RESUMEN
BACKGROUND: Vascular endothelial barrier function is maintained by cell-to-cell junctional proteins and contributes to vascular homeostasis. Various risk factors such as inflammation disrupt barrier function through down-regulation of these proteins and promote vascular diseases such as atherosclerosis. Previous studies have demonstrated that aged garlic extract (AGE) and its sulfur-containing constituents exert the protective effects against several vascular diseases such as atherosclerosis. In this study, we examined whether AGE and its sulfur-containing constituents improve the endothelial barrier dysfunction elicited by a pro-inflammatory cytokine, Tumor-necrosis factor-α (TNF-α), and explored their mode of action on TNF-α signaling pathway. METHODS: Human umbilical vein endothelial cells (HUVECs) were treated with test substances in the presence of TNF-α for various time periods. The endothelial permeability was measured by using a transwell permeability assay. The localization of cell-to-cell junctional proteins and actin cytoskeletons were visualized by immunostaining. RhoA and Rac activities were assessed by using GTP-binding protein pulldown assay. Gene and protein expression levels of signaling molecules were analyzed by real-time PCR and western blotting, respectively. RESULTS: We found that AGE and its major sulfur-containing constituent, S-1-propenylcysteine (S1PC), reduced hyperpermeability elicited by TNF-α in HUVECs. In addition, S1PC inhibited TNF-α-induced production of myosin light chain (MLC) kinase and inactivation of MLC phosphatase through the suppression of the Rac and RhoA signaling pathways, respectively, which resulted in the dephosphorylation of MLC2, a key factor of actin remodeling. Moreover, S1PC inhibited the phosphorylation and activation of guanine nucleotide exchange factor-H1 (GEF-H1), a common upstream key molecule and activator of Rac and RhoA. These effects of S1PC were accompanied by its ability to prevent the disruption of junctional proteins on the cell-cell contact regions and the increase of actin stress fibers induced by TNF-α. CONCLUSIONS: The present study suggested that AGE and its major constituent, S1PC, improve endothelial barrier disruption through the protection of junctional proteins on plasma membrane. Video abstract.
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Cisteína/análogos & derivados , Células Endoteliales de la Vena Umbilical Humana/efectos de los fármacos , Factor de Necrosis Tumoral alfa , Permeabilidad Capilar/efectos de los fármacos , Miosinas Cardíacas/metabolismo , Proliferación Celular/efectos de los fármacos , Células Cultivadas , Cisteína/farmacología , Células Endoteliales de la Vena Umbilical Humana/metabolismo , Humanos , Cadenas Ligeras de Miosina/metabolismo , Quinasa de Cadena Ligera de Miosina/genética , Quinasa de Cadena Ligera de Miosina/metabolismo , Proteínas Proto-Oncogénicas c-akt/metabolismo , ARN Interferente Pequeño/genética , Factores de Intercambio de Guanina Nucleótido Rho/genética , Factores de Intercambio de Guanina Nucleótido Rho/metabolismo , Transducción de Señal/efectos de los fármacos , Proteína de Unión al GTP rhoA/metabolismoRESUMEN
Chromosome instability, frequently found in cancer cells, is caused by a deficiency in cell division, including centrosomal amplification and cytokinesis failure, and can result in abnormal chromosome content or aneuploidy. The small GTPase pathways have been implicated as important processes in cell division. We found that knockdown of a tumor suppressor protein Kank1 increases the number of cells with a micronucleus or bi-/multi-nuclei, which was likely caused by centrosomal amplification. Kank1 interacts with Daam1, known to bind to and activate a small GTPase, RhoA, in actin assembly. Knockdown of Kank1 or overexpression of Daam1, respectively, hyperactivates RhoA, potentially leading to the modulation of the activity of Aurora-A, a key regulator of centrosomal functions, eventually resulting in centrosomal amplification. Kank1 is also associated with contractile ring formation in collaboration with RhoA, and its deficiency results in the interruption of normal daughter cell separation, generating multinucleate cells. Such abnormal segregation of chromosomes may cause further chromosomal instability and abnormal gene functions, leading to tumorigenesis. Thus, Kank1 plays a crucial role in regulating the activity of RhoA through retrieving excess Daam1 and balancing the activities of RhoA and its effectors.
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Proteínas Adaptadoras Transductoras de Señales/genética , Carcinogénesis/genética , Neoplasias/genética , Proteínas Supresoras de Tumor/genética , Proteína de Unión al GTP rhoA/genética , Animales , Aurora Quinasa A/genética , División Celular/genética , Centrosoma/metabolismo , Inestabilidad Cromosómica/genética , Segregación Cromosómica/genética , Proteínas del Citoesqueleto , Técnicas de Silenciamiento del Gen , Células HEK293 , Humanos , Ratones , Proteínas de Microfilamentos , Células 3T3 NIH , Neoplasias/patología , Proteínas de Unión al GTP rhoRESUMEN
S-1-Propenyl-l-cysteine (S1PC) is a stereoisomer of S-1-Propenyl-l-cysteine (SAC), an important sulfur-containing amino acid that plays a role for the beneficial pharmacological effects of aged garlic extract (AGE). The existence of S1PC in garlic preparations has been known since the 1960's. However, there was no report regarding the biological and/or pharmacological activity of S1PC until 2016. Recently, we performed a series of studies to examine the chemical, biological, pharmacological and pharmacokinetic properties of S1PC, and obtained some interesting results. S1PC existed only in trace amounts in raw garlic, but its concentration increased almost up to the level similar of SAC through aging process of AGE. S1PC showed immunomodulatory effects in vitro and in vivo, and reduced blood pressure in a hypertensive animal model. A pharmacokinetic study revealed that S1PC was readily absorbed after oral administration in rats and dogs with bioavailability of 88-100%. Additionally, S1PC had little inhibitory influence on human cytochrome P450 activities, even at a concentration of 1 mM. Based on these findings, S1PC was suggested to be another important, pharmacologically active and safe component of AGE similar to SAC. In this review, we highlight some results from recent studies on S1PC and discuss the potential medicinal value of S1PC.
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Cisteína/química , Cisteína/farmacología , Ajo/química , Extractos Vegetales/química , Extractos Vegetales/farmacología , Vías Biosintéticas , Cisteína/análogos & derivados , Cisteína/síntesis química , Cisteína/farmacocinética , Extractos Vegetales/farmacocinética , Azufre/química , Factores de TiempoRESUMEN
BACKGROUND: Aged garlic extract (AGE) has been shown to retard the progression of coronary calcification in patients with coronary artery disease. OBJECTIVE: To clarify the mechanism of AGE's action to retard atherosclerosis, we investigated whether AGE suppresses the formation and progression of atherosclerosis in Apolipoprotein E (Apoe)-knockout (ApoE-KO) mice. METHODS: Male C57BL/6J mice (control mice, 5 wk old) were fed a standard diet, whereas male ApoE-KO mice (5 wk old) were fed a standard diet with or without 3% AGE for 12 or 24 wk. After the treatment, blood samples, aortas, and spleens were collected from all mice. Concentrations of total cholesterol (TC), HDL cholesterol, and triglycerides (TGs) in serum were measured. The area of atherosclerotic lesion in the aorta was examined by Oil Red O staining. The relative abundances of monocytes plus macrophages (CD11b(+) cells) and interferon-γ-producing CD4(+) T cells in spleen were assessed by flow cytometric analysis. RESULTS: The atherosclerotic lesion areas in the aortas of ApoE-KO mice were 87 and 114 times as great (P < 0.01) as those in control mice at 12 and 24 wk, respectively. AGE feeding significantly inhibited the progression of atherosclerotic lesion area in ApoE-KO mice by 22% (P < 0.05) at 12 wk. In addition, serum concentrations of TC and TGs in ApoE-KO mice were significantly higher than those in control mice at 12 and 24 wk. Treatment with AGE significantly suppressed the increases in serum concentrations of TC and TGs in ApoE-KO mice by 21% (P < 0.05) and 19% (P < 0.05) at 24 wk, respectively, and reduced the relative abundance of CD11b(+) cells in ApoE-KO mice by 24% (P < 0.05) at 12 wk. CONCLUSION: These data suggest that the antiatherosclerotic activity of AGE is at least partly due to the suppression of inflammation and lipid deposition in the vessels during the early stage of atherosclerotic development in ApoE-KO mice.
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Aterosclerosis/prevención & control , Colesterol/sangre , Ajo , Inflamación/prevención & control , Fitoterapia , Extractos Vegetales/uso terapéutico , Triglicéridos/sangre , Animales , Aorta/patología , Apolipoproteínas E/sangre , Aterosclerosis/sangre , Aterosclerosis/etiología , Aterosclerosis/patología , Antígenos CD11/metabolismo , Progresión de la Enfermedad , Inflamación/sangre , Inflamación/inmunología , Mediadores de Inflamación/sangre , Interferón gamma/metabolismo , Macrófagos/metabolismo , Masculino , Ratones Endogámicos C57BL , Ratones Noqueados , Extractos Vegetales/farmacología , Placa Aterosclerótica/sangre , Placa Aterosclerótica/etiología , Placa Aterosclerótica/prevención & control , Bazo/efectos de los fármacos , Linfocitos T/metabolismoRESUMEN
The usefulness of Fluolid-Orange, a novel fluorescent dye, for DNA microarray and immunological assays has been examined. Fluolid-Orange-labeled probes (DNA and IgG) were stable as examined by laser-photo-bleaching and under heat and dry conditions. Statistical analyses were performed to evaluate the reproducibility of the microarray assay, while stage-specific immunostaining of marker proteins, Kank1 and calretinin, was performed for renal cancers, both giving satisfactory results. The stability of the dye should provide advantages for storing fluorescently labeled probes and re-examining the specimens later in genetic and pathological diagnostics.
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Colorantes Fluorescentes/química , Sondas Moleculares , Análisis de Secuencia por Matrices de Oligonucleótidos/métodos , Patología Molecular/métodos , Coloración y Etiquetado/métodos , ADN/química , Humanos , Inmunoensayo/métodos , Inmunoglobulina G/química , Sondas Moleculares/química , Reproducibilidad de los ResultadosRESUMEN
Atherosclerosis is a chronic inflammatory disease that may lead to the development of serious cardiovascular diseases. Aged garlic extract (AGE) has been reported to ameliorate atherosclerosis, although its mode of action remains unclear. We found that AGE increased the mRNA or protein levels of arginase1 (Arg1), interleukin-10 (IL-10), CD206 and hypoxia-inducible factor 2α (HIF2α) and decreased that of CD68, HIF1α and inducible nitric oxide synthase in the aorta and spleen of apolipoprotein E knockout mice. We also found that S-1-propenylcysteine (S1PC), a characteristic sulfur compound in AGE, increased the level of IL-10-induced Arg1 mRNA and the extent of M2c-like macrophage polarization in vitro. In addition, S1PC increased the population of M2c-like macrophages, resulting in suppressed the population of M1-like macrophages and decreased lipopolysaccharide-induced production of pro-inflammatory cytokines. These effects were accompanied by prolonged phosphorylation of the IL-10 receptor α (IL-10Rα) and signal transducer and activator of transcription 3 (STAT3) that inhibited the interaction between IL-10Rα and Src homology-2-containing inositol 5'-phosphatase 1 (SHIP1). In addition, administration of S1PC elevated the M2c/M1 macrophage ratio in senescence-accelerated mice. These findings suggest that S1PC may help improve atherosclerosis due to its anti-inflammatory effect to promote IL-10-induced M2c macrophage polarization.
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Polaridad Celular/efectos de los fármacos , Cisteína/análogos & derivados , Ajo/química , Interleucina-10/farmacología , Macrófagos/metabolismo , Extractos Vegetales/administración & dosificación , Receptores de Interleucina-10/metabolismo , Factor de Transcripción STAT3/metabolismo , Transducción de Señal/efectos de los fármacos , Animales , Aterosclerosis/prevención & control , Células Cultivadas , Cisteína/administración & dosificación , Modelos Animales de Enfermedad , Activación de Macrófagos/efectos de los fármacos , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados para ApoE , Fosforilación/efectos de los fármacos , Fitoterapia/métodos , Placa Aterosclerótica/prevención & control , Proteínas Recombinantes/farmacología , Resultado del TratamientoRESUMEN
Antizyme inhibitor (AIn), a homolog of ODC, binds to antizyme and inactivates it. We report here that AIn increased at the G1 phase of the cell cycle, preceding the peak of ODC activity in HTC cells in culture. During interphase AIn was present mainly in the cytoplasm and turned over rapidly with the half-life of 10 to 20 min, while antizyme was localized in the nucleus. The level of AIn increased again at the G2/M phase along with ODC, and the rate of turn-over of AIn in mitotic cells decreased with the half-life of approximately 40 min. AIn was colocalized with antizyme at centrosomes during the period from prophase through late anaphase and at the midzone/midbody during telophase. Thereafter, AIn and antizyme were separated and present at different regions on the midbody at late telophase. AIn disappeared at late cytokinesis, whereas antizyme remained at the cytokinesis remnant. Reduction of AIn by RNA interference caused the increase in the number of binucleated cells in HTC cells in culture. These findings suggested that AIn contributed to a rapid increase in ODC at the G1 phase and also played a role in facilitating cells to complete mitosis during the cell cycle.
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Proteínas Portadoras/metabolismo , Ciclo Celular/fisiología , Ornitina Descarboxilasa/metabolismo , Animales , Antineoplásicos/farmacología , Proteínas Portadoras/genética , Ciclo Celular/efectos de los fármacos , Línea Celular Tumoral , Sistema Libre de Células , Eflornitina/metabolismo , Estabilidad de Enzimas , Nocodazol/farmacología , Inhibidores de la Ornitina Descarboxilasa , Poliaminas/metabolismo , Proteínas/metabolismo , ARN Mensajero/metabolismo , ARN Interferente Pequeño/genética , ARN Interferente Pequeño/metabolismo , RatasRESUMEN
In order to find novel bioactive molecules regulating differentiation and hormone secretion of pancreatic endocrine cells, the effects of various substances including purinergic receptor agonists and inhibitors of polyamine biosynthesis were examined in pancreatic islets and several pancreatic cell lines. The nicotinic alpha3beta4 receptor was found to be present and capable of increasing cytoplasmic Ca(2+) concentration ([Ca(2+)](i)) and insulin secretion in mouse pancreatic Beta-TC6 cells. Activation of both nicotinic and muscarinic M(3)/M(4) receptors resulted in reduction of insulin release when compared with stimulation of muscarinic receptor alone in Beta-TC6 cells. In mouse islets, purinergic P2Y(1) and P2Y(6) receptors, which are coupled to Gq proteins, were expressed and appeared to regulate insulin secretion through Ca(2+) mobilization from intracellular stores. Similar results were observed in Beta-TC6 cells. Spermidine, one of polyamines, was found to modulate insulin synthesis and [Ca(2+)](i) in Beta-TC6 cells by use of a specific spermidine synthesis inhibitor, trans-4-methylcyclohexylamine (MCHA). Antizyme, which binds to ornithine decarboxylase (ODC) and thereby reduces the cellular polyamine level, was found to be necessary for conversion of ASPC-1 cells, a pancreatic ductal tumor cell line, into alpha-cells forming the islet-like structure and expressing glucagon gene. These findings help advance our understanding of the complex mechanisms involved in the regulation of pancreatic endocrine cell function and develop new therapeutic agents in diabetes mellitus.
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Diferenciación Celular/genética , Células Secretoras de Insulina/citología , Células Secretoras de Insulina/metabolismo , Insulina/metabolismo , Receptores Muscarínicos/fisiología , Receptores Nicotínicos/fisiología , Receptores Purinérgicos/fisiología , Adenosina Trifosfato/biosíntesis , Animales , Calcio/metabolismo , Glucagón/biosíntesis , Glucosa/metabolismo , Humanos , Insulina/biosíntesis , Secreción de Insulina , Ratones , PoliaminasRESUMEN
Aged garlic extract (AGE) has been shown to improve peripheral circulatory disturbances in both clinical trials and experimental animal models. To investigate the effect of S-1-propenylcysteine (S1PC), a characteristic sulfur compound in AGE, on cold-induced reduction in tail blood flow of rat, Wistar rats were individually placed in a restraint cage and given the treatment with cold water (15ËC) after the oral administration of AGE or its constituents S1PC, S-allylcysteine (SAC) and S-allylmercaptocysteine (SAMC). After the cold-treatment the tail blood flow of rats was measured at the indicated times. The pretreatment with AGE (2 g/kg BW) and S1PC (6.5 mg/kg BW) significantly alleviated the reduction of rat tail blood flow induced by cold treatment. The effect of S1PC was dose-dependent and maximal at the dose of 6.5 mg/kg BW, whereas SAC and SAMC were ineffective. To gain insight into the mechanism of S1PC action, the concentration of nitrogen oxide metabolites (NOx) in the plasma and the levels of phosphorylated endothelial nitric oxide synthase (eNOS) and 5'-AMP-activated protein kinase (AMPK) in the aorta were measured. The pretreatment with S1PC significantly increased the plasma concentration of NOx as well as the level of phosphorylated form of AMPK and eNOS in the aorta after cold-treatment. The present findings suggest that S1PC is a major constituent responsible for the effect of AGE to alleviate the cold-induced reduction of peripheral blood flow in rat by acting on the AMPK/eNOS/NO pathway in the aorta.
RESUMEN
AMP-activated protein kinase (AMPK) is an ubiquitously expressed serine/threonine kinase and an important regulator of energy metabolism. The decreased activity of AMPK induced by low-grade chronic inflammation has been implicated in several diseases, including type 2 diabetes and atherosclerosis. However, the activation of AMPK by natural and synthetic products can ameliorate these diseases through the inhibition of inflammation. For example, aged garlic extract (AGE) has been shown to enhance the phosphorylation of Thr172 of the α-subunit of AMPK in several tissues of disease model animals. In addition, AGE has been reported to suppress the progression of atherosclerotic plaque formation in an animal model of atherosclerosis. Moreover, AGE has been found to decrease the level of plasma glycated albumin and to improve hyperglycemia in an animal model of type 2 diabetes. These inhibitory effects of AGE are induced by the suppression of the inflammatory response. In the present review, we discuss the mechanisms through which AGE activates AMPK, as well as the mechanisms through which the activation of AMPK by AGE modulates the inflammatory response in disease models.
RESUMEN
Allium plants, such as garlic, onion and leek have long been known to be effective in the therapy of infectious diseases. In particular, garlic has a greater antimicrobial activity than other Allium plants as it contains several hydrophobic antimicrobial compounds, such as allicin, vinyldithiins, ajoenes and diallyl polysulfides. Allicin is a characteristic sulfur-containing compound found in raw garlic produced from alliin and exhibits antimicrobial activity against both Gram-positive and Gram-negative bacteria. In addition, allicin has been reported to inhibit the biofilm formation of bacteria, which is a major cause of bacterial resistance to the antibiotic treatment of infections, by regulating quorum sensing in microorganisms. Other hydrophobic compounds also have similar inhibitory effects on bacteria as allicin. These biological properties of garlic-derived hydrophobic compounds can be used to enhance the effects of existing drugs and may thus be used in the treatment of infections, such as by preventing drug resistance through the inhibition of biofilm formation. In this review, we summarize the effects of hydrophobic compounds of garlic on bacteria.
RESUMEN
Autophagy is a key event in cellular recycling processes due to its involvement in the intracellular degradation of proteins. It has been demonstrated that S-1-propenylcysteine (S1PC), a characteristic sulfur compound in aged garlic extract, induces the activation of autophagy. S1PC degrades the adaptor protein myeloid differentiation response protein 88 (MyD88) of downstream of Toll-like receptor (TLR) by activating autophagy in vitro and in vivo. The degradation of MyD88 inhibits the TLR signaling pathway, including the phosphorylation of interleukin 1 receptor associated kinase 4 (IRAK4) and nuclear factor (NF)-κB p65 in vitro, and eventually leads to the inhibition of interleukin (IL)-6 production in vitro and C-C motif chemokine ligand 2 (Ccl2) mRNA expression in vivo. S1PC also increases the level of intestinal immunoglobulin A (IgA) and the number of IgA-producing cells in Peyer's patches in vivo. In addition, S1PC triggers the mRNA expression of X-box binding protein 1 (Xbp1), an inducer of IgA-producing cell differentiation via the phosphorylation of extracellular signal-regulated kinase (ERK)1/2 and the degradation of paired box protein 5 (Pax5), a suppressor of Xbp1 mRNA expression. The present review summarizes the mechanisms through which the activation of autophagy by S1PC modulates the immune response.
RESUMEN
Human pancreatic tumor cell lines - AsPC-1, PANC-1, MIA paca2, KP-1 and KP-59 cells - can be induced to differentiate into pancreatic hormone-producing cells by brief trypsin treatment and subsequent culture in a serum-free, chemically defined medium. During culture, AsPC-1 cells formed cell clusters resembling the pancreatic islets, expressed genes associated with the pancreatic development and produced glucagon but not insulin. When PANC-1, MIA paca2, KP-1 and KP-59 cells were treated and cultured the same way, they underwent similar morphological changes and produced insulin and glucagon. We used these systems to identify intracellular regulatory molecules involved in the conversion of pancreatic tumor cells into glucagon-producing cells. We found that the expression of antizyme 1 (AZ1), a negative regulator of ornithine decarboxylase, was increased and its localization was altered from the nucleus to the cytoplasm during AsPC-1 cell differentiation. Transient transfection of AsPC-1 cells with AZ1 siRNA resulted in inhibition of the morphological and functional cell differentiation as well as the specific suppression of AZ1 expression. By contrast, constitutive overexpression of AZ1 in AsPC-1 cells led to the enhancement of glucagon production. We also found that PANC-1 cells reduced the expression of glucagon mRNA when treated with AZ1 siRNA. These results suggested that AZ1 was necessary for the conversion of pancreatic tumor cells into glucagon-producing cells. Glucagon production in AsPC-1 cells was not affected by addition of putrescine, suggesting that the polyamines were not directly involved in the AZ1-mediated conversion of pancreatic tumor cells to differentiated state.
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Adenocarcinoma/metabolismo , Diferenciación Celular , Inhibidores Enzimáticos/farmacología , Glucagón/biosíntesis , Neoplasias Pancreáticas/metabolismo , Proteínas/metabolismo , Adenocarcinoma/patología , Animales , Núcleo Celular/metabolismo , Citoplasma/metabolismo , Humanos , Neoplasias Pancreáticas/patología , Poliaminas/metabolismo , Proteínas/antagonistas & inhibidores , Proteínas/genética , ARN Interferente Pequeño/farmacología , Ratas , Células Tumorales CultivadasRESUMEN
The degradation of target proteins by small molecules utilizing the cellular proteolytic system is featured as a treatment strategy of several diseases. We found that S-1-propenylcysteine (S1PC) among several cysteine derivatives in aged garlic extract inhibited TLR-mediated IL-6 production by inducing the degradation of adaptor protein MyD88. We showed that S1PC directly denatured MyD88 and induced the formation of protein aggregates. Consequently, MyD88 was degraded by aggresome-autophagy pathway. On the other hand, S-allylcysteine, a structural analog of S1PC, failed to induce the degradation of MyD88 because of its inability to denature MyD88 although it also activated autophagy. Our findings suggest that S1PC induces MyD88 degradation through the denaturation of MyD88 and the activation of autophagy. Thus, S1PC may serve as the base to develop a therapeutic means for immune diseases associated with aberrant TLR signaling pathways.
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Antiinflamatorios/farmacología , Autofagia/efectos de los fármacos , Cisteína/análogos & derivados , Factor 88 de Diferenciación Mieloide/metabolismo , Transducción de Señal/efectos de los fármacos , Animales , Línea Celular , Humanos , Linfocitos/efectos de los fármacos , Linfocitos/metabolismo , Masculino , Ratas , Ratas Endogámicas WKY , Receptores Toll-Like/metabolismoRESUMEN
SCOPE: Chronic inflammation plays a major role in the formation and progression of atherosclerotic plaques. To clarify the mode of action of aged garlic extract (AGE) to retard atherosclerosis, we investigated whether AGE suppresses the inflammation in apolipoprotein E-knockout (ApoE-KO) mice. METHODS AND RESULTS: ApoE-KO mice were fed standard diet with or without 3% AGE for 12 wk. AGE feeding inhibited the progression of atherosclerotic lesion by 27% and reduced the level of C-reactive protein (CRP) and thromboxane B2 (TXB2 ), a marker of platelet activation, in serum by 39 and 33%, respectively, compared to ApoE-KO mice without AGE treatment. AGE treatment also decreased the level of tumor necrosis factor alpha (TNF-α), a major stimulus inducing CRP production, in the liver by 35%. AGE decreased the level of interleukin-1 receptor-associated kinase 4 (IRAK4) by 60% and almost doubled the level of phospho-AMP-activated protein kinase (p-AMPK) in the liver. CONCLUSION: The anti-atherosclerotic effect of AGE involves the suppression of inflammation by reducing the serum level of CRP and TXB2 , and the protein level of TNF-α and IRAK4, and increasing AMPK activity in liver.
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Ajo/química , Inflamación/tratamiento farmacológico , Extractos Vegetales/farmacología , Proteínas Quinasas Activadas por AMP/sangre , Animales , Aterosclerosis/prevención & control , Biomarcadores/sangre , Proteína C-Reactiva/metabolismo , Dieta , Progresión de la Enfermedad , Inflamación/sangre , Quinasas Asociadas a Receptores de Interleucina-1/sangre , Hígado/efectos de los fármacos , Hígado/metabolismo , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados para ApoE , Extractos Vegetales/sangre , Tromboxano B2/sangre , Factor de Necrosis Tumoral alfa/sangreRESUMEN
SCOPE: In this study, we investigated the effect of aged garlic extract (AGE) on the high level of blood glucose in Tsumura Suzuki Obese-Diabetes (TSOD) mice. METHODS AND RESULTS: TSOD mice were fed standard diet with or without 2% AGE for 19 weeks. AGE treatment lowered the blood glucose level and significantly reduced the plasma level of glycated albumin in TSOD mice as compared with those without AGE treatment. In addition, AGE treatment increased the level of phosphorylated AMP-activated protein kinase (AMPK) in the adipose tissue, liver and muscle that played an important role in the maintenance of insulin sensitivity. Moreover, AGE treatment also suppressed the mRNA expression of fatty acid synthase, a known factor regulated by AMPK, and monocyte chemoattractant protein 1, one of the representative inflammatory chemokines, in the adipose tissue but not in the liver. CONCLUSION: AGE treatment suppresses the increase of plasma glycated albumin level in TSOD mice and this effect is accompanied by the activation of AMPK in adipose tissue, and suggests that AGE may play a potential role in the prevention and treatment of type 2 diabetes.
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Proteínas Quinasas Activadas por AMP/metabolismo , Tejido Adiposo/efectos de los fármacos , Ajo/química , Extractos Vegetales/farmacología , Albúmina Sérica/metabolismo , Proteínas Quinasas Activadas por AMP/genética , Tejido Adiposo/metabolismo , Animales , Glucemia/metabolismo , Quimiocina CCL2/genética , Quimiocina CCL2/metabolismo , Diabetes Mellitus Tipo 2/tratamiento farmacológico , Dieta , Ácido Graso Sintasas/genética , Ácido Graso Sintasas/metabolismo , Manipulación de Alimentos , Productos Finales de Glicación Avanzada , Resistencia a la Insulina , Hígado/efectos de los fármacos , Hígado/metabolismo , Masculino , Ratones , Ratones Obesos , Músculo Esquelético/efectos de los fármacos , Músculo Esquelético/metabolismo , ARN Mensajero/genética , ARN Mensajero/metabolismo , Albúmina Sérica GlicadaRESUMEN
Viral protein R (Vpr), an accessory protein of human immunodeficiency virus type 1 (HIV-1), induces the G2 cell cycle arrest in fission yeast for which host factors, such as Wee1 and Rad24, are required. Catalyzing the inhibitory phosphorylation of Cdc2, Wee1 is known to serve as a major regulator of G2/M transition in the eukaryotic cell cycle. It has been reported that the G2 checkpoint induced by DNA damage or incomplete DNA replication is associated with phosphorylation and upregulation of Wee1 for which Chk1 and Cds1 kinase is required. In this study, we demonstrate that the G2 arrest induced by HIV-1 Vpr in fission yeast is also associated with increase in the phosphorylation and amount of Wee1, but in a Chk1/Cds1-independent manner. Rad24 and human 14-3-3 appear to contribute to Vpr-induced G2 arrest by elevating the level of Wee1 expression. It appears that Vpr could cause the G2 arrest through a mechanism similar to, but distinct from, the physiological G2 checkpoint controls. The results may provide useful insights into the mechanism by which HIV-1 Vpr causes the G2 arrest in eukaryotic cells. Vpr may also serve as a useful molecular tool for exploring novel cell cycle control mechanisms.
Asunto(s)
Proteínas de Ciclo Celular/metabolismo , Proteínas de Ciclo Celular/fisiología , Fase G2 , Productos del Gen vpr/fisiología , Péptidos y Proteínas de Señalización Intracelular/fisiología , Proteínas Nucleares/metabolismo , Proteínas Quinasas/fisiología , Proteínas Tirosina Quinasas/metabolismo , Proteínas de Schizosaccharomyces pombe/metabolismo , Proteínas de Schizosaccharomyces pombe/fisiología , Schizosaccharomyces/fisiología , Proteínas 14-3-3/metabolismo , Quinasa 1 Reguladora del Ciclo Celular (Checkpoint 1) , Regulación de la Expresión Génica , Productos del Gen vpr/genética , VIH-1 , Fosforilación , Schizosaccharomyces/citología , Schizosaccharomyces/genética , Regulación hacia Arriba , Productos del Gen vpr del Virus de la Inmunodeficiencia HumanaRESUMEN
OBJECTIVES: S-Allylcysteine (SAC) and S-1-propenylcysteine (S1PC) are the characteristic sulfur-containing amino acids in aged garlic extract. In this study, we investigated the effect of SAC and S1PC on intestinal immunoglobulin (Ig)A production to gain insight into the immunomodulatory effect of aged garlic extract. METHODS: In vitro study: Mouse splenic lymphocytes were treated with S1PC (0.1 and 0.3 mM) or SAC (0.1 and 0.3 mM) for 3 d, and IgA concentration in the culture medium was examined. In vivo study: Mice were orally administrated S1PC (7.5, 15, and 30 mg/kg) for 5 d and the IgA level in the intestinal lavage fluids as well as the population of IgA-producing cells in Peyer's patches were measured using mouse IgA enzyme-linked immunosorbent assay quantification set and flow cytometer, respectively. RESULTS: S1PC enhanced IgA production in mouse splenic lymphocytes in culture. However, SAC was ineffective. In addition, oral administration of S1PC to mice increased the IgA level and number of IgA-producing cells in Peyer's Patches. Furthermore, S1PC induced the expression of X-box binding protein 1 (Xbp1) mRNA, an inducer of plasma cell differentiation, in Peyer's patches. This induction was accompanied by the degradation of paired box protein 5 and the activation of mitogen activated protein/extracellular signal-regulated kinase signaling pathway. CONCLUSION: These results suggest that S1PC increases IgA-producing cells via the enhancement of Erk1/2-mediated Xbp1 expression in the intestine.
Asunto(s)
Linfocitos B/fisiología , Cisteína/análogos & derivados , Inmunoglobulina A/fisiología , Sistema de Señalización de MAP Quinasas/fisiología , Ganglios Linfáticos Agregados/metabolismo , Proteína 1 de Unión a la X-Box/metabolismo , Animales , Linfocitos B/efectos de los fármacos , Diferenciación Celular/efectos de los fármacos , Diferenciación Celular/fisiología , Cisteína/farmacología , Ensayo de Inmunoadsorción Enzimática , Femenino , Inmunoglobulina A/efectos de los fármacos , Sistema de Señalización de MAP Quinasas/efectos de los fármacos , Ratones , Ratones Endogámicos C57BL , Modelos AnimalesRESUMEN
Subtypes of purinergic receptors involved in modulation of cytoplasmic calcium ion concentration ([Ca(2+)](i)) and insulin release in mouse pancreatic beta-cells were examined in two systems, pancreatic islets in primary culture and beta-TC6 insulinoma cells. Both systems exhibited some physiological responses such as acetylcholine-stimulated [Ca(2+)](i) rise via cytoplasmic Ca(2+) mobilization. Addition of ATP, ADP, and 2-MeSADP (each 100 microM) transiently increased [Ca(2+)](i) in single islets cultured in the presence of 5.5 mM (normal) glucose. The potent P2Y(1) receptor agonist 2-MeSADP reduced insulin secretion significantly in islets cultured in the presence of high glucose (16.7 mM), whereas a slight stimulation occurred at 5.5 mM glucose. The selective P2Y(6) receptor agonist UDP (200 microM) transiently increased [Ca(2+)](i) and reduced insulin secretion at high glucose, whereas the P2Y(2/4) receptor agonist UTP and adenosine receptor agonist NECA were inactive. [Ca(2+)](i) transients induced by 2-MeSADP and UDP were antagonized by suramin (100 microM), U73122 (2 microM, PLC inhibitor), and 2-APB (10 or 30 microM, IP(3) receptor antagonist), but neither by staurosporine (1 microM, PKC inhibitor) nor depletion of extracellular Ca(2+). The effect of 2-MeSADP on [Ca(2+)](i) was also significantly inhibited by MRS2500, a P2Y(1) receptor antagonist. These results suggested that P2Y(1) and P2Y(6) receptor subtypes are involved in Ca(2+) mobilization from intracellular stores and insulin release in mouse islets. In beta-TC6 cells, ATP, ADP, 2-MeSADP, and UDP transiently elevated [Ca(2+)](i) and slightly decreased insulin secretion at normal glucose, while UTP and NECA were inactive. RT-PCR analysis detected mRNAs of P2Y(1) and P2Y(6), but not P2Y(2) and P2Y(4) receptors.
RESUMEN
The dynamic rearrangement of the actin cytoskeleton plays critical roles in T-cell receptor (TCR) signaling and immunological synapse (IS) formation in T cells. Following actin rearrangement in T cells upon TCR stimulation, we found a unique ring-shaped reorganization of actin called the "actin cloud," which was specifically induced by outside-in signals through lymphocyte function-associated antigen-1 (LFA-1) engagement. In T-cell-antigen-presenting cell (APC) interactions, the actin cloud is generated in the absence of antigen and localized at the center of the T-cell-APC interface, where it accumulates LFA-1 and tyrosine-phosphorylated proteins. The LFA-1-induced actin cloud formation involves ADAP (adhesion- and degranulation-promoting adaptor protein) phosphorylation, LFA-1/ADAP assembly, and c-Jun N-terminal kinase (JNK) activation, and occurs independent of TCR and its proximal signaling. The formation of the actin cloud lowers the threshold for subsequent T-cell activation. Thus, the actin cloud induced by LFA-1 engagement may serve as a possible platform for LFA-1-mediated costimulatory function for T-cell activation.