p38MAPK信号通路在猪源H9N2流感病毒导致小鼠肺损伤中作用的研究

The Role of p38MAPK in Acute Lung Injury Induced by H9N2 Influenza Virus Isolated from Swine

探讨p38MAPK信号通路在猪源H9N2流感病毒诱导小鼠肺损伤过程中的作用。将BALB/c小鼠随机分为病毒感染组(H9N2组)、模拟感染组(NS组)和H9N2+p38MAPK抑制剂组(H9N2+SB203580)。Western blot方法检测肺组织p38MAPK表达,观察各组小鼠肺组织病理学变化、测定肺湿/干重比,衡量肺损伤情况;同时进行支气管肺泡灌洗液(BALF)内细胞计数和肿瘤坏死因子α(TNF-α)及白细胞介素-1β(IL-1β)的测定。结果如下:Western blot结果显示感染组小鼠肺组织内p38MAPK表达显著高于H9N2+SB203580抑制剂组(P<0.01);感染组小鼠精神沉郁、呼吸困难、体重下降;肺组织学表现为肺泡间质水肿、炎性细胞渗出、出血为特征的弥漫性肺泡损伤。与感染组相比,p38MAPK抑制剂组症状较轻,一定程度上降低了死亡率,并明显延长小鼠存活时间(P<0.01);同时,小鼠BALF内炎性细胞渗出减少,TNF-α和IL-1β的含量(P<0.05)以及肺湿/干重较感染组显著下降(P<0.01)。本研究证实p38MAPK信号通路参与H9N2流感病毒诱导小鼠肺损伤过程,其抑制剂SB203580能够有效减少p38MAPK表达,进而减少TNF-α和IL-1β产生以及炎性细胞渗出,缓解肺损伤的严重程度,延长小鼠存活时间和降低死亡率,提示p38MAPK信号通路抑制剂SB203580在今后作为辅助预防和干预H9N2-SIV诱导肺损伤具有一定的应用前景。

The aim of this study was to investigate the role of p38MAPK in acute lung injury(ALI)induced by H9N2influenza virus isolated from swine(H9N2-SIV)in mouse model. BALB/c mice were divided into H9N2infected group,H9N2+ p38MAPK inhibitor(SB203580) group and mock infected group.The lungs were observed for lesion of pathological change and the lung wet weight/dry weight(W/D)were investigated;The quantity of MAP kinases protein were detected by Western blot analysis;The cell count and the contents of TNF-αand IL-1βin bronchial alveolar lavaged fluid(BALF)were measured.The results were as follows:the result of western blot showed that the quantity of MAP kinases protein in lung of H9N2group higher significantly compared with H9N2+SB203580group(P<0.01);Furthermore,depression,dyspnea and weight loss appeared on H9N2infected mice markedly;Histopathologically,the similar his-topathological changes such as alveolar and interstitial edema,hemorrhage,inflammation cell infiltration were also observed in lung in H9N2 + SB203580group mice,but the degree of lung lesions was not as serious as those in H9N2group;Moreover,the interventions of SB203580decreased the morality of infected mice(P<0.01),and prolonged the survival time of infected mice significantly.Meanwhile,it also decreased markedly W/D(wet weight/dry weight of lung),the number of inflammatory cell and levels of TNF-αand IL-1βin BALF(P<0.01).The results indicated that p38MAPK had an important role in the process of H9N2-SIV-induced ALI,and its inhibors SB203580may block effectively expression of p38MAPK,and ameliorate lung injuries by inhibiting excessive discharging of TNF-αand IL-1β,which suggesting that SB203580have benefit role to intervene the ALI induced by H9N2-SIV influenza virus in future.