Clathrin-coated vesicles form a unique net-like structure in liver sinusoidal endothelial cells by assembling along undisrupted microtubules

B Falkowska-Hansen, M Falkowski, P Metharom… - Experimental cell …, 2007 - Elsevier
B Falkowska-Hansen, M Falkowski, P Metharom, D Krunic, S Goerdt
Experimental cell research, 2007Elsevier
Liver sinusoidal endothelial cells (LSECs) are highly active professional scavenger cells
using clathrin-mediated endocytosis to clear the blood from macromolecular waste products.
Using confocal microscopy, we observed a remarkable net-like distribution of clathrin heavy
chain (CHC) in LSECs while all other cell types examined including various primary
endothelial cells and cell lines showed the well-known punctuate staining pattern
representing clathrin-coated vesicles (CCV). The net-like distribution of CHC in LSECs co …
Liver sinusoidal endothelial cells (LSECs) are highly active professional scavenger cells using clathrin-mediated endocytosis to clear the blood from macromolecular waste products. Using confocal microscopy, we observed a remarkable net-like distribution of clathrin heavy chain (CHC) in LSECs while all other cell types examined including various primary endothelial cells and cell lines showed the well-known punctuate staining pattern representing clathrin-coated vesicles (CCV). The net-like distribution of CHC in LSECs co-localized fully with microtubules, but not with actin. Upon 3D imaging, the net-like distribution of CHC resolved into numerous CCVs organized along the microtubules. The CCVs only partially co-localized with early endosome antigen 1 (EEA1) and adaptor protein 2 (AP-2). Endocytic vesicles containing ligand destined for degradation (FITC-AHGG) were organized along the clathrin/tubulin net-like structures, whereas transferrin-containing recycling vesicles co-localized to a much lower extent. Disruption of the microtubules by nocodazole treatment caused a collapse of the net-like organization of CCVs as well as a profound redistribution of EEA1, AP-2 and FITC-AHGG-containing vesicles, while transferrin internalization and recycling remained unaffected.
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