小鼠肺发育中细胞增殖与凋亡及相关调控基因的表达

目的 探讨小鼠肺发育过程细胞增殖与凋亡的变化规律及凋亡相关基因ｐ５３、ｂｃｌ－２ｄ在肺发育中的表达意义。方法 不同发育天数的小鼠肺组织，采用免疫组织化学及ＴＵＮＥＬ法，观察细胞增殖与凋亡及相关基因ｐ５３、ｂｃｌ－２的表达。结果 １．胎１４和１６ｄ肺ＰＣＮＡ阳性细胞数达到高峰；之后ＰＣＮＡ阳性率逐渐下降；生后４到１４ｄ，又恢复低水平的细胞增殖，２．小鼠肺发育过程中出现两个细胞凋亡高峰：即胎１４至１６

CELL PROLIFERATION, APOPTOSIS AND THE EXPRESSION OF RELATED GENES IN THE DEVELOPING LUNG OF MOUSE

Objective This study is to explore the dynamic trends of cell proliferation, apoptosis and the expression significance of involved genes as p53 and bcl|2 in developing lungs of mouse. Methods Lung tissues were taken from different developmental phases of Kunming mouse. Immunohistochemistry and TUNEL techniques were adopted to observe the variation of cell proliferation and apoptosis and the expression characteristics of p53 and bcl|2. Results 1 From the 14th to the 16th day of gestation the positive ratio of PCNA reached its peak. After that, it descended gradually. From the 4th day to the 14th day after birth, the proliferation maintained in low level; 2 Two peaks of apoptosis emerged during the development of lungs. The first one appeared from the 14th to the 16th day of gestation; the second one appeared at the 7th day after birth; 3 The expression of bcl|2 first appeared from the 19th day of gestation to the 14th day after birth, with constant expression sites in the epithelial cells lined in the proximal bronchia and the smooth muscle cells. 4 The expression of p53 was never seen in all phases during the developmental process. Conclusion 1 During the development of mouse lungs, cell proliferation was accompanied by apoptosis. The dynamic changes of both ratios might be correlated to the different structures appearing in different developmental phases; 2 The possible function of bcl|2 during the lung developmental process might be that it prevented the main frame structures of the bronchial tree and the capillary network from being destroyed by apoptosis; 3 Apoptosis during the development of lung might be independent of the regulation of p53.;