原花青素对盲肠结扎穿孔诱导脓毒症小鼠急性肺损伤的保护作用

Proantho cyanidins protects against cecal ligation and puncture-induced acute lung injury in septic mice by inhibiting nuclear factor-κB signaling pathway

目的观察原花青素对盲肠结扎穿孔（CLP）诱导脓毒症小鼠的保护作用，探讨其作用机制。方法将36只成年雄性C57βL／6小鼠按随机数表法随机分为Sham组、CLP组及治疗组。采用盲肠结扎穿孔建立脓毒症小鼠模型，Sham组仅做开腹处理，治疗组则在建模后腹腔注射原花青素（100mg／kg）。观察各组小鼠生存状态并记录72h内死亡情况。另-批小鼠于建模后24h处死，收集外周血及肺组织。酶联免疫吸附试验（ELISA）检测外周血及肺组织中肿瘤坏死因子-α（TNF-α）、白细胞介素（1L）-6及IL-1β含量；苏木素-伊红（HE）染色检测肺组织病理变化；精密称量仪称取烘干前后肺组织质量并测定湿／干质量比值；Western blot法检测肺组织胞质及胞核中核因子-κB（NF-κB）p65的蛋白表达情况；ELISA法检测肺组织中NF-κB p65的DNA结合活性。结果Sham组小鼠72h生存率为100％，CLP组小鼠72h生存率仅为20％，而治疗组小鼠72h生存率为46．7％，差异有统计学意义（P=0．005）。建模24h后，与CLP组比较，治疗组小鼠外周血及肺组织中炎性因子TNF-α（214．000±16．310比426．300±22．980，F=111．300，P=0．000；593．300±39．040比936．500±55．360，F=123．600，P=0．000）、IL-6（1020．000±72．150比1741．000±83．710，F=148．400，P=0．000；1107．000±68．530比1830．000±99．190，F=140．500，P=0．000）及IL-1β（507．200±28．780比820．700±47．770，F=127．700，P=0．000；154．200±7．769比257．300±20．390，F=63．590，P=0．000）的含量均显著降低；肺组织中肺泡间隔增宽及大量炎细胞浸润等病理改变明显减轻；肺组织湿／干质量比值显著降低（3．966±0．255比5．116±0．261，F=16．500，P=0．000）；肺组织胞质蛋白中NF-κB p65的表达明显增加（0．547±0．069比0．302±0．032，F=24．950，P=0．001），而胞核中NF-κB p65的蛋白表达显著减少（0．622±0．111比1．374±0．123，F=25．640，P=0．001）：NF-κB p65的DNA结合活性也显著降低（1．948±0．155比2．884±0．188，F=41．330，P：0．000）。结论原花青素对CLP诱导脓毒症小鼠具有明显的保护作用，其机制可能与抑制NF-κB p65入核有关。

Objective To investigate the protective effect of proantho cyanidins （PCs） against cecal ligation and puncture （CLP）-induced acute lung injury in septic mice and its mechanism. Methods 36 adult male C57BL/6 mice were randomly divided into three groups, including Sham group, CLP group and treatment group. Each group has 12 mice, sepsis model was set up by CLP and Proantho Cyanidins （100 mg/kg） was injected intraperitoneally. The survival state and mortality by 72 h was observed. The peripheral blood and lung tissue were collected at 24 h after CLP. The protein expressions of tumor necrosis factor-α （TNF-α）, interlukin （IL）-6 and IL- 1β in peripheral blood and lung tissues were measured by enzyme linked immunosorbent assay （ELISA）. The pathological changes in lung tissues were detected by hematoxylin and eosin （HE） staining. The wet/dry ratios of lung tissues were obtained by precision weighing instrument. The protein expressions of nuclear factor-κB （NF-κB） p65 in cytoplasm and nucleus were determined by Western blotting. The NF-κB p65 DNA binding activities were measured by ELISA.Results At 72 h after modeling, the smvival rate of Sham group, CLP group and treatment group were 100% , 20% and 46. 7% , respectively （P=0.005）. At 24 h, compared with CLP group, the protein expressions of TNF-α （214. 000±16. 310 vs. 426. 300±22. 980, F=111. 300, P=0. 000; 593. 300±39.040 vs. 936.500±55.360, F=123.600, P= 0.000）, IL-6 （1020.000±72.150 vs. 1 741.000±83.710, F= 148.400, P=0.000; 1 107.000±68.530 vs. 1 830.000±99. 190, F=140. 500, P =0. 000） and IL-1β （507.200±28. 780 vs. 820. 700±47. 770, F=127. 700, P =0. 000; 154. 200±7.769 vs. 257.300±20.390, F=63.590, P=0.000） in peripheral blood and lung tissues from treatment group were both significantly decreased. PCs treatment could remarkably ameliorate CLP-induced pathological changes, such as thickened alveolar septum and infiltration with inflammatory cells. The wet/dry ratios of lung tissues in treatment group was lower than that in CLP group （3.966 ±0. 255 vs. 5.116±0. 261, F=16. 500, P=0. 000）. Compared with CLP group, the cytoplastic protein level of NF-κB p65 in treatment group was significantly increased （ 0.547±0. 069 vs. 0.302±0. 032, F=24. 950, P=0. 001 ）, while the nuclear protein level of NF-κB p65 was remarkably decreased （0. 622±0.111 vs. 1. 374±0.123, F =25.640, P =0. 001 ）. The NF-κB 1965 DNA binding activity in treatment group was significantly lower than that in CLP group （1. 948±0.155 vs.2.884±0. 188, F=41.330, P=0.000）. Conclusion PCs had a protective effect against CLP-induced acute lung injury in septic mice, which may relate to the inhibition of NF-κB p65 nucleus translocation.