沉默转化生长因子β1基因对新生小鼠晚期肺泡发育的影响

Influence of knock-down TGF-β1 gene on development of alveolar in neonatal mice

目的:探讨以小分子干扰RNA技术沉默肺转化生长因子β1(TGF-β1)基因对新生小鼠晚期肺泡发育的影响。方法:75只新生KM小鼠,随机分为干扰组、空白对照组和阴性对照组各25只,构建TGF-β1 shRNA慢病毒载体,经鼻内吸入法导入干扰组生后3d新生小鼠肺内,同时设计一无关序列构建阴性表达慢病毒载体同法导入阴性对照组小鼠肺内,空白对照组不予干预。各组别按小鼠生后4、7、14、21、28d分别取肺组织观察其组织形态学变化,以RT-PCR和Western blot法检测肺组织中TGF-β1 mRNA和蛋白表达水平。结果:与两对照组相比,干扰组肺TGF-β1mRNA在小鼠生后4、7、14、21、28d明显降低,生后7、14、21、28d,干扰组肺TGF-β1蛋白水平也明显降低,同时肺泡平均截距明显增大,放射状肺泡计数减少,差异均有统计学意义。阴性对照组和空白对照组各时间点各项指标无统计学差异。结论:沉默TGF-β1基因可阻滞新生小鼠晚期肺泡发育。

Objective To explore the influence of knock-down TGF-β1 gene by small interfering RNA technique on development of alveolar in neonatal mice. Methods 75 KM mice were randomly divided into interference groups, negative control group and blank control group. Each group had 25 mice. TGF-β1 shRNA lentivirus vector was constructed and administered intranasally to lungs of newborn mice in interference group at postnatal days 3. The negative express vector containing unrelated sequence of TGF-β1 gene was administered to negative group as negative control. No interference treatment was processed in blank control group. Lung samples were taken for observing histomorphology changes and detecting the expression levels of TGF-β1 mRNA and TGF-β1 protein by RT-PCR and Western blot at postnatal days 4,7,14,21,28 respectively. Results Compared with two control groups, the expression levels of TGF-β1 mRNA in lungs decreased significantly in interference group at postnatal days 4,7,14,21,28. And the expression levels of TGF-β1 protein in lungs decreased significantly in interference group at postnatal days 7,14,21,28. Mean linear intercept of alveolar increased and radical alveolar counts decreased significantly than those of two control groups at postnatal days 7,14,21,28. All examination results showed no significant difference between two control groups at every time-point. Conclusion Knock-down TGF-β1 gene may arrest alveolar development in neonatal mice.