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1.
Chin J Physiol ; 64(4): 202-209, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34472451

RESUMO

Gamma-linolenic acid (GLA), a natural fatty acid obtained from oils of various vegetables and seeds, has been demonstrated as an anticancer agent. In this work, we investigated the anticancer effects of GLA on breast cancer BT-474 cells. GLA at 30 µM, a concentration reportedly within the range of circulating concentrations in clinical studies, caused apoptotic cell death. GLA caused an elevation in mitochondrial Ca2+ level and a decrease in mitochondrial membrane potential. GLA treatment depleted cyclopiazonic acid (CPA)-sensitive Ca2+ store and triggered substantial Ca2+ influx. Intracellular Ca2+ release triggered by GLA was suppressed by 3 µM xestospongin C (XeC, IP3 receptor-channel blocker) and 100 µM ryanodine (ryanodine receptor-channel blocker), suggesting that the Ca2+ release was via IP3 receptor-channel and ryanodine receptor-channel. Increased expressions of p-eIF2α and CHOP were observed in GLA-treated cells, suggesting GLA-treated cells had increased expressions of p-eIF2α and CHOP, which suggest endoplasmic reticulum (ER) stress. In addition, GLA elicited increased production of reactive oxygen species. Taken together, our results suggest a basal level of GLA induced apoptotic cell death by causing Ca2+ overload, mitochondrial dysfunction, Ca2+ store depletion, ER stress, and oxidative stress. This is the first report to show that GLA caused Ca2+ store depletion and ER stress. GLA-induced Ca2+ store depletion resulted from opening of IP3 receptor-channel and ryanodine receptor-channel.


Assuntos
Neoplasias da Mama , Ácido gama-Linolênico , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/metabolismo , Cálcio/metabolismo , Retículo Endoplasmático/metabolismo , Feminino , Humanos , Estresse Oxidativo , Ácido gama-Linolênico/metabolismo
2.
ACS Appl Mater Interfaces ; 12(51): 56741-56752, 2020 Dec 23.
Artigo em Inglês | MEDLINE | ID: mdl-33305564

RESUMO

Reversing the immunosuppressive tumor microenvironment (TME) is a strategic initiative to sensitize cancer immunotherapy. Emerging evidence shows that cyclic diguanylate monophosphate (c-di-GMP or cdG) can induce the stimulator of interferon genes (STING) pathway activation of antigen-presenting cells (APCs) and upregulate expression of type I interferons (IFNs) to enhance tumor immunogenicity. In vitro anionic cdG revealed fast plasma clearance, poor membrane permeability, and inadequate cytosolic bioavailability. Therefore, we explored a comprehensive "in situ vaccination" strategy on the basis of nanomedicine to trigger robust antitumor immunity. Rhodamine B isothiocyanate (RITC) fluorescent mesoporous silica nanoparticles (MSN) synthesized and modified with poly(ethylene glycol) (PEG) and an ammonium-based cationic molecule (TA) were loaded with negatively charged cdG via electrostatic interactions to form cdG@RMSN-PEG-TA. Treatment of RAW 264.7 cells with cdG@RMSN-PEG-TA markedly stimulated the secretion of IL-6, IL-1ß, and IFN-ß along with phospho-STING (Ser365) protein expression. In vivo cdG@RMSN-PEG-TA enhanced infiltration of leukocytes, including CD11c+ dendritic cells, F4/80+ macrophages, CD4+ T cells, and CD8+ T cells within the tumor microenvironment (TME), resulting in dramatic tumor growth inhibition in 4T1 breast tumor-bearing Balb/c mice. Our findings suggest that a nanobased platform can overcome the obstacles bare cdG can face in the TME. Our approach of an in situ vaccination using a STING agonist provides an attractive immunotherapy-based strategy for treating breast cancer.


Assuntos
Neoplasias da Mama/terapia , GMP Cíclico/análogos & derivados , Ativação Linfocitária/efeitos dos fármacos , Proteínas de Membrana/agonistas , Nanopartículas/química , Dióxido de Silício/química , Animais , Células Apresentadoras de Antígenos/imunologia , Linfócitos T CD8-Positivos/imunologia , Linhagem Celular Tumoral , GMP Cíclico/farmacologia , Feminino , Corantes Fluorescentes/química , Imunoterapia/métodos , Camundongos , Camundongos Endogâmicos BALB C , Porosidade , Células RAW 264.7 , Rodaminas/química , Transdução de Sinais/efeitos dos fármacos , Microambiente Tumoral/imunologia
3.
Nat Methods ; 16(11): 1119-1122, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-31659327

RESUMO

Two-photon microscopy is a mainstay technique for imaging in scattering media and normally provides frame-acquisition rates of ~10-30 Hz. To track high-speed phenomena, we created a two-photon microscope with 400 illumination beams that collectively sample 95,000-211,000 µm2 areas at rates up to 1 kHz. Using this microscope, we visualized microcirculatory flow, fast venous constrictions and neuronal Ca2+ spiking with millisecond-scale timing resolution in the brains of awake mice.


Assuntos
Encéfalo/irrigação sanguínea , Microscopia de Fluorescência por Excitação Multifotônica/métodos , Animais , Cálcio/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Microcirculação , Vigília
4.
Antioxidants (Basel) ; 9(1)2019 Dec 26.
Artigo em Inglês | MEDLINE | ID: mdl-31888113

RESUMO

Mulberry (Morus alba L.) leaves are used in Chinese medicine to treat metabolic disorders. Mulberry leaf polyphenol extracts (MLPE) have recently been shown to exhibit anticancer properties. Endoplasmic reticulum (ER) stress represents a pivotal obstacle in solid tumors, resulting in the antiapoptosis of tumor cells and drug resistance. In this study, pretreatment with the ER stress inducer tunicamycin (TM) attenuated the percentage of apoptosis induced by doxorubicin (DOX). Cotreatment with tunicamycin and MLPE reversed apoptosis induced by DOX. Simultaneously, induction of ER stress with tunicamycin resulted in an increased expression of Cyclooxygenase 2 (COX-2) and Glucose-regulated protein (GRP78) concomitant with the activation of p38 MAPK/PI3K/Akt in HepG2 cells. Furthermore, the suppression of ER stress with celecoxib or p38 MAPK inhibitor successfully recovered DOX-induced apoptosis. Consistent with the inhibition of COX-2 or p38 MAPK, copretreatment with TM and MLPE drastically recovered cytotoxicity and caspase-3 activation in the presence of DOX. These results reveal that MLPE reduces ER stress-induced resistance to DOX in hepatocellular carcinoma (HCC) cells through downregulation of COX-2- or p38 MAPK-mediated PI3K/Akt pathway.

5.
Biomed Pharmacother ; 107: 889-900, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-30257401

RESUMO

Staphylococcus aureus (S. aureus) can lead to many life-threatening diseases. It has the ability to invade normal endovascular tissue. The molecular mechanisms and pathological changes of endothelial cells after S. aureus infection are of interest, but the basic understanding of how S. aureus destroys this barrier is not clear. Here, we showed that S. aureus enhanced COX-2 expression and prostaglandin E2 (PGE2) secretion in human aortic endothelial cells (HAECs). In addition, S. aureus induced PGE2/interleukin-6 (IL-6)/matrix metallopeptidase-9 (MMP-9)-dependent cell migration. S. aureus-induced COX-2, IL-6, and MMP-9 levels were inhibited by transfection with siRNA of Toll-like receptor 2 (TLR2), p38, p42, p44, p50, or p65. S. aureus also induced p38 MAPK, ATF2, ERK1/2, and NF-κB p65 activation. Interestingly, we proved that S. aureus decreased intracellular generation of reactive oxygen species (ROS), which suggests that the inhibition of ROS production promoted inflammatory responses. Finally, we showed that S. aureus enhanced a variety of biomarkers of inflammation in cardiovascular diseases. However, the free radical scavenger (MCI-186) or antioxidant (N-acetyl-L-cysteine, NAC) markedly enhanced S. aureus-induced COX-2 mRNA levels in the aorta tissues. Taken together, these findings established that S. aureus promoted aorta inflammation via activation of p38 MAPK, ERK1/2, and NF-κB and inhibition of ROS generation.


Assuntos
Aorta/patologia , Inflamação/patologia , Infecções Estafilocócicas/fisiopatologia , Staphylococcus aureus/isolamento & purificação , Animais , Antioxidantes/farmacologia , Aorta/microbiologia , Doenças Cardiovasculares/microbiologia , Doenças Cardiovasculares/fisiopatologia , Ciclo-Oxigenase 2/metabolismo , Dinoprostona/metabolismo , Sequestradores de Radicais Livres/farmacologia , Humanos , Inflamação/microbiologia , Interleucina-6/metabolismo , Masculino , Metaloproteinase 9 da Matriz/metabolismo , Proteína Quinase 1 Ativada por Mitógeno/metabolismo , Proteína Quinase 3 Ativada por Mitógeno/metabolismo , NF-kappa B/metabolismo , Ratos , Ratos Sprague-Dawley , Espécies Reativas de Oxigênio/metabolismo , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismo
6.
Immunol Lett ; 203: 40-49, 2018 11.
Artigo em Inglês | MEDLINE | ID: mdl-30236480

RESUMO

Staphylococcus aureus (S. aureus) can often lead to many life-threatening diseases. It has the ability to invade normal endovascular tissue. Acute inflammation and its resolution are important to ensure bacterial clearance and limit tissue injury. Carbon monoxide (CO) has been shown to exert anti-inflammatory effects in various tissues and organ systems. In our study, we investigated the effects and the mechanisms of carbon monoxide releasing molecule-2 (CORM-2) on S. aureus-induced inflammatory responses in human aortic endothelial cells (HAECs). We proved that S. aureus induced cyclooxygenase-2 (COX-2)/prostaglandin E2 (PGE2)/interleukin-6 (IL-6)/matrix metallopeptidase-9 (MMP-9) expression and cell migration, which were decreased by CORM-2. Moreover, CORM-2 had no effects on TLR2 mRNA levels in response to S. aureus. Interestingly, we proved that S. aureus decreased intracellular ROS generation, suggesting that the inhibition of ROS further promoted inflammatory responses. However, CORM-2 significantly inhibited S. aureus-induced inflammation by increasing intracellular ROS generation. S. aureus-induced NF-κB activation was also inhibited by CORM-2. Finally, we proved that S. aureus induced levels of the biomarkers of inflammation in cardiovascular diseases, which were inhibited by CORM-2. Taken together, these results suggest that CORM-2 inhibits S. aureus-induced COX-2/PGE2/IL-6/MMP-9 expression and aorta inflammatory responses by increasing the ROS generation and reducing the inflammatory molecules levels.


Assuntos
Aorta/imunologia , Monóxido de Carbono/farmacologia , Movimento Celular/efeitos dos fármacos , Ciclo-Oxigenase 2/imunologia , Células Endoteliais/imunologia , Interleucina-6/imunologia , Metaloproteinase 9 da Matriz/imunologia , Infecções Estafilocócicas/imunologia , Staphylococcus aureus/imunologia , Aorta/patologia , Movimento Celular/imunologia , Células Cultivadas , Células Endoteliais/patologia , Humanos , Inflamação/imunologia , Inflamação/patologia , Compostos Organometálicos/farmacologia , Infecções Estafilocócicas/patologia
7.
Nat Methods ; 15(10): 789-792, 2018 10.
Artigo em Inglês | MEDLINE | ID: mdl-30202059

RESUMO

Optical imaging through the intact mouse skull is challenging because of skull-induced aberrations and scattering. We found that three-photon excitation provided improved optical sectioning compared with that obtained with two-photon excitation, even when we used the same excitation wavelength and imaging system. Here we demonstrate three-photon imaging of vasculature through the adult mouse skull at >500-µm depth, as well as GCaMP6s calcium imaging over weeks in cortical layers 2/3 and 4 in awake mice, with 8.5 frames per second and a field of view spanning hundreds of micrometers.


Assuntos
Encéfalo/fisiologia , Processamento de Imagem Assistida por Computador/métodos , Microscopia de Fluorescência por Excitação Multifotônica/métodos , Neuroimagem/métodos , Crânio/fisiologia , Animais , Encéfalo/anatomia & histologia , Feminino , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Crânio/anatomia & histologia
8.
Redox Biol ; 18: 93-103, 2018 09.
Artigo em Inglês | MEDLINE | ID: mdl-30007888

RESUMO

Pseudomonas aeruginosa (P. aeruginosa) infection in the lung is common in patients with cystic fibrosis (CF). Intercellular adhesion molecule-1 (ICAM-1) is known to play a key role in lung inflammation. Acute inflammation and its timely resolution are important to ensure bacterial clearance and limit tissue damage. Carbon monoxide (CO) has been shown to exert anti-inflammatory effects in various tissues and organ systems. Here, we explored the protective effects and mechanisms of carbon monoxide releasing molecule-2 (CORM-2) on P. aeruginosa-induced inflammatory responses in human pulmonary alveolar epithelial cells (HPAEpiCs). We showed that P. aeruginosa induced prostaglandin E2 (PGE2)/interleukin-6 (IL-6)/ICAM-1 expression and monocyte adherence to HPAEpiCs. Moreover, P. aeruginosa-induced inflammatory responses were inhibited by transfection with siRNA of Toll-like receptor 4 (TLR4), PKCα, p47phox, JNK2, p42, p50, or p65. P. aeruginosa also induced PKCα, JNK, ERK1/2, and NF-κB activation. We further demonstrated that P. aeruginosa increased intracellular ROS generation via NADPH oxidase activation. On the other hand, P. aeruginosa-induced inflammation was inhibited by pretreatment with CORM-2. Preincubation with CORM-2 had no effects on TLR4 mRNA levels in response to P. aeruginosa. However, CORM-2 inhibits P. aeruginosa-induced inflammation by decreasing intracellular ROS generation. P. aeruginosa-induced PKCα, JNK, ERK1/2, and NF-κB activation was inhibited by CORM-2. Finally, we showed that P. aeruginosa induced levels of the biomarkers of inflammation in respiratory diseases, which were inhibited by pretreatment with CORM-2. Taken together, these data suggest that CORM-2 inhibits P. aeruginosa-induced PGE2/IL-6/ICAM-1 expression and lung inflammatory responses by reducing the ROS generation and the inflammatory pathways.


Assuntos
Células Epiteliais Alveolares/efeitos dos fármacos , Anti-Inflamatórios/farmacologia , Molécula 1 de Adesão Intercelular/imunologia , Compostos Organometálicos/farmacologia , Infecções por Pseudomonas/imunologia , Pseudomonas aeruginosa/imunologia , Espécies Reativas de Oxigênio/imunologia , Células Epiteliais Alveolares/imunologia , Células Epiteliais Alveolares/microbiologia , Animais , Adesão Celular/efeitos dos fármacos , Linhagem Celular , Humanos , Inflamação/complicações , Inflamação/tratamento farmacológico , Inflamação/imunologia , Interleucina-6/imunologia , Masculino , Camundongos Endogâmicos ICR , Infecções por Pseudomonas/complicações , Infecções por Pseudomonas/tratamento farmacológico , Pseudomonas aeruginosa/efeitos dos fármacos
9.
Sci Rep ; 6: 38642, 2016 12 07.
Artigo em Inglês | MEDLINE | ID: mdl-27924924

RESUMO

Acarbose, an α-glucosidase inhibitor, is reported to reduce the incidence of silent myocardial infarction and slow the progression of intima-media thickening in patients with glucose intolerance. Here we investigate other impacts of acarbose on atherosclerosis development and the underlying mechanisms of atherosclerosis initiation and progression in vivo and in vitro. Rabbits fed a high cholesterol diet (HCD) were treated with acarbose (2.5-5.0 mg kg-1). Immunohistochemistry was used to assess the expression of inducible nitric oxide synthase (iNOS), Ras, proliferating cell nuclear antigen (PCNA), IL-6, ß-galactosidase, and p-AMPK in atherosclerotic lesions. Treatment with acarbose in HCD-fed rabbits was found to significantly reduce the severity of aortic atheroma and neointimal expression of α-actin, PCNA, IL-6, TNF-α, Ras, and ß-galactosidase; to significantly increase expression of iNOS and p-AMPK, but not to affect serum levels of glucose, total cholesterol, and LDL. Western blot analysis showed acarbose dose-dependently decreased ß-galactosidase and Ras expression and increased p-AMPK expression in TNF-α-treated A7r5 cells. In addition, acarbose restored p-AMPK and iNOS levels in AMPK inhibitor- and iNOS inhibitor-treated A7r5 cells, respectively. In conclusion, acarbose can pleiotropically inhibit rabbit atherosclerosis by reducing inflammation, senescence, and VSMCs proliferation/migration via upregulating AMPK signals.


Assuntos
Acarbose/efeitos adversos , Aterosclerose/etiologia , Aterosclerose/metabolismo , Inibidores de Glicosídeo Hidrolases/efeitos adversos , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Animais , Aterosclerose/patologia , Biomarcadores , Peso Corporal/efeitos dos fármacos , Movimento Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Modelos Animais de Doenças , Imuno-Histoquímica , Lipídeos/sangue , Masculino , Músculo Liso Vascular/metabolismo , Músculo Liso Vascular/patologia , Miócitos de Músculo Liso/efeitos dos fármacos , Miócitos de Músculo Liso/metabolismo , Coelhos
10.
Org Biomol Chem ; 13(45): 11096-104, 2015 Dec 07.
Artigo em Inglês | MEDLINE | ID: mdl-26399751

RESUMO

RNA is a drug target involved in diverse cellular functions and viral processes. Molecules that inhibit the HIV TAR RNA-Tat protein interaction may attenuate Tat/TAR-dependent protein expression and potentially serve as anti-HIV therapeutics. By incorporating positively charged residues with mixed side chain lengths, we designed peptides that bind TAR RNA with enhanced intracellular activity. Tat-derived peptides that were individually substituted with positively charged residues with varying side chain lengths were evaluated for TAR RNA binding. Positively charged residues with different side chain lengths were incorporated at each Arg and Lys position in the Tat-derived peptide to enhance TAR RNA binding. The resulting peptides showed enhanced TAR RNA binding affinity, cellular uptake, nuclear localization, proteolytic resistance, and inhibition of intracellular Tat/TAR-dependent protein expression compared to the parent Tat-derived peptide with no cytotoxicity. Apparently, the enhanced inhibition of protein expression by these peptides was not determined by RNA binding affinity, but by proteolytic resistance. Despite the high TAR binding affinity, a higher binding specificity would be necessary for practical purposes. Importantly, altering the positively charged residue side chain length should be a viable strategy to generate potentially useful RNA-targeting bioactive molecules.


Assuntos
Fármacos Anti-HIV/farmacologia , Regulação Viral da Expressão Gênica/efeitos dos fármacos , Produtos do Gene tat/farmacologia , Repetição Terminal Longa de HIV , HIV/genética , Peptídeos/farmacologia , RNA Viral/genética , Sequência de Aminoácidos , Fármacos Anti-HIV/química , Fármacos Anti-HIV/farmacocinética , Linhagem Celular , Produtos do Gene tat/química , Produtos do Gene tat/farmacocinética , HIV/efeitos dos fármacos , HIV/metabolismo , Infecções por HIV/tratamento farmacológico , Repetição Terminal Longa de HIV/efeitos dos fármacos , Humanos , Peptídeos/química , Peptídeos/farmacocinética , RNA Viral/metabolismo
11.
J Agric Food Chem ; 63(18): 4587-96, 2015 May 13.
Artigo em Inglês | MEDLINE | ID: mdl-25912298

RESUMO

Excess fat accumulation in the liver increases the risk of developing progressive liver injuries ranging from a fatty liver to hepatocarcinoma. In a previous study, we demonstrated that the polyphenol components of Sechium edule shoots attenuated hepatic lipid accumulation in vitro. Therefore, we investigated the effects and mechanisms of the extract of S. edule shoots (SWE) to modulate fat accumulation in a high-fat-diet (HFD)-induced animal model. In this study, we found that the SWE can reduce the body weight, adipose tissue fat, and regulate hepatic lipid contents (e.g., triglyceride and cholesterol). Additionally, treatment of caffeic acid (CA) and hesperetin (HPT), the main ingredients of SWE, also inhibited oleic acid (OA)-induced lipid accumulation in HepG2 cells. SWE enhanced the activation of AMP-activating protein kinase (AMPK) and decreased numerous lipogenic-related enzymes, such as sterol regulator element-binding proteins (SREBPs), e.g., SREBP-1 and SREBP-2, and HMG-CoA reductase (HMGCoR) proteins, which are critical regulators of hepatic lipid metabolism. Taken together, the results demonstrated that SWE can prevent a fatty liver and attenuate adipose tissue fat by inhibiting lipogenic enzymes and stimulating lipolysis via upregulating AMPK. It was also demonstrated that the main activation components of SWE are both CA and HPT.


Assuntos
Adipogenia/efeitos dos fármacos , Cucurbitaceae/química , Fígado Gorduroso/tratamento farmacológico , Lipogênese/efeitos dos fármacos , Fígado/efeitos dos fármacos , Obesidade/tratamento farmacológico , Extratos Vegetais/administração & dosagem , Proteínas Quinases Ativadas por AMP/genética , Proteínas Quinases Ativadas por AMP/metabolismo , Animais , Peso Corporal , Dieta Hiperlipídica/efeitos adversos , Fígado Gorduroso/genética , Fígado Gorduroso/metabolismo , Fígado Gorduroso/fisiopatologia , Humanos , Hidroximetilglutaril-CoA Redutases/genética , Hidroximetilglutaril-CoA Redutases/metabolismo , Fígado/metabolismo , Masculino , Obesidade/genética , Obesidade/metabolismo , Obesidade/fisiopatologia , Ácido Oleico/metabolismo , Extratos Vegetais/química , Brotos de Planta/química , Ratos , Ratos Wistar , Proteína de Ligação a Elemento Regulador de Esterol 1/genética , Proteína de Ligação a Elemento Regulador de Esterol 1/metabolismo
12.
Res Dev Disabil ; 35(11): 2735-43, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-25077832

RESUMO

Adolescent mental health is crucial for social competence and accomplishment in later life. The World Health Organization (WHO) estimates that approximately 20% of adolescents suffer from psychological symptoms. However, improving family risk and school environments can largely promote adolescent mental health. A longitudinal survey was conducted to investigate adolescent psychological well-being (PWB) status and associated factors in adolescents 15-20 years of age. Family and school context variables were interviewed and recorded. A total of 2896 participants were included from high, middle, and less urbanized resident areas in Northern Taiwan with completed interview data. Using multivariate regression analysis, factors associated with adolescent PWB at various stages included quarrelsome parents, quarrels with parents, severed friendships, and cigarette and alcohol use. In all three adolescent stages, females yielded higher psychological symptom scores than did males, and diverse weights of risk factors on PWB were observed between genders. Family arguments and cigarette and alcohol use were found to have more pronounced effects on outcomes among females than males. Whereas males are more sensitive to severed friendships than females, cigarette and alcohol use showed more harmful effects on mental health in earlier adolescence than in later life. Moreover, family arguments and severed friendships in earlier adolescence were found to have lasting effects on PWB in later adolescence. In this study, gender differences were observed in the temporal relationship on adolescent mental health. Variables of family arguments and severed friendships exhibited short-term and long-term effects on adolescent mental health across the early to late developmental stages. The family argument environment and regulating cigarette and alcohol use are worthy of focus to promote adolescent mental health.


Assuntos
Desenvolvimento do Adolescente , Consumo de Bebidas Alcoólicas/psicologia , Conflito Familiar/psicologia , Amigos/psicologia , Saúde Mental , Fumar/psicologia , Adolescente , Depressão/psicologia , Feminino , Hostilidade , Humanos , Masculino , Análise Multivariada , Análise de Regressão , Fatores Sexuais , Distúrbios do Início e da Manutenção do Sono/psicologia , Transtornos Somatoformes/psicologia , Taiwan , Adulto Jovem
13.
J Agric Food Chem ; 62(22): 5092-101, 2014 Jun 04.
Artigo em Inglês | MEDLINE | ID: mdl-24833292

RESUMO

Previous studies have shown that mulberry water extracts (MWEs), which contain polyphenolic compounds, have an antiatherosclerotic effect in rabbits. Apoptosis of vascular smooth muscle cells (VSMCs) is the key determinant of the number of VSMCs in remodeling. To improve the recovery from atherosclerosis pathology, it would be ideal to induce regression of atherosclerotic plaques and apoptosis of VSMCs. In this study, we treated high-cholesterol-diet-fed (HCD-fed) rabbits with MWEs, and we found that the MWEs effectively inhibited HCD-fed-induced intimal hyperplasia of vessel walls. We also found that MWEs initially activate JNK/p38 and p53, which in turn activate both Fas-ligand and mitochondria pathways, thereby causing mitochondria translocation of Bax and the reduction of Bcl-2 that trigger the cleavage of procaspases, finally resulting in apoptosis of VSMCs. In addition, 2.5-5.0 g/day of MWEs for humans may be enough to prevent atherosclerosis.


Assuntos
Apoptose/efeitos dos fármacos , Aterosclerose/tratamento farmacológico , Aterosclerose/fisiopatologia , Morus/química , Miócitos de Músculo Liso/efeitos dos fármacos , Extratos Vegetais/administração & dosagem , Proteína Supressora de Tumor p53/metabolismo , Animais , Aterosclerose/genética , Aterosclerose/metabolismo , Proliferação de Células , Regulação para Baixo/efeitos dos fármacos , Frutas/química , Humanos , Músculo Liso Vascular/citologia , Músculo Liso Vascular/efeitos dos fármacos , Músculo Liso Vascular/metabolismo , Miócitos de Músculo Liso/citologia , Miócitos de Músculo Liso/metabolismo , Proteínas Proto-Oncogênicas c-bcl-2/genética , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Coelhos , Proteína Supressora de Tumor p53/genética , Proteína X Associada a bcl-2/genética , Proteína X Associada a bcl-2/metabolismo
14.
Bioorg Med Chem ; 22(11): 3016-20, 2014 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-24767816

RESUMO

The six arginine (Arg) residues in the human immunodeficiency virus transactivator of transcription protein (HIV Tat protein) basic region (residues 47-57) are crucial for two bioactivities: RNA recognition and cellular uptake. Herein, we report a systematic study to investigate the role of the guanidinium group on Arg at each position in Tat-derived peptides for the two bioactivities. Tat-derived peptides, in which each guanidinium-bearing arginine was replaced with a urea-bearing citrulline (Cit) or an ammonium-bearing Lys, were synthesized by solid phase peptide synthesis. RNA recognition of the peptides was studied by electrophoretic mobility shift assays, and cellular uptake into Jurkat cells was determined by flow cytometry. Our results showed that removing the positive charge and altering the hydrogen bonding capacity of Arg affect the two biological functions differently. Furthermore, the effects are position dependent. These findings should be useful for the development of functional molecules containing guanidinium, urea, and ammonium groups for RNA recognition to affect biological processes and for cellular uptake for drug delivery.


Assuntos
Guanidina/metabolismo , Peptídeos/farmacocinética , RNA Viral/metabolismo , Produtos do Gene tat do Vírus da Imunodeficiência Humana/química , Citometria de Fluxo , Guanidina/química , Humanos , Células Jurkat , Peptídeos/química , Peptídeos/metabolismo , RNA Viral/química , Produtos do Gene tat do Vírus da Imunodeficiência Humana/metabolismo
15.
Amino Acids ; 46(8): 1867-83, 2014 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-24744084

RESUMO

The charge-containing hydrophilic functionalities of encoded charged amino acids are linked to the backbone via different numbers of hydrophobic methylenes, despite the apparent electrostatic nature of protein ion pairing interactions. To investigate the effect of side chain length of guanidinium- and carboxylate-containing residues on ion pairing interactions, α-helical peptides containing Zbb-Xaa (i, i + 3), (i, i + 4) and (i, i + 5) (Zbb = carboxylate-containing residues Aad, Glu, Asp in decreasing length; Xaa = guanidinium residues Agh, Arg, Agb, Agp in decreasing length) sequence patterns were studied by circular dichroism spectroscopy (CD). The helicity of Aad- and Glu-containing peptides was similar and mostly pH independent, whereas the helicity of Asp-containing peptides was mostly pH dependent. Furthermore, the Arg-containing peptides consistently exhibited higher helicity compared to the corresponding Agp-, Agb-, and Agh-containing peptides. Side chain conformational analysis by molecular mechanics calculations showed that the Zbb-Xaa (i, i + 3) and (i, i + 4) interactions mainly involved the χ 1 dihedral combinations (g+, g+) and (g-, g+), respectively. These low energy conformations were also observed in intrahelical Asp-Arg and Glu-Arg salt bridges of natural proteins. Accordingly, Asp and Glu provides variation in helix characteristics associated with Arg, but Aad does not provide features beyond those already delivered by Glu. Importantly, nature may have chosen the side chain length of Arg to support helical conformations through inherent high helix propensity coupled with stabilizing intrahelical ion pairing interactions with the carboxylate-containing residues.


Assuntos
Aminoácidos/química , Ácidos Carboxílicos/química , Guanidina/química , Peptídeos/química , Ácido 2-Aminoadípico/química , Alanina/análogos & derivados , Alanina/química , Sequência de Aminoácidos , Arginina/química , Ácido Aspártico/química , Dicroísmo Circular , Ácido Glutâmico/química , Interações Hidrofóbicas e Hidrofílicas , Modelos Moleculares , Conformação Molecular , Estrutura Secundária de Proteína , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz , Eletricidade Estática , Termodinâmica
16.
J Agric Food Chem ; 62(3): 750-9, 2014 Jan 22.
Artigo em Inglês | MEDLINE | ID: mdl-24377368

RESUMO

Fatty liver may have implications for metabolic syndrome, such as obesity, hypertension, and diabetes. Therefore, the development of pharmacological or natural agents to reduce fat accumulation in the liver is an important effort. The Sechium edule shoots have already been verified to decrease serum lipids and cholesterol and prevent atherosclerosis. However, how Sechium edule shoots modulate hepatic lipid metabolism is unclear. This study was designed to investigate the effects and mechanisms of polyphenol extracts (SPE) of Sechium edule shoots in reducing lipid accumulation in oleic acid-treated HepG2 cells. We found that water extracts (SWE) of Sechium edule shoots could decrease serum and hepatic lipid contents (e.g., triacylglycerol and cholesterol). Furthermore, SWE and SPE through the AMPK (AMP-activating protein kinase) signaling pathway could decrease lipogenic relative enzymes, such as FAS (fatty acid synthase), HMGCoR (HMG-CoA reductase), and SREBPs (sterol regulatory element binding proteins), and increase the expression of CPT-I (carnitine palmitoyltransferase I) and PPARα (peroxisome proliferators activated receptor α), which are critical regulators of hepatic lipid metabolism. These observations suggested that Sechium edule shoots have potential for developing health foods for preventing and remedying fatty liver.


Assuntos
Proteínas Quinases Ativadas por AMP/metabolismo , Cucurbitaceae/química , Lipogênese/efeitos dos fármacos , Lipólise/efeitos dos fármacos , Extratos Vegetais/farmacologia , Brotos de Planta/química , Polifenóis/farmacologia , Transdução de Sinais/efeitos dos fármacos , Acil Coenzima A/metabolismo , Fígado Gorduroso/tratamento farmacológico , Fígado Gorduroso/metabolismo , Células Hep G2 , Humanos , Metabolismo dos Lipídeos/efeitos dos fármacos , PPAR alfa/metabolismo , Proteína de Ligação a Elemento Regulador de Esterol 1/metabolismo
17.
ACS Appl Mater Interfaces ; 5(23): 12244-8, 2013 Dec 11.
Artigo em Inglês | MEDLINE | ID: mdl-24261815

RESUMO

Mesoporous silica nanoparticles (MSNs) are multifunctional nanocarriers with potential biomedical applications. However, MSNs are frequently trapped in endosomes upon cellular uptake through endocytosis, requiring endosomal escape. Herein, enhanced nonendocytosis was observed for 300 nm MSNs by conjugating peptides with noncanonical arginine analogs.


Assuntos
Arginina/química , Proteínas de Membrana Transportadoras/química , Nanopartículas , Dióxido de Silício/química , Endocitose , Células HeLa , Humanos , Microscopia Confocal
18.
Biochemistry ; 52(44): 7785-97, 2013 Nov 05.
Artigo em Inglês | MEDLINE | ID: mdl-24156236

RESUMO

ß-Sheets have been implicated in various neurological disorders, and ∼20% of protein residues adopt a sheet conformation. Therefore, studies on the structural origin of sheet stability can provide fundamental knowledge with potential biomedical applications. Oppositely charged amino acids are frequently observed across one another in antiparallel ß-sheets. Interestingly, the side chains of natural charged amino acids Asp, Glu, Arg, Lys have different numbers of hydrophobic methylenes linking the backbone to the hydrophilic charged functionalities. To explore the inherent effect of charged amino acid side chain length on antiparallel sheets, the stability of a designed hairpin motif containing charged amino acids with varying side chain lengths at non-hydrogen bonded positions was studied. Peptides with the guest position on the N-terminal strand and the C-terminal strand were investigated by NMR methods. The charged amino acids (Xaa) included negatively charged residues with a carboxylate group (Asp, Glu, Aad in increasing length), positively charged residues with an ammonium group (Dap, Dab, Orn, Lys in increasing length), and positively charged residues with a guanidinium group (Agp, Agb, Arg, Agh in increasing length). The fraction folded and folding free energy for each peptide were derived from the chemical shift deviation data. The stability of the peptides with the charged residues at the N-terminal guest position followed the trends: Asp > Glu > Aad, Dap < Dab < Orn ∼ Lys, and Agb < Arg < Agh < Agp. The stability of the peptides with the charged residues at the C-terminal guest position followed the trends: Asp < Glu < Aad, Dap ∼ Dab < Orn ∼ Lys, and Agb < Arg ∼ Agp < Agh. These trends were rationalized by thermodynamic sheet propensity and cross-strand interactions.


Assuntos
Aminoácidos/química , Proteínas/química , Sequência de Aminoácidos , Ligação de Hidrogênio , Conformação Molecular , Peptídeos/química , Estrutura Secundária de Proteína , Termodinâmica
19.
J Agric Food Chem ; 61(46): 11082-8, 2013 Nov 20.
Artigo em Inglês | MEDLINE | ID: mdl-24156384

RESUMO

This study investigated the influence of phenolic caffeic acid on obesity in mice fed a high fat diet and its underlying mechanisms base on adipose and hepatic lipid lipogenesis. C57BL/6 mice were fed a normal diet or a HFD (20% fat, w/w) with or without caffeic acid (0.02% and 0.08%, w/w) for 6 weeks. The effects of caffeic acid on hyperlipidemia, hyperglycemia, visceral fat accumulation, and related enzyme activities in HFD-mice are examined. The supplementation of caffeic acid significantly lowered body weight, visceral fat mass, plasma GOT and GPT levels, FAS activity, and free fatty acid compared to the HFD group. Caffeic acid also lowered triglyceride and cholesterol concentrations in plasma and liver. Furthermore, we showed that caffeic acid efficiently inhibited cholesterol biosynthesis as evidenced by 3-hydroxy-3-methylglutaryl CoA reductase in the liver. Caffeic acid supplementation suppressed the activity of lipogenesis via sterol regulatory element-binding protein 1 c and its target enzyme fatty acid synthase. In addition, caffeic acid resulted in increased phosphorylation of AMP-activated protein kinase and decreased acetyl carboxylase, a downstream target of AMPK, which are related to fatty acid ß-oxidation in the liver. In conclusion, these results indicate that caffeic acid exhibits a significant potential as an antiobesity agent by suppression of lipogenic enzymes and hepatic lipid accumulation.


Assuntos
Ácidos Cafeicos/administração & dosagem , Hiperlipidemias/prevenção & controle , Lipogênese/efeitos dos fármacos , Fígado/metabolismo , Obesidade/prevenção & controle , Proteínas Quinases Ativadas por AMP/genética , Proteínas Quinases Ativadas por AMP/metabolismo , Adipogenia/efeitos dos fármacos , Animais , Dieta Hiperlipídica/efeitos adversos , Humanos , Hiperlipidemias/genética , Hiperlipidemias/metabolismo , Fígado/enzimologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Obesidade/enzimologia , Obesidade/genética , Obesidade/metabolismo , Proteína de Ligação a Elemento Regulador de Esterol 1/genética , Proteína de Ligação a Elemento Regulador de Esterol 1/metabolismo , Triglicerídeos/metabolismo
20.
Curr Med Chem ; 20(31): 3944-53, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23848534

RESUMO

Vascular smooth muscle cell (VSMC) proliferation plays a central role in the pathogenesis of obesity-related atherosclerosis. The molecular mechanism of GA on oleic acid (OA)-induced proliferation of vascular smooth muscle cell is evaluated. Cells were treated with OA (150 µM), or co-treated with OA and GA (10-30 µM) for 48 h, MTT assay was performed for proliferation. Using flow cytometry analysis, the GA-treated cells caused an increase in G2/M phase. A decrease in cyclin B1 and cyclin-dependent kinase 1 (cdc2) and increase in kip/p27 and cip1/p21 were found by western blotting. Additional mechanistic studies showed that GA induced the activation of AMP-activated protein kinase (AMPK) and eNOS and the inhibition of fatty acid synthase (FAS) after stimulation with OA. Furthermore, the addition of compound C, a specific inhibitor of AMPK, reduced the activation of GA-mediated eNOS and NO production and increased the proliferation of cells. Inhibition of NOS by L-NAME had no further effect on VSMC proliferation. The present results indicate that GA was an effected and anti-atherogenic agent in VSMC. It attenuates cell cycle progression via AMPKmediated eNOS activation, which results in the production of NO and prevents atherosclerosis.


Assuntos
Ácido Gálico/farmacologia , Miócitos de Músculo Liso/efeitos dos fármacos , Substâncias Protetoras/farmacologia , Proteínas Quinases Ativadas por AMP/metabolismo , Animais , Ciclo Celular/efeitos dos fármacos , Linhagem Celular , Proliferação de Células/efeitos dos fármacos , Ácido Graxo Sintase Tipo I/metabolismo , Músculo Liso Vascular/citologia , Miócitos de Músculo Liso/citologia , Miócitos de Músculo Liso/metabolismo , Óxido Nítrico/metabolismo , Óxido Nítrico Sintase Tipo III/metabolismo , Ácido Oleico , Ratos
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