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1.
JAMA Dermatol ; 159(4): 403-410, 2023 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-36884234

RESUMO

Importance: Poor therapeutic results have been reported in patients with alopecia areata totalis (AT) or universalis (AU), the most severe and disabling types of alopecia areata (AA). Methotrexate, an inexpensive treatment, might be effective in AU and AT. Objective: To evaluate the efficacy and tolerance of methotrexate alone or combined with low-dose prednisone in patients with chronic and recalcitrant AT and AU. Design, Setting, and Participants: This academic, multicenter, double-blind, randomized clinical trial was conducted at 8 dermatology departments at university hospitals between March 2014 and December 2016 and included adult patients with AT or AU evolving for more than 6 months despite previous topical and systemic treatments. Data analysis was performed from October 2018 to June 2019. Interventions: Patients were randomized to receive methotrexate (25 mg/wk) or placebo for 6 months. Patients with greater than 25% hair regrowth (HR) at month 6 continued their treatment until month 12. Patients with less than 25% HR were rerandomized: methotrexate plus prednisone (20 mg/d for 3 months and 15 mg/d for 3 months) or methotrexate plus placebo of prednisone. Main Outcome and Measures: The primary end point assessed on photos by 4 international experts was complete or almost complete HR (Severity of Alopecia Tool [SALT] score <10) at month 12, while receiving methotrexate alone from the start of the study. Main secondary end points were the rate of major (greater than 50%) HR, quality of life, and treatment tolerance. Results: A total of 89 patients (50 female, 39 male; mean [SD] age, 38.6 [14.3] years) with AT (n = 1) or AU (n = 88) were randomized: methotrexate (n = 45) or placebo (n = 44). At month 12, complete or almost complete HR (SALT score <10) was observed in 1 patient and no patient who received methotrexate alone or placebo, respectively, in 7 of 35 (20.0%; 95% CI, 8.4%-37.0%) patients who received methotrexate (for 6 or 12 months) plus prednisone, including 5 of 16 (31.2%; 95% CI, 11.0%-58.7%) who received methotrexate for 12 months and prednisone for 6 months. A greater improvement in quality of life was observed in patients who achieved a complete response compared with nonresponder patients. Two patients in the methotrexate group discontinued the study because of fatigue and nausea, which were observed in 7 (6.9%) and 14 (13.7%) patients receiving methotrexate, respectively. No severe treatment adverse effect was observed. Conclusions and Relevance: In this randomized clinical trial, while methotrexate alone mainly allowed partial HR in patients with chronic AT or AU, its combination with low-dose prednisone allowed complete HR in up to 31% of patients. These results seem to be of the same order of magnitude as those recently reported with JAK inhibitors, with a much lower cost. Trial Registration: ClinicalTrials.gov Identifier: NCT02037191.


Assuntos
Alopecia em Áreas , Metotrexato , Adulto , Humanos , Masculino , Feminino , Metotrexato/efeitos adversos , Prednisona/efeitos adversos , Alopecia em Áreas/tratamento farmacológico , Qualidade de Vida , Recidiva Local de Neoplasia/tratamento farmacológico , Método Duplo-Cego , Resultado do Tratamento
2.
J Am Heart Assoc ; 11(4): e023409, 2022 02 15.
Artigo em Inglês | MEDLINE | ID: mdl-35112890

RESUMO

Background Changes in arterial wall viscosity, which dissipates the energy stored within the arterial wall, may contribute to the beneficial effect of heart rate (HR) reduction on arterial stiffness and cardiovascular coupling. However, it has never been assessed in humans and could be altered by aging. We evaluated the effect of a selective HR-lowering agent on carotid arterial wall viscosity and the impact of aging on this effect. Methods and Results This randomized, placebo-controlled, double-blind, crossover study performed in 19 healthy volunteers evaluated the effects of ivabradine (5 mg BID, 1-week) on carotid arterial wall viscosity, mechanics, hemodynamics, and cardiovascular coupling. Arterial wall viscosity was evaluated by the area of the hysteresis loop of the pressure-lumen cross-sectional area relationship, representing the energy dissipated (WV), and by the relative viscosity (WV/WE), with WE representing the elastic energy stored. HR reduction by ivabradine increased WV and WE whereas WV/WE remained stable. In middle-aged subjects (n=11), baseline arterial stiffness and cardiovascular coupling were less favorable, and WE was similar but WV and therefore WV/WE were lower than in youth (n=8). HR reduction increased WV/WE in middle-aged but not in young subjects, owing to a larger increase in WV than WE. These results were supported by the age-related linear increase in WV/WE after HR reduction (P=0.009), explained by a linear increase in WV. Conclusion HR reduction increases arterial wall energy dissipation proportionally to the increase in WE, suggesting an adaptive process to bradycardia. This mechanism is altered during aging resulting in a larger than expected energy dissipation, the impact of which should be assessed. Registration URL: https://www.clinicaltrials.gov; Unique identifier: 2015/077/HP. URL: https://www. eudract.ema.europa.eu; Unique identifier: 2015-002060-17.


Assuntos
Envelhecimento , Artérias Carótidas , Adolescente , Estudos Cross-Over , Frequência Cardíaca/fisiologia , Humanos , Ivabradina/farmacologia , Pessoa de Meia-Idade , Viscosidade
3.
Am J Clin Nutr ; 115(3): 694-704, 2022 03 04.
Artigo em Inglês | MEDLINE | ID: mdl-34791007

RESUMO

BACKGROUND: The effects of a dietary supplementation with the vegetable ω-3 α-linolenic acid (ALA) on cardiovascular homeostasis are unclear. In this context, it would be interesting to assess the effects of camelina oil. OBJECTIVE: This study aimed to assess the cardiovascular and metabolic effects of camelina oil in hypertensive patients with metabolic syndrome. METHODS: In a double-blind, placebo-controlled randomized study, treated essential hypertensive patients with metabolic syndrome received, during 6 mo, either cyclodextrin-complexed camelina oil containing ≈ 1.5 g ALA/d (n = 40) or an isocaloric placebo (n = 41), consisting of the same quantity of cyclodextrins and wheat starch. Anthropometric data, plasma lipids, glycemia, insulinemia, creatininemia, TBARs, high-sensitivity C-reactive protein, and n-3, n-6, and n-9 fatty acids in erythrocyte membranes were measured. Peripheral and central blood pressures, arterial stiffness, carotid intima-media thickness, and brachial artery endothelium-dependent flow-mediated dilatation (FMD) and endothelium-independent dilatation were assessed. RESULTS: Compared with placebo, camelina oil increased ALA (mean ± SD: 0 ± 0.04 compared with 0.08 ± 0.06%, P <0.001), its elongation product EPA (0 ± 0.5 compared with 0.16 ± 0.65%, P <0.05), and the n-9 gondoic acid (GA; 0 ± 0.04 compared with 0.08 ± 0.04%, P <0.001). No between-group difference was observed for cardiovascular parameters. However, changes in FMD were associated with the magnitude of changes in EPA (r = 0.26, P = 0.03). Compared with placebo, camelina oil increased fasting glycemia (-0.2 ± 0.6 compared with 0.3 ± 0.5 mmol/L, P <0.001) and HOMA-IR index (-0.8 ± 2.5 compared with 0.5 ± 0.9, P <0.01), without affecting plasma lipids, or inflammatory and oxidative stress markers. Changes in HOMA-IR index were correlated with the magnitude of changes in GA (r = 0.32, P <0.01). Nutritional intake remained similar between groups. CONCLUSION: ALA supplementation with camelina oil did not improve vascular function but adversely affected glucose metabolism in hypertensive patients with metabolic syndrome. Whether this adverse effect on insulin sensitivity is related to GA enrichment, remains to be elucidated.


Assuntos
Ácidos Graxos Ômega-3 , Hipertensão , Síndrome Metabólica , Espessura Intima-Media Carotídea , Método Duplo-Cego , Ácidos Graxos Ômega-3/farmacologia , Humanos , Hipertensão/tratamento farmacológico , Síndrome Metabólica/tratamento farmacológico
4.
Clin Gastroenterol Hepatol ; 20(8): 1857-1866.e1, 2022 08.
Artigo em Inglês | MEDLINE | ID: mdl-33189854

RESUMO

BACKGROUND & AIMS: Medico-economic data of patients suffering from chronic nausea and vomiting are lacking. In these patients, gastric electrical stimulation (GES) is an effective, but costly treatment. The aim of this study was to assess the efficacy, safety and medico-economic impact of Enterra therapy in patients with chronic medically refractory nausea and vomiting. METHODS: Data were collected prospectively from patients with medically refractory nausea and/or vomiting, implanted with an Enterra device and followed for two years. Gastrointestinal quality of life index (GIQLI) score, vomiting frequency, nutritional status and safety were evaluated. Direct and indirect expenditure data were prospectively collected in diaries. RESULTS: Complete clinical data were available for142 patients (60 diabetic, 82 non-diabetic) and medico-economic data were available for 96 patients (36 diabetic, 60 non-diabetic), 24 months after implantation. GIQLI score increased by 12.1 ± 25.0 points (p < .001), with a more significant improvement in non-diabetic than in diabetic patients (+15.8 ± 25.0 points, p < .001 versus 7.3 ± 24.5 points, p = .027, respectively). The proportion of patients vomiting less than once per month increased by 25.5% (p < .001). Hospitalisations, time off work and transport were the main sources of costs. Enterra therapy decreased mean overall healthcare costs from 8873 US$ to 5525 US$ /patient/year (p = .001), representing a saving of 3348 US$ per patient and per year. Savings were greater for diabetic patients (4096 US$ /patient/year) than for non-diabetic patients (2900 US$ /patient/year). CONCLUSIONS: Enterra therapy is an effective, safe and cost-effective option for patients with refractory nausea and vomiting. CLINICALTRIALS: gov Identifier: NCT00903799.


Assuntos
Terapia por Estimulação Elétrica , Gastroparesia , Estimulação Elétrica , Terapia por Estimulação Elétrica/efeitos adversos , Estresse Financeiro , Esvaziamento Gástrico , Humanos , Náusea/etiologia , Qualidade de Vida , Resultado do Tratamento , Vômito/etiologia , Vômito/terapia
5.
Gastroenterology ; 158(3): 506-514.e2, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-31647902

RESUMO

BACKGROUND & AIMS: There have been conflicting results from trials of gastric electrical stimulation (GES) for treatment of refractory vomiting, associated or not with gastroparesis. We performed a large, multicenter, randomized, double-blind trial with crossover to study the efficacy of GES in patients with refractory vomiting, with or without gastroparesis. METHODS: For 4 months, we assessed symptoms in 172 patients (66% women; mean age ± standard deviation, 45 ± 12 years; 133 with gastroparesis) with chronic (>12 months) of refractory vomiting (idiopathic, associated with a type 1 or 2 diabetes, or postsurgical). A GES device was implanted and left unactivated until patients were randomly assigned, in a double-blind manner, to groups that received 4 months of stimulation parameters (14 Hz, 5 mA, pulses of 330 µs) or no stimulation (control); 149 patients then crossed over to the other group for 4 months. Patients were examined at the end of each 4-month period (at 5 and 9 months after implantation). Primary endpoints were vomiting score, ranging from 0 (daily vomiting) to 4 (no vomiting), and the quality of life, assessed by the Gastrointestinal Quality of Life Index scoring system. Secondary endpoints were changes in other digestive symptoms, nutritional status, gastric emptying, and control of diabetes. RESULTS: During both phases of the crossover study, vomiting scores were higher in the group with the device on (median score, 2) than the control group (median score, 1; P < .001), in diabetic and nondiabetic patients. Vomiting scores increased significantly when the device was ON in patients with delayed (P < .01) or normal gastric emptying (P = .05). Gastric emptying was not accelerated during the ON period compared with the OFF period. Having the GES turned on was not associated with increased quality of life. CONCLUSIONS: In a randomized crossover study, we found that GES reduced the frequency of refractory vomiting in patients with and without diabetes, although it did not accelerate gastric emptying or increase of quality of life. Clinicaltrials.gov, Number: NCT00903799.


Assuntos
Terapia por Estimulação Elétrica/métodos , Gastroparesia/complicações , Vômito/terapia , Adulto , Estudos Cross-Over , Método Duplo-Cego , Terapia por Estimulação Elétrica/instrumentação , Eletrodos Implantados , Feminino , Esvaziamento Gástrico/fisiologia , Gastroparesia/fisiopatologia , Gastroparesia/terapia , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Qualidade de Vida , Índice de Gravidade de Doença , Resultado do Tratamento , Vômito/diagnóstico , Vômito/etiologia
6.
Thromb Res ; 155: 1-5, 2017 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-28460259

RESUMO

Thromboprophylaxis is a mainstay of hospital care in patients at high risk of thrombosis. Fixed doses of low-molecular-weight heparin (LMWH) are recommended for thromboprophylaxis in patients admitted to hospital for an acute medical condition. However, the distribution of LMWH is weight-based, and the efficacy of standard doses in obese patients may be decreased. Data for obese patients are mainly available in bariatric surgery with extremely obese patients who are at greater risk of venous thromboembolism than those hospitalized for a medical condition. We conducted a randomized control trial in medically obese inpatients (BMI≥30kg/m2) assessing two regimens of enoxaparin (40mg and 60mg SQ daily) in order to determine whether a stronger dosage would achieve higher anti-Xa level suitable for thromboprophylaxis. Between September 2013 and April 2015, 91 patients were included in the study (mean (±standard deviation) age was 70.4±10.7years, average BMI 37.8±6.4kg/m2). Main indications of thromboprophylaxis were mainly acute infection (50%), acute respiratory failure (10%), acute congestive heart failure (9%) and acute rheumatic disorders (18%). Average anti-Xa activity, measured 4h after the third administration of enoxaparin was 0.25±0.09IU/mL in group 1 (enoxaparin 40mg) and 0.35±0.13IU/mL in group 2 (enoxaparin 60mg) (P<10-3). The proportions of patients with normal anti-Xa activity (between 0.32 and 0.54IU/mL) were 31% (n=11) and 69% (n=24) in group 1 and 2 respectively (P=0.007). The proportions of anti-Xa activity measurement below the normal range were 64% and 36% in group 1 and 2 (P<10-3) respectively. Subgroup analysis focusing on high weight patients (above 100kg, n=45) showed a marked difference in the proportion of patients with normal anti-Xa activity between group 1 (9%) and 2 (44%) (P=0.009). No venous thromboembolism occurred during the study and one patient in group 1 died because of hemorrhagic shock due to a gastric ulcer. Incidence of adverse events was not different between the two groups (P=0.52). In conclusion, the ITOHENOX study shows in medically obese inpatients that thromboprophylaxis with enoxaparin 60mg provides higher control of anti-Xa activity, without more bleeding complications than the standard enoxaparin regimen. This trial is registered with ClinicalTrials.gov, number NCT01707732.


Assuntos
Enoxaparina/uso terapêutico , Inibidores do Fator Xa/uso terapêutico , Obesidade/complicações , Trombose/etiologia , Trombose/prevenção & controle , Idoso , Idoso de 80 Anos ou mais , Relação Dose-Resposta a Droga , Enoxaparina/administração & dosagem , Enoxaparina/efeitos adversos , Fator Xa/metabolismo , Inibidores do Fator Xa/administração & dosagem , Inibidores do Fator Xa/efeitos adversos , Feminino , Hospitalização , Humanos , Masculino , Pessoa de Meia-Idade , Trombose/metabolismo , Resultado do Tratamento
7.
Amino Acids ; 46(4): 1059-67, 2014 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-24449167

RESUMO

Glutamine, the most abundant amino acid in the human body, plays several important roles in the intestine. Previous studies showed that glutamine may affect protein expression by regulating ubiquitin-proteasome system. We thus aimed to evaluate the effects of glutamine on ubiquitinated proteins in human duodenal mucosa. Five healthy male volunteers were included and received during 5 h, on two occasions and in a random order, either an enteral infusion of maltodextrins alone (0.25 g kg(-1) h(-1), control), mimicking carbohydrate-fed state, or maltodextrins with glutamine (0.117 g kg(-1) h(-1), glutamine). Endoscopic duodenal biopsies were then taken. Total cellular protein extracts were separated by 2D gel electrophoresis and analyzed by an immunodetection using anti-ubiquitin antibody. Differentially ubiquitinated proteins were then identified by liquid chromatography-electrospray ionization MS/MS. Five proteins were differentially ubiquitinated between control and glutamine conditions. Among these proteins, we identified two chaperone proteins, Grp75 and hsp74. Grp75 was less ubiquitinated after glutamine infusion compared with control. In contrast, hsp74, also called Apg-2, was more ubiquitinated after glutamine. In conclusion, we provide evidence that glutamine may regulate ubiquitination processes of specific proteins, i.e., Grp75 and Apg-2. Grp75 has protective and anti-inflammatory properties, while Apg-2 indirectly regulates stress-induced cell survival and proliferation through interaction with ZO-1. Further studies should confirm these results in stress conditions.


Assuntos
Duodeno/metabolismo , Glutamina/metabolismo , Proteínas de Choque Térmico HSP110/metabolismo , Proteínas de Choque Térmico HSP70/metabolismo , Mucosa Intestinal/metabolismo , Proteínas de Membrana/metabolismo , Adulto , Western Blotting , Feminino , Proteínas de Choque Térmico HSP110/química , Proteínas de Choque Térmico HSP70/química , Humanos , Mucosa Intestinal/química , Masculino , Proteínas de Membrana/química , Espectrometria de Massas em Tandem , Ubiquitinação , Adulto Jovem
8.
Am J Clin Nutr ; 97(2): 286-94, 2013 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-23283505

RESUMO

BACKGROUND: Glutamine modulates duodenal protein metabolism in fasted healthy humans, but its effects in a fed state remain unknown. OBJECTIVE: We aimed to assess the effects of either glutamine or an isonitrogenous protein mixture on duodenal protein metabolism in humans in the fed state. DESIGN: Twenty-four healthy volunteers were randomly included in 2 groups. Each volunteer was studied on 2 occasions in a random order and received, during 5 h, either an enteral infusion of maltodextrins alone (0.25 g · kg⁻¹ · h⁻¹; both groups) that mimicked a carbohydrate fed state or maltodextrins with glutamine (group 1) or an isonitrogenous (22.4 mg N · kg⁻¹ · h⁻¹) protein powder (group 2). Simultaneously, a continuous intravenous infusion of ¹³C-leucine and ²H5-phenylalanine (both 9 µmol · kg⁻¹ · h⁻¹) was performed. Endoscopic duodenal biopsies were taken. Leucine and phenylalanine enrichments were assessed by using gas chromatography-mass spectrometry in duodenal proteins and the intracellular free amino acids pool to calculate the mucosal fractional synthesis rate (FSR). Proteasome proteolytic activities and phosphokinase expression were assessed by using specific fluorogenic substrates and macroarrays, respectively. RESULTS: The FSR and proteasome activity were not different after the glutamine supply compared with after maltodextrins alone. In contrast, the FSR increased (1.7-fold increase; P < 0.05) after protein-powder delivery without modification of total proteasome activity. The protein powder increased insulinemia, PI3 kinase, and erk phosphorylation but did not affect the mammalian target of rapamycin (mTOR) pathway and mitogen-activated protein kinase signal-integrating kinase 1 phosphorylation. A trend for an increase of eukaryotic translation initiation factor 4E phosphorylation was observed (P = 0.07). CONCLUSION: In the carbohydrate fed state, enteral proteins but not glutamine increased duodenal protein synthesis through an mTOR independent pathway in humans.


Assuntos
Proteínas Alimentares/administração & dosagem , Duodeno/metabolismo , Mucosa Intestinal/metabolismo , Biossíntese de Proteínas , Serina-Treonina Quinases TOR/metabolismo , Regulação para Cima , Adulto , Isótopos de Carbono , Deutério , Proteínas Alimentares/efeitos adversos , Proteínas Alimentares/metabolismo , Duodeno/enzimologia , Nutrição Enteral , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Glutamina/administração & dosagem , Glutamina/efeitos adversos , Glutamina/metabolismo , Humanos , Hiperinsulinismo/etiologia , Mucosa Intestinal/enzimologia , Leucina/metabolismo , Masculino , Fenilalanina/metabolismo , Fosfatidilinositol 3-Quinase/metabolismo , Fosforilação , Período Pós-Prandial , Processamento de Proteína Pós-Traducional , Adulto Jovem
9.
Hypertension ; 60(6): 1415-21, 2012 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-23090775

RESUMO

In young healthy subjects, epoxyeicosatrienoic acids synthesized by endothelial cytochrome P450 epoxygenases maintain basal conduit artery diameter during altered NO availability. Whether this compensatory mechanism is effective during essential hypertension is unknown. Radial artery diameter, blood flow, and mean wall shear stress were determined in 14 nontreated essential hypertensive patients and 14 normotensive control subjects during 8 minutes of brachial infusion for inhibitors of cytochrome P450 epoxygenases (fluconazole, 0.4 µmol/min) and NO synthase (N(G)-monomethyl-L-arginine, 8 µmol/min) alone and in combination. In controls, the radial artery diameter was reduced by fluconazole (-0.034 ± 0.012 mm) and N(G)-monomethyl-L-arginine (-0.037 ± 0.010 mm) and to a larger extent by their combination (-0.137 ± 0.011 mm), demonstrating a synergic effect. In contrast, the radial diameter in hypertensive patients was not affected by fluconazole (0.010 ± 0.014 mm) but was reduced by N(G)-monomethyl-L-arginine (-0.091 ± 0.008 mm) to a larger extent than in controls. In parallel, N(G)-monomethyl-L-arginine decreased local plasma nitrite to a lesser extent in hypertensive patients (-14 ± 5 nmol/L) than in controls (-50 ± 10 nmol/L). Moreover, the addition of fluconazole to N(G)-monomethyl-L-arginine did not further decrease radial diameter in patients (-0.086 ± 0.011 mm). Accordingly, fluconazole significantly decreased local epoxyeicosatrienoic acid plasma level in controls (-2.0 ± 0.6 ng/mL) but not in patients (-0.9 ± 0.4 ng/mL). Inhibitors effects on blood flow and endothelium-independent dilatation to sodium nitroprusside were similar between groups. These results show that, in contrast to normotensive subjects, epoxyeicosatrienoic acids did not contribute to the regulation of basal conduit artery diameter and did not compensate for altered NO availability to maintain this diameter in essential hypertensive patients.


Assuntos
Inibidores das Enzimas do Citocromo P-450 , Eicosanoides/fisiologia , Hipertensão/fisiopatologia , Artéria Radial/efeitos dos fármacos , Artéria Radial/fisiopatologia , Vasoconstrição/efeitos dos fármacos , Vasodilatação/efeitos dos fármacos , Adulto , Pressão Sanguínea/efeitos dos fármacos , Pressão Sanguínea/fisiologia , Citocromo P-450 CYP2J2 , Sistema Enzimático do Citocromo P-450 , Endotélio Vascular/efeitos dos fármacos , Endotélio Vascular/fisiopatologia , Hipertensão Essencial , Feminino , Fluconazol/farmacologia , Humanos , Masculino , Pessoa de Meia-Idade , Fluxo Sanguíneo Regional/efeitos dos fármacos , Fluxo Sanguíneo Regional/fisiologia , Vasoconstrição/fisiologia , Vasodilatação/fisiologia , ômega-N-Metilarginina/farmacologia
10.
Am J Clin Nutr ; 94(3): 784-94, 2011 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-21795435

RESUMO

BACKGROUND: Previous studies have shown that the glucose supply reduces postoperative insulin resistance and improves patient outcomes. However, the effects of luminal glucose on intestinal mucosal proteins remain unknown. OBJECTIVE: We aimed to assess the effects of an enteral glucose supply on protein synthesis, proteolytic pathways, and proteome in human duodenal mucosa. DESIGN: Twenty healthy volunteers received a 5-h enteral infusion of either saline or glucose (0.12 g · kg(-1) · h(-1)). Simultaneously, a continuous intravenous infusion of l-[1-(13)C]leucine (12 µmol · kg(-1) · h(-1)) was maintained until endoscopy. The duodenal mucosal protein fractional synthesis rate (FSR) was calculated from leucine enrichments assessed in protein and free amino acid pools by gas chromatography-mass spectrometry. Cathepsin D, calpains, and chymotrypsin-like proteasome mucosal activities were evaluated by using specific fluorogenic substrates. A 2-dimensional PAGE-based comparative proteomics analysis was also performed on additional duodenal mucosal biopsy samples to identify differentially expressed proteins. RESULTS: Duodenal mucosal protein FSR and protease activities were not affected by glucose infusion relative to saline. Nevertheless, the comparative proteomics analysis indicated that 10 protein spots were significantly differentially expressed (ie, at least ±1.5-fold modulated; Student's t test, P < 0.05) in response to the glucose infusion relative to saline. Of the 8 proteins identified by mass spectrometry, α-enolase, cytoplasmic aconitate hydratase, and glutathione S-transferase ω-1 were upregulated, whereas epoxide hydrolase 2 was downregulated. CONCLUSION: Enteral glucose supply affected neither duodenal mucosal protein FSR nor activities of mucosal proteases but altered the duodenal mucosal proteome by modulating the expression of several enzymes involved mainly in carbohydrate and xenobiotic metabolism. This trial is registered at clinicaltrials.gov as NCT00213551.


Assuntos
Carboidratos da Dieta/administração & dosagem , Duodeno/metabolismo , Glucose/farmacologia , Mucosa Intestinal/metabolismo , Peptídeo Hidrolases/metabolismo , Biossíntese de Proteínas/efeitos dos fármacos , Aconitato Hidratase/metabolismo , Adulto , Duodeno/enzimologia , Nutrição Enteral , Epóxido Hidrolases/metabolismo , Feminino , Glucose/administração & dosagem , Glutationa Transferase/metabolismo , Humanos , Mucosa Intestinal/enzimologia , Isótopos , Leucina/metabolismo , Masculino , Fosfopiruvato Hidratase/metabolismo , Proteoma , Coloração e Rotulagem , Adulto Jovem
11.
Am J Clin Nutr ; 93(6): 1255-62, 2011 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-21508089

RESUMO

BACKGROUND: Although leucine increases protein anabolism through the mammalian target of rapamycin (mTOR) pathway in human muscles, its effects on intestinal mucosal proteins remain unknown. OBJECTIVE: We aimed to assess the effects of leucine on duodenal protein metabolism in healthy humans and to elucidate the signaling pathways involved. DESIGN: Eleven healthy volunteers received for 5 h, on 2 occasions and in random order, an enteral supply of maltodextrins (0.25 g . kg(-1) . h(-1)) or maltodextrins and leucine (0.035 g . kg(-1) . h(-1)) simultaneously with a continuous intravenous infusion of [(2)H(5)]phenylalanine (9 µmol . kg(-1) .h(-1)). Endoscopic duodenal biopsy samples were collected and frozen until analyzed. Phenylalanine enrichment was assessed by gas chromatography-mass spectrometry in duodenal protein and in free intracellular amino acid pools used as precursor to calculate the mucosal fractional synthesis rate (FSR). Proteasome proteolytic activities and phosphokinase expression were assessed by using specific fluorogenic substrates or macroarrays, respectively. RESULTS: Leucine supplementation slightly reduced FSR (mean ± SEM: 81.3 ± 6.3%/d) compared with maltodextrins alone (91.7 ± 8.5%/d; P = 0.0537). In addition, total proteasome activity decreased significantly with leucine (236 ± 21 compared with 400 ± 58 relative fluorescence units/µg protein; P < 0.05), with no modification of chymotrypsin-like, trypsin-like, caspase-like, or peptidase activities. Leucine did not affect the mTOR pathway but did increase the phosphorylation states of PI3K, Akt, AMPK, p38 MAPK, JNK, GSK-3α/ß, STAT3, and STAT5 and increased cyclin D1 mRNA concentrations, which suggested that leucine may enhance cell proliferation. CONCLUSION: Enteral leucine supplementation decreased proteasome activity in duodenal mucosa and enhanced cell proliferation through the PI3K/Akt/GSK-3α/ß-catenin pathway. This trial was registered at clinicaltrials.gov as NCT01254110.


Assuntos
Proliferação de Células/efeitos dos fármacos , Duodeno/efeitos dos fármacos , Mucosa Intestinal/efeitos dos fármacos , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Leucina/farmacologia , Complexo de Endopeptidases do Proteassoma/metabolismo , Biossíntese de Proteínas/efeitos dos fármacos , Adolescente , Adulto , Suplementos Nutricionais , Duodeno/metabolismo , Feminino , Humanos , Mucosa Intestinal/metabolismo , Peptídeos e Proteínas de Sinalização Intracelular/genética , Leucina/metabolismo , Masculino , Fenilalanina/metabolismo , Fosforilação/efeitos dos fármacos , Biossíntese de Proteínas/fisiologia , RNA Mensageiro/metabolismo , Transdução de Sinais/efeitos dos fármacos , Adulto Jovem
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