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1.
J Perianesth Nurs ; 38(2): 339-348, 2023 04.
Artigo em Inglês | MEDLINE | ID: mdl-36464572

RESUMO

PURPOSE: To summarize and analyze available evidence on perioperative accelerated rehabilitation programs for patients diagnosed with breast cancer that have had a radical mastectomy. DESIGN: This article is a systematic review of literature based on evidence-based methodology. METHODS: The '6S' evidence resource pyramid model was used to systematically search a range of databases. FINDINGS: A total of 19 articles were extracted from the literature and used in this study, including 9 clinical decisions, 4 systematic evaluations, 4 expert consensuses, and 2 guidelines. We summarized a total of 47 lines of evidence with regard to various aspects, including preoperative, intraoperative, and postoperative nursing measures. CONCLUSIONS: In this systematic review, an evidence-based methodology was used to summarize and analyze the best suggestions for perioperative accelerated rehabilitation nursing programs for breast cancer inpatients undergoing radical mastectomy. We aimed to provide a good reference value and evidence-based guidelines for the continuous improvement and development of nursing practice for the breast cancer patient population.


Assuntos
Neoplasias da Mama , Humanos , Feminino , Neoplasias da Mama/cirurgia , Mastectomia/métodos , Mastectomia Radical
2.
Proc Natl Acad Sci U S A ; 116(46): 22966-22971, 2019 11 12.
Artigo em Inglês | MEDLINE | ID: mdl-31659022

RESUMO

We study the droplet-forming instability of a thin jet extruded from a nozzle moving horizontally below the surface of an isoviscous immiscible fluid bath. While this interfacial instability is a classic problem in fluid mechanics, it has never been studied in the context of the deposition of a thread into a reservoir, an open-sky version of microfluidics. As the nozzle translates through the reservoir, drops may form at the nozzle (dripping) or further downstream (jetting). We first focus on rectilinear printing paths and derive a scaling law to rationalize the transition between dripping and jetting. We then leverage the flexibility of our system and study the dynamics of breakup when printing sinusoidal paths. We unravel a methodology to control both the size of the drops formed by the instability and the distance that separates them.

3.
Microb Cell Fact ; 20(1): 45, 2021 Feb 16.
Artigo em Inglês | MEDLINE | ID: mdl-33593360

RESUMO

BACKGROUND: Pediococcus pentosaceus, a promising strain of lactic acid bacteria (LAB), is gradually attracting attention, leading to a rapid increase in experimental research. Due to increased demand for practical applications of microbes, the functional and harmless P. pentosaceus might be a worthwhile LAB strain for both the food industry and biological applications. RESULTS: As an additive, P. pentosaceus improves the taste and nutrition of food, as well as the storage of animal products. Moreover, the antimicrobial abilities of Pediococcus strains are being highlighted. Evidence suggests that bacteriocins or bacteriocin-like substances (BLISs) produced by P. pentosaceus play effective antibacterial roles in the microbial ecosystem. In addition, various strains of P. pentosaceus have been highlighted for probiotic use due to their anti-inflammation, anticancer, antioxidant, detoxification, and lipid-lowering abilities. CONCLUSIONS: Therefore, it is necessary to continue studying P. pentosaceus for further use. Thorough study of several P. pentosaceus strains should clarify the benefits and drawbacks in the future.


Assuntos
Pediococcus pentosaceus/química , Probióticos/química
4.
Soft Matter ; 16(12): 3137-3142, 2020 Mar 28.
Artigo em Inglês | MEDLINE | ID: mdl-32159541

RESUMO

In recent years the research community has paid significant attention to geometrically engineered materials. These materials derive their unique properties from their structure rather than their chemistry alone. Despite their success in the laboratory, the assembly of such soft functional materials remains an outstanding challenge. Here, we propose a robust fluid-mediated route for the rapid fabrication of soft elastomers architected with liquid inclusions. Our approach consists of depositing water drops at the surface of an immiscible liquid elastomer bath. As the elastomer cures, the drops are encapsulated in the polymer and impart shape and function to the newly formed elastic matrix. Using the framework of fluid mechanics, we show how this type of composite material can be tailored.

5.
J Cell Biochem ; 120(2): 2439-2453, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30324748

RESUMO

As a unique subtype of esophageal cancer, synchronous multiple primary esophageal squamous cell carcinomas (ESCCs) mostly occur in Asian patients with alcohol and/or tobacco abuse, or with a family history of cancer. Multiple ESCCs are associated with poor clinical outcomes. Growing evidence has addressed that long noncoding RNAs (lncRNAs) are involved in the carcinogenesis of various malignancies. We compared the lncRNA and messenger RNA (mRNA) profiles between solitary and multiple ESCC tissues through microarray analysis, aiming at studying their different mechanisms in tumor development. As a result, in multiple ESCCs, a total of 5257 lncRNAs and 3371 mRNAs were consistently differentially expressed compared with solitary ESCC, including 2986 upregulated and 2271 downregulated lncRNAs, and 2313 upregulated, and 1058 downregulated mRNAs. We validated the results in four differentially expressed lncRNAs using quantitative real-time polymerase chain reaction. There were 38 and 20 pathways significantly related to up- and downregulated transcripts. The pathways associated with mostly enriched up- and downregulated mRNAs were hsa01200 (carbon metabolism) and hsa05221 (acute myeloid leukemia- homo sapiens [human]). Gene ontology analysis suggested that upregulated and downregulated mRNAs were mainly enriched in bounding membrane of organelle involved in the cellular component and positive regulation of transport involved in the biological process. Further analysis identified 189 differentially expressed paired antisense lncRNAs and relative sense mRNA, as well as 2134 differentially expressed long intergenic noncoding RNAs and their adjacent mRNA pairs. In conclusion, the aberrantly expressed lncRNAs might play a role in the carcinogenesis of multiple ESCCs and could be candidates as diagnostic biomarkers and therapeutic targets.

6.
Am J Physiol Endocrinol Metab ; 308(10): E879-90, 2015 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-25783895

RESUMO

Adipose triglyceride lipase (ATGL) is the rate-limiting enzyme mediating triacylglycerol hydrolysis in virtually all cells, including adipocytes and skeletal myocytes, and hence, plays a critical role in mobilizing fatty acids. Global ATGL deficiency promotes skeletal myopathy and exercise intolerance in mice and humans, and yet the tissue-specific contributions to these phenotypes remain unknown. The goal of this study was to determine the relative contribution of ATGL-mediated triacylglycerol hydrolysis in adipocytes vs. skeletal myocytes to acute exercise performance. To achieve this goal, we generated murine models with adipocyte- and skeletal myocyte-specific targeted deletion of ATGL. We then subjected untrained mice to acute peak and submaximal exercise interventions and assessed exercise performance and energy substrate metabolism. Impaired ATGL-mediated lipolysis within adipocytes reduced peak and submaximal exercise performance, reduced peripheral energy substrate availability, shifted energy substrate preference toward carbohydrate oxidation, and decreased HSL Ser(660) phosphorylation and mitochondrial respiration within skeletal muscle. In contrast, impaired ATGL-mediated lipolysis within skeletal myocytes was not sufficient to reduce peak and submaximal exercise performance or peripheral energy substrate availability and instead tended to enhance metabolic flexibility during peak exercise. Furthermore, the expanded intramyocellular triacylglycerol pool in these mice was reduced following exercise in association with preserved HSL phosphorylation, suggesting that HSL may compensate for impaired ATGL action in skeletal muscle during exercise. These data suggest that adipocyte rather than skeletal myocyte ATGL-mediated lipolysis plays a greater role during acute exercise in part because of compensatory mechanisms that maintain lipolysis in muscle, but not adipose tissue, when ATGL is absent.


Assuntos
Adipócitos/metabolismo , Lipase/genética , Fibras Musculares Esqueléticas/metabolismo , Condicionamento Físico Animal/fisiologia , Esforço Físico/genética , Animais , Desempenho Atlético , Tolerância ao Exercício/genética , Feminino , Deleção de Genes , Lipase/metabolismo , Lipólise/genética , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout
7.
Front Pediatr ; 11: 1252875, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37691773

RESUMO

Purpose: The purpose of this study was to investigate the quantitative retinal vascular morphological characteristics of Retinopathy of Prematurity (ROP) and Familial Exudative Vitreoretinopathy (FEVR) in the newborn by the application of a deep learning network with artificial intelligence. Methods: Standard 130-degree fundus photographs centered on the optic disc were taken in the newborns. The deep learning network provided segmentation of the retinal vessels and the optic disc (OD). Based on the vessel segmentation, the vascular morphological characteristics, including avascular area, vessel angle, vessel density, fractal dimension (FD), and tortuosity, were automatically evaluated. Results: 201 eyes of FEVR, 289 eyes of ROP, and 195 eyes of healthy individuals were included in this study. The deep learning system of blood vessel segmentation had a sensitivity of 72% and a specificity of 99%. The vessel angle in the FEVR group was significantly smaller than that in the normal group and ROP group (37.43 ± 5.43 vs. 39.40 ± 5.61, 39.50 ± 5.58, P = 0.001, < 0.001 respectively). The normal group had the lowest vessel density, the ROP group was in between, and the FEVR group had the highest (2.64 ± 0.85, 2.97 ± 0.92, 3.37 ± 0.88 respectively). The FD was smaller in controls than in the FEVR and ROP groups (0.984 ± 0.039, 1.018 ± 0.039 and 1.016 ± 0.044 respectively, P < 0.001). The ROP group had the most tortuous vessels, while the FEVR group had the stiffest vessels, the controls were in the middle (11.61 ± 3.17, 8.37 ± 2.33 and 7.72 ± 1.57 respectively, P < 0.001). Conclusions: The deep learning technology used in this study has good performance in the quantitative analysis of vascular morphological characteristics in fundus photography. Vascular morphology was different in the newborns of FEVR and ROP compared to healthy individuals, which showed great clinical value for the differential diagnosis of ROP and FEVR.

8.
Sci Adv ; 8(27): eabq0828, 2022 Jul 08.
Artigo em Inglês | MEDLINE | ID: mdl-35857477

RESUMO

The breakup of liquid threads into droplets is prevalent in engineering and natural settings. While drop formation in these systems has a long-standing history, existing studies typically consider axisymmetric systems. Conversely, the physics at play when multiple threads are involved and the interaction of a thread with a symmetry breaking boundary remain unexplored. Here, we show that the breakup of closely spaced liquid threads sequentially printed in an immiscible bath locks into crystal-like lattices of droplets. We rationalize the hydrodynamics at the origin of this previously unknown phenomenon. We leverage this knowledge to tune the lattice pattern via the control of injection flow rate and nozzle translation speed, thereby overcoming the limitations in structural versatility typically seen in existing fluid manipulations paradigms. We further demonstrate that these drop crystals have the ability to self-correct and propose a simple mechanism to describe the convergence toward a uniform pattern of drops.

9.
J Lipid Res ; 52(2): 318-29, 2011 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-21068004

RESUMO

PNPLA3 (adiponutrin, calcium-independent phospholipase A(2) epsilon [iPLA(2)ε]) is an adipose-enriched, nutritionally regulated protein that belongs to the patatin-like phospholipase domain containing (PNPLA) family of lipid metabolizing proteins. Genetic variations in the human PNPLA3 gene (i.e., the rs738409 I148M allele) has been strongly and repeatedly associated with fatty liver disease. Although human PNPLA3 has triacylglycerol (TAG) hydrolase and transacylase activities in vitro, its in vivo function and physiological relevance remain controversial. The objective of this study was to determine the metabolic consequences of global targeted deletion of the Pnpla3 gene in mice. We found that Pnpla3 mRNA expression is altered in adipose tissue and liver in response to acute and chronic nutritional challenges. However, global targeted deletion of the Pnpla3 gene in mice did not affect TAG hydrolysis, nor did it influence energy/glucose/lipid homoeostasis or hepatic steatosis/injury. Experimental interventions designed to increase Pnpla3 expression (refeeding, high-sucrose diet, diet-induced obesity, and liver X receptor agonism) likewise failed to reveal differences in the above-mentioned metabolic phenotypes. Expression of the Pnpla3 paralog, Pnpla5, was increased in adipose tissue but not in liver of Pnpla3-deficient mice, but compensatory regulation of genes involved in TAG metabolism was not identified. Together these data argue against a role for Pnpla3 loss-of-function in fatty liver disease or metabolic syndrome in mice.


Assuntos
Fígado Gorduroso/metabolismo , Síndrome Metabólica/metabolismo , Fosfolipases A2 Independentes de Cálcio/deficiência , Tecido Adiposo/metabolismo , Animais , Metabolismo Energético , Fígado Gorduroso/etiologia , Masculino , Síndrome Metabólica/etiologia , Camundongos , Camundongos Knockout , Triglicerídeos/metabolismo
10.
J Biol Chem ; 284(44): 30218-29, 2009 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-19723629

RESUMO

Triacylglycerol accumulation in insulin target tissues is associated with insulin resistance. Paradoxically, mice with global targeted deletion of adipose triglyceride lipase (ATGL), the rate-limiting enzyme in triacylglycerol hydrolysis, display improved glucose tolerance and insulin sensitivity despite triacylglycerol accumulation in multiple tissues. To determine the molecular mechanisms for this phenotype, ATGL-deficient (ATGL(-/-)) and wild-type mice were injected with saline or insulin (10 units/kg, intraperitoneally), and then phosphorylation and activities of key insulin-signaling proteins were determined in insulin target tissues (liver, adipose tissue, and muscle). Insulin signaling and/or glucose transport was also evaluated in isolated adipocytes and skeletal muscle ex vivo. In ATGL(-/-) mice, insulin-stimulated phosphatidylinositol 3-kinase and Akt activities as well as phosphorylation of critical residues of IRS1 (Tyr(P)-612) and Akt (Ser(P)-473) were increased in skeletal muscle in vivo. Insulin-stimulated phosphatidylinositol 3-kinase activity and total insulin receptor and insulin receptor substrate 1, but not other parameters, were also increased in white adipose tissue in vivo. In contrast, in vivo measures of insulin signaling were decreased in brown adipose tissue and liver. Interestingly, the enhanced components of insulin signaling identified in skeletal muscle and white adipose tissue in vivo and their expected downstream effects on glucose transport were not present ex vivo. ATGL deficiency altered intramyocellular lipids as well as serum factors known to influence insulin sensitivity. Thus, skeletal muscle, rather than other tissues, primarily contributes to enhanced insulin sensitivity in ATGL(-/-) mice in vivo despite triacylglycerol accumulation, and both local and systemic factors contribute to tissue-specific effects of global ATGL deficiency on insulin action.


Assuntos
Tecido Adiposo/patologia , Insulina/metabolismo , Lipase/deficiência , Transdução de Sinais , Tecido Adiposo/metabolismo , Animais , Resistência à Insulina , Camundongos , Camundongos Knockout , Músculo Esquelético , Distribuição Tecidual , Triglicerídeos/metabolismo
11.
Cancer Res Treat ; 52(1): 31-40, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31048664

RESUMO

PURPOSE: The purpose of this study was to compare the survival and toxicities in cervical esophageal squamous cell carcinoma (CESCC) treated by concurrent chemoradiothrapy with either three-dimensional conformal radiotherapy (3D-CRT) or intensity-modulated radiotherapy (IMRT) techniques. MATERIALS AND METHODS: A total of 112 consecutive CESCC patients were retrospectively reviewed. 3D-CRT and IMRT groups had been analyzed by propensity score matching method, with sex, age, Karnofsky performance status, induction chemotherapy, and tumor stage well matched. The Kaplan-Meier method and Cox proportional hazards model were used for overall survival (OS) and progression-free survival (PFS). Toxicities were compared between two groups by Fisher exact test. RESULTS: With a median follow-up time of 34.9 months, the 3-year OS (p=0.927) and PFS (p=0.859) rate was 49.6% and 45.8% in 3D-CRT group, compared with 54.4% and 42.8% in IMRT group. The rates of grade ≥ 3 esophagitis, grade ≥ 2 pneumonitis, esophageal stricture, and hemorrhage were comparable between two groups, while the rate of tracheostomy dependence was much higher in IMRT group than 3D-CRT group (14.3% vs.1.8%, p=0.032). Radiotherapy technique (hazard ratio [HR], 0.09; 95% confidence interval [CI], 0.01 to 0.79) and pretreatment hoarseness (HR, 0.12; 95% CI 0.02 to 0.70) were independently prognostic of tracheostomy dependence. CONCLUSION: No survival benefits had been observed while comparing IMRT versus 3D-CRT in CESCC patients. IMRT with fraction dose escalation and pretreatment hoarseness were considered to be associated with a higher risk for tracheostomy dependence. Radiation dose escalation beyond 60 Gy should be taken into account carefully when using IMRT with hypofractionated regimen.


Assuntos
Carcinoma de Células Escamosas do Esôfago/terapia , Radioterapia Conformacional , Radioterapia de Intensidade Modulada , Adulto , Idoso , Idoso de 80 Anos ou mais , Quimiorradioterapia , Terapia Combinada , Carcinoma de Células Escamosas do Esôfago/diagnóstico , Carcinoma de Células Escamosas do Esôfago/mortalidade , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Prognóstico , Dosagem Radioterapêutica , Radioterapia Conformacional/efeitos adversos , Radioterapia Conformacional/métodos , Radioterapia de Intensidade Modulada/efeitos adversos , Radioterapia de Intensidade Modulada/métodos , Análise de Sobrevida , Resultado do Tratamento
12.
Chem Biodivers ; 4(7): 1472-9, 2007 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-17638327

RESUMO

A series of fluconazole (1) analogues, compounds 3a-k, were prepared as potential antifungal agents. They were designed by computational docking experiments to the active site of the cytochrome P450 14alpha-sterol demethylase (CYP51), whose crystal structure is known. Preliminary biological tests showed that most of the target compounds exhibit significant activities against the eight most-common pathogenic fungi. Thereby, the most potent congener, 1-[(4-tert-butylbenzyl)(cyclopropyl)amino]-2-(2,4-difluorophenyl)-3-(1H-1,2,4-triazol-1-yl)propan-2-ol (3j), was found to exhibit a broad antifungal spectrum, being more active against Candida albicans, Candida tropicalis, Cryptococcus neoformans, Microsporum canis, and Trichophyton rubrum (MIC80 < 0.125 microg/ml) than the standard clinical drug itraconazole (2). The observed affinities of the lead molecules towards CYP51 indicate that a cyclopropyl residue enhances binding to the target enzyme. Our results may provide some guidance for the development of novel triazole-based antifungal lead structures.


Assuntos
Antifúngicos/síntese química , Sistema Enzimático do Citocromo P-450/síntese química , Desenho de Fármacos , Oxirredutases/síntese química , Triazóis/síntese química , Antifúngicos/farmacologia , Sítios de Ligação/efeitos dos fármacos , Sítios de Ligação/fisiologia , Química Farmacêutica/métodos , Sistema Enzimático do Citocromo P-450/metabolismo , Hidrogênio , Testes de Sensibilidade Microbiana/métodos , Oxirredutases/metabolismo , Esterol 14-Desmetilase , Triazóis/farmacologia
13.
Endocrinology ; 156(10): 3610-24, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26196542

RESUMO

Emerging evidence suggests that impaired regulation of adipocyte lipolysis contributes to the proinflammatory immune cell infiltration of metabolic tissues in obesity, a process that is proposed to contribute to the development and exacerbation of insulin resistance. To test this hypothesis in vivo, we generated mice with adipocyte-specific deletion of adipose triglyceride lipase (ATGL), the rate-limiting enzyme catalyzing triacylglycerol hydrolysis. In contrast to previous models, adiponectin-driven Cre expression was used for targeted ATGL deletion. The resulting adipocyte-specific ATGL knockout (AAKO) mice were then characterized for metabolic and immune phenotypes. Lean and diet-induced obese AAKO mice had reduced adipocyte lipolysis, serum lipids, systemic lipid oxidation, and expression of peroxisome proliferator-activated receptor alpha target genes in adipose tissue (AT) and liver. These changes did not increase overall body weight or fat mass in AAKO mice by 24 weeks of age, in part due to reduced expression of genes involved in lipid uptake, synthesis, and adipogenesis. Systemic glucose and insulin tolerance were improved in AAKO mice, primarily due to enhanced hepatic insulin signaling, which was accompanied by marked reduction in diet-induced hepatic steatosis as well as hepatic immune cell infiltration and activation. In contrast, although adipocyte ATGL deletion reduced AT immune cell infiltration in response to an acute lipolytic stimulus, it was not sufficient to ameliorate, and may even exacerbate, chronic inflammatory changes that occur in AT in response to diet-induced obesity.


Assuntos
Adipócitos/metabolismo , Inflamação/genética , Resistência à Insulina/genética , Lipase/genética , Obesidade/genética , Tecido Adiposo/metabolismo , Animais , Antígenos de Diferenciação/genética , Antígenos de Diferenciação/metabolismo , Antígeno CD11c/genética , Antígeno CD11c/metabolismo , Células Dendríticas/metabolismo , Dieta Hiperlipídica/efeitos adversos , Expressão Gênica , Immunoblotting , Inflamação/sangue , Inflamação/metabolismo , Lipase/metabolismo , Metabolismo dos Lipídeos/genética , Lipídeos/sangue , Lipólise/genética , Fígado/metabolismo , Macrófagos/metabolismo , Camundongos da Linhagem 129 , Camundongos Endogâmicos C57BL , Camundongos Knockout , Obesidade/etiologia , Obesidade/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa
14.
Methods Mol Biol ; 1114: 399-411, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24557918

RESUMO

Gene correction is attractive for single gene mutation disorders, such as Duchenne muscular dystrophy (DMD). The mdx mouse model of DMD is dystrophin deficient due to a premature chain-terminating point mutation in exon 23 of the dystrophin gene. Gene editing of genomic DNA using single-stranded oligodeoxynucleotides (ssODNs) offers the potential to change the DNA sequence to alter mRNA and protein expression in defined ways. When applied to fetal skeletal muscle of mdx mice in utero, this technology leads to restoration of dystrophin protein expression, thus providing a valid gene-based therapeutic application at the earliest developmental stage. Here, we describe detailed methods for gene editing using muscle delivery of ssODNs to the fetal mdx mouse in utero at embryonic day 16 and to test correction of dystrophin deficiency at different ages after birth.


Assuntos
Técnicas de Transferência de Genes , Oligodesoxirribonucleotídeos/genética , Animais , DNA de Cadeia Simples/administração & dosagem , DNA de Cadeia Simples/genética , Distrofina/genética , Expressão Gênica , Terapia Genética , Camundongos , Camundongos Endogâmicos mdx , Músculo Esquelético/metabolismo , Distrofia Muscular de Duchenne/genética , Distrofia Muscular de Duchenne/terapia , Oligodesoxirribonucleotídeos/administração & dosagem
15.
Diabetes ; 62(10): 3350-61, 2013 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-23835334

RESUMO

Intramyocellular triacylglycerol (IMTG) accumulation is highly associated with insulin resistance and metabolic complications of obesity (lipotoxicity), whereas comparable IMTG accumulation in endurance-trained athletes is associated with insulin sensitivity (the athlete's paradox). Despite these findings, it remains unclear whether changes in IMTG accumulation and metabolism per se influence muscle-specific and systemic metabolic homeostasis and insulin responsiveness. By mediating the rate-limiting step in triacylglycerol hydrolysis, adipose triglyceride lipase (ATGL) has been proposed to influence the storage/production of deleterious as well as essential lipid metabolites. However, the physiological relevance of ATGL-mediated triacylglycerol hydrolysis in skeletal muscle remains unknown. To determine the contribution of IMTG hydrolysis to tissue-specific and systemic metabolic phenotypes in the context of obesity, we generated mice with targeted deletion or transgenic overexpression of ATGL exclusively in skeletal muscle. Despite dramatic changes in IMTG content on both chow and high-fat diets, modulation of ATGL-mediated IMTG hydrolysis did not significantly influence systemic energy, lipid, or glucose homeostasis, nor did it influence insulin responsiveness or mitochondrial function. These data argue against a role for altered IMTG accumulation and lipolysis in muscle insulin resistance and metabolic complications of obesity.


Assuntos
Tecido Adiposo/metabolismo , Resistência à Insulina , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Músculo Esquelético/metabolismo , Obesidade/metabolismo , Triglicerídeos/metabolismo , Animais , Dieta Hiperlipídica , Metabolismo Energético , Homeostase , Hidrólise , Resistência à Insulina/fisiologia , Metabolismo dos Lipídeos , Camundongos , Camundongos Knockout , Camundongos Transgênicos , Fenótipo , Fosforilação
16.
PLoS One ; 7(10): e47493, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-23115649

RESUMO

Skeletal muscle resistance to the key metabolic hormones, leptin and insulin, is an early defect in obesity. Suppressor of cytokine signaling 3 (SOCS3) is a major negative regulator of both leptin and insulin signaling, thereby implicating SOCS3 in the pathogenesis of obesity and associated metabolic abnormalities. Here, we demonstrate that SOCS3 mRNA expression is increased in murine skeletal muscle in the setting of diet-induced and genetic obesity, inflammation, and hyperlipidemia. To further evaluate the contribution of muscle SOCS3 to leptin and insulin resistance in obesity, we generated transgenic mice with muscle-specific overexpression of SOCS3 (MCK/SOCS3 mice). Despite similar body weight, MCK/SOCS3 mice develop impaired systemic and muscle-specific glucose homeostasis and insulin action based on glucose and insulin tolerance tests, hyperinsulinemic-euglycemic clamps, and insulin signaling studies. With regards to leptin action, MCK/SOCS3 mice exhibit suppressed basal and leptin-stimulated activity and phosphorylation of alpha2 AMP-activated protein kinase (α2AMPK) and its downstream target, acetyl-CoA carboxylase (ACC). Muscle SOCS3 overexpression also suppresses leptin-regulated genes involved in fatty acid oxidation and mitochondrial function. These studies demonstrate that SOC3 within skeletal muscle is a critical regulator of leptin and insulin action and that increased SOCS may mediate insulin and leptin resistance in obesity.


Assuntos
Insulina/metabolismo , Leptina/metabolismo , Transdução de Sinais/fisiologia , Proteínas Supressoras da Sinalização de Citocina/fisiologia , Adenilato Quinase/metabolismo , Animais , Homeostase , Hiperlipidemias/metabolismo , Inflamação/metabolismo , Camundongos , Camundongos Transgênicos , Músculo Esquelético/metabolismo , Obesidade/metabolismo , RNA Mensageiro/genética , Proteína 3 Supressora da Sinalização de Citocinas , Proteínas Supressoras da Sinalização de Citocina/genética , Proteínas Supressoras da Sinalização de Citocina/metabolismo
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