Giovanni Tossetta

IL-1β and TGF-β weaken the placental barrier through destruction of tight junctions: An in vivo and in vitro study

INTRODUCTION Chorioamnionitis is a gestational pathological condition characterized by acute inflammation of the amniochorionic membranes and placentas leading to high concentrations of IL-1β, Il-6, Il-8 and TGF-β 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 β-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-1β, IL-6, IL-8 and TGF-β by means of in vitro studies using HUVEC cultures and demonstrated a key role of IL-1β and TGF-β 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.

High temperature requirement A1 and fibronectin: two possible players in placental tissue remodelling

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.

The trophoblast cell surface antigen 2 and miR-125b axis in urothelial bladder cancer

Human trophoblast cell surface antigen 2 (Trop-2) is a 40-kDa transmembrane glycoprotein that was first identified as a marker of human trophoblast cells. Trop-2 acts on cell proliferation, adhesion, and migration by activating a number of intracellular signalling pathways. Elevated Trop-2 expression has been demonstrated in several types of cancer and correlated with aggressiveness and poor prognosis. Since no data are available on Trop-2 in bladder cancer (BC), the purpose of the study was to determine its levels in tissue specimens from normal individuals and patients with BC at different stages. Moreover, since according to recent evidence Trop-2 is a miR-125b target, miR-125b expression was also assessed in tissue specimens. Finally, the effect of the Trop-2/miR-125b axis on the proliferation and migration of BC cells was evaluated in vitro.The Trop-2/miR-125b axis was seen to be differentially expressed in normal urothelium, non-invasive BC and invasive BC tissue. Significant miR-125b down-regulation was associated with a significant increase in Trop-2 protein levels in BC tissue and correlated with disease severity. In vitro analysis confirmed the role of miR-125b in down-modulation of Trop-2 protein levels and showed that Trop-2/miR-125b axis affects cellular proliferation in bladder tissue.In conclusion, our findings highlight a role for the Trop-2/miR-125b axis in BC progression and suggest Trop-2 and miR-125b as diagnostic/prognostic marker candidates as well as druggable targets for innovative therapeutic approaches.Human trophoblast cell surface antigen 2 (Trop-2) is a 40-kDa transmembrane glycoprotein that was first identified as a marker of human trophoblast cells. Trop-2 acts on cell proliferation, adhesion, and migration by activating a number of intracellular signalling pathways. Elevated Trop-2 expression has been demonstrated in several types of cancer and correlated with aggressiveness and poor prognosis. Since no data are available on Trop-2 in bladder cancer (BC), the purpose of the study was to determine its levels in tissue specimens from normal individuals and patients with BC at different stages. Moreover, since according to recent evidence Trop-2 is a miR-125b target, miR-125b expression was also assessed in tissue specimens. Finally, the effect of the Trop-2/miR-125b axis on the proliferation and migration of BC cells was evaluated in vitro. The Trop-2/miR-125b axis was seen to be differentially expressed in normal urothelium, non-invasive BC and invasive BC tissue. Significant miR-125b down-regulation was associated with a significant increase in Trop-2 protein levels in BC tissue and correlated with disease severity. In vitro analysis confirmed the role of miR-125b in down-modulation of Trop-2 protein levels and showed that Trop-2/miR-125b axis affects cellular proliferation in bladder tissue. In conclusion, our findings highlight a role for the Trop-2/miR-125b axis in BC progression and suggest Trop-2 and miR-125b as diagnostic/prognostic marker candidates as well as druggable targets for innovative therapeutic approaches.

Analysis of tight junctions in placentas affected by chorioamnionitis: in vivo and in vitro analysis

The human placenta and fetal membranes provide a barrier regulating the transfer of materials between the mother and the developing fetus throughout gestation. Chorioamnionitis is an important risk factor for preterm delivery that is associated with high perinatal morbidity and mortality. Chorioamnionitis is the term applied to infections of the placenta and membranes resulting in high concentrations of IL- 1beta, IL-6, IL-8 and TGF-beta in the amniotic fluid (D’Alquen et al., 2005). With progression of inflammation, immune cells penetrate blood vessels and infiltrate the umbilical cord, resulting in funisitis (Romero and Mazor, 1988). In normal conditions the two important physical entities in endothelial/epithelial paracellular clefts are adherens junctions and tight junctions. Tight junction governs the paracellular movement of water, solutes and immune cells, through the intercellular space creating a boundary between the apical and basolateral sides of cellular barriers (Gruenheid and Finlay, 2003). We have evaluated the localization of tight junctions studying the Zonula Occludens-1 (ZO-1) and Occludin expressions as well as the localization of adherent junctions, testing the expression of VE-cadherin and beta-catenin in placentas from normal gestations, from preterm idiopathic deliveries and from chorioamnionitis by immunohistochemistry. In addition, we have evaluated the mRNAs by real time PCR, the protein levels of these molecules by Western blot analysis in placental tissues, and to better clarify the action of some cytokines on occludin we performed in vitro analysis of HUVEC cultures. Our more striking result is the decrease of occludin expression in placentas from chorioamnionitis and an evident action of the cytokines on this molecule.

Human trophoblast differentiation: possible role for trophoblast cell surface antigen 2

Human trophoblast cell surface antigen 2 (Trop2) is a 40-kDa transmembrane glycoprotein, encoded by TACSTD2 gene and identified for the first time in human trophoblast and choriocarcinoma cell lines. Trop2 has a short intracytoplasmic tail essential for the control of several pathways that regulate cellular functions such as cell- cell adhesion, cell proliferation and mobility [1]. We analysed the expression of Trop2 in human normal placentas during gestation and in placentas complicated by preeclampsia (PE). Trop2 protein expression and miR125b1 were analysed by morphological and bio-molecular techniques. Trop2 increased during gestation, i.e. from first to third trimester of gestation while it was low expressed in placental tissues collected from patients with PE. Since PE is a pathology associated with placental hypoxia, we demonstrated that Trop2 is downregulated in hypoxic conditions by in vitro model. Our study suggests a possible involvement of Trop2 in maintaining trophoblast morphology and function during placental development in normal and PE conditions.

Expression of the ciliary neurotrophic factor and its receptor α in human placenta of first and third trimester of gestation

The ciliary neurotrophic factor (CNTF) is a member of the IL-6 family of cytokines along with cardiotrophin-1, IL-11, leukemia inhibitory factor, oncostatin-M and IL-6 itself. These cytokines play an important role in the regulation of cellular processes such as gene activation and cell proliferation and differentiation. CNTF is a pleiotropic cytokine which effects are mediated via CNTF receptor α (CNTFRα). CNTF increases differentiation and/or survival in neuronal cells but it also has different effects on other cell types such as muscle cells, bone cells, adipocytes, retinal cells and pancreatic β-cells (1, 2). In addition, recent studies demonstrate that CNTF plays an important role in weight control since exogenously administration of CNTF has an anorectic effect in mice (3,4). Although many studies proved that CNTF plays different roles in many cell types, its role in the development of human placenta has never been investigated. In this study we investigated the expression of CNTF and CNTFRα in human trophoblast by, immunohistochemistry, immunocytochemistry and Western Blot analysis using normal first and third trimester human placentas and HTR-8/SVneo cell lines. Interestingly, using immunohistochemistry CNTF and CNTFRα were expressed in the cytotrophoblast and syncytiotrophoblast in the first and third trimester of gestation respectively. Moreover, the immunofluorescence analyses by confocal microscopy showed that CNTF is expressed in the cytoplasm and nuclei whereas CNTFRα is mainly expressed in the cell membrane and cytoplasm of HTR-8/SVneo cell line. In this study we demonstrated that CNTF and CNTFRα are normally expressed in human placenta and they may play an important role during placental development.

Analysis of cell-cell junctions in human amnion and chorionic plate affected by chorioamnionitis

Chorioamnionitis is an acute inflammatory reaction associated with the premature rupture of the fetal membranes. It is caused mainly by invasion of bacteria from the vaginal tract that can penetrate the intact membranes and invade the amnion cavity and the decidua. Tight junctions (TJs) and adherent junctions (AJs) are intercellular junctions crucial for epithelia adhesion and permeability regulation in a wide variety of tissues and organs. Our aim is to investigate if TJ and AJ molecules are involved in human chorioamnionitis. We studied the protein expression (by immunohistochemistry and western blotting) and the mRNA levels (by RT-PCR) of some junction proteins such as Zonula Occludens-1 (ZO-1), occludin, VE-cadherin and β-catenin in fetal membranes from women with chorioamnionitis compared to those membranes derived from idiopathic pregnancies. Western blotting and immunohistochemical data established that occludin expression was decreased in amnion with chorioamnionitis compared to amnion from idiopathic pregnancies. Samples tested for ZO-1, VE-cadherin and β-catenin (proteins and mRNAs) showed no differences between idiopathic and pathological membranes. One of the most relevant results is the decrease of occludin in membranes with chorioamnionitis. Since we have previously demonstrated that some cytokines, particularly elevated in the chorioamnionitis, cause the disruption of TJs in placental villi, we suggest that the decrease of occludin in amnion may be the first change that leads to the rupture of the amniotic membrane in this pathology.

Expression of Trop2 in bladder cancer is modulated by miR125b: in vivo and in vitro analyses

Human trophoblastic cell surface antigen 2 (Trop-2) is a 40-kDa transmembrane glycoprotein, first identified as a cell surface marker for human trophoblast cells (1). Elevated expression of Trop-2 has been shown in several types of epithelial cancers and correlated with tumour aggressive and poor prognosis (2-3). The first aim of this study was to evaluate the variation of the Trop-2 expression in normal urothelium and urothelial bladder cancer. The immunohistochemical results showed an increase of Trop-2 levels in bladder cancer tissues with the increase of the severity of the pathology. Recent data identified Trop-2 as a target for miR-125b suggesting a pos sible role of miR-125b in the modulation of Trop-2 protein expression (4). The second aim was to verify if Trop-2 could be a target for miR-125b in bladder cells and to evaluate the possible role of miR-125b in the modulation of Trop-2 protein expression in normal bladder as well as in urothelial bladder cancer. In vitro we showed a contribution of miR-125b in deregulation of Trop-2 protein expression in a bladder cell line and we found that the expression of miR-125b was inversely correlated with the expression of Trop-2 protein on a cohort of bladder cancer tissues. We concluded to investigate in a larger population the use of Trop-2 and/or miR-125b as potential diagnostic markers in urothelial bladder cancer.

miR125b1 and TROP2 in preeclampsia complicated by foetal growth restriction: a morphological and biomolecular study

Trophoblast cell surface antigen 2 (TROP2) is a transmembrane glycoprotein originally identified in human trophoblast cell lines and is highly expressed in a variety of epithelial cancers. The TROP2 gene was validated as a direct target of miR-125b1. The purpose of our study was: - to investigate the expression of TROP2 protein in normal placental tissues, in placentas affected by preeclampsia as well as in placentas with preeclampsia complicated by foetal growth restriction (IUGR); - to verify how miR-125b1 was involved in the regulation of TROP2 gene expression. TROP2 protein expression was assessed by immunohistochemistry and quantitative western blotting analyses while miR-125b1 expression was detected by quantitative real-time PCR. The studies were made in normal and pathologic placental tissues. Increasing expression of TROP2 was detected in physiological placental tissue, in according with the increasing gestational age. Probably, it means that TROP2 is related with the differentiation of the cytotrophoblast in syncytiotrophoblast, that occurs during the development of placenta. Moreover, miR-125b1 showed an unchanged expression during normal pregnancy. Higher expression of TROP2 protein was detected in placental tissues collected from patients with preeclampsia complicated by foetal growth restriction, compared with those from preeclampsia and gestational age-matched control samples. The miR-125b1 expression in samples from placentas affected by preeclampsia complicated by IUGR was detected higher than in normal placentas and in placentas affected by preeclampsia. These results suggest that miR-125b1 is not involved I the overproduction of the TROP2 mRNA although the high expression of the miRNA. Our study suggests a possible involvement of TROP2 in the differentiation of the syncytiotrophoblast from villous cytotrophoblast and a possible role of this protein in preeclampsia complicated by foetal growth restriction.

HtrA1 in differentiation and growth of human placental tissues

HtrA1 is a secreted multidomain protein with serine protease activity. We used immunohistochemistry, western blotting, real time PCR and ELISA techniques to analyse the role of HtrA1 in normal and pathological development of human placental villous trees. In addition, we evaluated the alterations of maternal plasma HtrA1 level in preeclampsia (PE) complicated by intrauterine growth restriction (IUGR). HtrA1 is expressed in the mesenchymal villi which are considered the basis of growth and differentiation of the villous trees and in the villous stroma directly opposed to cell islands and cell columns in first trimester placentas. In addition, the villous trophoblast, the syncytial knots and the foetal vessels are stained for HtrA1 in first as well as third trimester placentas [1]. When the placenta escapes the normal differentiation and growth control mechanisms, which are present during normal pregnancy, it may develop gestational diseases, such as trophoblastic disease as well as PE and IUGR [1,2]. The most striking finding of our investigation is the decrease of this protease in placental tissues with increasing severity of gestational diseases and the increase of HtrA1 in maternal plasma of PE complicated by IUGR [3]. Based on these data HtrA1 could be considered as a possible marker of an occurring IUGR in preeclamptic women.