空气污染颗粒物对自吞噬及炎性小体的调控研究

We propose to develop a predictive toxicological paradigm that links the physicochemical properties of air pollution particles collected locally in Zhengzhou and compare their effects with reference nanoparticles (carbon and quartz) to lung injury through the engagement of a pro-inflammatory pathway mediated by the NLRP3 inflammasome that is regulated by autophagy. This work is important because there has been no systematic dissection of the structure-activity relationships that are responsible for toxicological injury by air pollution particles (especially the ultrafine particles). While there is growing awareness of the role of the NLRP3 inflammasome, autophagy and functionally-related structures such as lysosomes in inflammatory disease (systemically as well as in the lung), it is unclear how engagement of this pathway by particles lead to lung injury. Exploration on this topic is timely because of our preliminary data indicate that the unique nanoscale properties of materials including multiwall carbon nanotubes, rare earth oxides (REOs) and CeO2 nanowires allow them to engage the NRLP3 inflammasome and autophagy play a major role in regulating the active inflammasome complexes. Our long-term goal remains the fundamental understanding of the mechanisms by which air pollution particles mediate toxicity. The overall objective of this new application is to develop a predictive paradigm for toxicity that takes into consideration the unique properties of the air pollution particles that allow them to engage the NLRP-3 inflammasome that is regulated by autophagy. Our central hypothesis is that the physicochemical properties of the selected particles are responsible for disruption of autophagy flux, initiating sustained NRLP3 activation, leading delayed or pulmonary inflammation and fibrosis. Our hypothesis is based on progress in the past 10 years in understanding the mechanisms of injury induced by diesel exhaust particles (DEP), as well as our progress indicating that nanomaterials such as MWCNTs, REOs and CeO2 nanowires induce pulmonary fibrosis by a pathway involving IL-1β production that is regulated by autophagy flux. The rationale for the proposed research is that, once it is known the mechanism of air pollution particles induced lung injury, we should be able to use this knowledge to develop methods to treat particle-induced lung diseases.

空气污染是影响我国及世界各国人民身体健康的重大问题。空气污染物可以引发严重的呼吸道疾病，例如慢性支气管炎、阻塞性肺疾病、肺纤维化、哮喘、肺泡病变等。在空气污染的致病因素中，空气污染颗粒物起着主要作用。最新的研究发现空气中PM10对NLRP3炎性小体引发肺疾病有影响，其中超细颗粒物（小于100纳米）起着更重要的作用甚至超过细颗粒物（PM2.5）。由于PM10与PM2.5和超细颗粒物的组分、理化性质在不同季节截然不同，我们假想多点、多时期收集的颗粒物，会由于大小、组分和理化性质不同对自吞噬调控的炎性小体的激活有不同效果，并影响其引发肺炎症和肺纤维化的能力。本课题拟收集河南省郑州市2个采集点的不同大小和季节的空气污染颗粒，采用最新技术详细研究其对自吞噬的影响和其对炎性小体的调控机理。此研究有望发现空气污染颗粒物引发肺疾病的机制，为其防治提供科学依据。研究结果有进一步申请知识产权和临床应用

研究表明，空气细颗粒物（PM2.5）能够引起急慢性呼吸道炎症和肺纤维化。本研究应用预测毒理学的方法探索PM2.5诱导的毒理学机制。在这项研究中，我们收集了2017年11月在中国河南郑州采集的八个PM2.5样品，用于比较它们在肺中的成纤维化作用。体外筛选结果显示，PM2.5颗粒没有引起明显的细胞毒性；然而，通过NLRP3-和ASC-缺陷细胞的清除反应及组织蛋白酶B抑制剂抑制IL-1β的分泌实验，我们发现，PM2.5可以引起THP-1细胞中白细胞介素-1β（IL-1β）明显升高，它涉及了NLRP3炎性小体的激活。经小鼠口咽呼入PM2.5证实，PM2.5可诱导支气管肺泡灌洗液中TGF-β1的产生，小鼠在暴露颗粒物质21天诱导肺组织胶原沉积，提示肺内炎症和肺纤维化。实验也证明体内PM2.5的促纤维化作用与体外实验结果完全一致。总之，本研究建立了应用NLRP3小体，评价空气污染颗粒引发慢性肺纤维化的预测毒理学方法；同时，本研究证实，郑州空气中PM2.5颗粒以激活NLRP3炎性小体为主的引发肺纤维化的致病机理。这一结果为空气污染引起疾病的防治提供了理论依据和科学指导。空气污染颗粒中含有的金属和金属氧化物纳米颗粒。我们系统性的研究了金属和金属氧化物纳米材料的理化性质和它们诱导NLRP3炎性小体的构效关系，以及它们引发肺纤维化的体内致病效应。我们同时利用纳米材料作为载体发展疫苗佐剂以及发展靶向ESCCAL-1基因的siRNA纳米复合物来研究体外对食管癌EC-9706的抑制作用。我们发现氧化铝纳米棒具有激活先天性免疫功能的作用，可以用来发展纳米佐剂的应用。我们进一步制备了装载靶向ESCCAL-1基因的siRNA纳米复合物，发现其体外对食管癌EC-9706细胞增殖有抑制作用。