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

BACKGROUND: Extracellular sulfatases (Sulfs), sulfatase 1 (Sulf1) and sulfatase 2 (Sulf2), play a pivotal role in cell signaling by remodeling the 6-O-sulfation of heparan sulfate proteoglycans on the cell surface. The present study examined the effects of Sulfs on angiotensin II (Ang II)-induced hypertensive mediator expression and vascular smooth muscle cells (VSMCs) proliferation in spontaneously hypertensive rats (SHR). METHODS: Ang II receptors, 12-lipoxygenase (12-LO), and endothelin-1 (ET-1) messenger RNA (mRNA) expressions in SHR VSMCs were analyzed by real-time polymerase chain reaction and Western blotting. VSMCs proliferation was determined by [³ H]-thymidine incorporation. RESULTS: Basal Sulfs mRNAs expression and enzyme activity were elevated in SHR VSMCs. However, Sulfs had no effect on the basal or Ang II-induced 12-LO and ET-1 mRNA expression in SHR VSMCs. The inhibition of Ang II-induced 12-LO and ET-1 expression by blockade of the Ang II type 2 receptor (AT₂ R) pathway was not observed in Sulf1 siRNA-transfected SHR VSMCs. However, Sulf2 did not affect the action of AT₂ R inhibitor on Ang II-induced 12-LO and ET-1 expression in SHR VSMCs. The down-regulation of Sulf1 induced a reduction of AT₂ R mRNA expression in SHR VSMCs. In addition, the inhibition of Ang II-induced VSMCs proliferation by blockade of the AT₂ R pathway was mediated by Sulf1 in SHR VSMCs. CONCLUSION: These findings suggest that extracellular sulfatase Sulf1 plays a modulatory role in the AT₂ R pathway that leads to an Ang II-induced hypertensive effects in SHR VSMCs.
Angiotensin II* ; Angiotensins* ; Arachidonate 12-Lipoxygenase ; Blotting, Western ; Down-Regulation ; Endothelin-1 ; Heparan Sulfate Proteoglycans ; Hypertension ; Muscle, Smooth, Vascular* ; Rats, Inbred SHR* ; Real-Time Polymerase Chain Reaction ; Receptor, Angiotensin, Type 2* ; RNA, Messenger ; Sulfatases

Cell therapy using stem cells has produced therapeutic benefits in animal models of COPD. Secretory mediators are proposed as one mechanism for stem cell effects because very few stem cells engraft after injection into recipient animals. Recently, nanovesicles that overcome the disadvantages of natural exosomes have been generated artificially from cells. We generated artificial nanovesicles from adipose-derived stem cells (ASCs) using sequential penetration through polycarbonate membranes. ASC-derived artificial nanovesicles displayed a 100 nm-sized spherical shape similar to ASC-derived natural exosomes and expressed both exosomal and stem cell markers. The proliferation rate of lung epithelial cells was increased in cells treated with ASC-derived artificial nanovesicles compared with cells treated with ASC-derived natural exosomes. The lower dose of ASC-derived artificial nanovesicles had similar regenerative capacity compared with a higher dose of ASCs and ASC-derived natural exosomes. In addition, FGF2 levels in the lungs of mice treated with ASC-derived artificial nanovesicles were increased. The uptake of ASC-derived artificial nanovesicles was inhibited by heparin, which is a competitive inhibitor of heparan sulfate proteoglycan that is associated with FGF2 signaling. Taken together, the data indicate that lower doses of ASC-derived artificial nanovesicles may have beneficial effects similar to higher doses of ASCs or ASC-derived natural exosomes in an animal model with emphysema, suggesting that artificial nanovesicles may have economic advantages that warrant future clinical studies.
Animals ; Cell- and Tissue-Based Therapy ; Emphysema* ; Epithelial Cells ; Exosomes ; Fibroblast Growth Factor 2 ; Heparan Sulfate Proteoglycans ; Heparin ; Lung ; Membranes ; Mice ; Models, Animal ; Pulmonary Disease, Chronic Obstructive ; Stem Cells

BACKGROUND: Extracellular sulfatases (Sulfs), sulfatase 1 (Sulf1) and sulfatase 2 (Sulf2), play a pivotal role in cell signaling by remodeling the 6-O-sulfation of heparan sulfate proteoglycans on the cell surface. The present study examined the effects of Sulfs on angiotensin II (Ang II)-induced hypertensive mediator expression and vascular smooth muscle cells (VSMCs) proliferation in spontaneously hypertensive rats (SHR).METHODS: Ang II receptors, 12-lipoxygenase (12-LO), and endothelin-1 (ET-1) messenger RNA (mRNA) expressions in SHR VSMCs were analyzed by real-time polymerase chain reaction and Western blotting. VSMCs proliferation was determined by [³ H]-thymidine incorporation.RESULTS: Basal Sulfs mRNAs expression and enzyme activity were elevated in SHR VSMCs. However, Sulfs had no effect on the basal or Ang II-induced 12-LO and ET-1 mRNA expression in SHR VSMCs. The inhibition of Ang II-induced 12-LO and ET-1 expression by blockade of the Ang II type 2 receptor (AT₂ R) pathway was not observed in Sulf1 siRNA-transfected SHR VSMCs. However, Sulf2 did not affect the action of AT₂ R inhibitor on Ang II-induced 12-LO and ET-1 expression in SHR VSMCs. The down-regulation of Sulf1 induced a reduction of AT₂ R mRNA expression in SHR VSMCs. In addition, the inhibition of Ang II-induced VSMCs proliferation by blockade of the AT₂ R pathway was mediated by Sulf1 in SHR VSMCs.CONCLUSION: These findings suggest that extracellular sulfatase Sulf1 plays a modulatory role in the AT₂ R pathway that leads to an Ang II-induced hypertensive effects in SHR VSMCs.
Angiotensin II ; Angiotensins ; Arachidonate 12-Lipoxygenase ; Blotting, Western ; Down-Regulation ; Endothelin-1 ; Heparan Sulfate Proteoglycans ; Hypertension ; Muscle, Smooth, Vascular ; Rats, Inbred SHR ; Real-Time Polymerase Chain Reaction ; Receptor, Angiotensin, Type 2 ; RNA, Messenger ; Sulfatases

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

Hepatitis B virus (HBV) is the prototype of hepatotropic DNA viruses (hepadnaviruses) infecting a wide range of human and non-human hosts. Previous studies with duck hepatitis B virus (DHBV) identified duck carboxypeptidase D (dCPD) as a host specific binding partner for full-length large envelope protein, and p120 as a binding partner for several truncated versions of the large envelope protein. p120 is the P protein of duck glycine decarboxylase (dGLDC) with restricted expression in DHBV infectible tissues. Several lines of evidence suggest the importance of dCPD, and especially p120, in productive DHBV infection, although neither dCPD nor p120 cDNA could confer susceptibility to DHBV infection in any cell line. Recently, sodium taurocholate cotransporting polypeptide (NTCP) has been identified as a binding partner for the N-terminus of HBV large envelope protein. Importantly, knock down and reconstitution experiments unequivocally demonstrated that NTCP is both necessary and sufficient for in vitro infection by HBV and hepatitis delta virus (HDV), an RNA virus using HBV envelope proteins for its transmission. What remains unclear is whether NTCP is the major HBV receptor in vivo. The fact that some HBV patients are homozygous with an NTCP mutation known to abolish its receptor function suggests the existence of NTCP-independent pathways of HBV entry. Also, NTCP very likely mediates just one step of the HBV entry process, with additional co-factors for productive HBV infection still to be discovered. NTCP offers a novel therapeutic target for the control of chronic HBV infection.
Animals ; Carboxypeptidases/genetics/*metabolism ; Gene Products, pol/genetics/metabolism ; Heparan Sulfate Proteoglycans/metabolism ; Hepatitis B virus/*physiology ; Hepatocytes/metabolism/virology ; Organic Anion Transporters, Sodium-Dependent/antagonists & inhibitors/genetics/metabolism ; RNA Interference ; Symporters/antagonists & inhibitors/genetics/metabolism ; Viral Envelope Proteins/metabolism ; Virus Internalization

OBJECTIVE: To observe growth inhibition effect of perlecan anti-sense cDNA (pAP) on human laryngeal carcinoma xnografted in nude mice. To vertify its antitumor effect and mechanism in vivo, and it may be useful as a biomarker in carcinoma of larynx cancer. METHOD: Created the model of human laryngeal carcinoma xnograft in nude mice. To observe growth of those xnografts in nude mice and draw growth curve of xnografted. The expression of perlecan mRNA and portein in xnografts were examined by RT-PCR and immunohistochemistry. RESULT: Volume of xnografts in the group transfected by the plasmids of pAP were significant small as compared with other two groups made by the wild type cells and phpApr-neol cells (P < 0.05). It was showed that the expression of perlecan mRNA and protein were significantly reduced in the tumor of pAP transfected Hep-2 cells as compared with the tumors transfected by the wild type cells and phβApr-neol cells (P < 0.01). CONCLUSION These data raise the possibility that pAP many play key roles in the growth of those xnografts in nude mice.
Animals ; DNA, Antisense ; therapeutic use ; DNA, Complementary ; Heparan Sulfate Proteoglycans ; genetics ; Heterografts ; Humans ; Laryngeal Neoplasms ; pathology ; therapy ; Mice ; Mice, Inbred BALB C ; Mice, Nude ; Plasmids ; RNA, Messenger ; metabolism ; Reverse Transcriptase Polymerase Chain Reaction ; Transfection