Effects of cigarette smoke extracts on cardiac stem cell Paracellular and Trans‐cellular permeability

Abstract

Cigarette smoking is a risk factor for several cardiovascular diseases and premature death. The integrity of tight junctions between cardiac cells is important in keeping proper cardiovascular function. The main objective of our study is to investigate the possibility of impairment of tight junction barrier by cigarette smoke extracts (CSE). We hypothesized that CSE cause increase in para‐cellular and trans‐cellular permeability in c‐kit positive rat cardiac stem cells (rCSC). CSE induced development of paracellular gaps has not been reported in cardiac stem cells. This is truly a novel area and there was only one report discussing CSE induced changes in endothelial cell permeability. In our study cell junction permeability was detected using para‐cellular permeability assay. Following establishment of rCSC monolayer on trans‐well polycarbonate inserts, Fluorescein isothiocyanate (FITC)‐labeled dextran was added to the inner chamber and Para‐cellular permeability of FITC‐dextran across the cell monolayer was detected at 490 λ. As an indicator of CSE induced changes in trans‐cellular permeability, trans–cell electrical resistance was also detected. In addition, CSE induced changes in cell membrane damage was assessed using LDH release cytotoxicity assay. CSE caused increase in Para‐cellular permeability, LDH release, and decrease in Trans–cell electrical resistance in a dose dependent manner. The mechanisms underlying CSE induced modulation of cell permeability is currently under investigation. Preliminary data indicates that oxidative stress play a role in CSE induced changes in permeability. Research support was provided by Sullivan University College of Pharmacy faculty development grant awarded to Dr. Wasana Sumanasekera.