The mechanisms underlying gravity perception in mammalian cells are unknown. We have recently discovered that the transcriptome of cells in the immune system, which is the most affected system during a spaceflight, responds rapidly and broadly to altered gravity. To pinpoint potential underlying mechanisms, we compared gene expression and three-dimensional (3D) chromosomal conformational changes in human Jurkat T cells during the short-term gravitational changes in parabolic flight and suborbital ballistic rocket flight experiments.
View Article and Find Full Text PDFICER (inducible cAMP early repressor) isoforms are transcriptional repressors encoded by the Crem (cAMP responsive element modulator) gene. They were linked to the regulation of a multitude of cellular processes and pathophysiological mechanisms. Here, we show for the first time that two independent induction patterns for CREM repressor isoforms exist in the heart, namely for ICER and smICER (small ICER), which are induced in response to β-adrenergic stimulation in a transient- and saturation-like manner, respectively.
View Article and Find Full Text PDFSerotonin 5-HT2C receptor is a G-protein coupled excitatory receptor that regulates several biochemical pathways and has been implicated in obesity, mental state, sleep cycles, autism, neuropsychiatric disorders and neurodegenerative diseases. The activity of 5-HT2CR is regulated via alternative splicing and A to I editing of exon Vb of its pre-mRNA. Snord115 is a small nucleolar RNA that is expressed in mouse neurons and displays an 18-nucleotide base complementary to exon Vb of 5-HT2CR pre-mRNA.
View Article and Find Full Text PDFThe gravitational force has been constant throughout Earth's evolutionary history. Since the cell nucleus is subjected to permanent forces induced by Earth's gravity, we addressed the question, if gene expression homeostasis is constantly shaped by the gravitational force on Earth. We therefore investigated the transcriptome in force-free conditions of microgravity, determined the time frame of initial gravitational force-transduction to the transcriptome and assessed the role of cation channels.
View Article and Find Full Text PDFIntroduction: Cardiomyocyte remodelling in atrial fibrillation (AF) has been associated with both oxidative stress and endoplasmic reticulum (ER) stress and is accompanied by a complex transcriptional regulation. Here, we investigated the role the oxidative stress and ER stress responsive bZIP transcription factor ATF4 plays in atrial cardiomyocyte viability and AF induced gene expression.
Methods: HL-1 cardiomyocytes were subjected to rapid field stimulation.
In the last decades, a plethora of in vitro studies with living human cells contributed a vast amount of knowledge about cellular and molecular effects of microgravity. Previous studies focused mostly on the identification of gravity-responsive genes, whereas a multi-platform analysis at an integrative level, which specifically evaluates the extent and robustness of transcriptional response to an altered gravity environment was not performed so far. Therefore, we investigated the stability of gene expression response in non-activated human Jurkat T lymphocytic cells in different gravity environments through the combination of parabolic flights with a suborbital ballistic rocket and 2D clinostat and centrifuge experiments, using strict controls for excluding all possible other factors of influence.
View Article and Find Full Text PDFBackground: Reduced expression of genes regulated by the transcription factors CREB/CREM (cAMP response element-binding protein/modulator) is linked to atrial fibrillation (AF) susceptibility in patients. Cardiomyocyte-directed expression of the inhibitory CREM isoform CREM-IbΔC-X in transgenic mice (TG) leads to spontaneous-onset AF preceded by atrial dilatation and conduction abnormalities. Here, we characterized the altered gene program linked to atrial remodeling and development of AF in CREM-TG mice.
View Article and Find Full Text PDFWe investigated the dynamics of immediate and initial gene expression response to different gravitational environments in human Jurkat T lymphocytic cells and compared expression profiles to identify potential gravity-regulated genes and adaptation processes. We used the Affymetrix GeneChip® Human Transcriptome Array 2.0 containing 44,699 protein coding genes and 22,829 non-protein coding genes and performed the experiments during a parabolic flight and a suborbital ballistic rocket mission to cross-validate gravity-regulated gene expression through independent research platforms and different sets of control experiments to exclude other factors than alteration of gravity.
View Article and Find Full Text PDFSolving problematic phylogenetic relationships often requires high quality genome data. However, for many organisms such data are still not available. Among rodents, the phylogenetic position of the beaver has always attracted special interest.
View Article and Find Full Text PDFRecent genome-wide association studies (GWAS) have confirmed known risk mutations for venous thromboembolism (VTE) and identified a number of novel susceptibility loci in adults. Here we present a GWAS in 212 nuclear families with pediatric VTE followed by targeted next-generation sequencing (NGS) to identify causative mutations contributing to the association. Three single nucleotide polymorphisms (SNPs) exceeded the threshold for genome-wide significance as determined by permutation testing using 100 000 bootstrap permutations ( < 10).
View Article and Find Full Text PDFCells of the immune system are highly sensitive to altered gravity, and the monocyte as well as the macrophage function is proven to be impaired under microgravity conditions. In our study, we investigated the surface expression of ICAM-1 protein and expression of ICAM-1 mRNA in cells of the monocyte/macrophage system in microgravity during clinostat, parabolic flight, sounding rocket, and orbital experiments. In murine BV-2 microglial cells, we detected a downregulation of ICAM-1 expression in clinorotation experiments and a rapid and reversible downregulation in the microgravity phase of parabolic flight experiments.
View Article and Find Full Text PDFIntroduction: Apoptosis is a crucial pathway in tumor growth and metastatic development. Apoptotic proteins regulate the underlying molecular cascades and are thought to modulate the tumor response to chemotherapy and radiation. However, the prognostic value of the expression of apoptosis regulators in localized non-small-cell lung cancer (NSCLC) is still unclear.
View Article and Find Full Text PDFAims: Dilated cardiomyopathy (DCM) is one of the leading causes for cardiac transplantations and accounts for up to one-third of all heart failure cases. Since extrinsic and monogenic causes explain only a fraction of all cases, common genetic variants are suspected to contribute to the pathogenesis of DCM, its age of onset, and clinical progression. By a large-scale case-control genome-wide association study we aimed here to identify novel genetic risk loci for DCM.
View Article and Find Full Text PDFBackground: Recent genome-wide association studies have identified several genetic loci linked to coronary artery disease (CAD) and myocardial infarction (MI). The 9p21.3 locus was verified by numerous replication studies to be the first common locus for CAD and MI.
View Article and Find Full Text PDFObjectives: We sought to replicate the association between the kinesin-like protein 6 (KIF6) Trp719Arg polymorphism (rs20455), and clinical coronary artery disease (CAD).
Background: Recent prospective studies suggest that carriers of the 719Arg allele in KIF6 are at increased risk of clinical CAD compared with noncarriers.
Methods: The KIF6 Trp719Arg polymorphism (rs20455) was genotyped in 19 case-control studies of nonfatal CAD either as part of a genome-wide association study or in a formal attempt to replicate the initial positive reports.
The serotonergic system plays a major role in the etiology of migraine. The rate-limiting enzyme in serotonin homeostasis and availability is tryptophan hydroxylase (TPH). The TPH2 isoform is responsible for the cerebral serotonin biosynthesis.
View Article and Find Full Text PDFBackground And Purpose: C-reactive protein (CRP) is an independent risk factor for cardiovascular disease and ischemic stroke. CRP serum levels are influenced by genetic variation in the CRP gene. Studies investigating the relationship between ischemic stroke and polymorphisms in the CRP gene produced equivocal results.
View Article and Find Full Text PDFZ-disks, the mechanical integration sites of heart and skeletal muscle cells, link anchorage of myofilaments to force reception and processing. The key molecules that enable the Z-disk to persistently withstand the extreme mechanical forces during muscle contraction have not yet been identified. Here we isolated nexilin (encoded by NEXN) as a novel Z-disk protein.
View Article and Find Full Text PDFBackground: Restenosis represents the major limiting factor for the long-term efficacy of percutaneous coronary intervention (PCI). Several genetic factors involved in the regulation of the vascular system have been described to play a role in the pathogenesis of restenosis. We investigated whether the EPHX2 K55R polymorphism, previously linked to significantly higher risk for coronary heart disease (CHD), was associated with the occurrence of restenosis after PCI.
View Article and Find Full Text PDFWe conducted a genome-wide association study testing single nucleotide polymorphisms (SNPs) and copy number variants (CNVs) for association with early-onset myocardial infarction in 2,967 cases and 3,075 controls. We carried out replication in an independent sample with an effective sample size of up to 19,492. SNPs at nine loci reached genome-wide significance: three are newly identified (21q22 near MRPS6-SLC5A3-KCNE2, 6p24 in PHACTR1 and 2q33 in WDR12) and six replicated prior observations (9p21, 1p13 near CELSR2-PSRC1-SORT1, 10q11 near CXCL12, 1q41 in MIA3, 19p13 near LDLR and 1p32 near PCSK9).
View Article and Find Full Text PDFTo clarify the role of protein Z (PZ) in children with stroke/thromboembolism (TE), the present haplotype (HT)-based family study was performed. We genotyped 365 pediatric stroke/TE families (stroke n = 216; TE n = 149) for 4 single nucleotide polymorphisms (SNPs; rs3024718, rs3024731, rs3024772, and rs3024778) to assess the association between genetic variation within a conserved block of linkage disequilibrium harboring the PZ gene and pediatric TE. Association was assessed with use of the transmission disequilibrium test (TDT), corrected for multiple testing (permutation testing: HAPLOVIEW).
View Article and Find Full Text PDFIn genome-wide studies, the intercellular adhesion molecule-1 (ICAM-1) locus has been associated with cardiovascular and inflammatory bowel diseases. To determine the functional relevance of five missense ICAM-1 variants (G241R; I316V; P352L; K469E; R478W), we generated wild-type and variant proteins [M2(241R); M3(469E); M4(352L); M5(478W); M6(316V); M7(352L/469E)] and transiently transfected CV1 cells. Reverse transcription PCR, western blot, and ELISA did not reveal any differences in mRNA and protein expression levels for any construct.
View Article and Find Full Text PDFThe search for genes involved in the pathogenesis of stroke has been highlighted as a field of needs. We followed the concept, that stroke represents a complex genetic disorder, and analyzed the contribution of 106 informative single nucleotide polymorphisms (SNPs) from 63 candidate genes for cardiovascular diseases for the risk of stroke. We conducted two independent case-control studies in two different German regions and recruited a total of 1,901 hospitalized stroke cases and 1,747 regional population controls.
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