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1.
Am J Physiol Cell Physiol ; 326(1): C89-C94, 2024 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-38009197

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/farmacologia
2.
J Diabetes Complications ; 37(8): 108552, 2023 08.
Artigo em Inglês | MEDLINE | ID: mdl-37356233

RESUMO

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/complicações
3.
Eur J Pharmacol ; 933: 175274, 2022 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-36108736

RESUMO

Oxidative stress and endoplasmic reticulum (ER) stress promote atherogenesis while transcription factor EB (TFEB) inhibits atherosclerosis. Since reducing oxidative stress with antioxidants have failed to reduce atherosclerosis possibly because of aggravation of ER stress, we studied the effect of TFEB on ER stress in human coronary artery endothelial cells. ER stress was measured using the secreted alkaline phosphatase assay. Expression and phosphorylation of key mediators of unfolded protein response (UPR). TFEB, inositol-requiring enzyme 1α (IRE1α), phospho-IRE1α, protein kinase R (PKR)-like endoplasmic reticulum kinase (PERK), phospho-PERK, and activating transcription factor 6 (ATF6) expression were measured by Western blot. The effect of TFEB gain- and loss-of-function on ER stress were assessed with a plasmid expressing a constitutively active form of TFEB and via siRNA-mediated silencing, respectively. Treatment with tunicamycin (TM) and thapsigargin (TG) increased TFEB expression by 42.8% and 42.3%, respectively. In HCAEC transfected with the TFEB siRNA, treatment with either TM, TG or high-dextrose increased IRE1α and PERK phosphorylation and ATF6 levels significantly more compared to cells transfected with the control siRNA and treated similarly. Furthermore, transient transfection with a plasmid expressing a constitutively active form of TFEB reduced ER stress. Increased expression of TFEB inhibited ER stress in HCAEC treated with pharmacologic (TM and TG) and physiologic (high-dextrose) ER stress inducers, while TFEB knockout aggravated ER stress caused by these ER stress inducers. TFEB-mediated ER stress reduction may contribute to its anti-atherogenic effects in HCAEC and may be a novel target for drug development.


Assuntos
Aterosclerose , Estresse do Retículo Endoplasmático , Fator 6 Ativador da Transcrição/genética , Fator 6 Ativador da Transcrição/metabolismo , Fosfatase Alcalina/metabolismo , Vasos Coronários/metabolismo , Endorribonucleases/genética , Endorribonucleases/metabolismo , Células Endoteliais/metabolismo , Glucose/farmacologia , Humanos , Inositol/farmacologia , Proteínas Serina-Treonina Quinases/genética , RNA Interferente Pequeno/metabolismo , Tapsigargina/farmacologia , Tunicamicina/farmacologia , Resposta a Proteínas não Dobradas , eIF-2 Quinase/genética , eIF-2 Quinase/metabolismo
4.
Eur J Pharmacol ; 931: 175221, 2022 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-35998751

RESUMO

Despite the advances made in cardiovascular disease prevention, there is still substantial residual risk of adverse cardiovascular events. Contemporary evidence suggests that additional reduction in cardiovascular disease risk can be achieved through amelioration of cellular stresses, notably inflammatory stress and endoplasmic reticulum (ER) stress. Only two clinical trials with anti-inflammatory agents have supported the role of inflammatory stress in cardiovascular risk. However, there are no clinical trials with selective ER stress modifiers to test the hypothesis that reducing ER stress can reduce cardiovascular disease. Nevertheless, the ER stress hypothesis is supported by recent pharmacologic studies revealing that currently available cardioprotective drugs share a common property of reducing ER stress. These drug classes include angiotensin converting enzyme inhibitors, angiotensin II receptor blockers, mineralocorticoid receptor blockers, ß-adrenergic receptor blockers, statins, and select antiglycemic agents namely, metformin, glucagon like peptide 1 receptor agonists and sodium glucose cotransporter 2 inhibitors. Although these drugs ameliorate common risk factors for cardiovascular disease, such as hypertension, hypercholesterolemia and hyperglycemia, their cardioprotective effects may be partially independent of their principal effects on cardiovascular risk factors. Clinical trials with selective ER stress modifiers are needed to test the hypothesis that reducing ER stress can reduce cardiovascular disease.


Assuntos
Doenças Cardiovasculares , Estresse do Retículo Endoplasmático , Humanos , Antagonistas Adrenérgicos beta/farmacologia , Antagonistas de Receptores de Angiotensina/farmacologia , Doenças Cardiovasculares/tratamento farmacológico , Doenças Cardiovasculares/prevenção & controle , Inibidores do Transportador 2 de Sódio-Glicose/farmacologia
5.
Drugs ; 82(10): 1055-1075, 2022 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-35861923

RESUMO

The cholesterol efflux protein ATP binding cassette protein A1 (ABCA) and apolipoprotein A1 (apo A1) are key constituents in the process of reverse-cholesterol transport (RCT), whereby excess cholesterol in the periphery is transported to the liver where it can be converted primarily to bile acids for either use in digestion or excreted. Due to their essential roles in RCT, numerous studies have been conducted in cells, mice, and humans to more thoroughly understand the pathways that regulate their expression and activity with the goal of developing therapeutics that enhance RCT to reduce the risk of cardiovascular disease. Many of the drugs and natural compounds examined target several transcription factors critical for ABCA1 expression in both macrophages and the liver. Likewise, several miRNAs target not only ABCA1 but also the same transcription factors that are critical for its high expression. However, after years of research and many preclinical and clinical trials, only a few leads have proven beneficial in this regard. In this review we discuss the various transcription factors that serve as drug targets for ABCA1 and provide an update on some important leads.


Assuntos
Transportadores de Cassetes de Ligação de ATP , Colesterol , Transportador 1 de Cassete de Ligação de ATP/genética , Transportadores de Cassetes de Ligação de ATP/genética , Transportadores de Cassetes de Ligação de ATP/metabolismo , Trifosfato de Adenosina , Animais , Colesterol/metabolismo , Expressão Gênica , Humanos , Camundongos , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo
6.
Methods Mol Biol ; 2399: 61-84, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35604553

RESUMO

Redox proteomics plays an increasingly important role characterizing the cellular redox state and redox signaling networks. As these datasets grow larger and identify more redox regulated sites in proteins, they provide a systems-wide characterization of redox regulation across cellular organelles and regulatory networks. However, these large proteomic datasets require substantial data processing and analysis in order to fully interpret and comprehend the biological impact of oxidative posttranslational modifications. We therefore developed ProteoSushi, a software tool to biologically annotate and quantify redox proteomics and other modification-specific proteomics datasets. ProteoSushi can be applied to differentially alkylated samples to assay overall cysteine oxidation, chemically labeled samples such as those used to profile the cysteine sulfenome, or any oxidative posttranslational modification on any residue.Here we demonstrate how to use ProteoSushi to analyze a large, public cysteine redox proteomics dataset. ProteoSushi assigns each modified peptide to shared proteins and genes, sums or averages signal intensities for each modified site of interest, and annotates each modified site with the most up-to-date biological information available from UniProt. These biological annotations include known functional roles or modifications of the site, the protein domain(s) that the site resides in, the protein's subcellular location and function, and more.


Assuntos
Cisteína , Proteômica , Cisteína/química , Oxirredução , Processamento de Proteína Pós-Traducional , Proteoma/metabolismo
7.
Artigo em Inglês | MEDLINE | ID: mdl-35483558

RESUMO

Black seed extract stimulates apolipoprotein A-I (apo A-I) gene expression in hepatocytes and intestinal cells in part by elevating peroxisome proliferator-activated receptor α (PPARα) and retinoid X receptor α (RXRα) levels. To explore potential ramifications of these observations, we examined the effects of black seed extract on hepatocyte lipid content and expression of key transcriptional regulators of fatty acid ß-oxidation and lipogenesis in HepG2 cells. PPARα, peroxisome proliferator-activated receptor γ (PPARγ), RXRα, thyroid hormone receptor ß (TRß), sterol-responsive element binding protein 1 (SREBP1), and sterol-responsive element binding protein 2 (SREBP2) levels were measured in black seed extract treated liver-derived HepG2 cells. Black seed extract treatment increased PPARα and RXRα expression and decreased intracellular neutral lipid content. Black seed extract treatment increased TRß expression and activity, and PPARα activity. In contrast, PPARγ, SREBP1 and SREBP2 levels were decreased in black seed extract treated cells. Black seed extract treatment also increased acyl-CoA synthetase long chain family member 5 (ACSL5), peroxisomal acyl-CoA oxidase 1 (ACOX1), and carnitine palmitoyl transferase 1A (CPT-1A) expression, three PPARα-dependent rate-limiting genes that facilitate fatty acid oxidation, similar to fenofibrate. PPARα knockdown reversed the effects of fenofibrate and blackseed on ACSL5, ACOX1, and CPT-1A expression. In conclusion, black seed extract-mediated lipid lowering in HepG2 cells is associated with increased expression of fatty acid oxidation enzymes and PPARα and reduced lipogenic signaling. Thus black seed extract may be potentially beneficial in metabolic diseases such as diabetes, cardiovascular disease, and metabolic syndrome.


Assuntos
Fenofibrato , Nigella sativa , Ácidos Graxos/metabolismo , Fenofibrato/farmacologia , Células Hep G2 , Humanos , Metabolismo dos Lipídeos , Lipídeos , Nigella sativa/metabolismo , PPAR alfa/metabolismo , PPAR gama/metabolismo , Extratos Vegetais/farmacologia , Sementes/metabolismo , Esteróis
8.
J Food Biochem ; 46(2): e14064, 2022 02.
Artigo em Inglês | MEDLINE | ID: mdl-34984676

RESUMO

Several nutrients modulate the transcriptional activity of the apolipoprotein A-I (apo A-I) gene. To determine the influence of rare sugars on apo A-I expression in hepatic (HepG2) and intestinal derived (Caco-2) cell lines, apo A-I, albumin, and SP1 were quantified with enzyme immunoassay and Western blots while mRNA levels were quantified with real-time polymerase chain reaction. The promoter activity was measured using transient transfection assays with plasmids containing various segments and mutations in the promoter. D-allulose and D-tagatose, increased apo A-I concentration in culture media while D-sorbose and D-allose did not have any measurable effects. D-allulose did not increase apo A-I levels in Caco-2 cells. These changes paralleled the increased mRNA levels and promoter activity. D-allulose-response was mapped at the insulin response core element (IRCE). Mutation of the IRCE decreased the ability of D-allulose and insulin to activate the promoter. Treatment of HepG2 cells, but not Caco-2 cells, with D-alluose and insulin increased SP1 expression relative to control cells. D-allulose augmented the expression and IRCE binding of SP1, an essential transcription factor for the insulin on apo A-I promoter activity. D-allulose can modulate some insulin-responsive genes and may have anti-atherogenic properties, in part due to increasing apo A-I production. PRACTICAL APPLICATIONS: Coronary artery disease (CAD) is the number one cause of mortality in industrialized countries. A risk factor associated with CAD is low high-density lipoprotein (HDL) cholesterol and apolipoprotein A-I (apo A-I) concentrations in plasma. Thus, novel therapeutic agents or nutrients that upregulate apo A-I production should be identified. D-allulose and D-tagatose are used as sweeteners and may have favorable effects on insulin resistance and diabetes. This study shows that D-allulose and D-tagatose increases apo A-I production through increased transcription factor SP1-binding to insulin response element of the promoter. These sweeteners modulate some insulin responsive genes, increase the production of apo-A-I, and therefore may have anti-atherogenic properties.


Assuntos
Apolipoproteína A-I , Frutose/farmacologia , Insulina , Apolipoproteína A-I/genética , Células CACO-2 , Células Hep G2 , Hexoses , Humanos
9.
Drugs Aging ; 39(1): 39-58, 2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-34921341

RESUMO

The increasing incidence of type 2 diabetes in the general population as well as enhanced life expectancy has resulted in a rapid rise in the prevalence of diabetes in the older population. Diabetes causes significant morbidity and impairs quality of life. Managing diabetes in older adults is a daunting task due to unique health and psychosocial challenges. Medical management is complicated by polypharmacy, cognitive impairment, urinary incontinence, injurious falls, and persistent pain. Health care providers now have several traditional and contemporary pharmacologic agents to manage diabetes. Avoidance of hypoglycemia is critical; however, evidence-based guidelines are lacking due to the paucity of clinical trials in older adults. For many in this population, maintaining independence is more important than adherence to published guidelines to prevent diabetes complications. The goal of diabetes care in older adults is to enhance the quality of life without subjecting these patients to intrusive and complicated interventions. Recent technological advancements such as continuous glucose monitoring systems can have crucial supplementary benefits in the geriatric population.


Assuntos
Diabetes Mellitus Tipo 2 , Hiperglicemia , Idoso , Glicemia , Automonitorização da Glicemia , Diabetes Mellitus Tipo 2/complicações , Diabetes Mellitus Tipo 2/tratamento farmacológico , Humanos , Hiperglicemia/complicações , Hiperglicemia/tratamento farmacológico , Qualidade de Vida
10.
Drugs Aging ; 39(1): 23-37, 2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-34664212

RESUMO

Type 1 diabetes represents an autoimmune condition with a strong inherited background, and its incidence is increasing worldwide. About 25% of such cases are diagnosed in adulthood, some even as late as the ninth decade of life. The number of older adults with type 1 diabetes is increasing due to improvements in care and decreased mortality rate. However, there is a lack of clinical trials in people older than 70 years of age with type 1 diabetes complicated with comorbidities, frailty, and dependency. The management of type 1 diabetes and the goals of therapy should be individualized based on the patient's health status and life expectancy. In healthier older adults, insulin treatment regimens (multiple daily insulin injections or insulin pump therapy) that approximate the normal physiology of insulin secretion should be used to achieve lower glycemic goals, while reducing the risk of hypoglycemia with frequent glucose monitoring (preferably using continuous glucose monitoring systems). For frail individuals with poor health, simpler insulin regimens and less stringent glycemic targets would be more appropriate. Poor cognition, vision and hearing, impaired mobility, depression, and chronic pain can interfere with complex insulin regimens. In these individuals, the principal goals of therapy are to reduce the acute effects of hyperglycemia, minimize hypoglycemia risk, and optimize quality of life. The newer insulin preparations and technological advances in insulin delivery and blood glucose monitoring have enhanced the management of type 1 diabetes in all age groups.


Assuntos
Diabetes Mellitus Tipo 1 , Insulina , Adulto , Idoso , Glicemia , Automonitorização da Glicemia , Diabetes Mellitus Tipo 1/tratamento farmacológico , Humanos , Hipoglicemiantes/uso terapêutico , Insulina/uso terapêutico , Qualidade de Vida
11.
Vascul Pharmacol ; 142: 106948, 2022 02.
Artigo em Inglês | MEDLINE | ID: mdl-34843981

RESUMO

Selective cyclooxygenase-2 (COX-2) inhibitor rofecoxib was pulled off the market because of its association with increased risk of adverse cardiovascular effects. The precise underlying mechanism for the differential effects of COX-2 inhibitors on cardiovascular risk is not known. Since endoplasmic reticulum (ER) stress is implicated in atherogenesis, we examined the effects of COX-2 inhibitors on ER stress in primary human coronary artery endothelial cells (HCAEC), human umbilical vein endothelial cells (HUVEC), and human pulmonary artery endothelial cells (HPAEC). ER stress was measured in HCAEC treated with either tunicamycin (TM) or high-concentrations (27.5 mM) of dextrose (HD) using the secreted alkaline phosphatase (ES-TRAP) assay. Markers of the unfolded protein response (UPR) such as activating transcription factor 6 (ATF6), glucose-regulated protein 78 (GRP78), inositol-requiring enzyme 1α (IRE1α), phospho-IRE1α, protein kinase R (PKR)-like endoplasmic reticulum kinase (PERK), and phospho-PERK were measured by Western blot. Treatment of HCAEC with TM and HD decreased secreted alkaline phosphatase activity indicating increased ER stress. Treatment of cells exposed to TM or HD with celecoxib, meloxicam, ibuprofen, and acetylsalicylic acid, but not rofecoxib, resulted in a dose-dependent decrease in ER stress. High-dextrose and TM increased IRE1α and PERK phosphorylation and ATF6 and GRP78 expression. Treatment with celecoxib, but not rofecoxib, inhibited these markers of the UPR. Treatment with selective COX-2 inhibitors, with the exception of rofecoxib, suppressed ER stress as measured with both alkaline phosphatase activity assays and markers for the UPR. The inability of rofecoxib to inhibit ER stress, unlike the other cyclooxygenase inhibitors tested, may have contributed to its unfavorable effects on cardiovascular outcomes.


Assuntos
Inibidores de Ciclo-Oxigenase 2 , Estresse do Retículo Endoplasmático , Endorribonucleases , Células Endoteliais/efeitos dos fármacos , Vasos Coronários/citologia , Ciclo-Oxigenase 2/metabolismo , Inibidores de Ciclo-Oxigenase 2/farmacologia , Retículo Endoplasmático/metabolismo , Endorribonucleases/metabolismo , Células Endoteliais da Veia Umbilical Humana , Humanos , Proteínas Serina-Treonina Quinases , Resposta a Proteínas não Dobradas
12.
Eur J Pharmacol ; 907: 174249, 2021 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-34116042

RESUMO

Endoplasmic reticulum (ER) stress plays a critical role in progression of diabetes and development of complications, notably cardiovascular disease. Some of the contemporary anti-hyperglycemic drugs have been shown to inhibit ER stress. To extend these observations, the effects of various anti-hyperglycemic agents were screened for their effects on ER stress. Seven classes of anti-hyperglycemic drugs were screened including sulfonylureas, meglitinides, metformin, α glucosidase inhibitors, thiazolidinedione, glucagon like peptide 1 (GLP-1) receptor agonists and sodium-glucose cotransporter 2 (SGLT-2) inhibitors. ER stress was measured in human coronary artery endothelial cells (HCAEC) either treated with tunicamycin (TM) or cultured in hyperglycemic conditions (27.5 mM dextrose). The ER stress was measured with the secreted alkaline phosphatase (ES-TRAP) assay. Mediators of the unfolded protein response, including activating transcription factor 6 (ATF6), glucose-regulated protein 78 (GRP78), phospho-inositol-requiring enzyme 1α (pIRE1α), IRE1α, phospho-protein kinase R (PKR)-like endoplasmic reticulum kinase (pPERK), and PERK were measured by Western blot. Metformin, GLP-1 receptor agonists (GLP-1, exendin 4, liraglutide, albiglutide, and lixisenatide) and SGLT-2 inhibitors (canagliflozin, dapagliflozin, and empagliflozin) were the only anti-hyperglycemic drugs screened that reduced ER stress caused by pharmacological (tunicamycin) or hyperglycemic conditions. High-dextrose and TM increased IRE1α and PERK phosphorylation and ATF6 and GRP78 expression, while treatment with metformin, liraglutide (a GLP-1 receptor agonist) and dapagliflozin (a SGLT-2 inhibitor), suppressed IRE1α and PERK phosphorylation as well as ATF6 and GRP78 expression. Thus, the cardioprotective effects of metformin, some of the GLP-1 receptor agonists and SGLT2 inhibitors may be partly related to their ability to reduce ER stress.


Assuntos
Endorribonucleases , Fator 6 Ativador da Transcrição , Vasos Coronários , Células Endoteliais , Humanos , Tunicamicina/farmacologia
13.
J Proteome Res ; 20(7): 3621-3628, 2021 07 02.
Artigo em Inglês | MEDLINE | ID: mdl-34056901

RESUMO

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-Traducional
14.
Toxicol Res (Camb) ; 10(2): 284-291, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33884179

RESUMO

Cigarette smoking is one of the major causes of coronary artery disease (CAD) as is diabetes. However, nicotine has been generally regarded as safe and is used in smoking cessation programs. This presumption of nicotine safety was examined in human coronary artery endothelial cells (HCAEC). Endoplasmic reticulum (ER) stress was measured using the secreted alkaline phosphatase (SAP) assay. The ER stress markers inositol-requiring enzyme 1α (IRE1α), phospho-IRE1α, double-stranded RNA-activated protein kinase-like endoplasmic reticulum kinase (PERK), phospho-PERK, activating transcription factor 6 (ATF6), and glucose-related protein 78 (GRP78) were measured by western blot. Cell viability was measured using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and crystal violet staining. Intact and cleaved caspase 3, BH3 interacting-domain death agonist (BID), and B-cell lymphoma 2 (Bcl2) were measured by western blot. In cells transfected with the SAP expression plasmid, treatment with nicotine resulted in a dose-dependent decrease in SAP expression with no noticeable toxicity. Nicotine (10 nM) also increased IRE1α and PERK phosphorylation, and ATF6 and GRP78 expression. Although nicotine at concentrations up to 10 µM did not cause cell death, treatment of HCAEC with 10 nM nicotine in the presence of 13.8 mM dextrose aggravated ER stress, increased cell death, increased cleaved caspase 3 and BID, and decreased BCL2. Nicotine at concentrations commonly achieved in nicotine-replacement therapy (NRT) significantly increased ER stress in HCAEC and aggravated dextrose-induced ER stress and cell apoptosis. People using electronic cigarettes and on NRT may be at increased risk for CAD.

15.
Physiol Rep ; 9(7): e14816, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33818012

RESUMO

Normal blood glucose levels in avian species are two to fourfold higher than that in humans and the higher blood glucose levels in birds do not cause adverse effects. Endothelial cells isolated from the aorta of the domestic hen (Gallus gallus domesticus) and chicken aortic smooth muscle cells (CAOSMC) were compared to human coronary artery endothelial cells (HCAEC) and human primary aortic smooth muscle cells (HASMC). Superoxide (SO) generation was measured using a superoxide-reactive probe. ER stress was measured using the placental alkaline phosphatase assay (ES-TRAP). Glucose transport kinetics were determined using the 3 H-2-deoxyglucose tracer. Dextrose-induced SO generation and ER stress were significantly blunted in avian endothelial cells compared to human cells. The Vmax of glucose uptake (in nmoles/mg protein/min) in avian endothelial cells (0.0018 ± 0.0001) and smooth muscle cells (0.0015 ± 0.0007) was approximately 18-25 fold lower compared to the Vmax in HCAEC (0.033 ± 0.0025) and HASMC (0.038 ± 0.004) (all p < 0.0001). The Michaelis-Menten constant (Km) of transport was also significantly different (p < 0.0001) in avian species. The relative resistance of avian cells to dextrose-induced oxidative stress and ER stress is mostly the result of reduced cellular dextrose transport.


Assuntos
Estresse do Retículo Endoplasmático , Células Endoteliais/metabolismo , Glucose/metabolismo , Estresse Oxidativo , Animais , Transporte Biológico , Células Cultivadas , Galinhas , Células Endoteliais/efeitos dos fármacos , Endotélio Vascular/citologia , Humanos , Oxidantes/farmacologia , Superóxidos/metabolismo
16.
Artigo em Inglês | MEDLINE | ID: mdl-33637605

RESUMO

INTRODUCTION: Current dietary guidelines recommend limiting sugar intake for the prevention of diabetes mellitus (DM). Reduction in sugar intake may require sugar substitutes. Among these, D-allulose is a non-calorie rare monosaccharide with 70% sweetness of sucrose, which has shown anti-DM effects in Asian populations. However, there is limited data on the effects of D-allulose in other populations, including Westerners. RESEARCH DESIGN AND METHODS: This was a prospective, randomized, double-blind, placebo-controlled, crossover study conducted in 30 subjects without DM. Study participants were given a standard oral (50 g) sucrose load and randomized to placebo or escalating doses of D-allulose (2.5, 5.0, 7.5, 10.0 g). Subjects crossed-over to the alternate study treatment after 7-14 days of wash out. Plasma glucose and insulin levels were measured at five time points: before and at 30, 60, 90 and 120 min after ingestion. RESULTS: D-allulose was associated with a dose-dependent reduction of plasma glucose at 30 min compared with placebo. In particular, glucose was significantly lower with the 7.5 g (mean difference: 11; 95% CI 3 to 19; p=0.005) and 10 g (mean difference: 12; 95% CI 4 to 20; p=0.002) doses. Although glucose was not reduced at the other time points, there was a dose-dependent reduction in glucose excursion compared with placebo, which was significant with the 10 g dose (p=0.023). Accordingly, at 30 min D-allulose was associated with a trend towards lower insulin levels compared with placebo, which was significant with the 10 g dose (mean difference: 14; 95% CI 4 to 25; p=0.006). D-allulose did not reduce insulin at any other time point, but there was a significant dose-dependent reduction in insulin excursion compared with placebo (p=0.028), which was significant with the 10 g dose (p=0.002). CONCLUSIONS: This is the largest study assessing the effects of D-allulose in Westerners demonstrating an early dose-dependent reduction in plasma glucose and insulin levels as well as decreased postprandial glucose and insulin excursion in subjects without DM. These pilot observations set the basis for large-scale investigations to support the anti-DM effects of D-allulose. TRIAL REGISTRATION NUMBER: NCT02714413.


Assuntos
Insulina , Sacarose , Glicemia , Estudos Cross-Over , Frutose , Glucose , Humanos , Estudos Prospectivos
17.
Acad Med ; 96(4): 599-606, 2021 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-33116061

RESUMO

PURPOSE: Faculty development (FD) has become increasingly important for clinician-educators. An array of FD programs has been developed, but the impact of these programs on clinician-educators and their learners and workplace is less known. The authors conducted a scoping review to explore the status of program evaluation in FD for clinician-educators to inform future planning and research. METHOD: Five databases were searched for articles published from January 1998 to August 2018 using Arksey and O'Malley's framework and the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Extension for Scoping Reviews. Studies that described evaluation methods and outcomes of FD programs for clinician-educators were included. Data were collected and organized according to program domain (teaching, research/scholarship, leadership, or a combination of skills). A modified version of the Kirkpatrick model was used to compare results among studies. RESULTS: From a total of 2,091 articles, 1,095 were eligible for full review, and 31 met the inclusion criteria. Seven programs targeted only teaching skills, 3 research/scholarship skills, 7 leadership skills, and 14 a combination of skills. Eighteen programs required the completion of a project; fewer offered fellowships, master's degrees, or certificates. Participant surveys were the most common evaluation method across all domains. Often used metrics included participant satisfaction and self-reported knowledge, skills, behavior changes, scholarly output, and leadership positions. Less common evaluation methods included learner and peer evaluations, interviews, and focus groups. Change at the institutional level was evaluated in 11 programs. CONCLUSIONS: Program evaluation remains an underdeveloped area in FD for clinician-educators. Developers expend significant effort on program design and implementation but approach evaluation less purposefully. Rigorous metrics that align with program goals and are used longitudinally are needed to accurately assess the impact of FD programs on participants and their learners, workplace, and institutions at large.


Assuntos
Currículo , Educação Profissionalizante/organização & administração , Educação Profissionalizante/estatística & dados numéricos , Docentes de Medicina/educação , Docentes de Medicina/estatística & dados numéricos , Desenvolvimento de Pessoal/organização & administração , Desenvolvimento de Pessoal/estatística & dados numéricos , Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade
18.
Handb Exp Pharmacol ; 264: 3-26, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-32767143

RESUMO

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 Sinais
19.
Am J Manag Care ; 26(4): 177-180, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-32270985

RESUMO

Several strategies have been proposed to improve referrals and communication between primary care providers (PCPs) and specialists. In this article, we describe the effectiveness of collaborative care plans (CCPs) in reducing utilization of specialist resources in a capitated health plan based in a safety net hospital. To operationalize individual care plans, a single clinic called the Total Care Clinic (TCC) was launched. Midlevel providers were assigned to subspecialties and trained in specific algorithms of care that they were responsible for. Midlevel providers in the TCC were invited to attend in-house education opportunities. These interventions resulted in an overall 33.6-percentage-point reduction in the referral rate over 7 years of observation. The largest decrease in referrals was observed in gastroenterology, which resulted mostly from colon cancer screening with fecal immunochemical tests in place of colonoscopies. No increase in emergency department (ED) visits or hospital admissions accompanied the decreased referrals to specialists. Combining CCPs with provider education and placing select specialists in proximity of the PCPs resulted in significant referral reductions to specialists without increases in ED visits or hospital admissions.


Assuntos
Comportamento Cooperativo , Planejamento de Assistência ao Paciente/organização & administração , Equipe de Assistência ao Paciente/organização & administração , Encaminhamento e Consulta/estatística & dados numéricos , Humanos , Visita a Consultório Médico/estatística & dados numéricos , Relações Médico-Paciente
20.
Eur J Pharmacol ; 879: 173119, 2020 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-32325145

RESUMO

Endoplasmic reticulum (ER) stress as well as oxidative stress have been shown to play important roles in metabolic and cardiovascular disease, and drugs that counteract the effects of ER and oxidative stresses may be clinically useful. To identify novel compounds that ameliorate ER and oxidative stresses, we screened two drug libraries purchased from Evotec, San Francisco, CA; the NIH clinical collection 1 (446 compounds) and the NIH clinical collection 2 (281 compounds). Human coronary artery endothelial cells (HCAEC) were tested for ER and oxidative stress. ER stress was measured with an ER stress-sensitive secreted alkaline phosphatase (SAP) assay. The cells were transfected with the plasmid pSAP2.Control, expressing a heat-resistant form of SAP, and treated with the ER stress inducer tunicamycin in the presence or absence of each of the various compounds for 24-h, at which time SAP activity was measured. Compounds exhibiting significant increases in SAP activity (41 compounds out of a total of 727 tested; 5.6%) were then assayed for their ability to suppress superoxide (SO) anion generation in cells treated with 27.5 mM dextrose. 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. Of the 41 compounds identified as ER stress reducers, only 33 (80.5%) suppressed dextrose-induced SO anion generation. Interestingly, 51% of the compounds found to be dual-stress modifiers consisted of cardioprotective drugs, including statins, angiotensin receptor blockers, angiotensin-converting enzyme inhibitors as well as ß-blockers. Future studies to validate the clinical effectiveness of these agents remain to be performed in pre-clinical and clinical trials.


Assuntos
Antioxidantes/farmacologia , Vasos Coronários/citologia , Estresse do Retículo Endoplasmático/efeitos dos fármacos , Células Endoteliais/efeitos dos fármacos , Ensaios de Triagem em Larga Escala , Estresse Oxidativo/efeitos dos fármacos , Antagonistas Adrenérgicos beta/farmacologia , Fosfatase Alcalina/metabolismo , Antagonistas de Receptores de Angiotensina/farmacologia , Inibidores da Enzima Conversora de Angiotensina/farmacologia , Calcitriol/farmacologia , Fármacos Cardiovasculares/farmacologia , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Células Endoteliais/metabolismo , Estradiol/farmacologia , Humanos , Inibidores de Hidroximetilglutaril-CoA Redutases/farmacologia , Espironolactona/farmacologia , Superóxidos/metabolismo
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