Department of Anesthesiology, Shandong Provincial Qianfoshan Hospital, Shandong University, Jinan, Shandong 250014; 2Department of Anesthesiology, Dezhou People's Hospital, Dezhou, Shandong 253014, China.
Department of Surgery, Rizhao People's Hospital, Rizhao, Shandong 276826, China.
Chin Med J (Engl). 2018 Apr 5;131(7):804-812. doi: 10.4103/0366-6999.228230.
Ventilator-induced lung injury (VILI) is commonly associated with barrier dysfunction and inflammation reaction. Glutamine could ameliorate VILI, but its role has not been fully elucidated. This study examined the relationship between inflammatory cytokines (interleukin [IL]-6, tumor necrosis factor [TNF]-α, and IL-10) and adherens junctions (E-cadherin, p120-catenin), which were ameliorated by glutamine in VILI, both in vitro and in vivo.
For the in vivo study, 30 healthy C57BL/6 mice weighing 25-30 g were randomly divided into five groups with random number table (n = 6 in each group): control (Group C); low tidal volume (Group L); low tidal volume + glutamine (Group L + G); high tidal volume (Group H); and high tidal volume + glutamine (Group H + G). Mice in all groups, except Group C, underwent mechanical ventilation for 4 h. For the in vitro study, mouse lung epithelial 12 (MLE-12) cells pretreated with glutamine underwent cyclic stretching at 20% for 4 h. Cell lysate and lung tissue were obtained to detect the junction proteins, inflammatory cytokines, and lung pathological changes by the Western blotting, cytokine assay, hematoxylin and eosin staining, and immunofluorescence.
In vivo, compared with Group C, total cell counts (t = -28.182, P < 0.01), the percentage of neutrophils (t = -28.095, P < 0.01), IL-6 (t = -28.296, P < 0.01), and TNF-α (t = -19.812, P < 0.01) in bronchoalveolar lavage (BAL) fluid, lung injury scores (t = -6.708, P < 0.01), and the wet-to-dry ratio (t = -15.595, P < 0.01) were increased in Group H; IL-10 in BAL fluid (t = 9.093, P < 0.01) and the expression of E-cadherin (t = 10.044, P < 0.01) and p120-catenin (t = 13.218, P < 0.01) were decreased in Group H. Compared with Group H, total cell counts (t = 14.844, P < 0.01), the percentage of neutrophils (t = 18.077, P < 0.01), IL-6 (t = 18.007, P < 0.01), and TNF-α (t = 10.171, P < 0.01) in BAL fluid were decreased in Group H + G; IL-10 in BAL fluid (t = -7.531, P < 0.01) and the expression of E-cadherin (t = -14.814, P < 0.01) and p120-catenin (t = -9.114, P < 0.01) were increased in Group H + G. In vitro, compared with the nonstretching group, the levels of IL-6 (t = -21.111, P < 0.01) and TNF-α (t = -15.270, P < 0.01) were increased in the 20% cyclic stretching group; the levels of IL-10 (t = 5.450, P < 0.01) and the expression of E-cadherin (t = 17.736, P < 0.01) and p120-catenin (t = 16.136, P < 0.01) were decreased in the 20% cyclic stretching group. Compared with the stretching group, the levels of IL-6 (t = 11.818, P < 0.01) and TNF-α (t = 8.631, P < 0.01) decreased in the glutamine group; the levels of IL-10 (t = -3.203, P < 0.05) and the expression of E-cadherin (t = -13.567, P < 0.01) and p120-catenin (t = -10.013, P < 0.01) were increased in the glutamine group.
High tidal volume mechanical ventilation and 20% cyclic stretching could cause VILI. Glutamine regulates VILI by improving cytokines and increasing the adherens junctions, protein E-cadherin and p120-catenin, to enhance the epithelial barrier function.
呼吸机相关性肺损伤（VILI）通常与屏障功能障碍和炎症反应有关。谷氨酰胺可以改善 VILI，但它的作用尚未完全阐明。本研究在体外和体内研究了谷氨酰胺改善 VILI 时炎症细胞因子（白细胞介素 [IL]-6、肿瘤坏死因子 [TNF]-α和 IL-10）和黏附连接（E-钙黏蛋白、p120-连环蛋白）之间的关系。
在体内研究中，30 只健康 C57BL/6 小鼠（体重 25-30 g），随机分为五组（每组 6 只）：对照组（C 组）；小潮气量组（L 组）；小潮气量+谷氨酰胺组（L+G 组）；大潮气量组（H 组）；大潮气量+谷氨酰胺组（H+G 组）。除 C 组外，所有组均进行机械通气 4 h。在体外研究中，用谷氨酰胺预处理的小鼠肺上皮 12 （MLE-12）细胞接受 20%的周期性拉伸 4 h。通过 Western blot、细胞因子测定、苏木精和伊红染色和免疫荧光检测细胞裂解物和肺组织中的连接蛋白、炎症细胞因子和肺病理变化。
体内，与 C 组相比，H 组支气管肺泡灌洗液（BAL）中总细胞计数（t=-28.182，P<0.01）、中性粒细胞百分比（t=-28.095，P<0.01）、IL-6（t=-28.296，P<0.01）和 TNF-α（t=-19.812，P<0.01）、肺损伤评分（t=-6.708，P<0.01）和湿干比（t=-15.595，P<0.01）均升高；BAL 中 IL-10（t=9.093，P<0.01）和 E-钙黏蛋白（t=10.044，P<0.01）和 p120-连环蛋白（t=13.218，P<0.01）的表达降低。与 H 组相比，H+G 组 BAL 中总细胞计数（t=14.844，P<0.01）、中性粒细胞百分比（t=18.077，P<0.01）、IL-6（t=18.007，P<0.01）和 TNF-α（t=10.171，P<0.01）均降低；BAL 中 IL-10（t=-7.531，P<0.01）和 E-钙黏蛋白（t=-14.814，P<0.01）和 p120-连环蛋白（t=-9.114，P<0.01）的表达增加。在体外，与非拉伸组相比，20%周期性拉伸组 IL-6（t=-21.111，P<0.01）和 TNF-α（t=-15.270，P<0.01）水平升高；IL-10（t=5.450，P<0.01）和 E-钙黏蛋白（t=17.736，P<0.01）和 p120-连环蛋白（t=16.136，P<0.01）的表达降低。与拉伸组相比，谷氨酰胺组 IL-6（t=11.818，P<0.01）和 TNF-α（t=8.631，P<0.01）水平降低；IL-10（t=-3.203，P<0.05）和 E-钙黏蛋白（t=-13.567，P<0.01）和 p120-连环蛋白（t=-10.013，P<0.01）的表达增加。
大潮气量机械通气和 20%周期性拉伸可引起 VILI。谷氨酰胺通过改善细胞因子和增加黏附连接蛋白 E-钙黏蛋白和 p120-连环蛋白来调节 VILI，增强上皮屏障功能。
