RESUMEN
BACKGROUND: Fat intake has been associated with respiratory diseases, with conflicting results. OBJECTIVE: We studied the association between asthma and rhinitis with dietary fats, and their food sources in an Italian population. METHODS: Clinical and nutritional information was collected for 871 subjects (aged 20-84) from the population-based multi-case-control study Genes Environment Interaction in Respiratory Diseases (GEIRD): 145 with current asthma (CA), 77 with past asthma (PA), 305 with rhinitis and 344 controls. Food intake was collected using the EPIC (European Investigation into Cancer and Nutrition) Food Frequency Questionnaire. The associations between fats and respiratory diseases were estimated by multinomial models. Fats and their dietary sources were analysed both as continuous variables and as quartiles. RESULTS: Monounsaturated fatty acids and oleic acid were associated with a reduced risk of CA in both continuous (RRR = 0.68, 95%CI: 0.48; 0.96; RRR = 0.69; 95%CI: 0.49; 0.97, per 10 g, respectively) and per-quartile analyses (p for trend = 0.028 and 0.024, respectively). Olive oil was associated with a decreased risk of CA (RRR = 0.80; 95%CI: 0.65; 0.98 per 10 g). An increased risk of rhinitis was associated with moderate total fat and SFA intake. CONCLUSIONS: High dietary intakes of oleic acid and of olive oil are associated with a lower risk of asthma but not of rhinitis.
Asunto(s)
Asma/epidemiología , Aceite de Oliva , Encuestas y Cuestionarios , Adulto , Anciano , Anciano de 80 o más Años , Femenino , Humanos , Italia , Masculino , Persona de Mediana Edad , Factores de RiesgoRESUMEN
BACKGROUND AND OBJECTIVE: Health-related quality of life (HRQL) in respiratory diseases has been generally investigated in clinical settings, focusing on a single disorder. In this study on a general population sample, we assessed the relationship between HRQL and several respiratory diseases studied simultaneously (COPD, current (CA) and past (PA) asthma, allergic (AR) and non-allergic (NAR) rhinitis and chronic bronchitis (CB). METHODS: Controls (n = 328) and cases of NAR (n = 95), AR (n = 163), CB (n = 48), CA (n = 224), PA (n = 126) and COPD (n = 28) were recruited in the centre of Verona in the frame of the Italian multi-case control GEIRD (Gene Environment Interactions in Respiratory Diseases) study; HRQL was measured through the SF-36 questionnaire. The relationships between HRQL (in terms of Physical (PCS) and Mental Component Scores (MCS)), respiratory diseases, and covariates were evaluated. RESULTS: With respect to controls, the adjusted PCS median score was worse in subjects suffering from current asthma (- 1.7; 95%CI:-2.8;-0.6), CB (- 3.8; 95%CI:-5.7;-1.9), and COPD (- 5.6; 95%CI:-8.1;-3.1). MCS was worse in current asthmatics (- 2.2; 95%CI:-4.1;-0.3), CB (- 5.5; 95%CI:-8.7;-2.2), and COPD cases (- 4.6; 95%CI:-8.8;-0.5) as well. CONCLUSIONS: To our knowledge, this is the first study in the general population that analyzed HRQL performing a simultaneous comparison of HRLQ in several respiratory disorders. We found that subjects suffering from COPD, CA, and CB had the poorest HRQL. Clinicians should carefully consider the possible impact of respiratory disorders as CB and not only that of CA and COPD.
Asunto(s)
Asma/epidemiología , Hipersensibilidad/epidemiología , Enfermedad Pulmonar Obstructiva Crónica/epidemiología , Calidad de Vida , Adulto , Asma/psicología , Estudios de Casos y Controles , Femenino , Humanos , Hipersensibilidad/psicología , Italia/epidemiología , Masculino , Persona de Mediana Edad , Enfermedad Pulmonar Obstructiva Crónica/psicología , Índice de Severidad de la Enfermedad , Encuestas y CuestionariosRESUMEN
The positive association between overweight, obesity, and cardiovascular and all-cause mortality is well established, even though this relation is typically U shaped with an increased risk also in low-weight subjects. However, being overweight or obese has been associated with a better prognosis in subjects suffering from chronic diseases, id est the "obesity paradox". In both community-dwelling and hospitalized patients with COPD, several studies have reported a significant protective effect of obesity on all-cause mortality, indicating that also in obstructive pulmonary diseases, an obesity paradox may be present. Interestingly, the "paradox" is more evident for subjects with severe bronchial obstruction (i.e., a lower FEV1), while in mild-moderate conditions, the weight-related mortality shows a behavior similar to that observed in the general population. Several factors may confound the relation between COPD, obesity and mortality. The lower FEV1 found in obese people may be linked to a restrictive defect rather than to an obstructive one. Due to the modified chest wall mechanical properties-related to increased fat mass-obese COPD patients may present, respect to their lean counterpart, a lower lung hyperinflation which is associated with higher mortality. The traditional classification of COPD attributes to obese "blue bloaters" a low-grade emphysema in opposition to lean "pink puffers"; the fact that emphysema extent is related to mortality may bias the relationship between weight and survival. It is also to underline that the majority of the studies, consider BMI rather than body composition (a better predictor of mortality) when studying the intriguing relation between weight, COPD, and mortality. Reverse bias has also to be taken into account, hypothesizing that an unintentional weight loss may be the deleterious factor related to mortality, rather than considering obesity a protective one. Further prospective studies are needed to shed light on the complexity of this emerging issue. LEVEL OF EVIDENCE: Level V: Narrative Review.
Asunto(s)
Peso Corporal/fisiología , Obesidad/complicaciones , Enfermedad Pulmonar Obstructiva Crónica/complicaciones , Índice de Masa Corporal , Humanos , Obesidad/mortalidad , Obesidad/fisiopatología , Pronóstico , Enfermedad Pulmonar Obstructiva Crónica/mortalidad , Enfermedad Pulmonar Obstructiva Crónica/fisiopatología , Tasa de SupervivenciaRESUMEN
BACKGROUND: Insulin-like growth factor (IGF)-1 and its binding proteins are important in cancer growth, especially in prostate cancer. Observational studies suggest that protein restriction can lower IGF-1 levels. However, it is unclear whether an isocaloric protein-restricted diet affects IGF-1 and IGFBPs in men with prostate cancer. METHODS: In this academic, single-center, parallel-group, prospective, randomized, open-label, blinded end-point trial, 38 consenting overweight (BMI 30.5 ± 5.5 kg/m2) men with localized prostate cancer, aged 43-72 years, were randomized (1:1) with permuted blocks to 4-6 weeks of customized isocaloric PR diets (0.8 g protein/kg lean body mass) or their usual diet. Biomarkers influencing cancer biology, including serum IGF-1 and its binding proteins were measured longitudinally. RESULTS: Contrary to our hypothesis, feeding individuals an isocaloric protein-restricted diet did not result in a significant reduction in serum IGF-1. Moreover, there was no observed increase in serum IGFBP-1 or IGFBP-3 concentration. CONCLUSION: These findings demonstrate that protein restriction without calorie restriction does not reduce serum IGF-1 concentration or increase IGFBP-1 and IGFBP-3 in men with localized prostate cancer. Further research is needed to identify dietary interventions for safely and effectively reducing IGF-1 in this patient group.
RESUMEN
Regular endurance exercise training is an effective intervention for the maintenance of metabolic health and the prevention of many age-associated chronic diseases. Several metabolic and inflammatory factors are involved in the health-promoting effects of exercise training, but regulatory mechanisms remain poorly understood. Cellular senescence-a state of irreversible growth arrest-is considered a basic mechanism of aging. Senescent cells accumulate over time and promote a variety of age-related pathologies from neurodegenerative disorders to cancer. Whether long-term intensive exercise training affect the accumulation of age-associated cellular senescence is still unclear. Here, we show that the classical senescence markers p16 and IL-6 were markedly higher in the colon mucosa of middle-aged and older overweight adults than in young sedentary individuals, but this upregulation was significantly blunted in age-matched endurance runners. Interestingly, we observe a linear correlation between the level of p16 and the triglycerides to HDL ratio, a marker of colon adenoma risk and cardiometabolic dysfunction. Our data suggest that chronic high-volume high-intensity endurance exercise can play a role in preventing the accumulation of senescent cells in cancer-prone tissues like colon mucosa with age. Future studies are warranted to elucidate if other tissues are also affected, and what are the molecular and cellular mechanisms that mediate the senopreventative effects of different forms of exercise training.
RESUMEN
OBJECTIVE: Whether blood eosinophils (bEOS) in chronic obstructive pulmonary disease (COPD) are associated with disease progression is a topic of debate. We aimed to evaluate whether the differential white blood cell (WBC) count, symptoms and treatment may predict lung function decline and exacerbations in COPD patients. METHODS: We retrospectively examined stable COPD patients with a minimum follow-up of 3 years at our outpatients' clinic. We collected information about lung volumes (FEV1, FVC), the total and differential WBC count, acute exacerbations of COPD (number in the 12 months before the beginning of the study=AE-COPD-B, and during the follow-up=AE-COPD-F), smoking status and treatment. FEV1 decline and AE-COPD-F were described by using a generalized linear model and a 2-level random intercept negative binomial regression, respectively. The models included eosinophil and neutrophil counts as potential predictors and were adjusted by sex, age, smoking status, AE-COPD-B, treatment with bronchodilators and inhaled corticosteroids (ICS). RESULTS: Sixty-eight patients were considered, 36 bEOS- (<170 cells/µL, the median value) and 32 bEOS+ (≥170 cells/µL). ∆FEV1 was higher in bEOS+ than bEOS- (34.86 mL/yr vs 4.49 mL/yr, p=0.029). After adjusting for potential confounders, the eosinophil count was positively (ß=19.4; CI 95% 2.8, 36.1; p=0.022) and ICS negatively (ß=-57.7; CI 95% -91.5,-23.9; p=0.001) associated with lung function decline. bEOS were not found to be associated with the number of AE-COPD-F. CONCLUSION: In stable COPD patients, a higher level of blood eosinophils (albeit in the normal range) predicts a greater FEV1 decline, while ICS are associated with a slower progression of airflow obstruction.
OBJETIVO: Discute-se se eosinófilos no sangue (EOS) na doença pulmonar obstrutiva crônica (DPOC) são associados à evolução da doença. O objetivo deste estudo foi avaliar se a contagem diferencial de células brancas do sangue (CBS), os sintomas e o tratamento podem prever o declínio da função pulmonar e as exacerbações em pacientes com DPOC. MÉTODOS: Foram retrospectivamente examinados pacientes com DPOC estável submetidos a um monitoramento mínimo de três anos em nossas clínicas ambulatoriais. Coletaram-se informações sobre volumes pulmonares (VEF1 e CVF), contagens total e diferencial de CBS, exacerbações agudas de DPOC (número nos 12 meses anteriores ao início do estudo = EA-DPOC-B; e durante o monitoramento = EA-DPOC-F), status tabagístico e tratamento. Os declínios de VEF1 e EA-DPOC-F foram descritos empregando modelo linear generalizado e regressão binomial negativa com interceptação aleatória de nível 2, respectivamente. Os modelos incluíram contagens de eosinófilo e neutrófilo como potenciais preditores e foram ajustados de acordo com sexo, idade, status tabagístico, EA-DPOC-B, tratamento com broncodilatadores e corticosteroides inalados (CSI). RESULTADOS: 68 pacientes foram considerados, dos quais 36 para EOS- (< 170 células/µL, valor da mediana) e 32 para EOS+ (≥ 170 células/µL). ∆VEF1 foi maior em EOS+ do que em EOS- (34,86 mL/ano vs 4,49 mL/ano, p = 0,029). Após o ajuste em relação aos potenciais confundidores, as contagens de eosinófilos (ß = 19,4; CI 95% 2,8,36,1; p = 0,022) e CSI (ß = -57,7; CI 95% -91,5,-23,9; p = 0,001) foram positivamente e negativamente associadas ao declínio da função pulmonar, respectivamente. Os EOS não foram associados ao número de EA-DPOC-F. CONCLUSÃO: Em pacientes com DPOC estável, o maior nível de EOS (embora em um intervalo regular) prevê um maior declínio de VEF1, enquanto os CSIs são associados a uma evolução mais lenta da obstrução do fluxo aéreo.
Asunto(s)
Enfermedad Pulmonar Obstructiva Crónica , Humanos , Estudios Retrospectivos , Estudios Longitudinales , PulmónRESUMEN
Cardiac hypertrophy and renal damage associated with hypertension are independent predictors of morbidity and mortality. In a model of hypertensive heart disease and renal damage, we tested the actions of continuous administration of Vastiras, a novel compound derived from the linear fragment of ANP (atrial natriuretic peptide), namely pro-ANP31-67, on blood pressure and associated renal and cardiac function and remodeling. Of note, this peptide, unlike the ring structured forms, does not bind to the classic natriuretic peptide receptors. Dahl/Salt-Sensitive rats fed a 4% NaCl diet for 6 weeks developed hypertension, cardiac hypertrophy, and renal damage. Four weeks of treatment with 50 to 100 ng/kg per day of Vastiras exhibited positive effects on renal function, independent of blood pressure regulation. Treated rats had increased urine excretion, natriuresis, and enhanced glomerular filtration rate. Importantly, these favorable renal effects were accompanied by improved cardiac structure and function, including attenuated cardiac hypertrophy, as indicated by decreased heart weight to body weight ratio, relative wall thickness, and left atrial diameter, as well as reduced fibrosis and normalized ratio of the diastolic mitral inflow E wave to A wave. A renal subtherapeutic dose of Vastiras (25 ng/kg per day) induced similar protective effects on the heart. At the cellular level, cardiomyocyte size and t-tubule density were preserved in Vastiras-treated compared with untreated animals. In conclusion, these data demonstrate the cardiorenal protective actions of chronic supplementation of a first-in-class compound, Vastiras, in a preclinical model of maladaptive cardiac hypertrophy and renal damage induced by hypertension.
Asunto(s)
Factor Natriurético Atrial/uso terapéutico , Cardiotónicos/uso terapéutico , Albuminuria/etiología , Animales , Factor Natriurético Atrial/farmacología , Remodelación Atrial/efectos de los fármacos , Presión Sanguínea/efectos de los fármacos , Cardiomegalia/etiología , Cardiomegalia/prevención & control , Cardiomegalia/orina , Cardiotónicos/farmacología , Dinoprostona/orina , Evaluación Preclínica de Medicamentos , Fibrosis , Tasa de Filtración Glomerular/efectos de los fármacos , Corazón/diagnóstico por imagen , Corazón/efectos de los fármacos , Hipertensión/etiología , Hipertensión/prevención & control , Hipertensión/orina , Riñón/efectos de los fármacos , Enfermedades Renales/etiología , Enfermedades Renales/prevención & control , Enfermedades Renales/orina , Masculino , Miocitos Cardíacos/efectos de los fármacos , Miocitos Cardíacos/metabolismo , Natriuresis/efectos de los fármacos , Fragmentos de Péptidos/farmacología , Fragmentos de Péptidos/uso terapéutico , Potasio/orina , Ratas , Ratas Endogámicas Dahl , Proteína Smad2/metabolismo , Cloruro de Sodio Dietético/toxicidad , Remodelación Ventricular/efectos de los fármacosRESUMEN
BACKGROUND: The research was conducted in the frame of a population-based, case control study, called Genes Environment Interaction in Respiratory Disease. OBJECTIVE: To assess the association between protein intake and physical performance in a general population sample. DESIGN: Researchers investigated the association between the participants' dietary information and their physical performance using the 6-min walking test and the distance walked in metres (6MWD) as main outcome measure. Information on dietary intake was collected using the validated European Investigation into Cancer and Nutrition food frequency questionnaires (FFQs). Then, daily intake of energy and macronutrients was estimated by means of the NAF software (nutritional analysis of FFQ). Linear regression models were used to evaluate the associations between vegetable, animal and total protein intakes and the 6MWD. The models were adjusted for socio-demographic features, total fats and available carbohydrate intakes. RESULTS: The participants were 223 subjects (57% females) aged between 23 and 68 years. Their mean vegetable and animal proteins intake for gram/kg of body weight/day were, respectively, 0.4 and 0.7. After adjusting for all the potential confounders, there was a significant increase of 20.0 (95% CI 0.8; 39.2) m in the distance walked for an increase in 10 g/day of vegetable proteins and non-significant variations of -1.8 (95% CI -9.3; 5.7) m for an increase in 10 g/day of animal proteins and of 0.5 (95% CI -6.8; 7.7) for an increase in 10 g/day of total proteins. DISCUSSION AND CONCLUSIONS: Our result suggests a positive role of vegetable proteins on physical performance. Whether this result is related to the high protein intake itself or may be a consequence of the other properties of plant-based foods deserves further investigation.
RESUMEN
RESUMO Objetivo Discute-se se eosinófilos no sangue (EOS) na doença pulmonar obstrutiva crônica (DPOC) são associados à evolução da doença. O objetivo deste estudo foi avaliar se a contagem diferencial de células brancas do sangue (CBS), os sintomas e o tratamento podem prever o declínio da função pulmonar e as exacerbações em pacientes com DPOC. Métodos Foram retrospectivamente examinados pacientes com DPOC estável submetidos a um monitoramento mínimo de três anos em nossas clínicas ambulatoriais. Coletaram-se informações sobre volumes pulmonares (VEF1 e CVF), contagens total e diferencial de CBS, exacerbações agudas de DPOC (número nos 12 meses anteriores ao início do estudo = EA-DPOC-B; e durante o monitoramento = EA-DPOC-F), status tabagístico e tratamento. Os declínios de VEF1 e EA-DPOC-F foram descritos empregando modelo linear generalizado e regressão binomial negativa com interceptação aleatória de nível 2, respectivamente. Os modelos incluíram contagens de eosinófilo e neutrófilo como potenciais preditores e foram ajustados de acordo com sexo, idade, status tabagístico, EA-DPOC-B, tratamento com broncodilatadores e corticosteroides inalados (CSI). Resultados 68 pacientes foram considerados, dos quais 36 para EOS- (< 170 células/μL, valor da mediana) e 32 para EOS+ (≥ 170 células/μL). ∆VEF1 foi maior em EOS+ do que em EOS- (34,86 mL/ano vs 4,49 mL/ano, p = 0,029). Após o ajuste em relação aos potenciais confundidores, as contagens de eosinófilos (β = 19,4; CI 95% 2,8,36,1; p = 0,022) e CSI (β = -57,7; CI 95% -91,5,-23,9; p = 0,001) foram positivamente e negativamente associadas ao declínio da função pulmonar, respectivamente. Os EOS não foram associados ao número de EA-DPOC-F. Conclusão Em pacientes com DPOC estável, o maior nível de EOS (embora em um intervalo regular) prevê um maior declínio de VEF1, enquanto os CSIs são associados a uma evolução mais lenta da obstrução do fluxo aéreo.
ABSTRACT Objective Whether blood eosinophils (bEOS) in chronic obstructive pulmonary disease (COPD) are associated with disease progression is a topic of debate. We aimed to evaluate whether the differential white blood cell (WBC) count, symptoms and treatment may predict lung function decline and exacerbations in COPD patients. Methods We retrospectively examined stable COPD patients with a minimum follow-up of 3 years at our outpatients' clinic. We collected information about lung volumes (FEV1, FVC), the total and differential WBC count, acute exacerbations of COPD (number in the 12 months before the beginning of the study=AE-COPD-B, and during the follow-up=AE-COPD-F), smoking status and treatment. FEV1 decline and AE-COPD-F were described by using a generalized linear model and a 2-level random intercept negative binomial regression, respectively. The models included eosinophil and neutrophil counts as potential predictors and were adjusted by sex, age, smoking status, AE-COPD-B, treatment with bronchodilators and inhaled corticosteroids (ICS). Results Sixty-eight patients were considered, 36 bEOS- (<170 cells/μL, the median value) and 32 bEOS+ (≥170 cells/μL). ∆FEV1 was higher in bEOS+ than bEOS- (34.86 mL/yr vs 4.49 mL/yr, p=0.029). After adjusting for potential confounders, the eosinophil count was positively (β=19.4; CI 95% 2.8, 36.1; p=0.022) and ICS negatively (β=-57.7; CI 95% -91.5,-23.9; p=0.001) associated with lung function decline. bEOS were not found to be associated with the number of AE-COPD-F. Conclusion In stable COPD patients, a higher level of blood eosinophils (albeit in the normal range) predicts a greater FEV1 decline, while ICS are associated with a slower progression of airflow obstruction.
RESUMEN
Obesity, metabolic syndrome, and hyperleptinemia are associated with aging and age-associated diseases including prostate cancer. One experimental approach to inhibit tumor growth is to reduce dietary protein intake and hence levels of circulating amino acids. Dietary protein restriction (PR) increases insulin sensitivity and suppresses prostate cancer cell tumor growth in animal models, providing a rationale for clinical trials. We sought to demonstrate that biomarkers derived from plasma extracellular vesicles (EVs) reflect systemic leptin and insulin signaling and respond to dietary interventions. We studied plasma samples from men with prostate cancer awaiting prostatectomy who participated in a randomized trial of one month of PR or control diet. We found increased levels of leptin receptor in the PR group in total plasma EVs and in a subpopulation of plasma EVs expressing the neuronal marker L1CAM. Protein restriction also shifted the phosphorylation status of the insulin receptor signal transducer protein IRS1 in L1CAM+ EVs in a manner suggestive of improved insulin sensitivity. Dietary PR modifies indicators of leptin and insulin signaling in circulating EVs. These findings are consistent with improved insulin and leptin sensitivity in response to PR and open a new window for following physiologic responses to dietary interventions in humans.
Asunto(s)
Dieta con Restricción de Proteínas , Vesículas Extracelulares/metabolismo , Insulina/sangre , Leptina/sangre , Neoplasias de la Próstata/sangre , Restricción Calórica , Metabolismo Energético , Humanos , Masculino , Persona de Mediana Edad , Neoplasias de la Próstata/dietoterapia , Neoplasias de la Próstata/patologíaRESUMEN
Calorie restriction (CR) retards aging, acts as a hormetic intervention, and increases serum corticosterone and HSP70 expression in rodents. However, less is known regarding the effects of CR on these factors in humans. Serum cortisol and molecular chaperones and autophagic proteins were measured in the skeletal muscle of subjects on CR diets for 3-15 years and in control volunteers. Serum cortisol was higher in the CR group than in age-matched sedentary and endurance athlete groups (15.6 ± 4.6 ng/dl versus 12.3 ± 3.9 ng/dl and 11.2 ± 2.7 ng/dl, respectively; p ≤ 0.001). HSP70, Grp78, beclin-1, and LC3 mRNA and/or protein levels were higher in the skeletal muscle of the CR group compared to controls. Our data indicate that CR in humans is associated with sustained rises in serum cortisol, reduced inflammation, and increases in key molecular chaperones and autophagic mediators involved in cellular protein quality control and removal of dysfunctional proteins and organelles.
Asunto(s)
Restricción Calórica , Músculo Esquelético/metabolismo , Adulto , Proteínas Reguladoras de la Apoptosis/genética , Proteínas Reguladoras de la Apoptosis/metabolismo , Beclina-1 , Índice de Masa Corporal , Análisis por Conglomerados , Chaperón BiP del Retículo Endoplásmico , Ejercicio Físico , Femenino , Regulación de la Expresión Génica , Proteínas HSP70 de Choque Térmico/genética , Proteínas HSP70 de Choque Térmico/metabolismo , Proteínas de Choque Térmico/genética , Proteínas de Choque Térmico/metabolismo , Humanos , Hidrocortisona/sangre , Masculino , Proteínas de la Membrana/genética , Proteínas de la Membrana/metabolismo , Proteínas Asociadas a Microtúbulos/genética , Proteínas Asociadas a Microtúbulos/metabolismo , Persona de Mediana Edad , ARN Mensajero/metabolismo , Factores de Tiempo , Factores de Transcripción/genética , Factores de Transcripción/metabolismoRESUMEN
Protein-restricted (PR), high-carbohydrate diets improve metabolic health in rodents, yet the precise dietary components that are responsible for these effects have not been identified. Furthermore, the applicability of these studies to humans is unclear. Here, we demonstrate in a randomized controlled trial that a moderate PR diet also improves markers of metabolic health in humans. Intriguingly, we find that feeding mice a diet specifically reduced in branched-chain amino acids (BCAAs) is sufficient to improve glucose tolerance and body composition equivalently to a PR diet via metabolically distinct pathways. Our results highlight a critical role for dietary quality at the level of amino acids in the maintenance of metabolic health and suggest that diets specifically reduced in BCAAs, or pharmacological interventions in this pathway, may offer a translatable way to achieve many of the metabolic benefits of a PR diet.
Asunto(s)
Aminoácidos de Cadena Ramificada/metabolismo , Obesidad/dietoterapia , Tejido Adiposo Blanco/patología , Aminoácidos de Cadena Ramificada/administración & dosificación , Animales , Glucemia , Proteínas en la Dieta/administración & dosificación , Factores de Crecimiento de Fibroblastos/metabolismo , Gluconeogénesis , Intolerancia a la Glucosa , Humanos , Células Secretoras de Insulina/metabolismo , Masculino , Ratones Endogámicos C57BL , Persona de Mediana Edad , Obesidad/sangre , Tamaño de los Órganos , Estrés FisiológicoRESUMEN
Reduced dietary protein intake and intermittent fasting (IF) are both linked to healthy longevity in rodents, and are effective in inhibiting cancer growth. The molecular mechanisms underlying the beneficial effects of chronic protein restriction (PR) and IF are unclear, but may be mediated in part by a down-regulation of the IGF/mTOR pathway. In this study we compared the effects of PR and IF on tumor growth in a xenograft mouse model of breast cancer. We also investigated the effects of PR and IF on the mechanistic Target Of Rapamycin (mTOR) pathway, inhibition of which extends lifespan in model organisms including mice. The mTOR protein kinase is found in two distinct complexes, of which mTOR complex 1 (mTORC1) is responsive to acute treatment with amino acids in cell culture and in vivo. We found that both PR and IF inhibit tumor growth and mTORC1 phosphorylation in tumor xenografts. In somatic tissues, we found that PR, but not IF, selectively inhibits the activity of the amino acid sensitive mTORC1, while the activity of the second mTOR complex, mTORC2, was relatively unaffected by PR. In contrast, IF resulted in increased S6 phosphorylation in multiple metabolic tissues. Our work represents the first finding that PR may reduce mTORC1 activity in tumors and multiple somatic tissues, and suggest that PR may represent a highly translatable option for the treatment not only of cancer, but also other age-related diseases.