Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 61
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Int J Nanomedicine ; 18: 4253-4274, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37534057

RESUMO

Background: Cancer multidrug resistance (MDR) is an important factor that severely affects the chemotherapeutic efficacy. Among various methods to bypass MDR, usage of cytokines, such as tumor necrosis factor alpha (TNFα) is attractive, which exerts antitumor effects of immunotherapeutic response and apoptotic/proinflammatory pathways. Nevertheless, the challenges remain how to implement targeted delivery of TNFα to reduce toxicity and manifest the involved signaling mechanism that subdues MDR. Methods: We synthesized a multifunctional nanosytem, in which TNFα covalently bound to doxorubicin (Dox)-loaded pH-responsive mesoporous silica nanoparticles (MSN) through bi-functional polyethylene glycol (TNFα-PEG-MSN-Hydrazone-Dox) as a robust design to overcome MDR. Results: The salient features of this nanoplatform are: 1) by judicious tailoring of TNFα concentration conjugated on MSN, we observed it could lead to a contrary effect of either proliferation or suppression of tumor growth; 2) the MSN-TNFα at higher concentration serves multiple functions, besides tumor targeting and inducer of apoptosis through extrinsic pathway, it inhibits the expression level of p-glycoprotein (P-gp), a cell membrane protein that functions as a drug efflux pump; 3) the enormous surface area of MSN provides for TNFα functionalization, and the nanochannels accommodate chemotherapeutics, Dox; 4) targeted intracellular release of Dox through the pH-dependent cleavage of hydrazone bonds induces apoptosis by the specific intrinsic pathway; and 5) TNFα-PEG-MSN-Hydrazone-Dox (MSN-Dox-TNFα) could infiltrate deep into the 3D spheroid tumor model through disintegration of tight junction proteins. When administered intratumorally in a Dox-resistant mouse tumor model, MSN-Dox-TNFα exhibited a synergistic therapeutic effect through the collective performances of TNFα and Dox. Conclusion: We hereby develop and demonstrate a multifunctional MSN-Dox-TNFα system with concentration-tailored TNFα that can abrogate the drug resistance mechanism, and significantly inhibit the tumor growth through both intrinsic and extrinsic apoptosis pathways, thus making it a highly potential nanomedicine translated in the treatment of MDR tumors.


Assuntos
Nanopartículas , Neoplasias , Camundongos , Animais , Citocinas , Fator de Necrose Tumoral alfa , Neoplasias/tratamento farmacológico , Neoplasias/patologia , Doxorrubicina , Apoptose , Resistência a Múltiplos Medicamentos , Nanopartículas/química , Proliferação de Células , Hidrazonas/farmacologia , Hidrazonas/uso terapêutico , Dióxido de Silício/química , Resistencia a Medicamentos Antineoplásicos , Porosidade
2.
Pharmacol Res ; 161: 105183, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-32896579

RESUMO

Non-small-cell lung cancer (NSCLC) is a leading cause of cancer-related death worldwide. NSCLC patients with overexpressed or mutated epidermal growth factor receptor (EGFR) related to disease progression are treated with EGFR-tyrosine kinase inhibitors (EGFR-TKIs). Acquired drug resistance after TKI treatments has been a major focus for development of NSCLC therapies. This study aimed to establish afatinib-resistant cell lines from which afatinib resistance-associated genes are identified and the underlying mechanisms of multiple-TKI resistance in NSCLC can be further investigated. Nude mice bearing subcutaneous NSCLC HCC827 tumors were administered with afatinib at different dose intensities (5-100 mg/kg). We established three HCC827 sublines resistant to afatinib (IC50 > 1 µM) with cross-resistance to gefitinib (IC50 > 5 µM). cDNA microarray revealed several of these sublines shared 27 up- and 13 down-regulated genes. The mRNA expression of selective novel genes - such as transmembrane 4 L six family member 19 (TM4SF19), suppressor of cytokine signaling 2 (SOCS2), and quinolinate phosphoribosyltransferase (QPRT) - are responsive to afatinib treatments only at high concentrations. Furthermore, c-MET amplification and activations of a subset of tyrosine kinase receptors were observed in all three resistant cells. PHA665752, a c-MET inhibitor, remarkably increased the sensitivity of these resistant cells to afatinib (IC50 = 12-123 nM). We established afatinib-resistant lung cancer cell lines and here report genes associated with afatinib resistance in human NSCLC. These cell lines and the identified genes serve as useful investigational tools, prognostic biomarkers of TKI therapies, and promising molecule targets for development of human NSCLC therapeutics.


Assuntos
Afatinib/farmacologia , Antineoplásicos/farmacologia , Biomarcadores Tumorais/genética , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Resistencia a Medicamentos Antineoplásicos/genética , Neoplasias Pulmonares/tratamento farmacológico , Inibidores de Proteínas Quinases/farmacologia , Animais , Biomarcadores Tumorais/metabolismo , Carcinoma Pulmonar de Células não Pequenas/genética , Carcinoma Pulmonar de Células não Pequenas/metabolismo , Carcinoma Pulmonar de Células não Pequenas/patologia , Linhagem Celular Tumoral , Receptores ErbB/antagonistas & inibidores , Receptores ErbB/genética , Receptores ErbB/metabolismo , Perfilação da Expressão Gênica , Regulação Neoplásica da Expressão Gênica , Humanos , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/metabolismo , Neoplasias Pulmonares/patologia , Masculino , Camundongos Nus , Análise de Sequência com Séries de Oligonucleotídeos , Transcriptoma , Ensaios Antitumorais Modelo de Xenoenxerto
3.
Chin Med ; 12: 11, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28450884

RESUMO

BACKGROUND: Herbochip® technology is a high throughput drug screening platform in a reverse screening manner, in which potential chemical leads in herbal extracts are immobilized and drug target proteins can be used as probes for screening process [BMC Complementary and Alternative Medicine (2015) 15:146]. While herbal medicines represent an ideal reservoir for drug screenings, here a molecular chaperone GRP78 is demonstrated to serve as a potential target for antiviral drug discovery. METHODS: We cloned and expressed a truncated but fully functional form of human GRP78 (hGRP781-508) and used it as a probe for anti-HBV drug screening on herbochips. In vitro cytotoxicity and in vitro anti-HBV activity of the herbal extracts were evaluated by MTT and ELISA assays, respectively. Finally, anti-HBV activity was confirmed by in vivo assay using DHBV DNA levels in DHBV-infected ducklings as a model. RESULTS: Primary screenings using GRP78 on 40 herbochips revealed 11 positives. Four of the positives, namely Dioscorea bulbifera, Lasiosphaera fenzlii, Paeonia suffruticosa and Polygonum cuspidatum were subjected to subsequent assays. None of the above extracts was cytotoxic to AML12 cells, but P. cuspidatum extract (PCE) was found to be cytotoxic to HepG2 2.2.15 cells. Both PCE and P. suffruticosa extract (PSE) suppressed secretion of HBsAg and HBeAg in HepG2 2.2.15 cells. The anti-HBV activity of PSE was further confirmed in vivo. CONCLUSION: We have demonstrated that GRP78 is a valid probe for anti-HBV drug screening on herbochips. We have also shown that PSE, while being non-cytotoxic, possesses in vitro and in vivo anti-HBV activities. Taken together, our data suggest that PSE may be a potential anti-HBV agent for therapeutic use.

4.
Eur J Med Chem ; 126: 202-217, 2017 Jan 27.
Artigo em Inglês | MEDLINE | ID: mdl-27776274

RESUMO

µ-Opioid receptor (MOR) agonists are analgesics used clinically for the treatment of moderate to severe pain, but their use is associated with severe adverse effects such as respiratory depression, constipation, tolerance, dependence, and rewarding effects. In this study, we identified N-({2-[(4-bromo-2-trifluoromethoxyphenyl)sulfonyl]-1,2,3,4-tetrahydro-1-isoquinolinyl}methyl)cyclohexanecarboxamide (1) as a novel opioid receptor agonist by high-throughput screening. Structural modifications made to 1 to improve potency and blood-brain-barrier (BBB) penetration resulted in compounds 45 and 46. Compound 45 was a potent MOR/KOR (κ-opioid receptor) agonist, and compound 46 was a potent MOR and medium KOR agonist. Both 45 and 46 demonstrated a significant anti-nociceptive effect in a tail-flick test performed in wild type (WT) B6 mice. The ED50 value of 46 was 1.059 mg/kg, and the brain concentrations of 45 and 46 were 7424 and 11696 ng/g, respectively. Accordingly, compounds 45 and 46 are proposed for lead optimization and in vivo disease-related pain studies.


Assuntos
Analgésicos/química , Analgésicos/farmacologia , Benzamidas/química , Benzamidas/farmacologia , Receptores Opioides mu/metabolismo , Adenilil Ciclases/metabolismo , Analgésicos/síntese química , Analgésicos/metabolismo , Animais , Benzamidas/síntese química , Benzamidas/metabolismo , Barreira Hematoencefálica/metabolismo , Linhagem Celular , Avaliação Pré-Clínica de Medicamentos , Canais de Potássio Corretores do Fluxo de Internalização Acoplados a Proteínas G/metabolismo , Masculino , Camundongos , Simulação de Dinâmica Molecular , Conformação Proteica , Receptores Opioides mu/química , Relação Estrutura-Atividade
5.
BMC Complement Altern Med ; 15: 146, 2015 May 12.
Artigo em Inglês | MEDLINE | ID: mdl-25963543

RESUMO

BACKGROUND: Geranium wilfordii is one of the major species used as Herba Geranii (lao-guan-cao) in China, it is commonly used solely or in polyherbal formulations for treatment of joint pain resulted from rheumatoid arthritis (RA) and gout. This herb is used to validate a target-based drug screening platform called Herbochip® and evaluate anti-inflammatory effects of Geranium wilfordii ethanolic extract (GWE) using tumor necrosis factor-alpha (TNF-α) as a drug target together with subsequent in vitro and in vivo assays. METHODS: A microarray-based drug screening platform was constructed by arraying HPLC fractions of herbal extracts onto a surface-activated polystyrene slide (Herbochip®). Using TNF-α as a molecular probe, fractions of 82 selected herbal extracts, including GWE, were then screened to identify plant extracts containing TNF-α-binding agents. Cytotoxicity of GWE and modulatory effects of GWE on TNF-α expression were evaluated by cell-based assays using TNF-α sensitive murine fibrosarcoma L929 cells as an in vitro model. RESULTS: The in vivo anti-inflammatory effects of GWE were further assessed by animal models including carrageenan-induced hind paw edema in rats and xylene-induced ear edema in mice, in comparison with aspirin. The hybridization data obtained by Herbochip® analysis showed unambiguous signals which confirmed TNF-α binding activity in 46 herbal extracts including GWE. In L929 cells GWE showed significant inhibitory effect on TNF-α expression with negligible cytotoxicity. GWE also significantly inhibited formation of carrageenan-induced hind paw edema and xylene-induced ear edema in animal models, indicating that it indeed possessed anti-inflammatory activity. CONCLUSION: We have thus validated effectiveness of the Herbochip® drug screening platform using TNF-α as a molecular target. Subsequent experiments on GWE lead us to conclude that the anti-RA activity of GWE can be attributed to inhibitory effect of GWE on the key inflammatory factor, TNF-α. Our results contribute towards validation of the traditional use of GWE in the treatment of RA and other inflammatory joint disorders.


Assuntos
Anti-Inflamatórios/uso terapêutico , Artrite Reumatoide/tratamento farmacológico , Medicamentos de Ervas Chinesas/farmacologia , Geranium/química , Inflamação/tratamento farmacológico , Fitoterapia , Fator de Necrose Tumoral alfa/metabolismo , Animais , Anti-Inflamatórios/análise , Anti-Inflamatórios/farmacologia , Artrite Reumatoide/metabolismo , Carragenina/uso terapêutico , Linhagem Celular , China , Medicamentos de Ervas Chinesas/química , Medicamentos de Ervas Chinesas/uso terapêutico , Edema/tratamento farmacológico , Edema/metabolismo , Inflamação/induzido quimicamente , Inflamação/metabolismo , Masculino , Camundongos Endogâmicos ICR , Análise em Microsséries/métodos , Ratos Sprague-Dawley , Xilenos
6.
Mol Nutr Food Res ; 58(6): 1168-76, 2014 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-24668568

RESUMO

SCOPE: We investigated whether rutin, a flavonoid isolated from Toona sinensis Roem, has the ability to enhance insulin-dependent receptor kinase (IRK) activity and glucose transporter 4 (GLUT4) translocation in differentiated myotubes. We also tested the effects of rutin treatment in insulin-resistant mice using an oral glucose tolerance test (OGTT). METHODS AND RESULTS: Rutin potentiated insulin receptor kinase (IRK) phosphorylation when IRK autophosphorylation was triggered by insulin in differentiated myotubes. Co-treatment of cells with rutin and insulin attenuated S961-mediated inhibition of insulin-dependent GLUT4 translocation. In S961-treated C57BL/6 mice, an in vivo model of insulin resistance and type 2 diabetes, rutin treatment showed a normoglycemic effect in the OGTT. CONCLUSION: This study shows evidence that rutin may serve as a potential agent for glycemic control through enhancement of IRK activity, thereby inducing the insulin signaling pathway causing increased GLUT4 translocation and increased glucose uptake.


Assuntos
Transportador de Glucose Tipo 4/metabolismo , Extratos Vegetais/farmacologia , Receptor de Insulina/metabolismo , Rutina/farmacologia , Animais , Glicemia , Células Cultivadas , Diabetes Mellitus Tipo 2/tratamento farmacológico , Teste de Tolerância a Glucose , Insulina/metabolismo , Resistência à Insulina , Masculino , Meliaceae/química , Camundongos , Camundongos Endogâmicos C57BL , Fibras Musculares Esqueléticas/citologia , Fibras Musculares Esqueléticas/efeitos dos fármacos , Mioblastos Esqueléticos/citologia , Mioblastos Esqueléticos/efeitos dos fármacos , Fosforilação , Transdução de Sinais
7.
Int J Mol Sci ; 14(9): 19169-85, 2013 Sep 18.
Artigo em Inglês | MEDLINE | ID: mdl-24051401

RESUMO

Treatment with geldanamycin (GA) leads to an increase in [Ca2+]c and the production of reactive oxygen species (ROS) in rat brain tumor 9L RBT cells. GA-exerted calcium signaling was blocked by BAPTA/AM and EGTA. The effect of GA on [Ca2+]c was significantly reduced in the presence of thapsigargin (TG) and ruthenium red (RR). GA-induced GRP78 expression is significantly decreased in the presence of BAPTA/AM, EGTA and RR, suggesting that the calcium influx from the extracellular space and intracellular calcium store oscillations are contributed to by the calcium mobilization and GRP78 expression induced by GA. The induced GRP78 expression is sensitive to added U73122 and Ro-31-8425, pinpointing the involvement of phospholipase C (PLC) and protein kinase C (PKC) in GA-induced endoplasmic reticulum (ER) stress. The antioxidants N-acetylcysteine (NAC), BAPTA/AM, EGTA and H7 also have significant inhibitory effects on ROS generation. Finally, neither H7 nor NAC was able to affect the calcium response elicited by GA. Our results suggest that the causal signaling cascade during GA-inducted GRP78 expression occurs via a pathway that connects PLC to cytoplasmic calcium increase, PKC activation and, then, finally, ROS generation. Our data provides new insights into the influence of GA on ER stress response in 9L RBT cells.


Assuntos
Antibióticos Antineoplásicos/toxicidade , Benzoquinonas/toxicidade , Cálcio/metabolismo , Expressão Gênica/efeitos dos fármacos , Proteínas de Choque Térmico/metabolismo , Lactamas Macrocíclicas/toxicidade , Espécies Reativas de Oxigênio/metabolismo , Animais , Neoplasias Encefálicas/metabolismo , Neoplasias Encefálicas/patologia , Linhagem Celular Tumoral , Quelantes/farmacologia , Chaperona BiP do Retículo Endoplasmático , Estresse do Retículo Endoplasmático/efeitos dos fármacos , Estrenos/farmacologia , Proteínas de Choque Térmico/genética , Indóis/farmacologia , Maleimidas/farmacologia , Proteína Quinase C/metabolismo , Pirrolidinonas/farmacologia , Ratos , Fosfolipases Tipo C/antagonistas & inibidores , Fosfolipases Tipo C/metabolismo
8.
Int J Med Mushrooms ; 15(3): 277-86, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23662615

RESUMO

In our previous research, Cordyceps militaris (CM) had a hypoglycemic effect in normal rats. In this study we wanted to elucidate whether CM also had an effect on diabetic rats. Twelve rats with streptozotocin-induced diabetes were separated randomly into 2 groups. First, aqueous extracts of CM 10 mg/kg (CM group) or saline (control group) was fed to the rats; then the plasma glucose levels were assayed. Second, the signaling proteins IRS-1 and GLUT-4 collected from the muscle were detected. Finally, another 2 groups of rats were injected with atropine 0.1 mg/kg intraperitoneally just before the CM/saline feeding, and the assays mentioned above were repeated. Blood glucose decreased 7.2% in the CM group but only 1.5% in the control group (P < 0.05). The IRS-1 signal was 2.9-fold higher than actin in the CM group but only 0.8-fold higher in the control group (P < 0.005). In GLUT-4 signal, the difference was 1.7- vs. 0.6-fold, respectively, compared with actin (P < 0.05). However, atropine injection made CM-induced hypoglycemia or elevation of IRS-1 and GLUT-4 not significant. In conclusion, CM had a hypoglycemic effect in diabetic rats and atropine blocked it. Therefore, the cholinergic activation also was considered to be involved in the hypoglycemic effect of CM in rats with streptozotocin-induced diabetes.


Assuntos
Glicemia/efeitos dos fármacos , Colinérgicos/farmacologia , Fibras Colinérgicas/efeitos dos fármacos , Cordyceps/química , Diabetes Mellitus Experimental/tratamento farmacológico , Hipoglicemiantes/farmacologia , Animais , Atropina/antagonistas & inibidores , Fracionamento Químico , Colinérgicos/química , Hipoglicemiantes/química , Masculino , Distribuição Aleatória , Ratos , Ratos Wistar , Água
9.
Biomaterials ; 34(17): 4223-34, 2013 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-23489927

RESUMO

Interactions between blood vessels and osteoblasts-bone-forming cells-are critical for successful bone development. We therefore investigated the endothelial differentiation capacity of mesenchymal stem cells (MSCs) derived from bone tissue. We found that fetal pre-osteoblast and adult trabecular bone-derived (TB) MSCs express similar surface markers as bone marrow (BM) MSCs and can differentiate into adipocytes, osteoblasts, and chondrocytes. However, when cultured in extracellular matrix (ECM) and endothelial differentiation conditions, bone-derived MSCs (B-MSCs) more readily form tubular structures and uptake acetylated low-density lipoproteins, fulfilling the functional criteria for endothelial cells (ECs). Moreover, addition of B-MSCs but not other cells significantly enhanced vessel formation in the in vivo chick chorioallantoic membrane assay. Mechanistically, this appears to be due to the upregulation of the endothelial transcription factor forkhead box protein C2 (FOXC2) and its downstream gene αvß3 integrin/CD61in B-MSCs but not BMMSCs by laminin, a component protein of the ECM. Our findings not only reveal discrepant differentiation capacity for various tissue-specific MSCs, but also highlight the critical role of the niche-in this case, the ECM and its component proteins-in determining lineage commitment of stem cells.


Assuntos
Diferenciação Celular , Proteínas da Matriz Extracelular/metabolismo , Células Endoteliais da Veia Umbilical Humana/citologia , Células-Tronco Mesenquimais/citologia , Células-Tronco Mesenquimais/metabolismo , Nicho de Células-Tronco , Adulto , Células-Tronco Adultas/citologia , Células-Tronco Adultas/metabolismo , Animais , Biomarcadores/metabolismo , Células da Medula Óssea/citologia , Células da Medula Óssea/metabolismo , Diferenciação Celular/genética , Embrião de Galinha , Matriz Extracelular/metabolismo , Feto/citologia , Fatores de Transcrição Forkhead/metabolismo , Técnicas de Silenciamento de Genes , Células Endoteliais da Veia Umbilical Humana/metabolismo , Humanos , Laminina/metabolismo , Neovascularização Fisiológica/genética , Osteoblastos/citologia , Osteoblastos/metabolismo , Nicho de Células-Tronco/genética , Fatores de Transcrição/metabolismo , Regulação para Cima/genética
10.
Biomed Res Int ; 2013: 170398, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23484086

RESUMO

Human ribonucleases A (hRNaseA) superfamily consists of thirteen members with high-structure similarities but exhibits divergent physiological functions other than RNase activity. Evolution of hRNaseA superfamily has gained novel functions which may be preserved in a unique region or domain to account for additional molecular interactions. hRNase3 has multiple functions including ribonucleolytic, heparan sulfate (HS) binding, cellular binding, endocytic, lipid destabilization, cytotoxic, and antimicrobial activities. In this study, three putative multifunctional regions, (34)RWRCK(38) (HBR1), (75)RSRFR(79) (HBR2), and (101)RPGRR(105) (HBR3), of hRNase3 have been identified employing in silico sequence analysis and validated employing in vitro activity assays. A heparin binding peptide containing HBR1 is characterized to act as a key element associated with HS binding, cellular binding, and lipid binding activities. In this study, we provide novel insights to identify functional regions of hRNase3 that may have implications for all hRNaseA superfamily members.


Assuntos
Proteína Catiônica de Eosinófilo/química , Modelos Químicos , Linhagem Celular , Proteína Catiônica de Eosinófilo/metabolismo , Heparina/química , Heparina/metabolismo , Humanos , Lipídeos/química , Ligação Proteica , Estrutura Terciária de Proteína
11.
Biomaterials ; 34(13): 3223-30, 2013 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-23410680

RESUMO

Current advances in stem cell biology have brought much hope for therapy of neuro-degenerative diseases. However, neural stem cells (NSCs) are rare adult stem cells, and the use of non-NSCs requires efficient and high-yielding lineage-specific differentiation prior to transplantation for efficacy. We report on the efficient differentiation of placental-derived multipotent cells (PDMCs) into a neural phenotype with use of Y-27632, a clinically compliant small molecular inhibitor of Rho kinase (ROCK) which is a major mediator of cytoskeleton dynamics. Y-27632 does not induce differentiation of PDMC toward the mesodermal lineages of adipogenesis and osteogenesis, but rather a neural-like morphology, with rapid development of cell extensions and processes within 24 h. Compared with conventional neurogenic differentiation agents, Y-27632 induces a higher percentage of neural-like cells in PDMCs without arresting proliferation or cell cycle dynamics. Y-27632-treated PDMCs express several neural lineage genes at the RNA and protein level, including nestin, MAP2, and GFAP. The effect of the ROCK inhibitor is cell-specific to PDMCs, and is mainly mediated through the ROCK2 isoform and its downstream target, myosin II. Our data suggest that ROCK inhibition and cytoskeletal rearrangement may allow for induction of a neural phenotype in PDMCs without compromising cell survival.


Assuntos
Amidas/farmacologia , Células-Tronco Multipotentes/citologia , Células-Tronco Multipotentes/enzimologia , Neurônios/citologia , Placenta/citologia , Piridinas/farmacologia , Quinases Associadas a rho/antagonistas & inibidores , Adipogenia/efeitos dos fármacos , Adipogenia/genética , Ciclo Celular/efeitos dos fármacos , Diferenciação Celular/efeitos dos fármacos , Diferenciação Celular/genética , Proliferação de Células/efeitos dos fármacos , Forma Celular/efeitos dos fármacos , Forma Celular/genética , Sobrevivência Celular/efeitos dos fármacos , Sobrevivência Celular/genética , Citoesqueleto/efeitos dos fármacos , Citoesqueleto/metabolismo , Células Epiteliais/citologia , Células Epiteliais/efeitos dos fármacos , Células Epiteliais/metabolismo , Feminino , Regulação da Expressão Gênica/efeitos dos fármacos , Humanos , Proteínas de Filamentos Intermediários/genética , Proteínas de Filamentos Intermediários/metabolismo , Proteínas Associadas aos Microtúbulos/genética , Proteínas Associadas aos Microtúbulos/metabolismo , Células-Tronco Multipotentes/efeitos dos fármacos , Miosina Tipo II/metabolismo , Proteínas do Tecido Nervoso/genética , Proteínas do Tecido Nervoso/metabolismo , Nestina , Neurônios/efeitos dos fármacos , Osteogênese/efeitos dos fármacos , Osteogênese/genética , Fenótipo , Gravidez , Quinases Associadas a rho/metabolismo
12.
FEMS Microbiol Ecol ; 84(3): 577-87, 2013 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-23398522

RESUMO

Phosphate is an essential nutrient for heterotrophic bacteria, affecting bacterioplankton in aquatic ecosystems and bacteria in biofilms. However, the influence of phosphate limitation on bacterial competition and biofilm development in multispecies populations has received limited attention in existing studies. To address this issue, we isolated 13 adhesive bacteria from paper machine aggregates. Intergeneric inhibition of Pseudomonas aeruginosa WW5 by Serratia marcescens WW4 was identified under phosphate-limited conditions, but not in Luria-Bertani medium or M9 minimal medium. The viable numbers of the pure S. marcescens WW4 culture decreased over 3 days in the phosphate-limited medium; however, the mortality of S. marcescens WW4 was significantly reduced when it was co-cultured with P. aeruginosa WW5, which appeared to sustain the S. marcescens WW4 biofilm. In contrast, viable P. aeruginosa WW5 cells immediately declined in the phosphate-limited co-culture. To identify the genetic/inhibitory element(s) involved in this process, we inserted a mini-Tn5 mutant of S. marcescens WW4 that lacked inhibitory effect. The results showed that an endonuclease bacteriocin was involved in this intergeneric inhibition by S. marcescens WW4 under phosphate limitation. In conclusion, this study highlights the importance of nutrient limitation in bacterial interactions and provides a strong candidate gene for future functional characterisation.


Assuntos
Biofilmes/crescimento & desenvolvimento , Interações Microbianas , Fosfatos/farmacologia , Pseudomonas aeruginosa/fisiologia , Serratia marcescens/fisiologia , Antibiose , Aderência Bacteriana , Bacteriocinas/metabolismo , Biofilmes/efeitos dos fármacos , Meios de Cultura , Elementos de DNA Transponíveis , Viabilidade Microbiana , Mutagênese Insercional , Papel , Pseudomonas aeruginosa/efeitos dos fármacos , Pseudomonas aeruginosa/isolamento & purificação , Serratia marcescens/efeitos dos fármacos , Serratia marcescens/genética , Serratia marcescens/isolamento & purificação
13.
J Pineal Res ; 54(1): 107-25, 2013 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-24446866

RESUMO

Mitochondrial dysfunction is a hallmark of amyloid ß-peptide (Aß)-induced neurodegeneration of Alzheimer's disease (AD). This study investigated whether mtDNA T8993G mutation-induced complex V inhibition, clinically associated with neurological muscle weakness, ataxia, and retinitis pigmentosa (NARP), is a potential risk factor for AD and the pathological link for long-term exposure of Aß-induced mitochondrial toxicity and apoptosis in NARP cybrids. Using noninvasive fluorescence probe-coupled laser scanning imaging microscopy and NARP cybrids harboring 98% mutant genes along with its parental 143B osteosarcoma cells, we demonstrated that Aß-augmented mitochondrial Ca(2+) (mCa(2+))-independent mitochondrial reactive oxygen species (mROS) formation for a cardiolipin (CL, a major mitochondrial protective phospholipid)-dependent lethal modulation of the mitochondrial permeability transition (MPT). Aß augmented not only the amount but also the propagation rate of mROS-induced mROS formation to significantly depolarize mitochondrial membrane potential (∆Ψ(m)) and reduce mCa(2+) stress. Aß-augmented mROS oxidized and depleted CL, thereby enhances mitochondrial fission and movement retardation, which promoted the NARP-augmented lethal transient-MPT (t-MPT) to switch to its irreversible mode of permanent-MPT (p-MPT). Interestingly, melatonin, a multiple mitochondrial protector, markedly reduced Aß-augmented mROS formation and therefore significantly reduced mROS-mediated depolarization of ∆Ψ(m), fission of mitochondria and retardation of mitochondrial movement to stabilize CL and hence the MPT. In the presence of melatonin, Aß-promoted p-MPT was reversed to a protective t-MPT, which preserved ∆Ψ(m) and lowered elevated mCa(2+) to sublethal levels for an enhanced mCa(2+)-dependent O(2) consumption. Thus, melatonin may potentially rescue AD patients associated with NARP symptoms.


Assuntos
Peptídeos beta-Amiloides/farmacologia , Cardiolipinas/metabolismo , Melatonina/uso terapêutico , Proteínas de Transporte da Membrana Mitocondrial/efeitos dos fármacos , Cálcio/metabolismo , Humanos , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Mitocôndrias/metabolismo , Miopatias Mitocondriais/tratamento farmacológico , Poro de Transição de Permeabilidade Mitocondrial , Espécies Reativas de Oxigênio/metabolismo , Retinose Pigmentar/tratamento farmacológico
14.
BMC Biotechnol ; 12: 83, 2012 Nov 07.
Artigo em Inglês | MEDLINE | ID: mdl-23134743

RESUMO

BACKGROUND: There are few studies that have examined the potential of RNA inference (RNAi) to increase protein production in the baculovirus expression vector system (BEVS). Spodoptera frugiperda (fall armyworm) (Sf)-caspase-1-repressed stable cells exhibit resistance to apoptosis and enhancement of recombinant protein production. However, the mechanism of recombinant protein augmentation in baculovirus-infected Caspase-repressed insect cells has not been elucidated. RESULTS: In the current study, we utilized RNAi-mediated Sf-caspase-1-repressed stable cells to clarify how the resistance to apoptosis can enhance both intracellular (firefly luciferase) and extracellular (secreted alkaline phosphatase [SEAP]) recombinant protein production in BEVS. Since the expression of molecular chaperones is strongly associated with the maximal production of exogenous proteins in BEVS, the differential expression of molecular chaperones in baculovirus-infected stable cells was also analyzed in this study. CONCLUSION: The data indicated that the retention of expression of molecular chaperones in baculovirus-infected Sf-caspase-1-repressed stable cells give the higher recombinant protein accumulation.


Assuntos
Caspases/metabolismo , Chaperonas Moleculares/metabolismo , Animais , Baculoviridae/genética , Caspases/química , Caspases/genética , Chaperonas Moleculares/genética , Plasmídeos/genética , Plasmídeos/metabolismo , Interferência de RNA , Proteínas Recombinantes/biossíntese , Proteínas Recombinantes/genética , Células Sf9 , Spodoptera , Transfecção
15.
Phytother Res ; 26(8): 1173-7, 2012 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-22821853

RESUMO

Previous studies have shown that Cordyceps militaris (CM) has a hypoglycemic effect, but the actual mechanism remains unclear. This study explored the hypoglycemic mechanism of aqueous extracts of CM in normal Wistar rats. First, the optimal dose of CM for lowering plasma glucose and insulin secretion was tested. Further, atropine and hemicholinium-3 (HC-3) were injected and a western blot was used to investigate insulin signaling. It was found that 10 mg/kg CM extracts had a stronger hypoglycemic effect than a higher dose (100 mg/kg); therefore, a dose of 10 mg/kg was used in subsequent experiments. In normal rats, CM extracts decreased plasma glucose by 21.0% and induced additional insulin secretion by 54.5% after 30 min. When atropine or HC-3 was injected, CM induced a hypoglycemic effect, but the enhancement of insulin secretion was blocked. By western blotting, significant increases in the insulin receptor substrate 1 (IRS-1) and glucose transporter 4 (GLUT-4) were observed after CM feeding. However, the elevation of these signaling proteins was abolished by atropine or HC-3. Taken together, these findings indicate that CM can lower plasma glucose via the stimulation of insulin secretion and cholinergic activation involved in the hypoglycemic mechanism of normal Wistar rats.


Assuntos
Glicemia/efeitos dos fármacos , Colinérgicos/farmacologia , Cordyceps/química , Hipoglicemiantes/farmacologia , Insulina/metabolismo , Animais , Atropina/administração & dosagem , Atropina/farmacologia , Glicemia/metabolismo , Western Blotting , Fibras Colinérgicas/efeitos dos fármacos , Fibras Colinérgicas/metabolismo , Modelos Animais de Doenças , Transportador de Glucose Tipo 4/metabolismo , Hemicolínio 3/administração & dosagem , Hemicolínio 3/farmacologia , Proteínas Substratos do Receptor de Insulina/metabolismo , Secreção de Insulina , Masculino , Ratos , Ratos Wistar
16.
Int J Oncol ; 41(3): 1068-84, 2012 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-22664961

RESUMO

Gastric cancer is one of the leading causes of cancer mortality and its malignancy, resulting from disseminated cancer cells of diffuse type, is clinically manifested as metastases to the liver and peritoneum. The aim of the present study was to identify putative tumor metastasis-associated genes in human gastric cancer cells of diffuse type. An MKN45 cell line constitutively expressing green fluorescent protein (MKN45-GFP) was established and selected using the Transwell® system for invasive sublines MKN45-GFP-4, MKN45-GFP-10 and MKN45-GFP-12. MKN45-GFP-10 and MKN45-GFP-12 are highly invasive compared to the others. The mRNA levels were measured with cDNA microarrays and correlated with their invasion abilities in these sublines. Many of the genes identified with a positive or negative correlation are associated with angiogenesis, cell cycle, cytoskeleton and cell motility, protease and cell adhesion, as well as cellular signal transduction. In particular, novel genes without known functions were also noted. RT-PCR and western blot analyses were applied to verify the expression of selective genes. Following orthotopical intraperitoneal implantation, MKN45-GFP-12 demonstrated significantly higher in vivo tumor malignancies than parental MKN45-GFP in ascites induction and liver -invasion in mice. We have identified putative gastric tumor metastasis-associated, as well as novel genes. These genes and their protein products are to be further explored for their functional roles associated with tumor metastasis. The molecular profiles of these identified genes, gene transcripts and proteins in the patient specimens are likely to be useful biomarkers for diagnostic, therapeutic and/or prognostics. Most importantly, they may be used as molecular targets for the discovery of antitumor drugs against human gastric cancer metastasis.


Assuntos
Regulação Neoplásica da Expressão Gênica , Metástase Neoplásica/genética , Neoplasias Gástricas/genética , Animais , Adesão Celular/genética , Ciclo Celular/genética , Linhagem Celular Tumoral , Movimento Celular/genética , Proliferação de Células , Citoesqueleto/genética , Perfilação da Expressão Gênica , Proteínas de Fluorescência Verde/biossíntese , Proteínas de Fluorescência Verde/genética , Humanos , Neoplasias Hepáticas/secundário , Masculino , Camundongos , Camundongos Nus , Neovascularização Patológica/genética , Neoplasias Peritoneais/secundário , Transdução de Sinais/genética
17.
World J Gastroenterol ; 18(17): 2035-42, 2012 May 07.
Artigo em Inglês | MEDLINE | ID: mdl-22563190

RESUMO

AIM: To investigate the role of transforming growth factor (TGF)-ß-inducible early gene 1 (TIEG1) in TGF-ß-induced growth inhibition in hepatocellular carcinoma (HCC) cells. METHODS: Human hepatocyte and HCC cell lines with varied susceptibilities to TGF-ß1 were tested by methylthiazoletetrazolium (MTT) assay. The expression changes of Smad2, Smad3, Smad4, Smad7, TIEG1 and TIEG2 gene following treatment with TGF-ß1 in a TGF-ß-sensitive hepatocyte cell line (MIHA), a TGF-ß-sensitive hepatoma cell line (Hep3B) and two TGF-ß-insensitive hepatoma cell lines (HepG2 and Bel7404) were examined. SiRNA targeting TIEG1 was transfected into Hep3B cells and the sensitivity of cells to TGF-ß1 was examined. Overexpression of TIEG1 was induced by lentiviral-mediated transduction in TGF-ß1-resistant hepatoma cell lines (Bel7404 and HepG2). MTT assay and 4',6-Diamidino-2-phenylindole staining were used to identify cell viability and apoptosis, respectively. The expression level of stathmin was measured by reverse transcriptase polymerase chain reaction and Western-blotting analysis, and stathmin promoter activity by TIEG1 was monitored by a luciferase reporter gene system. RESULTS: TIEG1 was significantly upregulated by TGF-ß1 in the TGF-ß1-sensitive HCC cell line, Hep3B, but not in the resistant cell lines. The suppression of TIEG1 by siRNAs decreased the sensitivity of Hep3B cells to TGF-ß1, whereas the overexpression of TIEG1 mediated growth inhibition and apoptosis in TGF-ß1-resistant HCC cell lines, which resembled those of TGF-ß1-sensitive HCC cells treated with TGF-ß1. Our data further suggested that stathmin was a direct target of TIEG1, as stathmin was significantly downregulated by TIEG1 overexpression, and stathmin promoter activity was inhibited by TIEG1 in a dose-dependent manner. CONCLUSION: Our data suggest that transactivation of TIEG1 conferred growth inhibition of TGF-ß-susceptible human HCC cells.


Assuntos
Carcinoma Hepatocelular/tratamento farmacológico , Fatores de Transcrição de Resposta de Crescimento Precoce/fisiologia , Fatores de Transcrição Kruppel-Like/fisiologia , Neoplasias Hepáticas/tratamento farmacológico , Ativação Transcricional , Fator de Crescimento Transformador beta1/farmacologia , Apoptose/efeitos dos fármacos , Carcinoma Hepatocelular/patologia , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Hepatócitos/efeitos dos fármacos , Humanos , Neoplasias Hepáticas/patologia , Regiões Promotoras Genéticas , Proteínas Smad/metabolismo , Estatmina/genética
18.
Clin Chim Acta ; 413(13-14): 1039-44, 2012 Jul 11.
Artigo em Inglês | MEDLINE | ID: mdl-22266375

RESUMO

BACKGROUND: The novel technique of blood volume detection can improve the reliability and accuracy of a self-monitoring blood glucose system. Self-management of diabetes can be improved, and the glycemic range can be efficiently controlled. METHODS: A total of 153 patients with diabetes mellitus participated in the clinical study. The accuracy, blood volume detection, interference, and altitude effect of the EGV1 self-monitoring blood glucose system were evaluated and compared among the fingerstick, alternative site testing, and venous blood. RESULTS: The EGV1 self-monitoring blood glucose system with fingertip demonstrated an excellent correlation with venous blood (linear regression analysis: slope=1.01, intercept=-0.8972 mg/dl, r(2)=0.96), and with other brands of glucose systems (linear regression analysis: slope=0.99, intercept=+3.5632 mg/dl, r(2)=0.94). The Clarke error grid analysis indicated that the results of fingertip and alternative sites were in the acceptable zones, A and B. The system required 0.6 ul of a blood sample to obtain an accurate reading, and was unaffected by several interferents and altitude. CONCLUSIONS: The EGV1 self-monitoring blood glucose system using various blood samples demonstrated acceptable accuracy and reliability compared to the laboratory reference and other self-monitoring blood glucose systems.


Assuntos
Automonitorização da Glicemia/métodos , Glicemia/análise , Diabetes Mellitus/sangue , Diabetes Mellitus/diagnóstico , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Modelos Lineares , Masculino , Pessoa de Meia-Idade , Reprodutibilidade dos Testes , Adulto Jovem
19.
Phytother Res ; 26(4): 528-34, 2012 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-21915931

RESUMO

7,7''-Dimethoxyagastisflavone (DMGF), a biflavonoid isolated from the needles of Taxus × media cv. Hicksii, was evaluated for its antiproliferative and antineoplastic effects in three human cancer cell lines. Interestingly, DMGF caused cell death via different pathways in different cancer cells. DMGF induced apoptosis, activated caspase-3 activity and changed the mitochondrial membrane potential in HT-29 human colon cancer cells. However, the apoptotic pathway is not the major pathway involved in DMGF-induced cell death in A549 human lung cancer cells and HepG2 human hepatoma cells. Treatment with 3-MA, an inhibitor of autophagy, significantly decreased DMGF-induced cell death in HepG2 and A549 cells, but did not affect DMGF-induced cell death in HT-29 cells. Following DMGF treatment, the HepG2 cells increased expression of LC3B-II, a marker used to monitor autophagy in cells. Thus, DMGF induced apoptotic cell death in HT-29 cells, triggered both apoptotic and autophagic death in A549 cells and induced autophagic cell death in HepG2 cells.


Assuntos
Antineoplásicos Fitogênicos/farmacologia , Apoptose , Autofagia , Biflavonoides/farmacologia , Alcaloides/isolamento & purificação , Antineoplásicos Fitogênicos/isolamento & purificação , Biflavonoides/isolamento & purificação , Biomarcadores Tumorais/metabolismo , Caspase 3/metabolismo , Sobrevivência Celular , Cromatografia Líquida de Alta Pressão , Ativação Enzimática , Células HT29 , Células Hep G2 , Humanos , Concentração Inibidora 50 , Potencial da Membrana Mitocondrial , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/metabolismo , Taxoides/isolamento & purificação , Taxus/química
20.
J Pineal Res ; 52(1): 93-106, 2012 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-21812817

RESUMO

Mitochondrial dynamics including morphological fission and mitochondrial movement are essential to normal mitochondrial and cellular physiology. This study investigated how mtDNA T8993G (NARP)-induced inhibition of mitochondrial complex V altered mitochondrial dynamics in association with a protective mitochondrial phospholipid, cardiolipin (CL), as a potential therapeutic target. NARP cybrids harboring 98% of mtDNA T8993G genes and its parental osteosarcoma 143B cells were studied for comparison, and protection provided by melatonin, a potent mitochondrial protector, was explored. We demonstrate for the first time that NARP mutation significantly enhances apoptotic death as a result of three distinct lethal mitochondrial apoptotic insults including oxidative, Ca(2+), and lipid stress. In addition, NARP significantly augmented pathological depletion of CL. NARP-augmented depletion of CL results in enhanced retardation of mitochondrial movement and fission and later swelling of mitochondria during all insults. These results suggest that CL is a common and crucial pathological target for mitochondrial apoptotic insults. Furthermore, CL possibly plays a central role in regulating mitochondrial dynamics that are associated with NARP-augmented mitochondrial pathologies. Intriguingly, melatonin, by differentially preserving CL during various stresses (oxidation > Ca(2+) > lipid), rescues differentially CL-altered mitochondrial dynamics and cell death (oxidation > Ca(2+) > lipid). Thus, melatonin, in addition to being a mitochondrial antioxidant to antagonize mitochondrial oxidative stress, a mitochondrial permeability transition modulator to antagonize mitochondrial Ca(2+) stress, may stabilize directly CL to prevent its oxidization and/or depletion and, therefore, exerts great potential in rescuing CL-dependent mitochondrial dynamics-associated mitochondrial pathologies for treatment of NARP-induced pathologies and diseases.


Assuntos
Proteína C-Reativa/genética , Cardiolipinas/metabolismo , DNA Mitocondrial/genética , Melatonina/metabolismo , Mitocôndrias/metabolismo , Mutação , Proteínas do Tecido Nervoso/genética , Análise de Variância , Ácido Araquidônico/farmacologia , Proteína C-Reativa/metabolismo , Linhagem Celular Tumoral , Movimento Celular/fisiologia , Sobrevivência Celular , Células Cultivadas , Engenharia Genética , Técnicas Genéticas , Humanos , Proteínas do Tecido Nervoso/metabolismo , Estresse Oxidativo/fisiologia , Espécies Reativas de Oxigênio/metabolismo
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...