62 research outputs found
A Grhl2-dependent gene network controls trophoblast branching morphogenesis
Healthy placental development is essential for reproductive success; failure of the feto-maternal interface results in pre-eclampsia and intrauterine growth retardation. We found that grainyhead-like 2 (GRHL2), a CP2-type transcription factor, is highly expressed in chorionic trophoblast cells, including basal chorionic trophoblast (BCT) cells located at the chorioallantoic interface in murine placentas. Placentas from Grhl2-deficient mouse embryos displayed defects in BCT cell polarity and basement membrane integrity at the chorioallantoic interface, as well as a severe disruption of labyrinth branching morphogenesis. Selective Grhl2 inactivation only in epiblast-derived cells rescued all placental defects but phenocopied intraembryonic defects observed in global Grhl2 deficiency, implying the importance of Grhl2 activity in trophectoderm-derived cells. ChIP-seq identified 5282 GRHL2 binding sites in placental tissue. By integrating these data with placental gene expression profiles, we identified direct and indirect Grhl2 targets and found a marked enrichment of GRHL2 binding adjacent to genes downregulated in Grhl2(-/-) placentas, which encoded known regulators of placental development and epithelial morphogenesis. These genes included that encoding the serine protease inhibitor Kunitz type 1 (Spint1), which regulates BCT cell integrity and labyrinth formation. In human placenta, we found that human orthologs of murine GRHL2 and its targets displayed co-regulation and were expressed in trophoblast cells in a similar domain as in mouse placenta. Our data indicate that a conserved Grhl2-coordinated gene network controls trophoblast branching morphogenesis, thereby facilitating development of the site of feto-maternal exchange. This might have implications for syndromes related to placental dysfunction
A framework for orthology assignment from gene rearrangement data
Abstract. Gene rearrangements have successfully been used in phylogenetic reconstruction and comparative genomics, but usually under the assumption that all genomes have the same gene content and that no gene is duplicated. While these assumptions allow one to work with organellar genomes, they are too restrictive when comparing nuclear genomes. The main challenge is how to deal with gene families, specifically, how to identify orthologs. While searching for orthologies is a common task in computational biology, it is usually done using sequence data. We approach that problem using gene rearrangement data, provide an optimization framework in which to phrase the problem, and present some preliminary theoretical results.
Narrowband Searches for Continuous and Long-duration Transient Gravitational Waves from Known Pulsars in the LIGO-Virgo Third Observing Run
Isolated neutron stars that are asymmetric with respect to their spin axis are possible sources of detectable continuous gravitational waves. This paper presents a fully coherent search for such signals from eighteen pulsars in data from LIGO and Virgo's third observing run (O3). For known pulsars, efficient and sensitive matched-filter searches can be carried out if one assumes the gravitational radiation is phase-locked to the electromagnetic emission. In the search presented here, we relax this assumption and allow both the frequency and the time derivative of the frequency of the gravitational waves to vary in a small range around those inferred from electromagnetic observations. We find no evidence for continuous gravitational waves, and set upper limits on the strain amplitude for each target. These limits are more constraining for seven of the targets than the spin-down limit defined by ascribing all rotational energy loss to gravitational radiation. In an additional search, we look in O3 data for long-duration (hours-months) transient gravitational waves in the aftermath of pulsar glitches for six targets with a total of nine glitches. We report two marginal outliers from this search, but find no clear evidence for such emission either. The resulting duration-dependent strain upper limits do not surpass indirect energy constraints for any of these targets
The role of kinin B(1) receptors in the nociception produced by peripheral protein kinase C activation in mice
The peripheral injection of phorbol myristate acetate (PMA) into the mouse paw induces nociception mediated through activation of protein kinase C (PKC). In the present study, we examine the contribution of kinin B(1) receptor to PMA-induced nociception. Nociception was assessed after intraplantar injection of PMA or the B(1) receptor agonist des-Arg(9)-bradykinin in mice. Mechanisms of nociception were studied using the combination of knockout mice, selective drugs, and measurement of B(1) receptor mRNA and protein levels. Peripheral injection of PMA (50pmol/paw) induced a nociceptive behaviour that was abolished by selective B(1) receptor antagonist des-Arg(9)-Leu(8)-bradykinin or by the B(1) receptor gene deletion. Moreover, PMA treatment did not alter B(1) receptor mRNA levels, but greatly increased B(1) receptor protein levels in the mouse paw. The injection of des-Arg(9)-bradykinin did not cause nociception in naive mice, but produced marked nociception in animals previously treated with a low dose of PMA (0.5nmol/paw). The co-treatment of PMA with selective PKC or protein synthesis inhibitors, but not with p38 mitogen activated protein kinase (MAPK) or transcription inhibitors significantly reduced des-Arg(9)-bradykinin-induced nociception. On the other hand, the co-administration of selective PKC or p38 MAPK inhibitors, but not of protein synthesis or transcription inhibitors, reduced des-Arg(9)-bradykinin-induced nociception when evaluated in PMA pre-injected animals. These results suggest that the B(1) receptor exerts a critical role in the nociception caused by PKC activation in peripheral tissues. Since the PKC pathway is downstream of several pro-inflammatory mediators, B(1) receptor stimulation appears to contribute to the acute inflammatory pain process
Accessible DNA and Relative Depletion of H3K9me2 at Maize Loci Undergoing RNA-Directed DNA Methylation
RNA-directed DNA methylation (RdDM) in plants is a well-characterized example of RNA interference-related transcriptional gene silencing. To determine the relationships between RdDM and heterochromatin in the repeat-rich maize (Zea mays) genome, we performed whole-genome analyses of several heterochromatic features: dimethylation of lysine 9 and lysine 27 (H3K9me2 and H3K27me2), chromatin accessibility, DNA methylation, and small RNAs; we also analyzed two mutants that affect these processes, mediator of paramutation1 and zea methyltransferase2. The data revealed that the majority of the genome exists in a heterochromatic state defined by inaccessible chromatin that is marked by H3K9me2 and H3K27me2 but that lacks RdDM. The minority of the genome marked by RdDM was predominantly near genes, and its overall chromatin structure appeared more similar to euchromatin than to heterochromatin. These and other data indicate that the densely staining chromatin defined as heterochromatin differs fundamentally from RdDM-targeted chromatin. We propose that small interfering RNAs perform a specialized role in repressing transposons in accessible chromatin environments and that the bulk of heterochromatin is incompatible with small RNA production
Serotonin regulates mammary gland development via an autocrine-paracrine loop
Mammary gland development is controlled by a dynamic interplay between endocrine hormones and locally produced factors. Biogenic monoamines (serotonin, dopamine, norepinephrine, and others) are an important class of bioregulatory molecules that have not been shown to participate in mammary development. Here we show that mammary glands stimulated by prolactin (PRL) express genes essential for serotonin biosynthesis (tryptophan hydroxylase [TPH] and aromatic amine decarboxylase). TPH mRNA was elevated during pregnancy and lactation, and serotonin was detected in the mammary epithelium and in milk. TPH was induced by PRL in mammosphere cultures and by milk stasis in nursing dams, suggesting that the gene is controlled by milk filling in the alveoli. Serotonin suppressed β-casein gene expression and caused shrinkage of mammary alveoli. Conversely, TPH1 gene disruption or antiserotonergic drugs resulted in enhanced secretory features and alveolar dilation. Thus, autocrine-paracrine serotonin signaling is an important regulator of mammary homeostasis and early involution
FHIT and FRA3B 3p14.2 allele loss are common in lung cancer and preneoplastic bronchial lesions and are associated with cancer-related FHIT cDNA splicing aberrations
We evaluated primary lung cancers, tumor cell lines, and preneoplastic bronchial lesions for molecular genetic abnormalities in the candidate tumor suppressor gene FHIT, which spans the FRA3B fragile site at 3p14.2. 3p14.2 allele loss was very frequent in 32 lung cancer cell lines [100% of small cell lung cancer and 88% of non-small cell lung cancer (NSCLC)] and 108 primary NSCLC cancers (45%), with numerous breakpoints indicating involvement of several distinct regions in the FRA3B site, 3p14 allele loss was least frequent in the adenocarcinoma subtype and occurred at the relatively late carcinoma irt situ stage of preneoplastic bronchial lesions found in NSCLC patients, Homozygous deletions within the FHIT/FRA3B region were found in 6 of 135 (4.4%) thoracic cancer cell lines. Northern blot showed low or absent FHIT expression in most thoracic cancer cell lines tested, whereas reverse transcription-PCR showed that 59-62% exhibited aberrant FHIT transcripts but nearly always (93-100%) also expressing the wild-type transcripts, Aberrant transcripts included precise deletions of FHIT exons, insertion of non-FHIT sequences between exons and insertions replacing exons. Complete open reading frame single-strand conformational polymorphism analysis of 102 lung cancer cDNAs revealed only one nonsplicing mutation, Normal cells including bronchial epithelium, lung, and trachea expressed wild-type FHIT transcript and a variant transcript deleted for exon 8 but not the other aberrant transcripts, arguing against exon 8-deleted FHIT transcripts being tumor specific, Our findings support the conclusion that FHIT/FRA3B abnormalities are associated with lung cancer pathogenesis but that FHIT abnormalities differ from the types of mutations and lad; of wild-type transcript found in classic tumor suppressor genes, and functional studies are needed to define the role of FHIT in thoracic tumorigenesis
The transcription factor grainyhead-like 2 regulates the molecular composition of the epithelial apical junctional complex
Differentiation of epithelial cells and morphogenesis of epithelial tubes or layers is closely linked with the establishment and remodeling of the apical junctional complex, which includes adherens junctions and tight junctions. Little is known about the transcriptional control of apical junctional complex components. Here, we show that the transcription factor grainyhead-like 2 (Grhl2), an epithelium-specific mammalian homolog of Drosophila Grainyhead, is essential for adequate expression of the adherens junction gene E-cadherin and the tight junction gene claudin 4 (Cldn4) in several types of epithelia, including gut endoderm, surface ectoderm and otic epithelium. We have generated Grhl2 mutant mice to demonstrate defective molecular composition of the apical junctional complex in these compartments that coincides with the occurrence of anterior and posterior neural tube defects. Mechanistically, we show that Grhl2 specifically associates with cis-regulatory elements localized at the Cldn4 core promoter and within intron 2 of the E-cadherin gene. Cldn4 promoter activity in epithelial cells is crucially dependent on the availability of Grhl2 and on the integrity of the Grhl2-associated cis-regulatory element. At the E-cadherin locus, the intronic Grhl2-associated cis-regulatory region contacts the promoter via chromatin looping, while loss of Grhl2 leads to a specific decrease of activating histone marks at the E-cadherin promoter. Together, our data provide evidence that Grhl2 acts as a target gene-associated transcriptional activator of apical junctional complex components and, thereby, crucially participates in epithelial differentiation
6 Jahre Erfahrungen mit einem Arzneimittelberatungsdienst für Patienten
BACKGROUND AND PURPOSE: Many patients are inadequately informed about their drug therapy. There is thus a need for providing additional drug information to patients. The authors here report on a 6-year experience with a drug information service for patients. PATIENTS AND METHODS: The information service was available by telephone, e-mail or regular mail and was addressed initially to patients in Saxony and since 2005 to patients throughout Germany. Demographic and drug therapy data of the patients were registered and analyzed using a relational database. All enquiries to the information service between August 2001 and January 2007 were evaluated. RESULTS: 5,587 enquiries were registered. 61.4% of the persons calling were female and 33.8% male (sex was unknown in 4.8% by anonymous calls). The most frequent reasons for an enquiry were a general need for information about drugs and therapy (27.5%) and adverse drug reactions (24.7%). The drug group most frequently enquired about were cardiovascular drugs, accounting for 34.4%, followed by neuropsychiatric drugs (15.1%). CONCLUSION: The results of this analysis show an evident need for a drug information service for patients. This need is possibly caused by the shortage of time that physicians can devote to patients. An independent and competent drug information service may improve the quality of medical care and the satisfaction of the patients involved
Genotype-Phenotype Comparison in POGZ-Related Neurodevelopmental Disorders by Using Clinical Scoring
POGZ-related disorders (also known as White-Sutton syndrome) encompass a wide range of neurocognitive abnormalities and other accompanying anomalies. Disease severity varies widely among POGZ patients and studies investigating genotype-phenotype association are scarce. Therefore, our aim was to collect data on previously unreported POGZ patients and perform a large-scale phenotype-genotype comparison from published data. Overall, 117 POGZ patients' genotype and phenotype data were included in the analysis, including 12 novel patients. A severity scoring system was developed for the comparison. Mild and severe phenotypes were compared with the types and location of the variants and the predicted presence or absence of nonsense-mediated RNA decay (NMD). Missense variants were more often associated with mild phenotypes (p = 0.0421) and truncating variants predicted to escape NMD presented with more severe phenotypes (p < 0.0001). Within this group, variants in the prolin-rich region of the POGZ protein were associated with the most severe phenotypes (p = 0.0004). Our study suggests that gain-of-function or dominant negative effect through escaping NMD and the location of the variants in the prolin-rich domain of the protein may play an important role in the severity of manifestations of POGZ-associated neurodevelopmental disorders
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