[The crucial toxic components of ambient fine particles promoted the maturation and differentiation of megakaryocytes].

Objective: To reveal the crucial toxic components of ambient fine particles (PM2.5) that affect the maturation and differentiation of megakaryocytes. Methods: Human megakaryocytes were exposed to the organic fractions, metallic fractions and water-soluble fractions of PM2.5 at two exposure doses (i.e. actual air proportion concentration or the same concentration), respectively. The cell viability was performed to screen the non-cytotoxic levels of toxic components of PM2.5 using the CCK-8 assay. CellTiter-Blue assay, morphological observation, flow cytometry analysis and WGA staining assay were used to evaluate the cell morphological changes, occurrence of DNA ploidy, alteration in the expressions of biomarkers and platelet formation, which were key indicators of the maturation and differentiation of megakaryocytes. Results: Compared to the control group, both metallic and organic components of PM2.5 resulted in a lag in megakaryocytes with an increase in cell volume and the onset of DNA ploidy. Flow cytometry analysis showed that CD33 (the marker of myeloid-specific) decreased and CD41a (a megakaryocyte maturation-associated antigen) increased in metallic and organic components of PM2.5 treatment groups. Moreover, compared to the control group, budding protrusions increased in metallic and organic components of PM2.5 treatment groups. The water-soluble components had no effect on the maturation and differentiation of macrophages. Conclusion: Metallic and organic components of PM2.5 are the crucial toxic components that promote the maturation and differentiation of megakaryocytes.目的： 分析大气细颗粒物（PM2.5）影响巨核细胞成熟以及分化为血小板的关键毒性组分。 方法： 将PM2.5有机组分（O-PM2.5）、金属组分（M-PM2.5）和水溶性组分（WS-PM2.5）使用实际大气环境占比浓度和各组分相同浓度两种暴露浓度处理人巨核细胞。采用CCK-8实验检测巨核细胞存活，利用CellTiter-Blue、明场形态观察、流式细胞术、麦胚凝集素（WGA）染色等方法评价巨核细胞形态大小、DNA倍体化、分化表面因子表达和血小板生成等巨核细胞成熟及分化的关键指标。 结果： PM2.5金属组分和有机组分处理巨核细胞后，细胞出现生长滞后，同时伴随着细胞体积增大、DNA倍体化发生、髓系特异性分子CD33表达减少以及巨核细胞成熟相关抗原CD41a表达增加。WGA染色结果显示，与对照组相比，PM2.5金属组分和有机组分暴露组细胞形成的芽状突起增多。水溶性组分对巨噬细胞成熟分化过程无影响。 结论： PM2.5金属组分和有机组分为促进巨核细胞成熟和分化的关键毒性组分。.