Background The amiloride-sensitive epithelial sodium channel a-subunit （a-ENaC） is an important factor for alveolar fluid clearance during acute lung injury. The relationship between adenosine receptor A2a （A2aAR）...Background The amiloride-sensitive epithelial sodium channel a-subunit （a-ENaC） is an important factor for alveolar fluid clearance during acute lung injury. The relationship between adenosine receptor A2a （A2aAR） expressed in alveolar epithelial cells and aα-ENaC is poorly understood. We targeted the A2aAR in this study to investigate its role in the expression of αa-ENaC and in acute lung injury.Methods A549 cells were incubated with different concentrations of A2aAR agonist CGS-21680 and with 100 μmol/L CGS-21680 for various times. Rats were treated with lipopolysaccharide （LPS） after CGS-21680 was injected. Animals were sacrificed and tissue was harvested for evaluation of lung injury by analysis of the lung wet-to-dry weight ratio, lung permeability and myeloperoxidase activity. RT-PCR and Western blotting were used to determine the mRNA and protein expression levels of α-ENaC in A549 cells and alveolar type II epithelial cells.Results Both mRNA and protein levels of α-ENaC were markedly higher from 4 hours to 24 hours after exposure to 100μmol/L CGS-21680. There were significant changes from 0.1 umol/L to 100 μmol/L CGS-21680, with a positive correlation between increased concentrations of CGS-21680 and expression of α-ENaC. Treatment with CGS-21680during LPS induced lung injury protected the lung and promoted α-ENaC expression in the alveolar epithelial cells.Conclusion Activation of A2aAR has a protective effect during the lung injury, which may be beneficial to the prognosis of acute lung injury展开更多
目的探讨PI3K/Akt信号通路对急性肺损伤(ALI)大鼠肺泡上皮钠通道(ENaC)α、β和γ亚基表达的影响。方法成年SD大鼠随机分为对照组、ALI组(脂多糖)、胰岛素组及渥曼青霉素组,每组5只。观察肺组织病理改变,收集支气管肺泡灌洗液(BALF),测...目的探讨PI3K/Akt信号通路对急性肺损伤(ALI)大鼠肺泡上皮钠通道(ENaC)α、β和γ亚基表达的影响。方法成年SD大鼠随机分为对照组、ALI组(脂多糖)、胰岛素组及渥曼青霉素组,每组5只。观察肺组织病理改变,收集支气管肺泡灌洗液(BALF),测量总肺水含量,RT-PCR和Western blot测定ENaC mRNA和蛋白、p-Akt表达。结果胰岛素组BALF蛋白含量、髓过氧化物酶(MPO)活性、总肺水含量较ALI组显著减少(P<0.05),渥曼青霉素组BALF蛋白含量、MPO活性及总肺水含量较胰岛素组显著增加(P<0.05)。ALI组α-、β-和γ-ENaC蛋白表达显著低于对照组(0.33±0.06 vs 1.27±0.07,0.18±0.04 vs 0.72±0.04,0.37±0.04 vs 0.69±0.05)(P<0.05)。胰岛素组蛋白表达α-ENaC(2.19±0.04)、β-ENaC(1.18±0.07)和γ-ENaC(1.18±0.08)显著高于ALI组(P<0.05)。渥曼青霉素组蛋白表达α-ENaC(0.86±0.09)、β-ENaC(0.58±0.05)和γ-ENaC(0.59±0.02)显著低于胰岛素组(P<0.05)。胰岛素组ENaC mRNA和p-Akt较ALI组显著升高(P<0.05)。渥曼青霉素组ENaC mRNA和p-Akt较胰岛素组显著降低(P<0.05)。结论激活PI3K/Akt通路上调3种ENaC亚基表达,从而清除肺水肿液。展开更多
基金This study was supported by a grant from the National Natural Science Foundation of China （No. 30971303）.
文摘Background The amiloride-sensitive epithelial sodium channel a-subunit （a-ENaC） is an important factor for alveolar fluid clearance during acute lung injury. The relationship between adenosine receptor A2a （A2aAR） expressed in alveolar epithelial cells and aα-ENaC is poorly understood. We targeted the A2aAR in this study to investigate its role in the expression of αa-ENaC and in acute lung injury.Methods A549 cells were incubated with different concentrations of A2aAR agonist CGS-21680 and with 100 μmol/L CGS-21680 for various times. Rats were treated with lipopolysaccharide （LPS） after CGS-21680 was injected. Animals were sacrificed and tissue was harvested for evaluation of lung injury by analysis of the lung wet-to-dry weight ratio, lung permeability and myeloperoxidase activity. RT-PCR and Western blotting were used to determine the mRNA and protein expression levels of α-ENaC in A549 cells and alveolar type II epithelial cells.Results Both mRNA and protein levels of α-ENaC were markedly higher from 4 hours to 24 hours after exposure to 100μmol/L CGS-21680. There were significant changes from 0.1 umol/L to 100 μmol/L CGS-21680, with a positive correlation between increased concentrations of CGS-21680 and expression of α-ENaC. Treatment with CGS-21680during LPS induced lung injury protected the lung and promoted α-ENaC expression in the alveolar epithelial cells.Conclusion Activation of A2aAR has a protective effect during the lung injury, which may be beneficial to the prognosis of acute lung injury
文摘目的探讨PI3K/Akt信号通路对急性肺损伤(ALI)大鼠肺泡上皮钠通道(ENaC)α、β和γ亚基表达的影响。方法成年SD大鼠随机分为对照组、ALI组(脂多糖)、胰岛素组及渥曼青霉素组,每组5只。观察肺组织病理改变,收集支气管肺泡灌洗液(BALF),测量总肺水含量,RT-PCR和Western blot测定ENaC mRNA和蛋白、p-Akt表达。结果胰岛素组BALF蛋白含量、髓过氧化物酶(MPO)活性、总肺水含量较ALI组显著减少(P<0.05),渥曼青霉素组BALF蛋白含量、MPO活性及总肺水含量较胰岛素组显著增加(P<0.05)。ALI组α-、β-和γ-ENaC蛋白表达显著低于对照组(0.33±0.06 vs 1.27±0.07,0.18±0.04 vs 0.72±0.04,0.37±0.04 vs 0.69±0.05)(P<0.05)。胰岛素组蛋白表达α-ENaC(2.19±0.04)、β-ENaC(1.18±0.07)和γ-ENaC(1.18±0.08)显著高于ALI组(P<0.05)。渥曼青霉素组蛋白表达α-ENaC(0.86±0.09)、β-ENaC(0.58±0.05)和γ-ENaC(0.59±0.02)显著低于胰岛素组(P<0.05)。胰岛素组ENaC mRNA和p-Akt较ALI组显著升高(P<0.05)。渥曼青霉素组ENaC mRNA和p-Akt较胰岛素组显著降低(P<0.05)。结论激活PI3K/Akt通路上调3种ENaC亚基表达,从而清除肺水肿液。
