heparitin-sulfate and Nervous-System-Diseases

Mucopolysaccharidosis IIIB (MPS IIIB, Sanfilippo syndrome type B) is caused by a deficiency in α-N-acetylglucosaminidase (NAGLU) activity, which leads to the accumulation of heparan sulfate (HS). MPS IIIB causes progressive neurological decline, with affected patients having an expected lifespan of approximately 20 years. No effective treatment is available. Recent pre-clinical studies have shown that intracerebroventricular (ICV) ERT with a fusion protein of rhNAGLU-IGF2 is a feasible treatment for MPS IIIB in both canine and mouse models. In this study, we evaluated the biochemical efficacy of a single dose of rhNAGLU-IGF2 via ICV-ERT in brain and liver tissue from Naglu

Topics: Acetylglucosaminidase; Animals; Animals, Newborn; Disease Models, Animal; Dogs; Enzyme Replacement Therapy; Heparitin Sulfate; Humans; Infusions, Intraventricular; Insulin-Like Growth Factor II; Mice; Mice, Knockout; Mucopolysaccharidosis III; Nervous System Diseases; Recombinant Fusion Proteins

Mucopolysaccharidosis type II (MPS II or Hunter syndrome) is a lysosomal storage disorder caused by a deficiency of iduronate-2-sulfatase (IDS), an enzyme that catabolizes glycosaminoglycans (GAGs) including heparan sulfate (HS) and dermatan sulfate (DS). GAG accumulation leads to severe neurological and somatic impairments. At present, the most common treatment for MPS II is intravenous enzyme replacement therapy; however, the inability of recombinant IDS to cross the blood-brain barrier (BBB) restricts therapeutic efficacy for neurological manifestations. We recently developed a BBB-penetrating IDS fusion protein, JR-141, and demonstrated its ability to reduce GAG accumulation in the brain of human transferrin receptor knock-in and Ids knock-out mice (TFRC-KI/Ids-KO), an animal model of MPS II, following intravenous administration. Given the impossibility of measuring GAG accumulation in the brains of human patients with MPS II, we hypothesized that GAG content in the cerebrospinal fluid (CSF) might serve as an indicator of brain GAG burden. To test this hypothesis, we optimized a high-sensitivity method for quantifying HS and DS in low-volume samples by combining acidic methanolysis and liquid chromatography-tandem mass spectrometry (LC/MS/MS). We employed this method to quantify HS and DS in samples from TFRC-KI/Ids-KO mice and revealed that HS but not DS accumulated in the central nerve system (CNS). Moreover, concentrations of HS in CSF correlated with those in brain. Finally, intravenous treatment with JR-141 reduced levels of HS in the CSF and brain in TFRC-KI/Ids-KO mice. These results suggest that CSF HS content may be a useful biomarker for evaluating the brain GAG accumulation and the therapeutic efficacy of drugs in patients with MPS II.

Topics: Animals; Biomarkers; Blood-Brain Barrier; Brain; Chromatography, Liquid; Dermatan Sulfate; Disease Models, Animal; Heparitin Sulfate; Humans; Iduronate Sulfatase; Mice; Mice, Knockout; Mucopolysaccharidosis II; Nervous System Diseases; Receptors, Transferrin; Tandem Mass Spectrometry

Mucopolysaccharidosis type IIIA (MPS IIIA) is an inherited neurodegenerative lysosomal storage disorder characterised by progressive loss of learned skills, sleep disturbance and behavioural problems. Reduced activity of sulphamidase (SGSH; EC 3.10.1.1) results in intracellular accumulation of heparan sulphate (HS), with the brain the primary site of pathology. We have used a naturally-occurring MPS IIIA mouse model to determine the effectiveness of SGSH replacement via the cerebrospinal fluid (CSF) to decrease neuropathology. This is a potential therapeutic option for patients with this disorder. Mice received intra-CSF injections of recombinant human SGSH (30, 50 or 70 mug) fortnightly from six-18 weeks of age, and the cumulative effect on neuropathology was examined and quantified. Anti-SGSH antibodies detected in plasma at euthanasia did not appear to impact upon the health of the mice or the experimental outcome, with significant, but region- and dose-dependent reductions in an HS-derived oligosaccharide observed in the brain and spinal cord using tandem mass spectrometry. SGSH infusion reduced the number of storage inclusions observed in the brain when visualised using electron microscopy and this correlated with a significant decrease in the immunohistochemical staining of a lysosomal membrane marker (LIMP-II). Reduced numbers of activated isolectin-B4-positive microglia and GFAP-positive astrocytes were seen in many, but not all, brain regions. Significant reductions in the number of ubiquitin-positive intracellular inclusions were also observed. These outcomes demonstrate the effectiveness of this method of enzyme delivery in reducing the spectrum of neuropathological changes in murine MPS IIIA brain.

Topics: Animals; Brain; Disease Models, Animal; Heparitin Sulfate; Humans; Hydrolases; Male; Mice, Transgenic; Mucopolysaccharidosis III; Nervous System Diseases

Given the high short-term risk of stroke after transient ischemic attack, we hypothesized that substantial acute neurological recovery in patients presenting with cerebral ischemia would be associated with a greater risk of subsequent neurological deterioration due to recurrent cerebral ischemia. Data from the Trial of ORG10172 in Acute Stroke Treatment, a randomized trial of the heparinoid danaparoid, were analyzed to determine whether substantial acute recovery, defined as an improvement of greater than or equal to 75% on National Institutes of Health Stroke Scale (NIHSS) between baseline and 24 hours, was associated with a greater risk of subsequent deterioration, defined as a worsening on the NIHSS between day 1 and day 90. Of 1,184 subjects meeting entry criteria, 63 (5.3%) had substantial acute recovery. Subsequent deterioration was more common in those with substantial acute recovery compared with others (48 vs 33%; p = 0.028 by Fisher's exact test). In multivariable models, substantial acute recovery remained an independent predictor of subsequent deterioration (odds ratio, 3.0; 95% confidence interval, 1.7-5.2; p < 0.001). Among patients with acute cerebral ischemia, those who recover substantially within 24 hours may be at greater risk of subsequent neurological deterioration due to causes other than hemorrhage.

Topics: Aged; Anticoagulants; Blood Glucose; Blood Pressure; Case-Control Studies; Chondroitin Sulfates; Dermatan Sulfate; Disease Progression; Drug Combinations; Female; Follow-Up Studies; Heart Rate; Heparitin Sulfate; Humans; Ischemic Attack, Transient; Male; Middle Aged; Nervous System Diseases; Neurologic Examination; Odds Ratio; Randomized Controlled Trials as Topic; Recovery of Function; Risk; Time Factors