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Brain metastatic breast cancer is particularly lethal largely due to therapeutic resistance. Almost half of the patients with metastatic HER2-positive breast cancer develop brain metastases, representing a major clinical challenge. We previously described that cancer-associated fibroblasts are an important source of resistance in primary tumors. Here, we report that breast cancer brain metastasis stromal cell interactions in 3D cocultures induce therapeutic resistance to HER2-targeting agents, particularly to the small molecule inhibitor of HER2/EGFR neratinib. We investigated the underlying mechanisms using a synthetic Notch reporter system enabling the sorting of cancer cells that directly interact with stromal cells. We identified mucins and bulky glycoprotein synthesis as top-up-regulated genes and pathways by comparing the gene expression and chromatin profiles of stroma-contact and no-contact cancer cells before and after neratinib treatment. Glycoprotein gene signatures were also enriched in human brain metastases compared to primary tumors. We confirmed increased glycocalyx surrounding cocultures by immunofluorescence and showed that mucinase treatment increased sensitivity to neratinib by enabling a more efficient inhibition of EGFR/HER2 signaling in cancer cells. Overexpression of truncated MUC1 lacking the intracellular domain as a model of increased glycocalyx-induced resistance to neratinib both in cell culture and in experimental brain metastases in immunodeficient mice. Our results highlight the importance of glycoproteins as a resistance mechanism to HER2-targeting therapies in breast cancer brain metastases.

BACKGROUND: Sepsis-associated destruction of the pulmonary microvascular endothelial glycocalyx (EGCX) creates a vulnerable endothelial surface, contributing to the development of acute respiratory distress syndrome (ARDS). Constituents of the EGCX shed into circulation, glycosaminoglycans and proteoglycans, may serve as biomarkers of endothelial dysfunction. We sought to define the patterns of plasma EGCX degradation products in children with sepsis-associated pediatric ARDS (PARDS), and test their association with clinical outcomes. METHODS: We retrospectively analyzed a prospective cohort (2018-2020) of children (≥1 month to 60% of the severe PARDS patients (test for trend, p = 0.04). Higher total heparan sulfate and N-sulfated disaccharide levels were independently associated with fewer 28-day ventilator-free days in children with sepsis-associated PARDS (all p

Selective detection of disease-associated changes in the glycocalyx is an emerging field in modern targeted therapies. Detecting minor glycan changes on the cell surface is a challenge exacerbated by the lack of correspondence between cellular DNA/RNA and glycan structures. We demonstrate that multivalent displays of lectins on DNA-barcoded phages—liquid lectin array (LiLA)—detect subtle differences in density of glycans on cells. LiLA constructs displaying 73 copies of diCBM40 (CBM) lectin per virion (φ-CBM 73) exhibit non-linear ON/OFF-like recognition of sialoglycans on the surface of normal and cancer cells. A high-valency φ-CBM 290 display, or soluble CBM protein, cannot amplify the subtle differences detected by φ-CBM 73. Similarly, multivalent displays of CBM and Siglec-7 detect differences in the glycocalyx between stem-like and non-stem populations in cancer. Multivalent display of lectins offer in situ detection of minor differences in glycocalyx in cells both in vitro and in vivo not feasible to currently available technologies. [Display omitted] • Liquid lectin array (LiLA) is a collection of DNA-barcoded lectin-phage conjugates • LiLA detects subtle changes in the glycocalyx of mammalian cells • DNA-barcoded lectin-phages are decodable by NGS and are in vivo compatible • Multivalent lectin presentation shows a steep ON/OFF response to sialic acid changes Glycans are ubiquitous, but they cannot be quantified directly using DNA-sequencing methods. Lima et al. demonstrate that DNA-barcoded multivalent lectin-phage conjugates enable multiplex profiling of the mammalian glycocalyx in vitro and in vivo. Next-generation sequencing of lectin-phage constructs detects subtle glycocalyx changes that are challenging to detect using traditional lectin reagents. [ABSTRACT FROM AUTHOR]

N-glycosylation is one of the most common protein modifications in eukaryotes, with immense importance at the molecular, cellular, and organismal level. Accurate and reliable N-glycan analysis is essential to obtain a systems-wide understanding of fundamental biological processes. Due to the structural complexity of glycans, their analysis is still highly challenging. Here we make publicly available a consistent N-glycome dataset of 20 different mouse tissues and demonstrate a multimodal data analysis workflow that allows for unprecedented depth and coverage of N-glycome features. This highly scalable, LC-MS/MS data-driven method integrates the automated identification of N-glycan spectra, the application of non-targeted N-glycome profiling strategies and the isomer-sensitive analysis of glycan structures. Our delineation of critical sub-structural determinants and glycan isomers across the mouse N-glycome uncovered tissue-specific glycosylation patterns, the expression of non-canonical N-glycan structures and highlights multiple layers of N-glycome complexity that derive from organ-specific regulations of glycobiological pathways. N-glycosylation is vital for biological processes but difficult to analyse. Here, the authors introduce a scalable method to profile N-glycans across 20 mouse tissues, revealing tissue-specific glycosylation patterns and novel N-glycan structures, offering new insights into glycobiology. [ABSTRACT FROM AUTHOR]

Objective: Endothelial dysfunction plays an important role in the pathogenesis of chronic kidney disease. Prostacyclin (PGI2), an endothelial cell‐produced endogenous prostaglandin, plays a crucial role in maintaining endothelial function. However, its effects on intestinal microcirculation and barrier function are not fully understood. We hypothesized that PGI2 improves intestinal microcirculation and barrier function via endothelial protective effects. Methods: ICR and ICGN (a spontaneous nephrotic model) mice were used in this study. Intestinal microcirculation was visualized in vivo to investigate PGI2 effects. Beraprost served as PGI2. PGI2 administration spanned 4 weeks, following which we assessed its influence on intestinal endothelial, intestinal barrier, and renal functions. Results: We visualized intestinal microcirculation and endothelial glycocalyx in the intestinal blood vessels. Beraprost administration induced a 1.2‐fold dilatation of the vascular diameter of the small intestine. Intestinal blood flow in ICGN mice was significantly reduced compared that in ICR mice but improved with beraprost administration. ICGN mice exhibited reduced serum albumin levels, decreased ambulation, an imbalance in intestinal reactive oxygen species (ROS)/nitric oxide (NO), and impaired tight junctions; all were ameliorated by beraprost administration. Conclusions: Beraprost improves intestinal microcirculation and barrier function by ameliorating ROS/NO imbalances, thereby reducing physical inactivity during renal failure. [ABSTRACT FROM AUTHOR]

In xenotransplantation, the vascular endothelium serves as the first point of contact between the recipient’s blood and the transplanted donor organ. The loss of the endothelium’s ability to control the plasma cascades plays a critical role in the dysregulation of the complement and coagulation systems, which greatly contribute to graft rejection and hinder long-term xenograft survival. Although it is known that an intact glycocalyx is a key feature of a resting endothelium that exhibits optimal anticoagulant and anti-inflammatory properties, the role of the endothelial glycocalyx in xenotransplantation is barely investigated so far. Here, we discuss the central role of endothelial cells and the sugar-rich endothelial glycocalyx in regulating the plasma cascades, and how the loss of these functions contributes to graft damage and rejection. We highlight the importance of preserving the regulatory functions of both endothelial cells and the glycocalyx as strategies to improve xenotransplantation outcomes. [ABSTRACT FROM AUTHOR]

Introduction: Phytohormones play a crucial role in regulating the abscission of plant organs and tissues. Methods: In this study, the ultrastructure of the sepals of Korla fragrant pears was observed using a transmission electron microscope, and high-performance liquid and gas chromatography were used to analyze the dynamic changes of phytohormones in the abscission zone during the calyx abscission process of Korla fragrant pears, and mass spectrometry imaging was applied to ascertain the spatial distribution of phytohormones. Results: The results revealed that the mitochondria in the abscission zone of the decalyx fruits were regularly distributed around the cell wall, and the chloroplasts were moderately present. In contrast, in the persistent calyx fruit, the corresponding parts of the abscission zone showed a scattered distribution of mitochondria within the cells, and there was a higher number of chloroplasts, which also contained starch granules inside. Mass spectrometry imaging revealed that ABA was enriched in the abscission zone of the decalyx fruit, and their ionic signal intensities were significantly stronger than those of the persistent calyx fruit. However, the ionic signal intensities of Indole-3-acetic acid (IAA) and Gibberellin A3 (GA3) of the persistent calyx fruit were significantly stronger than those in the abscission zone of the decalyx fruit and were concentrated in the persistent calyx fruit. 1-Aminocyclopropanecarboxylic Acid (ACC) did not show distinct regional distribution in both the decalyx and persistent calyx fruits. Furthermore, before the formation of the abscission zone, the levels of IAA, GA3, and zeatin (ZT) in the abscission zone of the decalyx fruits were significantly lower than those in the persistent calyx fruits by 37.9%, 57.7%, and 33.0%, respectively, while the levels of abscisic acid (ABA) and ethylene (ETH) were significantly higher by 21.9% and 25.0%, respectively. During the formation of the abscission zone, the levels of IAA, GA3, and ZT in the abscission zone of the decalyx fruits were significantly lower than those in the persistent calyx fruits by 41.7%, 71.7%, and 24.6%, respectively, while the levels of ABA and ETH were significantly higher by 15.2% and 80.0%, respectively. After the formation of the abscission zone, the levels of IAA and GA3 in the abscission zone of the decalyx fruits were lower than those in the persistent calyx fruits by 20.8% and 47.8%, respectively, while the levels of ABA and ETH were higher by 271.8% and 26.9%, respectively. In summary, during the calyx abscission process of Korla fragrant pears, IAA and GA3 in the abscission zone inhibited abscission, while ABA and ETH promoted calyx abscission. These research findings enrich the understanding of the regulatorymechanism of plant hormones on calyx abscission and provide a theoretical basis for the study of exogenous plant growth regulators for regulating calyx abscission in Korla fragrant pear. [ABSTRACT FROM AUTHOR]

The glycocalyx is a complex layer of carbohydrate and protein molecules that surrounds the cell membrane of many types of mammalian cells. It serves several important functions, including cell adhesion and communication, and maintain cell shape and stability, especially in the case of erythrocytes. Alteration of glycocalyx composition represents a cardiovascular health threatening. For example, in diabetes mellitus glycocalyx of erythrocytes and of endothelial cells is known to be impaired, a potential source of blood occlusion in microcirculation, which may lead to blindness, and renal failure of patients. The impact of glycocalyx impairment on erythrocyte aggregation remains a largely unexplored research area. We conduct here in vitro-experiments in microfluidic devices in order to investigate erythrocytes aggregation incubated with amylase, an enzyme that partially breaks down glycocalyx molecules. It is found that incubation of erythrocytes by amylase leads to a dramatic increase of their aggregation and stability and alters the aggregates morphologies. Confocal microscopy analysis reveals a significant degradation of the glycocalyx layer, correlated with enhanced erythrocytes aggregation. An increased erythrocyte aggregation in vivo should affect oxygen and other metabolites delivery to organs and tissues. This study brings new elements about elucidation of microscopic origins of erythrocyte aggregation and their potential impact on cardiovascular pathologies. [ABSTRACT FROM AUTHOR]

Glycan‐protein interactions play a key role in various biological processes from fertilization to infections. Many of these interactions take place at the glycocalyx—a heavily glycosylated layer at the cell surface. Despite its significance, studying the glycocalyx remains challenging due to its complex, dynamic, and heterogeneous nature. This study introduces a glycocalyx model allowing for the first time to control spatial organization and heterogeneity of the glycan moieties. Glycan‐mimetics with lipid‐moieties that partition into either liquid‐ordered (Lo, lipid rafts) or liquid‐disordered (Ld) phases of giant unilamellar vesicles (GUVs), which serve as simplified cell membrane models mimicking lipid rafts, are developed. This phase‐specific allocation allows controlled placement of glycan motifs in distinct membrane environments, creating heteromultivalent systems that replicate the natural glycocalyx's complexity. We show that phase localization of glycan mimetics significantly influences recruitment of protein receptors to the membrane. Glycan‐conjugates in the ordered phase demonstrate enhanced lectin binding, supporting the idea that raft‐like domains facilitate stronger receptor interactions. This study provides a platform for systematically investigating spatial and dynamic presentation of glycans in biological systems and presents the first experimental evidence that glycan accumulation in lipid rafts enhances receptor binding affinity, offering deeper insights into the glycocalyx‘s functional mechanisms. [ABSTRACT FROM AUTHOR]

The endothelial glycocalyx (eGC) is a carbohydrate‐rich layer on the vascular endothelium, and its damage can lead to endothelial and organ dysfunction. Heparanase (HPSE) degrades the eGC in response to cellular stress, but its role in organ dysfunction remains unclear. This study investigates HPSE's role in lung ischemia–reperfusion (I/R) injury. A left lung hilar occlusion model was used in B6 wildtype (WT) and HPSE genetic knockout (−/−) mice to induce I/R injury in vivo. The left lungs were ischemic for 1 h followed by reperfusion for 4 h prior to investigations of lung function and eGC status. Data were compared between uninjured lungs and I/R‐injured lungs in WT and HPSE−/− mice. WT lungs showed significant functional impairment after I/R injury, whereas HPSE−/− lungs did not. Inhibition or knockout of HPSE prevented eGC damage, inflammation, and cellular migration after I/R injury by reducing matrix metalloproteinase activities. HPSE−/− mice exhibited compensatory regulation of related gene expressions. HPSE facilitates eGC degradation leading to inflammation and impaired lung function after I/R injury. HPSE may be a therapeutic target to attenuate graft damage in lung transplantation. [ABSTRACT FROM AUTHOR]

Since its introduction, the number of heart surgeries has risen continuously. It is a high-risk procedure, usually involving cardiopulmonary bypass, which is associated with an inflammatory reaction that can lead to perioperative and postoperative organ dysfunction. The extent of complications following cardiac surgery has been the focus of interest for several years because of their impact on patient outcomes. Recently, numerous scientific efforts have been made to uncover the complex mechanisms of interaction between inflammation, oxidative stress, and endothelial dysfunction that occur after cardiac surgery. Numerous factors, such as surgical and anesthetic techniques, hypervolemia and hypovolemia, hypothermia, and various drugs used during cardiac surgery trigger the development of systemic inflammatory response and the release of oxidative species. They affect the endothelium, especially endothelial glycocalyx (EG), a thin surface endothelial layer responsible for vascular hemostasis, its permeability and the interaction between leukocytes and endothelium. This review highlights the current knowledge of the molecular mechanisms involved in endothelial dysfunction, particularly in the degradation of EG. In addition, the major inflammatory events and oxidative stress responses that occur in cardiac surgery, their interaction with EG, and the clinical implications of these events have been summarized and discussed in detail. A better understanding of the complex molecular mechanisms underlying cardiac surgery, leading to endothelial dysfunction, is needed to improve patient management during and after surgery and to develop effective strategies to prevent adverse outcomes that complicate recovery. [ABSTRACT FROM AUTHOR]

Desmoplasia in breast cancer leads to heterogeneity in physical properties of the tissue, resulting in disparities in drug delivery and treatment efficacy among patients, thus contributing to high disease mortality. Personalized in vitro breast cancer models hold great promise for high‐throughput testing of therapeutic strategies to normalize the aberrant microenvironment in a patient‐specific manner. Here, tumoroids assembled from breast cancer cell lines (MCF7, SKBR3, and MDA‐MB‐468) and patient‐derived breast tumor cells (TCs) cultured in microphysiological systems including perfusable microvasculature reproduce key aspects of stromal and vascular dysfunction causing impaired drug delivery. Models containing SKBR3 and MDA‐MB‐468 tumoroids show higher stromal hyaluronic acid (HA) deposition, vascular permeability, interstitial fluid pressure (IFP), and degradation of vascular HA relative to models containing MCF7 tumoroids or models without tumoroids. Interleukin 8 (IL8) secretion is found responsible for vascular dysfunction and loss of vascular HA. Interventions targeting IL8 or stromal HA normalize vascular permeability, perfusion, and IFP, and ultimately enhance drug delivery and TC death in response to perfusion with trastuzumab and cetuximab. Similar responses are observed in patient‐derived models. These microphysiological systems can thus be personalized by using patient‐derived cells and can be applied to discover new molecular therapies for the normalization of the tumor microenvironment. [ABSTRACT FROM AUTHOR]

Comprehensive Summary We report the design and development of a β‐glucuronidase (β‐Glu)‐responsive ManNAz derivative, Glu‐AAM, for tumor‐selective metabolic glycoengineering. Glu‐AAM enables specific labeling of tumor cell surface sialoglycans in the presence of overexpressed β‐Glu in cancer cells, including breast, leukemia, and colorectal cancer cells. We demonstrate the high selectivity and efficiency of Glu‐AAM‐mediated metabolic glycoengineering across multiple cancer cell lines. Furthermore, we synthesized multivalent antibody‐recruiting molecules (DBCO‐Rha) that can be covalently attached to the azido‐modified tumor cell surface, leading to potent antibody‐dependent cellular phagocytosis and complement‐dependent cytotoxicity. The octameric DBCO‐Rha8 construct exhibited the most effective immune response. This integrated strategy of β‐Glu‐responsive metabolic glycoengineering and antibody‐recruiting immunotherapy provides a promising platform for targeted cancer therapies and expands the toolbox of metabolic glycoengineering for cancer immunotherapy. We report the design and development of a β‐glucuronidase (β‐Glu)‐responsive ManNAz derivative, Glu‐AAM, for tumor‐selective metabolic glycoengineering. Glu‐AAM enables specific labeling of tumor cell surface sialoglycans in the presence of overexpressed β‐Glu in cancer cells, including breast, leukemia, and colorectal cancer cells. We demonstrate the high selectivity and efficiency of Glu‐AAM‐mediated metabolic glycoengineering across multiple cancer cell lines. Furthermore, we synthesized multivalent antibody‐recruiting molecules (DBCO‐Rha) that can be covalently attached to the azido‐modified tumor cell surface, leading to potent antibody‐dependent cellular phagocytosis and complement‐dependent cytotoxicity. The octameric DBCO‐Rha8 construct exhibited the most effective immune response. This integrated strategy of β‐Glu‐responsive metabolic glycoengineering and antibody‐recruiting immunotherapy provides a promising platform for targeted cancer therapies and expands the toolbox of metabolic glycoengineering for cancer immunotherapy. [ABSTRACT FROM AUTHOR]

Glycan recognition by lectins mediates important biological events. This Tutorial Review aims to introduce lectin–ligand interactions and show how these molecular recognition events inspire innovations such as: (i) glycomimetic ligands; (ii) multivalent ligand agonists/antagonists; (iii) ligands for precision delivery of therapies to cells, where therapies include vaccines, siRNA and LYTACs (iv) development of diagnostics. A small number of case studies are selected to demonstrate principles for development of new ligands for applications inspired by knowledge of natural glycan ligand structure and function. [ABSTRACT FROM AUTHOR]

Background/Objectives: Nasal vaccines are a promising strategy for enhancing mucosal immune responses and preventing diseases at mucosal sites by stimulating the secretion of secretory IgA, which is crucial for early pathogen neutralization. However, designing effective nasal vaccines is challenging due to the complex immunological mechanisms in the nasal mucosa, which must balance protection and tolerance against constant exposure to inhaled pathogens. The nasal route also presents unique formulation and delivery hurdles, such as the mucous layer hindering antigen penetration and immune cell access. Methods: This review focuses on cutting-edge approaches to enhance nasal vaccine delivery, particularly those targeting C-type lectin receptors (CLRs) like the mannose receptor and macrophage galactose-type lectin (MGL) receptor. It elucidates the roles of these receptors in antigen recognition and uptake by antigen-presenting cells (APCs), providing insights into optimizing vaccine delivery. Results: While a comprehensive examination of targeted glycoconjugate vaccine development is outside the scope of this study, we provide key examples of glycan-based ligands, such as lactobionic acid and mannose, which can selectively target CLRs in the nasal mucosa. Conclusions: With the rise of new viral infections, this review aims to facilitate the design of innovative vaccines and equip researchers, clinicians, and vaccine developers with the knowledge to enhance immune defenses against respiratory pathogens, ultimately protecting public health. [ABSTRACT FROM AUTHOR]

In this narrative review, we assess the pathophysiology of severe adverse events that presented after vaccination with DNA and mRNA vaccines against COVID‐19. The focus is on the perspective of an undersulfated and degraded glycocalyx, considering its impact on immunomodulation, inflammatory responses, coagulation and oxidative stress. The paper explores various factors that lead to glutathione and inorganic sulfate depletion and their subsequent effect on glycocalyx sulfation and other metabolites, including hormones. Components of COVID‐19 vaccines, such as DNA and mRNA material, spike protein antigen and lipid nanoparticles, are involved in possible cytotoxic effects. The common thread connecting these adverse events is endotheliopathy or glycocalyx degradation, caused by depleted glutathione and inorganic sulfate levels, shear stress from circulating nanoparticles, aggregation and formation of protein coronas; leading to imbalanced immune responses and chronic release of pro‐inflammatory cytokines, ultimately resulting in oxidative stress and systemic inflammatory response syndrome. By understanding the underlying pathophysiology of severe adverse events, better treatment options can be explored. [ABSTRACT FROM AUTHOR]

Extracorporeal membrane oxygenation (ECMO) is a life-saving intervention for patients with circulatory and/or pulmonary failure; however, the rate of complications remains high. ECMO induces systemic inflammation, which may activate and damage the endothelium, thereby causing edema and organ dysfunction. Advancing our understanding in this area is crucial for improving patient outcomes during ECMO. The goal of this review is to summarize the current evidence of the effects of ECMO on endothelial activation and damage in both animals and patients. PubMed and Embase databases were systematically searched for both clinical and animal studies including ECMO support. The outcome parameters were markers of endothelial activation and damage or (in)direct measurements of endothelial permeability, fluid leakage and edema. In total, 26 studies (patient n = 16, animal n = 10) fulfilled all eligibility criteria, and used VA-ECMO (n = 13) or VV-ECMO (n = 6), or remained undefined (n = 7). The most frequently studied endothelial activation markers were adhesion molecules (ICAM-1) and selectins (E- and P-selectin). The levels of endothelial activation markers were comparable to or higher than in healthy controls. Compared to pre-ECMO or non-ECMO, the majority of studies showed stable or decreased levels. Angiopoietin-2, von Willebrand Factor and extracellular vesicles were the most widely studied circulating markers of endothelial damage. More than half of the included studies showed increased levels when compared to normal ranges, and pre-ECMO or non-ECMO values. In healthy animals, ECMO itself leads to vascular leakage and edema. The effect of ECMO support in critically ill animals showed contradicting results. ECMO support (further) induces endothelial damage, but endothelial activation does not, in the critically ill. Further research is necessary to conclude on the effect of the underlying comorbidity and type of ECMO support applied on endothelial dysfunction. [ABSTRACT FROM AUTHOR]

The lining of blood vessels is constantly exposed to mechanical forces exerted by blood flow against the endothelium. Endothelial cells detect these tangential forces (i.e., shear stress), initiating a host of intracellular signaling cascades that regulate vascular physiology. Thus, vascular health is tethered to the endothelial cells' capacity to transduce shear stress. Indeed, the mechanotransduction of shear stress underlies a variety of cardiovascular benefits, including some of those associated with increased physical activity. However, endothelial mechanotransduction is impaired in aging and disease states such as obesity and type 2 diabetes, precipitating the development of vascular disease. Understanding endothelial mechanotransduction of shear stress, and the molecular and cellular mechanisms by which this process becomes defective, is critical for the identification and development of novel therapeutic targets against cardiovascular disease. In this review, we detail the primary mechanosensitive structures that have been implicated in detecting shear stress, including junctional proteins such as platelet endothelial cell adhesion molecule-1 (PECAM-1), the extracellular glycocalyx and its components, and ion channels such as piezo1. We delineate which molecules are truly mechanosensitive and which may simply be indispensable for the downstream transmission of force. Furthermore, we discuss how these mechanosensors interact with other cellular structures, such as the cytoskeleton and membrane lipid rafts, which are implicated in translating shear forces to biochemical signals. Based on findings to date, we also seek to integrate these cellular and molecular mechanisms with a view of deciphering endothelial mechanotransduction of shear stress, a tenet of vascular physiology. [ABSTRACT FROM AUTHOR]

The ultrastructure of the metasoma tegument of the developing acanthocephalan Neoechinorhynchus beringianus (Neoechinorhynchidae) was studied for the first time for representatives of the class Eoacanthocephala. The completely developed acanthellae of this species were shown to have no cyst, which is a characteristic feature of cystacanths at these stages of development in other acanthocephalan classes, and protection against the host response is provided by a thick layer of glycocalyx on the tegument surface. The tegument is represented by a typical symplast and includes a standard set of layers (cross-striated, felt-fibrous, radial-fibrous, and tubular), and is underlain by a basal plate and two layers of muscles. The absence of a cyst in the completely developed acanthellae under study does not permit us to use the term "cystacanth" concerning them. [ABSTRACT FROM AUTHOR]

[Objective] This study explored the cytological characteristics of different developmental stages of Prunus sibirica microspores and revealed the relationships between microspore periods and floral organ morphology to provide basis for reproductive biology research and germplasm innovation of Prunus sibirica. [Method] The flower buds of male sterile and fertile lines of Prunus sibirica were selected as the research subjects. The paraffin section technique and modified carmine acetate staining technique were used to observe morphology of microspores at various development stages. Phenotypic observation and analysis of flower organ morphology were also conducted during corresponding periods. [Result] The microspore development periods of Prunus sibirica included tetrad stage, microspore period and mature stage. The microspore period included uninucleate stage (early-uninucleate stage, mid-uninucleate stage, late-uninucleate stage) and binucleate stage (early-binucleate stage, middle-binucleate stage, late-binucleate stage) with distinct cytological features in each stage. In the early-binucleate stage, the microspores of the male sterile line were abnormal due to the failure to complete mitosis, but there was no abnormality in the development of floral organs. The bud transverse diameter, bud longitudinal diameter, anther transverse diameter and anther longitudinal diameter gradually increased with the advance of microspore development stage in Prunus sibirica. There were corresponding relationships between microspore periods and morphological characteristics of floral organs. The bud transverse diameter, anther transverse diameter and anther longitudinal diameter were utilized to differentiate microspores between various microspore stages ranging from early-binucleate stage to late-binucleate stage. The color of calyx was employed to differentiate microspores between mid-uninucleate stage and late-uninucleate stage. Additionally, microspore diameter distinguished different stages of microspores from early-uninucleate stage to early-binucleate stage. At the early-binucleate stage, bud transverse diameters of male sterile line and male fertile line in Prunus sibirica were 3.36 and 3.34 mm, respectively. The anther longitudinal diameters of male sterile line and male fertile line were 0.95 and 0.96 mm, respectively. The anther transverse diameters of male sterile line and male fertile line were both 0.73 mm. The microspore diameter of male sterile line and male fertile line were both 28.90 μm. [Conclusion] The microspore period of Prunus sibirica was correlated with bud transverse diameter, anther transverse diameter, anther longitudinal diameter, and calyx color, which could be used as an important basis for dividing microspore stages. [ABSTRACT FROM AUTHOR]

Skeletal muscle trauma such as fracture or crush injury can result in a life‐threatening condition called acute compartment syndrome (ACS), which involves elevated compartmental pressure within a closed osteo‐fascial compartment, leading to collapse of the microvasculature and resulting in necrosis of the tissue due to ischemia. Diagnosis of ACS is complex and controversial due to the lack of standardized objective methods, which results in high rates of misdiagnosis/late diagnosis, leading to permanent neuro‐muscular damage. ACS pathophysiology is poorly understood at a cellular level due to the lack of physiologically relevant models. In this context, microfluidics organ‐on‐chip systems (OOCs) provide an exciting opportunity to investigate the cellular mechanisms of microvascular dysfunction that leads to ACS. In this article, the state‐of‐the‐art OOCs designs and strategies used to investigate microvasculature dysfunction mechanisms is reviewed. The differential effects of hemodynamic shear stress on endothelial cell characteristics such as morphology, permeability, and inflammation, all of which are altered during microvascular dysfunction is highlighted. The article then critically reviews the importance of microfluidics to investigate closely related microvascular pathologies that cause ACS. The article concludes by discussing potential biomarkers of ACS with a special emphasis on glycocalyx and providing a future perspective. [ABSTRACT FROM AUTHOR]

A lactate/albumin ratio (LAR) greater than 0.5 measured early in the course of pediatric critical illness is associated with greater mortality. Whether the elevated LAR can be explained by microcirculation disorders in children with sepsis is not known. In this longitudinal retrospective study (January 2021-January 2024), serum albumin and lactate were measured on admission to the pediatric intensive care unit (PICU), with sublingual video microscopy performed simultaneously to measure microcirculation. A total of 178 children were included, 37% of whom had septic shock measured with the Phoenix Sepsis Score. Patients with remote sepsis had greater odds of an elevated LAR (aOR 6.87: 95% CI 1.98–23.73; p < 0.01). Children with an elevated LAR had more microvascular blood flow abnormalities (aOR 1.31 95% CI 1.08–1.58; p < 0.01), lower 4-6-micron capillary density (aOR 1.03 95% CI 1.01–1.05; p < 0.01) and greater odds of dying (aOR 3.55 95% CI 1.21–10.38; p = 0.02) compared to those with a low LAR. We found no association between LAR and endothelial glycocalyx degradation. A normal LAR is associated with less risk of microcirculatory injury (aOR 0.77 95% CI 0.65–0.93; p < 0.01). In children with sepsis, an elevated LAR is associated with microcirculation abnormalities (microvascular density and flow). The lactate/albumin ratio is a potentially useful biomarker for microcirculatory injury in sepsis. [ABSTRACT FROM AUTHOR]

Background: The alveolar epithelium is protected by a heparan sulfate-rich, glycosaminoglycan layer called the epithelial glycocalyx. It is cleaved in patients with acute respiratory distress syndrome (ARDS) and in murine models of influenza A (IAV) infection, shedding fragments into the airspace from the cell surface. Glycocalyx shedding results in increased permeability of the alveolar-capillary barrier, amplifying acute lung injury. The mechanisms underlying alveolar epithelial glycocalyx shedding in IAV infection are unknown. We hypothesized that induction of host sheddases such as matrix metalloproteinases (MMPs) during IAV infection results in glycocalyx shedding and increased lung injury. Materials and methods: We measured glycocalyx shedding and lung injury during IAV infection with and without treatment with the pan-MMP inhibitor Ilomastat (ILO) and in an MMP-7 knock out (MMP-7KO) mouse. C57BL/6 or MMP-7KO male and female mice were given IAV A/PR/8/34 (H1N1) at 30,000 PFU/mouse or PBS intratracheally. For some experiments, C56BL/6 mice were infected in the presence of ILO (100mg/kg) or vehicle given daily by IP injection. Bronchoalveolar lavage (BAL) and lung tissue were collected on day 1, 3, and 7 for analysis of glycocalyx shedding (BAL Syndecan-1) and lung injury (histology, BAL protein, BAL cytokines, BAL immune cell infiltrates, BAL RAGE). Expression and localization of the sheddase MMP-7 and its inhibitor TIMP-1 was examined by RNAScope. For in vitro experiments, MLE-12 mouse lung epithelial cells were cultured and treated with active or heat-inactivated heparinase (2.5 U/mL) prior to infection with IAV (MOI 1) and viral load and MMP-7 and TIMP-1 expression analyzed. Results: IAV infection caused shedding of the epithelial glycocalyx into the BAL. Inhibition of MMPs with ILO reduced glycocalyx shedding by 36% (p = 0.0051) and reduced lung epithelial injury by 40% (p = 0.0404). ILO also reduced viral load by 68% (p = 0.027), despite having no significant effect on lung cytokine production. Both MMP-7 and its inhibitor TIMP-1 were upregulated in IAV infected mice: MMP-7 colocalized with IAV, while TIMP-1 was limited to cells adjacent to infection. However, MMP-7KO mice had similar glycocalyx shedding, epithelial injury, and viral load compared to WT littermates, suggesting redundancy in MMP sheddase function in the lung. In vitro, heparinase treatment before infection led to a 52% increase in viral load (p = 0.0038) without altering MMP-7 or TIMP-1 protein levels. Conclusions: Glycocalyx shedding and MMPs play key roles in IAV-induced epithelial injury, with significant impact on IAV viral load. Further studies are needed to understand which specific MMPs regulate lung epithelial glycocalyx shedding. [ABSTRACT FROM AUTHOR]

Endothelial shear stress is a tangential stress derived from the friction of the flowing blood on the endothelial surface of the arterial wall and is expressed in units of force/unit area (dyne/cm2). Branches and bends of arteries are exposed to complex blood flow patterns that generate low or oscillatory endothelial shear stress, which impairs glycocalyx integrity, cytoskeleton arrangement and endothelial junctions (adherens junctions, tight junctions, gap junctions), thus increasing endothelial permeability. The lipoproteins and inflammatory cells penetrating intima due to the increased endothelial permeability characterizes the pathological changes in early stage of atherosclerosis. Endothelial cells are critical sensors of shear stress, however, the mechanisms by which the complex shear stress regulate endothelial permeability in atherosclerosis remain unclear. In this review, we focus on the molecular mechanisms of the endothelial permeability induced by low or oscillatory shear stress, which will shed a novel sight in early stage of atherosclerosis. [ABSTRACT FROM AUTHOR]

Introduction: Cells are covered with a glycan surface layer that is referred to as the glycocalyx (GCX). It has been reported that the formation of the GCX is promoted on cancer cells and is associated with tumor growth and metastasis. Heparan sulfate proteoglycan glypican‐1 (GPC1) is a core protein of the GCX that is overexpressed in esophageal squamous cell carcinoma (ESCC) and is involved in the development and progression of cancer cells. The purpose of the present study is to analyze the utility of GPC1 as a new biomarker ralated to glycocalyx that reflects therapeutic effect and prognosis of ESCC. Methods: We measured the concentration of GPC1 protein in preoperative plasma from advanced esophageal cancer patients and examined its relationships with clinicopathological factors and therapeutic efficacy, and the effects of extracellular GPC1 were investigated. Results: The following clinical factors were significantly correlated with the preoperative high GPC1 concentration: male, tumor size ≥30 mm, venous invasion, pT factor ≥2, pStage ≥3, residual tumor, and distant metastatic recurrence. Both overall and recurrence‐free survival were significantly worse in the high GPC1 group. Extracellular GPC1 protein concentration reflected intracellular GPC1 expression. Furthermore, we examined the effects of extracellular recombinant human (rh)GPC1 on ESCC cells, and found that extracellular rhGPC1 affects cell motility, including migration and invasion. Conclusions: These results demonstrated the utility of extracellular GPC1 as a biomarker, which can be assayed from a less invasive blood sample‐based liquid biopsy. Extracellular GPC1 protein plays a role in both tumor cell motility and cancer progression. Thus, plasma GPC1 is a useful biomarker for esophageal cancer progression and may be a potential candidate of therapeutic target. [ABSTRACT FROM AUTHOR]

Background Aim Methods Outcomes Results Clinical implications Strengths and limitations Conclusion Chronic periodontitis may induce erectile dysfunction (ED), however, the specific mechanism involved is unclear. The endothelial glycocalyx (eGlx) is a structure that can regulate endothelial nitric oxide synthase (eNOS) phosphorylation on the cavity surface of vessels.To investigate whether chronic periodontitis leads to ED by affecting the eGlx.Twenty‐four 4‐week‐old male Sprague‒Dawley rats were randomly divided into four groups (n = 6): the control group, chronic periodontitis group, chronic periodontitis + heparin group (subcutaneous heparin 200 U/kg/day, 7 days), and control + heparin group. Four weeks after the induction of periodontitis in the rats, the maximum intra‐cavernous pressure/mean arterial pressure (ICPmax/MAP), serum C‐reactive protein (CRP), tumor necrosis factor alpha (TNF‐α), interleukin‐6 (IL‐6), nitric oxide (NO), heparin sulfate (HS), syndecan‐1 (SDC‐1), heparanase (HPSE), eNOS, and phosphor‐eNOS (p‐eNOS) concentration were measured, and the eGlx of the penile corpus cavernosum was observed by transmission electron microscopy (TEM).Chronic periodontitis can degrade eGlx on the rat penile corpus cavernosum by increasing serum CRP, TNF‐α, and IL‐6 levels, reducing the p‐eNOS/eNOS ratio and the NO concentration in the penile corpus cavernosum, and resulting in the inhibition of the erectile function.Serum CRP, TNF‐α, and IL‐6 levels and HPSE expression in penile cavernous tissue were significantly greater in the chronic periodontitis group than in the control group and the chronic periodontitis + heparin group (P < 0.05). The average thickness of the eGlx muscle in the penile corpus cavernosum in the chronic periodontitis group was significantly lower than those in the control group and chronic periodontitis + heparin group (P < 0.05). The HS concentration, SDC‐1 expression, p‐eNOS/eNOS, NO concentration, and ICPmax/MAP in the chronic periodontitis group were significantly lower than those in the control group and chronic periodontitis+ heparin group (P < 0.01).The eGlx on penile cavernosum vessels may be a new therapeutic target for the treatment of ED.This study revealed that chronic periodontitis promotes the decomposition of vascular eGlx in the rat penile corpus cavernosum, however, it is not clear whether chronic periodontitis inhibits the synthesis of eGlx.Chronic periodontitis can degrade eGlx on the rat penile corpus cavernosum by increasing serum CRP, TNF‐α, and IL‐6 levels, reducing the p‐eNOS/eNOS ratio and the NO concentration in penile cavernous tissue, and resulting in the inhibition of the erectile function. Heparin inhibited eGlx decomposition and improved erectile function in rats with chronic periodontitis. [ABSTRACT FROM AUTHOR]

Background: Endothelial disorders with edema formation and microcirculatory perfusion disturbances are common in cardiac surgery with cardiopulmonary bypass (CPB) and contribute to disturbed tissue oxygenation resulting in organ dysfunction. Albumin is protective for the endothelium and could be a useful additive to CPB circuit priming. Therefore, this study aimed to compare organ edema and microcirculatory perfusion in rats on CPB primed with lactated Ringers, albumin and mannitol (LR/albumin/mannitol) compared to 6% hydroxyethyl starch (HES). Results: Male rats were subjected to 75 min of CPB primed with either LR/albumin/mannitol or with 6% HES. Renal and lung edema were determined by wet/dry weight ratio. Pulmonary wet/dry weight ratio was lower in rats on CPB primed with LR/albumin/mannitol compared to HES (4.77 [4.44–5.25] vs. 5.33 [5.06–6.33], p = 0.032), whereas renal wet/dry weight ratio did not differ between groups (4.57 [4.41–4.75] vs. 4.51 [4.47–4.73], p = 0.813). Cremaster microcirculatory perfusion was assessed before, during and after CPB with intravital microscopy. CPB immediately impaired microcirculatory perfusion compared to baseline (LR/albumin/mannitol: 2 [1–7] vs. 14 [12–16] vessels per recording, p = 0.008; HES: 4 [2–6] vs. 12 [10–13] vessels per recording, p = 0.037), which persisted after weaning from CPB without differences between groups (LR/albumin/mannitol: 5 [1–9] vs. HES: 1 [0–4], p = 0.926). In addition, rats on CPB primed with LR/albumin/mannitol required less fluids to reach sufficient flow rates (0.5 [0.0–5.0] mL vs. 9 [4.5–10.0], p < 0.001) and phenylephrine (20 [0–40] µg vs. 90 [40–200], p = 0.004). Circulating markers for inflammation (interleukin 6 and 10), adhesion (ICAM-1), glycocalyx shedding (syndecan-1) and renal injury (NGAL) were determined by ELISA or Luminex. Circulating interleukin-6 (16 [13–25] vs. 33 [24–51] ng/mL, p = 0.006), interleukin-10 (434 [295–782] vs. 2120 [1309–3408] pg/ml, p < 0.0001), syndecan-1 (5 [3–7] vs. 15 [11–16] ng/mL, p < 0.001) and NGAL (555 [375–1078] vs. 2200 [835–3671] ng/mL, p = 0.008) were lower in rats on CPB primed with LR/albumin/mannitol compared to HES. Conclusion: CPB priming with LR, albumin and mannitol resulted in less pulmonary edema, renal injury, inflammation and glycocalyx degradation compared to 6% HES. Furthermore, it enhanced hemodynamic stability compared with HES. Further research is needed to explore the specific role of albumin as a beneficial additive in CPB priming. [ABSTRACT FROM AUTHOR]

The alveolar surface of the lung is lined by an epithelium consisting of type I (AECI) and type II alveolar epithelial cells (AECII). This epithelium is covered by a liquid alveolar lining layer (ALL). Besides intra‐alveolar surfactant, ALL also contains the alveolar epithelial glycocalyx on the apical side of AECI and AECII. To better understand the alveolar epithelial glycocalyx, its ultrastructural visualization by transmission electron microscopy is required. The aim of this study was to systematically re‐evaluate routine cytochemical methods for visualization of the alveolar epithelial glycocalyx and specifically its glycan components. For this purpose, we used chemical fixation by vascular perfusion with aldehydes as a common routine approach in mice. After fixation, staining is needed for glycocalyx visualization. Cytochemical staining agents such as alcian blue, ruthenium red, and lanthanum nitrate were compared. In addition, SNL (Sambucus nigra lectin) and UEA1 (Ulex europaeus agglutinin I) were used for sialic acid and fucose‐specific labeling. Alcian blue showed the strongest staining, with cloud‐like structures, whereas ruthenium red appeared as thread‐like structures. On the other hand, lanthanum nitrate did not stain the alveolar epithelial glycocalyx. For specific sialic acid and fucose labeling, both lectins presented a specific signal. In conclusion, these methods can be used routinely for assessing ultrastructural changes of the alveolar epithelial glycocalyx in experimental in vivo models under different physiological and pathological conditions. In addition, cytochemical staining by tissue massage and post‐embedding lectin labeling after vascular perfusion support 3R (reduction, refinement, replacement) principles of animal welfare. [ABSTRACT FROM AUTHOR]

Fluid therapy is a fundamental part of supportive therapy in critical care. However, it is also a suspected risk for endothelial glycocalyx degradation which is associated with poor clinical outcomes. This secondary analysis of RESPONSE randomized trial compares the effect of follow-up strategy (FU) on endothelial biomarkers to that of 500 ml crystalloid fluid bolus (FB) in oliguric, hemodynamically optimized intensive care unit (ICU) patients. 130 adult subjects were enrolled in two Finnish ICUs from January 2017 to November 2020. Blood and urine samples of 63 patients in FU group and 67 patients in FB group were collected before and after the intervention and analyzed using enzyme-linked immunosorbent assays. Single fluid bolus, given after median of 3887 ml (interquartile range 2842; 5359 ml) resuscitation fluids in the preceding 24 h, increased plasma hyaluronan concentration compared to the follow-up strategy (difference in medians 29.2 ng/ml with 95% CI [14.5ng/ml; 55.5ng/ml], P < 0.001). No treatment effect was detected in the plasma levels of syndecan-1, , angiopoietin-2, angiopoietin receptors Tie2 and Tie1, or in soluble thrombomodulin in the adjusted median regression analysis. The increase in hyaluronan was independent of its simultaneous renal clearance but correlated moderately with the increase in endothelium-specific Tie1. The follow-up strategy did not show consistent endothelium-sparing effect but protected against hyaluronan increase. The mechanisms and consequences of hyaluronan fluctuations need further clarification. Trial registration: clinicaltrials.gov, NCT02860572. Registered 1 August 2016, https://www.clinicaltrials.gov/study/NCT02860572?term=NCT02860572&rank=1 [ABSTRACT FROM AUTHOR]

Introduction: The administration of intravenous thrombolysis (IVT) before mechanical thrombectomy (MT) in the treatment of acute ischemic stroke (AIS) has been a subject of debate, and its potential benefits remain uncertain. This retrospective study aimed to investigate the effect of preoperative IVT on glycocalyx damage in patients with cerebral ischemia-reperfusion injury (IRI). Methods: A cohort of 106 patients with acute large vessel occlusion in the anterior circulation treated with mechanical thrombectomy was enrolled. The levels of the glycocalyx damage marker, syndecan-1, were measured in the peripheral blood of these patients to assess glycocalyx damage during IRI, and clinical outcomes were compared between patients receiving MT alone vs. combined IVT and MT. Results: The study results indicate that thrombolytic drugs have a significant impact on syndecan-1 levels in the blood. Compared to patients who underwent direct MT, those who received preoperative IVT had significantly lower levels of syndecan-1 in their blood. Although preoperative IVT did not alter the final clinical outcomes, the levels of syndecan-1 shedding reflect the extent of damage to the endothelial glycocalyx. Discussion: This suggests that using thrombolytic drugs before mechanical thrombectomy may reduce endothelial glycocalyx damage in patients with ischemia-reperfusion injury. These findings provide indirect clinical evidence supporting the preoperative use of intravenous thrombolysis in such patients. [ABSTRACT FROM AUTHOR]

Background: Vascular endothelial damage is involved in the development and exacerbation of ventilator-induced lung injury (VILI). Pulmonary endothelial glycocalyx and neutrophil extracellular traps (NETs) are endothelial protective and damaging factors, respectively; however, their dynamics in VILI and the effects of recombinant thrombomodulin and antithrombin on these dynamics remain unclear. We hypothesized that glycocalyx degradation and NETs are induced by VILI and suppressed by recombinant thrombomodulin, recombinant antithrombin, or their combination. Methods: VILI was induced in male C57BL/6J mice by intraperitoneal lipopolysaccharide injection (20 mg/kg) and high tidal volume ventilation (20 mL/kg). In the intervention groups, recombinant thrombomodulin, recombinant antithrombin, or their combination was administered at the start of mechanical ventilation. Glycocalyx degradation was quantified by measuring serum syndecan-1, fluorescence-labeled lectin intensity, and glycocalyx-occupied area in the pulmonary vascular lumen. Double-stranded DNA in the bronchoalveolar fluid and fluorescent areas of citrullinated histone H3 and myeloperoxidase were quantified as NET formation. Results: Serum syndecan-1 increased, and lectin fluorescence intensity decreased in VILI. Electron microscopy revealed decreases in glycocalyx-occupied areas within pulmonary microvessels in VILI. Double-stranded DNA levels in the bronchoalveolar lavage fluid and the fluorescent area of citrullinated histone H3 and myeloperoxidase in lung tissues increased in VILI. Recombinant thrombomodulin, recombinant antithrombin, and their combination reduced glycocalyx injury and NET marker levels. There was little difference in glycocalyx injury and NET makers between the intervention groups. Conclusion: VILI induced glycocalyx degradation and NET formation. Recombinant thrombomodulin and recombinant antithrombin attenuated glycocalyx degradation and NETs in our VILI model. The effect of their combination did not differ from that of either drug alone. Recombinant thrombomodulin and antithrombin have the potential to be therapeutic agents for biotrauma in VILI. [ABSTRACT FROM AUTHOR]

Background: The mechanism involved in HBO2 preconditioning in preventing inflammation in diving is still unclear. Syndecan-1, which is an important part of glycocalyx, has never been studied for its involvement in HBO2 preconditioning to prevent inflammation in decompression diving. This study aims to determine how HBO2 preconditioning impacts inflammation through Syndecan-1, MDA, and IL-1a markers. Method: This study is a true experimental post-test design. Forty male 12- to 14-year-old Sprague Dawley rats were divided into four groups. HBO2 and decompression diving were carried out in an animal hyperbaric chamber. All data were collected 12 and 24 hours after the decompression diving. Result: The incidence of decompression sickness was less frequent in the HBO2 preconditioning treatment group as opposed to the control group (4 vs 9) but did not reach a significant level (p > 0.05). All parameters showed no difference between the control and treatment groups 12 hours after the dive (p > 0.05). Twenty-four hours after diving, the treatment group demonstrated substantially elevated IL-1a levels in comparison to the control group (p = 0.030), and the increase of IL-1a in the treatment group is significant (p = 0.001). Although MDA levels did not reach significant, the treatment group's increase in MDA levels 24 hours after diving was greater than that of the control group. Meanwhile, The treatment group had a smaller reduction in Syndecan-1 levels in comparison to the control group following diving 24 hours later. Conclusion: HBO2 preconditioning prolongs the inflammation, as evidenced by increased levels of MDA, Syndecan-1, and IL-1a, even though it can prevent decompression sickness. Further research is needed to find the right time and dose of HBO2 preconditioning to shorten the inflammation time. [ABSTRACT FROM AUTHOR]

Background: Septic shock is associated with high morbidity and mortality, the endothelium plays an important role. Crystalloids is standard of care to maintain intravascular volume. Plasma is associated with improved endothelial integrity and restoration of the glycocalyx layer. We evaluated the efficacy and safety aspects of cell‐free and pathogen inactivated pooled plasma (OctaplasLG®) as resuscitation in septic shock patients. Study Design and Methods: This randomized, investigator‐initiated phase IIa trial ran at a Danish single center intensive care unit, from 2017 to 2019. Patients were 18 years of age or older with septic shock and randomized to fluid optimization with OctaplasLG® or Ringer‐acetate in the first 24 h. The primary endpoints were changes in biomarkers indicative of endothelial activation, damage, and microvascular perfusion from baseline to 24 h. Safety events and mortality were assessed during 90 days. Results: Forty‐four patients were randomized, 20 to OctaplasLG versus 24 to Ringer‐acetate. The median age was 69, and 55% were men. Median Sequential Organ Failure Assessment score was 13. Baseline differences favoring the Ringer‐acetate group were observed. The OctaplasLG® group was resuscitated with 740 mL plasma and the Ringer‐acetate group with 841 mL crystalloids. There was no significant change in the microvascular perfusion or five biomarkers except VEGFR1 change, which was higher in patients receiving OctaplasLG® 0.12(SD 0.37) versus Ringer‐acetate −0.24 (SD 0.39), with mean difference 0.36 (95% CI, 0.13–0.59, p =.003) in favor of Ringer‐acetate. Discussion: This study found that fluid resuscitation with OctaplasLG® in critically ill septic shock patients is feasible. Baseline confounding prevented assessment of the potential effect of OctaplasLG®. [ABSTRACT FROM AUTHOR]

Introduction. Fluid therapy is an intervention widely used in clinical practice. However, its application is not without risks and requires a careful evaluation of patient’s tolerance and response to volume. The empirical practice of fluid resuscitation can be potentially lethal. The purpose of this review was to provide an overview of the physiological and therapeutic principles for the administration of intravenous fluids in critically ill patients, addressing special populations, such as surgical, septic, and trauma patients. Methods. A narrative review was carried out based on articles published in PUBMED, ScienceDirect, and LILACS between 2001 and 2023. MESH terms fluid therapy, crystalloid solutions, and colloids were employed. Results. A total of 371 articles were found, of which randomized clinical trials studies, narrative reviews, systematic reviews, and meta-analyses that analyzed the role of crystalloids and colloids were selected. Manuscripts published on dates outside the search range, which were considered relevant for the description of the pathophysiology and the rationale for the use of intravenous fluids, were included. Conclusion. Reflective resuscitation is based on a holistic understanding of physiology and individualization of fluid therapy. The liberal use of intravenous fluids has potential harmful effects and resuscitation strategies should be guided by individual dynamic and static measures, which provide a safe framework for fluid management. [ABSTRACT FROM AUTHOR]

Introduction: Hypercholesterolemia is a risk factor for premature arteriosclerosis. Inflammation and oxidative stress are thought to contribute to endothelial dysfunction preceding vasculopathy. We investigated the association between inflammation, glycocalyx biomarkers, endothelial function, and vascular parameters in children with hypercholesterolemia. Methods: In 22 patients (LDL-cholesterol >130 mg/dL; median age [IQR]: 13 [2.3] years) and 22 controls (13 [2.5] years), tumor necrosis factor-alpha (TNF-α), oxidized cholesterol (oxLDL), and glycocalyx biomarkers (Syndecan-1, Hyaluronan) were measured using immunoassays. Endothelial function was assessed by peripheral arterial tonometry, sublingual glycocalyx and microcirculation by videomicroscopy and carotid intima-media thickness by ultrasound. Results: OxLDL was significantly higher in patients (78.9 [38.2] vs. 50.3 [16.6] U/L, p = 0.002), whereas all other experimental parameters were comparable between groups. Multivariate analysis revealed a significant association of Syndecan-1 with TNF-α (β = 0.75, p < 0.001) and with hypercholesterolemia (β = 0.31, p = 0.030). The interaction term combining TNF-α and hypercholesterolemia showed a significant effect (p = 0.034). Sex was an independent predictor of endothelial function. Conclusion: The combined effect of hypercholesterolemia and inflammation on glycocalyx perturbation and the impact of sex in the premature development of arteriosclerosis deserve further evaluation. Therapeutic approaches tackling low-grade systemic inflammation may offer potential to prevent or delay progression of cardiovascular disease and cardiovascular complications. [ABSTRACT FROM AUTHOR]

MIL77-3 is one component of antibody cocktail that is produced in our lab and represents an effective regimen for animals suffering from Zaire Ebolavirus (EBOV) infection. MIL77-3 is engineered to increase its affinity for the FcγRIIIa (CD16a) by deleting the fucose in the framework region. The potential effects of this modification on host immune responses, however, remain largely unknown. Herein, we demonstrated that MIL77-3 recognized secreted glycoproptein (sGP), produced by EBOV, and formed the immunocomplex to potently augment antibody-dependent cytotoxicity of human peripheral blood-derived natural killer cells (pNKs), including CD56dim and CD56bright subpopulations, in contrast to the counterparts (Mab114, rEBOV548, fucosylated MIL77-3). Intriguingly, this effect was not observed when NK92-CD16a cell line was utilized and restored by the addition of beads-coupled or membrane-anchored sGP in combination with MIL77-3. Furthermore, sGP bound to unrecognized receptors on T cells contaminated in pNKs rather than NK92-CD16a cells. Administration of beads-coupled sGP/MIL77-3 complex in mice elicited NK activation. Overall, this work reveals an immune-stimulating function of sGP/MIL77-3 complex by triggering cytotoxic activity of NK cells, highlighting the necessity to evaluate the potential impact of MIL77-3 on host immune reaction in clinical trials. IMPORTANCE Zaire Ebolavirus (EBOV) is highly lethal and causes sporadic outbreaks. The passive administration of monoclonal antibodies (mAbs) represents a promising treatment regimen against EBOV. Mounting evidence has shown that the efficacy of a subset of therapeutic mAbs in vivo is intimately associated with its capacity to trigger NK activity, supporting glycomodification of Fc region of anti-EBOV mAbs as a putative strategy to enhance Fc-mediated immune effector function as well as protection in vivo. Our work here uncovers the potential harmful influence of this modification on host immune responses, especially for mAbs with cross-reactivity to secreted glycoproptein (sGP) (e.g., MIL77-3), and highlights it is necessary to evaluate the NK-stimulating activity of a fucosylated mAb engaged with sGP when a new candidate is developed. [ABSTRACT FROM AUTHOR]

OBJECTIVE To describe changes in circulating hyaluronic acid (HA) concentration, a biomarker of endothelial glycocalyx degradation, after administration of fresh-frozen plasma (FFP) in critically ill dogs. ANIMALS 12 client-owned dogs receiving an FFP transfusion due to underlying disease. METHODS Plasma samples were collected for HA concentration measurement pre-FFP transfusion (T0) and 10 minutes (T10) and 90 minutes (T90) following completion of FFP transfusion of a minimum volume of 7 mL/kg. Hyaluronic acid was also measured in the transfused FFP units following in-house validation of a commercial HA assay on citrate phosphate dextrose–anticoagulated plasma. Potential associations of the difference between pre-FFP and post-FFP HA plasma concentrations with the volume of FFP transfused, the cumulative volume of IV fluids administered during the study period, and the HA concentration in the transfused unit were explored. RESULTS Concentrations of HA were not significantly different between pre- and post-FFP transfusion measurements. The volume of FFP transfused, the cumulative volume of other IV fluids administered during the study time, and the concentration of HA in the FFP units had no significant effect on the change in HA concentration following FFP transfusion in this study. CLINICAL RELEVANCE This pilot study did not demonstrate an association between FFP administration and changes in plasma HA concentration. The results of this study may serve to help design future research. A commercial assay was validated to measure HA in citrate phosphate dextrose–anticoagulated plasma. [ABSTRACT FROM AUTHOR]

Background: In recent years, it has been demonstrated that when the endothelial glycocalyx, composed of proteoglycans, glycosaminoglycans and glycoproteins, is altered or modified, this property is lost, playing a fundamental role in cardiovascular pathologies. Cardiovascular risk factors can destroy the endothelial glycocalyx layer. Exercise has a positive effect on cardiovascular risk factors, but little is known about its direct effect on the integrity of the endothelial layer. Methods: The Cochrane Library, PubMed, Web of Science and Scopus databases were searched from their inception to June 30, 2022. The DerSimonian and Laird method was used to compute pooled effect size estimates and their respective 95% confidence intervals for the acute effect of exercise (within 24 h) on the endothelial glycocalyx and its components in healthy adults. Results: Ten studies were included in the meta‐analysis, with a total of 252 healthy subjects. The types of exercise included were resistance training, interval training, resistance training and maximal incremental exercise, with a duration range of 30–60 min. Glycocalyx assessment times included ranged from 0 to 90 min post‐exercise. Our findings showed that endothelial glycocalyx increases after acute effect of exercise in healthy population (.56, 95% CI:.38,.74). The acute effect of exercise on endothelial glycocalyx components were.47 (95% CIs:.27,.67) for glycosaminoglycans,.67 (95% CIs:.08, 1.26) for proteoglycans and.61 (95% CIs:.35,.86) for glycoproteins. Conclusions: In a healthy population, various types of exercise showed an acute improvement of the endothelial glycocalyx and its individual components. [ABSTRACT FROM AUTHOR]

Hepatopulmonary syndrome (HPS) is a serious pulmonary complication in the advanced stage of liver disease. The occurrence of pulmonary edema in HPS patients is life-threatening. Increased pulmonary vascular permeability is an important mechanism leading to pulmonary edema, and endothelial glycocalyx (EG) is a barrier that maintains stable vascular permeability. However, in HPS, whether the pulmonary vascular EG changes and its regulatory mechanism are still unclear. Spleen derived monocytes are involved in the pathogenesis of HPS. However, whether they regulate the pulmonary vascular permeability in HPS patients or rats and what is the mechanism is still unclear. Healthy volunteers and HPS patients with splenectomy or not were enrolled in this study. We found that the respiration of HPS patients was significantly improved in response to splenectomy, while the EG degradation and pulmonary edema were aggravated. In addition, HPS patients expressed higher levels of oncostatin M (OSM) and fibroblast growth factor (FGF). Subsequently, the co-culture system of monocytes and human umbilical vein endothelial cells (HUVECs) was constructed. It was found that monocytes secreted OSM and activated the FGF/FGFR1 signaling pathway in HUVECs. Then, an HPS rat model was constructed by common bile duct ligation (CBDL) for in vivo verification. HPS rats were intravenously injected with OSM recombinant protein and/or TNF-α into the rats via tail vein 30 min before CBDL. The results showed that the respiration of HPS rats was improved after splenectomy, while the degradation of EG in pulmonary vessels and vascular permeability were increased, and pulmonary edema was aggravated. Moreover, the expression of OSM and FGF was upregulated in HPS rats, while both were downregulated after splenectomy. Intravenous injection of exogenous OSM eliminated the effect of splenectomy on FGF and improved EG degradation. It can be seen that during HPS, spleen-derived monocytes secrete OSM to promote pulmonary vascular EG remodeling by activating the FGF/FGFR1 pathway, thereby maintaining stable vascular permeability, and diminishing pulmonary edema. This study provides a promising therapeutic target for the treatment of HPS. [ABSTRACT FROM AUTHOR]

Sepsis is a global health challenge that causes more than 11 million deaths annually and represents a substantial medical and economic burden. With rising treatment costs and significant mortality rates associated with organ dysfunction and septic shock, research efforts have focused on investigating the mechanism of glycocalyx (GCX) degradation as well as its regenerative capacity. Therefore, GCX has become a target in therapeutic strategies.

Abstract Background Endothelial disorders with edema formation and microcirculatory perfusion disturbances are common in cardiac surgery with cardiopulmonary bypass (CPB) and contribute to disturbed tissue oxygenation resulting in organ dysfunction. Albumin is protective for the endothelium and could be a useful additive to CPB circuit priming. Therefore, this study aimed to compare organ edema and microcirculatory perfusion in rats on CPB primed with lactated Ringers, albumin and mannitol (LR/albumin/mannitol) compared to 6% hydroxyethyl starch (HES). Results Male rats were subjected to 75 min of CPB primed with either LR/albumin/mannitol or with 6% HES. Renal and lung edema were determined by wet/dry weight ratio. Pulmonary wet/dry weight ratio was lower in rats on CPB primed with LR/albumin/mannitol compared to HES (4.77 [4.44–5.25] vs. 5.33 [5.06–6.33], p = 0.032), whereas renal wet/dry weight ratio did not differ between groups (4.57 [4.41–4.75] vs. 4.51 [4.47–4.73], p = 0.813). Cremaster microcirculatory perfusion was assessed before, during and after CPB with intravital microscopy. CPB immediately impaired microcirculatory perfusion compared to baseline (LR/albumin/mannitol: 2 [1–7] vs. 14 [12–16] vessels per recording, p = 0.008; HES: 4 [2–6] vs. 12 [10–13] vessels per recording, p = 0.037), which persisted after weaning from CPB without differences between groups (LR/albumin/mannitol: 5 [1–9] vs. HES: 1 [0–4], p = 0.926). In addition, rats on CPB primed with LR/albumin/mannitol required less fluids to reach sufficient flow rates (0.5 [0.0–5.0] mL vs. 9 [4.5–10.0], p

Abstract Fluid therapy is a fundamental part of supportive therapy in critical care. However, it is also a suspected risk for endothelial glycocalyx degradation which is associated with poor clinical outcomes. This secondary analysis of RESPONSE randomized trial compares the effect of follow-up strategy (FU) on endothelial biomarkers to that of 500 ml crystalloid fluid bolus (FB) in oliguric, hemodynamically optimized intensive care unit (ICU) patients. 130 adult subjects were enrolled in two Finnish ICUs from January 2017 to November 2020. Blood and urine samples of 63 patients in FU group and 67 patients in FB group were collected before and after the intervention and analyzed using enzyme-linked immunosorbent assays. Single fluid bolus, given after median of 3887 ml (interquartile range 2842; 5359 ml) resuscitation fluids in the preceding 24 h, increased plasma hyaluronan concentration compared to the follow-up strategy (difference in medians 29.2 ng/ml with 95% CI [14.5ng/ml; 55.5ng/ml], P

Abstract Background Vascular endothelial damage is involved in the development and exacerbation of ventilator-induced lung injury (VILI). Pulmonary endothelial glycocalyx and neutrophil extracellular traps (NETs) are endothelial protective and damaging factors, respectively; however, their dynamics in VILI and the effects of recombinant thrombomodulin and antithrombin on these dynamics remain unclear. We hypothesized that glycocalyx degradation and NETs are induced by VILI and suppressed by recombinant thrombomodulin, recombinant antithrombin, or their combination. Methods VILI was induced in male C57BL/6J mice by intraperitoneal lipopolysaccharide injection (20 mg/kg) and high tidal volume ventilation (20 mL/kg). In the intervention groups, recombinant thrombomodulin, recombinant antithrombin, or their combination was administered at the start of mechanical ventilation. Glycocalyx degradation was quantified by measuring serum syndecan-1, fluorescence-labeled lectin intensity, and glycocalyx-occupied area in the pulmonary vascular lumen. Double-stranded DNA in the bronchoalveolar fluid and fluorescent areas of citrullinated histone H3 and myeloperoxidase were quantified as NET formation. Results Serum syndecan-1 increased, and lectin fluorescence intensity decreased in VILI. Electron microscopy revealed decreases in glycocalyx-occupied areas within pulmonary microvessels in VILI. Double-stranded DNA levels in the bronchoalveolar lavage fluid and the fluorescent area of citrullinated histone H3 and myeloperoxidase in lung tissues increased in VILI. Recombinant thrombomodulin, recombinant antithrombin, and their combination reduced glycocalyx injury and NET marker levels. There was little difference in glycocalyx injury and NET makers between the intervention groups. Conclusion VILI induced glycocalyx degradation and NET formation. Recombinant thrombomodulin and recombinant antithrombin attenuated glycocalyx degradation and NETs in our VILI model. The effect of their combination did not differ from that of either drug alone. Recombinant thrombomodulin and antithrombin have the potential to be therapeutic agents for biotrauma in VILI.

Lipoprotein lipase (LPL), the enzyme that carries out the lipolytic processing of triglyceride-rich lipoproteins (TRLs), is synthesized by adipocytes and myocytes and secreted into the interstitial spaces. The LPL is then bound by GPIHBP1, a GPI-anchored protein of endothelial cells (ECs), and transported across ECs to the capillary lumen. The assumption has been that the LPL that is moved into capillaries remains attached to GPIHBP1 and that GPIHBP1 serves as a platform for TRL processing. In the current studies, we examined the validity of that assumption. We found that an LPL-specific monoclonal antibody (mAb), 88B8, which lacks the ability to detect GPIHBP1-bound LPL, binds avidly to LPL within capillaries. We further demonstrated, by confocal microscopy, immunogold electron microscopy, and nanoscale secondary ion mass spectrometry analyses, that the LPL detected by mAb 88B8 is located within the EC glycocalyx, distant from the GPIHBP1 on the EC plasma membrane. The LPL within the glycocalyx mediates the margination of TRLs along capillaries and is active in TRL processing, resulting in the delivery of lipoprotein-derived lipids to immediately adjacent parenchymal cells. Thus, the LPL that GPIHBP1 transports into capillaries can detach and move into the EC glycocalyx, where it functions in the intravascular processing of TRLs.

Abstract Background Endothelial cellular senescence is emerging as a key mechanism of age-related vascular dysfunction. Disruption of the endothelium glycocalyx and shedding of the syndecan (SDC) ectodomains have been associated with several age-related diseases. Although SDC4 is highly expressed in endothelial cells, its levels and shedding in senescent endothelial cells and vascular endothelial dysfunction associated with aging are still unknown. Methods To assess whether SDC4 expression was affected by inflammatory conditions, we evaluated its levels in young human umbilical vein endothelial cells (HUVECs) treated with TNF-α at a concentration of 50 ng/mL for 24 h and in cells undergoing replicative senescence. Plasma levels of SDC4 were evaluated in two previously recruited cohorts of (i) subjects with type 2 diabetes (T2D, n = 110) followed for a median of 16.8 years and age- and gender-matched healthy subjects (n = 100), and (ii) middle-aged subjects with mild-to-moderate dyslipidemia. Binomial logistic regression was used to assess whether SDC4 levels could be prognostic for major adverse cardiovascular events (MACE). Results In the in vitro study, we showed that HUVECs, when exposed to TNF-α or undergoing replicative senescence, exhibited elevated expression levels of SDC4 and matrix metallopeptidase 9 (MMP-9), as well as increased shedding of SDC4 into the extracellular microenvironment, in comparison to actively proliferating young HUVECs. Analysis of human samples revealed that patients with T2D without complications exhibited higher SDC4 levels compared to healthy controls and those with T2D vascular complications. In particular, patients with a history of major adverse cardiovascular events (MACE) had lower SDC4 levels. The longitudinal evaluation revealed that higher SDC4 levels predict the onset of new MACE during a 16.8-year follow-up. In the second cohort, no significant association was observed between SDC4 and endothelial dysfunction, assessed by flow-mediated dilation (FMD) or nitric oxide metabolites. SDC4 levels correlated positively with C-reactive protein (CRP) in both cohorts and with PAI-1 in the cohort of patients with T2D. Conclusion Overall, we conclude that the shedding of SDC4 from endothelial cells increases under acute (TNF-α treatment) and chronic (senescence) inflammatory conditions and that increased circulating SDC4 levels are associated with systemic inflammation in pathological aging.

Abstract The endothelial glycocalyx is damaged in postcardiac arrest syndrome (PCAS), but the prognostic value is unknown. We aimed to observe the expression and prognostic value of glycocalyx shedding products, including syndecan-1 (SDC-1), hyaluronan (HA), and heparan sulfate (HS) in PCAS. Data on clinical and 28-day outcomes of seventy-one consecutive patients with out-of-hospital cardiac arrest (OHCA) after the return of spontaneous circulation (ROSC) were collected. SDC-1, HA, and HS were measured on days 0, 1, and 3 after ROSC. Thirty healthy individuals were controls. Glycocalyx shedding was observed in human umbilical vein endothelial cells (HUVECs) stimulated during hypoxia and reoxygenation in vitro. Within 4 h of ROSC, SDC-1 and HA levels, significantly increased. In the 28-day non-survivors, HA levels showed a gradual upward trend, SDC-1 remained at a high level, and HS levels first increased, then decreased. Kaplan–Meier curves and binary logistic regression analysis showed the prognostic value of SDC-1 levels on days 0, 1, and 3, HA levels on days 1 and 3, and HS levels on day 1. Only HS levels on day 1 showed a prognostic value for 28-day neurological outcomes. SDC-1 and HA levels were positively correlated with the no-flow time. In vitro, HUVECs showed shedding of SDC-1 and HS during a prolonged duration of hypoxia. After ROSC, SDC-1, HA, and HS levels may predict the 28-day survival after PCAS, and HS levels are associated with functional outcomes.

Abstract Background Syndecan‐1 (SDC1) is an established marker of endothelial glycocalyx shedding. Most research on SDC1 has focused on plasma or serum concentrations, and little is known about urine concentrations. Objectives Measure urinary SDC1 concentrations in dogs undergoing anesthesia with either sevoflurane or isoflurane and assess the effects of anesthesia duration and IV crystalloids on urinary SDC1 concentrations. Animals Thirty‐one client‐owned dogs undergoing anesthesia for magnetic resonance imaging (MRI) with or without surgery for suspected intervertebral disk disease (IVDD) were used. Methods Dogs with suspected IVDD were randomized to undergo anesthesia with either sevoflurane or isoflurane. Urine was collected before and immediately after anesthesia for the analysis of SDC1. Urinary creatinine concentrations also were measured, and the ratio of urinary SDC1 to urinary creatinine (USCR) was used to account for dilution. Results Median (range) USCR was significantly higher after anesthesia compared with baseline for all groups combined (P

Abstract The present study aimed to investigate endothelial glycocalyx (eGCx) damage in cats with feline hemotropic mycoplasmosis caused by Mycoplasma haemofelis using selected biomarkers and to determine the diagnostic and prognostic significance of these biomarkers. The study included 25 cats with feline hemotropic mycoplasmosis and 10 healthy cats. Clinical examination, blood gas analysis, complete blood count, and biochemical analysis were performed. Hemotropic mycoplasmosis diagnosed by microscopic examination and molecularly confirmed by PCR targeting the Mycoplasma haemofelis 16s rRNA gene. To evaluate endothelial glycocalyx damage, syndecan-1, endothelin-1 (ET-1), asymmetric dimethylarginine (ADMA), and vascular endothelial growth factor-A (VEGF-A) concentrations were measured using cat-specific commercial ELISA kits. Of the cats with feline hemotropic mycoplasmosis, 14 (56%) survived and 11 (44%) died. While syndecan-1 and ET-1 concentrations were significantly higher in cats with hemotropic mycoplasmosis compared to the control group (p 0.05). Endothelial glycocalyx biomarkers showed significant correlations with each other and with hematological parameters (p

Aims: Cardiovascular disease remains a major global health concern, with atherosclerosis (AS) being a significant contributor. Vulnerable plaques play a critical role in acute cardiovascular events. Syndecan-1 (SDC-1), a vital membrane proteoglycan in the vascular endothelial glycocalyx, is believed to be associated with plaque progression. However, its precise relationship with severity and vulnerability of atherosclerotic plaque remains unclear. This study aimed to investigate SDC-1 expression and its potential correlation with plaque vulnerability in ApoE-/- atherosclerosis mouse model. Methods and results: Eight-week-old mice were induced into the AS model using a high-fat diet (HFD) and/or partial ligation of the left common carotid artery (PLCA), with a chow diet (CD) control group. After 16 weeks, plaques in the aortic root showed the following order: HFD + PLCA group > HFD group > CD + PLCA group > CD group. Immunohistochemistry revealed heightened accumulation of lipid/foam cells and CD68-labeled macrophages in the plaques, elevated vascular endothelial growth factor (VEGF), and matrix Metalloproteinase-9 (MMP-9) in the HFD + PLCA group's plaques, along with reduced collagen and α-SMA-labeled smooth muscle cells, resulting in the highest vulnerability index value. Immunohistofluorescence analysis of frozen plaque sections showed significantly higher SDC-1 expression in the AS mice group compared to the CD group, both positively correlated with plaque vulnerability. Serum analysis demonstrated elevated levels of SDC1, sphingosine 1-phosphate (S1P), and VEGF-A in the AS mice, all positively correlated with plaque vulnerability. Multivariate analysis identified SDC1 as an independent predictor of plaque vulnerability. Conclusion: This study enhances our understanding of plaque vulnerability mechanisms and presents SDC1 as a potential biomarker for atherosclerosis. These findings underscore the importance of addressing modifiable risk factors, such as diet and hemodynamics and suggest the utility of serum SDC1 as a valuable clinical marker. Ultimately, these insights may lead to more effective strategies in combating cardiovascular diseases and improving patient outcomes. [ABSTRACT FROM AUTHOR]