Perineuronal net deglycosylation associates with tauopathy-induced gliosis and neurodegeneration.

Alzheimer's disease (AD) is a progressive neurodegenerative disorder characterized by clinical symptoms of memory and cognitive deficiencies. Postmortem evaluation of AD brain tissue shows proteinopathy that closely associate with the progression of this dementing disorder, including the accumulation of extracellular beta amyloid (Aß) and intracellular hyperphosphorylated tau (pTau) with neurofibrillary tangles (NFTs). Current therapies targeting Aß have limited clinical efficacy and life-threatening side effects and highlight the need for alternative treatments targeting pTau and other pathophysiologic mechanisms driving AD pathogenesis. The brain's extracellular matrices (ECM), particularly perineuronal nets (PNNs), play a crucial role in brain functioning and neurocircuit stability, and reorganization of these unique PNN matrices has been associated with the progression of AD and accumulation of pTau in humans. We hypothesize that AD-associated changes in PNNs may in part be driven by the accumulation of pTau within the brain. In this work, we investigated whether the presence of pTau influenced PNN structural integrity and PNN chondroitin sulfate-glycosaminoglycan (CS-GAG) compositional changes in two transgenic mouse models expressing tauopathy-related AD pathology, PS19 (P301S) and Tau4RTg2652 mice. We show that PS19 mice exhibit an age-dependent loss of hippocampal PNN CS-GAGs, but not the underlying aggrecan core protein structures, in association with pTau accumulation, gliosis, and neurodegeneration. The loss of PNN CS-GAGs were linked to shifts in CS-GAG sulfation patterns to favor the neuroregenerative isomer, 2S6S-CS. Conversely, Tau4RTg2652 mice exhibit stable PNN structures and normal CS-GAG isomer composition despite robust pTau accumulation, suggesting a critical interaction between neuronal PNN glycan integrity and neighboring glial cell activation. Overall, our findings provide insights into the complex relationship between PNN CS-GAGs, pTau pathology, gliosis, and neurodegeneration in mouse models of tauopathy, and offer new therapeutic insights and targets for AD treatment.

Fucose-Rich Sulfated Polysaccharides from Two Vietnamese Sea Cucumbers Bohadschia argus and Holothuria (Theelothuria) spinifera: Structures and Anticoagulant Activity.

Fucosylated chondroitin sulfates (FCSs) FCS-BA and FCS-HS, as well as fucan sulfates (FSs) FS-BA-AT and FS-HS-AT were isolated from the sea cucumbers Bohadschia argus and Holothuria (Theelothuria) spinifera, respectively. Purification of the polysaccharides was carried out by anion-exchange chromatography on DEAE-Sephacel column. Structural characterization of polysaccharides was performed in terms of monosaccharide and sulfate content, as well as using a series of non-destructive NMR spectroscopic methods. Both FCSs were shown to contain a chondroitin core [→3)-ß-d-GalNAc-(1→4)-ß-d-GlcA-(1→]n bearing sulfated fucosyl branches at O-3 of every GlcA residue in the chain. These fucosyl residues were different in pattern of sulfation: FCS-BA contained Fuc2S4S, Fuc3S4S and Fuc4S at a ratio of 1:8:2, while FCS-HS contained these residues at a ratio of 2:2:1. Polysaccharides differed also in content of GalNAc4S6S and GalNAc4S units, the ratios being 14:1 for FCS-BA and 4:1 for FCS-HS. Both FCSs demonstrated significant anticoagulant activity in clotting time assay and potentiated inhibition of thrombin, but not of factor Xa. FS-BA-AT was shown to be a regular linear polymer of 4-linked α-L-fucopyranose 3-sulfate, the structure being confirmed by NMR spectra of desulfated polysaccharide. In spite of considerable sulfate content, FS-BA-AT was practically devoid of anticoagulant activity. FS-HS-AT cannot be purified completely from contamination of some FCS. Its structure was tentatively represented as a mixture of chains identical with FS-BA-AT and other chains built up of randomly sulfated alternating 4- and 3-linked α-L-fucopyranose residues.

Decoding perineuronal net glycan sulfation patterns in the Alzheimer's disease brain.

The extracellular matrix (ECM) of the brain comprises unique glycan "sulfation codes" that influence neurological function. Perineuronal nets (PNNs) are chondroitin sulfate-glycosaminoglycan (CS-GAG) containing matrices that enmesh neural networks involved in memory and cognition, and loss of PNN matrices is reported in patients with neurocognitive and neuropsychiatric disorders including Alzheimer's disease (AD). Using liquid chromatography tandem mass spectrometry (LC-MS/MS), we show that patients with a clinical diagnosis of AD-related dementia undergo a re-coding of their PNN-associated CS-GAGs that correlates to Braak stage progression, hyperphosphorylated tau (p-tau) accumulation, and cognitive impairment. As these CS-GAG sulfation changes are detectable prior to the regional onset of classical AD pathology, they may contribute to the initiation and/or progression of the underlying degenerative processes and implicate the brain matrix sulfation code as a key player in the development of AD clinicopathology.

Adherence of Candida albicans and Malassezia Species to Skin Cells Induces Changes in the Expression of Genes Responsible for Heparan and Chondroitin Sulfate Chain Synthesis. / La unión de Candida albicans y Malassezia spp. a células de piel promueve cambios de expresión en los genes responsables de la síntesis de las cadenas de heparán y condroitín sulfato.

Superficial fungal infections are common in dermatology and are often caused by opportunistic species in the Candida and Malassezia genera. The aim of this study was to analyze changes in the expression of genes coding for enzymes involved in the biosynthesis of glycosaminoglycans (GAGs) chains following the adherence of Candida and Malassezia yeasts to skin cell lines. Gene expression was analyzed using reverse transcriptase-quantitative polymerase chain reaction assays. Interactions between the yeasts and the skin cells induced the following changes in genes involved in the biosynthesis of heparan sulfate and chondroitin sulfate: downregulation of CHPF in keratinocytes and downregulation of EXT1, EXT2, CHSY3, and CHPF in fibroblasts. Adherence to fibroblasts had an even greater effect on GAG biosynthetic enzymes, inducing the downregulation of 13 genes and the upregulation of two (CHST15 and CHST7). Interactions between yeasts and skin cells might affect the binding affinity of GAG chains, possibly changing their ability to function as receptors for pathogens and interfering with a key stage at the start of infection.

Age-dependent microstructural changes of the intervertebral disc: a validation of proteoglycan-sensitive spectral CT.

OBJECTIVE: To analyze the two major components of the intervertebral disc (IVD) in an ex vivo phantom, as well as age-related changes in patients. METHODS: Collagen and chondroitin sulfate were imaged at different concentrations in agar solution. Age-related changes in disc density were retrospectively analyzed in normal-appearing discs in dual-energy computed tomography (DECT) images from a patient cohort with various spinal pathologies (n = 136). All computed tomography (CT) scans were acquired using single-source DECT at 80 and 135 kVp with automatic exposure calculation. In 136 patients, the attenuation of normal-appearing discs on collagen/chondroitin maps (cMaps) correlated with the patients' age with Pearson's r using standardized regions of interest in the anterior anulus fibrosus (AAF) and nucleus pulposus (NP). RESULTS: DECT collagen mapping revealed concentration-dependent Hounsfield units (HU) of IVD components. For collagen, we found Pearson's r = 0.9610 (95% CI 0.6789-0.9959), p = 0.0023 at 120 kVe, and r = 0.8824 (95% CI 0.2495-0.9871), p = 0.0199 in cMap. For chondroitin sulfate, Pearson's r was 0.9583 (95% CI 0.6603-0.9956), p = 0.0026 at 120 kVp, and r = 0.9646 (95% CI 0.7044-0.9963), p = 0.0019 in cMap. Analysis of normal-appearing IVDs revealed an inverse correlation of density with age in the AAF: Pearson's r = - 0.2294 at 135 kVp (95% CI - 0.4012 to - 0.04203; p=0.0141) and r = - 0.09341 in cMap (95% CI - 0.2777 to 0.09754; p = 0.0003). In the NP, age and density did not correlate significantly at 135 kVp (p = 0.9228) and in cMap (p = 0.3229). CONCLUSIONS: DECT-based collagen mapping allows microstructural analysis of the two main intervertebral disc components-collagen and chondroitin sulfate. IVD density declines with age, presumably due to a reduction in collagen and chondroitin sulfate content. Age-related alterations of disc microstructure appear most pronounced in the AAF. KEY POINTS: • DECT-based collagen mapping allows precise analysis of the two main intervertebral disc components-collagen and chondroitin sulfate. • Intervertebral disc (IVD) density declines with age, presumably due to a reduction in collagen and chondroitin sulfate content. • Age-related alterations of disc microstructure are most pronounced in the anterior anulus fibrosus (AAF).

Improving the barrier function of damaged cultured urothelium using chondroitin sulfate.

AIMS: To determine whether glycosaminoglycan (GAG) replenishment is able to improve recovery of a deficient urothelial barrier, chondroitin sulfate (CS) instillations were tested using an in vitro model. Porcine urothelial cells (Ucells) were terminally differentiated in culture conditions to construct a urothelial layer with a functional barrier. This layer was damaged to compromise barrier function to simulate a key characteristic of bladder pain syndrome/interstitial cystitis. The functional effect of subsequent treatment with CS was evaluated. METHODS: Primary porcine Ucells were isolated and cultured on inserts. Differentiation of cells was evaluated with immunohistochemical analysis for the presence of umbrella cells, tight junctions and CS. Transepithelial electrical resistance (TEER) measurements were performed to evaluate barrier function. Protamine was used to simulate mild urothelial damage. CS 0.2% (vol/vol), a GAG, was subsequently instilled in the treatment group. The recovery of barrier function was further evaluated with TEER measurements. The Student t test was used for the analysis of results. RESULTS: After induction of differentiation, the Ucells expressed barrier markers and a functional barrier was established (measured by high TEER). TEER decreased significantly after instillation with protamine. CS instillation improved recovery of TEER significantly measured after 7 hours (84% vs 22% in controls). After 24 hours; however, the TEER was comparable in both experimental groups. CONCLUSION: CS instillation improves the recovery of the urothelial barrier after damage in vitro. This functional experiment shows that CS improves recovery of damaged urothelial function, which supports the hypothesis behind the mechanism of action of GAG-replenishment therapy.

Targeting Chondroitin Sulfate Glycosaminoglycans to Treat Cardiac Fibrosis in Pathological Remodeling.

BACKGROUND: Heart failure is a leading cause of mortality and morbidity, and the search for novel therapeutic approaches continues. In the monogenic disease mucopolysaccharidosis VI, loss-of-function mutations in arylsulfatase B lead to myocardial accumulation of chondroitin sulfate (CS) glycosaminoglycans, manifesting as myriad cardiac symptoms. Here, we studied changes in myocardial CS in nonmucopolysaccharidosis failing hearts and assessed its generic role in pathological cardiac remodeling. METHODS: Healthy and diseased human and rat left ventricles were subjected to histological and immunostaining methods to analyze glycosaminoglycan distribution. Glycosaminoglycans were extracted and analyzed for quantitative and compositional changes with Alcian blue assay and liquid chromatography-mass spectrometry. Expression changes in 20 CS-related genes were studied in 3 primary human cardiac cell types and THP-1-derived macrophages under each of 9 in vitro stimulatory conditions. In 2 rat models of pathological remodeling induced by transverse aortic constriction or isoprenaline infusion, recombinant human arylsulfatase B (rhASB), clinically used as enzyme replacement therapy in mucopolysaccharidosis VI, was administered intravenously for 7 or 5 weeks, respectively. Cardiac function, myocardial fibrosis, and inflammation were assessed by echocardiography and histology. CS-interacting molecules were assessed with surface plasmon resonance, and a mechanism of action was verified in vitro. RESULTS: Failing human hearts displayed significant perivascular and interstitial CS accumulation, particularly in regions of intense fibrosis. Relative composition of CS disaccharides remained unchanged. Transforming growth factor-ß induced CS upregulation in cardiac fibroblasts. CS accumulation was also observed in both the pressure-overload and the isoprenaline models of pathological remodeling in rats. Early treatment with rhASB in the transverse aortic constriction model and delayed treatment in the isoprenaline model proved rhASB to be effective at preventing cardiac deterioration and augmenting functional recovery. Functional improvement was accompanied by reduced myocardial inflammation and overall fibrosis. Tumor necrosis factor-α was identified as a direct binding partner of CS glycosaminoglycan chains, and rhASB reduced tumor necrosis factor-α-induced inflammatory gene activation in vitro in endothelial cells and macrophages. CONCLUSIONS: CS glycosaminoglycans accumulate during cardiac pathological remodeling and mediate myocardial inflammation and fibrosis. rhASB targets CS effectively as a novel therapeutic approach for the treatment of heart failure.

Bottom-up analysis using liquid chromatography-Fourier transform mass spectrometry to characterize fucosylated chondroitin sulfates from sea cucumbers.

Fucosylated chondroitin sulfates (FCSs) from sea cucumbers have repetitive structures that exhibit minor structural differences based on the organism from which they are recovered. A detailed characterization of FCSs and their derivatives is important to establish their structure-activity relationship in the development of new anticoagulant drugs. In the current study, online hydrophilic interaction chromatography-Fourier transform mass spectrometry (FTMS) was applied to analyze the FCS oligosaccharides generated by selective degradation from four species of sea cucumbers, Isostichopus badionotus, Pearsonothuria graeffei, Holothuria mexicana and Acaudina molpadioides. These depolymerized FCS fragments were quantified and compared using the glycomics software package, GlycReSoft. The quantified fragments mainly had trisaccharide-repeating compositions and showed significant differences in fucosylation (including its sulfation) among different species of sea cucumbers. Detailed analysis of FTMS ion peaks and top-down nuclear magnetic resonance spectroscopy of native FCS polysaccharides verified the accuracy of this method. Thus, a new structural model for FCS chains from these different sea cucumbers was defined. This bottom-up approach provides rich detailed structural analysis and provides quantitative information with high accuracy and reproducibility and should be suitable for the quality control in FCSs as well as their oligosaccharides.

A prospective randomized controlled multicentre trial comparing intravesical DMSO and chondroïtin sulphate 2% for painful bladder syndrome/interstitial cystitis.

OBJECTIVE: To compare effectiveness of intravesical chondroïtin sulphate (CS) 2% and dimethyl sulphoxide (DMSO) 50% in patients with painful bladder syndrome/interstitial cystitis (PBS/IC). MATERIALS AND METHODS: Patients were randomized to receive either 6 weekly instillations of CS 2% or 50% DMSO. Primary endpoint was difference in proportion of patients achieving score 6 (moderately improved) or 7 (markedly improved) in both groups using the Global Response Assessment (GRA) scale. Secondary parameters were mean 24-hours frequency and nocturia on a 3-day micturition dairy, changes from baseline in O'Leary-Sant questionnaire score and visual analog scale (VAS) for suprapubic pain. RESULTS: Thirty-six patients were the intention to treat population (22 in CS and 14 in DMSO group). In DMSO group, 57% withdrew consent and only 6 concluded the trial. Major reasons were pain during and after instillation, intolerable garlic odor and lack of efficacy. In CS group, 27% withdrew consent. Compared with DMSO group, more patients in CS group (72.7% vs. 14%) reported moderate or marked improvement (P=0.002, 95% CI 0.05-0.72) and achieved a reduction in VAS scores (20% vs. 8.3%). CS group performed significantly better in pain reduction (-1.2 vs. -0.6) and nocturia (-2.4 vs. -0.7) and better in total O'Leary reduction (-9.8 vs. -7.2). CS was better tolerated. The trial was stopped due to high number of drop-outs with DMSO. CONCLUSIONS: Intravesical CS 2% is viable treatment for PBS/IC with minimal side effects. DMSO should be used with caution and with active monitoring of side effects. More randomized controlled studies on intravesical treatments are needed.

Open, Observational, Single-Arm, Multicenter Study Assessing the Effectiveness of a Dietary Supplement Containing Hydrolyzed Collagen, Chondroitin Sulfate, and Glucosamine for Osteoarthritis Pain Reduction.

Osteoarthritis (OA) is an age-related degenerative joint disease with a great impact on patients' well-being and quality of life. This is an observational, open, single-arm multicenter study aimed to evaluate the effectiveness of a nutritional supplement in patients with knee and/or hip OA. A total of 186 patients were recruited from Spanish centers and received a supplement containing hydrolyzed collagen (3000 mg), chondroitin sulfate (800 mg), glucosamine sulfate (700 mg), turmeric extract (250 mg) and devil's claw (150 mg), once daily during 6 months. The primary outcome was the patients' self-perceived pain in the affected joints measured with a visual analogue scale (VAS). Secondary outcome was the patient's functioning, measured with the Lequesne Functional Index and the Western Ontario and McMaster Universities Arthritis Index (WOMAC). Participants showed a significant reduction in self-perceived pain after 3 (mean reduction ± standard deviation, 1.99 ± 1.05) and 6 months (3.57 ± 1.39) of treatment (p < 0.0001 in both comparisons). Lequesne Functional Index score was significantly reduced at 3 months (3.86 ± 2.94) and at 6 months (6.73 ± 4.30) of treatment (p < 0.0001 in both comparisons). The WOMAC index was also significantly reduced after 3 (14.24 ± 10.04) and 6 months (26.43 ± 17.35) of treatment (p < 0.0001 in both comparisons). Significant reductions in WOMAC subdomains (p < 0.0001 in all comparisons) were observed. No severe adverse events were reported during the study. The main results arising from this study show that this nutritional supplementation can improve OA-related symptoms and physical function with a good safety profile in patients with hip and/or knee OA.

Multigram scale preparation of a semi-synthetic N-trifluoroacetyl protected chondroitin disaccharide building block: Towards the stereoselective synthesis of chondroitin sulfates disaccharides.

The chemoselective N-trifluoroacetylation of a chondroitin disaccharide obtained from controlled acid hydrolysis of a commercially available polymeric chondroitin sulfate is reported for the first time. We also described the multi-gram scale synthesis of a donor block having a benzylidene moiety further used for the expeditious and stereocontrolled synthesis of glycosides fitted with various aglycons. Stereocontrolled ß-glycosylation, sulfation and efficient N-TFA deprotection steps afforded the desired disaccharides in good yields.

Efficacy of the use of chondroitin sulphate and glucosamine for the treatment of temporomandibular joint dysfunction: A systematic review and meta-analysis.

OBJECTIVE: To evaluate the efficacy of chondroitin sulfate (CS) and glucosamine (GS), the most relevant drugs of "Symptomatic Slow Acting Drug for Osteoarthritis" (SYSADOA), in the functional and symptomatic improvement of temporomandibular dysfunction. Although, controversy exists regarding their benefit. METHODS: An electronic search was conducted to retrieve randomized controlled clinical trials (RCTs). The risk of bias assessment was evaluated using the Cochrane Collaboration's tool. Data were meta-analyzed with a random effect model whenever possible. RESULTS: Three RCTs were included. Qualitative results showed a decrease in pain, joint noise, and inflammatory biomarkers in synovial fluid and an improvement in maximum mouth opening without significant adverse effects. Meta-analysis showed a significant increase in maximum mouth opening with the use of CS-GS (p = 0.19). No statistically significant differences were found in pain reduction compared to tramadol. CONCLUSION: CS-GS is effective and safe in the symptomatic and functional improvement of patients with TMD.

Low-Molecular Weight Protamine Overcomes Chondroitin Sulfate Inhibition of Neural Regeneration.

Protamine is an arginine-rich peptide that replaces histones in the DNA-protein complex during spermatogenesis. Protamine is clinically used in cardiopulmonary bypass surgery to neutralize the effects of heparin that is required during the treatment. Here we demonstrate that protamine and its 14-22 amino acid long fragments overcome the neurite outgrowth inhibition by chondroitin sulfate proteoglycans (CSPGs) that are generally regarded as major inhibitors of regenerative neurite growth after injuries of the adult central nervous system (CNS). Since the full-length protamine was found to have toxic effects on neuronal cells we used the in vitro neurite outgrowth assay to select a protamine fragment that retains the activity to overcome the neurite outgrowth inhibition on CSPG substrate and ended up in the 14 amino acid fragment, low-molecular weight protamine (LMWP). In contrast to the full-length protamine, LMWP displays very low or no toxicity in our assays in vitro and in vivo. We therefore started studies on LMWP as a possible drug lead in treatment of CNS injuries, such as the spinal cord injury (SCI). LMWP mimicks HB-GAM (heparin-binding growth-associated molecule; pleiotrophin) in that it overcomes the CSPG inhibition on neurite outgrowth in primary CNS neurons in vitro and inhibits binding of protein tyrosine phosphatase (PTP) sigma, an inhibitory receptor in neurite outgrowth, to its CSPG ligand. Furthermore, the chondroitin sulfate (CS) chains of the cell matrix even enhance the LMWP-induced neurite outgrowth on CSPG substrate. In vivo studies using the hemisection and hemicontusion SCI models in mice at the cervical level C5 revealed that LMWP enhances recovery when administered through intracerebroventricular or systemic route. We suggest that LMWP is a promising drug lead to develop therapies for CNS injuries.

The "Loss" of Perineuronal Nets in Alzheimer's Disease: Missing or Hiding in Plain Sight?

Perineuronal nets (PNNs) are chondroitin-sulfate glycosaminoglycan (CS-GAG) containing extracellular matrix structures that assemble around neurons involved in learning, memory, and cognition. Owing to the unique patterning of negative charges stemming from sulfate modifications to the attached CS-GAGs, these matrices play key roles in mediating glycan-protein binding, signaling interactions, and charged ion buffering of the underlying circuitry. Histochemical loss of PNN matrices has been reported for a range of neurocognitive and neurodegenerative diseases, implying that PNNs might be a key player in the pathogenesis of neurological disorders. In this hypothesis and theory article, we begin by highlighting PNN changes observed in human postmortem brain tissue associated with Alzheimer's disease (AD) and corresponding changes reported in rodent models of AD neuropathology. We then discuss the technical limitations surrounding traditional methods for PNN analyses and propose alternative explanations to these historical findings. Lastly, we embark on a global re-evaluation of the interpretations for PNN changes across brain regions, across species, and in relation to other neurocognitive disorders.

[Reduction of social coverage for symptomatic slow-acting drugs for osteoarthritis: a disinvestment initiative in Argentina, 2015-2017]. / Reducción de la cobertura social para los fármacos antiartrósicos sintomáticos de acción lenta: una iniciativa de desinversión en Argentina, 2015-2017.

In April 2016, the National Institute of Social Services for Retirees and Pensioners discontinued its policy of 100% coverage for 159 drugs (the "social subsidy"), including symptomatic slow-acting drugs for osteoarthritis (SYSADOAs), due to insufficient evidence of significant clinical benefit. We evaluated the effect of this measure on the use of SYSADOAs as well as non-steroidal anti-inflammatory drugs (NSAIDs), which were unaffected by this policy change. We compared outpatient dispensations of SYSADOAs and NSAIDs from 2015 to 2017, measuring dispensed units, retail price, and out-of-pocket expenses for beneficiaries each month. After the change in coverage, there was a 61.6% total decrease in SYSADOA units dispensed, and a 63.4% decrease in the final sales price to the public, measured in constant values. Dispensation was not reoriented towards NSAIDs, which fell by 6.1%. The incidence of new treatments decreased (from 6.4 to 3.3 treatments per 1,000 beneficiaries per month), as did their continuity. Beneficiaries' out-of-pocket spending on SYSADOAs increased by 75.8% (at constant values). Disinvestment in interventions with questionable therapeutic value is an important tool in working toward the sustainability of health systems.

En abril de 2016, el Instituto Nacional de Servicios Sociales para Jubilados y Pensionados excluyó del subsidio social la cobertura al 100% de 159 fármacos, entre ellos, los antiartrósicos sintomáticos de acción lenta o symptomatic slow-acting drugs for osteoarthritis (SySADOA), por insuficiente evidencia de beneficio clínico significativo. Evaluamos el efecto de esta medida sobre la utilización de SySADOA y de los antiinflamatorios no esteroides (AINE), no afectados por la medida. Se compararon las dispensas ambulatorias de los SySADOA y los AINE de 2015 a 2017, midiendo unidades dispensadas, precio de venta al público y gasto de bolsillo del beneficiario para cada mes. Luego de la medida, descendieron un 61,6% los envases de SySADOA dispensados y un 63,4% el monto total del precio de venta al público, medido en valores constantes. La dispensa no se reorientó hacia los AINE, que descendieron un 6,1%. Disminuyó tanto la incidencia de nuevos tratamientos (de 6,4 a 3,3 tratamientos por 1.000 beneficiarios por mes) como su continuidad. El gasto de bolsillo de los beneficiarios en SySADOA aumentó un 75,8% (a valores constantes). La desinversión en intervenciones de valor terapéutico cuestionable es una herramienta valiosa para la sustentabilidad de los sistemas de salud.

Skate cartilage extracts containing chondroitin sulfate ameliorates hyperlipidemia-induced inflammation and oxidative stress in high cholesterol diet-fed LDL receptor knockout mice in comparison with shark chondroitin sulfate.

BACKGROUND/OBJECTIVES: In this study, we investigated the beneficial effects of skate cartilage extracts containing chondroitin sulfate (SCS) on hyperlipidemia-induced inflammation and oxidative stress in high cholesterol diet (HCD)-fed mice in comparison with the effects of shark cartilage-derived chondroitin sulfate (CS). MATERIALS/METHODS: Low-density lipoprotein receptor knockout (LDLR-KO) mice were fed HCD with an oral administration of CS (50 and 100 mg/kg BW/day), SCS (100 and 200 mg/kg BW/day), or water, respectively, for ten weeks. RESULTS: The administration of CS or SCS reduced the levels of serum triglyceride (TG), total cholesterol (TC), and LDL cholesterol and elevated the levels of high-density lipoprotein cholesterol, compared with those of the control group (P < 0.05). Furthermore, CS or SCS significantly attenuated inflammation by reducing the serum levels of interleukin (IL)-1ß and hepatic protein expression levels of nuclear factor kappa B, inducible nitric oxide synthase, cyclooxygenase-2, and IL-1beta (P < 0.05). In particular, the serum level of tumor necrosis factor-alpha was reduced only in the 100 mg/kg BW/day of SCS-fed group, whereas the IL-6 level was reduced in the 100 and 200 mg/kg BW/day of SCS-fed groups (P < 0.05). In addition, lipid peroxidation and nitric oxide production were attenuated in the livers of the CS and SCS groups mediated by the upregulation of hepatic proteins of antioxidant enzymes, such as superoxide dismutase, catalase, and glutathione peroxidase (P < 0.05). CONCLUSIONS: These results suggest that the biological effects of SCS, similar to those of CS, are attributed to improved lipid profiles as well as suppressed inflammation and oxidative stress induced by the intake of HCD.

Biocompatibility and structural characterization of glycosaminoglycans isolated from heads of silver-banded whiting (Sillago argentifasciata Martin & Montalban 1935).

Glycosaminoglycans (GAGs) were extracted from heads of silver-banded whiting (SBW) fish and subjected to preliminary biocompatibility testing per ISO 10993: intracutaneous irritation, maximization sensitization, systemic toxicity, and cytotoxicity. When the GAG solution was injected intradermally, the observed irritation was within ISO limits and comparable to a marketed control. There was no evidence of sensitization, systemic toxicity, or cellular toxicity on the test organisms treated with the GAG mixture from SBW fish heads. Fractionation by size-exclusion chromatography has shown three distinct fractions: F1 as low molecular weight hyaluronic acid (190 kDa), F2 (82 kDa) and F3 (64 kDa), both as chondroitin sulfates. Structural characterization by 1D and 2D nuclear magnetic resonance spectroscopy and disaccharide analysis have shown sulfation ratios at positions C4:C6 of the F2 and F3 fractions respectively as 70:20% and 50:30%, and the balance of non-sulfated and 4,6-di-sulfated units. The preliminary results here suggest that GAG-based extracts from SBW fish heads are suitable alternative products to be used in soft tissue augmentation, although further long-term biocompatibility studies are still required.

Hyaluronic acid has chondroprotective and joint-preserving effects on LPS-induced synovitis in horses.

The intra-articular use of hyaluronic acid (HA) for the treatment of synovitis and osteoarthritis is still controversial. As a consequence, corticosteroids remain the most frequently employed therapeutic agents, despite their potential systemic and local deleterious effects. This study examined the anti-inflammatory, antioxidant, and chondroprotective activities of low and high molecular weight hyaluronic acid (LMW-HA and HMW-HA) on lipopolysaccharide (LPS)-induced synovitis in horses compared to triamcinolone acetonide (TA). LPS was injected in the metacarpophalangeal joints, which were treated intra-articularly with either TA (as control) or LMW-HA or HMW-HA. Joint clinical evaluation and synovial fluid (SF) analysis were performed at 0, 8, 24, and 48 h. The white blood cell counts (WBC), prostaglandin E2 (PGE2), interleukin (IL)-1, IL-6, IL-10, tumor necrosis factor-α, chondroitin sulfate (CS) and HA concentrations, oxidative burst, and HA molecular weights were measured. TA reduced the lameness, swelling, and PGE2 release but increased the SF CS concentrations enormously at 24h and 48h, and decreased the SF HA modal molecular weight. These results indicate the breakdown of articular cartilage aggrecan and SF HA. In contrast, LMW-HA and HMW-HA were less effective in reducing the inflammation symptoms, but preserved the joints because only a modest increase in CS occurred at 24 h, decreasing at 48 h, and the SF HA was maintained. The HA-treatment also had anti-inflammatory actions, and LMW-HA was the most effective in reducing the release of cytokine. In summary, the HA treatment inhibited efficiently the digestion of cartilage proteoglycans and SF HA breakdown.

Regulatory roles of perineuronal nets and semaphorin 3A in the postnatal maturation of the central vestibular circuitry for graviceptive reflex.

Perineuronal nets (PN) restrict neuronal plasticity in the adult brain. We hypothesize that activity-dependent consolidation of PN is required for functional maturation of behavioral circuits. Using the postnatal maturation of brainstem vestibular nucleus (VN) circuits as a model system, we report a neonatal period in which consolidation of central vestibular circuitry for graviception is accompanied by activity-dependent consolidation of chondroitin sulfate (CS)-rich PN around GABAergic neurons in the VN. Postnatal onset of negative geotaxis was used as an indicator for functional maturation of vestibular circuits. Rats display negative geotaxis from postnatal day (P) 9, coinciding with the condensation of CS-rich PN around GABAergic interneurons in the VN. Delaying PN formation, by removal of primordial CS moieties on VN with chondroitinase ABC (ChABC) treatment at P6, postponed emergence of negative geotaxis to P13. Similar postponement was observed following inhibition of GABAergic transmission with bicuculline, in line with the reported role of PN in increasing excitability of parvalbumin neurons. We further reasoned that PN-CS restricts bioavailability of plasticity-inducing factors such as semaphorin 3A (Sema3A) to bring about circuit maturation. Treatment of VN explants with ChABC to liberate PN-bound Sema3A resulted in dendritic growth and arborization, implicating structural plasticity that delays synapse formation. Evidence is thus provided for the role of PN-CS-Sema3A in regulating structural and circuit plasticity at VN interneurons with impacts on the development of graviceptive postural control.

Method for Studying the Physical Effect of Extracellular Matrix on Voltage-Dependent Ion Channel Gating.

Divalent cations can change the actual electrical potential at the outer surface of the plasma membrane. They do so by the so-called Gouy-Chapman-Stern effect which is due to the electrical "masking" that certain ions, especially divalents, can exert onto the electrically negative charged polar heads of the membrane phospholipids.Chondroitin sulfates can chelate free calcium ions to a different extent based on the spatial arrangement of their sulfate groups and can thus alter the actual availability of screening divalent ions at the outer membrane surface.Voltage-dependent ion channels sense the actual potential difference between the two sides of the plasma membrane and are thus exquisite and extremely sensitive "devices" able to react to changes in the electrical potential across the membrane.Hence, by recording the shift in the activation curve of well-known voltage-dependent ionic channels it will be possible to study the physical effect of ECM chondroitin sulfates on membrane conductances.