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Introduction to Oral and Craniofacial Tissue Engineering
Published in Vincenzo Guarino, Marco Antonio Alvarez-Pérez, Current Advances in Oral and Craniofacial Tissue Engineering, 2020
María Verónica Cuevas González, Eduardo Villarreal-Ramírez, Adriana Pérez-Soria, Pedro Alberto López Reynoso, Vincenzo Guarino, Marco Antonio Alvarez-Pérez
In contrast to the predominantly fibrillar structure of collagen and elastin, proteoglycans adopt highly extended conformations that are essential for hydrogel constitution (Mouw et al. 2014). The hydrogel molecules support the high compression forces in the extracellular matrix, around the cells and interstitial matrix. As stated above, the biological function of proteoglycans derives from the biochemical and hydrodynamic properties of the GAG macromolecules, which combine chemically with water to provide hydration and compression resistance. GAG has been classified into subtypes according to the function and structure of these carbohydrate chains, as well as the distribution, density and length of these chains concerning the core protein (Iozzo and Schaefer 2015). The most common GAG chains found in the ECM are heparin sulfate, chondroitin sulfate, dermatan sulfate, hyaluronan and keratin sulfate. The proteoglycans are encoded by a little less than 50 genes, besides several of them can be subject to alternative splicing, which shows the enormous variety of members of proteoglycans present in the matrix. They also have a vast range of functions such as cell adhesion, migration, proliferation, signaling, communication, morphogenesis and growth. In turn, proteoglycans also participate in angiogenesis, the inflammatory response to pathogens and injuries (Kresse and Schönherr 2001; Iozzo and Schaefer 2015). After having explained the unique features, functions and essential members of the extracellular matrix some techniques to replicate or mimic the extracellular matrix need to be shown.
Experimental Arthritis
Published in Thomas F. Kresina, Monoclonal Antibodies, Cytokines, and Arthritis, 2020
Wim B. van den Berg, Maries F. van den Broek, Levinus B. A. van de Putte, Mieke C. J. van Bruggen, Peter L. E. M. van Lent
There is no doubt that adjuvant arthritis is T cell dependent. The strongest argument for an autoimmune process is the induction of arthritis by passive transfer of T cells from diseased animals (13). The pathogenetic mechanism has been further explored using T cell lines and clones reactive to Mycobacterium tuberculosis (Mt). Holoshitz et al. (14–16) showed that a T cell line, called A2, isolated from AA Lewis rats and further selected in vitro with Mt, could induce arthritis in irradiated syngeneic recipients. Subsequent cellular cloning yielded the arthritogenic T cell clone A2b. This clone did not show reactivity with collagen type II, which underscores the claim of different pathogenetic pathways in AA and CIA (17). Further characterization of reactivity revealed distinct responsiveness to cartilage proteoglycans (18). That the clone could induce arthritis only in irradiated recipients suggests that tolerance exists in normal animals against such threatening autoimmune responses. Further suggestive evidence for the existence of tolerance against proteoglycans, which is regulated by cross-reactive responses to bacteria, comes from the observations in germ-free animals. Pathogen-free or coventionally bred F344 are generally resistant to adjuvant arthritis, whereas germ-free F344 rats are highly susceptible. Colonization of the germ-free rats with gram-negative bacteria again suppressed the disease susceptibility (19,20). This issue is addressed later in the discussion of SCW arthritis.
Fascial Anatomy
Published in David Lesondak, Angeli Maun Akey, Fascia, Function, and Medical Applications, 2020
Ground substance provides viscosity and plasticity to the tissues. The ground substance is composed of water and GAGs (glycosaminoglycans). Ground substance itself is a gel-like material including extrafibrillar matrix, but no collagen or elastin fibers. In other words, the collagen and elastin fibers create the previously mentioned three-dimensional network, and the ground substance surrounds and fills the empty spaces. GAGs are long-chained polysaccharides attached to a core protein of the proteoglycan. Several different groups of GAGs have been identified. The most common are: hyaluronan, chondroitin-sulfate, dermatan sulfate, and heparan sulfate (Figure 2.5). Extra cellular proteins stabilize the aggregates of proteoglycans and together form a “bottle-brush-like” structure. GAGs have a negative charge and this attracts water, forming a hydrated gel. This gel is responsible for turgidity and viscoelasticity as well as for controlling the diffusion of various metabolites.4,12
Clinical development of an anti-GPC-1 antibody for the treatment of cancer
Published in Expert Opinion on Biological Therapy, 2022
Saikat Ghosh, Pie Huda, Nicholas Fletcher, Douglas Campbell, Kristofer J. Thurecht, Bradley Walsh
Proteoglycans are composed of glycosylated proteins with covalently attached glycosaminoglycan (GAG) chains [1]. In 1990, David et al. reported their seminal investigation of a novel membrane-associated proteoglycan present in human lung fibroblasts [2]. The cDNA of the proteoglycan was cloned and sequenced by the research group and the core protein was found to contain short hydrophobic amino acid sequences at its C-terminus without a proper cytoplasmic domain. Both these features were reminiscent of membrane-bound phosphatidylinositol-anchored proteins. At the time, the process of phospholipid anchoring through an enzyme-catalyzed transamidation reaction was known as glypiation. This led to proposal of the name ‘Glypican’ by David et al. for the newly discovered ‘glypiated proteoglycan.’
Skin proteomics – analysis of the extracellular matrix in health and disease
Published in Expert Review of Proteomics, 2020
Jörn Dengjel, Leena Bruckner-Tuderman, Alexander Nyström
Additional key regulators of collagen fibrillogenesis are proteoglycans and matricellular proteins. Decorin, a dermatan sulfate/chondroitin sulfate SLRP, and versican, a chondroitin sulfate proteoglycan, are the most abundant proteoglycans in the skin [84]. Decorin shows a higher abundance in the papillary ECM and versican in the reticular ECM [84,85]. The importance of these proteoglycans in the skin is reflected by skin fragility in decorin-deficient mice [86] and in dermatan sulfate-deficient humans [87]. Despite being of lower abundance, also other proteoglycans are important regulators of collagen fibrillogenesis in the dermis. These include the SLRPs biglycan, lumican and fibromodulin [88]. Proteoglycans can be present without GAG substitution as just the protein core. Furthermore, although not a protein, the GAG hyaluronan, which is distributed throughout the skin, shows its highest abundance in the papillary dermis [89].
Systemic drugs with impact on osteoarthritis
Published in Drug Metabolism Reviews, 2019
Dragos Apostu, Ondine Lucaciu, Alexandru Mester, Daniel Oltean-Dan, Mihaela Baciut, Grigore Baciut, Simion Bran, Florin Onisor, Andra Piciu, Roxana D. Pasca, Andrei Maxim, Horea Benea
Proteoglycans are produced by chondrocytes and represent between 10-20% of cartilage weight, providing the compressive strength of the articular cartilage (Bhosale and Richardson 2008). There are two main classes of proteoglycans: large aggregating proteoglycan monomers such as aggrecans or versican, and smaller proteoglycans such as decorin, biglycan, epiphycan, lumican and fibromodulin (Roughley 2001; Bhosale and Richardson 2008). The most common matrix molecule is the proteoglycan aggrecan, which forms macromolecular aggregates with hyaluronic acid (Poole et al. 2002). Aggrecan has in its structure glycosaminoglycan (GAG) side chains of chondroitin sulfate and keratin sulfate (Bhosale and Richardson 2008; Goldring 2012). The negatively charged chondroitin sulfate and keratin sulfate chains have the ability to bind water, thus creating a structure that provides good resistance for deformation and for compression (Poole et al. 2002; Bhosale and Richardson 2008; Titorencu et al. 2010).