RESUMO
Nest-building behavior is a widely observed innate behavior. A nest provides animals with a secure environment for parenting, sleep, feeding, reproduction, and temperature maintenance. Since animal infants spend their time in a nest, nest-building behavior has been generally studied as parental behaviors, and the medial preoptic area (MPOA) neurons are known to be involved in parental nest-building. However, nest-building of singly housed male mice has been less examined. Here we show that male mice spent longer time in nest-building at the early to middle dark phase and at the end of the dark phase. These two periods are followed by sleep-rich periods. When a nest was removed and fresh nest material was introduced, both male and female mice built nests at Zeitgeber time (ZT) 6, but not at ZT12. Using Fos-immunostaining combined with double in situ hybridization of Vgat and Vglut2, we found that Vgat- and Vglut2-positive cells of the lateral preoptic area (LPOA) were the only hypothalamic neuron population that exhibited a greater number of activated cells in response to fresh nest material at ZT6, compared to being naturally awake at ZT12. Fos-positive LPOA neurons were negative for estrogen receptor 1 (Esr1). Both Vgat-positive and Vglut2-positive neurons in both the LPOA and MPOA were activated at pup retrieval by male mice. Our findings suggest the possibility that GABAergic and glutamatergic neurons in the LPOA are associated with nest-building behavior in male mice.
Assuntos
Hipotálamo , Área Pré-Óptica , Humanos , Camundongos , Masculino , Feminino , Animais , Hipotálamo/fisiologia , Área Pré-Óptica/fisiologia , Neurônios/fisiologiaRESUMO
In mice and humans, sleep quantity is governed by genetic factors and exhibits age-dependent variation1-3. However, the core molecular pathways and effector mechanisms that regulate sleep duration in mammals remain unclear. Here, we characterize a major signalling pathway for the transcriptional regulation of sleep in mice using adeno-associated virus-mediated somatic genetics analysis4. Chimeric knockout of LKB1 kinase-an activator of AMPK-related protein kinase SIK35-7-in adult mouse brain markedly reduces the amount and delta power-a measure of sleep depth-of non-rapid eye movement sleep (NREMS). Downstream of the LKB1-SIK3 pathway, gain or loss-of-function of the histone deacetylases HDAC4 and HDAC5 in adult brain neurons causes bidirectional changes of NREMS amount and delta power. Moreover, phosphorylation of HDAC4 and HDAC5 is associated with increased sleep need, and HDAC4 specifically regulates NREMS amount in posterior hypothalamus. Genetic and transcriptomic studies reveal that HDAC4 cooperates with CREB in both transcriptional and sleep regulation. These findings introduce the concept of signalling pathways targeting transcription modulators to regulate daily sleep amount and demonstrate the power of somatic genetics in mouse sleep research.
Assuntos
Transdução de Sinais , Duração do Sono , Transcrição Gênica , Animais , Camundongos , Regulação da Expressão Gênica , Fosforilação , Transdução de Sinais/fisiologia , Sono de Ondas Lentas/genética , Perfilação da Expressão GênicaRESUMO
Control of gut microbes is crucial for not only local defense in the intestine but also proper systemic immune responses. Although intestinal epithelial cells (IECs) play important roles in cytokine-mediated control of enterobacteria, the underlying mechanisms are not fully understood. Here we show that deletion of IκBζ in IECs in mice leads to dysbiosis with marked expansion of segmented filamentous bacteria (SFB), thereby enhancing Th17 cell development and exacerbating inflammatory diseases. Mechanistically, the IκBζ deficiency results in decrease in the number of Paneth cells and impairment in expression of IL-17-inducible genes involved in IgA production. The decrease in Paneth cells is caused by aberrant activation of IFN-γ signaling and a failure of IL-17-dependent recovery from IFN-γ-induced damage. Thus, the IL-17R-IκBζ axis in IECs contributes to the maintenance of intestinal homeostasis by serving as a key component in a regulatory loop between the gut microbiota and immune cells.
Assuntos
Disbiose , Interleucina-17 , Células Th17 , Animais , Camundongos , Disbiose/metabolismo , Células Epiteliais , Expressão Gênica , Interleucina-17/genética , Interleucina-17/metabolismo , Mucosa Intestinal , Celulas de Paneth/metabolismoRESUMO
Cell senescence plays a key role in age-associated organ dysfunction, but the in vivo pathogenesis is largely unclear. Here, we generated a p16-CreERT2-tdTomato mouse model to analyze the in vivo characteristics of p16high cells at a single-cell level. We found tdTomato-positive p16high cells detectable in all organs, which were enriched with age. We also found that these cells failed to proliferate and had half-lives ranging from 2.6 to 4.2 months, depending on the tissue examined. Single-cell transcriptomics in the liver and kidneys revealed that p16high cells were present in various cell types, though most dominant in hepatic endothelium and in renal proximal and distal tubule epithelia, and that these cells exhibited heterogeneous senescence-associated phenotypes. Further, elimination of p16high cells ameliorated nonalcoholic steatohepatitis-related hepatic lipidosis and immune cell infiltration. Our new mouse model and single-cell analysis provide a powerful resource to enable the discovery of previously unidentified senescence functions in vivo.
Assuntos
Inibidor p16 de Quinase Dependente de Ciclina/metabolismo , Animais , Linhagem Celular , Senescência Celular , Humanos , Camundongos , Camundongos Endogâmicos C57BL , Modelos Biológicos , Análise de Célula ÚnicaRESUMO
Although sleep is one of the most conserved behaviors, the intracellular mechanism regulating sleep/wakefulness remains unknown. We recently identified a protein kinase, SIK3, as a sleep-regulating molecule. Mice that lack a well-conserved protein kinase A (PKA) phosphorylation site, S551, showed longer non-rapid eye movement (NREM) sleep and increased NREMS delta density. S551 of SIK3 is conserved in other members of the SIK family, such as SIK1 (S577) and SIK2 (S587). Here, we examined whether the PKA phosphorylation sites of SIK1 and SIK2 are involved in sleep regulation by generating Sik1S577A and Sik2S587A mice. The homozygous Sik1S577A mice showed a shorter wake time, longer NREMS time, and higher NREMS delta density than the wild-type mice. The heterozygous and homozygous Sik2S587A mice showed increased NREMS delta density. Both the Sik1S577A and Sik2S587A mice exhibited proper homeostatic regulation of sleep need after sleep deprivation. Despite abundant expression of Sik1 in the suprachiasmatic nucleus, the Sik1S577A mice showed normal circadian behavior. Although Sik2 is highly expressed in brown adipose tissue, the male and female Sik2S587A mice that were fed either a chow or high-fat diet showed similar weight gain as the wild-type littermates. These results suggest that PKA-SIK signaling is involved in the regulation of sleep need.
Assuntos
Proteínas Quinases Dependentes de AMP Cíclico/metabolismo , Proteínas Serina-Treonina Quinases/genética , Sono de Ondas Lentas/genética , Vigília/genética , Tecido Adiposo Marrom/metabolismo , Substituição de Aminoácidos/genética , Animais , Peso Corporal/genética , Ondas Encefálicas/genética , Linhagem Celular , Ritmo Circadiano/genética , Feminino , Células HEK293 , Humanos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Fosforilação , Proteínas Serina-Treonina Quinases/metabolismo , Transdução de Sinais/fisiologia , Sono de Ondas Lentas/fisiologia , Vigília/fisiologiaRESUMO
Testosterone is involved in male sexual, parental and aggressive behaviors through the androgen receptor (AR) and estrogen receptor (ER) α expressed in the brain. Although several studies have demonstrated that ERα and AR in the medial preoptic area (MPOA) are required for exhibiting sexual and aggressive behaviors of male mice, the molecular characteristics of ERα- and AR-expressing cells in the mouse MPOA are largely unknown. Here, we performed in situ hybridization for neurotransmitters and neuropeptides, combined with immunohistochemistry for ERα and AR to quantitate and characterize gonadal steroid receptor-expressing cells in the MPOA subregions of male mice. Prodynorphin, preproenkephalin (Penk), cocaine- and amphetamine-related transcript, neurotensin, galanin, tachykinin (Tac)1, Tac2 and thyrotropin releasing hormone (Trh) have distinct expression patterns in the MPOA subregions. Gad67-expressing cells were the most dominant neuronal subtype among the ERα- and AR-expressing cells throughout the MPOA. The percentage of ERα- and AR-immunoreactivities varied depending on the neuronal subtype. A substantial proportion of the neurotensin-, galanin-, Tac2- and Penk-expressing cells in the MPOA were positive for ERα and AR, whereas the vast majority of the Trh-expressing cells were negative. These results suggest that testosterone exerts differential effects depending on both the neuronal subtypes and MPOA subregions.
Assuntos
Receptor alfa de Estrogênio/genética , Expressão Gênica , Neuropeptídeos/farmacologia , Neurotransmissores/farmacologia , Área Pré-Óptica/metabolismo , Receptores Androgênicos/genética , Animais , Contagem de Células , Receptor alfa de Estrogênio/metabolismo , Imunofluorescência , Masculino , Camundongos , Receptores Androgênicos/metabolismoRESUMO
The lack of the neuropeptide orexin, also known as hypocretin, results in narcolepsy, a chronic sleep disorder characterized by frequent sleep/cataplexy attacks and rapid eye movement sleep abnormalities. However, the downstream pathways of orexin signaling are not clearly understood. Here, we show that orexin activates the mTOR pathway, a central regulator of cell growth and metabolism, in the mouse brain and multiple recombinant cell lines that express the G protein-coupled receptors (GPCRs), orexin 1 receptor (OX1R) or orexin 2 receptor (OX2R). This orexin/GPCR-stimulated mTOR activation is sensitive to rapamycin, an inhibitor of mTOR complex 1 (mTORC1) but is independent of two well known mTORC1 activators, Erk and Akt. Rather, our studies indicate that orexin activates mTORC1 via extracellular calcium influx and the lysosome pathway involving v-ATPase and Rag GTPases. Moreover, a cytoplasmic calcium transient is sufficient to mimic orexin/GPCR signaling to mTORC1 activation in a v-ATPase-dependent manner. Together, our studies suggest that the mTORC1 pathway functions downstream of orexin/GPCR signaling, which plays a crucial role in many physiological and metabolic processes.
Assuntos
Encéfalo/metabolismo , Complexos Multiproteicos/metabolismo , Neuropeptídeos/metabolismo , Receptores de Orexina/metabolismo , Serina-Treonina Quinases TOR/metabolismo , ATPases Vacuolares Próton-Translocadoras/metabolismo , Animais , Cálcio/metabolismo , Linhagem Celular , Citoplasma/metabolismo , Ativação Enzimática , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Regulação Enzimológica da Expressão Gênica , Células HEK293 , Humanos , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Lisossomos/metabolismo , Alvo Mecanístico do Complexo 1 de Rapamicina , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Orexinas , Proteínas Proto-Oncogênicas c-akt/metabolismo , Interferência de RNA , Transdução de SinaisRESUMO
There is growing evidence that aberrant transcriptional regulation is one of the key components of the pathophysiology of mood disorders. The repressor element-1 silencing transcription factor (REST) is a negative regulator of genes that contain the repressor element-1 (RE-1) binding site. REST has many target genes, including corticotropin releasing hormone (CRH), brain-derived neurotrophic factor, serotonin 1A receptor, which are suggested to be involved in the pathophysiology of depression and the action of antidepressants. However, a potential role for REST-mediated transcriptional regulation in mood disorders remains unclear. In this study, we examined the mRNA levels of REST and its known and putative target genes, using quantitative real-time PCR in peripheral blood cells of patients with major depressive and bipolar disorders in both a current depressive and a remissive state. We found reduced mRNA expression of REST and increased mRNA expression of CRH, adenylate cyclase 5, and the tumor necrosis factor superfamily, member 12-13 in patients with major depressive disorder in a current depressive state, but not in a remissive state. Altered expression of these mRNAs was not found in patients with bipolar disorder. Our results suggest that the aberrant REST-mediated transcriptional regulation of, at least, CRH, adenylate cyclase 5, and tumor necrosis factor superfamily, member 12-13, might be state-dependent and associated with the pathophysiology of major depression.
Assuntos
Adenilil Ciclases/metabolismo , Transtorno Bipolar/metabolismo , Hormônio Liberador da Corticotropina/metabolismo , Transtorno Depressivo Maior/metabolismo , Isoenzimas/metabolismo , Proteínas Repressoras/metabolismo , Fator de Necrose Tumoral alfa/metabolismo , Adenilil Ciclases/genética , Transtorno Bipolar/diagnóstico , Transtorno Bipolar/genética , Transtorno Bipolar/psicologia , Hormônio Liberador da Corticotropina/genética , Proteínas de Ligação a DNA/metabolismo , Transtorno Depressivo Maior/diagnóstico , Transtorno Depressivo Maior/genética , Transtorno Depressivo Maior/psicologia , Manual Diagnóstico e Estatístico de Transtornos Mentais , Regulação para Baixo/genética , Feminino , Humanos , Isoenzimas/genética , Masculino , Pessoa de Meia-Idade , RNA Mensageiro/metabolismo , Proteínas Repressoras/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Índice de Gravidade de Doença , Fatores de Transcrição/metabolismo , Transcrição Gênica , Fator de Necrose Tumoral alfa/genética , Regulação para Cima/genéticaRESUMO
Members of the basic helix-loop-helix (bHLH) family of transcription factors regulate the specification and differentiation of numerous cell types during embryonic development. Hand1 and Hand2 are expressed by a subset of neural crest cells in the anterior branchial arches and are involved in craniofacial development. However, the precise mechanisms by which Hand proteins mediate biological actions and regulate downstream target genes in branchial arches is largely unknown. Here, we report that Hand2 negatively regulates intramembranous ossification of the mandible by directly inhibiting the transcription factor Runx2, a master regulator of osteoblast differentiation. Hand proteins physically interact with Runx2, suppressing its DNA binding and transcriptional activity. This interaction is mediated by the N-terminal domain of the Hand protein and requires neither dimerization with other bHLH proteins nor DNA binding. We observed partial colocalization of Hand2 and Runx2 in the mandibular primordium of the branchial arch, and downregulation of Hand2 precedes Runx2-driven osteoblast differentiation. Hand2 hypomorphic mutant mice display insufficient mineralization and ectopic bone formation in the mandible due to accelerated osteoblast differentiation, which is associated with the upregulation and ectopic expression of Runx2 in the mandibular arch. Here, we show that Hand2 acts as a novel inhibitor of the Runx2-DNA interaction and thereby regulates osteoblast differentiation in branchial arch development.
Assuntos
Fatores de Transcrição Hélice-Alça-Hélice Básicos/metabolismo , Região Branquial/citologia , Região Branquial/metabolismo , Diferenciação Celular , Subunidade alfa 1 de Fator de Ligação ao Core/metabolismo , DNA/metabolismo , Osteoblastos/citologia , Animais , Fatores de Transcrição Hélice-Alça-Hélice Básicos/química , Imunoprecipitação da Cromatina , Subunidade alfa 1 de Fator de Ligação ao Core/antagonistas & inibidores , Subunidade alfa 1 de Fator de Ligação ao Core/genética , Embrião não Mamífero/citologia , Embrião não Mamífero/metabolismo , Camundongos , Camundongos Mutantes , Modelos Biológicos , Osteoblastos/metabolismo , Osteogênese , Ligação Proteica , Estrutura Terciária de Proteína , Ativação TranscricionalRESUMO
The neural mechanisms through which the state of anesthesia arises and dissipates remain unknown. One common belief is that emergence from anesthesia is the inverse process of induction, brought about by elimination of anesthetic drugs from their CNS site(s) of action. Anesthetic-induced unconsciousness may result from specific interactions of anesthetics with the neural circuits regulating sleep and wakefulness. Orexinergic agonists and antagonists have the potential to alter the stability of the anesthetized state. In this report, we refine the role of the endogenous orexin system in impacting emergence from, but not entry into the anesthetized state, and in doing so, we distinguish mechanisms of induction from those of emergence. We demonstrate that isoflurane and sevoflurane, two commonly used general anesthetics, inhibit c-Fos expression in orexinergic but not adjacent melanin-concentrating hormone (MCH) neurons; suggesting that wake-active orexinergic neurons are inhibited by these anesthetics. Genetic ablation of orexinergic neurons, which causes acquired murine narcolepsy, delays emergence from anesthesia, without changing anesthetic induction. Pharmacologic studies with a selective orexin-1 receptor antagonist confirm a specific orexin effect on anesthetic emergence without an associated change in induction. We conclude that there are important differences in the neural substrates mediating induction and emergence. These findings support the concept that emergence depends, in part, on recruitment and stabilization of wake-active regions of brain.
Assuntos
Anestesia Geral , Anestésicos Inalatórios , Peptídeos e Proteínas de Sinalização Intracelular/fisiologia , Neuropeptídeos/fisiologia , Anestesia Geral/efeitos adversos , Animais , Feminino , Peptídeos e Proteínas de Sinalização Intracelular/agonistas , Peptídeos e Proteínas de Sinalização Intracelular/antagonistas & inibidores , Peptídeos e Proteínas de Sinalização Intracelular/genética , Isoflurano , Masculino , Éteres Metílicos , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Neurônios/efeitos dos fármacos , Neurônios/metabolismo , Neuropeptídeos/agonistas , Neuropeptídeos/antagonistas & inibidores , Neuropeptídeos/genética , Orexinas , Transporte Proteico , Proteínas Proto-Oncogênicas c-fos/antagonistas & inibidores , Proteínas Proto-Oncogênicas c-fos/biossíntese , Proteínas Proto-Oncogênicas c-fos/genética , Proteínas Proto-Oncogênicas c-fos/metabolismo , Sevoflurano , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/genéticaRESUMO
The glucocorticoid receptor (GR) is a key regulator of the hypothalamic-pituitary-adrenal (HPA) axis. Mood disorder patients often exhibit abnormalities in this axis. Although the clinical benefit of antidepressants is associated with the normalization of the disturbed HPA activity by enhanced negative feedback of the HPA axis, the precise mechanism remains unknown. In order to examine the effect of antidepressants on the translocation of GR into the nucleus, we performed time-lapse observation on SY5Y cells that had been transiently transfected with plasmids expressing the green fluorescence protein (GFP)-tagged GRalpha. Clomipramine and desipramine facilitated dexamethasone (Dex)-induced GFP-GRalpha nuclear translocation. Coincubation of verapamil, an inhibitor of membrane steroid transporters, showed little or no additive effect on GFP-GRalpha nuclear translocation induced by both Dex and clomipramine. In the absence of Dex, antidepressants did not induce the translocation of GFP-GRalpha into the nucleus. Using real-time PCR, we examined the effect of antidepressants on splicing isoform of GR, GRalpha, and GRbeta in SY5Y and Jurkat cells. Incubation with paroxetine and desipramine for 48 h and 7 days increased GRalpha expression, whereas the expression of GRbeta remained stable. Antidepressants did not alter the expression of SRp30c that is associated with alternative splicing of GR transcript. Thus, antidepressants exert differential effects on the translocation and expression of GR to enhance GR signaling.