Biology of reproduction
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Biology of reproduction · Apr 2004
Progesterone and gravidity differentially regulate expression of extracellular matrix components in the pregnant rat myometrium.
Myometrial growth and remodeling during pregnancy depends on increased synthesis of interstitial matrix proteins. We hypothesize that the presence of mechanical tension in a specific hormonal environment regulates the expression of extracellular matrix (ECM) components in the uterus. Myometrial tissue was collected from pregnant rats on Gestational Days 0, 12, 15, 17, 19, 21, 22, 23 (labor), and 1 day postpartum and ECM expression was analyzed by Northern blotting. ⋯ Analysis of the uterine tissue from unilaterally pregnant rats revealed that most of the changes in ECM gene expression occurred specifically in the gravid horn. Our results show a decrease in expression of fibrillar collagens and a coordinated temporal increase in expression of components of the basement membrane near term associated with decreased P4 and increased mechanical tension. These ECM changes contribute to myometrial growth and remodeling during late pregnancy and the preparation for the synchronized contractions of labor.
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Biology of reproduction · Mar 2003
A role for alphavbeta3 integrin during implantation in the rabbit model.
The study of implantation has been facilitated by the identification of specific biomarkers that are associated with uterine receptivity. The alpha(v)beta(3) integrin is a cell surface adhesion receptor, whose expression has been shown to be elevated in the endometrium at the time of implantation in both humans and other mammalian species; however, the distribution of alpha(v)beta(3) in the rabbit model is unknown. The rabbit has been shown to be an excellent model for the study of implantation. ⋯ The left horn served as a control and received only saline injections. A significant reduction in the number of implantation sites was observed in the horns receiving anti-alpha(v)beta(3) antibody (P < 0.001) and the RGD peptides (P = 0.03). In the rabbit, the alpha(v)beta(3) integrin is present on the embryo and trophoblast and appears to be involved in early embryo-maternal interaction.
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Biology of reproduction · Mar 2003
Copper-deficient rat embryos are characterized by low superoxide dismutase activity and elevated superoxide anions.
The teratogenicity of copper (Cu) deficiency may result from increased oxidative stress and oxidative damage. Dams were fed either control (8.0 microg Cu/g) or Cu-deficient (0.5 microg Cu/g) diets. Embryos were collected on Gestational Day 12 for in vivo studies or on Gestational Day 10 and cultured for 48 h in Cu-deficient or Cu-adequate media for in vitro studies. ⋯ When assessed for lipid and DNA oxidative damage, conjugated diene concentrations were similar among the groups, but a tendency was observed for Cu-deficient embryos to have higher 8-hydroxy-2'-deoxyguanosine concentrations than controls. Thus, Cu deficiency resulted in embryos with malformations and reduced SOD enzyme activity. Increased ROS concentrations in the Cu-deficient embryo may cause oxidative damage and contribute to the occurrence of developmental defects.
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Biology of reproduction · Dec 2002
Production of matrix metalloproteinase-9 in lipopolysaccharide-stimulated human amnion occurs through an autocrine and paracrine proinflammatory cytokine-dependent system.
The objective of this study was to determine the presence of autocrine/paracrine regulation of matrix metalloproteinase-9 (MMP-9) expression mediated by proinflammatory cytokines in human fetal membranes. Fetal membranes obtained from women who underwent cesarean delivery before labor were manually separated into amnion and chorion layers and maintained in culture. These explants were stimulated with tumor necrosis factor alpha (TNFalpha), interleukin-1beta (IL-1beta), and either lipopolysaccharide (LPS) alone or LPS with anti-TNFalpha or anti-IL-1beta-neutralizing antibodies. ⋯ Therefore, these data indicate that proMMP-9 is produced by the amnion but not the chorion in response to LPS. Because anti-TNFalpha-neutralizing antibody inhibits proMMP-9 activity in the amnion, TNFalpha appears to upregulate proMMP-9 production by the amnion in an autocrine fashion. Meanwhile, TNFalpha and IL-1beta produced by the chorion may upregulate amnionic proMMP-9 production in a paracrine manner.
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Biology of reproduction · Aug 2001
Expression, activity, and subcellular localization of testicular hormone-sensitive lipase during postnatal development in the guinea pig.
The present work reports on testicular hormone-sensitive lipase (HSL), the biological significance of which has been documented in male fertility. The HSL protein levels and enzymatic activity were measured, respectively, by densitometry of immunoreactive bands in Western blots, performed with antibodies against recombinant rat HSL, and by spectrophotometry in seminiferous tubules (STf) and interstitial tissue (ITf) enriched fractions generated from neonatal, pubertal, and adult guinea pig testes. In addition, HSL was studied in subcellular fractions obtained from STf isolated from adult testes and in epididymal spermatozoa (Spz). ⋯ The findings of the 104- and 120-kDa HSL immunoreactive bands and of HSL activity in Spz as well, as the detection of the 104-, 110-, and 120-kDa immunoreactive bands in lysosomes, suggest that part of HSL may originate from germ cells and be imported in Sertoli cells. The HSL protein levels and enzymatic activity in ITf and STf were positively correlated with serum testosterone levels during development. To the best of our knowledge, this study is the first to contribute insights regarding the impact of HSL on FC:EC cholesterol ratios and TG levels in the interstitial tissue and tubules in relation to serum testosterone levels during postnatal development, and regarding the immunolocalization of the enzyme in regions of the male gamete consistent with spermatozoa-oocyte interaction.