Kinetics of the endocytotic pathway of Low Density Lipoprotein (LDL) in human endothelial cells line under shear stress: an in vitro confocal microscopy study

Clin Hemorheol Microcirc. 2005;33(3):243-51.


We studied the effect of mechanical forces (shear stress) on the kinetics of internalization of native LDL and ox-LDL in endothelial cell line ECV304. This study was performed by using Confocal microscopy and FRET with two carbocyanine dyes, 1,1'-dioctadecyl-3,3,3',3'-tetramethylindocarbocyanine perchlorate (DiO) as the donor and 3,3'-dioctadecyloxacarbocyanine perchlorate (DiI) as the receptor. The cells were incubated with a culture medium containing either 10 microg/ml DiI-LDL or DiO-LDL in static conditions or subjected to a laminar flow under a Confocal Laser Scanning Microscope (SP2 Leica, Germany). The results showed: (1) the possibility to evaluate the kinetics of LDL endocytosis in living cells, (2) shear stress in comparison with control group more effectively enhanced LDL uptake, (3) ox-LDL (>50 microg/ml) >4 hours incubation was found to affect the cells as reflected by their detachment at low shear stress.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Cell Line
  • Endocytosis*
  • Endothelial Cells / metabolism*
  • Fluorescence Resonance Energy Transfer
  • Fluorescent Dyes
  • Humans
  • Kinetics
  • Lipoproteins, LDL / metabolism*
  • Microscopy, Confocal
  • Stress, Mechanical


  • Fluorescent Dyes
  • Lipoproteins, LDL
  • oxidized low density lipoprotein