Vascular endothelial sampling and analysis of gene transcripts: a new quantitative approach to monitor vascular inflammation.

BACKGROUND Limited access to endothelial tissue is a major constraint when investigating the cellular mechanisms of vascular inflammation in patients with cardiovascular and metabolic diseases. We introduce venous endothelial sampling coupled to quantitative analysis of gene transcripts by real-time PCR, as a novel approach to study endothelial gene expression in human subjects. METHODS Endothelial cells were collected from a superficial forearm vein using five guide wires sequentially inserted through a 20-gauge angiocatheter in seven patients with history of cardiovascular events related to advanced vascular disease and in 17 healthy subjects. Endothelial cells were purified using magnetic beads coated with endothelial specific antibodies. Endothelial mRNA was amplified using RiboAmp HS RNA Amplification kit (Molecular Devices, Sunnyvale, CA). Amplified RNA was analyzed by real-time PCR. RESULTS Linearity of RNA amplification was validated by real-time PCR using RNA from 1,000 human umbilical endothelial cells (HUVECs) before and after amplification. In human subjects, vascular disease was associated with significant induction of proatherosclerotic genes: early growth response gene product (Egr-1) and monocyte chemoattractant protein-1 (MCP-1). CONCLUSION Venous endothelial sampling coupled to real-time PCR analysis is a minimally invasive, safe, and reliable technique to monitor vascular inflammation in human subjects. Expression of genes implicated in the atherosclerotic process is increased in the venous endothelium of patients with arterial vascular disease. Venous endothelial sampling and quantitative analysis of gene expression may help develop new vascular-targeted biomarkers to identify and track the impact of disease states and therapeutic interventions in vascular diseases.