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Dive into the research topics where Sandra Haider is active.

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Featured researches published by Sandra Haider.


Endocrinology | 2009

Identification of Novel Trophoblast Invasion-Related Genes: Heme Oxygenase-1 Controls Motility via Peroxisome Proliferator-Activated Receptor γ

Martin Bilban; Peter Haslinger; Johanna Prast; Florian Klinglmüller; Thomas Woelfel; Sandra Haider; Alexander Sachs; Leo E. Otterbein; Gernot Desoye; Ursula Hiden; Oswald Wagner; Martin Knöfler

Invasion of cytotrophoblasts (CTBs) into uterine tissues is essential for placental development. To identify molecules regulating trophoblast invasion, mRNA signatures of purified villous (CTB, poor invasiveness) and extravillous trophoblasts (EVTs) (high invasiveness) isolated from first trimester human placentae and villous explant cultures, respectively, were compared using GeneChip analyses yielding 991 invasion/migration-related transcripts. Several genes involved in physiological and pathological cell invasion, including A disintegrin and metalloprotease-12, -19, -28, as well as Spondin-2, were up-regulated in EVTs. Pathway prediction analyses identified several functional modules associated with either the invasive or noninvasive trophoblast phenotype. One of the genes that was down-regulated in the invasive mRNA pool, heme oxygenase-1 (HO-1), was selected for functional analyses. Real-time PCR analyses, Western blotting, and immunofluorescence of first trimester placentae and differentiating villous explant cultures demonstrated down-regulation of HO-1 in invasive EVTs as compared with CTBs. Modulation of HO-1 expression in loss-of as well as gain-of function cell models (BeWo and HTR8/SVneo, respectively) demonstrated an inverse relationship of HO-1 expression with trophoblast migration in transwell and wound healing assays. Importantly, HO-1 expression led to an increase in protein levels and activity of the nuclear hormone receptor peroxisome proliferator activated receptor (PPAR) gamma. Pharmacological inhibition of PPARgamma abrogated the inhibitory effects of HO-1 on trophoblast migration. Collectively, our results demonstrate that gene expression profiling of EVTs and CTBs can be used to unravel novel regulators of cell invasion. Accordingly, we identify HO-1 as a negative regulator of trophoblast motility acting via up-regulation of PPARgamma.


Journal of Nutrition Health & Aging | 2014

Association between nutritional status (MNA®-SF) and frailty (SHARE-FI) in acute hospitalised elderly patients

Thomas Dörner; Eva Luger; J. Tschinderle; K. V. Stein; Sandra Haider; Ali Kapan; Christian Lackinger; Karin Schindler

ObjectiveThis study aimed to explore the association between the impaired nutritional status and frailty in acute hospitalised elderly patients by using two tools, the MNA®-SF (Mini Nutritional Assessment® short-form) and the SHARE-FI (Frailty Instrument for Primary Care of the Survey of Health, Ageing and Retirement in Europe).DesignCross-sectional study.SettingAcute hospitalised, community-dwelling elderly patients were recruited at internal medicine wards in Vienna, Austria.Participants133 men (39%) and women (61%) aged 74 (65–97) years.MeasurementsMNA®-SF was used to investigate malnutrition (<7 points) and patients at risk of malnutrition (8 to 11 points). By using the SHARE-FI, subjects were classified as frail, pre-frail or robust. A factor analysis was applied to identify overlaps between the MNA®-SF and SHARE-FI items. Internal consistency of different dimensions was assessed by using Cronbach’s Alpha.ResultsMalnutrition or risk of malnutrition was found in 76.7% of the total sample and in 46.8% of robust, in 69.0% of pre-frail, and in 93.0% of frail participants. Frailty or prefrailty was found in 75.9% of the total sample and in 45.1% of the subjects with no risk of malnutrition, in 80.9% of subjects at risk of malnutrition, and in 94.1% of malnourished patients. The two used tools show overlaps in three dimensions: (1) nutrition problems, (2) mobility problems and (3) anthropometric items with a moderate to strong internal consistency (Cronbach’s Alpha of 0.670, 0.834 and 0.946, respectively). 64.7% of the total sample (79.5% of frail and 87.9% of malnourished subjects) would participate in a home-based muscle training and nutritional intervention program.ConclusionsThis study underlines the association and the overlap between frailty and impaired nutritional status. There is a high readiness to participate in a program to tackle the problems associated with malnutrition and frailty, especially in those, who would benefit most from it.


Endocrinology | 2014

Notch Signaling Plays a Critical Role in Motility and Differentiation of Human First-Trimester Cytotrophoblasts

Sandra Haider; Gudrun Meinhardt; Philipp Velicky; Gerlinde R. Otti; Guy Whitley; Christian Fiala; Jürgen Pollheimer; Martin Knöfler

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.


Endocrinology | 2011

Endostatin Suppresses IGF-II-Mediated Signaling and Invasion of Human Extravillous Trophoblasts

Jürgen Pollheimer; Peter Haslinger; Valerie Fock; Johanna Prast; Leila Saleh; Katarzyna Biadasiewicz; Reidunn Jetne-Edelmann; Guttorm Haraldsen; Sandra Haider; Kora Hirtenlehner-Ferber; Martin Knöfler

Endostatin, a biological active fragment of the extracellular matrix protein collagen XVIII, is known to interfere with cellular motility in the context of pathological angiogenesis. However, the physiological role of endostatin remains largely elusive. Recent evidence suggested that the inhibitor is produced in human decidual cells of early pregnancy, indicating that endostatin could be involved in diverse reproductive processes, such as implantation and/or placental differentiation. To gain more insights into the role of endostatin, we here analyzed its effects on trophoblast motility, proliferation, and signaling using purified primary trophoblasts, first-trimester villous explant cultures, and trophoblastic SGHPL-5 cells. In vitro Transwell assays demonstrated that purified endostatin inhibited both basal and IGF-II-induced migration and invasion as well as outgrowth from villous explant cultures. In contrast, basal and IGF-II-stimulated proliferation was unaffected upon addition of the inhibitor. Analyses of IGF-II-associated downstream signaling events showed that endostatin interfered with activation of various signaling kinases such as ERK1/2, protein kinase B (Akt)/mammalian target of rapamycin/p70 S6 kinase, and focal adhesion kinase. Furthermore, virus-mediated, stable gene silencing of Akt1 in SGHPL-5 cells using a micro-RNA-adapted short hairpin RNA-expressing plasmid revealed that endostatin-mediated inhibition of IGF-II-induced Akt phosphorylation was critically dependent on the expression of the particular isoform. In conclusion, the data suggest that endostatin could be a physiological inhibitor of IGF-II-dependent trophoblast cell motility by suppressing focal adhesion kinase/Akt/mammalian target of rapamycin/p70 S6 kinase signaling.


Biology of Reproduction | 2013

AKT Isoforms 1 and 3 Regulate Basal and Epidermal Growth Factor-Stimulated SGHPL-5 Trophoblast Cell Migration in Humans

Peter Haslinger; Sandra Haider; Stefan Eugen Sonderegger; Jan Velten Otten; Jürgen Pollheimer; Guy Whitley; Martin Knöfler

ABSTRACT Protein kinase B/AKT is critically involved in murine placental development and migration of human placental trophoblasts into maternal uterine tissue. However, localization of the three AKT isoforms within human placenta and their roles in extravillous trophoblasts have not been elucidated. Therefore, we analyzed the expression pattern and function of AKT1, AKT2, and AKT3 in migratory human trophoblasts using SGHPL-5 cell pools stably expressing small-hairpin microRNA (shRNAmir) against AKT1, AKT2, or AKT3 as a model. Western blot analyses using isoform-specific antibodies revealed ubiquitous expression of AKT1, AKT2, and AKT3 in primary villous and extravillous trophoblasts and the trophoblastic cell lines JEG-3, HTR-8/SVneo, and SGHPL-5. Immunofluorescence of first-trimester placentae localized AKT2 and AKT3 to the cytoplasm and nucleus, respectively, in all subtypes of cytotrophoblasts, whereas AKT1 was detected in both cellular compartments. A similar distribution of AKT isoforms was detectable in SGHPL-5 cells. Gene silencing using shRNAmir decreased protein expression of AKT1, AKT2, and AKT3 to 16%, 8%, and 11%, respectively, in SGHPL-5 cells. Compared with shRNAmir controls, proliferation and camptothecin-induced apoptosis were not affected in the different AKT knockdown cells. However, basal and epidermal growth factor (EGF)-induced trophoblast migration was significantly reduced in AKT1 and AKT3 gene-silenced cells, whereas downregulation of AKT2 was not effective. Accordingly, a decrease in EGF-stimulated phosphorylation of AKT (Ser473 and Thr308) and its downstream target mTORC1 (Ser2448) was noticed in AKT1 and AKT3 shRNAmir cell pools. In summary, the results suggest that the AKT isoforms 1 and 3 promote basal as well as EGF-induced trophoblast migration.


Proceedings of the National Academy of Sciences of the United States of America | 2016

Notch1 controls development of the extravillous trophoblast lineage in the human placenta

Sandra Haider; Gudrun Meinhardt; Leila Saleh; Christian Fiala; Jürgen Pollheimer; Martin Knöfler

Significance Progenitor trophoblast cells of the human placenta either fuse to form a syncytium or develop into invasive trophoblasts invading the maternal uterus. However, regulatory pathways controlling their development and distinct differentiation programs are poorly understood. In the present study, we demonstrate that Notch1 is a critical regulator of early pregnancy, promoting development of the invasive, extravillous trophoblast lineage and survival of its progenitors. In vivo, Notch1 is detected in extravillous trophoblast progenitors and clusters of villous trophoblast initiating the invasive differentiation program. In vitro, Notch1 repressed genes involved in self-renewal of fusogenic precursors, but induced genes specifically expressed by extravillous trophoblast progenitors. Our data delineate Notch1 as a key regulator promoting development of the human extravillous trophoblast lineage. Development of the human placenta and its different epithelial trophoblasts is crucial for a successful pregnancy. Besides fusing into a multinuclear syncytium, the exchange surface between mother and fetus, progenitors develop into extravillous trophoblasts invading the maternal uterus and its spiral arteries. Migration into these vessels promotes remodelling and, as a consequence, adaption of blood flow to the fetal–placental unit. Defects in remodelling and trophoblast differentiation are associated with severe gestational diseases, such as preeclampsia. However, mechanisms controlling human trophoblast development are largely unknown. Herein, we show that Notch1 is one such critical regulator, programming primary trophoblasts into progenitors of the invasive differentiation pathway. At the 12th wk of gestation, Notch1 is exclusively detected in precursors of the extravillous trophoblast lineage, forming cell columns anchored to the uterine stroma. At the 6th wk, Notch1 is additionally expressed in clusters of villous trophoblasts underlying the syncytium, suggesting that the receptor initiates the invasive differentiation program in distal regions of the developing placental epithelium. Manipulation of Notch1 in primary trophoblast models demonstrated that the receptor promotes proliferation and survival of extravillous trophoblast progenitors. Notch1 intracellular domain induced genes associated with stemness of cell columns, myc and VE-cadherin, in Notch1− fusogenic precursors, and bound to the myc promoter and enhancer region at RBPJκ cognate sequences. In contrast, Notch1 repressed syncytialization and expression of TEAD4 and p63, two regulators controlling self-renewal of villous cytotrophoblasts. Our results revealed Notch1 as a key factor promoting development of progenitors of the extravillous trophoblast lineage in the human placenta.


Biology of Reproduction | 2014

Extravillous Trophoblast-Associated ADAM12 Exerts Pro-Invasive Properties, Including Induction of Integrin Beta 1-Mediated Cellular Spreading

Katarzyna Biadasiewicz; Valerie Fock; Sabine Dekan; Katharina Proestling; Philipp Velicky; Sandra Haider; Martin Knöfler; Camilla Fröhlich; Jürgen Pollheimer

ABSTRACT ADAM12, consisting of a membrane-bound (ADAM12L) and a secreted (ADAM12S) form, is expressed exclusively in regenerating and developing tissue as well as in certain cancer types. Strong ADAM12 expression levels have been noticed in the human placenta, and deregulated ADAM12S levels were associated with various pregnancy-related disorders including pre-eclampsia and intrauterine growth restriction. However, the role of ADAM12 in trophoblast motility has not been investigated so far. Hence, the present study aimed to investigate the specific function of the protease by using different primary trophoblast cell models. Immunofluorescence and Western blot analyses of first trimester placental tissue and differentiating primary first trimester cytotrophoblasts (CTBs) indicated strong upregulation of both of the ADAM12 isoforms during extravillous trophoblast differentiation. Functional assays involving short interfering RNA (siRNA)-mediated knockdown studies in primary CTBs and first trimester explant cultures revealed a significant repression of trophoblast motility upon partial loss of ADAM12. Conversely, isoform-specific overexpression in the ADAM12-negative trophoblast cell line SGHPL-5 enhanced the invasive capacity of these cells. We further confirmed proteolytic activity of trophoblast-derived ADAM12S by demonstrating its potential to degrade insulin-like growth factor-binding protein 3. Finally, we suggest that ADAM12S exerts its pro-migratory function in trophoblasts by inducing integrin beta 1-mediated cellular spreading.


Reproductive Sciences | 2008

β-HCG/LH Receptor (β-HCG/LH-R) Expression in Eutopic Endometrium and Endometriotic Implants: Evidence for β-HCG Sensitivity of Endometriosis

Gernot Hudelist; Ambros Huber; Martin Knoefler; Sandra Haider; Andrea Kolbus; Klaus Czerwenka; Samir Helmy; E. Kubista; Christian F. Singer

Background: Luteinizing hormone (LH) and human chorionic gonadotropin (HCG) target their receptor in gonadal and nongonadal cells to stimulate steroidogenesis and cell growth. The aim of the present study was to investigate the expression of HCG/LH-R in endometriosis to elucidate a possible impact of LH and HCG on this disease. Materials and methods: Analysis of HCG/LH-R protein expression in 23 paired samples of ectopic and eutopic tissue of cycling women with endometriosis and in endometrial samples from 22 healthy controls was conducted via immunofluorescence. HCG and HCG/LH-R gene expression in endometriotic lesions was confirmed by reverse-transcriptase polymerase chain reaction. Results: In endometriotic implants, epithelial HCG/LH-R was found in 12/23 samples. No significant differences in HCG/LH-R levels were observed when compared with glands of uterine endometrium from the same patients or healthy controls. Messenger RNA transcripts for HCG were detected in all 12 samples, whereas HCG/LH-R mRNAs were observed in 10 of the 12 endometriotic lesions investigated. Conclusions: Although HCG/LH-R was not found to be selectively upregulated in endometriosis, the mere presence of HCG/LH-R in endometriotic tissue may suggest sensitivity of endometriosis to HCG and LH that target HCG/LH-R.


Archives of Gerontology and Geriatrics | 2017

Fear of falling reduced by a lay led home-based program in frail community-dwelling older adults: A randomised controlled trial.

Ali Kapan; Eva Luger; Sandra Haider; Karin Schindler; C. Lackinger; Thomas Dörner

BACKGROUND In older adults, fear of falling (FOF) leads to a decline in daily physical activity quality of life and an increased risk of falling. The aim of this randomised controlled trial was to assess the effects of a 12-week home-based intervention program carried out by lay volunteers on FOF in frail older adults. METHODS Thirty-nine participants were randomised to a physical training and nutrition (PTN) group and 41 participants to a social support (SOSU) group. In the PTN group, strength training and conversation about optimising nutrition were performed twice weekly, and the SOSU group received home visits without intervention. FOF and change of FOF were assessed using the Falls Efficacy Scale - International (FES-I). The Short Physical Performance Battery (SPPB), the Physical Activity Scale for the Elderly (PASE) and maximum handgrip strength and their changes were also assessed. RESULTS The mean FES-I score at baseline was 42.7 points and was significantly associated with the SPPB and PASE scores. The FES-I score significantly changed in the PTN group from 44.1 to 39.9 points over the course of the intervention. Twenty-seven percent of the participants showed a decreased FES-I score of at least 4 points. This decrease was associated with an increase in the SPPB score and an increase in handgrip strength CONCLUSION: A 12-week structured physical training and nutrition intervention carried out by lay volunteers, which leads to an increase in physical activity and improved physical performance, can reduce FOF by about 10%.


PLOS ONE | 2017

Impact of a Home-Based Physical and Nutritional Intervention Program Conducted by Lay-Volunteers on Handgrip Strength in Prefrail and Frail Older Adults: A Randomized Control Trial

Sandra Haider; Thomas Dörner; Eva Luger; Ali Kapan; Christian Lackinger; Karin Schindler

A randomized controlled trial was performed to compare the effects of a home-based physical and nutritional intervention program carried out by lay-volunteers to home visits with social support alone. Buddies visited 80 prefrail or frail older persons at home twice a week for 12 weeks. The physical training and nutrition group (PTN, n = 39) performed two sets of six strength exercises, discussed nutritional topics and received social support. The social support group (SoSu, n = 41) received home visits with social support only. In the PTN group, handgrip strength increased significantly by 2.4 kg (95% CI: 1.0–3.8). In the SoSu group we did not see a significant improvement. However, no significant between-group difference was found. Physical performance increased in both groups, although with a higher increase of 1.0 point (95% CI: 0.1–2.0) in the PTN group. In none of the groups muscle mass changed. Further results showed that frail individuals benefit more from the intervention than prefrail individuals (OR: 2.78; 95% CI: 1.01–7.66). Handgrip strength in the intervention group increased by a clinically relevant value and this effect is comparable to that obtained by health-care professionals. Therefore, home visits with a physical training and nutritional program could offer a new perspective in the care of community-dwelling prefrail and frail older persons.

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Dive into the Sandra Haider's collaboration.

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Thomas Dörner

Medical University of Vienna

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Ali Kapan

Medical University of Vienna

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Karin Schindler

Medical University of Vienna

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Martin Knöfler

Medical University of Vienna

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Eva Luger

Medical University of Vienna

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Jürgen Pollheimer

Medical University of Vienna

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Gudrun Meinhardt

Medical University of Vienna

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Igor Grabovac

Medical University of Vienna

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Leila Saleh

Medical University of Vienna

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Peter Haslinger

Medical University of Vienna

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