表达，通过蛋白质印迹法测量肺组织中TLR2和TLR4蛋白的表达，通过酶联免疫吸附测定（ELISA）测量肺组织中白细胞介素-6（IL-6）的含量。
高氧暴露后，与空气对照组相比，肺W/D比值升高（均P<0.01）。高氧48小时组（2.69±0.52）和72小时组（3.94±0.62）的肺损伤评分显著高于空气对照组（0.41±0.38，均P<0.01）。实时RT-PCR结果显示，高氧暴露组肺组织中TLR2 mRNA和TLR4 mRNA的表达显著高于空气对照组（0.67±0.15，0.63±0.19），并在24小时达到峰值（1.82±0.33，1.35±0.26，均P<0.05）。蛋白质印迹研究显示，与空气对照组相比，高氧组肺组织中TLR2和TLR4的蛋白表达增加[（7.20±0.51）%，（14.26±0.19）%]，并在48小时和72小时达到峰值[（28.12±0.24）%，（81.35±0.82）%，均P<0.05]。ELISA测定还表明，与空气对照组相比，高氧组肺组织中IL-6水平上调[（639.38±95.24）pg/L]，并在72小时达到峰值[（1 300.58±442.24）pg/L，P<0.05]。
长时间高氧暴露可能导致大鼠ALI，TLR2和TLR4在高氧诱导的大鼠ALI发生发展中起重要作用。
