Substitution of bovine dentine sialoprotein with chondroitin sulfate glycosaminoglycan chains

Dentine sialoprotein (DSP) represents 5-8% of all non-collagenous proteins present in the tooth, but, together with dentine phosphoprotein, has been shown to be vital for correct tooth formation. Recently, the existence of a highly glycosylated form of porcine DSP has been reported and it was shown to possess glycosaminoglycan (GAG) chains. The current investigation confirms that this is also the case for bovine DSP and has further characterized these carbohydrates. Dentine sialoprotein was purified from bovine dentine extracts by anion exchange chromatography and identified by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), western blotting, and mass spectroscopy. An increase in molecular mass was observed, from 120 kDa to greater than 250 kDa, with a corresponding rise in anionic strength. Cellulose acetate electrophoresis and western blotting indicated the presence of chondroitin sulfate GAG chains within these dentine fractions. Further examination using sequential digestion with chondroitinase AC and N-glycosidase cleaved the samples first to 95 kDa and then to 80 kDa, respectively, confirming a high level of glycosylation. These results support the classification of bovine DSP as a proteoglycan, and that the carbohydrate substitutions may contribute to the functional properties of DSP.     

Interstitial cystitis/bladder pain syndrome and glycosaminoglycans replacement therapy

Interstitial cystitis/bladder pain syndrome (IC/BPS) is a debilitating chronic disease characterized by discomfort or recurrent abdominal and pelvic pains in the absence of urinary tract infections. Its symptomatology includes discomfort, increased bladder pressure, sensitivity and intense pain in the bladder and pelvic areas, increased voiding frequency and urgency, or a combination of these symptoms. For these reasons, this pathology has a very negative impact on quality of life. The etiology of IC/BPS is still not well understood and different hypotheses have been formulated, including autoimmune processes, allergic reactions, chronic bacterial infections, exposure to toxins or dietary elements, and psychosomatic factors. The finding of an effective and specific therapy for IC/BPS remains a challenge for the scientific community because of the lack of a consensus regarding the causes and the inherent difficulties in the diagnosis. The last recent hypothesis is that IC/BPS could be pathophysiologically related to a disruption of the bladder mucosa surface layer with consequent loss of glycosaminoglycans (GAGs). This class of mucopolysaccharides has hydrorepellent properties and their alteration expose the urothelium to many urinary toxic agents. It has been hypothesized that when these substances penetrate the bladder wall a chain is triggered in the submucosa. In order to improve the integrity and function of the bladder lining, GAG layer replenishment therapy is widely accepted as therapy for patients with IC/BPS who have poor or inadequate response to conventional therapy. Currently, Chondroitin sulfate (CS), heparin, hyaluronic acid (HA), and pentosan polysulphate (PPS), and combinations of two GAGs (CS and HA) are the available substances with different effectiveness rates in patients with IC/BPS. There are four different commercially available products for GAG replenishment including CS, heparin, HA and PPS. Each product has different concentrations and dosage formulations. Recently, a combination of CS and HA is the latest commercially available product with promising results.     

Neurophysiology of hearing in patients with mucopolysaccharidosis type IV

Background

Hearing impairment is a common problem in patients with mucopolysaccharidosis IV (MPS IV) throughout their life. Many of the adult patients with MPS IV exhibit permanent or severe hearing loss. However, there has been no systematic review of detailed audiological test results in MPS IV.

Pores Created by Laser Surface Modification of Poly(vinylalcohol)-Collagen with Glycosaminoglycan Scaffold for Cell Culture in Tissue Engineering

A PVA-GAG-COL composite scaffold is fabricated by polyvinyl alcohol (PVA),glycosaminoglycan (GAG) and collagen (COL).Laser surface modification technology is used to make holes on the surface of the sc...     

CSGALNACT1‐congenital disorder of glycosylation: A mild skeletal dysplasia with advanced bone age

Congenital disorders of glycosylation (CDGs) comprise a large number of inherited metabolic defects that affect the biosynthesis and attachment of glycans. CDGs manifest as a broad spectrum of disease, most often including neurodevelopmental and skeletal abnormalities and skin laxity. Two patients with biallelic CSGALNACT1 variants and a mild skeletal dysplasia have been described previously. We investigated two unrelated patients presenting with short stature with advanced bone age, facial dysmorphism, and mild language delay, in whom trio‐exome sequencing identified novel biallelic CSGALNACT1 variants: compound heterozygosity for c.1294G>T (p.Asp432Tyr) and the deletion of exon 4 that includes the start codon in one patient, and homozygosity for c.791A>G (p.Asn264Ser) in the other patient. CSGALNACT1 encodes CSGalNAcT‐1, a key enzyme in the biosynthesis of sulfated glycosaminoglycans chondroitin and dermatan sulfate. Biochemical studies demonstrated significantly reduced CSGalNAcT‐1 activity of the novel missense variants, as reported previously for the p.Pro384Arg variant. Altered levels of chondroitin, dermatan, and heparan sulfate moieties were observed in patients’ fibroblasts compared to controls. Our data indicate that biallelic loss‐of‐function mutations in CSGALNACT1 disturb glycosaminoglycan synthesis and cause a mild skeletal dysplasia with advanced bone age, CSGALNACT1‐CDG.     

Keratan sulfate exacerbates experimental autoimmune encephalomyelitis

Proteoglycans (PGs) are the components of extracellular matrices in the central nervous system (CNS). Keratan sulfate (KS) is a glycosaminoglycan that is included in the KSPG that acts as an inhibitory factor in nerve regeneration after CNS injury. To investigate the role of KS in immune diseases, we induced experimental autoimmune encephalomyelitis (EAE) in mice that were deficient in the N‐acetylglucosamine (GlcNAc)‐6‐O‐sulfotransferase 1 (GlcNAc6ST1) gene (KS‐KO). KS‐KO mice developed less severe EAE and showed repressed recall response in the induction phase. Furthermore, GlcNAc6ST1 might have roles in the passage of the pathogenic lymphocytes through the blood–brain barrier via adhesion molecules. Thus, modulation of KS may become a treatment for neuroimmunological diseases. © 2015 Wiley Periodicals, Inc.     

非小细胞肺癌血清硫酸粘多糖片段、恶性肿瘤相关物质和癌胚抗原的表达及意义

目的探讨血清硫酸粘多糖片段（SGF）、恶性肿瘤相关物质（TSGF）及癌胚抗原（CEA）三种肿瘤标志物在非小细胞肺癌（NSCLC）患者血清中的表达及临床意义。方法采用胶乳凝集法、生化显色法和化学发光法检测50例NSCLC患者血清SGF、TSGF及CEA水平,比较不同的检测组合方式在NSCLC诊断中的价值。结果NSCLC Ⅰ～Ⅱ期与Ⅲ期间及Ⅲ期与Ⅳ期间SGF水平差异有统计学意义（P〈0．05）;SGF、TS．GF及CEA单项与SGF和TSGF组合检测特异性差异无统计学意义（P〉0．05）;SGF和TSGF组合与SGF、TS—GF及CEA组合间灵敏度差异无统计学意义（P〉0．05）,其特异性差异有统计学意义（P〈0．05）。结论三种肿瘤标志物在NSCLC患者血清中均有较高表达,不同的组合检测中SGF与TSGF组合对NSCLC诊断优于其他组合。     

Oversulfated chondroitin sulfate interaction with heparin-binding proteins: New insights into adverse reactions from contaminated heparins

An oversulfated chondroitin sulfate (OSCS) was identified as a contaminant to pharmaceutical heparin and severe anaphylactoid reactions were ascribed to this contaminant. An examination of the biochemistry underlying both the anticoagulant activity and the toxic effects of oversulfated chondroitin sulfate was undertaken. This study demonstrates that the anticoagulant activity of this oversulfated chondroitin sulfate is primarily dependent on heparin cofactor II mediated inhibition of thrombin. Heparin and oversulfated chondroitin sulfate binding to coagulation, kinin-kallikrein and complement proteins were studied by surface plasmon resonance. While oversulfated chondroitin sulfate binds tightly to antithrombin III, unlike heparin, OSCS does not induce antithrombin III to undergo the conformational change required for its inactivation of thrombin and factor Xa. In contrast to heparin, oversulfated chondroitin sulfate tightly binds factor XIIa suggesting a biochemical mechanism for the factor XIIa-based enhancement of vasoactive bradykinin production.