Visualizing of the cellular uptake and intracellular trafficking of exosomes by live-cell microscopy.
Cells release exosomes to transfer various molecules to other cells. Exosomes are involved in a number of physiological and pathological processes. They are emerging great potential utility for diseases diagnosis and treatment recently. However, the internalization and intracellular trafficking of exosomes have not been described clearly. In this work, exosomes were isolated from the culture medium of PC12 cells, labeled by lipophilic dye and amino-reactive fluorophore, incubated with resting PC12 cells. The results of live-cell microscopy indicated that exosomes were internalized through endocytosis pathway, trapped in vesicles, and transported to perinuclear region. Particle tracking fluorescent vesicles suggested that the active transport of exosomes may be mediated by cytoskeleton. The proteins on exosome membrane were found to be released from exosomes and trapped in lysosome. The inverted transport of lipophilic dye from perinuclear region to cell peripheries was revealed, possibly caused by recycling of the exosome lipids. This study provides new sight into the mechanisms of exosome uptake and intracellular fate.
State Key Laboratory of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University, Nanjing 210096, China.
Tian
T
Tian
Yuanyuan
Y
Wang
Haitao
H
Wang
Zhaoqi
Z
Zhu
Zhongdang
Z
Xiao
D000818:Animals; D001692:Biological Transport; D002477:Cells / Q000378:metabolism*; D003599:Cytoskeleton; D004705:Endocytosis; D055354:Exosomes / Q000737:chemistry / Q000378:metabolism* / Q000648:ultrastructure; D008055:Lipids; D008247:Lysosomes / Q000378:metabolism; D008565:Membrane Proteins / Q000378:metabolism; D008853:Microscopy; D016716:PC12 Cells; D051381:Rats
D008055:Lipids; D008565:Membrane Proteins