Porphyromonas gingivalis activates Human Coronary Artery Endothelial Cells during invasion

Porphyromonas gingivalis (Pg) is a major etiological agent in periodontitis. Pg has also been shown to accelerate the progression of atherosclerosis in animal models. Pg can invade several different cell lines and types, particularly Human Coronary Artery Endothelial Cells (HCAEC), in which it can be found in autophagic vacuoles. Objectives: The goal of this study was to identify HCAEC genes that are differentially regulated during Pg contact and invasion. Methods: Confluent monolayers of HCAEC were infected with Pg at MOI of 1:100 for 0.5, 2.5, 6.0, 12, and 24h as described in previous studies. At each time point, cells were lysed and total RNA was purified. A panel of 84 genes related to endothelial cell biology was investigated using SuperArray RT²Profiler PCR Arrays. Supernatants in every time point were collected to verify protein expression. Cell lysates of each time point were also plated on blood agar plates for quantification of internalized Pg. Results: Internalized Pg was found at all time points, although its numbers decreased during the progression of invasion. Several genes involved in cell stress and cytokine activity such as MCP-1, RANTES, GM-CSF, CX3CL1 and IL1b were differentially regulated during the time course of Pg invasion. In addition, adhesion molecules such as E-selectin, ICAM1 and VCAM1, and matrix metallopeptidases, particularly MMP9, were also affected by Pg invasion. Conclusion: Genes involved in monocyte recruitment, such as MCP-1, RANTES, IL1b, ICAM-1 and VCAM1, and in monocyte infiltration, such as MMP9, were up-regulated, indicating that upon invasion by Pg, HCAEC are activated. Both monocyte recruitment and infiltration are well associated with the progression of atherosclerosis. This research was supported by a UFCD Student Summer Research Fellowship, the Center for Molecular Microbiology, and NIH grant DE13545.