中文摘要：

目的筛选上皮-间充质转化细胞中可能介导肌成纤维细胞转分化的血清反应因子（SRF）结合蛋白，探讨其作为转录激活辅助子的分子生物学机制。方法应用噬菌体展示技术，从转化生长因子β1（TGF—β1）诱导转分化的人支气管上皮细胞16HBE及亲本细胞构建cDNA噬菌体展示文库，以调控平滑肌肌动蛋白α（α-SMA）基因表达的核心转录因子SRF作为固相筛选分子对两文库进行4轮“吸附-洗脱-扩增”的生物筛选过程，噬斑PCR扩增后，对所获克隆进行DNA序列测定和生物信息学分析后进行差异比对。瞬时转染半定量分析mRNA表达。结果两文库筛选所获噬菌体经富集，随机各挑选46个克隆，序列测定后进行同源性搜索，并经过剔除对照库来源的克隆，新发现3种SRF结合蛋白：PAI—RBP1、Nucleolin和HF100；PAI-RBP1能促进α—SMA的表达上调。结论通过构建病理模型细胞并与噬菌体展示技术结合，以已知核心转录因子为钓饵发现未知结合蛋白，是一种发现新的转录调节子的有效策略。从转分化的细胞中发现3种新的SRF结合蛋白；对PAI—RBP1的研究初步表明PAI—RBP1参与了α—SMA基因表达的的诱导，可能在肌成纤维细胞活化过程中发挥了一定作用。

英文摘要：

Objective To screen the possible regulatory proteins showing the ability for interaction with serum response factor （SRF） in the progress of myofibroblast activation, and to see if the proteinprotein interaction is contributing to induce the expression of smooth muscle α actin （α-SMA）. Methods Phage display eDNA libraries were constructed from the transdifferentiated airway epithelial cells and parental cells. Phage clones were then selectively amplified during the biopanning procedure by using SRF as a bait protein for the two eDNA libraries. Following four rounds of biopanning, recovered cDNAs were sequenced and the obtained sequences were aligned by BLAST tool to select the candidate gene. PAI-RBP1 of the candidate gene was cloned and sub-cloned into peDNA3.0 plasmid. Transient transfeetion and RT-PCR analysis were performed for investigation of the expression of α-SMA. Results Three candidate protein- binding partners, PAI-RBP1, Nueleolin, and HF100, were identified. Among them, PAI-RBP1 pcDNA3.0 plasmid was subjected to transient co-transfection with SRF, showing up-regulation of α-SMA expression. Conclusions Combined with phage display technique, through protein-protein interaction between core transcription factor and unknown proteins to find a new transcriptional regulator may serve as an effective strategy. Three novel SRF binding proteins were found from transdifferentiated cells. This study indicates that PAI-RBP1 involves in the activation of myofibroblast by induction of α-SMA expression.