0000000000004852

AUTHOR

Ulrich Zechner

Four unrelated patients with lubs X-linked mental retardation syndrome and different Xq28 duplications

The Lubs X-linked mental retardation syndrome (MRXSL) is caused by small interstitial duplications at distal Xq28 including the MECP2 gene. Here we report on four novel male patients with MRXSL and different Xq28 duplications delineated by microarray-based chromosome analysis. All mothers were healthy carriers of the duplications. Consistent with an earlier report [Bauters et al. (2008); Genome Res 18: 847-858], the distal breakpoints of all four Xq28 duplications were located in regions containing low-copy repeats (LCRs; J, K, and L groups), which may facilitate chromosome breakage and reunion events. The proximal breakpoint regions did not contain known LCRs. Interestingly, we identified …

research product

Interferon-α Suppresses cAMP to Disarm Human Regulatory T Cells

Abstract IFN-α is an antineoplastic agent in the treatment of several solid and hematologic malignancies that exerts strong immune- and autoimmune-stimulating activity. However, the mechanisms of immune activation by IFN-α remain incompletely understood, particularly with regard to CD4+CD25highFoxp+ regulatory T cells (Treg). Here, we show that IFN-α deactivates the suppressive function of human Treg by downregulating their intracellular cAMP level. IFN-α–mediated Treg inactivation increased CD4+ effector T-cell activation and natural killer cell tumor cytotoxicity. Mechanistically, repression of cAMP in Treg was caused by IFN-α–induced MAP–ERK kinase (MEK)/extracellular signal-regulated ki…

research product

The FOXP2-Driven Network in Developmental Disorders and Neurodegeneration

The transcription repressor FOXP2 is a crucial player in nervous system evolution and development of humans and songbirds. In order to provide an additional insight into its functional role we compared target gene expression levels between human neuroblastoma cells (SH-SY5Y) stably overexpressing either human FOXP2 cDNA or its orthologues from the common chimpanzee, Rhesus monkey, and marmoset, respectively. Subsequent RNA-seq led to identification of 27 genes with differential regulation under the control of human FOXP2, which were previously reported to have FOXP2-driven and/or songbird song-related expression regulation. Importantly, RT-qPCR and Western blotting indicated differential re…

research product

Conserved synteny of mammalian imprinted genes in chicken, frog, and fish genomes

Conservation of synteny of mammalian imprinted genes between chicken and human suggested that highly conserved gene clusters were selected long before these genes were recruited for genomic imprinting in mammals. Here we have applied in silico mapping of orthologous genes in pipid frog, zebrafish, spotted green and Japanese pufferfish to show considerable conservation of synteny in lower vertebrates. More than 400 million years ago in a common ancestor of teleost fish and tetrapods, ‘preimprinted’ chromosome regions homologous to human 6q25, 7q21, 7q32, 11p15, and 15q11→q12 already contained most present-day mammalian imprinted genes. Interestingly, some imprinted gene orthologues which are…

research product

Inheritance and variable expression in Rubinstein-Taybi syndrome.

Familial Rubinstein-Taybi syndrome (RTS) is very rare. Here we report on the 6th and 7th case of inherited RTS. Family 1 presents with incomplete or mild RTS over three generations; a 13-year-old girl (proband 1) with mild but typical facial features and learning disabilities, her very mildly affected mother (proband 2), and the maternal grandmother (proband 3). Family 2 includes three females with classical RTS (probands 4-6) and their father (proband 7) with broad thumbs and halluces. Proband 5 also had a brain tumor (ganglioglioma) at the age of 3 years. In probands 1-3, direct sequencing identified a novel CREBBP missense mutation, c.2728A > G (predicting p.Thr910Ala), that was absent i…

research product

The Disease-Specific Phenotype in Cardiomyocytes Derived from Induced Pluripotent Stem Cells of Two Long QT Syndrome Type 3 Patients

Long QT syndromes (LQTS) are heritable diseases characterized by prolongation of the QT interval on an electrocardiogram, which often leads to syncope and sudden cardiac death. Here we report the generation of induced pluripotent stems (iPS) cells from two patients with LQTS type 3 carrying a different point mutation in a sodium channel Nav1.5 (p.V240M and p.R535Q) and functional characterization of cardiomyocytes (CM) derived from them. The iPS cells exhibited all characteristic properties of pluripotent stem cells, maintained the disease-specific mutation and readily differentiated to CM. The duration of action potentials at 50% and 90% repolarization was longer in LQTS-3 CM as compared t…

research product

Gene Expression and Epigenetic Signatures of Germ Cell-Derived Pluripotent Stem Cells and Embryonic Stem Cells

Germ cell-derived Pluripotent Stem Cells (gPSCs) are pluripotent stem cells that originate from Spermatogonial Stem Cells (SSCs) of the testis. Several reports in the last few years have shown that it is possible to isolate and enrich the SSC population by different approaches and even reprogram these in vivo multipotent cells to gPSCs in vitro. As these cells could be an alternative to circumvent the ethical objections regarding the use of Embryonic Stem Cells (ESCs) for therapeutic approaches, these SSC-derived gPSCs were characterized in several studies comparatively to the gold standard of pluripotency, the ESCs. The results ­provide great promise that gPSCs can be of importance for pra…

research product

PSCDGs of mouse multipotent adult germline stem cells can enter and progress through meiosis to form haploid male germ cells in vitro

Spermatogonial stem cells (SSCs) provide the basis for spermatogenesis throughout adult life by undergoing self-renewal and differentiation into sperm. SSC-derived cell lines called multipotent adult germline stem cells (maGSCs) were recently shown to be pluripotent and to have the same potential as embryonic stem cells (ESCs). In a differentiation protocol using retinoic acid (RA) and based on a double selection strategy, we have shown that ESCs are able to undergo meiosis and produce haploid male germ cells in vitro. Using this differentiation protocol we have now succeeded to generate haploid male germ cells from maGSCs in vitro. maGSCs derived from a Stra8-EGFP transgenic mouse line wer…

research product

GADD45α is highly expressed in pancreatic ductal adenocarcinoma cells and required for tumor cell viability

Pancreatic ductal adenocarcinoma is one of the most common causes of cancer death in the western civilization. Recently, NF-kappaB has been shown to be activated in pancreatic ductal adenocarcinoma through constitutive activation of IkappaB kinase (IKK). Inhibition of NF-kappaB by a super-inhibitor of NF-kappaB--delta-N-IkappaBalpha--resulted in impaired proliferation and induction of apoptosis, suggesting an important role of NF-kappaB in pancreatic tumorigenesis. Downstream target genes of IkappaBalpha have not been elucidated in pancreatic ductal adenocarcinoma in detail. Using expression profiling by cDNA array analysis of pancreatic ductal adenocarcinoma cell lines stably transfected w…

research product

Expression profiling of uniparental mouse embryos is inefficient in identifying novel imprinted genes

AbstractImprinted genes are expressed from only one allele in a parent-of-origin-specific manner. We here describe a systematic approach to identify novel imprinted genes using quantification of allele-specific expression by Pyrosequencing, a highly accurate method to detect allele-specific expression differences. Sixty-eight candidate imprinted transcripts mapping to known imprinted chromosomal regions were selected from a recent expression profiling study of uniparental mouse embryos and analyzed. Three novel imprinted transcripts encoding putative non-protein-coding RNAs were identified on the basis of parent-of-origin-specific monoallelic expression in E11.5 (C57BL/6 × Cast/Ei)F1 and in…

research product

Inhibition of histone deacetylation rescues phenotype in a mouse model of Birk-Barel intellectual disability syndrome

Mutations in the actively expressed, maternal allele of the imprinted KCNK9 gene cause Birk-Barel intellectual disability syndrome (BBIDS). Using a BBIDS mouse model, we identify here a partial rescue of the BBIDS-like behavioral and neuronal phenotypes mediated via residual expression from the paternal Kcnk9 (Kcnk9pat) allele. We further demonstrate that the second-generation HDAC inhibitor CI-994 induces enhanced expression from the paternally silenced Kcnk9 allele and leads to a full rescue of the behavioral phenotype suggesting CI-994 as a promising molecule for BBIDS therapy. Thus, these findings suggest a potential approach to improve cognitive dysfunction in a mouse model of an impri…

research product

Identification of novel mutations in the ABCA12 gene, c.1857delA and c.5653–5655delTAT, causing harlequin ichthyosis

Abstract Harlequin ichthyosis (HI) is a severe autosomal recessive developmental disorder of the skin that is frequently but not always fatal in the first few days of life. In HI, mutations in both ABCA12 gene alleles must have a severe impact on protein function and most mutations are truncating. The presence of at least one nontruncating mutation (predicting a residual protein function) usually causes a less severe congenital ichthyosis (lamellar ichthyosis or congenital ichthyosiform erythroderma). Here we report on a girl with severe HI diagnosed by prenatal ultrasound at 33 5/7 week gestation. Ultrasound findings included ectropion, eclabium, deformed nose, hands and feet, joint contra…

research product

Stage-specific germ-cell marker genes are expressed in all mouse pluripotent cell types and emerge early during induced pluripotency.

Embryonic stem cells (ESCs) generated from the in-vitro culture of blastocyst stage embryos are known as equivalent to blastocyst inner cell mass (ICM) in-vivo. Though several reports have shown the expression of germ cell/pre-meiotic (GC/PrM) markers in ESCs, their functional relevance for the pluripotency and germ line commitment are largely unknown. In the present study, we used mouse as a model system and systematically analyzed the RNA and protein expression of GC/PrM markers in ESCs and found them to be comparable to the expression of cultured pluripotent cells originated from the germ line. Further, siRNA knockdown experiments have demonstrated the parallel maintenance and independen…

research product

In Vitro-Differentiated Embryonic Stem Cells Give Rise to Male Gametes that Can Generate Offspring Mice

SummaryMale gametes originate from a small population of spermatogonial stem cells (SSCs). These cells are believed to divide infinitely and to support spermatogenesis throughout life in the male. Here, we developed a strategy for the establishment of SSC lines from embryonic stem (ES) cells. These cells are able to undergo meiosis, are able to generate haploid male gametes in vitro, and are functional, as shown by fertilization after intracytoplasmic injection into mouse oocytes. Resulting two-cell embryos were transferred into oviducts, and live mice were born. Six of seven animals developed to adult mice. This is a clear indication that male gametes derived in vitro from ES cells by this…

research product

Promoter methylation status of ASC/TMS1/PYCARD is associated with decreased overall survival and TNM status in patients with early stage non-small cell lung cancer (NSCLC)

Background: Lung cancer is the leading cause of cancer-related death worldwide, with 5-year overall survival less than 15%. Therefore, it is essential to find biomarkers for early detection and prognosis. Aberrant DNA methylation is a common feature of human cancers and its utility is already recognized in cancer management. The aim of this study was to explore the diagnostic and prognostic value of the promoter methylation status of the ASC/TMS1/PYCARD and MyD88 genes, key adaptor molecules in the activation of the innate immune response and apoptosis pathways. Methods: A total of 50 non-small cell lung cancer (NSCLC) patients were enrolled in the study. Methylation of bisulphite converted…

research product

Isolation and differential expression of two isoforms of the ROBO2/Robo2 axon guidance receptor gene in humans and mice.

AbstractExpression of Robo receptor molecules is important for axon guidance across the midline of the mammalian central nervous system. Here we describe novel isoform a of human ROBO2, which is initially strongly expressed in the fetal human brain but thereafter only weakly expressed in adult brain and a few other tissues. The known isoform b of ROBO2 shows a more or less ubiquitous expression pattern, suggesting diverse functional roles. The genomic structure and distinct expression patterns of Robo2a and Robo2b have been conserved in the mouse, but in contrast to human ROBO2a mouse Robo2a is also abundant in adult brain. Exons 1 and 2 of human ROBO2a lie in an inherently unstable DNA seg…

research product

Extreme Methylation Values of Imprinted Genes in Human Abortions and Stillbirths

Imprinted genes play an important role in fetal and placental development. Using quantitative bisulfite pyrosequencing assays, we determined the DNA methylation levels at two paternally methylated (H19 and MEG3) and four maternally methylated (LIT1, NESP55, PEG3, and SNRPN) imprinted regions in fetal muscle samples from abortions and stillbirths. Two of 55 (4%) spontaneous abortions and 10 of 57 (18%) stillbirths displayed hypermethylation in multiple genes. Interestingly, none of 34 induced abortions had extreme methylation values in multiple genes. All but two abortions/stillbirths with multiple methylation abnormalities were male, indicating that the male embryo may be more susceptible t…

research product

Novel clinical findings in the first Egyptian case of Sotos syndrome caused by complete deletion of theNSD1gene

research product

Embryonic stem cell-related miRNAs are involved in differentiation of pluripotent cells originating from the germ line.

Cells originating from the germ cell lineage retain the remarkable property under special culture conditions to give rise to cells with embryonic stem cell (ESC) properties, such as the multipotent adult germline stem cells (maGSCs) derived from adult mouse testis. To get an insight into the mechanisms that control pluripotency and differentiation in these cells, we studied how differences observed during in vitro differentiation between ESCs and maGSCs are associated with differences at the level of microRNAs (miRNAs). In this work, we provide for a first time a connection between germ cell origin of maGSCs and their specific miRNA expression profile. We found that maGSCs express higher le…

research product

Confirmation of PDZD7 as a Nonsyndromic Hearing Loss Gene.

Objective PDZD7 was identified in 2009 in a family with apparent nonsyndromic sensorineural hearing loss. However, subsequent clinical reports have associated PDZD7 with digenic Usher syndrome, the most common cause of deaf-blindness, or as a modifier of retinal disease. No further reports have validated this gene for nonsyndromic hearing loss, intuitively calling correct genotype-phenotype association into question. This report describes a validating second case for biallelic mutations in PDZD7 causing nonsyndromic mild to severe sensorineural hearing loss. It also provides detailed audiometric and ophthalmologic data excluding Usher syndrome in both the present proband (proband 1) and the…

research product

Chicken orthologues of mammalian imprinted genes are clustered on macrochromosomes and replicate asynchronously.

In the chicken genome, most orthologues of mouse imprinted genes are clustered on macrochromosomes. Only a few orthologues are located in the microchromosome complement. Macrochromosomal and, to a lesser extent, microchromosomal regions containing imprinted gene orthologues exhibit asynchronous DNA replication. We conclude that highly conserved arrays of imprinted gene orthologues were selected during vertebrate evolution, long before these genes were recruited for parent-specific gene expression by genomic imprinting mechanisms. Evidently, the macrochromosome complement provides a better chromatin environment for the establishment of asynchronous DNA replication and imprinted gene expressi…

research product

Disruption of TCBA1 associated with a de novo t(1;6)(q32.2;q22.3) presenting in a child with developmental delay and recurrent infections

A boy with developmental delay, particularly of speech, a distinct face, antineutrophil cytoplasmic antibodies, and recurrent infections was found to have an apparently balanced de novo t(1;6)(q32.3;q22.3) translocation. Fluorescent in situ hybridisation with BAC/PAC clones and long range polymerase chain reaction products assessed in the human genome sequence localised the chromosome 1 breakpoint to a 9.8 kb segment within a hypothetical gene, LOC388735, and the chromosome 6 breakpoint to a 12.8 kb segment in intron 4 of the T-cell lymphoma breakpoint-associated target 1 (TCBA1) gene. Disruption and/or formation of TCBA1 fusion genes in T cell lymphoma and leukaemia cell lines suggests a r…

research product

Zfp819, a novel KRAB-zinc finger protein, interacts with KAP1 and functions in genomic integrity maintenance of mouse embryonic stem cells

AbstractPluripotency is maintained by both known and unknown transcriptional regulatory networks. In the present study, we have identified Zfp819, a KRAB-zinc finger protein, as a novel pluripotency-related factor and characterized its role in pluripotent stem cells. We show that Zfp819 is expressed highly in various types of pluripotent stem cells but not in their differentiated counterparts. We identified the presence of non-canonical nuclear localization signals in particular zinc finger motifs and identified them as responsible for the nuclear localization of Zfp819. Analysis of the Zfp819 promoter region revealed the presence of a transcriptionally active chromatin signature. Moreover,…

research product

Morphology and Progression in Primary Varicose Vein Disorder Due to 677C>T and 1298A>C Variants of MTHFR

Background: Clinical assessment and prognostic stratification of primary varicose veins have remained controversial and the molecular pathogenesis is unknown. Previous data have suggested a contribution of the MTHFR (methylenetetrahydrofolate reductase) polymorphism c.677C>T. Methods: We collected blood and vein specimens from 159 consecutive patients undergoing varicose vein surgery, or autologous vein reconstruction for arterial occlusive disease as controls. We compared the frequencies of c.677C>T and another polymorphism of MTHFR, c.1298A>C, with morphology and types of complicated disease. Morphology was recorded as a trunk or perforator type and peripheral congestive complication was …

research product

Fulminant hepatic failure requiring liver transplantation in 22q13.3 deletion syndrome.

We report on a 4-year-old girl with severe developmental delay, absent speech, and chromosome 22q13.3 deletion (Phelan-McDermid syndrome), karyotype 46,XX.ish del(22)(q13.31qter)(ARSA-,N85A-,SHANK3-). At the age of 3 years, she needed an emergency liver transplantation because of fulminant hepatic failure, most likely caused by hyperacute autoimmune hepatitis triggered by a viral infection. This is the second report of a patient with 22q13.3 deletion and fulminant liver failure. By array-CGH we identified in this patient a 5.675 Mb terminal deletion (22q13.31 --> qter; including approximately 55 genes; from NUP50 to RABL2B) and in the previous patient a 1.535 Mb deletion (22q13.32 --> qter;…

research product

Positive selection at codon 38 of the human KCNE1 (= minK) gene and sporadic absence of 38Ser-coding mRNAs in Gly38Ser heterozygotes

Abstract Background KCNE1 represents the regulatory beta-subunit of the slowly activating delayed rectifier potassium channel (IKs). Variants of KCNE1 have repeatedly been linked to the long-QT syndrome (LQTS), a disorder which predisposes to deafness, ventricular tachyarrhythmia, syncope, and sudden cardiac death. Results We here analyze the evolution of the common Gly38Ser variant (rs1805127), using genomic DNAs, complementary DNAs, and HEK293-expressed variants of altogether 19 mammalian species. The between species comparison reveals that the human-specific Gly38Ser polymorphism evolved under strong positive Darwinian selection, probably in adaptation to specific challenges in the fine-…

research product

261 INFLUENCE OF IN VITRO MATURATION ON EPIGENETIC MARKS AND GENE EXPRESSION IN BOVINE OOCYTES

In cattle, in vitro maturation (IVM) of oocytes is an integral part of assisted reproduction technology. However, only 30% of in vitro matured bovine oocytes develop to the blastocyst stage after fertilization (compared with 60% for in vivo matured oocytes), indicating critical involvement of maturation conditions in the developmental competence of oocytes. Oocytes for IVF and intracytoplasmic sperm injection in humans are typically allowed to mature in vivo after superovulation because IVM is not considered to be a safe medical procedure. Several studies have shown that assisted reproduction technology involving prolonged in vitro culture of human and ruminant embryos can be associated wi…

research product

Tissue-specific mosaicism in a patient with Rubinstein–Taybi syndrome and CREBBP exon 1 duplication

research product

BCL-2 UPREGULATION AFTER 3-NITROPROPIONIC ACID PRECONDITIONING IN WARM RAT LIVER ISCHEMIA

We aimed to determine whether 3-nitropropionic acid (3-NPA) preconditioning protects rat livers against warm ischemia/reperfusion injury. We hypothesized that 3-NPA mediates its protective effects by Bcl-2 upregulation. Brown-Norway rats (200 g) were injected with 3-NPA (10 mg/kg intraperitoneally) 24 h before 90 min of selective warm in situ ischemia. In additional experiments, 30-day survival was studied after 90 min of warm liver ischemia and resection of nonischemic liver tissue. We demonstrate increased mRNA and protein levels of Bcl-2 by real-time polymerase chain reaction, immunohistochemistry, and Western blot analysis in 3-NPA-pretreated rats. All treated animals survived, whereas …

research product

Global and gene-specific histone modification profiles of mouse multipotent adult germline stem cells

We previously reported the generation of multipotent adult germline stem cells (maGSCs) from spermatogonial stem cells (SSCs) isolated from adult mouse testis. In a later study, we substantiated the pluripotency of maGSCs by demonstrating their close similarity to pluripotent male embryonic stem cells (ESCs) at the epigenetic level of global and gene-specific DNA methylation. Here, we extended the comparative epigenetic analysis of maGSCs and male ESCs by investigating the second main epigenetic modification in mammals, i.e. global and gene-specific modifications of histones (H3K4 trimethylation, H3K9 acetylation, H3K9 trimethylation and H3K27 trimethylation). Using immunofluorescence stain…

research product

MicroRNA signature in various cell types of mouse spermatogenesis: Evidence for stage-specifically expressed miRNA-221, -203 and -34b-5p mediated spermatogenesis regulation

Background information Recently, it became apparent that microRNAs (miRNAs) can regulate gene expression post-transcriptionally. Despite the advances in identifying the testis-expressed miRNAs and their role in spermatogenesis, only few data are available showing the spatiotemporal expression of miRNAs during this process. Results To understand how different miRNAs can regulate germ cells differentiation, we generated a transgenic mouse model and purified pure populations of premeiotic (PrM) cells and primary spermatocytes (meiotic cells). We also established spermatogonial stem cell (SSC) culture using relatively simple and robust culture conditions. Comparison of global miRNA expression i…

research product

CAF-like state in primary skin fibroblasts with constitutional BRCA1 epimutation sheds new light on tumor suppressor deficiency-related changes in healthy tissue

Constitutive epimutations of tumor suppressor genes are increasingly considered as cancer predisposing factors equally to sequence mutations. In light of the emerging role of the microenvironment for cancer predisposition, initiation, and progression, we aimed to characterize the consequences of a BRCA1 epimutation in cells of mesenchymal origin. We performed a comprehensive molecular and cellular comparison of primary dermal fibroblasts taken from a monozygous twin pair discordant for recurrent cancers and BRCA1 epimutation, whose exceptional clinical case we previously reported in this journal. Comparative transcriptome analysis identified differential expression of extracellular matrix-r…

research product

Differences in DNA Methylation Patterns and Expression of the CCRK Gene in Human and Nonhuman Primate Cortices

Changes in DNA methylation patterns during embryo development and differentiation processes are linked to the transcriptional plasticity of our genome. However, little is known about the evolutionary conservation of DNA methylation patterns and the evolutionary impact of epigenetic differences between closely related species. Here we compared the methylation patterns of CpG islands (CGIs) in the promoter regions of seven genes in humans and chimpanzees. We identified a block of CpGs in the cell cycle-related kinase (CCRK) gene that is more methylated in the adult human cortex than in the chimpanzee cortex and, in addition, it exhibits considerable intraspecific variation both in humans and …

research product

Stochastic Loss of Silencing of the Imprinted Ndn/NDN Allele, in a Mouse Model and Humans with Prader-Willi Syndrome, Has Functional Consequences

Genomic imprinting is a process that causes genes to be expressed from one allele only according to parental origin, the other allele being silent. Diseases can arise when the normally active alleles are not expressed. In this context, low level of expression of the normally silent alleles has been considered as genetic noise although such expression has never been further studied. Prader-Willi Syndrome (PWS) is a neurodevelopmental disease involving imprinted genes, including NDN, which are only expressed from the paternally inherited allele, with the maternally inherited allele silent. We present the first in-depth study of the low expression of a normally silent imprinted allele, in path…

research product

Quantitative methylation analysis of developmentally important genes in human pregnancy losses after ART and spontaneous conception.

To study possible effects of assisted reproductive technologies (ART) on epigenetic reprogramming, we have analyzed the DNA methylation levels of differentially methylated regions (DMRs) of seven imprinted genes (H19, MEG3, LIT1, MEST, NESP55, PEG3 and SNRPN) as well as the promoter regions of the pluripotency gene NANOG and the tumor suppressor gene APC in chorionic villus samples (CVS) of 42 spontaneous miscarriages and stillbirths after ART and 29 abortions/stillbirths after spontaneous conception. We did not find an increased rate of faulty methylation patterns after ART, but significant and trend differences (ROC curve analysis, Wilcoxon test) in the methylation levels of LIT1 (P = 0.0…

research product

Asynchronous replication dynamics of imprinted and non-imprinted chromosome regions in early mouse embryos.

We have used interphase FISH to analyze the replication behavior of four imprinted chromosome regions (Snrpn, Zim1-Peg3, Dlk1-Gtl2, and Igf2r) and five non-imprinted regions in mouse one-cell to morula-stage embryos and embryonic fibroblasts. In general, imprinted chromosome regions showed the expected asynchronous pattern of replication throughout all analyzed stages of preimplantation development and in differentiated cells. The Dlk1-Gtl2 locus which is not expressed and Igf2r which is biallelically expressed in early embryos showed a relaxation of replication asynchrony at the morula stage. Asynchronous replication in zygotes and two-cell embryos was not specific to imprinted regions. Th…

research product

Lipid presentation by the protein C receptor links coagulation with autoimmunity.

A lipid-protein autoimmunity target Several autoimmune diseases, including systemic lupus erythematosus and primary antiphospholipid syndrome, are characterized by the presence of antiphospholipid antibodies (aPLs). These molecules can activate the complement and coagulation cascades, which contributes to pathologies such as thrombosis, stroke, and pregnancy complications. Müller-Calleja et al. found that endothelial protein C receptor (EPCR) in complex with lysobisphosphatidic acid (LBPA) is the cell-surface target for aPL and mediates its internalization (see the Perspective by Kaplan). aPL binding to EPCR-LBPA resulted in the activation of tissue factor–mediated coagulation and interfero…

research product

340 EPIGENETIC ANALYSIS OF DEVELOPMENTALLY IMPORTANT GENES IN BOVINE OOCYTES OF DIFFERENT ORIGINS

A critical step in assisted reproductive technologies (ART) is the IVM of oocytes. The quality of the oocyte is crucial for successful fertilization and subsequent embryo development. Studies in bovine ART, and epidemiological studies in children from ART, reveal a degree of abnormal development thought to be primarily caused by aberrant DNA methylation patterns in imprinted and non-imprinted genes. Due to the inherent similarities in bovine and human preimplantation embryonic development, bovine oocyte and embryo development is increasingly being used as a model for human development. The goal of this project is to investigate the effects of specific IVM conditions on the DNA methylation …

research product

Pattern of secondary genomic changes in pancreatic tumors ofTgfα/Trp53+/−transgenic mice

Trp53+/− mice overexpressing Tgfα in a pancreas-specific manner represent a well-established animal model for pancreatic cancer. In this study we analyzed 38 pancreatic adenocarcinomas of these mice for secondary genomic changes by comparative genomic hybridization (CGH), loss of heterozygosity (LOH) analysis, real-time PCR, and methylation-specific analysis. CGH screening of the tumors revealed a recurrent pattern of genomic changes. In more than 50% of the tumors, chromosome 11 was affected. The gain of the proximal part spans about 16 cM, including the genes for Egfr, Rel, and Stk10. The distal part of chromosome 11, which contains the Trp53 locus, was deleted. LOH analysis proved that a…

research product

The DNA methylation profile of human spermatogonia at single-cell- and single-allele-resolution refutes its role in spermatogonial stem cell function and germ cell differentiation.

Human spermatogonial stem cells (hSSCs) have potential in fertility preservation of prepubertal boys or in treatment of male adults suffering from meiotic arrest. Prior to therapeutic application, in vitro propagation of rare hSSCs is mandatory. As the published data points to epigenetic alterations in long-term cell culture of spermatogonia (SPG), an initial characterisation of their DNA methylation state is important. Testicular biopsies from five adult normogonadotropic patients were converted into aggregate-free cell suspensions. FGFR3-positive (FGFR3+) SPG, resembling a very early stem cell state, were labelled with magnetic beads and isolated in addition to unlabelled SPG (FGFR3-). DN…

research product

Comparative methylation profiles and telomerase biology of mouse multipotent adult germline stem cells and embryonic stem cells.

Recently, several groups described the isolation of mouse spermatogonial stem cells (SSCs) and their potential to develop to embryonic stem cell (ESC)-like cells, so-called multipotent germline stem cells (mGSCs). We were the first to derive such mGSCs from SSCs isolated from adult mouse testis and, therefore, called these mGSCs multipotent adult germline stem cells (maGSCs). Here, we compara- tively analyzed gene-specific and global DNA methylation profiles as well as the telomerase biology of several maGSC and male ESC lines. We show that undifferentiated maGSCs are very similar to undifferentiated male ESCs with regard to global DNA methylation, methylation of pluripotency marker gene lo…

research product

De-novo Williams–Beuren and inherited Marfan syndromes in a patient with developmental delay and lens dislocation

research product

Transcriptome Fingerprint of Bovine 2-Cell Stage Blastomeres Is Directly Correlated with the Individual Developmental Competence of the Corresponding Sister Blastomere1

To date, gene expression profiles of bovine preimplantation embryos have only been indirectly related to developmental potential due to the invasive nature of such procedures. This study sought to find a direct correlation between transcriptome fingerprint of blastomeres of bovine 2-cell stage embryos with developmental competence of the corresponding sister blastomeres. Isolated blastomeres were classified according to the sister blastomere's development into three groups: two groups displayed developmental incompetency, including those blastomeres whose corresponding sister blastomeres either stopped cleaving after separation (2CB) or were blocked after two additional cleavages before emb…

research product

Homozygous disruption of PDZD7 by reciprocal translocation in a consanguineous family: a new member of the Usher syndrome protein interactome causing congenital hearing impairment.

A homozygous reciprocal translocation, 46,XY,t(10;11),t(10;11), was detected in a boy with non-syndromic congenital sensorineural hearing impairment. Both parents and their four other children were heterozygous translocation carriers, 46,XX,t(10;11) and 46,XY,t(10;11), respectively. Fluorescence in situ hybridization of region-specific clones to patient chromosomes was used to localize the breakpoints within bacterial artificial chromosome (BAC) RP11-108L7 on chromosome 10q24.3 and within BAC CTD-2527F12 on chromosome 11q23.3. Junction fragments were cloned by vector ligation and sequenced. The chromosome 10 breakpoint was identified within the PDZ domain containing 7 (PDZD7) gene, disrupti…

research product

Skeletal abnormalities of the upper limbs--neonatal diagnosis of 49,XXXXY syndrome.

A case of neonatal diagnosis of 49,XXXXY syndrome is presented. Clinical identification was prompted by a bilateral thickening of the radioulnar joints and X-ray imaging disclosing almost complete radioulnar synostosis. Conventional karyotyping was initiated and revealed a karyotype of 49,XXXXY. Previously reported neonatal symptoms such as low birth weight, muscular hypotonia, or genital malformations were absent in this case. Microsatellite analysis showed two different X chromosomes each present in two copies, supporting that the four X chromosomes had arisen from a nondisjunction in maternal meiosis I followed by a second nondisjunction involving both X chromosomes in meiosis II. Multid…

research product

DNA integrity, growth pattern, spindle formation, chromosomal constitution and imprinting patterns of mouse oocytes from vitrified pre-antral follicles

Cryopreservation of follicles for culture and oocyte growth and maturation in vitro provides an option to increase the number of fertilizable oocytes and restore fertility in cases where transplantation of ovarian tissue poses a risk for malignant cell contamination. Vitrification for cryopreservation is fast and avoids ice crystal formation. However, the influences of exposure to high concentrations of cryoprotectants on follicle development, oocyte growth and maturation, and particularly, on the DNA integrity and methylation imprinting has not been studied systematically. Follicle survival and development, DNA damage, oocyte growth patterns, maturation, spindle formation and chromosomal c…

research product

Multiplex RT-PCR Expression Analysis of Developmentally Important Genes in Individual Mouse Preimplantation Embryos and Blastomeres1

We have developed a microfluidic chip-based qualitative assay for sensitive (10 RNA copies) detection of multiple transcripts in single cells. We determined the expression patterns of 17 developmentally important genes and isoforms in individual mouse preimplantation embryos from superovulated matings and blastomeres. The ubiquitously expressed histone variant H3f3a and the transcription factor Pou5f1 generated mRNA-derived products in all analyzed (1-cell, 2-cell, 4-cell, and morula stage) embryos and in all analyzed blastomeres from 16-cell embryos, indicating a uniform reactivation of pluripotency gene expression during mouse preimplantation development. In contrast, mRNA expression of d…

research product

NDST1 missense mutations in autosomal recessive intellectual disability.

NDST1 was recently proposed as a candidate gene for autosomal recessive intellectual disability in two families. It encodes a bifunctional GlcNAc N-deacetylase/N-sulfotransferase with important functions in heparan sulfate biosynthesis. In mice, Ndst1 is crucial for embryonic development and homozygous null mutations are perinatally lethal. We now report on two additional unrelated families with homozygous missense NDST1 mutations. All mutations described to date predict the substitution of conserved amino acids in the sulfotransferase domain, and mutation modeling predicts drastic alterations in the local protein conformation. Comparing the four families, we noticed significant overlap in …

research product

Multipotent adult germline stem cells and embryonic stem cells have similar microRNA profiles.

Spermatogonial stem cells (SSCs) isolated from the adult mouse testis and cultured have been shown to respond to culture conditions and become pluripotent, so called multipotent adult germline stem cells (maGSCs). microRNAs (miRNAs) belonging to the 290 and 302 miRNA clusters have been previously classified as embryonic stem cell (ESC) specific. Here, we show that these miRNAs generally characterize pluripotent cells. They are expressed not only in ESCs but also in maGSCs as well as in the F9 embryonic carcinoma cell (ECC) line. In addition, we tested the time-dependent influence of different factors that promote loss of pluripotency on levels of these miRNAs in all three pluripotent cell t…

research product

<i>In vitro</i> Modeling of Ryanodine Receptor 2 Dysfunction Using Human Induced Pluripotent Stem Cells

Background/Aims: Induced pluripotent stem (iPS) cells generated from accessible adult cells of patients with genetic diseases open unprecedented opportunities for exploring the pathophysiology of human diseases in vitro. Catecholaminergic polymorphic ventricular tachycardia type 1 (CPVT1) is an inherited cardiac disorder that is caused by mutations in the cardiac ryanodine receptor type 2 gene (RYR2) and is characterized by stress-induced ventricular arrhythmia that can lead to sudden cardiac death in young individuals. The aim of this study was to generate iPS cells from a patient with CPVT1 and determine whether iPS cell-derived cardiomyocytes carrying patient specific RYR2 mutation recap…

research product

Familial Sotos syndrome caused by a novel missense mutation, C2175S, in NSD1 and associated with normal intelligence, insulin dependent diabetes, bronchial asthma, and lipedema

We report a familial Sotos syndrome in two children, boy and girl, aged 17 and 8 years, and in their 44 year old mother, who displayed normal intelligence at adult age, but suffered from insulin dependent diabetes mellitus, bronchial asthma, and severe lipedema. The underlying missense mutation, C2175S, occurred in a conserved segment of the NSD1 gene. Our findings confirm that familial cases of SS are more likely to carry missense mutations. This case report may prove useful to avoid underestimation of the recurrence rate of SS, and to demonstrate that the developmental delay may normalize, enabling an independent life and having an own family.

research product

Two patients with EP300 mutations and facial dysmorphism different from the classic Rubinstein-Taybi syndrome

Rubinstein-Taybi syndrome (RTS) is characterized by mental retardation, broad thumbs and great toes and a recognizable craniofacial phenotype. Causative mutations have been described in the CREBBP and EP300 genes. Here we present a 19-year-old woman and an unrelated 3-year-old boy, both with broad thumbs and halluces, but with facial aspects distinct from those of typical RTS. The woman had a marked learning disability, but no mental retardation. We identified a de novo c.7100delC mutation in EP300 (which predicts p.P2366RfsX35) in the woman and an apparently de novo c.638delG mutation in the boy, which predicts p.G213EfsX6. Mutations in EP300 are a known but rare cause of RTS. Only five ot…

research product

Epigenetic profile of developmentally important genes in bovine oocytes

Assisted reproductive technologies are associated with an increased incidence of epigenetic aberrations, specifically in imprinted genes. Here, we used the bovine oocyte as a model to determine putative epigenetic mutations at three imprinted gene loci caused by the type of maturation, either in vitro maturation (IVM) in Tissue Culture Medium 199 (TCM) or modified synthetic oviduct fluid (mSOF) medium, or in vivo maturation. We applied a limiting dilution approach and direct bisulfite sequencing to analyze the methylation profiles of individual alleles (DNA molecules) for H19/IGF2, PEG3, and SNRPN, which are each associated with imprinting defects in humans and/or the mouse model, and are k…

research product

De novo t(12;17)(p13.3;q21.3) translocation with a breakpoint near the 5' end of the HOXB gene cluster in a patient with developmental delay and skeletal malformations.

A boy with severe mental retardation, funnel chest, bell-shaped thorax, and hexadactyly of both feet was found to have a balanced de novo t(12;17)(p13.3;q21.3) translocation. FISH with BAC clones and long-range PCR products assessed in the human genome sequence localized the breakpoint on chromosome 17q21.3 to a 21-kb segment that lies <30 kb upstream of the HOXB gene cluster and immediately adjacent to the 3′ end of the TTLL6 gene. The breakpoint on chromosome 12 occurred within telomeric hexamer repeats and, therefore, is not likely to affect gene function directly. We propose that juxtaposition of the HOXB cluster to a repetitive DNA domain and/or separation from required cis-regulatory …

research product

Epimutation at human chromosome 14q32.2 in a boy with a upd(14)mat-like clinical phenotype.

Recently, three reports described deletions and epimutations affecting the imprinted region at chromosome 14q32.2 in individuals with a phenotype typical for maternal uniparental disomy of chromosome 14 [upd(14)mat]. In this study, we describe another patient with upd(14)mat-like phenotype including low birth weight, neonatal feeding problems, muscular hypotonia, motor and developmental delay, small hands and feet, and truncal obesity. Conventional cytogenetic analyses, fluorescence in situ hybridization subtelomere screening, multiplex ligation-dependent probe amplification analysis of common microdeletion and microduplication syndromes, and methylation analysis of SNRPN all gave normal re…

research product

Deficient membrane integration of the novel p.N14D-GJB2mutant associated with non-syndromic hearing impairment

Mutations in GJB2, the gene encoding for the Gap Junction protein Connexin 26 (Cx26), have been established as the major cause of hereditary, non-syndromic hearing impairment (HI). We report here the identification of a novel point mutation in GJB2, c.40A>G [p.N14D], detected in compound heterozygosity with the c.35delG mutation in two brothers with moderate non-syndromic sensorineural HI. The mother who carried one wildtype and a p.N14D allele displayed normal hearing. The mutation leads to substitution of the neutral amino acid asparagine (N) by the negatively charged aspartic acid (D) at amino acid number 14, a position that is conserved among Cx26 of different organisms and among many o…

research product

Männliche Keimzellen aus embryonalen Stammzellen

Zusammenfassung Die Grundlage für die lebenslange Differenzierung männlicher Keimzellen sind die spermatogonialen Stammzellen (SSC) im Testis (etwa 0,03% aller Testiszellen). Es ist gelungen, aus embryonalen Stammzellen (ES-Zellen) der Maus SSC zu generieren, die die Meiose und die Haploidisierung durchlaufen. Werden die entstehenden Spermien mit Hilfe von ICSI in unbefruchtete Eizellen eingebracht und die entstandenen 2-Zeller in den Uterus pseudoschwangerer Mäuse transferiert, werden lebensfähige Mäuse geboren. Die von uns entwickelte Strategie ermöglicht molekulare und biochemische Untersuchungen zur männlichen Keimzelldifferenzierung, insbesondere auch zur Meiose und zur Haploidisierung.

research product

Sirtuin-6-dependent genetic and epigenetic alterations are associated with poor clinical outcome in hepatocellular carcinoma patients

Sirtuin 6 (SIRT6) is a member of the sirtuin family of NAD+–dependent deacetylases. Genetic deletion of Sirt6 in mice results in a severe degenerative phenotype with impaired liver function and premature death. The role of SIRT6 in development and progression of hepatocellular carcinoma is currently unknown. We first investigated SIRT6 expression in 153 primary human liver cancers and in normal and cirrhotic livers using microarray analysis. SIRT6 was significantly down-regulated in both cirrhotic livers and cancer. A Sirt6 knockout (KO) gene expression signature was generated from primary hepatoctyes isolated from 3-week-old Sirt6-deficient animals. Sirt6-deficient hepatocytes showed up-re…

research product

Induced Pluripotent Mesenchymal Stromal Cell Clones Retain Donor-derived Differences in DNA Methylation Profiles

Reprogramming of somatic cells into induced pluripotent stem cells (iPSCs) is an epigenetic phenomenon. It has been suggested that iPSC retain some tissue-specific memory whereas little is known about interindividual epigenetic variation. We have reprogrammed mesenchymal stromal cells from human bone marrow (iP-MSC) and compared their DNA methylation profiles with initial MSC and embryonic stem cells (ESCs) using high-density DNA methylation arrays covering more than 450,000 CpG sites. Overall, DNA methylation patterns of iP-MSC and ESC were similar whereas some CpG sites revealed highly significant differences, which were not related to parental MSC. Furthermore, hypermethylation in iP-MSC…

research product

Accelerated Evolution of Fetuin-A (FETUA, also AHSG) is Driven by Positive Darwinian Selection, not GC-Biased Gene Conversion

article i nfo Human Fetuin-A (FETUA, also termed AHSG) is a serum protein composed of two cystatin-like domains D1 and D2 of together 235 amino acids (aa) and an unrelated domain D3 of 114 aa. Though the protein plays a role in diverse physiological and pathological processes, comparably little is known about sequence evolution of FETUA. We therefore analyzed its molecular evolution on the basis of coding sequences of 16 primate species. Ratios of non-synonymous to synonymous substitution rates (dn/ds= ω) suggest that a previously reported acceleration of sequence evolution of exon 7, which encodes domain D3, is driven by positive selection instead of neutral evolution. Irrespective of the …

research product

Sequence-based bioinformatic prediction and QUASEP identify genomic imprinting of the KCNK9 potassium channel gene in mouse and human

Genomic imprinting is the epigenetic marking of gene subsets resulting in monoallelic or predominant expression of one of the two parental alleles according to their parental origin. We describe the systematic experimental verification of a prioritized 16 candidate imprinted gene set predicted by sequence-based bioinformatic analyses. We used Quantification of Allele-Specific Expression by Pyrosequencing (QUASEP) and discovered maternal-specific imprinted expression of the Kcnk9 gene as well as strain-dependent preferential expression of the Rarres1 gene in E11.5 (C57BL/6 3 Cast/Ei)F1 and informative (C57BL/6 3 Cast/ Ei) 3 C57BL/6 backcross mouse embryos. For the remaining 14 candidate impr…

research product

CpG islands in MyD88 and ASC/PYCARD/TMS1 promoter regions are differentially methylated in head and neck squamous cell carcinoma and primary lung squamous cell carcinoma

Abstract Background Patients with head and neck squamous cell carcinoma (HNSCC) can develop lung squamous cell carcinoma (LuSCC), which could be the second primary tumor or HNSCC metastasis. Morphologically it is difficult to distinguish metastatic HNSCC from a second primary tumor which presents a significant diagnostic challenge. Differentiation of those two malignancies is important because the recommended treatments for metastatic HNSCC and primary LuSCC differ significantly. We investigated if the quantification of the promotor methylation status in HNSCC and LuSCC differs. Methods Primary HNSCC (N = 36) and LuSCC (N = 17) were included in this study. Methylation status in the ASC/TMS1…

research product

Abnormal Hypermethylation at Imprinting Control Regions in Patients with S-Adenosylhomocysteine Hydrolase (AHCY) Deficiency

S-adenosylhomocysteine hydrolase (AHCY) deficiency is a rare autosomal recessive disorder in methionine metabolism caused by mutations in the AHCY gene. Main characteristics are psychomotor delay including delayed myelination and myopathy (hypotonia, absent tendon reflexes etc.) from birth, mostly associated with hypermethioninaemia, elevated serum creatine kinase levels and increased genome wide DNA methylation. The prime function of AHCY is to hydrolyse and efficiently remove S-adenosylhomocysteine, the by-product of transmethylation reactions and one of the most potent methyltransferase inhibitors. In this study, we set out to more specifically characterize DNA methylation changes in blo…

research product

Sex chromosomes in vertebrates: XX/XY against ZZ/ZW.

It was noted only recently that the mammalian X/Y sex chromosome system originated late in our therian ancestors. The question is, what makes the X/Y sex chromosome system so special that it has replaced the original Z/W sex chromosome system? Two classes of genes are overrepresented on the X chromosome: sex and reproduction genes and brain-related genes. The X chromosome has acquired bursts of young male-biased genes engaged in sex and reproduction which exemplifies the dynamics of sex chromosome evolution. Brain genes are old genes and display the most conserved transcriptome. The new therian X chromosome was formed by fusion of chromosome building blocks already bearing the highest densi…

research product