RESUMEN

High temperature requirement A1 (HtrA1) is a secreted protease involved in placental development. Fibronectin (FN) is involved in important process such as wound healing, cell adhesion and spreading, growth, migration, and differentiation. The purpose of this study was to analyse the expression patterns of HtrA1 in relationship to FN and to the key growth zones of placenta such as mesenchymal villi as well as cell islands and cell columns. We demonstrated that FN and HtrA1 are localized in the placental key growth zones suggesting a pivotal role in maintaining the balance among the molecules involved in the placental development and differentiation.

Asunto(s)

Vellosidades Coriónicas/metabolismo , Fibronectinas/biosíntesis , Regulación de la Expresión Génica/fisiología , Serina Endopeptidasas/biosíntesis , Femenino , Serina Peptidasa A1 que Requiere Temperaturas Altas , Humanos , Embarazo

RESUMEN

Increasing evidence supports the hypothesis that TGFb1 signalling may be mediated by high temperature requirement A1 (HtrA1) serine protease, acting on important regulatory mechanisms such as cell proliferation and mobility. Evidence is now accumulating to suggest that HtrA1 is involved in the development and progression of several pathologies. The aim of this study was to evaluate: i) if HtrA1 and TGFb1 expressions differ in eutopic and ectopic endometrium in women with endometriosis; ii) if HtrA1 correlates to TGFb1, pSmad and Ki67. This study was carried out including 10 women with ovarian endometriosis (cases) and 10 women with non endometriotic diseases (controls). Endometrial tissue underwent immunohistochemical H-score analysis for HtrA1, TGFb1, pSmad and Ki67 molecules. Data evaluation was performed by a nonparametric Kruskal-Wallis test and Spearman correlation was applied to evaluate the relationship among the molecules investigated in the epithelial and in the stromal compartment. The HtrA1 was significant decreased in ectopic and eutopic endometrium of women with endometriosis when compared with control endometrium in epithelial compartment. TGFb1was significantly increased in eutopic endometrium and decreased in ectopic endometrium in epithelial and stromal compartment. In addition, Ki67 was significant increased and an increase, but not significant, was detected for pSMAd2 in eutopic and ectopic endometrium compared to control one.  In summary, the significant direct correlation between TGFb1 and pSmad2 as well as between HtrA1 and TGFb1 and the very significant increase of Ki67 in stromal compartment of eutopic endometrium suggest a possible involvement of HtrA1 in the pathogenesis of endometriosis.

Asunto(s)

Endometriosis , Endometrio , Antígeno Ki-67/metabolismo , Serina Endopeptidasas/metabolismo , Proteína Smad2/metabolismo , Factor de Crecimiento Transformador beta1/metabolismo , Adulto , Endometriosis/metabolismo , Endometriosis/patología , Endometrio/metabolismo , Endometrio/patología , Femenino , Serina Peptidasa A1 que Requiere Temperaturas Altas , Humanos

RESUMEN

INTRODUCTION: Chorioamnionitis is a gestational pathological condition characterized by acute inflammation of the amniochorionic membranes and placentas leading to high concentrations of IL-1ß, Il-6, Il-8 and TGF-ß in the amniotic fluid. In normal conditions, the permeability of foeto-maternal barrier is due to the assembly and maintenance of different cellular junctional domains. METHODS: In the present study, first we aimed to evaluate the protein expression (by immunohistochemistry and western blotting) and mRNA (by real time PCR) levels of the molecular components of tight junctions (Zonula occludens-1 and occludin), and of adherent junctions (VE-cadherin and ß-catenin) in placentas from chorioamnionitis compared to that in normal pregnancies. RESULTS: Western blotting results showed a significant down-regulation of occludin in placentas affected with chorioamnionitis. No differences were detected for the other proteins analysed. We evaluated whether occludin expression was regulated by IL-1ß, IL-6, IL-8 and TGF-ß by means of in vitro studies using HUVEC cultures and demonstrated a key role of IL-1ß and TGF-ß in the disappearance of occludin at cellular border. CONCLUSIONS: We conclude by suggesting a pivotal role of these two cytokines in facilitating intra-placental infection via para-cellular way due to the disassembly of tight junctions at trophoblastic and endothelial cells in placental tissues.

Asunto(s)

Corioamnionitis/fisiopatología , Interleucina-1beta/fisiología , Placenta/fisiología , Uniones Estrechas/fisiología , Factor de Crecimiento Transformador beta/fisiología , Antígenos CD/genética , Antígenos CD/metabolismo , Cadherinas/genética , Cadherinas/metabolismo , Estudios de Casos y Controles , Permeabilidad de la Membrana Celular , Corioamnionitis/genética , Corioamnionitis/patología , Citocinas/metabolismo , Femenino , Células Endoteliales de la Vena Umbilical Humana , Humanos , Inmunohistoquímica , Intercambio Materno-Fetal , Ocludina/genética , Ocludina/metabolismo , Placenta/fisiopatología , Embarazo , ARN Mensajero/genética , ARN Mensajero/metabolismo , Uniones Estrechas/patología , Proteína de la Zonula Occludens-1/genética , Proteína de la Zonula Occludens-1/metabolismo , beta Catenina/genética , beta Catenina/metabolismo

RESUMEN

We evaluated the presence of HtrA1 in maternal plasma of normal pregnancies and of pregnancies complicated by preeclampsia (PE) without and with Intrauterine Growth Restriction (IUGR). We demonstrate that HtrA1 maternal plasma levels show significant different concentrations in first, second and third trimester of gestation and that HtrA1 concentration increases in maternal plasma of gestations complicated by PE with IUGR compared with control maternal plasma matched for gestational age. Based on these data high maternal plasma levels of HtrA1 could be considered as a possible marker of an occurring IUGR in preeclamptic women.

Asunto(s)

Retardo del Crecimiento Fetal/sangre , Preeclampsia/sangre , Serina Endopeptidasas/sangre , Adulto , Biomarcadores/sangre , Diagnóstico Precoz , Ensayo de Inmunoadsorción Enzimática , Femenino , Retardo del Crecimiento Fetal/diagnóstico , Edad Gestacional , Serina Peptidasa A1 que Requiere Temperaturas Altas , Humanos , Embarazo , Adulto Joven

RESUMEN

Insulin-like growth factors (IGFs) become bio-available following hydrolysis of binding proteins by homodimeric PAPP-A (dPAPP-A); this is a metzincin associated with the membranes of trophoblast phenotypes, the precise placental localization of which was unknown. Our study on placental samples of the first trimester shows the immunohistochemical localization of proMBP and dPAPP-A in the same cells. In contrast, dPAPP-A is mainly negative in the syncytium (ST) and positive in the villous cytotrophoblast (VCT) while htPAPP-A is strongly expressed in the ST and negative in the VCT at term, suggesting a progressive deactivation of the enzyme with gestational age. In agreement with the above, dPAPP-A is released only by first trimester placental explants in culture.

Asunto(s)

Regulación hacia Abajo , Placenta/metabolismo , Placentación , Proteína Plasmática A Asociada al Embarazo/metabolismo , Adulto , Dimerización , Femenino , Células Gigantes/citología , Células Gigantes/metabolismo , Humanos , Inmunohistoquímica , Placenta/citología , Embarazo , Primer Trimestre del Embarazo , Tercer Trimestre del Embarazo , Proteína Plasmática A Asociada al Embarazo/química , Técnicas de Cultivo de Tejidos , Trofoblastos/citología , Trofoblastos/metabolismo

RESUMEN

Preeclampsia (PE) is a serious disorder of human pregnancy, it is often associated with fetal growth restriction (FGR) which is a failure of the fetus to reach its own growth potential. Activator protein-1 (AP-1) is a family of transcription factors inducible in response to a variety of extracellular stimuli and functions. AP-1 plays a complex role in the regulation of different fundamental cellular processes, including cell proliferation, survival, death and transformation. We investigate the expression pattern of AP-1 transcription factors in normal placentas during gestation and in placentas from PE without and with FGR using semiquantitative RT-PCR and immunohistochemistry techniques. The most interesting data concern the alterations of protein expression patterns of c-fos, Jun D and c-jun in normal gestation as well as in PE and PE-FGR pathologies. In addition, alterations but not significant changes are detected in mRNA expressions for these transcription factors. We strongly suggest that c-fos is implicated in regulating invasiveness mechanism of extravillous trophoblast in normal gestation as well as in PE placentas. In addition, we suggest that the opposite modulation of Jun D and c-jun in PE and PE-FGR supports the recent hypothesis that PE and PE-FGR could be considered two pathologies with different origin (maternal and placental) each of which has a different molecular pattern of expression.

Asunto(s)

Retardo del Crecimiento Fetal/metabolismo , Placenta/metabolismo , Preeclampsia/metabolismo , Factor de Transcripción AP-1/metabolismo , Adulto , Femenino , Retardo del Crecimiento Fetal/genética , Regulación del Desarrollo de la Expresión Génica , Humanos , Inmunohistoquímica , Técnicas In Vitro , Recién Nacido , Preeclampsia/genética , Embarazo , Proteínas Proto-Oncogénicas c-fos/genética , Proteínas Proto-Oncogénicas c-fos/metabolismo , Proteínas Proto-Oncogénicas c-jun/genética , Proteínas Proto-Oncogénicas c-jun/metabolismo , ARN/química , ARN/genética , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Estadísticas no Paramétricas , Factor de Transcripción AP-1/genética , Adulto Joven

RESUMEN

The syndecan family consists of four distinct membrane glycoproteins in mammals. Syndecans control cell proliferation, differentiation, adhesion and migration through participation in cell-cell interactions, anchorage of cells to the extracellular environment, and modulation of multiple growth factors. Therefore, syndecans may play a pivotal role in the regulation of cell behaviour depending on the cellular microenvironment. Here, we demonstrate that syndecan-1, syndecan-2 and syndecan-4 are expressed in fetal membrane tissue with different immunolocalizations. Syndecan-1 is expressed in the amniotic epithelium, localizing at basolateral cell surfaces. Syndecan-2 and syndecan-4, in contrast, are mostly localized in intracellular compartments, in the extravillous cytotrophoblastic cells and in some fibroblasts of the chorionic plate as well as in the amniotic epithelial cells. In the latter, syndecan-4 is mainly localized in the apical part of the cells. Our results strongly suggest a key role of syndecan-1, syndecan-2 and syndecan-4 in the determination of structural and functional characteristics of human amnion and chorionic plate. Since the solute exchanges between fetus and mother take place in fetal membranes, our data suggest that syndecans are important players in the placenta for the establishment of the fetal-maternal inter-communication.

Asunto(s)

Amnios/metabolismo , Corion/metabolismo , Placenta/metabolismo , Sindecano-1/metabolismo , Sindecano-2/metabolismo , Sindecano-4/metabolismo , Amnios/citología , Corion/citología , Femenino , Fibroblastos/metabolismo , Humanos , Técnicas para Inmunoenzimas , Placenta/citología , Embarazo

RESUMEN

Basic fibroblast growth factor (bFGF) is a heparin-binding cationic protein involved in a variety of pathological conditions including angiogenesis and solid tumour growth. The basic fibroblast growth factor receptor (FGFR) family comprises at least 4 high affinity tyrosine kinase receptors that require syndecans for their function. Mounting evidence indicates that syndecans, that bind both bFGF and their FGFRs, will act as stimulators, whereas syndecans that only bind bFGF will act as inhibitors of signaling by sequestering the growth factor. Recent findings have highlighted the importance of syndecans in urological cancers. The aim of this study is to investigate the expression of bFGF, its receptors (R1 and R2) and syndecans (1-4) in invasive urothelial carcinoma and normal-looking urothelium by Western blotting, RT-PCR, and immunohistochemistry analyses. Interestingly, bFGF, FGFR1 and FGFR2 protein levels statistically increased in bladder cancer tissues. mRNA of FGFR1 and syndecans (1-4), showed a statistically significant increase while an mRNA increase in the other molecules analysed was not significant. bFGF, its receptors and syndecan immunostaining were mainly present in the urothelium both in normal-looking tissues and urothelial neoplastic cells. In conclusion, our data report that the bFGF, FGFR and syndecan expressions are altered in bladder tumours.

Asunto(s)

Carcinoma/química , Factor 2 de Crecimiento de Fibroblastos/análisis , Receptor Tipo 2 de Factor de Crecimiento de Fibroblastos/análisis , Sindecanos/análisis , Neoplasias de la Vejiga Urinaria/química , Anciano , Western Blotting , Carcinoma/genética , Carcinoma/patología , Carcinoma/cirugía , Cistectomía , Femenino , Factor 2 de Crecimiento de Fibroblastos/genética , Regulación Neoplásica de la Expresión Génica , Humanos , Inmunohistoquímica , Masculino , Persona de Mediana Edad , Estadificación de Neoplasias , ARN Mensajero/análisis , Receptor Tipo 1 de Factor de Crecimiento de Fibroblastos/análisis , Receptor Tipo 1 de Factor de Crecimiento de Fibroblastos/genética , Receptor Tipo 2 de Factor de Crecimiento de Fibroblastos/genética , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Sindecano-1/análisis , Sindecano-2/análisis , Sindecano-3/análisis , Sindecano-4/análisis , Sindecanos/genética , Regulación hacia Arriba , Neoplasias de la Vejiga Urinaria/genética , Neoplasias de la Vejiga Urinaria/patología , Neoplasias de la Vejiga Urinaria/cirugía , Urotelio/química

RESUMEN

Preeclampsia (PE) and intrauterine growth restriction (IUGR) are pregnancy-specific disorders that have in common abnormal placental implantation, a marked proliferation of villous cytotrophoblastic cells and focal necrosis of the syncytiotrophoblast. Several studies show an ischemic placenta with a high-resistance vasculature, which cannot deliver an adequate blood supply to the feto-placental unit. The cause of PE is a matter of debate, but recently studies in mice suggest that the primary feto-placental lesions are sufficient to initiate the disease. HtrA1, a member of the family of HtrA proteins, is a secreted multidomain protein with serine protease activity. It is expressed in first and third trimester of gestation. In specimens from the first trimester of gestation, immunostaining for HtrA1 is generally found in both layers of villous trophoblast, syncytiotrophoblast and cytotrophoblast. Cytoplasm of extravillous trophoblast and extracellular matrix of cell islands and cell columns are labeled for HtrA1. Specimens from third trimester of gestation show a more intense positivity for HtrA1 in the syncytiotrophoblast than in cytotrophoblast. The extravillous trophoblast and the decidual cells, is positive for HtrA1. The purpose of this study is to investigate the expression pattern of HtrA1 in placentas from PE without IUGR (maternal PE) and with IUGR (fetal PE) by quantitative western blotting and immunohistochemistry. By quantitative western blotting analysis we observed a significant upregulation of approximately 30 kDa HtrA1 form in PE. Differently, we detected a significant total HtrA1 down-regulation in PE-IUGR. Moreover, immunostaining for HtrA1 was positive in the villous trophoblast, in the syncytial knots and irregularly in the fetal vessel walls in PE placentas while immunostaining for HtrA1was present particularly in the syncytial knots in PE-IUGR placentas. In conclusion, we suggest that the approximately 30 kDa HtrA1 form can be correlated to maternal PE while that the significant down-regulation of total HtrA1 can be correlated to placental PE. These HtrA1 alterations could be considered as possible markers to discriminate placental PE from maternal PE.

Asunto(s)

Retardo del Crecimiento Fetal/metabolismo , Preeclampsia/metabolismo , Serina Endopeptidasas/metabolismo , Trofoblastos/metabolismo , Biomarcadores/metabolismo , Western Blotting , Regulación hacia Abajo , Femenino , Retardo del Crecimiento Fetal/patología , Técnica del Anticuerpo Fluorescente Directa , Técnica del Anticuerpo Fluorescente Indirecta , Serina Peptidasa A1 que Requiere Temperaturas Altas , Humanos , Técnicas para Inmunoenzimas , Preeclampsia/patología , Embarazo , Isoformas de Proteínas , Trofoblastos/patología

RESUMEN

This minireview reports current hypotheses concerning the remodeling of sympathetic innervation in rodent and human uterus during the estrous cycle and gestation. Neural modulation in this organ is related to sexual hormone concentrations, and a reduction in nerve density is observed when estrogen levels are high during the estrous cycle. Estrogen receptor alpha is considered to be the major receptor mediating the action of estrogen. In the uterus, the expression of neurotrophins, such as nerve growth factor, which are involved in the survival and growth of nerve fibers, changes in response to steroid levels. Despite much research, further studies are necessary to clarify various aspects of nerve growth control under diverse physiological conditions. These studies could be of importance, since alterations of the biological mechanisms of uterus innervation may play significant roles in various pathologies, such as infertility and spontaneous abortion.

Asunto(s)

Estrógenos/metabolismo , Ciclo Estral/fisiología , Neurogénesis/fisiología , Útero/inervación , Útero/ultraestructura , Animales , Estro/fisiología , Femenino , Humanos , Ratones , Factor de Crecimiento Nervioso/metabolismo , Receptor de Factor de Crecimiento Nervioso/metabolismo , Receptor trkA/metabolismo , Receptores de Estrógenos/metabolismo , Útero/fisiología

RESUMEN

Accumulation of visceral fat is a key phenomenon in the onset of obesity-associated metabolic disorders. Macrophage infiltration induces chronic mild inflammation widely considered as a causative factor for insulin resistance and eventually diabetes. We previously showed that >90% of macrophages infiltrating the adipose tissue of obese animals and humans are arranged around dead adipocytes, forming characteristic crown-like structures (CLS). In this study we quantified CLS in visceral and subcutaneous depots from two strains of genetically obese mice, db/db and ob/ob. In both strains, CLS were prevalent in visceral compared with subcutaneous fat. Adipocyte size and CLS density exhibited a positive correlation both in visceral and in subcutaneous depots; however, the finding that adipocyte size was smallest and CLS density highest in visceral fat suggests a different susceptibility of visceral and subcutaneous adipocytes to death. Visceral fat CLS density was 3.4-fold greater in db/db than in ob/ob animals, which at the age at which our experimental strain was used are more prone to glucose metabolic disorders.

Asunto(s)

Adipocitos/citología , Adipocitos/metabolismo , Grasa Intraabdominal/citología , Grasa Intraabdominal/metabolismo , Animales , Muerte Celular , Femenino , Ratones , Ratones Obesos

RESUMEN

Solitary chemosensory cells (SCCs), which resemble taste bud cells, are present in the epidermis and oropharynx of most primary aquatic vertebrates. Recent studies have led to the description of SCCs also in mammals too. In the airway and digestive apparatus, these elements form a diffuse chemosensory system. SCCs do not aggregate into groups and in SCCs, as in taste bud cells, immunoreactivity forthe G-protein subunit alpha-gustducin and for other molecules of the chemoreceptive cascade was found. Questions remain about the role of the diffuse chemosensory system in control of complex functions (e.g. airway surface liquid secretion) and about the involvement of chemoreceptors in respiratory diseases. Therapeutic actions targeting chemoreceptors could be tested in the treatment of respiratory diseases.

Asunto(s)

Células Quimiorreceptoras/citología , Sistema Respiratorio/citología , Papilas Gustativas/citología , Animales , Humanos

RESUMEN

There is evidence that alpha-smooth muscle actin (alpha-SMA) is a protein that plays a pivotal role in the production of contractile forces and it is induced by transforming growth factor-beta1 (TGF-beta1). We have analysed the expression of alpha-SMA, TGF-beta1, its receptor RI and the activator phospho-Smad2 in (a) fetal growth restriction pre-eclamptic placentae characterised by early onset and absence of end diastolic velocities in the umbilical arteries (FGR-AED) and (b) control placentae accurately matched for gestational age. The study was performed by immunohistochemical, quantitative Western blotting, ELISA, RT-PCR and in vitro analyses. We found that TGF-beta1 stimulates alpha-SMA production in chorionic villi cultured in vitro. In addition, we observed that in vivo TGF-beta1 concentration is significantly higher in FGR-AED placental samples than in control placentae and that this growth factor could have a paracrine action on villous stroma myofibroblasts expressing TGF-beta1 receptors and phospho-Smad2. Indeed, we report that alpha-SMA undergoes a redistribution in FGR-AED placental villous tree, i.e. we show that alpha-SMA is enhanced in medium and small stem villi and significantly decreased in the peripheral villi. Our data allow us to consider TGF-beta1 and alpha-SMA as key molecules related to FGR-AED placental villous tree phenotypic changes responsible for increased impedance to blood flow observable in this pathology.

Asunto(s)

Actinas/metabolismo , Retardo del Crecimiento Fetal/fisiopatología , Placenta/fisiopatología , Preeclampsia/fisiopatología , Complicaciones del Embarazo , Proteínas Serina-Treonina Quinasas/metabolismo , Receptores de Factores de Crecimiento Transformadores beta/metabolismo , Factor de Crecimiento Transformador beta1/metabolismo , Adulto , Femenino , Feto , Regulación de la Expresión Génica , Humanos , Placenta/irrigación sanguínea , Embarazo , Proteínas Serina-Treonina Quinasas/genética , ARN Mensajero/metabolismo , Receptor Tipo I de Factor de Crecimiento Transformador beta , Receptores de Factores de Crecimiento Transformadores beta/genética , Transducción de Señal , Factor de Crecimiento Transformador beta1/genética

RESUMEN

In this review we present data concerning the localization of some important growth factors and their receptors in the human placenta. We focus our attention on molecules playing a fundamental role in angiogenesis and morphologic processes as beta-FGF, EGF and TGF-beta. The distribution of these growth factors and their receptors in the placental villi during gestation suggests that these molecules play a pivotal role in growth and differentiation of the villous tree.

Asunto(s)

Sustancias de Crecimiento/metabolismo , Placenta/metabolismo , Placentación/fisiología , Receptores de Factores de Crecimiento/metabolismo , Vellosidades Coriónicas/irrigación sanguínea , Vellosidades Coriónicas/metabolismo , Vellosidades Coriónicas/ultraestructura , Femenino , Humanos , Microcirculación/crecimiento & desarrollo , Microcirculación/ultraestructura , Neovascularización Fisiológica/fisiología , Placenta/irrigación sanguínea , Circulación Placentaria/fisiología , Embarazo

RESUMEN

The present study evaluated vasoactive intestinal peptide (VIP) and substance P (SP) mRNA expressions and the localization of both peptides in first- and third-trimester human placentas. VIP and SP mRNAs were detected by slot blot analysis in first- and third-trimester placental tissues. By immunohistochemistry both neuropeptides were localized in the trophoblast (syncytium and cytotrophoblastic cells) of the chorionic villi. Because little information is available on the role of VIP and/or SP on the secretion of placental hormones, we investigated the effect of these neuropeptides on human chorionic gonadotropin (hCG) and progesterone release from primary cultured human trophoblastic and JEG-3 cells. The addition of increasing doses of VIP resulted in a dose-dependent stimulation of hCG release from cultured human trophoblast and JEG-3 cells. Increasing doses of VIP also dose-dependently stimulated progesterone secretion from primary cultured trophoblastic cells at all time points evaluated and from JEG-3 cells only after 3 h. SP did not affect hCG and progesterone secretion either in cultured human trophoblast or in JEG-3 cells. In conclusion, the present study demonstrates that VIP and SP are mainly expressed in human trophoblasts, and that VIP modulates the in vitro secretion of hCG and progesterone, suggesting a different role in trophoblastic function of the two peptides.

Asunto(s)

Gonadotropina Coriónica/metabolismo , Placenta/metabolismo , Progesterona/metabolismo , Sustancia P/análisis , Péptido Intestinal Vasoactivo/análisis , Células Cultivadas , Femenino , Humanos , Inmunohistoquímica , Embarazo , Precursores de Proteínas/análisis , Precursores de Proteínas/genética , Sustancia P/genética , Sustancia P/fisiología , Taquicininas/análisis , Taquicininas/genética

RESUMEN

Clearance of fibrin deposits within the human placenta is an ongoing process during normal placental development. Plasminogen is a circulating fibrinolytic protease zymogen activated in situ by plasminogen activators. We have previously reported that the receptor for urokinase plasminogen activator (uPAR) is expressed by cells either covering or enmeshed within the perivillous fibrinoid deposits. Whereas these cells seemed likely to be trophoblasts, a definitive identification was lacking, and this question is central to the understanding of the cellular mechanisms directing fibrinolysis in the placenta. In this study we have performed immunohistochemical co-localization studies and found that the uPAR-positive cells covering fibrinoid deposits are immunoreactive for CD31 and vWF, indicating that they are actually endothelial cells. In addition, we found that perivillous fibrinoid deposits not covered with uPAR-positive endothelial cells were covered with platelets identified by integrin alpha(IIb)beta(3)-immunoreactivity. Also surprisingly, the uPAR-positive cells enmeshed within fibrinoid deposits express a cell specific marker indicating that they are macrophages. Both uPAR-positive cell populations also express uPA immunoreactivity. Taken together, the data suggest that both fibrinoid-covering endothelial cells and fibrinoid-enmeshed macrophages can participate in the clearance process of perivillous fibrinoid deposits formed in the human placenta.

Asunto(s)

Endotelio/metabolismo , Fibrina/metabolismo , Macrófagos/metabolismo , Placenta/metabolismo , Receptores de Superficie Celular/metabolismo , Adulto , Biomarcadores/análisis , Plaquetas/metabolismo , Endotelio/citología , Femenino , Humanos , Macrófagos/citología , Placenta/citología , Molécula-1 de Adhesión Celular Endotelial de Plaqueta/metabolismo , Complejo GPIIb-IIIa de Glicoproteína Plaquetaria/metabolismo , Embarazo , Receptores del Activador de Plasminógeno Tipo Uroquinasa , Regulación hacia Arriba , Factor de von Willebrand/análisis

RESUMEN

Peroxisome proliferator-activated receptor (PPAR) gamma belongs to a subclass of nuclear hormone receptors that execute their transcriptional functions as heterodimers with the retinoid X receptors (RXR). PPARgamma plays a pivotal role in cellular differentiation. This study investigated PPARgamma protein expression in normal human placentas, hydatidiform moles and choriocarcinoma, using immunohistochemical and Western blot analyses. In first trimester normal placenta, PPARgamma was mainly localized in the nuclei of the villous cytotrophoblastic cells, whereas at term it was mainly localized in the nuclei of the syncytiotrophoblast. Extravillous cytotrophoblast of cell islands and cell columns also showed nuclear PPARgamma immunostaining. A striking result was the altered expression patterns of PPARgamma in pathological tissues; PPARgamma showed a reduced immunostaining in the trophoblastic diseases. In hydatidiform moles, PPARgamma was mainly localized in the nuclei of the trophoblastic collections of the pathological villi and in the extravillous trophoblastic cells, whereas in the choriocarcinoma, only a few trophoblastic cells showed weak PPARgamma nuclear immunostaining. These findings suggest an involvement of PPARgamma in trophoblast differentiation during normal placental development. The down-regulation of PPARgamma expression in the gestational trophoblastic diseases analysed in this study provides a new insight into the progression of these pathologies.

Asunto(s)

Coriocarcinoma/metabolismo , Mola Hidatiforme/metabolismo , Placenta/metabolismo , Receptores Citoplasmáticos y Nucleares/metabolismo , Factores de Transcripción/metabolismo , Neoplasias Uterinas/metabolismo , Coriocarcinoma/patología , Proteínas de Unión al ADN/genética , Proteínas de Unión al ADN/metabolismo , Femenino , Humanos , Mola Hidatiforme/patología , Proteínas Nucleares/genética , Proteínas Nucleares/metabolismo , Placenta/citología , Placentación , Embarazo , Trimestres del Embarazo , Receptores Citoplasmáticos y Nucleares/genética , Factores de Transcripción/genética , Neoplasias Uterinas/patología

RESUMEN

OBJECTIVE: To examine the role of plasminogen activator inhibitor type-1 (PAI-1), the major fibrinolytic inhibitor, in vivo during murine antigen-induced arthritis (AIA). METHODS: AIA was induced in PAI-1-deficient mice and control wild-type mice. Arthritis severity was evaluated by technetium 99m (99mTc) uptake in the knee joints and by histological scoring. Intra-articular fibrin deposition was examined by immunohistochemistry and synovial fibrinolysis quantitated by tissue D-dimer measurements and zymograms. RESULTS: Joint inflammation, quantitated by 99mTc uptake, was significantly reduced in PAI-1(-/-) mice on day 7 after arthritis onset (P<0.01). Likewise, synovial inflammation, evaluated by histological scoring, was significantly decreased in PAI-1-deficient mice on day 10 after arthritis onset (P<0.001). Articular cartilage damage was significantly decreased in PAI-1(-/-) mice, as shown by histological grading of safranin-O staining on day 10 after arthritis onset (P<0.005). Significantly decreased synovial accumulation of fibrin was observed by day 10 in arthritic joints of PAI-1(-/-) mice (P<0.005). Accordingly, the synovial tissue content of D-dimers, the specific fibrin degradation products generated by plasmin, were increased in PAI-1(-/-) mice (P<0.02). Finally, as expected, PA activity was increased in synovial tissues from PAI-1(-/-) mice, as shown by zymographic analysis. CONCLUSIONS: These results indicate that deficiency of PAI-1 results in increased synovial fibrinolysis, leading to reduced fibrin accumulation in arthritic joints and reduced severity of AIA.

Asunto(s)

Artritis Reumatoide/inmunología , Artritis Reumatoide/patología , Inhibidor 1 de Activador Plasminogénico/genética , Animales , Antígenos/inmunología , Artritis Reumatoide/metabolismo , Modelos Animales de Enfermedad , Fibrina/metabolismo , Fibrinólisis/inmunología , Articulación de la Rodilla/inmunología , Articulación de la Rodilla/metabolismo , Articulación de la Rodilla/patología , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Inhibidor 1 de Activador Plasminogénico/inmunología , Membrana Sinovial/inmunología , Membrana Sinovial/metabolismo , Membrana Sinovial/patología , Tecnecio/farmacocinética

RESUMEN

Heat production in brown adipose tissue (BAT) and brown adipocyte recruitment depend heavily on BAT vascular and parenchymal sympathetic and sensory innervation. The expression and distribution of Sema3a, a recently discovered chemorepellent neuronal factor active on both sympathetic and sensory peripheral nerves, were studied in interscapular rat BAT. In rats maintained in thermoneutral conditions, brown adipocytes produced both active isoforms of Sema3a and showed a distinct peripheral polarized immunostaining pattern. This suggests a role for Sema3a secreted by brown adipocytes in the guidance of axons toward their correct targets. In cold-acclimated rats, where parenchymal nerve density is higher, both the expression and the immunostaining of the two active isoforms were slightly but significantly reduced and the distinct staining pattern was not observed. These data suggest that the secretion of Sema3a is inhibited in the brown adipocytes of cold-acclimated rats. Thus, Sema3a could play a role in the plastic adjustment of BAT innervation observed in different conditions of functional demand.

Asunto(s)

Aclimatación/fisiología , Adipocitos/metabolismo , Tejido Adiposo Pardo/metabolismo , Glicoproteínas/metabolismo , Adipocitos/química , Tejido Adiposo Pardo/química , Tejido Adiposo Pardo/citología , Animales , Western Blotting , Frío , Glicoproteínas/análisis , Glicoproteínas/biosíntesis , Inmunohistoquímica , Masculino , Ratas , Ratas Sprague-Dawley , Semaforina-3A

RESUMEN

Hyaluronan (HA) and CD44 are involved in several processes such as cell migration and differentiation. In the present study, we examined the expression and distribution of both hyaluronan and its cell surface receptor (CD44) in the human placenta, which is a rapidly growing and differentiating organ that plays a fundamental role in fetal life. Hyaluronan was detected by a specific biotinylated binding probe, termed b-PG. In the first half of gestation, HA was strongly expressed in the stroma of the mesenchymal villi which have been previously identified as responsible for the growth and differentation of the villous trees. The other villous types showed an intense staining only in the fetal vessel walls and in the connective tissue closely underlying the trophoblastic cover. In addition, hyaluronan positive staining was also apparent in a restricted rim of villous stroma directly apposed to extravillous cytotrophoblastic cell islands and cell columns. In full term placentas, all villi expressed HA in their stromal tissue with a more homogenous staining than in the first half of gestation. In contrast to hyaluronan, in the first trimester CD44 was restricted to some of the Hofbauer cells which may be able to internalize hyaluronan, thus playing a significant role in its removal in early pregnancy. CD44 was primarily expressed starting from the 16th week of gestation. At the end of pregnancy it was expressed in the various villous types, especially in stem villi. Moreover, the plasma membrane of some extravillous cytotrophoblastic cells in the basal plate and the large majority of the decidual cells showed a positive immunostaining for this receptor. Taken together, these data suggest that HA is strongly involved in early villous morphogenesis, whereas CD44 seem to be play an important role in tissue remodelling later in gestation.

Asunto(s)

Receptores de Hialuranos/análisis , Ácido Hialurónico/análisis , Placenta/química , Femenino , Humanos , Embarazo