Abstract: Objective To investigate the expression of inflammatory factors and fibroblast growth factor 21（FGF21） in the kidneys of mice induced by fine natural inhalation of particulate matter 2.5（PM_2.5）,inferwhether FGF21 is expected to be a potential biological indicator in kidney damage caused by natural inhalation of PM_2.5. Methods According to the random number table method,52 healthy male mice aged 6 weeks were randomly divided into the control group（natural inhalation of air） and the experimental group（PM_2.5 exposure group）,with 26 mice in each group. The experimental group naturally inhaled PM_2.5 aerosol for 28 weeks. HE staining was used to observe the pathological morphology of the mouse kidneys. The immunohistochemical method was used to detect the protein expressions of tumor necrosis factor-α（TNF-α）,interleukin 1β（IL-1β）,interleukin 6（IL-6）and fibroblast growth factor 21（FGF21）.And the correlation between FGF21 and TNF-α,IL-1β and IL-6 was analyzed. Results Compared with the control group,the kidneys of the mice in the experimental group had obvious pathological damage,and the difference was statistically significant（P<0.05）. Compared with the control group,the expression levels of TNF-α,IL-1β and IL-6 in the kidney of mice in the experimental group increased,while the expression level of FGF21 decreased,and the differences were statistically significant（all P<0.05）. The FGF21 was negatively correlated with TNF-α,IL-1β and IL-6（all P<0.05）. Conclusions The natural inhalation of PM_2.5 can cause significant kidney damage in mice,inhibit the expression of FGF21 in the kidney,and promote the inflammatory factor TNF-α,IL-1β and IL-6 expression. The FGF21 is negatively correlated with TNF-α,IL-1β and IL-6.It is speculated that FGF21 may become a potential biological indicator in kidney damage caused by natural inhalation of PM_2.5.

Key words: Fine particulate matter, Kidney injury, Inflammatory factor, FGF21