Showing papers on "Keratan sulfate published in 2011"
TL;DR: RFUVA as a diagnostic tool reveals that keratocan and lumican core proteins interact with collagen very differently than do mimecan and decorin, and causes cross-linking of collagen molecules among themselves and PG core proteins among themselves.
148 citations
Journal Article•
TL;DR: In this paper, a model reaction system using purified, non-glycosylated PG core proteins in solution in vitro has been compared with reactions inside an intact cornea, ex vivo, revealing effects of RFUVA on interactions between PGs and collagen cross-linking.
Abstract: Corneal cross-linking using riboflavin and ultraviolet-A (RFUVA) is a clinical treatment targeting the stroma in progressive keratoconus. The stroma contains keratocan, lumican, mimecan, and decorin, core proteins of major proteoglycans (PGs) that bind collagen fibrils, playing important roles in stromal transparency. Here, a model reaction system using purified, non-glycosylated PG core proteins in solution in vitro has been compared with reactions inside an intact cornea, ex vivo, revealing effects of RFUVA on interactions between PGs and collagen cross-linking. Irradiation with UVA and riboflavin cross-links collagen α and β chains into larger polymers. In addition, RFUVA cross-links PG core proteins, forming higher molecular weight polymers. When collagen type I is mixed with individual purified, non-glycosylated PG core proteins in solution in vitro and subjected to RFUVA, both keratocan and lumican strongly inhibit collagen cross-linking. However, mimecan and decorin do not inhibit but instead form cross-links with collagen, forming new high molecular weight polymers. In contrast, corneal glycosaminoglycans, keratan sulfate and chondroitin sulfate, in isolation from their core proteins, are not cross-linked by RFUVA and do not form cross-links with collagen. Significantly, when RFUVA is conducted on intact corneas ex vivo, both keratocan and lumican, in their natively glycosylated form, do form cross-links with collagen. Thus, RFUVA causes cross-linking of collagen molecules among themselves and PG core proteins among themselves, together with limited linkages between collagen and keratocan, lumican, mimecan, and decorin. RFUVA as a diagnostic tool reveals that keratocan and lumican core proteins interact with collagen very differently than do mimecan and decorin.
126 citations
TL;DR: The detection of GAG chains with specific probes and fluorescence microscopy provides for the first time a detailed analysis of their compartmentalization in the human retina, by both GAG chain type and sulfation pattern.
Abstract: PURPOSE. To map the distribution of different classes of glycosaminoglycans (GAGs) in the healthy human retina, choroid, and sclera. METHODS. Frozen tissue sections were made from adult human donor eyes. The GAG chains of proteoglycans (PGs) were detected with antibodies directed against various GAG structures (either directly or after pretreatment with GAG-degrading enzymes); hyaluronan (HA) was detected using biotinylated recombinant G1-domain of human versican. The primary detection reagents were identified with FITC-labeled probes and analyzed by fluorescence microscopy. RESULTS. Heparan sulfate (HS), chondroitin sulfate (CS), dermatan sulfate (DS), and HA were present throughout the retina and choroid, but keratan sulfate (KS) was detected only in the sclera. HS labeling was particularly strong in basement membrane-containing structures, the nerve fiber layer (NFL), and retinal pigment epithelium (RPE)-for example, intense staining was seen with an antibody that binds strongly to sequences containing 3-O-sulfation in the internal limiting membrane (ILM) and in the basement membrane of blood vessels. Unsulfated CS was seen throughout the retina, particularly in the ILM and interphotoreceptor matrix (IPM) with 6-O-sulfated CS also prominent in the IPM. There was labeling for DS throughout the retina and choroid, especially in the NFL, ganglion cell layer, and blood vessels. CONCLUSIONS. The detection of GAG chains with specific probes and fluorescence microscopy provides for the first time a detailed analysis of their compartmentalization in the human retina, by both GAG chain type and sulfation pattern. This reference map provides a basis for understanding the functional regulation of GAG-binding proteins in health and disease processes.
97 citations
TL;DR: It is concluded that KS is essential for, and has an impact comparable to that of CS on, postinjury plasticity, and CS and KS are independent requirements for the proteoglycan-mediated inhibition of axonal regeneration/sprouting.
Abstract: Chondroitin sulfate (CS) proteoglycans are strong inhibitors of structural rearrangement after injuries of the adult CNS. In addition to CS chains, keratan sulfate (KS) chains are also covalently attached to some proteoglycans. CS and KS sometimes share the same core protein, but exist as independent sugar chains. However, the biological significance of KS remains elusive. Here, we addressed the question of whether KS is involved in plasticity after spinal cord injury. Keratanase II (K-II) specifically degraded KS, i.e., not CS, in vivo. This enzyme digestion promoted the recovery of motor and sensory function after spinal cord injury in rats. Consistent with this, axonal regeneration/sprouting was enhanced in K-II-treated rats. K-II and the CS-degrading enzyme chondroitinase ABC exerted comparable effects in vivo and in vitro. However, these two enzymes worked neither additively nor synergistically. These data and further in vitro studies involving artificial proteoglycans (KS/CS-albumin) and heat-denatured or reduced/alkylated proteoglycans suggested that all three components of the proteoglycan moiety, i.e., the core protein, CS chains, and KS chains, were required for the inhibitory activity of proteoglycans. We conclude that KS is essential for, and has an impact comparable to that of CS on, postinjury plasticity. Our study also established that KS and CS are independent requirements for the proteoglycan-mediated inhibition of axonal regeneration/sprouting.
79 citations
TL;DR: The patterns of expression of these SLRPs in the uterine tissues were found to be hormone-dependent and uterine compartment-related, reinforcing the existence of subpopulations of endometrial fibroblasts, localized into distinct functional uterine compartments, resembling the organization into basal and functional layers of the human endometrium.
Abstract: We have previously demonstrated that four members of the family of small leucine-rich-proteoglycans (SLRPs) of the extracellular matrix (ECM), named decorin, biglycan, lumican and fibromodulin, are deeply remodeled in mouse uterine tissues along the estrous cycle and early pregnancy. It is known that the combined action of estrogen (E2) and progesterone (P4) orchestrates the estrous cycle and prepares the endometrium for pregnancy, modulating synthesis, deposition and degradation of various molecules. Indeed, we showed that versican, another proteoglycan of the ECM, is under hormonal control in the uterine tissues. E2 and/or medroxiprogesterone acetate (MPA) were used to demonstrate, by real time PCR and immunoperoxidase staining, respectively, their effects on mRNA expression and protein deposition of these SLRPs, in the uterine tissues. Decorin and lumican were constitutively expressed and deposited in the ECM in the absence of the ovarian hormones, whereas deposition of biglycan and fibromodulin were abolished from the uterine ECM in the non-treated group. Interestingly, ovariectomy promoted an increase in decorin, lumican and fibromodulin mRNA levels, while biglycan mRNA conspicuously decreased. Hormone replacement with E2 and/or MPA differentially modulates their expression and deposition. The patterns of expression of these SLRPs in the uterine tissues were found to be hormone-dependent and uterine compartment-related. These results reinforce the existence of subpopulations of endometrial fibroblasts, localized into distinct functional uterine compartments, resembling the organization into basal and functional layers of the human endometrium.
36 citations
TL;DR: Internal amino acid sequencing using nano-LC/MS/MS revealed that the salmon proteoglycan was aggrecan, and the ratio of serine attached to sugar chains was calculated to be approximately 37.7% of total serine, that is, 46 of 123 serine residues.
32 citations
TL;DR: It is suggested that amastigote invasion also involves host cell surface heparan sulfate proteoglycans, which may provide new potential candidates for Chagas disease therapy.
Abstract: Cell surface glycosaminoglycans (GAGs) play an important role in the attachment and invasion process of a variety of intracellular pathogens. We have previously demonstrated that heparan sulfate proteoglycans (HSPG) mediate the invasion of trypomastigote forms of Trypanosoma cruzi in cardiomyocytes. Herein, we analysed whether GAGs are also implicated in amastigote invasion. Competition assays with soluble GAGs revealed that treatment of T. cruzi amastigotes with heparin and heparan sulfate leads to a reduction in the infection ratio, achieving 82% and 65% inhibition of invasion, respectively. Other sulfated GAGs, such as chondroitin sulfate, dermatan sulfate and keratan sulfate, had no effect on the invasion process. In addition, a significant decrease in infection occurred after interaction of amastigotes with GAG-deficient Chinese Hamster Ovary (CHO) cells, decreasing from 20% and 28% in wild-type CHO cells to 5% and 9% in the mutant cells after 2 h and 4 h of infection, respectively. These findings suggest that amastigote invasion also involves host cell surface heparan sulfate proteoglycans. The knowledge of the mechanism triggered by heparan sulfate-binding T. cruzi proteins may provide new potential candidates for Chagas disease therapy.
30 citations
TL;DR: It is demonstrated that lumican significantly differs from that of fibromodulin in the deformed disc and that IL-1 β induces a significant increase in lumican mRNA, but not in fibrommodulin mRNA, after 24∼48 h culture compared to cells cultured in the absence of IL- 1 β (P<0.05).
Abstract: Small leucine-rich repeat proteoglycans (SLRP) are present in the extracellular matrix of the temporomandibular joint (TMJ) disc. Lumican and fibromodulin, classified as class 2 SLRPs, play important roles in TMJ assembly, proliferation and inflammation. Degenerative change in the TMJ disc gives rise to the process of internal derangement (ID). In this study, we immunohistochemically examined the expression of lumican and fibromodulin in nine human TMJ specimens and examined the gene expression of both proteoglycans in cultured human TMJ disc cells under interleukin-1 beta (IL-1 β)-stimulated conditions. An articular disc cell line was established by collagenase treatment of a TMJ disc. The subcultured cells were then incubated for 1, 3, 6, 12, 24 or 48 h under both normal and IL-1 β (1 ng/mL) conditions. The gene expression of lumican and fibromodulin was examined using the reverse transcription-polymerase chain reaction (RT-PCR) and real-time RT-PCR. We demonstrated that the expression of lumican significantly differs from that of fibromodulin in the deformed disc and that IL-1 β induces a significant increase in lumican mRNA, but not in fibromodulin mRNA, after 24~48 h culture compared to cells cultured in the absence of IL-1 β (P<0.05). These results indicate that lumican and fibromodulin display different behaviors and that lumican may promote regeneration of the TMJ after degeneration and deformation induced by IL-1 β.
29 citations
TL;DR: FGF-2- and TGF-β1-activation of JNK signaling pathway may be partly responsible for the downregulation of keratocan and lumican expression in activated corneal keratocytes observed during cornesal stromal wound healing.
Abstract: The cornea is a transparent avascular refractive structure consisting of three tissue layers, epithelium, stroma, and endothelium. A well-organized extracellular matrix (ECM) containing densely packed and regularly spaced thin collagen fibrils of uniform diameter, is largely responsible for transparency in the corneal stroma.1–3 Keratan sulfate proteoglycans (KSPGs) in the stromal ECM play a critical role in the development and maintenance of corneal transparency. Keratocan and lumican, the major KSPGs in the corneal stroma, regulate both fibril diameter and interfibrillar spacing as evident from the phenotype of lumican and keratocan knockout mice.4–9 Keratocan knockout mice have a thinner corneal stroma with irregular collagen fibril organization compared with the normal mice,8 and lumican knockout mice have increased collagen fibril diameter and develop opaque corneas.4,5
Corneal stromal cells (keratocytes), which synthesize keratocan and lumican during development, become quiescent in a fully-developed cornea. However, after an injury to the cornea, growth factors and cytokines originating from corneal epithelial cells, inflammatory cells, and tear fluid activate the keratocytes to fibroblast or myofibroblast phenotypes (reviews, see Refs. 10–14). Keratocan and lumican synthesis is downregulated in the activated keratocytes during wound healing.15–18 KSPG expression is also downregulated in vitro when cultured keratocytes are activated with growth factors including FGF-2 and TGF-β1.19–23 Therefore, an in vitro model of keratocyte activation is useful to study the signaling mechanisms that downregulate the expression of KSPGs. We had previously demonstrated that activation of the small GTPase Rho and its downstream target Rho kinase (ROCK) regulate several undesirable phenotypic changes including the downregulation of KSPGs in the activated keratocytes.23 Jun N-terminal kinase (JNK), a member of the mitogen activated protein kinase (MAPK) family, has been shown to mediate some of the Rho/ROCK regulated events.24–26 The present study was designed to investigate whether JNK activation is responsible for the observed TGF-β1– and FGF-2–induced downregulation of KSPGs in activated keratocytes.
26 citations
TL;DR: Observations indicate that GlcN may exhibit chondroprotective action on joint diseases such as OA by modulating the expression of HA-synthesizing enzymes and inducing the production of HA (a major component of GAG contained in synovial fluid) especially bysynovial cells.
Abstract: Glucosamine (GlcN) has been widely used to treat osteoarthritis (OA) in humans. However, its chondroprotective action on the joint is poorly understood. In this study, to elucidate the chondroprotective action of GlcN, we examined the effects of GlcN-derivatives (GlcN and N-acetyl-D-glucosamine) and uronic acids (D-glucuronic acid and D-galacturonic acid) (0.1-1 mM) on the production of glycosaminoglycans (GAG), such as hyaluronic acid (HA), keratan sulfate and sulfated GAG by human synovial cells and chondrocytes. The results indicate that among GlcN-derivatives and uronic acids, GlcN but not N-acetyl-D-glucosamine, D-glucuronic acid and D-galacturonic acid induce the production of HA by synovial cells and chondrocytes at >0.25 and >0.1 mM (p 10-fold) in synovial cells compared to chondrocytes. In contrast, neither N-acetyl-D-glucosamine, D-glucuronic acid nor D-galacturonic acid affected the production of keratan sulfate and sulfated GAG by these cells. Moreover, the experiments with 3H-labeled GlcN indicated that GlcN can be incorporated and utilized for the production of GAG (including HA) by synovial cells and chondrocytes. In addition, GlcN (1 mM) up-regulates the expression of HA-synthesizing enzymes (hyaluronan synthases) in synovial cells and chondrocytes. Together these observations indicate that GlcN may exhibit chondroprotective action on joint diseases such as OA by modulating the expression of HA-synthesizing enzymes and inducing the production of HA (a major component of GAG contained in synovial fluid) especially by synovial cells.
25 citations
TL;DR: The proteomes will provide an insight into the lumican-deficient corneal phenotype of stromal thinning and loss of transparency and a better understanding of pathogenic changes in Corneal and ocular dystrophies.
Patent•
30 Jun 2011
TL;DR: In this paper, a first component, namely hyaluronic acid (HA), in combination with at least one stabilizer is provided for treating joint conditions, such as osteoarthritis and/or the pain associated therewith.
Abstract: Compositions and methods are provided for treating joint conditions, such as osteoarthritis and/or the pain associated therewith. The compositions and methods utilize a first component, namely hyaluronic acid (“HA”), in combination with at least one stabilizer. The composition can include a stabilizer that increases the stability and shelf-life of the HA. In another embodiment, the compositions and methods can also include an additional component, such as one or more glycosaminoglycans (“GAG”) or GAG precursors. Examples of GAGs or GAG precursors can include chondroitin sulfate (“CS”), dermatan sulfate, heparin, heparan sulfate, keratan sulfate, and glucosamine (“GlcN”).
TL;DR: V Vestigial KS chain or altered glycosylation in articular cartilage in GlcNAc6ST-1(-/-) mice may be protective against arthritis and associated cartilage damage as well ascartilage damage in culture.
TL;DR: Investigation of the possible mutations in the carbohydrate sulfotransferase 6 (CHST6) gene of 2 unrelated cases of macular corneal dystrophy confirmed the diagnosis of MCD in both cases and reported atypical stromal deposits in one of them.
Abstract: PURPOSE To investigate the possible mutations in the carbohydrate sulfotransferase 6 (CHST6) gene of 2 unrelated cases of macular corneal dystrophy (MCD) and to report atypical stromal deposits in one of them. METHODS Corneal tissues were stained with antisulfated keratan sulfate (KS), antitransforming growth factor beta 1-induced protein (TGFBIp), thioflavin-T, alcian blue, and Masson trichrome. Sequencing was performed to identify potential mutations in the CHST6 gene and the fourth and twelfth exons of the TGFBI gene. RESULTS Alcian blue staining revealed the presence of multiple subepithelial and intrastromal mucopolysaccharide deposits, confirming the diagnosis of MCD in both cases. Immunofluorescence staining in case 1 revealed the presence of sulfated KS only in the keratocytes and select endothelial cells, consistent with MCD type IA. Preferential expression of sulfated KS was observed in keratocytes and extracellular stromal matrix in case 2, consistent with MCD type II. Atypical subepithelial and superficial stromal deposits were observed in case 1, which stained positively with alcian blue, eosin, Masson trichrome, and thioflavin-T indicating the presence of hyaline and amyloid materials. CHST6 gene sequencing revealed 2 heterozygous mutations in case 1 (a p.Arg211Gln and a novel mutation of p.Arg177Gly) and a novel homozygous mutation of p.Pro186Arg in case 2. No mutations were found in exons 4 or 12 of the TGFBI gene in case 1. CONCLUSIONS Secondary hyalinosis and amyloidosis occur in a case of MCD type IA with a novel p.Arg177Gly mutation in CHST6. A novel p.Pro186Arg mutation in CHST6 is associated with MCD type II in an African American.
TL;DR: Glycosaminoglycans that accumulated in inflammatory fluids or used as a therapeutic drug (e.g., heparin) could act as pro- or anti-inflammatory mediators depending on different factors within the cell environment.
TL;DR: The aim of this study was to investigate the feasibility of utilizing this approach to evaluate the codistribution of more than one molecule of interest in a single tissue section.
Abstract: Objectives/Hypothesis: Immunofluorescence staining methods have been developed to study the distribution of macromolecules in archival formalin-fixed celloidin-embedded human temporal bone tissues. The aim of this study was to investigate the feasibility of utilizing this approach to evaluate the codistribution of more than one molecule of interest in a single tissue section. Study Design: Retrospective study of proteoglycan codistribution in archival human temporal bone tissues. Methods: The chondroitin sulfate and keratan sulfate proteoglycans were selected for evaluating this methodology. Human tissues with known proteoglycan staining patterns were studied as controls. Thirty-one formalin-fixed celloidin-embedded archival human temporal bones were evaluated, and the observations in 11 specimens are described. A dual immunofluorescence staining method was developed using primary antibodies of differing isotypes and secondary antibodies labeled with fluorophores having nonoverlapping emission characteristics. Results: The specificity of the dual immunofluorescence technique for chondroitin sulfate and keratan sulfate proteoglycans was demonstrated in control tissues and confirmed through inhibition studies. The normal human tectorial membrane exhibited intense chondroitin sulfate staining. Cochlear and vestibular hair cells exhibited predominantly keratan sulfate staining. Keratan sulfate staining predominated in spiral ganglion cell bodies and fibers. Alterations in the normal distribution pattern of proteoglycans were observed in cases of presbycusis and otosclerosis. Conclusions: The dual immunofluorescence staining methodology can be used to study archival formalin-fixed celloidinembedded human temporal bone tissues. This technique may be applied to the evaluation of other molecules in archival human temporal bone tissues and lead to improvement in our understanding of the function of these molecules and their role in disease processes.
Patent•
23 Feb 2011
TL;DR: In this article, the purpose of the present invention is to find a ligand for a DCIR and to search for a stimulant and an antagonist for the DCIR, which is the main purpose of this paper.
Abstract: The purpose of the present invention is to find a ligand for a DCIR and to search for a stimulant and an antagonist for the DCIR.
Specifically disclosed are: a dendritic cell immunoreceptor stimulant which contains keratan sulfate II (KS-II) as an active ingredient; an antibody against a dendritic cell immunoreceptor, which has a dendritic cell immunoreceptor stimulating action similar to that of keratan sulfate II; and an antibody against a dendritic cell immunoreceptor, which has a keratan sulfate II inhibitory dendritic cell immunoreceptor antagonistic action.
TL;DR: It was found that since the age of 2 months, bone mineral density in OXYS rats was lower than in Wistarrats, and there was general lack of keratan sulfate in the bone tissue of OxYS rats.
Abstract: Proteoglycans (PGs) play a famous role in bone tissue formation promoting collagen fibers consolidation and their connection with crystals of minerals. We have analyzed extracellular matrix PGs in the humerus of early aging OXYS rats with early symptoms of osteoporosis and Wistarrats aged 2, 4, 6, and 8 months. We found that since the age of 2 months, bone mineral density in OXYS rats was lower than in Wistarrats. Bone mineral density in OXYS rats increased until the rats were 6 months old, but in Wistarrats it increased during the entire monitoring period. In Wistarrats the formation of bone tissue peak mass was accompanied by changes of PGs pools in the bone matrix: the amount of high molecular weight PGs containing keratan sulfate increased, but the amount of uronic acid and sulfated glycosaminoglycans decreased. In the bone matrix of OXYS rats, the amount of uronic acid and sulfated glycosaminoglycans and chondroitin sulfate AC and dermatan sulfate increased. Unlike in Wistarrats, there was general lack of keratan sulfate in the bone tissue of OXYS rats.