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1.
Ecotoxicol Environ Saf ; 208: 111401, 2021 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-33038730

RESUMO

Dibromoacetic acid (DBA) is a by-product of disinfection in drinking water, which could cause many adverse effects in test animals. However, little research on its neurotoxicity has been conducted, and its mechanism has not been elucidated. In the present study, ninety Sprague-Dawley rats were administered DBA at doses of 0, 30, and 90 mg/kg body weight for 28 days via oral gavage. We found that DBA could induce obvious neurotoxicity in the pineal gland as indicated by histological changes and impaired rhythm of melatonin in pineal and serum. In the mechanism study, transcriptome data showed that DBA exposure could induce 732 differential expression genes. Besides, GO and KEGG analysis results indicated that these genes were enriched in circadian rhythms, among which CREB1 had the most significant fold change. And immunofluorescence staining (IF) and immunohistochemical staining (IHC) results showed that the number of amber-colored masculine neurons for the p-CREB1 in the 90 mg/kg group was markedly lower, and staining for the p-CREB1 was weaker. Moreover, the results of PCR and western blot showed that DBA exposure could down-regulate the expressions of CREB1 and p-CREB1, leading to the decreased expressions of gene and protein of arylalkylamine N-acetyltransferase (AANAT), and then resulting in the impaired melatonin synthesis in the pineal and serum. In conclusion, DBA exposure is associated with abnormal melatonin rhythm via inhibition of the p-CREB1-AANAT signalling pathway.


Assuntos
Acetatos/toxicidade , Substâncias Perigosas/toxicidade , Melatonina/metabolismo , Acetiltransferases/metabolismo , Animais , Arilalquilamina N-Acetiltransferase/biossíntese , Ritmo Circadiano , Proteína de Ligação ao Elemento de Resposta ao AMP Cíclico/metabolismo , Regulação para Baixo , Masculino , Glândula Pineal/efeitos dos fármacos , Glândula Pineal/metabolismo , Ratos , Ratos Sprague-Dawley , Transdução de Sinais
2.
Nat Commun ; 11(1): 5180, 2020 10 14.
Artigo em Inglês | MEDLINE | ID: mdl-33057013

RESUMO

Fear and extinction learning are adaptive processes caused by molecular changes in specific neural circuits. Neurons expressing the corticotropin-releasing hormone gene (Crh) in central amygdala (CeA) are implicated in threat regulation, yet little is known of cell type-specific gene pathways mediating adaptive learning. We translationally profiled the transcriptome of CeA Crh-expressing cells (Crh neurons) after fear conditioning or extinction in mice using translating ribosome affinity purification (TRAP) and RNAseq. Differential gene expression and co-expression network analyses identified diverse networks activated or inhibited by fear vs extinction. Upstream regulator analysis demonstrated that extinction associates with reduced CREB expression, and viral vector-induced increased CREB expression in Crh neurons increased fear expression and inhibited extinction. These findings suggest that CREB, within CeA Crh neurons, may function as a molecular switch that regulates expression of fear and its extinction. Cell-type specific translational analyses may suggest targets useful for understanding and treating stress-related psychiatric illness.


Assuntos
Núcleo Central da Amígdala/fisiologia , Condicionamento Psicológico/fisiologia , Proteína de Ligação ao Elemento de Resposta ao AMP Cíclico/metabolismo , Extinção Psicológica/fisiologia , Medo/fisiologia , Animais , Comportamento Animal , Núcleo Central da Amígdala/citologia , Hormônio Liberador da Corticotropina/genética , Hormônio Liberador da Corticotropina/metabolismo , Feminino , Masculino , Camundongos , Camundongos Transgênicos , Modelos Animais , Neurônios/metabolismo , RNA-Seq
3.
Sci Rep ; 10(1): 16686, 2020 10 07.
Artigo em Inglês | MEDLINE | ID: mdl-33028951

RESUMO

Nesfatin-1 (NESF) and NESF-like peptide (NLP), encoded in nucleobindin 2 and 1 (NUCB2 and NUCB1), respectively, are orphan ligands and metabolic factors. We hypothesized that NESF and NLP suppress growth hormone (GH) synthesis, and aimed to determine whether mammalian somatotrophs are a source and site of action of these peptides. Using immortalized rat somatotrophs (GH3 cells), NUCB expression was determined by qPCR, immunofluorescence and Western blot. NESF and NLP binding to GH3 cells was tested using fluorescence imaging. Both time- and concentration-dependent studies were performed to test whether NESF and NLP affect GH. Moreover, the ability of these peptides to modulate the effects of ghrelin, and cell-signaling pathways were studied. GH3 cells express NUCB mRNAs and protein. Labeled NESF and NLP bind to the surface of GH3 cells, and incubation with either NESF or NLP decreased GH mRNA and protein expression, downregulated pit-1 mRNA, and blocked the GH stimulatory effects of ghrelin. Pre-incubation with either of these peptides reduced CREB phosphorylation by an AC-activator, but not when PKA was directly activated by a cAMP analog. Our results indicate that rat somatotrophs are a source of NUCBs, and that NESF and NLP downregulate GH synthesis through the AC/PKA/CREB signaling pathway.


Assuntos
Hormônio do Crescimento/biossíntese , Nucleobindinas/farmacologia , Fragmentos de Peptídeos/farmacologia , Transdução de Sinais/efeitos dos fármacos , Somatotrofos/efeitos dos fármacos , Adenilil Ciclases/metabolismo , Animais , Linhagem Celular , Proteína de Ligação ao Elemento de Resposta ao AMP Cíclico/metabolismo , Proteínas Quinases Dependentes de AMP Cíclico/metabolismo , Ratos , Somatotrofos/metabolismo
4.
Sci Rep ; 10(1): 16714, 2020 10 07.
Artigo em Inglês | MEDLINE | ID: mdl-33028897

RESUMO

Acrylamide (ACR) is a known neurotoxicant which crosses the blood-brain barrier, passes the placenta and has been detected in breast milk. Hence, early-life exposure to ACR could lead to developmental neurotoxicity. The aim of this study was to elucidate if non-cytotoxic concentrations of ACR alter neuronal differentiation by studying gene expression of markers significant for neurodevelopment in the human neuroblastoma SH-SY5Y cell model. Firstly, by using RNASeq we identified two relevant pathways that are activated during 9 days of retinoic acid (RA) induced differentiation i.e. RA receptor (RAR) activation and the cAMP response element-binding protein (CREB) signalling pathways. Next, by qPCR we showed that 1 and 70 µM ACR after 9 days exposure alter the expression of 13 out of 36 genes in the RAR activation pathway and 18 out of 47 in the CREB signalling pathway. Furthermore, the expression of established neuronal markers i.e. BDNF, STXBP2, STX3, TGFB1 and CHAT were down-regulated. Decreased protein expression of BDNF and altered ratio of phosphorylated CREB to total CREB were confirmed by western blot. Our results reveal that micromolar concentrations of ACR sustain proliferation, decrease neurite outgrowth and interfere with signalling pathways involved in neuronal differentiation in the SH-SY5Y cell model.


Assuntos
Acrilamida/farmacologia , Diferenciação Celular/efeitos dos fármacos , Proteína de Ligação ao Elemento de Resposta ao AMP Cíclico/metabolismo , Neurônios/efeitos dos fármacos , Transdução de Sinais/efeitos dos fármacos , Tretinoína/metabolismo , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Humanos , Neuroblastoma/metabolismo , Crescimento Neuronal/efeitos dos fármacos , Neurônios/metabolismo
5.
PLoS One ; 15(10): e0240022, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33002038

RESUMO

Neurodegenerative diseases (NDDs) are becoming a major threat to public health, according to the World Health Organization (WHO). The most common form of NDDs is Alzheimer's disease (AD), boasting 60-70% share. Although some debates still exist, excessive aggregation of ß-amyloid protein (Aß) and neurofibrillary tangles has been deemed one of the major causes for the pathogenesis of AD. A growing number of evidences from studies, however, have suggested that reactive oxygen species (ROS) also play a key role in the onset and progression of AD. Although scientists have had some understanding of the pathogenesis of AD, the disease still cannot be cured, with existing treatment only capable of providing a temporary relief at best, partly due to the obstacle of blood-brain barrier (BBB). The study was aimed to ascertain the neuroprotective effect of thermal cycle hyperthermia (TC-HT) against hydrogen peroxide (H2O2) and Aß-induced cytotoxicity in SH-SY5Y cells. Treating cells with this physical stimulation beforehand significantly improved the cell viability and decreased the ROS content. The underlying mechanisms may be due to the activation of Akt pathway and the downstream antioxidant and prosurvival proteins. The findings manifest significant potential of TC-HT in neuroprotection, via inhibition of oxidative stress and cell apoptosis. It is believed that coupled with the use of drugs or natural compounds, this methodology can be even more effective in treating NDDs.


Assuntos
Peptídeos beta-Amiloides/toxicidade , Peróxido de Hidrogênio/toxicidade , Hipertermia Induzida , Estresse Oxidativo/efeitos dos fármacos , Proteínas Proto-Oncogênicas c-akt/metabolismo , Transdução de Sinais/efeitos dos fármacos , Linhagem Celular Tumoral , Proteína de Ligação ao Elemento de Resposta ao AMP Cíclico/metabolismo , Regulação da Expressão Gênica/efeitos dos fármacos , Proteínas de Choque Térmico/metabolismo , Humanos , Insulisina/metabolismo , Metaloproteinases da Matriz/metabolismo , Fator 2 Relacionado a NF-E2/metabolismo , Complexo de Endopeptidases do Proteassoma/metabolismo
6.
Science ; 370(6513)2020 10 09.
Artigo em Inglês | MEDLINE | ID: mdl-33033186

RESUMO

Excitotoxicity induced by NMDA receptors (NMDARs) is thought to be intimately linked to high intracellular calcium load. Unexpectedly, NMDAR-mediated toxicity can be eliminated without affecting NMDAR-induced calcium signals. Instead, excitotoxicity requires physical coupling of NMDARs to TRPM4. This interaction is mediated by intracellular domains located in the near-membrane portions of the receptors. Structure-based computational drug screening using the interaction interface of TRPM4 in complex with NMDARs identified small molecules that spare NMDAR-induced calcium signaling but disrupt the NMDAR/TRPM4 complex. These interaction interface inhibitors strongly reduce NMDA-triggered toxicity and mitochondrial dysfunction, abolish cyclic adenosine monophosphate-responsive element-binding protein (CREB) shutoff, boost gene induction, and reduce neuronal loss in mouse models of stroke and retinal degeneration. Recombinant or small-molecule NMDAR/TRPM4 interface inhibitors may mitigate currently untreatable human neurodegenerative diseases.


Assuntos
Proteína de Ligação ao Elemento de Resposta ao AMP Cíclico/metabolismo , Descoberta de Drogas , Doenças Neurodegenerativas/metabolismo , Fármacos Neuroprotetores/química , Receptores de N-Metil-D-Aspartato/metabolismo , Proteínas Recombinantes/metabolismo , Canais de Cátion TRPM/metabolismo , Animais , Sinalização do Cálcio , AMP Cíclico/metabolismo , Proteína de Ligação ao Elemento de Resposta ao AMP Cíclico/genética , Técnicas de Silenciamento de Genes , Humanos , Camundongos , Doenças Neurodegenerativas/tratamento farmacológico , Domínios Proteicos , Receptores de N-Metil-D-Aspartato/química , Receptores de N-Metil-D-Aspartato/uso terapêutico , Proteínas Recombinantes/química , Proteínas Recombinantes/uso terapêutico , Canais de Cátion TRPM/genética , Ativação Transcricional
7.
Sci Rep ; 10(1): 14945, 2020 09 10.
Artigo em Inglês | MEDLINE | ID: mdl-32913245

RESUMO

Cerebellar ataxia is a neurodegenerative disorder with no definitive treatment. Although several studies have demonstrated the neuroprotective effects of Hericium erinaceus (H.E.), its mechanisms in cerebellar ataxia remain largely unknown. Here, we investigated the neuroprotective effects of H.E. treatment in an animal model of 3-acetylpyridine (3-AP)-induced cerebellar ataxia. Animals administered 3-AP injection exhibited remarkable impairments in motor coordination and balance. There were no significant effects of 25 mg/kg H.E. on the 3-AP treatment group compared to the 3-AP saline group. Interestingly, there was also no significant difference in the 3-AP treatment group compared to the non-3-AP control, indicating a potential rescue of motor deficits. Our results revealed that 25 mg/kg H.E. normalised the neuroplasticity-related gene expression to the level of non-3-AP control. These findings were further supported by increased protein expressions of pERK1/2-pCREB-PSD95 as well as neuroprotective effects on cerebellar Purkinje cells in the 3-AP treatment group compared to the 3-AP saline group. In conclusion, our findings suggest that H.E. potentially rescued behavioural motor deficits through the neuroprotective mechanisms of ERK-CREB-PSD95 in an animal model of 3-AP-induced cerebellar ataxia.


Assuntos
Comportamento Animal/efeitos dos fármacos , Ataxia Cerebelar/tratamento farmacológico , Transtornos Motores/prevenção & controle , Fármacos Neuroprotetores/farmacologia , Neurotoxinas/toxicidade , Piridinas/toxicidade , Animais , Ataxia Cerebelar/induzido quimicamente , Ataxia Cerebelar/psicologia , Proteína de Ligação ao Elemento de Resposta ao AMP Cíclico/genética , Proteína de Ligação ao Elemento de Resposta ao AMP Cíclico/metabolismo , Modelos Animais de Doenças , Proteína 4 Homóloga a Disks-Large/genética , Proteína 4 Homóloga a Disks-Large/metabolismo , MAP Quinases Reguladas por Sinal Extracelular/genética , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Masculino , Transtornos Motores/genética , Transtornos Motores/metabolismo , Transtornos Motores/patologia , Células de Purkinje/efeitos dos fármacos , Células de Purkinje/patologia , Ratos , Ratos Sprague-Dawley
8.
Sci Rep ; 10(1): 15511, 2020 09 23.
Artigo em Inglês | MEDLINE | ID: mdl-32968182

RESUMO

Osmolytes are organic solutes that change the protein folding landscape shifting the equilibrium towards the folded state. Herein, we use osmolytes to probe the structuring and aggregation of the intrinsically disordered mutant Huntingtin (mHtt) vis-a-vis the pathogenicity of mHtt on transcription factor function and cell survival. Using an inducible PC12 cell model of Huntington's disease (HD), we show that stabilizing polyol osmolytes drive the aggregation of Htt103QExon1-EGFP from a diffuse ensemble into inclusion bodies (IBs), whereas the destabilizing osmolyte urea does not. This effect of stabilizing osmolytes is innate, generic, countered by urea, and unaffected by HSP70 and HSC70 knockdown. A qualitatively similar result of osmolyte-induced mHtt IB formation is observed in a conditionally immortalized striatal neuron model of HD, and IB formation correlates with improved survival under stress. Increased expression of diffuse mHtt sequesters the CREB transcription factor to repress CREB-reporter gene activity. This repression is mitigated either by stabilizing osmolytes, which deplete diffuse mHtt or by urea, which negates protein-protein interaction. Our results show that stabilizing polyol osmolytes promote mHtt aggregation, alleviate CREB dysfunction, and promote survival under stress to support the hypothesis that lower molecular weight entities of disease protein are relevant pathogenic species in neurodegeneration.


Assuntos
Proteína de Ligação ao Elemento de Resposta ao AMP Cíclico/metabolismo , Proteína Huntingtina/metabolismo , Doença de Huntington/metabolismo , Animais , Autofagia , Técnicas de Silenciamento de Genes , Glicerol/farmacologia , Proteínas de Choque Térmico HSC70/metabolismo , Proteínas de Choque Térmico HSP70/metabolismo , Proteína Huntingtina/genética , Mutação , Concentração Osmolar , Células PC12 , Agregação Patológica de Proteínas/genética , Agregação Patológica de Proteínas/metabolismo , Dobramento de Proteína , Ratos , Sorbitol/farmacologia , Sacarose/farmacologia , Trealose/farmacologia
9.
Biochem Pharmacol ; 180: 114193, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-32800853

RESUMO

Parkinson's disease (PD) is the second most common neurodegenerative disease, which is characterized by the progressive loss of dopaminergic neurons in the substantia nigra, leading to a decrease in striatal dopamine. There is no antiparkinsonian therapy that offers a true disease-modifying treatment till date and there is an urgent need for a safe and effective neuroprotective or neurorestorative therapy. Our previous study demonstrated that metformin upregulated dopamine in the mouse brain and provided significant neuroprotection in animal model of PD. Therefore, we designed this study to investigate the molecular mechanism underlying such pharmacological effect of metformin. Herein, we found that metformin enhanced the phosphorylation of tyrosine hydroxylase (TH) which was accompanied by increase in brain-derived neurotrophic factor (BDNF), glial cell line-derived neurotrophic factor (GDNF), and activation of their downstream signaling pathways in the mouse brain and SH-SY5Y cells. We further investigated the role of the neurotrophic factors in the activation of TH and observed that both BDNF and GDNF-induction were essential for metformin-induced TH activation. We found that the AMPK/aPKCζ/CREB pathway was essential for metformin-induced GDNF upregulation and TH activation. Thus, this study reveals the TH-activating property of metformin in the brain via induction of neurotrophic factors along with the signaling mechanism. These results potentiate the candidacy of metformin not only as a neuroprotective agent, but also as restorative therapy for the treatment of PD.


Assuntos
Proteínas Quinases Ativadas por AMP/metabolismo , Proteína de Ligação ao Elemento de Resposta ao AMP Cíclico/metabolismo , Dopamina/biossíntese , Fator Neurotrófico Derivado de Linhagem de Célula Glial/biossíntese , Metformina/farmacologia , Proteína Quinase C/metabolismo , Animais , Linhagem Celular Tumoral , Humanos , Hipoglicemiantes/farmacologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/fisiologia , Regulação para Cima/efeitos dos fármacos , Regulação para Cima/fisiologia
10.
PLoS One ; 15(8): e0236727, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32750068

RESUMO

Low-power laser irradiation (LPLI) is clinically used to modulate inflammation, proliferation and apoptosis. However, its molecular mechanisms are still not fully understood. This study aimed to describe the effects of LPLI upon inflammatory, apoptotic and proliferation markers in submandibular salivary glands (SMGs) in an experimental model of chronic disorder, 24h after one time irradiation. Diabetes was induced in rats by the injection of streptozotocin. After 29 days, these animals were treated with LPLI in the SMG area, and euthanized 24h after this irradiation. Treatment with LPLI significantly decreased diabetes-induced high mobility group box 1 (HMGB1) and tumor necrosis factor alpha (TNF-α) expression, while enhancing the activation of the transcriptional factor cAMP response element binding (CREB) protein. LPLI also reduced the expression of bax, a mitochondrial apoptotic marker, favoring the cell survival. These findings suggest that LPLI can hamper the state of chronic inflammation and favor homeostasis in diabetic rats SMGs.


Assuntos
Diabetes Mellitus Experimental/radioterapia , Terapia com Luz de Baixa Intensidade , Transdução de Sinais/efeitos da radiação , Glândula Submandibular/efeitos da radiação , Animais , Apoptose , AMP Cíclico/metabolismo , Proteína de Ligação ao Elemento de Resposta ao AMP Cíclico/metabolismo , Feminino , Proteína HMGB1/genética , Proteína HMGB1/metabolismo , Proteínas Quinases Ativadas por Mitógeno/metabolismo , NF-kappa B/metabolismo , Fosforilação , RNA Mensageiro/metabolismo , Ratos , Ratos Wistar , Fator de Necrose Tumoral alfa/metabolismo
11.
PLoS Biol ; 18(8): e3000826, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32776935

RESUMO

Ca2+/calmodulin-dependent kinase II (CaMKII) regulates synaptic plasticity in multiple ways, supposedly including the secretion of neuromodulators like brain-derived neurotrophic factor (BDNF). Here, we show that neuromodulator secretion is indeed reduced in mouse α- and ßCaMKII-deficient (αßCaMKII double-knockout [DKO]) hippocampal neurons. However, this was not due to reduced secretion efficiency or neuromodulator vesicle transport but to 40% reduced neuromodulator levels at synapses and 50% reduced delivery of new neuromodulator vesicles to axons. αßCaMKII depletion drastically reduced neuromodulator expression. Blocking BDNF secretion or BDNF scavenging in wild-type neurons produced a similar reduction. Reduced neuromodulator expression in αßCaMKII DKO neurons was restored by active ßCaMKII but not inactive ßCaMKII or αCaMKII, and by CaMKII downstream effectors that promote cAMP-response element binding protein (CREB) phosphorylation. These data indicate that CaMKII regulates neuromodulation in a feedback loop coupling neuromodulator secretion to ßCaMKII- and CREB-dependent neuromodulator expression and axonal targeting, but CaMKIIs are dispensable for the secretion process itself.


Assuntos
Astrócitos/metabolismo , Fator Neurotrófico Derivado do Encéfalo/genética , Proteína Quinase Tipo 2 Dependente de Cálcio-Calmodulina/genética , Cálcio/metabolismo , Neurônios/metabolismo , Subunidades Proteicas/genética , Animais , Astrócitos/citologia , Fator Neurotrófico Derivado do Encéfalo/metabolismo , Proteína Quinase Tipo 2 Dependente de Cálcio-Calmodulina/deficiência , Proteína de Ligação ao Elemento de Resposta ao AMP Cíclico/genética , Proteína de Ligação ao Elemento de Resposta ao AMP Cíclico/metabolismo , Retroalimentação Fisiológica , Regulação da Expressão Gênica , Hipocampo/citologia , Hipocampo/metabolismo , Camundongos , Camundongos Transgênicos , Neurônios/citologia , Fosforilação , Cultura Primária de Células , Subunidades Proteicas/deficiência , Sinapses/fisiologia , Transmissão Sináptica , Imagem com Lapso de Tempo
12.
J Stroke Cerebrovasc Dis ; 29(8): 104850, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32689640

RESUMO

BACKGROUND: Following the recent discovery that microRNA-134-5p (miR-134-5p) is elevated in the early stages of acute myocardial infarction (AMI), we examined the specific role of miR-134-5p in cardiomyocytes during AMI. METHODS: To study miR-134-5p's role in the context of AMI, we used a combination of in vitro experiments in H2O2-treated or hypoxic cardiomyocyte cell cultures as well as in vivo experiments in a murine model of AMI. RESULTS: H2O2- and hypoxia-induced cardiomyocyte injury upregulated miR-134-5p expression. miR-134-5p overexpression increased cardiomyocyte apoptosis, whereas miR-134-5p inhibition reduced cardiomyocyte apoptosis. We discovered that the transcription factor cAMP-responsive element binding protein 1 (Creb1) is a functional target of miR-134-5p responsible for regulating cardiomyocyte apoptosis. In vivo AMI resulted in the upregulation and downregulation of miR-134-5p and Creb1 in the infarct area, respectively. Circulating miR-134-5p levels were also increased at days 1 and 2 post-AMI. Modulation of myocardial miR-124-5p expression by intramyocardial injection of antagomiR-134-5p or agomiR-134-5p significantly affected cardiomyocyte apoptosis, infarct size, and cardiac function in vivo. CONCLUSIONS: miR-134-5p/Creb1 axis dysregulation plays a role in hypoxia- or oxidative stress-induced cardiomyocyte apoptosis as well as AMI. Circulating miR-134-5p may show promise as a biomarker for AMI or post-AMI cardiac dysfunction. Manipulating the miR-134-5p/Creb1 axis through either inhibition of miR-134-5p or overexpression of Creb1 may show promise as a novel therapeutic strategy to attenuate cardiac dysfunction following AMI.


Assuntos
Antagomirs/administração & dosagem , Apoptose , Proteína de Ligação ao Elemento de Resposta ao AMP Cíclico/metabolismo , MicroRNAs/antagonistas & inibidores , Infarto do Miocárdio/prevenção & controle , Miócitos Cardíacos/metabolismo , Regiões 3' não Traduzidas , Animais , Sítios de Ligação , Hipóxia Celular , Células Cultivadas , Proteína de Ligação ao Elemento de Resposta ao AMP Cíclico/genética , Modelos Animais de Doenças , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Peróxido de Hidrogênio/toxicidade , Proteínas Quinases JNK Ativadas por Mitógeno/metabolismo , MicroRNAs/genética , MicroRNAs/metabolismo , Infarto do Miocárdio/genética , Infarto do Miocárdio/metabolismo , Infarto do Miocárdio/patologia , Miócitos Cardíacos/patologia , Estresse Oxidativo , Transdução de Sinais , Regulação para Cima
13.
Life Sci ; 258: 118107, 2020 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-32682919

RESUMO

Cognitive impairment has been widely recognized as a common symptom of chronic stress. Ginsenoside Rd (GRd), the major active compound in Panax ginseng, was previously reported in various neurological researches. However, little research is available regarding on the effect of GRd on cognitive improvement in mice subjected to chronic stress. In the present study, we investigated the neuroprotective effects of GRd in chronic restraint stress (CRS)-induced cognitive deficits and explored the potential mechanism in male C57BL/6J mice. Our results demonstrated that oral administration of GRd for 28 days markedly increased the spontaneous alternation in Y-maze and the relative discrimination index in novel object or location recognition tests following CRS. Additionally, GRd treatment considerably increased the antioxidant enzymes activities in the hippocampus. The expression levels of hippocampus and serum inflammation factors in the CRS groups were also counter-regulated by GRd treatment. Meanwhile, GRd treatment could reverse CRS-induced the decrease in phosphorylated phosphoinositide 3-kinase (PI3K), camp-reflecting element binding protein (CREB), brain-derived neurotrophic factor (BDNF) and tyrosine kinase B (TrkB) expression in the hippocampus. These findings provided evidences that GRd improves cognitive impairment in CRS mice by mitigating oxidative stress and inflammation, while upregulating the hippocampal BDNF-mediated CREB signaling pathway.


Assuntos
Fator Neurotrófico Derivado do Encéfalo/metabolismo , Disfunção Cognitiva/tratamento farmacológico , Disfunção Cognitiva/metabolismo , Proteína de Ligação ao Elemento de Resposta ao AMP Cíclico/metabolismo , Ginsenosídeos/uso terapêutico , Restrição Física , Transdução de Sinais , Estresse Psicológico/tratamento farmacológico , Animais , Doença Crônica , Disfunção Cognitiva/sangue , Disfunção Cognitiva/fisiopatologia , Modelos Animais de Doenças , Ginsenosídeos/química , Ginsenosídeos/farmacologia , Hipocampo/efeitos dos fármacos , Hipocampo/enzimologia , Hipocampo/patologia , Hipocampo/fisiopatologia , Inflamação/sangue , Masculino , Aprendizagem em Labirinto/efeitos dos fármacos , Memória de Curto Prazo/efeitos dos fármacos , Camundongos Endogâmicos C57BL , Modelos Biológicos , Atividade Motora/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Receptor trkB/metabolismo , Transdução de Sinais/efeitos dos fármacos , Estresse Psicológico/sangue , Estresse Psicológico/fisiopatologia
14.
PLoS One ; 15(7): e0233161, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32645049

RESUMO

The beta blockers carvedilol, bisoprolol, and sustained-release metoprolol succinate reduce readmissions and mortality among patients with heart failure with reduced ejection fraction (HFrEF), based upon clinical trial and registry studies. Results from these studies may not generalize to the typical patient with HFrEF. We conducted a retrospective cohort study of beneficiaries in the Medicare 5% sample hospitalized for HFrEF between 2007 and 2013 and were discharged alive. We compared the 30-day and 365-day heart failure (HF) readmission, all-cause readmission, and mortality rates between beneficiaries who filled a prescription for an evidence-based beta blocker and those who did not after being hospitalized for HFrEF. Out of 12,127 beneficiaries hospitalized for HFrEF, 20% were readmitted for HF, 62% were readmitted for any cause, and 27% died within 365 days. In competing risk models adjusted for demographics, healthcare utilization, and comorbidities, beta blocker use was associated with a lower risk of HF readmission between 8-365 days post discharge (hazard ratio 0.79 [95% confidence interval 0.76, 0.82]), but was not significantly associated with all-cause readmission (1.02 [0.97-1.07]). In Cox models adjusted for the same covariates, beta blocker use was associated with lower mortality 8-365 days post discharge (0.65 [0.60-0.71]). Results were similar when follow up was truncated at 30 days post discharge. Increasing the use of beta blockers following HFrEF hospitalization may not decrease all-cause readmissions among Medicare beneficiaries, but may reduce HF-specific readmissions and mortality.


Assuntos
Astrócitos/virologia , Proteína Rica em Cisteína 61/metabolismo , Infecção por Zika virus/virologia , Zika virus/fisiologia , Animais , Astrócitos/metabolismo , Astrocitoma/metabolismo , Proteína Quinase Tipo 2 Dependente de Cálcio-Calmodulina/metabolismo , Linhagem Celular , Proteína de Ligação ao Elemento de Resposta ao AMP Cíclico/metabolismo , Proteína Rica em Cisteína 61/genética , Humanos , Camundongos , Camundongos Endogâmicos C57BL , Fosforilação , Serina Endopeptidases/metabolismo , Regulação para Cima , Proteínas não Estruturais Virais/metabolismo , Proteínas Virais/metabolismo , Replicação Viral , Infecção por Zika virus/metabolismo
15.
Life Sci ; 257: 118020, 2020 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-32603820

RESUMO

Alzheimer's disease (AD) is the most common form of dementia worldwide. ß-amyloid peptide (Aß) is currently assumed to be the main cause of synaptic dysfunction and cognitive impairments in AD, but the molecular signaling pathways underlying its neurotoxic consequences have not yet been completely explored. Additional investigations regarding these pathways will contribute to development of new therapeutic targets. In context, developing evidence suggest that Aß decreases brain-derived neurotrophic factor (BDNF) mostly by lowering phosphorylated cyclic adenosine monophosphate (cAMP) response element binding protein (CREB) protein. In fact, it has been observed that brain or serum levels of BDNF appear to be beneficial markers for cognitive condition. In addition, the participation of transcription mediated by CREB has been widely analyzed in the memory process and AD development. Designing pharmacologic or genetic therapeutic approaches based on the targeting of CREB-BDNF signaling could be a promising treatment potential for AD. In this review, we summarize data demonstrating the role of CREB-BDNF signaling pathway in cognitive status and mediation of Aß toxicity in AD. Finally, we also focus on the developing intervention methods for improvement of cognitive decline in AD based on targeting of CREB-BDNF pathway.


Assuntos
Doença de Alzheimer/terapia , Fator Neurotrófico Derivado do Encéfalo/metabolismo , Proteína de Ligação ao Elemento de Resposta ao AMP Cíclico/metabolismo , Doença de Alzheimer/tratamento farmacológico , Doença de Alzheimer/metabolismo , Peptídeos beta-Amiloides/metabolismo , Precursor de Proteína beta-Amiloide/metabolismo , Animais , Encéfalo/metabolismo , Fator Neurotrófico Derivado do Encéfalo/fisiologia , Cognição/fisiologia , Transtornos Cognitivos/metabolismo , Disfunção Cognitiva/metabolismo , Proteína de Ligação ao Elemento de Resposta ao AMP Cíclico/fisiologia , Modelos Animais de Doenças , Humanos , Memória/fisiologia , Neurônios/metabolismo , Fosforilação , Transdução de Sinais
16.
J Biol Chem ; 295(30): 10271-10280, 2020 07 24.
Artigo em Inglês | MEDLINE | ID: mdl-32487748

RESUMO

Transmembrane proteins are membrane-anchored proteins whose topologies are important for their functions. These properties enable regulation of certain transmembrane proteins by regulated intramembrane proteolysis (RIP) and regulated alternative translocation (RAT). RIP enables a protein fragment of a transmembrane precursor to function at a new location, and RAT leads to an inverted topology of a transmembrane protein by altering the direction of its translocation across membranes during translation. RIP mediated by site-1 protease (S1P) and site-2 protease (S2P) is involved in proteolytic activation of membrane-bound transcription factors. In resting cells, these transcription factors remain in the endoplasmic reticulum (ER) as inactive transmembrane precursors. Upon stimulation by signals within the ER, they are translocated from the ER to the Golgi. There, they are cleaved first by S1P and then by S2P, liberating their N-terminal domains from membranes and enabling them to activate genes in the nucleus. This signaling pathway regulates lipid metabolism, unfolded protein responses, secretion of extracellular matrix proteins, and cell proliferation. Remarkably, ceramide-induced RIP of cAMP response element-binding protein 3-like 1 (CREB3L1) also involves RAT. In resting cells, RIP of CREB3L1 is blocked by transmembrane 4 L6 family member 20 (TM4SF20). Ceramide inverts the orientation of newly synthesized TM4SF20 in membranes through RAT, converting TM4SF20 from an inhibitor to an activator of RIP of CREB3L1. Here, I review recent insights into RIP of membrane-bound transcription factors, focusing on CREB3L1 activation through both RIP and RAT, and discuss current open questions about these two signaling pathways.


Assuntos
Núcleo Celular/metabolismo , Proteína de Ligação ao Elemento de Resposta ao AMP Cíclico/metabolismo , Retículo Endoplasmático/metabolismo , Proteínas do Tecido Nervoso/metabolismo , Pró-Proteína Convertases/metabolismo , Proteólise , Serina Endopeptidases/metabolismo , Transdução de Sinais/fisiologia , Tetraspaninas/metabolismo , Transporte Ativo do Núcleo Celular/fisiologia , Animais , Complexo de Golgi/metabolismo , Humanos
17.
Histochem Cell Biol ; 154(3): 287-299, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32495040

RESUMO

In mammals, progressive activation of primordial follicles is essential for maintenance of the reproductive lifespan. Several reports have demonstrated that mitogen-activated protein kinases 3 and 1 (MAPK3/1)-mammalian target of rapamycin complex 1 (mTORC1) signaling in pre-granulosa cells promotes primordial follicle activation by increasing KIT ligand (KITL) expression and then stimulating phosphatidylinositol 3 kinase signaling in oocytes. However, the mechanism of mTORC1 signaling in the promotion of KITL expression is unclear. Immunofluorescence staining results showed that phosphorylated cyclic AMP response element-binding protein (CREB) was mainly expressed in pre-granulosa cells. The CREB inhibitor KG-501 and CREB knockdown by Creb siRNA significantly suppressed primordial follicle activation, reduced pre-granulosa cell proliferation and dramatically increased oocyte apoptosis. Western blotting results demonstrated that both the MAPK3/1 inhibitor U0126 and mTORC1 inhibitor rapamycin significantly decreased the levels of phosphorylated CREB, indicating that MAPK3/1-mTORC1 signaling is required for CREB activation. Furthermore, CREB could bind to the Kitl promoter region, and KG-501 significantly decreased the expression levels of KITL. In addition, KG-501 and CREB knockdown significantly decreased the levels of phosphorylated Akt, leading to a reduced number of oocytes with Foxo3a nuclear export. KG-501 also inhibited bpV (HOpic)-stimulated primordial follicle activation. Taken together, the results show that CREB is required for MAPK3/1-mTORC1 signaling-promoted KITL expression followed by the activation of primordial follicles.


Assuntos
Proteína de Ligação ao Elemento de Resposta ao AMP Cíclico/metabolismo , Alvo Mecanístico do Complexo 1 de Rapamicina/metabolismo , Folículo Ovariano/metabolismo , Animais , Apoptose/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Feminino , Masculino , Alvo Mecanístico do Complexo 1 de Rapamicina/genética , Camundongos , Camundongos Endogâmicos ICR , Naftóis/farmacologia , Organofosfatos/farmacologia , Folículo Ovariano/efeitos dos fármacos , Fosforilação , Transdução de Sinais/genética , Fator de Células-Tronco/antagonistas & inibidores , Fator de Células-Tronco/metabolismo , Técnicas de Cultura de Tecidos , Compostos de Vanádio/antagonistas & inibidores , Compostos de Vanádio/farmacologia
18.
Dev Cell ; 54(1): 92-105.e5, 2020 07 06.
Artigo em Inglês | MEDLINE | ID: mdl-32544391

RESUMO

Evolutionarily conserved signaling pathways are crucial for adjusting growth, reproduction, and cell maintenance in response to altered environmental conditions or energy balance. However, we have an incomplete understanding of the signaling networks and mechanistic changes that coordinate physiological changes across tissues. We found that loss of the cAMP response element-binding protein (CREB) transcription factor significantly slows Caenorhabditis elegans' reproductive decline, an early hallmark of aging in many animals. Our results indicate that CREB acts downstream of the transforming growth factor ß (TGF-ß) Sma/Mab pathway in the hypodermis to control reproductive aging, and that it does so by regulating a Hedgehog-related signaling factor, WRT-10. Overexpression of hypodermal wrt-10 is sufficient to delay reproductive decline and oocyte quality deterioration, potentially acting via Patched-related receptors in the germline. This TGF-ß-CREB-Hedgehog signaling axis allows a key metabolic tissue to communicate with the reproductive system to regulate oocyte quality and the rate of reproductive decline.


Assuntos
Envelhecimento/metabolismo , Proteínas de Caenorhabditis elegans/metabolismo , Proteína de Ligação ao Elemento de Resposta ao AMP Cíclico/metabolismo , Proteínas Hedgehog/metabolismo , Receptores Patched/metabolismo , Reprodução , Envelhecimento/genética , Envelhecimento/fisiologia , Animais , Caenorhabditis elegans , Proteínas de Caenorhabditis elegans/genética , Proteína de Ligação ao Elemento de Resposta ao AMP Cíclico/genética , Proteínas Hedgehog/genética , Oócitos/metabolismo , Receptores Patched/genética , Transdução de Sinais , Fator de Crescimento Transformador beta/metabolismo
19.
Sci Rep ; 10(1): 9666, 2020 06 15.
Artigo em Inglês | MEDLINE | ID: mdl-32541810

RESUMO

The villous cytotrophoblastic cells have the ability to fuse and differentiate, forming the syncytiotrophoblast (STB). The syncytialisation process is essential for placentation. Nevertheless, the mechanisms involved in cell fusion and differentiation are yet to be fully elucidated. It has been suggested that cell surface glucose-regulated protein 78 (GRP78) was involved in this process. In multiple cancer cells, cell membrane-located GRP78 has been reported to act as a receptor binding to the active form of α2-macroglobulin (α2M*), activating thus several cellular signalling pathways implicated in cell growth and survival. We hypothesised that GRP78 interaction with α2M* may also activate signalling pathways in trophoblastic cells, which, in turn, may promote cell fusion. Here, we observed that α2M mRNA is highly expressed in trophoblastic cells, whereas it is not expressed in the choriocarcinoma cell line BeWo. We thus took advantage of forskolin-induced syncytialisation of BeWo cells to study the effect of exogenous α2M* on syncytialisation. We first demonstrated that α2M* induced trophoblastic cell fusion. This effect is dependent on α2M*-GRP78 interaction, ERK1/2 and CREB phosphorylation, and unfolded protein response (UPR) activation. Overall, these data provide novel insights into the signalling molecules and mechanisms regulating trophoblastic cell fusion.


Assuntos
Coriocarcinoma/genética , Proteínas de Choque Térmico/metabolismo , Trofoblastos/citologia , Neoplasias Uterinas/genética , alfa-Macroglobulinas/genética , Fusão Celular , Linhagem Celular , Coriocarcinoma/metabolismo , Proteína de Ligação ao Elemento de Resposta ao AMP Cíclico/metabolismo , Regulação para Baixo , Feminino , Humanos , Sistema de Sinalização das MAP Quinases , Fosforilação , Gravidez , Transdução de Sinais , Trofoblastos/metabolismo , Resposta a Proteínas não Dobradas , Neoplasias Uterinas/metabolismo , alfa-Macroglobulinas/metabolismo
20.
Biochim Biophys Acta Mol Cell Res ; 1867(10): 118783, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-32569665

RESUMO

The NMDA receptor is crucial to several functions in CNS physiology and some of its effects are mediated by promoting nitric oxide production from L-arginine and activation of signaling pathways and the transcription factor CREB. Our previous work demonstrated in retinal cells that increasing intracellular free L-arginine levels directly correlates to nitric oxide (NO) generation and can be promoted by protein synthesis inhibition and increase of free L-arginine concentration. Eukaryotic elongation factor 2 kinase (eEF2K), a calcium/calmodulin-dependent kinase, is also known to be activated by NMDA receptors leading to protein synthesis inhibition. Here we explored how does eEF2K participate in NMDA-induced NO signaling. We found that when this enzyme is inhibited, NMDA loses its ability to promote NO synthesis. On the other hand, when NO synthesis is increased by protein synthesis inhibition with cycloheximide or addition of exogenous L-arginine, eEF2K has no participation, showcasing a specific link between this enzyme and NMDA-induced NO signaling. We have previously shown that inhibition of the canonical NO signaling pathway (guanylyl cyclase/cGMP/cGK) blocks CREB activation by glutamate in retinal cells. Interestingly, pharmacological inhibition of eEF2K fully prevents CREB activation by NMDA, once again demonstrating the importance of eEF2K in NMDA receptor signaling. In summary, we demonstrated here a new role for eEF2K, directly controlling NMDA-dependent nitrergic signaling and modulating L-arginine availability in neurons, which can potentially be a new target for the study of physiological and pathological processes involving NMDA receptors in the central nervous system.


Assuntos
Sistema Nervoso Central/metabolismo , Proteína de Ligação ao Elemento de Resposta ao AMP Cíclico/metabolismo , Quinase do Fator 2 de Elongação/metabolismo , N-Metilaspartato/farmacologia , Óxido Nítrico/biossíntese , Animais , Arginina/farmacologia , Galinhas , Cicloeximida/farmacologia , Quinase do Fator 2 de Elongação/antagonistas & inibidores , Indazóis/farmacologia , Masculino , Fosforilação/efeitos dos fármacos , Piridinas/farmacologia , Pirimidinas/farmacologia , Ratos
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