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1.
Adv Mater ; 34(4): e2107452, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34695246

RESUMO

Cephalopods can display variable body color/patterns upon environmental stimulation via bioelectricity-controlled muscle contraction/expansion of skin chromatophores. However, it remains challenging to produce artificial display analogs that exhibit reversible and rapid switching between multiple expected luminescent patterns, although such systems are very appealing for many practical uses (e.g., data encryption). Inspired by the bioelectromechanical display tactic of cephalopods, in this work, a conceptually new photomechanically modulated fluorescent system that enables on-demand display of fluorescent patterns via a cascading stimulation-mechanical movement-optical output conduction mechanism is presented. Specifically, this biomimetic system comprises a customizable hollow display panel and a bottom-tethered photothermally responsive fluorescent actuator. Under NIR light, the photomechanically bending movements of the fluorescent actuator will immediately cover the hollow window of the display panel and synchronously manifest as the display of fluorescent patterns. Owing to its desirable time- and light-power-dependent actuating behaviors, diverse fluorescent patterns/information can be dynamically and reversibly displayed by facilely controlling this single remote NIR signal. This bioinspired strategy is universal and promising for fabricating on-demand fluorescent display platforms that combine a wide choice of fluorophores, remote control with high spatial/temporal precision, and especially single-input multiple-output features.


Assuntos
Cefalópodes , Cromatóforos , Animais , Biomimética , Cromatóforos/fisiologia , Contração Muscular
2.
Exp Hematol Oncol ; 9: 11, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32523801

RESUMO

BACKGROUND: T cells expressing a chimeric antigen receptor (CAR) engineered to target CD19 can treat leukemia effectively but also increase the risk of complications such as cytokine release syndrome (CRS) and CAR T cell related encephalopathy (CRES) driven by interleukin-6 (IL-6). Here, we investigated whether IL-6 knockdown in CART-19 cells can reduce IL-6 secretion from monocytes, which may reduce the risk of adverse events. METHODS: Supernatants from cocultures of regular CART-19 cells and B lymphoma cells were added to monocytes in vitro, and the IL-6 levels in monocyte supernatants were measured 24 h later. IL-6 expression was knocked down in regular CART-19 cells by adding a short hairpin RNA (shRNA) (termed ssCART-19) expression cassette specific for IL-6 to the conventional CAR vector. Transduction efficiency and cell proliferation were measured by flow cytometry, and cytotoxicity was measured by evaluating the release of lactate dehydrogenase into the medium. Gene expression was assessed by qRT-PCR and RNA sequencing. A xenograft leukemia mouse model was established by injecting NOD/SCID/γc-/- mice with luciferase-expressing B lymphoma cells, and then the animals were treated with regular CART-19 cells or ssCART-19. Tumor growth was assessed by bioluminescence imaging. RESULTS: Both recombinant IL-6 and CART-19 derived IL-6 significantly triggered IL-6 release by monocytes. IL-6 knockdown in ssCART-19 cells dramatically reduced IL-6 release from monocytes in vitro stduy. In vivo study further demonstrated that the mice bearing Raji cells treated with ssCART-19 cells showed significant lower IL-6 levels in serum than those treated with regular CART-19 cells, but comparable anti-tumor efficacy between the animal groups. CONCLUSION: CAR T-derived IL-6 is one of the most important initiators to amplify release of IL-6 from monocytes that further drive sCRS development. IL-6 knockdown in ssCART-19 cells by shRNA technology provide a promising strategy to improve the safety of CAR T cell therapy.

3.
IEEE J Sel Top Appl Earth Obs Remote Sens ; 12(11): 4622-4633, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32637027

RESUMO

We have developed an approach for the measurement of the Effective Focal Length (EFL) and Band-to-Band Registration (BBR) of selected spectral bands of satellite-borne whiskbroom imaging sensors from on-orbit data. Our approach is based on simulating the coarser spatial resolution whiskbroom sensor data with finer spatial resolution Landsat 7 ETM+ or Landsat 8 OLI data using the geolocation (Earth location) information from each sensor, and computing the correlation between the simulated and original data. For each scan of a selected spectral band of the whiskbroom data set, various subsets of the data are examined to find the subset with the highest spatial correlation between the original and simulated data using the nominal geolocation information. Then, for this best subset, the focal length value and the spatial shift are varied to find the values that produce the highest spatial correlation between the original and simulated data. This best focal length value is taken to be the measured instrument EFL and the best spatial shift is taken to be the registration of the whiskbroom data relative to the Landsat data, from which the BBR is inferred. Best results are obtained with cloud-free subsets with contrasting land features. This measurement is repeated over other scans with cloud-free subsets. We demonstrate our approach with on-orbit data from the Aqua and Terra MODIS instruments and SNPP and J1 VIIRS instruments.

4.
Molecules ; 23(8)2018 Aug 17.
Artigo em Inglês | MEDLINE | ID: mdl-30126108

RESUMO

In this report, a series of polycations are designed and synthesized by conjugating reactive oxygen species (ROS)-responsive thioacetal-linkers to low molecular weight (LMW) polyethylenimine (PEI) via ring-opening polymerization. Their structure⁻activity relationships (SARs) as gene delivery vectors are systematically studied. Although the MWs of the target polymers are only ~9 KDa, they show good DNA binding ability. The formed polyplexes, which are stable toward serum but decomposed under ROS-conditions, have appropriate sizes (180~300 nm) and positive zeta-potentials (+35~50 mV). In vitro experiments reveal that these materials have low cytotoxicity, and higher transfection efficiency (TE) than controls. Furthermore, the title polymers exhibit excellent serum tolerance. With the present of 10% serum, the TE of the polymers even increases up to 10 times higher than 25 KDa PEI and 9 times higher than Lipofectamine 2000. The SAR studies also reveal that electron-withdrawing groups on the aromatic ring in 4a may benefit to balance between the DNA condensation and release for efficient gene transfection.


Assuntos
Técnicas de Transferência de Genes , Nanopartículas , Espécies Reativas de Oxigênio , Compostos de Sulfidrila , Linhagem Celular , Sobrevivência Celular , DNA/química , Vetores Genéticos/química , Humanos , Peso Molecular , Nanopartículas/química , Poliaminas/química , Polieletrólitos , Polímeros/síntese química , Polímeros/química , Espécies Reativas de Oxigênio/química , Compostos de Sulfidrila/química
5.
IEEE J Sel Top Appl Earth Obs Remote Sens ; 10(3): 1056-1067, 2017 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30057659

RESUMO

The Visible Infrared Imaging Radiometer Suite (VIIRS) instrument was launched 28 October 2011 onboard the Suomi National Polar-orbiting Partnership (SNPP) satellite. The VIIRS instrument is a whiskbroom system with 22 spectral and thermal bands split between 16 moderate resolution bands (M-bands), five imagery resolution bands (I-bands) and a day-night band. In this study we measure the along-scan and along-track band-to-band registration between the I-bands and M-bands from on-orbit data. This measurement is performed by computing the Normalized Mutual Information (NMI) between shifted image band pairs and finding the amount of shift required (if any) to produce the peak in NMI value. Subpixel accuracy is obtained by utilizing bicubic interpolation. The product of the NMI peak slope and the NMI peak value is shown to be a better criterion for evaluating the quality of the NMI result than just the NMI peak value. Registration shifts are found to be similar to pre-launch measurements and stable (within measurement error) over the instrument's first four years in orbit.

6.
Int J Syst Evol Microbiol ; 66(1): 243-247, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26493172

RESUMO

A Gram-stain-positive, rod-shaped, endospore-forming, motile bacterium, designated D33T, was isolated from a forest soil sample. The strain grew optimally at 30-37 °C, pH 8.0 and with 1 % (w/v) NaCl. The 16S rRNA gene sequence of the isolate showed similarities lower than 97 % with respect to species of the genus Paenibacillus. Strain D33T contained meso-diaminopimelic acid in the cell-wall peptidoglycan, and ribose and lower amounts of glucose and galactose as the whole-cell sugars. The major cellular fatty acid was anteiso-C15 : 0, and menaquinone-7 (MK-7) was the only respiratory quinone. The polar lipids were diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, phosphatidylmethylethanolamine, two glycolipids and an unknown lipid. The DNA G+C content was 51.1 mol%. The low DNA-DNA relatedness values between strain D33T and recognized species of the genus Paenibacillus, together with many phenotypic properties supported the classification of strain D33T as representative of a novel species of the genus Paenibacillus, for which the name Paenibacillus terreus sp. nov. is proposed. The type strain is D33T ( = KACC 18491T = DSM 100035T = CCTCC AB 2015273T).


Assuntos
Florestas , Paenibacillus/classificação , Filogenia , Microbiologia do Solo , Técnicas de Tipagem Bacteriana , Composição de Bases , China , DNA Bacteriano/genética , Ácido Diaminopimélico/química , Ácidos Graxos/química , Dados de Sequência Molecular , Hibridização de Ácido Nucleico , Paenibacillus/genética , Paenibacillus/isolamento & purificação , Peptidoglicano/química , Fosfolipídeos/química , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Vitamina K 2/análogos & derivados , Vitamina K 2/química
7.
Med Oncol ; 31(12): 327, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-25412936

RESUMO

Annexin A1 (ANXA1) belongs to the annexin superfamily of proteins, which contribute to the pathological consequence and sequelae of most serious human diseases. Recent studies have reported diverse roles of ANXA1 in various human cancers; however, its involvement in human hepatocellular carcinoma (HCC) still remains controversial. To investigate the expression pattern of ANXA1 in HCC tissues and evaluate its associations with tumor progression and patients' prognosis, immunohistochemistry was performed using 160 pairs of formalin-fixed and paraffin-embedded cancerous and adjacent non-cancerous tissues from patients with HCC. Then, the associations between ANXA1 expression, clinicopathological characteristics, and prognosis of HCC patients were statistically evaluated. In vitro migration and invasion assays of siRNA-targeted ANXA1-transfected cells were further performed. As a result, the expression levels of ANXA1 protein in HCC tissues were significantly higher than those in adjacent non-cancerous tissues (P < 0.001). High ANXA1 expression was closely correlated with advanced TNM stage (P = 0.001) and high Edmondson grade (P = 0.02). Then, univariate and multivariate analyses showed that the status of ANXA1 expression was an independent predictor for overall survival of HCC patients. Furthermore, knockdown of ANXA1 by transfection of siRNA-ANXA1 could suppress the migration and invasion abilities of HCC cells in vitro. Collectively, these findings offer the convincing evidence that ANXA1 may play an important role in HCC progression and can be used as a molecular marker to predict prognosis and a potential target for therapeutic intervention of HCC.


Assuntos
Anexina A1/metabolismo , Carcinoma Hepatocelular/patologia , Neoplasias Hepáticas/patologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Anexina A1/genética , Biomarcadores Tumorais/metabolismo , Carcinoma Hepatocelular/metabolismo , Carcinoma Hepatocelular/mortalidade , Carcinoma Hepatocelular/cirurgia , Movimento Celular/genética , Feminino , Humanos , Estimativa de Kaplan-Meier , Neoplasias Hepáticas/metabolismo , Neoplasias Hepáticas/mortalidade , Neoplasias Hepáticas/cirurgia , Masculino , Pessoa de Meia-Idade , Prognóstico , RNA Interferente Pequeno , Regulação para Cima , Adulto Jovem
8.
Mol Biol Rep ; 41(6): 4109-21, 2014 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-24562628

RESUMO

Heme oxygenase1 (HO1) is involved in protecting plants from environmental stimuli. In this study, a sunflower (Helianthus annuus L.) HO1 gene (HaHO1) was cloned and sequenced. It was confirmed that HaHO1 encodes a precursor protein of 32.93 kDa with an N-terminal plastid transit peptide which was validated by subcellular localization. The amino acid sequence of HaHO1 shared high homology with other plant HO1s. The predicted three-dimensional structure showed a high degree of structural conservation as compared to the known HO1 crystal structures. Phylogenetic analysis revealed that HaHO1 clearly grouped with the plant HO1-like sequences. Moreover, the purified recombinant mature HaHO1 expressed in Escherichia coli exhibits HO activity. Thus, it was concluded that HaHO1 encodes a functional HO1 in sunflower. Additionally, HaHO1 gene was ubiquitously expressed in all tested tissues, and induced differentially during different growth stages after germination, and could be differentially induced by several stresses and hemin treatment. For example, a pretreatment with a low concentration of NaCl (25 mM) could lead to the induction of HaHO1 gene expression and thereafter a salinity acclamatory response. Above cytoprotective effect could be impaired by the potent HO1 inhibitor zinc protoporphyrin IX (ZnPPIX), which was further rescued by the addition of 50% carbon monoxide aqueous solution (in particular) or bilirubin, two catalytic by-products of HO1, respectively. Similarly, a HO1 inducer, hemin, could mimic the salinity acclamatory response. Together, these findings strongly suggested that the up-regulation of HaHO1 might be required for the observed salinity acclimation in sunflower plants.


Assuntos
Helianthus/enzimologia , Heme Oxigenase-1/química , Heme Oxigenase-1/genética , Filogenia , Aclimatação , Clonagem Molecular , Cristalografia por Raios X , Regulação da Expressão Gênica de Plantas , Heme Oxigenase-1/biossíntese , Hemina/química , Hemina/genética , Raízes de Plantas/química , Raízes de Plantas/metabolismo , Salinidade , Cloreto de Sódio/metabolismo
9.
J Hazard Mater ; 260: 715-24, 2013 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-23846121

RESUMO

Hydrogen gas (H2) induces plant tolerance to several abiotic stresses, including salinity and paraquat exposure. However, the role of H2 in cadmium (Cd)-induced stress amelioration is largely unknown. Here, pretreatment with hydrogen-rich water (HRW) was used to characterize physiological roles and molecular mechanisms of H2 in the alleviation of Cd toxicity in alfalfa plants. Our results showed that the addition of HRW at 10% saturation significantly decreased contents of thiobarbituric acid reactive substances (TBARS) caused by Cd, and inhibited the appearance of Cd toxicity symptoms, including the improvement of root elongation and seedling growth. These responses were related to a significant increase in the total or isozymatic activities of representative antioxidant enzymes, or their corresponding transcripts. In vivo imaging of reactive oxygen species (ROS), and the detection of lipid peroxidation and the loss of plasma membrane integrity provided further evidence for the ability of HRW to improve Cd tolerance significantly, which was consistent with a significant enhancement of the ratio of reduced/oxidized (homo)glutathione ((h)GSH). Additionally, plants pretreated with HRW accumulated less amounts of Cd. Together, this study suggested that the usage of HRW could be an effective approach for Cd detoxification and could be explored in agricultural production systems.


Assuntos
Cádmio/química , Hidrogênio/química , Medicago sativa/efeitos dos fármacos , Medicago sativa/metabolismo , Água/química , Antioxidantes/química , Cádmio/toxicidade , DNA/química , Gases , Glutationa/química , Homeostase , Peroxidação de Lipídeos , Oxirredução , Estresse Oxidativo , Raízes de Plantas/metabolismo , Espécies Reativas de Oxigênio/análise , Plântula/efeitos dos fármacos , Substâncias Reativas com Ácido Tiobarbitúrico , Fatores de Tempo
10.
Proc Natl Acad Sci U S A ; 109(22): 8534-9, 2012 May 29.
Artigo em Inglês | MEDLINE | ID: mdl-22586122

RESUMO

The γ-secretase complex, composed of presenilin, anterior-pharynx-defective 1, nicastrin, and presenilin enhancer 2, catalyzes the intramembranous processing of a wide variety of type I membrane proteins, including amyloid precursor protein (APP) and Notch. Earlier studies have revealed that nicastrin, a type I membrane-anchored glycoprotein, plays a role in γ-secretase assembly and trafficking and has been proposed to bind substrates. To gain more insights regarding nicastrin structure and function, we generated a conformation-specific synthetic antibody and used it as a molecular probe to map functional domains within nicastrin ectodomain. The antibody bound to a conformational epitope within a nicastrin segment encompassing residues 245-630 and inhibited the processing of APP and Notch substrates in in vitro γ-secretase activity assays, suggesting that a functional domain pertinent to γ-secretase activity resides within this region. Epitope mapping and database searches revealed the presence of a structured segment, located downstream of the previously identified DAP domain (DYIGS and peptidase; residues 261-502), that is homologous to a tetratricopeptide repeat (TPR) domain commonly involved in peptide recognition. Mutagenesis analyses within the predicted TPR-like domain showed that disruption of the signature helical structure resulted in the loss of γ-secretase activity but not the assembly of the γ-secretase and that Leu571 within the TPR-like domain plays an important role in mediating substrate binding. Taken together, these studies offer provocative insights pertaining to the structural basis for nicastrin function as a "substrate receptor" within the γ-secretase complex.


Assuntos
Secretases da Proteína Precursora do Amiloide/metabolismo , Anticorpos/metabolismo , Glicoproteínas de Membrana/metabolismo , Oligopeptídeos/metabolismo , Sequência de Aminoácidos , Secretases da Proteína Precursora do Amiloide/química , Secretases da Proteína Precursora do Amiloide/genética , Precursor de Proteína beta-Amiloide/metabolismo , Animais , Sítios de Ligação/genética , Biocatálise , Western Blotting , Células Cultivadas , Dicroísmo Circular , Epitopos/química , Epitopos/genética , Epitopos/metabolismo , Células HEK293 , Humanos , Imuno-Histoquímica/métodos , Glicoproteínas de Membrana/química , Glicoproteínas de Membrana/genética , Camundongos , Camundongos Knockout , Mutação , Oligopeptídeos/química , Oligopeptídeos/genética , Ligação Proteica , Conformação Proteica , Estrutura Terciária de Proteína , Sequências Repetitivas de Aminoácidos/genética , Ressonância de Plasmônio de Superfície , Espectrometria de Massas em Tandem
11.
Matrix Biol ; 30(1): 43-52, 2011 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-20970500

RESUMO

Fibrillin proteins are the major components of extracellular microfibrils found in many connective tissues. Fibrillin-1 and fibrillin-2 are well studied and mutations in these proteins cause a number of fibrillinopathies including Marfan syndrome and congenital contractural arachnodactyly, respectively. Fibrillin-3 was more recently discovered and is much less well characterized. Fibrillin-1 is expressed throughout life, whereas fibrillins-2 and -3 are thought to be primarily present during development. Here, we report detailed fibrillin-3 expression patterns in early human development. A polyclonal antiserum against a C-terminal recombinant half of human fibrillin-3 was produced in rabbit. Anti-fibrillin-3 antibodies were affinity-purified and antibodies cross-reacting with the other fibrillins were removed by absorption resulting in specific anti-fibrillin-3 antibodies. Immunohistochemical analyses with these purified antibodies demonstrate that fibrillin-3 is temporally expressed in numerous tissues relatively evenly from the 6th to the 12th gestational week. Fibrillin-3 was found spatially expressed in perichondrium, perineurium, perimysium, skin, developing bronchi, glomeruli, pancreas, kidney, heart and testis and at the prospective basement membranes in developing epithelia and endothelia. Double immunohistochemical analyses showed that all fibrillins are globally expressed in the same organs, with a number of differences on the tissue level in cartilage, perichondrium and developing bronchi. These results suggest that fibrillin-3, compared to the other fibrillins, fulfills both overlapping and distinct functions in human development.


Assuntos
Embrião de Mamíferos/metabolismo , Proteínas dos Microfilamentos/metabolismo , Animais , Especificidade de Anticorpos , Membrana Basal/embriologia , Membrana Basal/metabolismo , Osso e Ossos/embriologia , Osso e Ossos/metabolismo , Sistema Cardiovascular/embriologia , Sistema Cardiovascular/metabolismo , Cartilagem/embriologia , Cartilagem/metabolismo , Sistema Nervoso Central/embriologia , Sistema Nervoso Central/metabolismo , Embrião de Mamíferos/anatomia & histologia , Feminino , Fibrilinas , Humanos , Soros Imunes , Músculo Esquelético/embriologia , Músculo Esquelético/metabolismo , Sistema Nervoso Periférico/embriologia , Sistema Nervoso Periférico/metabolismo , Gravidez , Coelhos
12.
Sheng Wu Yi Xue Gong Cheng Xue Za Zhi ; 27(5): 968-73, 2010 Oct.
Artigo em Chinês | MEDLINE | ID: mdl-21089650

RESUMO

In this paper is presented an active contour model applied to vascular image segmentation. This model can adaptively adjust the proportion of global and local intensity information in accord with the anastomosis status between local contour and boundaries. Our method is able to work effectively on segmentation of angiographic image with intensity inhomogeneity and noise. Compared with other methods, our method is not sensitive to initialization and it eliminates the need for manual adjustment of new parameter.


Assuntos
Algoritmos , Angiografia/métodos , Interpretação de Imagem Assistida por Computador/métodos , Modelos Cardiovasculares , Simulação por Computador , Meios de Contraste , Humanos
13.
Science ; 327(5971): 1325, 2010 Mar 12.
Artigo em Inglês | MEDLINE | ID: mdl-20223968
14.
Mol Immunol ; 45(3): 678-81, 2008 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-17707909

RESUMO

The crab-eating frog, Rana cancrivora, is one of only a handful of amphibians worldwide that tolerates saline waters. It typically inhabits brackish water of mangrove forests of Southeast Asia. A large amount of antimicrobial peptides belonging to different families have been identified from skins of amphibians inhabiting freshwater. No antimicrobial peptide from sea amphibians has been reported. In this paper, we firstly reported the antimicrobial peptide and its cDNA cloning from skin secretions of the crab-eating frog R. cancrivora. The antimicrobial peptide was named cancrin with an amino acid sequence of GSAQPYKQLHKVVNWDPYG. By BLAST search, cancrin had no significant similarity to any known peptides. The cDNA encoding cancrin was cloned from the cDNA library of the skin of R. cancrivora. The cancrin precursor is composed of 68 amino acid residues including a signal peptide, acidic spacer peptide, which are similar to other antimicrobial peptide precursors from Ranid amphibians and mature cancrin. The overall structure is similar to other amphibian antimicrobial peptide precursors although mature cancrin is different from known peptides. The current results reported a new family of amphibian antimicrobial peptide and the first antimicrobial peptide from sea amphibian.


Assuntos
Proteínas de Anfíbios/genética , Anti-Infecciosos , Peptídeos Catiônicos Antimicrobianos/genética , Peptídeos/genética , Ranidae/genética , Sequência de Aminoácidos , Proteínas de Anfíbios/imunologia , Animais , Peptídeos Catiônicos Antimicrobianos/imunologia , Clonagem Molecular , DNA Complementar/genética , DNA Complementar/imunologia , Dados de Sequência Molecular , Oceanos e Mares , Peptídeos/imunologia , Ranidae/imunologia , Pele/imunologia
15.
Peptides ; 28(5): 969-73, 2007 May.
Artigo em Inglês | MEDLINE | ID: mdl-17383773

RESUMO

Group IIA secretory phospholipases A(2) (sPLA(2)-II) is generally known to display potent gram-positive bactericidal activity, while group IA sPLA(2) (sPLA(2)-I) reportedly is not. In this work, a novel sPLA(2)-I named BFPA was identified from Bungarus fasciatus venom, and its antimicrobial activity was studied as well. The amino acid sequence of the venomous protein precursor was 145-amino acid in length, and contained a predicted 27-amino acid signal peptide and a 118-amino acid mature protein. Unlike the well-known sPLA(2)-Is, which have 14 half-cysteines forming 7 intramolecular disulfide bridges, BFPA possesses 15 half-cysteines. The additional cysteine might contribute to the formation of an intermolecular disulfide bridge of the homodimeric protein. In the biological activities assays, BFPA displayed the activities of anticoagulation and bactericidal against Escherichia coli and Staphylococcus aureus. This study is the first report about gram-positive bactericidal activity of sPLA(2)-I.


Assuntos
Antibacterianos/isolamento & purificação , Bungarus/metabolismo , Venenos Elapídicos/enzimologia , Fosfolipases A/isolamento & purificação , Sequência de Aminoácidos , Animais , Antibacterianos/química , Antibacterianos/farmacologia , Sequência de Bases , Coagulação Sanguínea/efeitos dos fármacos , Cromatografia em Gel , Cromatografia Líquida de Alta Pressão , Dimerização , Relação Dose-Resposta a Droga , Eletroforese em Gel de Poliacrilamida , Escherichia coli/efeitos dos fármacos , Fosfolipases A2 do Grupo IV , Dados de Sequência Molecular , Peso Molecular , Fosfolipases A/química , Fosfolipases A/farmacologia , Alinhamento de Sequência , Homologia de Sequência de Aminoácidos , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz , Staphylococcus aureus/efeitos dos fármacos
16.
Peptides ; 27(12): 3085-91, 2006 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-17000029

RESUMO

There are around 27 species of Amolops amphibian distributed in South-east of Asia. Seven antimicrobial peptides (AMPs) belonging to two different families were purified from skin of rufous-spotted torrent frog, Amolops loloensis, and designated brevinins-ALa, b, c, and d, and temporins-ALa, b, and c. The brevinins-AL family which is structurally related to brevinins-1 from skin secretions of the European frog, Rana brevipoda, is composed of 24 amino acids and has an intra-disulfide bridge at the C-terminus. The temporins-AL family, composed of 13 or 16 amino acid residues, is related with temporins from the skin secretions of R. temporaria. The findings of this study will facilitate the solutions to the taxonomic questions of the ranid genus Amolops and Staurois. In the work of this paper, both brevinins-ALb and temporin-Ma induced mast cell degranulation and histamine release, and had cytotoxic activity toward solid tumor cell line HepG(2). Brevinins-ALb also exerted strong hemolytic activity while temporin-Ma had no such activity.


Assuntos
Peptídeos Catiônicos Antimicrobianos/fisiologia , Pele/metabolismo , Sequência de Aminoácidos , Animais , Peptídeos Catiônicos Antimicrobianos/química , Peptídeos Catiônicos Antimicrobianos/genética , Peptídeos Catiônicos Antimicrobianos/isolamento & purificação , Feminino , Masculino , Dados de Sequência Molecular , Família Multigênica , Ranidae , Pele/química
17.
Am J Pathol ; 165(2): 383-96, 2004 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-15277214

RESUMO

There is growing evidence that the two small leucine-rich proteoglycans biglycan and decorin regulate the assembly of connective tissues and alter cell behavior during development and pathological processes. In this study, we have used an experimental animal model of unilateral ureteral ligation and mice deficient in either biglycan or decorin. We discovered that pressure-induced injury to the wild-type kidneys led to overexpression of decorin, biglycan, fibrillin-1, and fibrillin-2. In contrast, in biglycan-deficient kidneys the overexpression of fibrillin-1 was markedly attenuated and this was associated with cystic dilatation of Bowman's capsule and proximal tubules. Notably, we found that in ligated kidneys from decorin-null mice, fibrillin-1 expression was initially enhanced to the same extent as in wild-type animals. However, long-term obstruction resulted in down-regulation of fibrillin-1 and concurrent cystic dilatation of Bowman's capsule in 33% of kidneys at 5 months after obstruction. In all of the genotypes, no differences in fibrillin-2 expression were observed. These in vivo data correlated with a significant induction of fibrillin-1 expression in renal fibroblasts and mesangial cells by recombinant biglycan and decorin. Our results indicate a novel role for decorin and biglycan during pressure-induced renal injury by stimulating fibrillin-1 expression.


Assuntos
Regulação da Expressão Gênica , Rim/lesões , Rim/metabolismo , Proteínas dos Microfilamentos/metabolismo , Proteoglicanas/fisiologia , Animais , Biglicano , Decorina , Modelos Animais de Doenças , Proteínas da Matriz Extracelular/metabolismo , Fibrilina-1 , Fibrilina-2 , Fibrilinas , Fibroblastos/citologia , Fibroblastos/metabolismo , Fibrose/genética , Fibrose/patologia , Genótipo , Mesângio Glomerular/citologia , Mesângio Glomerular/metabolismo , Heterozigoto , Homozigoto , Rim/patologia , Camundongos , Camundongos Knockout , Pressão/efeitos adversos , Proteoglicanas/genética , Fator de Crescimento Transformador beta/antagonistas & inibidores
18.
J Biol Chem ; 279(31): 32924-31, 2004 Jul 30.
Artigo em Inglês | MEDLINE | ID: mdl-15161917

RESUMO

Mutations in fibrillin-1 lead to Marfan syndrome and some related genetic disorders. Many of the more than 600 mutations currently known in fibrillin-1 eliminate or introduce cysteine residues in epidermal growth factor-like modules. Here we report structural and functional consequences of three selected cysteine mutations (R627C, C750G, and C926R) in fibrillin-1. The mutations have been analyzed by means of recombinant polypeptides produced in mammalian expression systems. The mRNA levels for the mutation constructs were similar to wild-type levels. All three mutated polypeptides were secreted by embryonic kidney cells (293) into the culture medium. Purification was readily feasible for mutants R627C and C750G, but not for C926R, which restricted the availability of this mutant polypeptide to selected analyses. The overall folds of the mutant polypeptides were indistinguishable from the wild-type as judged by the ultrastructural shape, CD analysis, and reactivity with a specific antibody sensitive for intact disulfide bonds. Subtle structural changes caused by R627C and C750G, however, were monitored by proteolysis and heat denaturation experiments. These changes occurred in the vicinity of the mutations either as short range effects (R627C) or both short and long range effects (C750G). Enhanced proteolytic susceptibility was observed for R627C and C750G to a variety of proteases. These results expand and further strengthen the concept that proteolytic degradation of mutated fibrillin-1 might be an important potential mechanism in the pathogenesis of Marfan syndrome and other disorders caused by mutations in fibrillin-1.


Assuntos
Cálcio/metabolismo , Cisteína/genética , Fator de Crescimento Epidérmico/metabolismo , Proteínas dos Microfilamentos/metabolismo , Mutação , Sequência de Aminoácidos , Western Blotting , Linhagem Celular , Dicroísmo Circular , Cisteína/química , Mapeamento de Epitopos , Fibrilina-1 , Fibrilinas , Humanos , Microscopia Eletrônica , Dados de Sequência Molecular , Mutação de Sentido Incorreto , Peptídeos/química , Plasmídeos/metabolismo , Estrutura Secundária de Proteína , Estrutura Terciária de Proteína , RNA Mensageiro/metabolismo , Proteínas Recombinantes/química , Temperatura , Transfecção , Raios Ultravioleta
19.
J Biol Chem ; 277(52): 50795-804, 2002 Dec 27.
Artigo em Inglês | MEDLINE | ID: mdl-12399449

RESUMO

Fibrillin-1 and fibrillin-2 constitute the backbone of extracellular filaments, called microfibrils. Fibrillin assembly involves complex multistep mechanisms to result in a periodical head-to-tail alignment in microfibrils. Impaired assembly potentially plays a role in the molecular pathogenesis of genetic disorders caused by mutations in fibrillin-1 (Marfan syndrome) and fibrillin-2 (congenital contractural arachnodactyly). Presently, the basic molecular interactions involved in fibrillin assembly are obscure. Here, we have generated recombinant full-length human fibrillin-1, and two overlapping recombinant polypeptides spanning the entire human fibrillin-2 in a mammalian expression system. Characterization by gel electrophoresis, electron microscopy after rotary shadowing, and reactivity with antibodies demonstrated correct folding of these recombinant polypeptides. Analyses of homotypic and heterotypic interaction repertoires showed N- to C-terminal binding of fibrillin-1, and of fibrillin-1 with fibrillin-2. The interactions were of high affinity with dissociation constants in the low nanomolar range. However, the N- and C-terminal fibrillin-2 polypeptides did not interact with each other. These results demonstrate that fibrillins can directly interact in an N- to C-terminal fashion to form homotypic fibrillin-1 or heterotypic fibrillin-1/fibrillin-2 microfibrils. This conclusion was further strengthened by double immunofluorescence labeling of microfibrils. In addition, the binding epitopes as well as the entire fibrillin molecules displayed very stable properties.


Assuntos
Proteínas da Matriz Extracelular/metabolismo , Proteínas dos Microfilamentos/genética , Sequência de Aminoácidos , Sequência de Bases , Proteínas de Ligação ao Cálcio/genética , Linhagem Celular , Dicroísmo Circular , Primers do DNA , Fibrilina-1 , Fibrilina-2 , Fibrilinas , Humanos , Síndrome de Marfan/genética , Microfibrilas/patologia , Microfibrilas/ultraestrutura , Proteínas dos Microfilamentos/química , Proteínas dos Microfilamentos/metabolismo , Proteínas dos Microfilamentos/ultraestrutura , Microscopia Eletrônica , Dados de Sequência Molecular , Fragmentos de Peptídeos/química , Fragmentos de Peptídeos/metabolismo , Ligação Proteica , Proteínas Recombinantes/metabolismo , Alinhamento de Sequência , Homologia de Sequência de Aminoácidos , Transfecção
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