Chondroitin

Distribution by Scientific Domains
Distribution within Life Sciences

Terms modified by Chondroitin

  • chondroitin sulphate
  • chondroitin sulphate proteoglycan

  • Selected Abstracts


    THE FREE RADICAL-SCAVENGING PROPERTY OF CHONDROITIN SULFATE FROM PIG LARYNGEAL CARTILAGE IN VITRO

    JOURNAL OF FOOD BIOCHEMISTRY, Issue 1 2007
    SHUANG-LI XIONG
    ABSTRACT This study compared the free radical-scavenging properties of chondroitin sulfate (ChS) from pig laryngeal cartilage and its reduced or sulfonated derivatives. The binding behavior between Cu2+ and ChS and its derivatives, and the interaction between superoxide radical and ChS were studied by fluorescence quenching, equilibrium dialysis, infrared spectra and thermal analysis. Purified ChS inhibited the generation of hydroxyl radical and scavenged superoxide radical in a concentration-dependent manner. Reduced ChS did not scavenge hydroxyl radical and superoxide radical. Sulfonated ChS had no hydroxyl radical scavenging activity but scavenged superoxide radical as strongly as purified ChS. ChS showed strong binding activity with Cu2+ in deionized water but not in 0.01-M HCl. Both reduced ChS and sulfonated ChS did not exhibit such chelating behavior. The structural basis of hydroxyl radical inhibiting of ChS was attributed to a complex of the Cu2+ with the carboxyl group of glucuronic acid residue. The reaction of superoxide radical with the sulfate ester and the carboxyl group may be the basis of superoxide radical scavenging activity of ChS. [source]


    Developmental change and function of chondroitin sulfate deposited around cerebellar Purkinje cells

    JOURNAL OF NEUROSCIENCE RESEARCH, Issue 2 2005
    Yumiko Shimazaki
    Abstract Chondroitin sulfate is a long sulfated polysaccharide with enormous structural heterogeneity that binds with various proteins, such as growth factors, in a structure-dependent manner. In this study, we analyzed the expression of chondroitin sulfate in the postnatally developing cerebellar cortex by using three monoclonal antibodies against chondroitin sulfate, MO-225, 2H6, and CS-56, which recognize different structural domains in this polysaccharide. During the first postnatal week, the patterns of immunohistochemical staining made by these antibodies were quite similar, and the molecular layer, the granule cell layer, and Bergmann glial fibers in the external granular layer were densely stained. After postnatal day 12 (P12), the expression of 2H6 epitopes was down-regulated in the molecular layer, and the expression of CS-56 epitopes in this layer was also reduced after P16. On the other hand, the strong expression of MO-225 epitopes, GlcA(2S),1,3GalNAc(6S) (D unit)-containing structures, remained until adulthood. These chondroitin sulfate epitopes were observed around Purkinje cells, including cell soma and dendrites. Detailed immunohistochemical analysis suggested that chondroitin sulfate was deposited between Purkinje cell surfaces and the processes of Bergmann glia. Furthermore, the amount of pleiotrophin, a heparin-binding growth factor, in the cultured cerebellar slices was remarkably diminished after treatment with chondroitinase ABC or D unit-rich chondroitin sulfate. With the previous findings that pleiotrophin binds to D unit-rich chondroitin sulfate, we suggest that the D-type structure is important for the signaling of pleiotrophin, which plays roles in Purkinje cell,Bergmann glia interaction, and that the structural changes of chondroitin sulfate regulate this signaling pathway. © 2005 Wiley-Liss, Inc. [source]


    Occlusal hypofunction causes changes of proteoglycan content in the rat periodontal ligament

    JOURNAL OF PERIODONTAL RESEARCH, Issue 1 2001
    S. Kaneko
    The biological functions of proteoglycans and glycosaminoglycans are closely associated with mechanical stress on the tissue. In order to reveal the relationship between proteoglycans in the periodontal ligament and mechanical stress such as occlusal stimuli, occlusal hypofunction of rat unilateral mandibular molars was induced by extraction of the opposing first, second and third maxillary molars. Immunohistochemical analyses were performed using antibodies for chondroitin sulfate, decorin, biglycan, heparan sulfate and keratan sulfate, and hyaluronic acid-binding protein. Chondroitin sulfate, observed more strongly in the cervical side than in the apical side of the periodontal ligament of the unextracted sides of mandible, and uniformly present in the extracellular matrix of the periodontal ligament, decreased significantly from 1 wk post-extraction of the antagonists, with a decrease in thickness and disarrangement in fibrous components. Decorin core protein, uniformly present in the periodontal ligament of the unextracted sides, decreased as early on as 2 d post-extraction. Heparan sulfate, mainly localized on the cell surface of vascular endothelial cells and osteoclastic cells as well as in the extracellular matrix of the unextracted sides, decreased significantly in association with the decreased number of blood vessels and osteoclastic cells as early on as 2 d post-extraction. Biglycan, keratan sulfate and hyaluronic acid, uniformly distributed in the periodontal ligament of the unextracted sides, showed little change after the extraction. These results demonstrate that occlusal hypofunction causes tissue remodeling of the periodontal ligament, with a significant decrease of chondroitin sulfate, decorin and heparan sulfate. [source]


    Analytical aspects of pharmaceutical grade chondroitin sulfates

    JOURNAL OF PHARMACEUTICAL SCIENCES, Issue 12 2007
    Nicola Volpi
    Abstract Chondroitin sulfate is a very heterogeneous polysaccharide in terms of relative molecular mass, charge density, chemical properties, biological and pharmacological activities. It is actually recommended by EULAR as a symptomatic slow acting drug (SYSADOA) in Europe in the treatment of knee osteoarthritis based on meta-analysis of numerous clinical studies. Chondroitin sulfate is also utilized as a nutraceutical in dietary supplements mainly in the United States. On the other hand, chondroitin sulfate is derived from animal sources by extraction and purification processes. As a consequence, source material, manufacturing processes, the presence of contaminants, and many other factors contribute to the overall biological and pharmacological actions of these agents. The aim of this review is to evaluate new possible more specific analytical approaches to the determination of the origin and purity of chondroitin sulfate preparations for pharmaceutical application and in nutraceuticals, such as the evaluation of the molecular mass values, the constituent disaccharides, and the specific and sensitive agarose-gel electrophoresis technique. Furthermore, a critical evaluation is presented, together with a discussion of the limits of these analytical approaches. Finally, the necessity for reference standards having high specificity, purity and well-known physico-chemical properties useful for accurate and reproducible quantitative analyses will be discussed. © 2007 Wiley-Liss, Inc. and the American Pharmacists Association J Pharm Sci 96: 3168,3180, 2007 [source]


    Quality of different chondroitin sulfate preparations in relation to their therapeutic activity

    JOURNAL OF PHARMACY AND PHARMACOLOGY: AN INTERNATI ONAL JOURNAL OF PHARMACEUTICAL SCIENCE, Issue 10 2009
    Prof. Nicola Volpi
    Abstract Objectives Chondroitin sulfate is currently recommended by the European League Against Rheumatism (EULAR) as a SYSADOA (symptomatic slow acting drug for osteoarthritis) in Europe in the treatment of knee and hand osteoarthritis based on research evidence and meta-analysis of numerous clinical studies. Furthermore, recent clinical trials demonstrated its possible structure-modifying effects. Chondroitin sulfate, alone or in combination with glucosamine or other ingredients, is also utilized as a nutraceutical in dietary supplements in Europe and the USA. However, it is derived from animal sources by extraction and purification processes. As a consequence, source material, manufacturing processes, the presence of contaminants and many other factors contribute to the overall biological and pharmacological actions of these agents. We aim to review the quality control of chondroitin sulfate in pharmaceutical-grade preparations and nutraceuticals. Key findings Pharmaceutical-grade formulations of chondroitin sulfate are of high and standardized quality, purity and properties, due to the stricter regulations to which this drug is subjected by local national health institutes as regards production and characteristics. On the contrary, as several published studies available in literature indicate, the chondroitin sulfate quality of several nutraceuticals is poor. Additionally, there are no definite regulations governing the origin of the ingredients in these nutraceuticals and the origin of the ingredients in natural products is the most important factor ensuring quality, and thus safety and efficacy, in particular for chondroitin sulfate, due to its extraction from different sources. Conclusions Due to the poor chondroitin sulfate quality of some nutraceuticals, we conclude that stricter regulations regarding their quality control should be introduced to guarantee the manufacture of high quality products for nutraceutical utilization and to protect customers from low-quality, ineffective and potentially dangerous products. There is a need for specific and accurate analytical procedures, which should be enforced to confirm purity and label claims both for raw materials and finished chondroitin sulfate products, and also to govern the origin of ingredients. Until these stricter regulations are in place, then it is strongly recommended that pharmaceutical-grade chondroitin sulfate is used rather than food supplements. [source]


    Complement activation triggered by chondroitin sulfate released by thrombin receptor-activated platelets

    JOURNAL OF THROMBOSIS AND HAEMOSTASIS, Issue 8 2008
    O. A. HAMAD
    Summary.,Background:,Chondroitin sulfate (CS) is a glycosaminoglycan released by activated platelets. Objective:,Here we test the hypothesis that CS released by activated platelets can trigger complement activation in the fluid phase. Methods and results:,Thrombin receptor-activating peptide (TRAP)-6 was used to activate platelets in platelet-rich plasma and blood, anticoagulated with the thrombin inhibitor lepirudin. TRAP activation induced fluid-phase complement activation, as reflected by the generation of C3a and sC5b-9, which could be attenuated by the C3 inhibitor compstatin. Chondroitinase ABC treatment of supernatants from activated platelets totally inhibited the activation, indicating that platelet-derived CS had initiated the complement activation. Furthermore, addition of purified CS to plasma strongly triggered complement activation. C1q was identified as the recognition molecule, as it bound directly to CS, and CS-triggered complement activation could be restored in C1q-depleted serum by adding purified C1q. TRAP activation of whole blood increased the expression of CD11b on leukocytes and generation of leukocyte,platelet complexes. It was demonstrated that these leukocyte functions were dependent on C3 activation and signaling via C5a, as this expression could be inhibited by compstatin and by a C5aR antagonist. Conclusions:,We conclude that platelets trigger complement activation in the fluid phase by releasing CS, which leads to inflammatory signals mediated by C5a. [source]


    Chondroitin sulfate increases hyaluronan production by human synoviocytes through differential regulation of hyaluronan synthases: Role of p38 and Akt

    ARTHRITIS & RHEUMATISM, Issue 3 2009
    Maha David-Raoudi
    Objective To uncover the mechanism by which chondroitin sulfate (CS) enhances hyaluronan (HA) production by human osteoarthritic (OA) fibroblast-like synoviocytes (FLS). Methods The production of HA was investigated by exposing human OA FLS to CS in the presence or absence of interleukin-1, (IL-1,). HA levels were determined by enzyme-linked immunosorbent assay, and levels of messenger RNA (mRNA) for HA synthase 1 (HAS-1), HAS-2, and HAS-3 were determined by real-time polymerase chain reaction analysis. The effect of CS and IL-1, on signaling pathways was assessed by Western blotting. Specific inhibitors were used to determine their effects on both HA production and HAS expression. The molecular size of HA was analyzed by high-pressure liquid chromatography. Results CS increased HA production by FLS through up-regulation of the expression of HAS1 and HAS2. This was associated with activation of ERK-1/2, p38, and Akt, although to a lesser extent. Both p38 and Akt were involved in CS-induced HA accumulation. IL-1, increased HA production and levels of mRNA for HAS1, HAS2, and HAS3. CS enhanced the IL-1,,induced level of HAS2 mRNA and reduced the level of HAS3 mRNA. IL-1,,induced activation of p38 and JNK was slightly decreased by CS, whereas that of ERK-1/2 and Akt was enhanced. More high molecular weight HA was found in CS plus IL-1,,treated FLS than in FLS treated with IL-1, alone. Conclusion CS stimulates the synthesis of high molecular weight HA in OA FLS through up-regulation of HAS1 and HAS2. It reduces the IL-1,,enhanced transcription of HAS3 and increases the production of HA of large molecular sizes. These effects may be beneficial for maintaining viscosity and antiinflammatory properties in the joint. [source]


    Chondroitin Sulfate Inhibits the Nuclear Translocation of Nuclear Factor-,B in Interleukin-1,-Stimulated Chondrocytes

    BASIC AND CLINICAL PHARMACOLOGY & TOXICOLOGY, Issue 1 2008
    Claudia Jomphe
    In addition, chondroitin sulfate prevents joint space narrowing of the knee. We hypothesized that the anti-inflammatory effect of chondroitin sulfate is associated to a decrease in the activation of mitogen-activated protein kinases (MAPK) and of the transcription factors nuclear factor-,B (NF-,B) and activator protein-1 (AP-1). Cultured rabbit chondrocytes were stimulated with interleukin-1, (IL-1,) in presence of chondroitin sulfate. Nuclear translocation of NF-,B and AP-1, and nitrite concentrations (as an index for nitric oxide) was assessed 48 hr later. The effect of chondroitin sulfate on IL-1, activation of extracellular signal-regulated kinase 1/2 (Erk1/2) and p38MAPK was documented by immunoblot. The effect of chondroitin sulfate on sodium nitroprusside-induced apoptosis was evaluated with the terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labelling assay. Chondroitin sulfate reduced IL-1,-induced NF-,B nuclear translocation, but not AP-1 translocation, it decreased IL-1,-induced phosphorylation of Erk1/2 and abrogated p38MAPK phosphorylation, but did not prevent IL-1,-induced increase in nitrite. Finally, chondroitin sulfate decreased nitroprusside-induced apoptosis of the chondrocytes. These results suggest that some of the biological activities of chondroitin sulfate may be associated to the reduction in Erk1/2 and p38MAPK phosphorylation and nuclear transactivation of NF-,B. [source]


    Multicenter Study of the Safety and Efficacy of a 585 nm Pulsed-Dye Laser for the Nonablative Treatment of Facial Rhytides

    DERMATOLOGIC SURGERY, Issue 1 2005
    T. S. Jeffrey Hsu MD
    Objective The objective of this study was to assess the safety and efficacy of a 585 nm flashlamp pulsed-dye laser for the nonablative treatment of facial rhytides. Methods A multicenter prospective randomized controlled study on 58 volunteers was performed. A split-face approach was adopted, with one periorbital region acting as a control and the other receiving either one or two treatments. Patients were photographed and imaged three-dimensionally before and after treatment. Histologic sections were analyzed. Results Three-dimensional topographic evaluation showed improvements of 9.8% (p= .0022) and 15% (p= .0029) in surface roughness for single and double treatments, respectively. Histology revealed an increase in type I collagen messenger ribonucleic acid expression, type III procollagen, chondroitin sulfate, and grenz zone thickness. Two treatments resulted in greater improvement than one treatment. Conclusion Clinical improvement was achieved following a single treatment. Further improvement was observed following a second treatment. The subjective evaluation of clinical improvement was consistent with both histologic and topographic quantitative measurements. SUZANNE KILMER, MD, AND JAY BURNS, MD, RECEIVED THE USE OF THE LASER FOR RESEARCH AND A DISCOUNTED PURCHASE AGREEMENT. THEY BOTH ACKNOWLEDGE RECEIVING HONORARIA FOR LECTURING FROM THE MANUFACTURER. BRIAN ZELICKSON, MD, RECEIVED RESEARCH GRANTS FROM ICN. [source]


    Repulsive guidance of axons of spinal sensory neurons in Xenopus laevis embryos: Roles of Contactin and notochord-derived chondroitin sulfate proteoglycans

    DEVELOPMENT GROWTH & DIFFERENTIATION, Issue 7 2005
    Naoko Fujita
    An immunoglobulin superfamily neuronal adhesion molecule, Contactin, has been implicated in axon guidance of spinal sensory neurons in Xenopus embryos. To identify the guidance signaling molecules that Contactin recognizes in tailbud embryos, an in situ binding assay was performed using recombinant Contactin-alkaline phosphatase fusion protein (Contactin-AP) as a probe. In the assay of whole-mount or sectioned embryos, Contactin-AP specifically bound to the notochord and its proximal regions. This binding was completely blocked by either digestion of embryo sections with chondroitinase ABC or pretreatment of Contactin-AP with chondroitin sulfate A. When the spinal cord and the notochord explants were co-cultured in collagen gel, growing Contactin-positive spinal axons were repelled by notochord-derived repulsive activity. This repulsive activity was abolished by the addition of either a monoclonal anti-Contactin antibody, chondroitin sulfate A or chondroitinase ABC to the culture medium. An antibody that recognizes chondroitin sulfate A and C labeled immunohistochemically the notochord in embryo sections and the collagen gel matrix around the cultured notochord explant. Addition of chondroitinase ABC into the culture eliminated the immunoreactivity in the gel matrix. These results suggest that the notochord-derived chondroitin sulfate proteoglycan acts as a repulsive signaling molecule that is recognized by Contactin on spinal sensory axons. [source]


    Activity-dependent formation and functions of chondroitin sulfate-rich extracellular matrix of perineuronal nets

    DEVELOPMENTAL NEUROBIOLOGY, Issue 5 2007
    Alexander Dityatev
    Abstract Extracellular matrix molecules,including chondroitin sulfate proteoglycans, hyaluronan, and tenascin-R,are enriched in perineuronal nets (PNs) associated with subsets of neurons in the brain and spinal cord. In the present study, we show that similar cell type-dependent extracellular matrix aggregates are formed in dissociated cell cultures prepared from early postnatal mouse hippocampus. Starting from the 5th day in culture, accumulations of lattice-like extracellular structures labeled with Wisteria floribunda agglutinin were detected at the cell surface of parvalbumin-expressing interneurons, which developed after 2,3 weeks into conspicuous PNs localized around synaptic contacts at somata and proximal dendrites, as well as around axon initial segments. Physiological recording and intracellular labeling of PN-expressing neurons revealed that these are large fast-spiking interneurons with morphological characteristics of basket cells. To study mechanisms of activity-dependent formation of PNs, we performed pharmacological analysis and found that blockade of action potentials, transmitter release, Ca2+ permeable AMPA subtype of glutamate receptors or L-type Ca2+ voltage-gated channels strongly decreased the extracellular accumulation of PN components in cultured neurons. Thus, we suggest that Ca2+ influx via AMPA receptors and L-type channels is necessary for activity-dependent formation of PNs. To study functions of chondroitin sulfate-rich PNs, we treated cultures with chondroitinase ABC that resulted in a prominent reduction of several major PN components. Removal of PNs did not affect the number and distribution of perisomatic GABAergic contacts but increased the excitability of interneurons in cultures, implicating the extracellular matrix of PNs in regulation of interneuronal activity. © 2007 Wiley Periodicals, Inc. Develop Neurobiol, 2007 [source]


    Binding characteristics of chondroitin sulfate proteoglycans and laminin-1, and correlative neurite outgrowth behaviors in a standard tissue culture choice assay

    DEVELOPMENTAL NEUROBIOLOGY, Issue 4 2002
    Diane M. Snow
    Abstract Neuronal growth cones are capable of sophisticated discrimination of environmental cues, on cell surfaces and in the extracellular matrix, to accomplish navigation during development (generation) and following nervous system injury (regeneration). Choices made by growth cones are commonly examined using tissue culture paradigms in which molecules of interest are purified and substratum-bound. From observations of growth cone behaviors using these paradigms, assertions are made about choices neuronal growth cones may make in vivo. However, in many cases, the binding, interactions, and conformations of these molecules have not been determined. In the present study, we investigated the binding characteristics of two commonly studied outgrowth regulatory molecules: chondroitin sulfate proteoglycans (CSPGs), which are typically inhibitory to neurite outgrowth during development and following nervous system injury, and laminin, which is typically outgrowth promoting for many neuronal types. Using a novel combination of radiolabeling and quantitative fluorescence, we determined the precise concentrations of CSPGs and laminin-1 that were bound separately and together in a variety of choice assays. For identically prepared cultures, we correlated neurite outgrowth behaviors with binding characteristics. The data support our working hypothesis that neuronal growth cones are guided by the ratio of outgrowth-promoting to outgrowth-inhibiting influences in their environment, i.e., they summate local molecular cues. The response of growth cones to these molecular combinations is most likely mediated by integrins and subsequent activation of signal transduction cascades in growth cones. © 2002 Wiley Periodicals, Inc. J Neurobiol 51: 285,301, 2002 [source]


    Improved workup for glycosaminoglycan disaccharide analysis using CE with LIF detection

    ELECTROPHORESIS, Issue 22 2008
    Alicia M. Hitchcock
    Abstract This work describes improved workup and instrumental conditions to enable robust, sensitive glycosaminoglycan (GAG) disaccharide analysis from complex biological samples. In the process of applying CE with LIF to GAG disaccharide analysis in biological samples, we have made improvements to existing methods. These include (i) optimization of reductive amination conditions, (ii) improvement in sensitivity through the use of a cellulose cleanup procedure for the derivatization, and (iii) optimization of separation conditions for robustness and reproducibility. The improved method enables analysis of disaccharide quantities as low as 1,pmol prior to derivatization. Biological GAG samples were exhaustively digested using lyase enzymes, the disaccharide products and standards were derivatized with the fluorophore 2-aminoacridone and subjected to reversed polarity CE-LIF detection. These conditions resolved all known chondroitin sulfate (CS) disaccharides or 11 of 12 standard heparin/heparan sulfate disaccharides, using 50,mM phosphate buffer, pH 3.5, and reversed polarity at 30,kV with 0.3,psi pressure. Relative standard deviation in migration times of CS ranged from 0.1 to 2.0% over 60 days, and the relative standard deviations of peak areas were less than 3.2%, suggesting that the method is reproducible and precise. The CS disaccharide compositions are similar to those obtained by our group using tandem MS. The reversed polarity CE-LIF disaccharide analysis protocol yields baseline resolution and quantification of heparin/heparan sulfate and CS/dermatan sulfate disaccharides from both standard preparations and biologically relevant proteoglycan samples. The improved CE-LIF method enables disaccharide quantification of biologically relevant proteoglycans from small samples of intact tissue. [source]


    A novel ultra-sensitive method for the quantification of glycosaminoglycan disaccharides using an automated DNA sequencer

    ELECTROPHORESIS, Issue 7 2006
    Kay Vogel
    Abstract Analysis of glycosaminoglycans (GAGs) is of increasing importance concerning alterations in extracellular matrix composition and selectivity of glomerular basement membrane. In this report we describe the analysis of chondroitin sulfate disaccharides as an example of GAG ,disaccharide analysis using standard DNA sequencing equipment (DNA sequencer-assisted GAG disaccharide separation, DSA-GAGS). The presented methodology allows nanomolar quantification of 8-aminopyrene-1,3,6-trisulfonic acid (APTS)-derived GAG disaccharides. In comparison to RP-HPLC the established method is much more sensitive, showing detection limits of 38,fmol/,L. Variation coefficients were approximately 10%, enabling exact quantifications after run times of 17,min at 30°C and an electrophoresis voltage of 15,kV; using a capillary DNA sequencer, available in many molecular laboratories, presented advantages like automated sample injection, opportunity of high-throughput analyses, separation of even sulfated disaccharide epimers, and the possibility of using APTS-derived fucose as an internal standard. Furthermore, highly reproducible retention times rendered easy identification of specific signals (SD,0.02). With regard to these results, the described method is a useful tool for the quantification of GAG disaccharides in low amounts, indicating advantages of obverse RP-HPLC and slab gel polyacrylamide electrophoresis in sensitivity, error-proneness, automation, and handling. [source]


    Maintenance of the relative proportion of oligodendrocytes to axons even in the absence of BAX and BAK

    EUROPEAN JOURNAL OF NEUROSCIENCE, Issue 11 2009
    Kumi Kawai
    Abstract Highly purified oligodendroglial lineage cells from mice lacking functional bax and bak genes were resistant to apoptosis after in-vitro differentiation, indicating an essential role of the intrinsic apoptotic pathway in apoptosis of oligodendrocytes in the absence of neurons (axons) and other glial cells. These mice therefore provide a valuable tool with which to evaluate the significance of the intrinsic apoptotic pathway in regulating the population sizes of oligodendrocytes and oligodendroglial progenitor cells. Quantitative analysis of the optic nerves and the dorsal columns of the spinal cord revealed that the absolute numbers of mature oligodendrocytes immunolabeled for aspartoacylase and adult glial progenitor cells expressing NG2 chondroitin sulfate proteoglycan were increased in both white matter tracts of adult bax/bak -deficient mice and, to a lesser extent, bax -deficient mice, except that there was no increase in NG2-positive progenitor cells in the dorsal columns of these strains of mutant mice. These increases in mature oligodendrocytes and progenitor cells in bax/bak -deficient mice were unexpectedly proportional to increases in numbers of axons in these white matter tracts, thus retaining the oligodendroglial lineage to axon ratios of at most 1.3-fold of the physiological numbers. This is in contrast to the prominent expansion in numbers of neural precursor cells in the subventricular zones of these adult mutant mice. Our study indicates that homeostatic control of cell number is different for progenitors of the oligodendroglial and neuronal lineages. Furthermore, regulatory mechanism(s) operating in addition to apoptotic elimination through the intrinsic pathway, appear to prevent the overproduction of highly mitotic oligodendroglial progenitor cells. [source]


    Aberrant trajectory of thalamocortical axons associated with abnormal localization of neurocan immunoreactivity in the cerebral neocortex of reeler mutant mice

    EUROPEAN JOURNAL OF NEUROSCIENCE, Issue 11 2005
    Hong-Peng Li
    Abstract We examined the molecular mechanisms underlying the formation of the thalamocortical pathway in the cerebral neocortex of normal and reeler mutant mice. During normal development of the mouse neocortex, thalamic axons immunoreactive for the neural cell adhesion molecule L1 rarely invaded the cortical plate and ran centered in the subplate which is immunoreactive for neurocan, a brain-specific chondroitin sulfate proteoglycan. On the other hand, in homozygous reeler mutant mice, thalamic axons took an aberrant course to run obliquely through the cortical plate. Injection of bromodeoxyuridine at embryonic day 11 specifically labeled subplate neurons in normal mice, whilst in the reeler neocortex it labeled cells scattered in the cortical plate as well as in the superficial layer (superplate). Neurocan immunoreactivity was associated with the bromodeoxyuridine-positive cells in the superplate, as well as being present in oblique bands within the cortical plate, along which L1-bearing thalamic axons preferentially ran. The present results support our previous hypothesis proposed for normal rats that a heterophilic molecular interaction between L1 and neurocan is involved in determining the thalamocortical pathway within the neocortical anlage [T. Fukuda et al. (1997)Journal of Comparative Neurology, 382, 141,152]. [source]


    Pleiotrophin inhibits HIV infection by binding the cell surface-expressed nucleolin

    FEBS JOURNAL, Issue 18 2005
    Elias A. Said
    The growth factor pleiotrophin (PTN) has been reported to bind heparan sulfate and nucleolin, two components of the cell surface implicated in the attachment of HIV-1 particles to cells. Here we show that PTN inhibits HIV-1 infection by its capacity to inhibit HIV-1 particle attachment to the surface of permissive cells. The ,-sheet domains of PTN appear to be implicated in this inhibitory effect on the HIV infection, in particular the domain containing amino acids 60,110. PTN binding to the cell surface is mediated by high and low affinity binding sites. Other inhibitors of HIV attachment known to bind specifically surface expressed nucleolin, such as the pseudopeptide HB-19 and the cytokine midkine prevent the binding of PTN to its low affinity-binding site. Confocal immunofluorescence laser microscopy revealed that the cross-linking of surface-bound PTN with a specific antibody results in the clustering of cell surface-expressed nucleolin and the colocalization of both PTN and nucleolin signals. Following its binding to surface-nucleolin, PTN is internalized by a temperature sensitive mechanism, a process which is inhibited by HB-19 and is independent of heparan and chondroitin sulfate proteoglycans. Nevertheless, proteoglycans might play a role in the concentration of PTN on the cell surface for a more efficient interaction with nucleolin. Our results demonstrate for the first time that PTN inhibits HIV infection and suggest that the cell surface-expressed nucleolin is a low affinity receptor for PTN binding to cells and it is also implicated in PTN entry into cells by an active process. [source]


    Human proteoglycan testican-1 inhibits the lysosomal cysteine protease cathepsin L

    FEBS JOURNAL, Issue 19 2003
    Jeffrey P. Bocock
    Testican-1, a secreted proteoglycan enriched in brain, has a single thyropin domain that is highly homologous to domains previously shown to inhibit cysteine proteases. We demonstrate that purified recombinant human testican-1 is a strong competitive inhibitor of the lysosomal cysteine protease, cathepsin L, with a Ki of 0.7 nm, but it does not inhibit the structurally related lysosomal cysteine protease cathepsin B. Testican-1 inhibition of cathepsin L is independent of its chondroitin sulfate chains and is effective at both pH 5.5 and 7.2. At neutral pH, testican-1 also stabilizes cathepsin L, slowing pH-induced denaturation and allowing the protease to remain active longer, although the rate of proteolysis is reduced. These data indicate that testican-1 is capable of modulating cathepsin L activity both in intracellular vesicles and in the extracellular milieu. [source]


    Identification of the epidermal growth factor-like domains of thrombomodulin essential for the acceleration of thrombin-mediated inactivation of single-chain urokinase-type plasminogen activator

    FEBS JOURNAL, Issue 21 2001
    Ellen A. M. Schenk-Braat
    Single-chain urokinase-type plasminogen activator (scu-PA) can be cleaved by thrombin into a virtually inactive form called thrombin-cleaved two-chain urokinase-type plasminogen activator (tcu-PA/T), a process accelerated by thrombomodulin, which contains six epidermal growth factor (EGF)-like domains. In this study, we identified the EGF-like domains of thrombomodulin required for the acceleration of the inactivation of scu-PA by thrombin using various forms of thrombomodulin (TM). scu-PA was treated with thrombin in the absence and presence of full-length rabbit TM (containing EGF1-6), recombinant TM comprising all of the extracellular domains including EGF1-6 (TMLEO) and recombinant TM comprising EGF4-6 plus the interconnecting region between EGF3 and EGF4 (TMEi4-6), and the tcu-PA/T generated was quantitated in each case. Rabbit TM accelerated the inactivation of scu-PA ,,35-fold, while both recombinant forms accelerated it only threefold due to the absence of a critical chondroitin sulfate moiety. Subsequently, TME5-6 was prepared by cyanogen bromide digestion of TMEi4-6. TME5-6 bound to thrombin but did not accelerate the activation of protein C. In contrast, the inactivation of scu-PA by thrombin was accelerated to the same extent as that induced by TMLEO and TMEi4-6. This study demonstrates that, in addition to the chondroitin sulfate moiety, only EGF-like domains 5 and 6 are essential for the acceleration of the inactivation of scu-PA by thrombin. This differs from the domains that are critical for activation of protein C (EGF-like domains i4,6) and thrombin activatable fibrinolysis inhibitor (EGF-like domains 3,6). [source]


    Nanofibrous Patches for Spinal Cord Regeneration

    ADVANCED FUNCTIONAL MATERIALS, Issue 9 2010
    Yiqian Zhu
    Abstract The difficulty in spinal cord regeneration is related to the inhibitory factors for axon growth and the lack of appropriate axon guidance in the lesion region. Here scaffolds are developed with aligned nanofibers for nerve guidance and drug delivery in the spinal cord. Blended polymers including poly(L -lactic acid) (PLLA) and poly(lactide- co -glycolide) (PLGA) are used to electrospin nanofibrous scaffolds with a two-layer structure: aligned nanofibers in the inner layer and random nanofibers in the outer layer. Rolipram, a small molecule that can enhance cAMP (cyclic adenosine monophosphate) activity in neurons and suppress inflammatory responses, is immobilized onto nanofibers. To test the therapeutic effects of nanofibrous scaffolds, the nanofibrous scaffolds loaded with rolipram are used to bridge the hemisection lesion in 8-week old athymic rats. The scaffolds with rolipram increase axon growth through the scaffolds and in the lesion, promote angiogenesis through the scaffold, and decrease the population of astrocytes and chondroitin sulfate proteoglycans in the lesion. Locomotor scale rating analysis shows that the scaffolds with rolipram significantly improved hindlimb function after 3 weeks. This study demonstrates that nanofibrous scaffolds offer a valuable platform for drug delivery for spinal cord regeneration. [source]


    Methylprednisolone inhibits the expression of glial fibrillary acidic protein and chondroitin sulfate proteoglycans in reactivated astrocytes

    GLIA, Issue 13 2008
    Wei-Lin Liu
    Abstract Reactive gliosis caused by post-traumatic injury often results in marked expression of chondroitin sulfate proteoglycan (CSPG), which inhibits neurite outgrowth and regeneration. Methylprednisolone (MP), a synthetic glucocorticoid, has been shown to have neuroprotective and anti-inflammatory effects for the treatment of acute spinal cord injury (SCI). However, the effect of MP on CSPG expression in reactive glial cells remains unclear. In our study, we induced astrocyte reactivation using ,-amino-3-hydroxy-5-methyl-4-isoxazole propionate (AMPA) and cyclothiazide to mimic the excitotoxic stimuli of SCI. The expression of glial fibrillary acidic protein (GFAP), a marker of astrocyte reactivation, and CSPG neurocan and phosphacan were significantly elevated by AMPA treatment. The conditioned media from AMPA-treated astrocytes strongly inhibited neurite outgrowth of rat dorsal root ganglion neurons, and this effect was reversed by pretreatment with MP. Furthermore, MP downregulated GFAP and CSPG expression in adult rats with SCI. Additionally, both the glucocorticoid receptor (GR) antagonist RU486 and GR siRNA reversed the inhibitory effects of MP on GFAP and neurocan expression. Taken together, these results suggest that MP may improve neuronal repair and promote neurite outgrowth after excitotoxic insult via GR-mediated downregulation of astrocyte reactivation and inhibition of CSPG expression. © 2008 Wiley-Liss, Inc. [source]


    Protease,proteoglycan complexes of mouse and human mast cells and importance of their ,-tryptase,heparin complexes in inflammation and innate immunity

    IMMUNOLOGICAL REVIEWS, Issue 1 2007
    Richard L. Stevens
    Summary:, Approximately 50% of the weight of a mature mast cell (MC) consists of varied neutral proteases stored in the cell's secretory granules ionically bound to serglycin proteoglycans that contain heparin and/or chondroitin sulfate E/diB chains. Mouse MCs express the exopeptidase carboxypeptidase A3 and at least 15 serine proteases [designated as mouse MC protease (mMCP) 1,11, transmembrane tryptase/tryptase ,/protease serine member S (Prss) 31, cathepsin G, granzyme B, and neuropsin/Prss19]. mMCP-6, mMCP-7, mMCP-11/Prss34, and Prss31 are the four members of the chromosome 17A3.3 family of tryptases that are preferentially expressed in MCs. One of the challenges ahead is to understand why MCs express so many different protease,proteoglycan macromolecular complexes. MC-like cells that contain tryptase,heparin complexes in their secretory granules have been identified in the Ciona intestinalis and Styela plicata urochordates that appeared approximately 500 million years ago. Because sea squirts lack B cells and T cells, it is likely that MCs and their tryptase,proteoglycan granule mediators initially appeared in lower organisms as part of their innate immune system. The conservation of MCs throughout evolution suggests that some of these protease,proteoglycan complexes are essential to our survival. In support of this conclusion, no human has been identified that lacks MCs. Moreover, transgenic mice lacking the ,-tryptase mMCP-6 are unable to combat a Klebsiella pneumoniae infection effectively. Here we summarize the nature and function of some of the tryptase,serglycin proteoglycan complexes found in mouse and human MCs. [source]


    An interaction between opticin and heparan sulfate may provide the molecular basis for vitreoretinal adhesion

    INTERNATIONAL JOURNAL OF EXPERIMENTAL PATHOLOGY, Issue 4 2004
    V. John Hindson
    Introduction Opticin is a member of the extracellular matrix small leucine-rich repeat (SLRP) proteoglycan/protein family, which was originally identified in the eye associated with the collagen fibrils of the vitreous humour. A putative heparin/heparan sulfate (HS) binding motif (RKERKRR) was identified at the N-terminus of human opticin, but this is absent in the bovine form. Furthermore, the strength of attachment between the vitreous and the retina was observed to be species-dependent and related to the presence or absence of this motif. We hypothesized that opticin cross-links the collagen fibrils of the vitreous to HS proteoglycans in the inner limiting lamina (a basement membrane on the inner surface of the retina), contributing towards vitreoretinal adhesion. Materials and methods Recombinant human and bovine opticin were expressed in 293-EBNA cells and purified to apparent homogeneity. Solid phase assays and surface plasmon resonance studies were used to characterize interactions between immobilized heparin/HS and opticin. Results Solid phase and BIAcore data revealed that human opticin binds heparin/HS and binds to heparin with a dissociation constant of approximately 20 nm. By contrast bovine opticin, which lacks the basic cluster, bound severalfold less tightly. Competition studies with heparin oligosaccharides indicated that the heparin/HS binding site is greater than 6 monosaccharides in length. Heparin, HS, chondroitin sulfate A (CS-A), dermatan sulfate and hyaluronan all competed with heparin for binding to human opticin but CS-C did not. Discussion Work to date suggests that the N-terminal sequence RKERKRR contributes significantly to the binding of opticin to heparin/HS. Vitreoretinal adhesion plays a key role in a number of eye diseases and inhibitors of the opticin,HS interaction could be of therapeutic value. [source]


    An immunohistochemical study of the triangular fibrocartilage complex of the wrist: regional variations in cartilage phenotype

    JOURNAL OF ANATOMY, Issue 1 2007
    S. Milz
    Abstract The triangular fibrocartilage complex (TFCC) transmits load from the wrist to the ulna and stabilizes the distal radioulnar joint. Damage to it is a major cause of wrist pain. Although its basic structure is well established, little is known of its molecular composition. We have analysed the immunohistochemical labelling pattern of the extracellular matrix of the articular disc and the meniscal homologue of the TFCC in nine elderly individuals (age range 69,96 years), using a panel of monoclonal antibodies directed against collagens, glycosaminoglycans, proteoglycans and cartilage oligomeric matrix protein (COMP). Although many of the molecules (types I, III and VI collagen, chondroitin 4 sulphate, dermatan sulphate and keratan sulphate, the oversulphated epitope of chondroitin 6 sulphate, versican and COMP) were found in all parts of the TFCC, aggrecan, link protein and type II collagen were restricted to the articular disc and to entheses. They were thus not a feature of the meniscal homologue. The shift in tissue phenotype within the TFCC, from a fibrocartilaginous articular disc to a more fibrous meniscal homologue, correlates with biomechanical data suggesting that the radial region is stiff and subject to considerable stress concentration. The presence of aggrecan, link protein and type II collagen in the articular disc could explain why the TFCC is destroyed in rheumatoid arthritis, given that it has been suggested that autoimmunity to these antigens results in the destruction of articular cartilage. The differential distribution of aggrecan within the TFCC is likely to be reflected by regional differences in water content and mobility on the radial and ulnar side. This needs to be taken into account in the design of improved MRI protocols for visualizing this ulnocarpal complex of the wrist. [source]


    Expression of extracellular matrix molecules typical of articular cartilage in the human scapholunate interosseous ligament

    JOURNAL OF ANATOMY, Issue 6 2006
    S. Milz
    Abstract The scapholunate interosseous ligament (SLIL) connects the scaphoid and lunate bones and plays a crucial role in carpal kinematics. Its rupture leads to carpal instability and impairment of radiocarpal joint function. As the ligament is one of the first structures affected in rheumatoid arthritis, we conducted an immunohistochemical study of cadaveric tissue to determine whether it contains known autoantigens for rheumatoid arthritis. We immunolabelled the ligament from one hand in 12 cadavers with monoclonal antibodies directed against a wide range of extracellular matrix (ECM) molecules associated with both fibrous and cartilaginous tissues. The labelling profile has also enabled us to comment on how the molecular composition of the ligament relates to its mechanical function. All regions of the ligament labelled for types I, III and VI collagens, chondroitin 4 and 6 sulphates, keratan sulphate, dermatan sulphate, versican, tenascin and cartilage oligomeric matrix protein (COMP). However, both entheses labelled strongly for type II collagen, aggrecan and link protein and were distinctly fibrocartilaginous. In some regions, the ligament attached to bone via a region of hyaline cartilage that was continuous with articular cartilage. Labelling for cartilage molecules in the midsubstance was most evident dorsally. We conclude that the SLIL has an ECM which is typical of other highly fibrocartilaginous ligaments that experience both tensile load and shear. The presence of aggrecan, link protein, COMP and type II collagen could explain why the ligament may be a target for autoantigenic destruction in some forms of rheumatoid arthritis. [source]


    Fibrocartilage at the entheses of the suprascapular (superior transverse scapular) ligament of man,a ligament spanning two regions of a single bone

    JOURNAL OF ANATOMY, Issue 5 2001
    B. MORIGGL
    The suprascapular ligament converts the suprascapular notch into a foramen separating the vessels and nerve of the same name. It connects 2 regions of the same bone and does not cross any joint, and no mechanical function has yet been attributed to it. Nevertheless, variations in its thickness and length, and its tendency to ossify, suggest that the ligament responds to changes in mechanical load. This should be reflected in the composition of the extracellular matrix. The primary purpose of the present study is to demonstrate that the suprascapular ligament has fibrocartilaginous entheses (i.e. insertion sites), even though there is no obvious change in insertional angle that directly results from joint movement. Such a change is more typical of tendons or ligaments that cross highly mobile joints. The complete ligament (including both entheses) was removed from 7 cadavers shortly after death and fixed in 90% methanol. Cryosections were immunolabelled with a panel of monoclonal antibodies against collagens (types I, II, III, VI), glycosaminoglycans (chondroitin 4 sulphate, chondroitin 6 sulphate, dermatan sulphate and keratan sulphates), proteoglycans (aggrecan and versican) and link protein. Both entheses were strongly fibrocartilaginous, and a moderately fibrocartilaginous matrix was also detected throughout the remainder of the ligament. The extracellular matrix of both entheses labelled strongly for type II collagen, aggrecan and link protein. The fibrocartilaginous character of the entheses suggests that the insertion sites of the ligament are subject to both compressive and tensile loading and are regions of stress concentration. This in turn probably reflects the complex shape of the scapula and the presence of a conspicuous indentation (the suprascapular notch) near the ligament. The loading patterns may reflect either the attachment of muscles and/or the forces transmitted to the suprascapular ligament from the neighbouring coracoclavicular ligament. [source]


    Safety and therapeutic efficacy of undenatured type-ii collagen (UC-II) in comparison to glucosamine and chondroitin in arthritic horses

    JOURNAL OF ANIMAL PHYSIOLOGY AND NUTRITION, Issue 2 2009
    R. C. Gupta
    Osteoarthritis (OA) is the most common form of arthritis, which causes severe inflammation and loss of cartilage. It is a debilitating disease that commonly affects thousands of horses each year. Recently, we assessed the anti-arthritic and anti-inflammatory potential of undenatured type II collagen (UC-II) in horses. This comparative investigation evaluated arthritic pain in horses receiving daily placebo, UC-II 320 mg/day (providing 80 mg active UC-II), 480 mg/day (providing 120 mg active UC-II), or 640 mg/day (providing 160 mg active UC-II), and glucosamine and chondroitin (5.4 g/day and 1.8 g/day, respectively, bid for the first month, and thereafter once daily) for 150 days. Pain in each leg was evaluated using the flexion test and the lameness-grading system after the initial two strides. Average pain of all four legs represented the pain for each horse. Horses receiving placebo showed no change in arthritic condition, while those receiving 320, 480, or 640 mg UC-II exhibited significant reduction in arthritic pain (P < 0.05). UC-II at 480 mg dose provided optimal effects. With this dose, reduction in overall pain was from 5.7 ± 0.0.42 (100%) to 0.7 ± 0.42 (12%); and in pain upon limb manipulation from 2.35 ± 0.37 (100%) to 0.52 ± 0.18 (22%). In regards to glucosamine and chondroitin treated group, although reduction in pain was significant compared to pretreated values, the efficacy was significantly less compared with that observed with UC-II. UC-II was found to be twice as effective as glucosamine and chondroitin in arthritic horses. Clinically, physical condition, and liver (ALP, GGT, and bilirubin), kidney (BUN and creatinine), and heart (CK) functions remained unchanged, suggesting that these supplements were well tolerated. Overall, these results demonstrate that UC-II was significantly more efficacious than glucosamine and chondroitin in arthritic horses. [source]


    Oversulfated chondroitin sulfate-E binds to BMP-4 and enhances osteoblast differentiation

    JOURNAL OF CELLULAR PHYSIOLOGY, Issue 3 2008
    Tatsuya Miyazaki
    Small leucine-rich proteoglycans, such as biglycan, and their side chain sulfated glycosaminoglycans (GAGs), have been suggested to be involved in bone formation and mineralization processes. The present study was designed to investigate whether chondroitin sulfate (CS), one of the GAG, and its oversulfated structures coupled with bone morphogenetic protein-4 (BMP-4) alter the differentiation and subsequent mineralization of MC3T3-E1 osteoblastic cells. CS-E, one of the oversulfated CS structure, enhanced cell growth, alkaline phosphatase (ALP) activity, collagen deposition, and mineralization whereas heparin enhanced only ALP activity and mineralization. As well as CS-E, CS-H, and CPS also enhanced the mineralization of the cells. CS-E enhanced the mineralization of the cells by interacting with protein in the conditioned medium. CS-E induced mineralization was significantly inhibited by an antibody against BMP-4. The addition of exogenous BMP-4 further increased the capacity of CS-E to enhance mineralization. Fluorescence correlation spectroscopy method using fluoresceinamine-labeled GAG revealed that the oversulfated GAGs have a high affinity for BMP-4. The disaccharide analysis of the cells indicated that MC3T3-E1 cells are capable of producing oversulfated structures of CS by themselves. The lack of CS from the cells after chondroitinase treatment resulted in the inhibition of mineralization. These results in the present study indicate that oversulfated CS, which possesses 4,6-disulfates in N -acetyl-galactosamine, binds to BMP-4 and promotes osteoblast differentiation and subsequent mineralization. J. Cell. Physiol. 217: 769,777, 2008. © 2008 Wiley-Liss, Inc. [source]


    Sperm surface arylsulfatase A can disperse the cumulus matrix of cumulus oocyte complexes,

    JOURNAL OF CELLULAR PHYSIOLOGY, Issue 1 2007
    Alexander Wu
    Cumulus cell layers of expanded cumulus oocyte complexes (COCs) are interlinked with networks of hyaluronic acid, chondroitin sulfate B proteoglycans and link proteins, and they can be dispersed by sperm surface hyaluronidases. In this report, we showed that arylsulfatase A (AS-A), existing on the sperm head surface, also had this dispersion action. Purified AS-A free of protease, hyaluronidase and chondroitinase activities could disperse the cumulus matrix of expanded COCs. However, this COC dispersion action was not associated with AS-A desulfation activity, assayed by using p -nitrocatecholsulfate (artificial substrate). COCs incubated for 1 h with sperm pretreated with anti-AS-A IgG in the presence of apigenin (a hyaluronidase inhibitor) did not exhibit matrix dispersion, whereas several cumulus layers were already dispersed in COCs incubated with sperm pretreated with preimmune IgG. Furthermore, sperm from AS-A null mice showed a significant delay in COC dispersion, compared with wild-type sperm. Within 1 h of sperm-COC co-incubation, the size of COCs incubated with AS-A null sperm was 65% of the original dimension, whereas that of COCs inseminated with wild-type sperm was only 17%. A further delay in COC dispersion by AS-A(,/,) mouse sperm was observed when apigenin was present in the co-incubation. We also showed for the first time that AS-A had a specific affinity for chondroitin sulfate B, a component of cumulus matrix proteoglycan networks; this might provide a mechanism of cumulus matrix destabilization induced by sperm surface AS-A. J. Cell. Physiol. 213: 201,211, 2007. © 2007 Wiley-Liss, Inc. [source]


    THE FREE RADICAL-SCAVENGING PROPERTY OF CHONDROITIN SULFATE FROM PIG LARYNGEAL CARTILAGE IN VITRO

    JOURNAL OF FOOD BIOCHEMISTRY, Issue 1 2007
    SHUANG-LI XIONG
    ABSTRACT This study compared the free radical-scavenging properties of chondroitin sulfate (ChS) from pig laryngeal cartilage and its reduced or sulfonated derivatives. The binding behavior between Cu2+ and ChS and its derivatives, and the interaction between superoxide radical and ChS were studied by fluorescence quenching, equilibrium dialysis, infrared spectra and thermal analysis. Purified ChS inhibited the generation of hydroxyl radical and scavenged superoxide radical in a concentration-dependent manner. Reduced ChS did not scavenge hydroxyl radical and superoxide radical. Sulfonated ChS had no hydroxyl radical scavenging activity but scavenged superoxide radical as strongly as purified ChS. ChS showed strong binding activity with Cu2+ in deionized water but not in 0.01-M HCl. Both reduced ChS and sulfonated ChS did not exhibit such chelating behavior. The structural basis of hydroxyl radical inhibiting of ChS was attributed to a complex of the Cu2+ with the carboxyl group of glucuronic acid residue. The reaction of superoxide radical with the sulfate ester and the carboxyl group may be the basis of superoxide radical scavenging activity of ChS. [source]