RESUMO
Cellular stress, notably oxidative, inflammatory, and endoplasmic reticulum (ER) stress, is implicated in the pathogenesis of cardiovascular disease. Modifiable risk factors for cardiovascular disease such as diabetes, hypercholesterolemia, saturated fat consumption, hypertension, and cigarette smoking cause ER stress whereas currently known cardioprotective drugs with diverse pharmacodynamics share a common pleiotropic effect of reducing ER stress. Selective targeting of oxidative stress with known antioxidative vitamins has been ineffective in reducing cardiovascular risk. This "antioxidant paradox" is partially attributed to the unexpected aggravation of ER stress by the antioxidative agents used. In contrast, some of the contemporary antihyperglycemic drugs inhibit both oxidative stress and ER stress in human coronary artery endothelial cells. Unlike sulfonylureas, meglitinides, α glucosidase inhibitors, and thiazolidinediones, metformin, glucagon-like peptide 1 receptor agonists, and sodium-glucose cotransporter 2 inhibitors are the only antihyperglycemic drugs that reduce ER stress caused by pharmacological agents (tunicamycin) or hyperglycemic conditions. Clinical trials with selective ER stress modifiers are needed to test the suitability of ER stress as a therapeutic target for cardiovascular disease.
Assuntos
Doenças Cardiovasculares , Hipoglicemiantes , Humanos , Hipoglicemiantes/farmacologia , Hipoglicemiantes/uso terapêutico , Doenças Cardiovasculares/tratamento farmacológico , Células Endoteliais , Estresse do Retículo Endoplasmático , Antioxidantes/farmacologiaRESUMO
Human beings have a natural craving for sweets. The intensity of this craving varies with genetic and environmental factors; however, excessive use of table sugar has been associated with adverse health outcomes, including increased risk of obesity, diabetes mellitus, and cardiovascular disease. As such, the World Health Organization has called for restricting sugar consumption to less than 5% of total energy intake. For those who have a "sweet tooth," implementing these guidelines is not easy. Hence, the interest in alternative sweeteners. There are eight high-intensity sweeteners that are either approved by the Food and Drug Administration or designated as generally regarded to be safe. The safety of the currently available sweeteners has been questioned. Large cohort studies have reported a positive correlation between sweetener use with weight gain and metabolic risk. A recent meta-analysis, however, concluded that using low- or no-calorie sweetener was associated with small improvements in body weight and cardiometabolic risk factors without evidence of harm. Nevertheless, the World Health Organization advises against the use of nonsugar sweeteners. The biological effects of natural sweeteners such as steviol, monk fruit extract, tagatose, allulose, and sweet proteins (eg, brazzien, miraculin, thaumatin) are not well studied. Eating less sugar is a prudent thing to do, but for people with diabetes mellitus and those at risk of diabetes mellitus, diversifying the type of the sweetener and limiting the quantity may be reasonable.
Assuntos
Edulcorantes , Humanos , Edulcorantes/efeitos adversos , ObesidadeRESUMO
Large-scale proteomic profiling of protein post-translational modifications has provided important insights into the regulation of cell signaling and disease. These modification-specific proteomics workflows nearly universally enrich modified peptides prior to mass spectrometry analysis, but protein-centric proteomic software tools have many limitations evaluating and interpreting these peptide-centric data sets. We, therefore, developed ProteoSushi, a software tool tailored to analysis of each modified site in peptide-centric proteomic data sets that is compatible with any post-translational modification or chemical label. ProteoSushi uses a unique approach to assign identified peptides to shared proteins and genes, minimizing redundancy by prioritizing shared assignments based on UniProt annotation score and optional user-supplied protein/gene lists. ProteoSushi simplifies quantitation by summing or averaging intensities for each modified site, merging overlapping peptide charge states, missed cleavages, spectral matches, and variable modifications into a single value. ProteoSushi also annotates each PTM site with the most up-to-date biological information available from UniProt, such as functional roles or known modifications, the protein domain in which the site resides, the protein's subcellular location and function, and more. ProteoSushi has a graphical user interface for ease of use. ProteoSushi's flexibility and combination of analysis features streamlines peptide-centric data processing and knowledge mining of large modification-specific proteomics data sets.
Assuntos
Proteômica , Software , Humanos , Espectrometria de Massas , Peptídeos , Processamento de Proteína Pós-TraducionalRESUMO
We present ProteoClade, a Python toolkit that performs taxa-specific peptide assignment, protein inference, and quantitation for multi-species proteomics experiments. ProteoClade scales to hundreds of millions of protein sequences, requires minimal computational resources, and is open source, multi-platform, and accessible to non-programmers. We demonstrate its utility for processing quantitative proteomic data derived from patient-derived xenografts and its speed and scalability enable a novel de novo proteomic workflow for complex microbiota samples.
Assuntos
Proteínas , Proteômica/métodos , Software , Animais , Bases de Dados de Proteínas , Humanos , Camundongos , Microbiota/genética , Proteínas/química , Proteínas/classificação , Proteínas/genética , Análise de Sequência de Proteína/métodosRESUMO
The hypothesis that reactive oxygen species (ROS) can be not just associated with but causally implicated in disease was first made in 1956, but so far, the oxidative stress theory of disease has not led to major therapeutic breakthrough, and the use of antioxidant is now confined to the field of complementary medicine. This chapter reviews the lack of high-level clinical evidence for the effectiveness of antioxidants in preventing disease and the epistemological problems of the oxidative stress theory of disease. We conclude on possible ways forward to test this hypothesis with approaches that take into account personalized medicine. The previous oxidative stress model has helped neither to diagnose nor to treat possibly ROS-related or ROS-dependent diseases. The redox balance concept that low ROS levels are beneficial or tolerable and high levels are disease triggers and best reduced is apparently wrong. Physiological ROS signalling may become dysfunctional or a disease trigger by at least five mechanisms: a physiological source may appear at an unphysiological site, a physiological source may be underactivated (less common) or overactivated (more common), a new source may appear, a physiological source may be overactivated or underactivated, and a toxifying enzyme may convert an ROS signal molecule into a more reactive molecule. The latter three mechanisms may reach a physiological or nonphysiological target. All of these dysregulations may be the direct and essential cause of a disease (rarely the case) or just a secondary epiphenomenon, which will disappear once the non-ROS-related cause of the disease is cured (much more common). Importantly, these mechanisms are the same for almost every signalling system. Causal target validation (sources, toxifiers and targets) is essential in order to identify effective drugs and therapies for ROSopathies.
Assuntos
Antioxidantes , Estresse Oxidativo , Antioxidantes/uso terapêutico , Humanos , Oxirredução , Espécies Reativas de Oxigênio , Transdução de SinaisRESUMO
Because of potential use of naturally occurring rare sugars as sweeteners, their effect on superoxide (SO), hydroxyl and peroxyl radicals and endoplasmic reticulum (ER) stress was examined in human coronary artery endothelial cells. SO generation was measured using the superoxide-reactive probe 2-methyl-6-(4-methoxyphenyl)-3,7-dihydroimidazo[1,2-A]pyrazin-3-one hydrochloride chemiluminescence. Phycoerythrin fluorescence based assay was used to monitor scavenging activity of sugars in the presence of hydroxyl or peroxyl radical generators [CuSO4 and azobis (2 amidinopropane) hydrochloride respectively]. Measurements were made in relative light units (RLU). ER stress was measured with an ER stress-sensitive secreted alkaline phosphatase (SAP) assay and by Western blot analysis of the expression and phosphorylation of key proteins in the unfolded protein response, namely CHOP47, eIF2α and JNK1. D-Glucose (27.5 mM) increased SO generation (5536 ± 283 vs. 2963 ± 205 RLU in controls; p < 0.0007) and decreased SAP secretion (73411 ± 3971 vs. 101749 ± 7652 RLU in controls; p < 0.005) indicating ER stress. Treatment of cells with 5.5 or 27.5 mM of D-allulose, D-allose, D-sorbose and D-tagatose reduced SO generation (all p < 0.05). This could not be attributed to inhibition of cellular uptake of dextrose by the rare sugars tested. In a cell free system, all four rare sugars had significantly more SO, hydroxyl and peroxyl radical scavenging activity compared to dextrose (all p < 0.01). Treatment of cells with rare sugars reduced ER stress. However, unlike other three rare sugars, D-sorbose did not inhibit tunicamycin-induced eIF2α phosphorylation. Naturally occurring rare sugars are free radical scavengers and can reduce ER stress.
Assuntos
Estresse do Retículo Endoplasmático , Células Endoteliais/química , Sequestradores de Radicais Livres , Superóxidos/química , Humanos , Açúcares/metabolismoRESUMO
BACKGROUND: Endothelial cell dysfunction in diabetes is involved in the pathogenesis and progression of premature atherosclerosis. High-dextrose has been shown to induce both oxidative stress and endoplasmic reticulum stress in cultured human coronary artery endothelial cells (HCAEC). STUDY QUESTION: To determine whether or not several classes of cardioprotective drugs inhibit proinflammatory cytokine expression by HCAEC. MEASURES AND OUTCOMES: To determine the effects of high dextrose on expression of proinflammatory cytokines by HCAEC, cells were treated with either 5.5 mM or 27.5 mM dextrose for 24 hours and interleukin-1ß (IL-1ß), interleukin-2 (IL-2), interleukin-6 (IL-6), interleukin-8 (IL-8), and tumor necrosis factor α were measured by enzyme immunoassay in the presence or absence of known cardioprotective drugs, including select ß-blockers, statins, and renin-angiotensin system inhibitors. RESULTS: IL-1ß levels increased significantly in cells treated with high dextrose; however, IL-6 and IL-8 levels did not change. Treatment of cells with carvedilol, atenolol, and propranolol decreased levels of all 3 cytokines in cells exposed to either 5.5 or 27.5 mM dextrose. Similar effects on IL-1ß, IL-6, and IL-8 levels were observed when cells were treated with simvastatin, pravastatin, and the renin-angiotensin system inhibitors spironolactone, captopril, lisinopril, candesartan, and losartan. No Il-2 or tumor necrosis factor α expression was observed in any of the experiments indicating that HCAEC do not express these cytokines. CONCLUSIONS: We conclude that each of the classes of drugs tested possess pleiotropic anti-inflammatory activities and are effective in both low- and high-dextrose-treated cells.
Assuntos
Anti-Inflamatórios/farmacologia , Cardiotônicos/farmacologia , Vasos Coronários/efeitos dos fármacos , Citocinas/metabolismo , Glucose/administração & dosagem , Linhagem Celular , Vasos Coronários/citologia , Vasos Coronários/metabolismo , Relação Dose-Resposta a Droga , Estresse do Retículo Endoplasmático/efeitos dos fármacos , Células Endoteliais/efeitos dos fármacos , Células Endoteliais/metabolismo , Endotélio Vascular/citologia , Endotélio Vascular/efeitos dos fármacos , Endotélio Vascular/metabolismo , Glucose/efeitos adversos , Humanos , Estresse Oxidativo/efeitos dos fármacosRESUMO
Consumption of table sugar has been increasing despite the warnings of public health officials as to the potential adverse consequences of sugar consumption. The World Health Organization recommends restricting consumption of sugars to no more than 10% of daily caloric intake, with a proposal to lower this level to 5% or less for optimal health. Unfortunately substituting sugar with the currently available artificial sweeteners does not appear to have favorable clinical effects. Given the health-related concerns with the currently available sweeteners such as increased risk of obesity and type 2 diabetes there is renewed interest in identifying a safe and palatable sweetener. The sweet extracts of natural plants such as stevia and monk fruit as well as naturally occurring rare sugars have become attractive alternatives. Although most of the sweeteners are sugars, there are some proteins such as braziien and miraculin that have intense sweetness and are being developed as sweeteners. Several companies are pursuing the development of "bitterness-blockers" to remove flavor defects. Other novel approaches include coating mineral carriers with sugar or hollowing out the sugar crystals. Naturally occurring rare sugars such as D-allulose (D-psicose), D-tagatose, D-sorbose and D-allose are attractive sweeteners. They do have the bulk and the mouth fill of table sugar with reduced caloric content (0.2 kcal/g for D-allulose). Additional randomized controlled trials are necessary to define the long term safety and efficacy of these sugars.
Assuntos
Diabetes Mellitus Tipo 2 , Açúcares , Edulcorantes/metabolismo , Diabetes Mellitus Tipo 2/metabolismo , Sacarose Alimentar , Humanos , Obesidade , Edulcorantes/químicaRESUMO
Hip fracture and myocardial infarction cause significant morbidity and mortality. In vivo studies raising serum cholesterol levels as well as pro-inflammatory cytokines such as TNF α manifest bone loss and atherosclerotic vascular disease, suggesting that abnormalities of cholesterol transport may contribute to osteoporosis. We used the mouse osteocyte cell line (MLO-Y4) to investigate the effects of TNF α on the expression of cholesterol acceptor proteins such as apolipoprotein A-I (apo A-I) and apolipoprotein E (apo E), as well as on the cholesterol transporters ATP-binding cassette-1 (ABCA1), scavenger receptor class B type 1 (SRB1), and cluster of differentiation 36 (CD36). MLO-Y4 cells do not express apo A-I or apo E; however, they do express all three cholesterol transporters (ABCA1, SRB1, and CD36). Treatment of MLO-Y4 cells with TNF α had no effect on SRB1, CD36, and osteocalcin levels; however, TNF α reduced ABCA1 protein levels in a dose-dependent manner and cholesterol efflux to apo A-I. Interestingly, TNF α treatment increased ABCA1 promoter activity and ABCA1 mRNA levels, and increased liver X receptor α protein expression, but had no effect on retinoid X receptor α and retinoic acid receptor α levels. Pharmacological inhibition of p38 mitogen-activated protein (MAP) kinase, but not c-jun-N-terminal kinase 1 or mitogen-activated protein kinase (MEK), restored ABCA1 protein levels in TNF α-treated cells. These results suggest that pro-inflammatory cytokines regulate cholesterol metabolism in osteocytes in part by suppressing ABCA1 levels post-translationally in a p38 MAP kinase-dependent manner.
Assuntos
Transportador 1 de Cassete de Ligação de ATP/biossíntese , Colesterol/metabolismo , Osteócitos/metabolismo , Fator de Necrose Tumoral alfa/farmacologia , Animais , Western Blotting , Antígenos CD36/metabolismo , Linhagem Celular , Camundongos , Reação em Cadeia da Polimerase em Tempo Real , Receptores Depuradores Classe B/metabolismo , Transfecção , Fator de Necrose Tumoral alfa/metabolismoRESUMO
Type 2 diabetes is a heterogeneous disease with multiple underlying pathophysiological processes. Several new antidiabetic agents are presently available for clinical use, yet very few clinical trials have been performed on the efficacy of combination pill therapy. Combination pill use is easily justified as a second-line therapy in which the advantages of added efficacy, enhanced adherence, and only modest increase in risk are recognized. In contrast, combination pill use as first-line therapy has some drawbacks, such as increased risk of hypoglycemia, difficulty in attribution of side effects to the constituents, and less than additive efficacy of the components of the pill. In general, combinations of drugs with synergistic mechanisms of action are preferable. However, the efficacy of currently available combination pills when used as first-line therapy is less than the sum of the efficacy of its components. The current guidelines recommend initiation of dual therapy in drug-naive individuals depending on baseline HbA1c at the time of diagnosis. When the HbA1c is above 8.5%-9%, the likelihood of achieving glycemic targets with a single agent diminishes sharply. These patients may be better candidates for treatment with a combination of antihyperglycemic agents as first-line therapy.
Assuntos
Diabetes Mellitus Tipo 2/tratamento farmacológico , Hipoglicemiantes/administração & dosagem , Guias de Prática Clínica como Assunto , Animais , Glicemia/efeitos dos fármacos , Diabetes Mellitus Tipo 2/fisiopatologia , Combinação de Medicamentos , Sinergismo Farmacológico , Hemoglobinas Glicadas/metabolismo , Humanos , Hipoglicemiantes/efeitos adversos , Hipoglicemiantes/farmacologiaRESUMO
Beta blockers are known to have favorable effects on endothelial function partly because of their capacity to reduce oxidative stress. To determine whether beta blockers can also prevent dextrose-induced endoplasmic reticulum (ER) stress in addition to their antioxidative effects, human coronary artery endothelial cells and hepatocyte-derived HepG2 cells were treated with 27.5 mM dextrose for 24 hours in the presence of carvedilol (a lipophilic beta blockers with alpha blocking activity), propranolol (a lipophilic nonselective beta blockers), and atenolol (a water-soluble selective beta blockers), and ER stress, oxidative, stress and cell death were measured. ER stress was measured using the placental alkaline phosphatase assay and Western blot analysis of glucose regulated protein 78, c-Jun-N-terminal kinase (JNK), phospho-JNK, eukaryotic initiating factor 2α (eIF2α), and phospho-eIF2α and measurement of X-box binding protein 1 (XBP1) mRNA splicing using reverse transcriptase-polymerase chain reaction. Superoxide (SO) generation was measured using the superoxide-reactive probe 2-methyl-6-(4-methoxyphenyl)-3,7-dihydroimidazo[1,2-A]pyrazin-3-one hydrochloride (MCLA) chemiluminescence. Cell viability was measured by propidium iodide staining method. The ER stress, SO production, and cell death induced by 27.5 mM dextrose were inhibited by all 3 beta blockers tested. The antioxidative and ER stress reducing effects of beta blockers were also observed in HepG2 cells. The salutary effects of beta blockers on endothelial cells in reducing both ER stress and oxidative stress may contribute to the cardioprotective effects of these agents.
Assuntos
Antagonistas Adrenérgicos beta/farmacologia , Apoptose/efeitos dos fármacos , Estresse do Retículo Endoplasmático/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Atenolol/farmacologia , Carbazóis/farmacologia , Cardiotônicos/farmacologia , Carvedilol , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Vasos Coronários/efeitos dos fármacos , Vasos Coronários/patologia , Células Endoteliais/efeitos dos fármacos , Células Endoteliais/patologia , Glucose/toxicidade , Células Hep G2 , Humanos , Propanolaminas/farmacologia , Propranolol/farmacologia , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Superóxidos/metabolismoRESUMO
Statins have favorable effects on endothelial function partly because of their capacity to reduce oxidative stress. However, antioxidant vitamins, unlike statins, are not as cardioprotective, and this paradox has been explained by failure of vitamin antioxidants to ameliorate endoplasmic reticulum (ER) stress. To determine whether statins prevent dextrose-induced ER stress in addition to their antioxidative effects, human umbilical vein endothelial cells and HepG2 hepatocytes were treated with 27.5 mM dextrose in the presence of simvastatin (lipophilic statin that is a prodrug) and pravastatin (water-soluble active drug), and oxidative stress, ER stress, and cell death were measured. Superoxide generation was measured using 2-methyl-6-(4-methoxyphenyl)-3,7-dihydroimidazo[1,2-A]pyrazin-3-one hydrochloride. ER stress was measured using the placental alkaline phosphatase assay and Western blot of glucose-regulated protein 75, c-jun-N-terminal kinase, phospho-JNK, eukaryotic initiating factor 2α and phospho-eIF2α, and X-box binding protein 1 mRNA splicing. Cell viability was measured by propidium iodide staining. Superoxide anion production, ER stress, and cell death induced by 27.5 mM dextrose were inhibited by therapeutic concentrations of simvastatin and pravastatin. The salutary effects of statins on endothelial cells in reducing both ER stress and oxidative stress observed with pravastatin and the prodrug simvastatin suggest that the effects may be independent of cholesterol-lowering activity.
Assuntos
Antioxidantes/farmacologia , Estresse do Retículo Endoplasmático/efeitos dos fármacos , Inibidores de Hidroximetilglutaril-CoA Redutases/farmacologia , Estresse Oxidativo/efeitos dos fármacos , Morte Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Glucose/toxicidade , Células Hep G2 , Células Endoteliais da Veia Umbilical Humana/efeitos dos fármacos , Humanos , Pravastatina/farmacologia , Sinvastatina/farmacologia , Superóxidos/metabolismoRESUMO
OBJECTIVES: Although low-fat diets (LFD) have been the cornerstone of dietary guidelines for weight reduction, low-carbohydrate diets (LCD) continue to gain attention and popularity. Which diet can achieve significant and sustainable weight loss in unclear, however. Our objective in this study was to compare LCDs with LFDs and their impact on weight loss. METHODS: We performed a MEDLINE/PubMed search for English-language articles of randomized controlled studies conducted with adults who were overweight or obese for at least 6 months for the time period of January 2001-October 2014. Two reviewers independently abstracted data, including participants' characteristics, diet composition and duration, and change in weight from baseline at 6 and 12 months. RESULTS: A total of 17 studies were analyzed. At 6 months, the mean weight loss for participants on an LCD was -1.439 kg (95% confidence interval -2.319 to -0.558) compared with participants on an LFD (P < 0.001). At 12 months, the difference was smaller, -0.769 kg (95% confidence interval -1.361 to -0.178) but remained statistically significant (P < 0.010). The mean difference in the weight loss between the two diets was attenuated over time. CONCLUSIONS: Reducing carbohydrate intake may help patients achieve weight loss. The mean difference in weight change between an LCD and an LFD was too small to have a meaningful impact on weight loss. More studies are needed to better elucidate the role of LCDs in weight loss efforts.
Assuntos
Dieta com Restrição de Carboidratos/métodos , Dieta com Restrição de Gorduras/métodos , Dieta Redutora/métodos , Obesidade/dietoterapia , Adulto , Humanos , Ensaios Clínicos Controlados Aleatórios como AssuntoRESUMO
Tumor necrosis factor alpha (TNF α) signals in part through the mitogen activated protein (MAP) kinase c-jun-N-terminal kinase (JNK). Activation of JNK has been shown to promote insulin resistance and dyslipidemia, including reductions in plasma high-density lipoprotein (HDL) and apolipoprotein A-I (apo A-I). To examine how TNF α-mediated JNK activation inhibits hepatic apo A-I production, the effects of c-jun activation on apo A-I gene expression were examined in HepG2 cells. Apo A-I gene expression and promoter activity were measured by Northern and Western blotting and transient transfection. Transient transfection and siRNA were used to specifically over-express or knockout c-jun, c-jun-N-terminal kinase-1 and -2 (JNK1 and JNK2, respectively) and mitogen-activated protein kinase-4 (MKK4). TNF α-treatment of HepG2 cells induced rapid phosphorylation of c-jun on serine 63. In cells treated with phorbol-12-myristate-13-acetate (PMA), apo A-I gene promoter activity was inhibited and apo A-I mRNA content and apo A-I protein secretion decreased. Likewise, over-expression of JNK1 and JNK2 inhibited apo A-I promoter activity. Over-expression of constitutively active MKK4, an upstream protein kinase that directly activates JNK, also inhibited apo A-I promoter activity, while over-expression of a dominant-negative MKK4 de-repressed apo A-I promoter activity in TNF α-treated cells. Inhibition of c-jun synthesis using siRNA but not a control siRNA prevented TNF α-mediated inhibition of apo A-I. These results suggest that the MKK4/JNK/c-jun signaling pathway mediates TNF α-dependent inhibition of apo A-I synthesis.
Assuntos
Apolipoproteína A-I/biossíntese , Proteína Quinase 8 Ativada por Mitógeno/biossíntese , Proteína Quinase 9 Ativada por Mitógeno/genética , Fator de Necrose Tumoral alfa/biossíntese , Apolipoproteína A-I/antagonistas & inibidores , Dislipidemias/genética , Regulação Neoplásica da Expressão Gênica , Técnicas de Inativação de Genes , Células Hep G2 , Humanos , Proteína Quinase 9 Ativada por Mitógeno/biossíntese , RNA Interferente Pequeno , Transdução de Sinais/genética , Fator de Necrose Tumoral alfa/genéticaRESUMO
In order to define the molecular anatomy of the blood-brain barrier (BBB) that may be relevant to either barrier or transport function, proteins that are overexpressed in the cerebral microvessels should be identified. We used differential display to identify novel proteins that are overexpressed or unique to the BBB. DNA sequence analysis is one of the differentially expressed transcripts showed that it is highly homologous with the ATPase class I, type 8B, and member 1 (ATP8B1) protein and contains an ATPase domain and a phospholipid-binding domain. ATP8B1 is expressed in the BBB microvessels but not brain tissue lacking microvessels. Likewise, ATP8B1 was enriched in BBB microvessels similar to glucose transporter 1. Immunohistochemistry using an ATP8B1-specific antibody demonstrated preferential staining of the microvessels within the cerebral tissue. These results suggest that ATP8B1, a P-type aminophospholipid translocase, is enriched in cerebral microvessels and may have a role in plasma membrane lipid transport.
Assuntos
Adenosina Trifosfatases/metabolismo , Barreira Hematoencefálica/metabolismo , Membrana Celular/metabolismo , Endotélio Vascular/metabolismo , Microvasos/metabolismo , Proteínas de Transferência de Fosfolipídeos/metabolismo , Animais , Perfilação da Expressão Gênica , Proteínas de Membrana Transportadoras/metabolismo , Ratos Endogâmicos F344RESUMO
Black seed extracts are known to alter cellular metabolism through multiple signaling pathways. Since Forkhead box transcription factor 3 (FOXO3) has a significant role in regulating cellular metabolism, the effect of lipid extracts of black seed (Sativa nigella) on FOXO3 levels and AKT and 5-AMP activated protein kinase α (AMPKα) signaling was measured in HepG2 hepatoma cells. FOXO3 levels, phosphorylation, and nuclear exclusion were measured by Western blot, as were AKT and AMPK expression and activity using phosphorylation-specific antibodies. Apolipoprotein A-I expression, a black seed-responsive gene, was measured by Western blot. Treatment with black seed extract increased FOXO3 phosphorylation and decreased its expression. In contrast to control cells where FOXO3 was located primarily in the nucleus, in black seed-treated HepG2 cells, FOXO3 was localized primarily to the cytoplasm. These changes in FOXO3 phosphorylation, expression, and localization were accompanied by increased AKT activity. Black seed also decreased AMPKα activity but increased AMPKα expression. Lipid extracts from black seeds inhibit FOXO3 activity and thereby modulate the expression of FOXO3-dependent genes.
Assuntos
Fatores de Transcrição Forkhead/metabolismo , Hepatócitos/efeitos dos fármacos , Nigella sativa/química , Extratos Vegetais/farmacologia , Proteínas Quinases Ativadas por AMP/metabolismo , Proteína Forkhead Box O3 , Células Hep G2 , Hepatócitos/metabolismo , Humanos , Fosforilação/efeitos dos fármacos , Proteínas Proto-Oncogênicas c-akt/metabolismo , Sementes/química , Transdução de Sinais/efeitos dos fármacosRESUMO
CONTEXT: Black seed [Nigella sativa L. (Ranunculaceae)] has been shown in animal models to lower serum cholesterol levels. OBJECTIVES: In order to determine if extracts from black seed have any effects on high-density lipoprotein (HDL), we characterized the effects of black seed extract on apolipoprotein A-I (apo A-I) gene expression, the primary protein component of HDL. MATERIALS AND METHODS: Hepatocytes (HepG2) and intestinal cells (Caco-2) were treated with black seed extracts, and Apo A-I, peroxisome proliferator-activated receptor α (PPARα), and retinoid-x-receptor α (RXRα) were measured by Western blot analysis. Apo A-I mRNA levels were measured by quantitative real-time polymerase chain reaction and apo A-I gene transcription was measured by transient transfection of apo A-I reporter plasmids. RESULTS: Extracts from black seeds significantly increased hepatic and intestinal apo A-I secretion, as well as apo A-I mRNA and gene promoter activity. This effect required a PPARα binding site in the apo A-I gene promoter. Treatment of the extract with either heat or trypsin had no effect on its ability to induce apo A-I secretion. Treatment with black seed extract induced PPARα expression 9-fold and RXRα expression 2.5-fold. Furthermore, the addition of PPARα siRNA but not a control siRNA prevented some but not all the positive effects of black seed on apo A-I secretion. DISCUSSION: Black seed extract is a potent inducer of apo A-I gene expression, presumably by enhancing PPARα/RXRα expression. CONCLUSIONS: We conclude that black seed may have beneficial effects in treating dyslipidemia and coronary heart disease.
Assuntos
Apolipoproteína A-I/genética , Lipoproteínas HDL/efeitos dos fármacos , Nigella sativa/química , Extratos Vegetais/farmacologia , Células CACO-2 , Regulação da Expressão Gênica/efeitos dos fármacos , Células Hep G2 , Hepatócitos/efeitos dos fármacos , Hepatócitos/metabolismo , Humanos , Lipoproteínas HDL/metabolismo , PPAR alfa/genética , Regiões Promotoras Genéticas/efeitos dos fármacos , RNA Mensageiro/metabolismo , Reação em Cadeia da Polimerase em Tempo Real , Receptor X Retinoide alfa/genética , SementesRESUMO
The need to improve the health of individuals and populations by providing high-quality health care has become a priority and has led to the implementation of various quality indicators to measure performance and outcomes. However, significant disparities exist in the health care delivery and outcomes among individuals that can only intensify, considering the future projections for an aging and increasingly diverse population. This article provides the authors' perspectives on how these issues can be addressed and overcome by redesigning medical education so the future generations of physicians have the necessary knowledge, skills, and attitudes to provide high-quality, patient-centered, and culturally sensitive care.
Assuntos
Atenção à Saúde/normas , Educação Médica/organização & administração , Melhoria de Qualidade , Resultado do Tratamento , Competência Cultural , Humanos , Comunicação Interdisciplinar , Assistência Centrada no Paciente , Saúde PúblicaRESUMO
One of the hallmarks of health is the integrity of barriers at the cellular and tissue levels. The two cardinal functions of barriers include preventing access of deleterious elements of the environment (barrier function) while facilitating the transport of essential ions, signaling molecules and nutrients needed to maintain the internal milieu (transport function). There are several cellular and subcellular barriers and some of these barriers can be interrelated. The principal physiologic barriers include blood-retinal barrier, blood-brain barrier, blood-testis barrier, renal glomerular/tubular barrier, intestinal barrier, pulmonary blood-alveolar barrier, blood-placental barrier and skin barrier. Tissue specific barriers are the result of the vasculature, cellular composition of the tissue and extracellular matrix within the tissue. Uncontrolled diabetes and acute hyperglycemia may disrupt the integrity of physiologic barriers, primarily through altering the vascular integrity of the tissues and may well contribute to the clinically recognized complications of diabetes. Although diabetes is a systemic disease, some of the organs display clinically significant deterioration in function while others undergo subclinical changes. The pathophysiology of the disruption of these barriers is not entirely clear but it may be related to diabetes-related cellular stress. Understanding the mechanisms of diabetes related dysfunction of various physiologic barriers might help identifying novel therapeutic targets for reducing clinically significant complications of diabetes.
Assuntos
Complicações do Diabetes , Diabetes Mellitus , Hiperglicemia , Feminino , Gravidez , Masculino , Humanos , Placenta , Barreira Hematoencefálica , Barreira Hematorretiniana , Hiperglicemia/complicaçõesRESUMO
The prevalence of diabetes mellitus increases with age and causes significant morbidity and poor quality of life in older adults. To review the current literature on the diagnosis and management of diabetes in the elderly, the relevant manuscripts were identified through a MEDLINE (2000-September 1, 2010) search of the English literature. The key phrase used was diabetes in older adults or diabetes in the elderly. The literature search was limited to core clinical journals that have accessible full texts. A total of 480 manuscripts were reviewed. Managing diabetes in older adults is a challenging task. Some features of the disease are unique to the older patient. Several new antidiabetic agents are now available for clinical use, and yet very few clinical trials have been carried out in this age group. For many older adults, maintaining independence is more important than adherence to published guidelines to prevent diabetes complications. The goals of diabetes care in older adults are to enhance quality of life without subjecting the residents to inappropriate interventions.