PDGF-BB对泡球蚴感染所致Nestin+干细胞募集和肝血管新生的作用及其临床意义

Hepatic alveolar echinococcosis (AE), commonly known as "parasitic cancer", is a serious zoonoses. However, the mechanism of liver regeneration in the AE patients who were treated by autologous liver transplantation (ALT), remains unclear. Our team found that platelet derived growth factor (PDGF-BB) and Nestin positive stem cells were related to vascular proliferation in the region adjacent to AE liver lesions. We proposed a scientific hypothesis that "PDGF-BB could recruit and promote the proliferation of Nestin positive stem cells, participate into the formation of neovascularization, and may be benefit to the liver regeneration of AE". We envisaged to confirm the hypothesis by in vivo (Em mice and AE patients) and in vitro experiments. We would identify the recruitment function of PDGF-BB on the Nestin positive stem cell by genetic lineage tracing method. To explore the mechanism of PDGF-BB promote the angiogenesis and participate into the liver repair, We would interfere with the key elements of PDGF-BB signal pathway, by PDGF-BB signaling pathway inhibitor, the PDGF receptor β knockout mice, and detect the content of PDGF-BB, the number of Nestin positive stem cells, newborn blood vessel, the proliferation of liver and liver function. Identifying key angiogenesis molecules that target PDGF-BB and Nestin+ stem cells would be useful to develop new target and a new method for the treatment of echinococcosis, and lay a foundation for revealing the mechanism of liver regeneration in the AE patients who were treated by ALT.

肝泡型包虫病（AE）俗称“虫癌”，危害严重，但自体肝移植患者肝脏增殖的分子机制不明。我们前期发现AE患者肝脏病灶旁血小板衍生生长因子（PDGF-BB）高表达及Nestin+干细胞数量增多，与血管增多相关，提出“PDGF-BB通过对Nestin+干细胞的募集、增殖促肝新生血管生成，参与AE肝再生”的科学假说。本项目拟采用遗传谱系示踪法，激活和靶向干预PDGF-BB信号通路关键分子，在PDGF受体β基因条件性敲除小鼠、Em感染小鼠、AE临床病例标本和细胞水平，检测PDGF-BB表达、Nestin+干细胞迁移和增殖、新生血管生成、肝增殖和肝功等指标，阐明PDGF-BB对Nestin+干细胞的募集、促增殖和促血管新生的作用及其分子机制，靶向PDGF-BB和Nestin+干细胞促血管形成过程中的关键分子将成为包虫病治疗的新靶点和新方法，为揭示临床实施自体肝移植术式AE患者肝增殖的分子机制奠定基础。

肝泡型包虫病（AE）俗称“虫癌”，危害严重，但自体肝移植患者肝脏增殖的分子机制不明。我们前期发现AE患者肝脏病灶旁血小板衍生生长因子（PDGF-BB）高表达及Nestin+干细胞数量增多，与血管增多相关，本研究围绕“PDGF-BB通过对Nestin+干细胞的募集、增殖促肝新生血管生成，参与AE肝再生”的这一科学问题展开。通过外周血和临床手术切除肝脏标本，研究AE患者外周血和肝脏区域PDGF-BB表达水平，结果显示血清中PDGF-BB低表达，与AE患者肝脏病灶活性呈负相关性；病灶旁肝脏组织中PDGF-BB和CD31高表达，与AE的PNM分级、病灶活性、病灶大小呈正相关性。在泡球蚴感染小鼠模型中，随着感染时间延长肝脏损伤加剧，病灶周围Nestin+细胞数量增多，新生血管明显，PDGF-BB的表达增多，免疫荧光检测发现Nestin、CD31与PDGFR-β具有细胞共定位特性。体外干预实验发现泡球蚴蛋白激活PDGF-BB/DGFR-β/PI3K通路促进Nestin+细胞迁移、增殖、向内皮分化并形成管腔的机制。该研究成果将为寻找包虫病治疗新靶点和新方法提供理论依据。