Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 21.761
Filtrar
1.
J Med Microbiol ; 70(9)2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34499027

RESUMO

Introduction. Zika virus (ZIKV) emerged as a public health concern on the American continent during late 2015. As the number of infected grew so did the concerns about its capability to cause long-term damage especially with the appearance of the congenital Zika syndrome (CZS). Proteins from the TAM family of receptor tyrosine kinases (RTKs) were proposed as the cellular receptors, however, due to the ability of the virus to infect a variety of cell lines different strategies to elucidate the tropism of the virus should be investigated.Hypothesis. Pseudotyping is a powerful tool to interrogate the ability of the glycoprotein (GP) to permit entry of viruses.Aim. We aimed to establish a highly tractable pseudotype model using lenti- and retro-viral backbones to investigate the entry pathway of ZIKV.Methodology. We used different glycoprotein constructs and different lenti- or retro-viral backbones, in a matrix of ratios to investigate production of proteins and functional pseudotypes.Results. Varying the ratio of backbone and glycoprotein plasmids did not yield infectious pseudotypes. Moreover, the supplementation of the ZIKV protease or the substitution of the backbone had no positive impact on the infectivity. We showed production of the proteins in producer cells implying the lack of infectious pseudotypes is due to a lack of successful glycoprotein incorporation, rather than lack of protein production.Conclusion. In line with other reports, we were unable to successfully produce infectious pseudotypes using the variety of methods described. Other strategies may be more suitable in the development of an efficient pseudotype model for ZIKV and other flaviviruses.


Assuntos
Glicoproteínas/genética , Proteínas Virais/genética , Virologia/métodos , Infecção por Zika virus/virologia , Zika virus/isolamento & purificação , Glicoproteínas/metabolismo , Humanos , Proteínas Virais/metabolismo , Internalização do Vírus , Zika virus/classificação , Zika virus/genética , Zika virus/fisiologia
2.
Adv Exp Med Biol ; 1325: 3-24, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34495528

RESUMO

N-glycosylation is a highly conserved glycan modification, and more than 7000 proteins are N-glycosylated in humans. N-glycosylation has many biological functions such as protein folding, trafficking, and signal transduction. Thus, glycan modification to proteins is profoundly involved in numerous physiological and pathological processes. The N-glycan precursor is biosynthesized in the endoplasmic reticulum (ER) from dolichol phosphate by sequential enzymatic reactions to generate the dolichol-linked oligosaccharide composed of 14 sugar residues, Glc3Man9GlcNAc2. The oligosaccharide is then en bloc transferred to the consensus sequence N-X-S/T (X represents any amino acid except proline) of nascent proteins. Subsequently, the N-glycosylated nascent proteins enter the folding step, in which N-glycans contribute largely to attaining the correct protein fold by recruiting the lectin-like chaperones, calnexin, and calreticulin. Despite the N-glycan-dependent folding process, some glycoproteins do not fold correctly, and these misfolded glycoproteins are destined to degradation by proteasomes in the cytosol. Properly folded proteins are transported to the Golgi, and N-glycans undergo maturation by the sequential reactions of glycosidases and glycosyltransferases, generating complex-type N-glycans. N-Acetylglucosaminyltransferases (GnT-III, GnT-IV, and GnT-V) produce branched N-glycan structures, affording a higher complexity to N-glycans. In this chapter, we provide an overview of the biosynthetic pathway of N-glycans in the ER and Golgi.


Assuntos
Glicoproteínas , Dobramento de Proteína , Retículo Endoplasmático/metabolismo , Glicoproteínas/metabolismo , Glicosilação , Humanos , Lectinas , Polissacarídeos/metabolismo
3.
Int J Mol Sci ; 22(16)2021 Aug 18.
Artigo em Inglês | MEDLINE | ID: mdl-34445590

RESUMO

Leucine-rich a-2-glycoprotein 1 (LRG1) is a candidate therapeutic target for treating the neovascular form of age-related macular degeneration (nvAMD). In this study we examined the expression of LRG1 in eyes of nvAMD patients. Choroidal neovascular membranes (CNVMs) from patients who underwent submacular surgery for retinal pigment epithelium-choroid graft transplantation were collected from 5 nvAMD patients without any prior intravitreal anti-VEGF injection, and from six patients who received intravitreal anti-VEGF injections before surgery. As controls free of nvAMD, retina sections were obtained from the eyes resected from a patient with lacrimal sac tumor and from a patient with neuroblastoma. CNVMs were immunostained for CD34, LRG1, and α-smooth muscle actin (α-SMA). Aqueous humor samples were collected from 58 untreated-naïve nvAMD patients prior to the intravitreal injection of anti-VEGF and 51 age-matched cataract control patients, and LRG1 concentration was measured by ELISA. The level of LRG1 immunostaining is frequently high in both the endothelial cells of the blood vessels, and myofibroblasts in the surrounding tissue of CNVMs of treatment-naïve nvAMD patients. Furthermore, the average concentration of LRG1 was significantly higher in the aqueous humor of nvAMD patients than in controls. These observations provide a strong experimental basis and scientific rationale for the progression of a therapeutic anti-LRG1 monoclonal antibody into clinical trials with patients with nvAMD.


Assuntos
Neovascularização de Coroide/diagnóstico , Olho/patologia , Glicoproteínas/metabolismo , Degeneração Macular/diagnóstico , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Estudos de Casos e Controles , Neovascularização de Coroide/metabolismo , Olho/metabolismo , Feminino , Humanos , Degeneração Macular/metabolismo , Masculino , Pessoa de Meia-Idade
4.
Theranostics ; 11(16): 8112-8128, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34335983

RESUMO

The coiled-coil domain containing protein members have been well documented for their roles in many diseases including cancers. However, the function of the coiled-coil domain containing 65 (CCDC65) remains unknown in tumorigenesis including gastric cancer. Methods: CCDC65 expression and its correlation with clinical features and prognosis of gastric cancer were analyzed in tissue. The biological role and molecular basis of CCDC65 were performed via in vitro and in vivo assays and a various of experimental methods including co-immunoprecipitation (Co-IP), GST-pull down and ubiquitination analysis et al. Finally, whether metformin affects the pathogenesis of gastric cancer by regulating CCDC65 and its-mediated signaling was investigated. Results: Here, we found that downregulated CCDC65 level was showed as an unfavourable factor in gastric cancer patients. Subsequently, CCDC65 or its domain (a.a. 130-484) was identified as a significant suppressor in GC growth and metastasis in vitro and in vivo. Molecular basis showed that CCDC65 bound to ENO1, an oncogenic factor has been widely reported to promote the tumor pathogenesis, by its domain (a.a. 130-484) and further promoted ubiquitylation and degradation of ENO1 by recruiting E3 ubiquitin ligase FBXW7. The downregulated ENO1 decreased the binding with AKT1 and further inactivated AKT1, which led to the loss of cell proliferation and EMT signal. Finally, we observed that metformin, a new anti-cancer drug, can significantly induce CCDC65 to suppress ENO1-AKT1 complex-mediated cell proliferation and EMT signals and finally suppresses the malignant phenotypes of gastric cancer cells. Conclusion: These results firstly highlight a critical role of CCDC65 in suppressing ENO1-AKT1 pathway to reduce the progression of gastric cancer and reveals a new molecular mechanism for metformin in suppressing gastric cancer. Our present study provides a new insight into the mechanism and therapy for gastric cancer.


Assuntos
Biomarcadores Tumorais/metabolismo , Proteínas de Ligação a DNA/metabolismo , Glicoproteínas/metabolismo , Fosfopiruvato Hidratase/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Neoplasias Gástricas/metabolismo , Proteínas Supressoras de Tumor/metabolismo , Animais , Linhagem Celular Tumoral , Movimento Celular/genética , Proliferação de Células/genética , China , Feminino , Expressão Gênica/genética , Regulação Neoplásica da Expressão Gênica/genética , Genes Supressores de Tumor/fisiologia , Glicoproteínas/genética , Humanos , Masculino , Metformina/metabolismo , Metformina/farmacologia , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Oncogenes , Prognóstico , Proteínas Proto-Oncogênicas c-akt/fisiologia , Transdução de Sinais/genética , Neoplasias Gástricas/genética , Neoplasias Gástricas/patologia , Ubiquitina-Proteína Ligases/metabolismo , Ubiquitinação
5.
Nat Commun ; 12(1): 4844, 2021 08 11.
Artigo em Inglês | MEDLINE | ID: mdl-34381053

RESUMO

Acute leukemia relapsing after chemotherapy plus allogeneic hematopoietic stem cell transplantation can be treated with donor-derived T cells, but this is hampered by the need for donor/recipient MHC-matching and often results in graft-versus-host disease, prompting the search for new donor-unrestricted strategies targeting malignant cells. Leukemia blasts express CD1c antigen-presenting molecules, which are identical in all individuals and expressed only by mature leukocytes, and are recognized by T cell clones specific for the CD1c-restricted leukemia-associated methyl-lysophosphatidic acid (mLPA) lipid antigen. Here, we show that human T cells engineered to express an mLPA-specific TCR, target diverse CD1c-expressing leukemia blasts in vitro and significantly delay the progression of three models of leukemia xenograft in NSG mice, an effect that is boosted by mLPA-cellular immunization. These results highlight a strategy to redirect T cells against leukemia via transfer of a lipid-specific TCR that could be used across MHC barriers with reduced risk of graft-versus-host disease.


Assuntos
Antígenos CD1/imunologia , Glicoproteínas/imunologia , Leucemia/imunologia , Lisofosfolipídeos/imunologia , Receptores de Antígenos de Linfócitos T/imunologia , Linfócitos T/imunologia , Doadores de Tecidos , Animais , Apresentação do Antígeno , Antígenos CD1/metabolismo , Glicoproteínas/metabolismo , Humanos , Imunoterapia Adotiva , Leucemia/metabolismo , Leucemia/terapia , Ativação Linfocitária , Camundongos , Receptores de Antígenos de Linfócitos T/genética , Receptores de Antígenos Quiméricos/genética , Receptores de Antígenos Quiméricos/imunologia , Resultado do Tratamento , Ensaios Antitumorais Modelo de Xenoenxerto
6.
J Insect Sci ; 21(4)2021 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-34401920

RESUMO

Glycosylation is one of the most common post-translational modifications to occur during protein biosynthesis, but remains poorly understood in insects. In this study, we collected serum proteins from two silkworm developmental stages, namely day 7 of the fifth instar larval stage and day 2 of the pupal stage. Results of SDS-PAGE and periodic acid-Schiff staining revealed that most serum proteins with high abundance were putative glycoproteins. LC-MS/MS identified 149 larval and 303 pupal serum proteins in the Con A lectin-enriched fractions. GO analysis revealed that many serum proteins were involved in the proteolysis and carbohydrate metabolic process. 82 N-linked glycoproteins with at least one glycosylation site were identified. N-Linked glycosylation occurred at the sequon, Asn-X-Ser/Thr, and the proportions of Ser and Thr glycosylation at the hydroxy position were found 39.6% and 60.3%, respectively. The N-glycan structures found in serum glycoproteins were mainly Man2FucGlcNAc2 (67.9%). Since storage protein 1 and transferrin had a relatively high abundance in the serum and could be significantly enriched by Con A lectin, their glycosylation was analyzed in detail. Glycoside hydrases, serine proteases and serpins were found to form three interacting glycoprotein networks using the website STRING. This study provides important clues for the understanding of the function of N-linked glycosylation in metabolism, immunity, and metamorphosis.


Assuntos
Bombyx/metabolismo , Glicoproteínas/metabolismo , Receptores de Concanavalina A/metabolismo , Animais , Cromatografia de Afinidade , Glicosilação , Proteínas de Insetos/metabolismo , Espectrometria de Massas , Proteômica , Transferrina/metabolismo
7.
Molecules ; 26(12)2021 Jun 10.
Artigo em Inglês | MEDLINE | ID: mdl-34200965

RESUMO

Glycosylation is the most prevalent and varied form of post-translational protein modifications. Protein glycosylation regulates multiple cellular functions, including protein folding, cell adhesion, molecular trafficking and clearance, receptor activation, signal transduction, and endocytosis. In particular, membrane proteins are frequently highly glycosylated, which is both linked to physiological processes and of high relevance in various disease mechanisms. The cellular glycome is increasingly considered to be a therapeutic target. Here we describe a new strategy to compare membrane glycoproteomes, thereby identifying proteins with altered glycan structures and the respective glycosites. The workflow started with an optimized procedure for the digestion of membrane proteins followed by the lectin-based isolation of glycopeptides. Since alterations in the glycan part of a glycopeptide cause mass alterations, analytical size exclusion chromatography was applied to detect these mass shifts. N-glycosidase treatment combined with nanoUPLC-coupled mass spectrometry identified the altered glycoproteins and respective glycosites. The methodology was established using the colon cancer cell line CX1, which was treated with 2-deoxy-glucose-a modulator of N-glycosylation. The described methodology is not restricted to cell culture, as it can also be adapted to tissue samples or body fluids. Altogether, it is a useful module in various experimental settings that target glycan functions.


Assuntos
Glicoproteínas/metabolismo , Proteínas de Membrana/metabolismo , Linhagem Celular Tumoral , Glucose/metabolismo , Glicopeptídeos/metabolismo , Glicosilação , Humanos , Polissacarídeos/metabolismo , Proteômica/métodos
8.
Anal Chem ; 93(30): 10435-10443, 2021 08 03.
Artigo em Inglês | MEDLINE | ID: mdl-34279906

RESUMO

Glycoproteins are inherently heterogeneous and therefore resolving structures in their entirety remains a major challenge in structural biology. Native mass spectrometry has transformed our ability to study glycoproteins, and despite advances in high-resolution instrumentation, there are comparatively a few studies demonstrating its potential with data largely limited to an overall measure of monosaccharide composition for all glycans across glycosylation sites for a given protein. Clearly, these readouts lack glycan topology information, namely, monosaccharide linkage and glycan branching. To address this deficiency, we developed a new approach that joins native mass spectrometry with glycan exoglycosidase sequencing, the combination of which provides remarkable glycoprotein structural details. We show how N-glycan branching, terminal fucosylation, LacNAc extensions, and N- and O-glycan occupancy (i.e., total number of glycans) can be directly characterized on intact glycoproteins with minimal sample preparation. Taken together, native exoglycosidase sequencing mass spectrometry (NES-MS) notably improves our ability to characterize protein glycosylation, addressing a significant need in structural biology that will enable new routes to understand glycoprotein function.


Assuntos
Glicômica , Glicoproteínas , Glicoproteínas/metabolismo , Glicosilação , Espectrometria de Massas , Polissacarídeos
9.
Int J Mol Sci ; 22(14)2021 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-34299211

RESUMO

Glaucoma is a leading cause of irreversible blindness worldwide, and increased intraocular pressure (IOP) is a major risk factor. We aimed to determine if early functional and molecular differences in the glaucomatous retina manifest before significant retinal ganglion cell (RGC) loss is apparent. Adenoviral vectors expressing a pathogenic form of myocilin (Ad5.MYOC) were used to induce IOP elevation in C57BL/6 mice. IOP and pattern electroretinograms (pERG) were recorded, and retinas were prepared for RNA sequencing, immunohistochemistry, or to determine RGC loss. Ocular injection of Ad5.MYOC leads to reliable IOP elevation, resulting in significant loss of RGC after nine weeks. A significant decrease in the pERG amplitude was evident in eyes three weeks after IOP elevation. Retinal gene expression analysis revealed increased expression for 291 genes related to complement cascade, inflammation, and antigen presentation in hypertensive eyes. Decreased expression was found for 378 genes associated with the γ-aminobutyric acid (GABA)ergic and glutamatergic systems and axon guidance. These data suggest that early functional changes in RGC might be due to reduced GABAA receptor signaling and neuroinflammation that precedes RGC loss in this glaucoma model. These initial changes may offer new targets for early detection of glaucoma and the development of new interventions.


Assuntos
Neurônios GABAérgicos/metabolismo , Glaucoma/patologia , Células Ganglionares da Retina/patologia , Ácido gama-Aminobutírico/metabolismo , Animais , Proteínas do Citoesqueleto/genética , Proteínas do Citoesqueleto/metabolismo , Modelos Animais de Doenças , Proteínas do Olho/genética , Proteínas do Olho/metabolismo , Feminino , Neurônios GABAérgicos/patologia , Regulação da Expressão Gênica , Glaucoma/etiologia , Glaucoma/metabolismo , Glicoproteínas/genética , Glicoproteínas/metabolismo , Inflamação/metabolismo , Inflamação/patologia , Pressão Intraocular , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Células Ganglionares da Retina/metabolismo
10.
Cancer Sci ; 112(9): 3585-3597, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34252986

RESUMO

Diffuse large B cell lymphoma (DLBCL) heterogeneity promotes recurrence and anti-CD20-based therapeutic resistance. Previous studies have shown that downregulation of MS4A1/CD20 expression after chemoimmunotherapy with rituximab leads to rituximab resistance. However, the mechanisms of CD20 loss remain unknown. We identified that pyruvate dehydrogenase kinase 4 (PDK4) is markedly elevated in DLBCL cells derived from both patients and cell lines with R-CHOP (rituximab plus cyclophosphamide, doxorubicin, vincristine, and prednisone) resistance. We found that overexpression of PDK4 in DLBCL cells resulted in cell proliferation and resistance to rituximab in vitro and in vivo. Furthermore, loss of PDK4 expression or treatment with the PDK4 inhibitor dichloroacetate was able to significantly increase rituximab-induced cell apoptosis in DLBCL cells. Further studies suggested PDK4 mediates a metabolic shift, in that the main energy source was changed from oxidative phosphorylation to glycolysis, and the metabolic changes could play an important role in rituximab resistance. Importantly, by knocking down or overexpressing PDK4 in DLBCL cells, we showed that PDK4 has a negative regulation effect on MS4A1/CD20 expression. Collectively, this is the first study showing that targeting PDK4 has the potential to overcome rituximab resistance in DLBCL.


Assuntos
Antígenos CD20/metabolismo , Antineoplásicos Imunológicos/administração & dosagem , Reprogramação Celular/genética , Resistencia a Medicamentos Antineoplásicos/genética , Glicoproteínas/metabolismo , Linfoma Difuso de Grandes Células B/tratamento farmacológico , Linfoma Difuso de Grandes Células B/metabolismo , Piruvato Desidrogenase Quinase de Transferência de Acetil/metabolismo , Rituximab/administração & dosagem , Transdução de Sinais/genética , Adolescente , Adulto , Idoso , Animais , Apoptose/efeitos dos fármacos , Apoptose/genética , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Proliferação de Células/genética , Sobrevivência Celular/efeitos dos fármacos , Sobrevivência Celular/genética , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Feminino , Humanos , Linfoma Difuso de Grandes Células B/genética , Linfoma Difuso de Grandes Células B/patologia , Masculino , Camundongos , Pessoa de Meia-Idade , Piruvato Desidrogenase Quinase de Transferência de Acetil/genética , Transfecção , Resultado do Tratamento , Carga Tumoral/efeitos dos fármacos , Carga Tumoral/genética , Ensaios Antitumorais Modelo de Xenoenxerto , Adulto Jovem
11.
Biomolecules ; 11(6)2021 06 09.
Artigo em Inglês | MEDLINE | ID: mdl-34207636

RESUMO

Proteomics-large-scale studies of proteins-has over the last decade gained an enormous interest for studies aimed at revealing proteins and pathways involved in disease. To fully understand biological and pathological processes it is crucial to also include post-translational modifications in the "omics". To this end, glycomics (identification and quantification of glycans enzymatically or chemically released from proteins) and glycoproteomics (identification and quantification of peptides/proteins with the glycans still attached) is gaining interest. The study of protein glycosylation requires a workflow that involves an array of sample preparation and analysis steps that needs to be carefully considered. Herein, we briefly touch upon important steps such as sample preparation and preconcentration, glycan release, glycan derivatization and quantification and advances in mass spectrometry that today are the work-horse for glycomics and glycoproteomics studies. Several proteins related to Alzheimer disease pathogenesis have altered protein glycosylation, and recent glycomics studies have shown differences in cerebrospinal fluid as well as in brain tissue in Alzheimer disease as compared to controls. In this review, we discuss these techniques and how they have been used to shed light on Alzheimer disease and to find glycan biomarkers in cerebrospinal fluid.


Assuntos
Doença de Alzheimer/metabolismo , Glicoproteínas/análise , Polissacarídeos/análise , Doença de Alzheimer/líquido cefalorraquidiano , Biomarcadores/líquido cefalorraquidiano , Biomarcadores/metabolismo , Líquido Cefalorraquidiano/química , Líquido Cefalorraquidiano/metabolismo , Cromatografia Líquida/métodos , Glicômica/métodos , Glicoproteínas/líquido cefalorraquidiano , Glicoproteínas/metabolismo , Glicosilação , Humanos , Polissacarídeos/líquido cefalorraquidiano , Polissacarídeos/metabolismo , Processamento de Proteína Pós-Traducional , Proteômica/métodos , Espectrometria de Massas em Tandem/métodos
12.
J Proteomics ; 245: 104283, 2021 08 15.
Artigo em Inglês | MEDLINE | ID: mdl-34102345

RESUMO

Human milk is the first source of nutrition for infants, which delivers an array of unique bioactive components to offspring. Modern bovine-milk-based infant formulas are good substitutes when mother's milk is not available. As the third most abundant component in human milk, human free oligosaccharides (HMOs) may interference the analysis of total N-glycans on the glycoproteins in human milk. Herein, we combined acetone precipitation protein with the filter aided sample preparation method (FASP) to thoroughly remove HMOs and purify N-glycans. Furthermore, we also compared both N-glycosylation and glycoproteins between human and bovine milk, which may provide new ideas for the composition adjustment of infant formula in the food industry. SIGNIFICANCE: We described a new method, which can successfully remove HMOs, further extract and purify the N-glycans on glycoproteins from pooled human milk for MALDI-TOF MS analysis by applying acetone precipitation and FASP together. We applied the new method to purify the N-glycans from whey proteins in pooled bovine milk and compared the N-glycosylation differences between pooled human and bovine milk by MALDI-TOF MS. We first reported the difference of N-glycan pattern of glycoproteins between pooled bovine and human milk by lectin blotting, and found significant differences in types and abundance of glycoproteins between the two sourced milk.


Assuntos
Leite Humano , Leite , Animais , Bovinos , Glicoproteínas/metabolismo , Glicosilação , Humanos , Lactente , Leite/metabolismo , Leite Humano/metabolismo , Oligossacarídeos , Polissacarídeos
13.
Development ; 148(11)2021 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-34106226

RESUMO

Defects in the evolutionarily conserved protein-glycosylation machinery during embryonic development are often fatal. Consequently, congenital disorders of glycosylation (CDG) in human are rare. We modelled a putative hypomorphic mutation described in an alpha-1,3/1,6-mannosyltransferase (ALG2) index patient (ALG2-CDG) to address the developmental consequences in the teleost medaka (Oryzias latipes). We observed specific, multisystemic, late-onset phenotypes, closely resembling the patient's syndrome, prominently in the facial skeleton and in neuronal tissue. Molecularly, we detected reduced levels of N-glycans in medaka and in the patient's fibroblasts. This hypo-N-glycosylation prominently affected protein abundance. Proteins of the basic glycosylation and glycoprotein-processing machinery were over-represented in a compensatory response, highlighting the regulatory topology of the network. Proteins of the retinal phototransduction machinery, conversely, were massively under-represented in the alg2 model. These deficiencies relate to a specific failure to maintain rod photoreceptors, resulting in retinitis pigmentosa characterized by the progressive loss of these photoreceptors. Our work has explored only the tip of the iceberg of N-glycosylation-sensitive proteins, the function of which specifically impacts on cells, tissues and organs. Taking advantage of the well-described human mutation has allowed the complex interplay of N-glycosylated proteins and their contribution to development and disease to be addressed.


Assuntos
Manosiltransferases/genética , Manosiltransferases/metabolismo , Oryzias/genética , Oryzias/metabolismo , Animais , Defeitos Congênitos da Glicosilação/genética , Defeitos Congênitos da Glicosilação/metabolismo , Modelos Animais de Doenças , Fibroblastos/metabolismo , Glicoproteínas/genética , Glicoproteínas/metabolismo , Glicosilação , Humanos , Mutação , Fenótipo , Polissacarídeos , Retinite Pigmentosa
14.
Int J Biol Macromol ; 184: 339-348, 2021 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-34097968

RESUMO

Salivary glycoproteins are known as an important barrier to inhibit influenza infection by presenting sialic acid (Sia) ligands that can bind with viral hemagglutination. Here, to further understand why pregnant women are more vulnerable to avian influenza virus (AIV), we investigated the alteration of protein sialylation in the saliva of women during pregnancy and postpartum, and its impact on the saliva binding affinity to AIV. Totally 1200 saliva samples were collected, the expression levels of terminal α2-3/6-linked Sia on salivary proteins were tested and validated, and the binding activities of salivary proteins were assessed against 3 strains of AIV and the H1N1 vaccine. Result showed that the expression of terminal α2-3-linked Sia in the saliva of women decreased dramatically during pregnancy compared to that of non-pregnancy control, especially for women in the second or third trimester (fold change = 0.53 and 0.37, p < 0.001). And their salivary protein binding ability to AIV declined accordingly. The variation of terminal α2-3-linked Sia on salivary MUC5B and IgA was consistent with the above results. This study indicates that the decrease of terminal α2-3-linked Sia on salivary glycoproteins of pregnant women affects their binding ability to AIV, which may provide new insights into AIV prevention and control.


Assuntos
Regulação para Baixo , Glicoproteínas/metabolismo , Vírus da Influenza A Subtipo H1N1/metabolismo , Vírus da Influenza A/metabolismo , Ácido N-Acetilneuramínico/química , Saliva/metabolismo , Adulto , Estudos de Casos e Controles , Feminino , Idade Gestacional , Glicoproteínas/química , Humanos , Imunoglobulina A/química , Imunoglobulina A/metabolismo , Virus da Influenza A Subtipo H5N1/metabolismo , Vírus da Influenza A Subtipo H9N2/metabolismo , Vacinas contra Influenza/metabolismo , Mucina-5B/química , Mucina-5B/metabolismo , Gravidez , Adulto Jovem
15.
Int J Mol Sci ; 22(10)2021 May 13.
Artigo em Inglês | MEDLINE | ID: mdl-34068002

RESUMO

How millions of axons navigate accurately toward synaptic targets during development is a long-standing question. Over decades, multiple studies have enriched our understanding of axonal pathfinding with discoveries of guidance molecules and morphogens, their receptors, and downstream signalling mechanisms. Interestingly, classification of attractive and repulsive cues can be fluid, as single guidance cues can act as both. Similarly, guidance cues can be secreted, chemotactic cues or anchored, adhesive cues. How a limited set of guidance cues generate the diversity of axonal guidance responses is not completely understood. Differential expression and surface localization of receptors, as well as crosstalk and spatiotemporal patterning of guidance cues, are extensively studied mechanisms that diversify axon guidance pathways. Posttranslational modification is a common, yet understudied mechanism of diversifying protein functions. Many proteins in axonal guidance pathways are glycoproteins and how glycosylation modulates their function to regulate axonal motility and guidance is an emerging field. In this review, we discuss major classes of glycosylation and their functions in axonal pathfinding. The glycosylation of guidance cues and guidance receptors and their functional implications in axonal outgrowth and pathfinding are discussed. New insights into current challenges and future perspectives of glycosylation pathways in neuronal development are discussed.


Assuntos
Axônios/fisiologia , Glicoproteínas/metabolismo , Fatores de Crescimento Neural/metabolismo , Animais , Glicosilação , Humanos , Transdução de Sinais
16.
Ecotoxicol Environ Saf ; 220: 112392, 2021 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-34102395

RESUMO

Understanding the molecular mechanisms of cadmium (Cd) tolerance and accumulation in plants is important to address Cd pollution. In the present study, we performed comparative transcriptome analysis to identify the Cd response processes in the roots of two turnip landraces, KTRG-B14 (high-Cd accumulation) and KTRG-B36 (low-Cd accumulation). Two common enhanced processes, glutathione metabolism and antioxidant system, were identified in both landraces. However, some differential antioxidant processes are likely employed by two landraces, namely, several genes encoding peptide methionine sulfoxide reductases and thioredoxins were up-regulated in B14, whereas flavonoid synthesis was potentially induced to fight against oxidative stress in B36. In addition to the commonly upregulated ZINC INDUCED FACILITATOR 1-like gene in two landraces, different metal transporter-encoding genes identified in B14 (DETOXIFICATION 1) and B36 (PLANT CADMIUM RESISTANCE 2-like, probable zinc transporter 10, and ABC transporter C family member 3) were responsible for Cd accumulation and distribution in cells. Several genes that encode extensins were specifically upregulated in B14, which may improve Cd accumulation in cell walls or regulate root development to absorb more Cd. Meanwhile, the induced high-affinity nitrate transporter 2.1-like gene was also likely to contribute to the higher Cd accumulation in B14. However, Cd also caused some toxic symptoms in both landraces. Cd stress might inhibit iron uptake in both landraces whereas many apoenzyme-encoding genes were influenced in B36, which may be attributed to the interaction between Cd and other metal ions. This study provides novel insights into the molecular mechanism of plant root response to Cd at an early stage. The transporters and key enzymes identified in this study are helpful for the molecular-assisted breeding of low- or high-Cd-accumulating plant resources.


Assuntos
Brassica napus/genética , Cádmio/metabolismo , Regulação da Expressão Gênica de Plantas , Genes de Plantas , Proteínas de Plantas/genética , Raízes de Plantas/metabolismo , Poluentes do Solo/metabolismo , Antioxidantes/metabolismo , Biodegradação Ambiental , Brassica napus/metabolismo , Glutationa/metabolismo , Glicoproteínas/genética , Glicoproteínas/metabolismo , Ferro/metabolismo , Estresse Oxidativo , Proteínas de Plantas/metabolismo , Transcriptoma
17.
Cell Mol Life Sci ; 78(14): 5569-5585, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-34089345

RESUMO

The macrophage mannose receptor (CD206, MR) is an endocytic lectin receptor which plays an important role in homeostasis and innate immunity, however, the endogenous glycan and glycoprotein ligands recognized by its C-type lectin domains (CTLD) have not been well studied. Here we used the murine MR CTLD4-7 coupled to the Fc-portion of human IgG (MR-Fc) to investigate the MR glycan and glycoprotein recognition. We probed 16 different cancer and control tissues using the MR-Fc, and observed cell- and tissue-specific binding with varying intensity. All cancer tissues and several control tissues exhibited MR-Fc ligands, intracellular and/or surface-located. We further confirmed the presence of ligands on the surface of cancer cells by flow cytometry. To characterize the fine specificity of the MR for glycans, we screened a panel of glycan microarrays. Remarkably, the results indicate that the CTLD4-7 of the MR is highly selective for specific types of pauci- and oligomannose N-glycans among hundreds of glycans tested. As lung cancer tissue and the lung cancer cell line A549 showed intense MR-Fc binding, we further investigated the MR glycoprotein ligands in those cells by immunoprecipitation and glycoproteomic analysis. All enriched glycoproteins, of which 42 were identified, contained pauci- or oligomannose N-glycans, confirming the microarray results. Our study demonstrates that the MR CTLD4-7 is highly selective for pauci- and oligomannosidic N-glycans, structures that are often elevated in tumor cells, and suggest a potential role for the MR in tumor biology.


Assuntos
Glicoproteínas/metabolismo , Lectinas Tipo C/metabolismo , Neoplasias Pulmonares/patologia , Lectinas de Ligação a Manose/metabolismo , Oligossacarídeos/metabolismo , Polissacarídeos/metabolismo , Receptores de Superfície Celular/metabolismo , Células A549 , Glicoproteínas/genética , Glicosilação , Humanos , Lectinas Tipo C/genética , Ligantes , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/metabolismo , Lectinas de Ligação a Manose/genética , Modelos Moleculares , Receptores de Superfície Celular/genética
18.
Commun Biol ; 4(1): 674, 2021 06 03.
Artigo em Inglês | MEDLINE | ID: mdl-34083726

RESUMO

The terminal galactose residues of N- and O-glycans in animal glycoproteins are often sialylated and/or fucosylated, but sulfation, such as 3-O-sulfated galactose (3-O-SGal), represents an additional, but poorly understood modification. To this end, we have developed a novel sea lamprey variable lymphocyte receptor (VLR) termed O6 to explore 3-O-SGal expression. O6 was engineered as a recombinant murine IgG chimera and its specificity and affinity to the 3-O-SGal epitope was defined using a variety of approaches, including glycan and glycoprotein microarray analyses, isothermal calorimetry, ligand-bound crystal structure, FACS, and immunohistochemistry of human tissue macroarrays. 3-O-SGal is expressed on N-glycans of many plasma and tissue glycoproteins, but recognition by O6 is often masked by sialic acid and thus exposed by treatment with neuraminidase. O6 recognizes many human tissues, consistent with expression of the cognate sulfotransferases (GAL3ST-2 and GAL3ST-3). The availability of O6 for exploring 3-O-SGal expression could lead to new biomarkers for disease and aid in understanding the functional roles of terminal modifications of glycans and relationships between terminal sulfation, sialylation and fucosylation.


Assuntos
Epitopos/metabolismo , Galactose/análogos & derivados , Glicoproteínas/metabolismo , Lampreias/metabolismo , Polissacarídeos/metabolismo , Sequência de Aminoácidos , Animais , Células CHO , Cricetinae , Cricetulus , Fucose/metabolismo , Galactose/metabolismo , Glicoproteínas/química , Glicosilação , Células HEK293 , Humanos , Lampreias/imunologia , Ligantes , Espectrometria de Massas/métodos , Ácido N-Acetilneuramínico/metabolismo , Sulfatos/metabolismo , Sulfotransferases/química , Sulfotransferases/genética , Sulfotransferases/metabolismo
19.
Chem Commun (Camb) ; 57(51): 6249-6252, 2021 Jun 24.
Artigo em Inglês | MEDLINE | ID: mdl-34059853

RESUMO

A hydrophilic probe is employed to enrich exosomes from three kinds of cancer cells by TiO2-phosphate interaction and exosomal glycoproteins by hydrophilic interaction in succession. The probe performs efficiently in both the enrichment processes. And the analytical results confirm that unique exosomal glycoproteins can distinguish parent exosomes from others.


Assuntos
Exossomos/metabolismo , Glicoproteínas/análise , Sondas Moleculares/metabolismo , Linhagem Celular Tumoral , Óxido Ferroso-Férrico/química , Glutationa/química , Glutationa/metabolismo , Glicoproteínas/metabolismo , Glicosilação , Humanos , Interações Hidrofóbicas e Hidrofílicas , Nanopartículas de Magnetita/química , Sondas Moleculares/química , Proteômica/métodos , Titânio/química
20.
Am J Med Sci ; 362(2): 161-172, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-34099278

RESUMO

BACKGROUND: Aerobic glycolysis is one of the metabolic characteristics of tumor cells, which is regulated by many genes. The aim of our study was to construct glycolysis-related gene signature to accurately predict the prognosis of laryngeal cancer (LC) patients. METHODS: We analyzed the mRNA expression profiles of LC patients from The Cancer Genome Atlas (TCGA). Eleven glycolysis-related gene sets were analyzed by gene set enrichment analysis (GSEA). In order to acquire the gene signature related to prognosis, we used univariate and multivariate Cox regression analysis. RESULTS: We confirmed that a gene signature composed of two genes (STC2, LHPP) can predict the overall survival (OS) of patients with LC. Based on each patient's risk score, we found that the survival results of patients in the high-risk group were significantly lower than those in the low-risk group (log-rank test P-value=0.002). Multivariate Cox regression analysis confirmed that gene signature could independently predict OS in LC patients (HR = 1.981, 95% CI 1.446-2.714 P<0.001). In addition, a nomogram including the age, sex, grade and risk score was constructed. The nomogram demonstrated good accuracy for OS prediction, with a C-index of 0.752. CONCLUSION: The glycolysis-related two-gene risk score model could be used as a biomarker for LC prognosis.


Assuntos
Regulação Neoplásica da Expressão Gênica , Glicólise/fisiologia , Glicoproteínas/metabolismo , Pirofosfatase Inorgânica/metabolismo , Peptídeos e Proteínas de Sinalização Intercelular/metabolismo , Neoplasias Laríngeas/genética , Neoplasias Laríngeas/patologia , Idoso , Feminino , Glicoproteínas/genética , Humanos , Pirofosfatase Inorgânica/genética , Peptídeos e Proteínas de Sinalização Intercelular/genética , Neoplasias Laríngeas/classificação , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Gradação de Tumores , Estadiamento de Neoplasias , Prognóstico
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...