Infiltrating Granulocytes Contribute to Rapid Estrogen-Induced Uterine Stromal Matrix Remodeling in the Immature Ovariectomized Rat

Program: Abstracts - Orals, Featured Poster Presentations, and Posters
Session: SUN 554-573-Ovarian & Uterine Function I
Sunday, June 16, 2013: 1:45 PM-3:45 PM
Expo Halls ABC (Moscone Center)

Poster Board SUN-569
Louise A Russo*, Lisa M Shihanian and Russell M Gardner
Villanova University, Villanova, PA
The immature rat uterus has long been used as a model system to study estrogen-based regulation of endometrial stromal matrix remodeling and matrix metalloproteinase (MMP) regulation (1).  During estrogen-induced uterine growth, a rapid inflammatory-like response occurring within hours of hormone treatment and infiltrating leukocytes may contribute chemical mediators that drive matrix remodeling. This study examined the correlation between granulocyte influx and stromal matrix remodeling in response to a physiological does of 17beta-estradiol (E2:40 mg/kg).  Immature OVX animals were treated with anti-PMN (polymorphonuclear cell) antiserum to induce a state of granulocytopenia prior to E2 administration and subsequent changes in stromal collagen matrix density were assessed via quantitative analysis of transmission electron micrographs.  In addition, changes in uterine chemokine expression were analyzed via real time qPCR to further characterize the E2-tisue inflammatory response. The data show that granulocyte depletion partially abrogated stromal matrix remodeling.  Collagen density levels were significantly higher than in saline-treated control and saline-treated normal-serum treated animals and were significantly lower than in E2-treated control animals at 4 hours post-hormone adminstration. Granulocytopenia had no significant impact on E2-induced expression of the chemoattractant chemokines IL-8, eotaxin, or MCP-1 indicating that the absence of infiltrating granulocytes does not alter the inherent tissue inflammatory response to E2.  These data demonstrate that while granulocyte infiltration significantly contributes to the E2-induced stromal matrix remodeling response, inherent tissue matrix processing is also initiated by hormone receptor signaling.

(1) Russo LA et al. Reproductive Biology and Endocrinology 2009: 7:124

Nothing to Disclose: LAR, LMS, RMG

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