205: Progesterone maintains a balance in collagen metabolism while estrogen drives production in cervical stromal cells

Abstract

metabolism while estrogen drives production in cervical stromal cells Huiling Ji, Joshua Dahlke, Edward Chien Warren Alpert School of Medicine of Brown University, Obstetrics and Gynecology, Providence, RI OBJECTIVE: Cervical remodeling is associated with extracellular matrix (ECM) remodeling. Collagen is the main ECM component in the cervix contributing to tissue resistance. Collagen remodeling in the cervix during gestation is thought to be hormone regulated and involves both the production of new protein as well as degradation of existing fibers. We have previously shown that estrogen increases collagen secretion. The purpose of this study is to investigate the effects of estradiol and progesterone on both collagen production and degradation in rat cervical stromal cells. STUDY DESIGN: Primary rat cervical stromal cells were cultured using an explant method approved by the IACUC. Passage 2-6 cells were plated on six well plates in serum free media. Cells were treated for 3 days with estradiol or progesterone. Vehicle treated cells were used as controls. Culture medium was collected for soluble collagen assay. The ECM collagen that was adherent to the culture dish was extracted using 0.5M acetic acid. Sircol Red Assay was used to quantify soluble and ECM collagen. Western Blot was performed to evaluate the expression of Type I and III collagen, MMP2, MMP9 and MMP13. Zymography was used to detect MMP2 and MMP9 expression. Data was analyzed using Sigma Stat. RESULTS: Similar to prior studies estradiol increased soluble collagen secretion while no change was observed with progesterone. Estradiol and progesterone had similar effects on ECM collagen. Estradiol stimulated collagen I /III expression and decreased MMP2 expression. Progesterone did not change Type I/III collagen expression but increased MMP13 expression. MMP9 expression did not change in either estradiol or progesterone treated rat cervical stromal cells. CONCLUSION: Estradiol increased overall collagen production by stimulating protein secretion and polymerization while inhibiting the production of collagenases. Collagen content was maintained by progesterone by balancing production and degradation.