Human endothelium: endovascular biopsy and molecular analysis

To develop a safe and reproducible method for harvesting viable vascular endothelium to analyze gene expression at sites of vascular lesions.

Coaxial curved stainless-steel guide wires were used to obtain samples of endothelial cells from large arteries and veins in 29 patients undergoing routine endovascular procedures. Three immunocytochemical markers were used to identify cells as endothelial. Cellular viability was evaluated in terms of cell membrane integrity, energy-dependent uptake of acetylated low-density lipoprotein, and cellular response to lipopolysaccharide. Single-cell reverse transcription polymerase chain reaction (PCR) and immunocytochemistry were used to study endothelial gene expression.

Cells with endothelial morphology and immunoreactivity for von Willebrand factor, thrombomodulin, and angiotensin-converting enzyme were consistently obtained from iliac and carotid arteries and large veins (average yield [+/- standard error] from 26 iliac arteries, 262 endothelial cells +/- 45, 20%-30% of which were viable). These cells displayed induction of E-selection messenger RNA at PCR after exposure to lipopolysaccharide. Expression of vascular cell adhesion molecule 1 transcripts in endothelial cells increased with patient age (P < .01), whereas expression of intercellular adhesion molecule 1 did not.

Viable endothelium can be obtained during routine angiography. Immunocytochemical and reverse transcription PCR analyses of these cells allowed determination of transcripts and proteins expressed by endothelium at sites of vascular lesions. Such information could aid in understanding mechanisms of vascular diseases and in clinical decision making.