萝卜硫素对脓毒症急性肺损伤大鼠肺组织Toll样受体4/核因子κB信号通路的影响

目的评价萝卜硫素对于脓毒症急性肺损伤（ALI）大鼠肺组织炎症反应以及Toll样受体4（TLR4）/核因子κB（NF-κB）信号通路的影响。 方法将30只雄性Sprague Dawley大鼠按随机数字表法分成假手术组、模型组和治疗组，每组各10只。模型组和治疗组大鼠采用盲肠结扎穿孔（CLP）法制备大鼠脓毒症模型，治疗组大鼠在术后立即腹腔注射50 mg/kg的萝卜硫素注射液，其余两组注入等量等渗NaCl溶液；于术后24 h大鼠右侧颈总动脉采集动脉血标本，然后处死大鼠取肺组织测定肺组织湿/干比。采用酶联免疫吸附测定（ELISA）法检测三组大鼠肺组织匀浆标本肿瘤坏死因子α（TNF-α）、白细胞介素1β（IL-1β）、NF-κB p65表达水平；荧光实时定量PCR检测三组大鼠肺组织TLR4 mRNA的表达。 结果假手术组、模型组及治疗组大鼠肺组织湿/干比[（4.00 ± 0.13）、（6.10 ± 0.05）、（5.80 ± 0.08）]、氧合指数[（315 ± 11）、（177 ± 7）、（200 ± 12）mmHg]、TNF-α[（6.05 ± 0.29）、（45.06 ± 0.52）、（27.09 ± 0.85）ng/L]、IL-1β[（8.02 ± 0.21）、（38.23 ± 0.81）、（32.73 ± 1.12）ng/L]及NF-κB p65[（0.375 ± 0.013）、（1.230 ± 0.045）、（0.988 ± 0.043）ng/L]表达水平比较，差异均有统计学意义（F = 480.891、255.309、4 245.262、1 918.168、564.842，P均< 0.001）。进一步两两比较发现，模型组和治疗组大鼠肺组织湿/干比、TNF-α、IL-1β、NF-κB p65表达水平均较假手术组大鼠显著升高（P均< 0.05），治疗组大鼠肺组织湿/干比、TNF-α、IL-1β、NF-κB p65表达水平均较模型组大鼠显著降低（P均< 0.05）；而模型组和治疗组大鼠氧合指数均较假手术组大鼠显著降低（P均< 0.05），治疗组大鼠氧合指数较模型组大鼠显著升高（P < 0.05）。荧光实时定量PCR结果显示，三组大鼠肺组织TLR4 mRNA表达水平比较，差异具有统计学意义（F= 224.538，P < 0.001）。进一步两两比较发现，与假手术组比较，模型组及治疗组大鼠肺组织TLR4 mRNA表达均显著升高（P均< 0.05）；而治疗组大鼠肺组织TLR4 mRNA表达较模型组显著降低（P < 0.05）。 结论萝卜硫素可减轻脓毒症急性肺损伤大鼠肺组织炎症反应、肺水肿程度，改善缺氧状态，对于肺组织具有一定保护作用，且其作用机制可能与干预TLR4/NF-κB信号途径相关。

Effect of sulforaphane on Toll like receptor 4/nuclear factor-kappa B signaling pathway in rats with sepsis-induced acute lung injury

ObjectiveTo evaluate the effects of sulforaphane on inflammatory reaction and Toll like receptor 4 (TLR4)/ nuclear factor-kappa B (NF-κB) signaling pathway in rats with sepsis-induced acute lung injury (ALI). MethodsThirty male Sprague Dawley rats were randomly divided into the sham operation group, model group and treatment group, with 10 rats in each group. Rats in the model group and treatment group were prepared by cecal ligation and puncture (CLP). Rats in the treatment group were intraperitoneally injected with 50 mg/kg sulforaphane immediately after operation, while the other two groups were injected with isosmotic NaCl solution. Arterial blood samples were collected from the right common carotid artery 24 hours after operation, and then lung tissues were taken from rats to determine their wet/dry ratio. The expression levels of tumor necrosis factor-alpha (TNF-α), interleukin-1 beta (IL-1β) and NF-κB p65 in the lung tissue homogenate of rats in three groups were detected by enzyme-linked immunosorbent assay (ELISA), and TLR4 mRNA expressions were measured by real-time fluorescence quantitative PCR. ResultsThe expression levels of lung tissue wet/dry ratio [(4.00 ± 0.13), (6.10 ± 0.05), (5.80 ± 0.08)], oxygenation index [(315 ± 11), (177 ± 7), (200 ± 12) mmHg], TNF-α [(6.05 ± 0.29), (45.06 ± 0.52), (27.09 ± 0.85) ng/L], IL-1β [(8.02 ± 0.21), (38.23 ± 0.81), (32.73 ± 1.12) ng/L] and NF-κB p65 [(0.375 ± 0.013), (1.230 ± 0.045), (0.988 ± 0.043) ng/L] were statistically significantly different in three groups (F = 480.891, 255.309, 4 245.262, 1 918.168, 564.842; all P < 0.001). Further comparison showed that the wet/dry ratio, TNF-α, IL-1β and NF-κB p65expressions of lung tissue in the model group and treatment group were all significantly higher than those in the sham operation group (all P < 0.05); in the same time, the wet/dry ratio, TNF-α, IL-1β and NF-κB p65 expressions in the treatment group were all significantly lower than those in the model group (all P < 0.05). The oxygenation index of rats in the model group and treatment group was significantly lower than that in the sham operation group (both P < 0.05), while the oxygenation index in the treatment group was significantly higher than that in the model group (P < 0.05). The results of real-time quantitative PCR showed that there was significant difference in the expression of TLR4 mRNA among these three groups (F = 224.538, P < 0.001). Compared with the sham operation group, the expression of TLR4 mRNA of lung tissue in the model group and treatment group were significantly higher (both P < 0.05), while the expression of TLR4 mRNA in the treatment group was significantly lower than that in the model group (P < 0.05). ConclusionsSulforaphane can reduce lung tissue inflammatoryreaction and pulmonary edema and improve anoxic state in rats with acute lung injury caused by sepsis. It has a protective effect on lung tissue, and its mechanism may be related to the intervention of TLR4/NF-κB signaling pathway.