Publications by authors named "Hargita Hegyesi"

The release of extracellular vesicles (EVs) is increased under cellular stress and cardiomyocyte damaging conditions. However, whether the cardiomyocyte-derived EVs eventually reach the systemic circulation and whether their number in the bloodstream reflects cardiac injury, remains unknown. Wild type C57B/6 and conditional transgenic mice expressing green fluorescent protein (GFP) by cardiomyocytes were studied in lipopolysaccharide (LPS)-induced systemic inflammatory response syndrome (SIRS).

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Combination antitumor treatments are essential parts of modern tumor therapy as-compared to monotherapies-(i) they are more effective; (ii) the dose of the compounds can be reduced; and (iii) therefore the side effects are improved. Our research group previously demonstrated the antitumor character of bortezomib (BOZ) in A2058 melanoma cells. Unfortunately, dose-related side effects are common during BOZ therapy, which could be prevented by reducing the dose of BOZ.

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Stem cell-based therapies raise hope for cell replacement and provide opportunity for cardiac regenerative medicine and tumor therapy. Extracellular vesicles are a membrane-enclosed intercellular delivery system with the potential to improve the therapeutic efficacy of the treatment of a variety of disorders. As the incidence of breast cancer continues to rise, radiotherapy has emerged as a leading treatment modality.

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Article Synopsis
  • There's been a lot of new research on tiny structures called extracellular vesicles (EVs) that cells release, which help us understand how cells work and what goes wrong in diseases.
  • Scientists have had a hard time studying these EVs because they come in different types and can be tough to separate and analyze properly.
  • The International Society for Extracellular Vesicles updated their guidelines, called MISEV2018, to help researchers share clear information about how to study EVs and ensure their findings are accurate and reliable.
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Background/aim: Radiation-induced heart disease (RIHD) is a concern during radiotherapy. For its comprehensive study, an in vivo selective heart irradiation model was developed.

Materials And Methods: Sprague-Dawley rats were irradiated with 50 Gy and functional imaging, biochemical (circulating growth differentiation factor-15 (GDF-15), transforming growth factor-beta (TGF-beta) and morphological (picrosirius red staining of the heart) objectives were tested.

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T-cell receptor (TCR)-transgenic models of acute graft-versus-host disease (aGvHD) offer a straightforward and highly controlled approach to study the mechanisms and consequences of T-cell activation following allogeneic hematopoietic stem cell transplantation (aHSCT). Here, we report that aHSCT involving OT-I mice as donors, carrying an ovalbumin-specific CD8+ TCR, and Act-mOVA mice as recipients, expressing membrane-bound ovalbumin driven by the β-actin promoter, induces lethal aGvHD in a CD8+ T-cell-dependent, highly reproducible manner, within 4-7 days. Tracking of UBC-GFP/OT-I graft CD8+ T cells disclosed heavy infiltration of the gastrointestinal tract, liver, and lungs at the onset of the disease, and histology confirmed hallmark features of gastrointestinal aGVHD, hepatic aGvHD, and aGvHD-associated lymphocytic bronchitis in infiltrated organs.

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We have investigated the importance of GDF-15 (secreted cytokine belonging to the TGF-β superfamily) in low and high dose radiation-induced cellular responses. A telomerase immortalized human fibroblast cell line (F11hT) was used in the experiments. A lentiviral system encoding small hairpin RNAs (shRNA) was used to establish GDF-15 silenced cells.

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Tumor protein 53-induced nuclear protein-1 (TP53inp1) is expressed by activation via p53 and p73. The purpose of our study was to investigate the role of TP53inp1 in response of fibroblasts to ionizing radiation. γ-Ray radiation dose-dependently induces the expression of TP53inp1 in human immortalized fibroblast (F11hT) cells.

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Background: High-dose radiation-induced blood-brain barrier breakdown contributes to acute radiation toxicity syndrome and delayed brain injury, but there are few data on the effects of low dose cranial irradiation. Our goal was to measure blood-brain barrier changes after low (0.1 Gy), moderate (2 Gy) and high (10 Gy) dose irradiation under in vivo and in vitro conditions.

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Objective: Radiotherapy affects antitumor immune responses; therefore, it is important to study radiation effects on various compartments of the immune system. Here we report radiation effects on the homeostasis and function of regulatory T (Treg) cells, which are important in down-regulating antitumor immune responses.

Methods: C57Bl/6 mice were irradiated with 2 Gy and alterations in splenic lymphocyte fractions analyzed at different intervals.

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Purpose: Recent research has suggested that serotonin may play an important role in the expression of radiation-induced bystander effects. Serotonin levels in serum were reported to range from 6-22 μM and to correlate inversely with the magnitude of cellular colony-forming ability in medium transfer bystander assays. That is, high serotonin concentration correlated with a low cloning efficiency in cultures receiving medium derived from irradiated cells.

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Unlabelled: We have analyzed the architectural aspects of progenitor-cell-driven regenerative growth in rat liver by applying the 2-acetaminofluorene/partial hepatectomy experimental model. The regeneration is initiated by the proliferation of so-called oval cells. The oval cells at the proximal tips of the ductules have a more differentiated phenotype and higher proliferative rate.

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One of the key issues of current radiation research is the biological effect of low doses. Unfortunately, low dose science is hampered by the unavailability of easily performable, reliable and sensitive quantitative biomarkers suitable detecting low frequency alterations in irradiated cells. We applied a quantitative real time polymerase chain reaction (qRT-PCR) based protocol detecting common deletions (CD) in the mitochondrial genome to assess direct and non-targeted effects of radiation in human fibroblasts.

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We previously showed that transgenic enhancement of histamine production in B16-F10 melanomas strongly supports tumor growth in C57BL/6 mice. In the present study, gene expression profiles of transgenic mouse melanomas, secreting different amounts of histamine, were compared by whole genome microarrays. Array results were validated by real-time PCR, and genes showing histamine-affected behavior were further analyzed by immunohistochemistry.

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The purpose of the present study was to investigate the influence of lack of histamine (HA) on tumor growth and functions of T cells in order further to illustrate the mechanism of immunological tolerance induction by HA. We assessed the phenotype and cytokine production of splenic lymphocytes in syngeneic HA-free (histidine decarboxylase knock-out) (HDC KO) and wild-type mice, inoculated subcutaneously with the LM2 murine breast cancer cell line. Relative quantification of target mRNA was performed with a TaqMan real-time RT-PCR assay.

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Evidence indicates that repeated-bouts of eccentric exercise (EE) do not exacerbate the extent of muscle damage indices, as compared to a single-bout. We hypothesized that molecular adaptations, under repeated-bouts of EE, would include suppression of muscle repair inhibitory factors such as myostatin and up-regulation of muscle repair positive regulatory factors such as myogenic regulatory factors (MRFs). Fifteen males were recruited for this study.

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In the present study, the impact of acquired neoplastic L-histidine decarboxylase (HDC) expression, and its direct consequence, the release of histamine in the tumor environment, was assessed on melanoma tumor progression. B16-F10 mouse melanoma cells were manipulated via stable transfection, and nine novel transgenic variants were generated in triplicates, constitutively expressing the full-length sense mouse HDC mRNA, a mock control, and an antisense HDC RNA segment, respectively. Establishing both primary skin tumors and lung metastases in C57BL/6 mice, the nine variants with different histamine-releasing capacities were subjected to a comprehensive comparative progression profiling in vivo.

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Background: Ets-1 controls the expression of critical genes involved in matrix remodeling. The matrix metalloproteinase-3 (MMP-3) and urokinase type plasminogen activator (uPA) are typical ets-1 responsive genes. Recent studies have shown an increase in histamine synthesis and content in various human neoplasias.

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Histamine is known to act, at least in part, as a growth factor for several cell types, and as production of this biogen amine has been found to accelerate the rate of tissue proliferation in wound repair, embryogenesis and malignant growth. Abundant experimental and clinical data suggest that histamine augments in vivo tumour cell proliferation via histamine H2 receptors (H2R). Here, we report that exogenously added histamine stimulates Ets-1 (v-ets erythroblastosis virus E26 oncogene homolog 1) synthesis in human melanoma cells.

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Chlamydophila (Chlamydia) pneumoniae (C. pneumoniae) is the third most common cause of community-acquired pneumonia and is probably involved in the development of certain chronic inflammatory diseases, including atherosclerosis and adult-onset asthma. Histamine, synthesized by histidine decarboxylase (HDC) from L-histidine, plays an essential role in allergic and inflammatory processes and in cell differentiation.

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Melanoma cells constitutively produce various cytokines as well as growth factors and express their corresponding receptors. Exogenous histamine is known to be a growth factor for some tumours while in other cases histamine inhibits tumour growth, and acts on G protein-coupled H1 and H2 histamine receptors. In previous studies we have detected the expression of the l-histidine decarboxylase (HDC) gene and the presence of HDC protein in human melanoma cell lines.

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Genetic/genomic polymorphism, i.e. variations in DNA sequences are ideally assayed by direct nucleotide sequencing of a gene region or other homologous segment of the genome.

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Huntington chorea (HC) is a serious neurodegenerative disease. Its genetic background has recently been discovered by positional cloning due to the enormous progress in molecular biology. This disease is caused by the mutation of CAG, a changeable, repetitive Citosin-Adenin-Guanin trinucleotide sequence.

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Melanoma cells and tissues contain considerable amounts of histamine and express histamine receptors, suggesting the existence of autocrine and paracrine regulation by histamine. Our previous in vitro results suggested that histamine elevates melanoma cell growth through the H2 receptor. In this work we show that in vivo tumour proliferation in immunodeficient mice xenotransplanted with a human melanoma cell line is diminished by cimetidine, an H2 receptor antagonist, if combined with a tamoxifen derivate acting on cytochrome p450 molecules (DPPE).

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Interleukin-6 (IL-6) binds to a receptor complex consisting of an 80 kDa binding unit (IL-6R) and gp130 responsible for signal transduction. Due to alternative splicing and/or proteolytic digestion IL-6R occurs in soluble form (sIL-6R), as well. Soluble IL-6R is able to bind to gp130 expressing on nucleated cells, thus sIL-6R makes most cells responsive to IL-6.

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