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1.
Chem Biol Drug Des ; 103(1): e14365, 2024 01.
Artigo em Inglês | MEDLINE | ID: mdl-37749066

RESUMO

A mannose-binding protein from the mushroom Agaricus bisporus (Abmb) inhibits the growth of MDA-MB-231 cells, which is of an aggressive breast cancer subtype. This ability was observed in a monolayer cell (2D) culture setup, which often is unable to capture changes in cell morphology, polarity and division. That shortcoming may overestimate Abmb potency for its development as a pharmaceutical agent and its use in a therapy. Hence, Abmb's inhibition to the cell growth was performed in the 3D cell (spheroid) culture, which is more representative to the situation in vivo. The result showed that, although the presence of Abmb at ~14.7 µM already disrupted the MDA-MB-231 cell morphology in the 2D culture, its presence at ~16.5 µM only ceased the growth of the MDA-MB-231 spheroid. Further, Abmb is unique because structurally it belongs to the R-type lectin (RTL) family; most of mannose-binding protein is of the C-type lectin (CTL). As the natural ligand of Abmb is unknown thus the mechanism of action is unclear, Abmb effect on the cancer cells was assessed via observation of the altered expression of genes involved in the Wnt/ß-catenin signalling, which is one of the canonical pathways in the proliferation of cancer cells. The results suggested that Abmb did not alter the pathway upon exerting its anti-proliferative activity to the MDA-MB-231 cells.


Assuntos
Agaricus , Neoplasias da Mama , Lectina de Ligação a Manose , Humanos , Feminino , Lectina de Ligação a Manose/farmacologia , Lectinas/farmacologia , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/metabolismo , Proliferação de Células , Linhagem Celular Tumoral
2.
Cell Mol Gastroenterol Hepatol ; 14(1): 75-99, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35381393

RESUMO

BACKGROUND & AIMS: Liver fibrosis represents a hallmark of most chronic liver diseases (CLD) triggered by recurrent liver injury and subsequent myofibroblast transdifferentiations of resident hepatic stellate cells (HSCs). Mannan-binding lectin (MBL) is potentially involved in hepatic fibrosis in CLD through unclear mechanisms. Therefore, we investigated the crosstalk between MBL and HSCs, and the consequent effects on fibrosis progression. METHODS: Samples from patients with liver cirrhosis were collected. MBL deficiency (MBL-/-) and wild-type (WT) C57BL/6J mice were used to construct a CCl4-induced liver fibrosis model. Administration of MBL-expressing, liver-specific, adeno-associated virus was performed to restore hepatic MBL expression in MBL-/- mice. The human HSC line LX-2 was used for in vitro experiments. RESULTS: MBL levels in patients with liver cirrhosis were correlated with disease severity. In the CCl4-induced liver fibrosis model, MBL-/- mice showed severer liver fibrosis accompanied by reduced senescent activated HSCs in liver tissue compared with WT mice, which could be inhibited by administering MBL-expressing, liver-specific, adeno-associated virus. Moreover, depleting senescent cells with senolytic treatment could abrogate these differences owing to MBL absence. Furthermore, MBL could interact directly with calreticulin associated with low-density lipoprotein receptor-related protein 1 on the cell surface of HSCs, which further promotes senescence in HSCs by up-regulating the mammalian target of rapamycin/p53/p21 signaling pathway. CONCLUSIONS: MBL as a newfound senescence-promoting modulator and its crosstalk with HSCs in the liver microenvironment is essential for the control of hepatic fibrosis progression, suggesting its potential therapeutic use in treating CLD associated with liver fibrosis.


Assuntos
Células Estreladas do Fígado , Lectina de Ligação a Manose , Animais , Calreticulina/metabolismo , Calreticulina/farmacologia , Fibrose , Células Estreladas do Fígado/patologia , Humanos , Cirrose Hepática/patologia , Mamíferos/metabolismo , Lectina de Ligação a Manose/metabolismo , Lectina de Ligação a Manose/farmacologia , Camundongos , Camundongos Endogâmicos C57BL
3.
Korean J Parasitol ; 59(2): 173-178, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33951774

RESUMO

The DM9 domain is a protein unit of 60-75 amino acids that has been first detected in the fruit fly Drosophila as a repeated motif of unknown function. Recent research on proteins carrying DM9 domains in the mosquito Anopheles gambiae and the oyster Crassostrea gigas indicated an association with the uptake of microbial organisms. Likewise, in the trematode Fasciola gigantica DM9-1 showed intracellular relocalization following microbial, heat and drug stress. In the present research, we show that FgDM9-1 is a lectin with a novel mannose-binding site that has been recently described for the protein CGL1 of Crassostrea gigas. This property allowed FgDM9-1 to agglutinate gram-positive and -negative bacteria with appropriate cell surface glycosylation patterns. Furthermore, FgDM9-1 caused hemagglutination across all ABO blood group phenotypes. It is speculated that the parenchymal located FgDM9-1 has a role in cellular processes that involve the transport of mannose-carrying molecules in the parenchymal cells of the parasite.


Assuntos
Proteínas de Helminto/farmacologia , Lectina de Ligação a Manose/farmacologia , Aglutinação , Sequência de Aminoácidos , Animais , Bactérias/citologia , Bactérias/efeitos dos fármacos , Eritrócitos/citologia , Eritrócitos/efeitos dos fármacos , Fasciola/química , Fasciola/genética , Proteínas de Helminto/química , Proteínas de Helminto/genética , Proteínas de Helminto/metabolismo , Hemaglutinação/efeitos dos fármacos , Humanos , Lectina de Ligação a Manose/química , Lectina de Ligação a Manose/genética , Lectina de Ligação a Manose/metabolismo , Alinhamento de Sequência , Streptococcus/citologia , Streptococcus/efeitos dos fármacos
4.
Blood Adv ; 4(19): 4788-4797, 2020 10 13.
Artigo em Inglês | MEDLINE | ID: mdl-33017467

RESUMO

The therapy of advanced mycosis fungoides (MF) presents a therapeutic challenge, and the search for new therapeutic targets is ongoing. Poly(ADP-ribose) polymerase 1 was shown to be upregulated in patients with advanced MF and could be druggable by a new class of chemotherapeutic agents, PARP-1 inhibitors, which are already in clinical trials for other malignancies; however, the role of PARP-1 inhibitors in MF has never been established. We examined the efficacy of talazoparib in the murine model of cutaneous T-cell lymphoma. The cytotoxic effect of talazoparib on Moloney MuLV-induced T-cell lymphoma (MBL2) cells was a result of G2/M cell cycle arrest via the upregulation of p53. The in vivo experiments confirmed the clinical impact of talazoparib on MF tumors. When talazoparib was combined with the histone deacetylase (HDAC) inhibitor, romidepsin, the cytotoxic effect was synergized via downregulation of the DNA-repair genes Fanconianemia complementation group A (FANCA), Fanconi anemia complementation group D2 (FANCD2), and DNA topoisomerase II binding protein 1(TOPBP1)and stimulation of apoptosis via Blimp-1 (PRDM1)/Bax axis. Romidepsin increased the expression of IRF8 and Bcl-6, leading to upregulation of Blimp1and Bax; whereas talazoparib upregulated Blimp-1 and Bax via upregulation of interferon regulatory factor 4 (IRF4), leading to cleavage of caspases 6 and 7. Thus, a combination of talazoparib with romidepsin demonstrated the synergistic antilymphoma effect and warranted further investigation in a clinical trial.


Assuntos
Linfoma Cutâneo de Células T , Lectina de Ligação a Manose , Animais , Apoptose , Histona Desacetilases/farmacologia , Humanos , Linfoma Cutâneo de Células T/tratamento farmacológico , Linfoma Cutâneo de Células T/genética , Lectina de Ligação a Manose/farmacologia , Camundongos , Ftalazinas/farmacologia , Inibidores de Poli(ADP-Ribose) Polimerases/farmacologia
5.
Methods Mol Biol ; 2132: 99-109, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32306318

RESUMO

Native and recombinant collectins are purified by using mannan-agarose and an anti-collectin antibody column. The use of sandwich enzyme-linked immunosorbent assay (ELISA) with two antibodies against human mannan-binding lectin (MBL) enables elucidation of the collectin concentration in the blood, serum, and plasma. The collectin sugar specificity is demonstrated by determining the concentration of saccharide required to inhibit sugar binding by 50% in a saccharide-binding assay. Biological analyses including the complement-dependent hemolysis test and several other methods are used to evaluate collectin.


Assuntos
Glicoproteínas de Hemaglutininação de Vírus da Influenza/metabolismo , Vírus da Influenza A/efeitos dos fármacos , Lectina de Ligação a Manose/isolamento & purificação , Lectina de Ligação a Manose/farmacologia , Animais , Galinhas , Cromatografia em Agarose , Cães , Ensaio de Imunoadsorção Enzimática , Hemólise , Humanos , Células Madin Darby de Rim Canino , Mananas/metabolismo , Lectina de Ligação a Manose/sangue
6.
Biomolecules ; 10(2)2020 02 19.
Artigo em Inglês | MEDLINE | ID: mdl-32092955

RESUMO

Lectins have the ability to bind specific carbohydrates and they have potential applications as medical and pharmacological agents. The unique structure and usefulness of red algal lectin have been reported, but these lectins are limited to a few marine algal groups. In this study, a novel mannose-binding lectin from Grateloupia chiangii (G. chiangii lectin, GCL) was purified using antiviral screens and affinity chromatography. We characterized the molecular weight, agglutination activity, hemagglutination activity, and heat stability of GCL. To determine the carbohydrate specificity, a glycan microarray was performed. GCL showed strong binding affinity for Maltohexaose-ß-Sp1 and Maltoheptaose-ß-Sp1 with weak affinity for other monosaccharides and preferred binding to high-mannan structures. The N-terminal sequence and peptide sequence of GCL were determined using an Edman degradation method and LC-MS/MS, and the cDNA and peptide sequences were deduced. GCL was shown to consist of 231 amino acids (24.9 kDa) and the N-terminus methionine was eliminated after translation. GCL possessed a tandem repeat structure of six domains, similar to the other red algal lectins. The mannose binding properties and tandem repeat structure of GCL may confer it the potential to act as an antiviral agent for protection against viral infection.


Assuntos
Proteínas de Algas/química , Antivirais/química , Lectina de Ligação a Manose/química , Rodófitas/química , Proteínas de Algas/metabolismo , Proteínas de Algas/farmacologia , Animais , Antivirais/metabolismo , Antivirais/farmacologia , Cães , Testes de Hemaglutinação , Cavalos , Células Madin Darby de Rim Canino , Lectina de Ligação a Manose/metabolismo , Lectina de Ligação a Manose/farmacologia , Ligação Proteica , Rodófitas/metabolismo , Ovinos , Viroses/tratamento farmacológico , Vírus/efeitos dos fármacos
7.
Fish Shellfish Immunol ; 98: 25-33, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31904539

RESUMO

Mannose-binding lectin (MBL) is a crucial pattern recognition receptor in the host innate immune system. Previously, we reported the biological function of Ctenopharyngodon idella MBL (CiMBL) in initiating the lectin pathway of the complement system. In the present study, we further explored its biological function including the agglutinating ability, binding capacity and protective role in vitro and in vivo. After Aeromonas hydrophila infection, western blot analysis revealed that the CiMBL were fluctuated and expressed in the serum and major immune-related tissues. The result of quantitative PCR (qPCR) showed that the recombinant CiMBL (rCiMBL) significantly inhibited the mRNA expression of interleukin-1ß (IL-1ß) and tumor necrosis factor-α (TNF-α) in liver, spleen and hepatic cells. Due to rCiMBL bound to d-mannose, d-galactose, d-glucose, N-acetyl-d-glucosamine (GlcNAc), lipopolysaccharide (LPS), peptidoglycan (PGN) and Agar in the presence of Ca2+, herein gram-positive (Staphylococcus aureus and Micrococcus luteus) and gram-negative (A. hydrophila and Vibrio anguillarum) bacteria were agglutinated by rCiMBL in a Ca2+-dependent manner. More importantly, rCiMBL enhanced the survival rate of grass carp following bacterial infection. Overall, the results provide an evidence that CiMBL can protect grass carp against A. hydrophila infection in aquaculture.


Assuntos
Aglutinação , Carpas/imunologia , Doenças dos Peixes/imunologia , Lectina de Ligação a Manose/imunologia , Monossacarídeos/metabolismo , Polissacarídeos/metabolismo , Aeromonas hydrophila/fisiologia , Animais , Carpas/metabolismo , Proteínas de Peixes/imunologia , Proteínas de Peixes/farmacologia , Bactérias Gram-Negativas/fisiologia , Infecções por Bactérias Gram-Negativas/imunologia , Infecções por Bactérias Gram-Negativas/veterinária , Bactérias Gram-Positivas/fisiologia , Lectina de Ligação a Manose/farmacologia , Substâncias Protetoras/farmacologia
8.
Biochemistry ; 59(6): 818-828, 2020 02 18.
Artigo em Inglês | MEDLINE | ID: mdl-31942789

RESUMO

Dual-acting virucidal entry inhibitors (DAVEIs) have previously been shown to cause irreversible inactivation of HIV-1 Env-presenting pseudovirus by lytic membrane transformation. This study examined whether this transformation could be generalized to include membranes of Env-presenting cells. Flow cytometry was used to analyze HEK293T cells transiently transfected with increasing amounts of DNA encoding JRFL Env, loaded with calcein dye, and treated with serial dilutions of microvirin (Q831K/M83R)-DAVEI. Comparing calcein retention against intact Env expression (via Ab 35O22) on individual cells revealed effects proportional to Env expression. "Low-Env" cells experienced transient poration and calcein leakage, while "high-Env" cells were killed. The cell-killing effect was confirmed with an independent mitochondrial activity-based cell viability assay, showing dose-dependent cytotoxicity in response to DAVEI treatment. Transfection with increasing quantities of Env DNA showed further shifts toward "High-Env" expression and cytotoxicity, further reinforcing the Env dependence of the observed effect. Controls with unlinked DAVEI components showed no effect on calcein leakage or cell viability, confirming a requirement for covalently linked DAVEI compounds to achieve Env transformation. These data demonstrate that the metastability of Env is an intrinsic property of the transmembrane protein complex and can be perturbed to cause membrane disruption in both virus and cell contexts.


Assuntos
Proteínas de Bactérias/farmacologia , Membrana Celular/metabolismo , Membrana Celular/virologia , Inibidores da Fusão de HIV/farmacologia , Lectina de Ligação a Manose/farmacologia , Internalização do Vírus/efeitos dos fármacos , Produtos do Gene env do Vírus da Imunodeficiência Humana/metabolismo , Sequência de Aminoácidos , Membrana Celular/efeitos dos fármacos , Células HEK293 , Humanos , Estabilidade Proteica/efeitos dos fármacos , Estrutura Secundária de Proteína , Produtos do Gene env do Vírus da Imunodeficiência Humana/antagonistas & inibidores , Produtos do Gene env do Vírus da Imunodeficiência Humana/química
9.
J Cereb Blood Flow Metab ; 40(8): 1608-1620, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-31495300

RESUMO

Mannose-binding lectin (MBL), an initiator of the lectin pathway, is detrimental in ischemic stroke. MBL deposition on the ischemic endothelium indicates the beginning of its actions, but downstream mechanisms are not clear yet.We investigated MBL interactions with the ischemic endothelium by exposing human brain microvascular endothelial cells (hBMECs) to protocols of ischemia. Cells were exposed to hypoxia or oxygen-glucose deprivation (OGD), and re-oxygenated with human serum (HS) or recombinant MBL (rhMBL). Hypoxic hBMECs re-oxygenated with HS showed increased complement system activation (C3c deposition, +59%) and MBL deposition (+93%) than normoxic cells. Super-resolution microscopy showed MBL internalization in hypoxic cells and altered cytoskeletal organization, indicating a potential MBL action on the endothelial structure. To isolate MBL effect, hBMECs were re-oxygenated with rhMBL after hypoxia/OGD. In both conditions, MBL reduced viability (hypoxia: -25%, OGD: -34%) compared to conditions without MBL, showing a direct toxic effect. Ischemic cells also showed greater MBL deposition (hypoxia: +143%, OGD: +126%) than normoxic cells. These results were confirmed with primary hBMECs exposed to OGD (increased MBL-induced cell death: +226%, and MBL deposition: +104%). The present findings demonstrate that MBL can exert a direct deleterious effect on ischemic brain endothelial cells in vitro, independently from complement activation.


Assuntos
Isquemia Encefálica/metabolismo , Células Endoteliais/efeitos dos fármacos , Endotélio Vascular/efeitos dos fármacos , Lectina de Ligação a Manose/metabolismo , Isquemia Encefálica/patologia , Hipóxia Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Lectina de Ligação a Manose da Via do Complemento/efeitos dos fármacos , Células Endoteliais/metabolismo , Células Endoteliais/patologia , Endotélio Vascular/metabolismo , Endotélio Vascular/patologia , Glucose/metabolismo , Humanos , Lectina de Ligação a Manose/genética , Lectina de Ligação a Manose/farmacologia , Oxigênio/metabolismo , Cultura Primária de Células , Soro/metabolismo
10.
Biochem Biophys Res Commun ; 519(4): 773-776, 2019 11 19.
Artigo em Inglês | MEDLINE | ID: mdl-31547987

RESUMO

Agaricus bisporus mannose binding protein (Abmb) demonstrates permeability to epithelial monolayer barrier of the intestine, resistance to gastrointestinal tract conditions and to proteolysis therefore it holds potential as a drug carrier for oral route administration. Abmb also display antiproliferative activity to breast cancer cells and stimulation of immune system thus could potentially be also developed for therapeutic purpose. It is not immunogenic or toxic thereby safe for use. In this paper we further provide evidence that Abmb also lacks of agglutinating activity despite sharing high structural homology to lectins. Abmb is thereby the only mannose specific binding protein that is not member of lectin family. This evidence provides further support on the use of Abmb as pharmaceutical or medicinal agent. Its molecular globularity that may contribute to its lack of agglutination capacity was also evaluated.


Assuntos
Agaricus/metabolismo , Proteínas Fúngicas/farmacologia , Lectinas/farmacologia , Lectina de Ligação a Manose/farmacologia , Animais , Eritrócitos/efeitos dos fármacos , Eritrócitos/imunologia , Proteínas Fúngicas/administração & dosagem , Proteínas Fúngicas/química , Hemaglutinação/efeitos dos fármacos , Hemaglutinação/imunologia , Testes de Hemaglutinação , Humanos , Interações Hidrofóbicas e Hidrofílicas , Lectinas/administração & dosagem , Lectinas/química , Lectina de Ligação a Manose/administração & dosagem , Lectina de Ligação a Manose/química , Modelos Moleculares , Conformação Proteica
11.
Exp Dermatol ; 28(9): 1017-1024, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31260126

RESUMO

Psoriasis is a chronic, relapsing inflammatory skin disorder. Numerous experimental evidence and therapeutic evidence have shown that the innate immune response is critical for the pathogenesis and development of psoriasis. Mannan-binding lectin (MBL), a prototypic pattern recognition molecule of the innate immune system, plays an essential role in the host defense against certain infections and also appears to be a major regulator of inflammation. In this study, we investigated the function of MBL on the course of experimental murine imiquimod (IMQ)-induced psoriasis. Our data showed that MBL-deficient (MBL-/- ) mice exhibited attenuated skin damage characterized by greatly decreased erythema compared with wild-type control mice during the early stages of IMQ-induced psoriasis-like skin inflammation. The reduced skin inflammation in MBL-/- mice was associated with the decreased infiltration of neutrophils. Furthermore, we have determined that MBL deficiency limited the chemokine CXCL1 production from skin keratinocytes upon IMQ stimulation, which might be responsible for the impaired skin recruitment of neutrophils. Additionally, we have provided the data that MBL protein promotes the IMQ-induced expression of CXCL1 and activation of MAPK/NF-κB signalling pathway in human keratinocyte HaCaT cells in vitro. In summary, our study revealed an unexpected role of MBL on keratinocyte function in skin, thus offering a new insight into the pathogenic mechanisms of psoriasis.


Assuntos
Quimiocina CXCL1/biossíntese , Quimiotaxia de Leucócito , Queratinócitos/metabolismo , Lectina de Ligação a Manose/fisiologia , Neutrófilos/fisiologia , Psoríase/imunologia , Animais , Linhagem Celular Transformada , Quimiocina CXCL1/genética , Derme/imunologia , Derme/patologia , Feminino , Humanos , Imiquimode/toxicidade , Inflamação , Queratinócitos/efeitos dos fármacos , Lectina de Ligação a Manose/deficiência , Lectina de Ligação a Manose/genética , Lectina de Ligação a Manose/imunologia , Lectina de Ligação a Manose/farmacologia , Erros Inatos do Metabolismo/complicações , Erros Inatos do Metabolismo/imunologia , Camundongos , Camundongos Knockout , Psoríase/induzido quimicamente , Psoríase/metabolismo , Organismos Livres de Patógenos Específicos , Regulação para Cima
12.
F1000Res ; 8: 108, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31275563

RESUMO

Background: Fc-mannose-binding lectin (FcMBL), an engineered version of the blood opsonin MBL that contains the carbohydrate recognition domain (CRD) and flexible neck regions of MBL fused to the Fc portion of human IgG1, has been shown to bind various microbes and pathogen-associated molecular patterns (PAMPs). FcMBL has also been used to create an enzyme-linked lectin sorbent assay (ELLecSA) for use as a rapid (<1 h) diagnostic of bloodstream infections. Methods: Here we extended this work by using the ELLecSA to test FcMBL's ability to bind to more than 190 different isolates from over 95 different pathogen species. Results: FcMBL bound to 85% of the isolates and 97 of the 112 (87%) different pathogen species tested, including bacteria, fungi, viral antigens and parasites. FcMBL also bound to PAMPs including, lipopolysaccharide endotoxin (LPS) and lipoteichoic acid (LTA) from Gram-negative and Gram-positive bacteria, as well as lipoarabinomannan (LAM) and phosphatidylinositol mannoside 6 (PIM 6) from Mycobacterium tuberculosis. Conclusions: The efficiency of pathogen detection and variation between binding of different strains of the same species could be improved by treating the bacteria with antibiotics, or mechanical disruption using a bead mill, prior to FcMBL capture to reveal previously concealed binding sites within the bacterial cell wall. As FcMBL can bind to pathogens and PAMPs in urine as well as blood, its broad-binding capability could be leveraged to develop a variety of clinically relevant technologies, including infectious disease diagnostics, therapeutics, and vaccines.


Assuntos
Antibacterianos , Bactérias , Lectina de Ligação a Manose , Fungos , Humanos , Lectinas Tipo C , Manose/metabolismo , Lectina de Ligação a Manose/farmacologia
13.
Biochem Biophys Res Commun ; 515(1): 99-103, 2019 07 12.
Artigo em Inglês | MEDLINE | ID: mdl-31128918

RESUMO

A recently discovered lectin-like protein from mushroom tyrosinase designated as orf239342 inhibits proliferation of the MCF-7 breast cancer cells. This characteristic is likely derived from its ability to recognize sugar entity on the cell surface. Thereby, the binding specificity of orf239342 to sugars was studied. Orf239342 was found to bind specifically to mannose upon analysis with the surface plasmon resonance technique. Finally, our in vitro study showed that mannose impeded orf239342 ability to inhibit proliferation of the MCF-7 breast cancer cells, providing further evidence for the mannose binding onto the protein. Our finding is a breakthrough to characterise orf239342 i.e. to define its functioning in the mushroom, association to the tyrosinase, or even possible application in breast cancer therapy. In addition, the finding allows the more appropriate designation of the protein as Agaricus bisporus mannose binding-protein (AbMb).


Assuntos
Agaricus/metabolismo , Proteínas Fúngicas/metabolismo , Lectina de Ligação a Manose/metabolismo , Manose/metabolismo , Neoplasias da Mama/metabolismo , Neoplasias da Mama/patologia , Neoplasias da Mama/prevenção & controle , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Proteínas Fúngicas/farmacologia , Humanos , Células MCF-7 , Lectina de Ligação a Manose/farmacologia , Monofenol Mono-Oxigenase/metabolismo , Ligação Proteica
14.
F1000Res ; 7: 616, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30271580

RESUMO

Background: There is a need to prevent and treat infection in newborns. One approach is administration of antimicrobial proteins and peptides (APPs) such as LL-37, a membrane-active cathelicidin antimicrobial peptide, and mannose-binding lectin (MBL), a pattern-recognition protein that binds to microbial surface polysaccharides resulting in opsonization and complement activation. Low plasma/serum levels of LL-37 and of MBL have been correlated with infection and exogenous administration of these agents may enhance host defense. Methods: The antimicrobial activity of LL-37 (15 µg/ml) or rMBL (0.5, 2 and 10 µg/ml) was tested in hirudin-anticoagulated preterm and term human cord blood (N = 12-14) against Staphylococcus aureus (SA) USA 300 (2x10 4 CFU/ml), Staphylococcus epidermis (SE) 1457 (2x10 4 CFU/ml) and Candida albicans (CA) SC5314 (1x10 4 CFU/ml). After incubation (1, 45, or 180 min), CFUs were enumerated by plating blood onto agar plates. Supernatants were collected for measurement of MBL via ELISA. Results: Preterm cord blood demonstrated impaired endogenous killing capacity against SA and SE compared to term blood. Addition of LL-37 strongly enhanced antimicrobial/antifungal activity vs SA, SE and CA in term blood and SE and CA in preterm blood. By contrast, rMBL showed modest fungistatic activity vs CA in a sub-analysis of term newborns with high basal MBL levels. Baseline MBL levels varied within preterm and term cohorts with no correlation to gestational age. In summary, exogenous LL-37 demonstrated significant antimicrobial activity against SA, SE and CA in term and SE and CA in preterm human blood tested in vitro. rMBL demonstrated modest antifungal activity in term cord blood of individuals with high baseline MBL levels. Conclusions: To the extent that our in vitro results predict the effects of APPs in vivo, development of APPs for prevention and treatment of infection should take into account host age as well as the target pathogen.


Assuntos
Catelicidinas/metabolismo , Sangue Fetal/imunologia , Lectina de Ligação a Manose/metabolismo , Peptídeos Catiônicos Antimicrobianos/farmacologia , Candida albicans/efeitos dos fármacos , Catelicidinas/farmacologia , Feminino , Sangue Fetal/química , Idade Gestacional , Humanos , Recém-Nascido , Masculino , Lectina de Ligação a Manose/farmacologia , Proteínas Recombinantes/metabolismo , Staphylococcus aureus , Staphylococcus epidermidis/efeitos dos fármacos
15.
Mol Biotechnol ; 60(4): 290-301, 2018 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-29492788

RESUMO

Lectins are carbohydrate-binding proteins with wide array of functions including plant defense against pathogens and insect pests. In the present study, a putative mannose-binding lectin (WsMBP1) of 1124 bp was isolated from leaves of Withania somnifera. The gene was expressed in E. coli, and the recombinant WsMBP1 with a predicted molecular weight of 31 kDa was tested for its insecticidal properties against Hyblaea puera (Lepidoptera: Hyblaeidae) and Probergrothius sanguinolens (Hemiptera: Pyrrhocoridae). Delay in growth and metamorphosis, decreased larval body mass and increased mortality was recorded in recombinant WsMBP1-fed larvae. Histological studies on the midgut of lectin-treated insects showed disrupted and diffused secretory cells surrounding the gut lumen in larvae of H. puera and P. sanguinolens, implicating its role in disruption of the digestive process and nutrient assimilation in the studied insect pests. The present study indicates that WsMBP1 can act as a potential gene resource in future transformation programs for incorporating insect pest tolerance in susceptible plant genotypes.


Assuntos
Lepidópteros/efeitos dos fármacos , Lectina de Ligação a Manose/genética , Lectina de Ligação a Manose/farmacologia , Withania/metabolismo , Animais , Clonagem Molecular , Hemípteros/efeitos dos fármacos , Lectina de Ligação a Manose/metabolismo , Peso Molecular , Filogenia , Folhas de Planta/genética , Folhas de Planta/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Análise de Sequência de DNA , Withania/genética
16.
Biomed Pharmacother ; 93: 654-665, 2017 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-28686979

RESUMO

Breast cancer known for its high metastatic potential is responsible for large mortality rate amongst women; hence it is imperative to search for effective anti-metastatic molecules despite anticancer drugs. The current study describes the potential of Remusatia vivipara lectin (RVL), inducing apoptosis in breast cancer cells there by limiting motility and invasiveness. RVL binds to the cell surface glycans of MDA-MB-468 and MCF-7 cells, exhibiting strong glycan mediated cytotoxic effect, but show marginal effect on non-tumorigenic MCF-10A cells. RVL elicits increased cellular stress, apoptotic vacuoles and nuclear disintegration in both MDA-MB-468 and MCF-7 cells accompanied by depletion of G0/G1, S and G2/M phases. Lectin interaction induced production of reactive oxygen species through altering mitochondrial membrane potential progressing to apoptosis. Further, RVL strongly elicited reproductive cell death in MDA-MB-468 cells and showed strong inhibitory effect on neovascularization demonstrated in chorioallantoic membrane assay. Treatment of MDA-MB-468 cells with RVL, suppress the motility and invasive property as shown by scratch wound heal and Boyden chamber transwell assays respectively. These results provide an insight into significance of interaction of RVL with specific cell surface high mannose N-glycans resulting in curtailing the metastatic ability of cancer cells.


Assuntos
Antineoplásicos/farmacologia , Araceae/química , Neoplasias da Mama/tratamento farmacológico , Proliferação de Células/efeitos dos fármacos , Lectina de Ligação a Manose/farmacologia , Invasividade Neoplásica/patologia , Polissacarídeos/metabolismo , Animais , Apoptose/efeitos dos fármacos , Neoplasias da Mama/metabolismo , Neoplasias da Mama/patologia , Ciclo Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Movimento Celular/efeitos dos fármacos , Galinhas , Feminino , Humanos , Células MCF-7 , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Espécies Reativas de Oxigênio/metabolismo
17.
Biosci Rep ; 37(3)2017 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-28507200

RESUMO

Microvirin (MVN) is a carbohydrate-binding protein which shows high specificity for high-mannose type N-glycan structures. In the present study, we tried to identify whether MVN could bind to high-mannose containing hepatitis C virus (HCV) envelope glycoproteins, which are heavily decorated high-mannose glycans. In addition, recombinantly expressed MVN oligomers in di-, tri- and tetrameric form were evaluated for their viral inhibition. MVN oligomers bound more efficiently to HCV virions, and displayed in comparison with the MVN monomer a higher neutralization potency against HCV infection. The antiviral effect was furthermore affected by the peptide linker sequence connecting the MVN monomers. The results indicate that MVN oligomers such as trimers and tetramers may be used as future neutralization agents against HCV infections.


Assuntos
Antivirais/química , Antivirais/farmacologia , Proteínas de Bactérias/química , Proteínas de Bactérias/farmacologia , Hepacivirus/efeitos dos fármacos , Lectina de Ligação a Manose/química , Lectina de Ligação a Manose/farmacologia , Microcystis/química , Antivirais/metabolismo , Proteínas de Bactérias/genética , Linhagem Celular , Clonagem Molecular , Hepatite C/tratamento farmacológico , Humanos , Lectina de Ligação a Manose/genética , Microcystis/genética , Multimerização Proteica , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/farmacologia
18.
Int J Biol Macromol ; 102: 1146-1155, 2017 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-28472687

RESUMO

Dioscorea bulbifera or air potato has been used as a folk remedy to treat cancer. A mannose binding lectin from bulbils of D. bulbifera was purified in a single step by affinity chromatography on mucin coupled Sepharose 4B column, determined by its fine sugar specificity by glycan array analysis and studied for its clinical potential in cancer and HIV research. SDS-PAGE showed that lectin is a monomer of Mr 24kDa. DBL agglutinated only rabbit erythrocytes and was inhibited by mucin, asialomucin, fetuin, asialofetuin and transferrin but not by any monosaccharides. Glycan array analysis of DBL revealed its affinity toward high mannose N-linked glycans with enhanced affinity for terminal mannose including N-linked glycans of HIV envelope glycoprotein gp120 and has strong anti-reverse transcriptase activity. DBL showed strong binding to non-metastatic human colon epithelial cancer HT 29, metastatic SW 620 and hepatocellular HepG2 cell lines. DBL showed dose and time dependent growth inhibitory effects on all the three cell lines HT 29, SW 620 and HepG2 with IC50 of 110µg, 9.8µg, 40µg respectively at 72h. Inhibitory effect of DBL was effectively blocked in presence of competing glycans like mucin. DBL has promising clinical potential both in cancer and HIV research.


Assuntos
Dioscorea , Lectina de Ligação a Manose/isolamento & purificação , Lectina de Ligação a Manose/farmacologia , Animais , Proliferação de Células/efeitos dos fármacos , Transcriptase Reversa do HIV/antagonistas & inibidores , Células HT29 , Haptenos/metabolismo , Hemaglutinação/efeitos dos fármacos , Humanos , Lectina de Ligação a Manose/química , Lectina de Ligação a Manose/metabolismo , Peso Molecular , Coelhos , Especificidade por Substrato
19.
Carbohydr Res ; 437: 1-8, 2017 Jan 02.
Artigo em Inglês | MEDLINE | ID: mdl-27871013

RESUMO

The opportunistic Gram-negative bacterium Burkholderia cenocepacia causes lethal infections in cystic fibrosis patients. Multivalent mannoside derivatives were prepared as potential inhibitors of lectin BC2L-A, one of the virulence factors deployed by B. cenocepacia in the infection process. An (α1→2)-thio-linked mannobioside mimic bearing an azide functionalized aglycon was conjugated to different multivalent scaffolds such as propargylated calix[4]arenes, methyl gallate and pentaerythritol by azide-alkyne 1,3-dipolar cycloaddition. The interaction between the glycoclusters and the mannose binding BC2L-A lectin from B. cenocepacia was examined by isothermal microcalorimetry, surface plasmon resonance, inhibition of yeast agglutination and analytical ultracentrifugation.


Assuntos
Burkholderia cenocepacia/química , Lectina de Ligação a Manose/química , Manosídeos/química , Testes de Aglutinação , Calorimetria/métodos , Técnicas de Química Sintética , Ligantes , Lectina de Ligação a Manose/metabolismo , Lectina de Ligação a Manose/farmacologia , Manosídeos/síntese química , Manosídeos/metabolismo , Ressonância de Plasmônio de Superfície , Ultracentrifugação/métodos , Leveduras/efeitos dos fármacos
20.
Sci Rep ; 6: 37339, 2016 11 17.
Artigo em Inglês | MEDLINE | ID: mdl-27853317

RESUMO

To characterize the interaction potential of the human vaginal isolate Lactobacillus plantarum CMPG5300, its genome was mined for genes encoding lectin-like proteins. cmpg5300.05_29 was identified as the gene encoding a putative mannose-binding lectin. Phenotypic analysis of a gene knock-out mutant of cmpg5300.05_29 showed that expression of this gene is important for auto-aggregation, adhesion to the vaginal epithelial cells, biofilm formation and binding to mannosylated glycans. Purification of the predicted lectin domain of Cmpg5300.05_29 and characterization of its sugar binding capacity confirmed the specificity of the lectin for high- mannose glycans. Therefore, we renamed Cmpg5300.05_29 as a mannose-specific lectin (Msl). The purified lectin domain of Msl could efficiently bind to HIV-1 glycoprotein gp120 and Candida albicans, and showed an inhibitory activity against biofilm formation of uropathogenic Escherichia coli, Staphylococcus aureus and Salmonella Typhimurium. Thus, using a combination of molecular lectin characterization and functional assays, we could show that lectin-sugar interactions play a key role in host and pathogen interactions of a prototype isolate of the vaginal Lactobacillus microbiota.


Assuntos
Proteínas de Bactérias/fisiologia , Lactobacillus plantarum/fisiologia , Lectina de Ligação a Manose/fisiologia , Vagina/microbiologia , Aglutinação , Aderência Bacteriana , Proteínas de Bactérias/farmacologia , Biofilmes , Candida albicans/fisiologia , Configuração de Carboidratos , Sequência de Carboidratos , Células Epiteliais/microbiologia , Feminino , Proteína gp120 do Envelope de HIV/química , Proteína gp41 do Envelope de HIV/química , HIV-1/fisiologia , Humanos , Mananas/química , Lectina de Ligação a Manose/farmacologia , Interações Microbianas , Ligação Proteica , Saccharomyces cerevisiae/fisiologia , Salmonella typhimurium/efeitos dos fármacos , Salmonella typhimurium/fisiologia
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