Comparative studies on microvascular endothelial cells isolated from periodontal tissue

Most available periodontal studies regarding the endothelial cell (EC) were investigated by using human umbilical vein endothelial cells (HUVECs); however, ECs can display remarkable heterogeneity in vascular beds of different origins. The aim of the present study, therefore, is to characterize microvascular ECs isolated from periodontal tissue and investigate their growth and gene expression compared to HUVECs (macrovascular).

Periodontal ligament ECs (PDL-ECs) and gingiva ECs (G-ECs) were isolated by coupling to monoclonal anti-CD31 antibody magnetic beads. Both PDL-ECs and G-ECs were characterized to definitively demonstrate that the culture represented pure ECs. Their growth was determined by resazurin reduction assay. Interleukin (IL)-8, intercellular adhesion molecule 1 (ICAM-1), and E-selectin gene expression were determined by real-time quantitative reverse-transcription polymerase chain reaction after treatment with Escherichia coli lipopolysaccharide (LPS).

PDL-ECs and G-ECs revealed specific EC characteristics but formed tube-like structures and had slower growth rates than HUVECs. After E. coli LPS treatment, PDL-ECs and G-ECs showed similar dose-dependently increased levels of IL-8, ICAM-1, and E-selectin mRNA expression; however, their expressions were in contrast to HUVECs. PDL-ECs and G-ECs showed obviously increased ICAM-1 mRNA expression, whereas HUVECs showed markedly increased E-selectin mRNA expression after treatment with 0.1 μg/mL E. coli LPS.

ECs isolated from periodontal tissue show different growth and gene expression from those of HUVECs. Thus, these microvascular ECs appear to be a more valuable in vitro model system than HUVECs (macrovascular) to further study pathogenesis and angiogenesis of periodontal disease.