A5040194271- Barrier Structure and Function Studies
- Ion Transport and Channel Regulation
- Gut microbiota and health
- Helicobacter pylori-related gastroenterology studies
- Neurological Disease Mechanisms and Treatments
- Berberine and alkaloids research
- Inflammatory Bowel Disease
- Plant-based Medicinal Research
- Neonatal and fetal brain pathology
- Connexins and lens biology
- Hormonal Regulation and Hypertension
- Drug Transport and Resistance Mechanisms
- Clostridium difficile and Clostridium perfringens research
- Electrolyte and hormonal disorders
- Gastrointestinal motility and disorders
- Oral microbiology and periodontitis research
- Microscopic Colitis
- Salmonella and Campylobacter epidemiology
- Yersinia bacterium, plague, ectoparasites research
- Trace Elements in Health
- Ion channel regulation and function
- Ion Channels and Receptors
- Whipple's Disease and Interleukins
- Neuroinflammation and Neurodegeneration Mechanisms
- Mycobacterium research and diagnosis
Charité - Universitätsmedizin Berlin
2013-2025
Humboldt-Universität zu Berlin
2009-2023
Freie Universität Berlin
2011-2023
Franklin University
2015
Czech Academy of Sciences, Institute of Physiology
2010-2011
Istituto di Fisiologia Clinica
2010-2011
Institute of Clinical Cancer Research
2011
Center for Rheumatology
2009
Vehicle Technologies Office
2008
TNFα-mediated tight junction defects contribute to diarrhea in inflammatory bowel diseases (IBDs). In our study, the signaling pathways of TNFα effect on barrier- or pore-forming claudins were analyzed HT-29/B6 human colon monolayers. Berberine, a herbal therapeutic agent that has been recently established as therapy for diabetes and hypercholesterinemia, was able completely antagonize barrier cell model rat colon. Ussing chamber experiments two-path impedance spectroscopy revealed decrease...
<h3>Background</h3> Epithelial barrier defects are well known in coeliac disease, but the mechanisms only poorly defined. It is unclear, whether disturbance reflects upregulated epithelial transcytosis or paracellular leakage. <h3>Objective</h3> To characterise molecular structure and function of tight junction (TJ) its dysregulation. <h3>Methods</h3> Molecular analysis proteins involved TJ assembly their regulation was performed by western blotting confocal microscopy correlated to...
Members of the claudin protein family are major constituents tight junction strands and determine permeability properties paracellular pathway. In kidney, each nephron segment expresses a distinct subset claudins that form either barriers against solute transport or charge- size-selective channels. It was aim present study to compare permeation these renal ion channel-forming claudins. MDCK II cells, in which five had been knocked out (claudin quintupleKO), were stably transfected with...
In Inflammatory bowel disease (IBD), elevated cytokines are responsible for disturbed intestinal transport and barrier function. The mechanisms of cytokine action have usually been studied in cell culture models only; therefore the aim this study was to establish an vitro model based on native intestine analyze distinct effects function, mucosal structure, inherent regulatory mechanisms.Rat colon exposed tumor necrosis factor alpha (TNFalpha) interferon gamma (IFNgamma) Ussing chambers....
The tight junction proteins claudin-2 and claudin-10a form paracellular cation anion channels, respectively, are expressed in the proximal tubule. However, physiologic role of kidney has been unclear.To investigate claudin-10a, we generated claudin-10a-deficient mice, confirmed successful knockout by Southern blot, Western immunofluorescence staining, analyzed urine serum wild-type animals. We also used electrophysiologic studies to functionality isolated tubules, studied compensatory...
Background. Aeromonads cause a variety of infections, including gastroenteritis, sepsis, and wound necrosis. Pathogenesis Aeromonas hydrophila its hemolysin has been characterized, but the mechanism epithelial barrier dysfunction is currently poorly understood. Methods. Human colon monolayers HT-29/B6 were apically inoculated with clinical isolates A. or secreted pore-forming toxin aerolysin. Epithelial resistance permeability for several markers determined in Ussing chambers, using 2-path...
Claudins constitute the major component of tight junctions and regulate paracellular permeability epithelia. Claudin-10 occurs in two isoforms that form channels with ion selectivity. We report on families segregating an autosomal recessive disorder characterized by generalized anhidrosis, severe heat intolerance mild kidney failure. All affected individuals carry a rare homozygous missense mutation c.144C>G, p.(N48K) specific for claudin-10b isoform. Immunostaining sweat glands from...
Clostridium perfringens enterotoxin (CPE) causes food poisoning and antibiotic-associated diarrhea. It uses some claudin tight junction proteins (eg, claudin-4) as receptors to form Ca2+-permeable pores in the membrane, damaging epithelial cells small intestine colon. We demonstrate that only a subpopulation of colonic enterocytes which are characterized by apical dislocation claudins CPE-susceptible. CPE-mediated damage was enhanced if paracellular barrier impaired Ca2+ depletion,...
Aldosterone is the principal hormonal regulator of sodium homeostasis in vertebrates. It exerts its actions through mineralocorticoid receptor (MR) that regulates transcription specific target genes. In recent years, a number MR genes have been identified are involved regulation epithelial channel (ENaC), key modulator renal absorption. Here we report identification cnksr3 as direct gene up-regulated response to physiological concentrations aldosterone. The promoter exhibits two functional...
Abstract Claudins are integral components of tight junctions (TJs) in epithelia and endothelia. When expressed cell lines devoid TJs, claudins able to form TJ‐like strands at contacts between adjacent cells. According a current model TJ strand formation, claudin protomers assemble an antiparallel double row within the plasma membrane each ( cis ‐interaction) while binding corresponding rows from neighboring cells trans ‐interaction). Cis ‐interaction was proposed involve two interfaces...
Campylobacter jejuni (C. jejuni) is the most common cause of foodborne gastroenteritis worldwide. The bacteria induce diarrhea and inflammation by invading intestinal epithelium. Curcumin a natural polyphenol from turmeric rhizome Curcuma longa, medical plant, commonly used in curry powder. aim this study was investigation protective effects curcumin against immune-induced epithelial barrier dysfunction C. infection. indirect jejuni-induced defects its protection were analyzed co-cultures...
Key points Interleukin‐13 (IL‐13) causes intestinal epithelial barrier dysfunction, and is implicated in the pathogenesis of Th2‐driven inflammation (e.g. ulcerative colitis). However, it unclear whether sodium channel (ENaC) – main limiting factor for absorption distal colon also influenced by IL‐13 if so, what mechanism(s). We demonstrate an cell model as well mouse that reduced ENaC activity. show impairs ENaC‐dependent transport activating JAK1/2–STAT6 signalling pathway. These results...