Regulated expression of matrix metalloproteinases, inflammatory mediators, and endometrial matrix remodeling by 17beta-estradiol in the immature rat uterus.
BACKGROUND
Administration of a single physiological dose of 17beta-estradiol (E2:40 microg/kg) to the ovariectomized immature rat rapidly induces uterine growth and remodeling. The response is characterized by changes in endometrial stromal architecture during an inflammatory-like response that likely involves activated matrix-metalloproteinases (MMPs). While estrogen is known as an inducer of endometrial growth, its role in specific expression of MMP family members in vivo is poorly characterized. E2-induced changes in MMP-2, -3, -7, and -9 mRNA and protein expression were analyzed to survey regulation along an extended time course 0-72 hours post-treatment. Because E2 effects inflammatory-like changes that may alter MMP expression, we assessed changes in tissue levels of TNF-alpha and MCP-1, and we utilized dexamethasone (600 microg/kg) to better understand the role of inflammation on matrix remodeling.


METHODS
Ovariectomized 21 day-old female Sprague-Dawley rats were administered E2 and uterine tissues were extracted and prepared for transmission electron microscopy (TEM), mRNA extraction and real-time RT-PCR, protein extraction and Western blot, or gelatin zymography. In inhibitor studies, pretreatment compounds were administered prior to E2 and tissues were harvested at 4 hours post-hormone challenge.


RESULTS
Using a novel TEM method to quantitatively assess changes in stromal collagen density, we show that E2-induced matrix remodeling is rapid in onset (< 1 hour) and leads to a 70% reduction in collagen density by 4 hours. Matrix remodeling is MMP-dependent, as pretreatment with batimastat ablates the hormone effect. MMP-3, -7, and -9 and inflammatory markers (TNF-alpha and MCP-1) are transiently upregulated with peak expression at 4 hours post-E2 treatment. MMP-2 expression is increased by E2 but highest expression and activity occur later in the response (48 hours). Dexamethasone inhibits E2-modulated changes in collagen density and expression of MMPs although these effects are variable. Dexamethasone upregulates MMP-3 mRNA but not protein levels, inhibiting E2-induced upregulation of MMP-7, and -9, and MCP-1 mRNA and protein but not inhibiting the hormone-induced increase in TNF-alpha mRNA.


CONCLUSIONS
The data demonstrate that E2-regulated endometrial remodeling is rapid in onset (<1 hour) and peak expression of MMPs and inflammatory mediators correlates temporally with the period of lowest stromal collagen density during uterine tissue hypertrophy.
Russo
Louise A
LA
Villanova University Department of Biology, 800 Lancaster Avenue, Villanova, PA 19085, USA. louise.russo@villanova.edu
Peano
Bryan J
BJ
Trivedi
Shreya P
SP
Cavalcanto
Todd D
TD
Olenchock
Benjamin A
BA
Caruso
Joseph A
JA
Smolock
Amanda R
AR
Vishnevsky
Oleg
O
Gardner
Russell M
RM
D000818:Animals; D003094:Collagen / Q000378:metabolism; D004717:Endometrium / Q000187:drug effects* / Q000378:metabolism / Q000502:physiology / Q000648:ultrastructure; D004958:Estradiol / Q000494:pharmacology*; D005109:Extracellular Matrix / Q000187:drug effects / Q000378:metabolism / Q000648:ultrastructure; D005260:Female; D005786:Gene Expression Regulation / Q000187:drug effects; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects; D018836:Inflammation Mediators / Q000378:metabolism*; D020782:Matrix Metalloproteinases / Q000235:genetics* / Q000378:metabolism; D010052:Ovariectomy; D051381:Rats; D017207:Rats, Sprague-Dawley; D012741:Sexual Maturation / Q000187:drug effects / Q000235:genetics*; D017154:Stromal Cells / Q000187:drug effects / Q000378:metabolism / Q000648:ultrastructure; D013997:Time Factors; D014599:Uterus / Q000187:drug effects* / Q000201:enzymology / Q000378:metabolism
D018836:Inflammation Mediators; D004958:Estradiol; D003094:Collagen; D020782:Matrix Metalloproteinases