Objective To study the effects of oral ingestion of microplastics(MPs)on lung tissue in mice and explore the mechanism.Methods Firstly,Polystyrene microplastics(PS-MPs)were used to simulate MPs in the environment.Balb/c male mice were randomly divided into three groups:control group,and 0.05 µm and 0.5 μm MPs groups.The exposure doses of the mice were designed as follows:MPs of 0.05 μm,0.5 μm(0.3 mg/day)was given orally for 4 consecutive weeks at the puberty stage,and the dose was changed to 0.6mg/day for another 8 weeks at the maturity stage.The control group was given the same volume of distilled water,and all mice were sacrificed at the 16th week.Then,HE staining was used to observe lung morphology,and the cell clusters expressing NLRP3 in lung samples of mice in PanglaoDB database were analyzed.Finally,the expres-sion of NLRP3 and Caspase-1 in lung samples were determined by Western blotting.Results HE staining of lung samples showed that MPs group of 0.05 μm and 0.5 μm could induce inflammatory injury to lungs of mice.The cell clusters expressing NLRP3 are macrophages in lung samples of mice in PanglaoDB database.Meanwhile,the results of Western blot showed that:compared with the control group,the protein expression in the lung tissue of mice in the MPs groups had an increased trend,but only the 0.05 μm MPs group had statistic difference(P＜0.05).In addition,compared with the 0.5 μm MPs group,the protein expression level of the 0.05 μm MPs group was significantly increased(P＜0.05).Conclusion Oral administration of MPs may promote the activa-tion of NLRP3 inflammasome and cause the inflammatory damage to lung.For 0.05 μm and 0.5 μm MPs,the smaller the particle size,the more serious inflammatory damage to lung.
维普
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