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- Fock, V, et al.
(författare)
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Neuregulin-1-mediated ErbB2-ErbB3 signalling protects human trophoblasts against apoptosis to preserve differentiation
- 2015
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Ingår i: Journal of cell science. - : The Company of Biologists. - 1477-9137 .- 0021-9533. ; 128:23, s. 4306-4316
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Tidskriftsartikel (refereegranskat)abstract
- During placentation foetal trophoblasts invade deeply into maternal tissue to establish a foeto-maternal circulation. We have previously shown that extravillous trophoblast (EVT) lineage cells express ErbB2/ErbB3, whose potential as oncogenic unit is well established. However, a physiological function of this receptor combination in humans remains a puzzling question. Here we could demonstrate neuregulin (NRG) 1 expression and secretion by human decidual stromal cells. Stimulation of human primary trophoblasts with exogenous NRG1 induced phosphorylation of ErbB2, ErbB3 and related downstream effectors. Co-immunoprecipitation experiments confirmed the formation of ErbB2/ErbB3 dimers upon ligand engagement. Along this line, receptor knockdowns and ErbB3 neutralization strongly diminished NRG1-dependent activation of the signalling unit. Functional studies revealed that NRG1 promotes EVT formation in placental explant cultures. While in the presence of NRG1 basal and camptothecin-induced trophoblast apoptosis was significantly repressed, this effect was abolished upon ErbB3 inhibition. Notably, camptothecin provoked a strong reduction of trophoblast cell columns in size, whereas NRG1-treated explants were refractory to the compound. Together, our findings highlight a novel physiological function of the NRG1/ErbB2/ErbB3 axis in trophoblast survival during human placental development.
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- Haider, S, et al.
(författare)
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Notch signaling plays a critical role in motility and differentiation of human first-trimester cytotrophoblasts
- 2014
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Ingår i: Endocrinology. - : The Endocrine Society. - 1945-7170 .- 0013-7227. ; 155:1, s. 263-274
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Tidskriftsartikel (refereegranskat)abstract
- Failures in human extravillous trophoblast (EVT) development could be involved in the pathogenesis of pregnancy diseases. However, the underlying mechanisms have been poorly characterized. Here, we provide evidence that Notch signaling could represent a key regulatory pathway controlling trophoblast proliferation, motility, and differentiation. Immunofluorescence of first-trimester placental tissues revealed expression of Notch receptors (Notch2 and Notch3) and membrane-anchored ligands (delta-like ligand [DLL] 1 and -4 and Jagged [JAG] 1 and -2) in villous cytotrophoblasts (vCTBs), cell column trophoblasts (CCTs), and EVTs. Notch4 and Notch1 were exclusively expressed in vCTBs and in CCTs, respectively. Both proteins decreased in Western blot analyses of first-trimester, primary cytotrophoblasts (CTBs) differentiating on fibronectin. Luciferase reporter analyses suggested basal, canonical Notch activity in SGHPL-5 cells and primary cells that was increased upon seeding on DLL4-coated dishes and diminished in the presence of the Notch/γ-secretase inhibitors N-[N-(3,5-difluorophenacetyl-l-alanyl)]-S-phenylglycine t-butyl ester (DAPT) or L-685,458. Bromodeoxyuridine labeling, cyclin D1 mRNA expression, and cell counting indicated that chemical inhibition of Notch signaling elevated proliferation in the different primary trophoblast model systems. Notch inhibition also increased motility of SGHPL-5 cells through uncoated and fibronectin-coated Transwells, motility of primary CTBs, as well as migration in villous explant cultures on collagen I. Accordingly, small interfering RNA-mediated gene silencing of Notch1 also elevated SGHPL-5 cell migration. In contrast, motility of primary cultures and SGHPL-5 cells was diminished in the presence of DLL4. Moreover, DAPT increased markers of differentiated EVT, ie, human leukocyte antigen G1, integrin α5, and T-cell factor 4, whereas DLL4 provoked the opposite. In summary, the data suggest that canonical Notch signaling impairs motility and differentiation of first-trimester CTBs.
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- Meinhardt, G, et al.
(författare)
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Wingless ligand 5a is a critical regulator of placental growth and survival
- 2016
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Ingår i: Scientific reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 6, s. 28127-
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Tidskriftsartikel (refereegranskat)abstract
- The maternal uterine environment is likely critical for human placental morphogenesis and development of its different trophoblast subtypes. However, factors controlling growth and differentiation of these cells during early gestation remain poorly elucidated. Herein, we provide evidence that the ligand Wnt5a could be a critical regulator of trophoblast proliferation and survival. Immunofluorescence of tissues and western blot analyses of primary cultures revealed abundant Wnt5a expression and secretion from first trimester decidual and villous stromal cells. The ligand was also detectable in decidual glands, macrophages and NK cells. Wnt5a increased proliferation of villous cytotrophoblasts and cell column trophoblasts, outgrowth on collagen I as well as cyclin A and D1 expression in floating explant cultures, but suppressed camptothecin-induced apoptosis. Similarly, Wnt5a stimulated BrdU incorporation and decreased caspase-cleaved cytokeratin 18 neo-epitope expression in primary cytotrophoblasts. Moreover, Wnt5a promoted activation of the MAPK pathway in the different trophoblast models. Chemical inhibition of p42/44 MAPK abolished cyclin D1 expression and Wnt5a-stimulated proliferation. Compared to controls, MAPK phosphorylation and proliferation of cytotrophoblasts declined upon supplementation of supernatants from Wnt5a gene-silenced decidual or villous stromal cells. In summary, non-canonical Wnt5a signalling could play a role in early human trophoblast development by promoting cell proliferation and survival.
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