Methoxamine (Mox) is a well-known α1-adrenoceptor agonist, clinically used as a longer-acting analogue of epinephrine. 1R,2S-Mox (NRL001) has been also undergoing clinical testing to increase the canal resting pressure in patients with bowel incontinence. Here we show, that Mox hydrochloride acts as an inhibitor of base excision repair (BER). The effect is mediated by the inhibition of apurinic/apyrimidinic endonuclease APE1. We link this observation to our previous report showing the biologically relevant effect of Mox on BER - prevention of converting oxidative DNA base damage to double-stranded breaks. We demonstrate that its effect is weaker, but still significant when compared to a known BER inhibitor methoxyamine (MX). We further determined Mox's relative IC50 at 19 mmol L-1, demonstrating a significant effect of Mox on APE1 activity in clinically relevant concentrations.

• MeSH
• adrenalin * MeSH
• adrenergní receptory MeSH
• endonukleasy MeSH
• lidé MeSH
• methoxamin MeSH
• oprava DNA * MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH

BACKGROUND: The mammalian Major Histocompatibility Complex (MHC) is a genetic region containing highly polymorphic genes with immunological functions. MHC class I and class II genes encode antigen-presenting molecules expressed on the cell surface. The MHC class II sub-region contains genes expressed in antigen presenting cells. The antigen binding site is encoded by the second exon of genes encoding antigen presenting molecules. The exon 2 sequences of these MHC genes have evolved under the selective pressure of pathogens. Interspecific differences can be observed in the class II sub-region. The family Equidae includes a variety of domesticated, and free-ranging species inhabiting a range of habitats exposed to different pathogens and represents a model for studying this important part of the immunogenome. While equine MHC class II DRA and DQA loci have received attention, the genetic diversity and effects of selection on DRB and DQB loci have been largely overlooked. This study aimed to provide the first in-depth analysis of the MHC class II DRB and DQB loci in the Equidae family. RESULTS: Three DRB and two DQB genes were identified in the genomes of all equids. The genes DRB2, DRB3 and DQB3 showed high sequence conservation, while polymorphisms were more frequent at DRB1 and DQB1 across all species analyzed. DQB2 was not found in the genome of the Asiatic asses Equus hemionus kulan and E. h. onager. The bioinformatic analysis of non-zero-coverage-bases of DRB and DQB genes in 14 equine individual genomes revealed differences among individual genes. Evidence for recombination was found for DRB1, DRB2, DQB1 and DQB2 genes. Trans-species allele sharing was identified in all genes except DRB1. Site-specific selection analysis predicted genes evolving under positive selection both at DRB and DQB loci. No selected amino acid sites were identified in DQB3. CONCLUSIONS: The organization of the MHC class II sub-region of equids is similar across all species of the family. Genomic sequences, along with phylogenetic trees suggesting effects of selection as well as trans-species polymorphism support the contention that pathogen-driven positive selection has shaped the MHC class II DRB/DQB sub-regions in the Equidae.

• MeSH
• Equidae klasifikace   genetika   MeSH
• fylogeneze MeSH
• hlavní histokompatibilní komplex genetika   MeSH
• molekulární evoluce * MeSH
• polymorfismus genetický * MeSH
• rekombinace genetická MeSH
• selekce (genetika) * MeSH
• vznik druhů (genetika) MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH

We describe the association of Becker muscular dystrophy (BMD) derived heart failure with the impairment of tissue homeostasis and remodeling capabilities of the affected heart tissue. We report that BMD heart failure is associated with a significantly decreased number of cardiovascular progenitor cells, reduced cardiac fibroblast migration, and ex vivo survival.BACKGROUND: Becker muscular dystrophy belongs to a class of genetically inherited dystrophin deficiencies. It affects male patients and results in progressive skeletal muscle degeneration and dilated cardiomyopathy leading to heart failure. It is a relatively mild form of dystrophin deficiency, which allows patients to be on a heart transplant list. In this unique situation, the explanted heart is a rare opportunity to study the degenerative process of dystrophin-deficient cardiac tissue. Heart tissue was excised, dissociated, and analyzed. The fractional content of c-kit+/CD45- cardiovascular progenitor cells (CVPCs) and cardiac fibroblast migration were compared to control samples of atrial tissue. Control tissue was obtained from the hearts of healthy organ donor's during heart transplantation procedures. RESULTS: We report significantly decreased CVPCs (c-kit+/CD45-) throughout the heart tissue of a BMD patient, and reduced numbers of phase-bright cells presenting c-kit positivity in the dystrophin-deficient cultured explants. In addition, ex vivo CVPCs survival and cardiac fibroblasts migration were significantly reduced, suggesting reduced homeostatic support and irreversible tissue remodeling. CONCLUSIONS: Our findings associate genetically derived heart failure in a dystrophin-deficient patient with decreased c-kit+/CD45- CVPCs and their resilience, possibly hinting at a lack of cardioprotective capability and/or reduced homeostatic support. This also correlates with reduced plasticity of the explanted cardiac tissue, related to the process of irreversible remodeling in the BMD patient's heart.

• MeSH
• dilatační kardiomyopatie * MeSH
• Duchennova muskulární dystrofie * MeSH
• dystrofin MeSH
• kmenové buňky MeSH
• lidé MeSH
• myokard MeSH
• Check Tag
• lidé MeSH
• mužské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Maintenance of human embryonic stem cells (hESCs) with stable genome is important for their future use in cell replacement therapy and disease modeling. Our understanding of the mechanisms maintaining genomic stability of hESC and our ability to modulate them is essential in preventing unwanted mutation accumulation during their in vitro cultivation. In this study, we show the DNA damage response mechanism in hESCs is composed of known, yet unlikely components. Clustered oxidative base damage is converted into DNA double-strand breaks (DSBs) by base excision repair (BER) and then quickly repaired by ligase (Lig)3-mediated end-joining (EJ). If there is further induction of clustered oxidative base damage by irradiation, then BER-mediated DSBs become essential in triggering the checkpoint response in hESCs. hESCs limit the mutagenic potential of Lig3-mediated EJ by DNA break end protection involving p53 binding protein 1 (53BP1), which results in fast and error-free microhomology-mediated repair and a low mutant frequency in hESCs. DSBs in hESCs are also repaired via homologous recombination (HR); however, DSB overload, together with massive end protection by 53BP1, triggers competition between error-free HR and mutagenic nonhomologous EJ.-Kohutova, A., Raška, J., Kruta, M., Seneklova, M., Barta, T., Fojtik, P., Jurakova, T., Walter, C. A., Hampl, A., Dvorak, P., Rotrekl, V. Ligase 3-mediated end-joining maintains genome stability of human embryonic stem cells.

• MeSH
• DNA-ligasa ATP genetika   metabolismus   MeSH
• dvouřetězcové zlomy DNA účinky záření   MeSH
• homologní rekombinace MeSH
• kultivované buňky MeSH
• lidé MeSH
• lidské embryonální kmenové buňky cytologie   fyziologie   MeSH
• nestabilita genomu * MeSH
• oprava DNA spojením konců fyziologie   účinky záření   MeSH
• oprava DNA fyziologie   účinky záření   MeSH
• proteiny vázající poly-ADP-ribosu genetika   metabolismus   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Recent data on Duchenne muscular dystrophy (DMD) show myocyte progenitor's involvement in the disease pathology often leading to the DMD patient's death. The molecular mechanism underlying stem cell impairment in DMD has not been described. We created dystrophin-deficient human pluripotent stem cell (hPSC) lines by reprogramming cells from two DMD patients, and also by introducing dystrophin mutation into human embryonic stem cells via CRISPR/Cas9. While dystrophin is expressed in healthy hPSC, its deficiency in DMD hPSC lines induces the release of reactive oxygen species (ROS) through dysregulated activity of all three isoforms of nitric oxide synthase (further abrev. as, NOS). NOS-induced ROS release leads to DNA damage and genomic instability in DMD hPSC. We were able to reduce both the ROS release as well as DNA damage to the level of wild-type hPSC by inhibiting NOS activity.

• Publikační typ
• časopisecké články MeSH

Primárně extranodální lymfomy (tzn. lymfomy vyrůstající z mimouzlinových orgánů) tvoří asi 30 % všech nehodgkinských lymfomů (NHL), z nich asi 40 % je diagnostikováno právě v gastrointestinálním traktu (GIT). Primární lymfomy gastrointestinálního traktu tedy tvoří asi 5–10 % ze všech NHL. Jejich výskyt oproti karcinomům je sice výrazně nižší, nicméně lymfom je druhý nejčastější nádor žaludku a střeva. Místem postižení bývá zejména žaludek (v cca 60–75 % případů) a tenké střevo, v ileu, céku a rektu se lymfom objevuje méně. Pokud jde o typy lymfomů, nejčastěji bývá diagnostikován difuzní velkobuněčný B-lymfom (DLBCL) a MALT lymfom (MALT = mucosa associated lymphatic tissue), následován ostatními zralými B a T lymfoproliferacemi. Některé typy NHL primárně se vyskytujících v GIT bývají asociovány s chronickou zánětlivou reakcí v důsledku infekčních agens (Helicobacter pylori, Campylobacter jejuni, EBV), nebo glutenové enteropatie, jako je tomu v případě T-lymfomu sdruženého s enteropatií. Zatímco primární či sekundární postižení GIT u NHL je časté, Hodgkinův lymfom se v této oblasti nachází raritně. Důležitým nástrojem v diagnostice a stanovení rozsahu postižení (stagingu) primárních lymfomů horního GIT je endoskopická ultrasonografie. Strategie léčby závisí na typu lymfomu, rozsahu choroby a etiologii. V případě lokalizovaného MALT lymfomu sdruženého s infekcí Helicobacterem pylori je indikována antibiotická eradikace, která může navodit remisi. Radioterapie je obecně vhodná pro lokalizovaná stadia lymfomů, zejména tam, kde nelze použít antibiotika nebo po selhání antibiotické terapie. V případě pokročilých nebo agresivních lymfomů je indikována imunoterapie, respektive imunochemoterapie. Chirurgická léčba se uplatňuje dominantně v rámci diagnostiky, její místo v léčbě lymfomů GIT je velmi specifické a limitované.

Primary extranodal lymphomas (lymphomas arising from extranodal organs) comprise approximately 30% of all of lymphomas, from which about 40% is diagnosed in gastrointestinal tract (GIT). Primary gastrointestinal lymphomas form nearly 5–10% of all non-Hodgkin's lymphomas. Their frequency is much lower than carcinomas; nevertheless lymphoma is second most frequent tumour of stomach and gut. The most common localization of lymphoma manifestation is stomach (about 60–75% cases) and small bowel; ileum, caecum and rectum are involved less often. Regarding of type, diffuse large B-cell lymphoma (DLBCL) and Mucosa associated lymphoid tissue lymphoma (MALT) are diagnosed most frequently, followed by other mature B- and T-lymphoproliferative diseases. Some of primary GIT lymphomas are associated with a chronic inflammation, in particular of infection (Helicobacter pylori, Campylobacter jejuni, EBV), or gluten enteropathy, how it is in the case of enteropathy associated T-lymphoma. Whereas non-Hodgkin's lymphomas are common in GIT, the impairment of Hodgkin's disease in this localization is rare. The important tool for diagnosis, staging and follow up of upper GIT lymphoma, especially in stomach, is endoscopic ultrasonography. Treatment strategy depends on type of lymphoma, stage and etiology. In principle, localized stages of MALT lymphoma associated with H. pylori infection should be treated by antibiotics with Helicobacter eradication, which can lead to remission. Radiotherapy should be used in localized cases not suitable for antibiotics or with antibiotics failure. Immunotherapy or immunochemotherapy is indicated for the treatment of aggressive or more advanced lymphomas. Surgery is useful in diagnostics but in the treatment of GIT lymphoma has very limited place. .

• MeSH
• Burkittův lymfom MeSH
• difúzní velkobuněčný B-lymfom diagnóza   etiologie   komplikace   patologie   terapie   MeSH
• folikulární lymfom diagnóza   terapie   MeSH
• gastrointestinální nádory * diagnóza   patologie   terapie   MeSH
• imunofenotypizace MeSH
• infekce vyvolané Helicobacter pylori komplikace   MeSH
• lidé MeSH
• lymfom z B-buněk marginální zóny diagnóza   etiologie   patologie   terapie   MeSH
• lymfom z plášťových buněk diagnóza   terapie   MeSH
• lymfom z T-buněk asociovaný s enteropatií diagnóza   patologie   terapie   MeSH
• lymfom * diagnóza   etiologie   klasifikace   patologie   terapie   MeSH
• přežití MeSH
• prognóza MeSH
• směrnice pro lékařskou praxi jako téma MeSH
• staging nádorů MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• přehledy MeSH