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1.
Nat Immunol ; 21(6): 684-694, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32231301

RESUMO

Aging is associated with remodeling of the immune system to enable the maintenance of life-long immunity. In the CD8+ T cell compartment, aging results in the expansion of highly differentiated cells that exhibit characteristics of cellular senescence. Here we found that CD27-CD28-CD8+ T cells lost the signaling activity of the T cell antigen receptor (TCR) and expressed a protein complex containing the agonistic natural killer (NK) receptor NKG2D and the NK adaptor molecule DAP12, which promoted cytotoxicity against cells that expressed NKG2D ligands. Immunoprecipitation and imaging cytometry indicated that the NKG2D-DAP12 complex was associated with sestrin 2. The genetic inhibition of sestrin 2 resulted in decreased expression of NKG2D and DAP12 and restored TCR signaling in senescent-like CD27-CD28-CD8+ T cells. Therefore, during aging, sestrins induce the reprogramming of non-proliferative senescent-like CD27-CD28-CD8+ T cells to acquire a broad-spectrum, innate-like killing activity.


Assuntos
Linfócitos T CD8-Positivos/imunologia , Linfócitos T CD8-Positivos/metabolismo , Senescência Celular/imunologia , Células Matadoras Naturais/imunologia , Células Matadoras Naturais/metabolismo , Proteínas Nucleares/genética , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Citotoxicidade Imunológica , Perfilação da Expressão Gênica , Humanos , Proteínas de Membrana/metabolismo , Subfamília K de Receptores Semelhantes a Lectina de Células NK/metabolismo , Proteínas Nucleares/metabolismo , Receptores de Antígenos de Linfócitos T/metabolismo , Receptores de Células Matadoras Naturais/metabolismo , Transdução de Sinais , Febre Amarela/genética , Febre Amarela/imunologia , Febre Amarela/metabolismo , Febre Amarela/virologia , Vírus da Febre Amarela/imunologia
2.
Nature ; 631(8019): 189-198, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38898278

RESUMO

The COVID-19 pandemic is an ongoing global health threat, yet our understanding of the dynamics of early cellular responses to this disease remains limited1. Here in our SARS-CoV-2 human challenge study, we used single-cell multi-omics profiling of nasopharyngeal swabs and blood to temporally resolve abortive, transient and sustained infections in seronegative individuals challenged with pre-Alpha SARS-CoV-2. Our analyses revealed rapid changes in cell-type proportions and dozens of highly dynamic cellular response states in epithelial and immune cells associated with specific time points and infection status. We observed that the interferon response in blood preceded the nasopharyngeal response. Moreover, nasopharyngeal immune infiltration occurred early in samples from individuals with only transient infection and later in samples from individuals with sustained infection. High expression of HLA-DQA2 before inoculation was associated with preventing sustained infection. Ciliated cells showed multiple immune responses and were most permissive for viral replication, whereas nasopharyngeal T cells and macrophages were infected non-productively. We resolved 54 T cell states, including acutely activated T cells that clonally expanded while carrying convergent SARS-CoV-2 motifs. Our new computational pipeline Cell2TCR identifies activated antigen-responding T cells based on a gene expression signature and clusters these into clonotype groups and motifs. Overall, our detailed time series data can serve as a Rosetta stone for epithelial and immune cell responses and reveals early dynamic responses associated with protection against infection.


Assuntos
COVID-19 , Multiômica , SARS-CoV-2 , Análise de Célula Única , Feminino , Humanos , Masculino , COVID-19/genética , COVID-19/imunologia , COVID-19/patologia , COVID-19/virologia , Células Epiteliais/imunologia , Perfilação da Expressão Gênica , Interferons/imunologia , Macrófagos/imunologia , Macrófagos/virologia , Nasofaringe/virologia , Nasofaringe/imunologia , SARS-CoV-2/crescimento & desenvolvimento , SARS-CoV-2/imunologia , SARS-CoV-2/patogenicidade , SARS-CoV-2/fisiologia , Linfócitos T/citologia , Linfócitos T/imunologia , Linfócitos T/metabolismo , Linfócitos T/virologia , Fatores de Tempo , Replicação Viral
3.
J Cell Sci ; 136(1)2023 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-36594787

RESUMO

Cdc28, the homolog of mammalian Cdk1, is a conserved key regulatory kinase for all major cell cycle transitions in yeast. We have found that defects in mitochondrial respiration (including deletion of ATP2, an ATP synthase subunit) inhibit growth of cells carrying a degron allele of Cdc28 (cdc28td) or Cdc28 temperature-sensitive mutations (cdc28-1 and cdc28-1N) at semi-permissive temperatures. Loss of cell proliferation in the atp2Δcdc28td double mutant is associated with aggravated cell cycle arrest and mitochondrial dysfunction, including mitochondrial hyperpolarization and fragmentation. Unexpectedly, in mutants defective in mitochondrial respiration, steady-state protein levels of mutant cdc28 are strongly reduced, accounting for the aggravated growth defects. Stability of Cdc28 is promoted by the Hsp90-Cdc37 chaperone complex. Our results show that atp2Δcdc28td double-mutant cells, but not single mutants, are sensitive to chemical inhibition of the Hsp90-Cdc37 complex, and exhibit reduced levels of additional Hsp90-Cdc37 client kinases, suggesting an inhibition of this complex. In agreement, overexpression of CDC37 improved atp2Δcdc28td cell growth and Cdc28 levels. Overall, our study shows that simultaneous disturbance of mitochondrial respiration and Cdc28 activity reduces the capacity of Cdc37 to chaperone client kinases, leading to growth arrest.


Assuntos
Proteínas de Ciclo Celular , Chaperonas Moleculares , Humanos , Animais , Proteínas de Ciclo Celular/genética , Proteínas de Ciclo Celular/metabolismo , Chaperonas Moleculares/metabolismo , Proteína Quinase CDC28 de Saccharomyces cerevisiae/genética , Proteína Quinase CDC28 de Saccharomyces cerevisiae/metabolismo , Proteínas de Choque Térmico HSP90/genética , Proteínas de Choque Térmico HSP90/metabolismo , Saccharomyces cerevisiae/metabolismo , Mitocôndrias/genética , Mitocôndrias/metabolismo , Ligação Proteica , Mamíferos/metabolismo , Chaperoninas/metabolismo , Proteína Quinase CDC2/genética , Proteína Quinase CDC2/metabolismo
5.
Rheumatology (Oxford) ; 63(4): 999-1006, 2024 Apr 02.
Artigo em Inglês | MEDLINE | ID: mdl-37354498

RESUMO

OBJECTIVE: Data on ANCA-associated vasculitis (AAV) induced by anti-thyroid drugs (ATD) are scarce. We aimed to describe the characteristics and outcome of these patients in comparison to primary AAV. METHODS: We performed a retrospective multicentre study including patients with ATD-induced AAV. We focused on ATD-induced microscopic polyangiitis (MPA) and compared them with primary MPA by matching each case with four controls by gender and year of diagnosis. RESULTS: Forty-five patients with ATD-induced AAV of whom 24 MPA were included. ANCA were positive in 44 patients (98%), including myeloperoxidase (MPO)-ANCA in 21 (47%), proteinase 3 (PR3)-ANCA in six (13%), and double positive MPO- and PR3-ANCA in 15 (33%). Main clinical manifestations were skin involvement (64%), arthralgia (51%) and glomerulonephritis (20%). ATD was discontinued in 98% of cases, allowing vasculitis remission in seven (16%). All the remaining patients achieved remission after glucocorticoids, in combination with rituximab in 11 (30%) or cyclophosphamide in four (11%). ATD were reintroduced in seven cases (16%) without any subsequent relapse. Compared with 96 matched primary MPA, ATD-induced MPA were younger at diagnosis (48 vs 65 years, P < 0.001), had more frequent cutaneous involvement (54 vs 25%, P = 0.007), but less frequent kidney (38 vs 73%, P = 0.02), and a lower risk of relapse (adjusted HR 0.07; 95% CI 0.01, 0.65, P = 0.019). CONCLUSION: ATD-induced AAV were mainly MPA with MPO-ANCA, but double MPO- and PR3-ANCA positivity was frequent. The most common manifestations were skin and musculoskeletal manifestations. ATD-induced MPA were less severe and showed a lower risk of relapse than primary MPA.


Assuntos
Vasculite Associada a Anticorpo Anticitoplasma de Neutrófilos , Granulomatose com Poliangiite , Poliangiite Microscópica , Humanos , Granulomatose com Poliangiite/diagnóstico , Estudos Retrospectivos , Anticorpos Anticitoplasma de Neutrófilos , Estudos de Casos e Controles , Vasculite Associada a Anticorpo Anticitoplasma de Neutrófilos/tratamento farmacológico , Vasculite Associada a Anticorpo Anticitoplasma de Neutrófilos/diagnóstico , Mieloblastina , Recidiva , Peroxidase
6.
Nutr Health ; 30(1): 5-13, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-37499218

RESUMO

Background: Cardiovascular disease is the leading cause of mortality associated with diabetes, which is characterized by chronic hyperglycemia. Low-carbohydrate diet has gained popularity as an intervention in patients with type 2 diabetes mellitus, acting to improve glycemic profile and serum lipids. In its turn, exercise in hypoxia induces specific adaptations, mostly modulated via hypoxia-induced transcription factor signaling cascade, which increases with exposure to altitude, and promotes angiogenesis, glycogen supply, glucose tolerance, and raises GLUT-4 expression. Aim: Given that hyperglycemia decreases HIF-1α and it is better controlled when following a low-carbohydrate diet, this study aims to examine the hypothesis that a combination of both low-carbohydrate diet and chronic exercise in hypoxia in type 2 diabetes mellitus is associated with improved glycemic control and cardiovascular parameters, whose protocol is described. Methods: Patients with type 2 diabetes mellitus (n = 48) will be recruited and randomized into one of the three groups: (a) Control group: Control diet (low-fat and moderate-carbohydrate diet) + exercise in normoxia; (2) exercise in hypoxia group: Control diet + exercise in hypoxia; (3) intervention group: Low-carbohydrate diet (low-carbohydrate and high-fat diet) + exercise in hypoxia. Before and after 8 weeks of interventions, cardiopulmonary tests (Bruce protocol), body composition and blood pressure will be evaluated. Blood samples will be collected to measure hypoxia-induced transcription factor, C-reactive protein, glycemic and lipid profiles. Summary: This will be the first trial to examine the isolated and combined effect of chronic exercise in hypoxia and low-carbohydrate diet in type 2 diabetes mellitus. This trial will help to fill a significant research gap, guide future research and contribute to the combined nutrition and exercise approach to type 2 diabetes mellitus.


Assuntos
Doenças Cardiovasculares , Diabetes Mellitus Tipo 2 , Hiperglicemia , Humanos , Doenças Cardiovasculares/etiologia , Doenças Cardiovasculares/prevenção & controle , Glicemia/metabolismo , Controle Glicêmico , Fatores de Risco , Dieta com Restrição de Carboidratos , Composição Corporal , Fatores de Risco de Doenças Cardíacas , Hipóxia , Fatores de Transcrição/metabolismo , Ensaios Clínicos Controlados Aleatórios como Assunto
7.
Int J Mol Sci ; 24(5)2023 Mar 03.
Artigo em Inglês | MEDLINE | ID: mdl-36902357

RESUMO

This Special Issue was devoted to unravelling novel aspects of yeast biology and signal transduction in numerous yet intricate basic processes [...].


Assuntos
Proteínas de Saccharomyces cerevisiae , Saccharomyces cerevisiae , Saccharomyces cerevisiae/metabolismo , Transdução de Sinais/fisiologia , Proteínas de Saccharomyces cerevisiae/metabolismo
8.
Int J Mol Sci ; 24(7)2023 Mar 25.
Artigo em Inglês | MEDLINE | ID: mdl-37047194

RESUMO

Niemann-Pick type C1 (NPC1) is an endolysosomal transmembrane protein involved in the export of cholesterol and sphingolipids to other cellular compartments such as the endoplasmic reticulum and plasma membrane. NPC1 loss of function is the major cause of NPC disease, a rare lysosomal storage disorder characterized by an abnormal accumulation of lipids in the late endosomal/lysosomal network, mitochondrial dysfunction, and impaired autophagy. NPC phenotypes are conserved in yeast lacking Ncr1, an orthologue of human NPC1, leading to premature aging. Herein, we performed a phosphoproteomic analysis to investigate the effect of Ncr1 loss on cellular functions mediated by the yeast lysosome-like vacuoles. Our results revealed changes in vacuolar membrane proteins that are associated mostly with vesicle biology (fusion, transport, organization), autophagy, and ion homeostasis, including iron, manganese, and calcium. Consistently, the cytoplasm to vacuole targeting (Cvt) pathway was increased in ncr1∆ cells and autophagy was compromised despite TORC1 inhibition. Moreover, ncr1∆ cells exhibited iron overload mediated by the low-iron sensing transcription factor Aft1. Iron deprivation restored the autophagic flux of ncr1∆ cells and increased its chronological lifespan and oxidative stress resistance. These results implicate iron overload on autophagy impairment, oxidative stress sensitivity, and cell death in the yeast model of NPC1.


Assuntos
Sobrecarga de Ferro , Doença de Niemann-Pick Tipo C , Humanos , Saccharomyces cerevisiae/metabolismo , Peptídeos e Proteínas de Sinalização Intracelular/genética , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Ferro/metabolismo , Longevidade , Receptor 1 Desencadeador da Citotoxicidade Natural/metabolismo , Proteínas de Membrana/metabolismo , Lisossomos/metabolismo , Vacúolos/metabolismo , Autofagia , Sobrecarga de Ferro/metabolismo , Doença de Niemann-Pick Tipo C/metabolismo
10.
Scand J Med Sci Sports ; 32 Suppl 1: 73-80, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-34087016

RESUMO

The present study aimed to investigate the prevalence of dietary supplements usage (types, reasons for usage, sources of information, purchase venues) among elite female football players, using a self-administered questionnaire. The study participants (n = 103) were recruited through team physicians during an official international tournament. Overall, 82% reported using dietary supplements at least once during the last 12 months. The most common dietary supplements were vitamin D (52%), omega-3 fatty acids (49%), and protein (45%). Primary reasons for dietary supplement use were to stay healthy (66%), to accelerate recovery (58%), and to increase energy/reduce fatigue (54%). Supplement advice came mainly from medical doctors (46%), dietitians/nutritionists (43%), and coaches/fitness coaches (41%). Most dietary supplements were acquired from supplement stores (30%), a sponsor (26%), or drugstores/pharmacies (22%). Elite female football players are frequent dietary supplement users. Further research needs to explore the frequency, dose, and timing of these supplements.


Assuntos
Futebol , Feminino , Humanos , Atletas , Suplementos Nutricionais , Inquéritos e Questionários
11.
J Sports Sci ; 40(16): 1857-1864, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-36101017

RESUMO

It is unclear if different bioelectrical impedance (BI) devices provide similar results regarding raw parameters [Resistance (R), Reactance (Xc), Phase Angle (PhA), and Impedance (Z)] for the same population/individual undergoing a weight loss intervention. The aim was to evaluate the cross-sectional and longitudinal agreement of raw data obtained by two BI devices in former athletes with overweight/obesity. Fifty-nine participants [mean (SD): 43.5 (9.2) years, 30.5 (4.0) kg/m2, 42% females] were included. All the assessments were performed before and after a 4-months lifestyle intervention targeting weight loss (WL). BI parameters were assessed at 50 kHz by two devices: a BI spectroscopy (Xitron Technologies, 4200B, San Diego, USA) and a phase-sensitive single-frequency device (BIA 101 AKERN, Florence, Italy). Cross-sectionally, BIS provided lower mean values for all parameters (0.4% for R, 1.6% for Xc, 1.0% for PhA and 0.4% for Z, p <0.001) compared to SF-BIA. In individuals with a WL≥2.5% (n =18), no longitudinal differences were found in any of the raw parameters between devices (p≥0.128) and there was no proportional bias (p≥0.408). Despite small baseline differences in raw BI parameters, both devices agreed in tracking changes over time at the group level but interpretation should be careful at the individual level.


Assuntos
Composição Corporal , Redução de Peso , Feminino , Humanos , Masculino , Estudos Transversais , Impedância Elétrica , Atletas , Estilo de Vida
12.
Ann Rheum Dis ; 80(11): 1475-1482, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-34215646

RESUMO

OBJECTIVES: To assess the sensitivity to change of ultrasound halo features and their association with disease activity and glucocorticoid (GC) treatment in patients with newly diagnosed giant cell arteritis (GCA). METHODS: Prospective study of patients with ultrasound-confirmed GCA who underwent serial ultrasound assessments of the temporal artery (TA) and axillary artery (AX) at fixed time points. The number of segments with halo and maximum halo intima-media thickness (IMT) was recorded. Time points in which >80% of patients were assessed were considered for analysis. Halo features at disease presentation and first relapse were compared. RESULTS: 49 patients were assessed at 354 visits. Halo sensitivity to change was assessed at weeks 1, 3, 6, 12 and 24 and showed a significant standardised mean difference between all time points and baseline for the TA halo features but only after week 6 for the AX halo features. The number of TA segments with halo and sum and maximum TA halo IMT showed a significant correlation with erythrocyte sedimentation rate (0.41, 0.44 and 0.48), C reactive protein (0.34, 0.39 and 0.41), Birmingham Vasculitis Activity Score (0.29, 0.36 and 0.35) and GC cumulative dose (-0.34, -0.37 and -0.32); no significant correlation was found for the AX halo features. Halo sign was present in 94% of first disease relapses but with a lower mean number of segments with halo and sum of halo IMT compared with disease onset (2.93±1.59 mm vs 4.85±1.51 mm, p=0.0012; 2.01±1.13 mm vs 4.49±1.95 mm, p=0.0012). CONCLUSIONS: Ultrasound is a useful imaging tool to assess disease activity and response to treatment in patients with GCA.


Assuntos
Artéria Axilar/diagnóstico por imagem , Arterite de Células Gigantes/diagnóstico por imagem , Artérias Temporais/diagnóstico por imagem , Túnica Íntima/diagnóstico por imagem , Idoso , Idoso de 80 Anos ou mais , Feminino , Arterite de Células Gigantes/tratamento farmacológico , Glucocorticoides/uso terapêutico , Humanos , Masculino , Estudos Prospectivos , Recidiva , Resultado do Tratamento , Ultrassonografia
13.
Rheumatology (Oxford) ; 60(1): 359-365, 2021 01 05.
Artigo em Inglês | MEDLINE | ID: mdl-32856066

RESUMO

OBJECTIVE: Eosinophilic granulomatosis with polyangiitis (EGPA) is a systemic small-vessel vasculitis characterized by asthma, hypereosinophilia and ANCA positivity in 40% of patients. Renal involvement is rare and poorly described, leading to this renal biopsy-proven based study in a large EGPA cohort. METHODS: We conducted a retrospective multicentre study including patients fulfilling the 1990 ACR criteria and/or the 2012 revised Chapel Hill Consensus Conference criteria for EGPA and/or the modified criteria of the MIRRA trial, with biopsy-proven nephropathy. RESULTS: Sixty-three patients [27 women, median age 60 years (18-83)] were included. Renal disease was present at vasculitis diagnosis in 54 patients (86%). ANCA were positive in 53 cases (84%) with anti-MPO specificity in 44 (83%). All patients had late-onset asthma. Peripheral neuropathy was present in 29 cases (46%), alveolar haemorrhage in 10 (16%). The most common renal presentation was acute renal failure (75%). Renal biopsy revealed pauci-immune necrotizing GN in 49 cases (78%). Membranous nephropathy (10%) and membranoproliferative GN (3%) were mostly observed in ANCA-negative patients. Pure acute interstitial nephritis was found in six cases (10%); important interstitial inflammation was observed in 28 (44%). All patients received steroids with adjunctive immunosuppression in 54 cases (86%). After a median follow-up of 51 months (1-296), 58 patients (92%) were alive, nine (14%) were on chronic dialysis and two (3%) had undergone kidney transplantation. CONCLUSION: Necrotizing pauci-immune GN is the most common renal presentation in ANCA-positive EGPA. ANCA-negative patients had frequent atypical renal presentation with other glomerulopathies such as membranous nephropathy. An important eosinophilic interstitial infiltration was observed in almost 50% of cases.


Assuntos
Injúria Renal Aguda/patologia , Síndrome de Churg-Strauss/patologia , Rim/patologia , Injúria Renal Aguda/etiologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Síndrome de Churg-Strauss/complicações , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Adulto Jovem
14.
Rheumatology (Oxford) ; 60(9): 4355-4360, 2021 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-33347592

RESUMO

OBJECTIVES: Only a third of patients with eosinophilic granulomatosis with polyangiitis (EGPA) are ANCA-positive, mainly directed against MPO. ANCA directed against PR3 are rarely found in EGPA. We aimed to examine the significance of PR3-ANCA in EGPA. METHODS: We set up a retrospective European multicentre cohort including 845 patients. Baseline characteristics and outcomes were analysed and compared according to ANCA status. RESULTS: ANCA status was available for 734 patients: 508 (69.2%) ANCA-negative, 210 (28.6%) MPO-ANCA and 16 (2.2%) PR3-ANCA. At baseline, PR3-ANCA patients, compared with those with MPO-ANCA and ANCA-negative, less frequently had active asthma (69% vs 91% and 93%, P = 0.003, respectively) and peripheral neuropathy (31% vs 71% and 47%, P < 0.0001), more frequently had cutaneous manifestations (63% vs 38% and 34%, P = 0.03) and pulmonary nodules (25% vs 10% and 8%, P = 0.046), and lower median eosinophil count (1450 vs 5400 and 3224/mm3, P < 0.0001). Vasculitis relapse-free survival was shorter for PR3-ANCA (hazard ratio 6.05, P = 0.005) and MPO-ANCA patients (hazard ratio 1.88, P = 0.0002) compared with ANCA-negative patients. CONCLUSION: PR3-ANCA EGPA patients differ from those with MPO-ANCA and negative ANCA, and share clinical features with granulomatosis with polyangiitis. This suggests that PR3-ANCA EGPA could be a particular form of PR3-ANCA-associated vasculitis.


Assuntos
Anticorpos Anticitoplasma de Neutrófilos/imunologia , Síndrome de Churg-Strauss/imunologia , Granulomatose com Poliangiite/imunologia , Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos
15.
Int J Mol Sci ; 22(16)2021 Aug 20.
Artigo em Inglês | MEDLINE | ID: mdl-34445723

RESUMO

Lipid droplets (LDs) are ubiquitous organelles that fulfill essential roles in response to metabolic cues. The identification of several neutral lipid synthesizing and regulatory protein complexes have propelled significant advance on the mechanisms of LD biogenesis in the endoplasmic reticulum (ER). However, our understanding of signaling networks, especially transcriptional mechanisms, regulating membrane biogenesis is very limited. Here, we show that the nutrient-sensing Target of Rapamycin Complex 1 (TORC1) regulates LD formation at a transcriptional level, by targeting DGA1 expression, in a Sit4-, Mks1-, and Sfp1-dependent manner. We show that cytosolic pH (pHc), co-regulated by the plasma membrane H+-ATPase Pma1 and the vacuolar ATPase (V-ATPase), acts as a second messenger, upstream of protein kinase A (PKA), to adjust the localization and activity of the major transcription factor repressor Opi1, which in turn controls the metabolic switch between phospholipid metabolism and lipid storage. Together, this work delineates hitherto unknown molecular mechanisms that couple nutrient availability and pHc to LD formation through a transcriptional circuit regulated by major signaling transduction pathways.


Assuntos
Proteínas Quinases Dependentes de AMP Cíclico/metabolismo , Gotículas Lipídicas/metabolismo , Proteínas de Saccharomyces cerevisiae/metabolismo , Fatores de Transcrição/metabolismo , Proteínas Quinases Dependentes de AMP Cíclico/fisiologia , Citosol/metabolismo , Retículo Endoplasmático/metabolismo , Concentração de Íons de Hidrogênio , Gotículas Lipídicas/fisiologia , Metabolismo dos Lipídeos/fisiologia , Alvo Mecanístico do Complexo 1 de Rapamicina/metabolismo , Alvo Mecanístico do Complexo 1 de Rapamicina/fisiologia , Proteínas de Membrana/metabolismo , Proteína Fosfatase 2/metabolismo , Proteínas Repressoras/metabolismo , Saccharomyces cerevisiae/metabolismo , Proteínas de Saccharomyces cerevisiae/fisiologia , Transdução de Sinais , Fatores de Transcrição/fisiologia
16.
Eat Weight Disord ; 25(5): 1377-1385, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31520301

RESUMO

PURPOSE: This study aims at identifying behavioural and psychological pretreatment predictors of 12- and 36-month weight loss in women with overweight/obesity enrolled in a behavioural weight management intervention. METHODS: A sample of 221 women participated in a randomized controlled trial on weight management (n12 month = 184; n36 month = 156). Multiple linear regressions were used to identify pretreatment predictors of successful weight loss, separately for intervention and control groups. Completers-only and baseline observation carried forward analyses were performed. This study is a secondary analysis of data from the 'Promotion of Exercise and Health in Obesity' randomized controlled trial. RESULTS: Fewer weight loss attempts in the last year positively predicted weight loss at 12 months in the intervention group, explaining 6% of the variance. At 36 months, in the intervention group, 20.2% of the variance in weight change was explained by lower eating disinhibition and higher weight-related quality of life in completers-only analyses, while baseline observation carried forward analyses explained only 9.8% of the variance in weight change via higher self-esteem and lower weight loss expectations. In the control group, higher exercise self-efficacy and a more internal weight locus of control predicted weight loss at 36 months, explaining 13.9% of the variance (completers-only analyses). CONCLUSIONS: Previous weight loss attempts were identified as the most efficient pretreatment predictor of 12-month weight loss. Eating disinhibition, weight-related quality of life, self-esteem, weight loss expectations, exercise self-efficacy, and weight locus of control seem to be key factors for long-term success. LEVEL OF EVIDENCE: Level I, randomized controlled trial. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov identifier NCT00513084.


Assuntos
Qualidade de Vida , Redução de Peso , Exercício Físico , Feminino , Humanos , Obesidade/terapia , Sobrepeso/terapia
17.
Nutr J ; 18(1): 3, 2019 01 11.
Artigo em Inglês | MEDLINE | ID: mdl-30634981

RESUMO

There is not much evidence about how diet strictness during weekends and holidays influence long-term weight loss maintenance. Our aim was to examine how dieting more or less strictly during weekends and holidays (vs. weekdays and non-holiday periods) influence weight loss maintenance.Participants (n = 108) from the Portuguese Weight Control Registry indicated whether they had a more or less strict diet regimen during weekends compared to weekdays. A similar question about holiday and non-holiday period' diet regimen was answered. Weight and height were measured at baseline and 1y follow-up. A 3% maximum weight variation defined participants as "non-regainers".General level on dieting strictness on weekends vs. weekdays (r = - 0.28, p < 0.01) and holidays vs. non-holidays (r = - 0.33, p < 0.001) predicted 1y weight change.Participants who reported being less strict on weekends (OR = 0.34, 95% CI: 0.15-0.81) were more likely to be non-regainers when compared with the ones who reported being more strict on weekends. Non-significant results were found during holidays (OR = 0.47, 95% CI: 0.20-1.09).Adopting a less strict diet regimen during weekends, when compared to weekdays, was a behavioral strategy associated with long-term weight management in our sample.


Assuntos
Manutenção do Peso Corporal , Dieta , Férias e Feriados , Redução de Peso , Adulto , Índice de Massa Corporal , Dieta/psicologia , Dieta/estatística & dados numéricos , Feminino , Seguimentos , Comportamentos Relacionados com a Saúde , Férias e Feriados/psicologia , Férias e Feriados/estatística & dados numéricos , Humanos , Masculino , Pessoa de Meia-Idade , Razão de Chances , Portugal , Sistema de Registros , Redução de Peso/fisiologia , Programas de Redução de Peso/estatística & dados numéricos
18.
Biochim Biophys Acta Mol Basis Dis ; 1864(1): 79-88, 2018 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-28988886

RESUMO

The Niemann-Pick type C is a rare neurodegenerative disease that results from loss-of-function point mutations in NPC1 or NPC2, which affect the homeostasis of sphingolipids and sterols in human cells. We have previously shown that yeast lacking Ncr1, the orthologue of human NPC1 protein, display a premature ageing phenotype and higher sensitivity to oxidative stress associated with mitochondrial dysfunctions and accumulation of long chain bases. In this study, a lipidomic analysis revealed specific changes in the levels of ceramide species in ncr1Δ cells, including decreases in dihydroceramides and increases in phytoceramides. Moreover, the activation of Sit4, a ceramide-activated protein phosphatase, increased in ncr1Δ cells. Deletion of SIT4 or CDC55, its regulatory subunit, increased the chronological lifespan and hydrogen peroxide resistance of ncr1Δ cells and suppressed its mitochondrial defects. Notably, Sch9 and Pkh1-mediated phosphorylation of Sch9 decreased significantly in ncr1Δsit4Δ cells. These results suggest that phytoceramide accumulation and Sit4-dependent signaling mediate the mitochondrial dysfunction and shortened lifespan in the yeast model of Niemann-Pick type C1, in part through modulation of the Pkh1-Sch9 pathway.


Assuntos
Mitocôndrias/fisiologia , Dinâmica Mitocondrial/genética , Doença de Niemann-Pick Tipo C/genética , Doença de Niemann-Pick Tipo C/patologia , Proteína Fosfatase 2/fisiologia , Proteínas de Saccharomyces cerevisiae/fisiologia , Esfingolipídeos/metabolismo , Proteínas Quinases Dependentes de 3-Fosfoinositídeo/metabolismo , Humanos , Metabolismo dos Lipídeos/genética , Modelos Biológicos , Organismos Geneticamente Modificados , Proteínas Serina-Treonina Quinases/metabolismo , Saccharomyces cerevisiae , Proteínas de Saccharomyces cerevisiae/metabolismo , Transdução de Sinais/genética
19.
Artigo em Inglês | MEDLINE | ID: mdl-29032057

RESUMO

Iron acquisition systems have to be tightly regulated to assure a continuous supply of iron, since it is essential for survival, but simultaneously to prevent iron overload that is toxic to the cells. In budding yeast, the low­iron sensing transcription factor Aft1p is a master regulator of the iron regulon. Our previous work revealed that bioactive sphingolipids modulate iron homeostasis as yeast cells lacking the sphingomyelinase Isc1p exhibit an upregulation of the iron regulon. In this study, we show that Isc1p impacts on iron accumulation and localization. Notably, Aft1p is activated in isc1Δ cells due to a decrease in its phosphorylation and an increase in its nuclear levels. Consistently, the expression of a phosphomimetic version of Aft1p-S210/S224 that favours its nuclear export abolished iron accumulation in isc1Δ cells. Notably, the Hog1p kinase, homologue of mammalian p38, interacts with and directly phosphorylates Aft1p at residues S210 and S224. However, Hog1p-Aft1p interaction decreases in isc1Δ cells, which likely contributes to Aft1p dephosphorylation and consequently to Aft1p activation and iron overload in isc1Δ cells. These results suggest that alterations in sphingolipid composition in isc1Δ cells may impact on iron homeostasis by disturbing the regulation of Aft1p by Hog1p. To our knowledge, Hog1p is the first kinase reported to directly regulate Aft1p, impacting on iron homeostasis.


Assuntos
Ferro/metabolismo , Proteínas Quinases Ativadas por Mitógeno/fisiologia , Proteínas de Saccharomyces cerevisiae/metabolismo , Proteínas de Saccharomyces cerevisiae/fisiologia , Fatores de Transcrição/metabolismo , Transporte Ativo do Núcleo Celular/genética , Núcleo Celular/metabolismo , Homeostase/genética , Proteínas Quinases Ativadas por Mitógeno/genética , Organismos Geneticamente Modificados , Fosforilação/genética , Ligação Proteica , Saccharomyces cerevisiae , Proteínas de Saccharomyces cerevisiae/genética , Fatores de Transcrição/genética
20.
Biochim Biophys Acta ; 1861(1): 21-33, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26477382

RESUMO

The vacuoles play important roles in cellular homeostasis and their functions include the digestion of cytoplasmic material and organelles derived from autophagy. Conserved nutrient signaling pathways regulate vacuolar function and autophagy, ensuring normal cell and organismal development and aging. Recent evidence implicates sphingolipids in the modulation of these processes, but the impact of ceramide signaling on vacuolar dynamics and autophagy remains largely unknown. Here, we show that yeast cells lacking Isc1p, an orthologue of mammalian neutral sphingomyelinase type 2, exhibit vacuolar fragmentation and dysfunctions, namely decreased Pep4p-mediated proteolysis and V-ATPase activity, which impairs vacuolar acidification. Moreover, these phenotypes are suppressed by downregulation of the ceramide-activated protein phosphatase Sit4p. The isc1Δ cells also exhibit defective Cvt and vesicular trafficking in a Sit4p-dependent manner, ultimately contributing to a reduced autophagic flux. Importantly, these phenotypes are also suppressed by downregulation of the nutrient signaling kinase TORC1, which is known to inhibit Sit4p and autophagy, or Sch9p. These results support a model in which Sit4p functions downstream of Isc1p in a TORC1-independent, ceramide-dependent signaling branch that impairs vacuolar function and vesicular trafficking, leading to autophagic defects in yeast.


Assuntos
Autofagia/fisiologia , Ceramidas/fisiologia , Proteína Fosfatase 2/fisiologia , Proteínas de Saccharomyces cerevisiae/fisiologia , Fosfolipases Tipo C/fisiologia , Vacúolos/fisiologia , Transdução de Sinais , Vesículas Transportadoras/fisiologia , Resposta a Proteínas não Dobradas
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