COVID-19 represents the most serious public health event in the past few decades of the 21^st century. The development of vaccines, neutralizing antibodies, and small molecule chemical agents have effectively prevented the rapid spread of COVID-19. However, the continued emergence of SARS-CoV-2 variants have weakened the efficiency of these vaccines and antibodies, which brought new challenges for searching novel anti-SARS-CoV-2 drugs and methods. In the process of SARS-CoV-2 infection, the virus firstly attaches to heparan sulphate on the cell surface of respiratory tract, then specifically binds to hACE2. The S protein of SARS-CoV-2 is a highly glycosylated protein, and glycosylation is also important for the binding of hACE2 to S protein. Furthermore, the S protein is recognized by a series of lectin receptors in host cells. These finding implies that glycosylation plays important roles in the invasion and infection of SARS-CoV-2. Based on the glycosylation pattern and glycan recognition mechanisms of SARS-CoV-2, it is possible to develop glycan inhibitors against COVID-19. Recent studies have shown that sulfated polysaccharides originated from marine sources, heparin and some other glycans display anti-SARS-CoV-2 activity. This review summarized the function of glycosylation of SARS-CoV-2, discoveries of glycan inhibitors and the underpinning molecular mechanisms, which will provide guidelines to develop glycan-based new drugs against SARS-CoV-2.
Antibodies, Neutralizing ; Glycosylation ; Heparin ; Heparitin Sulfate ; Humans ; Polysaccharides/chemistry* ; Receptors, Mitogen/metabolism* ; SARS-CoV-2 ; Spike Glycoprotein, Coronavirus/metabolism* ; COVID-19 Drug Treatment

Heparin and heparan sulfate are a class of glycosaminoglycans for clinical anticoagulation. Heparosan N-sulfate-glucuronate 5-epimerase (C5, EC 5.1.3.17) is a critical modifying enzyme in the synthesis of heparin and heparan sulfate, and catalyzes the inversion of carboxyl group at position 5 on D-glucuronic acid (D-GlcA) of N-sulfoheparosan to form L-iduronic acid (L-IdoA). In this study, the heparin C5 epimerase gene Glce from zebrafish was expressed and molecularly modified in Escherichia coli. After comparing three expression vectors of pET-20b (+), pET-28a (+) and pCold Ⅲ, C5 activity reached the highest ((1 873.61±5.42) U/L) with the vector pCold Ⅲ. Then we fused the solution-promoting label SET2 at the N-terminal for increasing the soluble expression of C5. As a result, the soluble protein expression was increased by 50% compared with the control, and the enzyme activity reached (2 409±6.43) U/L. Based on this, site-directed mutations near the substrate binding pocket were performed through rational design, the optimal mutant (V153R) enzyme activity and specific enzyme activity were (5 804±5.63) U/L and (145.1±2.33) U/mg, respectively 2.41-fold and 2.28-fold of the original enzyme. Modification and expression optimization of heparin C5 epimerase has laid the foundation for heparin enzymatic catalytic biosynthesis.
Animals ; Carbohydrate Epimerases ; biosynthesis ; chemistry ; genetics ; Escherichia coli ; Gene Expression ; Heparin ; metabolism ; Heparitin Sulfate ; metabolism ; Iduronic Acid ; metabolism ; Zebrafish Proteins ; biosynthesis ; chemistry ; genetics

Mucopolysaccharidosis type II (MPS II) is a rare X-linked recessive lysosomal storage disease caused by mutation of the iduronate-2-sulfatase gene. The mutation results in iduronate-2-sulfatase deficiency, which causes the progressive accumulation of heparan sulfate and dermatan sulfate in cellular lysosomes. The phenotype, age of onset, and symptoms of MPS II vary; accordingly, the disease can be classified into either the early-onset type or the late-onset type, depending on the age of onset and the severity of the symptoms. In patients with severe MPS II, symptoms typically first appear between 2 and 5 years of age. Patients with severe MPS II usually die in the second decade of life although some patients with less severe disease have survived into their fifth or sixth decade. Here, we report the establishment of a preimplantation genetic diagnosis (PGD) strategy using multiplex nested polymerase chain reaction, direct sequencing, and linkage analysis. Unaffected embryos were selected via the diagnosis of a single blastomere, and a healthy boy was delivered by a female carrier of MPS II. This is the first successful application of PGD in a patient with MPS II in Korea
Age of Onset ; Blastomeres ; Dermatan Sulfate ; Diagnosis ; Embryonic Structures ; Female ; Heparitin Sulfate ; Humans ; Korea ; Lysosomal Storage Diseases ; Lysosomes ; Male ; Mucopolysaccharidoses ; Mucopolysaccharidosis II ; Multiplex Polymerase Chain Reaction ; Parturition ; Phenotype ; Polymerase Chain Reaction ; Preimplantation Diagnosis ; Prostaglandins D

Heparinases can produce biologically active oligosaccharides by specifically cleaving the α-(1,4) glycosidic linkages of heparin and heparan sulphate. Heparinases are divided into heparinase and heparanase. Because heparinase is an effective biocatalyst, more and more researchers pay attention to the application of heparinase in medical field in the recent years. Combined with the related research work in our group, the application value of heparinase in the medical field was summarized, such as the determination of the structure of heparin, the preparation of low-molecular-weight heparin and ultra-low-molecular-weight heparin, tumor therapy and as a heparin antagonist. In addition, we summarized the definition, source of heparinase and its application in the medicine field. Heparinases have a great application prospect in the field of medicine.
Heparin ; Heparin Lyase ; metabolism ; Heparitin Sulfate ; Oligosaccharides ; Polysaccharide-Lyases

Mucopolysaccharidosis type III (MPS III) is a rare genetic disorder caused by lysosomal storage of heparan sulfate. MPS IIIB results from a deficiency in the enzyme alpha-N-acetyl-D-glucosaminidase (NAGLU). Affected patients begin showing behavioral changes, progressive profound mental retardation, and severe disability from the age of 2 to 6 years. We report a patient with MPS IIIB with a long-term follow-up duration. He showed normal development until 3 years. Subsequently, he presented behavioral changes, sleep disturbance, and progressive motor dysfunction. He had been hospitalized owing to recurrent pneumonia and epilepsy with severe cognitive dysfunction. The patient had compound heterozygous c.1444C>T (p.R482W) and c.1675G>T (p.D559Y) variants of NAGLU. Considering that individuals with MPS IIIB have less prominent facial features and skeletal changes, evaluation of long-term clinical course is important for diagnosis. Although no effective therapies for MPS IIIB have been developed yet, early and accurate diagnosis can provide important information for family planning in families at risk of the disorder.
Diagnosis ; Epilepsy ; Family Planning Services ; Follow-Up Studies ; Heparitin Sulfate ; Humans ; Intellectual Disability ; Lysosomal Storage Diseases ; Mucopolysaccharidoses* ; Mucopolysaccharidosis III* ; Pneumonia

BACKGROUND AND PURPOSE: Atherothrombotic cerebral infarction [atherothrombotic stroke (ATS)] shares common risk factors and pathophysiological mechanisms with coronary artery disease (CAD), and both diseases appear to have common susceptibility loci. The muscle RAS oncogene homolog gene (MRAS) has been identified as a susceptibility locus for CAD and is implicated in atherosclerosis. The aim of this study was to elucidate whether the single-nucleotide polymorphisms (SNPs) and haplotypes of MRAS are associated with increased risk of ATS in a population of Han Chinese. METHODS: A case-controlled association study was conducted in which only patients with ATS (identified as a major subtype in the Korean modification of the Trial of Org 10172 in Acute Stroke Treatment classification) were enrolled. Subgroup analyses were carried out to determine whether the effect of the MRAS polymorphism was specific to age and gender among the subjects. RESULTS: In total, 194 ATS and 186 control subjects were included in the present study. Two tagging SNPs were identified in MRAS (rs40593 and rs3755751). A multivariate regression analysis revealed a positive association between rs40593 and ATS under dominant and additive models after adjustment for covariates. Subgroup analyses revealed that there were no gender differences with respect to allele or genotype frequencies between the groups. The AG genotype for rs40593 (p=0.028), the CT genotype for rs3755751 (p=0.036), and G-allele carriers (AG plus GG) for rs40593 (p=0.015) exhibited a significant protective effect among those aged > or =45 years. For the haplotype analysis, ATS subjects aged > or =45 years had a higher frequency of the ACAC haplotype (76.0%) than the controls (68.1%; p<0.05); that haplotype was associated with an increased risk of ATS. CONCLUSIONS: The obtained data suggest a positive association between MRAS and ATS among the Han Chinese. Further studies should be performed with larger sample and among different ethnic populations, and gene-gene or gene-environment interactions should be considered.
Alleles ; Asian Continental Ancestry Group* ; Atherosclerosis ; Case-Control Studies ; Cerebral Infarction ; Chondroitin Sulfates ; Coronary Artery Disease ; Dermatan Sulfate ; Gene-Environment Interaction ; Genes, ras ; Genetic Variation* ; Genotype ; Haplotypes ; Heparitin Sulfate ; Humans ; Muscles ; Polymorphism, Single Nucleotide ; Risk Factors ; Stroke*

Mucopolysaccharidosis (MPS) III has 4 enzymatically distinct forms (A, B, C, and D), and MPS IIIC, also known as Sanfilippo C syndrome, is an autosomal recessive lysosomal storage disease caused by a deficiency of heparan acetyl-CoA:alpha-glucosaminide N-acetyltransferase (HGSNAT). Here, we report a case of MPS IIIC that was confirmed by molecular genetic analysis. The patient was a 2-yr-old girl presenting with skeletal deformity, hepatomegaly, and delayed motor development. Urinary excretion of glycosaminoglycan (GAG) was markedly elevated (984.4 mg GAG/g creatinine) compared with the age-specific reference range (<175 mg GAG/g creatinine), and a strong band of heparan sulfate was recognized on performing thin layer chromatography. HGSNAT enzyme activity in leukocytes was 0.7 nmol/17 hr/mg protein, which was significantly lower than the reference range (8.6-32 nmol/17 hr/mg protein). PCR and direct sequencing of the HGSNAT gene showed 2 mutations: c.234+1G>A (IVS2+1G>A) and c.1150C>T (p.Arg384*). To the best of our knowledge, this is the first case of MPS IIIC to be confirmed by clinical, biochemical, and molecular genetic findings in Korea.
Acetyltransferases/*genetics ; Asian Continental Ancestry Group/*genetics ; Base Sequence ; Child, Preschool ; Chromatography, Thin Layer ; Female ; Glycosaminoglycans/urine ; Heparitin Sulfate/chemistry/metabolism ; Humans ; Leukocytes/immunology/metabolism ; Mucopolysaccharidosis III/*diagnosis/genetics/radiography ; Mutation ; Republic of Korea ; Sequence Analysis, DNA

BACKGROUND AND PURPOSE: Understanding the mechanisms underlying stroke can aid the development of therapies and improve the final outcome. The purposes of this study were to establish whether there are characteristic mechanistic differences in the frequency, severity, functional outcome, and mortality between left- and right-hemisphere ischemic stroke and, given the velocity differences in the carotid circulation and direct branching of the left common carotid artery from the aorta, whether large-vessel ischemia (including cardioembolism) is more common in the territory of the left middle cerebral artery. METHODS: Trial cohorts were combined into a data set of 476 samples. Using Trial of Org 10172 in Acute Stroke Treatment criteria, ischemic strokes in a total 317 patients were included in the analysis. Hemorrhagic stroke, stroke of undetermined etiology, cryptogenic stroke, and bilateral ischemic strokes were excluded. Laterality and vascular distribution were correlated with outcomes using a logistic regression model. The etiologies of the large-vessel strokes were atherosclerosis and cardioembolism. RESULTS: The overall event frequency, mortality, National Institutes of Health Stroke Scale (NIHSS) score, Glasgow Coma Scale score, and rate of mechanical thrombectomy interventions differed significantly between the hemispheres. Left-hemispheric strokes (54%) were more common than right-hemispheric strokes (46%; p=0.0073), and had higher admission NIHSS scores (p=0.011), increased mortality (p=0.0339), and higher endovascular intervention rates (p< or =0.0001). ischemic strokes were more frequent in the distribution of the left middle cerebral artery (122 vs. 97; p=0.0003) due to the higher incidence of large-vessel ischemic stroke in this area (p=0.0011). CONCLUSIONS: Left-hemispheric ischemic strokes appear to be more frequent and often have a worse outcome than their right-hemispheric counterparts. The incidence of large-vessel ischemic strokes is higher in the left middle cerebral artery distribution, contributing to these hemispheric differences. The hemispheric differences exhibit a nonsignificant trend when strokes in the middle cerebral artery distribution are excluded from the analysis.
Aorta ; Atherosclerosis ; Carotid Artery, Common ; Chondroitin Sulfates ; Cohort Studies ; Dermatan Sulfate ; Glasgow Coma Scale ; Heparitin Sulfate ; Humans ; Incidence ; Ischemia ; Logistic Models ; Middle Cerebral Artery ; National Institutes of Health (U.S.) ; Stroke ; Thrombectomy

Glycosaminoglycans are important structural components in the skin and exist as various proteoglycan forms, except hyaluronic acid. Heparan sulfate (HS), one of the glycosaminoglycans, is composed of repeated disaccharide units, which are glucuronic acids linked to an N-acetyl-glucosamine or its sulfated forms. To investigate acute ultraviolet (UV)-induced changes of HS and HS proteoglycans (HSPGs), changes in levels of HS and several HSPGs in male human buttock skin were examined by immunohistochemistry and real-time quantitative polymerase chain reaction (qPCR) after 2 minimal erythema doses (MED) of UV irradiation (each n = 4-7). HS staining revealed that 2 MED of UV irradiation increased its expression, and staining for perlecan, syndecan-1, syndecan-4, CD44v3, and CD44 showed that UV irradiation increased their protein levels. However, analysis by real-time qPCR showed that UV irradiation did not change mRNA levels of CD44 and agrin, and decreased perlecan and syndecan-4 mRNA levels, while increased syndecan-1 mRNA level. As HS-synthesizing or -degrading enzymes, exostosin-1 and heparanase mRNA levels were increased, but exostosin-2 was decreased by UV irradiation. UV-induced matrix metalloproteinase-1 expression was confirmed for proper experimental conditions. Acute UV irradiation increases HS and HSPG levels in human skin, but their increase may not be mediated through their transcriptional regulation.
Adult ; Agrin/genetics ; Antigens, CD44/genetics ; Base Sequence ; DNA Primers/genetics ; Gene Expression/radiation effects ; Glucuronidase/genetics ; Heparan Sulfate Proteoglycans/genetics/*metabolism ; Heparitin Sulfate/metabolism ; Humans ; Male ; Matrix Metalloproteinase 1/genetics ; N-Acetylglucosaminyltransferases/genetics ; RNA, Messenger/genetics/metabolism ; Skin/*metabolism/*radiation effects ; Skin Aging/genetics/physiology ; Syndecan-1/genetics ; Syndecan-4/genetics ; Ultraviolet Rays/*adverse effects ; Young Adult

BACKGROUND: Impaired renal function may contribute to development of stroke and small vessel pathology in the brain. We investigated whether stroke subtype, initial stroke severity, early neurologic outcomes, time to cerebral infarction occurrence, and the presence of small vessel pathology in the brain are different between patients with end stage renal disease (ESRD) and those with renal transplantation (RT). METHODS: A total of 57 consecutive de novo RT patients (RT group) and 120 patients undergoing dialysis due to ESRD (ESRD group) who developed a first-ever acute cerebral infarction were enrolled. We compared stroke subtypes based on the Trial of Org 10172 in Acute Stroke Treatment classification, the presence of small vessel pathology (cerebral microbleed, leukoaraiosis and silent lacunar infarction) on MRI, stroke severity based on the National Institutes of Health Stroke Scale (NIHSS) and in-hospital mortality between the groups. RESULTS: The stroke subtypes, NIHSS scores at admission and in-hospital mortality were not different between the two groups. On multivariate analysis, the presence of high grade periventricular white matter changes tended to be more frequently detected in the ESRD group than the RT (P=0.078). The time from starting dialysis to stroke was longer in the RT group (129.9+/-60.9 months) than in the ESRD group (51.1+/-46.1 months). CONCLUSIONS: The stroke patterns, severity and short term outcomes were not different between RT and ESRD. The risk of cerebral infarction and high grade periventricular white matter changes may be reduced after RT in patients with ESRD.
Brain ; Cerebral Infarction ; Chondroitin Sulfates ; Dermatan Sulfate ; Dialysis ; Glycosaminoglycans ; Heparitin Sulfate ; Hospital Mortality ; Humans ; Kidney Failure, Chronic ; Kidney Transplantation ; Leukoaraiosis ; Multivariate Analysis ; National Institutes of Health (U.S.) ; Stroke