人胚肺发育不同阶段表面活性物质相关蛋白-D的表达及意义

目的 观察肺表面活性物质相关蛋白-D(SP-D)在人胚胎肺发育成熟过程中表达的特征。方法 取11~36周人胎肺组织常规石蜡包埋切片,HE染色观察胚肺各个发育阶段的成熟度,免疫组化检测SP-D时相性表达特征。结果 人胚胎发育至12周肺组织开始表达SP-D,定位于胚肺支气管上皮和肺泡Ⅱ型细胞(AEC II)胞质内,在胚肺发育小管期和囊泡期逐渐表达增强;开始由支气管近端逐渐向肺泡Ⅱ型细胞迁移。肺发育末期至出生后,SP-D均在AEC II中稳定表达。结论 SP-D随着胎肺发育成熟,表达逐渐增强,阳性细胞开始出现于胚肺支气管上皮细胞,逐渐定位于肺泡Ⅱ型细胞。

Expression of pulmonary surfactant-associated protein D and its significance in human fetal lung

Objective To observe the expression of pulmonary surfactant-associated protein D (SP-D) during human fetal lung development.Methods Human fetal lung tissues from 11- to 36-week-old fetuses were assayed for lung maturity with HE staining and SP-D expression by means of immunohistochemistry.Results SP-D expression was located in the bronchial epithelium and alveolar epithelial type Ⅱ cells(AECⅡ) of the lung tissues since the 12th week, and gradually increased during the canalicular to saccular stages with fetal development, at the point of which SP-D-positivity began a shift from the proximal bronchial epithelium to AECⅡ,and evidently located in the alveoli from the advanced stage of lung development till postnatal stage.Conclusions SP-D expression gradually intensifies with the maturation of the fetal lungs, and SP-D-positive cells begin to be detected in the bronchial epithelium and finally in AECⅡ.