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1.
Nan Fang Yi Ke Da Xue Xue Bao ; 40(8): 1127-1133, 2020 Aug 30.
Artigo em Chinês | MEDLINE | ID: mdl-32895176

RESUMO

OBJECTIVE: To explore the glucose-lowering effect of the polysaccharide fractions of Trametes orientalis. METHODS: The crude polysaccharides of T. orientalis were chromatographed on DEAE cellulose column using H2O and 0.5 mol/L NaCl solution as the eluent and DEAE-water and DEAE-salt with high polysaccharide contents were collected. The two fractions were separated using Sephadex G-100 gel column to obtain 4 polysaccharide fractions TOPW-1, TOPW-2, TOPS-1, and TOPS-2. The anti-oxidation activity of the polysaccharide fractions was investigated with ABTS method. The fractions TOPW-1 and TOPS-1 with consistent UV detection signals were collected and HPGPC was used to determine their relative molecular mass. The monosaccharide composition in homogeneous TOPW-1 was determined by acid hydrolysis combined with HPLC. The in vitro inhibitory activities of TOPW-1 and TOPS-1 against DPP4, adipocyte glucose intake and lipase activity were tested to preliminarily assess their glucose-lowering effect. In a mouse model of hyperglycemic and hyperlipidemic, the glucose-lowering effect of TOPS-1 (0.1, 0.2, and 0.4 g/kg) and its effect on blood lipid metabolism were investigated in comparison with Xiaoke pills (5 pills/kg) and Danshen tablets (0.5 g/kg). RESULTS: TOPW-1 was a homogeneous polysaccharide composed mainly of D-mannose, D-glucose, D-galactose, and D-fucose, with weak antioxidant and hypoglycemic effects. TOPS-1 was not a single polysaccharide and at the concentration of 500 µg/mL showed an high ABTS clearance rate (90.15%). In the mouse model of hyperglycemia and hyperlipidemia, treatment with TOPS-1 (0.2 g/kg) enhanced the activity of lipase and significantly reduced fasting glucose level and serum contents of total cholesterol, triacylglycerol, and low-density lipoprotein cholesterol without causing death in the mice. The glucose-lowering effects of TOPS-1 was not significant at the low (0.1 g/kg) or high (0.4 g/kg) dose, and a high dose tended to increase the mortality of the mice. CONCLUSIONS: T. orientalis polysaccharides have anti-oxidation, glucose-lowering and lipid-lowering effects in mice, and their glucose-lowering effect is probably medicated by reducing oxidative stress and ameliorating lipid metabolism disorder.


Assuntos
Trametes , Animais , Antioxidantes , Glucose , Hipoglicemiantes , Camundongos , Polissacarídeos
2.
Carbohydr Polym ; 247: 116740, 2020 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-32829859

RESUMO

Pulmonary fibrosis (PF) is a lung disease with highly heterogeneous and mortality rate, but its therapeutic options are now still limited. Corona virus disease 2019 (COVID-19) has been characterized by WHO as a pandemic, and the global number of confirmed COVID-19 cases has been more than 8.0 million. It is strongly supported for that PF should be one of the major complications in COVID-19 patients by the evidences of epidemiology, viral immunology and current clinical researches. The anti-PF properties of naturally occurring polysaccharides have attracted increasing attention in last two decades, but is still lack of a comprehensively understanding. In present review, the resources, structural features, anti-PF activities, and underlying mechanisms of these polysaccharides are summarized and analyzed, which was expected to provide a scientific evidence supporting the application of polysaccharides for preventing or treating PF in COVID-19 patients.


Assuntos
Betacoronavirus , Produtos Biológicos/uso terapêutico , Infecções por Coronavirus/complicações , Pandemias , Pneumonia Viral/complicações , Polissacarídeos/uso terapêutico , Fibrose Pulmonar/tratamento farmacológico , Animais , Antioxidantes/farmacologia , Antioxidantes/uso terapêutico , Bleomicina/toxicidade , Modelos Animais de Doenças , Avaliação Pré-Clínica de Medicamentos , Proteína Forkhead Box O3/fisiologia , Fungos/química , Ribonucleoproteína Nuclear Heterogênea D0/fisiologia , Humanos , Macrófagos/efeitos dos fármacos , Medicina Tradicional Chinesa , Camundongos , Neutrófilos/efeitos dos fármacos , Fitoterapia , Plantas Medicinais/química , Polissacarídeos/farmacologia , Fibrose Pulmonar/induzido quimicamente , Fibrose Pulmonar/etiologia , Fibrose Pulmonar/prevenção & controle , RNA Longo não Codificante/antagonistas & inibidores , Ratos , Alga Marinha/química , Transdução de Sinais/efeitos dos fármacos , Proteína Smad2/fisiologia , Proteína Smad3/fisiologia , Fator de Crescimento Transformador beta1/antagonistas & inibidores
3.
Nat Commun ; 11(1): 3990, 2020 08 10.
Artigo em Inglês | MEDLINE | ID: mdl-32778659

RESUMO

The molecular mechanisms regulating lymphocyte homing into lymph nodes are only partly understood. Here, we report that B cell-specific deletion of the X-linked gene, Cosmc, and the consequent decrease of protein O-glycosylation, induces developmental blocks of mouse B cells. After transfer into wild-type recipient, Cosmc-null B cells fail to home to lymph nodes as well as non-lymphoid organs. Enzymatic desialylation of wild-type B cells blocks their migration into lymph nodes, indicating a requirement of sialylated O-glycans for proper trafficking. Mechanistically, Cosmc-deficient B cells have normal rolling and firm arrest on high endothelium venules (HEV), thereby attributing their inefficient trafficking to alterations in the subsequent transendothelial migration step. Finally, Cosmc-null B cells have defective chemokine signaling responses. Our results thus demonstrate that Cosmc and its effects on O-glycosylation are important for controlling B cell homing.


Assuntos
Linfócitos B/metabolismo , Linfonodos/metabolismo , Chaperonas Moleculares/metabolismo , Animais , Movimento Celular , Feminino , Glicosilação , Humanos , Imunidade Humoral/fisiologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Chaperonas Moleculares/genética , Polissacarídeos/metabolismo , Transcriptoma , Vênulas
4.
Nat Commun ; 11(1): 4017, 2020 08 11.
Artigo em Inglês | MEDLINE | ID: mdl-32782292

RESUMO

The thick mucus layer of the gut provides a barrier to infiltration of the underlying epithelia by both the normal microbiota and enteric pathogens. Some members of the microbiota utilise mucin glycoproteins as a nutrient source, but a detailed understanding of the mechanisms used to breakdown these complex macromolecules is lacking. Here we describe the discovery and characterisation of endo-acting enzymes from prominent mucin-degrading bacteria that target the polyLacNAc structures within oligosaccharide side chains of both animal and human mucins. These O-glycanases are part of the large and diverse glycoside hydrolase 16 (GH16) family and are often lipoproteins, indicating that they are surface located and thus likely involved in the initial step in mucin breakdown. These data provide a significant advance in our knowledge of the mechanism of mucin breakdown by the normal microbiota. Furthermore, we also demonstrate the potential use of these enzymes as tools to explore changes in O-glycan structure in a number of intestinal disease states.


Assuntos
Microbioma Gastrointestinal , Hexosaminidases/metabolismo , Glicoproteínas de Membrana/metabolismo , Mucinas/metabolismo , Animais , Bactérias/classificação , Bactérias/enzimologia , Bactérias/genética , Bactérias/metabolismo , Cristalografia por Raios X , Glicosídeo Hidrolases/genética , Glicosídeo Hidrolases/metabolismo , Hexosaminidases/química , Hexosaminidases/genética , Humanos , Glicoproteínas de Membrana/química , Estrutura Molecular , Mucinas/química , Filogenia , Polissacarídeos/química , Polissacarídeos/metabolismo , Relação Estrutura-Atividade , Especificidade por Substrato
5.
Nat Commun ; 11(1): 4033, 2020 08 20.
Artigo em Inglês | MEDLINE | ID: mdl-32820167

RESUMO

Peptide hormones and neuropeptides encompass a large class of bioactive peptides that regulate physiological processes like anxiety, blood glucose, appetite, inflammation and blood pressure. Here, we execute a focused discovery strategy to provide an extensive map of O-glycans on peptide hormones. We find that almost one third of the 279 classified peptide hormones carry O-glycans. Many of the identified O-glycosites are conserved and are predicted to serve roles in proprotein processing, receptor interaction, biodistribution and biostability. We demonstrate that O-glycans positioned within the receptor binding motifs of members of the neuropeptide Y and glucagon families modulate receptor activation properties and substantially extend peptide half-lives. Our study highlights the importance of O-glycosylation in the biology of peptide hormones, and our map of O-glycosites in this large class of biomolecules serves as a discovery platform for an important class of molecules with potential opportunities for drug designs.


Assuntos
Hormônios Peptídicos/química , Hormônios Peptídicos/metabolismo , Polissacarídeos/química , Polissacarídeos/metabolismo , Idoso , Animais , Linhagem Celular , Desenho de Fármacos , Feminino , Glicosilação , Células HEK293 , Humanos , Masculino , Pessoa de Meia-Idade , Neuropeptídeos/metabolismo , Ligação Proteica , Conformação Proteica em alfa-Hélice , Estabilidade Proteica , Ratos , Suínos
6.
Nat Commun ; 11(1): 3963, 2020 08 07.
Artigo em Inglês | MEDLINE | ID: mdl-32770134

RESUMO

Polysaccharides are the most abundant biomolecules in nature, but are the least understood in terms of their chemical structures and biological functions. Polysaccharides cannot be simply sequenced because they are often highly branched and lack a uniform structure. Furthermore, large polymeric structures cannot be directly analyzed by mass spectrometry techniques, a problem that has been solved for polynucleotides and proteins. While restriction enzymes have advanced genomic analysis, and trypsin has advanced proteomic analysis, there has been no equivalent enzyme for universal polysaccharide digestion. We describe the development and application of a chemical method for producing oligosaccharides from polysaccharides. The released oligosaccharides are characterized by advanced liquid chromatography-mass spectrometry (LC-MS) methods with high sensitivity, accuracy and throughput. The technique is first used to identify polysaccharides by oligosaccharide fingerprinting. Next, the polysaccharide compositions of food and feces are determined, further illustrating the utility of technique in food and clinical studies.


Assuntos
Oligossacarídeos/química , Polissacarídeos/metabolismo , Bactérias/metabolismo , Glucanos/química , Glucanos/metabolismo , Humanos , Lactente , Mananas/química , Mananas/metabolismo , Oxirredução , Polimerização , Fatores de Tempo , Xilanos/química , Xilanos/metabolismo
7.
Molecules ; 25(15)2020 Jul 28.
Artigo em Inglês | MEDLINE | ID: mdl-32731428

RESUMO

In 2020, the world is being ravaged by the coronavirus, SARS-CoV-2, which causes a severe respiratory disease, Covid-19. Hundreds of thousands of people have succumbed to the disease. Efforts at curing the disease are aimed at finding a vaccine and/or developing antiviral drugs. Despite these efforts, the WHO warned that the virus might never be eradicated. Countries around the world have instated non-pharmaceutical interventions such as social distancing and wearing of masks in public to curb the spreading of the disease. Antiviral polysaccharides provide the ideal opportunity to combat the pathogen via pharmacotherapeutic applications. However, a layer-by-layer nanocoating approach is also envisioned to coat surfaces to which humans are exposed that could harbor pathogenic coronaviruses. By coating masks, clothing, and work surfaces in wet markets among others, these antiviral polysaccharides can ensure passive prevention of the spreading of the virus. It poses a so-called "eradicate-in-place" measure against the virus. Antiviral polysaccharides also provide a green chemistry pathway to virus eradication since these molecules are primarily of biological origin and can be modified by minimal synthetic approaches. They are biocompatible as well as biodegradable. This surface passivation approach could provide a powerful measure against the spreading of coronaviruses.


Assuntos
Antivirais/uso terapêutico , Infecções por Coronavirus/prevenção & controle , Pandemias/prevenção & controle , Pneumonia Viral/prevenção & controle , Polissacarídeos/uso terapêutico , Antivirais/farmacologia , Betacoronavirus/efeitos dos fármacos , Betacoronavirus/metabolismo , Materiais Revestidos Biocompatíveis/farmacologia , Materiais Revestidos Biocompatíveis/uso terapêutico , Química Verde , Humanos , Nanopartículas , Nanotecnologia , Polissacarídeos/farmacologia
8.
J Chromatogr A ; 1625: 461194, 2020 Aug 16.
Artigo em Inglês | MEDLINE | ID: mdl-32709309

RESUMO

Quantitative analysis of glycans released from glycoproteins using high-performance liquid chromatography (HPLC) requires fluorescent tag labeling to enhance sensitivity and selectivity. However, the methods required to remove large amounts of excess labeling reagents from the reaction mixture are time-consuming. Furthermore, these methods, including solvent extraction and solid phase extraction (SPE), often impair quantitative analysis. Here, we developed an online sample cleanup procedure for HPLC analysis of 2-aminopyridine (AP)-labeled glycans using a six-port/two-way valve and two small columns: one packed with a strong cation exchange resin (SCX) and the other comprising ODS silica gel. AP-labeled glycans delivered from an injection port were separated from excess AP by passing through an SCX column (4.6 mm i.d., 1 cm long) regulated to 40°C. The AP-labeled glycans were trapped on an ODS column (4.6 mm i.d., 1 cm long) to further separate them from inorganic contaminants. By changing the valve position after 2 min to connect the ODS column to an analysis column, AP-labeled glycans trapped in the ODS column were eluted with an acetonitrile-containing eluent followed by hydrophilic interaction liquid chromatography (HILIC) separation on an amide column or reversed-phase mode separation on a C30 column. This method was successfully used to analyze N-linked glycans released from several glycoprotein samples.


Assuntos
Aminopiridinas/química , Cromatografia Líquida de Alta Pressão/métodos , Polissacarídeos/química , Cromatografia por Troca Iônica , Cromatografia de Fase Reversa , Glicoproteínas/metabolismo , Concentração de Íons de Hidrogênio , Interações Hidrofóbicas e Hidrofílicas , Peptídeo-N4-(N-acetil-beta-glucosaminil) Asparagina Amidase/metabolismo , Polissacarídeos/isolamento & purificação , Extração em Fase Sólida
9.
Nat Protoc ; 15(8): 2668-2704, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32681150

RESUMO

The glycocalyx comprises glycosylated proteins and lipids and fcorms the outermost layer of cells. It is involved in fundamental inter- and intracellular processes, including non-self-cell and self-cell recognition, cell signaling, cellular structure maintenance, and immune protection. Characterization of the glycocalyx is thus essential to understanding cell physiology and elucidating its role in promoting health and disease. This protocol describes how to comprehensively characterize the glycocalyx N-glycans and O-glycans of glycoproteins, as well as intact glycolipids in parallel, using the same enriched membrane fraction. Profiling of the glycans and the glycolipids is performed using nanoflow liquid chromatography-mass spectrometry (nanoLC-MS). Sample preparation, quantitative LC-tandem MS (LC-MS/MS) analysis, and data processing methods are provided. In addition, we discuss glycoproteomic analysis that yields the site-specific glycosylation of membrane proteins. To reduce the amount of sample needed, N-glycan, O-glycan, and glycolipid analyses are performed on the same enriched fraction, whereas glycoproteomic analysis is performed on a separate enriched fraction. The sample preparation process takes 2-3 d, whereas the time spent on instrumental and data analyses could vary from 1 to 5 d for different sample sizes. This workflow is applicable to both cell and tissue samples. Systematic changes in the glycocalyx associated with specific glycoforms and glycoconjugates can be monitored with quantitation using this protocol. The ability to quantitate individual glycoforms and glycoconjugates will find utility in a broad range of fundamental and applied clinical studies, including glycan-based biomarker discovery and therapeutics.


Assuntos
Glicocálix/metabolismo , Glicômica/métodos , Linhagem Celular , Humanos , Polissacarídeos/metabolismo
10.
PLoS One ; 15(7): e0235515, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32692781

RESUMO

BACKGROUND: The skin provides a predominant barrier against chemical, physical and microbial incursion. The intemperate exposure to ultraviolet A (UVA) radiation can cause excessive cellular oxidative stress, leading to skin damage, proteins damage and mitochondrial dysfunction. There is sufficient evidences supporting the proposal that mitochondria is highly implicated in skin photo-damage. METHODS: In the present study, a polysaccharide isolated from Astragalus membranaceus was further purified to be an α-glucan, which was further investigated its beneficial influence on UVA-induced photo-damage in HaCaT cells. RESULTS: Our results showed that the purified Astragalus membranaceus polysaccharide (AP) can protect HaCaT cells from UVA-induced photo-damage through reducing UVA-induced intracellular ROS production and mitochondrial membrane potential, thereby altering ATP content. It was found that the UVA induced damage in HaCaT cells could be effectively restored by co-treatment with AP. CONCLUSIONS: AP exhibited promising potential for advanced application as multifunctional skin care products and drugs.


Assuntos
Astragalus propinquus/química , Queratinócitos/efeitos dos fármacos , Queratinócitos/efeitos da radiação , Polissacarídeos/farmacologia , Protetores contra Radiação/farmacologia , Raios Ultravioleta/efeitos adversos , Trifosfato de Adenosina/metabolismo , Apoptose/efeitos dos fármacos , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Humanos , Queratinócitos/citologia , Queratinócitos/metabolismo , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Polissacarídeos/química , Protetores contra Radiação/química , Espécies Reativas de Oxigênio/metabolismo
11.
Sci Total Environ ; 741: 140365, 2020 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-32610234

RESUMO

Geobacter sulfurreducens biofilms have promising applications in renewable energy, pollutant bioremediation, and bioelectronic applications. Genetically manipulating G. sulfurreducens biofilms is an effective strategy to improve the capacity of extracellular electron transfer (EET). Extracellular polysaccharide, a sticky component surrounding microbes, plays an important role in EET. Herein, we constructed a mutant of G. sulfurreducens strain PCA overexpressing the gene GSU1501 (part of the ATP-dependent exporter of the polysaccharide biosynthesis gene operon), designated strain PCA-1501, to increase EET capacity. Experimental results showed that the overexpression of GSU1501 increased extracellular polysaccharide secretion by 25.5%, which promoted the formation of biofilm with higher thickness and viability, as well as the content of extracellular c-type cytochromes. Compared with the control strain, the mutant showed a higher capacity of Fe(III) oxide reduction and current generation (increased by 20.4% and 22.2%, respectively). Interestingly, the overexpression of GSU1501 hindered the pili formation by reducing the transcription level of pilA; a compensatory relationship between extracellular polysaccharide and pili in promoting biofilm formation deserves further investigation. This study provides a feasible method to promote the EET capacity of G. sulfurreducens biofilms, which benefit their bioelectrochemical applications.


Assuntos
Geobacter , Biofilmes , Elétrons , Compostos Férricos , Oxirredução , Polissacarídeos
12.
J Chromatogr A ; 1625: 461297, 2020 Aug 16.
Artigo em Inglês | MEDLINE | ID: mdl-32709340

RESUMO

In this study superficially porous silica particles with a nominal pore size of 450 Å and average particle size of 2.6 micrometers was compared to fully porous silica particles with nominal particle size 3 micrometers and nominal pore size 1000 A as carriers for a polysaccharide based chiral selector for the separation of enantiomers in high-performance liquid chromatography. In addition, the effects of chiral selector loading onto the silica support and of column internal dimeter in the case of both, superficially porous and totally porous silica, as well as of the pore size of superficially porous silica on column performance were studied. The dependence of plate height on mobile phase flow rate was also studied and attempts were made for shortening analysis time. The baseline separation of enantiomers of some chiral sulfoxides was obtained within 2.0-4.5 s.


Assuntos
Cromatografia Líquida de Alta Pressão/métodos , Polissacarídeos/química , Dióxido de Silício/química , Tamanho da Partícula , Porosidade , Estereoisomerismo
13.
Nat Commun ; 11(1): 3396, 2020 07 07.
Artigo em Inglês | MEDLINE | ID: mdl-32636380

RESUMO

Arabinosyltransferase B (EmbB) belongs to a family of membrane-bound glycosyltransferases that build the lipidated polysaccharides of the mycobacterial cell envelope, and are targets of anti-tuberculosis drug ethambutol. We present the 3.3 Å resolution single-particle cryo-electron microscopy structure of Mycobacterium smegmatis EmbB, providing insights on substrate binding and reaction mechanism. Mutations that confer ethambutol resistance map mostly around the putative active site, suggesting this to be the location of drug binding.


Assuntos
Mycobacterium smegmatis/enzimologia , Pentosiltransferases/química , Pentosiltransferases/ultraestrutura , Antituberculosos/farmacologia , Domínio Catalítico , Microscopia Crioeletrônica , Farmacorresistência Bacteriana , Etambutol/farmacologia , Lipídeos/química , Mutação , Mycobacterium tuberculosis/enzimologia , Polissacarídeos/química , Ligação Proteica
14.
Nat Commun ; 11(1): 3285, 2020 07 03.
Artigo em Inglês | MEDLINE | ID: mdl-32620774

RESUMO

The early life human gut microbiota exerts life-long health effects on the host, but the mechanisms underpinning its assembly remain elusive. Particularly, the early colonization of Clostridiales from the Roseburia-Eubacterium group, associated with protection from colorectal cancer, immune- and metabolic disorders is enigmatic. Here, we describe catabolic pathways that support the growth of Roseburia and Eubacterium members on distinct human milk oligosaccharides (HMOs). The HMO pathways, which include enzymes with a previously unknown structural fold and specificity, were upregulated together with additional glycan-utilization loci during growth on selected HMOs and in co-cultures with Akkermansia muciniphila on mucin, suggesting an additional role in enabling cross-feeding and access to mucin O-glycans. Analyses of 4599 Roseburia genomes underscored the preponderance and diversity of the HMO utilization loci within the genus. The catabolism of HMOs by butyrate-producing Clostridiales may contribute to the competitiveness of this group during the weaning-triggered maturation of the microbiota.


Assuntos
Butiratos/metabolismo , Clostridiales/metabolismo , Leite Humano/metabolismo , Mucinas/metabolismo , Oligossacarídeos/metabolismo , Bifidobacterium/metabolismo , Clostridiales/genética , Colo/microbiologia , Eubacterium/metabolismo , Microbioma Gastrointestinal/fisiologia , Humanos , Lactente , Recém-Nascido , Metabolismo/fisiologia , Leite Humano/química , Polissacarídeos/metabolismo , Verrucomicrobia/metabolismo , Desmame
15.
Int J Nanomedicine ; 15: 4151-4169, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32606670

RESUMO

Purpose: Focused ultrasound (FUS) is a noninvasive method to produce thermal and mechanical destruction along with an immune-stimulatory effect against cancer. However, FUS ablation alone appears insufficient to generate consistent antitumor immunity. In this study, a multifunctional nanoparticle was designed to boost FUS-induced immune effects and achieve systemic, long-lasting antitumor immunity, along with imaging and thermal enhancement. Materials and Methods: PEGylated PLGA nanoparticles encapsulating astragalus polysaccharides (APS) and gold nanorods (AuNRs) were constructed by a simple double emulsion method, characterized, and tested for cytotoxicity. The abilities of PA imaging and thermal-synergetic ablation efficiency were analyzed in vitro and in vivo. The immune-synergistic effect on dendritic cell (DC) differentiation in vitro and the immune response in vivo were also evaluated. Results: The obtained APS/AuNR/PLGA-PEG nanoparticles have an average diameter of 255.00±0.1717 nm and an APS-loading efficiency of 54.89±2.07%, demonstrating their PA imaging capability and high biocompatibility both in vitro and in vivo. In addition, the as-prepared nanoparticles achieved a higher necrosis cell rate and induced apoptosis rate in an in vitro cell suspension assay, greater necrosis area and decreased energy efficiency factor (EEF) in an in vivo rabbit liver assay, and remarkable thermal-synergic performance. In particular, the nanoparticles upregulated the expression of MHC-II, CD80 and CD86 on cocultured DCs in vitro, followed by declining phagocytic function and enhanced interleukin (IL)-12 and interferon (INF)-γ production. Furthermore, they boosted the production of tumor necrosis factor (TNF)-α, IFN-γ, IL-4, IL-10, and IgG1 (P< 0.001) but not IgG2a. Immune promotion peaked on day 3 after FUS in vivo. Conclusion: The multifunctional APS/AuNR/PLGA-PEG nanoparticles can serve as an excellent synergistic agent for FUS therapy, facilitating real-time imaging, promoting thermal ablation effects, and boosting FUS-induced immune effects, which have the potential to be used for further clinical FUS treatment.


Assuntos
Astrágalo (Planta)/química , Neoplasias da Mama/terapia , Ouro/química , Nanopartículas Multifuncionais/química , Nanotubos/química , Polissacarídeos/química , Terapia por Ultrassom , Animais , Antígenos CD/metabolismo , Apoptose , Morte Celular , Diferenciação Celular , Linhagem Celular Tumoral , Proliferação de Células , Citocinas/metabolismo , Células Dendríticas/citologia , Feminino , Células Endoteliais da Veia Umbilical Humana/metabolismo , Humanos , Imunoglobulina G/metabolismo , Linfócitos do Interstício Tumoral/imunologia , Camundongos Endogâmicos BALB C , Fagocitose , Técnicas Fotoacústicas , Poliésteres/síntese química , Poliésteres/química , Polietilenoglicóis/síntese química , Polietilenoglicóis/química , Coelhos , Nanomedicina Teranóstica , Fator A de Crescimento do Endotélio Vascular/metabolismo
16.
Int J Mol Sci ; 21(12)2020 Jun 26.
Artigo em Inglês | MEDLINE | ID: mdl-32604730

RESUMO

The recently emerged SARS-CoV-2 is the cause of the global health crisis of the coronavirus disease 2019 (COVID-19) pandemic. No evidence is yet available for CoV infection into hosts upon zoonotic disease outbreak, although the CoV epidemy resembles influenza viruses, which use sialic acid (SA). Currently, information on SARS-CoV-2 and its receptors is limited. O-acetylated SAs interact with the lectin-like spike glycoprotein of SARS CoV-2 for the initial attachment of viruses to enter into the host cells. SARS-CoV-2 hemagglutinin-esterase (HE) acts as the classical glycan-binding lectin and receptor-degrading enzyme. Most ß-CoVs recognize 9-O-acetyl-SAs but switched to recognizing the 4-O-acetyl-SA form during evolution of CoVs. Type I HE is specific for the 9-O-Ac-SAs and type II HE is specific for 4-O-Ac-SAs. The SA-binding shift proceeds through quasi-synchronous adaptations of the SA-recognition sites of the lectin and esterase domains. The molecular switching of HE acquisition of 4-O-acetyl binding from 9-O-acetyl SA binding is caused by protein-carbohydrate interaction (PCI) or lectin-carbohydrate interaction (LCI). The HE gene was transmitted to a ß-CoV lineage A progenitor by horizontal gene transfer from a 9-O-Ac-SA-specific HEF, as in influenza virus C/D. HE acquisition, and expansion takes place by cross-species transmission over HE evolution. This reflects viral evolutionary adaptation to host SA-containing glycans. Therefore, CoV HE receptor switching precedes virus evolution driven by the SA-glycan diversity of the hosts. The PCI or LCI stereochemistry potentiates the SA-ligand switch by a simple conformational shift of the lectin and esterase domains. Therefore, examination of new emerging viruses can lead to better understanding of virus evolution toward transitional host tropism. A clear example of HE gene transfer is found in the BCoV HE, which prefers 7,9-di-O-Ac-SAs, which is also known to be a target of the bovine torovirus HE. A more exciting case of such a switching event occurs in the murine CoVs, with the example of the ß-CoV lineage A type binding with two different subtypes of the typical 9-O-Ac-SA (type I) and the exclusive 4-O-Ac-SA (type II) attachment factors. The protein structure data for type II HE also imply the virus switching to binding 4-O acetyl SA from 9-O acetyl SA. Principles of the protein-glycan interaction and PCI stereochemistry potentiate the SA-ligand switch via simple conformational shifts of the lectin and esterase domains. Thus, our understanding of natural adaptation can be specified to how carbohydrate/glycan-recognizing proteins/molecules contribute to virus evolution toward host tropism. Under the current circumstances where reliable antiviral therapeutics or vaccination tools are lacking, several trials are underway to examine viral agents. As expected, structural and non-structural proteins of SARS-CoV-2 are currently being targeted for viral therapeutic designation and development. However, the modern global society needs SARS-CoV-2 preventive and therapeutic drugs for infected patients. In this review, the structure and sialobiology of SARS-CoV-2 are discussed in order to encourage and activate public research on glycan-specific interaction-based drug creation in the near future.


Assuntos
Betacoronavirus/metabolismo , Infecções por Coronavirus/virologia , Evolução Molecular , Interações entre Hospedeiro e Microrganismos/fisiologia , Pneumonia Viral/virologia , Receptores Virais/metabolismo , Internalização do Vírus , Acetilesterase/metabolismo , Animais , Betacoronavirus/genética , Sítios de Ligação , Linhagem Celular , Coronavirus/genética , Esterases , Transferência Genética Horizontal , Glicosaminoglicanos/metabolismo , Hemaglutininas Virais/genética , Humanos , Lectinas/metabolismo , Pandemias , Polissacarídeos , Receptores Virais/química , Ácidos Siálicos/química , Ácidos Siálicos/metabolismo , Glicoproteína da Espícula de Coronavírus/química , Glicoproteína da Espícula de Coronavírus/fisiologia , Torovirus , Proteínas Virais de Fusão/genética
17.
Blood Adv ; 4(13): 2967-2978, 2020 07 14.
Artigo em Inglês | MEDLINE | ID: mdl-32609845

RESUMO

Thrombocytopenia is a common complication of influenza virus infection, and its severity predicts the clinical outcome of critically ill patients. The underlying cause(s) remain incompletely understood. In this study, in patients with an influenza A/H1N1 virus infection, viral load and platelet count correlated inversely during the acute infection phase. We confirmed this finding in a ferret model of influenza virus infection. In these animals, platelet count decreased with the degree of virus pathogenicity varying from 0% in animals infected with the influenza A/H3N2 virus, to 22% in those with the pandemic influenza A/H1N1 virus, up to 62% in animals with a highly pathogenic A/H5N1 virus infection. This thrombocytopenia is associated with virus-containing platelets that circulate in the blood. Uptake of influenza virus particles by platelets requires binding to sialoglycans and results in the removal of sialic acids by the virus neuraminidase, a trigger for hepatic clearance of platelets. We propose the clearance of influenza virus by platelets as a paradigm. These insights clarify the pathophysiology of influenza virus infection and show how severe respiratory infections, including COVID-19, may propagate thrombocytopenia and/or thromboembolic complications.


Assuntos
Plaquetas/virologia , Vírus da Influenza A/patogenicidade , Influenza Humana/complicações , Ácido N-Acetilneuramínico/metabolismo , Polissacarídeos/metabolismo , Trombocitopenia/etiologia , Animais , Plaquetas/metabolismo , Plaquetas/patologia , Modelos Animais de Doenças , Furões , Interações Hospedeiro-Patógeno , Humanos , Vírus da Influenza A Subtipo H1N1/patogenicidade , Vírus da Influenza A Subtipo H1N1/fisiologia , Vírus da Influenza A Subtipo H3N2/patogenicidade , Vírus da Influenza A Subtipo H3N2/fisiologia , Virus da Influenza A Subtipo H5N1/patogenicidade , Virus da Influenza A Subtipo H5N1/fisiologia , Vírus da Influenza A/fisiologia , Influenza Humana/metabolismo , Influenza Humana/patologia , Influenza Humana/virologia , Infecções por Orthomyxoviridae/complicações , Infecções por Orthomyxoviridae/metabolismo , Infecções por Orthomyxoviridae/patologia , Infecções por Orthomyxoviridae/virologia , Trombocitopenia/metabolismo , Trombocitopenia/patologia , Trombocitopenia/virologia , Internalização do Vírus
18.
Wei Sheng Yan Jiu ; 49(3): 458-462, 2020 May.
Artigo em Chinês | MEDLINE | ID: mdl-32693897

RESUMO

OBJECTIVE: To investigate the effects of mannose, the major component of Lycium barbarum polysaccharide, and its potential target metabolite, inositol, on mouse islet ß-TC6 cells. METHODS: Different concentrations(0, 4. 6875, 9. 375, 18. 75, 37. 5, 75 and 150 µg/mL) of mannose or inositol were used to intervene ß-TC6 cells for 24 hours, and the proliferation activity of cells was determined by CCK-8 method. Enzyme-linked immunosorbent assay was used to detect insulin secretion after the intervention of the ß-TC6 cells from different concentration of the mannose or inositol(0, 18. 75, 75 and 150 µg/mL) combining with glucose stimulation(20 mmol/L) for 60 minutes. Pioglitazone(3. 92 mg/L) was set up as positive group, and after intervention of the mannose or inositol(0, 9. 375, 18. 75, 75 and 150 µg/mL) for 24 h, the expression levels of insulin, glucose kinase(GK), glucose transporter 4(GLUT4) and glycogen synthase(GS) mRNA were detected by real-time quantitative PCR. RESULTS: Compared with the control group, mannose and inositol promoted the proliferation of ß-TC6 cells in a concentration-dependent manner(18. 75-150 µg/mL)(P<0. 05). Although the inositol solution of 4. 6875 µg/mL and 9. 375 µg/mL had a tendency to promote cell proliferation, there was no statistical difference(P>0. 05). After stimulation with 20 mmol/L glucose combining with different intervention concentrations(18. 75, 75 and 150 µg/mL) of mannose or inositol, no significant difference was observed in the insulin secretion of each group(P>0. 05) comparing with the control group. RT-qPCR result showed that 150 µg/mL mannose increased the expression level of GLUT4(P<0. 01) and the expression levels of GK and GLUT4 genes in the 75 µg/mL inositol group were significantly increased(P<0. 01). The expression level of GLUT4 was improved only when the concentration was decreased to 18. 75 µg/mL in inositol group(P<0. 01). CONCLUSION: Mannose and inositol can improve the expression of GLUT4 mRNA, which may help to increase glucose uptake by peripheral cells. In addition, inositol can improve insulin sensitivity and glucose metabolism by increasing the expression level of GK mRNA.


Assuntos
Lycium , Manose , Animais , Medicamentos de Ervas Chinesas , Glucose , Inositol , Insulina , Camundongos , Polissacarídeos
19.
Int J Mol Sci ; 21(15)2020 Jul 23.
Artigo em Inglês | MEDLINE | ID: mdl-32718020

RESUMO

The ongoing pandemic of coronavirus disease-2019 (COVID-19) is being caused by severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2). The disease continues to present significant challenges to the health care systems around the world. This is primarily because of the lack of vaccines to protect against the infection and the lack of highly effective therapeutics to prevent and/or treat the illness. Nevertheless, researchers have swiftly responded to the pandemic by advancing old and new potential therapeutics into clinical trials. In this review, we summarize potential anti-COVID-19 therapeutics that block the early stage of the viral life cycle. The review presents the structures, mechanisms, and reported results of clinical trials of potential therapeutics that have been listed in clinicaltrials.gov. Given the fact that some of these therapeutics are multi-acting molecules, other relevant mechanisms will also be described. The reviewed therapeutics include small molecules and macromolecules of sulfated polysaccharides, polypeptides, and monoclonal antibodies. The potential therapeutics target viral and/or host proteins or processes that facilitate the early stage of the viral infection. Frequent targets are the viral spike protein, the host angiotensin converting enzyme 2, the host transmembrane protease serine 2, and clathrin-mediated endocytosis process. Overall, the review aims at presenting update-to-date details, so as to enhance awareness of potential therapeutics, and thus, to catalyze their appropriate use in combating the pandemic.


Assuntos
Antivirais/uso terapêutico , Betacoronavirus/fisiologia , Infecções por Coronavirus/tratamento farmacológico , Pneumonia Viral/tratamento farmacológico , Anticorpos Monoclonais/química , Anticorpos Monoclonais/farmacologia , Anticorpos Monoclonais/uso terapêutico , Antivirais/química , Antivirais/farmacologia , Betacoronavirus/efeitos dos fármacos , Ensaios Clínicos como Assunto , Humanos , Pandemias , Peptídeos/química , Peptídeos/farmacologia , Peptídeos/uso terapêutico , Polissacarídeos/química , Polissacarídeos/farmacologia , Polissacarídeos/uso terapêutico , Bibliotecas de Moléculas Pequenas/química , Bibliotecas de Moléculas Pequenas/farmacologia , Bibliotecas de Moléculas Pequenas/uso terapêutico , Ligação Viral/efeitos dos fármacos , Internalização do Vírus/efeitos dos fármacos
20.
Comput Biol Med ; 122: 103849, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32658736

RESUMO

SARS-CoV and SARS-CoV-2 do not appear to have functions of a hemagglutinin and neuraminidase. This is a mystery, because sugar binding activities appear essential to many other viruses including influenza and even most other coronaviruses in order to bind to and escape from the glycans (sugars, oligosaccharides or polysaccharides) characteristic of cell surfaces and saliva and mucin. The S1 N terminal Domains (S1-NTD) of the spike protein, largely responsible for the bulk of the characteristic knobs at the end of the spikes of SARS-CoV and SARS-CoV-2, are here predicted to be "hiding" sites for recognizing and binding glycans containing sialic acid. This may be important for infection and the ability of the virus to locate ACE2 as its known main host cell surface receptor, and if so it becomes a pharmaceutical target. It might even open up the possibility of an alternative receptor to ACE2. The prediction method developed, which uses amino acid residue sequence alone to predict domains or proteins that bind to sialic acids, is naïve, and will be advanced in future work. Nonetheless, it was surprising that such a very simple approach was so useful, and it can easily be reproduced in a very few lines of computer program to help make quick comparisons between SARS-CoV-2 sequences and to consider the effects of viral mutations.


Assuntos
Betacoronavirus/química , Biologia Computacional , Infecções por Coronavirus/virologia , Pneumonia Viral/virologia , Glicoproteína da Espícula de Coronavírus/química , Algoritmos , Motivos de Aminoácidos , Sítios de Ligação , Humanos , Conformação Molecular , Ácido N-Acetilneuramínico/química , Pandemias , Polissacarídeos/química , Vírus da SARS , Triptofano/química
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