Defense Date

2010

Document Type

Thesis

Degree Name

Master of Science

Department

Physiology

First Advisor

Scott Walsh

Abstract

Neutrophils infiltrate myometrium and decidual tissue prior to parturition. Activated neutrophils release reactive oxygen species (ROS) and tumor necrosis factor α (TNFα), which might increase expression of pro-labor genes such as matrix metalloproteinase-1 (MMP-1), progesterone receptor (PR) A/B ratio, and cause demethylation of DNA. These changes might cause labor. Decidual tissue was obtained from consented, healthy women at term (37+ weeks of gestation) not in labor (no contractions, without cervical effacement), term labor and preterm labor (under 37 weeks of pregnancy). Decidual and myometrial cells in culture were treated with (1) ROS, (2) TNFα, or (3) 5-aza-2’-deoxycytidine. Total RNA was extracted, converted to cDNA and evaluated by qRT-PCR for MMP-1, PR-A+B and PR-B. TNFα increased MMP-1 by 17 fold in decidual cells and more than 12 fold in myometrial cells. PR-A/B was increased by 5.6 fold in decidua. ROS up-regulated MMP-1 by 6 fold and elevated the PR-A/B ratio by 4.5 fold in decidual tissue. DNA demethylation increased MMP-1 by about 4 and 11 fold in decidual and myometrium, respectively. The PR-A/B ratio was increased by 4 fold in decidua and the PR-B was decreased by 40% in the myometrium due to DNA demethylation. Decidual tissue in preterm labor showed a 7-fold increase in MMP-1 over term laboring and over a 15-fold increase over term not in labor tissue. In conclusion, MMP-1 expression and PR-A/B ratio was increased by neutrophil products possibly through a mechanism of DNA methylation in decidua and myometrium. Preterm decidua showed a dramatic increase in MMP-1 over normal labor tissue. TNFα and ROS increased expression of MMP-1 to possibly initiate parturition. These data might help explain mechanisms responsible for preterm labor unrelated to infection or premature rupture of membranes.

Rights

© The Author

Is Part Of

VCU University Archives

Is Part Of

VCU Theses and Dissertations

Date of Submission

May 2010

Included in

Physiology Commons

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