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2.
Sci Rep ; 9(1): 19976, 2019 12 27.
Artigo em Inglês | MEDLINE | ID: mdl-31882638

RESUMO

Muscle atrophy is a physiological response to disuse and malnutrition, but hibernating bears are largely resistant to this phenomenon. Unlike other mammals, they efficiently reabsorb amino acids from urine, periodically activate muscle contraction, and their adipocytes differentially responds to insulin. The contribution of myocytes to the reduced atrophy remains largely unknown. Here we show how metabolism and atrophy signaling are regulated in skeletal muscle of hibernating grizzly bear. Metabolic modeling of proteomic changes suggests an autonomous increase of non-essential amino acids (NEAA) in muscle and treatment of differentiated myoblasts with NEAA is sufficient to induce hypertrophy. Our comparison of gene expression in hibernation versus muscle atrophy identified several genes differentially regulated during hibernation, including Pdk4 and Serpinf1. Their trophic effects extend to myoblasts from non-hibernating species (including C. elegans), as documented by a knockdown approach. Together, these changes reflect evolutionary favored adaptations that, once translated to the clinics, could help improve atrophy treatment.

3.
Mol Ecol ; 25(21): 5396-5411, 2016 11.
Artigo em Inglês | MEDLINE | ID: mdl-27598849

RESUMO

Populations distributed across a broad thermal cline are instrumental in addressing adaptation to increasing temperatures under global warming. Using a space-for-time substitution design, we tested for parallel adaptation to warm temperatures along two independent thermal clines in Zostera marina, the most widely distributed seagrass in the temperate Northern Hemisphere. A North-South pair of populations was sampled along the European and North American coasts and exposed to a simulated heatwave in a common-garden mesocosm. Transcriptomic responses under control, heat stress and recovery were recorded in 99 RNAseq libraries with ~13 000 uniquely annotated, expressed genes. We corrected for phylogenetic differentiation among populations to discriminate neutral from adaptive differentiation. The two southern populations recovered faster from heat stress and showed parallel transcriptomic differentiation, as compared with northern populations. Among 2389 differentially expressed genes, 21 exceeded neutral expectations and were likely involved in parallel adaptation to warm temperatures. However, the strongest differentiation following phylogenetic correction was between the three Atlantic populations and the Mediterranean population with 128 of 4711 differentially expressed genes exceeding neutral expectations. Although adaptation to warm temperatures is expected to reduce sensitivity to heatwaves, the continued resistance of seagrass to further anthropogenic stresses may be impaired by heat-induced downregulation of genes related to photosynthesis, pathogen defence and stress tolerance.


Assuntos
Adaptação Fisiológica , Temperatura , Transcriptoma , Zosteraceae/genética , Europa (Continente) , América do Norte , Filogenia , Filogeografia
4.
Diabetes Obes Metab ; 18(9): 847-54, 2016 09.
Artigo em Inglês | MEDLINE | ID: mdl-27160961

RESUMO

The gut incretin hormones glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1) are secreted after meal ingestion and work in concert to promote postprandial insulin secretion and regulate glucagon secretion. GLP-1 also slows gastric emptying and suppresses appetite, whereas GIP seems to affect lipid metabolism. The introduction of selective GLP-1 receptor (GLP-1R) agonists for the treatment of type 2 diabetes and obesity has increased the scientific and clinical interest in incretins. Combining the body weight-lowering and glucose-lowering effects of GLP-1 with a more potent improvement of ß cell function through additional GIP action could potentially offer a more effective treatment of diabetes and obesity, with fewer adverse effects than selective GLP-1R agonists; therefore, new drugs designed to co-activate both the GIP receptor (GIPR) and the GLP-1R simultaneously are under development. In the present review, we address advances in the field of GIPR and GLP-1R co-agonism and review in vitro studies, animal studies and human trials involving co-administration of the two incretins, as well as results from a recently developed GIPR/GLP-1R co-agonist, and highlight promising areas and challenges within the field of incretin dual agonists.


Assuntos
Diabetes Mellitus Tipo 2/tratamento farmacológico , Receptor do Peptídeo Semelhante ao Glucagon 1/agonistas , Incretinas/uso terapêutico , Obesidade/tratamento farmacológico , Receptores dos Hormônios Gastrointestinais/agonistas , Animais , Glicemia/efeitos dos fármacos , Glicemia/metabolismo , Diabetes Mellitus Tipo 2/complicações , Diabetes Mellitus Tipo 2/metabolismo , Polipeptídeo Inibidor Gástrico/metabolismo , Polipeptídeo Inibidor Gástrico/farmacologia , Peptídeo 1 Semelhante ao Glucagon/metabolismo , Peptídeo 1 Semelhante ao Glucagon/farmacologia , Humanos , Técnicas In Vitro , Insulina/metabolismo , Células Secretoras de Insulina/efeitos dos fármacos , Células Secretoras de Insulina/metabolismo , Obesidade/complicações , Obesidade/metabolismo , Redução de Peso
5.
Endocr Connect ; 3(2): R55-80, 2014 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-24743684

RESUMO

Chronic psychosocial stress has been proposed as a risk factor for the development of the metabolic syndrome (MES). This review gives a systematic overview of prospective cohort studies investigating chronic psychosocial stress as a risk factor for incident MES and the individual elements of MES. Thirty-nine studies were included. An association between chronic psychosocial stress and the development of MES was generally supported. Regarding the four elements of MES: i) weight gain: the prospective studies supported etiological roles for relationship stress, perceived stress, and distress, while the studies on work-related stress (WS) showed conflicting results; ii) dyslipidemi: too few studies on psychosocial stress as a risk factor for dyslipidemia were available to draw a conclusion; however, a trend toward a positive association was present; iii) type 2 diabetes mellitus (DM2): prospective studies supported perceived stress and distress as risk factors for the development of DM2 among men, but not among women, while WS was generally not supported as a risk factor among neither men nor women; iv) hypertension: marital stress and perceived stress might have an influence on blood pressure (BP), while no association was found regarding distress. Evaluating WS the results were equivocal and indicated that different types of WS affected the BP differently between men and women. In conclusion, a longitudinal association between chronic psychosocial stress and the development of MES seems present. However, the number of studies with sufficient quality is limited and the design of the studies is substantially heterogeneous.

6.
Pneumologie ; 63(6): 307-13, 2009 Jun.
Artigo em Alemão | MEDLINE | ID: mdl-19517357

RESUMO

BACKGROUND: The purpose of this study was to evaluate the long-term safety and therapeutic effects of IFN-alpha in patients with severe persistent uncontrolled asthma on long-term oral glucocorticoid (GC) treatment. PATIENTS AND METHODS: The study included 16 patients (2 male, 14 female; age 39 years [range: 24 - 63]) with severe persistent asthma. Diagnosis and severity classification of asthma were established according to the guidelines of the "Deutsche Atemwegsliga". Eight patients stopped the therapy within 7 months due to side effects (n = 3), costs not covered by health insurance (n = 2), non-compliance (n = 2), and change of residence (n = 1). 8 patients (8 female, age 49 years [range: 35 - 68], duration of disease 16 years [range: 5 - 24]) were treated for at least 12 months with IFN-alpha (9 microg) 3 times/week. All patients were on oral glucocorticoids (GCs) for more than 5 years (average dose 17.5 [range: 5.0 - 64.0] mg/d). Clinical signs, lung function, need for reliever medication, number of emergency visits and hospitalisations and diary were assessed prior to and after 12 months of treatment. Data are given as percent of normal or median [range]. RESULTS: IFN-alpha improved lung function after 12 months: FEV1 64 vs. 75 %; FEV1/IVC 76 vs. 89 %; RV 153 % vs. 129 %; Rtot 193 vs. 111 % and morning PEF by 50 - 190 L/min. IFN-alpha also significantly reduced the use of reliever medication (10 [2 - 20] vs. 1 [0 - 3] puffs/d), nocturnal awakening (11 [4 - 30] vs. 1 [0 - 5]/month), emergency visits (7 [2 - 15] vs. 0 [0 - 5]/month) and hospitalisations (4 [1 - 8] vs. 0 [0 - 5]/year). In 5 patients the asthma attacks and nightly disturbances disappeared completely. The improvements were achieved despite a tapering of the oral GCs in all patients from 17.5 (5.0 - 64.0) to 2 (0 - 16) mg/d. In 5 patients GC treatment could be discontinued. The number of blood eosinophils decreased from 0.46 to 0.28 Gpt/L. Adverse events were transient and usually decreased within 3 to 4 weeks. Two patients developed an autoimmune thyreoiditis. CONCLUSION: In severe persistent, uncontrolled, and GC-dependent asthma, treatment with IFN-alpha leads to sustained clinical improvement and allows the reduction or discontinuation of oral GCs. Severe side effects may occur in isolated cases.


Assuntos
Asma/diagnóstico , Asma/tratamento farmacológico , Interferon-alfa/uso terapêutico , Adulto , Doença Crônica , Feminino , Humanos , Fatores Imunológicos/uso terapêutico , Masculino , Pessoa de Meia-Idade , Resultado do Tratamento , Adulto Jovem
8.
Glycobiology ; 6(3): 313-20, 1996 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-8724139

RESUMO

Mutants of the yeast Saccharomyces cerevisiae were identified, in which O-glycosylation at threonine 29 of a heterologous protein, human insulin-like growth factor (hIGF-1), is defective. In mutant M195, O-glycosylation of hIGF-1, but not of yeast proteins chitinase and a-agglutinin, was reduced; in mutant M577 yeast proteins were affected besides hIGF-1. The mutations of M195 and M577 did not affect viability and could not be complemented by the PMT1 or PMT2 genes. The mutant phenotype of strain M195 was reconstituted in an in vitro system, in which a hIGF-1-derived peptide encompassing residues 24-34 was not used as acceptor for mannosylation, while unrelated peptides were glycosylated at wild-type levels. hIGF-1 glycosylation was drastically reduced in pmt1 disruptants and to a lesser extent in pmt2 disruptants, suggesting interaction between the PMT gene products and components mutated in M195 and M577 cells. The results suggest that mutations may only affect O-glycosylation of a specific subset of secreted proteins in yeast.


Assuntos
Fator de Crescimento Insulin-Like I/genética , Fator de Crescimento Insulin-Like I/metabolismo , Mutação , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo , Sequência de Aminoácidos , Quitinases/química , Quitinases/metabolismo , Genes Fúngicos , Teste de Complementação Genética , Glicosilação , Humanos , Fator de Crescimento Insulin-Like I/química , Manosiltransferases/genética , Manosiltransferases/metabolismo , Fator de Acasalamento , Dados de Sequência Molecular , Peptídeos/química , Peptídeos/metabolismo , Fenótipo , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Treonina/química
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