IL-1β and TGF-β weaken the placental barrier through destruction of tight junctions: an in vivo and in vitro study.
BACKGROUND
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.
Department of Experimental and Clinical Medicine, Università Politecnica delle Marche, 60020 Ancona, Italy. Electronic address: g.tossetta@univpm.it.
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Tossetta
Department of Experimental and Clinical Medicine, Università Politecnica delle Marche, 60020 Ancona, Italy. Electronic address: francesca.paolinelli@email.it.
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Paolinelli
Department of Experimental and Clinical Medicine, Università Politecnica delle Marche, 60020 Ancona, Italy. Electronic address: c.avellini@univpm.it.
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Avellini
Department of Molecular and Clinical Sciences-Histology, Università Politecnica delle Marche, 60020 Ancona, Italy. Electronic address: e.salvolini@univpm.it.
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Salvolini
Department of Experimental and Clinical Medicine, Università Politecnica delle Marche, 60020 Ancona, Italy. Electronic address: p.ciarmela@univpm.it.
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Ciarmela
Department of Experimental and Clinical Medicine, Università Politecnica delle Marche, 60020 Ancona, Italy. Electronic address: teresalorenzi@yahoo.it.
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Lorenzi
Department of Clinical Sciences, Section of Biochemistry, Università Politecnica delle Marche, 60131 Ancona, Italy. Electronic address: m.emanuelli@univpm.it.
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Emanuelli
Department of Medical Biotechnologies, Pathology Unit, University of Siena, Siena, Italy. Electronic address: paolot@unisi.it.
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Toti
Department of Clinical Sciences, Section of Biochemistry, Università Politecnica delle Marche, 60131 Ancona, Italy. Electronic address: rachela.g@libero.it.
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Giuliante
Department of Biomedical Sciences and Public Health, Epidemiological and Bio-statistic Centre, Università Politecnica delle Marche, 60020 Ancona, Italy. Electronic address: r.gesuita@univpm.it.
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Gesuita
Faculty of Engineering, Architecture and Physical Education, Università Kore, 94100 Enna, Italy. Electronic address: ccrescimanno@yahoo.it.
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Crescimanno
Department of Molecular and Developmental Medicine-Obstetrics and Gynecology, University of Siena, 53100 Siena, Italy. Electronic address: chiaravolt@yahoo.it.
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Voltolini
Department of Molecular and Clinical Sciences-Histology, Università Politecnica delle Marche, 60020 Ancona, Italy. Electronic address: r.diprimio@univpm.it.
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Di Primio
Department of Molecular and Developmental Medicine-Obstetrics and Gynecology, University of Siena, 53100 Siena, Italy. Electronic address: petraglia@unisi.it.
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Petraglia
Department of Experimental and Clinical Medicine, Università Politecnica delle Marche, 60020 Ancona, Italy. Electronic address: m.castellucci@univpm.it.
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Castellucci
Department of Experimental and Clinical Medicine, Università Politecnica delle Marche, 60020 Ancona, Italy. Electronic address: d.marzioni@univpm.it.
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Marzioni
D015703:Antigens, CD / Q000235:genetics / Q000378:metabolism; D015820:Cadherins / Q000235:genetics / Q000378:metabolism; D016022:Case-Control Studies; D002463:Cell Membrane Permeability; D002821:Chorioamnionitis / Q000235:genetics / Q000473:pathology / Q000503:physiopathology*; D016207:Cytokines / Q000378:metabolism; D005260:Female; D061307:Human Umbilical Vein Endothelial Cells; D006801:Humans; D007150:Immunohistochemistry; D053583:Interleukin-1beta / Q000502:physiology*; D008431:Maternal-Fetal Exchange; D062793:Occludin / Q000235:genetics / Q000378:metabolism; D010920:Placenta / Q000502:physiology* / Q000503:physiopathology; D011247:Pregnancy; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D019108:Tight Junctions / Q000473:pathology / Q000502:physiology*; D016212:Transforming Growth Factor beta / Q000502:physiology*; D062826:Zonula Occludens-1 Protein / Q000235:genetics / Q000378:metabolism; D051176:beta Catenin / Q000235:genetics / Q000378:metabolism; D000099152:Cadherin 5
D015703:Antigens, CD; D015820:Cadherins; D016207:Cytokines; D053583:Interleukin-1beta; D062793:Occludin; D012333:RNA, Messenger; D016212:Transforming Growth Factor beta; D062826:Zonula Occludens-1 Protein; D051176:beta Catenin; D000099152:Cadherin 5; C495270:CTNNB1 protein, human; C568985:OCLN protein, human; C569042:TJP1 protein, human
Chorioamnionitis; Cytokines; Occludin; Tight junction