Xu Liyan, Liu Yao, Han Wenwen, Nan Chao, Li Dong, Hong Guangliang, Zhao Guangju, Lu Zhongqiu
Department of Emergency, the First Affiliated Hospital, Wenzhou Medical College, Wenzhou 325000, Zhejiang, China. Corresponding author: Lu Zhongqiu, Email:
Zhonghua Wei Zhong Bing Ji Jiu Yi Xue. 2014 May;26(5):315-20. doi: 10.3760/cma.j.issn.2095-4352.2014.05.006.
To investigate the effects of somatostatin on inflammation in endotoxin-induced acute lung injury mice and its underlying mechanisms.
72 ICR male mice of specific pathogen free (SPF) were randomly divided into four groups: control group, SST control group, model group and SST intervention group, each group included 18 mice. The ALI model was reproduced by intraperitoneal injection of 40 mL/kg endotoxin, and the mice in control group was given intraperitoneal injection of equivalent normal saline. The mice in SST intervention group was given the subcutaneous injection of SST (20 μg, 20 mL/kg) at 0.5, 2, 6 and 12 hours after model reproduction. Six mice were sacrificed at 3, 8 and 16 hours after the first injection of LPS or NS. The lung wet/dry ratio (W/D) was calculated with oven drying method. Pathological changes in lung tissues were observed by light microscope. Serum SST, tumor necrosis factor-α (TNF-α), interleukins (IL-6, IL-10) levels were determined by enzyme linked immunosorbent assay (ELISA). The mRNA and protein expressions of Toll like receptor 4 (TLR4) and nuclear factor-ΚBp65 (NF-ΚBp65) were determined by reverse transcription-polymerase chain reaction (RT-PCR) and Western Blot.
There were no significant differences in above indexes between control group and SST control group. Compared with control group, lung W/D ratio, serum SST, TNF-α, IL-6, IL-10, and the mRNA and protein expressions of TLR4 and NF-ΚBp65 in model group were significantly increased. The W/D ratio, IL-6, IL-10, and the mRNA and protein expressions of TLR4 all peaked at 16 hours (W/D ratio: 6.32±0.18 vs. 4.14±0.14, IL-6: 673.78±56.13 ng/L vs. 50.17±7.06 ng/L, IL-10: 481.13±40.78 ng/L vs. 61.71±10.05 ng/L, TLR4 mRNA: 0.740±0.099 vs. 0.180±0.028, TLR4 protein: 0.935±0.067 vs. 0.222±0.019, all P<0.05), and SST, TNF-α, the mRNA and protein expressions of NF-ΚBp65 peaked at 8 hours (SST: 254.97±38.75 ng/L vs. 95.87±13.95 ng/L, TNF-α: 139.69±19.06 ng/L vs. 21.90±4.52 ng/L, NF-ΚBp65 mRNA: 0.753±0.065 vs. 0.190±0.026, NF-ΚBp65 protein: 1.214±0.079 vs. 0.303±0.067, all P<0.05). Compared with model group, the lung injury in SST intervention group was significantly improved, and the indexes were significantly decreased except for serum SST which was gradually increased (16-hour W/D ratio: 5.21±0.14 vs. 6.32±0.18, 8-hour TNF-α: 80.48±8.52 ng/L vs. 139.69±19.06 ng/L, 16-hour IL-6: 394.99±37.17 ng/L vs. 673.78±56.13 ng/L, 16-h IL-10: 326.95±36.41 ng/L vs. 481.13±40.78 ng/L, 16-hour TLR4 mRNA: 0.240±0.028 vs. 0.740±0.099, 16-hour TLR4 protein: 0.618±0.066 vs. 0.935±0.067, 8-hour NF-ΚBp65 mRNA: 0.240±0.045 vs. 0.753±0.065, 8-hour NF-ΚBp65 protein: 0.784±0.041 vs. 1.214±0.079, all P<0.05).
SST has significant protective effects on endotoxin-induced ALI via direct suppression of the TLR4-NF-ΚB cytokine pathway, thus alleviate lung tissue inflammation.
探讨生长抑素对内毒素诱导的急性肺损伤小鼠炎症反应的影响及其潜在机制。
将72只无特定病原体（SPF）的ICR雄性小鼠随机分为四组：对照组、生长抑素对照组、模型组和生长抑素干预组，每组18只。通过腹腔注射40 mL/kg内毒素复制急性肺损伤模型，对照组小鼠腹腔注射等量生理盐水。生长抑素干预组在造模后0.5、2、6和12小时皮下注射生长抑素（20 μg，20 mL/kg）。在首次注射脂多糖或生理盐水后3、8和16小时处死6只小鼠。采用烘干法计算肺组织湿/干比（W/D）。用光镜观察肺组织病理变化。采用酶联免疫吸附测定（ELISA）法测定血清生长抑素、肿瘤坏死因子-α（TNF-α）、白细胞介素（IL-6、IL-10）水平。采用逆转录-聚合酶链反应（RT-PCR）和蛋白质免疫印迹法（Western Blot）测定Toll样受体4（TLR4）和核因子-κB p65（NF-κB p65）的mRNA和蛋白表达。
对照组和生长抑素对照组上述指标无显著差异。与对照组相比，模型组肺W/D比值、血清生长抑素、TNF-α、IL-6、IL-10以及TLR4和NF-κB p65的mRNA和蛋白表达均显著升高。W/D比值、IL-6、IL-10以及TLR4的mRNA和蛋白表达均在16小时达到峰值（W/D比值：6.32±0.18 vs. 4.14±0.14，IL-6：673.78±56.13 ng/L vs. 50.17±7.06 ng/L，IL-10：481.13±40.78 ng/L vs. 61.71±10.05 ng/L，TLR4 mRNA：0.740±0.099 vs. 0.180±0.028，TLR4蛋白：0.935±0.067 vs. 0.222±0.019，均P<0.05），生长抑素、TNF-α以及NF-κB p65的mRNA和蛋白表达在8小时达到峰值（生长抑素：254.97±38.75 ng/L vs. 95.87±13.95 ng/L，TNF-α：139.69±19.06 ng/L vs. 21.90±4.52 ng/L，NF-κB p65 mRNA：0.753±0.065 vs. 0.190±0.026，NF-κB p65蛋白：1.214±0.079 vs. 0.303±0.067，均P<0.05）。与模型组相比，生长抑素干预组肺损伤明显改善，除血清生长抑素逐渐升高外，其余指标均显著降低（16小时W/D比值：5.21±0.14 vs. 6.32±0.18，8小时TNF-α：80.48±8.52 ng/L vs. 139.69±19.06 ng/L，16小时IL-6：394.99±37.17 ng/L vs. 673.78±56.13 ng/L，16小时IL-10：326.95±36.41 ng/L vs. 481.13±40.78 ng/L，16小时TLR4 mRNA：0.240±0.028 vs. 0.740±0.099，16小时TLR4蛋白：0.618±0.066 vs. 0.935±0.067，8小时NF-κB p65 mRNA：0.240±0.045 vs. 0.753±0.065，8小时NF-κB p65蛋白：0.784±0.041 vs. 1.214±0.079，均P<0.05）。
生长抑素通过直接抑制TLR-NF-κB细胞因子通路对内毒素诱导的急性肺损伤具有显著保护作用，从而减轻肺组织炎症。
