RESUMO
Serum and plasma exhibit a broad dynamic range of protein concentrations, posing challenges for proteome analysis. Various technologies have been developed to reduce this complexity, including high-abundance depletion methods utilizing antibody columns, extracellular vesicle enrichment techniques, and trace protein enrichment using nanobead cocktails. Here, we employed lectins to address this, thereby extending the scope of biomarker discovery in serum or plasma using a novel approach. We enriched serum proteins using 37 different lectins and subjected them to LC-MS/MS analysis with data-independent acquisition. Solanum tuberosum lectin (STL) and Lycopersicon esculentum lectin (LEL) enabled the detection of more serum proteins than the other lectins. STL and LEL bind to N-acetylglucosamine oligomers, emphasizing the significance of capturing these oligomer-binding proteins when analyzing serum trace proteins. Combining STL and LEL proved more effective than using them separately, allowing us to identify over 3000 proteins from serum through single-shot proteome analysis. We applied the STL/LEL trace-protein enrichment method to the sera of systemic lupus erythematosus model mice. This revealed differences in >1300 proteins between the systemic lupus erythematosus model and control mouse sera, underscoring the utility of this method for biomarker discovery.
Assuntos
Lúpus Eritematoso Sistêmico , Solanum lycopersicum , Solanum tuberosum , Animais , Camundongos , Proteoma , Solanum tuberosum/metabolismo , Cromatografia Líquida , Espectrometria de Massas em Tandem , Lectinas de Plantas/metabolismo , Lectinas/metabolismo , Proteínas Sanguíneas , BiomarcadoresRESUMO
BACKGROUND: Garlic (Allium sativum) from the family Amaryllidaceae is widely used in culinary and is reported to have potential anticancer, anti-diabetic, antimicrobial, and cardioprotective activities. Allium sativum agglutinin (ASA) is a bulb-type lectin (BTL) domaincontaining lectin isolated from garlic and has been studied for its various biological functions. Previous studies have reported the anti-cancer effects of ASA on histiocytic lymphoma (U937), promyelocytic leukemia (HL60), and oral cancer (KB). METHODS: In this study, we have purified and characterized ASA and evaluated it for its anticancer effects on other cancer cell lines. MTT assay and FACS analysis was done to corroborate the anticancer findings against cervical (HeLa) and lung cancer (A549) cell lines. RESULTS: IC50 value of 37 µg/ml in HeLa and a weak activity (26.4 ± 1.9% cellular inhibition at 100µg/ml treatment) in A549 were found in the MTT assay. FACS analysis further corroborated these findings and showed the apoptotic effects of ASA in these cell lines. CONCLUSION: Anticancer activity for members of bulb-type lectin (BTL) domain-containing lectins has been widely reported, and we hope that our study forms a basis for the development of ASA as a therapeutic agent.
Assuntos
Produtos Biológicos , Alho , Aglutininas/farmacologia , Antioxidantes , Alho/metabolismo , Lectinas , Lectinas de Plantas/metabolismo , Lectinas de Plantas/farmacologiaRESUMO
Plant lectins are widely used in medical glycosciences and glycotechnology. Many lectin-based techniques have been applied for the detection of disease-associated glycans and glycoconjugates. In this study, Butea monosperma agglutinin (BMA), a lectin purified from seeds of the medicinal plant Butea monosperma, was used for the detection of cholangiocarcinoma (CCA)-associated glycans. Expression of BMA-binding N-acetyl galactosamine/galactose (GalNAc/Gal)-associated glycan (BMAG) in CCA tissues was determined using BMA lectin histochemistry; the results showed that BMAG was undetectable in normal bile ducts and drastically increased in preneoplastic bile ducts and CCA. The study in hamsters showed that an increase of BMAG was associated with carcinogenesis of CCA. Using an in-house double BMA sandwich enzyme-linked lectin assay, BMAG was highly detected in the sera of CCA patients. The level of serum BMAG in CCA patients (N = 83) was significantly higher than non-CCA controls (N = 287) and it was applicable for diagnosis of CCA with 55.4% sensitivity, 81.9% specificity, and 76.0% accuracy. A high level of serum BMAG (≥82.5 AU/mL) was associated with unfavorable survival of CCA patients; this information suggested the potential of serum BMAG as a poor prognostic indicator of CCA. In summary, BMAG was aberrantly expressed in preneoplastic bile ducts and CCA, it was also highly detected in patient serum which potentially used as a marker for diagnosis and prognostic prediction of CCA.
Assuntos
Aglutininas/metabolismo , Neoplasias dos Ductos Biliares/sangue , Neoplasias dos Ductos Biliares/diagnóstico , Butea/química , Colangiocarcinoma/sangue , Colangiocarcinoma/diagnóstico , Extratos Vegetais/metabolismo , Lectinas de Plantas/metabolismo , Polissacarídeos/metabolismo , Animais , Neoplasias dos Ductos Biliares/patologia , Biomarcadores Tumorais/sangue , Colangiocarcinoma/patologia , Cricetinae , Modelos Animais de Doenças , Feminino , Histocitoquímica/métodos , Humanos , Masculino , Pessoa de Meia-Idade , Plantas Medicinais/química , Prognóstico , Sementes/químicaRESUMO
Therapeutically important chitin-binding lectins have been already reported in the literature for Solanum tuberosum and Solanum lycopersicum, but their structural data are unavailable. Therefore, we have done comparative structural and functional analysis of chitin-binding lectins from S. tuberosum (STL) and S. lycopersicum (SLL). From the sequence analysis, it has been observed that there is high percentage of proline residues in STL and SLL, 21% and 30% respectively. We utilized the hybrid homology modeling-ab initio approaches to predict the 3D structures of STL and SLL, which are used for in silico interaction studies with N,N'-Diacetylchitobiose, Triacetylchitotriose and Tetra-N-acetylglucosamine. The best STL-glycan and SLL-glycan complexes were subjected to Molecular dynamics simulation to understand and compare the structural stability and the binding patterns of glycans toward STL and SLL. We observed that the structural stability of the STL and SLL had been improved significantly due to the binding of glycans. Together with the results of global, essential dynamics and MM-PBSA analysis, indicated that N,N'-Diacetylchitobiose has more binding affinity towards STL, whereas Triacetylchitotriose has more binding affinity with SLL. This comprehensive and comparative structural and functional analysis provides critical insights about the structures and their binding sites, binding orientation, and binding affinity of chitin oligomers towards the structures of STL and SLL. These findings can be used to design further experimental studies to explore the potential therapeutic properties of STL and SLL. Communicated by Ramaswamy H. Sarma.
Assuntos
Lectinas , Solanum , Sítios de Ligação , Quitina , Lectinas/metabolismo , Lectinas de Plantas/metabolismo , Solanum/metabolismoRESUMO
BACKGROUND: In our previous study, we isolated and characterized a lectin called Helja from Helianthus annuus (sunflower) and then, in a further study, demonstrated its antifungal activity against Candida spp. Since Candida infections are a major health concern due to the increasing emergence of antifungal resistant strains, the search for new antifungal agents offers a promising opportunity for improving the treatment strategies against candidiasis. PURPOSE: The aim of this work was to get insights about the mechanism of action of Helja, an antifungal lectin of H. annuus, and to explore its ability to inhibit Candida albicans biofilm development and adherence to buccal epithelial cells (BEC). STUDY DESIGN/METHODS: Yeast viability was evaluated by Evans Blue uptake and counting of colony forming units (CFU). The yeast cell integrity was assessed using Calcofluor White (CFW) as a cell wall perturbing agent and sorbitol as osmotic protectant. The induction of oxidative stress was evaluated using 3,3'-diaminobenzidine (DAB) for detection of hydrogen peroxide. The adherence was determined by counting the yeast cells attached to BEC after methylene blue staining. The biofilms were developed on polystyrene microplates, visualized by confocal laser scanning microscopy and the viable biomass was quantified by CFU counting. The binding lectin-Candida was assessed using Helja conjugated to fluorescein isothiocyanate (Helja-FITC) and simultaneous staining with CFW. The cellular surface hydrophobicity (CSH) was determined using a microbial adhesion to hydrocarbons method. RESULTS: C. albicans cells treated with 0.1⯵g/µl of Helja showed a drastic decrease in yeast survival. The lectin affected the fungal cell integrity, induced the production of hydrogen peroxide and inhibited the morphological transition from yeast to filamentous forms. Helja caused a significant reduction of adherent cells and a decrease in biofilm biomass and coverage area. The treatment with the protein also reduced the surface hydrophobicity of fungal cells. We show the binding of Helja-FITC to yeast cells distributed as a thin outer layer to the CFW signal, and this interaction was displaced by mannose and Concanavalin A. CONCLUSION: The results demonstrate the interaction of Helja with the mannoproteins of C. albicans cell wall, the disruption of the cell integrity, the induction of oxidative stress, the inhibition of the morphological transition from yeast to filamentous forms and the fungal cell viability loss. The binding Helja-Candida also provides a possible explanation of the lectin effect on cell adherence, biofilm development and CSH, relevant features related to virulence of the pathogen.
Assuntos
Antifúngicos/metabolismo , Candida albicans/efeitos dos fármacos , Helianthus/química , Lectinas de Plantas/metabolismo , Lectinas de Plantas/farmacologia , Antifúngicos/farmacologia , Biofilmes/efeitos dos fármacos , Candida albicans/patogenicidade , Candida albicans/fisiologia , Membrana Celular/química , Membrana Celular/efeitos dos fármacos , Parede Celular/efeitos dos fármacos , Parede Celular/metabolismo , Células Cultivadas , Células Epiteliais/microbiologia , Fluoresceína-5-Isotiocianato/química , Fluoresceína-5-Isotiocianato/metabolismo , Humanos , Peróxido de Hidrogênio/metabolismo , Interações Hidrofóbicas e HidrofílicasRESUMO
BACKGROUND: Along with the rapid development of glycomic tools, the study of lectin-carbohydrate interactions has expanded, opening the way for applications in the fields of analytic, diagnostic, and drug delivery. Chitin-binding lectins (CBLs) play roles in immune defense against chitin-containing pathogens. CBLs from species of the Solanaceae family, such as tomato, potato and jimsonweed, display different binding specificities to sugar chains containing poly-N-acetyllactosamine. RESULTS: In this report, CBLs from Solanum integrifolium were isolated by ion exchange chromatography. The fractions showed hemagglutination activity (HA). The recombinant CBL in the 293F cell culture supernatant was able to inhibit the growth of Rhizoctonia solani and Colletotrichum gloeosporioide. Furthermore, the carbohydrate-binding property of CBLs was confirmed with the inhibition of HA. Binding of CBL to Spodoptera frugiperda (sf21) insect cells can partly be inhibited by N-Acetylglucosamine (GlcNAc), which is related to decrease mitochondrial membrane potential of sf21 cells. CONCLUSIONS: The results showed that CBL exhibited antifungal properties and inhibited insect cell growth, which is directly correlated to the lectin-carbohydrate interaction. Further identification and characterization of CBLs will help to broaden their scope of application in plant defense and in biomedical applications.
Assuntos
Colletotrichum/efeitos dos fármacos , Fungicidas Industriais/farmacologia , Inseticidas/farmacologia , Lectinas de Plantas/genética , Rhizoctonia/efeitos dos fármacos , Solanum/genética , Spodoptera/efeitos dos fármacos , Sequência de Aminoácidos , Animais , Sequência de Bases , Quitina/metabolismo , Cromatografia por Troca Iônica , Larva/crescimento & desenvolvimento , Larva/fisiologia , Lectinas de Plantas/metabolismo , Solanum/metabolismo , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz , Spodoptera/crescimento & desenvolvimentoRESUMO
Perineuronal nets (PNNs) are highly organized components of the extracellular matrix that surround a subset of mature neurons in the CNS. These structures play a critical role in regulating neuronal plasticity, particularly during neurodevelopment. Consistent with this role, their presence is associated with functional and structural stability of the neurons they ensheath. A loss of PNNs in the prefrontal cortex (PFC) has been suggested to contribute to cognitive impairment in disorders such as schizophrenia. However, the direct consequences of PNN loss in medial PFC (mPFC) on cognition has not been demonstrated. Here, we examined behavior after disruption of PNNs in mPFC of Long-Evans rats following injection of the enzyme chondroitinase ABC (ChABC). Our data show that ChABC-treated animals were impaired on tests of object oddity perception. Performance in the cross-modal object recognition (CMOR) task was not significantly different for ChABC-treated rats, although ChABC-treated rats were not able to perform above chance levels whereas control rats were. ChABC-treated animals were not significantly different from controls on tests of prepulse inhibition (PPI), set-shifting (SS), reversal learning, or tactile and visual object recognition memory. Posthumous immunohistochemistry confirmed significantly reduced PNNs in mPFC due to ChABC treatment. Moreover, PNN density in the mPFC predicted performance on the oddity task, where higher PNN density was associated with better performance. These findings suggest that PNN loss within the mPFC impairs some aspects of object oddity perception and recognition and that PNNs contribute to cognitive function in young adulthood.
Assuntos
Transtornos Cognitivos/patologia , Rede Nervosa/fisiopatologia , Córtex Pré-Frontal/patologia , Estimulação Acústica , Animais , Proteínas de Ligação ao Cálcio/metabolismo , Transtornos Cognitivos/induzido quimicamente , Condicionamento Operante/efeitos dos fármacos , Condicionamento Operante/fisiologia , Discriminação Psicológica/efeitos dos fármacos , Discriminação Psicológica/fisiologia , Masculino , Aprendizagem em Labirinto/efeitos dos fármacos , Aprendizagem em Labirinto/fisiologia , Proteínas dos Microfilamentos/metabolismo , Microglia/efeitos dos fármacos , Microglia/metabolismo , Rede Nervosa/efeitos dos fármacos , Proteínas do Tecido Nervoso/metabolismo , Parvalbuminas/metabolismo , Penicilinase/farmacologia , Lectinas de Plantas/metabolismo , Córtex Pré-Frontal/efeitos dos fármacos , Ratos , Ratos Long-Evans , Receptores de N-Acetilglucosamina/metabolismo , Reflexo de Sobressalto/efeitos dos fármacos , Reflexo de Sobressalto/fisiologia , Sulfotransferases/toxicidadeRESUMO
Atomic force microscopy (AFM) is emerging as an innovative tool to phenotype the brain. This study demonstrates the utility of AFM to determine nanomechanical and nanostructural features of the murine dorsolateral frontal cortex from weaning to adulthood. We found an increase in tissue stiffness of the primary somatosensory cortex with age, along with an increased cortical mechanical heterogeneity. To characterize the features potentially responsible for this heterogeneity, we applied AFM scan mode to directly image the topography of thin sections of the primary somatosensory cortical layers II/III, IV and V/VI. Topographical mapping of the cortical layers at successive ages showed progressive smoothing of the surface. Topographical images were also compared with histochemically derived morphological information, which demonstrated the deposition of perineuronal nets, important extracellular components and markers of maturity. Our work demonstrates that high-resolution AFM images can be used to determine the nanostructural properties of cortical maturation, well beyond embryonic and postnatal development. Furthermore, it may offer a new method for brain phenotyping and screening to uncover topographical changes in early stages of neurodegenerative diseases.
Assuntos
Mapeamento Encefálico , Lobo Frontal/crescimento & desenvolvimento , Lobo Frontal/ultraestrutura , Microscopia de Força Atômica , Fatores Etários , Análise de Variância , Animais , Animais Recém-Nascidos , Fenômenos Biomecânicos , Biotina , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Lectinas de Plantas/metabolismo , Receptores de N-Acetilglucosamina/metabolismoRESUMO
Aberrant O-glycans expressed at the surface of cancer cells consist of membrane-tethered glycoproteins (T and Tn antigens) and glycolipids (Lewis a, Lewis x and Forssman antigens). All of these O-glycans have been identified as glyco-markers of interest for the diagnosis and the prognosis of cancer diseases. These epitopes are specifically detected using T/Tn-specific lectins isolated from various plants such as jacalin from Artocarpus integrifola, and fungi such as the Agaricus bisporus lectin. These lectins accommodate T/Tn antigens at the monosaccharide-binding site; residues located in the surrounding extended binding-site of the lectins often participate in the binding of more extended epitopes. Depending on the shape and size of the extended carbohydrate-binding site, their fine sugar-binding specificity towards complex O-glycans readily differs from one lectin to another, resulting in a great diversity in their sugar-recognition capacity. T/Tn-specific lectins have been extensively used for the histochemical detection of cancer cells in biopsies and for the follow up of the cancer progression and evolution. T/Tn-specific lectins also induce a caspase-dependent apoptosis in cancer cells, often associated with a more or less severe inhibition of proliferation. Moreover, they provide another potential source of molecules adapted to the building of photosensitizer-conjugates allowing a specific targeting to cancer cells, for the photodynamic treatment of tumors.
Assuntos
Membrana Celular/metabolismo , Neoplasias/metabolismo , Lectinas de Plantas , Polissacarídeos/metabolismo , Antígenos Glicosídicos Associados a Tumores/metabolismo , Expressão Gênica , Humanos , Neoplasias/diagnóstico , Neoplasias/mortalidade , Neoplasias/terapia , Fotoquimioterapia , Lectinas de Plantas/química , Lectinas de Plantas/metabolismo , Polissacarídeos/química , Prognóstico , Relação Estrutura-Atividade , Especificidade por SubstratoRESUMO
Fifty-five mono- and disaccharide analogues were prepared and used for the construction of microarrays to uncover lectin-selective ligands. The microarray study showed that two disaccharide analogues, 28' and 44', selectively bind to Solanum tuberosum lectin (STL) and wheat germ agglutinin (WGA), respectively. Cell studies indicated that 28' and 44' selectively block the binding of STL and WGA to mammalian cells, unlike the natural ligand LacNAc, which suppresses binding of both STL and WGA to cells.
Assuntos
Dissacarídeos/farmacologia , Monossacarídeos/farmacologia , Lectinas de Plantas/metabolismo , Aglutininas do Germe de Trigo/metabolismo , Carbocianinas/química , Configuração de Carboidratos , Dissacarídeos/química , Relação Dose-Resposta a Droga , Corantes Fluorescentes/química , Células HeLa , Humanos , Ligantes , Análise em Microsséries , Monossacarídeos/química , Lectinas de Plantas/antagonistas & inibidores , Lectinas de Plantas/química , Lectinas de Plantas/isolamento & purificação , Ligação Proteica/efeitos dos fármacos , Solanum tuberosum/química , Coloração e Rotulagem , Triticum/química , Aglutininas do Germe de Trigo/antagonistas & inibidores , Aglutininas do Germe de Trigo/química , Aglutininas do Germe de Trigo/isolamento & purificaçãoRESUMO
BACKGROUND: Chronic neuropathic pain is a common symptom of multiple sclerosis (MS). MOG35-55-induced experimental autoimmune encephalomyelitis (EAE) has been used as an animal model to investigate the mechanisms of pain in MS. Previous studies have implicated sensitization of spinal nociceptive networks in the pathogenesis of pain in EAE. However, the involvement of supraspinal sites of nociceptive integration, such as the primary somatosensory cortex (S1), has not been defined. We therefore examined functional, structural, and immunological alterations in S1 during the early stages of EAE, when pain behaviors first appear. We also assessed the effects of the antidepressant phenelzine (PLZ) on S1 alterations and nociceptive (mechanical) sensitivity in early EAE. PLZ has been shown to restore central nervous system (CNS) tissue concentrations of GABA and the monoamines (5-HT, NA) in EAE. We hypothesized that PLZ treatment would also normalize nociceptive sensitivity in EAE by restoring the balance of excitation and inhibition (E-I) in the CNS. METHODS: We used in vivo flavoprotein autofluorescence imaging (FAI) to assess neural ensemble responses in S1 to vibrotactile stimulation of the limbs in early EAE. We also used immunohistochemistry (IHC), and Golgi-Cox staining, to examine synaptic changes and neuroinflammation in S1. Mechanical sensitivity was assessed at the clinical onset of EAE with Von Frey hairs. RESULTS: Mice with early EAE exhibited significantly intensified and expanded FAI responses in S1 compared to controls. IHC revealed increased vesicular glutamate transporter (VGLUT1) expression and disrupted parvalbumin+ (PV+) interneuron connectivity in S1 of EAE mice. Furthermore, peri-neuronal nets (PNNs) were significantly reduced in S1. Morphological analysis of excitatory neurons in S1 revealed increased dendritic spine densities. Iba-1+ cortical microglia were significantly elevated early in the disease. Chronic PLZ treatment was found to normalize mechanical thresholds in EAE. PLZ also normalized S1 FAI responses, neuronal morphologies, and cortical microglia numbers and attenuated VGLUT1 reactivity-but did not significantly attenuate the loss of PNNs. CONCLUSIONS: These findings implicate a pro-excitatory shift in the E-I balance of the somatosensory CNS, arising early in the pathogenesis EAE and leading to large-scale functional and structural plasticity in S1. They also suggest a novel antinociceptive effect of PLZ treatment.
Assuntos
Encefalomielite Autoimune Experimental/complicações , Neuralgia/etiologia , Neuralgia/patologia , Limiar da Dor/fisiologia , Córtex Somatossensorial/patologia , Sinapses/metabolismo , Animais , Antidepressivos/farmacologia , Antidepressivos/uso terapêutico , Proteínas de Ligação ao Cálcio/metabolismo , Modelos Animais de Doenças , Encefalomielite Autoimune Experimental/induzido quimicamente , Encefalomielite Autoimune Experimental/imunologia , Feminino , Adjuvante de Freund/toxicidade , Hiperalgesia/etiologia , Camundongos , Camundongos Endogâmicos C57BL , Proteínas dos Microfilamentos/metabolismo , Glicoproteína Mielina-Oligodendrócito/imunologia , Glicoproteína Mielina-Oligodendrócito/toxicidade , Neuralgia/tratamento farmacológico , Neurônios/citologia , Neurônios/metabolismo , Neurônios/ultraestrutura , Medição da Dor/efeitos dos fármacos , Limiar da Dor/efeitos dos fármacos , Parvalbuminas/metabolismo , Fragmentos de Peptídeos/imunologia , Fragmentos de Peptídeos/toxicidade , Fenelzina/farmacologia , Fenelzina/uso terapêutico , Lectinas de Plantas/metabolismo , Receptores de N-Acetilglucosamina/metabolismo , Córtex Somatossensorial/efeitos dos fármacos , Córtex Somatossensorial/ultraestrutura , Sinapses/patologia , Sinapses/ultraestruturaRESUMO
BACKGROUND: Warfarin and rivaroxaban are highly effective in reducing stroke risk in patients with atrial fibrillation (AF). However, their effects on anticoagulation and neurovascular unit (NVU) change remain elusive. In this study, we assessed the risks and benefits of pre-treatment with warfarin or rivaroxaban after tissue-type plasminogen activator (tPA) thrombolysis in ischemic rat brain. METHODS: Pre-treatment with warfarin (.2 mg/kg/day), low dose rivaroxaban (60 mg/kg/day), high dose rivaroxaban (120 mg/kg/day) or vehicle was performed for 2 weeks, transient middle cerebral artery occlusion (tMCAO) was induced for 90 min, then followed by reperfusion with tPA. At 24 hours (h) after reperfusion, we observed the changes of matrix metalloproteinase-9 (MMP-9), tissue factor, caspase 3 and NVU dissociation. RESULTS: Prothrombin time (PT) was significantly prolonged in the warfarin and rivaroxaban pretreated groups. MMP-9 expression greatly increased in the warfarin group, and this was reduced in the rivaroxaban groups compared with the vehicle group. Tissue factor expression remarkably decreased in the warfarin and rivaroxaban groups. The number of caspase 3-positive cells had no difference among all the groups. Marked dissociations between astrocyte foot processes and the basal lamina or pericytes were observed in the warfarin pretreated group, but such dissociations were improved in the rivaroxaban groups. CONCLUSIONS: Our present study shows that pre-treatment with rivaroxaban was noninferior to warfarin in the anticoagulation, but a lower risk of NVU dysfunction and dissociation after tPA treatment in rivaroxaban. This finding could partly explain the mechanism of reducing hemorrhagic complications by rivaroxaban in clinical studies.
Assuntos
Anticoagulantes/administração & dosagem , Encéfalo , Regulação da Expressão Gênica/efeitos dos fármacos , Infarto da Artéria Cerebral Média/prevenção & controle , Rivaroxabana/administração & dosagem , Varfarina/administração & dosagem , Animais , Peso Corporal/efeitos dos fármacos , Encéfalo/efeitos dos fármacos , Encéfalo/metabolismo , Encéfalo/patologia , Caspase 3/metabolismo , Colágeno/metabolismo , Modelos Animais de Doenças , Esquema de Medicação , Proteína Glial Fibrilar Ácida/metabolismo , Masculino , Metaloproteinase 9 da Matriz/metabolismo , Lectinas de Plantas/metabolismo , Ratos , Ratos Wistar , Receptores do Fator de Crescimento Derivado de Plaquetas/metabolismoRESUMO
Complementary treatment possibilities for the therapy of cancer are increasing in demand due to the severe side effects of the standard cytostatics used in the first-line therapy. A common approach as a complementary treatment is the use of aqueous extracts of Viscum album L. (Santalaceace). The therapeutic activity of these extracts is attributed to Mistletoe lectins which are Ribosome-inactivating proteins type II. Besides these main constituents the extract of Viscum album L. comprises also a mixture of lipophilic ingredients like triterpene acids of the oleanane, lupane and ursane type. However, these constituents are not contained in commercially available aqueous extracts due to their high lipophilicity and insolubility in aqueous extraction media. To understand the impact of the extract ingredients in cancer therapy, the intracellular uptake of the mistletoe lectin I (ML) by cultured tumor cells was investigated in relation to the mistletoe triterpene acids, mainly oleanolic acid. Firstly, these hydrophobic triterpene acids were solubilized using cyclodextrins ("TT" extract). Afterwards, the uptake of either single compounds (isolated ML and the aqueous "viscum" extract) or in combination with the TT extract (ML+TT, viscumTT), was analyzed. The uptake of ML was studied inTHP-1-, HL-60-, 143B- and Ewing TC-71-cells and determined after 30, 60 and 120 minutes by an enzyme linked immunosorbent assay which quantifies the A-chain of the hololectin. It could be shown that the intracellular uptake after 120 minutes amounted to 20% in all cell lines after incubation with viscumTT. The studies further revealed that the uptake in THP-1-, HL-60- and Ewing TC-71-cells was independent of the addition of TT extract. Interestingly, the uptake of ML by 143B-cells could only be measured after addition of triterpenes pointing to resistance to mistletoe lectin.
Assuntos
Antineoplásicos Fitogênicos/farmacologia , Leucemia/tratamento farmacológico , Extratos Vegetais/farmacologia , Proteínas Inativadoras de Ribossomos Tipo 2/metabolismo , Sarcoma/tratamento farmacológico , Toxinas Biológicas/metabolismo , Triterpenos/farmacologia , Viscum album/química , Apoptose/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Humanos , Leucemia/patologia , Lectinas de Plantas/metabolismo , Sarcoma/patologia , Células Tumorais CultivadasRESUMO
AIM: Growing interest in lectins is based on their diagnostic and pharmacological potential, especially the ability to inhibit proliferation and initiate apoptosis of cancer cells. In our research microplate lectinoassay able to detect carbohydrate containing structures (receptors) on erythrocyte surface have been proposed for Chornobyl cleanup workers (1986) monitoring. It was expected to reveal specific abnormalities associated with pathological condition arising as a result of late radiation effects. MATERIALS AND METHODS: Red blood cell (RBC) specimens were taken from 171 persons distributed into the six cohorts: nonexposed donors (1); chronically exposed to the doses below (2) and over 50 cGy (3); exposed to acute radiation without (4) and with manifestation of acute radiation syndrome (5 and 6). Lectins from 24 species of medicinal plants were purified by ethanol fractionation and electrofocusing. Intensity of lectin-receptor interactions was determined in reaction of hemagglutination. Method of flow cytofluorometry was used to study B-cell counts. Hormone levels in blood serum were determined by radioimmunoassay. RESULTS: An elevated ability of RBC to interact with the panel of lectins was found in all cohorts of exposed persons versus nonexposed donors, moreover, changes in the intensity of lectin-receptor binding depended on the dose of irradiation. Diagnostic value of specific RBC reactions with some individual lectins has been elucidated. Elevated intensity of RBC reaction with Zea mays lectin was accompanied by a decrease in serum content of thyroid hormones T4 and T3, as well as reduction of B-cell counts. In the case of Rubus caesius lectin the more intensive reaction with RBC, the higher level of hormone cortisol was observed. CONCLUSIONS: Deviations from donor's norm in intensity of lectin - RBC interactions in radiation exposed men are supposed to carry information about negative changes in their health status following Chornobyl catastrophe and show the diagnostic potential. The most sensitive reactions have been associated primarily with shifts in endocrine and immune systems. This article is a part of a Special Issue entitled "The Chornobyl Nuclear Accident: Thirty Years After".
Assuntos
Acidente Nuclear de Chernobyl , Eritrócitos/metabolismo , Eritrócitos/efeitos da radiação , Hemaglutinação/efeitos da radiação , Lectinas/metabolismo , Lesões por Radiação/metabolismo , Adulto , Biomarcadores , Estudos de Coortes , Testes de Hemaglutinação , Humanos , Hidrocortisona/sangue , Masculino , Lectinas de Plantas/metabolismo , Doses de Radiação , Lesões por Radiação/sangue , Hormônios Tireóideos/sangue , Adulto JovemRESUMO
Plant lectins and protease inhibitors constitute a class of proteins which plays a crucial role in plant defense. In our continuing investigations on lectins from plants, we have isolated, purified and characterized a protein of about 20 kDa, named PotHg, showing hemagglutination activity from tubers of Indian potato, Solanum tuberosum. De novo sequencing and MS/MS analysis confirmed that the purified protein was a Kunitz-type serine protease inhibitor having two chains (15 kDa and 5 kDa). SDS and native PAGE analysis showed that the protein was glycosylated and was a heterodimer of about 15 and 5 kDa subunits. PotHg agglutinated rabbit erythrocytes with specific activity of 640 H.U./mg which was inhibited by complex sugars like fetuin. PotHg retained hemagglutination activity over a pH range 4-9 and up to 80°C. Mannose and galactose interacted with the PotHg with a dissociation constant (Kd) of 1.5×10(-3) M and 2.8×10(-3) M, respectively as determined through fluorescence studies. Fluorescence studies suggested the involvement of a tryptophan in sugar binding which was further confirmed through modification of tryptophan residues using N-bromosuccinimide. Circular dichroism (CD) studies showed that PotHg contains mostly ß sheets (â¼45%) and loops which is in line with previously characterized protease inhibitors and modeling studies. There are previous reports of Kunitz-type protease inhibitors showing lectin like activity from Peltophorum dubium and Labramia bojeri. This is the first report of a Kunitz-type protease inhibitor showing lectin like activity from a major crop plant and this makes PotHg an interesting candidate for further investigation.
Assuntos
Peptídeos/metabolismo , Peptídeos/farmacologia , Lectinas de Plantas/metabolismo , Proteínas de Plantas/metabolismo , Proteínas de Plantas/farmacologia , Inibidores de Serina Proteinase/metabolismo , Inibidores de Serina Proteinase/farmacologia , Solanum tuberosum/química , Sequência de Aminoácidos , Animais , Bromosuccinimida/farmacologia , Metabolismo dos Carboidratos , Biologia Computacional , Hemaglutinação/efeitos dos fármacos , Concentração de Íons de Hidrogênio , Dados de Sequência Molecular , Peso Molecular , Peptídeos/química , Peptídeos/isolamento & purificação , Proteínas de Plantas/química , Proteínas de Plantas/isolamento & purificação , Coelhos , Inibidores de Serina Proteinase/química , Inibidores de Serina Proteinase/isolamento & purificação , Especificidade por SubstratoRESUMO
BACKGROUND: Tamoxifen (TAM) is an important cancer therapeutic and an experimental tool for effecting genetic recombination using the inducible Cre-Lox technique. Despite its widespread use in the clinic and laboratory, we know little about its effects on the nervous system. This is of significant concern because TAM, via unknown mechanisms, induces cognitive impairment in humans. A hallmark of cellular stress is induction of Activating Transcription Factor 3 (Atf3), and so to determine whether TAM induces cellular stress in the adult nervous system, we generated a knock-in mouse in which Atf3 promoter activity drives transcription of TAM-dependent Cre recombinase (Cre-ERT2); when crossed with tdtomato reporter mice, Atf3 induction results in robust and permanent genetic labeling of cells in which it is up-regulated even transiently. RESULTS: We found that granular neurons of the olfactory bulb and dentate gyrus, vascular cells and ependymal cells throughout the brain, and peripheral sensory neurons expressed tdtomato in response to TAM treatment. We also show that TAM induced Atf3 up-regulation through inhibition of cholesterol epoxide hydrolase (ChEH): reporter expression was mitigated by delivery in vitamin E-rich wheat germ oil (vitamin E depletes ChEH substrates), and was partially mimicked by a ChEH-specific inhibitor. CONCLUSIONS: This work demonstrates that TAM stresses cells of the adult central and peripheral nervous systems and highlights concerns about clinical and experimental use of TAM. We propose TAM administration in vitamin E-rich vehicles such as wheat germ oil as a simple remedy.
Assuntos
Colesterol/metabolismo , Sistema Nervoso/citologia , Neurônios/fisiologia , Moduladores Seletivos de Receptor Estrogênico/farmacologia , Tamoxifeno/farmacologia , Regulação para Cima/efeitos dos fármacos , Fator 3 Ativador da Transcrição/genética , Animais , Peptídeo Relacionado com Gene de Calcitonina/metabolismo , Relação Dose-Resposta a Droga , Epóxido Hidrolases/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Mutação/genética , Proteínas do Tecido Nervoso/metabolismo , Neurônios/efeitos dos fármacos , Lectinas de Plantas/genética , Lectinas de Plantas/metabolismo , Óleos de Plantas/farmacologia , Regiões Promotoras Genéticas , Vitamina E/farmacologiaRESUMO
To gain a better understanding of the neuroplasticity of afferent neurons during postnatal ontogenesis, the distribution of neuronal nitric oxide synthase (nNOS) immunoreactivity was studied in the nodose ganglion (NG) and Th2 and L4 dorsal root ganglia (DRG) from vehicle-treated and capsaicin-treated female Wistar rats at different ages (10-day-old, 20-day-old, 30-day-old, and two-month-old). The percentage of nNOS-immunoreactive (IR) neurons decreased after capsaicin treatment in all studied ganglia in first 20 days of life, from 55.4% to 36.9% in the Th2 DRG, from 54.6% to 26.1% in the L4 DRG and from 37.1% to 15.0% in the NG. However, in the NG, the proportion of nNOS-IR neurons increased after day 20, from 11.8% to 23.9%. In the sensory ganglia of all studied rats, a high proportion of nNOS-IR neurons bound isolectin B4. Approximately 90% of the sensory nNOS-IR neurons bound to IB4 in the DRG and approximately 80% in the NG in capsaicin-treated and vehicle-treated rats. In 10-day-old rats, a large number of nNOS-IR neurons also expressed TrkA, and the proportion of nNOS(+)/TrkA(+) neurons was larger in the capsaicin-treated rats compared with the vehicle-treated animals. During development, the percentage of nNOS(+)/TrkA(+) cells decreased in the first month of life in both groups. The information provided here will also serve as a basis for future studies investigating mechanisms of sensory neuron development.
Assuntos
Capsaicina/farmacologia , Gânglios Sensitivos/citologia , Regulação da Expressão Gênica no Desenvolvimento/efeitos dos fármacos , Neurônios/efeitos dos fármacos , Neurônios/metabolismo , Óxido Nítrico Sintase Tipo I/metabolismo , Fármacos do Sistema Sensorial/farmacologia , Fatores Etários , Animais , Animais Recém-Nascidos , Feminino , Masculino , Lectinas de Plantas/metabolismo , Gravidez , Ratos , Ratos WistarRESUMO
Allium sativum is well known for its medicinal properties. The A. sativum lectin 50 (ASL50, 50 kDa) was isolated from aged A. sativum bulbs and purified by gel filtration chromatography on Sephacryl S-200 column. Agar well diffusion assay were used to evaluate the antimicrobial activity of ASL50 against Candida species and bacteria then minimal inhibitory concentration (MIC) was determined. The lipid A binding to ASL50 was determined by surface plasmon resonance (SPR) technology with varying concentrations. Electron microscopic studies were done to see the mode of action of ASL50 on microbes. It exerted antimicrobial activity against clinical Candida isolates with a MIC of 10-40 µg/ml and clinical Pseudomonas aeruginosa isolates with a MIC of 10-80 µg/ml. The electron microscopic study illustrates that it disrupts the cell membrane of the bacteria and cell wall of fungi. It exhibited antiproliferative activity on oral carcinoma KB cells with an IC50 of 36 µg/ml after treatment for 48 h and induces the apoptosis of cancer cells by inducing 2.5-fold higher caspase enzyme activity than untreated cells. However, it has no cytotoxic effects towards HEK 293 cells as well as human erythrocytes even at higher concentration of ASL50. Biological properties of ASL50 may have its therapeutic significance in aiding infection and cancer treatments.
Assuntos
Anti-Infecciosos/farmacologia , Antineoplásicos/farmacologia , Alho/química , Lectinas de Plantas/farmacologia , Caules de Planta/química , Sequência de Aminoácidos , Anti-Infecciosos/química , Anti-Infecciosos/isolamento & purificação , Anti-Infecciosos/metabolismo , Antineoplásicos/química , Antineoplásicos/isolamento & purificação , Antineoplásicos/metabolismo , Apoptose/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Células HEK293 , Hemólise/efeitos dos fármacos , Humanos , Células KB , Lipídeo A/metabolismo , Peso Molecular , Lectinas de Plantas/química , Lectinas de Plantas/isolamento & purificação , Lectinas de Plantas/metabolismo , Análise de SequênciaRESUMO
Two jacalin-related lectins (JRLs) were purified by mannose-agarose and melibiose-agarose from seeds of Treculia africana. One is galactose-recognizing JRL (gJRL), named T. africana agglutinin-G (TAA-G), and another one is mannose-recognizing JRL (mJRL), TAA-M. The yields of the two lectins from the seed flour were approximately 7.0 mg/g for gJRL and 7.2 mg/g for mJRL. The primary structure of TAA-G was determined by protein sequencing of lysyl endopeptic peptides and chymotryptic peptides. The sequence identity of TAA-G to other gJRLs was around 70%. Two-residue insertion was found around the sugar-binding sites, compared with the sequences of other gJRLs. Crystallographic studies on other gJRLs have shown that the primary sugar-binding site of gJRLs can accommodate Gal, GalNAc, and GalNAc residue of T-antigen (Galß1-3GalNAcα-). However, hemagglutination inhibition and glycan array showed that TAA-G did not recognize GalNAc itself and T-antigen. TAA-G preferred melibiose and core 3 O-glycan.
Assuntos
Artocarpus/química , Lectinas de Plantas/química , Sementes/química , Sequência de Aminoácidos , Sítios de Ligação , Sequência de Carboidratos , Galactose/química , Galactose/metabolismo , Manose/química , Manose/metabolismo , Dados de Sequência Molecular , Peptídeos/química , Extratos Vegetais/química , Lectinas de Plantas/isolamento & purificação , Lectinas de Plantas/metabolismo , Ligação Proteica , Proteólise , Homologia de Sequência de AminoácidosRESUMO
Evidence is accumulating that commonly used pesticides are linked to decline of pollinator populations; adverse effects of three neonicotinoids on bees have led to bans on their use across the European Union. Developing insecticides that pose negligible risks to beneficial organisms such as honeybees is desirable and timely. One strategy is to use recombinant fusion proteins containing neuroactive peptides/proteins linked to a 'carrier' protein that confers oral toxicity. Hv1a/GNA (Galanthus nivalis agglutinin), containing an insect-specific spider venom calcium channel blocker (ω-hexatoxin-Hv1a) linked to snowdrop lectin (GNA) as a 'carrier', is an effective oral biopesticide towards various insect pests. Effects of Hv1a/GNA towards a non-target species, Apis mellifera, were assessed through a thorough early-tier risk assessment. Following feeding, honeybees internalized Hv1a/GNA, which reached the brain within 1 h after exposure. However, survival was only slightly affected by ingestion (LD50>100 µg bee(-1)) or injection of fusion protein. Bees fed acute (100 µg bee(-1)) or chronic (0.35 mg ml(-1)) doses of Hv1a/GNA and trained in an olfactory learning task had similar rates of learning and memory to no-pesticide controls. Larvae were unaffected, being able to degrade Hv1a/GNA. These tests suggest that Hv1a/GNA is unlikely to cause detrimental effects on honeybees, indicating that atracotoxins targeting calcium channels are potential alternatives to conventional pesticides.