巨噬细胞M1表型偏移通过诱导METs形成加剧COPD炎症反应的机制研究

It is generally believed that the development of COPD is closely related to excessive inflammation in the lungs, and excessive release of extracellular traps (METs) or METs clearing delay is the cause of excessive inflammation. In our previous studies, we found that the ratio of M1:M2 in peripheral blood and bronchoalveolar lavage fluid (BALF) of grade III COPD patients was significantly increased than grade II patients, and the numbers of METs was also increased in grade III patients. Thus we speculate that the skew of macrophage toward M1 phenotype in COPD patients may be one of the reasons for the excessive production of METs which may be associated with the overactive TLRs/MYD88 signaling pathway in M1..In this research, we’ll compare the differences in METs formation between M1 and M2, and verify the role of TLRs/MYD88 signaling pathway to regulate METs formation from M1 through intervening this pathway. Meanwhile, we’ll establish a model of COPD in rats, assessing the level of inflammation-associated cytokines and the difference of pathological changes in lung tissue by intervening TLRs/MYD88 pathway. It will provide us with a new direction and strategy for the treatment of COPD to illustrate the feasibility and efficacy of anti-inflammatory treatment through inhibiting TLRs/MYD88 signaling and METs.

目前普遍认为，COPD的发生发展与肺部过度的炎症反应密切相关，而肺巨噬细胞释放过多的胞外陷阱（METs）或METs不能被及时清除则是过度炎症反应的诱因。我们在前期研究中发现，COPD肺功能分级为III级的患者外周血和肺泡灌洗液中单核/巨噬细胞M1:M2比例均明显高于分级为II级患者，并且分级为III级的患者肺泡灌洗液中METs含量也较II级多。另外，与M2相比，M1普遍高表达定位于细胞膜表面的TLRs，因此我们推测COPD患者巨噬细胞分型向M1偏移可能是METs产生过多的原因之一，并且此过程可能和M1中TLRs/MYD88信号通路过度活化有关。.本课题将比较M1和M2形成METs的能力差异，并通过干预TLRs/MYD88通路明确其是否参与调控M1产生METs。同时，我们将建立COPD大鼠模型，并对TLRs/MYD88通路和METs进行干预，评估干预前后COPD肺部炎症相关因子表达水平的差异以及肺组织病理病变的差异。阐明通过抑制TLR2/MYD88和METs对COPD进行抗炎治疗的效果和可行性将为我们治疗COPD提供一个新的方向和策略。

目前普遍认为COPD的发生发展与肺部过度的炎症反应密切相关，而肺巨噬细胞释放过多的胞外陷阱（METs）或METs不能被及时清除则是过度炎症反应的诱因。我们在前期研究中发现，COPD肺功能分级为III级的患者外周血和肺泡灌洗液中单核/巨噬细胞M1:M2比例均明显高于分级为II级患者，并且分级为III级的患者肺泡灌洗液中METs含量也较II级多。因此我们推测COPD患者巨噬细胞分型向M1偏移可能是METs产生过多的原因之一。.本项目主要研究外周血中单核/巨噬细胞亚群分布规律，在体外诱导METs形成的实验中比较M1和M2形成METs的能力差异，并明确干预TLRs信号通路可调控M1极化。我们发现，COPD患者外周血中CD163+CD206+中间型单核细胞的占比，以及该亚群细胞中CD206+/CD206-比值与COPD严重程度相关。我们也在体外诱导成功诱导THP-1向M1和M2分化，分别刺激M1和M2后，二者在METs形成量上并无明显差异，但METs形成的相关基因在M1中表达较高。抑制TLRs/MYD88信号通路后，M0型巨噬细胞向M1型的极化被部分抑制。以上结果为我们后续以METs为靶标调控COPD中巨噬细胞极化提供了理论基础。