Super-resolution (SR) microscopy is a cutting-edge method that can provide detailed structural information with high resolution. However, the thickness of the specimen has been a major limitation for SR methods, and large biological structures have posed a challenge. To overcome this, the key step is to optimise sample preparation to ensure optical homogeneity and clarity, which can enhance the capabilities of SR methods for the acquisition of thicker structures. Oocytes are the largest cells in the mammalian body and are crucial objects in reproductive biology. They are especially useful for studying membrane proteins. However, oocytes are extremely fragile and sensitive to mechanical manipulation and osmotic shocks, making sample preparation a critical and challenging step. We present an innovative, simple and sensitive approach to oocyte sample preparation for 3D STED acquisition. This involves alcohol dehydration and mounting into a high refractive index medium. This extended preparation procedure allowed us to successfully obtain a unique two-channel 3D STED SR image of an entire mouse oocyte. By optimising sample preparation, it is possible to overcome current limitations of SR methods and obtain high-resolution images of large biological structures, such as oocytes, in order to study fundamental biological processes. Lay Abstract: Super-resolution (SR) microscopy is a cutting-edge tool that allows scientists to view incredibly fine details in biological samples. However, it struggles with larger, thicker specimens, as they need to be optically clear and uniform for the best imaging results. In this study, we refined the sample preparation process to make it more suitable for SR microscopy. Our method includes carefully dehydrating biological samples with alcohol and then transferring them into a mounting medium that enhances optical clarity. This improved protocol enables high-resolution imaging of thick biological structures, which was previously challenging. By optimizing this preparation method, we hope to expand the use of SR microscopy for studying large biological samples, helping scientists better understand complex biological structures.

• MeSH
• alkoholy MeSH
• fluorescenční mikroskopie metody   MeSH
• myši MeSH
• odběr biologického vzorku metody   MeSH
• oocyty * MeSH
• refraktometrie metody   MeSH
• zobrazování trojrozměrné * metody   MeSH
• zvířata MeSH
• Check Tag
• myši MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH

Accumulating evidence suggests that manganese oxide nanoparticles (NPs) show multiple enzyme-mimicking antioxidant activities, which supports their potential in redox-targeting therapeutic strategies for diseases with impaired redox signaling. However, the systemic administration of any NP requires thorough hemocompatibility testing. In this study, we assessed the hemocompatibility of synthesized Mn3O4 NPs, identifying their ability to induce spontaneous hemolysis and eryptosis or impair osmotic fragility. Concentrations of up to 20 mg/L were found to be safe for erythrocytes. Eryptosis assays were shown to be more sensitive than hemolysis and osmotic fragility as markers of hemocompatibility for Mn3O4 NP testing. Flow cytometry- and confocal microscopy-based studies revealed that eryptosis induced by Mn3O4 NPs was accompanied by Ca2+ overload, altered redox homeostasis verified by enhanced intracellular reactive oxygen species (ROS) and reactive nitrogen species (RNS), and a decrease in the lipid order of cell membranes. Furthermore, Mn3O4 NP-induced eryptosis was calpain- and caspase-dependent.

• MeSH
• buněčná membrána * metabolismus   účinky léků   MeSH
• eryptóza * účinky léků   MeSH
• erytrocyty účinky léků   metabolismus   MeSH
• hemolýza účinky léků   MeSH
• kalpain * metabolismus   MeSH
• kaspasy * metabolismus   MeSH
• lidé MeSH
• nanočástice * chemie   MeSH
• oxidy * farmakologie   chemie   MeSH
• reaktivní formy dusíku * metabolismus   MeSH
• reaktivní formy kyslíku * metabolismus   MeSH
• sloučeniny manganu * farmakologie   chemie   MeSH
• vápník * metabolismus   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH

The transient receptor potential ion channel TRPA1 is a Ca2+-permeable nonselective cation channel widely expressed in sensory neurons, but also in many nonneuronal tissues typically possessing barrier functions, such as the skin, joint synoviocytes, cornea, and the respiratory and intestinal tracts. Here, the primary role of TRPA1 is to detect potential danger stimuli that may threaten the tissue homeostasis and the health of the organism. The ability to directly recognize signals of different modalities, including chemical irritants, extreme temperatures, or osmotic changes resides in the characteristic properties of the ion channel protein complex. Recent advances in cryo-electron microscopy have provided an important framework for understanding the molecular basis of TRPA1 function and have suggested novel directions in the search for its pharmacological regulation. This chapter summarizes the current knowledge of human TRPA1 from a structural and functional perspective and discusses the complex allosteric mechanisms of activation and modulation that play important roles under physiological or pathophysiological conditions. In this context, major challenges for future research on TRPA1 are outlined.

• MeSH
• alosterická regulace MeSH
• elektronová kryomikroskopie metody   MeSH
• kationtové kanály TRP metabolismus   chemie   fyziologie   MeSH
• kationtový kanál TRPA1 * metabolismus   chemie   fyziologie   MeSH
• lidé MeSH
• vztahy mezi strukturou a aktivitou MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH

• MeSH
• fúzní onkogenní proteiny genetika   MeSH
• lidé MeSH
• nádorové biomarkery MeSH
• nádory měkkých tkání * MeSH
• protein EWS vázající RNA MeSH
• protein FUS vázající RNA MeSH
• sarkom * diagnóza   genetika   MeSH
• transkripční faktory NFATC MeSH
• transkripční faktory metabolismus   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• dopisy MeSH

Calcineurin-nuclear factor of activated T cells (CN-NFAT) inhibitors are widely clinically used drugs for immunosuppression, but besides their required T cell response inhibition, they also undesirably affect innate immune cells. Disruption of innate immune cell function can explain the observed susceptibility of CN-NFAT inhibitor-treated patients to opportunistic fungal infections. Neutrophils play an essential role in innate immunity as a defense against pathogens; however, the effect of CN-NFAT inhibitors on neutrophil function was poorly described. Thus, we tested the response of human neutrophils to opportunistic fungal pathogens, namely Candida albicans and Aspergillus fumigatus, in the presence of CN-NFAT inhibitors. Here, we report that the NFAT pathway members were expressed in neutrophils and mediated part of the neutrophil response to pathogens. Upon pathogen exposure, neutrophils underwent profound transcriptomic changes with subsequent production of effector molecules. Importantly, genes and proteins involved in the regulation of the immune response and chemotaxis, including the chemokines CCL2, CCL3, and CCL4 were significantly upregulated. The presence of CN-NFAT inhibitors attenuated the expression of these chemokines and impaired the ability of neutrophils to chemoattract other immune cells. Our results amend knowledge about the impact of CN-NFAT inhibition in human neutrophils.

• MeSH
• Aspergillus fumigatus imunologie   MeSH
• Candida albicans imunologie   MeSH
• chemotaxe MeSH
• kalcineurin * metabolismus   MeSH
• lidé MeSH
• mykózy imunologie   MeSH
• neutrofily * imunologie   metabolismus   MeSH
• signální transdukce * MeSH
• transkripční faktory NFATC * metabolismus   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH

Long-term peritoneal dialysis is associated with the development of peritoneal membrane alterations, both in morphology and function. Impaired ultrafiltration (UF) is the most important functional change, and peritoneal fibrosis is the major morphological alteration. Both are caused by the continuous exposure to dialysis solutions that are different from plasma water with regard to the buffer substance and the extremely high-glucose concentrations. Glucose has been incriminated as the major cause of long-term peritoneal membrane changes, but the precise mechanism has not been identified. We argue that glucose causes the membrane alterations by peritoneal pseudohypoxia and by the formation of advanced glycosylation end products (AGEs). After a summary of UF kinetics including the role of glucose transporters (GLUT), and a discussion on morphologic alterations, relationships between function and morphology and a survey of the pathogenesis of UF failure (UFF), it will be argued that impaired UF is partly caused by a reduction in small pore fluid transport as a consequence of AGE-related vasculopathy and - more importantly - in diminished free water transport due to pseudohypoxia, caused by increased peritoneal cellular expression of GLUT-1. The metabolism of intracellular glucose will be reviewed. This occurs in the glycolysis and in the polyol/sorbitol pathway, the latter is activated in case of a large supply. In both pathways the ratio between the reduced and oxidised form of nicotinamide dinucleotide (NADH/NAD+ ratio) will increase, especially because normal compensatory mechanisms may be impaired, and activate expression of hypoxia-inducible factor-1 (HIF-1). The latter gene activates various profibrotic factors and GLUT-1. Besides replacement of glucose as an osmotic agent, medical treatment/prevention is currently limited to tamoxifen and possibly Renin/angiotensis/aldosteron (RAA) inhibitors.

• MeSH
• dialyzační roztoky škodlivé účinky   metabolismus   MeSH
• glukosa škodlivé účinky   metabolismus   MeSH
• glykosylace MeSH
• lidé MeSH
• peritoneální dialýza * škodlivé účinky   MeSH
• peritoneum metabolismus   MeSH
• ultrafiltrace MeSH
• voda metabolismus   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH

Exokrinní pankreatická nedostatečnost (EPI – exocrine pancreatic insufficiency) je charakterizována nedostatečnou sekrecí pankreatických trávicích enzymů. Dle mechanistické teorie není nedostatkem pankreatických enzymů v tenkém střevě zajištěno trávení potravy, což je spojeno především s nedostatkem esenciálních mastných kyselin a liposolubilních vitaminů a ve svém důsledku vede k neschopnosti zajistit nutriční a metabolické potřeby organizmu. V diagnostice je standardem stanovení fekální elastázy. Toto stanovení je jednoduché, limitací je malá senzitivita stanovit možné změny pankreatické funkce již v tzv. iniciálních stadiích nemoci. Alternativou vyšetření fekální elastázy je použití dechových testů s využitím mixu triglyceridů označených radioaktivně na uhlíku C13. Test je sice neinvazivní, ale časově náročný a obtížněji dostupný. Klinickými symptomy EPI jsou především takové příznaky, které souvisí s mikrobiálním trávením a následnou malabsorbcí/maldigescí mikro- i makronutrientů. Kromě subjektivního pocitu nadýmání, borborygmů nebo osmotického průjmu jsou častým nálezem nízké hladiny liposolubilních vitaminů a některých stopových prvků. Do obrazu EPI patří i osteoporóza nebo sarkopenie. V terapii EPI je zásadním přístupem dietoterapie a substituce pankreatickými enzymy. Zásadou je podání odpovídající dávky především pankreatické lipázy: 40 000–50 000 jednotek k hlavním jídlům, s aplikací během jídla. Menší jídla (svačiny) jsou substituovány poloviční dávkou. Optimální galenickou formou jsou kapsle s ochranným obalem proti inaktivaci enzymů žaludeční kyselinou solnou před jejich vstupem do duodena. Galenickou formou jsou kapsle s obsahem enzymů v mikročásticích o velikosti 1,0–2,0 mm, které se z kapsle uvolní při vstupu do duodena. Jedná se o tzv. řízenou synchronizaci liberalizace enzymů, které obsahuje kapsle. EPI je stavem v populaci poddiagnostikovaným a podléčeným. Kontrola pacientů tak musí zahrnout kromě zhodnocení celkového klinického stavu i sledování změn, které mohou manifestovat malabsorpci. Nutriční stav je doporučeno sledovat alespoň jednou ročně, a to v pravidelných intervalech.

Exocrine pancreatic insufficiency (EPI) is characterized by insufficient secretion of pancreatic digestive enzymes. According to the mechanistic theory, the lack of pancreatic enzymes in the small intestine does not ensure the digestion of food, which is mainly associated with the lack of essential fatty acids and liposoluble vitamins and, as a result, leads to the inability to ensure the nutritional and metabolic needs of the organism. In diagnostics, the standard is determination of fecal elastase. This determination is simple, the limitation is the low sensitivity to determine possible changes in pancreatic function already in the so-called initial stages of the dis ease. An alternative to fecal elastase testing is the use of breath tests using a mixture of triglycerides, radioactively labeled with carbon C13. Although the test is non-invasive, it is time-consuming and more difficult to access. The clinical symptoms of EPI are mainly those related to microbial digestion and subsequent malabsorption/maldigestion of micro- and macronutrients. In addition to the subjective feeling of bloating, borborygmy or osmotic diarrhea, low levels of liposoluble vitamins and some trace elements are frequent findings. Osteoporosis or sarcopenia belong to the picture of EPI. In EPI therapy, diet therapy and pancreatic enzyme replacement are essential approaches. The principle is to administer an adequate dose, especially of pancreatic lipase: 40,000–50,000 units with main meals, with application during meals. Smaller meals (snacks) are substituted with half the dose. The optimal galenic form is capsules with a protective cover, against the inactivation of enzymes by gastric acid, before they enter the duodenum. The galenic form is capsules containing enzymes in microparticles, 1.0–2.0 mm in size, which are released from the capsule upon entering the duodenum. This is the so-called controlled synchronization of the liberalization of the enzymes contained in the capsule. EPI is an underdiagnosed and undertreated condition in the population. The control of patients must therefore include, in addition to the evaluation of the overall clinical condition, the monitoring of changes that may manifest malabsorption. It is recommended to monitor the nutritional status at least once a year, at regular intervals.

• MeSH
• dietoterapie metody   MeSH
• enzymoterapie metody   MeSH
• exokrinní pankreatická insuficience * diagnóza   terapie   MeSH
• lidé MeSH
• malabsorpční syndromy etiologie   MeSH
• osteoporóza etiologie   MeSH
• pankreatická elastasa analýza   MeSH
• pankreatin terapeutické užití   MeSH
• Check Tag
• lidé MeSH

Cryopreservation of spheroids requires development of new improved methods. The plasma membranes permeability coefficients for water and cryoprotectants determine time characteristics of mass transfer through the cell membranes, and therefore the optimal modes of cells cryopreservation. Here we proposed an approach to cryopreservation of multicellular spheroids which considers their generalized characteristics as analogues of the membranes' permeability coefficients of the individual cells. We have determined such integral characteristics of spheroids from mesenchymal stromal cells (MSCs) as osmotically inactive volume; permeability coefficients for water and Me2SO molecules and the activation energy of their penetration. Based on these characteristics, we calculated the osmotic behavior of multicellular spheroids under cooling conditions to select the optimal cooling rate. We also determined the optimal cooling rate of spheroids using the probabilistic model developed based on the two-factor theory of cryodamage. From the calculation it follows that the optimal cooling rate of the MSC-based spheroids is 0.75°С/min. To verify the obtained theoretical estimates, we conducted experiments on freezing MSC-based spheroids under different modes. The obtained results of primary viability screening indicate that freezing at a constant linear cooling rate of 0.75-1.0°С/min gives a good result. Theoretical prediction of the spheroid osmotic behavior during cooling provided the basis for experimental verification of varying the temperature to which slow cooling should be carried out before immersion in liquid nitrogen. Slow freezing of spheroids to -40 °C followed by immersion in liquid nitrogen was shown to preserve cells better than slow freezing to -80 °C. Obtained data allow more effective use of MSC-based spheroids in drug screening and regenerative medicine.

• MeSH
• buněčné sféroidy * cytologie   MeSH
• kryoprezervace * metody   MeSH
• kryoprotektivní látky * farmakologie   MeSH
• kultivované buňky MeSH
• lidé MeSH
• mezenchymální kmenové buňky * cytologie   MeSH
• permeabilita buněčné membrány MeSH
• viabilita buněk * MeSH
• voda chemie   MeSH
• zmrazování MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH

Sodium is the main osmotically active ion in the extracellular fluid and its concentration goes hand in hand with fluid volume. Under physiological conditions, homeostasis of sodium and thus amount of fluid is regulated by neural and humoral interconnection of body tissues and organs. Both heart and kidneys are crucial in maintaining volume status. Proper kidney function is necessary to excrete regulated amount of water and solutes and adequate heart function is inevitable to sustain renal perfusion pressure, oxygen supply etc. As these organs are bidirectionally interconnected, injury of one leads to dysfunction of another. This condition is known as cardiorenal syndrome. It is divided into five subtypes regarding timeframe and pathophysiology of the onset. Hemodynamic effects include congestion, decreased cardiac output, but also production of natriuretic peptides. Renal congestion and hypoperfusion leads to kidney injury and maladaptive activation of renin-angiotensin-aldosterone system and sympathetic nervous system. In cardiorenal syndromes sodium and water excretion is impaired leading to volume overload and far-reaching negative consequences, including higher morbidity and mortality of these patients. Keywords: Cardiorenal syndrome, Renocardiac syndrome, Volume overload, Sodium retention.

• MeSH
• homeostáza * fyziologie   MeSH
• kardiorenální syndrom * metabolismus   patofyziologie   MeSH
• ledviny metabolismus   patofyziologie   MeSH
• lidé MeSH
• sodík * metabolismus   MeSH
• voda metabolismus   MeSH
• vodní a elektrolytová nerovnováha metabolismus   patofyziologie   MeSH
• vodní a elektrolytová rovnováha * fyziologie   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH

Osmoregulation is the homeostatic mechanism essential for the survival of organisms in hypoosmotic and hyperosmotic conditions. In freshwater or soil dwelling protists this is frequently achieved through the action of an osmoregulatory organelle, the contractile vacuole. This endomembrane organelle responds to the osmotic challenges and compensates by collecting and expelling the excess water to maintain the cellular osmolarity. As compared with other endomembrane organelles, this organelle is underappreciated and under-studied. Here we review the reported presence or absence of contractile vacuoles across eukaryotic diversity, as well as the observed variability in the structure, function, and molecular machinery of this organelle. Our findings highlight the challenges and opportunities for constructing cellular and evolutionary models for this intriguing organelle.

• MeSH
• Eukaryota * fyziologie   MeSH
• osmoregulace fyziologie   MeSH
• vakuoly * MeSH
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH