The impact of Rho GTPases on the cell uptake of single-walled carbon nanohorns

Rho GTP激酶对调控细胞骨架具有重要影响,其可控制微丝、微管的生长与维持,进而对细胞形态发生、细胞迁移、内吞转运等生命活动产生影响。已知细胞对纳米药物的摄取离不开细胞骨架的调控作用,但已有研究却很少关注Rho GTP激酶对细胞摄取纳米药物或纳米药物递送载体的影响。为了探究这一问题,本研究选择了单壁碳纳米角作为纳米药物或纳米药物递送载体的一种模型,其独特的物理化学性质使其成为药物递送领域热门研究对象。利用激光共聚焦显微镜和TEM观察细胞对纳米材料的摄取情况以及胞内分布;随后以各类内吞抑制剂处理细胞,分析细胞对单壁碳纳米角的摄取机制。实验结果表明,Rho GTP激酶中的Rho A被抑制后会显著减少细胞对单壁碳纳米角的摄取。单壁碳纳米角经网格蛋白介导的内吞入胞,入胞后主要分布在溶酶体中。Rho GTPases play an important role on the regulation of cytoskeleton, which can affect the cell morphogenesis, cell migration, endocytosis and vesicle transport by controlling the growth and maintenance of microfilaments and microtubules. It has been known that regulation of cell cytoskeleton is inseparable from the cell uptake of nano-medicine or nano-drug delivery systems. However, only few studies have focused on the impacts of Rho GTPases on cell uptake of nano-medicine or nano-drug delivery systems. This study selected single-walled carbon nanohorns (SWCNHs), which have emerged as promising drug delivery systems, to explore the impacts of Rho GTPases on cell uptake of nano-drug delivery systems. SWCNHs were oxidized with concentrated nitric acid and prepared into nano dispersion by ultrasonic dispersion. Confocal laser scanning microscope (CLSM) and transmission electron microscopy (TEM) were used to observe the cell uptake and intracellular distribution of nanoparticles after incubated A549 cells with the dispersion mentioned above. Mechanism of cell uptake was assessed using various inhibitors. The results showed that the cell uptake of oxSWCNHs was significantly reduced when RhoA was inhibited. The oxSWCNHs were internalized through clathrin-mediated endocytosis and mainly positioned in lysosomes of A549 cells.National Basic Research Program of China (973 Program),National Natural Science Foundation of China中国科学引文数据库(CSCD)06395-4032