PC3/BTG2调节Ⅱ型肺泡上皮细胞修复作用研究

Alveolar epithelial cells type Ⅱ(AEC II) is an important repaired function stem cell of tissue in acute lung injury, which is rapidly proliferating and differentiating into alveolar type I cells; however, its mechanism of regulating differentiation is unclear. PC3/BTG2 is immediate-early response gene of cell cycle regulation induced by p53; it's an important bridge molecule by regulating proliferation and differentiation of stem cells and tumor cells. In earlier stages, we discovered the amount of ACEII and PC3/BTG2 expression restricted in space and time after acute lung injury of rat, preliminary trail has proved that PC3/BTG2 is expressed in AECII. Since "p53-PC3/BTG2 - cell cycle" is an important regulated pathway in cell differentiation selection, we put forward the hypothesis: according to cyclin protein regulation, PC3/BTG2 affects ACE II differentiation that mediates in repairing tissue of acute lung injury. In order to confirm this hypothesis, we will use AEC II primary culture, separation and purification and facture an acute lung injuried animal sample to observe dynamicly about AEC II expression, differentiation and characteristics of stem cell during the process of acute lung injury. And we will use some methods named Workstation of living cells,plasmid transfection, siRNA, Western Blot etc to discuss the pathway of PC3/BTG2 cell cycle in AEC II cell differentiation regulation; we hope to acquire regulated molecule and mechanism about differentiation of AEC II and its characteristic of stem maintenance. Our destination is to provide a new way for strategy of tissue repaired in clinical acute lung injury.

AECⅡ是急性肺损伤组织修复的重要干/祖细胞，能增殖分化为AECⅠ，然目前为止其调控机制仍不明确；PC3/BTG2是p53诱导产生调控细胞周期的早期反应基因，是干细胞、肿瘤细胞增殖分化调节的重要桥梁分子。前期我们发现大鼠急性肺损伤后AECⅡ与PC3/BTG2具有时空性表达特征，且PC3/BTG2表达于AECⅡ上，鉴于"p53-PC3/BTG2-细胞周期"是细胞增殖分化的重要调节通路，我们提出假说：PC3/BTG2可能通过调控细胞周期素蛋白参与AECⅡ干性调节促进急性肺损伤内源性修复。本课题以前期研究为基础，通过AECⅡ原代培养、分离纯化、球细胞募集及急性肺损伤大鼠动物模型，借助活细胞工作站、质粒转染、siRNA、WB等方法探讨体内外PC3/BTG2在AECⅡ干性调节中的细胞周期作用途径，以期获得AECⅡ分化和干性维持的具体调控分子和可能机制，为临床急性肺损伤修复的干细胞治疗策略提供新思路。

AECⅡ是急性肺损伤组织修复的重要干/祖细胞，能增殖分化为AECⅠ，然目前为止其调控机制仍不明确；PC3/BTG2是p53诱导产生调控细胞周期的早期反应基因，是干细胞、肿瘤细胞增殖分化调节的重要桥梁分子。本课题在前期研究基础上，通过构建急性肺损伤大鼠动物模型，借助活细胞工作站、质粒转染、siRNA、WB等方法观察到急性肺损伤后不同时间点肺内各种细胞的动态变化，完成PC3/BTG2在急性肺损伤后不同时间点表达变化以及与II型肺泡上皮细胞表达变化相关性研究；获得急性肺损伤后不同时间点肺组织匀浆液中各种细胞因子表达情况；并利用II型肺泡上皮细胞株（A549）为体外研究平台，阐明细胞因子HGF通过调节BTG2作用于II型肺泡上皮细胞的增殖、凋亡、细胞周期调控参与急性肺组织损伤修复的作用机制，为临床急性肺损伤修复的细胞治疗策略提供新思路。