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1.
Placenta ; 35(9): 763-71, 2014 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-25002363

RESUMO

INTRODUCTION: Shallow trophoblast invasion of the maternal spiral arteries contributes to impaired placental perfusion and is hypothesized to be involved in the pathophysiology of preeclampsia. Hypoxia is a potent stimulus for the release of adenosine. METHODS: We investigated the effects of hypoxia and A2B adenosine receptor signaling on migration, invasion, proteolytic activity of matrix metalloproteinase (MMP)-2, expression of MMP-2 and vascular endothelial growth factor (VEGF) mRNA, and production of human chorionic gonadotropin (hCG) in trophoblast cells (HTR-8/SVneo, BeWo). RESULTS: The adenosine A2B receptor agonist 5-N-ethylcarboxamidoadenosine (NECA) reduced trophoblast (HTR-8/SVneo and BeWo) migration at 2%, 8% and 21% O2 compared to untreated control cells. A2B adenosine receptor stimulation decreased phosphorylation of extracellular signal-regulated kinases 1 and 2 (ERK1/2) and stress-activated protein kinase/Jun-amino-terminal kinase (SAPK/JNK) at all three O2 concentrations. ProMMP-2 activity, MMP-2 mRNA levels and hCG levels were markedly decreased after A2B adenosine receptor activation in trophoblast cells. Adenosine receptor A2B stimulation decreased VEGF expression at 2% and 8% O2 but led to increased levels at 21% O2. CONCLUSIONS: These data indicate A2B receptor activation blunts trophoblast migration possibly as a result of reduced activation of the MAPK signaling pathway and lower proMMP-2 levels. These data suggest a role for adenosine receptor A2B in placental development and possibly in the pathophysiology of preeclampsia.


Assuntos
Sistema de Sinalização das MAP Quinases , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Receptor A2B de Adenosina/metabolismo , Trofoblastos/metabolismo , Linhagem Celular , Movimento Celular , Gonadotropina Coriônica/metabolismo , Feminino , Humanos , Metaloproteinase 2 da Matriz/metabolismo , Oxigênio/metabolismo , Pré-Eclâmpsia/etiologia , Gravidez , Fator A de Crescimento do Endotélio Vascular/metabolismo
2.
Placenta ; 30(5): 434-42, 2009 May.
Artigo em Inglês | MEDLINE | ID: mdl-19303140

RESUMO

Placental hypoxia as a result of impaired trophoblast invasion is suggested to be involved in the pathophysiology of preeclampsia. Hypoxia is a potent stimulus for the release of adenosine, and the actions of adenosine are mediated through four adenosine receptors, A(1), A(2A), A(2B) and A(3). We investigated the presence, distribution and expression of adenosine receptor subtypes in the human placenta, the expression of the adenosine receptors in placentas from pregnancies complicated by preeclampsia, small for gestational age (SGA) infants and uncomplicated pregnancies, and the effect of hypoxia on placental adenosine receptor expression. Immunofluorescent microscopy localized A(1), A(2A), A(2B) and A(3) adenosine receptors to the syncytiotrophoblast, endothelial cells and myofibroblasts within the human placenta. Adenosine receptor protein and message expression levels were significantly higher in placentas from preeclamptic pregnancies with or without SGA infants, but not different in pregnancies with SGA infants alone. In vitro exposure of placental villous explants to hypoxia (2% oxygen) increased the expression of A(2A) adenosine receptor 50%. These data indicate that all four known adenosine receptors are expressed in the human placenta and adenosine receptor expression is significantly higher in pregnancies complicated by preeclampsia. These data are consistent with the hypothesis that differences in placental adenosine receptors may contribute to alterations in placental function in preeclampsia.


Assuntos
Hipóxia/metabolismo , Placenta/metabolismo , Pré-Eclâmpsia/metabolismo , Receptor A2A de Adenosina/biossíntese , Receptores Purinérgicos P1/genética , Adulto , Feminino , Humanos , Recém-Nascido , Recém-Nascido Pequeno para a Idade Gestacional , Gravidez
3.
Placenta ; 30(4): 361-7, 2009 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-19203792

RESUMO

BACKGROUND: Amino acids are important nutrients during fetal development, and the activity of placental amino acid transporters is crucial in the regulation of fetal growth. Leptin, an adipocyte- and placenta-derived hormone, has been proposed to act as a peripheral signal in reproduction in humans. Leptin is elevated during pregnancy and elevated further in pathologic pregnancies such as preeclampsia. However, the role of leptin in placental function has not been fully elucidated. We hypothesize that leptin plays a role in the regulation of placental amino acid transport by activation of the JAK-STAT pathway. METHODS: Placental amino acid transport, specifically system A transport was studied in placental villous fragments using the amino acid analog, methylaminoisobutyric acid (MeAIB). Specific inhibitors of the JAK-STAT signal transduction pathway were used to further elucidate their role in leptin-mediated effects on amino acid transport activity. Western blotting was performed to identify STAT3 phosphorylation as a measure of leptin receptor activation. RESULTS: Leptin significantly increased system A amino acid transporter activity by 22-42% after 1h of incubation. Leptin activated JAK-STAT signaling pathway as evidenced by STAT3 phosphorylation, and inhibition of STAT3 or JAK2 resulted in 36-45% reduction in system A amino acid transporter activity. Furthermore, blocking endogenously produced leptin also decreased system A transport by 45% comparable to STAT3 inhibition. CONCLUSIONS: These data demonstrate that leptin stimulates system A by JAK-STAT dependent pathway in placental villous fragments. Our findings support the autocrine/paracrine role of leptin in regulating amino acid transport in the human placenta.


Assuntos
Sistema A de Transporte de Aminoácidos/metabolismo , Leptina/farmacologia , Placenta/efeitos dos fármacos , Placenta/metabolismo , Fator de Transcrição STAT3/metabolismo , Vilosidades Coriônicas/efeitos dos fármacos , Vilosidades Coriônicas/metabolismo , Feminino , Humanos , Técnicas In Vitro , Janus Quinases/metabolismo , L-Lactato Desidrogenase/metabolismo , Leptina/metabolismo , Fosforilação , Gravidez , Transdução de Sinais/efeitos dos fármacos
4.
Placenta ; 30(1): 25-34, 2009 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-19010535

RESUMO

Pregnant women who develop preeclampsia exhibit higher circulating levels of the soluble VEGF receptor-1 (sFlt-1). Recent findings suggest that soluble Flt-1 may contribute to the pathogenesis of preeclampsia by binding and neutralizing vascular endothelial growth factors (VEGF) and placental growth factor (PlGF). Existing literature identifies sFlt-1 as a 100 kDa glycoprotein, a product of an mRNA splice variant. We hypothesized that sFlt-1 expression may be more complex with multiple variants of sFlt-1 as well as multiple sources during normal pregnancy and preeclampsia. Using a combination of affinity purification of sFlt-1 by heparin-agarose and epitope specific antibodies, we performed Western blot analysis with epitope specific antibodies for sFlt-1. Plasma of preeclamptic women exhibits significantly higher amounts of a novel 145 kDa variant of sFlt-1, along with the 100 kDa isoform. We identified sFlt-1 variants in the conditioned medium from placental explant cultures that are hypoxia responsive with varying sizes, including 185, 145,100 and 60 kDa forms, as well as antigenicity. The 145 kDa was similar in antigenicity to the 100 kDa found in plasma whereas the 185 and 60 kDa sFlt-1 demonstrated different epitopes. Deglycosylation studies also confirm that there are multiple sFlt-1 polypeptides. Co-immunoprecipitation with VEGF suggests that these different sFlt isoforms can bind VEGF and therefore, may be of functional importance. Finally, comparison of sFlt-1 in the conditioned medium obtained from cultured cytotrophoblasts, peripheral blood mononuclear cells (PBMCs) and human uterine microvascular cells (HUtMVECs) exhibit mainly the100 kDa sFlt-1. Collectively these data suggest the presence of multiple isoforms of sFlt-1 in the circulation of women with preeclampsia as well as in uncomplicated pregnancies and the possibility of multiple sources. Placental hypoxia may contribute to sFlt-1 over expression but other regulatory mechanisms cannot be ruled out.


Assuntos
Vilosidades Coriônicas/metabolismo , Pré-Eclâmpsia/sangue , Receptor 1 de Fatores de Crescimento do Endotélio Vascular/sangue , Adulto , Western Blotting , Células Cultivadas , Meios de Cultivo Condicionados/química , Meios de Cultivo Condicionados/metabolismo , Células Endoteliais/metabolismo , Feminino , Idade Gestacional , Humanos , Pessoa de Meia-Idade , Técnicas de Cultura de Órgãos , Gravidez , Ligação Proteica , Isoformas de Proteínas/análise , Isoformas de Proteínas/sangue , Fator A de Crescimento do Endotélio Vascular/metabolismo , Receptor 1 de Fatores de Crescimento do Endotélio Vascular/análise
5.
Placenta ; 29(10): 879-82, 2008 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-18718657

RESUMO

Preeclampsia and intrauterine growth restriction (IUGR) are both associated with abnormal remodeling of maternal spiral arteries perfusing the placental site. This would be expected to be associated with reduced fetal growth, yet only one third of infants of mothers with preeclampsia are growth restricted. Infants with IUGR have decreased concentrations of amino acids in their blood and system A amino acid transporter activity is reduced in their placentas. Since infants of preeclamptic pregnancies have increased circulating amino acids, we tested system A amino acid transport activity of placental villous fragments from pregnancies with small for gestational age (SGA) infants with and without maternal preeclampsia and from uncomplicated and preeclamptic pregnancies with normal sized infants. We confirm the reduced uptake of amino acids in SGA pregnancies without preeclampsia but report that placental amino acid uptake of SGA infants with maternal preeclampsia is not reduced and is identical to uptake by normal and preeclamptic pregnancies with normal weight infants.


Assuntos
Sistema A de Transporte de Aminoácidos/metabolismo , Recém-Nascido Pequeno para a Idade Gestacional , Placenta/metabolismo , Pré-Eclâmpsia/metabolismo , Adulto , Feminino , Humanos , Recém-Nascido , Gravidez
6.
Mol Hum Reprod ; 12(9): 551-6, 2006 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-16870954

RESUMO

Leptin, an adipocyte hormone involved in energy homeostasis, is important in reproduction and pregnancy. Questions yet to be addressed include the source of higher leptin during pregnancy and its relationship to pregnancy outcome and fetal growth. The objective of this study was to investigate the relationship between placental leptin gene expression, placental leptin protein concentration and maternal plasma leptin concentration among control pregnant women, women with pre-eclampsia and women with growth-restricted infants. We also investigated the relationship between placental leptin expression and the placental expression of enzymes involved in cellular lipid balance: fatty acid translocase (CD36), carnitine palmitoyltransferase I (CPT-1B) and lipoprotein lipase (LPL). Placental leptin expression, placental protein and maternal plasma concentration were higher in pre-eclampsia than in controls but not in women with growth-restricted infants. Placental leptin expression and placental protein were higher in the preterm pre-eclamptic subjects, whereas maternal leptin was higher in the term pre-eclamptic subjects. The placental gene expression of CD36, CPT-1B and LPL were not different among the groups. This study suggests that despite similar failed placental bed vascular remodelling in pre-eclampsia and intrauterine growth restriction (IUGR), leptin gene expression is higher only in preterm pre-eclampsia.


Assuntos
Retardo do Crescimento Fetal/metabolismo , Leptina/metabolismo , Placenta/metabolismo , Pré-Eclâmpsia/metabolismo , Gravidez/metabolismo , RNA Mensageiro/metabolismo , Adulto , Antígenos CD36/genética , Antígenos CD36/metabolismo , Carnitina O-Palmitoiltransferase/genética , Carnitina O-Palmitoiltransferase/metabolismo , Feminino , Retardo do Crescimento Fetal/sangue , Humanos , Recém-Nascido , Recém-Nascido Prematuro , Leptina/sangue , Leptina/genética , Lipase Lipoproteica/metabolismo , Troca Materno-Fetal , Pré-Eclâmpsia/sangue , Gravidez/sangue , Receptores para Leptina , Estudos Retrospectivos
7.
Am J Obstet Gynecol ; 193(1): 185-91, 2005 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-16021077

RESUMO

OBJECTIVE: We measured maternal serum soluble fms-like tyrosine kinase 1 concentrations across pregnancy and immediately postpartum in women who developed preeclampsia and normal pregnant women. STUDY DESIGN: This was a nested case control study of 113 normal pregnant women and 55 women with preeclampsia. RESULTS: Serum soluble fms-like tyrosine kinase 1 concentrations increased similarly in early pregnancy in both groups. Mean serum soluble fms-like tyrosine kinase 1 concentrations were increased in women who developed preeclampsia, compared with normal pregnant women, and this increase was most pronounced in severe preeclampsia. However, many women with preeclampsia had soluble fms-like tyrosine kinase 1 concentrations similar to normal pregnant women. Lastly, soluble fms-like tyrosine kinase 1 decreased rapidly after delivery, but this decrease was significantly slower in women with severe preeclampsia. CONCLUSION: Increased soluble fms-like tyrosine kinase 1 is not an early-pregnancy event among women who later develop preeclampsia. Increased soluble fms-like tyrosine kinase 1 is more likely to be present in women with severe preeclampsia, but it is not present in all women with preeclampsia. Soluble fms-like tyrosine kinase 1 concentrations decrease more slowly after delivery in women with preeclampsia, consistent with a decreased rate of excretion or continued production.


Assuntos
Período Pós-Parto/sangue , Pré-Eclâmpsia/sangue , Primeiro Trimestre da Gravidez/sangue , Gravidez/sangue , Receptor 1 de Fatores de Crescimento do Endotélio Vascular/sangue , Adulto , Estudos de Casos e Controles , Feminino , Humanos , Isoenzimas/sangue , Trabalho de Parto/sangue , Concentração Osmolar , Fumar , Fatores de Tempo
8.
Reproduction ; 125(6): 785-90, 2003 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-12773100

RESUMO

The pathophysiology of pre-eclampsia is contested, but one hypothesis indicates that it is a heterogeneous condition in which only a subset of affected women bear small-for-gestational age (SGA) babies. In intrauterine growth-restricted (IUGR) infants, placental transport of amino acids is diminished and the resulting decrease in cord-blood amino acid concentrations is thought to contribute to their stunted growth. In contrast, the metabolic syndrome (dyslipidaemia, hyperinsulinaemia, hyperglycaemia, hypertension and obesity) which is associated with high amino acid concentrations is more prevalent in women with pre-eclampsia. The focus of this study was to compare maternal and fetal serum amino acid concentrations during normal pregnancy and pre-eclampsia and to evaluate the associations between the amino acid concentrations and fetal growth. The results indicate that maternal and cord-blood amino acid concentrations were significantly higher in women with pre-eclampsia compared with normal pregnant women and the concentrations were inversely associated with measures of infant growth. Maternal and cord-blood amino acid concentrations were also significantly higher in pre-eclamptic mothers with SGA infants compared with pre-eclamptic mothers whose babies were not SGA. These data indicate that, in contrast to IUGR, pre-eclampsia is associated with enhanced placental amino acid transport or reduced fetal amino acid utilization. Furthermore, the data are consistent with the hypothesis that pre-eclampsia is a heterogeneous disease associated with the metabolic syndrome.


Assuntos
Aminoácidos/sangue , Sangue Fetal/química , Recém-Nascido Pequeno para a Idade Gestacional , Pré-Eclâmpsia/sangue , Adulto , Análise de Variância , Biomarcadores/sangue , Estudos de Casos e Controles , Feminino , Humanos , Recém-Nascido , Masculino , Gravidez
9.
Hypertens Pregnancy ; 20(1): 69-77, 2001.
Artigo em Inglês | MEDLINE | ID: mdl-12044315

RESUMO

OBJECTIVE: The objective of this study was to confirm that endothelial dysfunction is present in preeclampsia and absent in transient hypertension of pregnancy, and to determine whether the cardiovascular risk factor homocysteine is associated with the degree of endothelial dysfunction. METHODS: We measured cellular fibronectin (as a marker of endothelial injury) and total plasma homocysteine in samples collected at the time of admittance to labor and delivery in 17 women with preeclampsia (increased blood pressure, proteinuria, and hyperuricemia), 16 women with transient hypertension of pregnancy (only increased blood pressure), and 34 normal pregnant women. Each subject with preeclampsia was matched by prepregnancy body mass index, race, and gestational age at delivery to one subject with transient hypertension of pregnancy and two controls. RESULTS: Cellular fibronectin was found to be significantly increased in women with preeclampsia compared to subjects with transient hypertension of pregnancy or normal pregnant women (22.9 +/- 14.1 microg/mL versus 10.9 +/- 5.4 and 10.1 +/- 6.2 microg/mL, respectively, p<0.0001). Similarly, total plasma homocysteine was also significantly increased in the women with preeclampsia compared to subjects with transient hypertension of pregnancy or normal pregnant women (8.3 +/- 2.5 microM versus <5.5 +/- 2.2 and 5.4 +/- 3.4 microM respectively, p<0.01). However, contrary to our hypothesis, there was no apparent association between cellular fibronectin and homocysteine. CONCLUSIONS: The increased concentrations of homocysteine observed in preeclampsia are not a general feature of all hypertensive complications of pregnancy. Furthermore, endothelial dysfunction is present in preeclampsia and is not evident in transient hypertension of pregnancy. However, the apparent endothelial dysfunction in preeclampsia is not explained by the increase in homocysteine concentrations observed.


Assuntos
Fibronectinas/análise , Homocisteína/sangue , Hipertensão/sangue , Pré-Eclâmpsia/metabolismo , Complicações Cardiovasculares na Gravidez/metabolismo , Feminino , Humanos , Pré-Eclâmpsia/sangue , Gravidez , Complicações Cardiovasculares na Gravidez/sangue
10.
Am J Obstet Gynecol ; 181(5 Pt 1): 1192-6, 1999 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-10561644

RESUMO

OBJECTIVE: We assessed tobacco exposure in nulliparous women with preeclampsia compared with that in control subjects by measuring urinary cotinine to confirm the reduced risk of preeclampsia associated with tobacco exposure during pregnancy. STUDY DESIGN: A case-control study group of 50 women with preeclampsia after 35 weeks of gestation and a group of 50 control subjects matched for gestational age, date of delivery, and body mass index were selected from the project database. Urine obtained on admission was assayed for cotinine. Self-reported smoking information was blinded during patient selection and laboratory assay. RESULTS: Thirty-five patients had detectable urinary cotinine levels, 11 (22%) with preeclampsia and 24 (48%) control women. Mean cotinine concentrations among exposed women were 331 ng/mL for those with preeclampsia and 540 ng/mL for control subjects. The odds ratio of preeclampsia developing in an exposed woman was 0.31 (95% confidence interval, 0.12-0.79). CONCLUSION: These findings, obtained by using laboratory assay, confirm the reduced risk of developing preeclampsia with tobacco exposure.


Assuntos
Cotinina/urina , Exposição Materna , Nicotiana , Plantas Tóxicas , Pré-Eclâmpsia/prevenção & controle , Complicações na Gravidez/prevenção & controle , Adulto , Peso ao Nascer , Índice de Massa Corporal , Estudos de Casos e Controles , Feminino , Idade Gestacional , Humanos , Recém-Nascido , Idade Materna , Nicotina/urina , Razão de Chances , Paridade , Pré-Eclâmpsia/urina , Gravidez , Complicações na Gravidez/urina , Fatores de Risco , Método Simples-Cego , Fumar , Nicotiana/metabolismo
11.
J Soc Gynecol Investig ; 6(2): 74-9, 1999.
Artigo em Inglês | MEDLINE | ID: mdl-10205777

RESUMO

OBJECTIVES: To test the hypothesis that the common missense mutation of 5,10-methylenetetrahydrofolate reductase (MTHFR) (677 C to T, ala to val) is more prevalent among nulliparous preeclamptic women compared with control and transient hypertension of pregnancy patients. The correlation of the MTHFR T677/T677 genotype in mothers and fetuses was also investigated to test for possible maternal-fetal interactions. Lastly, possible differences in serum folate concentrations between control and preeclampsia patients and the possibility of a correlation between serum folate and MTHFR genotype were investigated as well. METHODS: The MTHFR genotype was determined for 114 control subjects, 99 preeclamptic patients, and 24 patients with transient hypertension of pregnancy by a polymerase chain reaction/restriction fragment length polymorphism (PCR) method. To ensure homogeneity of ethnic background, only samples from white women were analyzed. Results were analyzed with a chi 2 test for homogeneity. Serum folate was determined by radioimmunoassay (RIA). RESULTS: The prevalence of the MTHFR T677/T677 genotype was not significantly different between the populations studied. There was no significant difference in the prevalence of the MTHFR T677/T677 genotype between the infants of preeclamptic and control mothers. Furthermore, there was no difference in serum folate concentrations between control and preeclampsia patients, and there was no correlation between serum folate and MTHFR genotype. CONCLUSION: These data suggest that contrary to previous published reports, the C677T missense mutation of MTHFR is not a risk factor for preeclampsia in this nulliparous patient population. Furthermore, this mutation is not related to serum folate status in late pregnancy.


Assuntos
Ácido Fólico/sangue , Predisposição Genética para Doença , Oxirredutases atuantes sobre Doadores de Grupo CH-NH/genética , Polimorfismo de Fragmento de Restrição , Pré-Eclâmpsia/enzimologia , DNA/sangue , Feminino , Sangue Fetal/enzimologia , Genótipo , Humanos , Metilenotetra-Hidrofolato Redutase (NADPH2) , Reação em Cadeia da Polimerase , Pré-Eclâmpsia/genética , Gravidez
12.
Am J Obstet Gynecol ; 179(6 Pt 1): 1605-11, 1998 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-9855605

RESUMO

OBJECTIVE: We tested the hypothesis that the independent risk factor for atherosclerosis of increased plasma homocysteine concentration is associated with the pregnancy syndrome of preeclampsia. We further hypothesized that increased plasma homocysteine concentration during pregnancy may advance endothelial dysfunction in preeclampsia by promoting oxidative stress. STUDY DESIGN: Antepartum blood samples were collected >/=6 hours after the last meal from 33 women with normal, uncomplicated pregnancies and from 21 women with preeclampsia. These plasma samples were analyzed for concentrations of total homocysteine; folate; triglycerides; creatinine; a marker of endothelial activation, cellular fibronectin; and a marker of oxidative stress, malondialdehyde. RESULTS: The mean value of total plasma homocysteine in preeclampsia was significantly higher than that observed in normal pregnancy (P <. 04). Similarly, plasma malondialdehyde (P <.001), triglyceride (P <. 001), and cellular fibronectin (P <.006) concentrations were also greater in women with preeclampsia than in control subjects. However, no differences were observed between women with preeclampsia and control subjects in folate (P =.97) or creatinine (P =.28) concentrations. Homocysteine concentration did not correlate with plasma creatinine (P =.61), malondialdehyde (P =.32), or triglyceride (P =.89) concentrations. However, cellular fibronectin concentration correlated positively with homocysteine concentration in both women with preeclampsia and control subjects (r = 0.87, P <. 0001, and r = 0.50, P <.004, respectively), and folate concentrations were weakly but negatively correlated with homocysteine values (P =.03, r = 0.32). CONCLUSIONS: Total plasma homocysteine concentration is increased in preeclampsia and is significantly correlated with cellular fibronectin concentration, suggesting that homocysteine plays a role in promoting endothelial dysfunction in preeclampsia. Furthermore, despite the use of pregnancy multivitamins and no indications of overt folate deficiency in this subject population, homocysteine concentration weakly and negatively correlates with plasma folate concentration.


Assuntos
Endotélio Vascular/fisiopatologia , Homocisteína/sangue , Hiper-Homocisteinemia/fisiopatologia , Pré-Eclâmpsia/sangue , Gravidez/sangue , Adulto , Feminino , Fibronectinas/sangue , Ácido Fólico/sangue , Humanos , Hiper-Homocisteinemia/complicações , Pré-Eclâmpsia/complicações , Pré-Eclâmpsia/fisiopatologia , Fatores de Risco
13.
J Biol Chem ; 271(32): 19409-14, 1996 Aug 09.
Artigo em Inglês | MEDLINE | ID: mdl-8702628

RESUMO

The direct interaction of hyaluronic acid (HA) and proteins of the inter-alpha-inhibitor family plays a critical role in organization and stabilization of the expanding cumulus extracellular matrix (cECM) following an ovulatory stimulus. Despite similarities in the morphology of cumulus oocyte complexes (COCs) expanding in vivo and in vitro, we find that the cECM of COCs which expand within intact follicles are more elastic and resistant to shear stress than the cECM of those stabilized in vitro. Western blot analysis shows that only the heavy chains of inter-alpha-inhibitor are incorporated into the cECM and appears to be covalently linked to HA after stabilization in vivo while intact inter-alpha-inhibitor is bound to the HA-enriched cECM by a non-covalent mechanism in in vitro stabilized COCs. However, purified pre-alpha-inhibitor and HA can form covalent linkage in the presence of granulosa cells or with granulosa cell-conditioned medium. In addition, COCs resistance to shear stress is also enhanced by coincubation with granulosa cells. Upon formation of the apparent covalent linkage between heavy chains and HA in culture medium, the light chain (bikunin) is concomitantly released into the medium as a complex with chondroitin sulfate moieties of inter-alpha-inhibitor supporting the possibility that HA may replace the chondroitin sulfate linkage to the heavy chains. We speculate that a factor(s) secreted by granulosa cells within the follicle may catalyze a transesterification reaction resulting in an exchange of chondroitin sulfate with HA at the heavy chain/chondroitin sulfate junction followed by release of chondroitin sulfate-bikunin into the follicular fluid. It is also possible that the consequent further stabilization of the cECM through the covalent interaction of HA and heavy chains of inter-alpha-inhibitor may play an important role in the process of ovulation.


Assuntos
alfa-Globulinas/metabolismo , Fatores Biológicos/metabolismo , Células da Granulosa/metabolismo , Ácido Hialurônico/metabolismo , Animais , Fatores Biológicos/biossíntese , Condroitinases e Condroitina Liases/metabolismo , Cromatografia em Gel , Cromatografia Líquida de Alta Pressão , Eletroforese em Gel de Poliacrilamida , Feminino , Hialuronoglucosaminidase/metabolismo , Cinética , Camundongos , Ligação Proteica
14.
Endocrinology ; 137(7): 3101-10, 1996 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-8770936

RESUMO

The activity of nitric oxide (NO) has been implicated as an important mediator in ovarian function, including the regulation of the blood-follicle barrier and ovulation. Both clinical and experimental diabetes have been found to impair endothelial-dependent vascular activity through the inactivation of NO. It has also been shown that diabetes-induced inactivation of NO can be rescued with administration of insulin as well as with free radical scavengers such as superoxide dismutase (SOD). In this study, we report decreases in both ovulation and the activity of the blood-follicle barrier in insulin-dependent diabetic prepubertal mice treated with exogenous gonadotropic hormones. Moreover, these ovarian defects are rescued with administration of insulin, nitroprusside, L-arginine, and the free radical scavengers citiolone and 4,5-dihydroxy-1,3-benzene disulfonic acid (Tiron). We found that the activity of Cu/Zn SOD in the ovaries of diabetic mice used in this study is decreased by 48% compared to that in nondiabetic mice. In contrast, inhibition of SOD activity in nondiabetic mice induces defects in the blood-follicle barrier and ovulation similar to those observed in diabetic mice. Lastly, we report the localization of endothelial nitric oxide synthase, inducible NOS, Cu/Zn SOD, and the LH receptor to the same population of endothelial cells surrounding the preovulatory follicle, supporting our hypothesis that the signaling of ovarian NO within the ovarian microvasculature at the time of ovulation may be compromised in these diabetic mice as a consequence of the loss of the protective activity of Cu/Zn SOD.


Assuntos
Diabetes Mellitus Experimental/enzimologia , Diabetes Mellitus Experimental/fisiopatologia , Diabetes Mellitus Tipo 1/enzimologia , Gonadotropinas Equinas/farmacologia , Folículo Ovariano/irrigação sanguínea , Ovário/enzimologia , Ovulação , Superóxido Dismutase/metabolismo , Sal Dissódico do Ácido 1,2-Di-Hidroxibenzeno-3,5 Dissulfônico/farmacologia , Animais , Arginina/farmacologia , Permeabilidade Capilar/efeitos dos fármacos , Catalase/metabolismo , Diabetes Mellitus Experimental/patologia , Diabetes Mellitus Tipo 1/patologia , Diabetes Mellitus Tipo 1/fisiopatologia , Endotélio Vascular/enzimologia , Feminino , Sequestradores de Radicais Livres/farmacologia , Insulina/farmacologia , Junções Intercelulares/efeitos dos fármacos , Isoenzimas/metabolismo , Camundongos , Camundongos Endogâmicos , Óxido Nítrico/fisiologia , Óxido Nítrico Sintase/biossíntese , Nitroprussiato/farmacologia , Folículo Ovariano/patologia , Ovário/efeitos dos fármacos , Valores de Referência , Tiofenos/farmacologia
15.
Am J Physiol ; 269(2 Pt 1): E290-8, 1995 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-7544532

RESUMO

Although initially described over 30 years ago, the blood-follicle barrier has remained a biological enigma. In this study, we characterize the blood-follicle barrier with respect to its regulation of intrafollicular inter-alpha-trypsin inhibitor protein (I alpha I) influx after an ovulatory stimulus. We have found that I alpha I is localized within the ovarian vasculature but is excluded from the follicular compartment until an ovulatory stimulus is given. Within minutes after an ovulatory dose of human chorionic gonadotropin, I alpha I is localized within the follicular fluid of responding follicles where this protein becomes associated with and stabilizes the newly synthesized hyaluronic acid-rich cumulus extracellular matrix. Analysis of this process has shown that intravenous injection of sodium nitroprusside or excess substrate for nitric oxide synthase, L-arginine, mimics the effect of gonadotropic hormones on the influx of I alpha I into the follicular compartment of preovulatory follicles. Moreover, intravenous injection of specific nitric oxide synthase inhibitors, NG-nitro-L-arginine methyl ester and NG-nitro-L-arginine, inhibits gonadotropin-mediated intrafollicular influx of I alpha I and also inhibits ovulation in the mouse.


Assuntos
Gonadotropinas/farmacologia , Óxido Nítrico/fisiologia , Folículo Ovariano/irrigação sanguínea , alfa-Globulinas/metabolismo , Aminoácido Oxirredutases/metabolismo , Animais , Vasos Sanguíneos/efeitos dos fármacos , Endotélio Vascular/enzimologia , Feminino , Fase Folicular , Meia-Vida , Hormônios/farmacologia , Camundongos , Camundongos Endogâmicos ICR , Óxido Nítrico/antagonistas & inibidores , Óxido Nítrico Sintase , Ovário/metabolismo , Ovulação , Fatores de Tempo , Inibidores da Tripsina/metabolismo
16.
J Biol Chem ; 269(45): 28282-7, 1994 Nov 11.
Artigo em Inglês | MEDLINE | ID: mdl-7525572

RESUMO

We have previously identified a glycoprotein of the inter-alpha-trypsin inhibitor family of proteins as a serum factor responsible for the stabilization of the expanding cumulus mass. In this study, the mechanism of interaction of this cumulus extracellular matrix stabilizing factor (cESF) with hyaluronic acid (HA) has been explored. It was found that the pH optimum for binding of cESF and HA is 7 and that binding is sensitive to ionic strength. The dissociation constant is about 1.9 x 10(-8) M in 10 mM sodium phosphate buffer (pH 7.2). Circular dichroism studies show that cESF contains about 24% alpha-helical and 42% beta-sheet structure. Gross conformational changes in cESF, however, are not detected in the presence of HA. We also found that modification of lysine residues of cESF with citraconic anhydride greatly reduced its binding with HA and completely abolished its cumulus stabilizing activity, and deblocking lysine residues restored its capacity to bind with HA and its cumulus matrix stabilizing activity. This evidence supports the hypotheses that cESF stabilizes the expanding cumulus extracellular matrix by directly binding with HA and that cESF may serve as a structural protein to organize the formation of the cumulus extracellular matrix. Our evidence also supports the view that binding of cESF and HA is through a stereo-specific charge interaction. Putative binding sites of cESF that interact with HA are postulated.


Assuntos
alfa-Globulinas/farmacologia , Matriz Extracelular/fisiologia , Ácido Hialurônico/metabolismo , Oócitos/fisiologia , Folículo Ovariano/fisiologia , alfa-Globulinas/química , alfa-Globulinas/isolamento & purificação , Sequência de Aminoácidos , Animais , Sítios de Ligação , Bovinos , Dicroísmo Circular , Matriz Extracelular/ultraestrutura , Feminino , Ácido Hialurônico/isolamento & purificação , Cinética , Lisina , Camundongos , Camundongos Endogâmicos , Dados de Sequência Molecular , Oócitos/ultraestrutura , Folículo Ovariano/ultraestrutura , Fragmentos de Peptídeos/química , Maturidade Sexual , Inibidores da Tripsina/farmacologia
17.
Surgery ; 94(5): 781-91, 1983 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-6356430

RESUMO

During the 23-year period from January 1959 to February 1982, 142 patients (78 men and 64 women) underwent arterial reconstructive operations for obstruction of the brachiocephalic arteries. A single vessel was involved in 75% and multiple vessels were involved in 25% of the cases. Distal involvement of internal carotid and vertebral arteries was present in 58 (41%) patients. Transthoracic operation was performed in 43 (31%) and extrathoracic operation was performed in 99 (69%) patients. One hundred and thirty-nine patients (98%) survived, and 134 (94%) experienced relief of symptoms. Follow-up was obtained for 136 patients for periods up to 22 years (mean of 7.5 years). Of these, 113 patients remained asymptomatic, eight developed transient strokes, four developed persistent strokes, and 11 (8%) died of stroke. The mean interval after operation in the latter cases was 9.3 years. Survival rates at 5, 10, and 15 years were 85%, 58%, and 25%, respectively.


Assuntos
Arteriopatias Oclusivas/cirurgia , Tronco Braquiocefálico , Doenças das Artérias Carótidas/cirurgia , Artéria Subclávia , Adolescente , Adulto , Idoso , Prótese Vascular , Tronco Braquiocefálico/cirurgia , Artéria Carótida Interna/cirurgia , Transtornos Cerebrovasculares/etiologia , Doença das Coronárias/complicações , Doença das Coronárias/cirurgia , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Complicações Pós-Operatórias , Artéria Subclávia/cirurgia , Fatores de Tempo
18.
J Surg Oncol ; 13(3): 269-73, 1980.
Artigo em Inglês | MEDLINE | ID: mdl-7374161

RESUMO

Lobular carcinoma in situ remains controversial in nomenclature, histology, and therapy. The original description and therapeutic recommendations remain a significant contribution to better control of breast cancer. We believe the sophistication of mammography, not available at the time of the earliest therapeutic recommendations, provides the clinician with a valuable and accurate new diagnostic tool for this disease. The risk factors from this disease entity have been well outlined by McDivitt [1] and others. We believe the patient should permitted to participate in the therapeutic decision after proper education about the risk factors of cancer in the ipsilateral and contralateral breast. Patients have requested bilateral mastectomies; some of these patients then wanted plastic reconstruction. Many others, however, have no such interest. The properly informed and responsible patient who elects to have close observation, with mammograms every six months, we feel has elected an acceptable clinical strategy for this disease.


Assuntos
Neoplasias da Mama/cirurgia , Carcinoma in Situ/cirurgia , Feminino , Humanos , Mastectomia/normas , Aceitação pelo Paciente de Cuidados de Saúde , Risco
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