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1.
ACS Nano ; 16(2): 1813-1825, 2022 02 22.
Artigo em Inglês | MEDLINE | ID: mdl-34979079

RESUMO

Despite the increasing prevalence of obesity, the current medications, which act indirectly on the central nervous system to suppress appetite or on the gastrointestinal tract to inhibit fat absorption, suffer from poor effectiveness and side effects. Here, we developed a transdermal mild photothermal therapy directly acting on the root of evil (subcutaneous white adipose depot) to induce its ameliorating remodeling (browning, lipolysis, and apoptosis), based on the injectable thermoresponsive hydrogel encapsulated with copper sulfide nanodots. Further, combining pharmaceutical therapy with codelivery of mirabegron leads to a strong therapeutic synergy. This method not only ensures high effectiveness and low side effects due to localized and targeted application but also remotely creates significant improvements in systemic metabolism. Specifically, as compared to the untreated group, it totally inhibits obesity development in high-fat-diet fed mice (15% less in body weight) with decreased masses of both subcutaneous (40%) and visceral fats (54%), reduced serum levels of cholesterol (54%)/triglyceride (18%)/insulin (74%)/glucose (45%), and improved insulin sensitivity (65% less in insulin resistance index). This self-administrable method is amenable for long-term home-based treatment. Finally, multiple interconnected signaling pathways are revealed, providing mechanistic insights to develop effective strategies to combat obesity and associated metabolic disorders.


Assuntos
Resistência à Insulina , Obesidade , Tecido Adiposo/metabolismo , Animais , Peso Corporal , Dieta Hiperlipídica/efeitos adversos , Camundongos , Camundongos Endogâmicos C57BL , Obesidade/tratamento farmacológico
2.
J Card Fail ; 28(5): 736-743, 2022 05.
Artigo em Inglês | MEDLINE | ID: mdl-34655774

RESUMO

BACKGROUND: This study aimed to (1) investigate the association of prognostic awareness with psychological (distress level and emotional well-being) and spiritual well-being among patients with heart failure, and (2) assess the main and moderating effects of illness acceptance on the relationship between prognostic awareness and psychological and spiritual well-being. METHODS AND RESULTS: This study used baseline data of a Singapore cohort of patients with heart failure (N = 245) who had New York Heart Association class 3 or 4 symptoms. Patients reported their awareness of prognosis and extent of illness acceptance. Multivariable linear regressions were used to investigate the associations. Prognostic awareness was not significantly associated with psychological and spiritual well-being. Illness acceptance was associated with lower levels of distress (ß [SE] = -0.9 [0.2], P < .001), higher emotional well-being (ß [SE] = 2.2 [0.4], P < .001), and higher spiritual well-being (ß [SE] = 5.4 [0.7], P < .001). Illness acceptance did not moderate the associations of prognostic awareness with psychological and spiritual well-being. CONCLUSIONS: This study suggests that illness acceptance could be a key factor in improving patient well-being. Illness acceptance should be regularly assessed and interventions to enhance illness acceptance should be considered for those with poor acceptance.


Assuntos
Insuficiência Cardíaca , Adaptação Psicológica , Estudos de Coortes , Insuficiência Cardíaca/diagnóstico , Insuficiência Cardíaca/psicologia , Insuficiência Cardíaca/terapia , Humanos , Prognóstico , Qualidade de Vida/psicologia , Singapura/epidemiologia
3.
Cureus ; 13(5): e15101, 2021 May 18.
Artigo em Inglês | MEDLINE | ID: mdl-34159009

RESUMO

Chronic recurrent multifocal osteomyelitis (CRMO) is a rare idiopathic aseptic inflammatory bone disorder affecting primarily children and adolescents characterized by an insidious onset of pain, swelling, and tenderness over the affected bones. The clinical signs and symptoms of CRMO are nonspecific, radiological and histopathological tests are essential for its diagnosis. We present a case of an 18-year-old young man who was diagnosed with CRMO by a combination of clinical data, laboratory results, radiological imaging, and bone biopsy. The patient started anti-inflammatory and immunosuppressant therapy, and his lower extremity pain and swelling improved. This report highlights to investigate promptly in children and adolescents with chronic leg pain, to emphasize the importance of combined clinical, laboratory, and imaging tests for early identification, to have a greater understanding of the imaging appearance and increasing knowledge of this condition, which help shorten time to reach a diagnosis and prevent permanent osseous damage and long-term disabilities.

4.
Nat Biomed Eng ; 5(9): 1008-1018, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-33941895

RESUMO

Cell therapies for the treatment of skin disorders could benefit from simple, safe and efficient technology for the transdermal delivery of therapeutic cells. Conventional cell delivery by hypodermic-needle injection is associated with poor patient compliance, requires trained personnel, generates waste and has non-negligible risks of injury and infection. Here, we report the design and proof-of-concept application of cryogenic microneedle patches for the transdermal delivery of living cells. The microneedles are fabricated by stepwise cryogenic micromoulding of cryogenic medium with pre-suspended cells, and can be easily inserted into porcine skin and dissolve after deployment of the cells. In mice, cells delivered by the cryomicroneedles retained their viability and proliferative capability. In mice with subcutaneous melanoma tumours, the delivery of ovalbumin-pulsed dendritic cells via the cryomicroneedles elicited higher antigen-specific immune responses and led to slower tumour growth than intravenous and subcutaneous injections of the cells. Biocompatible cryomicroneedles may facilitate minimally invasive cell delivery for a range of cell therapies.


Assuntos
Sistemas de Liberação de Medicamentos , Agulhas , Administração Cutânea , Animais , Antígenos , Injeções Subcutâneas , Camundongos , Suínos
5.
Small ; 16(31): e2002872, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32603020

RESUMO

Obesity is a serious epidemic health problem that can cause many other diseases including type 2 diabetes and cardiovascular diseases. Current approaches to combat obesity suffer from low effectiveness and adverse side effects. Here, a new self-administrable and minimally invasive transdermal drug delivery strategy for home-based long-term treatment of obesity and other diseases is developed. Specifically, ultrathin, core-shelled, and lance-shaped polymeric drug reservoirs (micro-lances [MLs]) are readily fabricated by a thermal pressing molding method and totally implanted into subcutaneous fat by lancing through the skin. Using a diet-induced obese mouse model, it is shown that the development of obesity and associated metabolic disorders is effectively inhibited by applying therapeutic core-shelled MLs once every 2 weeks. The outstanding therapeutic effects are attributable to highly localized and biphasic drug release, as well as combination therapy based on browning transformation of white fat and enhanced insulin sensitivity.


Assuntos
Diabetes Mellitus Tipo 2 , Preparações Farmacêuticas , Animais , Camundongos , Obesidade , Gordura Subcutânea
6.
Nat Commun ; 9(1): 4433, 2018 11 06.
Artigo em Inglês | MEDLINE | ID: mdl-30401883

RESUMO

Eye diseases and injuries impose a significant clinical problem worldwide. Safe and effective ocular drug delivery is, however, challenging due to the presence of ocular barriers. Here we report a strategy using an eye patch equipped with an array of detachable microneedles. These microneedles can penetrate the ocular surface tissue, and serve as implanted micro-reservoirs for controlled drug delivery. The biphasic drug release kinetics enabled by the double-layered micro-reservoirs largely enhances therapeutic efficacy. Using corneal neovascularization as the disease model, we show that delivery of an anti-angiogenic monoclonal antibody (DC101) by such eye patch produces ~90% reduction of neovascular area. Furthermore, quick release of an anti-inflammatory compound (diclofenac) followed by a sustained release of DC101 provides synergistic therapeutic outcome. The eye patch application is easy and minimally invasive to ensure good patient compliance. Such intraocular drug delivery strategy promises effective home-based treatment of many eye diseases.


Assuntos
Sistemas de Liberação de Medicamentos , Olho/efeitos dos fármacos , Preparações Farmacêuticas/administração & dosagem , Próteses e Implantes , Animais , Preparações de Ação Retardada , Inflamação/patologia , Camundongos , Agulhas , Sus scrofa , Fator A de Crescimento do Endotélio Vascular/antagonistas & inibidores , Fator A de Crescimento do Endotélio Vascular/metabolismo
8.
Biomater Sci ; 6(4): 779-784, 2018 Mar 26.
Artigo em Inglês | MEDLINE | ID: mdl-29134987

RESUMO

Hydrogen sulfide (H2S), being an important gaseous signaling molecule, has been gaining increasing attention for its involvement in a wide range of physiological processes. Herein, we developed a novel fluorescence turn-on nanoprobe for selective and sensitive detection of H2S based on graphene quantum dots (GQDs) conjugated with (2,4-dinitrophenoxy)tyrosine (DNPTYR). Taking advantage of its high fluorescence quantum yield, biocompatibility, photostability, and ease to be uptaken by cells, the GQD-based fluorescence probe was further employed for real-time monitoring of the triggered dynamic change of the intracellular H2S level in live cells.


Assuntos
Grafite/química , Sulfeto de Hidrogênio/análise , Pontos Quânticos/química , Técnicas Biossensoriais/métodos , Corantes Fluorescentes/química , Fluorometria/métodos , Humanos , Sulfeto de Hidrogênio/metabolismo , Células MCF-7 , Tirosina/análogos & derivados
9.
Artigo em Inglês | MEDLINE | ID: mdl-29263921

RESUMO

Brown adipose tissue dissipates energy in the form of heat. Recent studies have shown that adult humans possess both classical brown and beige adipocytes (brown-like adipocytes in white adipose tissue, WAT), and stimulating brown and beige adipocyte formation can be a new avenue to treat obesity. Angiotensin II (AngII) is a peptide hormone that plays important roles in energy metabolism via its angiotensin type 1 or type 2 receptors (AT1R and AT2R). Adipose tissue is a major source of AngII and expresses both types of its receptors, implying the autocrine and paracrine role of AngII in regulating adipose functions and self-remodeling. Here, based on the in vitro studies on primary cultures of mouse white adipocytes, we report that, AT2R activation, either by AngII or AT2R agonist (C21), induces white adipocyte browning, by increasing PPARγ expression, at least in part, via ERK1/2, PI3kinase/Akt and AMPK signaling pathways. It is also found that AngII-AT2R enhances brown adipogenesis. In the in vivo studies on mice, administration of AT1R antagonist (ZD7155) or AT2R agonist (C21) leads to the increase of WAT browning, body temperature and serum adiponectin, as well as the decrease of WAT mass and the serum levels of TNFα, triglycerides and free fatty acids. In addition, AT2R-induced browning effect is also observed in human white adipocytes, as evidenced by the increased UCP1 expression and oxygen consumption. Finally, we provide evidence that AT2R plays important roles in hormone T3-induced white adipose browning. This study, for the first time, reveals the browning and brown adipogenic effects of AT2R and suggests a potential therapeutic target to combat obesity and related metabolic disorders.

10.
Adv Mater ; 29(37)2017 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-28714117

RESUMO

Skin interstitial fluid (ISF) is an emerging source of biomarkers for disease diagnosis and prognosis. Microneedle (MN) patch has been identified as an ideal platform to extract ISF from the skin due to its pain-free and easy-to-administrated properties. However, long sampling time is still a serious problem which impedes timely metabolic analysis. In this study, a swellable MN patch that can rapidly extract ISF is developed. The MN patch is made of methacrylated hyaluronic acid (MeHA) and further crosslinked through UV irradiation. Owing to the supreme water affinity of MeHA, this MN patch can extract sufficient ISF in a short time without the assistance of extra devices, which remarkably facilitates timely metabolic analysis. Due to covalent crosslinked network, the MN patch maintains the structure integrity in the swelling hydrated state without leaving residues in skin after usage. More importantly, the extracted ISF metabolites can be efficiently recovered from MN patch by centrifugation for the subsequent offline analysis of metabolites such as glucose and cholesterol. Given the recent trend of easy-to-use point-of-care devices for personal healthcare monitoring, this study opens a new avenue for the development of MN-based microdevices for sampling ISF and minimally invasive metabolic detection.


Assuntos
Líquido Extracelular , Biomarcadores , Glucose , Agulhas , Pele
11.
ACS Nano ; 10(12): 11475-11482, 2016 12 27.
Artigo em Inglês | MEDLINE | ID: mdl-28024361

RESUMO

Monitoring cellular redox homeostasis is critical to the understanding of many physiological functions ranging from immune reactions to metabolism, as well as to the understanding of pathological development ranging from tumorigenesis to aging. Nevertheless, there is currently a lack of appropriate probes for this ambition, which should be reversibly, sensitively, and promptly responsive to a wide range of physiological oxidants and reductants. In this work, a redox-sensitive fluorescence-switchable probe is designed based on graphene quantum dots (GQDs) functionalized with a chelated redox Fe2+/Fe3+ couple. The underlying mechanism is investigated and discussed. The high sensitivity and fast response are attributable to the fact that the GQD's photoluminescence is highly sensitive to photon-induced electron transfer because of its ultrasmall size and associated prominent quantum confinement effect. Also taking advantages of GQDs' excellent photostability, biocompatibility, and readiness for cell uptake, our reversibly tunable fluorescence probe is employed to monitor in real time the triggered dynamic change of the intracellular redox state. This addition to the limited arsenal of available redox probes shall be useful to the still poorly understood redox biology, as well as for monitoring environment or chemical processes involving redox reactions.

12.
ACS Nano ; 10(3): 3622-9, 2016 Mar 22.
Artigo em Inglês | MEDLINE | ID: mdl-26928434

RESUMO

Graphene quantum dots (GQDs) are emerging fluorescence reporters attractive for optical sensing, owing to their high photostability, highly tunable photoluminescence, molecular size, atomically thin structure, biocompatibility, and ease of functionalization. Herein, we present a fluorometric sensing platform based on tyramine-functionalized GQDs, which is able to detect a spectrum of metabolites with high sensitivity and specificity. Furthermore, multiparametric blood analysis (glucose, cholesterol, L-lactate, and xanthine) is demonstrated. This convenient metabolite profiling technique could be instrumental for diagnosis, study, and management of metabolic disorders and associated diseases, such as diabetes, obesity, lactic acidosis, gout, and hypertension.


Assuntos
Fluorometria/métodos , Grafite/química , Pontos Quânticos/química , Tiramina/química , Animais , Análise Química do Sangue/métodos , Glicemia/análise , Colesterol/sangue , Ácido Láctico/sangue , Camundongos , Pontos Quânticos/ultraestrutura , Xantina/sangue
13.
J Biol Chem ; 290(23): 14679-91, 2015 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-25931124

RESUMO

Brown adipose tissue expends energy in the form of heat via the mitochondrial uncoupling protein UCP1. Recent studies showed that brown adipose tissue is present in adult humans and may be exploited for its anti-obesity and anti-diabetes actions. Apelin is an adipocyte-derived hormone that plays important roles in energy metabolism. Here, we report that apelin-APJ signaling promotes brown adipocyte differentiation by increasing the expressions of brown adipogenic and thermogenic transcriptional factors via the PI3K/Akt and AMPK signaling pathways. It is also found that apelin relieves the TNFα inhibition on brown adipogenesis. In addition, apelin increases the basal activity of brown adipocytes, as evidenced by the increased PGC1α and UCP1 expressions, mitochondrial biogenesis, and oxygen consumption. Finally, we provide both in vitro and in vivo evidence that apelin is able to increase the brown-like characteristics in white adipocytes. This study, for the first time, reveals the brown adipogenic and browning effects of apelin and suggests a potential therapeutic route to combat obesity and related metabolic disorders.


Assuntos
Adipócitos Marrons/citologia , Adipócitos Brancos/citologia , Adipogenia , Peptídeos e Proteínas de Sinalização Intercelular/metabolismo , Adipócitos Marrons/metabolismo , Adipócitos Brancos/metabolismo , Adipocinas , Animais , Apelina , Receptores de Apelina , Linhagem Celular , Células Cultivadas , Humanos , Peptídeos e Proteínas de Sinalização Intercelular/análise , Canais Iônicos/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Proteínas Mitocondriais/metabolismo , Ratos , Receptores Acoplados a Proteínas G/análise , Receptores Acoplados a Proteínas G/metabolismo , Transdução de Sinais , Proteína Desacopladora 1
14.
Nanoscale ; 7(17): 8159-65, 2015 May 07.
Artigo em Inglês | MEDLINE | ID: mdl-25875153

RESUMO

Graphene quantum dots (GQDs) are emerging zero-dimensional materials promising a wide spectrum of applications, particularly, as superior fluorescent reporters for bio-imaging and optical sensing. Heteroatom doping can endow GQDs with new or improved photoluminescence properties. Here, we demonstrate a simple strategy for the synthesis of nitrogen and phosphorus co-doped GQDs from a single biomolecule precursor (adenosine triphosphate - ATP). Such ATP-GQDs exhibit high fluorescence quantum yield, strong two-photon upconversion, small molecular weight, high photostability, and good biocompatibility. Furthermore, transferrin conjugated ATP-GQDs have been used for imaging and real-time tracking of transferrin receptors in live cells.


Assuntos
Trifosfato de Adenosina/química , Grafite/química , Nitrogênio/química , Fósforo/química , Pontos Quânticos/química , Técnicas Citológicas , Corantes Fluorescentes , Células HeLa , Humanos , Microscopia Confocal
15.
J Biol Chem ; 289(6): 3763-74, 2014 Feb 07.
Artigo em Inglês | MEDLINE | ID: mdl-24362107

RESUMO

It has been recently recognized that the increased oxidative stress (ROS overproduction) in obese condition is a key contributor to the pathogenesis of obesity-associated metabolic diseases. Apelin is an adipocytokine secreted by adipocytes, and known for its anti-obesity and anti-diabetic properties. In obesity, both oxidative stress and plasma level of apelin are increased. However, the regulatory roles of apelin on oxidative stress in adipocytes remain unknown. In the present study, we provide evidence that apelin, through its interaction with apelin receptor (APJ), suppresses production and release of reactive oxygen species (ROS) in adipocytes. This is further supported by the observations that apelin promotes the expression of anti-oxidant enzymes via MAPK kinase/ERK and AMPK pathways, and suppresses the expression of pro-oxidant enzyme via AMPK pathway. We further demonstrate that apelin is able to relieve oxidative stress-induced dysregulations of the expression of anti- and pro-oxidant enzymes, mitochondrial biogenesis and function, as well as release of pro- and anti-inflammatory adipocytokines. This study, for the first time, reveals the antioxidant properties of apelin in adipocytes, and suggests its potential as a novel therapeutic target for metabolic diseases.


Assuntos
Antioxidantes/metabolismo , Regulação Enzimológica da Expressão Gênica/fisiologia , Peptídeos e Proteínas de Sinalização Intercelular/metabolismo , Sistema de Sinalização das MAP Quinases/fisiologia , Estresse Oxidativo/fisiologia , Oxirredutases/biossíntese , Adipócitos , Apelina , Receptores de Apelina , Células Cultivadas , Humanos , Peptídeos e Proteínas de Sinalização Intercelular/genética , Masculino , Oxirredutases/genética , Espécies Reativas de Oxigênio/metabolismo , Receptores Acoplados a Proteínas G/genética , Receptores Acoplados a Proteínas G/metabolismo
16.
ACS Nano ; 7(7): 6278-86, 2013 Jul 23.
Artigo em Inglês | MEDLINE | ID: mdl-23799995

RESUMO

Graphene quantum dots (GQDs) hold great promise as a new class of fluorophores for bioimaging, owing to their remarkable physicochemical properties including tunable photoluminescence, excellent photostability, and biocompatibility. Despite their highly anticipated potentials, GQDs have yet to be used to specifically label and track molecular targets involved in dynamic cellular processes in live cells. Here, we demonstrate that GQDs can serve as universal fluorophores for bioimaging because they can be readily conjugated with a wide range of biomolecules while preserving their functionalities. As a proof-of-concept demonstration, insulin-conjugated GQDs have been synthesized and utilized for specific labeling and dynamic tracking of insulin receptors in 3T3-L1 adipocytes. Our experiments reveal, for the first time, that the internalization and recycling of insulin receptors in adipocytes are oppositely regulated by apelin and TNFα, which may contribute to the regulations of these two cytokines in insulin sensitivity.


Assuntos
Grafite/química , Microscopia de Fluorescência/métodos , Nanopartículas/química , Pontos Quânticos , Receptor de Insulina/metabolismo , Células 3T3-L1 , Animais , Meios de Contraste/síntese química , Corantes Fluorescentes , Camundongos , Transporte Proteico
17.
Phys Chem Chem Phys ; 15(23): 9170-6, 2013 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-23652812

RESUMO

Biofuel cells (BFCs), which use enzymes as catalysts to harvest energy from green and sustainable fuels abundantly producible from biological systems, are promising next-generation energy devices. However, the poor stability and high specificity to only one fuel type of these bio-catalysts largely limits the practical use of current BFCs. In this contribution, we demonstrate a unique fuel cell which, equipped with two identical enzyme-free electrodes based on Co3O4 coated 3D graphene, is able to efficiently harvest electricity from various sweet biofuels (glucose, sucrose, or lactose). Taking advantage of the dual catalytic ability of nanostructured Co3O4 for both glucose oxidation and oxygen reduction as well as the exceptional electrical and structural properties of 3D graphene, our glucose-powered fuel cell, with good long-term stability, offers high open circuit voltage (~1.1 V) and power density output (2.38 ± 0.17 mW cm(-2)).


Assuntos
Fontes de Energia Bioelétrica , Cobalto/química , Glucose/química , Grafite/química , Lactose/química , Óxidos/química , Sacarose/química , Eletrodos , Desenho de Equipamento , Nanoestruturas/química , Oxirredução
18.
J Biol Chem ; 288(22): 15520-31, 2013 May 31.
Artigo em Inglês | MEDLINE | ID: mdl-23592774

RESUMO

Angiotensin II (AngII), a peptide hormone released by adipocytes, can be catabolized by adipose angiotensin-converting enzyme 2 (ACE2) to form Ang(1-7). Co-expression of AngII receptors (AT1 and AT2) and Ang(1-7) receptors (Mas) in adipocytes implies the autocrine regulation of the local angiotensin system upon adipocyte functions, through yet unknown interactive mechanisms. In the present study, we reveal the adipogenic effects of Ang(1-7) through activation of Mas receptor and its subtle interplays with the antiadipogenic AngII-AT1 signaling pathways. Specifically, in human and 3T3-L1 preadipocytes, Ang(1-7)-Mas signaling promotes adipogenesis via activation of PI3K/Akt and inhibition of MAPK kinase/ERK pathways, and Ang(1-7)-Mas antagonizes the antiadipogenic effect of AngII-AT1 by inhibiting the AngII-AT1-triggered MAPK kinase/ERK pathway. The autocrine regulation of the AngII/AT1-ACE2-Ang(1-7)/Mas axis upon adipogenesis has also been revealed. This study suggests the importance of the local regulation of the delicately balanced angiotensin system upon adipogenesis and its potential as a novel therapeutic target for obesity and related metabolic disorders.


Assuntos
Adipogenia/fisiologia , Comunicação Autócrina/fisiologia , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Sistema de Sinalização das MAP Quinases/fisiologia , Proteínas Proto-Oncogênicas/metabolismo , Receptor Tipo 1 de Angiotensina/metabolismo , Receptores Acoplados a Proteínas G/metabolismo , Células 3T3-L1 , Adulto , Animais , MAP Quinases Reguladas por Sinal Extracelular/genética , Humanos , Masculino , Camundongos , Obesidade/genética , Obesidade/metabolismo , Obesidade/terapia , Proto-Oncogene Mas , Proteínas Proto-Oncogênicas/genética , Receptor Tipo 1 de Angiotensina/genética , Receptores Acoplados a Proteínas G/genética
19.
Mol Cell Endocrinol ; 362(1-2): 227-41, 2012 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-22842084

RESUMO

Apelin is an adipokine secreted by adipocytes. Co-expression of apelin and apelin receptor (APJ) in adipocytes implies the autocrine regulations of apelin on adipocyte functions through yet unknown molecular mechanisms. In the present study, we provide evidence that apelin, through its interaction with APJ receptor, inhibits adipogenesis of pre-adipocytes and lipolysis in mature adipocytes. The detailed molecular pathways underlying apelin signaling is proposed based on our experimental observations. Specifically, we show that apelin suppresses adipogenesis through MAPK kinase/ERK dependent pathways. And by preventing lipid droplet fragmentation, apelin inhibits basal lipolysis through AMP kinase dependent enhancement of perilipin expression and inhibits hormone-stimulated acute lipolysis through decreasing perilipin phosphorylation. Apelin induced decrease of free fatty acid release can be attributed to its dual inhibition on adipogenesis and lipolysis. This study suggests that the autocrine signaling of apelin may serve as a novel therapeutic target for obesity and other metabolic disorders.


Assuntos
Adipogenia , Peptídeos e Proteínas de Sinalização Intercelular/fisiologia , Lipólise , Células-Tronco/fisiologia , Células 3T3-L1 , Adipocinas , Animais , Apelina , Receptores de Apelina , Comunicação Autócrina , Proteínas Estimuladoras de Ligação a CCAAT/metabolismo , Proteínas de Transporte/metabolismo , Retroalimentação Fisiológica , Flavonoides/farmacologia , Expressão Gênica , Peptídeos e Proteínas de Sinalização Intercelular/genética , Peptídeos e Proteínas de Sinalização Intercelular/metabolismo , Metabolismo dos Lipídeos , Sistema de Sinalização das MAP Quinases , Camundongos , Proteínas Quinases Ativadas por Mitógeno/antagonistas & inibidores , Proteínas Quinases Ativadas por Mitógeno/metabolismo , PPAR gama/metabolismo , Perilipina-1 , Fosfoproteínas/metabolismo , Fosforilação , Processamento de Proteína Pós-Traducional , Ratos , Ratos Sprague-Dawley , Receptores Acoplados a Proteínas G/metabolismo , Células-Tronco/metabolismo , Gordura Subcutânea/citologia
20.
Mol Cell Endocrinol ; 351(2): 296-305, 2012 Apr 04.
Artigo em Inglês | MEDLINE | ID: mdl-22249006

RESUMO

Adipocytes play pivotal roles in regulating metabolism through secretion of a variety of adipokines, which in turn is regulated by other metabolic factors (e.g., insulin). Understanding the regulations of adipokine secretion is important because adipokines are implicated with metabolic disorders, such as, obesity and diabetes mellitus. Here, we investigated the regulatory roles of angiotensin II (AngII) on the secretion of apelin in 3T3-L1 adipocytes, and distinct signaling pathways mediated by AngII receptor type 1 (AT1) and type 2 (AT2) were revealed. It was found that activation of AT1 receptors stimulates apelin secretion in Ca²âº, protein kinase C, and MAPK kinase dependent ways while activation of AT2 receptors inhibits apelin secretion through cAMP and cGMP dependent pathways. Furthermore, we demonstrate that the expression of apelin receptor (APJ) is also similarly regulated by AT1 and AT2 receptors. Finally, a detailed AngII signaling map is proposed.


Assuntos
Adipócitos/metabolismo , Peptídeos e Proteínas de Sinalização Intercelular/metabolismo , Receptor Tipo 1 de Angiotensina/metabolismo , Receptor Tipo 2 de Angiotensina/metabolismo , Receptores Acoplados a Proteínas G/biossíntese , Células 3T3-L1 , Adipocinas , Angiotensina II/metabolismo , Animais , Apelina , Receptores de Apelina , Cálcio/metabolismo , Linhagem Celular , AMP Cíclico/metabolismo , GMP Cíclico/metabolismo , Flavonoides/farmacologia , Regulação da Expressão Gênica , Imidazóis/farmacologia , Sistema de Sinalização das MAP Quinases/fisiologia , Camundongos , Proteínas Quinases Ativadas por Mitógeno/antagonistas & inibidores , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Naftiridinas/farmacologia , Proteína Quinase C/metabolismo , Piridinas/farmacologia
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