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1.
Commun Biol ; 7(1): 219, 2024 Feb 22.
Artigo em Inglês | MEDLINE | ID: mdl-38388698

RESUMO

Recent evidence suggests a role of sensory neurons expressing the sodium channel Nav1.8 on the energy homeostasis control. Using a murine diphtheria toxin ablation strategy and ad libitum and time-restricted feeding regimens of control or high-fat high-sugar diets, here we further explore the function of these neurons on food intake and on the regulation of gastrointestinal elements transmitting immune and nutrient sensing.The Nav1.8+ neuron ablation increases food intake in ad libitum and time-restricted feeding, and exacerbates daily body weight variations. Mice lacking Nav1.8+ neurons show impaired prandial regulation of gut hormone secretion and gut microbiota composition, and altered intestinal immunity.Our study demonstrates that Nav1.8+ neurons are required to control food intake and daily body weight changes, as well as to maintain physiological enteroendocrine and immune responses and the rhythmicity of the gut microbiota, which highlights the potential of Nav1.8+ neurons to restore energy balance in metabolic disorders.


Assuntos
Microbioma Gastrointestinal , Animais , Camundongos , Peso Corporal , Dieta Hiperlipídica , Ingestão de Alimentos/fisiologia , Microbioma Gastrointestinal/fisiologia , Células Receptoras Sensoriais/metabolismo
2.
Mol Nutr Food Res ; 68(3): e2300474, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38038153

RESUMO

SCOPE: Sensory neurons expressing the sodium channel Nav1.8 contain a repertoire of receptors for nutrient, hormonal, and inflammatory ligands. However, their function in key regulators of energy homeostasis control is not well understood and is completely unexplored in females. METHODS AND RESULTS: Mice lacking neurons expressing the sodium channel Nav1.8 were generated using an ablation strategy based on cre recombinase-mediated expression of diphtheria toxin fragment A (DTA) (Nav1.8-cre/DTA mice) to investigate whether these neurons modulate body weight, food intake, gut hormone secretion, gastrointestinal transit, and glucose tolerance in response to nutrient challenges in a sex-dependent manner. Male Nav1.8-cre/DTA mice show resistance to gain weight in response to high-fat high-sugar diet (HFHSD), whereas females lacking Nav1.8+ neurons have improved oral glucose tolerance accompanied by higher insulin levels and attenuated glucagon secretion after an oral glucose load. Female Nav1.8-cre/DTA mice also show higher fasting and postprandial glucagon like peptide-1 (GLP-1) levels with an increased number of GLP-1-positive cells. Finally, ablation of Nav1.8-expressing neurons accelerates the gastrointestinal transit in female mice under HFHSD. CONCLUSION: This data demonstrates sex-dependent differences in the Nav1.8-mediated regulation of energy metabolism, and provides new insights that may help in the design of sex-specific neuromodulation therapies for metabolic disorders induced by diets rich in fats and simple sugars.


Assuntos
Peptídeo 1 Semelhante ao Glucagon , Glucose , Camundongos , Masculino , Feminino , Animais , Peptídeo 1 Semelhante ao Glucagon/genética , Peptídeo 1 Semelhante ao Glucagon/metabolismo , Camundongos Obesos , Glucose/metabolismo , Células Receptoras Sensoriais/metabolismo , Dieta Hiperlipídica/efeitos adversos , Obesidade/metabolismo , Homeostase , Canais de Sódio , Insulina/metabolismo , Glicemia/metabolismo
3.
Anal Bioanal Chem ; 415(20): 4961-4971, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-37338567

RESUMO

Bile acids (BAs) are a complex class of metabolites that have been described as specific biomarkers of gut microbiota activity. The development of analytical methods allowing the quantification of an ample spectrum of BAs in different biological matrices is needed to enable a wider implementation of BAs as complementary measures in studies investigating the functional role of the gut microbiota. This work presents results from the validation of a targeted ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) method for the determination of 28 BAs and six sulfated BAs, covering primary, secondary, and conjugated BAs. The analysis of 73 urine and 20 feces samples was used to test the applicability of the method. Concentrations of BAs in human urine and murine feces were reported, ranging from 0.5 to 50 nmol/g creatinine and from 0.012 to 332 nmol/g, respectively. Seventy-nine percent of BAs present in human urine samples corresponded to secondary conjugated BAs, while 69% of BAs present in murine feces corresponded to primary conjugated BAs. Glycocholic acid sulfate (GCA-S) was the most abundant BA in human urine samples, while taurolithocholic acid was the lowest concentrated compound detected. In murine feces, the most abundant BAs were α-murocholic, deoxycholic, dehydrocholic, and ß-murocholic acids, while GCA-S was the lowest concentrated BA. The presented method is a non-invasive approach for the simultaneous assessment of BAs and sulfated BAs in urine and feces samples, and the results will serve as a knowledge base for future translational studies focusing on the role of the microbiota in health.


Assuntos
Ácidos e Sais Biliares , Espectrometria de Massas em Tandem , Humanos , Camundongos , Animais , Ácidos e Sais Biliares/análise , Espectrometria de Massas em Tandem/métodos , Sulfatos/análise , Cromatografia Líquida de Alta Pressão/métodos , Fezes/química
4.
Front Microbiol ; 13: 834622, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35903477

RESUMO

Increasing knowledge of the microbiome has led to significant advancements in the agrifood system. Case studies based on microbiome applications have been reported worldwide and, in this review, we have selected 14 success stories that showcase the importance of microbiome research in advancing the agrifood system. The selected case studies describe products, methodologies, applications, tools, and processes that created an economic and societal impact. Additionally, they cover a broad range of fields within the agrifood chain: the management of diseases and putative pathogens; the use of microorganism as soil fertilizers and plant strengtheners; the investigation of the microbial dynamics occurring during food fermentation; the presence of microorganisms and/or genes associated with hazards for animal and human health (e.g., mycotoxins, spoilage agents, or pathogens) in feeds, foods, and their processing environments; applications to improve HACCP systems; and the identification of novel probiotics and prebiotics to improve the animal gut microbiome or to prevent chronic non-communicable diseases in humans (e.g., obesity complications). The microbiomes of soil, plants, and animals are pivotal for ensuring human and environmental health and this review highlights the impact that microbiome applications have with this regard.

5.
Mol Neurobiol ; 58(10): 4959-4979, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34228269

RESUMO

Food addiction (FA) is characterized by behavioral and neurochemical changes linked to loss of food intake control. Gut microbiota may influence appetite and food intake via endocrine and neural routes. The gut microbiota is known to impact homeostatic energy mechanisms, but its role in regulating the reward system is less certain. We show that the administration of Bacteroides uniformis CECT 7771 (B. uniformis) in a rat FA model impacts on the brain reward response, ameliorating binge eating and decreasing anxiety-like behavior. These effects are mediated, at least in part, by changes in the levels of dopamine, serotonin, and noradrenaline in the nucleus accumbens and in the expression of dopamine D1 and D2 receptors in the prefrontal cortex and intestine. B. uniformis reverses the fasting-induced microbiota changes and increases the abundance of species linked to healthy metabolotypes. Our data indicate that microbiota-based interventions might help to control compulsive overeating by modulating the reward response.


Assuntos
Ansiedade/metabolismo , Bacteroides/metabolismo , Transtorno da Compulsão Alimentar/metabolismo , Encéfalo/metabolismo , Microbioma Gastrointestinal/fisiologia , Recompensa , Animais , Ansiedade/terapia , Bacteroides/isolamento & purificação , Transtorno da Compulsão Alimentar/terapia , Humanos , Recém-Nascido , Masculino , Microdiálise/métodos , Ratos , Ratos Endogâmicos WKY
6.
Int J Mol Sci ; 22(11)2021 May 29.
Artigo em Inglês | MEDLINE | ID: mdl-34072450

RESUMO

Obesity currently represents a major societal and health challenge worldwide. Its prevalence has reached epidemic proportions and trends continue to rise, reflecting the need for more effective preventive measures. Hypothalamic circuits that control energy homeostasis in response to food intake are interesting targets for body-weight management, for example, through interventions that reinforce the gut-to-brain nutrient signalling, whose malfunction contributes to obesity. Gut microbiota-diet interactions might interfere in nutrient sensing and signalling from the gut to the brain, where the information is processed to control energy homeostasis. This gut microbiota-brain crosstalk is mediated by metabolites, mainly short chain fatty acids, secondary bile acids or amino acids-derived metabolites and subcellular bacterial components. These activate gut-endocrine and/or neural-mediated pathways or pass to systemic circulation and then reach the brain. Feeding time and dietary composition are the main drivers of the gut microbiota structure and function. Therefore, aberrant feeding patterns or unhealthy diets might alter gut microbiota-diet interactions and modify nutrient availability and/or microbial ligands transmitting information from the gut to the brain in response to food intake, thus impairing energy homeostasis. Herein, we update the scientific evidence supporting that gut microbiota is a source of novel dietary and non-dietary biological products that may beneficially regulate gut-to-brain communication and, thus, improve metabolic health. Additionally, we evaluate how the feeding time and dietary composition modulate the gut microbiota and, thereby, the intraluminal availability of these biological products with potential effects on energy homeostasis. The review also identifies knowledge gaps and the advances required to clinically apply microbiome-based strategies to improve the gut-brain axis function and, thus, combat obesity.


Assuntos
Encéfalo/fisiologia , Metabolismo Energético , Microbioma Gastrointestinal/fisiologia , Trato Gastrointestinal/fisiologia , Homeostase , Microbiota/fisiologia , Ritmo Circadiano , Dieta , Suscetibilidade a Doenças , Ingestão de Alimentos , Comportamento Alimentar , Humanos , Micronutrientes , Nutrientes , Obesidade/etiologia , Obesidade/metabolismo
7.
FASEB J ; 35(7): e21734, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-34143451

RESUMO

Impaired glucose homeostasis in obesity is mitigated by enhancing the glucoregulatory actions of glucagon-like peptide 1 (GLP-1), and thus, strategies that improve GLP-1 sensitivity and secretion have therapeutic potential for the treatment of type 2 diabetes. This study shows that Holdemanella biformis, isolated from the feces of a metabolically healthy volunteer, ameliorates hyperglycemia, improves oral glucose tolerance and restores gluconeogenesis and insulin signaling in the liver of obese mice. These effects were associated with the ability of H. biformis to restore GLP-1 levels, enhancing GLP-1 neural signaling in the proximal and distal small intestine and GLP-1 sensitivity of vagal sensory neurons, and to modify the cecal abundance of unsaturated fatty acids and the bacterial species associated with metabolic health. Our findings overall suggest the potential use of H biformis in the management of type 2 diabetes in obesity to optimize the sensitivity and function of the GLP-1 system, through direct and indirect mechanisms.


Assuntos
Diabetes Mellitus Tipo 2/metabolismo , Diabetes Mellitus Tipo 2/microbiologia , Firmicutes/fisiologia , Peptídeo 1 Semelhante ao Glucagon/metabolismo , Camundongos Obesos/metabolismo , Camundongos Obesos/microbiologia , Animais , Glicemia/metabolismo , Modelos Animais de Doenças , Gluconeogênese/fisiologia , Glucose/metabolismo , Teste de Tolerância a Glucose/métodos , Hiperglicemia/metabolismo , Insulina/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Obesidade/metabolismo , Obesidade/microbiologia
8.
Sci Rep ; 11(1): 11788, 2021 06 03.
Artigo em Inglês | MEDLINE | ID: mdl-34083551

RESUMO

This study investigated the immune mechanisms whereby administration of Bacteroides uniformis CECT 7771 reduces metabolic dysfunction in obesity. C57BL/6 adult male mice were fed a standard diet or a Western diet high in fat and fructose, supplemented or not with B. uniformis CECT 7771 for 14 weeks. B. uniformis CECT 7771 reduced body weight gain, plasma cholesterol, triglyceride, glucose, and leptin levels; and improved oral glucose tolerance in obese mice. Moreover, B. uniformis CECT 7771 modulated the gut microbiota and immune alterations associated with obesity, increasing Tregs and reducing B cells, total macrophages and the M1/M2 ratio in both the gut and epididymal adipose tissue (EAT) of obese mice. B. uniformis CECT 7771 also increased the concentration of the anti-inflammatory cytokine IL-10 in the gut, EAT and peripheral blood, and protective cytokines TSLP and IL-33, involved in Treg induction and type 2 innate lymphoid cells activation, in the EAT. It also restored the obesity-reduced TLR5 expression in the ileum and EAT. The findings indicate that the administration of a human intestinal bacterium with immunoregulatory properties on the intestinal mucosa helps reverse the immuno-metabolic dysfunction caused by a Western diet acting over the gut-adipose tissue axis.


Assuntos
Infecções por Bacteroides/metabolismo , Infecções por Bacteroides/microbiologia , Bacteroides/fisiologia , Gastroenterite/metabolismo , Gastroenterite/microbiologia , Transdução de Sinais , Receptor 5 Toll-Like/metabolismo , Imunidade Adaptativa , Tecido Adiposo/metabolismo , Animais , Infecções por Bacteroides/patologia , Citocinas/metabolismo , Modelos Animais de Doenças , Metabolismo Energético , Gastroenterite/patologia , Microbioma Gastrointestinal , Imunidade Inata , Mediadores da Inflamação/metabolismo , Camundongos , Camundongos Obesos , Fenótipo
9.
Best Pract Res Clin Endocrinol Metab ; 35(3): 101542, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-33980476

RESUMO

Obesity has reached epidemic proportions and is associated with chronic-low-grade inflammation and metabolic morbidities. Energy-dense diets and a sedentary lifestyle are determinants of obesity. The gut microbiome is a novel biological factor involved in obesity via interactions with the host and the diet. The gut microbiome act as a synergistic force protecting or aggravating the effects of the diet on the metabolic phenotype. The role of the microbiome in the regulation of intestinal and systemic immunity is one of the mechanisms by which it contributes to the host's response to the diet and to the pathophysiology of diet-induced obesity. Here, we review the mechanisms whereby "obesogenic" diets and the microbiome impact immunity, locally and systemically, focusing on the consequences in the gut-adipose tissue axis. We also review the structural and microbial metabolites that influence immunity and how advances in this field could help design microbiome-informed strategies to tackle obesity-related disorders more effectively.


Assuntos
Microbioma Gastrointestinal , Doenças Metabólicas , Dieta , Humanos , Fatores Imunológicos , Doenças Metabólicas/etiologia , Obesidade
10.
Gut Microbes ; 13(1): 1-20, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33499721

RESUMO

Gut microbiota represents a therapeutic target for obesity. We hypothesize that B. uniformis CECT 7771 combined with wheat bran extract (WBE), its preferred carbon source, may exert superior anti-obesity effects. We performed a 17-week intervention in diet-induced obese mice receiving either B. uniformis, WBE, or their combination to identify interactions and independent actions on metabolism and immunity. B. uniformis combined with WBE was the most effective intervention, curbing weight gain and adiposity, while exerting more modest effects separately. The combination restored insulin-dependent metabolic routes in fat and liver, although the bacterium was the primary driver for improving whole-body glucose disposal. Moreover, B. uniformis-combined with WBE caused the highest increases in butyrate and restored the proportion of induced intraepithelial lymphocytes and type-3 innate lymphoid cells in the intestinal epithelium. Thus, strengthening the first line of immune defense against unhealthy diets and associated dysbiosis in the intestine. This intervention also attenuated the altered IL22 signaling and liver inflammation. Our study shows opportunities for employing B. uniformis, combined with WBE, to aid in the treatment of obesity.


Assuntos
Bacteroides , Fibras na Dieta , Obesidade/dietoterapia , Tecido Adiposo/metabolismo , Animais , Ceco/metabolismo , Ceco/microbiologia , Dieta Hiperlipídica/efeitos adversos , Epididimo/metabolismo , Ácidos Graxos/metabolismo , Microbioma Gastrointestinal , Inflamação , Insulina/metabolismo , Interleucinas/metabolismo , Mucosa Intestinal/imunologia , Fígado/metabolismo , Linfócitos/metabolismo , Masculino , Camundongos , Obesidade/etiologia , Obesidade/imunologia , Obesidade/metabolismo , Transdução de Sinais , Termogênese , Aumento de Peso
11.
Clin Nutr ; 39(2): 414-424, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-30904186

RESUMO

The aim of EU project MyNewGut is to contribute to future public health-related recommendations supported by new insight in gut microbiome and nutrition-host relationship. In this Opinion Paper, we first revisit the concept of dietary fiber, taking into account their interaction with the gut microbiota. This paper also summarizes the main effects of dietary fibers with prebiotic properties in intervention studies in humans, with a particular emphasis on the effects of arabinoxylans and arabinoxylo-oligosaccharides on metabolic alterations associated with obesity. Based on the existing state of the art and future development, we elaborate the steps required to propose dietary guidelines related to dietary fibers, taking into account their interaction with the gut microbiota.


Assuntos
Fibras na Dieta/uso terapêutico , Microbioma Gastrointestinal/efeitos dos fármacos , Estado Nutricional , Obesidade/dietoterapia , Prebióticos/administração & dosagem , Humanos , Obesidade/microbiologia
12.
Clin Nutr ; 38(6): 2504-2520, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-30655101

RESUMO

BACKGROUND AND AIMS: Studies indicate that dietary fat quantity and quality influence the gut microbiota composition which may as a consequence impact metabolic health. This systematic review aims to summarize the results of available studies in humans on dietary fat intake (quantity and quality), the intestinal microbiota composition and related cardiometabolic health outcomes. METHODS: We performed a systematic review (CRD42018088685) following PRISMA guidelines and searched for literature in Medline, EMBASE, and Cochrane databases. RESULTS: From 796 records, 765 records were excluded based on title or abstract. After screening of 31 full-text articles six randomized controlled trials (RCT) and nine cross-sectional observational studies were included. Our results of interventional trials do not suggest strong effects of different amounts and types of dietary fat on the intestinal microbiota composition or on metabolic health outcomes while observational studies indicate associations with the microbiota and health outcomes. High intake of fat and saturated fatty acids (SFA) may negatively affect microbiota richness and diversity and diets high in monounsaturated fatty acids (MUFA) may decrease total bacterial numbers whereas dietary polyunsaturated fatty acids (PUFA) had no effect on richness and diversity. CONCLUSIONS: High fat and high SFA diets can exert unfavorable effects on the gut microbiota and are associated with an unhealthy metabolic state. Also high MUFA diets may negatively affect gut microbiota whereas PUFA do not seem to negatively affect the gut microbiota or metabolic health outcomes. However, data are not consistent and most RCT and observational studies showed risks of bias.


Assuntos
Dieta , Gorduras na Dieta , Microbioma Gastrointestinal/fisiologia , Adulto , Idoso , Dieta/métodos , Dieta/estatística & dados numéricos , Humanos , Masculino , Pessoa de Meia-Idade , Adulto Jovem
13.
Clin Nutr ; 37(6 Pt A): 2191-2197, 2018 12.
Artigo em Inglês | MEDLINE | ID: mdl-30033172

RESUMO

The gut microbiota coexists in partnership with the human host through adaptations to environmental and physiological changes that help maintain dynamic homeostatic healthy states. Break-down of this delicate balance under sustained exposure to stressors (e.g. unhealthy diets) can, however, contribute to the onset of disease. Diet is a key modifiable environmental factor that modulates the gut microbiota and its metabolic capacities that, in turn, could impact human physiology. On this basis, the diet and the gut microbiota could act as synergistic forces that provide resilience against disease or that speed the progress from health to disease states. Associations between unhealthy dietary patterns, non-communicable diseases and intestinal dysbiosis can be explained by this hypothesis. Translational studies showing that dietary-induced alterations in microbial communities recapitulate some of the pathological features of the original host further support this notion. In this introductory paper by the European project MyNewGut, we briefly summarize the investigations conducted to better understand the role of dietary patterns and food components in metabolic and mental health and the specificities of the microbiome-mediating mechanisms. We also discuss how advances in the understanding of the microbiome's role in dietary health effects can help to provide acceptable scientific grounds on which to base dietary advice for promoting healthy living.


Assuntos
Dieta , Microbioma Gastrointestinal , Saúde Mental , Metabolismo , Animais , Humanos , Camundongos
14.
Front Neurosci ; 12: 155, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29615850

RESUMO

Obesity continues to be one of the major public health problems due to its high prevalence and co-morbidities. Common co-morbidities not only include cardiometabolic disorders but also mood and cognitive disorders. Obese subjects often show deficits in memory, learning and executive functions compared to normal weight subjects. Epidemiological studies also indicate that obesity is associated with a higher risk of developing depression and anxiety, and vice versa. These associations between pathologies that presumably have different etiologies suggest shared pathological mechanisms. Gut microbiota is a mediating factor between the environmental pressures (e.g., diet, lifestyle) and host physiology, and its alteration could partly explain the cross-link between those pathologies. Westernized dietary patterns are known to be a major cause of the obesity epidemic, which also promotes a dysbiotic drift in the gut microbiota; this, in turn, seems to contribute to obesity-related complications. Experimental studies in animal models and, to a lesser extent, in humans suggest that the obesity-associated microbiota may contribute to the endocrine, neurochemical and inflammatory alterations underlying obesity and its comorbidities. These include dysregulation of the HPA-axis with overproduction of glucocorticoids, alterations in levels of neuroactive metabolites (e.g., neurotransmitters, short-chain fatty acids) and activation of a pro-inflammatory milieu that can cause neuro-inflammation. This review updates current knowledge about the role and mode of action of the gut microbiota in the cross-link between energy metabolism, mood and cognitive function.

15.
Curr Opin Clin Nutr Metab Care ; 20(6): 484-491, 2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-28862999

RESUMO

PURPOSE OF REVIEW: Update on the development of microbiome-based interventions and dietary supplements to combat obesity and related comorbidities, which are leading causes of global mortality. RECENT FINDINGS: The role of intestinal dysbiosis, partly resulting from unhealthy diets, in the development of obesity and metabolic disorders, is well documented by recent translational research. Human experimental trials with whole-faecal transplants are ongoing, and their results will be crucial as proof of concept that interventions intended to modulate the microbiome composition and function could be alternatives for the management of obesity and related comorbidities. Potential next-generation probiotic bacteria (Akkermansia, Bacteroides spp., Eubacterium halli) and microbiota-derived molecules (e.g. membrane proteins, short-chain fatty acids) are being evaluated in preclinical and clinical trials to promote the development of innovative dietary supplements. The fact that live or inactivated bacteria and their products can regulate pathways that increase energy expenditure, and reduce energy intake, and absorption and systemic inflammation make them attractive research targets from a nutritional and clinical perspective. SUMMARY: Understanding which are the beneficial bacteria and their bioactive products is helping us to envisage innovative microbiome-based dietary interventions to tackle obesity. Advances will likely result from future refinements of these strategies according to the individual's microbiome configuration and its particular response to interventions, thereby progressing towards personalized nutrition.


Assuntos
Dieta , Microbioma Gastrointestinal , Probióticos , Animais , Bacteroides , Gerenciamento Clínico , Modelos Animais de Doenças , Eubacterium , Ácidos Graxos Voláteis/metabolismo , Trato Gastrointestinal/microbiologia , Humanos , Proteínas de Membrana/metabolismo , Obesidade/terapia
16.
Endocrinology ; 156(11): 4226-37, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-26252058

RESUMO

Control of estrous cycle and reproductive capacity involves a large number of central and peripheral factors, integrating numerous nutritional and metabolic signals. Here we show that glucagon-like peptide-1 (GLP-1), a peptide with anorexigenic and insulinotropic actions, and the GLP-1 receptor agonist Exendin-4 (Ex4) exert a regulatory influence on the gonadal axis, in both adult and prepubertal female rats. In adult rats, Glp-1 receptor expression varies during the estrous cycle at the hypothalamus, pituitary, and ovary. Furthermore, acute treatment with GLP-1 in the morning proestrus doubled the amplitude of the preovulatory LH surge, as well as influencing estradiol and progesterone levels along the estrous cycle. These changes provoked an important increase in the number of Graafian follicles and corpora lutea, as well as in the litter size. Conversely, Ex4 diminished the levels of LH, later producing a partial blockade at the preovulatory surge, yet not affecting either the number of mature follicles or corpora lutea. Chronic administration of low doses of GLP-1 to prepubertal rats synchronized vaginal opening and increased LH levels on the 35th day of life, yet at these doses it did not modify their body weight, food intake, or ovarian and uterine weight. By contrast, chronic exposure to Ex4 produced a significant reduction in ovarian and uterine weight, and serum LH, and the animals treated chronically with Ex4 showed no vaginal opening in the period studied. Overall, our results demonstrate that GLP-1 and Ex4 act on the gonadal axis, involving the hypothalamic kisspeptin system, to influence reproductive efficiency in female rats.


Assuntos
Peptídeo 1 Semelhante ao Glucagon/farmacologia , Hormônio Luteinizante/sangue , Folículo Ovariano/efeitos dos fármacos , Hipófise/efeitos dos fármacos , Maturidade Sexual/efeitos dos fármacos , Animais , Estradiol/sangue , Ciclo Estral/sangue , Ciclo Estral/efeitos dos fármacos , Exenatida , Feminino , Hormônio Foliculoestimulante/sangue , Receptor do Peptídeo Semelhante ao Glucagon 1/genética , Receptor do Peptídeo Semelhante ao Glucagon 1/metabolismo , Kisspeptinas/genética , Kisspeptinas/metabolismo , Folículo Ovariano/citologia , Peptídeos/farmacologia , Hipófise/metabolismo , Ratos , Ratos Sprague-Dawley , Receptores Acoplados a Proteínas G/genética , Receptores Acoplados a Proteínas G/metabolismo , Receptores de Kisspeptina-1 , Peçonhas/farmacologia
17.
Endocrinology ; 156(10): 3559-69, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26196539

RESUMO

Diabetes alters microvascular function in the vascular beds of organs, including the lungs. Cardiovascular complications of pulmonary vascular affectation may be a consequence of the overactivation of the vasoconstrictive and proliferative components of the renin-angiotensin system. We previously reported that pulmonary physiology and surfactant production is improved by the glucagon-like peptide 1 receptor (GLP-1R) agonist liraglutide (LIR) in a rat model of lung hypoplasia. Because we hypothesized that streptozotocin-induced diabetes rats would show deficiencies in lung function, including surfactant proteins, and develop an imbalance of the renin-angiotensin system in the lungs. This effect would in turn be prevented by long-acting agonists of the GLP-1R, such as LIR. The induction of diabetes reduced the surfactant protein A and B in the lungs and caused the vasoconstrictor component of the renin-angiotensin system to predominate, which in turn increased angiotensin II levels, and ultimately being associated with right ventricle hypertrophy. LIR restored surfactant protein levels and reversed the imbalance in the renin-angiotensin system in this type 1 diabetes mellitus rat model. Moreover, LIR provoked a strong increase in angiotensin-converting enzyme 2 expression in the lungs of both diabetic and control rats, and in the circulating angiotensin(1-7) in diabetic animals. These effects prompted complete reversion of right ventricle hypertrophy. The consequences of LIR administration were independent of glycemic control and of glucocorticoids, and they involved NK2 homeobox 1 signaling. This study demonstrates by first time that GLP-1R agonists, such as LIR, might improve the cardiopulmonary complications associated with diabetes.


Assuntos
Diabetes Mellitus Tipo 1/metabolismo , Receptor do Peptídeo Semelhante ao Glucagon 1/metabolismo , Liraglutida/uso terapêutico , Peptidil Dipeptidase A/metabolismo , Proteína A Associada a Surfactante Pulmonar/metabolismo , Proteína B Associada a Surfactante Pulmonar/metabolismo , Angiografia , Enzima de Conversão de Angiotensina 2 , Animais , Diabetes Mellitus Experimental/metabolismo , Modelos Animais de Doenças , Regulação da Expressão Gênica , Hipertrofia Ventricular Direita/metabolismo , Insulina/metabolismo , Pulmão/metabolismo , Pulmão/patologia , Masculino , Ratos , Ratos Sprague-Dawley , Tensoativos/química
18.
Endocrinology ; 155(7): 2511-23, 2014 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-24731096

RESUMO

Glucagon-like peptide-1 (GLP-1) and the GLP-1 receptor agonist, exendin-4 (Ex-4), potently stimulate hypothalamic-pituitary-adrenal (HPA) axis activity after either central or peripheral administration. Because several GLP-1 derivative drugs, including synthetic Ex-4, are currently in use to treat patients with type II diabetes mellitus, the characterization of Ex-4 effects on the HPA axis is highly relevant. Herein, the roles of CRH and AVP on these effects were investigated by administering the antagonists astressin and d(CH2)5Tyr(Me)AVP, respectively. The role of the sympathoadrenal system (SAS) was explored in bilateral adrenal enucleated and guanethidine-treated rats, whereas primary pituitary cell cultures were used to study direct effects on the corticotropes. Astressin completely abrogated (P < .05) the effects of Ex-4 central administration on ACTH secretion but only slightly reduced (by 35%) the ACTH response to Ex-4 peripheral administration. Moreover, astressin significantly (P < .05) decreased the corticosterone response to centrally but not peripherally administered Ex-4, suggesting different mechanisms depending on the route of administration. Pretreatment with d(CH2)5Tyr(Me)AVP failed to diminish either the ACTH or corticosterone response to Ex-4 and no direct effect of Ex-4 or GLP-1 was observed on pituitary cell cultures. In contrast, a significant (P < .05) reduction in the corticosterone response elicited by Ex-4 peripheral administration was observed in enucleated and guanethidine-treated rats, indicating a role of the SAS in the glucocorticoid stimulatory effects of Ex-4. Our data demonstrate that the effects of Ex-4 on the HPA axis are partially mediated by CRH and the sympathoadrenal system, and stress the relevance of Ex-4 as a corticosterone secretagogue.


Assuntos
Glândulas Suprarrenais/fisiologia , Hormônio Liberador da Corticotropina/farmacologia , Sistema Hipotálamo-Hipofisário/efeitos dos fármacos , Peptídeos/farmacologia , Sistema Hipófise-Suprarrenal/efeitos dos fármacos , Sistema Nervoso Simpático/fisiologia , Peçonhas/farmacologia , Hormônio Adrenocorticotrópico/sangue , Hormônio Adrenocorticotrópico/metabolismo , Animais , Arginina Vasopressina/análogos & derivados , Arginina Vasopressina/farmacologia , Células Cultivadas , Corticosterona/sangue , Corticosterona/metabolismo , Corticotrofos/efeitos dos fármacos , Corticotrofos/metabolismo , Hormônio Liberador da Corticotropina/antagonistas & inibidores , Exenatida , Peptídeo 1 Semelhante ao Glucagon/farmacologia , Guanetidina/farmacologia , Sistema Hipotálamo-Hipofisário/fisiologia , Masculino , Fragmentos de Peptídeos/farmacologia , Sistema Hipófise-Suprarrenal/fisiologia , Ratos , Ratos Sprague-Dawley , Receptores de Hormônio Liberador da Corticotropina/metabolismo , Fatores de Tempo
19.
Am J Physiol Endocrinol Metab ; 304(10): E1105-17, 2013 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-23531615

RESUMO

Exendin-4 (Ex-4) is a natural agonist of the glucagon-like peptide-1 (GLP-1) receptor, currently being used as a treatment for type 2 diabetes mellitus due to its insulinotropic properties. Previous studies have revealed that acute administration of both GLP-1 and, in particular, Ex-4 potently stimulates hypothalamic-pituitary-adrenal (HPA) axis activity. In this work, the effects of prolonged Ex-4 exposure on HPA function were explored. To this end, Sprague-Dawley rats were subjected to a daily regimen of two Ex-4 injections (5 µg/kg sc) for a minimum of 7 days. We found that subchronic Ex-4 administration produced a number of effects that resemble chronic stress situations, including hyperactivation of the HPA axis during the trough hours, disruption of glucocorticoid circadian secretion, hypertrophy of the adrenal gland, decreased adrenal gland sensitivity, impaired pituitary-adrenal stress responses, and reductions in both food intake and body weight. In addition, a threefold increase in diuresis was observed followed by a 1.5-fold increase in water intake; these latter effects were abolished by adrenalectomy. Together, these findings indicate that Ex-4 induces a profound dysregulation of HPA axis activity that may also affect renal function.


Assuntos
Glândulas Suprarrenais/efeitos dos fármacos , Sistema Hipotálamo-Hipofisário/efeitos dos fármacos , Peptídeos/farmacologia , Sistema Hipófise-Suprarrenal/efeitos dos fármacos , Peçonhas/farmacologia , Equilíbrio Hidroeletrolítico/efeitos dos fármacos , Glândulas Suprarrenais/fisiologia , Hormônio Adrenocorticotrópico/sangue , Animais , Peso Corporal/fisiologia , Ritmo Circadiano/fisiologia , Corticosterona/sangue , Ingestão de Alimentos/fisiologia , Exenatida , Peptídeo 1 Semelhante ao Glucagon/agonistas , Peptídeo 1 Semelhante ao Glucagon/metabolismo , Sistema Hipotálamo-Hipofisário/fisiologia , Masculino , Sistema Hipófise-Suprarrenal/fisiologia , Ratos , Ratos Sprague-Dawley , Estresse Fisiológico/fisiologia
20.
Endocrinology ; 154(3): 1144-55, 2013 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-23354098

RESUMO

The glucagon-like peptide-1 receptor (GLP-1R) is found in a variety of tissues outside of the pancreas. For example, GLP-1R is expressed in the lung, where it has been implicated in the regulation of the lipid fraction of surfactants, suggesting it fulfills an important role in lung function. Here, we show that GLP-1R expression is strongly up-regulated immediately after birth in neonatal rats, particular in male offspring. Moreover, administering long half-life GLP-1R agonists to the mother from gestational day 14 to birth (exendin-4 or liraglutide) increased surfactant protein (SP)-A and SP-B mRNA expression and the amount of SPs in the amniotic fluid at the end of pregnancy. These effects were similar or more potent to those induced by the glucocorticoid dexamethasone, which also increased GLP-1R expression in fetuses just before delivery. Lir increased fetal SP-A and GLP-1R expression in control rats and in a nitrofen-induced model of lung hypoplasia. Moreover, lung size increased in controls after Lir administration, which also prevented the decrease in lung weight and the poor neonatal survival of the offspring from nitrofen-treated dams, effects that were not produced by dexamethasone. Taken together, our results demonstrate the importance of the GLP-1 system in regulating SP production and lung development.


Assuntos
Pulmão/metabolismo , Proteínas Associadas a Surfactantes Pulmonares/metabolismo , Receptores de Glucagon/agonistas , Receptores de Glucagon/metabolismo , Animais , Animais Recém-Nascidos , Dexametasona/farmacologia , Exenatida , Feminino , Feto/efeitos dos fármacos , Feto/metabolismo , Peptídeo 1 Semelhante ao Glucagon/análogos & derivados , Peptídeo 1 Semelhante ao Glucagon/farmacologia , Receptor do Peptídeo Semelhante ao Glucagon 1 , Liraglutida , Pulmão/efeitos dos fármacos , Pulmão/crescimento & desenvolvimento , Pulmão/patologia , Masculino , Peptídeos/farmacologia , Éteres Fenílicos/toxicidade , Gravidez , Proteína A Associada a Surfactante Pulmonar/genética , Proteína A Associada a Surfactante Pulmonar/metabolismo , Proteína B Associada a Surfactante Pulmonar/genética , Proteína B Associada a Surfactante Pulmonar/metabolismo , Proteínas Associadas a Surfactantes Pulmonares/genética , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Ratos , Ratos Sprague-Dawley , Receptores de Glucagon/genética , Regulação para Cima/efeitos dos fármacos , Peçonhas/farmacologia
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