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Whether in real or simulated microgravity, Humans or animals, the kinetics of cardiovascular adaptation and its regulation by the autonomic nervous system (ANS) remain controversial. In this study, we used hindlimb unloading (HU) in 10 conscious mice. Blood pressure (BP), heart rate (HR), temperature, and locomotor activity were continuously monitored with radio-telemetry, during 3 days of control, 5 days of HU, and 2 days of recovery. Six additional mice were used to assess core temperature. ANS activity was indirectly determined by analyzing both heart rate variability (HRV) and baroreflex sensitivity (BRS). Our study showed that HU induced an initial bradycardia, accompanied by an increase in vagal activity markers of HRV and BRS, together with a decrease in water intake, indicating the early adaptation to fluid redistribution. During HU, BRS was reduced; temperature and BP circadian rhythms were altered, showing a loss in day/night differences, a decrease in cycle amplitude, a drop in core body temperature, and an increase in day BP suggestive of a rise in sympathetic activity. Reloading induced resting tachycardia and a decrease in BP, vagal activity, and BRS. In addition to cardiovascular deconditioning, HU induces disruption in day/night rhythmicity of locomotor activity, temperature, and BP.
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Insulin resistance is a key event in type 2 diabetes onset and a major comorbidity of obesity. It results from a combination of fat excess-triggered defects, including lipotoxicity and metaflammation, but the causal mechanisms remain difficult to identify. Here, we report that hyperactivation of the tyrosine phosphatase SHP2 found in Noonan syndrome (NS) led to an unsuspected insulin resistance profile uncoupled from altered lipid management (for example, obesity or ectopic lipid deposits) in both patients and mice. Functional exploration of an NS mouse model revealed this insulin resistance phenotype correlated with constitutive inflammation of tissues involved in the regulation of glucose metabolism. Bone marrow transplantation and macrophage depletion improved glucose homeostasis and decreased metaflammation in the mice, highlighting a key role of macrophages. In-depth analysis of bone marrow-derived macrophages in vitro and liver macrophages showed that hyperactive SHP2 promoted a proinflammatory phenotype, modified resident macrophage homeostasis, and triggered monocyte infiltration. Consistent with a role of SHP2 in promoting inflammation-driven insulin resistance, pharmaceutical SHP2 inhibition in obese diabetic mice improved insulin sensitivity even better than conventional antidiabetic molecules by specifically reducing metaflammation and alleviating macrophage activation. Together, these results reveal that SHP2 hyperactivation leads to inflammation-triggered metabolic impairments and highlight the therapeutical potential of SHP2 inhibition to ameliorate insulin resistance.
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Diabetes Mellitus Experimental , Diabetes Mellitus Tipo 2 , Resistência à Insulina , Tecido Adiposo , Animais , Humanos , Inflamação , Macrófagos , Camundongos , Camundongos KnockoutRESUMO
Bone metastasis remains the most frequent and the deadliest complication of prostate cancer (PCa). Mechanisms leading to the homing of tumor cells to bone remain poorly characterized. Role of chemokines in providing navigational cues to migrating cancer cells bearing specific receptors is well established. Bone is an adipocyte-rich organ since 50 to 70% of the adult bone marrow (BM) volume comprise bone marrow adipocytes (BM-Ads), which are likely to produce chemokines within the bone microenvironment. Using in vitro migration assays, we demonstrated that soluble factors released by human primary BM-Ads are able to support the directed migration of PCa cells in a CCR3-dependent manner. In addition, we showed that CCL7, a chemokine previously involved in the CCR3-dependent migration of PCa cells outside of the prostate gland, is released by human BM-Ads. These effects are amplified by obesity and ageing, two clinical conditions known to promote aggressive and metastatic PCa. In human tumors, we found an enrichment of CCR3 in bone metastasis vs. primary tumors at mRNA levels using Oncomine microarray database. In addition, immunohistochemistry experiments demonstrated overexpression of CCR3 in bone versus visceral metastases. These results underline the potential importance of BM-Ads in the bone metastatic process and imply a CCR3/CCL7 axis whose pharmacological interest needs to be evaluated.
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Adipócitos/metabolismo , Adipócitos/patologia , Medula Óssea/patologia , Osso e Ossos/patologia , Neoplasias da Próstata/metabolismo , Neoplasias da Próstata/patologia , Receptores CCR3/metabolismo , Envelhecimento/patologia , Medula Óssea/efeitos dos fármacos , Osso e Ossos/efeitos dos fármacos , Linhagem Celular Tumoral , Quimiocina CCL7/metabolismo , Quimiotaxia/efeitos dos fármacos , Meios de Cultivo Condicionados/farmacologia , Humanos , Masculino , Metástase Neoplásica , Obesidade/complicações , Neoplasias da Próstata/complicaçõesRESUMO
Extracellular vesicles are emerging key actors in adipocyte communication. Notably, small extracellular vesicles shed by adipocytes stimulate fatty acid oxidation and migration in melanoma cells and these effects are enhanced in obesity. However, the vesicular actors and cellular processes involved remain largely unknown. Here, we elucidate the mechanisms linking adipocyte extracellular vesicles to metabolic remodeling and cell migration. We show that adipocyte vesicles stimulate melanoma fatty acid oxidation by providing both enzymes and substrates. In obesity, the heightened effect of extracellular vesicles depends on increased transport of fatty acids, not fatty acid oxidation-related enzymes. These fatty acids, stored within lipid droplets in cancer cells, drive fatty acid oxidation upon being released by lipophagy. This increase in mitochondrial activity redistributes mitochondria to membrane protrusions of migrating cells, which is necessary to increase cell migration in the presence of adipocyte vesicles. Our results provide key insights into the role of extracellular vesicles in the metabolic cooperation that takes place between adipocytes and tumors with particular relevance to obesity.
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Adipócitos/citologia , Vesículas Extracelulares/metabolismo , Ácidos Graxos/metabolismo , Melanoma/metabolismo , Obesidade/complicações , Células 3T3 , Adipócitos/metabolismo , Animais , Autofagia , Linhagem Celular Tumoral , Movimento Celular , Humanos , Metabolismo dos Lipídeos , Masculino , Camundongos , Mitocôndrias/metabolismo , Dinâmica Mitocondrial , Obesidade/metabolismo , OxirreduçãoRESUMO
Novel mechanisms and health benefits have been recently suggested for the antidepressant drug phenelzine (PHE), known as a nonselective monoamine oxidase inhibitor. They include an antilipogenic action that could have an impact on excessive fat accumulation and obesity-related metabolic alterations. We evaluated the metabolic effects of an oral PHE treatment on mice fed a high-fat diet (HFD). Eleven-week-old male C57BL/6 mice were fed a HFD and either a 0.028% PHE solution (HFD + PHE) or water to drink for 11 weeks. PHE attenuated the increase in body weight and adiposity without affecting food consumption. Energy efficiency was lower in HFD + PHE mice. Lipid content was reduced in subcutaneous fat pads, liver, and skeletal muscle. In white adipose tissue (WAT), PHE reduced sterol regulatory element-binding protein-1c and phosphoenolpyruvate carboxykinase mRNA levels, inhibited amine-induced lipogenesis, and did not increase lipolysis. Moreover, HFD + PHE mice presented diminished levels of hydrogen peroxide release in subcutaneous WAT and reduced expression of leukocyte transmigration markers and proinflammatory cytokines in visceral WAT and liver. PHE reduced the circulating levels of glycerol, triacylglycerols, high-density lipoprotein cholesterol, and insulin. Insulin resistance was reduced, without affecting glucose levels and glucose tolerance. In contrast, PHE increased rectal temperature and slightly increased energy expenditure. The mitigation of HFD-induced metabolic disturbances points toward a promising role for PHE in obesity treatment and encourages further research on its mechanisms of action. SIGNIFICANCE STATEMENT: Phenelzine reduces body fat, markers of oxidative stress, inflammation, and insulin resistance in high-fat diet mice. Semicarbazide-sensitive amine oxidase, monoamine oxidase, phosphoenolpyruvate carboxykinase, and sterol regulatory element-binding protein-1c are involved in the metabolic effects of phenelzine. Phenelzine could be potentially used for the treatment of obesity-related complications.
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Tecido Adiposo/efeitos dos fármacos , Tecido Adiposo/metabolismo , Dieta Hiperlipídica/efeitos adversos , Resistência à Insulina/fisiologia , Inibidores da Monoaminoxidase/administração & dosagem , Fenelzina/administração & dosagem , Administração Oral , Animais , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Estresse Oxidativo/efeitos dos fármacos , Estresse Oxidativo/fisiologia , Resultado do TratamentoRESUMO
INTRODUCTION: Clinical studies suggest that obesity, in addition to promoting breast cancer aggressiveness, is associated with a decrease in chemotherapy efficacy, although the mechanisms involved remain elusive. As chemotherapy is one of the main treatments for aggressive or metastatic breast cancer, we investigated whether adipocytes can mediate resistance to doxorubicin (DOX), one of the main drugs used to treat breast cancer, and the mechanisms associated. METHODS: We used a coculture system to grow breast cancer cells with in vitro differentiated adipocytes as well as primary mammary adipocytes isolated from lean and obese patients. Drug cellular accumulation, distribution, and efflux were studied by immunofluorescence, flow cytometry, and analysis of extracellular vesicles. Results were validated by immunohistochemistry in a series of lean and obese patients with cancer. RESULTS: Adipocytes differentiated in vitro promote DOX resistance (with cross-resistance to paclitaxel and 5-fluorouracil) in a large panel of human and murine breast cancer cell lines independently of their subtype. Subcellular distribution of DOX was altered in cocultivated cells with decreased nuclear accumulation of the drug associated with a localized accumulation in cytoplasmic vesicles, which then are expelled into the extracellular medium. The transport-associated major vault protein (MVP), whose expression was upregulated by adipocytes, mediated both processes. Coculture with human mammary adipocytes also induced chemoresistance in breast cancer cells (as well as the related MVP-induced DOX efflux) and their effect was amplified by obesity. Finally, in a series of human breast tumors, we observed a gradient of MVP expression, which was higher at the invasive front, where tumor cells are at close proximity to adipocytes, than in the tumor center, highlighting the clinical relevance of our results. High expression of MVP in these tumor cells is of particular interest since they are more likely to disseminate to give rise to chemoresistant metastases. CONCLUSIONS: Collectively, our study shows that adipocytes induce an MVP-related multidrug-resistant phenotype in breast cancer cells, which could contribute to obesity-related chemoresistance.
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Adipócitos/metabolismo , Antineoplásicos/farmacologia , Neoplasias da Mama/tratamento farmacológico , Obesidade/complicações , Partículas de Ribonucleoproteínas em Forma de Abóbada/metabolismo , Células 3T3 , Tecido Adiposo/citologia , Adulto , Idoso , Animais , Antineoplásicos/uso terapêutico , Mama/citologia , Mama/patologia , Mama/cirurgia , Neoplasias da Mama/patologia , Neoplasias da Mama/cirurgia , Linhagem Celular Tumoral , Técnicas de Cocultura , Doxorrubicina/farmacologia , Doxorrubicina/uso terapêutico , Resistência a Múltiplos Medicamentos , Resistencia a Medicamentos Antineoplásicos , Feminino , Fluoruracila/farmacologia , Fluoruracila/uso terapêutico , Humanos , Mastectomia , Camundongos , Pessoa de Meia-Idade , Paclitaxel/farmacologia , Paclitaxel/uso terapêutico , Cultura Primária de Células , RNA Interferente Pequeno/metabolismo , Partículas de Ribonucleoproteínas em Forma de Abóbada/genéticaRESUMO
Prostate gland is surrounded by periprostatic adipose tissue (PPAT), which is increasingly believed to play a paracrine role in prostate cancer progression. Our previous work demonstrates that adipocytes promote homing of prostate cancer cells to PPAT and that this effect is upregulated by obesity. Here, we show that once tumor cells have invaded PPAT (mimicked by an in vitro model of coculture), they establish a bidirectional crosstalk with adipocytes, which promotes tumor cell invasion. Indeed, tumor cells induce adipocyte lipolysis and the free fatty acids (FFA) released are taken up and stored by tumor cells. Incubation with exogenous lipids also stimulates tumor cell invasion, underlining the importance of lipid transfer in prostate cancer aggressiveness. Transferred FFAs (after coculture or exogenous lipid treatment) stimulate the expression of one isoform of the pro-oxidant enzyme NADPH oxidase, NOX5. NOX5 increases intracellular reactive oxygen species (ROS) that, in turn, activate a HIF1/MMP14 pathway, which is responsible for the increased tumor cell invasion. In obesity, tumor-surrounding adipocytes are more prone to activate the depicted signaling pathway and to induce tumor invasion. Finally, the expression of NOX5 and MMP14 is upregulated at the invasive front of human tumors where cancer cells are in close proximity to adipocytes and this process is amplified in obese patients, underlining the clinical relevance of our results. IMPLICATIONS: Our work emphasizes the key role of adjacent PPAT in prostate cancer dissemination and proposes new molecular targets for the treatment of obese patients exhibiting aggressive diseases.
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Tecido Adiposo/fisiopatologia , Obesidade/complicações , Neoplasias da Próstata/etiologia , Animais , Técnicas de Cultura de Células , Humanos , Masculino , Camundongos , Estresse Oxidativo , Neoplasias da Próstata/patologia , TransfecçãoRESUMO
Sarcopenia, the degenerative loss of skeletal muscle mass, quality and strength, lacks early diagnostic tools and new therapeutic strategies to prevent the frailty-to-disability transition often responsible for the medical institutionalization of elderly individuals. Herein we report that production of the endogenous peptide apelin, induced by muscle contraction, is reduced in an age-dependent manner in humans and rodents and is positively associated with the beneficial effects of exercise in older persons. Mice deficient in either apelin or its receptor (APLNR) presented dramatic alterations in muscle function with increasing age. Various strategies that restored apelin signaling during aging further demonstrated that this peptide considerably enhanced muscle function by triggering mitochondriogenesis, autophagy and anti-inflammatory pathways in myofibers as well as enhancing the regenerative capacity by targeting muscle stem cells. Taken together, these findings revealed positive regulatory feedback between physical activity, apelin and muscle function and identified apelin both as a tool for diagnosis of early sarcopenia and as the target of an innovative pharmacological strategy to prevent age-associated muscle weakness and restore physical autonomy.
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Envelhecimento/patologia , Apelina/sangue , Sarcopenia/sangue , Adenilato Quinase/metabolismo , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Animais , Apelina/biossíntese , Receptores de Apelina/deficiência , Receptores de Apelina/metabolismo , Peso Corporal , Exercício Físico , Humanos , Cinética , Camundongos Endogâmicos C57BL , Células Musculares/metabolismo , Debilidade Muscular/tratamento farmacológico , Debilidade Muscular/patologia , Músculo Esquelético/efeitos dos fármacos , Músculo Esquelético/metabolismo , Biogênese de Organelas , Biossíntese de Proteínas , Proteínas Proto-Oncogênicas c-akt/metabolismo , Regeneração , Proteínas Quinases S6 Ribossômicas 70-kDa/metabolismo , Sarcopenia/patologia , Células Satélites de Músculo Esquelético/metabolismoRESUMO
BACKGROUND AND PURPOSE: Phenelzine is an antidepressant drug known to increase the risk of hypertensive crisis when dietary tyramine is not restricted. However, this MAO inhibitor inhibits other enzymes not limited to the nervous system. Here we investigated if its antiadipogenic and antilipogenic effects in cultured adipocytes could contribute to decreased body fat in vivo, without unwanted hypertensive or cardiovascular effects. EXPERIMENTAL APPROACH: Mice were fed a standard chow and given 0.028% phenelzine in drinking water for 12 weeks. Body composition was determined by NMR. Cardiovascular dysfunction was assessed by heart rate variability analyses and by evaluation of cardiac oxidative stress markers. MAO activity, hydrogen peroxide release and triacylglycerol turnover were assayed in white adipose tissue (WAT), alongside determination of glucose and lipid circulating levels. KEY RESULTS: Phenelzine-treated mice exhibited lower body fat content, subcutaneous WAT mass and lipid content in skeletal muscles than control, without decreased body weight gain or food consumption. A modest alteration of cardiac sympathovagal balance occurred without depressed aconitase activity. In WAT, phenelzine impaired the lipogenic but not the antilipolytic actions of insulin, MAO activity and hydrogen peroxide release. Phenelzine treatment lowered non-fasting blood glucose and phosphoenolpyruvate carboxykinase expression. In vitro, high doses of phenelzine decreased both lipolytic and lipogenic responses in mouse adipocytes. CONCLUSION AND IMPLICATIONS: As phenelzine reduced body fat content without affecting cardiovascular function in mice, it may be of benefit in the treatment of obesity-associated complications, with the precautions of use recommended for antidepressant therapy.
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Tecido Adiposo/efeitos dos fármacos , Antidepressivos/farmacologia , Inibidores da Monoaminoxidase/farmacologia , Monoaminoxidase/metabolismo , Fenelzina/farmacologia , Tecido Adiposo/metabolismo , Administração Oral , Animais , Antidepressivos/administração & dosagem , Sistema Cardiovascular/efeitos dos fármacos , Sistema Cardiovascular/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Inibidores da Monoaminoxidase/administração & dosagem , Fenelzina/administração & dosagemRESUMO
PURPOSE: Apelin treatment has been shown to improve insulin sensitivity in insulin resistant mice by acting in skeletal muscles. However, the effects of systemic apelin on the hepatic energy metabolism have not been addressed. We thus aimed to determine the effect of chronic apelin treatment on the hepatic lipid metabolism in insulin resistant mice. The apelin receptor (APJ) expression was also studied in this context since its regulation has only been reported in severe liver pathologies. METHODS: Mice were fed a high-fat diet (HFD) in order to become obese and insulin resistant compared to chow fed mice (CD). HFD mice then received a daily intraperitoneal injection of apelin (0.1 µmol/kg) or PBS during 28 days. RESULTS: Triglycerides content and the expression of different lipogenesis-related genes were significantly decreased in the liver of HFD apelin-treated compared to PBS-treated mice. Moreover, at this stage of insulin resistance, the beta-oxidation was increased in liver homogenates of HFD PBS-treated mice compared to CD mice and reduced in HFD apelin-treated mice. Finally, APJ expression was not up-regulated in the liver of insulin resistant mice. In isolated hepatocytes from chow and HFD fed mice, apelin did not induce significant effect. CONCLUSIONS: Altogether, these results suggest that systemic apelin treatment decreases steatosis in insulin resistant mice without directly targeting hepatocytes.
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Apelina/farmacologia , Resistência à Insulina/fisiologia , Metabolismo dos Lipídeos/efeitos dos fármacos , Fígado/efeitos dos fármacos , Obesidade/metabolismo , Animais , Metabolismo Energético/efeitos dos fármacos , Fígado Gorduroso/metabolismo , Hepatócitos/efeitos dos fármacos , Hepatócitos/metabolismo , Fígado/metabolismo , Masculino , Camundongos , Triglicerídeos/metabolismoRESUMO
OBJECTIVE: Decreasing duodenal contraction is now considered as a major focus for the treatment of type 2 diabetes. Therefore, identifying bioactive molecules able to target the enteric nervous system, which controls the motility of intestinal smooth muscle cells, represents a new therapeutic avenue. For this reason, we chose to study the impact of oral galanin on this system in diabetic mice. METHODS: Enteric neurotransmission, duodenal contraction, glucose absorption, modification of gut-brain axis, and glucose metabolism (glucose tolerance, insulinemia, glucose entry in tissue, hepatic glucose metabolism) were assessed. RESULTS: We show that galanin, a neuropeptide expressed in the small intestine, decreases duodenal contraction by stimulating nitric oxide release from enteric neurons. This is associated with modification of hypothalamic nitric oxide release that favors glucose uptake in metabolic tissues such as skeletal muscle, liver, and adipose tissue. Oral chronic gavage with galanin in diabetic mice increases insulin sensitivity, which is associated with an improvement of several metabolic parameters such as glucose tolerance, fasting blood glucose, and insulin. CONCLUSION: Here, we demonstrate that oral galanin administration improves glucose homeostasis via the enteric nervous system and could be considered a therapeutic potential for the treatment of T2D.
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Glicemia/metabolismo , Sistema Nervoso Entérico/efeitos dos fármacos , Galanina/farmacologia , Hipoglicemiantes/farmacologia , Neurônios/efeitos dos fármacos , Administração Oral , Animais , Sistema Nervoso Entérico/metabolismo , Galanina/administração & dosagem , Hipoglicemiantes/administração & dosagem , Hipotálamo/metabolismo , Insulina/sangue , Resistência à Insulina , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Neurônios/metabolismo , Óxido Nítrico/metabolismo , Óxido Nítrico Sintase Tipo I/genética , Óxido Nítrico Sintase Tipo I/metabolismoRESUMO
Glioblastoma are highly aggressive brain tumours that are associated with an extremely poor prognosis. Within these tumours exists a subpopulation of highly plastic self-renewing cancer cells that retain the ability to expand ex vivo as tumourspheres, induce tumour growth in mice, and have been implicated in radio- and chemo-resistance. Although their identity and fate are regulated by external cues emanating from endothelial cells, the nature of such signals remains unknown. Here, we used a mass spectrometry proteomic approach to characterize the factors released by brain endothelial cells. We report the identification of the vasoactive peptide apelin as a central regulator for endothelial-mediated maintenance of glioblastoma patient-derived cells with stem-like properties. Genetic and pharmacological targeting of apelin cognate receptor abrogates apelin- and endothelial-mediated expansion of glioblastoma patient-derived cells with stem-like properties in vitro and suppresses tumour growth in vivo. Functionally, selective competitive antagonists of apelin receptor were shown to be safe and effective in reducing tumour expansion and lengthening the survival of intracranially xenografted mice. Therefore, the apelin/apelin receptor signalling nexus may operate as a paracrine signal that sustains tumour cell expansion and progression, suggesting that apelin is a druggable factor in glioblastoma.
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Neoplasias Encefálicas/metabolismo , Glioblastoma/metabolismo , Peptídeos e Proteínas de Sinalização Intercelular/metabolismo , Receptores Acoplados a Proteínas G/antagonistas & inibidores , Animais , Apelina , Receptores de Apelina , Neoplasias Encefálicas/tratamento farmacológico , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Células Endoteliais , Glioblastoma/tratamento farmacológico , Células HEK293 , Humanos , Técnicas In Vitro , Espectrometria de Massas , Camundongos , Terapia de Alvo Molecular , Proteômica , RNA Interferente Pequeno , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
Apelin signaling plays an important role during embryo development and regulates angiogenesis, cardiovascular activity, and energy metabolism in adulthood. Overexpression and hyperactivity of this signaling pathway is observed in various pathologic states, such as cardiovascular diseases and cancer, which highlights the importance of inhibiting apelin receptor (APJ); therefore, we developed a cell-based screening assay that uses fluorescence microscopy to identify APJ antagonists. This approach led us to identify the U.S. Food and Drug Administration-approved compound protamine-already used clinically after cardiac surgery-as an agent to bind to heparin and thereby reverse its anticlotting activity. Protamine displays a 390-nM affinity for APJ and behaves as a full antagonist with regard to G protein and ß-arrestin-dependent intracellular signaling. Ex vivo and in vivo, protamine abolishes well-known apelin effects, such as angiogenesis, glucose tolerance, and vasodilatation. Remarkably, protamine antagonist activity is fully reversed by heparin treatment both in vitro and in vivo Thus, our results demonstrate a new pharmacologic property of protamine-blockade of APJ-that could explain some adverse effects observed in protamine-treated patients. Moreover, our data reveal that the established antiangiogenic activity of protamine would rely on APJ antagonism.-Le Gonidec, S., Chaves-Almagro, C., Bai, Y., Kang, H. J., Smith, A., Wanecq, E., Huang, X.-P., Prats, H., Knibiehler, B., Roth, B. L., Barak, L. S., Caron, M. G., Valet, P., Audigier, Y., Masri, B. Protamine is an antagonist of apelin receptor, and its activity is reversed by heparin.
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Heparina/farmacologia , Protaminas/farmacologia , Receptores Acoplados a Proteínas G/antagonistas & inibidores , Animais , Receptores de Apelina , Linhagem Celular Tumoral , Feminino , Regulação da Expressão Gênica/efeitos dos fármacos , Regulação da Expressão Gênica/fisiologia , Células HEK293 , Humanos , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Receptores Acoplados a Proteínas G/genética , Receptores Acoplados a Proteínas G/metabolismoRESUMO
In breast cancer, a key feature of peritumoral adipocytes is their loss of lipid content observed both in vitro and in human tumors. The free fatty acids (FFAs), released by adipocytes after lipolysis induced by tumor secretions, are transferred and stored in tumor cells as triglycerides in lipid droplets. In tumor cell lines, we demonstrate that FFAs can be released over time from lipid droplets through an adipose triglyceride lipase-dependent (ATGL-dependent) lipolytic pathway. In vivo, ATGL is expressed in human tumors where its expression correlates with tumor aggressiveness and is upregulated by contact with adipocytes. The released FFAs are then used for fatty acid ß-oxidation (FAO), an active process in cancer but not normal breast epithelial cells, and regulated by coculture with adipocytes. However, in cocultivated cells, FAO is uncoupled from ATP production, leading to AMPK/acetyl-CoA carboxylase activation, a circle that maintains this state of metabolic remodeling. The increased invasive capacities of tumor cells induced by coculture are completely abrogated by inhibition of the coupled ATGL-dependent lipolysis/FAO pathways. These results show a complex metabolic symbiosis between tumor-surrounding adipocytes and cancer cells that stimulate their invasiveness, highlighting ATGL as a potential therapeutic target to impede breast cancer progression.
Assuntos
Adipócitos/metabolismo , Neoplasias da Mama/metabolismo , Carcinoma Ductal de Mama/metabolismo , Carcinoma Lobular/metabolismo , Ácidos Graxos não Esterificados/metabolismo , Lipase/metabolismo , Lipólise , Acetil-CoA Carboxilase/metabolismo , Trifosfato de Adenosina/metabolismo , Adenilato Quinase/metabolismo , Idoso , Animais , Neoplasias da Mama/patologia , Carcinoma Ductal de Mama/patologia , Carcinoma Lobular/patologia , Linhagem Celular Tumoral , Proliferação de Células , Técnicas de Cocultura , Feminino , Humanos , Camundongos , Pessoa de Meia-Idade , Invasividade Neoplásica , Oxirredução , Triglicerídeos/metabolismoRESUMO
OBJECTIVE: The gut-brain axis is considered as a major regulatory checkpoint in the control of glucose homeostasis. The detection of nutrients and/or hormones in the duodenum informs the hypothalamus of the host's nutritional state. This process may occur via hypothalamic neurons modulating central release of nitric oxide (NO), which in turn controls glucose entry into tissues. The enteric nervous system (ENS) modulates intestinal contractions in response to various stimuli, but the importance of this interaction in the control of glucose homeostasis via the brain is unknown. We studied whether apelin, a bioactive peptide present in the gut, regulates ENS-evoked contractions, thereby identifying a new physiological partner in the control of glucose utilisation via the hypothalamus. DESIGN: We measured the effect of apelin on electrical and mechanical duodenal responses via telemetry probes and isotonic sensors in normal and obese/diabetic mice. Changes in hypothalamic NO release, in response to duodenal contraction modulated by apelin, were evaluated in real time with specific amperometric probes. Glucose utilisation in tissues was measured with orally administrated radiolabeled glucose. RESULTS: In normal and obese/diabetic mice, glucose utilisation is improved by the decrease of ENS/contraction activities in response to apelin, which generates an increase in hypothalamic NO release. As a consequence, glucose entry is significantly increased in the muscle. CONCLUSIONS: Here, we identify a novel mode of communication between the intestine and the hypothalamus that controls glucose utilisation. Moreover, our data identified oral apelin administration as a novel potential target to treat metabolic disorders.
Assuntos
Adipocinas/farmacologia , Sistema Nervoso Entérico/efeitos dos fármacos , Glucose/metabolismo , Hipotálamo/efeitos dos fármacos , Peptídeos e Proteínas de Sinalização Intercelular/farmacologia , Contração Muscular/efeitos dos fármacos , Animais , Apelina , Técnicas Biossensoriais , Diabetes Mellitus/fisiopatologia , Duodeno/efeitos dos fármacos , Duodeno/metabolismo , Sistema Nervoso Entérico/fisiologia , Motilidade Gastrointestinal/efeitos dos fármacos , Homeostase , Hipotálamo/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Músculo Liso/fisiologia , Óxido Nítrico/metabolismo , Obesidade/fisiopatologia , TelemetriaRESUMO
Apelin is a bioactive peptide involved in the control of energy metabolism. In the hypothalamus, chronic exposure to high levels of apelin is associated with an increase in hepatic glucose production, and then contributes to the onset of type 2 diabetes. However, the molecular mechanisms behind deleterious effects of chronic apelin in the brain and consequences on energy expenditure and thermogenesis are currently unknown. We aimed to evaluate the effects of chronic intracerebroventricular (icv) infusion of apelin in normal mice on hypothalamic inflammatory gene expression, energy expenditure, thermogenesis and brown adipose tissue functions. We have shown that chronic icv infusion of apelin increases the expression of pro-inflammatory factors in the hypothalamus associated with an increase in plasma interleukin-1 beta. In parallel, mice infused with icv apelin exhibit a significant lower energy expenditure coupled to a decrease in PGC1alpha, PRDM16 and UCP1 expression in brown adipose tissue which could explain the alteration of thermogenesis in these mice. These data provide compelling evidence that central apelin contributes to the development of type 2 diabetes by altering energy expenditure, thermogenesis and fat browning.
Assuntos
Tecido Adiposo Marrom/efeitos dos fármacos , Apelina/farmacologia , Metabolismo Energético/efeitos dos fármacos , Termogênese/efeitos dos fármacos , Tecido Adiposo Marrom/metabolismo , Animais , Apelina/administração & dosagem , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/metabolismo , Diabetes Mellitus Tipo 2/sangue , Diabetes Mellitus Tipo 2/genética , Diabetes Mellitus Tipo 2/metabolismo , Expressão Gênica/efeitos dos fármacos , Hipotálamo/efeitos dos fármacos , Hipotálamo/metabolismo , Infusões Intraventriculares , Interleucina-1beta/genética , Interleucina-1beta/metabolismo , Camundongos , Óxido Nítrico Sintase Tipo II/genética , Óxido Nítrico Sintase Tipo II/metabolismo , Coativador 1-alfa do Receptor gama Ativado por Proliferador de Peroxissomo/genética , Coativador 1-alfa do Receptor gama Ativado por Proliferador de Peroxissomo/metabolismo , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Proteína Desacopladora 1/genética , Proteína Desacopladora 1/metabolismoRESUMO
Obesity favours the occurrence of locally disseminated prostate cancer in the periprostatic adipose tissue (PPAT) surrounding the prostate gland. Here we show that adipocytes from PPAT support the directed migration of prostate cancer cells and that this event is strongly promoted by obesity. This process is dependent on the secretion of the chemokine CCL7 by adipocytes, which diffuses from PPAT to the peripheral zone of the prostate, stimulating the migration of CCR3 expressing tumour cells. In obesity, higher secretion of CCL7 by adipocytes facilitates extraprostatic extension. The observed increase in migration associated with obesity is totally abrogated when the CCR3/CCL7 axis is inhibited. In human prostate cancer tumours, expression of the CCR3 receptor is associated with the occurrence of aggressive disease with extended local dissemination and a higher risk of biochemical recurrence, highlighting the potential benefit of CCR3 antagonists in the treatment of prostate cancer.
Assuntos
Adenocarcinoma/metabolismo , Adipócitos/metabolismo , Movimento Celular , Quimiocina CCL7/metabolismo , Recidiva Local de Neoplasia/metabolismo , Obesidade/metabolismo , Neoplasias da Próstata/metabolismo , Receptores CCR3/metabolismo , Adenocarcinoma/patologia , Tecido Adiposo/citologia , Adulto , Idoso , Animais , Linhagem Celular Tumoral , Progressão da Doença , Ensaio de Imunoadsorção Enzimática , Citometria de Fluxo , Humanos , Imuno-Histoquímica , Masculino , Espectrometria de Massas , Camundongos , Pessoa de Meia-Idade , Prognóstico , Próstata , Neoplasias da Próstata/patologia , Reação em Cadeia da Polimerase Via Transcriptase ReversaRESUMO
Anaplastic Lymphoma Kinase-positive Anaplastic Large Cell Lymphomas (ALK+ ALCL) occur predominantly in children and young adults. Their treatment, based on aggressive chemotherapy, is not optimal since ALCL patients can still expect a 30% 2-year relapse rate. Tumor relapses are very aggressive and their underlying mechanisms are unknown. Crizotinib is the most advanced ALK tyrosine kinase inhibitor and is already used in clinics to treat ALK-associated cancers. However, crizotinib escape mechanisms have emerged, thus preventing its use in frontline ALCL therapy. The process of autophagy has been proposed as the next target for elimination of the resistance to tyrosine kinase inhibitors. In this study, we investigated whether autophagy is activated in ALCL cells submitted to ALK inactivation (using crizotinib or ALK-targeting siRNA). Classical autophagy read-outs such as autophagosome visualization/quantification by electron microscopy and LC3-B marker turn-over assays were used to demonstrate autophagy induction and flux activation upon ALK inactivation. This was demonstrated to have a cytoprotective role on cell viability and clonogenic assays following combined ALK and autophagy inhibition. Altogether, our results suggest that co-treatment with crizotinib and chloroquine (two drugs already used in clinics) could be beneficial for ALK-positive ALCL patients.
Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/farmacologia , Autofagia/efeitos dos fármacos , Cloroquina/farmacologia , Linfoma Anaplásico de Células Grandes/tratamento farmacológico , Inibidores de Proteínas Quinases/farmacologia , Pirazóis/farmacologia , Piridinas/farmacologia , Receptores Proteína Tirosina Quinases/antagonistas & inibidores , Quinase do Linfoma Anaplásico , Animais , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Crizotinibe , Relação Dose-Resposta a Droga , Sinergismo Farmacológico , Feminino , Humanos , Linfoma Anaplásico de Células Grandes/enzimologia , Linfoma Anaplásico de Células Grandes/genética , Linfoma Anaplásico de Células Grandes/patologia , Camundongos Endogâmicos NOD , Camundongos SCID , Proteínas Associadas aos Microtúbulos/metabolismo , Interferência de RNA , Receptores Proteína Tirosina Quinases/genética , Receptores Proteína Tirosina Quinases/metabolismo , Transdução de Sinais/efeitos dos fármacos , Fatores de Tempo , Transfecção , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
LEOPARD syndrome (multiple Lentigines, Electrocardiographic conduction abnormalities, Ocular hypertelorism, Pulmonary stenosis, Abnormal genitalia, Retardation of growth, sensorineural Deafness; LS), also called Noonan syndrome with multiple lentigines (NSML), is a rare autosomal dominant disorder associating various developmental defects, notably cardiopathies, dysmorphism, and short stature. It is mainly caused by mutations of the PTPN11 gene that catalytically inactivate the tyrosine phosphatase SHP2 (Src-homology 2 domain-containing phosphatase 2). Besides its pleiotropic roles during development, SHP2 plays key functions in energetic metabolism regulation. However, the metabolic outcomes of LS mutations have never been examined. Therefore, we performed an extensive metabolic exploration of an original LS mouse model, expressing the T468M mutation of SHP2, frequently borne by LS patients. Our results reveal that, besides expected symptoms, LS animals display a strong reduction of adiposity and resistance to diet-induced obesity, associated with overall better metabolic profile. We provide evidence that LS mutant expression impairs adipogenesis, triggers energy expenditure, and enhances insulin signaling, three features that can contribute to the lean phenotype of LS mice. Interestingly, chronic treatment of LS mice with low doses of MEK inhibitor, but not rapamycin, resulted in weight and adiposity gains. Importantly, preliminary data in a French cohort of LS patients suggests that most of them have lower-than-average body mass index, associated, for tested patients, with reduced adiposity. Altogether, these findings unravel previously unidentified characteristics for LS, which could represent a metabolic benefit for patients, but may also participate to the development or worsening of some traits of the disease. Beyond LS, they also highlight a protective role of SHP2 global LS-mimicking modulation toward the development of obesity and associated disorders.
Assuntos
Dieta , Síndrome LEOPARD/genética , Obesidade/prevenção & controle , Proteína Tirosina Fosfatase não Receptora Tipo 11/genética , Magreza/genética , Adipócitos/citologia , Tecido Adiposo/metabolismo , Adiposidade , Animais , Composição Corporal , Diferenciação Celular , Modelos Animais de Doenças , Metabolismo Energético , Insulina/metabolismo , Lentivirus/metabolismo , Lipólise , MAP Quinase Quinase Quinase 1/antagonistas & inibidores , Masculino , Camundongos , Camundongos Transgênicos , Mutação , Fenótipo , Recombinação GenéticaRESUMO
Cancer-associated fibroblasts (CAF) comprise the majority of stromal cells in breast cancers, yet their precise origins and relative functional contributions to malignant progression remain uncertain. Local invasion leads to the proximity of cancer cells and adipocytes, which respond by phenotypical changes to generate fibroblast-like cells termed as adipocyte-derived fibroblasts (ADF) here. These cells exhibit enhanced secretion of fibronectin and collagen I, increased migratory/invasive abilities, and increased expression of the CAF marker FSP-1 but not α-SMA. Generation of the ADF phenotype depends on reactivation of the Wnt/ß-catenin pathway in response to Wnt3a secreted by tumor cells. Tumor cells cocultivated with ADFs in two-dimensional or spheroid culture display increased invasive capabilities. In clinical specimens of breast cancer, we confirmed the presence of this new stromal subpopulation. By defining a new stromal cell population, our results offer new opportunities for stroma-targeted therapies in breast cancer.