酗酒者易患肺部感染及高致死率的发病机制研究

Alcoholism seriously endanger human health, easily induced pulmonary bacterial infection. Clinical studies have shown that such patients were often accompanied by a significant decrease in neutrophil, which is the main reason of the high mortality rate of patients with pneumonia, but the mechanism is unclear. It is reported that myeloid progenitor cells expressing G-CSF receptor, in combination with G-CSF, can proliferate and differentiate into neutrophil, and can promote neutrophil of bone marrow storage pool to be released into the blood circulation. The applicant research group preliminary experiment indicated that alcohol can suppress G-CSF-induced activation of the p44/42-CyclinD pathway in myeloid progenitor cells, while enhance the activation of STAT3-p27Kip1 negative feedback signal, which might be a new mechanism of alcohol inhibiting the granulocytes reactions. Therefore, the project intends to prepare the alcoholism pneumonia animal model and 32D-G-CSFR cell model, utilizing pcDNA3.1/Zeo (+) , shRNA transfection technology, to further investigate the molecular mechanisms of the role of alcohol inhibiting neutrophil response. The study will focus on regulatory mechanisms of alcohol inhibition p44/42-CyclinD signal pathway activation and enhancement STAT3-p27Kip1 negative feedback signal activation, which will provide new targets and inspire new ideas and for prevention and treatment of clinical bacterial pneumonia caused by alcoholism.

酗酒严重危害健康，极易诱发肺部细菌感染。临床研究发现：该类患者常伴中性粒细胞明显减少，可能是高死亡率的主要原因，但其发生机制尚不清楚。已知髓系祖细胞表达 G-CSF受体，与G-CSF结合，能增殖分化为中性粒细胞，并能促进骨髓储存池的中性粒细胞释放入血循环。申请者课题组预实验发现：酒精具有抑制G-CSF介导髓系祖细胞p44/42-CyclinD通路激活和增强STAT3- p27Kip1负反馈信号活化的作用，可能是酒精抑制中性粒细胞数量增加的一种新机制。因此，本项目拟通过酒精中毒肺细菌感染动物模型和32D-G-CSFR细胞模型，应用pcDNA3.1/Zeo(+)、shRNA转染等技术方法，深入探讨酒精抑制中性粒细胞反应性增加的分子机制，重点关注酒精抑制p44/42-CyclinD通路激活和酒精增强STAT3- p27Kip1信号活化的调控机制，为临床酗酒所致细菌性肺炎的防治提供新思路和新靶点。

酗酒严重危害健康，极易诱发肺部细菌感染。临床研究发现：该类患者常伴中性粒细胞明显减少，可能是高死亡率的主要原因，但其发生机制尚不清楚。已知髓系祖细胞表达 G-CSF受体，与G-CSF结合，能增殖分化为中性粒细胞，并能促进骨髓储存池的中性粒细胞释放入血循环。本课题主要研究酒精摄入过量抑制中性粒细胞反应性增加的分子机制，重点关注酒精抑制G-CSF介导髓系祖细胞p44/42-CyclinD通路激活和酒精增强G-CSF介导髓系祖细胞STAT3- p27Kip1信号活化的调控机制。研究结果表明酒精不是由其代谢过程中醇脱氢酶途径的氧化应激产生效应，而是直接抑制髓系祖细胞的增殖。通过慢性酒精饮食基础上急性酒精中毒肺细菌感染小鼠模型，在体研究证实酒精通过抑制G-CSF介导髓系祖细胞p44/42-CyclinD信号传导通路和酒精增强G-CSF介导髓系祖细胞STAT3-p27Kip1负反馈信号通路影响粒系祖细胞的增殖；通过髓系祖细胞系32D-G-CSFR细胞模型和流式细胞仪分选正常小鼠新鲜骨髓lin-c-kit+细胞，体外研究证实酒精通过抑制G-CSF介导髓系祖细胞p44/42-CyclinD信号传导通路和酒精增强G-CSF介导髓系祖细胞STAT3-p27Kip1负反馈信号通路影响粒系祖细胞的增殖。利用动物模型和细胞模型，深入研究酗酒者易致严重肺部感染及高致死率的发生机制，为临床酗酒所致细菌性肺炎以及免疫力低下肺部感染患者的防治提供新思路和新靶点。从细胞因子和髓系祖细胞增殖的调控机制入手，阐明酒精抑制肺部细菌感染引起粒细胞反应性增加的分子机制，为预防酗酒危害人类健康的理论提供直接实验依据。