聚苯乙烯纳米塑料对大鼠主动脉平滑肌细胞泡沫化的影响

Effects of Polystyrene Nanoplastics on Foam Cell Formation in Rat Aortic Smooth Muscle Cells

目的探讨聚苯乙烯纳米塑料(Polystyrene nanoplastics,NPs)对大鼠主动脉平滑肌细胞(Rat aortic smooth muscle cells,RASMCs)泡沫化的影响。方法体外培养大鼠主动脉平滑肌细胞,用不同水平的直径为80纳米的绿色荧光NPs(80 nm NPs)处理RASMCs 24小时;采用细胞计数试剂盒(Cell counting kit-8,CCK8)检测细胞活力,并检测细胞释放的乳酸脱氢酶(Lactate dehydrogenase,LDH)活性以评估细胞损伤程度;利用DiI荧光标记的氧化型低密度脂蛋白(Dioctadecyl-3,3,3,3-tetramethylin docarbocyanine-oxidized low density lipoprotein,DiI-oxLDL)诱导平滑肌细胞泡沫细胞形成,并行油红O染色显示脂滴;采用蛋白免疫印迹法检测自噬相关指标(Microtubule-associated protein 1 light chain 3B,MAP1LC3B)的表达水平。结果80 nm NPs可被RASMCs吞噬并产生细胞毒性,呈水平依赖性促进RASMCs摄取oxLDL,自噬相关指标(LC3B)表达水平降低。结论聚苯乙烯纳米塑料可被血管平滑肌细胞吞噬并促进泡沫细胞形成,其潜在机制可能是通过抑制RASMCs自噬来实现的。

Objective To investigate the role of polystyrene nanoplastics(NPs)in foam cell formation in rat aortic smooth muscle cells(RASMCs).Methods RASMCs were treated with green fluorescent NPs of 80-nanometer diameter(80 nm NPs)at different concentrations for 24 hours.Cell viability was assessed using the CCK-8 assay.Lactate dehydrogenase(LDH)activity assay kit was used to measure LDH release as an indicator of cell damage.Foam cell formation was induced using DiI-labeled oxidized low-density lipoprotein(DiI-oxLDL).Oil Red O staining was performed to visualize lipid droplets.Protein immunoblotting was conducted to assess the expression levels of autophagy-related marker microtubule-associated protein 1 light chain 3B(MAP1LC3B/LC3B).Results The results demonstrated that RASMCs internalized the 80 nm NPs,and their uptake was associated with concentration-dependent cytotoxicity.Furthermore,the NPs promoted the uptake of oxLDL by RASMCs and downregulated the expression level of the autophagy-related marker LC3B.Conclusion The 80nm NPs promote the uptake of oxLDL by RASMCs and induce foam cell formation.The potential mechanism underlying this effect may involve the inhibition of autophagy in RASMCs.