88 research outputs found

    E–N-cadherin heterodimers define novel adherens junctions connecting endoderm-derived cells

    Get PDF
    Contradicting the “cadherin switch” model, mixed E-cadherin–N-cadherin heterodimeric adherens junctions are prevalent in a variety of endodermal cells and endoderm-derived tumors

    Unique Cell Type-Specific Junctional Complexes in Vascular Endothelium of Human and Rat Liver Sinusoids

    Get PDF
    Liver sinusoidal endothelium is strategically positioned to control access of fluids, macromolecules and cells to the liver parenchyma and to serve clearance functions upstream of the hepatocytes. While clearance of macromolecular debris from the peripheral blood is performed by liver sinusoidal endothelial cells (LSECs) using a delicate endocytic receptor system featuring stabilin-1 and -2, the mannose receptor and CD32b, vascular permeability and cell trafficking are controlled by transcellular pores, i.e. the fenestrae, and by intercellular junctional complexes. In contrast to blood vascular and lymphatic endothelial cells in other organs, the junctional complexes of LSECs have not yet been consistently characterized in molecular terms. In a comprehensive analysis, we here show that LSECs express the typical proteins found in endothelial adherens junctions (AJ), i.e. VE-cadherin as well as α-, β-, p120-catenin and plakoglobin. Tight junction (TJ) transmembrane proteins typical of endothelial cells, i.e. claudin-5 and occludin, were not expressed by rat LSECs while heterogenous immunreactivity for claudin-5 was detected in human LSECs. In contrast, junctional molecules preferentially associating with TJ such as JAM-A, B and C and zonula occludens proteins ZO-1 and ZO-2 were readily detected in LSECs. Remarkably, among the JAMs JAM-C was considerably over-expressed in LSECs as compared to lung microvascular endothelial cells. In conclusion, we show here that LSECs form a special kind of mixed-type intercellular junctions characterized by co-occurrence of endothelial AJ proteins, and of ZO-1 and -2, and JAMs. The distinct molecular architecture of the intercellular junctional complexes of LSECs corroborates previous ultrastructural findings and provides the molecular basis for further analyses of the endothelial barrier function of liver sinusoids under pathologic conditions ranging from hepatic inflammation to formation of liver metastasis

    The Bank Vole (Clethrionomys glareolus) - Small Animal Model for Hepacivirus Infection

    Get PDF
    Many people worldwide suffer from hepatitis C virus (HCV) infection, which is frequently persistent. The lack of efficient vaccines against HCV and the unavailability of or limited compliance with existing antiviral therapies is problematic for health care systems worldwide. Improved small animal models would support further hepacivirus research, including development of vaccines and novel antivirals. The recent discovery of several mammalian hepaciviruses may facilitate such research. In this study, we demonstrated that bank voles (Clethrionomys glareolus) were susceptible to bank vole-associated Hepacivirus F and Hepacivirus J strains, based on the detection of hepaciviral RNA in 52 of 55 experimentally inoculated voles. In contrast, interferon α/β receptor deficient C57/Bl6 mice were resistant to infection with both bank vole hepaciviruses (BvHVs). The highest viral genome loads in infected voles were detected in the liver, and viral RNA was visualized by in situ hybridization in hepatocytes, confirming a marked hepatotropism. Furthermore, liver lesions in infected voles resembled those of HCV infection in humans. In conclusion, infection with both BvHVs in their natural hosts shares striking similarities to HCV infection in humans and may represent promising small animal models for this important human disease

    Cardiovascular risk categories in patients with nonalcoholic fatty liver disease and the role of low-density lipoprotein cholesterol

    Get PDF
    Cardiovascular disease (CVD) is the leading cause of death in patients with nonalcoholic fatty liver disease (NAFLD). The current analysis expands the knowledge on atherogenic lipid profiles in NAFLD by modeling changes in low-density lipoprotein cholesterol (LDL-C) and total cholesterol (TC) in a prospectively enrolling real-life study cohort to inform physicians on the cardiovascular (CV) event risk based on these changes. A total of 304 patients with histologically confirmed NAFLD were included (mean age, 52 years; equal sex distribution). Of these, 129 (42.4%) patients exhibited a NAFLD activity score ≥4 and 186 (61.2%) had at least intermediate fibrosis ≥F2. The median TC levels were 209 mg/dL (interquartile range [IQR], 183, 239), LDL-C 131 mg/dL (IQR, 103, 152), and high density lipoprotein cholesterol (HDL-C) 45 mg/dL (IQR, 38, 52). Only 16.9% of patients received lipid-lowering therapy. According to the LDL/HDL ratio, 69 (23.7%) patients exhibited a high CV risk. The 10-year CV event risk according to the Framingham risk score (FRS) was low in 91 (41.2%), intermediate in 59 (26.7%), and high in 71 (32.1%) patients and higher in the ≥F2 NAFLD population. A moderate increase in LDL-C levels by 20 mg/dL led to a transition of 20% of patients into the high-risk group when assessing the LDL/HDL ratio. According to the FRS, 6 (2.7%) patients moved from low to intermediate and 11 (4.9%) from intermediate to high CV risk. Conclusion: Patients with NAFLD exhibit a substantial CV event risk and are frequently undertreated with lipid-lowering medication. Moderate increases in LDL-C would result in worsening of the CV event risk in approximately 7.8% of all patients without a history of CVD. E

    Biallelic mutations in NBAS cause recurrent acute liver failure with onset in infancy

    Get PDF
    Acute liver failure (ALF) in infancy and childhood is a life-threatening emergency. Few conditions are known to cause recurrent acute liver failure (RALF), and in about 50% of cases, the underlying molecular cause remains unresolved. Exome sequencing in five unrelated individuals with fever-dependent RALF revealed biallelic mutations in NBAS. Subsequent Sanger sequencing of NBAS in 15 additional unrelated individuals with RALF or ALF identified compound heterozygous mutations in an additional six individuals from five families. Immunoblot analysis of mutant fibroblasts showed reduced protein levels of NBAS and its proposed interaction partner p31, both involved in retrograde transport between endoplasmic reticulum and Golgi. We recommend NBAS analysis in individuals with acute infantile liver failure, especially if triggered by fever

    Распространенность болезни Помпе у пациентов с идиопатической гиперкреатинкиназемией и слабостью поясно-конечностных мышц (анализ 3076 случаев)*

    Get PDF
    .Проведен проспективный скрининг дефицита фермента кислой α-глюкозидазы (GAA) европейской когорты пациентов с гиперкреатинкиназемией (гиперКК) и / или слабостью поясно-конечностных мышц (СПКМ) неустановленной этиологии с помощью метода сухого пятна крови (dry blood spot, DBS).Материалы и методы. Образцы DBS были собраны у 3076 взрослых пациентов, проходивших обследование в 7 немецких и британских нервно-мышечных центрах. Все образцы были исследованы на дефицит GAA методом флуорометрии. При выявлении пониженной ферментативной активности определяли наличие мутации гена GAA.Результаты. Из 3076 образцов DBS в 232 (7,6 %) случаях обнаружена низкая ферментативная активность GAA. У 55 (24 %) из 232 пациентов наблюдали изолированную гиперКК, а у 176 (76 %) – гиперКК и СПКМ. При комбинации 2 признаков у 94 % больных активность GAA была снижена. Мутационный анализ выявил мутации гена GAA у 74 (2,4 %) пациентов, при этом 70 больных были гетерозиготными по распространенной мутации сайта сплайсинга гена GAA c.-32-13T>G. У пациентов с подтвержденной болезнью Помпе основной симптомокомплекс состоял из СПКМ (85,3 %) в сочетании с дыхательной недостаточностью (61 %). У 12,0 % больных наблюдали изолированную гиперКК, а у 2,7 % – гиперКК и дыхательную недостаточность.Заключение. В большой когорте пациентов с гиперКК и / или СПКМ  распространенность болезни Помпе с поздним началом составляет 2,4 %, что требует проведения целевого скрининга активности GAA у пациентов с гиперКК и / или СПКМнеустановленной этиологии

    A language-based sum score for the course and therapeutic intervention in primary progressive aphasia

    Get PDF
    Background: With upcoming therapeutic interventions for patients with primary progressive aphasia (PPA), instruments for the follow-up of patients are needed to describe disease progression and to evaluate potential therapeutic effects. So far, volumetric brain changes have been proposed as clinical endpoints in the literature, but cognitive scores are still lacking. This study followed disease progression predominantly in language-based performance within 1 year and defined a PPA sum score which can be used in therapeutic interventions. Methods: We assessed 28 patients with nonfluent variant PPA, 17 with semantic variant PPA, 13 with logopenic variant PPA, and 28 healthy controls in detail for 1 year. The most informative neuropsychological assessments were combined to a sum score, and associations between brain atrophy were investigated followed by a sample size calculation for clinical trials. Results: Significant absolute changes up to 20% in cognitive tests were found after 1 year. Semantic and phonemic word fluency, Boston Naming Test, Digit Span, Token Test, AAT Written language, and Cookie Test were identified as the best markers for disease progression. These tasks provide the basis of a new PPA sum score. Assuming a therapeutic effect of 50% reduction in cognitive decline for sample size calculations, a number of 56 cases is needed to find a significant treatment effect. Correlations between cognitive decline and atrophy showed a correlation up to r = 0.7 between the sum score and frontal structures, namely the superior and inferior frontal gyrus, as well as with left-sided subcortical structures. Conclusion: Our findings support the high performance of the proposed sum score in the follow-up of PPA and recommend it as an outcome measure in intervention studies

    MPI-Ding reference glasses for in situ microanalysis: New reference values for element concentrations and isotope ratios

    Get PDF
    We present new analytical data of major and trace elements for the geological MPI-DING glasses KL2-G, ML3B-G, StHs6/80-G, GOR128-G, GOR132-G, BM90/21-G, T1-G, and ATHO-G. Different analytical methods were used to obtain a large spectrum of major and trace element data, in particular, EPMA, SIMS, LA-ICPMS, and isotope dilution by TIMS and ICPMS. Altogether, more than 60 qualified geochemical laboratories worldwide contributed to the analyses, allowing us to present new reference and information values and their uncertainties (at 95% confidence level) for up to 74 elements. We complied with the recommendations for the certification of geological reference materials by the International Association of Geoanalysts (IAG). The reference values were derived from the results of 16 independent techniques, including definitive (isotope dilution) and comparative bulk (e.g., INAA, ICPMS, SSMS) and microanalytical (e.g., LA-ICPMS, SIMS, EPMA) methods. Agreement between two or more independent methods and the use of definitive methods provided traceability to the fullest extent possible. We also present new and recently published data for the isotopic compositions of H, B, Li, O, Ca, Sr, Nd, Hf, and Pb. The results were mainly obtained by high-precision bulk techniques, such as TIMS and MC-ICPMS. In addition, LA-ICPMS and SIMS isotope data of B, Li, and Pb are presented
    corecore