scholarly journals The role of insulin-like growth factor 2 receptor-mediated homeobox gene expression in human placental apoptosis, and its implications in idiopathic fetal growth restriction

2019 ◽  
Vol 25 (9) ◽  
pp. 572-585 ◽  
Author(s):  
Lynda K Harris ◽  
Priyadarshini Pantham ◽  
Hannah E J Yong ◽  
Anita Pratt ◽  
Anthony J Borg ◽  
...  

Abstract Fetal growth restriction (FGR) is caused by poor placental development and function early in gestation. It is well known that placentas from women with FGR exhibit reduced cell growth, elevated levels of apoptosis and perturbed expression of the growth factors, cytokines and the homeobox gene family of transcription factors. Previous studies have reported that insulin-like growth factor-2 (IGF2) interacts with its receptor-2 (IGF2R) to regulate villous trophoblast survival and apoptosis. In this study, we hypothesized that human placental IGF2R-mediated homeobox gene expression is altered in FGR and contributes to abnormal trophoblast function. This study was designed to determine the association between IGF2R, homeobox gene expression and cell survival in pregnancies affected by FGR. Third trimester placentas were collected from FGR-affected pregnancies (n = 29) and gestation matched with control pregnancies (n = 30). Functional analyses were then performed in vitro using term placental explants (n = 4) and BeWo trophoblast cells. mRNA expression was determined by real-time PCR, while protein expression was examined by immunoblotting and immunohistochemistry. siRNA transfection was used to silence IGF2R expression in placental explants and the BeWo cell-line. cDNA arrays were used to screen for downstream targets of IGF2R, specifically homeobox gene transcription factors and apoptosis-related genes. Functional effects of silencing IGF2R were then verified by β-hCG ELISA, caspase activity assays and a real-time electrical cell-impedance assay for differentiation, apoptosis and cell growth potential, respectively. IGF2R expression was significantly decreased in placentas from pregnancies complicated by idiopathic FGR (P < 0.05 versus control). siRNA-mediated IGF2R knockdown in term placental explants and the trophoblast cell line BeWo resulted in altered expression of homeobox gene transcription factors, including increased expression of distal-less homeobox gene 5 (DLX5), and decreased expression of H2.0-Like Homeobox 1 (HLX) (P < 0.05 versus control). Knockdown of IGF2R transcription increased the expression and activity of caspase-6 and caspase-8 in placental explants, decreased BeWo proliferation and increased BeWo differentiation (all P < 0.05 compared to respective controls). This is the first study linking IGF2R placental expression with changes in the expression of homeobox genes that control cellular signalling pathways responsible for increased trophoblast cell apoptosis, which is a characteristic feature of FGR.

2008 ◽  
Vol 20 (9) ◽  
pp. 1
Author(s):  
A. Chui ◽  
B. Kalionis ◽  
S. Brennecke ◽  
P. Murthi

Trophoblast cells carry out important functions required for the development of the normal placenta. Disruption of these functions is associated with significant pregnancy disorders such as fetal growth restriction and pre-eclampsia. Transcription factors regulate trophoblast functions. We are interested in one such class of transcription factors known as homeobox genes. The homeobox gene Distal-less 3 (DLX3) plays a vital role in the development of the mouse placenta (Morasso, Grinberg et al. 1999) and increased levels of DLX3 have been found in placentae affected by human fetal growth restriction (Murthi and Chui, unpubl. data). However, the function of DLX3 in the human placenta is not well established. Here, we investigated whether DLX3 regulates trophoblast differentiation using a plasmid construct to overexpress DLX3 in the human trophoblast cell line, BeWo. Real-time PCR showed a significant increase in DLX3 mRNA (3.1 ± 0.1 v. 1.0 ± 0.2 control, P < 0.05, n = 3), as well as the mRNA of two known markers of differentiation 3-β-hydroxysteroid dehydrogenase (3β-HSD) (8.1 ± 1.8 v. 1.2 ± 0.1 control, P < 0.05, n = 3) and β-human chorionic gonadotropin (β-hCG) (54.9 ± 0.9 v. 49.2 ± 1.6 control, P < 0.05, n = 3). Furthermore, forskolin mediated trophoblast differentiation was verified in BeWo cells. Following forskolin induction, real-time PCR showed a significant increase in the expression of DLX3 mRNA (12.9 ± 1.2 v. 3.8 ± 0.9 control, P < 0.05, n = 4), as well as a significant increase in the mRNA expression of the differentiation markers previously tested, 3β-HSD (28.3 ± 2.4 v. 1.0 ± 0.08 control, P < 0.05, n = 4) and β-hCG (2.3 ± 1.9 v. 30.9 ± 0.08 control, P < 0.001, n = 3). The expression of an additional differentiation marker, syncytin, was also significantly increased (4.0 ± 1.9 v. 1.0 ± 0.08 control, P < 0.05, n = 4). Thus, we have shown that DLX3 is a regulator of human trophoblast cell differentiation, and that forskolin acts through DLX3 to induce trophoblast differentiation. (1) Morasso, M. I., A. Grinberg et al. (1999).


2008 ◽  
Vol 20 (9) ◽  
pp. 20
Author(s):  
G. Rajaraman ◽  
P. Murthi ◽  
S. P. Brennecke ◽  
B. Kalionis

Homeobox gene transcription factors play critical roles in normal placental development and are expressed in specialised trophoblast cells. Abnormal trophoblast cell function is associated with pregnancy disorders including fetal growth restriction. Our studies show homeobox gene HLX expression in trophoblast cells (1) and that HLX is significantly decreased in fetal growth restriction (2). HLX gene inactivation in cultured trophoblast cells shows that HLX is a regulator of cytokine-dependent trophoblast proliferation (3). Hepatocyte growth factor (HGF) activates trophoblast cell migration in a paracrine fashion and its receptor, c-met, is expressed in trophoblast cells. This study investigates the regulation of HGF/c-met mediated trophoblast migration by HLX, in two human trophoblast cell lines SGHPL-4 and HTR-8/SVNeo. HGF stimulation significantly increased HLX mRNA expression (e.g. 43.2 ± 2.5, HGF v. 18.4 ± 1.7 control, densitometric units, P < 0.001, n = 3). siRNA-mediated inactivation of HLX resulted in significantly decreased trophoblast migration (e.g. 32 ± 4, siRNA v. 127 ± 12 control, migrated cells, P < 0.05, n = 4). When HLX was inactivated in the presence of HGF stimulation, migration remained significantly decreased (e.g. 112 ± 15, siRNA + HGF v. 368 ± 44 HGF, migrated cells, P < 0.05, n = 4). In order to determine if HGF is acting via the c-met receptor, the Met tyrosine kinase inhibitor, SU11274, was employed to inhibit c-met activity. c-met inhibition resulted in significantly reduced HLX mRNA expression (e.g. 2.1 ± 0.32, SU11274 v. 12.3 ± 1.4 control, densitometric units, P < 0.05, n = 3). HLX expression remained significantly reduced with HGF stimulation and SU11274 mediated c-met inhibition (e.g. 8.02 ± 1.3, SU11274 v. 38.3 ± 5.4 HGF, densitometric units, P < 0.05, n = 3). This is the first study to show that homeobox gene HLX is a downstream effector gene of HGF, that HLX regulates trophoblast migration and that HGF, via its receptor c-met, acts through HLX to control cell migration. (1) Rajaraman G, Murthi P, Quinn L, Brennecke SP, Kalionis B. Homeodomain protein HLX is expressed primarily in cytotrophoblast cell types in the early human placenta. (2008) Reproduction, Fertility a (2) Murthi P, Doherty V, Said J, Donath S, Brennecke SP, Kalionis B. Homeobox gene HLX1 expression is decreased in idiopathic human fetal growth restriction. (2006) Am J Pathol. 2006 Feb;168(2):511–8. (3) Rajaraman G, Murthi P, Leo B, Brennecke SP, Kalionis B. Homeobox gene HLX1 is a regulator of colony stimulating factor-1 dependent cell proliferation. (2007) Placenta Volume 28, Issue 10, October


2002 ◽  
Vol 283 (4) ◽  
pp. E794-E798 ◽  
Author(s):  
Randall J. Urban ◽  
Yvonne Bodenburg

An insulin-like growth factor I (IGF-I) response element (IGFRE) in the porcine P-450 cholesterol side-chain cleavage gene (P450scc) binds two transcription factors, Sp1 and polypyrimidine tract-binding protein-associated splicing factor (PSF). In this study, we investigated expression of these transcription factors in mouse Y1 adrenal cells, a cell line that does not increase P450scc expression in response to IGF-I. Western blot analysis showed a greater expression of PSF in Y1 cells when compared with a mouse fibroblast cell line (NWTb3) in which IGF-I stimulates the P450scc IGFRE. The two cell lines expressed Sp1 equally, and IGF-I did not increase expression of either transcription factor. Chromatin immunoprecipitation analysis with Y1 chromatin confirmed that PSF and Sp1 bound to the IGFRE. When increasing amounts of Sp1 were expressed in Y1 cells, the IGFRE became responsive to IGF-I. Moreover, a mutant oligonucleotide IGFRE reporter construct that lacks PSF binding was responsive to IGF-I. In conclusion, Y1 adrenal cells are a physiological example of PSF repression of growth factor-stimulated (IGF-I) gene expression (P450scc). The dynamic nature of this repression is consistent with PSF functioning as a regulator of growth factor-stimulated gene expression in mammalian cells.


1995 ◽  
Vol 129 (3) ◽  
pp. 843-851 ◽  
Author(s):  
J Zheng ◽  
O Saksela ◽  
S Matikainen ◽  
A Vaheri

Various factors are known to regulate cell growth and differentiation in epithelial-mesenchymal interactions. Keratinocyte growth factor (KGF), an epithelial-specific cytokine produced by dermal fibroblasts and other mesenchymal cells, appears to affect growth, migration, and differentiation in epithelial-mesenchymal interactions. We have previously shown that human embryonic skin fibroblasts induce anchorage-independent growth of HPV16 DNA-immortalized human uterine exocervical epithelial cells (HCE16/3 cell line) in cocultures of HCE16/3 cells and fibroblasts. Here we report that KGF may be a major factor influencing growth and behavior of HCE16/3 cells in the coculture system. KGF stimulated both DNA synthesis and proliferation of normal human cervical epithelial (HCE) cells and HCE16/3 cells and the increase was stronger in HCE16/3 cells than in HCE cells. SiHa cells, a cervical carcinoma cell line with integrated HPV16 DNA, did not respond to the KGF mitogen signal. KGF receptor (KGFR) studies suggested that the different responses to the KGF mitogen signal may be correlated with KGFR. In addition, KGF alone was able to induce anchorage-independent growth of HCE16/3 cells, suggesting a potential role for KGF in the transformation process of epithelial cells. However, the transcription of HPV16 early genes was suppressed by KGF in the immortalized HCE16/3 cells, and this appeared to be due to transcriptional repression rather than a posttranscriptional process according to nuclear run-on analysis. In contrast, viral gene expression was not affected by KGF in SiHa cells. Our results suggest that KGF is a bifunctional growth factor in the HPV-immortalized cells, a positive regulator of cell growth and negative regulator of HPV16 early gene expression.


2000 ◽  
Vol 278 (5) ◽  
pp. C982-C988 ◽  
Author(s):  
Roni Levy ◽  
Steven D. Smith ◽  
Kala Chandler ◽  
Yoel Sadovsky ◽  
D. Michael Nelson

Preeclampsia and fetal growth restriction are associated with placental hypoperfusion and villous hypoxia. The villous response to this environment includes diminished trophoblast differentiation and enhanced apoptosis. We tested the hypothesis that hypoxia induces apoptosis in cultured trophoblasts, and that epidermal growth factor (EGF), an enhancer of trophoblast differentiation, diminishes hypoxia-induced apoptosis. Trophoblasts isolated from placentas of term-uncomplicated human pregnancies were cultured up to 72 h in standard ([Formula: see text]= 120 mmHg) or hypoxic ([Formula: see text] < 15 mmHg) conditions. Exposure to hypoxia for 24 h markedly enhanced trophoblast apoptosis as determined by DNA laddering, internucleosomal in situ DNA fragmentation, and histomorphology, as well as by the reversibility of the apoptotic process with a caspase inhibitor. Apoptosis was accompanied by increased expression of p53 and Bax and decreased expression of Bcl-2. Addition of EGF to cultured trophoblasts or exposure of more differentiated trophoblasts to hypoxia significantly lowered the level of apoptosis. We conclude that hypoxia enhances apoptosis in cultured trophoblasts by a mechanism that involves an increase in p53 and Bax expression. EGF and enhancement of cell differentiation protect against hypoxic-induced apoptosis.


2016 ◽  
Vol 46 (14) ◽  
pp. 2999-3011 ◽  
Author(s):  
A. B. Janssen ◽  
L. E. Capron ◽  
K. O'Donnell ◽  
S. J. Tunster ◽  
P. G. Ramchandani ◽  
...  

BackgroundMaternal prenatal stress during pregnancy is associated with fetal growth restriction and adverse neurodevelopmental outcomes, which may be mediated by impaired placental function. Imprinted genes control fetal growth, placental development, adult behaviour (including maternal behaviour) and placental lactogen production. This study examined whether maternal prenatal depression was associated with aberrant placental expression of the imprinted genes paternally expressed gene 3 (PEG3), paternally expressed gene 10 (PEG10), pleckstrin homology-like domain family a member 2 (PHLDA2) and cyclin-dependent kinase inhibitor 1C (CDKN1C), and resulting impaired placental human placental lactogen (hPL) expression.MethodA diagnosis of depression during pregnancy was recorded from Manchester cohort participants’ medical notes (n = 75). Queen Charlotte's (n = 40) and My Baby and Me study (MBAM) (n = 81) cohort participants completed the Edinburgh Postnatal Depression Scale self-rating psychometric questionnaire. Villous trophoblast tissue samples were analysed for gene expression.ResultsIn a pilot study, diagnosed depression during pregnancy was associated with a significant reduction in placental PEG3 expression (41%, p = 0.02). In two further independent cohorts, the Queen Charlotte's and MBAM cohorts, placental PEG3 expression was also inversely associated with maternal depression scores, an association that was significant in male but not female placentas. Finally, hPL expression was significantly decreased in women with clinically diagnosed depression (44%, p < 0.05) and in those with high depression scores (31% and 21%, respectively).ConclusionsThis study provides the first evidence that maternal prenatal depression is associated with changes in the placental expression of PEG3, co-incident with decreased expression of hPL. This aberrant placental gene expression could provide a possible mechanistic explanation for the co-occurrence of maternal depression, fetal growth restriction, impaired maternal behaviour and poorer offspring outcomes.


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