China
Africa
Explore chapters and articles related to this topic
The Beneficial Effect of Omega-3 PUFA and L-Arginine on Endothelial Nitric Oxide (NO) Bioavailability
Published in Robert Fried, Richard M. Carlton, Flaxseed, 2023
Robert Fried, Richard M. Carlton
Cells defective of glycosylation, having a thinner glycocalyx, showed increased attachment of neutrophils. Hence, in normal conditions, the soluble components of the glycocalyx seem to shield adhesion molecules, thereby preventing interaction. Stimuli that degrade the glycocalyx or induce a more open mesh, such as enzymes, cytokines or ischemia and reperfusion, appear to uncover the adhesion molecules, which, in turn, allows blood cells to interact with the endothelium, which, again, is bad because it favors clot formation. (22)
Carbohydrate Histochemistry
Published in Joan Gil, Models of Lung Disease, 2020
Bradley A. Schulte, Russell A. Harley, Samuel S. Spicer
Highly specialized cells line the airways and alveoli of the adult respiratory tract. These cells produce diverse GCs that form the glycocalyx at the cell’s surface. We have little knowledge about the structure of GCs that form the glycocalyx of respiratory tract epithelial cells, since the glycocalyx of one cell type is not biochemically separable from that of another and glycocalyx GCs cannot be reliably isolated from the more abundant secretory glycoproteins that form the mucous surface coat. Cytochemistry provides advantages over biochemical methods for analyzing cell surface components including (1) revealing differences in the structure of the glycocalyx of histologically different cell types, (2) providing the capacity to show differences in GCs of the apical and the basolateral plasmalemma of a cell, and (3) showing changes in the chemical nature of a given cell’s surface during fetal and postnatal development or resulting from pathological change or experimental manipulation.
Control of the Large Bowel Microflora
Published in Michael J. Hill, Philip D. Marsh, Human Microbial Ecology, 2020
Bohumil S. Drasar, April K. Roberts
As implied above, infants can only be colonized by the bacteria to which they are exposed, and those organisms that persist are capable of forming relatively permanent communities on the gut mucus surface. Many organisms produce a glycocalyx that acts as an anchor for the organism. Bacteria such as Escherichia coli produce fimbriae that extend from the cell wall and may act as specific adhesions anchoring the cell to the mucus layer. The glycocalyx also provides a local protected environment for bacterial growth, allowing multiplication and helping the formation of microcolonies. The glycocalyxes of several different organisms may intermingle to form a diverse community which is in effect co-operatively attached to the mucosa.28 Thus, for initial colonization, attachment/adhesion must be among the predominant influences. The role of metabolic end products and diet is more important in the later stages of community development.
HYAL1 deficiency attenuates lipopolysaccharide-triggered renal injury and endothelial glycocalyx breakdown in septic AKI in mice
Published in Renal Failure, 2023
Hongxia Xing, Shensen Li, Yongchao Fu, Xin Wan, Annan Zhou, Feifei Cao, Qing Sun, Nana Hu, Mengqing Ma, Wenwen Li, Changchun Cao
As a protective barrier with delicate latticework structure, glycocalyx is located on the luminal surface of vascular endothelium and exerts protective effects on endothelial cells [64]. Endothelial glycocalyx can inhibit intravascular coagulation and regulate leukocyte migration to maintain the permeability of endothelium [65]. Syndecan (a proteoglycan) and hyaluronan (a glyocosaminoglycan) are essential for maintenance of endothelial glycocalyx integrity [66]. The glycocalyx performs important physiological functions by transmission to the endothelial surface and shielding it from access by cellular components in the bloodstream [67]. Sepsis resulted in degradation of the endothelial glycocalyx, which is associated with impaired vascular permeability [11]. In our study, injection of LPS contributed to reduction in syndecan-1 level, and elevation of heparanase-1 level, hyaluronidase activity and hyaluronic acid, all of which were offset by silenced HYAL1. Moreover, kidney endothelium glycocalyx layer in the sham-operated mice remained complete and continuous, while the renal capillary glycocalyx of the LPS-treated mice was not continuous with loose and thin structure. Thus, we concluded that deficiency of HYAL1 protected against LPS-induced renal endothelial glycocalyx degradation in septic AKI in vivo.
Cell membrane-camouflaged PLGA biomimetic system for diverse biomedical application
Published in Drug Delivery, 2022
Jingjing Yan, Weidong Fei, Qianqian Song, Yao Zhu, Na Bu, Li Wang, Mengdan Zhao, Xiaoling Zheng
Erythrocytes or red blood cells (RBCs) are the most numerous blood cells in the systemic circulation. In the last century, researchers have developed RBC-based drug carriers via encapsulation or adsorption onto membranes (Mao et al., 2021). The red blood cell membrane (RBCM) possesses the merits of RBC, especially long circulation time and biocompatibility. The transmembrane protein CD47, which is a self-marker, presents ‘do not eat me’ signals to phagocytes (Oldenborg et al., 2000). Moreover, a dense coat of polysaccharides, called ‘glycocalyx’, exhibits spatial stability and also plays a vital role in immune escape. By harnessing the biocompatibility of RBCM coating on PLGA NPs, the acute inflammatory response of the biomaterial scaffold can be eliminated (Fan et al., 2018). Compared with PEGylation, RBCM derived-NPs have twice the cycle time (39.6 h vs. 15.8 h) (Hu et al., 2011). However, the disadvantages of RBCM coating technology are lack of targeting and weak tissue penetration, which inspired scientists to develop other biofilms.
Surface charge, glycocalyx, and blood-brain barrier function
Published in Tissue Barriers, 2021
Fruzsina R. Walter, Ana R. Santa-Maria, Mária Mészáros, Szilvia Veszelka, András Dér, Mária A. Deli
The brain endothelial surface glycocalyx is a sugar-protein matrix layer covering the luminal surface that is mainly composed of proteoglycans, glycoproteins, and glycosaminoglycans (GAGs), as detailed in a recent review.17 The endothelial glycocalyx acts as a mechanosensor to detect blood flow induced shear stress and modulates signaling pathways, gene expression, endothelial function and morphology.18,19 The basic structure of the glycocalyx consists of core proteins and long GAG side chains attached to them. The three negatively charged GAGs present in the glycocalyx of endothelial cells are hyaluronic acid, chondroitin sulfate and heparan sulfate (Figure 1).18 Heparan sulfate is the most abundant endothelial GAG, and is attached to core proteins such as transmembrane proteins syndecans and the membrane-bound protein glypican.18,19 The glycocalyx thickness of endothelial cells (0.2–5 µm) varies depending on the organ and different parts of the vascular bed20 as well as on the regions within cultured brain endothelial cells.21 Mostly sialo-glycoconjugates and heparan sulfate proteoglycans provide the negative charge barrier at the BBB as revealed by enzyme digestions combined with ultrastructural studies in mouse brain cortex.22