Biomedical subjects

Frederick Schatz

Publications and source records attributed to Frederick Schatz.

At least 19 recordsLinked to original sources

PubMed2006

Differential regulation of colony stimulating factor 1 and macrophage migration inhibitory factor expression by inflammatory cytokines in term human decidua: implications for macrophage trafficking at the fetal-maternal interface.

Macrophages are a major component of the leukocyte population of human pregnant endometrium. Although several crucial functions have been ascribed to these cells, the mechanisms underlying macrophage trafficking in the placental bed are poorly understood. The aim of this study was to evaluate the in vivo expression of two potentially antagonistic macrophage-targeting chemokines, colony stimulating factor 1 (CSF1, also known as M-CSF) and macrophage migration inhibitory factor (MIF), in term decidua, and to examine the effects of the inflammatory cytokines tumor necrosis factor (TNF, also known as TNF alpha) and interleukin 1beta (IL1B) on CSF1 and MIF expression in cultured decidual cells. The expression of CSF1 and MIF in term decidua was evaluated by immunohistochemistry. Cultured decidual cells were primed with estradiol (E2) or with E2+medroxyprogesterone acetate (MPA), and then incubated with corresponding steroid(s) with or without TNF or IL1B. The levels of CSF1 and MIF protein and mRNA were assessed by ELISA and quantitative RT-PCR, respectively. Immunostaining for CSF1 and MIF was observed in term decidua. The levels of secreted CSF1 and MIF were similarly unchanged whether the decidual cells were incubated with E2 or with E2+MPA. The CSF1 levels significantly increased in cultures exposed to E2 or E2+MPA plus TNF or IL1B. In contrast, the MIF levels in TNF- and IL1B-treated cells were not changed significantly from the control cultures. The ELISA data were confirmed by quantitative RT-PCR analysis. These results indicate that CSF1 and MIF are involved in regulating macrophage trafficking at the fetal-maternal interface, and suggest a mechanism by which inflammatory cytokines influence pregnancy by regulating decidual macrophage infiltration.

Cell Movement↗

PubMed2006

Tibolone exerts progestational inhibition of matrix metalloproteinase expression in human endometrial stromal cells.

Tibolone and its metabolites were evaluated on matrix metalloproteinase (MMP) expression in human endometrial stromal cells (HESCs) under the hypothesis that these steroids would act as progestins on MMP-1, -2, and -3 expression. After 7 days of priming and 24h experimental incubation of confluent cultured HESCs, 10(-7) M medroxyprogesterone acetate (P) reduced MMP-1 to 49+/-34% (p<0.05) and MMP-3 to 33+/-22% of basal levels (mean+/-S.E.M., p<0.05, n=5). Although HESCs were unaffected by 10(-8) M estradiol (E), E+P reduced MMP-1 and MMP-3 levels an additional 2.5-fold from P alone. Tibolone and Delta-4 tibolone were equivalent to E+P in inhibiting MMP-1 and MMP-3 output, whereas 10(-6)M of 3alpha-OH or 3beta-OH tibolone was required to elicit significant inhibition of both MMPs (p<0.05). By contrast, none of the treatments affected HESC-secreted MMP-2 output. The ELISA results were confirmed by Western blotting and by substrate gel zymography. Quantitative RT-PCR demonstrated corresponding changes in MMP-1 and MMP-3 mRNA levels. Inhibition of MMP-1 and MMP-3 expression by tibolone and Delta-4 tibolone is consistent with the metabolism of tibolone to Delta-4 tibolone, and subsequent binding of Delta-4 tibolone to the progesterone receptor. Since 3alpha-OH and 3beta-OH tibolone bind exclusively to the estrogen receptor, their inhibition of MMP-1 and MMP-3 suggests metabolism by HESCs to Delta-4 tibolone. These observations help to explain the paradox that the endometrium becomes atrophic after tibolone administration despite the persistence in the circulation of 3alpha-OH and 3beta-OH tibolone, but not tibolone or Delta-4 tibolone.

Cells, Cultured↗

PubMed2006

Long-term progestin-only contraceptives result in reduced endometrial blood flow and oxidative stress.

CONTEXT: Because of their safety and efficacy, long-term progestin-only contraceptives (LTPOCs) are well-suited for women with restricted access to health care. However, abnormal uterine bleeding (AUB) causes half of all users to discontinue therapy within 12 months. Endometria of LTPOC-treated patients display aberrant angiogenesis with abnormally enlarged, thin-walled, fragile blood vessels, inflammation, and focal hemorrhage. In this study, similar effects were observed with a new third-generation implantable LTPOC. OBJECTIVE: We hypothesized that LTPOC reduces uterine and endometrial blood flow, leading to hypoxia/reperfusion, which triggers the generation of reactive oxygen species. The latter induce aberrant angiogenesis, causing AUB. DESIGN: Endometrial perfusion was measured by laser-Doppler fluxmetry in women requesting LTPOCs. Endometrial biopsies were obtained for in vivo and in vitro experiments. SETTING: The study was conducted in the Yale University School of Medicine and Family-Planning Center in Western Australia. PATIENTS: Seven women 18 yr or older requesting implantable LTPOCs were recruited in Western Australia. INTERVENTION: Women received etonorgestrel implants. MAIN OUTCOME: LTPOC treatment resulted in reduced endometrial perfusion and increased endometrial oxidative damage. CONCLUSIONS: We propose that LTPOCs result in hypoxia reperfusion, which leads to aberrant angiogenesis resulting in AUB.

Adult↗

PubMed2006

Thrombin and interleukin-1beta regulate HOXA10 expression in human term decidual cells: implications for preterm labor.

CONTEXT: Preterm delivery is commonly caused by intraamniotic infection with expression of proinflammatory cytokines (IL-1beta) or by abruption resulting in generation of decidual thrombin. Although human parturition is not preceded by overt progesterone withdrawal, progesterone resistance likely leads to labor. The uteri of Hoxa10(-/-) mice demonstrate progesterone resistance; several genes, including prostaglandin receptors, are inappropriately regulated in response to progesterone. OBJECTIVE: We hypothesized that IL-1beta or thrombin would decrease HOXA10 expression, contributing to the progestin-resistant environment. We analyzed expression of HOX genes and their regulation by IL-1beta or thrombin in decidual cells. DESIGN AND SETTING: We conducted an in vitro experiment at an academic medical center. INTERVENTION: Term decidual cells were treated with estradiol (E(2)) or E(2) plus medroxyprogesterone acetate followed by addition of thrombin or IL-1beta. MAIN OUTCOME MEASURE: HOX mRNA was evaluated by microarray and confirmed by quantitative RT-PCR. Protein expression was detected using immunohistochemistry and Western analysis. RESULTS: HOXA9, HOXA10, and HOXA11 were expressed in decidual cells and regulated by IL-1beta and thrombin. HOXA10 was further analyzed because of its association with progesterone responsiveness. After E(2) treatment, IL-1beta and thrombin decreased HOXA10 mRNA by 94 and 81%, respectively. After E(2) plus medroxyprogesterone acetate treatment, IL-1beta and thrombin resulted in an 86 and 72% decrease in HOXA10 mRNA, respectively. A similar decrease was noted in HOXA10 protein expression. CONCLUSION: The expression of HOXA10 protein at term indicates that it may have a role in maintaining decidual cell phenotype and pregnancy. The dramatic decrease of HOXA10 in response to IL-1beta or thrombin may contribute to progestin resistance in preterm labor, mimicking progesterone resistance seen in Hoxa10(-/-) mice.

Cells, Cultured↗

PubMed2006

Intercellular adhesion molecule-1 expression in human endometrium: implications for long term progestin only contraception.

BACKGROUND: Neutrophils infiltrate the endometrium pre-menstrually and after long-term progestin only-contraceptive (LTPOC) treatment. Trafficking of neutrophils involves endothelial cell-expressed intercellular adhesion molecule (ICAM-1). Previous studies observed that ICAM-1 was immunolocalized to the endothelium of endometrial specimens across the menstrual cycle, but disagreed as to whether extra-endothelial cell types express ICAM-1 and whether ICAM-1 expression varies across the menstrual cycle. METHODS: Endometrial biopsies were obtained from women across the menstrual cycle and from those on LTPOC treatment (either Mirena or Norplant). The biopsies were formalin-fixed and paraffin-embedded with subsequent immunohistochemical staining for ICAM-1. RESULTS: The current study found prominent ICAM-1 staining in the endometrial endothelium that was of equivalent intensity in different blood vessel types irrespective of the steroidal or inflammatory endometrial milieu across the menstrual cycle and during LTPOC therapy. Unlike the endothelial cells, the glands were negative and the stromal cells were weakly positive for ICAM immunostaining. CONCLUSION: The results of the current study suggest that altered expression of ICAM-1 by endothelial cells does not account for the influx of neutrophils into the premenstrual and LTPOC-derived endometrium. Such neutrophil infiltration may depend on altered expression of neutrophil chemoattractants.

Adult↗

PubMed2006

Gonadotropin stimulation of steroid synthesis and metabolism in the Rana pipiens ovarian follicle: sequential changes in endogenous steroids during ovulation, fertilization and cleavage stages.

Steroid synthesis and metabolism have been followed in Rana pipiens ovarian follicles, denuded oocytes and eggs during ovulation, fertilization and cleavage stages (blastula formation). Under physiological conditions, gonadotropin stimulation of the fully grown follicle leads to progesterone synthesis from [(3)H]acetate as well as formation of much smaller amounts of 17alpha-hydroxyprogesterone, androstenedione, pregnanedione and pregnanediol. Progesterone levels increase during completion of the first meiotic division, but by ovulation progesterone disappears from the egg. Plasma membrane-bound progesterone is taken up into the oocyte cortical granules and is largely metabolized to 5alpha-pregnane-3alphaol,20-one and 5beta-pregnane-3alpha,17alpha,20beta-triol coincident with internalization of 60% of the oocyte surface (and >90% of bound progesterone) by the end of the hormone-dependent period. The principal steroid in the ovulated egg is 5beta-pregnane-3alpha,17alpha,20beta-triol. There is a rapid efflux of 5beta-pregnane-3alpha,17alpha,20beta-triol into the medium immediately following fertilization and residual steroid levels remain low in the developing blastula. Dissociated blastulae cells prepared from stage 9 1/2 embryos concentrate both pregnenolone and progesterone from the medium with minimal metabolism. The results indicate that the ovarian follicle has the ability to synthesize and metabolize progesterone but that this ability disappears in the ovulated egg. The progesterone metabolites formed during meiosis are largely released at fertilization.

17-alpha-Hydroxyprogesterone↗

PubMed2006

Regulation of monocyte chemoattractant protein-1 expression by tumor necrosis factor-alpha and interleukin-1beta in first trimester human decidual cells: implications for preeclampsia.

The current study describes a statistically significant increase in macrophages (CD68-positive cells) in the decidua of preeclamptic patients. To elucidate the regulation of this monocyte infiltration, expression of monocyte chemoattractant protein-1 (MCP-1) was assessed in leukocyte-free first trimester decidual cells. Confluent decidual cells were primed for 7 days in either estradiol or estradiol plus medroxyprogesterone acetate to mimic the decidualizing steroidal milieu of the luteal phase and early pregnancy. The medium was exchanged for a serum-free defined medium containing corresponding steroids +/- tumor necrosis factor (TNF)-alpha or interleukin (IL)-1beta. After 24 hours, enzyme-linked immunosorbent assay measurements indicated that the addition of medroxyprogesterone acetate did not affect MCP-1 output, whereas 10 ng/ml of TNF-alpha or IL-1beta increased output by 83.5-fold +/- 20.6 and 103.1-fold +/- 14.7, respectively (mean +/- SEM, n = 8, P < 0.05). Concentration-response comparisons revealed that even 0.01 ng/ml of TNF-alpha or IL-1beta elevated MCP-1 output by more than 15-fold. Western blotting confirmed the enzyme-linked immunosorbent assay results, and quantitative reverse transcriptase-polymerase chain reaction confirmed corresponding effects on MCP-1 mRNA levels. The current study demonstrates that TNF-alpha and IL-1beta enhance MCP-1 in first trimester decidua. This finding suggests a mechanism by which recruitment of excess macrophages to the decidua impairs endovascular trophoblast invasion, the primary placental defect of preeclampsia.

Antineoplastic Agents, Hormonal↗

PubMed2006

Tumor necrosis factor-alpha and interleukin-1beta regulate interleukin-8 expression in third trimester decidual cells: implications for the genesis of chorioamnionitis.

Chorioamnionitis is associated with intense neutrophil infiltration of the decidua. We therefore determined whether chorioamnionitis enhances decidual interleukin-8 (IL-8) expression and examined cytokine-regulated decidual IL-8 expression. Decidua from chorioamnionitis-complicated pregnancies, but not term controls, displayed marked IL-8 immunohistochemical staining and a dense neutrophil infiltrate. Reverse transcriptase-polymerase chain reaction of microdissected decidual cells identified IL-8 mRNA, confirming decidual synthesis of IL-8. Confluent leukocyte-free term decidual cells were primed with 10(-8) mol/L estradiol (E2) or E2 + 10(-7) mol/L medroxyprogesterone acetate to mimic the steroidal milieu of pregnancy. Compared with cultures maintained in E2 alone, E2 + medroxyprogesterone acetate neither significantly affected IL-8 levels nor altered the response to the cytokines. The addition of 1.0 ng/ml tumor necrosis factor-alpha (TNF-alpha) or interleukin-1 beta (IL-1beta) increased IL-8 secretion levels by 236.6 +/- 51.4- and 1062.6 +/- 254.3-fold, respectively (n = 8, mean +/- SEM, P < 0.05), as measured by enzyme-linked immunosorbent assay. Concentration-response studies revealed that 0.01 ng/ml TNF-alpha and IL-1beta elevated IL-8 output by 10- and 100-fold, respectively. Western blotting confirmed these results, and quantitative reverse transcriptase-polymerase chain reaction demonstrated parallel changes in mRNA levels. In conclusion, IL-8 is strongly expressed in term decidua during chorioamnionitis, and TNF-alpha and IL-1beta enhance IL-8 expression in term decidual cells, suggesting that these cytokines are important regulators of chorioamnionitis-related decidual neutrophil infiltration.

Cells, Cultured↗

PubMed2005

Progestin suppresses thrombin- and interleukin-1beta-induced interleukin-11 production in term decidual cells: implications for preterm delivery.

CONTEXT: Decidual inflammation and hemorrhage are major contributors to the pathogenesis of preterm delivery (PTD). IL-11 is a cytokine with pleiotropic biological effects, including induction of T helper cell type 2 and inhibition of T helper cell type 1 cytokine responses. Paradoxically, it enhances the synthesis of prostaglandins, which induce labor. OBJECTIVE: The objectives of this study were to evaluate in vivo IL-11 expression in decidua after term and preterm deliveries and evaluate the effects of the primary mediators of inflammation, IL-1beta and TNF-alpha, as well as the primary regulator of hemostasis, thrombin, on IL-11 expression in cultured term decidual cells (DCs). INTERVENTIONS AND MAIN OUTCOME MEASURES: Human decidua from uncomplicated term deliveries and chorioamnionitis- or placental abruption-related PTDs were immunostained for IL-11. Cultures of DCs were primed with estradiol (E2) or with E2 and medroxyprogesterone acetate (MPA), then incubated in a defined medium with corresponding steroid(s) with or without IL-1beta, TNF-alpha, or thrombin. IL-11 levels in DC-defined media were assessed by ELISA and Western blotting; IL-11 mRNA levels were measured by quantitative RT-PCR. RESULTS: IL-11 immunostaining was significantly higher in DCs after PTD compared with those after term delivery (P < 0.05). In the absence of cytokines or thrombin, IL-11 levels in the defined medium were 47% lower in incubations with E2 plus MPA vs. E2 alone (P = 0.001). IL-1beta and thrombin elevated IL-11 output during incubations with E2 [24-fold (P < 0.05) and 120-fold (P < 0.05), respectively]. These increases were blunted by the addition of MPA [13-fold (P < 0.05) and 36-fold (P < 0.05), respectively]. Western blot analysis confirmed the ELISA results, and RT-PCR demonstrated corresponding effects on IL-11 mRNA levels. Unexpectedly, TNF-alpha did not affect IL-11 levels. CONCLUSION: Because excess IL-1beta and thrombin generation are associated with chorioamnionitis- and abruption-related PTD, respectively, these findings add to our understanding of the genesis of inflammation- and abruption-associated prematurity.

Cells, Cultured↗

PubMed2005

Inflammatory cytokine and thrombin regulation of interleukin-8 and intercellular adhesion molecule-1 expression in first trimester human decidua.

CONTEXT: Decidual neutrophil infiltration complicates spontaneous abortions associated with inflammation and hemorrhage. Transendothelial neutrophil migration into inflamed tissues involves IL-8-mediated chemoattraction, then neutrophil attachment to endothelial cell-expressed intercellular adhesion molecule-1 (ICAM-1). OBJECTIVE: The aim of this study was to assess IL-8 and ICAM-1 regulation in decidual inflammation and hemorrhage; the effects of the proinflammatory cytokines, TNFalpha, IL-1beta and the hemostatic, proinflammatory cytokine thrombin were measured on IL-8 expression in first trimester decidual cells (DCs), and ICAM-1 immunostaining was compared in normal, inflamed, and hemorrhagic first trimester decidua. DESIGN: Immunohistochemistry of human decidua and in vitro treatment of human decidual cells were performed. SETTING: The study was conducted at the Academic Medical Center. INTERVENTION: . DCs were passaged until they were leukocyte-free (CD45 free by FACS), then were incubated with estradiol or medroxyprogesterone acetate alone or with TNFalpha or IL-1beta or thrombin. Normal, inflamed, and hemorrhagic decidua were immunostained for ICAM-1 and the neutrophil marker CD14. MAIN OUTCOME MEASURE: ICAM-1 immunostaining was performed in decidua. IL-8 levels in DC-conditioned media were assessed by ELISA and immunoblotting; IL-8 mRNA levels were measured by quantitative RT-PCR. RESULTS: Endothelial cell ICAM-1 immunostaining was similar in normal and inflamed or hemorrhagic decidua. In cultured DCs, optimal concentrations of IL-1beta, TNFalpha, and thrombin elevated secreted IL-8 levels by 1083 +/- 261-, 370 +/- 77-, and 45 +/- 15-fold, respectively (mean +/- SEM; P < 0.05; n = 8). The effects were dose dependent and were unaffected by medroxyprogesterone acetate. Western blotting confirmed the ELISA results, and corresponding effects on IL-8 mRNA levels were observed. CONCLUSIONS: Cytokine/thrombin-enhanced DC IL-8 expression interacts with constitutively expressed ICAM-1 in decidual endothelium to modulate neutrophil trafficking into hemorrhagic and inflamed first trimester decidua.

Cells, Cultured↗

PubMed2005

Tibolone and its metabolites enhance tissue factor and PAI-1 expression in human endometrial stromal cells: Evidence of progestogenic effects.

Tibolone is a highly effective postmenopausal hormone treatment that has its biological activity dependent on metabolism to 3alpha- and 3beta-OH tibolone, which bind solely to the estrogen receptor. Despite the high levels of estrogen receptor-binding metabolites in the circulation, the endometrium becomes atrophic, suggesting inactivation of the estrogen response in this tissue which may be due to the progestogenic activity of tibolone and the Delta-4 tibolone metabolite. We evaluated the effects of tibolone and its metabolites on tissue factor (TF) and plasminogen activator inhibitor type 1 (PAI-1) expression in human endometrial stromal cells (HESCs). Since TF and PAI-1 exhibit long-term in vivo and in vitro up-regulation by progestin they serve as endpoints for assessing chronic effects of progestin exposure. Confluent HESCs were primed in serum-containing medium with vehicle control, 10(-8)mol/L estradiol, 10(-7)mol/L medroxyprogesterone acetate, or 10(-8) to 10(-6)mol/L tibolone or its metabolites, then switched to a defined medium with corresponding vehicle or steroids. After 24h, ELISAs indicated that the progestin elevated TF (6.2-fold +/-3.0; p<0.05) and PAI-1 (eight-fold +/-2.1; p<0.05) levels, whereas the cells were refractory to estradiol exposure. Tibolone and Delta-4 tibolone (10(-8) to 10(-6)mol/L) were as effective as 10(-7)mol/L medroxyprogesterone acetate in enhancing TF and PAI-1 output (p<0.05). Unexpectedly, at the higher concentrations 3alpha- and 3beta-OH tibolone also elevated TF and PAI-1 expression (p<0.05). Western blotting confirmed the ELISA results. Our findings suggest that HESCs metabolize 3alpha- and 3beta-OH tibolone to tibolone and subsequently to Delta-4 tibolone, which can both stimulate the progesterone receptor. Since TF and PAI-1 promote hemostasis by complementary mechanisms, our findings account for the reduced occurrence of abnormal uterine bleeding associated with tibolone therapy.

Androgen Antagonists↗

PubMed2005

Mechanisms of abruption-induced premature rupture of the fetal membranes: thrombin-enhanced interleukin-8 expression in term decidua.

Recent evidence has linked preterm premature rupture of the fetal membranes (PPROM) to placental abruption. Because neutrophils are a rich source of proteases that can degrade extracellular matrix in abruption-associated PPROM, we examined whether decidual neutrophil infiltration complicates abruption-associated PPROM. Accordingly, immunostaining for the neutrophil marker CD15 was performed in placentas obtained after overt abruption (decidual hemorrhage) with or without PPROM and in control placentas. Abruptions were associated with a marked decidual neutrophil infiltration that peaked after PPROM, whereas decidua from gestational age-matched controls were virtually devoid of neutrophils. Neutrophil infiltrates co-localized with fibrin deposition. Because abruptions elicit intense decidua-enhanced thrombin production, we examined the regulation of abruption-induced neutrophil infiltration. Expression of the primary neutrophil chemoattractant interleukin-8 (IL-8) was evaluated in leukocyte-free term decidual cells incubated with estradiol (E2; control) or with E2+medroxyprogesterone acetate (to mimic pregnancy)+/-thrombin. After 24 hours, enzyme-linked immunosorbent assay measurements indicated that thrombin (0.1 to 2.5 U/ml) elicited a dose-dependent elevation in secreted IL-8 (P<0.05) with 2.5 U/ml of thrombin increasing IL-8 levels by >14-fold in E2 and E2+medroxyprogesterone incubations. Results were validated by Western blot and quantitative reverse transcriptase-polymerase chain reaction. In summary, thrombin-enhanced IL-8 expression in term decidual cells may explain how abruption-associated PPROM promotes decidual neutrophil infiltration.

Abruptio Placentae↗

PubMed2004

Endometrial endothelial cell steroid receptor expression and steroid effects on gene expression.

Controversy exists regarding the expression of specific steroid receptor proteins and mRNA in human microvascular endometrial endothelial cells (HEECs). Thus, we studied steroid receptor expression in early passaged HEEC cultures and freshly isolated HEECs. Analysis of estrogen receptor (ER) and progesterone receptor (PR) mRNA levels was carried out with real-time quantitative RT-PCR, and the repertoire of genes activated by their respective steroid ligands was assessed by mRNA microarray analyses of 18,400 genes and expressed sequence tags. We observed that cultured and freshly isolated HEECs each express ER-beta mRNA but not ER-alpha. In addition, PR mRNA was also detectable in both HEEC sources. Microarray analysis demonstrated that treatment of HEEC cultures with either estradiol or medroxyprogesterone acetate produced differential effects on a wide variety of genes, and cluster analysis demonstrated that many of the genes are involved in intracellular signaling and enzymatic pathways. Thus, quantitative RT-PCR and microarray analyses demonstrate that HEECs express ER-beta and PR mRNA and that gene expression by HEECs is differentially regulated by treatment with estrogen or progestin.

Cells, Cultured↗

PubMed2004

A novel immortalized human endometrial stromal cell line with normal progestational response.

Obtaining primary human endometrial stromal cells (HESCs) for in vitro studies is limited by the scarcity of adequate human material and the inability to passage these cells in culture for long periods. Immortalization of these cells would greatly facilitate studies; however, the process of immortalization often results in abnormal karyotypes and aberrant functional characteristics. To meet this need, we have introduced telomerase into cultured HESCs to prevent the normal shortening of telomeres observed in adult somatic cells during mitosis. We have now developed and analyzed a newly immortalized HESC line that contains no clonal chromosomal structural or numerical abnormalities. In addition, when compared with the primary unpassaged parent cells, the new cell line displayed similar biochemical endpoints after treatment with ovarian steroids. Classical decidualization response to estradiol plus medroxyprogesterone acetate were seen in both morphologically, and progestin was seen to induce or regulate the expression of IGF binding protein-1, fibronectin, prolactin, tissue factor, plasminogen activator inhibitor-1, and Fas/Fas ligand. In summary, an immortalized HESC line has been developed that is karyotypically, morphologically, and phenotypically similar to the primary parent cells, and it is a powerful and consistent resource for in vitro work.

Cell Line, Transformed↗

PubMed2004

Mechanisms of abruption-induced premature rupture of the fetal membranes: Thrombin enhanced decidual matrix metalloproteinase-3 (stromelysin-1) expression.

OBJECTIVE: The aim of the study was to evaluate thrombin and progestin effects on matrix metalloproteinase-3 expression in term decidual cells as a mechanism of abruption-related preterm delivery. STUDY DESIGN: Decidual cells were isolated by standard techniques, purified to homogeneity, grown to confluence, and passaged. Cultures were primed with 10 (-8) M estradiol or estradiol plus 10 (-7) progestin and then incubated in a defined medium with corresponding steroid(s) plus or minus thrombin or the protease-activated thrombin receptor-1 agonist for 24 hours. Secreted matrix metalloproteinase-3 levels were assessed by enzyme-linked immunosorbent assay, and immunoblotting and messenger RNA levels were measured by Northern blotting and quantitative reverse transcription-polymerase chain reaction. RESULTS: Immunoreactive matrix metalloproteinase-3 levels were inhibited 66% by estradiol plus progestin versus estradiol ( P < .05). Thrombin elicited a dose-dependent reversal in this progestin inhibition, producing a 2.5-fold increase at 2.5 U/mL ( P < .05) that attained 33% of matrix metalloproteinase-3 levels in parallel incubations with estradiol plus thrombin. Protease-activated thrombin receptor-1 agonist mimicked 60% of thrombin-enhanced matrix metalloproteinase-3 output. Immunoblotting validated the enzyme-linked immunosorbent assay results. Northern blotting and quantitative reverse transcription-polymerase chain reaction demonstrated corresponding effects on steady-state messenger RNA levels. CONCLUSION: Abruption-generated thrombin promotes preterm delivery by mediating fetal membrane extracellular matrix degradation via enhanced decidual cell matrix metalloproteinase-3 expression, whereas progesterone blunts this thrombin-induced effect.

Base Sequence↗

PubMed2004

Endometrial angiopoietin expression and modulation by thrombin and steroid hormones: a mechanism for abnormal angiogenesis following long-term progestin-only contraception.

The angiopoietins (Ang) are endothelial cell-related factors necessary for the development and maintenance of all vessels. Altering the expression of these proteins would be expected to result in aberrant angiogenesis. Indeed the fragile endometrial vasculature and bleeding observed in women treated with long-term progestin-only contraceptives has been associated with changes in the expression of Ang-1 and Ang-2. Since bleeding would result in thrombin formation, we have assessed the effects of thrombin on the expression of the Angs in human endometrial cells. This study shows that thrombin significantly reduces the expression of Ang-1 protein and mRNA expression in human endometrial stromal cells (HESCs) and minimally decreases the production of Ang-2 protein in human endometrial endothelial cells (HEECs). Hence the presence of thrombin due to aberrant bleeding could affect the angiogenic potential of the endometrium, creating a feed forward loop resulting in more thrombin, weak vasculature, and more bleeding. In addition, since the exact localization of Ang in the human endometrium remains a subject of controversy, we have addressed this issue in an in vivo system by analyzing the expression of Angs by microdissection of HESCs, HEECs, and human endometrial glandular epithelial cells followed by real time, quantitative RT-PCR.

Angiopoietin-1↗

PubMed2004

Effects of thrombin, hypoxia, and steroids on interleukin-8 expression in decidualized human endometrial stromal cells: implications for long-term progestin-only contraceptive-induced bleeding.

Abnormal uterine bleeding is the major reason for discontinuing long-term progesterone-only contraceptives (LTPOCs). Prior studies demonstrated that endometria exposed to the LTPOC, Norplant, display aberrant angiogenesis, leukocyte infiltration, and hypoxia-associated impaired blood flow. Paradoxically, human endometrial stromal cells (HESCs) of these specimens exhibit elevated expression of tissue factor (TF), the primary initiator of hemostasis via thrombin generation. The current study demonstrates that TF levels are also elevated in HESCs that are decidualized after insertion of Mirena, an intrauterine system that releases levonorgestrel directly into the endometrial canal and produces elevated perivascular levels of the proinflammatory and angiognenic cytokine IL-8. Because bleeding, inflammation, and ischemia-associated increased vascular permeability enhance access of plasma factor VII to HESC-expressed TF to generate thrombin, we evaluated the effects of steroids, thrombin, and hypoxia on HESC expression of IL-8. Confluent HESCs were incubated in a serum-containing medium for 7 d with vehicle control or estradiol (E(2)) plus medroxyprogesterone acetate (MPA). The medium was then exchanged for corresponding defined medium with and without thrombin, and the cultures were incubated in parallel for up to 48 h in a standard incubator (normoxia) or a sealed chamber at 0-1% O(2) (hypoxia). Under normoxia, immunoreactive IL-8 levels in the conditioned medium were reduced to one-third of control levels during decidualization with E(2)+MPA (P < 0.05; n = 5). In E(2)+MPA-treated cultures, thrombin (0.1 U/ml to 2.5 U/m) elicited a dose-dependent reversal of this inhibition, elevating IL-8 up to 60-fold (P < 0.05; n = 5) for more than 24 h and steady-state IL-8 mRNA levels by 3-fold for 3 h. The specific inactivator, hirudin, blocked most of the effects of thrombin, whereas TRAP-14, an agonist of the protease-activated receptor for thrombin, enhanced IL-8 output. In the absence of thrombin, hypoxia elevated IL-8 output 5-fold in E(2)+MPA-treated HESCs (P < 0.02, n = 4), with thrombin exerting additive effects. In contrast to its effects in progestin-treated HESCs, hypoxia did not elevate IL-8 output in control cultures. This study suggests that inhibition of IL-8 expression in decidualized HESCs contributes to the antiinflammatory milieu of the luteal phase. However, LTPOC-induced hypoxia and excess thrombin generation enhance IL-8 expression in decidualized HESCs, thereby eliciting aberrant angiogenesis and inflammation that promote the onset of abnormal uterine bleeding.

Cells, Cultured↗

PubMed2003

Human decidual natural killer cells are a unique NK cell subset with immunomodulatory potential.

Natural killer cells constitute 50-90% of lymphocytes in human uterine decidua in early pregnancy. Here, CD56(bright) uterine decidual NK (dNK) cells were compared with the CD56(bright) and CD56(dim) peripheral NK cell subsets by microarray analysis, with verification of results by flow cytometry and RT-PCR. Among the approximately 10,000 genes studied, 278 genes showed at least a threefold change with P < or = 0.001 when comparing the dNK and peripheral NK cell subsets, most displaying increased expression in dNK cells. The largest number of these encoded surface proteins, including the unusual lectinlike receptors NKG2E and Ly-49L, several killer cell Ig-like receptors, the integrin subunits alpha(D), alpha(X), beta1, and beta5, and multiple tetraspanins (CD9, CD151, CD53, CD63, and TSPAN-5). Additionally, two secreted proteins, galectin-1 and progestagen-associated protein 14, known to have immunomodulatory functions, were selectively expressed in dNK cells.

CD56 Antigen↗