Objective: To study the role of miR-431 in lung development and morphology.
Methods: According to the stage of lung development in rats, Sprague-Dawley rats at embryonic day 16 (E16), embryonic day (E19), embryonic day (E21), postnatal day 1 (P1), postnatal day 3 (P3), postnatal day 7 (P7), postnatal day 14 (P14) and 10 weeks after birth (P10 weeks) were selected, and lung tissue samples were collected for observation. Hematoxylin-eosin staining and transmission electron microscopy were performed to observe the morphology of lung tissue. Fluorescence in situ hybridization and real-time PCR were used to measure the expression of miR-431 during the critical stages of lung development (E19, E21 and P3).
Results: The E19 group had the formation of the lamellar body and type II alveolar epithelial cells in the fetal lung tissue. The number of lamellar bodies increased with the increasing gestational age, with aggregation and excretion. Pulmonary alveoli formed rapidly, the lung interstitium became thinner, and the microvascular system became mature after birth. Fluorescence in situ hybridization and real-time PCR showed that the expression of miR-431 gradually decreased with the increasing gestational age (P<0.05).
Conclusions: The systematic and continuous morphological data of lung development is obtained in this experiment. In addition, miR-431 may play an important role in the negative regulation of lung development, which provides basis and direction for further research on the mechanism of lung development and related diseases.
目的: 探讨miR-431在肺发育形态学中的潜在作用。
方法: 根据肺发育分期，选择SpragueDawley大鼠孕16 d（E16）、孕19 d（E19）、孕21 d（E21）、生后1 d（P1）、生后3 d（P3）、生后7 d（P7）、生后14 d（P14）及生后10周（P10周）成年大鼠的肺组织作为观察点，利用苏木精-伊红染色（HE）及透射电镜方法进行肺组织形态学观察；利用荧光原位杂交和实时荧光定量PCR技术检测肺发育关键时期（E19、E21及P3）肺组织中miR-431的表达情况。
结果: E19组胎肺组织发现关键事件板层小体及Ⅱ型肺泡上皮细胞的出现；随胎龄增加板层小体数量增加，并出现聚集与排出；生后肺泡形成迅速发生，间质变薄，微血管系统逐渐成熟。荧光原位杂交及实时荧光定量PCR结果均显示随着胎龄的增加，miR-431的表达量逐渐降低（P < 0.05）。
结论: 获得系统而连续的肺发育形态学资料。miR-431在肺发育过程中可能起重要的负向调控作用，为后续进一步研究肺发育及相关性疾病的机制提供基础和方向。