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1.
PLoS One ; 15(9): e0238465, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32903269

RESUMO

A negative energy balance (NEB) is detrimental to reproduction in animals. A suggested link between NEB and reproductive failure is the gastrointestinal hormone ghrelin, because of the association between ghrelin and the hypothalamo-pituitary-gonadal axis. The [D-Lys3]-Growth Hormone Releasing Peptide-6 ([D-Lys3]-GHRP-6) is a ghrelin antagonist that acts on ghrelin receptors (GHS-R1). The objective of this study was to evaluate the effect of [D-Lys3]-GHRP-6 on reproduction variables in feed restricted ewes. Two experiments were conducted. Experiment I was conducted for 30 days; and Experiment II for 13 days. In both experiments the ewes (n = 18) were randomly assigned to: Control (CO): fed to meet maintenance requirements; Feed restriction (FR): 80% of maintenance restriction; or Ghrelin antagonist (GA): feed restricted and daily subcutaneous of 7.5µg/kg of [D-Lys3]-GHRP-6. Plasma was collected to measure hormones and metabolite concentration. In Experiment II, the hypothalamus and ovaries were collected on day 13. In both Experiments, sheep allocated to the FR and GA treatments decreased their body weight compared with sheep in the CO group (P < 0.06); progesterone however, did not differ between treatments (P > 0.10). Experiment I: Plasma ghrelin concentration was greater (P < 0.01) in FR and GA compared with CO ewes. Plasma non-esterified fatty acids concentration was greater (P < 0.01) in GA and FR than CO. Experiment II: Kisspeptin1-Receptor (Kiss1-R) mRNA expression was greater in FR (P < 0.01) and tended to be greater in GA (P = 0.10) compared with CO ewes. The neuro peptide-Y (NPY) mRNA expression was greater (P = 0.03) in FR than CO; and tended to be greater (P = 0.06) compared with GA ewes. Growth hormone releasing hormone (GhRH) mRNA expression was greater in GA (P = 0.04) and tended to be greater in FR (P = 0.07) compared with CO ewes. Feed restriction increased GhRH, NPY, and Kiss-R mRNA expression in hypothalamus without affecting reproductive variables.Ghrelin antagonist may prevent an increase inNPY expression in ewes.


Assuntos
Grelina/metabolismo , Oligopeptídeos/farmacologia , Reprodução/efeitos dos fármacos , Animais , Peso Corporal , Feminino , Grelina/antagonistas & inibidores , Hormônio do Crescimento/metabolismo , Hormônio Liberador de Hormônio do Crescimento/metabolismo , Hipotálamo/metabolismo , Neuropeptídeo Y/metabolismo , Oligopeptídeos/metabolismo , RNA Mensageiro/metabolismo , Receptores de Grelina/metabolismo , Ovinos/genética
2.
Nat Commun ; 11(1): 4360, 2020 08 31.
Artigo em Inglês | MEDLINE | ID: mdl-32868762

RESUMO

The hypothalamus is a central regulator of many innate behaviors essential for survival, but the molecular mechanisms controlling hypothalamic patterning and cell fate specification are poorly understood. To identify genes that control hypothalamic development, we have used single-cell RNA sequencing (scRNA-Seq) to profile mouse hypothalamic gene expression across 12 developmental time points between embryonic day 10 and postnatal day 45. This identified genes that delineated clear developmental trajectories for all major hypothalamic cell types, and readily distinguished major regional subdivisions of the developing hypothalamus. By using our developmental dataset, we were able to rapidly annotate previously unidentified clusters from existing scRNA-Seq datasets collected during development and to identify the developmental origins of major neuronal populations of the ventromedial hypothalamus. We further show that our approach can rapidly and comprehensively characterize mutants that have altered hypothalamic patterning, identifying Nkx2.1 as a negative regulator of prethalamic identity. These data serve as a resource for further studies of hypothalamic development, physiology, and dysfunction.


Assuntos
Diferenciação Celular , Hipotálamo , Neurônios/metabolismo , Fator Nuclear 1 de Tireoide/metabolismo , Animais , Sequência de Bases , Padronização Corporal , Regulação da Expressão Gênica no Desenvolvimento , Hipotálamo/citologia , Hipotálamo/embriologia , Hipotálamo/crescimento & desenvolvimento , Hipotálamo/metabolismo , Camundongos , Mutação , Análise de Célula Única , Fator Nuclear 1 de Tireoide/genética
3.
Life Sci ; 259: 118229, 2020 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-32781065

RESUMO

AIMS: Cholinergic neurons are distributed in brain areas containing growth hormone (GH)-responsive cells. We determined if cholinergic neurons are directly responsive to GH and the metabolic consequences of deleting the GH receptor (GHR) specifically in choline acetyltransferase (ChAT)-expressing cells. MAIN METHODS: Mice received an acute injection of GH to detect neurons co-expressing ChAT and phosphorylated STAT5 (pSTAT5), a well-established marker of GH-responsive cells. For the physiological studies, mice carrying ablation of GHR exclusively in ChAT-expressing cells were produced and possible changes in energy and glucose homeostasis were determined when consuming regular chow or high-fat diet (HFD). KEY FINDINGS: The majority of cholinergic neurons in the arcuate nucleus (60%) and dorsomedial nucleus (84%) of the hypothalamus are directly responsive to GH. Approximately 34% of pre-ganglionic parasympathetic neurons in the dorsal motor nucleus of the vagus also exhibited GH-induced pSTAT5. GH-induced pSTAT5 in these ChAT neurons was absent in GHR ChAT knockout mice. Mice carrying ChAT-specific GHR deletion, either in chow or HFD, did not exhibit significant changes in body weight, body adiposity, lean body mass, food intake, energy expenditure, respiratory quotient, ambulatory activity, serum leptin levels, glucose tolerance, insulin sensitivity and metabolic responses to 2-deoxy-d-glucose. However, GHR deletion in ChAT neurons caused decreased hypothalamic Pomc mRNA levels in HFD mice. SIGNIFICANCE: Cholinergic neurons that regulate the metabolism are directly responsive to GH, although GHR signaling in these cells is not required for energy and glucose homeostasis. Thus, the physiological importance of GH action on cholinergic neurons still needs to be identified.


Assuntos
Neurônios Colinérgicos/metabolismo , Hormônio do Crescimento/metabolismo , Receptores da Somatotropina/metabolismo , Acetilcolina/metabolismo , Animais , Núcleo Arqueado do Hipotálamo/metabolismo , Peso Corporal , Colina O-Acetiltransferase/genética , Colina O-Acetiltransferase/metabolismo , Neurônios Colinérgicos/efeitos dos fármacos , Dieta Hiperlipídica , Metabolismo Energético , Glucose/metabolismo , Hormônio do Crescimento/fisiologia , Hipotálamo/metabolismo , Resistência à Insulina/genética , Leptina/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Receptores da Somatotropina/genética , Fator de Transcrição STAT5/metabolismo , Nervo Vago/metabolismo
4.
Proc Natl Acad Sci U S A ; 117(33): 20149-20158, 2020 08 18.
Artigo em Inglês | MEDLINE | ID: mdl-32747560

RESUMO

The C2 domain containing protein extended synaptotagmin (E-Syt) plays important roles in both lipid homeostasis and the intracellular signaling; however, its role in physiology remains largely unknown. Here, we show that hypothalamic E-Syt3 plays a critical role in diet-induced obesity (DIO). E-Syt3 is characteristically expressed in the hypothalamic nuclei. Whole-body or proopiomelanocortin (POMC) neuron-specific ablation of E-Syt3 ameliorated DIO and related comorbidities, including glucose intolerance and dyslipidemia. Conversely, overexpression of E-Syt3 in the arcuate nucleus moderately promoted food intake and impaired energy expenditure, leading to increased weight gain. Mechanistically, E-Syt3 ablation led to increased processing of POMC to α-melanocyte-stimulating hormone (α-MSH), increased activities of protein kinase C and activator protein-1, and enhanced expression of prohormone convertases. These findings reveal a previously unappreciated role for hypothalamic E-Syt3 in DIO and related metabolic disorders.


Assuntos
Regulação da Expressão Gênica/fisiologia , Obesidade/induzido quimicamente , Obesidade/genética , Sinaptotagminas/metabolismo , Animais , Dieta Hiperlipídica/efeitos adversos , Predisposição Genética para Doença , Hipotálamo/metabolismo , Masculino , Camundongos , Camundongos Knockout , Neurônios/metabolismo , Pró-Proteína Convertase 1/genética , Pró-Proteína Convertase 1/metabolismo , Pró-Proteína Convertase 2/genética , Pró-Proteína Convertase 2/metabolismo , Sinaptotagminas/genética
5.
Nat Commun ; 11(1): 4063, 2020 08 13.
Artigo em Inglês | MEDLINE | ID: mdl-32792525

RESUMO

The neuroendocrine hypothalamus is the central regulator of vital physiological homeostasis and behavior. However, the cellular and molecular properties of hypothalamic neural progenitors remain unexplored. Here, hypothalamic radial glial (hRG) and hypothalamic mantle zone radial glial (hmRG) cells are found to be neural progenitors in the developing mammalian hypothalamus. The hmRG cells originate from hRG cells and produce neurons. During the early development of hypothalamus, neurogenesis occurs in radial columns and is initiated from hRG cells. The radial glial fibers are oriented toward the locations of hypothalamic subregions which act as a scaffold for neuronal migration. Furthermore, we use single-cell RNA sequencing to reveal progenitor subtypes in human developing hypothalamus and characterize specific progenitor genes, such as TTYH1, HMGA2, and FAM107A. We also demonstrate that HMGA2 is involved in E2F1 pathway, regulating the proliferation of progenitor cells by targeting on the downstream MYBL2. Different neuronal subtypes start to differentiate and express specific genes of hypothalamic nucleus at gestational week 10. Finally, we reveal the developmental conservation of nuclear structures and marker genes in mouse and human hypothalamus. Our identification of cellular and molecular properties of neural progenitors provides a basic understanding of neurogenesis and regional formation of the non-laminated hypothalamus.


Assuntos
Hipotálamo/citologia , Hipotálamo/metabolismo , Células-Tronco Neurais/citologia , Células-Tronco Neurais/metabolismo , Animais , Análise por Conglomerados , Feminino , Genes Supressores de Tumor , Proteína HMGA2/genética , Proteína HMGA2/metabolismo , Humanos , Hibridização In Situ , Mamíferos , Proteínas de Membrana/genética , Proteínas de Membrana/metabolismo , Camundongos , Neurogênese/genética , Neurogênese/fisiologia , Proteínas Nucleares/genética , Proteínas Nucleares/metabolismo , Gravidez
6.
Proc Natl Acad Sci U S A ; 117(34): 20874-20880, 2020 08 25.
Artigo em Inglês | MEDLINE | ID: mdl-32764144

RESUMO

Maintaining energy homeostasis requires coordinating physiology and behavior both on an acute timescale to adapt to rapid fluctuations in caloric intake and on a chronic timescale to regulate body composition. Hypothalamic agouti-related peptide (AgRP)-expressing neurons are acutely activated by caloric need, and this acute activation promotes increased food intake and decreased energy expenditure. On a longer timescale, AgRP neurons exhibit chronic hyperactivity under conditions of obesity and high dietary fat consumption, likely due to leptin resistance; however, the behavioral and metabolic effects of chronic AgRP neuronal hyperactivity remain unexplored. Here, we use chemogenetics to manipulate Gq signaling in AgRP neurons in mice to explore the hypothesis that chronic activation of AgRP neurons promotes obesity. Inducing chronic Gq signaling in AgRP neurons initially increased food intake and caused dramatic weight gain, in agreement with published data; however, food intake returned to baseline levels within 1 wk, and body weight returned to baseline levels within 60 d. Additionally, we found that, when mice had elevated body weight due to chronic Gq signaling in AgRP neurons, energy expenditure was not altered but adiposity and lipid metabolism were both increased, even under caloric restriction. These findings reveal that the metabolic and behavioral effects of chronic Gq signaling in AgRP neurons are distinct from the previously reported effects of acute Gq signaling and also of leptin insensitivity.


Assuntos
Proteína Relacionada com Agouti/metabolismo , Subunidades alfa Gq-G11 de Proteínas de Ligação ao GTP/metabolismo , Obesidade/metabolismo , Adiposidade/efeitos dos fármacos , Animais , Peso Corporal , Restrição Calórica , Ingestão de Alimentos/efeitos dos fármacos , Ingestão de Energia , Metabolismo Energético/efeitos dos fármacos , Metabolismo Energético/fisiologia , Feminino , Homeostase/efeitos dos fármacos , Hipotálamo/metabolismo , Leptina/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Neurônios/metabolismo , Obesidade/fisiopatologia , Transdução de Sinais , Ganho de Peso/efeitos dos fármacos
7.
Proc Natl Acad Sci U S A ; 117(36): 22514-22521, 2020 09 08.
Artigo em Inglês | MEDLINE | ID: mdl-32848057

RESUMO

Learning to fear danger is essential for survival. However, overactive, relapsing fear behavior in the absence of danger is a hallmark of disabling anxiety disorders that affect millions of people. Its suppression is thus of great interest, but the necessary brain components remain incompletely identified. We studied fear suppression through a procedure in which, after acquiring fear of aversive events (fear learning), subjects were exposed to fear-eliciting cues without aversive events (safety learning), leading to suppression of fear behavior (fear extinction). Here we show that inappropriate, learning-resistant fear behavior results from disruption of brain components not previously implicated in this disorder: hypothalamic melanin-concentrating hormone-expressing neurons (MNs). Using real-time recordings of MNs across fear learning and extinction, we provide evidence that fear-inducing aversive events elevate MN activity. We find that optogenetic disruption of this MN activity profoundly impairs safety learning, abnormally slowing down fear extinction and exacerbating fear relapse. Importantly, we demonstrate that the MN disruption impairs neither fear learning nor related sensory responses, indicating that MNs differentially control safety and fear learning. Thus, we identify a neural substrate for inhibition of excessive fear behavior.


Assuntos
Extinção Psicológica/fisiologia , Medo/fisiologia , Hormônios Hipotalâmicos/metabolismo , Hipotálamo/citologia , Melaninas/metabolismo , Neurônios/metabolismo , Hormônios Hipofisários/metabolismo , Animais , Hipotálamo/metabolismo , Masculino , Camundongos , Optogenética
8.
Life Sci ; 257: 118036, 2020 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-32622949

RESUMO

AIMS: Anti-obesity effects and improved leptin sensitivity from n-3 polyunsaturated fatty acids (n-3 PUFAs) have been reported in diet-induced obese animals. This study sought to determine the beneficial central effects and mechanism of docosahexaenoic acid (DHA, 22:6 n-3) in high-fat (HF) diet fed mice. MAIN METHODS: Male C57BL/6J mice were given HF diet with or without intracerebroventricular (icv) injection of docosahexaenoic acid (DHA, 22:6 n-3) for two days. Central leptin sensitivity, hypothalamic inflammation, leptin signaling molecules and tyrosine hydroxylase (TH) were examined by central leptin sensitivity test and Western blot. Furthermore, the expression of hepatic genes involved in lipid metabolism was examined by RT-PCR. KEY FINDINGS: We found that icv administration of DHA not only reduced energy intake and body weight gain but also corrected the HF diet-induced hypothalamic inflammation. DHA decreased leptin signaling inhibitor SOCS3 and improved the leptin JAK2-Akt signaling pathways in the hypothalamus. Furthermore, icv administration of DHA improved the effects of leptin in the regulation of mRNA expression of enzymes related to lipogenesis, fatty acid ß-oxidation, and cholesterol synthesis in the liver. DHA increased leptin-induced activation of TH in the hypothalamus. SIGNIFICANCE: Therefore, increasing central DHA concentration may prevent the deficit of hypothalamic regulation, which is associated with disorders of energy homeostasis in the liver as a result of a high-fat diet.


Assuntos
Ácidos Docosa-Hexaenoicos/metabolismo , Ácidos Docosa-Hexaenoicos/farmacologia , Leptina/metabolismo , Animais , Peso Corporal/efeitos dos fármacos , Dieta Hiperlipídica/efeitos adversos , Ingestão de Energia/efeitos dos fármacos , Metabolismo Energético/efeitos dos fármacos , Hipotálamo/efeitos dos fármacos , Hipotálamo/metabolismo , Inflamação/metabolismo , Metabolismo dos Lipídeos/efeitos dos fármacos , Fígado/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Obesidade/metabolismo , Transdução de Sinais/efeitos dos fármacos
9.
Gene ; 754: 144885, 2020 Sep 05.
Artigo em Inglês | MEDLINE | ID: mdl-32535046

RESUMO

BACKGROUND: Congenital hypogonadotropic hypogonadism (CHH) is a rare genetically heterogeneous disorder. We aimed to determine the prevalence and pathogenesis of NECL2 (Nectin-like molecule 2) variants in a cohort of female patients with CHH. METHODS: We sequenced and determined the prevalence of NECL2 variants in 68 female patients with CHH and 243 healthy controls collected from an academic medical center. Further cellular and animal studies were performed to verify the pathogenicity of the mutations. Necl2 knockout female mice were generated, and their puberty development was observed. RESULTS: A novel NECL2 variant (c.1052_1060del, p.Thr351_Thr353del) was detected in 4 of 68 (5.9%) patients with CHH. Its prevalence was significantly higher in CHH patients than in healthy controls (0%). At the cellular level, the necl2 variant leads to a decrease in gonadotropin-releasing hormone. In animal models, we found that the Necl2 protein was expressed in the hypothalamus, especially in the ventromedial hypothalamic nucleus of mice. Necl2 knockout female mice showed delayed puberty and an irregular estrous cycle, consistent with CHH patient phenotypes. CONCLUSIONS: Our findings predict that NECL2 may be a new candidate gene for CHH and that the NECL2 protein plays a critical role in the progression of puberty development.


Assuntos
Molécula 1 de Adesão Celular/genética , Molécula 1 de Adesão Celular/metabolismo , Hipogonadismo/patologia , Mutação , Puberdade , Maturidade Sexual , Adolescente , Adulto , Animais , Apoptose , Estudos de Casos e Controles , Adesão Celular , Proliferação de Células , Células Cultivadas , Estudos de Coortes , Ciclo Estral , Feminino , Hormônio Liberador de Gonadotropina , Humanos , Hipogonadismo/genética , Hipogonadismo/metabolismo , Hipotálamo/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Fenótipo , Prognóstico , Adulto Jovem
10.
Life Sci ; 255: 117867, 2020 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-32479954

RESUMO

Obesity continues to be a growing health concern around the world, and elevated levels of free fatty acids as a result of high-fat intake might play a role in neuroendocrine alterations leading to obesity. However, it is unclear how fatty acids affect neuroendocrine functions and energy metabolism. Since hypothalamic monoamines play a crucial role in regulating neuroendocrine functions relating to energy balance, we investigated the direct effects of oleic acid on hypothalamic monoamines and hypothesized that oleic acid would activate peroxisome proliferator-activated receptor alpha (PPAR-α), a nuclear transcription factor involved with fatty acid metabolism, to affect monoamines. We also hypothesized that this response would be subdued in diet-induced obesity (DIO). To test these hypotheses, hypothalami from Sprague Dawley and DIO rats were incubated with 0 (Control), 0.00132 mM, 0.132 mM, 1.32 mM oleic acid, 50 µM MK 886 (a selective PPAR- α antagonist), or oleic acid + MK 886 in Krebs Ringers Henseleit (KRH) solution. HPLC-EC was used to measure monoamine levels in perfusates. Oleic acid produced a significant increase in norepinephrine, dopamine, and serotonin levels in a dose-dependent manner, and incubation with MK886 blocked these effects. The effect of oleic acid on hypothalamic monoamines was attenuated in DIO rats. These findings suggest that PPARα probably plays an essential role in fatty acid sensing in the hypothalamus, by affecting monoamine efflux and DIO rats are resistant to the effects of oleic acid.


Assuntos
Hipotálamo/efeitos dos fármacos , Obesidade/fisiopatologia , Ácido Oleico/farmacologia , PPAR alfa/metabolismo , Animais , Dieta Hiperlipídica/efeitos adversos , Dopamina/metabolismo , Relação Dose-Resposta a Droga , Ácidos Graxos não Esterificados/metabolismo , Hipotálamo/metabolismo , Indóis/farmacologia , Masculino , Norepinefrina/metabolismo , Ácido Oleico/administração & dosagem , Ratos , Ratos Sprague-Dawley , Serotonina/metabolismo
11.
Ecotoxicol Environ Saf ; 201: 110712, 2020 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-32502905

RESUMO

Exposure to manganese (Mn) can cause male reproductive damage and lead to abnormal secretion of sex hormones. Gonadotropin-releasing hormone (GnRH) plays an important role in the neuromodulation of vertebrate reproduction. Astrocytes can indirectly regulate the secretion of GnRH by binding paracrine prostaglandin E2 (PGE2) specifically to the EP1 and EP2 receptors on GnRH neurons. Prior studies assessed the abnormal secretion of GnRH caused by Mn exposure, but the specific mechanism has not been reported in detail. This study investigated the effects of Mn exposure on the reproductive system of male mice to clarify the role of PGE2 in the abnormal secretion of GnRH in the hypothalamus caused by exposure to Mn. Our data demonstrate that antagonizing the EP1 and EP2 receptors of PGE2 can restore abnormal levels of GnRH caused by Mn exposure. Mn exposure causes reduced sperm count and sperm shape deformities. These findings suggest that EP1 and EP2, the receptors of PGE2, may be the key to abnormal GnRH secretion caused by Mn exposure. Antagonizing the PGE2 receptors may reduce reproductive damage caused by Mn exposure.


Assuntos
Hormônio Liberador de Gonadotropina/metabolismo , Hipotálamo/efeitos dos fármacos , Manganês/toxicidade , Receptores de Prostaglandina E Subtipo EP1/metabolismo , Receptores de Prostaglandina E Subtipo EP2/metabolismo , Reprodução/efeitos dos fármacos , Animais , Hipotálamo/metabolismo , Masculino , Manganês/metabolismo , Camundongos , Neurônios/efeitos dos fármacos , Neurônios/metabolismo , Receptores de Prostaglandina E Subtipo EP1/antagonistas & inibidores , Receptores de Prostaglandina E Subtipo EP2/antagonistas & inibidores
12.
Nature ; 582(7811): 246-252, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32499648

RESUMO

A wealth of specialized neuroendocrine command systems intercalated within the hypothalamus control the most fundamental physiological needs in vertebrates1,2. Nevertheless, we lack a developmental blueprint that integrates the molecular determinants of neuronal and glial diversity along temporal and spatial scales of hypothalamus development3. Here we combine single-cell RNA sequencing of 51,199 mouse cells of ectodermal origin, gene regulatory network (GRN) screens in conjunction with genome-wide association study-based disease phenotyping, and genetic lineage reconstruction to show that nine glial and thirty-three neuronal subtypes are generated by mid-gestation under the control of distinct GRNs. Combinatorial molecular codes that arise from neurotransmitters, neuropeptides and transcription factors are minimally required to decode the taxonomical hierarchy of hypothalamic neurons. The differentiation of γ-aminobutyric acid (GABA) and dopamine neurons, but not glutamate neurons, relies on quasi-stable intermediate states, with a pool of GABA progenitors giving rise to dopamine cells4. We found an unexpected abundance of chemotropic proliferation and guidance cues that are commonly implicated in dorsal (cortical) patterning5 in the hypothalamus. In particular, loss of SLIT-ROBO signalling impaired both the production and positioning of periventricular dopamine neurons. Overall, we identify molecular principles that shape the developmental architecture of the hypothalamus and show how neuronal heterogeneity is transformed into a multimodal neural unit to provide virtually infinite adaptive potential throughout life.


Assuntos
Regulação da Expressão Gênica no Desenvolvimento , Hipotálamo/citologia , Hipotálamo/embriologia , Morfogênese , Animais , Diferenciação Celular , Linhagem da Célula , Dopamina/metabolismo , Neurônios Dopaminérgicos/citologia , Neurônios Dopaminérgicos/metabolismo , Ectoderma/citologia , Ectoderma/metabolismo , Feminino , Neurônios GABAérgicos/citologia , Neurônios GABAérgicos/metabolismo , Redes Reguladoras de Genes , Estudo de Associação Genômica Ampla , Ácido Glutâmico/metabolismo , Hipotálamo/metabolismo , Masculino , Camundongos , Morfogênese/genética , Proteínas do Tecido Nervoso/metabolismo , Neuroglia/citologia , Neuroglia/metabolismo , Neuropeptídeos/metabolismo , Neurotransmissores/metabolismo , Receptores Imunológicos/metabolismo , Regulon/genética , Transdução de Sinais , Fatores de Transcrição/metabolismo , Ácido gama-Aminobutírico/metabolismo
13.
Poult Sci ; 99(5): 2533-2542, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32359589

RESUMO

In documents, maternal betaine modulates hypothalamic cholesterol metabolism in chicken posthatchings, but it remains unclear whether this effect can be passed on by generations. In present study, eggs were injected with saline or betaine at 2.5 mg/egg, and the hatchlings (F1) were raised under the same condition until sexual maturation. Both the control group and the betaine group used artificial insemination to collect sperm from their cockerels. Fertilized eggs were incubated, and the hatchlings of the following generation (F2) were raised up to 64 D of age. F2 cockerels in betaine group showed significantly (P < 0.05) lower body weight, which was associated with significantly decreased (P < 0.05) hypothalamic content of total cholesterol and cholesterol ester. Concordantly, hypothalamic expression of cholesterol biosynthetic genes, SREBP2 and HMGCR, were significantly downregulated (P < 0.05), together with cholesterol conversion-related and excretion-related genes, CYP46A1 and ABCA1. These changes coincided with a significant downregulation in mRNA expression of regulatory neuropeptides including brain-derived neurotrophic factor, neuropeptide Y, and corticotropin-releasing hormone. Moreover, genes involved in methyl transfer cycle were also modified. Betaine homocysteine methyltransferase (P < 0.05) was downregulated, yet DNA methyltransferase1 tended to be upregulated (P = 0.06). S-adenosyl methionine/S-adenosylhomocysteine ratio was higher in the hypothalamus of betaine-treated F2 cockerels, which was associated with significantly modified CpG methylation on the promoter of those affected genes. These results suggested that betaine might regulate central cholesterol metabolism and hypothalamic expression of genes related to brain function by altering promoter DNA methylation in F2 cockerels.


Assuntos
Proteínas Aviárias/genética , Betaína/administração & dosagem , Embrião de Galinha/efeitos dos fármacos , Colesterol/genética , Expressão Gênica/efeitos dos fármacos , Hipotálamo/metabolismo , Animais , Proteínas Aviárias/metabolismo , Galinhas , Colesterol/metabolismo , Metilação de DNA , Masculino , Regiões Promotoras Genéticas/genética
14.
Proc Natl Acad Sci U S A ; 117(23): 12772-12783, 2020 06 09.
Artigo em Inglês | MEDLINE | ID: mdl-32467166

RESUMO

The luteinizing hormone surge is essential for fertility as it triggers ovulation in females and sperm release in males. We previously reported that secretoneurin-a, a neuropeptide derived from the processing of secretogranin-2a (Scg2a), stimulates luteinizing hormone release, suggesting a role in reproduction. Here we provide evidence that mutation of the scg2a and scg2b genes using TALENs in zebrafish reduces sexual behavior, ovulation, oviposition, and fertility. Large-scale spawning within-line crossings (n = 82 to 101) were conducted. Wild-type (WT) males paired with WT females successfully spawned in 62% of the breeding trials. Spawning success was reduced to 37% (P = 0.006), 44% (P = 0.0169), and 6% (P < 0.0001) for scg2a -/- , scg2b -/- , and scg2a -/- ;scg2b -/- mutants, respectively. Comprehensive video analysis indicates that scg2a -/- ;scg2b -/- mutation reduces all male courtship behaviors. Spawning success was 47% in saline-injected WT controls compared to 11% in saline-injected scg2a -/- ;scg2b -/- double mutants. For these mutants, spawning success increased 3-fold following a single intraperitoneal (i.p.) injection of synthetic secretoneurin-a (P = 0.0403) and increased 3.5-fold with injection of human chorionic gonadotropin (hCG). Embryonic survival at 24 h remained on average lower in scg2a -/- ;scg2b -/- fish compared to WT injected with secretoneurin-a (P < 0.001). Significant reductions in the expression of gonadotropin-releasing hormone 3 in the hypothalamus, and luteinizing hormone beta and glycoprotein alpha subunits in the pituitary provide evidence for disrupted hypothalamo-pituitary function in scg2a and scg2b mutant fish. Our results indicate that secretogranin-2 is required for optimal reproductive function and support the hypothesis that secretoneurin is a reproductive hormone.


Assuntos
Fertilidade , Preferência de Acasalamento Animal , Mutação , Secretogranina II/genética , Proteínas de Peixe-Zebra/genética , Animais , Feminino , Hormônio Liberador de Gonadotropina/metabolismo , Hipotálamo/metabolismo , Hormônio Luteinizante/metabolismo , Masculino , Neuropeptídeos/metabolismo , Oviposição , Ovulação , Hipófise/metabolismo , Secretogranina II/metabolismo , Peixe-Zebra , Proteínas de Peixe-Zebra/metabolismo
15.
Am J Physiol Endocrinol Metab ; 319(1): E81-E90, 2020 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-32396496

RESUMO

We have previously shown that systemic injection of erythropoietin-producing hepatocellular receptor A7 (EPHA7)-Fc raises serum luteinizing hormone (LH) levels before ovulation in female rats, indicating the induction of EPHA7 in ovulation. In this study, we aimed to identify the mechanism and hypothalamus-pituitary-ovary (HPO) axis level underlying the promotion of LH secretion by EPHA7. Using an ovariectomized (OVX) rat model, in conjunction with low-dose 17ß-estradiol (E2) treatment, we investigated the association between EPHA7-ephrin (EFN)A5 signaling and E2 negative feedback. Various rat models (OVX, E2-treated OVX, and abarelix treated) were injected with the recombinant EPHA7-Fc protein through the caudal vein to investigate the molecular mechanism underlying the promotion of LH secretion by EPHA7. Efna5 was observed strongly expressed in the arcuate nucleus of the female rat by using RNAscope in situ hybridization. Our results indicated that E2, combined with estrogen receptor (ER)α, but not ERß, inhibited Efna5 and gonadotropin-releasing hormone 1 (Gnrh1) expressions in the hypothalamus. In addition, the systemic administration of EPHA7-Fc restrained the inhibition of Efna5 and Gnrh1 by E2, resulting in increased Efna5 and Gnrh1 expressions in the hypothalamus as well as increased serum LH levels. Collectively, our findings demonstrated the involvement of EPHA7-EFNA5 signaling in the regulation of LH and the E2 negative feedback pathway in the hypothalamus, highlighting the functional role of EPHA7 in female reproduction.


Assuntos
Efrina-A5/metabolismo , Receptor alfa de Estrogênio/metabolismo , Hormônio Liberador de Gonadotropina/metabolismo , Hipotálamo/metabolismo , Hormônio Luteinizante/metabolismo , Precursores de Proteínas/metabolismo , Animais , Núcleo Arqueado do Hipotálamo/efeitos dos fármacos , Núcleo Arqueado do Hipotálamo/metabolismo , Efrina-A5/efeitos dos fármacos , Efrina-A5/genética , Estradiol/farmacologia , Receptor beta de Estrogênio/metabolismo , Estrogênios/farmacologia , Retroalimentação Fisiológica/efeitos dos fármacos , Retroalimentação Fisiológica/fisiologia , Feminino , Hormônio Liberador de Gonadotropina/efeitos dos fármacos , Antagonistas de Hormônios/farmacologia , Sistema Hipotálamo-Hipofisário/efeitos dos fármacos , Sistema Hipotálamo-Hipofisário/metabolismo , Hipotálamo/efeitos dos fármacos , Hormônio Luteinizante/efeitos dos fármacos , Oligopeptídeos/farmacologia , Ovariectomia , Ovário/efeitos dos fármacos , Ovário/metabolismo , Precursores de Proteínas/efeitos dos fármacos , Ratos , Receptor EphA7/genética , Receptor EphA7/metabolismo , Receptor EphA7/farmacologia , Proteínas Recombinantes
16.
Am J Physiol Endocrinol Metab ; 318(5): E765-E778, 2020 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-32228320

RESUMO

We report here that the neuronal (pro)renin receptor (PRR), a key component of the brain renin-angiotensin system (RAS), plays a critical role in the central regulation of high-fat-diet (HFD)-induced metabolic pathophysiology. The neuronal PRR is known to mediate formation of the majority of angiotensin (ANG) II, a key bioactive peptide of the RAS, in the central nervous system and to regulate blood pressure and cardiovascular function. However, little is known about neuronal PRR function in overnutrition-related metabolic physiology. Here, we show that PRR deletion in neurons reduces blood pressure, neurogenic pressor activity, and fasting blood glucose and improves glucose tolerance without affecting food intake or body weight following a 16-wk HFD. Mechanistically, we found that a HFD increases levels of the PRR ligand (pro)renin in the circulation and hypothalamus and of ANG II in the hypothalamus, indicating activation of the brain RAS. Importantly, PRR deletion in neurons reduced astrogliosis and activation of the astrocytic NF-κB p65 (RelA) in the arcuate nucleus and the ventromedial nucleus of the hypothalamus. Collectively, our findings indicate that the neuronal PRR plays essential roles in overnutrition-related metabolic pathophysiology.


Assuntos
Astrócitos/metabolismo , Glicemia/metabolismo , Pressão Sanguínea/fisiologia , Hipotálamo/metabolismo , Inflamação/metabolismo , Neurônios/metabolismo , Receptores de Superfície Celular/metabolismo , Animais , Peso Corporal/fisiologia , Dieta Hiperlipídica , Ingestão de Alimentos/fisiologia , Camundongos , Camundongos Knockout , Receptores de Superfície Celular/genética , Renina/metabolismo
17.
Nat Commun ; 11(1): 1885, 2020 04 20.
Artigo em Inglês | MEDLINE | ID: mdl-32313029

RESUMO

The oxytocin receptor (OTR) plays critical roles in social behavior development. Despite its significance, brain-wide quantitative understanding of OTR expression remains limited in postnatally developing brains. Here, we develop postnatal 3D template brains to register whole brain images with cellular resolution to systematically quantify OTR cell densities. We utilize fluorescent reporter mice (Otrvenus/+) and find that cortical regions show temporally and spatially heterogeneous patterns with transient postnatal OTR expression without cell death. Cortical OTR cells are largely glutamatergic neurons with the exception of cells in layer 6b. Subcortical regions show similar temporal regulation except the hypothalamus and two hypothalamic nuclei display sexually dimorphic OTR expression. Lack of OTR expression correlates with reduced dendritic spine densities in selected cortical regions of developing brains. Lastly, we create a website to visualize our high-resolution imaging data. In summary, our research provides a comprehensive resource for postnatal OTR expression in the mouse brain.


Assuntos
Encéfalo/crescimento & desenvolvimento , Encéfalo/metabolismo , Receptores de Ocitocina/genética , Receptores de Ocitocina/metabolismo , Animais , Encéfalo/diagnóstico por imagem , Mapeamento Encefálico , Regulação para Baixo , Feminino , Regulação da Expressão Gênica no Desenvolvimento , Hipotálamo/metabolismo , Masculino , Camundongos , Camundongos Knockout , Camundongos Transgênicos , Sistema Nervoso/crescimento & desenvolvimento , Neurônios/metabolismo , Ocitocina/metabolismo , Caracteres Sexuais
18.
Nat Commun ; 11(1): 1914, 2020 04 20.
Artigo em Inglês | MEDLINE | ID: mdl-32313051

RESUMO

Obesity is associated with the activation of cellular responses, such as endoplasmic reticulum (ER) stress. Here, we show that leptin-deficient ob/ob mice display elevated hypothalamic ER stress as early as postnatal day 10, i.e., prior to the development of obesity in this mouse model. Neonatal treatment of ob/ob mice with the ER stress-relieving drug tauroursodeoxycholic acid (TUDCA) causes long-term amelioration of body weight, food intake, glucose homeostasis, and pro-opiomelanocortin (POMC) projections. Cells exposed to ER stress often activate autophagy. Accordingly, we report that in vitro induction of ER stress and neonatal leptin deficiency in vivo activate hypothalamic autophagy-related genes. Furthermore, genetic deletion of autophagy in pro-opiomelanocortin neurons of ob/ob mice worsens their glucose homeostasis, adiposity, hyperphagia, and POMC neuronal projections, all of which are ameliorated with neonatal TUDCA treatment. Together, our data highlight the importance of early life ER stress-autophagy pathway in influencing hypothalamic circuits and metabolic regulation.


Assuntos
Autofagia/fisiologia , Estresse do Retículo Endoplasmático/fisiologia , Metabolismo Energético/fisiologia , Hipotálamo/metabolismo , Leptina/metabolismo , Neurogênese/fisiologia , Adiposidade , Animais , Antivirais/farmacologia , Autofagia/efeitos dos fármacos , Autofagia/genética , Proteína 7 Relacionada à Autofagia/genética , Peso Corporal/efeitos dos fármacos , Peso Corporal/fisiologia , Colagogos e Coleréticos/farmacologia , Modelos Animais de Doenças , Ingestão de Alimentos , Estresse do Retículo Endoplasmático/efeitos dos fármacos , Metabolismo Energético/efeitos dos fármacos , Metabolismo Energético/genética , Comportamento Alimentar , Homeostase , Hiperfagia/metabolismo , Leptina/genética , Masculino , Doenças Metabólicas/genética , Doenças Metabólicas/metabolismo , Camundongos , Camundongos Endogâmicos , Camundongos Knockout , Neuroendocrinologia , Neurogênese/efeitos dos fármacos , Obesidade/metabolismo , Pró-Opiomelanocortina/metabolismo , Ácido Tauroquenodesoxicólico
19.
Am J Physiol Regul Integr Comp Physiol ; 318(6): R1027-R1035, 2020 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-32292064

RESUMO

There are examples of physiological conditions under which thirst is inappropriately exaggerated, and the mechanisms for these paradoxical ingestive behaviors remain unknown. We are interested in thirst mechanisms across the female life cycle and have identified a novel mechanism through which ingestive behavior may be activated. We discovered a previously unrecognized endogenous hypothalamic peptide, phoenixin (PNX), identified physiologically relevant actions of the peptide in brain and pituitary gland to control reproductive hormone secretion in female rodents, and in the process identified the previously orphaned G protein-coupled receptor Gpr173 to be a potential receptor for the peptide. Labeled PNX binding distribution in brain parallels areas known to be important in ingestive behaviors as well in areas where gonadal steroids feedback to control estrous cyclicity (Stein LM, Tullock CW, Mathews SK, Garcia-Galiano D, Elias CF, Samson WK, Yosten GLC, Am J Physiol Regul Integr Comp Physiol 311: R489-R496, 2016). We have demonstrated upregulation of Gpr173 during puberty, fluctuations across the estrous cycle, and, importantly, upregulation during the last third of gestation. It is during this hypervolemic, hyponatremic state that both vasopressin secretion and thirst are inappropriately elevated in humans. Here, we show that central administration of PNX stimulated water drinking in both males and females under ad libitum conditions, increased water drinking after overnight fluid deprivation, and increased both water and 1.5% NaCl ingestion under fed and hydrated conditions. Importantly, losartan pretreatment blocked the effect of PNX on water drinking, and knockdown of Gpr173 by use of short interfering RNA constructs significantly attenuated water drinking in response to overnight fluid deprivation. These actions, together with the stimulatory action of PNX on vasopressin secretion, suggest that this recently discovered neuropeptide may impact the recruitment of critically important neural circuits through which ingestive behaviors and endocrine mechanisms that maintain fluid and electrolyte homeostasis are regulated.


Assuntos
Comportamento de Ingestão de Líquido/fisiologia , Hipotálamo/metabolismo , Hormônios Peptídicos/metabolismo , Receptores Acoplados a Proteínas-G/metabolismo , Sede/fisiologia , Animais , Ciclo Estral/metabolismo , Feminino , Homeostase/fisiologia , Masculino , Hormônios Peptídicos/genética , RNA Interferente Pequeno , Ratos , Ratos Sprague-Dawley , Receptores Acoplados a Proteínas-G/genética
20.
Obesity (Silver Spring) ; 28(6): 1117-1128, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32347662

RESUMO

OBJECTIVES: The purpose of this study was to determine changes in the expression levels of kisspeptin-1 (Kiss1) in the hypothalamus during the development of polycystic ovary syndrome (PCOS) and after treatment with sleeve gastrectomy (SG). METHODS: This study used chronic dehydroepiandrosterone (DHEA) alone and DHEA plus a high-fat diet (HFD) to generate a PCOS rat model. Subsequently, SG was performed in the animals with PCOS and the effects on glucose tolerance, insulin sensitivity, sex hormones, estrous cyclicity, adiponectin, and Kiss1 expression in the hypothalamus were investigated. RESULTS: Impaired glucose tolerance, decreased insulin sensitivity, reduced adiponectin levels, disrupted estrous cyclicity, and elevated sex hormone levels associated with PCOS models were restored to normal following SG. In addition, SG was able to restore the increase in the expression of Kiss1 mRNA and Kiss1-positive neurons in the arcuate nucleus of rats with PCOS. Interestingly, although SG did not result in a significant loss of body weight in rats administered DHEA under a chow diet, it resulted in comparable metabolic improvements and Kiss1 expression in rats that had been administered DHEA along with an HFD. CONCLUSIONS: The recovery of normal levels of Kiss1 expression in the hypothalamus after SG in this study suggests that Kiss1 might play an important role in the development of PCOS and its improvement by SG.


Assuntos
Gastrectomia/métodos , Hipotálamo/metabolismo , Kisspeptinas/metabolismo , Síndrome do Ovário Policístico/genética , Síndrome do Ovário Policístico/cirurgia , Animais , Feminino , Humanos , Síndrome do Ovário Policístico/metabolismo , Ratos , Ratos Sprague-Dawley
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