Bruton 酪氨酸激酶信号通路在严重烧伤库普弗细胞活化中的作用机制研究

Bruton's tyrosine kinase (Btk), a member of the Tec family of non-receptor tyrosine kinases, plays a pivotal role in cell growth, development and activation. BTK has recently been implicated in LPS/TLR4 signalling and was closely related to inflammatory response. However, there is little information regarding on the role of BTK in the systemic inflammatory response after burn injury. Our preliminary experiment found that BTK was activated in the lung of severely burned rats. It is possible that BTK can activate the MAPK and NF-κB signal transduction pathways and contributed to the development of uncontrolled systemic inflammatory response postburn. This study is to investigate BTK expression and effect in lung and live tissue of severely burned rats by using molecular biology methods such as siRNA interference on Kupffer cell; to study effect of BTK kinase on activiation of MAPK and NF-κB signal pathways and cytokine-related transcription factor; to preliminarily analyze regulatory realtionship between BTK with possible relevant signal transduction pathways. Implementation of this study will help to deeply understand the pathogenesis of systemic inflammatory response after severe burns and guide the effective treatment.

Bruton 酪氨酸激酶(BTK）是非受体酪氨酸激酶Tec 家族成员之一，在细胞生长、增殖、分化中具有重要的作用。近年研究发现，BTK 参与了LPS/TLR4 介导的信号通路，与炎症反应关系密切。根据文献检索，有关BTK 在严重烧伤后全身炎症反应发生发展中的作用尚不清楚。我们预实验发现严重烧伤后肺脏BTK 出现活化。我们推断:BTK 的活化并通过MAPK 和NF-κB信号通路的激活，导致烧伤后全身失控炎症反应的发生。本项目以库普弗细胞为主要研究对象，采用基因转染技术等方法，观察BTK 在严重烧伤大鼠肺脏和肝脏等组织的表达和作用，并研究BTK 对严重烧伤后的MAPK 信号通路活化和NF-κB 信号通路活化的影响以及对细胞因子相关转录因子活化的作用，初步分析BTK 与可能相关信号转导通路之间的相互调控关系。本项目的实施将对深入理解严重烧伤后全身炎症反应的发病机制及指导有效治疗均具有重要意义。

Bruton 酪氨酸激酶（Bruton's tyrosine kinase，BTK）是非受体酪氨酸激酶Tec 家族成员之一，在细胞生长、增殖、分化中具有重要的作用，并与炎症反应关系密切。本研究建立了稳定、高纯度的大鼠肝脏库普弗细胞（Kupffer cells，KCs）的分离方法。以大鼠库普弗细胞为主要研究对象，发现了BTK激酶参与严重烧伤后库普弗细胞促炎性细胞因子TNF-α和IL-1β的产生；在此基础上采用BTK激酶特异性抑制剂PCI-32765观察BTK激酶活化对严重烧伤后库普弗细胞内p38 MAPK、NF-κB等信号转导通路活化的影响。结果显示BTK激酶抑制剂PCI-32765可以明显抑制烧伤后KCs中p38 MAPK和NF-B的活化。研究提示：BTK激酶通过激活p38 MAPK和NF-B信号通路，介导KCs TNF-α和IL-1β的产生，初步揭示了BTK激酶在库普弗细胞分泌促炎性细胞因子作用中的分子机制，并为烧伤后全身炎症反应的防治提供新的思路和线索。