RESUMO
Prostate cancer is a leading cause of cancer death in men. Inflammation and overexpression of inducible nitric oxide synthase (NOS2) have been implicated in prostate carcinogenesis. We aimed to explore the hypothesis that nitric oxide NO exerts pro-tumorigenic effects on prostate cells at physiologically relevant levels contributing to carcinogenesis. We investigated the impact of acute exposure of normal immortalised prostate cells (RWPE-1) to NO on cell proliferation and activation of DNA damage repair pathways. Furthermore we investigated the long term effects of chronic NO exposure on RWPE-1 cell migration and invasion potential and hallmarks of transformation. Our results demonstrate that NO induces DNA damage as indicated by γH2AX foci and p53 activation resulting in a G1/S phase block and activation of 53BP1 DNA damage repair protein. Long term adaption to NO results in increased migration and invasion potential, acquisition of anchorage independent growth and increased resistance to chemotherapy. This was recapitulated in PC3 and DU145 prostate cancer cells which upon chronic exposure to NO displayed increased cell migration, colony formation and increased resistance to chemotherapeutics. These findings indicate that NO may play a key role in the development of prostate cancer and the acquisition of an aggressive metastatic phenotype.
Assuntos
Próstata , Neoplasias da Próstata , Carcinogênese , Linhagem Celular Tumoral , Humanos , Masculino , Óxido Nítrico/metabolismo , Fenótipo , Próstata/metabolismo , Próstata/patologia , Neoplasias da Próstata/tratamento farmacológico , Neoplasias da Próstata/genética , Neoplasias da Próstata/metabolismoRESUMO
Obesity, dyslipidemia, and insulin resistance, the increasingly common metabolic syndrome, are risk factors for CVD and type 2 diabetes that warrant novel therapeutic interventions. The flavonoid nobiletin displays potent lipid-lowering and insulin-sensitizing properties in mice with metabolic dysfunction. However, the mechanisms by which nobiletin mediates metabolic protection are not clearly established. The central role of AMP-activated protein kinase (AMPK) as an energy sensor suggests that AMPK is a target of nobiletin. We tested the hypothesis that metabolic protection by nobiletin required phosphorylation of AMPK and acetyl-CoA carboxylase (ACC) in mouse hepatocytes, in mice deficient in hepatic AMPK (Ampkß1-/-), in mice incapable of inhibitory phosphorylation of ACC (AccDKI), and in mice with adipocyte-specific AMPK deficiency (iß1ß2AKO). We fed mice a high-fat/high-cholesterol diet with or without nobiletin. Nobiletin increased phosphorylation of AMPK and ACC in primary mouse hepatocytes, which was associated with increased FA oxidation and attenuated FA synthesis. Despite loss of ACC phosphorylation in Ampkß1-/- hepatocytes, nobiletin suppressed FA synthesis and enhanced FA oxidation. Acute injection of nobiletin into mice did not increase phosphorylation of either AMPK or ACC in liver. In mice fed a high-fat diet, nobiletin robustly prevented obesity, hepatic steatosis, dyslipidemia, and insulin resistance, and it improved energy expenditure in Ampkß1-/-, AccDKI, and iß1ß2AKO mice to the same extent as in WT controls. Thus, the beneficial metabolic effects of nobiletin in vivo are conferred independently of hepatic or adipocyte AMPK activation. These studies further underscore the therapeutic potential of nobiletin and begin to clarify possible mechanisms.
Assuntos
Proteínas Quinases Ativadas por AMP/antagonistas & inibidores , Antioxidantes/farmacologia , Citrus/química , Flavonas/farmacologia , Substâncias Protetoras/farmacologia , Proteínas Quinases Ativadas por AMP/deficiência , Proteínas Quinases Ativadas por AMP/metabolismo , Animais , Antioxidantes/química , Dieta Hiperlipídica/efeitos adversos , Flavonas/química , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Substâncias Protetoras/químicaRESUMO
Proprotein convertase subtilisin/kexin type-9 (PCSK9) is a secreted zymogen expressed primarily in the liver. PCSK9 circulates in plasma, binds to cell surface low-density lipoprotein (LDL) receptors, is internalized, and then targets the receptors to lysosomal degradation. Studies of naturally occurring PCSK9 gene variants that caused extreme plasma LDL cholesterol (LDL-C) deviations and altered atherosclerosis risk unleashed a torrent of biological and pharmacological research. Rapid progress in understanding the physiological regulation of PCSK9 was soon translated into commercially available biological inhibitors of PCSK9 that reduced LDL-C levels and likely also cardiovascular outcomes. Here we review the swift evolution of PCSK9 from novel gene to drug target, to animal and human testing, and finally to outcome trials and clinical applications. In addition, we explore how the genetics-guided path to PCSK9 inhibitor development exemplifies a new paradigm in pharmacology. Finally, we consider some potential challenges as PCSK9 inhibition becomes established in the clinic.
Assuntos
Sistemas de Liberação de Medicamentos/métodos , Descoberta de Drogas/métodos , Dislipidemias/tratamento farmacológico , Inibidores de PCSK9 , Pró-Proteína Convertase 9/fisiologia , Animais , LDL-Colesterol/antagonistas & inibidores , LDL-Colesterol/sangue , Sistemas de Liberação de Medicamentos/tendências , Descoberta de Drogas/tendências , Dislipidemias/sangue , Dislipidemias/enzimologia , Inibidores Enzimáticos/administração & dosagem , Inibidores Enzimáticos/metabolismo , Humanos , Hipercolesterolemia/sangue , Hipercolesterolemia/tratamento farmacológico , Hipercolesterolemia/enzimologiaRESUMO
OBJECTIVE: Stress granules (SGs) are dynamic cytoplasmic aggregates containing mRNA, RNA-binding proteins, and translation factors that form in response to cellular stress. SGs have been shown to contribute to the pathogenesis of several human diseases, but their role in vascular diseases is unknown. This study shows that SGs accumulate in vascular smooth muscle cells (VSMCs) and macrophages during atherosclerosis. Approach and Results: Immunohistochemical analysis of atherosclerotic plaques from LDLR-/- mice revealed an increase in the stress granule-specific markers Ras-G3BP1 (GTPase-activating protein SH3 domain-binding protein) and PABP (poly-A-binding protein) in intimal macrophages and smooth muscle cells that correlated with disease progression. In vitro, PABP+ and G3BP1+ SGs were rapidly induced in VSMC and bone marrow-derived macrophages in response to atherosclerotic stimuli, including oxidized low-density lipoprotein and mediators of mitochondrial or oxidative stress. We observed an increase in eIF2α (eukaryotic translation initiation factor 2-alpha) phosphorylation, a requisite for stress granule formation, in cells exposed to these stimuli. Interestingly, SG formation, PABP expression, and eIF2α phosphorylation in VSMCs is reversed by treatment with the anti-inflammatory cytokine interleukin-19. Microtubule inhibitors reduced stress granule accumulation in VSMC, suggesting cytoskeletal regulation of stress granule formation. SG formation in VSMCs was also observed in other vascular disease pathologies, including vascular restenosis. Reduction of SG component G3BP1 by siRNA significantly altered expression profiles of inflammatory, apoptotic, and proliferative genes. CONCLUSIONS: These results indicate that SG formation is a common feature of the vascular response to injury and disease, and that modification of inflammation reduces stress granule formation in VSMC.
Assuntos
Aterosclerose/metabolismo , Grânulos Citoplasmáticos/genética , DNA Helicases/genética , Regulação da Expressão Gênica , Proteínas de Ligação a Poli-ADP-Ribose/genética , RNA Helicases/genética , Proteínas com Motivo de Reconhecimento de RNA/genética , Lesões do Sistema Vascular/metabolismo , Animais , Aterosclerose/patologia , Biópsia por Agulha , Células Cultivadas , Colesterol/farmacologia , DNA Helicases/metabolismo , Modelos Animais de Doenças , Humanos , Imuno-Histoquímica , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Músculo Liso Vascular/citologia , Estresse Oxidativo , RNA Helicases/metabolismo , Distribuição Aleatória , Sensibilidade e Especificidade , Lesões do Sistema Vascular/patologiaRESUMO
PURPOSE OF REVIEW: Bempedoic acid has emerged as a potent inhibitor of ATP-citrate lyase (ACLY), a target for the reduction of LDL cholesterol (LDL-C). We review the impact of bempedoic acid treatment on lipoprotein metabolism and atherosclerosis in preclinical models and patients with hypercholesterolemia. RECENT FINDINGS: The liver-specific activation of bempedoic acid inhibits ACLY, a key enzyme linking glucose catabolism to lipogenesis by catalyzing the formation of acetyl-CoA from mitochondrial-derived citrate for de novo synthesis of fatty acids and cholesterol. Adenosine monophosphate-activated protein kinase activation by bempedoic acid is not required for its lipid-regulating effects in vivo. Mendelian randomization of large human study cohorts has validated ACLY inhibition as a target for LDL-C lowering and atheroprotection. In rodents, bempedoic acid decreases plasma cholesterol and triglycerides, and prevents hepatic steatosis. In apolipoprotein E-deficient (Apoe) mice, LDL receptor-deficient (Ldlr) mice and LDLR-deficient miniature pigs, bempedoic acid reduces LDL-C and attenuates atherosclerosis. LDLR expression and activity are increased in primary human hepatocytes and in Apoe mouse liver treated with bempedoic acid suggesting a mechanism for LDL-C lowering, although additional pathways are likely involved. Phase 2 and 3 clinical trials revealed that bempedoic acid effectively lowers LDL-C as monotherapy, combined with ezetimibe, added to statin therapy and in statin-intolerant hypercholesterolemic patients. Treatment does not affect plasma concentrations of triglyceride or other lipoproteins. SUMMARY: The LDL-C-lowering and attenuated atherosclerosis in animal models and reduced LDL-C in hypercholesterolemic patients has validated ACLY inhibition as a therapeutic strategy. Positive results from phase 3 long-term cardiovascular outcome trials in high-risk patients are required for bempedoic acid to be approved for prevention of atherosclerosis.
Assuntos
Aterosclerose/tratamento farmacológico , Aterosclerose/metabolismo , Ácidos Dicarboxílicos/farmacologia , Ácidos Graxos/farmacologia , Lipoproteínas/metabolismo , ATP Citrato (pro-S)-Liase/antagonistas & inibidores , Animais , Ácidos Dicarboxílicos/uso terapêutico , Ácidos Graxos/uso terapêutico , Humanos , Terapia de Alvo Molecular , Triglicerídeos/metabolismoRESUMO
OBJECTIVE: Bempedoic acid (BemA; ETC-1002) is a novel drug that targets hepatic ATP-citrate lyase to reduce cholesterol biosynthesis. In phase 2 studies, BemA lowers elevated low-density lipoprotein cholesterol (LDL-C) in hypercholesterolemic patients. In the present study, we tested the ability of BemA to decrease plasma cholesterol and LDL-C and attenuate atherosclerosis in a large animal model of familial hypercholesterolemia. APPROACH AND RESULTS: Gene targeting has been used to generate Yucatan miniature pigs heterozygous (LDLR+/-) or homozygous (LDLR-/-) for LDL receptor deficiency (ExeGen). LDLR+/- and LDLR-/- pigs were fed a high-fat, cholesterol-containing diet (34% kcal fat; 0.2% cholesterol) and orally administered placebo or BemA for 160 days. In LDLR+/- pigs, compared with placebo, BemA decreased plasma cholesterol and LDL-C up to 40% and 61%, respectively. In LDLR-/- pigs, in which plasma cholesterol and LDL-C were 5-fold higher than in LDLR+/- pigs, BemA decreased plasma cholesterol and LDL-C up to 27% and 29%, respectively. Plasma levels of triglycerides and high-density lipoprotein cholesterol, fasting glucose and insulin, and liver lipids were unaffected by treatment in either genotype. In the aorta of LDLR+/- pigs, BemA robustly attenuated en face raised lesion area (-58%) and left anterior descending coronary artery cross-sectional lesion area (-40%). In LDLR-/- pigs, in which lesions were substantially more advanced, BemA decreased aortic lesion area (-47%) and left anterior descending coronary artery lesion area (-48%). CONCLUSIONS: In a large animal model of LDLR deficiency and atherosclerosis, long-term treatment with BemA reduces LDL-C and attenuates the development of aortic and coronary atherosclerosis in both LDLR+/- and LDLR-/- miniature pigs.
Assuntos
Anticolesterolemiantes/farmacologia , Doenças da Aorta/prevenção & controle , Aterosclerose/prevenção & controle , LDL-Colesterol/sangue , Doença da Artéria Coronariana/prevenção & controle , Ácidos Dicarboxílicos/farmacologia , Ácidos Graxos/farmacologia , Hiperlipoproteinemia Tipo II/tratamento farmacológico , Receptores de LDL/deficiência , Animais , Animais Geneticamente Modificados , Anticolesterolemiantes/farmacocinética , Doenças da Aorta/sangue , Doenças da Aorta/genética , Doenças da Aorta/patologia , Aterosclerose/sangue , Aterosclerose/genética , Aterosclerose/patologia , Biomarcadores/sangue , Doença da Artéria Coronariana/sangue , Doença da Artéria Coronariana/genética , Doença da Artéria Coronariana/patologia , Ácidos Dicarboxílicos/farmacocinética , Modelos Animais de Doenças , Regulação para Baixo , Ácidos Graxos/farmacocinética , Feminino , Regulação da Expressão Gênica , Predisposição Genética para Doença , Hiperlipoproteinemia Tipo II/sangue , Hiperlipoproteinemia Tipo II/genética , Masculino , Fenótipo , Placa Aterosclerótica , Receptores de LDL/genética , Suínos , Porco MiniaturaRESUMO
PURPOSE OF REVIEW: Regression, or reversal, of atherosclerosis has become an important clinical objective. The development of consistent models of murine atherosclerosis regression has accelerated this field of research. The purpose of this review is to highlight recent mouse studies that reveal molecular mechanisms as well as therapeutics targeted for regression. RECENT FINDINGS: Atherosclerosis regression does not involve the same mechanisms as progression in reverse order. Distinct molecular processes within the plaque characterize regression. These processes remained elusive until the advent of murine regression models including aortic transplant, the Reversa mouse, gene complementation and dietary intervention. Studies revealed that depletion of plaque macrophages is a quintessential characteristic of regression, driven by reduced monocyte recruitment into plaques, increased egress of macrophages from plaques and reduced macrophage proliferation. In addition, regression results in polarization of remaining plaque macrophages towards an anti-inflammatory phenotype, smaller necrotic cores and promotion of an organized fibrous cap. Furthermore, type 1 diabetes hinders plaque regression, and several therapeutic interventions show promise in slowing plaque progression or inducing regression. SUMMARY: Mouse models of atherosclerosis regression have accelerated our understanding of the molecular mechanisms governing lesion resolution. These insights will be valuable in identifying therapeutic targets aimed at atherosclerosis regression.
Assuntos
Aterosclerose , Animais , Animais Geneticamente Modificados , Aterosclerose/complicações , Aterosclerose/genética , Aterosclerose/patologia , Modelos Animais de Doenças , Progressão da Doença , Humanos , CamundongosRESUMO
Obesity and its associated metabolic dysfunction and cardiovascular disease risk represent a leading cause of adult morbidity worldwide. Currently available pharmacological therapies for obesity have had limited success in reversing existing obesity and metabolic dysregulation. Previous prevention studies demonstrated that the citrus flavonoids, naringenin and nobiletin, protect against obesity and metabolic dysfunction in Ldlr-/- mice fed a high-fat cholesterol-containing (HFHC) diet. However, their effects in an intervention model are unknown. In this report, we show that, in Ldlr-/- mice with diet-induced obesity, citrus flavonoid supplementation to a HFHC diet reversed existing obesity and adipocyte size and number through enhanced energy expenditure and increased hepatic fatty acid oxidation. Caloric intake was unaffected and no evidence of white adipose tissue browning was observed. Reversal of adiposity was accompanied by improvements in hyperlipidemia, insulin sensitivity, hepatic steatosis, and a modest reduction in blood monocytes. Together, this resulted in atherosclerotic lesions that were unchanged in size, but characterized by reduced macrophage content, consistent with a more stable plaque phenotype. These studies further suggest potential therapeutic utility of citrus flavonoids, especially in the context of existing obesity, metabolic dysfunction, and cardiovascular disease.
Assuntos
Aterosclerose/complicações , Citrus/química , Flavonoides/farmacologia , Síndrome Metabólica/complicações , Obesidade/complicações , Obesidade/tratamento farmacológico , Receptores de LDL/deficiência , Tecido Adiposo/efeitos dos fármacos , Tecido Adiposo/patologia , Animais , Peso Corporal/efeitos dos fármacos , Colesterol/metabolismo , Dieta Hiperlipídica/efeitos adversos , Metabolismo Energético/efeitos dos fármacos , Flavonoides/uso terapêutico , Hiperlipidemias/complicações , Resistência à Insulina , Macrófagos/efeitos dos fármacos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Monócitos/efeitos dos fármacos , Obesidade/metabolismo , Obesidade/patologiaRESUMO
Mesenchymal stem cells (MSCs) are a heterogeneous population of multipotent cells that are capable of differentiating into osteocytes, chondrocytes and adipocytes. Recently, MSCs have been found to home to the tumour site and engraft in the tumour stroma. However, it is not yet known whether they have a tumour promoting or suppressive function. We investigated the interaction between prostate cancer cell lines 22Rv1, DU145 and PC3, and bone marrow-derived MSCs. MSCs were 'educated' for extended periods in prostate cancer cell conditioned media and PC3-educated MSCs were found to be the most responsive with a secretory profile rich in pro-inflammatory cytokines. PC3-educated MSCs secreted increased osteopontin (OPN), interleukin-8 (IL-8) and fibroblast growth factor-2 (FGF-2) and decreased soluble fms-like tyrosine kinase-1 (sFlt-1) compared to untreated MSCs. PC3-educated MSCs showed a reduced migration and proliferation capacity that was dependent on exposure to PC3-conditioned medium. Vimentin and α-smooth muscle actin (αSMA) expression was decreased in PC3-educated MSCs compared to untreated MSCs. PC3 and DU145 education of healthy donor and prostate cancer patient-derived MSCs led to a reduced proportion of FAP+ αSMA+ cells contrary to characteristics commonly associated with cancer associated fibroblasts (CAFs). The migration of PC3 cells was increased toward both PC3-educated and DU145-educated MSCs compared to untreated MSCs, while DU145 migration was only enhanced toward patient-derived MSCs. In summary, MSCs developed an altered phenotype in response to prostate cancer conditioned medium which resulted in increased secretion of pro-inflammatory cytokines, modified functional activity and the chemoattraction of prostate cancer cells.
Assuntos
Citocinas/metabolismo , Citocinas/farmacologia , Células-Tronco Mesenquimais/efeitos dos fármacos , Neoplasias da Próstata/metabolismo , Adulto , Linhagem Celular Tumoral , Movimento Celular/efeitos dos fármacos , Meios de Cultivo Condicionados , Humanos , Masculino , Células-Tronco Mesenquimais/patologia , Pessoa de Meia-Idade , Metástase Neoplásica , Neoplasias da Próstata/patologia , Adulto JovemRESUMO
OBJECTIVE: Bempedoic acid (ETC-1002, 8-hydroxy-2,2,14,14-tetramethylpentadecanedioic acid) is a novel low-density lipoprotein cholesterol-lowering compound. In animals, bempedoic acid targets the liver where it inhibits cholesterol and fatty acid synthesis through inhibition of ATP-citrate lyase and through activation of AMP-activated protein kinase. In this study, we tested the hypothesis that bempedoic acid would prevent diet-induced metabolic dysregulation, inflammation, and atherosclerosis. APPROACH AND RESULTS: Ldlr-/- mice were fed a high-fat, high-cholesterol diet (42% kcal fat, 0.2% cholesterol) supplemented with bempedoic acid at 0, 3, 10 and 30 mg/kg body weight/day. Treatment for 12 weeks dose-dependently attenuated diet-induced hypercholesterolemia, hypertriglyceridemia, hyperglycemia, hyperinsulinemia, fatty liver and obesity. Compared to high-fat, high-cholesterol alone, the addition of bempedoic acid decreased plasma triglyceride (up to 64%) and cholesterol (up to 50%) concentrations, and improved glucose tolerance. Adiposity was significantly reduced with treatment. In liver, bempedoic acid prevented cholesterol and triglyceride accumulation, which was associated with increased fatty acid oxidation and reduced fatty acid synthesis. Hepatic gene expression analysis revealed that treatment significantly increased expression of genes involved in fatty acid oxidation while suppressing inflammatory gene expression. In full-length aorta, bempedoic acid markedly suppressed cholesteryl ester accumulation, attenuated the expression of proinflammatory M1 genes and attenuated the iNos/Arg1 ratio. Treatment robustly attenuated atherosclerotic lesion development in the aortic sinus by 44%, with beneficial changes in morphology, characteristic of earlier-stage lesions. CONCLUSIONS: Bempedoic acid effectively prevents plasma and tissue lipid elevations and attenuates the onset of inflammation, leading to the prevention of atherosclerotic lesion development in a mouse model of metabolic dysregulation.
Assuntos
ATP Citrato (pro-S)-Liase/antagonistas & inibidores , Aterosclerose/prevenção & controle , Ácidos Dicarboxílicos/farmacologia , Dieta Hiperlipídica , Dislipidemias/prevenção & controle , Inibidores Enzimáticos/farmacologia , Ácidos Graxos/farmacologia , Inflamação/prevenção & controle , Fígado/efeitos dos fármacos , Obesidade/prevenção & controle , Receptores de LDL/deficiência , ATP Citrato (pro-S)-Liase/metabolismo , Animais , Aterosclerose/sangue , Aterosclerose/enzimologia , Aterosclerose/genética , Biomarcadores/sangue , Glicemia/efeitos dos fármacos , Glicemia/metabolismo , Modelos Animais de Doenças , Dislipidemias/sangue , Dislipidemias/enzimologia , Dislipidemias/genética , Regulação da Expressão Gênica , Predisposição Genética para Doença , Inflamação/sangue , Inflamação/enzimologia , Inflamação/genética , Mediadores da Inflamação/sangue , Insulina/sangue , Lipídeos/sangue , Fígado/enzimologia , Masculino , Camundongos Knockout , Obesidade/sangue , Obesidade/enzimologia , Obesidade/genética , Fenótipo , Receptores de LDL/genética , Fatores de TempoRESUMO
PURPOSE OF REVIEW: ATP-citrate lyase (ACLY) has re-emerged as a drug target for LDL cholesterol (LDL-C) lowering. We review ACLY as a therapeutic strategy, its genetics, its molecular and cellular biology, and also its inhibition. RECENT FINDINGS: ACLY is a critical enzyme linking glucose catabolism to lipogenesis by providing acetyl-CoA from mitochondrial citrate for fatty acid and cholesterol biosynthesis. Human genetic variants have been associated with enhanced growth and survival of several cancers, and with attenuated plasma triglyceride responses to dietary fish oil. In mice, liver-specific Acly deficiency protects from hepatic steatosis and dyslipidemia, whereas adipose tissue-specific Acly deletion has no phenotype, supporting therapeutic inhibition of ACLY. A lipid-regulating compound, bempedoic acid, was discovered to potently inhibit ACLY, and in animal models, it prevents dyslipidemia and attenuates atherosclerosis. Phase 2 clinical trials revealed that bempedoic acid effectively lowers LDL-C as monotherapy, combined with ezetimibe, added to statin therapy and in statin-intolerant hypercholesterolemic patients. SUMMARY: The efficacy of bempedoic acid as an LDL-C-lowering agent has validated ACLY inhibition as a therapeutic strategy. Positive results of phase 3 patient studies, together with long-term cardiovascular disease outcome trials, are required to establish ACLY as a major new target in cardiovascular medicine.
Assuntos
ATP Citrato (pro-S)-Liase/genética , ATP Citrato (pro-S)-Liase/metabolismo , Dislipidemias/tratamento farmacológico , Dislipidemias/enzimologia , Terapia de Alvo Molecular/métodos , ATP Citrato (pro-S)-Liase/antagonistas & inibidores , Animais , Ácidos Dicarboxílicos/metabolismo , Dislipidemias/genética , Dislipidemias/patologia , Inibidores Enzimáticos/farmacologia , Ácidos Graxos/metabolismo , HumanosRESUMO
Citrus flavonoids are polyphenolic compounds with significant biological properties. This review summarizes recent advances in understanding the ability of citrus flavonoids to modulate lipid metabolism, other metabolic parameters related to the metabolic syndrome, and atherosclerosis. Citrus flavonoids, including naringenin, hesperitin, nobiletin, and tangeretin, have emerged as potential therapeutics for the treatment of metabolic dysregulation. Epidemiological studies reveal an association between the intake of citrus flavonoid-containing foods and a decreased incidence of cardiovascular disease. Studies in cell culture and animal models, as well as a limited number of clinical studies, reveal the lipid-lowering, insulin-sensitizing, antihypertensive, and anti-inflammatory properties of citrus flavonoids. In animal models, supplementation of rodent diets with citrus flavonoids prevents hepatic steatosis, dyslipidemia, and insulin resistance primarily through inhibition of hepatic fatty acid synthesis and increased fatty acid oxidation. Citrus flavonoids blunt the inflammatory response in metabolically important tissues including liver, adipose, kidney, and the aorta. The mechanisms underlying flavonoid-induced metabolic regulation have not been completely established, although several potential targets have been identified. In mouse models, citrus flavonoids show marked suppression of atherogenesis through improved metabolic parameters as well as through direct impact on the vessel wall. Recent studies support a role for citrus flavonoids in the treatment of dyslipidemia, insulin resistance, hepatic steatosis, obesity, and atherosclerosis. Larger human studies examining dose, bioavailability, efficacy, and safety are required to promote the development of these promising therapeutic agents.
Assuntos
Aterosclerose/prevenção & controle , Citrus/química , Suplementos Nutricionais , Flavonoides/uso terapêutico , Hiperlipidemias/dietoterapia , Hipolipemiantes/uso terapêutico , Lipoproteínas/metabolismo , Animais , Anti-Inflamatórios não Esteroides/uso terapêutico , Fármacos Antiobesidade/uso terapêutico , Antioxidantes/uso terapêutico , Aterosclerose/epidemiologia , Aterosclerose/etiologia , Diabetes Mellitus Tipo 2/dietoterapia , Diabetes Mellitus Tipo 2/imunologia , Diabetes Mellitus Tipo 2/metabolismo , Diabetes Mellitus Tipo 2/fisiopatologia , Humanos , Hiperlipidemias/imunologia , Hiperlipidemias/metabolismo , Hiperlipidemias/fisiopatologia , Resistência à Insulina , Lipoproteínas/sangue , Hepatopatia Gordurosa não Alcoólica/dietoterapia , Hepatopatia Gordurosa não Alcoólica/imunologia , Hepatopatia Gordurosa não Alcoólica/metabolismo , Hepatopatia Gordurosa não Alcoólica/fisiopatologia , Sobrepeso/dietoterapia , Sobrepeso/imunologia , Sobrepeso/metabolismo , Sobrepeso/fisiopatologia , Fatores de RiscoRESUMO
OBJECTIVE: The peroxisome proliferator-activated receptor (PPAR) δ regulates systemic lipid homeostasis and inflammation. However, the ability of PPARδ agonists to improve the pathology of pre-established lesions and whether PPARδ activation is atheroprotective in the setting of insulin resistance have not been reported. Here, we examine whether intervention with a selective PPARδ agonist corrects metabolic dysregulation and attenuates aortic inflammation and atherosclerosis. APPROACH AND RESULTS: Low-density lipoprotein receptor knockout mice were fed a chow or a high-fat, high-cholesterol (HFHC) diet (42% fat, 0.2% cholesterol) for 4 weeks. For a further 8 weeks, the HFHC group was fed either HFHC or HFHC plus GW1516 (3 mg/kg per day). GW1516 significantly attenuated pre-established fasting hyperlipidemia, hyperglycemia, and hyperinsulinemia, as well as glucose and insulin intolerance. GW1516 intervention markedly reduced aortic sinus lesions and lesion macrophages, whereas smooth muscle α-actin was unchanged and collagen deposition enhanced. In aortae, GW1516 increased the expression of the PPARδ-specific gene Adfp but not PPARα- or γ-specific genes. GW1516 intervention decreased the expression of aortic proinflammatory M1 cytokines, increased the expression of the anti-inflammatory M2 cytokine Arg1, and attenuated the iNos/Arg1 ratio. Enhanced mitogen-activated protein kinase signaling, known to induce inflammatory cytokine expression in vitro, was enhanced in aortae of HFHC-fed mice. Furthermore, the HFHC diet impaired aortic insulin signaling through Akt and forkhead box O1, which was associated with elevated endoplasmic reticulum stress markers CCAAT-enhancer-binding protein homologous protein and 78kDa glucose regulated protein. GW1516 intervention normalized mitogen-activated protein kinase activation, insulin signaling, and endoplasmic reticulum stress. CONCLUSIONS: Intervention with a PPARδ agonist inhibits aortic inflammation and attenuates the progression of pre-established atherosclerosis.
Assuntos
Anti-Inflamatórios/farmacologia , Aortite/prevenção & controle , Aterosclerose/prevenção & controle , Resistência à Insulina , PPAR delta/agonistas , Receptores de LDL/deficiência , Tiazóis/farmacologia , Animais , Aortite/sangue , Aortite/etiologia , Aortite/genética , Aortite/patologia , Aterosclerose/sangue , Aterosclerose/etiologia , Aterosclerose/genética , Aterosclerose/patologia , Biomarcadores/sangue , Glicemia/metabolismo , Colesterol na Dieta , Dieta Hiperlipídica , Modelos Animais de Doenças , Dislipidemias/sangue , Dislipidemias/tratamento farmacológico , Dislipidemias/genética , Dislipidemias/metabolismo , Mediadores da Inflamação/metabolismo , Insulina/sangue , Lipídeos/sangue , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , PPAR delta/metabolismo , Receptores de LDL/genética , Transdução de Sinais/efeitos dos fármacos , Fatores de TempoRESUMO
Objective: Visual arts-based exposure and training are effective tools to enhance medical education. The visual arts can increase emotional intelligence and critical thinking skills. This study, conducted at Georgetown University School of Medicine (GUSoM) and the National Gallery of Art (NGA) in Washington, DC, was designed to measure the effect of a visual arts elective course on medical students' self-perception of their communication skills. Methods: This 6-week course involved lessons at the NGA and GUSoM for16 second-year medical students. The intervention students were age and gender-matched to14 second-year medical student control participants who took different elective courses. Prior to and following the intervention, the participants completed the Communication Skills Attitude Scale (CSAS). Statistical analysis was performed with either the 2-sided t-test or 2-sided Wilcoxon rank-sum test. Results: There were no statistically significant differences in the presurvey scores between the groups. However, there were 6 CSAS questions in the postsurveys that had statistically significant differences between the 2 groups. Within each group, there were also numerous statistically significant differences between their presurvey and postsurvey responses, with positive changes occurring in the intervention group (IG) and primarily negative changes occurring in the control group (CG). The NGA course improved the self-perception of communication skills, with students reporting stronger views on the importance of communication skills in teamwork and patient rapport. The CG, on the other hand, did not have as many improved perceptions of communication skills and had stronger opinions regarding not needing the ability to communicate well to be a good physician. Conclusion: This study indicates that medical student communication skills can benefit from exposure to visual arts activities and experiences. Future physicians must become effective communicators, and this study paves the way for research investigating the relationship between visual arts education and the development of a physician's communication skills.
RESUMO
Some mice demonstrate excessive food-grinding behaviors in which food pellets are broken down into crumbs (orts). This is considered abnormal behavior and is undesirable in a research environment, as it is thought to potentially be a stereotypic behavior suggestive of a negative welfare state in these animals. Further, food grinding often necessitates more frequent food and bedding changes. Research outcomes may also be affected if investigators do not exclude food losses due to grinding when measuring food consumption. We hypothesized some mice may excessively grind food in part to expend energy and access to a running wheel would contribute to a reduction in food grinding. Total daily food usage (the combined weight of food consumption and ort production) was measured for 40 d in CD-1 mice that exhibited food grinding. Median daily food usage was compared 10 d before, 20 d during, and 10 d after access to a running wheel. Additional cages of similar food-grinding mice that did not have access to a running wheel were monitored during the same period for comparison. A significant reduction in food usage was observed in 8 out of the 20 d in which mice had access to a running wheel compared with controls (P < 0.05). This reduction was significantly less than the median daily food usage before and after the running wheels were available (P < 0.01). Food usage significantly increased sharply in the 3 d following removal of the running wheel compared with controls during the same period (P < 0.05). A positive correlation between relative humidity and median daily food usage was observed (P < 0.05). Despite fluctuations in relative humidity, providing a running wheel effectively reduced excessive food-grinding behavior.
RESUMO
Newborn screening (NBS) is hailed as a public health success, but little is known about the long-term outcomes following a positive newborn screen. There has been difficulty gathering long-term follow-up (LTFU) data consistently, reliably, and with minimal effort. Six programs developed and tested a core set of minimal LTFU data elements. After an iterative data collection process and the development of a data collection tool, the group agreed on the minimal LTFU data elements. The denominator captured all infants with an NBS diagnosis, accounting for children who moved or died prior to the follow-up year. They also agreed on three LTFU outcomes: if the child was still alive, had contact with a specialist, and received appropriate care specific to their diagnosis within the year. The six programs representing NBS public health programs, clinical providers, and research programs provided data across multiple NBS disorders. In 2022, 83.8% (563/672) of the children identified by the LTFU programs were alive and living in the jurisdiction; of those, 92.0% (518/563) saw a specialist, and 87.7% (494/563) received appropriate care. The core LTFU data elements can be applied as a foundation to address the impact of early diagnosis by NBS within and across jurisdictions.
RESUMO
Nitric oxide (NO) is a short-lived, pleiotropic molecule that affects numerous critical functions in the body. Presently, there are markedly conflicting findings in the literature regarding NO and its role in carcinogenesis and tumor progression. NO has been shown to have dichotomous effects on cellular proliferation, apoptosis, migration, invasion, angiogenesis and many other important processes in cancer biology. It has been shown to be both pro- and antitumorigenic, depending on the concentration and the tumor microenvironment in question. NO is generated by three isoforms of NO synthase (NOS) that are widely expressed and sometimes upregulated in human tumors. Due to its vast array of physiological functions, it presents a huge challenge to researchers to discover its true potential in cancer biology and consequently, its use in anticancer therapies. In this study, we review the current knowledge in this area, with an emphasis placed on NO modulation as an anticancer therapy, focusing on NO-donating drugs and NOS inhibitors.
Assuntos
Neoplasias/metabolismo , Óxido Nítrico/fisiologia , Animais , Apoptose , Proliferação de Células , Progressão da Doença , Epigênese Genética , Transição Epitelial-Mesenquimal , Humanos , Terapia de Alvo Molecular , Neoplasias/patologia , Neoplasias/terapia , Neovascularização Patológica/metabolismo , Óxido Nítrico Sintase/metabolismo , Tolerância a RadiaçãoAssuntos
Reforma dos Serviços de Saúde , Cobertura do Seguro/tendências , Patient Protection and Affordable Care Act , Adolescente , Adulto , Etnicidade/estatística & dados numéricos , Feminino , Humanos , Renda , Cobertura do Seguro/estatística & dados numéricos , Seguro Saúde , Masculino , Pessoa de Meia-Idade , Estados Unidos , Adulto JovemRESUMO
BACKGROUND: Low-density lipoprotein (LDL) cholesterol lowering is a primary goal in clinical management of patients with cardiovascular disease, but traditional cholesterol levels may not accurately reflect the true atherogenicity of plasma lipid profiles. The size and concentration of lipoprotein particles, which transport cholesterol and triglycerides, may provide additional information for accurately assessing cardiovascular risk. This study evaluated changes in plasma lipoprotein profiles determined by nuclear magnetic resonance (NMR) spectroscopy in patients participating in a prospective, nonrandomized lifestyle modification program designed to reverse or stabilize progression of coronary artery disease (CAD) to improve our understanding of lipoprotein management in cardiac patients. RESULTS: The lifestyle intervention was effective in producing significant changes in lipoprotein subclasses that contribute to CAD risk. There was a clear beneficial effect on the total number of LDL particles (-8.3%, p < 0.05 compared to matched controls), small dense LDL particles (-9.5%, p < 0.05), and LDL particle size (+0.8%; p < 0.05). Likewise, participants showed significant improvement in traditional CAD risk factors such as body mass index (-9.9%, p < 0.01 compared to controls), total cholesterol (-5.5%, p < 0.05), physical fitness (+37.2%, p < 0.01), and future risk for CAD (-7.9%, p < 0.01). Men and women responded differently to the program for all clinically-relevant variables, with men deriving greater benefit in terms of lipoprotein atherogenicity. Plasma lipid and lipoprotein responses to the lifestyle change program were not confounded by lipid-lowering medications. CONCLUSION: In at risk patients motivated to participate, an intensive lifestyle change program can effectively alter traditional CAD risk factors and plasma lipoprotein subclasses and may reduce risk for cardiovascular events. Improvements in lipoprotein subclasses are more evident in men compared to women.
Assuntos
Doença da Artéria Coronariana/sangue , Estilo de Vida , Lipoproteínas/sangue , Lipoproteínas/classificação , Anticolesterolemiantes/uso terapêutico , Estudos de Casos e Controles , Doença da Artéria Coronariana/tratamento farmacológico , Feminino , Humanos , Lipoproteínas LDL/sangue , Espectroscopia de Ressonância Magnética , Masculino , Fatores de Risco , Caracteres SexuaisRESUMO
SCOPE: Naringenin is a citrus-derived flavonoid that has potent lipid-lowering and insulin-sensitizing effects in obese mouse models of metabolic dysfunction. However, in these models, a significant effect of naringenin supplementation is the prevention of weight gain, which in itself can confer metabolic protection. Therefore, in the present study, the effect of naringenin supplementation in lean, chow-fed Ldlr-/- mice is investigated. METHODS AND RESULTS: In Ldlr-/- mice with isocaloric food consumption, treatment with naringenin for 8 weeks reduces body weight and adiposity compared to littermate controls pair-fed the chow diet alone. Furthermore, naringenin treatment reduces plasma lipids and enhances insulin sensitivity compared to chow-fed controls. Metabolic cage studies reveal that naringenin-treated mice have elevated energy expenditure with no change in ambulatory activity. Additionally, naringenin-treated mice have an increased respiratory exchange ratio and food consumption during the dark cycle. Treatment increases the expression of fatty acid oxidation genes in liver, and increased ß-hydroxybutyrate concentrations in plasma, indicating that one mechanism through which naringenin mediates metabolic improvement is enhanced hepatic fatty acid oxidation. CONCLUSIONS: These studies highlight the potential therapeutic utility of naringenin and suggest that this flavonoid maintains potent metabolic properties in the absence of obesity or a high-fat diet.