title: Regulated expression of matrix metalloproteinases, inflammatory mediators, and endometrial matrix remodeling by 17beta-estradiol in the immature rat uterus.
abstract: 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.
authors.affiliation: Villanova University Department of Biology, 800 Lancaster Avenue, Villanova, PA 19085, USA. louise.russo@villanova.edu
authors.forename: Louise A
authors.initials: LA
authors.lastname: Russo
authors.forename: Bryan J
authors.initials: BJ
authors.lastname: Peano
authors.forename: Shreya P
authors.initials: SP
authors.lastname: Trivedi
authors.forename: Todd D
authors.initials: TD
authors.lastname: Cavalcanto
authors.forename: Benjamin A
authors.initials: BA
authors.lastname: Olenchock
authors.forename: Joseph A
authors.initials: JA
authors.lastname: Caruso
authors.forename: Amanda R
authors.initials: AR
authors.lastname: Smolock
authors.forename: Oleg
authors.initials: O
authors.lastname: Vishnevsky
authors.forename: Russell M
authors.initials: RM
authors.lastname: Gardner
mesh_terms: 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
chemical_list: D018836:Inflammation Mediators; D004958:Estradiol; D003094:Collagen; D020782:Matrix Metalloproteinases