The Toxicology of Native Fucosylated Glycosaminoglycans and the Safety of Their Depolymerized Products as Anticoagulants.

Fucosylated glycosaminoglycan (FG) from sea cucumber is a potent anticoagulant by inhibiting intrinsic coagulation tenase (iXase). However, high-molecular-weight FGs can activate platelets and plasma contact system, and induce hypotension in rats, which limits its application. Herein, we found that FG from T. ananas (TaFG) and FG from H. fuscopunctata (HfFG) at 4.0 mg/kg (i.v.) could cause significant cardiovascular and respiratory dysfunction in rats, even lethality, while their depolymerized products had no obvious side effects. After injection, native FG increased rat plasma kallikrein activity and levels of the vasoactive peptide bradykinin (BK), consistent with their contact activation activity, which was assumed to be the cause of hypotension in rats. However, the hemodynamic effects of native FG cannot be prevented by the BK receptor antagonist. Further study showed that native FG induced in vivo procoagulation, thrombocytopenia, and pulmonary embolism. Additionally, its lethal effect could be prevented by anticoagulant combined with antiplatelet drugs. In summary, the acute toxicity of native FG is mainly ascribed to pulmonary microvessel embolism due to platelet aggregation and contact activation-mediated coagulation, while depolymerized FG is a safe anticoagulant candidate by selectively targeting iXase.

Sulfonated azo dyes enhance the genome release of enterovirus A71 VP1-98K variants by preventing the virions from being trapped by sulfated glycosaminoglycans at acidic pH.

Enterovirus A71 (EV-A71) is a causative agent of hand, foot and mouth disease and occasionally causes death in children. Its infectivity and pathogenesis, however, remain to be better understood. Three sulfonated azo dyes, including acid red 88 (Ar88), were identified to enhance the infectivity of EV-A71, especially isolates with VP1-98K, 145E (-KE), by mainly promoting viral genome release in vitro. Enzymatic removal of sulfated glycosaminoglycans (GAGs) or knockout of xylosyltransferase II (XT2) responsible for biosynthesis of sulfated GAGs weakened the Ar88 enhanced EV-A71 infection. Ar88 is proposed to prevent the -KE variants from being trapped by sulfated GAGs at acidic pH and to facilitate the viral interaction with uncoating factors for genome release in endosomes. The results suggest dual roles of sulfated GAGs as attachment factors and as decoys during host interaction of EV-A71 and caution that these artificial dyes in our environment can enhance viral infection.

LC-MS/MS characterization of xyloside-primed glycosaminoglycans with cytotoxic properties reveals structural diversity and novel glycan modifications.

Structural characterization of glycosaminoglycans remains a challenge but is essential for determining structure-function relationships between glycosaminoglycans and the biomolecules with which they interact and for gaining insight into the biosynthesis of glycosaminoglycans. We have recently reported that xyloside-primed chondroitin/dermatan sulfate derived from a human breast carcinoma cell line, HCC70, has cytotoxic effects and shown that it differs in disaccharide composition from nontoxic chondroitin/dermatan sulfate derived from a human breast fibroblast cell line, CCD-1095Sk. To further investigate the structural requirements for the cytotoxic effect, we developed a novel LC-MS/MS approach based on reversed-phase dibutylamine ion-pairing chromatography and negative-mode higher-energy collision dissociation and used it in combination with cell growth studies and disaccharide fingerprinting. This strategy enabled detailed structural characterization of linkage regions, internal oligosaccharides, and nonreducing ends, revealing not only differences between xyloside-primed chondroitin/dermatan sulfate from HCC70 cells and CCD-1095Sk cells, but also sialylation of the linkage region and previously undescribed methylation and sulfation of the nonreducing ends. Although the xyloside-primed chondroitin/dermatan sulfate from HCC70 cells was less complex in terms of presence and distribution of iduronic acid than that from CCD-1095Sk cells, both glucuronic acid and iduronic acid appeared to be essential for the cytotoxic effect. Our data have moved us one step closer to understanding the structure of the cytotoxic chondroitin/dermatan sulfate from HCC70 cells primed on xylosides and demonstrate the suitability of the LC-MS/MS approach for structural characterization of glycosaminoglycans.

Practical management of behavioral problems in mucopolysaccharidoses disorders.

The mucopolysaccharidosis (MPS) disorders are caused by deficiencies of specific lysosomal enzymes, resulting in progressive glycosaminoglycan (GAG) accumulation in cells and tissues throughout the body. Excessive GAG storage can lead to a variety of somatic manifestations as well as primary and secondary neurological symptoms. Behavioral problems (like hyperactivity, attention difficulties, and severe frustration) and sleeping problems are typical primary neurological symptoms of MPS caused by GAG accumulation in neurons, and are frequently observed in patients with MPS I, II, III, and VII. As these problems often place a significant burden on the family, proper management is important. This review summarizes current insights into behavioral and sleeping problems in MPS disorders and the most optimal management approaches, as presented and discussed during a meeting of an international group of experts with extensive experience in managing and treating MPS.

Epilepsy in mucopolysaccharidosis disorders.

The mucopolysaccharidosis (MPS) disorders are caused by deficiencies of specific lysosomal enzymes involved in the catabolism of glycosaminoglycans (GAGs). The resulting GAG accumulation in cells and tissues throughout the body leads to progressive multi-organ dysfunction. MPS patients present with several somatic manifestations, including short stature, musculoskeletal abnormalities, and cardiorespiratory dysfunction, and several primary and secondary neurological signs and symptoms. Epileptic seizures are neurological signs of MPS thought to develop due to accumulation of GAGs in the brain, triggering alterations in neuronal connectivity and signaling, and release of inflammatory mediators. The amount of literature on the prevalence, pathophysiology, clinical features, and management of epileptic seizures in patients with MPS is limited. This review discusses current knowledge on this topic, as well as two case examples, presented and discussed during a closed meeting on MPS and the brain among an international group of experts with extensive experience in managing and treating MPS.

Treatment of brain disease in the mucopolysaccharidoses.

The mucopolysaccharidosis (MPS) disorders are a group of lysosomal storage diseases caused by lysosomal enzyme deficits that lead to glycosaminoglycan accumulation, affecting various tissues throughout the body based on the specific enzyme deficiency. These disorders are characterized by their progressive nature and a variety of somatic manifestations and neurological symptoms. There are established treatments for some MPS disorders, but these mostly alleviate somatic and non-neurological symptoms and do not cure the disease. Patients with MPS I, II, III, and VII can present with neurological manifestations such as neurocognitive decline and behavioral problems. Treatment of these neurological manifestations remains challenging due to the blood-brain barrier (BBB) that limits delivery of therapeutic agents to the central nervous system (CNS). New therapies that circumvent this barrier and target brain disease in MPS are currently under development. They primarily focus on facilitating penetration of drugs through the BBB, delivery of recombinant enzyme to the brain by gene therapy, or direct CNS administration. This review summarizes existing and potential future treatment approaches that target brain disease in MPS. The information in this review is based on current literature and presentations and discussions during a closed meeting by an international group of experts with extensive experience in managing and treating MPS.

Surgical management of neurological manifestations of mucopolysaccharidosis disorders.

The mucopolysaccharidosis (MPS) disorders are ultra-rare lysosomal storage disorders associated with progressive accumulation of glycosaminoglycans (GAGs) in cells and tissues throughout the body. Clinical manifestations and progression rates vary widely across and within the different types of MPS. Neurological symptoms occur frequently, and may result directly from brain damage caused by infiltration of GAGs, or develop secondary to somatic manifestations such as spinal cord compression, hydrocephalus, and peripheral nerve entrapment. Management of secondary neurological manifestations often requires surgical correction of the underlying somatic cause. The present review discusses the surgical management of neurological disease in patients with MPS, including diagnostic imaging. Background information is derived from presentations and discussions during a meeting on the brain in MPS, attended by an international group of experts (April 28-30, 2016, Stockholm, Sweden), and additional literature searches.

Assessments of neurocognitive and behavioral function in the mucopolysaccharidoses.

The mucopolysaccharidoses (MPS) are a group of rare, inherited lysosomal storage disorders in which accumulation of glycosaminoglycans (GAGs) leads to progressive tissue and organ dysfunction. In addition to a variety of somatic signs and symptoms, patients with rapidly progressing MPS I (Hurler), II, III, and VII can present with significant neurological manifestations, including impaired cognitive abilities, difficulties in language and speech, behavioral abnormalities, sleep problems, and/or seizures. Neurological symptoms have a substantial impact on the quality of life of MPS patients and their families. Due to the progressive nature of cognitive impairment in these MPS patients, neurocognitive function is a sensitive indicator of disease progression, and a relevant outcome when testing efficacy of therapies for these disorders. In order to effectively manage and develop therapies that address neurological manifestations of MPS, it is important to use appropriate neurocognitive assessment tools that are sensitive to changes in neurocognitive function in MPS patients. This review discusses expert opinions on key issues and considerations for effective neurocognitive testing in MPS patients. In addition, it describes the neurocognitive assessment tools that have been used in clinical practice for these patients. The content of this review is based on existing literature and information from a meeting of international experts with extensive experience in managing and treating MPS disorders.

Quantitative neuroimaging in mucopolysaccharidoses clinical trials.

The mucopolysaccharidosis (MPS) disorders are rare lysosomal storage disorders caused by mutations in lysosomal enzymes involved in glycosaminoglycan (GAG) degradation. The resulting intracellular accumulation of GAGs leads to widespread tissue and organ dysfunction. In addition to somatic signs and symptoms, patients with MPS can present with neurological manifestations such as cognitive decline, behavioral problems (e.g. hyperactivity and aggressiveness), sleep disturbances, and/or epilepsy. These are associated with significant abnormalities of the central nervous system (CNS), including white and gray matter lesions, brain atrophy, ventriculomegaly, and spinal cord compression. In order to effectively manage and develop therapies for MPS that target neurological disease, it is important to visualize and quantify these CNS abnormalities. This review describes optimal approaches for conducting magnetic resonance imaging assessments in multi-center clinical studies, and summarizes current knowledge from neuroimaging studies in MPS disorders. The content of the review is based on presentations and discussions on these topics that were held during a meeting of an international group of experts.

Developmental and behavioral aspects of mucopolysaccharidoses with brain manifestations - Neurological signs and symptoms.

The mucopolysaccharidoses (MPS) are a group of rare, inherited lysosomal storage disorders, caused by mutations in lysosomal enzymes involved in the degradation of glycosaminoglycans (GAGs). The resulting accumulation of GAGs in the body leads to widespread tissue and organ dysfunction. The spectrum, severity, and progression rate of clinical manifestations varies widely between and within the different MPS types. In addition to somatic signs and symptoms, which vary between the different MPS disorders, patients with MPS I, II, III, and VII present with significant neurological signs and symptoms, including impaired cognitive abilities, difficulties in language and speech, and/or behavioral and sleep problems. To effectively manage and develop therapies that target these neurological manifestations, it is of utmost importance to have a profound knowledge of their natural history and pathophysiology. This review describes the appearance and progression of neurological signs and symptoms in patients with MPS I, II, and III, based on presentations and discussions among an international group of experts during a meeting on the brain in MPS on April 28-30, 2016, and additional literature searches on this subject.

Pathophysiology, evaluation, and management of sleep disorders in the mucopolysaccharidoses.

The mucopolysaccharidoses (MPS) represent a heterogeneous group of lysosomal storage disorders, each one associated with a deficiency in one of the enzymes involved in glycosaminoglycan degradation. Sleep disorders are a frequent manifestation of all types of MPS. Underlying causes are diverse and comprised of both respiratory and central nervous system (CNS) abnormalities. Sleep disordered breathing such as obstructive sleep apnea and nocturnal hypoventilation can arise in patients with upper airway obstruction and/or with alterations in respiratory mechanics, causing restrictive pulmonary disease. MPS patients with CNS disease can also develop sleep disturbances unrelated to ventilatory impairments, often associated with severe behavioral problems or night-time epileptic seizures. The present review discusses the pathophysiology, evaluation, and management of sleep disorders in MPS based on information from a meeting on the brain in MPS, attended by an international group of experts (April 28-30, 2016, Stockholm, Sweden), and additional literature searches.

Toxicological evaluation of RGTA OTR4120, a heparan sulfate mimetic.

Heparan sulfate mimetic polymers promotes tissue repair when injected locally in doses of 1-2mg/kg by various routes. These biopolymers, have been extensively studied for their diverse biological activities. However, there is no detailed report investigating the toxicity of OTR4120. In this study, the acute and subchronic (30 days) toxicity of varying levels of OTR4120 was investigated in mice after intraperitoneal administration. The results showed that no significant toxicological changes were observed when 50mg/kg body weight per day OTR4120 was administered to mice. But when the dose was increased to 60 and 70 mg/kg body weight per day, the clotting time was significantly prolonged. Alanine aminotransferase (ALT), aspartate aminotransferase (AST) and alkaline phosphatase (ALP) activities were reduced female and male at dose 70 mg/kg body weight per day. These blood biochemistry data suggest that OTR4120 have a hepatoprotective effect. Based on these results, it can be concluded that the no adverse effect level of OTR4120 is 50 mg/kg body weight per day.

Histologic and histomorphometric evaluation of two bone substitute materials for bone regeneration: an experimental study in sheep.

INTRODUCTION: In the past decade, there has been an increase focus on regeneration approaches as related to periodontics and implant therapies. The main objective of the present study is the evaluation of quality, density, and thickness of the newly formed bone in experimental defects treated with deproteinized bovine bone mineral (DBBM) and bioapatite-collagen. MATERIALS: Fifteen identical cuboidal defects were prepared in the alveolar edentulous mandibular ridges in 10 male sheep. Defects were randomly assigned to be treated either with DBBM, Bioapatite-collagen or remained unfilled as the control group. Defects of these 3 groups were histologically examined after 6 months. RESULTS: The mean percentages of bone regeneration with DBBM, Bioapatite-collagen, and control group were 51.40% +/- 3.57%, 27.66% +/- 4.18%, and 19% +/- 1%, respectively (P < 0.05). Defects filled with Bio-Oss and control defects did not show foreign body reaction, whereas Biostite particles had a reaction in 40% of the specimens. Trabecular thickness and type of new regenerated bone were also significantly different between Bio-Oss and Biostite (P < 0.05) and control group (P < 0.05). CONCLUSION: The results of the present study suggest that using of DBBM particles can promote bone regeneration more effectively than Bioapatite-collagen, and both materials were more promising than the control group.

Optimization of UV cross-linking density for durable and nontoxic collagen GAG dermal substitute.

Artificial dermal constructs, based upon collagen-glycosaminoglycan matrices (CGMs), provide new options in treating skin defects. However, their clinical effectiveness may be limited by cytotoxicity related to residual aldehydes left over from the manufacturing process. Although both chemical and dehydrothermal (DHT) cross-linking are used to produce CGMs, we hypothesize that optimized nonchemical cross-linking, using ultra-violet (UV) and DHT treatment combinations, may limit cytotoxicity without sacrificing mechanical strength. Porous CGMs were physically cross-linked using a combination of DHT and varying intensities of UV light. These were compared to glutaraldehyde cross-linked controls. Human keratinocytes were seeded in each matrix, and cellular proliferation measured using a microculture tetrazolium dye assay. A scoring system (based on the in vitro contraction rate, stiffness, and cellular growth of a small cylindrical specimen) was developed to assess the best overall physical cross-linking method. More cellular growth was observed in the 90-120 min UV cross-linked group than in the glutaraldehyde-treated group (p < 0.05). Stiffness was maximized after 0-30 min of UV cross-linking. On the basis of our scoring system, DHT combined with 45 min of UV cross-linking produced the best overall matrix in terms of cellular growth and physical durability. UV cross-linked collagen-based biomaterials could be a viable alternative for use in biological applications to eliminate glutaraldehyde-associated cytotoxicity.

Randomised, double blind, multicentre, placebo controlled study of sulodexide in the treatment of venous leg ulcers.

Sulodexide, a highly purified glycosaminoglycan, was investigated for treatment of venous leg ulcers. Patients (n = 235) undergoing local treatment including wound care and compression bandaging, were randomised to receive either sulodexide or matching placebo for three months. Primary study endpoint was complete ulcer healing after 2 months; secondary endpoints were ulcer healing at 3 months and the time-course changes of ulcer areas. The proportion of patients with complete ulcer healing was higher with sulodexide at 2 months (p = 0.018) and 3 months. The "number needed to treat" to obtain one additional patient healed with sulodexide was 7 at 2 months and 5 at 3 months. The changes in ulcer surface area with time were significant for sulodexide only (p = 0.004). Fibrinogen significantly decreased in sulodexide patients (p = 0.006). In conclusion, sulodexide associated with local treatment proved to be effective and well tolerated in the management of venous leg ulcers.

Mucopolysaccharides from psyllium involved in wound healing.

Mucopolysaccharides derived from the husk of psyllium (Plantago ovata) have properties beneficial for wound cleansing and wound healing. Recent studies indicate that these mucopolysaccharides also limit scar formation. Our in vitro and in vivo studies aimed to investigate the mechanisms involved, e.g., fluid absorption, bacterial adherence and in vitro stimulatory effects on macrophages, which are pivotal in wound healing. The mucopolysaccharides contained in a sachet (Askina Cavity) or in a hydrocolloid mixture (Askina Hydro) were found to have a gradual and sustained absorbency over a period of 7 days, amounting to 4-6 times their weight in water. The swelling index was 9 mm after 312 h. Adherence of wound bacteria to the mucopolysaccharides started after 2 h and was more pronounced after 3 h. Semiquantitative measurements of bacterial adherence used centrifugation and subsequent optical density determinations of supernatant. These confirmed the strong adherence potential of psyllium particles. Lactic acid dehydrogenase staining of pretreated cultured human skin explants did not reveal toxicity of the mucopolysaccharides derived from psyllium husk. Langerhans' cell migration from the epidermis was negligible and interleukin-1 beta expression in the explants was not significant, supporting the very low allergenic potential of psyllium. The characteristics of mucopolysaccharide granulate derived from psyllium husk in Askina Cavity and Askina Hydro related to fluid absorption, bacterial adherence, biocompatibility, stimulation of macrophages, irritancy response and allergenicity showed an optimal profile, supporting the good clinical performance of wound healing products containing psyllium husk.

Treatment of intermittent claudication with mesoglycan--a placebo-controlled, double-blind study.

OBJECTIVE: To assess the effect of treatment with mesoglycan, a sulphated polysaccharide compound, on the walking capacity of patients with stage II peripheral arterial disease. METHODS: Non-diabetic outpatients with intermittent claudication, duplex ultrasound evidence of peripheral atherosclerosis, ankle/arm index <0.80, systolic ankle pressure >50 mmHg, and absolute walking distance (AWD) between 100 and 300 m (standardised treadmill test) were eligible. After a 5-week run-in on single-blind placebo, patients were randomised to double-blind treatment with mesoglycan, 30 mg/day intramuscularly for 3 weeks followed by 100 mg/day orally for 20 weeks, or matching placebo. All patients received low-dose aspirin and lifestyle instructions. Clinical response was defined as an AWD increase at Week 23 >50% over baseline. Health-related quality of life and ischaemic events were assessed as secondary efficacy variables. RESULTS: 242 patients were randomised and 237 were assessed for clinical response. Patients achieving clinical response were 59/118 with mesoglycan (50.0%) and 31/119 with placebo (26.1%; p <0.001). Geometric mean AWD increased from 192 to 298 m with mesoglycan, and from 192 to 238 m with placebo (p <0.001). Pain-free walking distance showed a non-significant increase with mesoglycan (p = 0.057). Changes in quality of life scores were in favour of mesoglycan. The rate of ischaemic events was 1/120 on mesoglycan and 6/122 on placebo (p = 0.053). The rate of non-ischaemic adverse events leading to treatment discontinuation was 7/120 and 4/122, respectively. CONCLUSION: Treatment with mesoglycan improves the walking capacity of patients with intermittent claudication, and might confer additional antithrombotic protection over that of aspirin.

Heparin-induced thrombocytopenia: clinical considerations of alternative anticoagulation with various glycosaminoglycans and thrombin inhibitors.

Heparin-induced thrombocytopenia (HIT), the most common complication of heparin therapy, is also the most common form of the drug-induced thrombocytopenias. HIT is classified as type I and type II, the first being benign and the latter severe. HIT type II is attributed to an immune response characterized by complexes of heparin and platelet factor (PF) 4. Enzyme-linked immunosorbent assays allow easy and simple determination of these antibody titers; however, because specificity and sensitivity is not optimal, there is concern that the clinical relevance may be low. In clinical trials many patients were shown to form HIT-IgG in response to heparin without developing manifestations of HIT type II. Therefore, routine screening of clinically asymptomatic patients for antiheparin/PF 4 antibodies is not recommended. HIT type II is a clinico-pathologic syndrome that ideally should be confirmed by laboratory testing. If any clinical suspicion arises, however, heparin and low molecular weight heparin therapy should be discontinued and an alternative anticoagulant therapy started. Alternative drugs have been evaluated in significant numbers of patients including danaparoid and thrombin inhibitors. In the case of danaparoid, it is highly recommended that an in vitro test for cross-reactivity be performed before the onset of therapy. If testing cannot be performed, immediate administration of a thrombin inhibitor is preferred.

Effect of intramuscular polysulfated glycosaminoglycans on bovine semen production and quality of the cryopreserved semen.

Polysulfated glycosaminoglycans (PSGAG) are widely used to treat cartilage disease in horses. The drug's safety in breeding animals has not been documented. This study determined whether im PSGAG is detrimental to the bull's health and, in particular, the quantity of semen produced or the quality of the cryopreserved product. No clinically significant effect of treatment on hematologic or serum biochemistry parameters was detected, but a significant treatment x time interaction for mean corpuscular volume warrants further investigation. There was an unexplained treatment effect on total daily sperm numbers collected, even though the pre-treatment values were included as co-variates in the statistical analysis to control for any day 0 variability. There was no effect on the percent forward motile sperm in the fresh ejaculate. Although there was no significant effect of treatment on the post-thaw semen data, the power of each statistical analysis was low, ranging from 10% to 19%. Further studies using larger sample sizes are warranted. These preliminary studies suggest that im PSGAG is safe to use in bulls on an experimental basis.

Orgaran (Org 10172): its pharmacological profile in experimental models.

Orgaran is a mixture of glycosaminoglycans extracted from animal mucosa. It consists of heparan, dermatan and chondroitin sulfate; a small proportion of heparan sulfate (4%) has high affinity for antithrombin III (AT III). Orgaran is devoid of heparin or heparin fragments. Orgaran catalyses the inactivation of factor Xa and thrombin. Compared to heparin and most low-molecular-weight heparins, Orgaran has a much higher anti-Xa/anti-IIa ratio. The inactivation of factor Xa is mediated by AT III and that of thrombin by both AT III and heparin cofactor II. Compared to heparin, which is a strong inhibitor of thrombin generation, Orgaran has only moderate inhibitory effects on thrombin generation. Orgaran shows minimal or no effects on platelet function in vitro or in vivo. It inhibits the formation of various types of thrombi (clot-like and mixed thrombi) with approximately the same potency as heparin. Both the high- and low-affinity fraction for AT III contribute to the antithrombotic activity. In contrast to heparin, Orgaran does not inhibit platelet deposition in experimental mixed thrombi unless very high doses of the heparinoid are used. Orgaran is more efficacious than heparin in preventing the extension of established venous thrombosis. Orgaran promotes less bleeding-enhancing activity than heparin in various experimental models. In addition, compared to heparin, it has only minimal effects on platelet degranulation during hemostatic plug formation.(ABSTRACT TRUNCATED AT 250 WORDS)