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1.
Mol Cell ; 83(23): 4255-4271.e9, 2023 Dec 07.
Artigo em Inglês | MEDLINE | ID: mdl-37995687

RESUMO

Endogenous retroviruses (ERVs) are remnants of ancient parasitic infections and comprise sizable portions of most genomes. Although epigenetic mechanisms silence most ERVs by generating a repressive environment that prevents their expression (heterochromatin), little is known about mechanisms silencing ERVs residing in open regions of the genome (euchromatin). This is particularly important during embryonic development, where induction and repression of distinct classes of ERVs occur in short temporal windows. Here, we demonstrate that transcription-associated RNA degradation by the nuclear RNA exosome and Integrator is a regulatory mechanism that controls the productive transcription of most genes and many ERVs involved in preimplantation development. Disrupting nuclear RNA catabolism promotes dedifferentiation to a totipotent-like state characterized by defects in RNAPII elongation and decreased expression of long genes (gene-length asymmetry). Our results indicate that RNA catabolism is a core regulatory module of gene networks that safeguards RNAPII activity, ERV expression, cell identity, and developmental potency.


Assuntos
Retrovirus Endógenos , Retrovirus Endógenos/genética , RNA Nuclear , Epigênese Genética , Heterocromatina , Expressão Gênica
2.
Cell Host Microbe ; 31(7): 1154-1169.e10, 2023 07 12.
Artigo em Inglês | MEDLINE | ID: mdl-37339625

RESUMO

Targeted protein degradation (TPD), as exemplified by proteolysis-targeting chimera (PROTAC), is an emerging drug discovery platform. PROTAC molecules, which typically contain a target protein ligand linked to an E3 ligase ligand, recruit a target protein to the E3 ligase to induce its ubiquitination and degradation. Here, we applied PROTAC approaches to develop broad-spectrum antivirals targeting key host factors for many viruses and virus-specific antivirals targeting unique viral proteins. For host-directed antivirals, we identified a small-molecule degrader, FM-74-103, that elicits selective degradation of human GSPT1, a translation termination factor. FM-74-103-mediated GSPT1 degradation inhibits both RNA and DNA viruses. Among virus-specific antivirals, we developed viral RNA oligonucleotide-based bifunctional molecules (Destroyers). As a proof of principle, RNA mimics of viral promoter sequences were used as heterobifunctional molecules to recruit and target influenza viral polymerase for degradation. This work highlights the broad utility of TPD to rationally design and develop next-generation antivirals.


Assuntos
Antivirais , Vírus , Humanos , Antivirais/farmacologia , Proteólise , RNA Viral/metabolismo , Ligantes , Vírus/metabolismo , Ubiquitina-Proteína Ligases/metabolismo , Proteínas Virais/metabolismo , Proteínas de Transporte/metabolismo
3.
Biol Psychiatry ; 91(7): 676-689, 2022 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-34961622

RESUMO

BACKGROUND: The reward system regulates motivated behavior, and repeated practice of specific motivated behavior might conversely modify the reward system. However, the detailed mechanisms by which they reciprocally regulate each other are not clearly understood. METHODS: Mice subjected to chronic restraint stress show long-lasting depressive-like behavior, which is rescued by continual engagement with playable objects. A series of molecular, pharmacological, genetic, and behavioral analyses, combined with microarray, liquid chromatography, and chemogenetic tools, are used to investigate the neural mechanisms of antidepressive effects of playable objects. RESULTS: Here, we show that repeated restraint induces dopamine surges into the nucleus accumbens-lateral shell (NAc-lSh), which cause upregulation of the neuropeptide PACAP in the NAc-lSh. As repeated stress is continued, the dopamine surge by stressors is adaptively suppressed without restoring PACAP upregulation, and the resulting enhanced PACAP inputs from NAc-lSh neurons to the ventral pallidum facilitate depressive-like behaviors. Continual engagement with playable objects in mice subjected to chronic stress remediates reduced dopamine response to new stressors, enhanced PACAP upregulation, and depressive-like behaviors. Overactivation of dopamine D1 receptors over the action of D2 receptors in the NAc-lSh promotes depressive-like behaviors. Conversely, inhibition of D1 receptors or PACAP upregulation in the NAc-lSh confers resilience to chronic stress-induced depressive-like behaviors. Histochemical and chemogenetic analyses reveal that engagement with playable objects produces antidepressive effects by reshaping the ventral tegmental area-to-NAc-lSh and NAc-lSh-to-ventral pallidum circuits. CONCLUSIONS: These results suggest that behavioral engagement with playable objects remediates depressive-like behaviors by resolving stress-induced maladaptive changes in the reward system.


Assuntos
Dopamina , Polipeptídeo Hipofisário Ativador de Adenilato Ciclase , Animais , Antidepressivos/farmacologia , Camundongos , Núcleo Accumbens , Polipeptídeo Hipofisário Ativador de Adenilato Ciclase/farmacologia , Recompensa , Área Tegmentar Ventral
4.
Mol Psychiatry ; 26(12): 7308-7315, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-34234280

RESUMO

Major depressive disorder (MDD) is a severe, common mood disorder. While reduced cerebrospinal fluid (CSF) flow adversely affects brain metabolism and fluid balance in the aging population and during development, only indirect evidence links aberrant CSF circulation with many diseases including neurological, neurodegenerative, and psychiatric disorders, such as anxiety and depression. Here we show a very high concentration of p11 as a key molecular determinant for depression in ependymal cells, which is significantly decreased in patients with MDD, and in two mouse models of depression induced by chronic stress, such as restraint and social isolation. The loss of p11 in ependymal cells causes disoriented ependymal planar cell polarity (PCP), reduced CSF flow, and depression-like and anxiety-like behaviors. p11 intrinsically controls PCP core genes, which mediates CSF flow. Viral expression of p11 in ependymal cells specifically rescues the pathophysiological and behavioral deficits caused by loss of p11. Taken together, our results identify a new role and a key molecular determinant for ependymal cell-driven CSF flow in mood disorders and suggest a novel strategy for development of treatments for stress-associated neurological, neurodegenerative, and psychiatric disorders.


Assuntos
Transtorno Depressivo Maior , Idoso , Animais , Transtornos de Ansiedade , Depressão/metabolismo , Modelos Animais de Doenças , Humanos , Camundongos , Neuroglia
5.
Commun Biol ; 3(1): 292, 2020 06 05.
Artigo em Inglês | MEDLINE | ID: mdl-32504071

RESUMO

Brain aging proceeds with cellular and molecular changes in the limbic system. Aging-dependent changes might affect emotion and stress coping, yet the underlying mechanisms remain unclear. Here, we show aged (18-month-old) mice exhibit upregulation of NADPH oxidase and oxidative stress in the hippocampus, which mirrors the changes in young (2-month-old) mice subjected to chronic stress. Aged mice that lack p47phox, a key subunit of NADPH oxidase, do not show increased oxidative stress. Aged mice exhibit depression-like behavior following weak stress that does not produce depressive behavior in young mice. Aged mice have reduced expression of the epigenetic factor SUV39H1 and its upstream regulator p-AMPK, and increased expression of Ppp2ca in the hippocampus-changes that occur in young mice exposed to chronic stress. SUV39H1 mediates stress- and aging-induced sustained upregulation of p47phox and oxidative stress. These results suggest that aging increases susceptibility to stress by upregulating NADPH oxidase in the hippocampus.


Assuntos
Envelhecimento , Depressão/patologia , NADPH Oxidases/fisiologia , Estresse Oxidativo , Estresse Fisiológico , Animais , Comportamento Animal , Depressão/etiologia , Depressão/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Oxirredução , Espécies Reativas de Oxigênio/metabolismo
6.
Trends Pharmacol Sci ; 41(7): 487-497, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32418644

RESUMO

p11 (S100A10, annexin II light chain, calpactin I light chain) is a multifunctional protein that forms a heterotetrameric complex with Annexin A2, particularly at cell membranes. p11, alone or together with Annexin A2, interacts with several ion channels and receptors and regulates their cellular localization and function. Altered levels of p11 are implicated in the pathophysiology of several forms of cancer, psychiatric disorders, and neurodegeneration. Via interactions with ion channels and receptors, p11 modulates therapeutic actions of drugs targeting brain disorders. By serving as a plasminogen receptor, p11 plays an important role in plasmin generation, fibrinolysis, angiogenesis, tumor progression, and metastasis. Here, we review mechanisms whereby p11 regulates functions of ion channels and receptors in health and disease states.


Assuntos
Anexina A2/metabolismo , Canais Iônicos/metabolismo , Proteínas S100/metabolismo , Membrana Celular/metabolismo , Humanos
7.
Brain Behav Immun ; 87: 765-776, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32201254

RESUMO

Although over one-third of stroke patients may develop post-stroke cognitive impairment (PSCI), the mechanisms underlying PSCI remain unclear. We explored here, the involvement of post-stroke inflammasomes in long-term PSCI development, using a 45 min-middle cerebral artery occlusion (MCAO)/reperfusion-induced PSCI model. Immunohistological assessment on day 1, 3, and 7 was followed by cognitive function test 28 days post-stroke. Evaluation of inflammasome sensor gene expression in aged mouse brains showed dominant expression of absent in melanoma 2 (Aim2) in 6-, 12-, and 18-month-old mouse brains. AIM2 mRNA and protein increased until 7 days post-stroke. PSCI decreased anxiety in elevated plus maze test and impaired spatial learning and memory functions in Morris water maze test 28 days post-stroke. AIM2 and other inflammasome subunit immunoreactivities, including those for caspase-1, interleukin (IL)-1ß, and IL-18, were higher in the hippocampus and cortex of the PSCI than in those of the sham group 7 days post-stroke. AIM2 immunoreactivity of the PSCI group was primarily co-localized with Iba-1 (microglial marker) and CD31 (endothelial cell marker) immunoreactivities but not NeuN (neuronal marker) and GFAP (astrocyte marker) immunoreactivities, suggesting that microglia or endothelial cell-induced AIM2 production mediated PSCI pathogenesis. Additionally, inflammasome-induced pyroptosis might contribute to acute and chronic neuronal death after stroke. AIM2 knockout (KO) and Ac-YVAD-CMK-induced caspase-1 inhibition in mice significantly improved cognitive function and reversed brain volume in the hippocampus relative to those in stroke mice. Conclusively, AIM2 inflammasome-mediated inflammation and pyroptosis likely aggravated PSCI; therefore, targeting and controlling AIM2 inflammasome could potentially treat PSCI.


Assuntos
Lesões Encefálicas , Disfunção Cognitiva , Acidente Vascular Cerebral , Animais , Disfunção Cognitiva/etiologia , Proteínas de Ligação a DNA , Inflamassomos , Camundongos , Acidente Vascular Cerebral/complicações
8.
Mol Psychiatry ; 25(10): 2641, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31520066

RESUMO

A correction to this paper has been published and can be accessed via a link at the top of the paper.

9.
Mol Psychiatry ; 25(10): 2517-2533, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-30659288

RESUMO

Many of the genes disrupted in autism are identified as histone-modifying enzymes and chromatin remodelers, most prominently those that mediate histone methylation/demethylation. However, the role of histone methylation enzymes in the pathophysiology and treatment of autism remains unknown. To address this, we used mouse models of haploinsufficiency of the Shank3 gene (a highly penetrant monogenic autism risk factor), which exhibits prominent autism-like social deficits. We found that histone methyltransferases EHMT1 and EHMT2, as well as histone lysine 9 dimethylation (specifically catalyzed by EHMT1/2), were selectively increased in the prefrontal cortex (PFC) of Shank3-deficient mice and autistic human postmortem brains. Treatment with the EHMT1/2 inhibitor UNC0642 or knockdown of EHMT1/2 in PFC induced a robust rescue of autism-like social deficits in Shank3-deficient mice, and restored NMDAR-mediated synaptic function. Activity-regulated cytoskeleton-associated protein (Arc) was identified as one of the causal factors underlying the rescuing effects of UNC0642 on NMDAR function and social behaviors in Shank3-deficient mice. UNC0642 treatment also restored a large set of genes involved in neural signaling in PFC of Shank3-deficient mice. These results suggest that targeting histone methylation enzymes to adjust gene expression and ameliorate synaptic defects could be a potential therapeutic strategy for autism.


Assuntos
Transtorno Autístico/tratamento farmacológico , Histona-Lisina N-Metiltransferase/antagonistas & inibidores , Proteínas dos Microfilamentos/deficiência , Proteínas do Tecido Nervoso/deficiência , Animais , Transtorno Autístico/genética , Modelos Animais de Doenças , Feminino , Haploinsuficiência , Histona-Lisina N-Metiltransferase/metabolismo , Histonas/metabolismo , Masculino , Metilação/efeitos dos fármacos , Camundongos , Proteínas dos Microfilamentos/genética , Proteínas do Tecido Nervoso/genética , Córtex Pré-Frontal/efeitos dos fármacos , Córtex Pré-Frontal/metabolismo , Quinazolinas/farmacologia
10.
Clin Exp Emerg Med ; 4(4): 208-213, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-29306269

RESUMO

OBJECTIVE: Chest pain is one of the most common complaints in the emergency department (ED). Cardiac computed tomography angiography (CCTA) is a frequently used tool for the early triage of patients with low- to intermediate-risk acute chest pain. We present a study protocol for a multicenter prospective randomized controlled clinical trial testing the hypothesis that a low-dose CCTA protocol using prospective electrocardiogram (ECG)-triggering and limited-scan range can provide sufficient diagnostic safety for early triage of patients with acute chest pain. METHODS: The trial will include 681 younger adult (aged 20 to 55) patients visiting EDs of three academic hospitals for acute chest pain or equivalent symptoms who require further evaluation to rule out acute coronary syndrome. Participants will be randomly allocated to either low-dose or conventional CCTA protocol at a 2:1 ratio. The low-dose group will undergo CCTA with prospective ECG-triggering and restricted scan range from sub-carina to heart base. The conventional protocol group will undergo CCTA with retrospective ECG-gating covering the entire chest. Patient disposition is determined based on computed tomography findings and clinical progression and all patients are followed for a month. The primary objective is to prove that the chance of experiencing any hard event within 30 days after a negative low-dose CCTA is less than 1%. The secondary objectives are comparisons of the amount of radiation exposure, ED length of stay and overall cost. RESULTS AND CONCLUSION: Our low-dose protocol is readily applicable to current multi-detector computed tomography devices. If this study proves its safety and efficacy, dose-reduction without purchasing of expensive newer devices would be possible.

11.
Cell Rep ; 16(6): 1653-1663, 2016 08 09.
Artigo em Inglês | MEDLINE | ID: mdl-27477270

RESUMO

Emerging evidence has shown that noncoding RNAs, particularly microRNAs (miRNAs), contribute to the pathogenesis of mood and anxiety disorders, although the molecular mechanisms are poorly understood. Here, we show that altered levels of miR-17-92 in adult hippocampal neural progenitors have a significant impact on neurogenesis and anxiety- and depression-related behaviors in mice. miR-17-92 deletion in adult neural progenitors decreases neurogenesis in the dentate gyrus, while its overexpression increases neurogenesis. miR-17-92 affects neurogenesis by regulating genes in the glucocorticoid pathway, especially serum- and glucocorticoid-inducible protein kinase-1 (Sgk1). miR-17-92 knockout mice show anxiety- and depression-like behaviors, whereas miR-17-92 overexpressing mice exhibit anxiolytic and antidepression-like behaviors. Furthermore, we show that miR-17-92 expression in the adult mouse hippocampus responds to chronic stress, and miR-17-92 rescues proliferation defects induced by corticosterone in hippocampal neural progenitors. Our study uncovers a crucial role for miR-17-92 in adult neural progenitors through regulation of neurogenesis and anxiety- and depression-like behaviors.


Assuntos
Ansiedade/genética , Comportamento Animal/fisiologia , Depressão/genética , Hipocampo/metabolismo , MicroRNAs/genética , Neurogênese/genética , Envelhecimento , Animais , Ansiedade/patologia , Corticosterona/farmacologia , Modelos Animais de Doenças , Hipocampo/efeitos dos fármacos , Camundongos Knockout , Neurônios/efeitos dos fármacos , Neurônios/metabolismo
12.
Exp Neurobiol ; 24(4): 341-50, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26713081

RESUMO

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease that affects motor neurons in the brain and spinal cord, resulting in paralysis of voluntary skeletal muscles and eventually death, usually within 2~3 years of symptom onset. The pathophysiology mechanism underlying ALS is not yet clearly understood. Moreover the available medication for treating ALS, riluzole, only modestly improves neurological symptoms and increases survival by a few months. Therefore, improved therapeutic strategies are urgently needed. In the present study, we investigated whether rosmarinic acid has a therapeutic potential to alleviate neurological deterioration in the G93A-SOD1 transgenic mouse model of ALS. Treatment of G93A-SOD1 transgenic mice with rosmarinic acid from 7 weeks of age at the dose of 400 mg/kg/day significantly extended survival, and relieved motor function deficits. Specifically, disease onset and symptom progression were delayed by more than one month. These symptomatic improvements were correlated with decreased oxidative stress and reduced neuronal loss in the ventral horns of G93A-SOD1 mice. These results support that rosmarinic acid is a potentially useful supplement for relieving ALS symptoms.

13.
Front Behav Neurosci ; 8: 368, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25389395

RESUMO

In order to investigate roles of dopamine receptor subtypes in reward-based learning, we examined choice behavior of dopamine D1 and D2 receptor-knockout (D1R-KO and D2R-KO, respectively) mice in an instrumental learning task with progressively increasing reversal frequency and a dynamic two-armed bandit task. Performance of D2R-KO mice was progressively impaired in the former as the frequency of reversal increased and profoundly impaired in the latter even with prolonged training, whereas D1R-KO mice showed relatively minor performance deficits. Choice behavior in the dynamic two-armed bandit task was well explained by a hybrid model including win-stay-lose-switch and reinforcement learning terms. A model-based analysis revealed increased win-stay, but impaired value updating and decreased value-dependent action selection in D2R-KO mice, which were detrimental to maximizing rewards in the dynamic two-armed bandit task. These results suggest an important role of dopamine D2 receptors in learning from past choice outcomes for rapid adjustment of choice behavior in a dynamic and uncertain environment.

14.
Scand J Trauma Resusc Emerg Med ; 22: 59, 2014 Oct 28.
Artigo em Inglês | MEDLINE | ID: mdl-25348723

RESUMO

OBJECTIVE: We aimed to compare rescuer fatigue and cardiopulmonary resuscitation (CPR) quality between standard 30:2 CPR (ST-CPR) and chest compression only CPR (CO-CPR) performed for 8 minutes on a realistic manikin by following the 2010 CPR guidelines. METHODS: All 36 volunteers (laypersons; 18 men and 18 women) were randomized to ST-CPR or CO-CPR at first, and then each CPR technique was performed for 8 minutes with a 3-hour rest interval. We measured the mean blood pressure (MBP) of the volunteers before and after performing each CPR technique, and continuously monitored the heart rate (HR) of the volunteers during each CPR technique using the MRx monitor. CPR quality measures included the depth of chest compression (CC) and the number of adequate CCs per minute. RESULTS: The adequate CC rate significantly differed between the 2 groups after 2 minutes, with it being higher in the ST-CPR group than in the CO-CPR group. Additionally, the adequate CC rate significantly differed between the 2 groups during 8 minutes for male volunteers (p =0.012). The number of adequate CCs was higher in the ST-CPR group than in the CO-CPR group after 3 minutes (p =0.001). The change in MBP before and after performing CPR did not differ between the 2 groups. However, the change in HR during 8 minutes of CPR was higher in the CO-CPR group than in the ST-CPR group (p =0.007). CONCLUSIONS: The rate and number of adequate CCs were significantly lower with the CO-CPR than with the ST-CPR after 2 and 6 minutes, respectively, and performer fatigue was higher with the CO-CPR than with the ST-CPR during 8 minutes of CPR.


Assuntos
Reanimação Cardiopulmonar/métodos , Fidelidade a Diretrizes , Parada Cardíaca/terapia , Massagem Cardíaca/métodos , Manequins , Adolescente , Estudos Cross-Over , Feminino , Seguimentos , Humanos , Masculino , Pressão , Estudos Prospectivos , Fatores de Tempo
15.
PLoS One ; 8(8): e71469, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23977047

RESUMO

Nurr1 is an orphan nuclear receptor best known for its essential role in the development and maintenance of midbrain dopaminergic (DA) neurons. During DA neurogenesis, Nurr1 directly targets human tyrosine hydroxylase (hTH). Here we investigated this targeting to identify the molecular mechanisms by which Nurr1 regulates DA neurogenesis. We previously cloned the hTH promoter and found three consensus elements for Nurr1 binding: NBRE-A, -B, and -C. In the present study, gel retardation and luciferase assays using hTH constructs showed that Nurr1 preferentially bound to NBRE-A, through which it mediated transcriptional activity. Furthermore, Nurr1 displayed dual-function transcriptional activities depending on the cell type. In DA-like SH-SY5Y cells, Nurr1 dose-dependently stimulated hTH-3174 promoter activity by 7- to 11-fold. However, in the human neural stem cell (hNSC) line HB1.F3, Nurr1 strongly repressed transcription from the same promoter. This repression was relieved by mutation of only the NBRE-A element and by nicotinamide [an inhibitor of class III histone deacetylases (HDACs), such as SIRT1], but not by trichostatin A (an inhibitor of class I and II HDACs). SIRT1 was strongly expressed in the nucleus of HB1.F3 cells, while it was localized in the cytoplasm in SH-SY5Y cells. ChIP assays of HB1.F3 cells showed that Nurr1 overexpression significantly increased the SIRT1 occupancy of the NBRE-A hTH promoter region, while low SIRT1 levels were observed in control cells. In contrast, no significant SIRT1 recruitment was observed in SH-SY5Y cells. These results indicate that differential SIRT1 localization may be involved in hTH gene regulation. Overall, our findings suggest that Nurr1 exists in dual transcriptional complexes, including co-repressor complexes that can be remodeled to become co-activators and can fine-tune hTH gene transcription during human DA neurogenesis.


Assuntos
Células-Tronco Neurais/metabolismo , Membro 2 do Grupo A da Subfamília 4 de Receptores Nucleares/metabolismo , Proteínas Repressoras/metabolismo , Sirtuína 1/metabolismo , Tirosina 3-Mono-Oxigenase/genética , Sequência de Bases , Biomarcadores/metabolismo , Linhagem Celular , Linhagem da Célula/efeitos dos fármacos , Linhagem da Célula/genética , Histona Desacetilases/metabolismo , Humanos , Modelos Biológicos , Dados de Sequência Molecular , Células-Tronco Neurais/efeitos dos fármacos , Niacinamida/farmacologia , Membro 2 do Grupo A da Subfamília 4 de Receptores Nucleares/química , Regiões Promotoras Genéticas/genética , Ligação Proteica/efeitos dos fármacos , Ligação Proteica/genética , Fatores de Transcrição/metabolismo , Ativação Transcricional/efeitos dos fármacos , Ativação Transcricional/genética , Tirosina 3-Mono-Oxigenase/metabolismo
16.
Exp Neurobiol ; 22(1): 31-7, 2013 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-23585720

RESUMO

Alzheimer's disease (AD) is a neurodegenerative disease that proceeds with the age-dependent neuronal loss, an irreversible event which causes severe cognitive and psychiatric devastations. In the present study, we investigated whether the compound, AAD-2004 [2-hydroxy-5-[2-(4-trifluoromethylphenyl)-ethylaminobenzoic acid] which has anti-oxidant and anti-inflammatory properties, is beneficial for the brain of Tg-betaCTF99/B6 mice, a murine AD model that was recently developed to display age-dependent neuronal loss and neuritic atrophy in the brain. Administration of AAD-2004 in Tg-betaCTF99/B6 mice from 10 months to 18 months of age completely repressed the accumulation of lipid peroxidation in the brain. AAD-2004 markedly suppressed neuronal loss and neuritic atrophy, and partially reversed depleted expression of calbindin in the brain of Tg-beta-CTF99/B6. These results suggest that AAD-2004 affords neurodegeneration in the brain of AD mouse model.

17.
Cell ; 152(4): 831-43, 2013 Feb 14.
Artigo em Inglês | MEDLINE | ID: mdl-23415230

RESUMO

p11, through unknown mechanisms, is required for behavioral and cellular responses to selective serotonin reuptake inhibitors (SSRIs). We show that SMARCA3, a chromatin-remodeling factor, is a target for the p11/annexin A2 heterotetrameric complex. Determination of the crystal structure indicates that SMARCA3 peptide binds to a hydrophobic pocket in the heterotetramer. Formation of this complex increases the DNA-binding affinity of SMARCA3 and its localization to the nuclear matrix fraction. In the dentate gyrus, both p11 and SMARCA3 are highly enriched in hilar mossy cells and basket cells. The SSRI fluoxetine induces expression of p11 in both cell types and increases the amount of the ternary complex of p11/annexin A2/SMARCA3. SSRI-induced neurogenesis and behavioral responses are abolished by constitutive knockout of SMARCA3. Our studies indicate a central role for a chromatin-remodeling factor in the SSRI/p11 signaling pathway and suggest an approach to the development of improved antidepressant therapies. PAPERCLIP:


Assuntos
Anexina A2/metabolismo , Proteínas de Ligação a DNA/metabolismo , Giro Denteado/metabolismo , Proteínas S100/metabolismo , Inibidores Seletivos de Recaptação de Serotonina/farmacologia , Fatores de Transcrição/metabolismo , Sequência de Aminoácidos , Animais , Proteínas de Ligação a DNA/química , Feminino , Masculino , Modelos Moleculares , Dados de Sequência Molecular , Fibras Musgosas Hipocampais/metabolismo , Alinhamento de Sequência , Transdução de Sinais , Fatores de Transcrição/química , Difração de Raios X
18.
J Neurosci ; 32(28): 9690-9, 2012 Jul 11.
Artigo em Inglês | MEDLINE | ID: mdl-22787054

RESUMO

Stress is a potent risk factor for depression, yet the underlying mechanism is not clearly understood. In the present study, we explored the mechanism of development and maintenance of depression in a stress-induced animal model. Mice restrained for 2 h daily for 14 d showed distinct depressive behavior, and the altered behavior persisted for >3 months in the absence of intervention. Acute restraint induced a surge of oxidative stress in the brain, and stress-induced oxidative stress progressively increased with repetition of stress. In vitro, the stress hormone glucocorticoid generated superoxide via upregulation of NADPH oxidase. Consistently, repeated restraints increased the expression of the key subunits of NADPH oxidase, p47phox and p67phox, in the brain. Moreover, stressed brains markedly upregulated the expression of p47phox to weak restress evoked in the poststress period, and this molecular response was reminiscent of amplified ROS surge to restress. Pharmacological inhibition of NADPH oxidase by the NADPH oxidase inhibitor apocynin during the stress or poststress period completely blocked depressive behavior. Consistently, heterozygous p47phox knock-out mice (p47phox(+/-)) or molecular inhibition of p47phox with Lenti shRNA-p47phox in the hippocampus suppressed depressive behavior. These results suggest that repeated stress promotes depressive behavior through the upregulation of NADPH oxidase and the resultant metabolic oxidative stress, and that the inhibition of NADPH oxidase provides beneficial antidepression effects.


Assuntos
Transtorno Depressivo/enzimologia , Transtorno Depressivo/etiologia , NADPH Oxidases/metabolismo , Fosfoproteínas/metabolismo , Restrição Física/efeitos adversos , Acetofenonas/administração & dosagem , Análise de Variância , Animais , Antidepressivos Tricíclicos/administração & dosagem , Antioxidantes/administração & dosagem , Ácido Ascórbico/administração & dosagem , Encéfalo/metabolismo , Linhagem Celular , Corticosterona/metabolismo , Corticosterona/farmacologia , Transtorno Depressivo/genética , Transtorno Depressivo/prevenção & controle , Modelos Animais de Doenças , Esquema de Medicação , Regulação Enzimológica da Expressão Gênica/efeitos dos fármacos , Regulação Enzimológica da Expressão Gênica/genética , Proteínas de Fluorescência Verde/genética , Proteínas de Fluorescência Verde/metabolismo , Elevação dos Membros Posteriores , Hipocampo/efeitos dos fármacos , Hipocampo/patologia , Humanos , Peróxido de Hidrogênio/farmacologia , Imipramina/administração & dosagem , Peroxidação de Lipídeos/efeitos dos fármacos , Peroxidação de Lipídeos/genética , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , NADPH Oxidases/genética , Neuroblastoma/patologia , Neurônios/efeitos dos fármacos , Neurônios/metabolismo , Fosfoproteínas/genética , RNA Mensageiro/metabolismo , RNA Interferente Pequeno/metabolismo , RNA Interferente Pequeno/farmacologia , Espécies Reativas de Oxigênio/metabolismo , Comportamento Social , Superóxidos/metabolismo , Natação/psicologia , Fatores de Tempo
19.
Exp Mol Med ; 44(8): 492-502, 2012 Aug 31.
Artigo em Inglês | MEDLINE | ID: mdl-22644036

RESUMO

Adequate assessment of plaque deposition levels in the brain of mouse models of Alzheimer disease (AD) is required in many core issues of studies on AD, including studies on the mechanisms underlying plaque pathogenesis, identification of cellular factors modifying plaque pathology, and developments of anti-AD drugs. The present study was undertaken to quantitatively evaluate plaque deposition patterns in the brains of the two popular AD models, Tg2576 and Tg-APPswe/ PS1dE9 mice. Coronally-cut brain sections of Tg2576 and Tg-APPswe/PS1dE9 mice were prepared and plaque depositions were visualized by staining with anti- amyloid ß peptides antibody. Microscopic images of plaque depositions in the prefrontal cortex, parietal cortex, piriform cortex and hippocampus were obtained and the number of plaques in each region was determined by a computer-aided image analysis method. A series of optical images representing a gradual increase of plaque deposition levels were selected in the four different brain regions and were assigned in each with a numerical grade of 1-6, where +1 was lowest and +6, highest, so that plaques per unit in mm(2) increased "sigmoidally" over the grading scales. Analyzing plaque depositions using the photographic plaque reference panels and a computer-aid image analysis method, it was demonstrated that the brains of Tg2576 mice started to accumulate predominantly small plaques, while the brains of Tg-APPswe/PS1dE9 mice deposited relatively large plaques.


Assuntos
Doença de Alzheimer/patologia , Placa Amiloide/patologia , Doença de Alzheimer/genética , Precursor de Proteína beta-Amiloide/genética , Precursor de Proteína beta-Amiloide/metabolismo , Animais , Modelos Animais de Doenças , Humanos , Camundongos , Camundongos Transgênicos
20.
Free Radic Biol Med ; 50(11): 1526-35, 2011 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-21382475

RESUMO

Basic and clinical studies have reported that behavioral stress worsens the pathology of Alzheimer disease (AD), but the underlying mechanism has not been clearly understood. In this study, we determined the mechanism by which behavioral stress affects the pathogenesis of AD using Tg-APPswe/PS1dE9 mice, a murine model of AD. Tg-APPswe/PS1dE9 mice that were restrained for 2h daily for 16 consecutive days (2-h/16-day stress) from 6.5months of age had significantly increased Aß(1-42) levels and plaque deposition in the brain. The 2-h/16-day stress increased oxidative stress and induced mitochondrial dysfunction in the brain. Treatment with glucocorticoid (corticosterone) and Aß in SH-SY5Y cells increased the expression of 17ß-hydroxysteroid dehydrogenase (ABAD), mitochondrial dysfunction, and levels of ROS, whereas blockade of ABAD expression by siRNA-ABAD in SH-SY5Y cells suppressed glucocorticoid-enhanced mitochondrial dysfunction and ROS accumulation. The 2-h/16-day stress up-regulated ABAD expression in mitochondria in the brain of Tg-APPswe/PS1dE9 mice. Moreover, all visible Aß plaques were costained with anti-ABAD in the brains of Tg-APPswe/PS1dE9 mice. Together, these results suggest that behavioral stress aggravates plaque pathology and mitochondrial dysfunction via up-regulation of ABAD in the brain of a mouse model of AD.


Assuntos
17-Hidroxiesteroide Desidrogenases/metabolismo , Doença de Alzheimer/metabolismo , Encéfalo/metabolismo , Mitocôndrias/metabolismo , Estresse Psicológico/metabolismo , 17-Hidroxiesteroide Desidrogenases/genética , Doença de Alzheimer/genética , Doença de Alzheimer/patologia , Animais , Encéfalo/patologia , Células Cultivadas , Modelos Animais de Doenças , Humanos , Camundongos , Camundongos Endogâmicos , Camundongos Transgênicos , Mitocôndrias/genética , Mitocôndrias/patologia , Mutação/genética , Estresse Oxidativo , Presenilina-1/genética , Restrição Física/efeitos adversos , Proteína Amiloide A Sérica/genética , Estresse Psicológico/etiologia , Estresse Psicológico/genética , Regulação para Cima
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