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1.
Anal Bioanal Chem ; 414(18): 5595-5607, 2022 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-35359181

RESUMO

Apolipoprotein E containing high-density lipoprotein (apoE-HDL) and apoE-HDL cholesterol (apoE-HDL-C) are recently recognized as potential biomarkers for coronary heart disease (CHD). We herein developed a two-stage, enzyme-assisted, dual-signal aptasensor that enables a useful electrochemical sensing platform for simultaneous determination of apoE-HDL, apoE-HDL-C, and total HDL-C presented in the sample. The detection scheme consists of two subsystems. In subsystem (I), the level of apoE-HDL is evaluated upon the binding of apoE-specific aptamer and subsequently methylene blue (MB)-labeled DNA displacement occurs on the electrode surface, resulting in electrochemical reduction of methylene blue. In subsystem (II), two kinds of cholesterol levels (apoE-HDL-C and total HDL-C) can be measured. For apoE-HDL-C, the amount of cholesterol in apoE-HDL captured by the aptamer in the first step can be further determined with the aid of surfactant, cholesterol esterase, cholesterol oxidase, and p-aminophenol-mediated electrochemical signal amplification. As for total HDL-C, the amount of cholesterol is determined by the same approach as that used for apoE-HDL-C determination, but without washing (separation). The linear dynamic range for apoE-HDL determination is from 1 to 100 mg/dL (R2 = 1.00). For cholesterol standards, the linear dynamic range is determined to be 0-250 mg/dL (R2 = 0.98). Finally, serial dilutions of purified human HDL preparations were examined using the newly developed aptasensor; the percentage of apoE-HDL-C to HDL-C was found to be ~10%, which correlated well with previously reported values. In conclusion, we successfully developed an electrochemical aptasensor that allows concurrent quantification of apoE-HDL, apoE-HDL-C, and HDL-C on the same platform, offering an efficient, convenient, and purification-free sensing strategy for predictive CHD biomarkers.


Assuntos
Apolipoproteínas E , HDL-Colesterol , Doença das Coronárias , Fatores de Risco de Doenças Cardíacas , Doença das Coronárias/diagnóstico , Humanos , Azul de Metileno
2.
J Nanobiotechnology ; 19(1): 89, 2021 Mar 29.
Artigo em Inglês | MEDLINE | ID: mdl-33781277

RESUMO

BACKGROUND: Areas of hypoxia are often found in triple-negative breast cancer (TNBC), it is thus more difficult to treat than other types of breast cancer, and may require combination therapies. A new strategy that combined bioreductive therapy with photodynamic therapy (PDT) was developed herein to improve the efficacy of cancer treatment. Our design utilized the characteristics of protoporphyrin IX (PpIX) molecules that reacted and consumed O2 at the tumor site, which led to the production of cytotoxic reactive oxygen species (ROS). The low microenvironmental oxygen levels enabled activation of a bioreductive prodrug, tirapazamine (TPZ), to become a toxic radical. The TPZ radical not only eradicated hypoxic tumor cells, but it also promoted therapeutic efficacy of PDT. RESULTS: To achieve the co-delivery of PpIX and TPZ for advanced breast cancer therapy, thin-shell hollow mesoporous Ia3d silica nanoparticles, designated as MMT-2, was employed herein. This nanocarrier designed to target the human breast cancer cell MDA-MB-231 was functionalized with PpIX and DNA aptamer (LXL-1), and loaded with TPZ, resulting in the formation of TPZ@LXL-1-PpIX-MMT-2 nanoVector. A series of studies confirmed that our nanoVectors (TPZ@LXL-1-PpIX-MMT-2) facilitated in vitro and in vivo targeting, and significantly reduced tumor volume in a xenograft mouse model. Histological analysis also revealed that this nanoVector killed tumor cells in hypoxic regions efficiently. CONCLUSIONS: Taken together, the synergism and efficacy of this new therapeutic design was confirmed. Therefore, we concluded that this new therapeutic strategy, which exploited a complementary combination of PpIX and TPZ, functioned well in both normoxia and hypoxia, and is a promising medical procedure for effective treatment of TNBC.


Assuntos
Antineoplásicos/farmacologia , Nanopartículas/uso terapêutico , Fotoquimioterapia/métodos , Neoplasias de Mama Triplo Negativas/tratamento farmacológico , Animais , Aptâmeros de Nucleotídeos , Linhagem Celular Tumoral , Terapia Combinada , Feminino , Humanos , Camundongos , Oxigênio , Pró-Fármacos , Espécies Reativas de Oxigênio , Dióxido de Silício , Tirapazamina , Carga Tumoral , Hipóxia Tumoral/efeitos dos fármacos , Ensaios Antitumorais Modelo de Xenoenxerto
3.
Biol Blood Marrow Transplant ; 24(8): 1554-1562, 2018 08.
Artigo em Inglês | MEDLINE | ID: mdl-29684562

RESUMO

Allogeneic hematopoietic stem cell transplantation (HSCT) can be curative for patients with sickle cell disease (SCD). However, morbidity associated with myeloablative conditioning and graft-versus-host disease has limited its utility. To this end, autologous HSCT for SCD using lentiviral gene-modified bone marrow (BM) or peripheral blood stem cells has been undertaken, although toxicities of fully ablative conditioning with busulfan and incomplete engraftment have been encountered. Treosulfan, a busulfan analog with a low extramedullary toxicity profile, has been used successfully as part of a myeloablative conditioning regimen in the allogeneic setting in SCD. To further minimize toxicity of conditioning, noncytotoxic monoclonal antibodies that clear stem cells from the marrow niche, such as anti-c-Kit (ACK2), have been considered. Using a murine model of SCD, we sought to determine whether nonmyeloablative conditioning followed by transplantation with syngeneic BM cells could ameliorate the disease phenotype. Treosulfan and ACK2, in a dose-dependent manner, decreased BM cellularity and induced cytopenia in SCD mice. Conditioning with treosulfan alone at nonmyeloablative dosing (3.6 g/kg), followed by transplantation with syngeneic BM donor cells, permitted long-term mixed-donor chimerism. Level of chimerism correlated with improvement in hematologic parameters, normalization of urine osmolality, and improvement in liver and spleen pathology. Addition of ACK2 to treosulfan conditioning did not enhance engraftment. Our data suggests that pretransplant conditioning with treosulfan alone may allow sufficient erythroid engraftment to reverse manifestations of SCD, with clinical application as a preparative regimen in SCD patients undergoing gene-modified autologous HSCT.


Assuntos
Anemia Falciforme/terapia , Transplante de Medula Óssea/métodos , Bussulfano/análogos & derivados , Condicionamento Pré-Transplante/métodos , Animais , Anticorpos/uso terapêutico , Antineoplásicos Alquilantes/uso terapêutico , Bussulfano/uso terapêutico , Modelos Animais de Doenças , Sobrevivência de Enxerto , Camundongos , Proteínas Proto-Oncogênicas c-kit/imunologia , Resultado do Tratamento
4.
Am J Hematol ; 92(10): 981-988, 2017 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-28646491

RESUMO

Sickle erythrocytes' (SSRBCs) unique physical adaptation to hypoxic conditions renders them able to home to hypoxic tumor niches in vivo, shut down tumor blood flow and induce tumoricidal responses. SSRBCs are also useful vehicles for transport of encapsulated drugs and oncolytic virus into hypoxic tumors with enhanced anti-tumor effects. In search of additional modes for arming sickle cells with cytotoxics, we turned to a lentiviral ß-globin vector with optimized Locus Control Region/ß-globin coding region/promoter/enhancers. We partially replaced the ß-globin coding region of this vector with genes encoding T cell cytolytics, perforin and granzyme or immune modulating superantigens SEG and SEI. These modified vectors efficiently transduced Sca+ ckit- Lin- hematopoietic stem cells (HSCs) from humanized sickle cell knockin mice. Irradiated mice reconstituted with these HSCs displayed robust expression of transgenic RNAs and proteins in host sickle cells that was sustained for more than 10 months. SSRBCs from reconstituted mice harboring SEG/SEI transgenes induced robust proliferation and a prototypical superantigen-induced cytokine reaction when exposed to human CD4+/CD8+ cells. The ß-globin lentiviral vector therefore produces a high level of functional, erythroid-specific immune modulators and cytotoxics that circulate without toxicity. Coupled with their unique ability to target and occlude hypoxic tumor vessels these armed SSRBCs constitute a potentially useful tool for treatment of solid tumors.


Assuntos
Anemia Falciforme , Citotoxicidade Imunológica , Eritrócitos Anormais/imunologia , Neoplasias Experimentais/imunologia , Neovascularização Patológica/imunologia , Globinas beta/genética , Anemia Falciforme/sangue , Animais , Citotoxicidade Imunológica/genética , Sistemas de Liberação de Medicamentos , Eritrócitos Anormais/metabolismo , Eritrócitos Anormais/transplante , Técnicas de Introdução de Genes , Vetores Genéticos , Transplante de Células-Tronco Hematopoéticas , Hipóxia , Lentivirus/genética , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Neoplasias Experimentais/irrigação sanguínea , Neoplasias Experimentais/terapia , Neovascularização Patológica/patologia , Neovascularização Patológica/terapia
5.
Methods ; 56(2): 223-9, 2012 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-22062957

RESUMO

Due to its physiologic role in modulating adhesive interactions between blood cells and the endothelium during inflammatory processes or at injury sites, the adhesion molecule P-selectin is of great interest. The level of soluble P-selectin in plasma or serum can be detected and used as a clinical predictor for adverse cardiovascular events, leading to the presumption that it is secreted, shed or cleaved from the cell membrane during the process of diseases. Increased levels of soluble P-selectin in the plasma have been shown to be associated with a range of cardiovascular disorders, including coronary artery disease, hypertension and atrial fibrillation. Therefore, it is of huge significance to develop simple, rapid and sensitive methods for the detection of such pathological predictors, not only for facilitating the surveillance of cardiovascular mortality/sudden cardiac death, but also for effectively monitoring the drug potency on platelets based on measurement of P-selectin performed on fixed blood samples following platelet stimulation in whole blood in a remote setting. We herein developed a simple, yet novel and sensitive electrochemical sandwich immunosensor for the detection of P-selectin; it operates through covalent linkage of anti-P-selectin antibody on CNT@GNB nanocomposites-modified disposable screen-printed electrode as the detection platform, with the potassium ferrocyanide-encapsulated, anti-P-selectin-tagged liposomal biolabels as the electrochemical signal probes. The immunorecognition of the sample P-selectin by the liposomal biolabels occurred on the surface of the electrodes; the release of potassium ferrocyanide from the bound liposomal biolabels extensively contributed to the increase in electrochemical signal, which was acquired in HCl solution at +0.32V in square wave voltammetry mode. The resulting sigmoidally shaped dose-response curves possessed a linear dynamic working range from 1×10(-13) to 1×10(-5)g/mL. This liposome-based electrochemical immunoassay provides an amplification approach for detecting P-selectin at trace levels, leading to a detection limit as low as 4.3fg (equivalent to 5µL of 0.85pg/mL solution). A commercially available ELISA kit was used as a reference method to validate the newly-developed assay through the analysis of mouse serum samples. A strong correlation was observed between the two data sets as the R-squared value of 0.997 from the linear regression line. This electrochemical immunosensor will be useful for the detection of P-selectin in biological fluids and tissue extracts.


Assuntos
Técnicas Biossensoriais/instrumentação , Doenças Cardiovasculares/diagnóstico , Imunoensaio/instrumentação , Selectina-P/sangue , Animais , Biomarcadores/sangue , Biomarcadores/química , Técnicas Biossensoriais/métodos , Doenças Cardiovasculares/imunologia , Membrana Celular/química , Técnicas Eletroquímicas/instrumentação , Técnicas Eletroquímicas/métodos , Eletrodos , Ensaio de Imunoadsorção Enzimática , Ferrocianetos/química , Ácido Clorídrico/química , Imunoensaio/métodos , Limite de Detecção , Modelos Lineares , Lipossomos/química , Camundongos , Nanocompostos/química , Reprodutibilidade dos Testes , Fatores de Risco , Solubilidade , Fatores de Tempo
6.
Adv Sci (Weinh) ; 10(7): e2204643, 2023 03.
Artigo em Inglês | MEDLINE | ID: mdl-36638276

RESUMO

The characteristics of global prevalence and high recurrence of bladder cancer has led numerous efforts to develop new treatments. The spontaneous voiding and degradation of the chemodrug hamper the efficacy and effectiveness of intravesical chemotherapy following tumor resection. Herein, the externally thiolated hollow mesoporous silica nanoparticles (MSN-SH(E)) is fabricated to serve as a platform for improved bladder intravesical therapy. Enhanced mucoadhesive effect of the thiolated nanovector is confirmed with porcine bladder. The permeation-enhancing effect is also verified, and a fragmented distribution pattern of a tight junction protein, claudin-4, indicates the opening of tight junction. Moreover, MSN-SH(E)-associated reprogramming of M2 macrophages to M1-like phenotype is observed in vitro. The antitumor activity of the mitomycin C (MMC)-loaded nanovector (MMC@MSN-SH(E)) is more effective than that of MMC alone in both in vitro and in vivo. In addition, IHC staining is used to analyze IFN-γ, TGF-ß1, and TNF-α. These observations substantiated the significance of MMC@MSN-SH(E) in promoting anticancer activity, holding the great potential for being used in intravesical therapy for non-muscle invasive bladder cancer (NMIBC) due to its mucoadhesivity, enhanced permeation, immunomodulation, and prolonged and very efficient drug exposure.


Assuntos
Nanopartículas , Neoplasias da Bexiga Urinária , Animais , Suínos , Antibióticos Antineoplásicos , Adjuvantes Imunológicos/uso terapêutico , Dióxido de Silício , Neoplasias da Bexiga Urinária/tratamento farmacológico , Neoplasias da Bexiga Urinária/patologia , Mitomicina/uso terapêutico
7.
Stem Cells ; 29(2): 229-40, 2011 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-21732481

RESUMO

Polycomb repressive complex two (PRC2) has been implicated in embryonic stem (ES) cell pluripotency; however, the mechanistic roles of this complex are unclear. It was assumed that ES cells contain PRC2 with the same subunit composition as that identified in HeLa cells and Drosophila embryos. Here, we report that PRC2 in mouse ES cells contains at least three additional subunits: JARID2, MTF2, and a novel protein denoted esPRC2p48. JARID2, MTF2, and esPRC2p48 are highly expressed in mouse ES cells compared to differentiated cells. Importantly, knockdowns of JARID2, MTF2, or esPRC2p48 alter the level of PRC2-mediated H3K27 methylation and result in the expression of differentiation-associated genes in ES cells. Interestingly, expression of JARID2, MTF2, and esPRC2p48 together, but not individually, enhances Oct4/Sox2/Klf4-mediated reprogramming of mouse embryonic fibroblasts (MEFs) into induced pluripotent stem cells, whereas knockdown or knockout of JARID2, MTF2, or esPRC2p48 significantly inhibits reprogramming. JARID2, MTF2, and esPRC2p48 modulate H3K27 methylation and facilitate repression of lineage-associated gene expression when transduced into MEFs, and synergistically stimulate the histone methyltransferase activity of PRC2 in vitro. Therefore, these studies identify JARID2, MTF2, and esPRC2p48 as important regulatory subunits of PRC2 in ES cells and reveal critical functions of these subunits in modulating PRC2's activity and gene expression both in ES cells and during somatic cell reprogramming.


Assuntos
Células-Tronco Embrionárias/metabolismo , Proteínas do Tecido Nervoso/metabolismo , Células-Tronco Pluripotentes/metabolismo , Proteínas Repressoras/metabolismo , Animais , Diferenciação Celular , Células Cultivadas , Regulação da Expressão Gênica no Desenvolvimento , Histona Metiltransferases , Histona-Lisina N-Metiltransferase/metabolismo , Histonas/metabolismo , Fator 4 Semelhante a Kruppel , Fatores de Transcrição Kruppel-Like/metabolismo , Camundongos , Proteínas do Tecido Nervoso/genética , Fator 3 de Transcrição de Octâmero/metabolismo , Complexo Repressor Polycomb 2 , Proteínas do Grupo Polycomb , Ligação Proteica , RNA Interferente Pequeno/genética , Proteínas Repressoras/genética , Fatores de Transcrição SOXB1/metabolismo
8.
J Biomed Sci ; 18: 74, 2011 Oct 11.
Artigo em Inglês | MEDLINE | ID: mdl-21988805

RESUMO

BACKGROUND: Pigmentation is one of the essential defense mechanisms against oxidative stress or UV irradiation; however, abnormal hyperpigmentation in human skin may pose a serious aesthetic problem. C-phycocyanin (Cpc) is a phycobiliprotein from spirulina and functions as an antioxidant and a light harvesting protein. Though it is known that spirulina has been used to reduce hyperpigmentation, little literature addresses the antimelanogenic mechanism of Cpc. Herein, we investigated the rationale for the Cpc-induced inhibitory mechanism on melanin synthesis in B16F10 melanoma cells. METHODS: Cpc-induced inhibitory effects on melanin synthesis and tyrosinase expression were evaluated. The activity of MAPK pathways-associated molecules such as MAPK/ERK and p38 MAPK, were also examined to explore Cpc-induced antimelanogenic mechanisms. Additionally, the intracellular localization of Cpc was investigated by confocal microscopic analysis to observe the migration of Cpc. RESULTS: Cpc significantly (P < 0.05) reduced both tyrosinase activity and melanin production in a dose-dependent manner. This phycobiliprotein elevated the abundance of intracellular cAMP leading to the promotion of downstream ERK1/2 phosphorylation and the subsequent MITF (the transcription factor of tyrosinase) degradation. Further, Cpc also suppressed the activation of p38 causing the consequent disturbed activation of CREB (the transcription factor of MITF). As a result, Cpc negatively regulated tyrosinase gene expression resulting in the suppression of melanin synthesis. Moreover, the entry of Cpc into B16F10 cells was revealed by confocal immunofluorescence localization and immunoblot analysis. CONCLUSIONS: Cpc exerted dual antimelanogenic mechanisms by upregulation of MAPK/ERK-dependent degradation of MITF and downregulation of p38 MAPK-regulated CREB activation to modulate melanin formation. Cpc may have potential applications in biomedicine, food, and cosmetic industries.


Assuntos
Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Melaninas/antagonistas & inibidores , Monofenol Mono-Oxigenase/biossíntese , Ficocianina/farmacologia , Proteínas Quinases p38 Ativadas por Mitógeno/efeitos dos fármacos , Ativação Enzimática , Regulação da Expressão Gênica , Humanos , Hiperpigmentação/prevenção & controle , Sistema de Sinalização das MAP Quinases/genética , Melaninas/biossíntese , Melanoma Experimental/enzimologia , Fator de Transcrição Associado à Microftalmia/efeitos dos fármacos , Fosforilação , Proteínas Proto-Oncogênicas c-akt/efeitos dos fármacos , Proteínas Proto-Oncogênicas c-akt/genética , Proteínas Proto-Oncogênicas c-akt/metabolismo , Transdução de Sinais , Spirulina/metabolismo , Fatores de Transcrição/efeitos dos fármacos , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Proteínas Quinases p38 Ativadas por Mitógeno/genética , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismo
9.
Nanotechnology ; 22(18): 185601, 2011 May 06.
Artigo em Inglês | MEDLINE | ID: mdl-21415469

RESUMO

A novel method was developed for the one-pot synthesis of ultrafine poly(lactic-co-glycolic acid) nanoparticles (PLGA NPs), using an emulsion solvent evaporation formulation method. Using either cetyltrimethylammonium bromide (CTAB) or poly(ethylene glycol)-distearyl phosphoethanolamine (PEGPE) as an oily emulsifier during the emulsion process, produced PLGA particle sizes of less than 50 nm, constituting a breakthrough in emulsion formulation methods. The yield of ultrafine PLGA NPs increased with PEGPE/PLGA ratio, reaching a plateau at around 85%, when the PEGPE/PLGA ratio reached 3:1. The PEGPE-PLGA NPs exhibited high drug loading content, reduced burst release, good serum stability, and enhanced cell uptake rate compared with traditional PLGA NPs. Sub-50 nm diameter PEG-coated ultrafine PLGA NPs show great potential for in vivo drug delivery systems.


Assuntos
Portadores de Fármacos/química , Ácido Láctico/química , Nanopartículas/química , Nanotecnologia/métodos , Polietilenoglicóis/química , Ácido Poliglicólico/química , Portadores de Fármacos/farmacocinética , Células HeLa , Humanos , Nanopartículas/ultraestrutura , Tamanho da Partícula , Copolímero de Ácido Poliláctico e Ácido Poliglicólico , Tensoativos
10.
Anal Chem ; 82(14): 5944-50, 2010 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-20557064

RESUMO

The development of rapid and sensitive methods for the detection of immunogenic tumor-associated antigen is important not only for understanding their roles in cancer immunology but also for the development of clinical diagnostics. Alpha-enolase (ENO1), a p48 molecule, is widely distributed in a variety of tissues, whereas gamma-enolase (ENO2) and beta-enolase (ENO3) are found exclusively in neuron/neuroendocrine and muscle tissues, respectively. Because ENO1 has been correlated with small cell lung cancer, nonsmall cell lung cancer, and head and neck cancer, it can be used as a potential diagnostic marker for lung cancer. In this study, we developed a simple, yet novel and sensitive, electrochemical sandwich immunosensor for the detection of ENO1; it operates through physisorption of anti-ENO1 monoclonal antibody on polyethylene glycol-modified disposable screen-printed electrode as the detection platform, with polyclonal secondary anti-ENO1-tagged, gold nanoparticle (AuNP) congregates as electrochemical signal probes. The immunorecognition of the sample ENO1 by the congregated AuNP@antibody occurred on the surface of the electrodes; the electrochemical signal from the bound AuNP congregates was obtained after oxidizing them in 0.1 M HCl at 1.2 V for 120 s, followed by the reduction of AuCl(4-) in square wave voltammetry (SWV) mode. The resulting sigmoidally shaped dose-response curves possessed a linear dynamic working range from 10(-8) to 10(-12) g/mL. This AuNP congregate-based assay provides an amplification approach for detecting ENO1 at trace levels, leading to a detection limit as low as 11.9 fg (equivalent to 5 microL of a 2.38 pg/mL solution).


Assuntos
Antígenos de Neoplasias/análise , Técnicas Eletroquímicas/métodos , Ouro/química , Neoplasias Pulmonares/diagnóstico , Nanopartículas Metálicas/química , Anticorpos Monoclonais/química , Anticorpos Monoclonais/imunologia , Antígenos de Neoplasias/imunologia , Técnicas Biossensoriais/métodos , Eletrodos , Humanos , Fosfopiruvato Hidratase/análise , Fosfopiruvato Hidratase/imunologia , Polietilenoglicóis/química
11.
Biomed Res Int ; 2020: 6936879, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32382565

RESUMO

BACKGROUND: Grip-force performance can be affected by aging, and hand-grip weakness is associated with functional limitations of dasily living. However, using an appropriate digital hand-held dynamometer with continuous hand-grip force data collection shows age-related changes in the quality of hand-grip force control may provide more valuable information for clinical diagnoses rather than merely recording instantaneous maximal hand-grip force in frail elderly adults or people with a disability. Therefore, the purpose of this study was to indicate the construct validity of the digital MicroFET3 dynamometer with Jamar values for maximal grip-force assessments in elderly and young adults and confirmed age-related changes in the maximal and the quality of grip-force performance using the MicroFET3 dynamometer in elderly people. METHODS: Sixty-five healthy young (23.3 ± 4.5 years) and 50 elderly (69.5 ± 5.8 years) adults were recruited and asked to perform a validity test of the grip-force maximum voluntary contraction (MVC) using both the dominant and nondominant hands with a Jamar dynamometer and a MicroFET3 dynamometer. RESULTS: A strong correlation of maximal grip-force measurements was found between the MicroFET3 dynamometer and Jamar standard dynamometer for both hands in all participants (p < 0.05). Although, the results showed that a lower grip force was measured in both hands by the MicroFET3 dynamometer than with the Jamar dynamometer by 49.9%~57% (p < 0.05), but confidently conversion formulae were also developed to convert MicroFET3 dynamometer values to equivalent Jamar values for both hands. Both dynamometers indicated age-related declines in the maximum grip-force performance by 36.7%~44.3% (p < 0.05). We also found that the maximal hand-grip force values generated in both hand by the elderly adults were slower and more inconsistent than those of the young adults when using the MicroFET3 dynamometer. CONCLUSIONS: This study demonstrated that the digital MicroFET3 dynamometer has good validity when used to measure the maximal grip force of both hands, and conversion formulae were also developed to convert MicroFET3 dynamometer force values to Jamar values in both hands. Comparing with the Jamar dynamometer for measuring grip force, the MicroFET3 dynamometer not only indicated age-related declines in the maximum grip-force performance but also showed slower and more inconsistent maximal hand-grip strength generation by the elderly.


Assuntos
Envelhecimento/fisiologia , Força da Mão/fisiologia , Dinamômetro de Força Muscular , Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade
12.
Anal Chem ; 81(14): 5671-7, 2009 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-19518067

RESUMO

A folic acid-anchored, poly(ethylene glycol)-linked (PEGgylated) phospholipid and an immunoaffinity chromatographic column were prepared and employed to develop a liposomal immunodiagnostic assay for the direct determination of folic acid (FA) in this study. Distearoylphosphatidylethanolamine-poly(ethylene glycol)2000-folic acid (DSPE-PEG2000-FA) was synthesized through carbodiimide-mediated coupling of FA and DSPE-PEG2000-amine and characterized using thin layer chromatography, 1H nuclear magnetic resonance spectroscopy, and electrospray ionization-mass spectrometry. Liposomal biolabels were constructed using the synthesized DSPE-PEG2000-FA in conjunction with other phospholipids. A stationary phase having affinity for FA was prepared by covalently linking purified anti-FA monoclonal antibodies onto N-hydroxysuccinimide-activated Sepharose beads, which were subsequently packed into a 1.9 cm diameter polypropylene column. The calibration curve for FA had a linear range from 10(-8) to 10(-4) M. The limit of detection was 6.8 ng (equivalent to 500 microL of 3.1 x 10(-8) M FA). The elution buffer (35% methanol in Tris buffered saline containing 0.1% Tween 20) also served as the regeneration buffer, which allowed the same column to be used for up to 50 times without any observable loss of reactivity. The immunoaffinity chromatographic column was reusable and capable of concentrating analytes from sample solution; in conjunction with folic acid-sensitized liposomal biolabels, however, they hold great potential as sensitive immunoaffinity assays for the determination for FA. To confirm the feasibility of using this system in the analysis of real samples, the folic acid contents of three over-the-counter vitamin supplements were tested. The recoveries of folic acid of 90-112% for these three samples were obtained, suggesting contents that were consistent with the information obtained from their nutritional facts panels.


Assuntos
Ácido Fólico/análise , Ácido Fólico/química , Imunoensaio/métodos , Lipossomos/química , Fosfatidiletanolaminas/química , Polietilenoglicóis/química , Anticorpos Imobilizados/química , Anticorpos Imobilizados/imunologia , Ligação Competitiva , Reações Cruzadas , Ácido Fólico/imunologia , Coloração e Rotulagem
13.
Talanta ; 200: 450-457, 2019 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-31036208

RESUMO

Non enzymatic detection of NADH and H2O2 is of practical significance for both environmental and biological prospective. However, there is no simple, straight forward electrochemical sensor available for sensing of them in real samples. Addressing this challenge, we report a simple stimuli responsive aminophenol, pre-anodized screen printed carbon electrode (SPCE*/AP) based electrochemical probes for dual detection of NADH and H2O2. Aminophenol prepared and adsorbed on the electrode from aminophenylboronic acid via boronic acid deprotection with H2O2. The SPCE*/AP fabricated with this process was characterized by cyclic voltammetry (CV), scanning electron microscope (SEM), Raman spectroscopy, UV-visible spectroscopy, and X-ray photoelectron spectroscopy (XPS). Amperometric detection results showed that SPCE*/AP electrodes exhibited linearity from 50 µM to 500 µM and from 200 µM to 2 mM with a detection limit (S/N = 3) of 4.2 µM and 28.9 µM for NADH and H2O2, respectively. Excellent reproducibility and selectivity for NADH and H2O2 were observed for this electrochemical platform. In addition, the matrix effect was investigated further using the same technique to analyze NADH and H2O2 in human urine samples, human serum samples, cell culture medium (containing 10% fetal bovine serum, FBS), and environmental water samples (tap water and rain water). Also, the present sensor demonstrated promising outcomes with living cells (normal cells and cancer cells).


Assuntos
Aminofenóis/química , Técnicas Eletroquímicas , Corantes Fluorescentes/química , Peróxido de Hidrogênio/análise , NAD/análise , Células 3T3 , Animais , Carbono/química , Linhagem Celular Tumoral , Eletrodos , Humanos , Camundongos
14.
JCI Insight ; 4(7)2019 04 04.
Artigo em Inglês | MEDLINE | ID: mdl-30944254

RESUMO

Hypoxic tumor niches are chief causes of treatment resistance and tumor recurrence. Sickle erythrocytes' (SSRBCs') intrinsic oxygen-sensing functionality empowers them to access such hypoxic niches wherein they form microaggregates that induce focal vessel closure. In search of measures to augment the scale of SSRBC-mediated tumor vaso-occlusion, we turned to the vascular disrupting agent, combretastatin A-4 (CA-4). CA-4 induces selective tumor endothelial injury, blood stasis, and hypoxia but fails to eliminate peripheral tumor foci. In this article, we show that introducing deoxygenated SSRBCs into tumor microvessels treated with CA-4 and sublethal radiation (SR) produces a massive surge of tumor vaso-occlusion and broadly propagated tumor infarctions that engulfs treatment-resistant hypoxic niches and eradicates established lung tumors. Tumor regression was histologically corroborated by significant treatment effect. Treated tumors displayed disseminated microvessels occluded by tightly packed SSRBCs along with widely distributed pimidazole-positive hypoxic tumor cells. Humanized HbS-knockin mice (SSKI) but not HbA-knockin mice (AAKI) showed a similar treatment response underscoring SSRBCs as the paramount tumoricidal effectors. Thus, CA-4-SR-remodeled tumor vessels license SSRBCs to produce an unprecedented surge of tumor vaso-occlusion and infarction that envelops treatment-resistant tumor niches resulting in complete tumor regression. Strategically deployed, these innovative tools constitute a major conceptual advance with compelling translational potential.


Assuntos
Anemia Falciforme/sangue , Antineoplásicos Fitogênicos/administração & dosagem , Eritrócitos Anormais/transplante , Neoplasias Pulmonares/terapia , Recidiva Local de Neoplasia/terapia , Animais , Adesão Celular , Hipóxia Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Terapia Combinada/métodos , Feminino , Técnicas de Introdução de Genes , Hemoglobina Falciforme/genética , Humanos , Pulmão/irrigação sanguínea , Pulmão/diagnóstico por imagem , Pulmão/efeitos dos fármacos , Pulmão/patologia , Neoplasias Pulmonares/irrigação sanguínea , Neoplasias Pulmonares/diagnóstico por imagem , Neoplasias Pulmonares/patologia , Masculino , Camundongos , Camundongos Transgênicos , Microvasos/citologia , Microvasos/efeitos dos fármacos , Microvasos/patologia , Recidiva Local de Neoplasia/irrigação sanguínea , Recidiva Local de Neoplasia/diagnóstico por imagem , Recidiva Local de Neoplasia/patologia , Estilbenos/administração & dosagem , Transplante Heterólogo/métodos , Carga Tumoral/efeitos dos fármacos , Ensaios Antitumorais Modelo de Xenoenxerto
15.
J Agric Food Chem ; 56(7): 2341-9, 2008 Apr 09.
Artigo em Inglês | MEDLINE | ID: mdl-18321049

RESUMO

Spilanthes acmella (Paracress), a common spice, has been administered as a traditional folk medicine for years to cure toothaches, stammering, and stomatitis. Previous studies have demonstrated its diuretic, antibacterial, and anti-inflammatory activities. However, the active compounds contributing to the anti-inflammatory effect have seldom been addressed. This study isolates the active compound, spilanthol, by a bioactivity-guided approach and indicates significant anti-inflammatory activity on lipopolysaccharide-activated murine macrophage model, RAW 264.7. The anti-inflammatory mechanism of paracress is also investigated. Extracts of S. acmella are obtained by extraction with 85% ethanol, followed by liquid partition against hexane, chloroform, ethyl acetate, and butanol. The ethyl acetate extract exhibits a stronger free radical scavenging capacity than other fractions do, as determined by DPPH and ABTS radical scavenging assays. The chloroform extract significantly inhibits nitric oxide production ( p < 0.01) and is selected for further fractionation to yield the active compound, spilanthol. The diminished levels of LPS-induced inducible nitric oxide synthase (iNOS) and cyclooxygenase (COX-2) mRNA and protein expression support the postulation that spilanthol inhibits proinflammatory mediator production at the transcriptional and translational levels. Additionally, the LPS-stimulated IL-1beta, IL-6, and TNF-alpha productions are dose-dependently reduced by spilanthol. The LPS-induced phosphorylation of cytoplasmic inhibitor-kappaB and the nuclear NF-kappaB DNA binding activity are both restrained by spilanthol. Results of this study suggest that spilanthol, isolated from S. acmella, attenuates the LPS-induced inflammatory responses in murine RAW 264.7 macrophages partly due to the inactivation of NF-kappaB, which negatively regulates the production of proinflammatory mediators.


Assuntos
Amidas/farmacologia , Anti-Inflamatórios/farmacologia , Asteraceae/química , Lipopolissacarídeos/farmacologia , Macrófagos/efeitos dos fármacos , Extratos Vegetais/farmacologia , Animais , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Ciclo-Oxigenase 2/genética , Inibidores de Ciclo-Oxigenase 2/farmacologia , Inibidores Enzimáticos/farmacologia , Camundongos , NF-kappa B/efeitos dos fármacos , Óxido Nítrico/antagonistas & inibidores , Óxido Nítrico Sintase Tipo II/antagonistas & inibidores , Óxido Nítrico Sintase Tipo II/genética , Alcamidas Poli-Insaturadas
16.
Biosens Bioelectron ; 87: 142-149, 2017 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-27543858

RESUMO

Tyramine (4-hydroxyphenethylamine), which is a monoamine metabolized by monoamine oxidase (MAO), exists widely in plants, animals, fermented foods, and salted foods. The incidence of hypertension, or "cheese effect", which is associated with a large dietary intake of tyramine while taking MAO inhibitors has been reported; therefore, the measurement of tyramine is an urgent concern. Herein, an efficient approach that integrates a molecular imprinting polymer for solid phase extraction (MISPE) technique with a sensitive electrochemical sensing platform (SPCE/PEDOT: PSS/AuNP/1-m-4-MP) for the quantification of tyramine is presented. Enhanced electrode conductivity was achieved sequentially by constructing a conductive polymer (PEDOT: PSS) on a screen-printed carbon electrode (SPCE), followed by electrodeposition with gold nanoparticles (AuNPs) and, finally, by modification with positively charged 1-methyl-4-mercaptopyridine (1-m-4-MP) using an Au-S bond. Tyramine was isolated selectively and pre-concentrated by the MISPE technique; electroanalysis that used differential pulse voltammetry (DPV) in NaOH (0.1M, pH 13) was conducted successively. Experimental parameters (such as modes of electrode modification, ratio of PEDOT: PSS, pH of electrolyte, time required for AuNP deposition, and 1-m-4-MP concentrations) that were associated with optimal detection conditions were evaluated also. We obtained a linear concentration range (5-100nM, R2=0.9939) with LOD and sensitivity at 2.31nM, and 3.11µAnM-1cm-2, respectively. The applicability of our technique was demonstrated by analyzing tyramine in spiked serum and milk. The feature of our newly developed analytical methods that coupled sample pre-treatment (sample clean-up and pre-concentration) with sensitive detection makes it a promising tool for quantifying of tyramine.


Assuntos
Técnicas Eletroquímicas/métodos , Leite/química , Impressão Molecular/métodos , Poliestirenos/química , Extração em Fase Sólida/métodos , Tiofenos/química , Tiramina/análise , Tiramina/sangue , Animais , Técnicas Biossensoriais/instrumentação , Técnicas Biossensoriais/métodos , Carbono/química , Técnicas Eletroquímicas/instrumentação , Eletrodos , Desenho de Equipamento , Ouro/química , Humanos , Nanopartículas Metálicas/química , Impressão Molecular/instrumentação , Piridinas/química , Extração em Fase Sólida/instrumentação
17.
Stem Cells Transl Med ; 6(4): 1168-1177, 2017 04.
Artigo em Inglês | MEDLINE | ID: mdl-28233474

RESUMO

Recruitment of neutrophils and monocytes/macrophages to the site of vascular injury is mediated by binding of chemoattractants to interleukin (IL) 8 receptors RA and RB (IL8RA/B) C-C chemokine receptors (CCR) 2 and 5 expressed on neutrophil and monocyte/macrophage membranes. Endothelial cells (ECs) derived from rat-induced pluripotent stem cells (RiPS) were transduced with adenovirus containing cDNA of IL8RA/B and/or CCR2/5. We hypothesized that RiPS-ECs overexpressing IL8RA/B (RiPS-IL8RA/B-ECs), CCR2/5 (RiPS-CCR2/5-ECs), or both receptors (RiPS-IL8RA/B+CCR2/5-ECs) will inhibit inflammatory responses and neointima formation in balloon-injured rat carotid artery. Twelve-week-old male Sprague-Dawley rats underwent balloon injury of the right carotid artery and intravenous infusion of (a) saline vehicle, (b) control RiPS-Null-ECs (ECs transduced with empty virus), (c) RiPS-IL8RA/B-ECs, (d) RiPS-CCR2/5-ECs, or (e) RiPS-IL8RA/B+CCR2/5-ECs. Inflammatory mediator expression and leukocyte infiltration were measured in injured and uninjured arteries at 24 hours postinjury by enzyme-linked immunosorbent assay (ELISA) and immunohistochemistry, respectively. Neointima formation was assessed at 14 days postinjury. RiPS-ECs expressing the IL8RA/B or CCR2/5 homing device targeted the injured arteries and decreased injury-induced inflammatory cytokine expression, neutrophil/macrophage infiltration, and neointima formation. Transfused RiPS-ECs overexpressing IL8RA/B and/or CCR2/5 prevented inflammatory responses and neointima formation after vascular injury. Targeted delivery of iPS-ECs with a homing device to inflammatory mediators in injured arteries provides a novel strategy for the treatment of cardiovascular diseases. Stem Cells Translational Medicine 2017;6:1168-1177.


Assuntos
Células Endoteliais/citologia , Células Endoteliais/metabolismo , Células-Tronco Pluripotentes Induzidas/citologia , Receptores CCR2/metabolismo , Receptores CCR5/metabolismo , Receptores de Interleucina-8/metabolismo , Lesões do Sistema Vascular/metabolismo , Lesões do Sistema Vascular/terapia , Animais , Terapia Baseada em Transplante de Células e Tecidos , Células-Tronco Pluripotentes Induzidas/metabolismo , Inflamação/metabolismo , Macrófagos/metabolismo , Masculino , Neutrófilos/metabolismo , Ratos , Ratos Sprague-Dawley
18.
Nutrients ; 9(9)2017 Aug 28.
Artigo em Inglês | MEDLINE | ID: mdl-28846663

RESUMO

Luobuma (Apocynum venetum L. (AVL)) is a popular beverage in Asia and has been reportedly to be associated with the bioactivities such as cardiotonic, diuretic, antioxidative, and antihypertensive. However, its biofunction as chemoprevention activity is seldom addressed. Herein, we aimed to characterize the anti-androgen-insensitive-prostate-cancer (anti-AIPC) bioactive compounds of Luobuma, and to investigate the associated molecular mechanisms. Activity-guided-fractionation (antioxidative activity and cell survivability) of Luobuma ethanolic extracts was performed to isolate and characterize the major bioactive compounds using Ultra Performance Liquid Chromatography (UPLC), Liquid Chromatography-Mass Spectrometry (LC-MS), and Nuclear Magnetic Resonance (NMR). Plant sterols (lupeol, stigamasterol and ß-sitosterol) and polyphenolics (isorhamnetin, kaempferol, and quercetin) were identified. Lupeol, a triterpene found in the fraction (F8) eluted by 10% ethyl acetate/90% hexane and accounted for 19.3% (w/w) of F8, inhibited the proliferation of PC3 cells. Both lupeol and F8 induced G2/M arrest, inhibition of ß-catenin signaling, regulation of apoptotic signal molecules (cytochrome c, Bcl-2, P53, and caspase 3 and 8), and suppression DNA repair enzyme expression (Uracil-DNA glycosylase (UNG)). To our knowledge, our study is the first report that lupeol inhibited the expression of UNG to elicit the cytotoxicity against androgen-insensitive-prostate-cancer cells. Collectively, Luobuma, which contains several antitumor bioactive compounds, holds the potential to be a dietary chemopreventive agent for prostate cancer.


Assuntos
Anticarcinógenos/metabolismo , Apocynum/química , Extratos Vegetais/metabolismo , Folhas de Planta/química , Neoplasias de Próstata Resistentes à Castração/prevenção & controle , Anticarcinógenos/química , Antineoplásicos Fitogênicos/análise , Antineoplásicos Fitogênicos/química , Antineoplásicos Fitogênicos/isolamento & purificação , Antineoplásicos Fitogênicos/metabolismo , Proteínas Reguladoras de Apoptose/metabolismo , Linhagem Celular Tumoral , Proliferação de Células , Sobrevivência Celular , Suplementos Nutricionais , Etnofarmacologia , Fase G2 , Humanos , Masculino , Estrutura Molecular , Proteínas de Neoplasias/metabolismo , Triterpenos Pentacíclicos/análise , Triterpenos Pentacíclicos/química , Triterpenos Pentacíclicos/isolamento & purificação , Triterpenos Pentacíclicos/farmacologia , Extratos Vegetais/análise , Neoplasias de Próstata Resistentes à Castração/metabolismo , Neoplasias de Próstata Resistentes à Castração/patologia , Taiwan , Uracila-DNA Glicosidase/antagonistas & inibidores , Uracila-DNA Glicosidase/metabolismo , Via de Sinalização Wnt , beta Catenina/antagonistas & inibidores , beta Catenina/metabolismo
19.
Front Oncol ; 6: 166, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27458571

RESUMO

Insights from the study of cancer resistance in animals have led to the discovery of novel anticancer pathways and opened new venues for cancer prevention and treatment. Sickle cells (SSRBCs) from subjects with homozygous sickle cell anemia (SCA) have been shown to target hypoxic tumor niches, induce diffuse vaso-occlusion, and potentiate a tumoricidal response in a heme- and oxidant-dependent manner. These findings spawned the hypothesis that SSRBCs and the vasculopathic microenvironment of subjects with SCA might be inimical to tumor outgrowth and thereby constitute a natural antitumor defense. We therefore implanted the B16F10 melanoma into humanized hemoglobin SS knockin mice which exhibit the hematologic and vasculopathic sequelae of human SCA. Over the 31-day observation period, hemoglobin SS mice showed no significant melanoma outgrowth. By contrast, 68-100% of melanomas implanted in background and hemoglobin AA knockin control mice reached the tumor growth end point (p < 0.0001). SS knockin mice also exhibited established markers of underlying vasculopathy, e.g., chronic hemolysis (anemia, reticulocytosis) and vascular inflammation (leukocytosis) that differed significantly from all control groups. Genetic differences or normal AA gene knockin do not explain the impaired tumor outgrowth in SS knockin mice. These data point instead to the chronic pro-oxidative vasculopathic network in these mice as the predominant cause. In related studies, we demonstrate the ability of the sickle cell component of this system to function as a therapeutic vehicle in potentiating the oncolytic/vasculopathic effect of RNA reovirus. Sickle cells were shown to efficiently adsorb and transfer the virus to melanoma cells where it induced apoptosis even in the presence of anti-reovirus neutralizing antibodies. In vivo, SSRBCs along with their viral cargo rapidly targeted the tumor and initiated a tumoricidal response exceeding that of free virus and similarly loaded normal RBCs without toxicity. Collectively, these data unveil two hitherto unrecognized findings: hemoglobin SS knockin mice appear to present a natural barrier to melanoma tumorigenesis while SSRBCs demonstrate therapeutic function as a vehicle for enhancing the oncolytic effect of free reovirus against established melanoma.

20.
Sci Rep ; 6: 30422, 2016 07 27.
Artigo em Inglês | MEDLINE | ID: mdl-27460639

RESUMO

CRISPR/Cas enhanced correction of the sickle cell disease (SCD) genetic defect in patient-specific induced Pluripotent Stem Cells (iPSCs) provides a potential gene therapy for this debilitating disease. An advantage of this approach is that corrected iPSCs that are free of off-target modifications can be identified before differentiating the cells into hematopoietic progenitors for transplantation. In order for this approach to be practical, iPSC generation must be rapid and efficient. Therefore, we developed a novel helper-dependent adenovirus/Epstein-Barr virus (HDAd/EBV) hybrid reprogramming vector, rCLAE-R6, that delivers six reprogramming factors episomally. HDAd/EBV transduction of keratinocytes from SCD patients resulted in footprint-free iPSCs with high efficiency. Subsequently, the sickle mutation was corrected by delivering CRISPR/Cas9 with adenovirus followed by nucleoporation with a 70 nt single-stranded oligodeoxynucleotide (ssODN) correction template. Correction efficiencies of up to 67.9% (ß(A)/[ß(S)+ß(A)]) were obtained. Whole-genome sequencing (WGS) of corrected iPSC lines demonstrated no CRISPR/Cas modifications in 1467 potential off-target sites and no modifications in tumor suppressor genes or other genes associated with pathologies. These results demonstrate that adenoviral delivery of reprogramming factors and CRISPR/Cas provides a rapid and efficient method of deriving gene-corrected, patient-specific iPSCs for therapeutic applications.


Assuntos
Adenoviridae/metabolismo , Anemia Falciforme/genética , Anemia Falciforme/terapia , Sistemas CRISPR-Cas/genética , Terapia Genética , Vetores Genéticos/metabolismo , Vírus Auxiliares/metabolismo , Sequência de Bases , Linhagem Celular , Herpesvirus Humano 4 , Homozigoto , Humanos , Células-Tronco Pluripotentes Induzidas/metabolismo
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