Immune surveillance involves the continual migration of antigen-scavenging immune cells from the tissues to downstream lymph nodes via lymphatic vessels. To enable such passage, cells first dock with the lymphatic entry receptor LYVE-1 on the outer surface of endothelium, using their endogenous hyaluronan glycocalyx, anchored by a second hyaluronan receptor, CD44. Why the process should require two different hyaluronan receptors and by which specific mechanism the LYVE-1•hyaluronan interaction enables lymphatic entry is however unknown. Here we describe the crystal structures and binding mechanics of murine and human LYVE-1•hyaluronan complexes. These reveal a highly unusual, sliding mode of ligand interaction, quite unlike the conventional sticking mode of CD44, in which the receptor grabs free hyaluronan chain-ends and winds them in through conformational re-arrangements in a deep binding cleft, lubricated by a layer of structured waters. Our findings explain the mode of action of a dedicated lymphatic entry receptor and define a distinct, low tack adhesive interaction that enables migrating immune cells to slide through endothelial junctions with minimal resistance, while clinging onto their hyaluronan glycocalyx for essential downstream functions.
- MeSH
- antigeny CD44 * metabolismus MeSH
- glykokalyx metabolismus MeSH
- krystalografie rentgenová MeSH
- kyselina hyaluronová * metabolismus chemie MeSH
- leukocyty metabolismus MeSH
- lidé MeSH
- lymfatické cévy * metabolismus MeSH
- membránové transportní proteiny metabolismus MeSH
- myši MeSH
- vazba proteinů * MeSH
- vezikulární transportní proteiny metabolismus MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- myši MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- antigeny CD44 * MeSH
- kyselina hyaluronová * MeSH
- LYVE1 protein, human MeSH Prohlížeč
- membránové transportní proteiny MeSH
- vezikulární transportní proteiny MeSH
- Xlkd1 protein, mouse MeSH Prohlížeč
BackgroundSulodexide is a glycosaminoglycan-based drug prescribed to patients with angiopathy. We performed a pilot study to investigate whether sulodexide positively modulates the endothelial glycocalyx (EG) layer and the microcirculation in a porcine model of EG enzymatic damage. The EG is a sugar-based endothelial lining that is involved in the physiology of the capillary wall and the pathogenesis of many diseases.MethodsEG damage was induced in eight piglets by hyaluronidase III and heparanase I given intravenously. Four animals received sulodexide 600 IU intravenously before the enzymes and four animals after the enzymes were administered. Four animals constituted a control group. Sublingual microcirculation by side-stream dark field imaging and plasmatic concentration of syndecan-1 by ELISA were measured at baseline, 20 min after intervention, and at the 40th, and 60th minute onwards. The statistics were performed with a one-way ANOVA test with Turkey's correction for multiple comparisons testing. Timepoint comparison was performed by Student t-test or Mann-Whitney test.ResultsAt baseline, there were no statistically significant differences between the animal groups. After the intervention, the levels of syndecan-1 were significantly lower in the control group. While there were no differences between the two intervention groups. The sublingual microcirculation analysis showed that the DeBacker score was significantly higher in the control group. At 60 min, there was also a statistically significant difference in DeBacker score between the groups (8.1 ± 1.6 mm-1 in the group with enzymes given first and 11 ± 0.92 mm-1 in the group with sulodexide given first, p = 0.03). The analysis of the proportion of perused vessels did not show any statistically significant differences.ConclusionThe results of the study demonstrated a working model of EG damage but no specific action of sulodexide on EG modulation. In the sublingual microcirculation analysis, the sulodexide reduced the fall in absolute tissue perfusion in 60 min.
- Klíčová slova
- Sulodexide, endothelial glycocalyx, heparanase, hyaluronidase, microcirculation, syndecan-1,
- MeSH
- cévní endotel * účinky léků MeSH
- glykokalyx * účinky léků metabolismus MeSH
- glykosaminoglykany * farmakologie MeSH
- hyaluronoglukosaminidasa MeSH
- mikrocirkulace účinky léků MeSH
- modely nemocí na zvířatech MeSH
- pilotní projekty MeSH
- prasata MeSH
- syndekan-1 krev MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- glucuronyl glucosamine glycan sulfate MeSH Prohlížeč
- glykosaminoglykany * MeSH
- hyaluronoglukosaminidasa MeSH
- syndekan-1 MeSH
Mammalian spermatozoa have a surface covered with glycocalyx, consisting of heterogeneous glycoproteins and glycolipids. This complexity arises from diverse monosaccharides, distinct linkages, various isomeric glycans, branching levels, and saccharide sequences. The glycocalyx is synthesized by spermatozoa developing in the testis, and its subsequent alterations during their transit through the epididymis are a critical process for the sperm acquisition of fertilizing ability. In this study, we performed detailed analysis of the glycocalyx on the sperm surface of bull spermatozoa in relation to individual parts of the epididymis using a wide range (24) of lectins with specific carbohydrate binding preferences. Fluorescence analysis of intact sperm isolated from the bull epididymides was complemented by Western blot detection of protein extracts from the sperm plasma membrane fractions. Our experimental results revealed predominant sequential modification of bull sperm glycans with N-acetyllactosamine (LacNAc), followed by subsequent sialylation and fucosylation in a highly specific manner. Additionally, variations in the lectin detection on the sperm surface may indicate the acquisition or release of glycans or glycoproteins. Our study is the first to provide a complex analysis of the bull sperm glycocalyx modification during epididymal maturation.
- Klíčová slova
- cattle, epididymis, glycan, lectin, plasma membrane, sperm surface, spermatozoa,
- MeSH
- epididymis * metabolismus cytologie MeSH
- glykokalyx * metabolismus MeSH
- glykoproteiny metabolismus MeSH
- lektiny * metabolismus MeSH
- polysacharidy metabolismus MeSH
- skot MeSH
- spermie * metabolismus MeSH
- zvířata MeSH
- Check Tag
- mužské pohlaví MeSH
- skot MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- glykoproteiny MeSH
- lektiny * MeSH
- polysacharidy MeSH
BACKGROUND: Endothelial glycocalyx (EG) plays a crucial role in maintaining the plasma proteins within the intravascular space. OBJECTIVE: We studied whether exogenous albumin protects the EG in an experimental model of EG enzymatic damage in rats. METHODS: Rats were divided into three groups of 10 animals that received (1) Evans blue (2) Evans blue + hyaluronidase, or (3) Evans blue + hyaluronidase + 20% human albumin via the tail vein. Spectrophotometric analysis was performed 2 h later to quantify the leakage of Evans blue-labeled albumin into the heart, lungs, brain, kidneys, liver, small intestine, spleen, and skeletal muscle. RESULTS: Administration of hyaluronidase numerically increased the capillary leakage of Evans blue in all examined tissues. Co-administration of albumin decreased the leakage of albumin in all tissues except the heart. In the lungs, the ratio between the absorbance and dry organ weight decreased from 5.3 ± 2.4 to 1.7 ± 0.5 (mean ± SD) (P < 0.002), and in the liver, the absorbance decreased from 2.2 ± 0.7 to 1.5 ± 0.4 (P < 0.011). CONCLUSION: Exogenous albumin decreased the capillary leakage of albumin which was interpreted as a sign of maintained EG integrity.
- Klíčová slova
- Albumin, endothelial glycocalyx, evans blue, microcirculation, spectrophotometry,
- MeSH
- albuminy * metabolismus MeSH
- cévní endotel účinky léků metabolismus MeSH
- Evansova modř MeSH
- glykokalyx * metabolismus účinky léků MeSH
- hyaluronoglukosaminidasa farmakologie MeSH
- kapilární permeabilita * účinky léků MeSH
- krysa rodu Rattus MeSH
- lidé MeSH
- modely nemocí na zvířatech MeSH
- potkani Wistar MeSH
- zvířata MeSH
- Check Tag
- krysa rodu Rattus MeSH
- lidé MeSH
- mužské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- albuminy * MeSH
- Evansova modř MeSH
- hyaluronoglukosaminidasa MeSH
BACKGROUND: Hydrogen is a potent antioxidant agent that can easily be administered by inhalation. The aim of the study was to evaluate whether hydrogen protects the endothelial glycocalyx layer after successful cardiopulmonary resuscitation (CPR). METHODS: Fourteen anesthetized pigs underwent CPR after induced ventricular fibrillation. During CPR and return of spontaneous circulation, 2% hydrogen gas was administered to seven pigs (hydrogen group) and seven constituted a control group. Biochemistry and sublingual microcirculation were assessed at baseline, during CPR, at the 15th, 30th, 60th, 120th minute. RESULTS: All seven subjects from the hydrogen group and six subjects in the control group were successfully resuscitated after 6-10 minutes. At baseline, there were no statistically significant differences in examined variables. After the CPR, blood pH, base excess, and lactate showed significantly smaller deterioration in the hydrogen group than in the control group. By contrast, plasma syndecan-1 and the measured variables obtained via sublingual microcirculation did not change after the CPR; and were virtually identical between the two groups. CONCLUSION: In pigs, hydrogen gas inhalation during CPR and post-resuscitation care was associated with less pronounced metabolic acidosis compared to controls. However, we could not find evidence of injury to the endothelium or glycocalyx in any studied groups.
- Klíčová slova
- Hydrogen, endothelial glycocalyx, microcirculation, post-resuscitation care, sudden cardiac arrest,
- MeSH
- endotel MeSH
- glykokalyx MeSH
- kardiopulmonální resuscitace * MeSH
- lidé MeSH
- modely nemocí na zvířatech MeSH
- prasata MeSH
- reperfuzní poškození * MeSH
- srdeční zástava * terapie MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
Elevated levels of galectin-3 are associated with tumorigenesis. Its inhibition with high-affinity carbohydrate ligands opens new therapeutic routes. Targeting of intracellular galectin-3 is challenging for polar inhibitors like carbohydrates. We demonstrate the potential of novel biomedical research tools, glycocalix[4]arenes, to enter epithelial cells, which may allow their interaction with galectin-3.
- MeSH
- buněčná membrána MeSH
- galektin 3 * MeSH
- galektiny MeSH
- glykokalyx * MeSH
- sacharidy farmakologie MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- galektin 3 * MeSH
- galektiny MeSH
- sacharidy MeSH
INTRODUCTION: Surgical treatment is associated with an unwanted response of the organism to the so-called surgical trauma. This response is called surgical stress. Ischaemia-reperfusion injury is one of essential causes of tissue damage. It comprises functional and structural changes in tissue that occur after the restoration of circulation, after an episode of ischaemia. Necrosis of irreversibly changed cells and endothelial and mitochondrial-induced tissue swelling occur. METHODS: Physiology, pathophysiology of endothelial glycocalyx: Endothelial glycocalyx is a 0.2 to 5 micrometres thin heteropolysaccharide layer that covers the endothelium on its intraluminal side. Backbone molecules of the glycocalyx include proteoglycans, glycoproteins, and glycosaminoglycans. Damage of the endothelial glycocalyx was described in trauma patients, in patients with septic shock, in ischemia and reperfusion injury, and during extensive surgical procedures. Approaches to prevent endothelial glycocalyx damage: Remote ischemic preconditioning was tested as a method of ischemia and reperfusion injury prevention during and after surgery. Nevertheless, the expected effect was not confirmed in performed meta-analyses. Endothelial glycocalyx damage can be prevented pharmacologically with a broad spectrum of substances, such as antithrombin III, doxycycline, hydrocortisone, etanercept, or nitric oxide donors. Hydrogen inhalation or albumin affects glycocalyx positively. Sulodexide provides a positive effect on the protection and reparation of endothelial glycocalyx. This proteoglycan with antithrombotic, fibrinolytic, hypofibrinogenemic, and lipolytic function is used for the treatment of venous diseases, ischaemic heart disease, and peripheral arterial disease. A positive effect of sulodexide on renal dysfunction was documented in a model of ischaemia and reperfusion injury. Equally, a positive effect of sulodexide was described on endothelium repair after its mechanical damage. CONCLUSION: Further research needs to be performed to evaluate the effect of endothelium-protectives on glycocalyx damage prevention and repair in ischaemia and reperfusion models involving large laboratory animals or in clinical trials in patients undergoing surgical revascularisation procedures.
- MeSH
- cévní endotel MeSH
- glykokalyx * fyziologie MeSH
- ischemie MeSH
- lidé MeSH
- reperfuzní poškození * MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
Galectins are lectins that bind β-galactosides. They are involved in important extra- and intracellular biological processes such as apoptosis, and regulation of the immune system or the cell cycle. High-affinity ligands of galectins may introduce new therapeutic approaches or become new tools for biomedical research. One way of increasing the low affinity of β-galactoside ligands to galectins is their multivalent presentation, e.g., using calixarenes. We report on the synthesis of glycocalix[4]arenes in cone, partial cone, 1,2-alternate, and 1,3-alternate conformations carrying a lactosyl ligand on three different linkers. The affinity of the prepared compounds to a library of human galectins was determined using competitive ELISA assay and biolayer interferometry. Structure-affinity relationships regarding the influence of the linker and the core structure were formulated. Substantial differences were found between various linker lengths and the position of the triazole unit. The formation of supramolecular clusters was detected by atomic force microscopy. The present work gives a systematic insight into prospective galectin ligands based on the calix[4]arene core.
- MeSH
- galektiny * chemie MeSH
- glykokalyx * MeSH
- lidé MeSH
- ligandy MeSH
- molekulární konformace MeSH
- prospektivní studie MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- galektiny * MeSH
- ligandy MeSH
BACKGROUND: Coronavirus disease (COVID-19) associated endotheliopathy and microvascular dysfunction are of concern. OBJECTIVE: The objective of the present single-center observational pilot study was to compare endothelial glycocalyx (EG) damage and endotheliopathy in patients with severe COVID-19 (COVID-19 group) with patients with bacterial pneumonia with septic shock (non-COVID group). METHODS: Biomarkers of EG damage (syndecan-1), endothelial cells (EC) damage (thrombomodulin), and activation (P-selectin) were measured in blood on three consecutive days from admission to the intensive care unit (ICU). The sublingual microcirculation was studied by Side-stream Dark Field (SDF) imaging with automatic assessment. RESULTS: We enrolled 13 patients in the non-COVID group (mean age 70 years, 6 women), and 15 in the COVID-19 group (64 years old, 3 women). The plasma concentrations of syndecan-1 were significantly higher in the COVID-19 group during all three days. Differences regarding other biomarkers were not statistically significant. The assessment of the sublingual microcirculation showed improvement on Day 2 in the COVID-19 group. Plasma levels of C-reactive protein (CRP) were significantly higher on the first two days in the COVID-19 group. Plasma syndecan-1 and CRP were higher in patients suffering from severe COVID-19 pneumonia compared to bacterial pneumonia patients. CONCLUSIONS: These findings support the role of EG injury in the microvascular dysfunction in COVID-19 patients who require ICU.
- Klíčová slova
- glycocalyx, pneumonia, sepsis,
- MeSH
- biologické markery MeSH
- COVID-19 * patologie MeSH
- endoteliální buňky * patologie MeSH
- glykokalyx * metabolismus MeSH
- lidé středního věku MeSH
- lidé MeSH
- pilotní projekty MeSH
- prospektivní studie MeSH
- senioři MeSH
- syndekan-1 metabolismus MeSH
- umělé dýchání MeSH
- Check Tag
- lidé středního věku MeSH
- lidé MeSH
- mužské pohlaví MeSH
- senioři MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- pozorovací studie MeSH
- Názvy látek
- biologické markery MeSH
- syndekan-1 MeSH
BACKGROUND: The endothelial glycocalyx (EG) plays a vital role in the physiology and pathophysiology of human microcirculation. Having relevant EG damage model would be important tool for testing new interventions aiming at EG protection and recovery. We describe the first in vivo EG damage model in pig. OBJECTIVE: To investigate the course of animal EG damage induced by specific enzymes. MATERIAL AND METHODS: Four anesthetized piglets received enzymes: 1g hyaluronidase and 25 IU heparanase I intravenously. Blood and urine samples were collected at baseline and 20/40/60/80/100/120 min for detecting markers of endothelial and EG function. Sublingual microcirculation and EG thickness were assessed by Side-stream Dark Field (SDF) imaging and Perfused Boundary Region (PBR) respectively. EG of the mesentery artery was visualized in fluorescent microscopy. RESULTS: Biochemical marker of EG damage syndecan-1 showed temporary increase with return to baseline and was reflected by PBR values. Albumin levels suggested brief period of capillary leakage (decrease in the serum, increase in the urine) with a trend to normalization. Urine glycosaminoglycans peaked at 120 minutes. Microcirculatory perfusion parameter showed significant alteration. Diffusion parameters were altered with no statistical significance. CONCLUSION: EG damage induced by specific enzymes was reflected by temporary changes of biochemical makers together with alteration of microcirculation and changes in fluorescent microscopy of EG layer. Our results support to further validate presented model of EG damage on a larger number of animals.
- Klíčová slova
- Microcirculation, albuminuria, endothelial glycocalyx, heparanase, hyaluronidase,
- MeSH
- glykokalyx * MeSH
- kapiláry MeSH
- mikrocirkulace MeSH
- pilotní projekty MeSH
- prasata MeSH
- trávení MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
