surface alteration
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BACKGROUND: The effect of long-term exposure of live cells to lithium cations (Li) was studied in HEK293 cells cultivated in the presence of 1mM LiCl for 7 or 21days. The alteration of Na+/K+-ATPase level, protein composition and biophysical state of plasma membrane was determined with the aim to characterize the physiological state of Li-treated cells. METHODS: Na+/K+-ATPase level was determined by [3H]ouabain binding and immunoblot assays. Overall protein composition was determined by 2D electrophoresis followed by proteomic analysis by MALDI-TOF MS/MS and LFQ. Li interaction with plasma membrane was characterized by fluorescent probes DPH, TMA-DPH and Laurdan. RESULTS: Na+/K+-ATPase was increased in plasma membranes isolated from cells exposed to Li. Identification of Li-altered proteins by 2D electrophoresis, MALDI-TOF MS/MS and LFQ suggests a change of energy metabolism in mitochondria and cytosol and alteration of cell homeostasis of calcium. Measurement of Laurdan generalized polarization indicated a significant alteration of surface layer of isolated plasma membranes prepared from both types of Li-treated cells. CONCLUSIONS: Prolonged exposure of HEK293 cells to 1mM LiCl results in up-regulation of Na+/K+-ATPase expression, reorganization of overall cellular metabolism and alteration of the surface layer/polar head-group region of isolated plasma membranes. GENERAL SIGNIFICANCE: Our findings demonstrate adaptation of live HEK293 cell metabolism to prolonged exposure to therapeutic concentration of Li manifested as up-regulation of Na+/K+-ATPase expression, alteration of protein composition and change of the surface layer of plasma membrane.
- MeSH
- buněčná membrána účinky léků metabolismus MeSH
- buněčné linie MeSH
- cytosol účinky léků metabolismus MeSH
- energetický metabolismus účinky léků MeSH
- HEK293 buňky MeSH
- lidé MeSH
- lithium farmakologie MeSH
- mitochondrie účinky léků metabolismus MeSH
- ouabain farmakologie MeSH
- proteomika metody MeSH
- sodíko-draslíková ATPasa metabolismus MeSH
- up regulace účinky léků MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
The aim of the present study was to investigate the reflection of psychoemotional stress in the body surface potential distribution as documented by isointegral maps of cardiac activation and recovery. In 72 young men (18.3+/- 7.3 y.) with no cardiovascular history body surface potential maps (BSPMs) at rest and during the test of mental arithmetic were recorded. The digitalized data for each point of the QRS, STT and QRST integral maps, for each subject in both situations, were processed and evaluated by methods of univariate as well as spatial mathematical and statistical modeling. The results showed during MA a significant decrease of repolarization integral values over the sternum and right precordium, which contributed to analogically localized decrements also in the QRST BSM. The decrease occurred in more than 2/3 of lead points. The most pronounced changes were observed in the right precordial area, where potentials decreased in more than in 70 % of subjects. In conclusion, the discriminative power of the difference STT and QRST integral maps was strong enough to distinguish the mental arithmetic induced changes in the superficial cardiac electric field. These adrenergic transient alterations in ventricular recovery may be of importance in subjects at risk for ventricular arrhythmias.
- MeSH
- elektrokardiografie MeSH
- lidé MeSH
- mapování potenciálů tělesného povrchu * MeSH
- převodní systém srdeční patofyziologie MeSH
- psychický stres patofyziologie MeSH
- srdeční komory patofyziologie MeSH
- statistické modely MeSH
- Check Tag
- lidé MeSH
- mužské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Cílem studie bylo zhodnocení výtěžnosti analýzy ventrální jaterní kontury v rámci detekce iregularit přítomných při mikronodulárním typu cirhózy. Sonografickému vyšetření vysoce rozlišující lineární sondou o frekvenci 7,5 MHz se podrobilo 87 pacientů s difúzni hepatopatií (cirhóza, n = 65) a 24 zdravých jedinců. Za objektivní sonograficky znak cirhotického postižení bylo považováno pouze zobrazení mnohočetných iregularit ventrální jaterní kontury. Typ jaterního postižení byl stanoven invazivně pomocí laparoskopie (n = 64) a jaterní biopsie (n s 72), případně oběma metodami (n = 60); v 9 případech se diagnóza cirhózy opírala o kombinaci laboratorních hodnot a o výsledky jiných diagnostických metod, včetně průkazu přítomnosti portální hypertenze. Dosažená specificita metody byla 95,7 %, při 87,7% senzitivitě a 91,0% celkové přesnosti. Metoda se jeví být klinicky spolehlivým neinvazivním testem při diagnóze jaterní cirhózy.
The objective of the study was to evaluate the usefulness of analyses of the ventral contour of the liver when investigating irregularities in the micronodular type of cirrhosis. Eighty-seven patients with diffuse hepatopathies (cirrhosis, n = 65) and 24 normal subjects were subjected to sonographic examination by means of a high resolution probe with a frequency of 7.5 MHz. Only visualization of multiple irregularities of the ventral hepatic contour was considered an objective sonographic sign of cirrhotic affection. The type of hepatic affection was assessed invasively by laparoscopy (n = 64) and hver biopsy (n = 72), or by both methods (n = 60); in nine patients the diagnosis of cirrhosis was based on combined laboratory values and results of other diagnostic methods, incl. evidence of portal hypertension. The achieved specificity of the method was 95.7%, the sensitivity 87.7% and the overall accuracy 91.0%. The method appears to be a clinically reliable non-invasive test for the diagnosis of hepatic cirrhosis.
Endothelial cell (EC) glycocalyx (GLX) comprise a multicomponent layer of proteoglycans and glycoproteins. Alteration of its integrity contributes to chronic vascular inflammation and leads to the development of cardiovascular diseases. Myeloperoxidase (MPO), a highly abundant enzyme released by polymorphonuclear neutrophils, binds to the GLX and deleteriously affects vascular EC functions. The focus of this study was to elucidate the mechanisms of MPO-mediated alteration of GLX molecules, and to unravel subsequent changes in endothelial integrity and function. MPO binding to GLX of human ECs and subsequent internalization was mediated by cell surface heparan sulfate chains. Moreover, interaction of MPO, which is carrying a cationic charge, with anionic glycosaminoglycans (GAGs) resulted in reduction of their relative charge. By means of micro-viscometry and atomic force microscopy, we disclosed that MPO can crosslink GAG chains. MPO-dependent modulation of GLX structure was further supported by alteration of wheat germ agglutinin staining. Increased expression of ICAM-1 documented endothelial cell activation by both catalytically active and also inactive MPO. Furthermore, MPO increased vascular permeability connected with reorganization of intracellular junctions, however, this was dependent on MPO's catalytic activity. Novel proteins interacting with MPO during transcytosis were identified by proteomic analysis. Altogether, these findings provide evidence that MPO through interaction with GAGs modulates overall charge of the GLX, causing modification of its structure and thus affecting EC function. Importantly, our results also suggest a number of proteins interacting with MPO that possess a variety of cellular localizations and functions.
- MeSH
- cévní endotel MeSH
- endoteliální buňky MeSH
- lidé MeSH
- neutrofily MeSH
- peroxidasa * MeSH
- proteomika * MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
