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

OBJECTIVE: To observe the effects of histones on lung injury and von Willebrand factor (vWF) and fibrinogen (FIB) levels in mice, and to explore the protective effect of heparin. METHODS: Twenty-four male C57BL/6 mice aged 6-10 weeks were divided into control group, histone group and histone+heparin group according to random number table method with 8 mice in each group. The mice in the histone group were injected with histone (50 mg/kg) via the tail vein, and the mice in the histone+heparin group were injected with unfractionated heparin (400 U/kg) via the tail vein at 1 hour after administration of histone, and those in the control group were given the same amount of normal saline. Four hours after histone injection, the lungs of the mice were harvested and the lung wet/dry weight ratio (W/D) and the pulmonary water contents were measured. The pathological changes in lung tissue were observed by hematoxylin and eosin (HE) staining under microscope, and the extent of lung injury was evaluated. The positive expression of vWF which was the marker of endothelial cell injury was observed by immunohistochemistry. The real-time fluorescence quantitative reverse transcription-polymerase chain reaction (RT-PCR) was used to determine the expression level of FIB mRNA in lung tissue. RESULTS: The lung W/D ratio and pulmonary water contents in the histone group were significantly higher than those in the control group [lung W/D ratio: 6.19±0.53 vs. 4.54±0.25, pulmonary water contents: (82.59±2.03)% vs. (78.52±1.51)%, both P < 0.01]. The lung W/D ratio and pulmonary water contents in the histone+heparin group were significantly lower than those in the histone group [lung W/D ratio: 4.84±0.35 vs. 6.19±0.53, pulmonary water contents: (79.21±1.48)% vs. (82.59±2.03)%, both P < 0.01], indicating that the heparin could reduce histone-induced pulmonary edema. Histological examination showed that the alveolar structure of the control group was intact, and the alveolar cavity was clean without exudation. In the histone group, the lungs were significantly damaged. The alveolar wall was thickened, infiltrated by inflammatory cells and focally alveolar hemorrhage, edema, associated with alveolar fibrin deposition and micro-thrombus formation. The lung histopathological score in the histone group was significantly higher than that in the control group (5.15±0.87 vs. 0.18±0.17, P < 0.01). All of the pathological changes were significantly alleviated in the histone+heparin group, and the histopathological score of the lung was significantly lower than that in the histone group (2.28±0.72 vs. 5.15±0.87, P < 0.01), indicating that the histone-induced lung injury was improved by heparin. Immunohistochemistry showed that high vWF expressions of lung tissue were observed in the histone group while there was almost no positive expression in the control group, and the vWF expression in the histone+heparin group was significantly reduced, indicating that heparin protected mice against histone-induced endothelial cell injury. The FIB mRNA expression of lung tissue in the histone group was about 49.82 times of the control group (2^-ΔΔCT: 55.30±18.84 vs. 1.11±0.45, P < 0.01), and the expression of FIB mRNA in the histone+heparin group was decreased, which was 23.87 times of the control group (2^-ΔΔCT: 26.50±9.97 vs. 1.11±0.45, P < 0.01), but it was significantly lower than that in the histone group (2^-ΔΔCT: 26.50±9.97 vs. 55.30±18.84, P < 0.01), indicating that heparin could inhibit histone-induced hypercoagulable environment in lung. CONCLUSIONS Histone causes pulmonary edema, endothelial cell injury and coagulation activation. Heparin could effectively attenuate histone-induced lung injury and coagulation activation.
Animals ; Fibrinogen/metabolism* ; Fibrinolytic Agents/therapeutic use* ; Heparin/therapeutic use* ; Histones ; Lung/metabolism* ; Male ; Mice ; Mice, Inbred C57BL ; von Willebrand Factor/metabolism*

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

We conducted this study to investigate the synergistic effect of human urine-derived stem cells (USCs) and surface modified composite scaffold for bladder reconstruction in a rat model. The composite scaffold (Polycaprolactone/Pluronic F127/3 wt% bladder submucosa matrix) was fabricated using an immersion precipitation method, and heparin was immobilized on the surface via covalent conjugation. Basic fibroblast growth factor (bFGF) was loaded onto the heparin-immobilized scaffold by a simple dipping method. In maximal bladder capacity and compliance analysis at 8 weeks post operation, the USCs-scaffold(heparin-bFGF) group showed significant functional improvement (2.34 ± 0.25 mL and 55.09 ± 11.81 microL/cm H2O) compared to the other groups (2.60 ± 0.23 mL and 56.14 ± 9.00 microL/cm H2O for the control group, 1.46 ± 0.18 mL and 34.27 ± 4.42 microL/cm H2O for the partial cystectomy group, 1.76 ± 0.22 mL and 35.62 ± 6.69 microL/cm H2O for the scaffold group, and 1.92 ± 0.29 mL and 40.74 ± 7.88 microL/cm H2O for the scaffold(heparin-bFGF) group, respectively). In histological and immunohistochemical analysis, the USC-scaffold(heparin-bFGF) group showed pronounced, well-differentiated, and organized smooth muscle bundle formation, a multi-layered and pan-cytokeratin-positive urothelium, and high condensation of submucosal area. The USCs seeded scaffold(heparin-bFGF) exhibits significantly increased bladder capacity, compliance, regeneration of smooth muscle tissue, multi-layered urothelium, and condensed submucosa layers at the in vivo study.
Adult Stem Cells/cytology/metabolism/*transplantation ; Animals ; Biocompatible Materials/chemistry ; Cell Differentiation ; Fibroblast Growth Factor 2/administration & dosage ; Heparin/administration & dosage ; Humans ; Materials Testing ; Models, Animal ; Poloxamer ; Polyesters ; Rats ; Reconstructive Surgical Procedures ; Regeneration ; Tissue Engineering/*methods ; Tissue Scaffolds/chemistry ; Urinary Bladder/anatomy & histology/physiology/*surgery ; Urine/*cytology

OBJECTIVETo investigate the mechanisms underlying the ability ofheparin-treated dendritic cells (DCs) to promote Th0 to Th1 differentiation in chronic hepatitis B (CHB).

METHODSPeripheral blood mononuclear cells (PBMCs) were isolated from CHB patients and cultured in RPMI-1640 with recombinant GM-CSF and IL-4 with or without heparin to obtain DCs for study. The levels of Toll-like receptors (TLRs) on the DCs were measured using FACS and qPCR techniques.DC subsets with high expression of TLRs were selected for analysis of functional changes by treatment with the corresponding TLR-siRNA. The CD4+ T cell subpopulation was purified from peripheral blood by Dynal immunomagnetic beads, and then the production of IL-12 by DCs in the presence of poly(I:C) or R848 and ofIFN and IL-4 by Th cells co-cultured with DCs was evaluated by ELISA. The t-test was used for statistical analysis.

RESULTSTLR3 expression, and not expression of TLR 7 or TLR8,was significantly increased in heparin-treated DCs as compared to levels detected in the DCs without heparin treatment (t =2.849,P less than 0.05;t =3.027,P less than 0.05). The level of IL-12 produced by heparin-treated DCs stimulated with poly(I:C) was obviously higher than that produced by DCs without heparin treatment and stimulated with poly(I: C) (t =8.68,P less than 0.01) or with R848 (t =19.01,P less than 0.01). However, the IL-12 production by TLR3-siRNA transfected-DCs was significantly reduced (t =31.49, P less than 0.01).When Th cells from allogenic patients with CHB were co-cultured with the TLR3-siRNA transfectedDCs, the frequency ofCD4+ IFN+ cells was significantly reduced (1.64+/-0.57% vs.6.31+/-0.88%,P less than 0.01),as was the capability of Thl to generate IFNg (t =20.83,Pless than 0.01).

CONCLUSIONHeparin may have up-regulated the TLR3 expression level of DCs, and sequentially promoted Th0 to Th1 differentiation.

CD4-Positive T-Lymphocytes ; cytology ; Cell Differentiation ; Coculture Techniques ; Dendritic Cells ; cytology ; Granulocyte-Macrophage Colony-Stimulating Factor ; pharmacology ; Heparin ; pharmacology ; Hepatitis B, Chronic ; immunology ; Humans ; Interferon-gamma ; metabolism ; Interleukin-12 ; metabolism ; Interleukin-4 ; pharmacology ; Monocytes ; cytology ; Recombinant Proteins ; pharmacology ; Toll-Like Receptor 3 ; metabolism

OBJECTIVETo establish the rat model of acute pulmonary embolism, and study the changes of vascular active substances in pulmonary embolism rats, and investigate the interventive effect of anticoagulant drugs on vascular active substances.

METHODSOne hundred and twenty-eight rats were randomly divided into four groups: control group, model group, low-molecular-weight heparin and warfarin treated group and rivaroxaban-treated group (n = 32 in each group). The method of autologous thrombosis was used to establish the animal model of acute pulmonary embolism. The animals were treated with saline or different anticoagulant drugs. The physiological and biochemical parameters were detected at different time points after embolization. The rats were killed after embolism of 24 h, 3 d, 5 d or 1 week respectively and the pathologic samples of lung tissues were collected to analyze the pulmonary pathological changes in different groups.

RESULTSRats in embolization group after blood clots injection showed shortness of breath, oral cyanosis; quicken heart rates and other symptoms. All embolization groups had pulmonary hypertension, the levels of type B natriuretic peptide (BNP) were increased significantly. The ratio of endothelin-1 (ET-1)/NO and thromboxane (TXB2) and prostacyclin (6-k-PGFla) were abnormal. After treated with effective anticoagulant drugs, the levels of BNP, ET-1, NO, TXB2 and 6-k-PGF1a were tended to the normal levels in the control group. The pulmonary hypertensions were gradually decreased. The efficacy of rivaroxaban on pulmonary embolism was the same as that of the low molecular weight heparin or warfarin.

CONCLUSIONAnticoagulation therapy can effectively improve endothelial function after pulmonary embolism, reduce pulmonary hypertension, and revise the increased BNP levels to normal levels. The efficacy of rivaroxaban is not inferior to that of low molecular weight heparin and warfarin.

Animals ; Anticoagulants ; pharmacology ; Disease Models, Animal ; Endothelin-1 ; metabolism ; Heparin, Low-Molecular-Weight ; pharmacology ; Hypertension, Pulmonary ; drug therapy ; metabolism ; Lung ; pathology ; Morpholines ; pharmacology ; Pulmonary Embolism ; drug therapy ; metabolism ; Rats ; Rivaroxaban ; Thiophenes ; pharmacology ; Warfarin ; pharmacology

OBJECTIVETo investigate the effect of the anticoagulants on PRP quality, so as to clarify the appropriate anticoagulant used in PRP production.

METHODSThe microstructure change of platelets collected via heparin, citrate, acid citrate dextrose (ACD) and citrate-theophylline-adenosine-dipyridamole ( CTAD) was observed by TEM following time course. The extent of spontaneous activation of platelets in four groups was detected by measuring sP-selectin in plasma. The TGF-β1 release amount of activated PRP of four groups was measured.

RESULTSCTAD is superior to other anticoagulants in maintaining the integrity of platelet structures for a long time and preventing platelet spontaneous activation. ACD slightly surpassed heparin and citrate in above two aspects. ACD-PRP and CTAD-PRP released significantly more TGF-β1 compared with heparin and citrate.

CONCLUSIONSThe PRP quality and biological effects were strongly associated with the type of Anticoagulants. ACD and CTAD are optimal anticoagulants in PRP production for they can maintain platelet viability at a high level.

Adenosine ; pharmacology ; Anticoagulants ; pharmacology ; Blood Platelets ; drug effects ; physiology ; Citrates ; pharmacology ; Citric Acid ; pharmacology ; Dipyridamole ; pharmacology ; Drug Combinations ; Glucose ; analogs & derivatives ; pharmacology ; Heparin ; pharmacology ; Platelet Activation ; drug effects ; Platelet-Rich Plasma ; Theophylline ; pharmacology ; Transforming Growth Factor beta1 ; metabolism

OBJECTIVE: To explore the relationship between activity of plasma heparin cofactor II (HC II) and the incidence of in-stent restenosis aft er the intervention of arteriosclerosis obliterans in lower extremity. METHODS: A total of 62 patients with arteriosclerosis obliterans in lower extremity underwent femoropopliteal stent implantation. They were divided into 2 groups: A high HC II activity group (≥100%, n=40) and a low HC II activity group (<100%, n=22). All patients filled in follow up tables and conducted body examination. Possible risk factors resulting in restenosis were collected. Patients were followed up for 6 months after femoropopliteal stent implantation. RESULTS: Baseline clinical characteristics were not significantly different between the 2 groups. The degree and incidence of angiographic restenosis at the end of the 6th month after the implantation in the high HC II activity group were all significantly lower than those in the low HC II activity group (P<0.05). Multivariate analysis demonstrated that high plasma HC II activity was an independent factor in reducing the incidence of angiographic restenosis (OR=0.982, P=0.048, 95%CI, 0.966, 0.998). CONCLUSION High plasma HC II activity is an independent factor in reducing the degree of in-stent restenosis. The lower the plasma HC II activity, the severer the degree of in-stent restenosis.
Arteriosclerosis Obliterans ; surgery ; Constriction, Pathologic ; Heparin Cofactor II ; metabolism ; Humans ; Incidence ; Lower Extremity ; Risk Factors ; Stents

OBJECTIVE: To explore the effects of low molecular weight heparin (LMWH) on cisplatin (DDP)- induced apoptosis in human hepatocellular carcinoma cell and the underlying mechanisms.
 METHODS: Hepatocellular carcinoma SMMC-7721 cells were divided into a control group, a LMWH group, a DDP group and a LMWH plus DDP group. The effect of the drugs on proliferation of hepatocellular carcinoma SMMC-7721 cells were evaluated by 3-(4,5)-dimethylthiahiazo (-z-y1)-3,5-di- phenytetrazoliumromide (MTT) assay, and the apoptosis were detected by acridine orange/ethidium bromide (AO/EB) double fluorescence method and flow cytometry method. The expression levels of apoptosis-related protein Fas, Bcl-2 and Bax were detected by quantitative real-time PCR and Western blot.
 RESULTS: Compared with the control group, the proliferation of SMMC-7721 cells was inhibited in the DDP group and the LMWH plus DDP group (both P<0.05). The mRNA and protein levels of Fas, Bcl-2, Bax in the SMMC-7721 cells were not obviously changed in the LMWH group (all P>0.05). The Fas level was increased obviously (P<0.05), while the Bcl-2 level moderately reduced (P<0.05), Bax were not obviously changed in the DDP group (P>0.05). Compared with the control group and the DDP group, the Bcl-2 level was reduced significantly in the LMWH plus DDP group (both P<0.05), while the level of Bax was increased obviously (both P<0.05). Compared with control group, the Fas level was increased significantly in the LMWH plus DDP group (P<0.05), but the increase was not significant compared with the DDP group (P>0.05).
 CONCLUSION LMWH can enhance the cisplatin-induced apoptosis in SMMC-7721 cells, which might be related to activation of mitochondrial pathway.
Antineoplastic Agents ; pharmacology ; Apoptosis ; drug effects ; Carcinoma, Hepatocellular ; pathology ; Cell Line, Tumor ; drug effects ; Cisplatin ; pharmacology ; Flow Cytometry ; Heparin, Low-Molecular-Weight ; pharmacology ; Humans ; Liver Neoplasms ; pathology ; Proto-Oncogene Proteins c-bcl-2 ; metabolism ; Real-Time Polymerase Chain Reaction ; bcl-2-Associated X Protein ; metabolism ; fas Receptor ; metabolism