Pediatrics and Nephrology Research Group

Budapest, Hungary

Pediatrics and Nephrology Research Group

Budapest, Hungary
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PubMed | MTA SE Molecular Biophysics Research Group and, Hungarian Academy of Sciences, Semmelweis University, National Institute of Oncology and 3 more.
Type: Journal Article | Journal: Journal of the American Society of Nephrology : JASN | Year: 2015

Intrarenal changes in cytoplasmic calcium levels have a key role in determining pathologic and pharmacologic responses in major kidney diseases. However, cell-specific delivery of calcium-sensitive probes in vivo remains problematic. We generated a transgenic rat stably expressing the green fluorescent protein-calmodulin-based genetically encoded calcium indicator (GCaMP2) predominantly in the kidney proximal tubules. The transposon-based method used allowed the generation of homozygous transgenic rats containing one copy of the transgene per allele with a defined insertion pattern, without genetic or phenotypic alterations. We applied in vitro confocal and in vivo two-photon microscopy to examine basal calcium levels and ligand- and drug-induced alterations in these levels in proximal tubular epithelial cells. Notably, renal ischemia induced a transient increase in cellular calcium, and reperfusion resulted in a secondary calcium load, which was significantly decreased by systemic administration of specific blockers of the angiotensin receptor and the Na-Ca exchanger. The parallel examination of in vivo cellular calcium dynamics and renal circulation by fluorescent probes opens new possibilities for physiologic and pharmacologic investigations.


Beres N.J.,Semmelweis University | Szabo D.,Semmelweis University | Kocsis D.,Semmelweis University | Szucs D.,University of Szeged | And 13 more authors.
Inflammatory Bowel Diseases | Year: 2016

Background: Evidence suggests the central role of tumor necrosis factor (TNF)-α in the pathomechanism of inflammatory bowel disease (IBD); however, its effect on epigenetic factors, including small non-coding microRNAs (miRs), is less known. Our present aim was the comparative investigation of the expression of TNF-α and immune response-related miRs in children with Crohn's disease (CD) and ulcerative colitis (UC). Methods: Fresh-frozen (FF) and formalin-fixed, paraffin-embedded (FFPE) biopsies were used to analyze the expression of miR-146a,-155,-122, and TNF-α by real-time reverse transcription polymerase chain reaction in macroscopically inflamed (CD: 12 FFPE and 24 FF; UC: 10 FF) and intact (CD: 12 FFPE; 14 FF) colonic biopsies of children with IBD and controls (16 FFPE; 23 FF). The expression of miR-146a,-155, and-122 was also determined in TNF-α-treated HT-29 colonic epithelial cells. Results: Increased expression of TNF-α was observed in the colonic mucosa of children with CD and UC in comparison with controls. Expression of miR-146a and-155 was higher in the inflamed mucosa of children with CD and UC than in the intact mucosa. Expression of miR-122 elevated in the macroscopically intact colonic regions of CD compared with controls and patients with UC. In HT-29 cells, TNF-α treatment increased the expression of miR-146a and-155, but not that of miR-122. Conclusions: Our results showed altered expression of miR-146a,-155, and-122 in the colonic mucosa of children with IBD and in TNF-α-treated colonic epithelial cells. Our data suggest the TNF-α-related involvement of these miRs in the pathogenesis of IBD. © 2016 Crohn's & Colitis Foundation of America, Inc.


Szebenyi K.,Hungarian Academy of Sciences | Furedi A.,Hungarian Academy of Sciences | Kolacsek O.,Hungarian Academy of Sciences | Csohany R.,Semmelweis University | And 11 more authors.
Journal of the American Society of Nephrology | Year: 2015

Intrarenal changes in cytoplasmic calciumlevels have a key role in determining pathologic and pharmacologic responses inmajor kidney diseases. However, cell-specific delivery of calcium-sensitive probes in vivo remains problematic. We generated a transgenic rat stably expressing the green fluorescent protein-calmodulin- based genetically encoded calcium indicator (GCaMP2) predominantly in the kidney proximal tubules. The transposon-based method used allowed the generation of homozygous transgenic rats containing one copy of the transgene per allele with a defined insertion pattern, without genetic or phenotypic alterations. We applied in vitro confocal and in vivo two-photon microscopy to examine basal calcium levels and ligand- and drug-induced alterations in these levels in proximal tubular epithelial cells. Notably, renal ischemia induced a transient increase in cellular calcium, and reperfusion resulted in a secondary calcium load, which was significantly decreased by systemic administration of specific blockers of the angiotensin receptor and the Na-Ca exchanger. The parallel examination of in vivo cellular calcium dynamics and renal circulation by fluorescent probes opens new possibilities for physiologic and pharmacologic investigations. Copyright © 2015 by the American Society of Nephrology.


Sziksz E.,Pediatrics and Nephrology Research Group | Sziksz E.,Semmelweis University | Pap D.,Semmelweis University | Lippai R.,Semmelweis University | And 5 more authors.
Mediators of Inflammation | Year: 2015

Importance of chronic fibroproliferative diseases (FDs) including pulmonary fibrosis, chronic kidney diseases, inflammatory bowel disease, and cardiovascular or liver fibrosis is rapidly increasing and they have become a major public health problem. According to some estimates about 45% of all deaths are attributed to FDs in the developed world. Independently of their etiology the common hallmark of FDs is chronic inflammation. Infiltrating immune cells, endothelial, epithelial, and other resident cells of the injured organ release an orchestra of inflammatory mediators, which stimulate the proliferation and excessive extracellular matrix (ECM) production of myofibroblasts, the effector cells of organ fibrosis. Abnormal amount of ECM disturbs the original organ architecture leading to the decline of function. Although our knowledge is rapidly expanding, we still have neither a diagnostic tool to detect nor a drug to specifically target fibrosis. Therefore, there is an urgent need for the more comprehensive understanding of the pathomechanism of fibrosis and development of novel diagnostic and therapeutic strategies. In the present review we provide an overview of the common key mediators of organ fibrosis highlighting the role of interleukin-10 (IL-10) cytokine family members (IL-10, IL-19, IL-20, IL-22, IL-24, and IL-26), which recently came into focus as tissue remodeling-related inflammatory cytokines. © 2015 Erna Sziksz et al.


Szalay B.,Semmelweis University | Cseh A.,Semmelweis University | Meszaros G.,Semmelweis University | Kovacs L.,University of Szeged | And 3 more authors.
PLoS ONE | Year: 2014

Rheumatoid arthritis (RA) is a chronic autoimmune disease characterized by a systemic dysfunction of T-cells. In this study we tested the impact of DMARD and anti-TNF agents on short-term activation characteristics of T-cells. We enrolled 12 patients with newly diagnosed RA (naïve RA) who were treated with methothrexate (MTX) and glucocorticsteroid (GCS) and 22 patients with established RA non responding to conventional DMARD therapy who were treated with different anti-TNF agents. Nine healthy volunteers served as controls. Blood samples were taken at baseline, then at 4th and 8th week of therapy. The characteristics of several intracellular activation processes during short-term activation of T-cells including cytoplasmic Ca2+ level, mitochondrial Ca2+ level, reactive oxygen species (ROS) and nitric oxide (NO) generation were determined by a novel flow-cytometry technique. At baseline, the tested processes were comparable to controls in naïve RA. During GCS therapy, cytoplasmic Ca2+ level and ROS generation decreased. After the addition of MTX to GCS cytoplasmic Ca2+ level became comparable to controls, while ROS generation decreased further. In DMARD non responders, cytoplasmic Ca2+ level was higher than controls at baseline. The cytoplasmic Ca2+ level became comparable to controls and ROS generation decreased during each of the three anti-TNF-α agent therapies. Mitochondrial Ca2+ level and NO generation were unaltered in all of the patient groups. These results indicate that intracellular machinery is affected in T-cells of RA patients. This may alter the behavior of T-cells during activation. Different therapeutic approaches may modulate the abnormal T-cell functions. © 2014 Szalay et al.


Orban C.,Semmelweis University | Szabo D.,Semmelweis University | Bajnok A.,Semmelweis University | Vasarhelyi B.,Semmelweis University | And 8 more authors.
Oncotarget | Year: 2016

Objective: Crohn's disease is a chronic inflammation of the gastrointestinal tract with an abnormal immune phenotype. We investigated how intracellular calcium kinetics of Th1 and Th2 lymphocytes alter upon specific inhibition of Kv1.3 and IKCa1 channels in pediatric Crohn's disease. Study design: Blood was taken from 12 healthy and 29 Crohn's disease children. Of those, 6 were switched to infliximab and re-sampled after the 4th infliximab treatment. Intracellular calcium levels were monitored using flow cytometry in the presence or absence of specific inhibitors of Kv1.3 and IKCa1 potassium channels. Results: In Crohn's disease treated with standard therapy, calcium response during activation was higher than normal in Th2 cells. This was normalized in vitro by inhibition of Kv1.3 or IKCa1 potassium channels. After the switch to infliximab, potassium channel function and expression in Th2 lymphocytes were comparable to those in Th1 cells. Conclusion: These results may indicate that potassium channels are potential immune modulatory targets in Crohn's disease.


Orban C.,Semmelweis University | Bajnok A.,Semmelweis University | Vasarhelyi B.,Semmelweis University | Vasarhelyi B.,Pediatrics and Nephrology Research Group | And 4 more authors.
Cytometry Part A | Year: 2014

Functional imbalance between T helper subsets plays important role in the pathogenesis of autoimmune disorders. Transient increase of cytoplasmic calcium level, and sustention of negative membrane potential by voltage sensitive Kv1.3 and calcium-dependent IKCa1 potassium channels are essential for short-term lymphocyte activation, thus present possible target for selective immunomodulation. We aimed to investigate calcium influx sensitivity to the inhibition of potassium channels in the main T helper subsets. Peripheral blood from 11 healthy individuals was drawn and calcium influx kinetics following activation with phytohemagglutinin in Th1, Th2, Th17, and Treg cells were evaluated. Alteration of calcium influx induced by specific inhibitors of Kv1.3 and IKCa1 potassium channels, and the expression of Kv1.3 channels were also assessed. Highest cytoplasmic calcium concentration was observed in stimulated Th1 cells, while the lowest level was measured in Treg cells. In Th1 and Th17 cells, inhibition of both investigated potassium channels decreased calcium influx. In Th2 cells only the inhibitor of Kv1.3 channels, while in Treg cells none of the inhibitors had significant effect. Upon the inhibition of IKCa1 channels, short-term activation of proinflammatory cells was specifically decreased without affecting anti-inflammatory subsets, indicating that selective immunomodulation is possible in healthy individuals. © 2014 International Society for Advancement of Cytometry.


Folyovich A.,Szent Janos Hospital | Biro E.,Semmelweis University | Orban C.,Semmelweis University | Bajnok A.,Semmelweis University | And 4 more authors.
CNS and Neurological Disorders - Drug Targets | Year: 2014

Stroke-induced immunosuppression (SIIS) leads to severe complications in stroke patients, including an increased risk of infections. However, functional alterations of T lymphocytes during SIIS are poorly described in acute ischemic stroke (AIS). We aimed to characterize Ca2+ influx kinetics in major lymphocyte subsets (CD4, Th1, Th2, CD8) in AIS patients without infection 6 hours and one week after the CNS insult. We also assessed the sensitivity of the above subsets to specific inhibition of the Kv1.3 and IKCa1 lymphocyte K+ channels. We took peripheral blood samples from 12 non-stroke individuals and 12 AIS patients. We used an innovative flow cytometry approach to determine Ca2+ influx kinetics and the surface expression of Kv1.3 channels. Our results indicate that Ca2+ influx kinetics is altered in the Th2 and CD8 subsets in AIS which may play a role in the development of SIIS. Specific inhibition of Kv1.3 channels selectively decreased Ca2+ influx in the CD8 and Th2 subsets of AIS patients. The surface expression of Kv1.3 channels is also altered compared to non-stroke individuals. Kv1.3 channel inhibition might have beneficial therapeutic consequences in AIS, selectively targeting two distinct T cell subsets at two different time points following the CNS insult. Within hours after the insult, it might prevent excessive tissue injury through the inhibition of CD8 cells, while at one week after the insult, it may improve the inflammatory response through the inhibition of Th2 cells, thus reducing the unwanted clinical consequences of SIIS. © 2014 Bentham Science Publishers.

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