2013-01-012024-05-13https://scholars.lib.ntu.edu.tw/handle/123456789/649391摘要：我們主要是在分析Pofut1F/-;ShhCre/+ mutants (Pofut1cnull)出生後肺臟的發育。我們發現這些肺臟上皮細胞缺乏Notch訊息的條件型基因剃除鼠出生後會有生長遲緩的情形，同時出生後兩週內死亡率高達80%。存活的Pofut1cnull突變成鼠其呼吸上皮會開始出現鱗狀上皮化(squamous metaplasia)及局部纖毛細胞過度增生的情況。另外，我們也發現Pofut1cnull突變鼠會有肺泡發育不良的狀況，這有可能和呼吸道缺乏Clara細胞有關。小鼠的肺泡發育是出生後3天開始直到14天才發育完全，而3天大的Pofut1cnull突變鼠其初始肺泡的壁比較薄、很少二級肺泡隔間(secondary crest)而且肺泡的肌肉纖維母細胞 (myofibroblast)的分化也很差。在成鼠階段，其肺臟出現典型的肺氣腫表現型。我們發現Notch2而非Notch1確實會表現在第二型肺泡上皮細胞 (type II pneumocyte)，這可能可以部份解釋為何失去肺臟上皮的Notch訊息和肺泡發育相關。因此，這些結果顯示肺臟上皮細胞上的Notch訊息，對維持呼吸道上皮的恆定以及肺泡的發育是很重要的。這種肺臟表現型和成人的慢性阻塞性肺疾病以及早產兒的慢性肺疾病很像。我們目前正在探討其可能的致病機轉。另外，為了看Notch2是否為肺泡生成所必須，我們打算在明年的研究計畫中和日本Morimoto Mitsuru博士合作，分析他製造的三種基因剃除鼠，包括：Notch1單獨、Nothc2單獨、以及Notch1 & Notch2雙重條件型基因剃除鼠，看是哪一個Notch receptor是主要調控肺泡的發育。<br> Abstract: we focus on postnatal lung development in the Pofut1F/-;ShhCre/+ mutants (Pofut1cnull). We found this mutant showed failure to thrive since postnatal day 3 and the mortality rate was around 80% within 2 weeks after birth. Beside the absence of Clara cells, we found that most of the airways lined by a thin metaplastic squamous epithelium with focal cilia hyperplasia at adult stage. In addition, poor alveolarization was also found in mutant lungs. This may due to the consequence of absence of Clara cells. The poor alveolarization started on postnatal day 3 resulted from less secondary crest, thin septal wall thickness and poor myofibrobalst differentiation. The phenotype was confirmed by a panel of alveolar myofibroblast markers, such as PDGFR-α and SMA. At adult stage, the Pofut1cnull mice clearly showed the emphysema phenotype. In addition, we found Noch2, but not Notch1 was expressed in type II pneumocytes. From these data, we demonstrated that Notch signaling is required for alveogenesis and airway epithelial homeostasis. This phenotype mimics the human chronic obstructive pulmonary disease (COPD) in adult and bronchopulmonary dysplasia (BPD) in preterm infants. The possible mechanism may be due to Notch regulates PDGF-A, which is crucial for alveolar myofibroblast differentiation and alveogenesis. In the next year, to test whether Notch2 is required for appropriate alveogenesis, we plan to cooperate with Dr. Mitusru Morimoto to analyze the postnatal lung phenotype of Notch1 conditional knockout, Notch2 conditional knockout and Notch1/Notch2 double knockout, which only Notch1, only Notch2 or both Notch1 and Notch2 were specifically deleted in lung endoderm at very early stage.Notch肺泡形成血小板生長因子慢性肺疾病NotchalveloarizationPDGFchronic lung disease