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1.
Cell ; 151(1): 25-40, 2012 Sep 28.
Artigo em Inglês | MEDLINE | ID: mdl-23021213

RESUMO

Astrocytes release glutamate upon activation of various GPCRs to exert important roles in synaptic functions. However, the molecular mechanism of release has been controversial. Here, we report two kinetically distinct modes of nonvesicular, channel-mediated glutamate release. The fast mode requires activation of G(αi), dissociation of G(ßγ), and subsequent opening of glutamate-permeable, two-pore domain potassium channel TREK-1 through direct interaction between G(ßγ) and N terminus of TREK-1. The slow mode is Ca(2+) dependent and requires G(αq) activation and opening of glutamate-permeable, Ca(2+)-activated anion channel Best1. Ultrastructural analyses demonstrate that TREK-1 is preferentially localized at cell body and processes, whereas Best1 is mostly found in microdomains of astrocytes near synapses. Diffusion modeling predicts that the fast mode can target neuronal mGluR with peak glutamate concentration of 100 µM, whereas slow mode targets neuronal NMDA receptors at around 1 µM. Our results reveal two distinct sources of astrocytic glutamate that can differentially influence neighboring neurons.


Assuntos
Astrócitos/metabolismo , Proteínas do Olho/metabolismo , Ácido Glutâmico/metabolismo , Canais Iônicos/metabolismo , Canais de Potássio de Domínios Poros em Tandem/metabolismo , Receptores Acoplados a Proteínas G/metabolismo , Sequência de Aminoácidos , Animais , Bestrofinas , Células Cultivadas , Exocitose , Proteínas do Olho/genética , Células HEK293 , Humanos , Canais Iônicos/genética , Camundongos , Camundongos Knockout , Dados de Sequência Molecular , Canais de Potássio de Domínios Poros em Tandem/genética , Alinhamento de Sequência , Transdução de Sinais
2.
Respiration ; 103(5): 257-267, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38499001

RESUMO

INTRODUCTION: Data on factors related to mortality in patients with bronchiectasis exacerbation are insufficient. Computed tomography (CT) can measure the pectoralis muscle area (PMA) and is a useful tool to diagnose sarcopenia. This study aimed to evaluate whether PMA can predict mortality in patients with bronchiectasis exacerbation. METHODS: Patients hospitalized due to bronchiectasis exacerbation at a single center were retrospectively divided into survivors and non-survivors based on 1-year mortality. Thereafter, a comparison of the clinical and radiologic characteristics was conducted between the two groups. RESULTS: A total of 66 (14%) patients died at 1 year. In the multivariate analysis, age, BMI <18.4 kg/m2, sex-specific PMA quartile, ≥3 exacerbations in the previous year, serum albumin <3.5 g/dL, cystic bronchiectasis, tuberculosis-destroyed lung, and diabetes mellitus were independent predictors for the 1-year mortality in patients hospitalized with bronchiectasis exacerbation. A lower PMA was associated with a lower overall survival rate in the survival analysis according to sex-specific quartiles of PMA. PMA had the highest area under the curve during assessment of prognostic performance in predicting the 1-year mortality. The lowest sex-specific PMA quartile group exhibited higher disease severity than the highest quartile group. CONCLUSIONS: CT-derived PMA was an independent predictor of 1-year mortality in patients hospitalized with bronchiectasis exacerbation. Patients with lower PMA exhibited higher disease severity. These findings suggest that PMA might be a useful marker for providing additional information regarding prognosis of patients with bronchiectasis exacerbation.


Assuntos
Bronquiectasia , Progressão da Doença , Músculos Peitorais , Tomografia Computadorizada por Raios X , Humanos , Masculino , Feminino , Bronquiectasia/mortalidade , Bronquiectasia/diagnóstico por imagem , Idoso , Músculos Peitorais/diagnóstico por imagem , Estudos Retrospectivos , Pessoa de Meia-Idade , Hospitalização , Sarcopenia/diagnóstico por imagem , Sarcopenia/mortalidade , Sarcopenia/diagnóstico , Prognóstico
3.
Proc Natl Acad Sci U S A ; 118(37)2021 09 14.
Artigo em Inglês | MEDLINE | ID: mdl-34504016

RESUMO

Expression and function of odorant receptors (ORs), which account for more than 50% of G protein-coupled receptors, are being increasingly reported in nonolfactory sites. However, ORs that can be targeted by drugs to treat diseases remain poorly identified. Tumor-derived lactate plays a crucial role in multiple signaling pathways leading to generation of tumor-associated macrophages (TAMs). In this study, we hypothesized that the macrophage OR Olfr78 functions as a lactate sensor and shapes the macrophage-tumor axis. Using Olfr78+/+ and Olfr78-/- bone marrow-derived macrophages with or without exogenous Olfr78 expression, we demonstrated that Olfr78 sensed tumor-derived lactate, which was the main factor in tumor-conditioned media responsible for generation of protumoral M2-TAMs. Olfr78 functioned together with Gpr132 to mediate lactate-induced generation of protumoral M2-TAMs. In addition, syngeneic Olfr78-deficient mice exhibited reduced tumor progression and metastasis together with an increased anti- versus protumoral immune cell population. We propose that the Olfr78-lactate interaction is a therapeutic target to reduce and prevent tumor progression and metastasis.


Assuntos
Proteínas de Ciclo Celular/metabolismo , Receptores Acoplados a Proteínas G/metabolismo , Receptores Odorantes/metabolismo , Macrófagos Associados a Tumor/metabolismo , Animais , Proteínas de Ciclo Celular/fisiologia , Linhagem Celular Tumoral , Feminino , Humanos , Ácido Láctico/metabolismo , Macrófagos/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Fenótipo , Receptores Acoplados a Proteínas G/fisiologia , Receptores Odorantes/fisiologia , Transdução de Sinais , Microambiente Tumoral , Macrófagos Associados a Tumor/fisiologia
4.
EMBO Rep ; 21(2): e48097, 2020 02 05.
Artigo em Inglês | MEDLINE | ID: mdl-31782602

RESUMO

TMEM16A, a Ca2+ -activated Cl- channel, is known to modulate the excitability of various types of cells; however, its function in central neurons is largely unknown. Here, we show the specific expression of TMEM16A in the medial habenula (mHb) via RNAscope in situ hybridization, immunohistochemistry, and electrophysiology. When TMEM16A is ablated in the mHb cholinergic neurons (TMEM16A cKO mice), the slope of after-hyperpolarization of spontaneous action potentials decreases and the firing frequency is reduced. Reduced mHb activity also decreases the activity of the interpeduncular nucleus (IPN). Moreover, TMEM16A cKO mice display anxiogenic behaviors and deficits in social interaction without despair-like phenotypes or cognitive dysfunctions. Finally, chemogenetic inhibition of mHb cholinergic neurons using the DREADD (Designer Receptors Exclusively Activated by Designer Drugs) approach reveals similar behavioral phenotypes to those of TMEM16A cKO mice. We conclude that TMEM16A plays a key role in anxiety-related behaviors regulated by mHb cholinergic neurons and could be a potential therapeutic target against anxiety-related disorders.


Assuntos
Habenula , Animais , Ansiedade/genética , Neurônios Colinérgicos , Camundongos , Camundongos Endogâmicos C57BL
5.
J Infect Chemother ; 28(1): 47-53, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34627705

RESUMO

INTRODUCTION: Patients with aspiration pneumonia (AP) exhibit higher mortality than those with non-AP. However, data regarding predictors of short-term prognosis in patients with community-acquired AP are limited. METHODS: Patients hospitalized with community-acquired pneumonia (CAP) were retrospectively classified into aspiration pneumonia (AP) and non-AP groups. The AP patients were further divided into nonsurvivors and survivors by 30-day mortality, and various clinical variables were compared between the groups. RESULTS: Of 1249 CAP patients, 254 (20.3%) were classified into the AP group, of whom 76 patients (29.9%) died within 30 days. CURB-65, pneumonia severity index (PSI), and Infectious Diseases Society of America/American Thoracic Society criteria for severe CAP (SCAP) showed only modest prognostic performance for the prediction of 30-day mortality (c-statistics, 0.635, 0.647, and 0.681, respectively). Along with the PSI and SCAP, Eastern Cooperative Oncology Group performance status (ECOG-PS) and blood biomarkers, including, N-terminal of prohormone brain natriuretic peptide (NT-proBNP) and albumin, were independent predictors of 30-day mortality. In models based on clinical prediction rules, including CURB-65, PSI, and SCAP, the addition of ECOG-PS further improved their c-statistics compared to the clinical prediction rules alone. In the four combinations based on SCAP, ECOG-PS, and two blood biomarkers (NT-proBNP and albumin), the c-statistics further increased to reach approximately 0.8. CONCLUSIONS: CURB-65, PSI, and SCAP exhibited only modest discriminatory power in predicting the 30-day mortality of patients with community-acquired AP. The addition of performance status and blood biomarkers, including NT-proBNP and albumin, further increased prognostic performance, showing good predictive accuracy in the SCAP-based model.


Assuntos
Infecções Comunitárias Adquiridas , Pneumonia Aspirativa , Pneumonia , Humanos , Prognóstico , Estudos Retrospectivos , Índice de Gravidade de Doença
6.
Int J Mol Sci ; 23(18)2022 Sep 10.
Artigo em Inglês | MEDLINE | ID: mdl-36142409

RESUMO

Tweety family member 3 (TTYH3) is a calcium-activated chloride channel with a non-pore-forming structure that controls cell volume and signal transduction. We investigated the role of TTYH3 as a cancer-promoting factor in bladder cancer. The mRNA expression of TTYH3 in bladder cancer patients was investigated using various bioinformatics databases. The results demonstrated that the increasingly greater expression of TTYH3 increasingly worsened the prognosis of patients with bladder cancer. TTYH3 knockdown bladder cancer cell lines were constructed by their various cancer properties measured. TTYH3 knockdown significantly reduced cell proliferation and sphere formation. Cell migration and invasion were also significantly reduced in knockdown bladder cancer cells, compared to normal bladder cancer cells. The knockdown of TTYH3 led to the downregulation of H-Ras/A-Raf/MEK/ERK signaling by inhibiting fibroblast growth factor receptor 1 (FGFR1) phosphorylation. This signaling pathway also attenuated the expression of c-Jun and c-Fos. The findings implicate TTYH3 as a potential factor regulating the properties of bladder cancer and as a therapeutic target.


Assuntos
Canais de Cloreto/metabolismo , Sistema de Sinalização das MAP Quinases , Neoplasias da Bexiga Urinária , Linhagem Celular Tumoral , Proliferação de Células , Humanos , Quinases de Proteína Quinase Ativadas por Mitógeno/metabolismo , RNA Mensageiro/metabolismo , Receptor Tipo 1 de Fator de Crescimento de Fibroblastos/genética , Receptor Tipo 1 de Fator de Crescimento de Fibroblastos/metabolismo , Neoplasias da Bexiga Urinária/metabolismo , Neoplasias da Bexiga Urinária/patologia
7.
J Cell Physiol ; 236(11): 7625-7641, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-33949692

RESUMO

The ability to generate astrocytes from human pluripotent stem cells (hPSCs) offers a promising cellular model to study the development and physiology of human astrocytes. The extant methods for generating functional astrocytes required long culture periods and there remained much ambiguity on whether such paradigms follow the innate developmental program. In this report, we provided an efficient and rapid method for generating physiologically functional astrocytes from hPSCs. Overexpressing the nuclear factor IB in hPSC-derived neural precursor cells induced a highly enriched astrocyte population in 2 weeks. RNA sequencing and functional analyses demonstrated progressive transcriptomic and physiological changes in the cells, resembling in vivo astrocyte development. Further analyses substantiated previous results and established the MAPK pathway necessary for astrocyte differentiation. Hence, this differentiation paradigm provides a prospective in vitro model for human astrogliogenesis studies and the pathophysiology of neurological diseases concerning astrocytes.


Assuntos
Astrócitos/metabolismo , Diferenciação Celular , Proliferação de Células , Fatores de Transcrição NFI/metabolismo , Células-Tronco Neurais/metabolismo , Células-Tronco Pluripotentes/metabolismo , Linhagem Celular , Regulação da Expressão Gênica no Desenvolvimento , Humanos , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Fatores de Transcrição NFI/genética , Fenótipo , Transdução de Sinais , Transcriptoma
8.
Glia ; 68(9): 1794-1809, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32077526

RESUMO

Finding causative genetic mutations is important in the diagnosis and treatment of hereditary peripheral neuropathies. This study was conducted to find new genes involved in the pathophysiology of hereditary peripheral neuropathy. We identified a new mutation in the EBP50 gene, which is co-segregated with neuropathic phenotypes, including motor and sensory deficit in a family with Charcot-Marie-Tooth disease. EBP50 is known to be important for the formation of microvilli in epithelial cells, and the discovery of this gene mutation allowed us to study the function of EBP50 in the nervous system. EBP50 was strongly expressed in the nodal and paranodal regions of sciatic nerve fibers, where Schwann cell microvilli contact the axolemma, and at the growth tips of primary Schwann cells. In addition, EBP50 expression was decreased in mouse models of peripheral neuropathy. Knockout mice were used to study EBP50 function in the peripheral nervous system. Interestingly motor function deficit and abnormal histology of nerve fibers were observed in EBP50+/- heterozygous mice at 12 months of age, but not 3 months. in vitro studies using Schwann cells showed that NRG1-induced AKT activation and migration were significantly reduced in cells overexpressing the I325V mutant of EBP50 or cells with knocked-down EBP50 expression. In conclusion, we show for the first time that loss of function due to EBP50 gene deficiency or mutation can cause peripheral neuropathy.


Assuntos
Doença de Charcot-Marie-Tooth , Animais , Doença de Charcot-Marie-Tooth/genética , Camundongos , Camundongos Knockout , Mutação , Nervos Periféricos , Sistema Nervoso Periférico
9.
Biochem Biophys Res Commun ; 533(3): 319-324, 2020 12 10.
Artigo em Inglês | MEDLINE | ID: mdl-32958249

RESUMO

We previously demonstrated that CPNE1 induces neuronal differentiation and identified two binding proteins of CPNE1 (14-3-3γ and Jab1) as potential regulators of CPNE1-mediated neuronal differentiation in hippocampal progenitor cells. To better understand the cellular processes in which CPNE1 participates in neuronal differentiation, we here carried out a yeast two-hybrid screening to find another CPNE1 binding protein. Among the identified proteins, HCLS1-related protein X-1 (HAX1) directly interacts with CPNE1. Immunostaining experiments showed that a fraction of CPNE1 and HAX1 co-localized in the cytosol, particularly in the plasma membrane. In addition, the physical interaction as well as the specific binding regions between CPNE1 and HAX1 were confirmed in vitro and in vivo. Moreover, AKT phosphorylation, Tuj1 (neuronal marker protein) expression, and neurite outgrowth are all reduced in CPNE1/HAX1 overexpressing cells compared to CPNE1 only overexpressing HiB5 cells. Conversely, the HAX1 mutant that does not bind to CPNE1 was unable to inhibit the CPNE1-mediated neuronal differentiation. Together these results indicate that HAX1 is a binding partner of CPNE1 and CPNE1-mediated neuronal differentiation is negatively affected through the binding of HAX1, especially its N-terminal region, with CPNE1.


Assuntos
Proteínas de Ligação ao Cálcio/genética , Diferenciação Celular/genética , Peptídeos e Proteínas de Sinalização Intracelular/genética , Neurônios/metabolismo , Proteínas Proto-Oncogênicas c-akt/genética , Tubulina (Proteína)/genética , Proteínas 14-3-3/genética , Proteínas 14-3-3/metabolismo , Animais , Complexo do Signalossomo COP9/genética , Complexo do Signalossomo COP9/metabolismo , Células COS , Proteínas de Ligação ao Cálcio/metabolismo , Linhagem Celular , Membrana Celular/metabolismo , Chlorocebus aethiops , Regulação da Expressão Gênica , Células HEK293 , Humanos , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Mutação , Neurônios/citologia , Fosforilação , Ligação Proteica , Proteínas Proto-Oncogênicas c-akt/metabolismo , Ratos , Transdução de Sinais , Tubulina (Proteína)/metabolismo , Técnicas do Sistema de Duplo-Híbrido
10.
Cell Biochem Funct ; 38(2): 167-175, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31782179

RESUMO

TREK-1 (TWIK-related K+ channel), a member of the two-pore domain K+ (K2P) channel family, is highly expressed in astrocytes, where it plays a key role in glutamate release and passive conductance. In addition, TREK-1 is induced to protect neurons under pathological conditions such as hypoxia. However, the upstream regulation of TREK-1 remains poorly understood. In this study, we found that AEG-1 (astrocyte elevated gene-1) regulates the expression of astrocytic TREK-1 under hypoxic conditions. Upregulation of AEG-1 increased expression of TREK-1 in astrocytes, and knockdown of AEG-1 dramatically decreased the mRNA and protein levels of TREK-1, which were restored by expression of shRNA-insensitive AEG-1. In addition, expression of TREK-1 was not regulated in the absence of AEG-1, even when HIF1α was present. Together, these results suggest that AEG-1 acts as a major upstream regulator of TREK-1 channels in astrocytes under hypoxia. SIGNIFICANCE OF THE STUDY: Previous studies have reported that hypoxia increases the expression of astrocytic TREK-1 and that increased TREK-1 expression protects neuronal cells from apoptosis. However, its cellular mechanism is not clear. In this study we first showed that AEG-1 is a major mediator of hypoxic-regulated TREK-1 expression in normal astrocytes independently of HIF-1α.


Assuntos
Astrócitos/metabolismo , Hipóxia Celular , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Proteínas de Membrana/metabolismo , Canais de Potássio de Domínios Poros em Tandem/metabolismo , Proteínas de Ligação a RNA/metabolismo , Animais , Apoptose , Astrócitos/citologia , Eletroporação , Ácido Glutâmico/metabolismo , Células HEK293 , Humanos , Infarto da Artéria Cerebral Média/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos ICR , Neurônios/metabolismo , RNA Mensageiro/metabolismo
11.
Int J Mol Sci ; 21(24)2020 Dec 17.
Artigo em Inglês | MEDLINE | ID: mdl-33348878

RESUMO

Astrocytes, the most abundant cell type in the brain, are non-excitable cells and play critical roles in brain function. Mature astrocytes typically exhibit a linear current-voltage relationship termed passive conductance, which is believed to enable astrocytes to maintain potassium homeostasis in the brain. We previously demonstrated that TWIK-1/TREK-1 heterodimeric channels mainly contribute to astrocytic passive conductance. However, the molecular identity of astrocytic passive conductance is still controversial and needs to be elucidated. Here, we report that spadin, an inhibitor of TREK-1, can dramatically reduce astrocytic passive conductance in brain slices. A series of gene silencing experiments demonstrated that spadin-sensitive currents are mediated by TWIK-1/TREK-1 heterodimeric channels in cultured astrocytes and hippocampal astrocytes from brain slices. Our study clearly showed that TWIK-1/TREK-1-heterodimeric channels can act as the main molecular machinery of astrocytic passive conductance, and suggested that spadin can be used as a specific inhibitor to control astrocytic passive conductance.


Assuntos
Astrócitos/fisiologia , Encéfalo/fisiologia , Regulação da Expressão Gênica/efeitos dos fármacos , Peptídeos/farmacologia , Canais de Potássio de Domínios Poros em Tandem/antagonistas & inibidores , Multimerização Proteica , Animais , Astrócitos/citologia , Astrócitos/efeitos dos fármacos , Encéfalo/citologia , Encéfalo/efeitos dos fármacos , Feminino , Masculino , Camundongos , Camundongos Endogâmicos C57BL
12.
Biochem Biophys Res Commun ; 514(1): 344-350, 2019 06 18.
Artigo em Inglês | MEDLINE | ID: mdl-31036321

RESUMO

The bestrophin family comprises well-known Ca2+-activated chloride channels (CaCC) that are expressed in a variety tissues including the brain, eye, gastrointestinal tract, and muscle tissues. Among the family members, bestrophin-1 (BEST1) is known to exist mainly in retinal pigment epithelium cells, but we recently reported that BEST1 mediates Ca2+-activated Cl- currents in hippocampal astrocytes. Despite its critical roles in physiological processes, including tonic γ-aminobutyric acid release and glutamate transport, the mechanisms that regulate BEST1 are poorly understood. In this study, we identified NEDD4L (NEDD4-2), an E3 ubiquitin ligase, as a binding partner of BEST1. A series of deletion constructs revealed that the WW3-4 domains of NEDD4L were important for interaction with BEST1. We observed that BEST1 underwent ubiquitin-dependent proteolysis and found that the conserved lysine370 residue in the C-terminus of BEST1 was important for its ubiquitination. Finally, we demonstrated that NEDD4L inhibited whole cell currents mediated by BEST1 but not by the BEST1(K370R) mutant. Collectively, our data demonstrated that NEDD4L played a critical role in regulating the surface expression of BEST1 by promoting its internalization and degradation.


Assuntos
Bestrofinas/metabolismo , Ubiquitina-Proteína Ligases Nedd4/metabolismo , Animais , Bestrofinas/genética , Células HEK293 , Humanos , Lisina/metabolismo , Camundongos , Ubiquitina-Proteína Ligases Nedd4/genética , Complexo de Endopeptidases do Proteassoma/metabolismo , Domínios Proteicos , Domínios e Motivos de Interação entre Proteínas , Ubiquitinação , Ubiquitinas/metabolismo
13.
Respiration ; 97(6): 508-517, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30625485

RESUMO

BACKGROUND: Data regarding community-acquired pneumonia (CAP) identified on chest computed tomography (CT) but not on chest radiography (CR) are limited. OBJECTIVES: The present study aimed to investigate the clinical and radiological features of these patients. METHODS: We retrospectively compared the clinical characteristics, etiological agents, treatment outcomes, and CT findings between CAP patients with negative CR and positive CT findings (negative CR group) and those with positive CR as well as CT findings (control group). RESULTS: Of 1,925 patients, 94 patients (4.9%) were included in the negative CR group. Negative CR findings could be attributed to the location of the lesions (e.g., those located in the dependent lung) and CT pattern with a low attenuation, such as ground-glass opacity (GGO). The negative CR group was characterized by a higher frequency of aspiration pneumonia, lower incidences of complicated parapneumonic effusion or empyema and pleural drainage, and lower blood levels of inflammatory markers than the control group. On CT, the negative CR group exhibited higher rates of GGO- and bronchiolitis-predominant patterns and a lower rate of consolidation pattern. Despite shorter length of hospital stay in the negative CR group, 30-day and in-hospital mortalities were similar between the two groups. CONCLUSIONS: CAP patients with negative CR findings are characterized by lower blood levels of inflammatory markers, a higher incidence of aspiration pneumonia, and a lower incidence of complicated para-pneumonic effusion or empyema than those with positive CR findings. Chest CT scan should be considered in suspected CAP patients with a negative CR, especially in bedridden patients.


Assuntos
Infecções Comunitárias Adquiridas/diagnóstico por imagem , Infecções Comunitárias Adquiridas/microbiologia , Pneumonia/diagnóstico por imagem , Pneumonia/microbiologia , Idoso , Antibacterianos/uso terapêutico , Infecções Comunitárias Adquiridas/terapia , Reações Falso-Negativas , Feminino , Hospitalização , Humanos , Masculino , Pessoa de Meia-Idade , Pneumonia/terapia , Radiografia Torácica , Estudos Retrospectivos , Tomografia Computadorizada por Raios X , Resultado do Tratamento
14.
Int J Mol Sci ; 20(23)2019 Nov 24.
Artigo em Inglês | MEDLINE | ID: mdl-31771312

RESUMO

TWIK-related potassium channel-1 (TREK-1) is broadly expressed in the brain and involved in diverse brain diseases, such as seizures, ischemia, and depression. However, the cell type-specific roles of TREK-1 in the brain are largely unknown. Here, we generated a Cre-dependent TREK-1 knockdown (Cd-TREK-1 KD) transgenic mouse containing a gene cassette for Cre-dependent TREK-1 short hairpin ribonucleic acid to regulate the cell type-specific TREK-1 expression. We confirmed the knockdown of TREK-1 by injecting adeno-associated virus (AAV) expressing Cre into the hippocampus of the mice. To study the role of hippocampal neuronal TREK-1 in a lipopolysaccharide (LPS)-induced depression model, we injected AAV-hSyn-BFP (nCTL group) or AAV-hSyn-BFP-Cre (nCre group) virus into the hippocampus of Cd-TREK-1 KD mice. Interestingly, the immobility in the tail suspension test after LPS treatment did not change in the nCre group. Additionally, some neurotrophic factors (BDNF, VEGF, and IGF-1) significantly increased more in the nCre group compared to the nCTL group after LPS treatment, but there was no difference in the expression of their receptors. Therefore, our data suggest that TREK-1 in the hippocampal neurons has antidepressant effects, and that Cd-TREK-1 KD mice are a valuable tool to reveal the cell type-specific roles of TREK-1 in the brain.


Assuntos
Transtorno Depressivo/etiologia , Hipocampo/metabolismo , Canais de Potássio de Domínios Poros em Tandem/genética , Animais , Comportamento Animal/efeitos dos fármacos , Corticosterona/sangue , Citocinas/genética , Citocinas/metabolismo , Giro Denteado/metabolismo , Dependovirus/genética , Transtorno Depressivo/metabolismo , Modelos Animais de Doenças , Vetores Genéticos/genética , Vetores Genéticos/metabolismo , Lipopolissacarídeos/toxicidade , Camundongos , Camundongos Transgênicos , RNA Interferente Pequeno/genética , RNA Interferente Pequeno/metabolismo
15.
Circulation ; 135(23): 2288-2298, 2017 Jun 06.
Artigo em Inglês | MEDLINE | ID: mdl-28356442

RESUMO

BACKGROUND: Bone morphogenetic protein (BMP) signaling has multiple roles in the development and function of the blood vessels. In humans, mutations in BMP receptor type 2 (BMPR2), a key component of BMP signaling, have been identified in the majority of patients with familial pulmonary arterial hypertension (PAH). However, only a small subset of individuals with BMPR2 mutation develops PAH, suggesting that additional modifiers of BMPR2 function play an important role in the onset and progression of PAH. METHODS: We used a combination of studies in zebrafish embryos and genetically engineered mice lacking endothelial expression of Vegfr3 to determine the interaction between vascular endothelial growth factor receptor 3 (VEGFR3) and BMPR2. Additional in vitro studies were performed by using human endothelial cells, including primary lung endothelial cells from subjects with PAH. RESULTS: Attenuation of Vegfr3 in zebrafish embryos abrogated Bmp2b-induced ectopic angiogenesis. Endothelial cells with disrupted VEGFR3 expression failed to respond to exogenous BMP stimulation. Mechanistically, VEGFR3 is physically associated with BMPR2 and facilitates ligand-induced endocytosis of BMPR2 to promote phosphorylation of SMADs and transcription of ID genes. Conditional, endothelial-specific deletion of Vegfr3 in mice resulted in impaired BMP signaling responses, and significantly worsened hypoxia-induced pulmonary hypertension. Consistent with these data, we found significant decrease in VEGFR3 expression in pulmonary arterial endothelial cells from human PAH subjects, and reconstitution of VEGFR3 expression in PAH pulmonary arterial endothelial cells restored BMP signaling responses. CONCLUSIONS: Our findings identify VEGFR3 as a key regulator of endothelial BMPR2 signaling and a potential determinant of PAH penetrance in humans.


Assuntos
Receptores de Proteínas Morfogenéticas Ósseas Tipo II/biossíntese , Endotélio Vascular/metabolismo , Hipertensão Pulmonar/metabolismo , Receptor 3 de Fatores de Crescimento do Endotélio Vascular/biossíntese , Animais , Receptores de Proteínas Morfogenéticas Ósseas Tipo II/genética , Células Cultivadas , Endotélio Vascular/patologia , Humanos , Hipertensão Pulmonar/genética , Hipertensão Pulmonar/patologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Receptor 3 de Fatores de Crescimento do Endotélio Vascular/genética , Peixe-Zebra
16.
Biochem Biophys Res Commun ; 497(1): 424-429, 2018 02 26.
Artigo em Inglês | MEDLINE | ID: mdl-29448099

RESUMO

Copine1 (CPNE1), has tandem C2 domains and an A domain. We previously demonstrated that CPNE1 directly induces neuronal differentiation via Protein kinase B (AKT) phosphorylation in the hippocampal progenitor cell line, HiB5. To better understand its cellular function, we carried out a yeast two-hybrid screening to find CPNE1 binding partners. Among the identified proteins, Jun activation domain-binding protein 1 (JAB1) appears to directly interact with CPNE1. Between CPNE1 and JAB1, the physical interaction was confirmed in vitro and in vivo. In addition the specific binding regions of CPNE1 and JAB1 was confirmed with truncated mutant assay. Furthermore, our results also demonstrate that AKT phosphorylation and expression of the neuronal marker protein are increased when JAB1 is overexpressed in CPNE1 high expressed HiB5 cells. Moreover, overexpression of both CPNE1 and JAB1 in HiB5 cells effectively increased neurite outgrowth. Collectively, our findings suggest that JAB1 activates the neuronal differentiation ability of CPNE1 through the binding of C2A domain in CPNE1 with MPN domain in JAB1.


Assuntos
Complexo do Signalossomo COP9/metabolismo , Proteínas de Ligação ao Cálcio/metabolismo , Diferenciação Celular/fisiologia , Hipocampo/citologia , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Células-Tronco Neurais/metabolismo , Neurogênese/fisiologia , Neurônios/metabolismo , Peptídeo Hidrolases/metabolismo , Sítios de Ligação , Linhagem Celular , Regulação da Expressão Gênica no Desenvolvimento/fisiologia , Hipocampo/metabolismo , Humanos , Células-Tronco Neurais/citologia , Neurônios/citologia , Ligação Proteica
17.
Biochem Biophys Res Commun ; 495(1): 168-173, 2018 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-29101038

RESUMO

Copine 1 (CPNE1) is a well-known phospholipid binding protein in plasma membrane of various cell types. In brain cells, CPNE1 is closely associated with AKT signaling pathway, which is important for neural stem cell (NSC) functions during brain development. Here, we investigated the role of CPNE1 in the regulation of brain NSC functions during brain development and determined its underlying mechanism. In this study, abundant expression of CPNE1 was observed in neural lineage cells including NSCs and immature neurons in human. With mouse brain tissues in various developmental stages, we found that CPNE1 expression was higher at early embryonic stages compared to postnatal and adult stages. To model developing brain in vitro, we used primary NSCs derived from mouse embryonic hippocampus. Our in vitro study shows decreased proliferation and multi-lineage differentiation potential in CPNE1 deficient NSCs. Finally, we found that the deficiency of CPNE1 downregulated mTOR signaling in embryonic NSCs. These data demonstrate that CPNE1 plays a key role in the regulation of NSC functions through the activation of AKT-mTOR signaling pathway during brain development.


Assuntos
Encéfalo/embriologia , Proteínas de Ligação ao Cálcio/metabolismo , Células-Tronco Neurais/citologia , Neurogênese , Animais , Encéfalo/citologia , Encéfalo/metabolismo , Linhagem Celular , Células Cultivadas , Células-Tronco Embrionárias/citologia , Células-Tronco Embrionárias/metabolismo , Humanos , Camundongos Endogâmicos C57BL , Células-Tronco Neurais/metabolismo , Transdução de Sinais , Serina-Treonina Quinases TOR/metabolismo
19.
Exp Cell Res ; 356(1): 85-92, 2017 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-28412242

RESUMO

Copine1 (CPNE1), known as a calcium-dependent membrane-binding protein, has tandem C2 domains and an A domain. We previously demonstrated that CPNE1 directly induces neuronal differentiation via Protein kinase B (AKT) phosphorylation in the hippocampal progenitor cell line, HiB5. To better understand its cellular function, we carried out a yeast two-hybrid screening to find CPNE1 binding partners. Among the identified proteins, 14-3-3γ appears to directly interact with CPNE1. Between CPNE1 and 14-3-3γ, the physical interaction as well as the specific binding regions of CPNE1 was confirmed in vitro and in vivo. Furthermore, among the seven 14-3-3 isotypes, only 14-3-3γ directly interacts with CPNE1. Our results also demonstrate that AKT phosphorylation, neurite outgrowth and expression of the neuronal marker protein are increased when 14-3-3γ is overexpressed in CPNE1 high expressed HiB5 cells. Furthermore, the neighboring Ser54 amino acids residue of C2A domain in CPNE1 has an important role in binding with 14-3-3γ, and in differentiation-related function of CPNE1. Moreover, mutation of Ser54 amino acids residue in CPNE1 effectively decreased association with 14-3-3γ and neuronal differentiation of HiB5 cells. Collectively, our findings indicate that 14-3-3γ regulates the differentiation ability of CPNE1 through the binding with C2A domain of CPNE1 in HiB5 cells.


Assuntos
Proteínas 14-3-3/metabolismo , Proteínas de Ligação ao Cálcio/metabolismo , Hipocampo/citologia , Neurogênese/genética , Células-Tronco/citologia , Proteínas 14-3-3/genética , Animais , Células COS , Proteínas de Ligação ao Cálcio/genética , Linhagem Celular , Chlorocebus aethiops , Células HEK293 , Humanos , Fosforilação , Ligação Proteica/genética , Domínios Proteicos , Proteínas Proto-Oncogênicas c-akt/metabolismo , Interferência de RNA , RNA Interferente Pequeno/genética
20.
Stem Cells ; 34(4): 888-901, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-26701067

RESUMO

Neurogenesis occurs spontaneously in the subventricular zone (SVZ) of the lateral ventricle in adult rodent brain, but it has long been debated whether there is sufficient adult neurogenesis in human SVZ. Subcallosal zone (SCZ), a posterior continuum of SVZ closely associated with posterior regions of cortical white matter, has also been reported to contain adult neural stem cells (aNSCs) in both rodents and humans. However, little is known whether SCZ-derived aNSC (SCZ-aNSCs) can produce cortical neurons following brain injury. We found that SCZ-aNSCs exhibited limited neuronal differentiation potential in culture and after transplantation in mice. Neuroblasts derived from SCZ initially migrated toward injured cortex regions following brain injury, but later exhibited apoptosis. Overexpression of anti-apoptotic bcl-xL in the SCZ by retroviral infection rescued neuroblasts from cell death in the injured cortex, but neuronal maturation was still limited, resulting in atrophy. In combination with Bcl-xL, infusion of brain-derived neurotropic factor rescued atrophy, and importantly, a subset of such SCZ-aNSCs differentiated and attained morphological and physiological characteristics of mature, excitatory neurons. These results suggest that the combination of anti-apoptotic and neurotrophic factors might enable the use of aNSCs derived from the SCZ in cortical neurogenesis for neural replacement therapy.


Assuntos
Lesões Encefálicas/terapia , Diferenciação Celular/genética , Células-Tronco Neurais/transplante , Neurogênese/genética , Células-Tronco Adultas/transplante , Animais , Apoptose , Lesões Encefálicas/patologia , Proliferação de Células/genética , Humanos , Camundongos , Neurônios/patologia , Córtex Pré-Frontal
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