49: Inflammation provokes a cytokine response and disrupts the epithelial barrier: a possible mechanism of premature cervical remodeling and preterm birth

Abstract

Premature cervical remodeling is likely an obligatory step the pathogenesis of spontaneous preterm birth (PTB). We hypothesize that an inflammatory challenge disrupts the cervical epithelial barrier and promotes cervical remodeling. For this study, we used immortalized ectocervical and endocervical cells. The cells were plated at a concentration of 4.8 x 104 per well for 24 hours. Cells were treated with 25 ug/mL of lipopolysaccharide (LPS) or vehicle. Media was collected at 6 and 24 hours; the cytokines IL6 and IL8, and soluble E-cadherin (SECAD) were assessed at both time points. The integrity of the epithelial cell barrier was assessed using an in vitro permeability assay. Cell lines were grown in a monolayer across a semi permeable membrane, treated with LPS or vehicle for 24 hours. After 24 hours, FITC-dextran was added for 2 hours. The extent of permeability was determined by measuring the fluorescence on the receiver plates well solution. Exposure to LPS significantly increased IL6 and IL8 levels at 6 (p<0.05) and 24 (p<0.001) hours for both endocervical and ectocervical cells. SECAD, a measure of epithelial break down, was significantly increased at 24 hours (p<0.001) only, again for both cell lines. Permeability increased in the presence of inflammation for both ectocervical (p<0.001) and endocervical (p<0.005) cells. These studies demonstrate that an inflammatory challenge to cervical epithelial cells promotes not just a cytokine release but functionally alters the cervical epithelial barrier. These results provide a mechanism by which cervicovaginal inflammation may lead to premature cervical remodeling and play an essential role in preterm birth.