15 research outputs found

    Quercetin elevates p27Kip1 and arrests both primary and HPV16 E6/E7 transformed human keratinocytes in G1

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    Our previous work with primary bovine fibroblasts demonstrated that quercetin, a potent mutagen found in high levels in bracken fern (Pteridium aquilinum), arrested cells in G1 and G2/M, in correlation with p53 activation. The expression of bovine papillomavirus type 4 (BPV-4) E7 overcame this arrest and lead to the development of tumorigenic cells lines (Beniston et al., 2001). Given the possible link between papillomavirus infection, bracken fern in the diet and cancer of the upper gastrointestinal (GI) tract in humans, we investigated whether a similar situation would occur in human cells transformed by human papillomavirus type 16 (HPV-16) oncoproteins. Quercetin arrested primary human foreskin keratinocytes in G1. Arrest was linked to an elevation of the cyclin-dependent kinase inhibitor (cdki) p27Kip1. Expression of the HPV16 E6 and E7 oncoproteins in transformed cells failed to abrogate cell cycle arrest. G1 arrest in the transformed cells was also linked to an increase of p27Kip1 with a concomitant reduction of cyclin E-associated kinase activity. This elevation of p27Kip1 was due not only to increased protein half-life, but also to increased mRNA transcription

    Periodontal Ehlers-Danlos Syndrome Is Caused by Mutations in C1R and C1S, which Encode Subcomponents C1r and C1s of Complement

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    Periodontal Ehlers-Danlos syndrome (pEDS) is an autosomal-dominant disorder characterized by early-onset periodontitis leading to premature loss of teeth, joint hypermobility, and mild skin findings. A locus was mapped to an approximately 5.8 Mb region at 12p13.1 but no candidate gene was identified. In an international consortium we recruited 19 independent families comprising 107 individuals with pEDS to identify the locus, characterize the clinical details in those with defined genetic causes, and try to understand the physiological basis of the condition. In 17 of these families, we identified heterozygous missense or in-frame insertion/deletion mutations in C1R (15 families) or C1S (2 families), contiguous genes in the mapped locus that encode subunits C1r and C1s of the first component of the classical complement pathway. These two proteins form a heterotetramer that then combines with six C1q subunits. Pathogenic variants involve the subunit interfaces or inter-domain hinges of C1r and C1s and are associated with intracellular retention and mild endoplasmic reticulum enlargement. Clinical features of affected individuals in these families include rapidly progressing periodontitis with onset in the teens or childhood, a previously unrecognized lack of attached gingiva, pretibial hyperpigmentation, skin and vascular fragility, easy bruising, and variable musculoskeletal symptoms. Our findings open a connection between the inflammatory classical complement pathway and connective tissue homeostasis

    The association between maternal serum first trimester free ÎČhCG, second trimester intact hCG levels and foetal growth restriction and preeclampsia

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    The purpose of this study was to analyse the association between free beta hCG (fÎČhCG) increased levels and pregnancy complications (PC), foetal growth restriction (FGR) and preeclampsia (PE). This connection was evaluated in two stages (i) investigating the association between those PC with first trimester fÎČhCG and second trimester intact hCG (ihCG), and (ii) studying the association between these two analytes in the same pregnancy. This was a retrospective study in two settings: medical centre that provided data on fÎČhCG and ihCG levels in pregnancies with FGR and PE, and central laboratory that provided fÎČhCG and ihCG levels that were compared in the same pregnancy. No association was found between those PC and the hCG analytes, except for elevated ihCG levels and FGR. Elevated fÎČhCG (>3.00 MoM) was found in 570/16,849 (3.4%) women. However, only 14% of whom had elevated second trimester ihCG. A positive correlation was found between the magnitude of first trimester fÎČhCG levels and the percentage of women who had elevated second trimester ihCG. This association was determined by the magnitude of the elevation of fÎČhCG levels.Impact statement What is already known on this subject: The two analytes, first trimester fÎČhCG and second trimester ihCG, are independently produced and parameters of the biochemical screening during pregnancy. What the results of this study add: Referring to 3.00 MoM as cut-off levels, most pregnancies with elevated levels of first trimester fÎČhCG will have normal ihCG second trimester levels. What the implications are of these findings for clinical practice and/or further research: The risk of developing pregnancy complications, FGR and PE should be associated with second trimester ihCG levels. About 3.5% of women had high fÎČhCG levels during the first trimester. However, only 14% also had increased ihCG levels, defined as >3.00 MoM; additional studies are needed to explore the association between increased first trimester fÎČhCG levels and the risk of developing pregnancy complications, independent of ihCG levels in the second trimester

    The 2017 international classification of the Ehlers–Danlos syndromes

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    The Ehlers-Danlos syndromes (EDS) are a clinically and genetically heterogeneous group of heritable connective tissue disorders (HCTDs) characterized by joint hypermobility, skin hyperextensibility, and tissue fragility. Over the past two decades, the Villefranche Nosology, which delineated six subtypes, has been widely used as the standard for clinical diagnosis of EDS. For most of these subtypes, mutations had been identified in collagen-encoding genes, or in genes encoding collagen-modifying enzymes. Since its publication in 1998, a whole spectrum of novel EDS subtypes has been described, and mutations have been identified in an array of novel genes. The International EDS Consortium proposes a revised EDS classification, which recognizes 13 subtypes. For each of the subtypes, we propose a set of clinical criteria that are suggestive for the diagnosis. However, in view of the vast genetic heterogeneity and phenotypic variability of the EDS subtypes, and the clinical overlap between EDS subtypes, but also with other HCTDs, the definite diagnosis of all EDS subtypes, except for the hypermobile type, relies on molecular confirmation with identification of (a) causative genetic variant(s). We also revised the clinical criteria for hypermobile EDS in order to allow for a better distinction from other joint hypermobility disorders. To satisfy research needs, we also propose a pathogenetic scheme, that regroups EDS subtypes for which the causative proteins function within the same pathway. We hope that the revised International EDS Classification will serve as a new standard for the diagnosis of EDS and will provide a framework for future research purposes
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