Transepithelial electrical resistance
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Caco-2 cells (exhibiting characteristics of mature villus enterocytes) were used to determine bacteria (Salmonella enteritidis causing human gastroenteritis)-intestinal cell interactions. The interference of bacteria with the transepithelial electrical resistance (TEER) of filter-grown Caco-2 cells and the production of IL-8 after exposure of the cells to S. enteritidis 857 and/or Lactobacillus strains (L. gasseri LF221 and L. rhamnosus BGT10) was evaluated. The strain 857 decreased TEER of filter-grown Caco-2 cells; in contrast, lactobacilli had a little or no effect. The effect of S. enteritidis on the TEER decreased if Caco-2 cells were pre-incubated with lactobacilli. This strain induced high levels of IL-8 (which can lead to cell damage). Compared to the IL-8 synthesis after exposure of Caco-2 cells to S. enteritidis 857, simultaneous exposure of Caco-2 cells to S. enteritidis and lactobacilli inhibited the IL-8 synthesis after short recovery periods.
- MeSH
- Caco-2 buňky metabolismus mikrobiologie MeSH
- elektrická impedance MeSH
- interleukin-8 metabolismus MeSH
- Lactobacillus fyziologie MeSH
- lidé MeSH
- Salmonella enteritidis patogenita MeSH
- salmonelóza imunologie MeSH
- slizniční imunita MeSH
- střevní sliznice metabolismus mikrobiologie MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- interleukin-8 MeSH
The functional heterogeneity of different segments of the rat large intestine was investigated by means of transepithelial potential difference (PD), short-circuit current (Isc) and transepithelial resistance (Rt) measurements in control rats and after deoxycorticosterone acetate (DOCA) pretreatment. Rt and PD were low in caecum and proximal colon but higher in the distal colon and rectum. Isc was highest in the distal colon, lower in the caecum, proximal colon, and rectum. None of the electrical properties was sensitive to amiloride in control conditions. DOCA increased PD and Isc in the caecum, distal colon and rectum but had no effect in the proximal colon. The increase of the Isc after DOCA in the distal colon and rectum was reached by induction of the amiloride-sensitive Isc associated with reduction of the amiloride-insensitive Isc. The effect of DOCA could be completely prevented by concurrent spironolactone treatment. The results suggest that the epithelia of the proximal parts of the large intestine are "leaky" whereas those of the distal colon and rectum are relatively "tight". It is concluded that there is a marked quantitative and qualitative segmental heterogeneity along the rat large intestine.
- MeSH
- amilorid farmakologie MeSH
- cékum účinky léků fyziologie MeSH
- deoxykortikosteron farmakologie MeSH
- elektrofyziologie MeSH
- epitel účinky léků fyziologie MeSH
- inbrední kmeny potkanů MeSH
- iontové kanály účinky léků metabolismus MeSH
- kolon účinky léků fyziologie MeSH
- krysa rodu Rattus MeSH
- rektum účinky léků fyziologie MeSH
- sodík metabolismus MeSH
- spironolakton farmakologie MeSH
- tlusté střevo účinky léků fyziologie MeSH
- zvířata MeSH
- Check Tag
- krysa rodu Rattus MeSH
- mužské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- amilorid MeSH
- deoxykortikosteron MeSH
- iontové kanály MeSH
- sodík MeSH
- spironolakton MeSH
This paper is devoted to yet unpublished electrode-less methods (ELM) of cell layers impedance measurement based on transformer principle. The main advantage of ELM is elimination uncertainties caused by interface between electrodes and measured electrolyte. The method of avoiding distortion caused by non-ideal transformer transfer function ("deconvolution") and errors caused by residual voltage is described. The modification of original transformer based method allowing to measure an impedance of inserted object is proposed. Results of several calibration measurements confirming the proper function of ELM including example of transepithelial resistance of cells layer are presented. Crucial parts of measuring system and recommendation for their realization are included.
- MeSH
- design vybavení MeSH
- elektrická impedance * MeSH
- elektrofyziologické jevy fyziologie MeSH
- elektrofyziologie metody MeSH
- fyziologie buňky * MeSH
- lidé MeSH
- software MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- přehledy MeSH
Calpain2 is a conventional member of the non-lysosomal calpain protease family that has been shown to affect the dynamics of focal and cell-cell adhesions by proteolyzing the components of adhesion complexes. Here, we inactivated calpain2 using CRISPR/Cas9 in epithelial MDCK cells. We show that depletion of calpain2 has multiple effects on cell morphology and function. Calpain2-depleted cells develop epithelial shape, however, they cover a smaller area, and cell clusters are more compact. Inactivation of calpain2 enhanced restoration of transepithelial electrical resistance after calcium switch, decreased cell migration, and delayed cell scattering induced by HGF/SF. In addition, calpain2 depletion prevented morphological changes induced by ERK2 overexpression. Interestingly, proteolysis of several calpain2 targets, including E-cadherin, β-catenin, talin, FAK, and paxillin, was not discernibly affected by calpain2 depletion. Taken together, these data suggest that calpain2 regulates the stability of cell-cell and cell-substratum adhesions indirectly without affecting the proteolysis of these adhesion complexes.
- Klíčová slova
- Actin, Adherens junctions, Calpains, Cell scattering, ERK, Epithelial polarity, Focal adhesions, HGF/SF, Migration, Proteases, Tight junctions, Transepithelial electrical resistance,
- MeSH
- beta-katenin metabolismus MeSH
- buněčná adheze * MeSH
- buňky MDCK MeSH
- CRISPR-Cas systémy MeSH
- epitelové buňky * metabolismus cytologie MeSH
- hepatocytární růstový faktor metabolismus MeSH
- kadheriny metabolismus MeSH
- kalpain * metabolismus MeSH
- mitogenem aktivovaná proteinkinasa 1 metabolismus MeSH
- pohyb buněk MeSH
- proteolýza MeSH
- psi MeSH
- vápník metabolismus MeSH
- zvířata MeSH
- Check Tag
- psi MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- beta-katenin MeSH
- hepatocytární růstový faktor MeSH
- kadheriny MeSH
- kalpain * MeSH
- mitogenem aktivovaná proteinkinasa 1 MeSH
- vápník MeSH
Gasoline engine emissions have been classified as possibly carcinogenic to humans and represent a significant health risk. In this study, we used MucilAir™, a three-dimensional (3D) model of the human airway, and BEAS-2B, cells originating from the human bronchial epithelium, grown at the air-liquid interface to assess the toxicity of ordinary gasoline exhaust produced by a direct injection spark ignition engine. The transepithelial electrical resistance (TEER), production of mucin, and lactate dehydrogenase (LDH) and adenylate kinase (AK) activities were analyzed after one day and five days of exposure. The induction of double-stranded DNA breaks was measured by the detection of histone H2AX phosphorylation. Next-generation sequencing was used to analyze the modulation of expression of the relevant 370 genes. The exposure to gasoline emissions affected the integrity, as well as LDH and AK leakage in the 3D model, particularly after longer exposure periods. Mucin production was mostly decreased with the exception of longer BEAS-2B treatment, for which a significant increase was detected. DNA damage was detected after five days of exposure in the 3D model, but not in BEAS-2B cells. The expression of CYP1A1 and GSTA3 was modulated in MucilAir™ tissues after 5 days of treatment. In BEAS-2B cells, the expression of 39 mRNAs was affected after short exposure, most of them were upregulated. The five days of exposure modulated the expression of 11 genes in this cell line. In conclusion, the ordinary gasoline emissions induced a toxic response in MucilAir™. In BEAS-2B cells, the biological response was less pronounced, mostly limited to gene expression changes.
- Klíčová slova
- MucilAir™, air-liquid interface, bronchial epithelial cells, gasoline emissions, toxicity,
- MeSH
- adenylátkinasa metabolismus MeSH
- bronchy cytologie MeSH
- dvouřetězcové zlomy DNA MeSH
- elektrická impedance MeSH
- epitelové buňky účinky léků metabolismus MeSH
- kultivované buňky MeSH
- L-laktátdehydrogenasa metabolismus MeSH
- lidé MeSH
- muciny metabolismus MeSH
- testy toxicity metody MeSH
- transkriptom MeSH
- výfukové emise vozidel toxicita MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- adenylátkinasa MeSH
- L-laktátdehydrogenasa MeSH
- muciny MeSH
- výfukové emise vozidel MeSH
The biological effects induced by complete engine emissions in a 3D model of the human airway (MucilAirTM) and in human bronchial epithelial cells (BEAS-2B) grown at the air-liquid interface were compared. The cells were exposed for one or five days to emissions generated by a Euro 5 direct injection spark ignition engine. The general condition of the cells was assessed by the measurement of transepithelial electrical resistance and mucin production. The cytotoxic effects were evaluated by adenylate kinase (AK) and lactate dehydrogenase (LDH) activity. Phosphorylation of histone H2AX was used to detect double-stranded DNA breaks. The expression of the selected 370 relevant genes was analyzed using next-generation sequencing. The exposure had minimal effects on integrity and AK leakage in both cell models. LDH activity and mucin production in BEAS-2B cells significantly increased after longer exposures; DNA breaks were also detected. The exposure affected CYP1A1 and HSPA5 expression in MucilAirTM. There were no effects of this kind observed in BEAS-2B cells; in this system gene expression was rather affected by the time of treatment. The type of cell model was the most important factor modulating gene expression. In summary, the biological effects of complete emissions exposure were weak. In the specific conditions used in this study, the effects observed in BEAS-2B cells were induced by the exposure protocol rather than by emissions and thus this cell line seems to be less suitable for analyses of longer treatment than the 3D model.
- Klíčová slova
- 3D models, cell monocultures, complete engine emissions, gene expression,
- MeSH
- biologické markery MeSH
- biologické modely * MeSH
- chaperon endoplazmatického retikula BiP MeSH
- elektrická impedance MeSH
- epitelové buňky účinky léků metabolismus MeSH
- exprese genu MeSH
- lidé MeSH
- muciny biosyntéza MeSH
- respirační sliznice účinky léků metabolismus MeSH
- výfukové emise vozidel toxicita MeSH
- vystavení vlivu životního prostředí škodlivé účinky MeSH
- zlomy DNA MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- biologické markery MeSH
- chaperon endoplazmatického retikula BiP MeSH
- HSPA5 protein, human MeSH Prohlížeč
- muciny MeSH
- výfukové emise vozidel MeSH
The standard Ussing method was used to electrophysiologically characterize the effects of three analogs of arginine-vasopressin (AVP) on the frog skin, a model Na-transporting epithelium. The analogs tested were N-terminally extended Arg8-vasopressins: Ala-AVP, Ser-Ala-AVP and Thr-Ser-Ala-AVP; synthetic Arg8-AVP was used as the reference agent. The vasopressins were applied to the basolateral side of the frog skin in concentrations ranging between 10(-8) to 10(-5) mol.l-1. All the three analogs increased both the short-circuit current (Isc) and the open-circuit transepithelial potential (Voc), and decreased the transepithelial d.c. resistance (Rt) similarly as did synthetic Arg8-AVP. The results show that N-terminal extension of the Arg8-AVP did not alter the natriferic properties of AVP.
- MeSH
- arginin vasopresin analogy a deriváty farmakologie MeSH
- elektrofyziologie MeSH
- epitel účinky léků fyziologie MeSH
- fyziologie kůže * MeSH
- kůže účinky léků MeSH
- membránové potenciály účinky léků MeSH
- Rana temporaria MeSH
- sodík metabolismus MeSH
- techniky in vitro MeSH
- zvířata MeSH
- Check Tag
- mužské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- arginin vasopresin MeSH
- sodík MeSH
The placenta plays a critical role in maternal-fetal nutrient transport and fetal protection against drugs. Creating physiological in vitro models to study these processes is crucial, but technically challenging. This study introduces an efficient cell model that mimics the human placental barrier using co-cultures of primary trophoblasts and primary human umbilical vein endothelial cells (HUVEC) on a Transwell®-based system. Monolayer formation was examined over 7 days by determining transepithelial electrical resistance (TEER), permeability of Lucifer yellow (LY) and inulin, localization of transport proteins at the trophoblast membrane (immunofluorescence), and syncytialization markers (RT-qPCR/ELISA). We analysed diffusion-based (caffeine/antipyrine) and transport-based (leucine/Rhodamine-123) processes to study the transfer of physiologically relevant compounds. The latter relies on the adequate localization and function of the amino-acid transporter LAT1 and the drug transporter P-glycoprotein (P-gp) which were studied by immunofluorescence microscopy and application of respective inhibitors (2-Amino-2-norbornanecarboxylic acid (BCH) for LAT1; cyclosporine-A for P-gp). The formation of functional monolayer(s) was confirmed by increasing TEER values, low LY transfer rates, minimal inulin leakage, and appropriate expression/release of syncytialization markers. These results were supported by microscopic monitoring of monolayer formation. LAT1 was identified on the apical and basal sides of the trophoblast monolayer, while P-gp was apically localized. Transport assays confirmed the inhibition of LAT1 by BCH, reducing both intracellular leucine levels and leucine transport to the basal compartment. Inhibiting P-gp with cyclosporine-A increased intracellular Rhodamine-123 concentrations. Our in vitro model mimics key aspects of the human placental barrier. It represents a powerful tool to study nutrient and drug transport mechanisms across the placenta, assisting in evaluating safer pregnancy therapies.
- Klíčová slova
- LAT1, P‐gp, co‐culture, endothelial cell, placental barrier, polarized monolayer, primary trophoblast, transport,
- MeSH
- biologické modely MeSH
- biologický transport MeSH
- endoteliální buňky pupečníkové žíly (lidské) * metabolismus MeSH
- inulin metabolismus MeSH
- isochinoliny MeSH
- kokultivační techniky MeSH
- leucin metabolismus MeSH
- lidé MeSH
- maternofetální výměna látek * MeSH
- P-glykoprotein metabolismus MeSH
- placenta * metabolismus MeSH
- rhodamin 123 metabolismus MeSH
- těhotenství MeSH
- trofoblasty * metabolismus MeSH
- Check Tag
- lidé MeSH
- těhotenství MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- inulin MeSH
- isochinoliny MeSH
- leucin MeSH
- lucifer yellow MeSH Prohlížeč
- P-glykoprotein MeSH
- rhodamin 123 MeSH
While two-dimensional (2D) cell cultures, such as Caco-2 and Madin-Darby canine kidney (MDCK) cells are widely used in a variety of biological models, these two-dimensional in vitro systems present inherent limitations in replicating the complexities of in vivo biology. Recent progress in three-dimensional organoid technology has the potential to address these limitations. In this study, the characteristics of conventional 2D cell culture systems were compared to those of canine intestinal organoids (enteroids, ENT, and colonoids, COL). Light microscopy and transmission electron microscopy were employed to evaluate the microanatomy of ENT, COL, Caco-2, and MDCK cell monolayers, while transepithelial electrical resistance (TEER) values were measured to assess monolayer integrity. The TEER values of canine ENT monolayers more closely approximated reported TEER values for human small intestines compared to Caco-2 and MDCK monolayers. Additionally, canine ENT demonstrated greater monolayer stability than Caco-2 and MDCK cells. Notably, while all systems displayed desmosomes, canine ENT and COL exclusively produced mucus. These findings highlight the potential of the canine organoid system as a more biologically relevant model for in vitro studies, addressing the limitations of conventional 2D cell culture systems.
The airway epithelium restricts the penetration of inhaled pathogens into the underlying tissue and plays a crucial role in the innate immune defense against respiratory infections. The whooping cough agent, Bordetella pertussis, adheres to ciliated cells of the human airway epithelium and subverts its defense functions through the action of secreted toxins and other virulence factors. We examined the impact of B. pertussis infection and of adenylate cyclase toxin-hemolysin (CyaA) action on the functional integrity of human bronchial epithelial cells cultured at the air-liquid interface (ALI). B. pertussis adhesion to the apical surface of polarized pseudostratified VA10 cell layers provoked a disruption of tight junctions and caused a drop in transepithelial electrical resistance (TEER). The reduction of TEER depended on the capacity of the secreted CyaA toxin to elicit cAMP signaling in epithelial cells through its adenylyl cyclase enzyme activity. Both purified CyaA and cAMP-signaling drugs triggered a decrease in the TEER of VA10 cell layers. Toxin-produced cAMP signaling caused actin cytoskeleton rearrangement and induced mucin 5AC production and interleukin-6 (IL-6) secretion, while it inhibited the IL-17A-induced secretion of the IL-8 chemokine and of the antimicrobial peptide beta-defensin 2. These results indicate that CyaA toxin activity compromises the barrier and innate immune functions of Bordetella-infected airway epithelia.
- Klíčová slova
- Bordetella pertussis, CyaA, adenylate cyclase toxin, airway epithelia, antimicrobial peptides, cyclic AMP, epithelial cells, immunomodulatory cytokines, tight junctions,
- MeSH
- adenylátcyklasový toxin genetika metabolismus toxicita MeSH
- AMP cyklický metabolismus MeSH
- Bordetella pertussis genetika metabolismus MeSH
- bronchy cytologie metabolismus mikrobiologie MeSH
- cytoskelet metabolismus MeSH
- epitelové buňky metabolismus mikrobiologie MeSH
- interleukin-6 metabolismus MeSH
- lidé MeSH
- mucin 5AC metabolismus MeSH
- pertuse genetika metabolismus mikrobiologie MeSH
- signální transdukce účinky léků MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- adenylátcyklasový toxin MeSH
- AMP cyklický MeSH
- interleukin-6 MeSH
- mucin 5AC MeSH