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1.
Chem Biol Interact ; 328: 109144, 2020 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-32653415

RESUMO

The debilitating nature of cognitive impairment in epilepsy and the potential of some traditional antiepileptics to further deteriorate cognitive function are areas of growing concern. Glucagon-like peptide-1 (GLP-1) deficiency has been linked to reduced seizure threshold as well as cognitive dysfunction. Here, we tested whether sitagliptin (SITA), by virtue of its neuroprotective properties, could alleviate both epilepsy and associated cognitive dysfunction in a rat model of kindling epilepsy. Chemical kindling was induced by subconvulsive doses of pentylenetetrazol (PTZ) (30 mg/kg; i.p). SITA (50 mg/kg; p.o) was administered 1 h before PTZ injections. SITA conceivably attenuated PTZ hippocampal histological insult, preserved neuronal integrity and amended neurotransmitter perturbations in rat hippocampi paralleled with enhanced hippocampal GLP-1 levels as well as the downstream cAMP content and protein kinase A (PKA) activity. Moreover, SITA improved cognitive functioning of rats in the Morris water maze which was coupled with hampered hippocampal p(Ser404)-tau and ß-amyloid proteins. SITA replenished p(Ser9)-glycogen synthase kinase-3ß (GSK-3ß). It also opposed the boosted matrix metalloproteinase-9 (MMP-9), brain-derived neurotrophic factor (BDNF), and insulin-like growth factor-1 (IGF-1) levels associated with PTZ administration along with mitigation of both ß-secretase-1 (BACE1) immunoreactivity and receptor for advanced glycation end products (RAGE) protein level in rat hippocampi. In conclusion, SITA subdues epileptic and cognitive upshots of PTZ kindling in rats, which might correspond to the modulation of BACE1, amyloidogenic/RAGE axis as well as GSK-3ß/MMP-9/BDNF signaling cascade. SITA effects are probably mediated via boosting GLP-1 and subsequently enhancing GLP-1/GLP-1R signaling.


Assuntos
Secretases da Proteína Precursora do Amiloide/metabolismo , Amiloide/metabolismo , Ácido Aspártico Endopeptidases/metabolismo , Transtornos Cognitivos/induzido quimicamente , Transtornos Cognitivos/metabolismo , Excitação Neurológica/efeitos dos fármacos , Receptor para Produtos Finais de Glicação Avançada/metabolismo , Transdução de Sinais , Fosfato de Sitagliptina/farmacologia , Peptídeos beta-Amiloides/metabolismo , Animais , Biomarcadores/metabolismo , Fator Neurotrófico Derivado do Encéfalo/metabolismo , Transtornos Cognitivos/patologia , Peptídeo 1 Semelhante ao Glucagon/metabolismo , Glicogênio Sintase Quinase 3 beta/metabolismo , Hipocampo/efeitos dos fármacos , Hipocampo/patologia , Fator de Crescimento Insulin-Like I/metabolismo , Masculino , Metaloproteinase 9 da Matriz/metabolismo , Inibição Neural/efeitos dos fármacos , Neurônios/efeitos dos fármacos , Neurônios/metabolismo , Neurônios/patologia , Neurotransmissores/metabolismo , Pentilenotetrazol , Ratos Wistar , Convulsões/induzido quimicamente , Convulsões/metabolismo , Convulsões/patologia , Transdução de Sinais/efeitos dos fármacos , Memória Espacial/efeitos dos fármacos , Proteínas tau/metabolismo
2.
Am J Chin Med ; 48(4): 945-966, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32476431

RESUMO

Tetramethylpyrazine has shown neuroprotective and axonal outgrowth-promoting effects and can improve cognitive deficit in a rat model of chronic hypoperfusion. However, the role of tetramethylpyrazine in sevoflurane-induced neurotoxicity is still vague. Therefore, this study was designed to investigate the effects and mechanisms of tetramethylpyrazine on sevoflurane-induced autophagy, apoptosis, and the expression of BACE1 and A[Formula: see text] in SH-SY5Y cells. We measured the expression levels of the apoptosis protein markers Bax and Bcl-2, autophagy protein markers Atg5 and LC3-II, BACE1, and A[Formula: see text] in SH-SY5Y cells after sevoflurane treatment and determined the effects of tetramethylpyrazine on sevoflurane-induced expression of these proteins after silencing GPR50 or Atg5 with siRNA in vitro. We found that exposure to 3.4% sevoflurane for 6 h decreased the expression of autophagy protein markers and increased the expression of the apoptosis protein markers, BACE1, and A[Formula: see text] in SH-SY5Y cells. The number of red puncta (autolysosomes) and yellow puncta (autophagosomes) in each SH-SY5Y cell decreased after transient transfection with the mRFP-GFP-LC3 expression plasmid. Silencing of GPR50 decreased the expression of pCREB, Atg5, and LC3-II, while silencing of Atg5 increased the expression of BACE1 and A[Formula: see text] in SH-SY5Y cells. Our results demonstrate that tetramethylpyrazine attenuated sevoflurane-induced neurotoxicity by enhancing autophagy through the GPR50/CREB pathway in SH-SY5Y cells.


Assuntos
Autofagia/efeitos dos fármacos , Autofagia/genética , Proteína de Ligação a CREB/metabolismo , Proteínas do Tecido Nervoso/metabolismo , Neuroprostanos , Pirazinas/farmacologia , Pirazinas/uso terapêutico , Receptores Acoplados a Proteínas-G/metabolismo , Sevoflurano/toxicidade , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/genética , Secretases da Proteína Precursora do Amiloide/genética , Secretases da Proteína Precursora do Amiloide/metabolismo , Peptídeos beta-Amiloides/genética , Peptídeos beta-Amiloides/metabolismo , Apoptose/efeitos dos fármacos , Apoptose/genética , Ácido Aspártico Endopeptidases/genética , Ácido Aspártico Endopeptidases/metabolismo , Proteína 5 Relacionada à Autofagia/genética , Proteína 5 Relacionada à Autofagia/metabolismo , Expressão Gênica/efeitos dos fármacos , Humanos , Proteínas Associadas aos Microtúbulos/genética , Proteínas Associadas aos Microtúbulos/metabolismo , Células Tumorais Cultivadas
3.
PLoS One ; 15(5): e0232679, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32437351

RESUMO

Skin aspartic acid protease (SASPase) is believed to be a key enzyme involved in filaggrin processing during epidermal terminal differentiation. Since little is known about the regulation of SASPase function, the aim of this study was to identify involved protein partners in the process. Yeast two hybrid analyses using SASPase as bait against a human reconstructed skin library identified that the N-terminal domain of filaggrin 2 binds to the N-terminal fragment of SASPase. This interaction was confirmed in reciprocal yeast two hybrid screens and by Surface Plasmon Resonance analyses. Immunohistochemical studies in human skin, using specific antibodies to SASPase and the N-terminal domain of filaggrin 2, showed that the two proteins partially co-localized to the stratum granulosum. In vitro enzymatic assays showed that the N-terminal domain of filaggrin 2 enhanced the autoactivation of SASPase to its 14 kDa active form. Taken together, the data suggest that the N-terminal domain of filaggrin 2 regulates the activation of SASPase that may be a key event upstream of filaggrin processing to natural moisturizing factors in the human epidermis.


Assuntos
Ácido Aspártico Endopeptidases/metabolismo , Proteínas S100/metabolismo , Pele/metabolismo , Ácido Aspártico Endopeptidases/análise , Ativação Enzimática , Humanos , Domínios e Motivos de Interação entre Proteínas , Mapas de Interação de Proteínas , Proteínas S100/análise
4.
Compr Psychiatry ; 100: 152176, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32430144

RESUMO

OBJECTIVE: Early-onset schizophrenia is a severe and rare form of schizophrenia that is clinically and neurobiologically continuous with the adult form of schizophrenia. Neuregulin1 (NRG1)-mediated signaling is crucial for early neurodevelopment, which exerts its function by limited ß-secretase 1 (BACE1) proteolysis processing. However, circulating neuregulin1-ß1 (NRG1-ß1), an isoform of NRG1, and its cleavage enzyme BACE1 have not been studied in early-onset patients with schizophrenia. METHODS: In this study, we collected plasma and clinical information from 71 young patients (7 ≤ age years ≤20) with schizophrenia and 53 age- and sex-matched healthy controls. Immunoassay was used to test levels of circulating NRG1-ß1 and BACE1 expression. We further analyzed the relationship of disease-onset age and gender with NRG1-ß1 and BACE1 levels. RESULTS: We found that circulating plasma levels of NRG1-ß1 were significantly decreased in young patients with early-onset schizophrenia. In males with childhood onset schizophrenia (COS), NRG1-ß1 was reduced and was inversely correlated with positive symptom of PANSS; moreover, these male patients with higher plasma BACE1 levels showed more severe general symptoms of PANSS and defective social functioning; whereas, no aforementioned results were found in adolescent-onset schizophrenia (AOS). Notably, young female patients with COS and AOS had no significant change in NRG1-ß1 and BACE1, which demonstrated a sex-dependent effect in early-onset schizophrenia. CONCLUSION: Our results suggest that decreased levels of NRG1-ß1 and its cleavage enzyme BACE1 contribute to increased risk of etiology of schizophrenia. Synthetic biomarkers may have clinical applications for the early diagnosis of male COS.


Assuntos
Secretases da Proteína Precursora do Amiloide/sangue , Ácido Aspártico Endopeptidases/sangue , Neuregulina-1/sangue , Esquizofrenia/sangue , Adolescente , Idade de Início , Secretases da Proteína Precursora do Amiloide/metabolismo , Ácido Aspártico Endopeptidases/metabolismo , Biomarcadores/sangue , Estudos de Casos e Controles , Criança , Feminino , Humanos , Masculino , Esquizofrenia/etiologia , Esquizofrenia/metabolismo , Fatores Sexuais , Transdução de Sinais , Adulto Jovem
5.
PLoS One ; 15(5): e0221669, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32437347

RESUMO

Alzheimer's disease (AD) is a neurodegenerative disorder characterized by progressive memory loss and cognitive disturbance as a consequence of the loss of cholinergic neurons in the brain, neuritic plaques and hyperphosphorylation of TAU protein. Although the underlying mechanisms leading to these events are unclear, mutations in presenilin 1 (PSEN1), e.g., E280A (PSEN1 E280A), are causative factors for autosomal dominant early-onset familial AD (FAD). Despite advances in the understanding of the physiopathology of AD, there are no efficient therapies to date. Limitations in culturing brain-derived live neurons might explain the limited effectiveness of AD research. Here, we show that mesenchymal stromal (stem) cells (MSCs) can be used to model FAD, providing novel opportunities to study cellular mechanisms and to establish therapeutic strategies. Indeed, we cultured MSCs with the FAD mutation PSEN1 E280A and wild-type (WT) PSEN1 from umbilical cords and characterized the transdifferentiation of these cells into cholinergic-like neurons (ChLNs). PSEN1 E280A ChLNs but not WT PSEN1 ChLNs exhibited increased intracellular soluble amyloid precursor protein (sAPPf) fragments and extracellular Aß42 peptide and TAU phosphorylation (at residues Ser202/Thr205), recapitulating the molecular pathogenesis of FAD caused by mutant PSEN1. Furthermore, PSEN1 E280A ChLNs presented oxidative stress (OS) as evidenced by the oxidation of DJ-1Cys106-SH into DJ-1Cys106-SO3 and the detection of DCF-positive cells and apoptosis markers such as activated pro-apoptosis proteins p53, c-JUN, PUMA and CASPASE-3 and the concomitant loss of the mitochondrial membrane potential and DNA fragmentation. Additionally, mutant ChLNs displayed Ca2+ flux dysregulation and deficient acetylcholinesterase (AChE) activity compared to control ChLNs. Interestingly, the inhibitor JNK SP600125 almost completely blocked TAU phosphorylation. Our findings demonstrate that FAD MSC-derived cholinergic neurons with the PSEN1 E280A mutation provide important clues for the identification of targetable pathological molecules.


Assuntos
Doença de Alzheimer , Neurônios Colinérgicos , Células-Tronco Mesenquimais , Presenilina-1 , Cordão Umbilical , Doença de Alzheimer/metabolismo , Doença de Alzheimer/patologia , Secretases da Proteína Precursora do Amiloide/metabolismo , Apoptose , Ácido Aspártico Endopeptidases/metabolismo , Cálcio/metabolismo , Neurônios Colinérgicos/metabolismo , Neurônios Colinérgicos/patologia , Humanos , Células-Tronco Mesenquimais/metabolismo , Células-Tronco Mesenquimais/patologia , Mutação , Estresse Oxidativo , Presenilina-1/genética , Presenilina-1/metabolismo , Cordão Umbilical/metabolismo , Cordão Umbilical/patologia , Proteínas tau/metabolismo
6.
Int. j. morphol ; 38(2): 247-251, abr. 2020. tab, graf
Artigo em Inglês | LILACS | ID: biblio-1056430

RESUMO

Nine tumor and various potential biomarkers were measured and combined the information to diagnose disease, all patients accepted fiber bronchoscopy brush liquid based cytologyand histopathology examination in order to reliably detect lung cancer. The samples from 314 Chinese lung cancer patients were obtained and CK5/6, P63, P40, CK7, TTF-1, NapsinA CD56, Syn and CgA were measured with the immunohistochemical SP method and analyzed correlation of the expression of these markers with pathological and clinical features of squamous cell carcinoma, adenocarcinoma, and small cell lung carcinoma. Squamous cell carcinoma, adenocarcinoma and small cell carcinoma were 61 cases, 114 cases and 139 cases,CK5/6 and P63 expression were more frequent in squamous cell carcinoma, with sensitivity and specificity of 77.05 % and 96.44 %, 83.61 % and 88.93 %,and compared with adenocarcinoma and small cell carcinoma difference was statistically significant (P<0.05), The incidences of a positive P40 expression were 100 % in squamous cell carcinoma, with specificity of 98.81 %.CK7, TTF-1 and NapsinA expression were more frequent in adenocarcinoma, with sensitivity and specificity of 85.09 % and 78.69 %, 79.82 % and 93.44 %, 56.14 % and 95.08 %, and compared with squamous cell carcinoma and small cell carcinoma difference was statistically significant (P<0.05). TTF-1, Syn, CgA and CD56 expression were more frequent in adenocarcinoma, with sensitivity and specificity of 86.33 % and 93.44 %, 89.21 % and 98.36 %, 74.10 % and 100 %, 96.40 % and 96.72 %. The combined detection of CK5/6, P63 and P40 were more useful and specific in differentiating squamous cell carcinoma. CK7, TTF-1 and NapsinA were more useful and specific in differentiating lung adenocarcinoma. The impaired CD56, TTF-1, Syn and CgA reflects the progression of small cell lung cancer.


Se midieron tumores y utilizaron nueve biomarcadores potenciales y se analizó la información para diagnosticar la enfermedad. A todos los pacientes se les realizó citología en líquido con broncoscopía de fibra y examen histopatológico para detectar de manera confiable el cáncer pulmonar. Se obtuvieron muestras de 314 pacientes chinos con cáncer de pulmón y CK5 / 6, P63, P40, CK7, TTF-1, Napsina A, CD56, Syn y CgA se midieron a través de histoquímica SP y analizaron la correlación de la expresión de estos marcadores con características patológicas y clínicas de carcinoma de células escamosas, adenocarcinoma y carcinoma de células pequeñas en el cáncer de pulmón. El carcinoma de células escamosas, el adenocarcinoma y el carcinoma de células pequeñas fueron 61 casos, 114 casos y 139 casos, respectivamente, la expresión de CK5 / 6 y P63 fueron más frecuentes en el carcinoma de células escamosas, con una sensibilidad y especificidad del 77,05 % y 96,44 %, 83,61 % y 88,93 %, y en comparación con el adenocarcinoma y el carcinoma de células pequeñas, la diferencia fue estadísticamente significativa (P <0,05). La incidencia de ap la expresión positiva P40 fue del 100 % en el carcinoma de células escamosas, con una especificidad del 98,81 %. La expresión de CK7, TTF-1 y NapsinA fueron más frecuentes en el adenocarcinoma, con una sensibilidad y especificidad del 85,09 % y 78,69 %, 79,82 % y 93,44 %, 56,14 % y 95,08 %, y en comparación con el carcinoma de células escamosas y la diferencia de carcinoma de células pequeñas fue estadísticamente significativa (P <0,05) .TTF-1, Syn, CgA y la expresión de CD56 fueron más frecuentes en adenocarcinoma, con sensibilidad y especificidad de 86.33 % y 93.44 %, 89.21 % y 98.36 %, 74.10 % y 100 %, 96.40 % y 96.72 %. La detección combinada de CK5 / 6, P63 y P40 fue más útil y específica en la diferenciación del carcinoma de células escamosas. CK7, TTF-1 y NapsinA fueron más útiles y específicos para diferenciar el adenocarcinoma de pulmón. El deterioro de CD56, TTF-1, Syn y CgA refleja la progresión del cáncer de pulmón de células pequeñas.


Assuntos
Humanos , Carcinoma/metabolismo , Carcinoma/patologia , Neoplasias Pulmonares/metabolismo , Neoplasias Pulmonares/patologia , Fragmentos de Peptídeos/metabolismo , Fatores de Transcrição/metabolismo , Imuno-Histoquímica , Carcinoma de Células Escamosas/metabolismo , Carcinoma de Células Escamosas/patologia , Adenocarcinoma/metabolismo , Adenocarcinoma/patologia , Biomarcadores Tumorais/metabolismo , Ácido Aspártico Endopeptidases/metabolismo , Sensibilidade e Especificidade , Carcinoma de Células Pequenas/metabolismo , Carcinoma de Células Pequenas/patologia , Antígeno CD56/metabolismo , Proteínas Supressoras de Tumor/metabolismo , Queratinas Tipo II/metabolismo , Queratina-7/metabolismo , Fator Nuclear 1 de Tireoide/metabolismo
7.
Toxicology ; 437: 152436, 2020 05 15.
Artigo em Inglês | MEDLINE | ID: mdl-32169473

RESUMO

Alzheimer's disease (AD) is a public health crisis due to debilitating cognitive symptoms and lack of curative treatments, in the context of increasing prevalence. Thus, it is critical to identify modifiable risk factors. High levels of meat consumption may increase AD risk. Many toxins are formed during meat cooking such as heterocyclic aromatic amines (HAAs). Our prior studies have shown that HAAs produce dopaminergic neurotoxicity. Given the mechanistic and pathological overlap between AD and dopaminergic disorders we investigated whether exposure to 2-amino-1-methyl-6-phenylimidazo [4,5-b] pyridine (PhIP), a prevalent dietary HAA formed during high-temperature meat cooking, may produce AD-relevant neurotoxicity. Here, C57BL/6 mice were treated with 100 or 200 mg/kg PhIP for 8 h or 75 mg/kg for 4 weeks and 16 weeks. PhIP exposure for 8 h produced oxidative damage, and AD-relevant alterations in hippocampal synaptic proteins, Amyloid-beta precursor protein (APP), and ß-Site amyloid precursor protein cleaving enzyme 1 (BACE1). PhIP exposure for 4 weeks resulted in an increase in BACE1. PhIP exposure for 16 weeks resulted in increased hippocampal oxidative damage, APP, BACE1, Aß aggregation, and tau phosphorylation. Quantification of intracellular nitrotyrosine revealed oxidative damage in cholinergic neurons after 8 h, 4 weeks and 16 weeks of PhIP exposure. Our study demonstrates that increase in oxidative damage, APP and BACE1 might be a possible mechanism by which PhIP promotes Aß aggregation. Given many patients with AD or PD exhibit neuropathological overlap, our study suggests that HAA exposure should be further studied for roles in mediating pathogenic overlap.


Assuntos
Doença de Alzheimer/patologia , Contaminação de Alimentos , Hipocampo/patologia , Imidazóis , Neurônios/patologia , Doença de Alzheimer/induzido quimicamente , Doença de Alzheimer/metabolismo , Secretases da Proteína Precursora do Amiloide/metabolismo , Peptídeos beta-Amiloides/metabolismo , Precursor de Proteína beta-Amiloide/metabolismo , Animais , Ácido Aspártico Endopeptidases/metabolismo , Modelos Animais de Doenças , Progressão da Doença , Hipocampo/metabolismo , Masculino , Camundongos Endogâmicos C57BL , Neurônios/metabolismo , Estresse Oxidativo , Fosforilação , Agregação Patológica de Proteínas , Fatores de Tempo , Proteínas tau/metabolismo
8.
Cell Mol Life Sci ; 77(15): 2959-2979, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32052089

RESUMO

Intramembrane proteolysis describes the cleavage of substrate proteins within their hydrophobic transmembrane segments. Several families of intramembrane proteases have been identified including the aspartyl proteases Signal peptide peptidase (SPP) and its homologues, the SPP-like (SPPL) proteases SPPL2a, SPPL2b, SPPL2c and SPPL3. As presenilin homologues, they employ a similar catalytic mechanism as the well-studied γ-secretase. However, SPP/SPPL proteases cleave transmembrane proteins with a type II topology. The characterisation of SPP/SPPL-deficient mouse models has highlighted a still growing spectrum of biological functions and also promoted the substrate discovery of these proteases. In this review, we will summarise the current hypotheses how phenotypes of these mouse models are linked to the molecular function of the enzymes. At the cellular level, SPP/SPPL-mediated cleavage events rather provide specific regulatory switches than unspecific bulk proteolysis. By this means, a plethora of different cell biological pathways is influenced including signal transduction, membrane trafficking and protein glycosylation.


Assuntos
Ácido Aspártico Endopeptidases/metabolismo , Secretases da Proteína Precursora do Amiloide/metabolismo , Animais , Ácido Aspártico Endopeptidases/química , Humanos , Proteínas de Membrana/metabolismo , Transporte Proteico , Proteólise , Transdução de Sinais , Especificidade por Substrato
9.
Mol Biol Rep ; 47(3): 2047-2059, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32036572

RESUMO

Alzheimer's disease (AD) is a neurodegenerative disorder, and the pathological mechanism of the disease is still far to understand. According to the amyloid cascade hypothesis in AD, Amyloid-ß (Aß) is considered as a key substance that contributes AD development. Aß is a ß-cleaving product from Amyloid-ß protein precursor (APP). Mutations of APP including APPKM670/671670NL (Swedish mutation) result in Aß overproduction and the development of early-onset familial AD. Increase of oxidative stress and damage also occurs in early stage of AD. In this study, we used a SH-SY5Y cell line that stably expresses APP gene with Swedish mutation (SH-SY5Y-APPswe), and the inhibitory effects of curcumin on H2O2-induced cell damage and APP processing were investigated. Cells were treated with curcumin (0 ~ 5 µM) for 4 h before hydrogen peroxide (H2O2). Cell growth was detected with CCK-8 assay, and cell damage was determined through the evaluation of release of lactate dehydrogenase (LDH) from the cytosol to the culture medium and the morphological change of nucleus. The ability of mitochondrial stress and the depolarization of mitochondrial membrane potential were assayed through the measuring the oxygen consumption rate (OCR) and the green/red fluorescence ratio of JC-1 dye respectively. The protein levels of APP, sAPPα, sAPPß, and BACE1 were analyzed with Western blot assay. Aß production was measured with enzyme-linked immunosorbent assay (ELISA). The results indicated that curcumin inhibits H2O2-induced decrease of cell growth and cell damage. Curcumin attenuates H2O2-induced damage on the ability to mitochondrial oxidative phosphorylation and membrane potential. Curcumin inhibits H2O2-induced increase of APP cleavage through ß-cleavage pathway and of intracellular Aß production. These results imply that curcumin can be used to treat AD through inhibiting oxidative damage-induced APP ß-cleavage and intracellular Aß generation.


Assuntos
Precursor de Proteína beta-Amiloide/genética , Curcumina/farmacologia , Expressão Gênica , Peróxido de Hidrogênio/farmacologia , Mutação , Estresse Oxidativo/efeitos dos fármacos , Doença de Alzheimer/genética , Doença de Alzheimer/metabolismo , Doença de Alzheimer/patologia , Secretases da Proteína Precursora do Amiloide/genética , Secretases da Proteína Precursora do Amiloide/metabolismo , Ácido Aspártico Endopeptidases/genética , Ácido Aspártico Endopeptidases/metabolismo , Biomarcadores , Linhagem Celular Tumoral , Membrana Celular/efeitos dos fármacos , Membrana Celular/metabolismo , Sobrevivência Celular/genética , Humanos , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/metabolismo , Proteólise , Transfecção
10.
Artigo em Inglês | MEDLINE | ID: mdl-32005402

RESUMO

Drought is an environmental stress that severely affects plant growth and crop production. Different studies have focused on drought responses but the molecular bases that regulate these mechanisms are still unclear. We report the participation of Aspartic Protease (APA1) in drought tolerance. Overexpressing APA1 Arabidopsis plants (OE-APA1), showed a phenotype more tolerant to drought compared with WT. On the contrary, apa1 insertional lines were more sensitive to this stress compared to WT plants. Morphological and physiological differences related with the water loss were observed between leaves of OE- APA1 and WT plants. OE-APA1 leaves showed lower stomata index and stomata density as well as a smaller of the stomatic aperture compared to WT plants. qPCR analysis in OE-APA1 leaves, showed higher expression levels of genes related to ABA signaling and synthesis. Analysis of plant lines expressing APA1 promoter fused to GUS showed that APA1 is expressed in epidermal and stomata cells. In summary, this work suggests that APA1 is involved in ABA-dependent response that its overexpression confers drought tolerance in Arabidopsis.


Assuntos
Ácido Abscísico/metabolismo , Proteínas de Arabidopsis/genética , Arabidopsis/fisiologia , Ácido Aspártico Endopeptidases/genética , Secas , Regulação da Expressão Gênica de Plantas , Transdução de Sinais , Aclimatação , Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Ácido Aspártico Endopeptidases/metabolismo
11.
Sci Rep ; 10(1): 1358, 2020 Jan 28.
Artigo em Inglês | MEDLINE | ID: mdl-31992816

RESUMO

We previously demonstrated that cyclic guanosine monophosphate (cGMP) stimulates amyloid precursor protein (APP) and beta-secretase (BACE1) approximation in neuronal endo-lysosomal compartments, thus boosting the production of amyloid-ß (Aß) peptides and enhancing synaptic plasticity and memory. Here, we further investigated the mechanism by which cGMP regulates the subcellular localization of APP and BACE1, finding that the cyclic nucleotide inhibits the activity of Rab5, a small GTPase associated with the plasma membrane and early endosomes. Accordingly, we also found that expression of a dominant-negative Rab5 mutant increases both APP-BACE1 approximation and Aß extracellular levels, therefore mimicking the effects induced by cGMP. These results reveal a functional correlation between the cGMP/Aß pathway and the activity of Rab5 that may contribute to the understanding of Alzheimer's disease pathophysiology.


Assuntos
Doença de Alzheimer/metabolismo , Secretases da Proteína Precursora do Amiloide/metabolismo , Precursor de Proteína beta-Amiloide/metabolismo , Ácido Aspártico Endopeptidases/metabolismo , Membrana Celular/metabolismo , Sistemas do Segundo Mensageiro , Proteínas rab5 de Ligação ao GTP/metabolismo , Doença de Alzheimer/genética , Doença de Alzheimer/patologia , Secretases da Proteína Precursora do Amiloide/genética , Precursor de Proteína beta-Amiloide/genética , Animais , Ácido Aspártico Endopeptidases/genética , Linhagem Celular , Membrana Celular/genética , Membrana Celular/patologia , GMP Cíclico , Endossomos/genética , Endossomos/metabolismo , Endossomos/patologia , Camundongos , Proteínas rab5 de Ligação ao GTP/genética
12.
Nat Commun ; 11(1): 140, 2020 01 09.
Artigo em Inglês | MEDLINE | ID: mdl-31919415

RESUMO

Antimicrobial resistance is a major global threat that calls for new antibiotics. Globomycin and myxovirescin are two natural antibiotics that target the lipoprotein-processing enzyme, LspA, thereby compromising the integrity of the bacterial cell envelope. As part of a project aimed at understanding their mechanism of action and for drug development, we provide high-resolution crystal structures of the enzyme from the human pathogen methicillin-resistant Staphylococcus aureus (MRSA) complexed with globomycin and with myxovirescin. Our results reveal an instance of convergent evolution. The two antibiotics possess different molecular structures. Yet, they appear to inhibit identically as non-cleavable tetrahedral intermediate analogs. Remarkably, the two antibiotics superpose along nineteen contiguous atoms that interact similarly with LspA. This 19-atom motif recapitulates a part of the substrate lipoprotein in its proposed binding mode. Incorporating this motif into a scaffold with suitable pharmacokinetic properties should enable the development of effective antibiotics with built-in resistance hardiness.


Assuntos
Ácido Aspártico Endopeptidases/metabolismo , Proteínas de Bactérias/metabolismo , Macrolídeos/metabolismo , Staphylococcus aureus Resistente à Meticilina/enzimologia , Peptídeos/metabolismo , Sítios de Ligação/fisiologia , Membrana Celular/efeitos dos fármacos , Cristalografia por Raios X , Farmacorresistência Bacteriana/genética , Farmacorresistência Bacteriana/fisiologia , Macrolídeos/farmacologia , Peptídeos/farmacologia , Ligação Proteica/fisiologia , Estrutura Terciária de Proteína
13.
FASEB J ; 34(2): 2465-2482, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-31908000

RESUMO

The protease beta-site APP cleaving enzyme 1 (BACE1) has fundamental functions in the nervous system. Its inhibition is a major therapeutic approach in Alzheimer's disease, because BACE1 cleaves the amyloid precursor protein (APP), thereby catalyzing the first step in the generation of the pathogenic amyloid beta (Aß) peptide. Yet, BACE1 cleaves numerous additional membrane proteins besides APP. Most of these substrates have been identified in vitro, but only few were further validated or characterized in vivo. To identify BACE1 substrates with in vivo relevance, we used isotope label-based quantitative proteomics of wild type and BACE1-deficient (BACE1 KO) mouse brains. This approach identified known BACE1 substrates, including Close homolog of L1 and contactin-2, which were found to be enriched in the membrane fraction of BACE1 KO brains. VWFA and cache domain-containing protein 1 (CACHD)1 and MAM domain-containing glycosylphosphatidylinositol anchor protein 1 (MDGA1), which have functions in synaptic transmission, were identified and validated as new BACE1 substrates in vivo by immunoblots using primary neurons and mouse brains. Inhibition or deletion of BACE1 from primary neurons resulted in a pronounced inhibition of substrate cleavage and a concomitant increase in full-length protein levels of CACHD1 and MDGA1. The BACE1 cleavage site in both proteins was determined to be located within the juxtamembrane domain. In summary, this study identifies and validates CACHD1 and MDGA1 as novel in vivo substrates for BACE1, suggesting that cleavage of both proteins may contribute to the numerous functions of BACE1 in the nervous system.


Assuntos
Secretases da Proteína Precursora do Amiloide/metabolismo , Ácido Aspártico Endopeptidases/metabolismo , Encéfalo/metabolismo , Moléculas de Adesão de Célula Nervosa/metabolismo , Proteômica , Doença de Alzheimer/genética , Doença de Alzheimer/metabolismo , Doença de Alzheimer/patologia , Secretases da Proteína Precursora do Amiloide/genética , Animais , Ácido Aspártico Endopeptidases/genética , Encéfalo/patologia , Camundongos , Camundongos Knockout , Moléculas de Adesão de Célula Nervosa/genética
14.
Mol Cell Biochem ; 463(1-2): 161-173, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31595422

RESUMO

Alzheimer's disease (AD) is the leading cause of dementia, which characterized by toxic senile plaques is composed of amyloid-ß (Aß). ß-site amyloid precursor protein-cleaving enzyme 1 (BACE1) is the rate-limiting protease in Aß generation. Therefore, pharmacology BACE1 inhibition is one of the prime targets for potential treatment of AD. Curcumin, a yellow polyphenol derived from the rhizomes of the plant Curcuma longa Linn, has been reported to cross the blood-brain barrier and prevent Aß aggregation in AD models. However, its neuroprotective mechanism is still unclear. In the present study, we find that curcumin markedly reduces Aß levels in HEK293-APPswe cells. Our results show that curcumin inhibits BACE1 gene expression in SH-SY5Y cells at transcriptional and translational levels. Furthermore, we reveal that nuclear factor kappa B (NFκB) signaling is involved in the regulation of curcumin on BACE1. Interestingly, the estrogenicity of curcumin is found to partially contribute to its protective action. Our data show that curcumin activates estrogen receptor ß (ERß) selectively and the activation of ERß directly effects on the upstream factors of the NFκB signaling pathway. The above results indicate that curcumin reduces BACE1 expression through ERß and NFκB pathway, providing a novel mechanism for curcumin as a candidate for AD therapy.


Assuntos
Doença de Alzheimer/tratamento farmacológico , Secretases da Proteína Precursora do Amiloide/metabolismo , Ácido Aspártico Endopeptidases/metabolismo , Curcumina/farmacologia , Receptor beta de Estrogênio/metabolismo , NF-kappa B/metabolismo , Transdução de Sinais/efeitos dos fármacos , Doença de Alzheimer/genética , Doença de Alzheimer/metabolismo , Doença de Alzheimer/patologia , Secretases da Proteína Precursora do Amiloide/genética , Ácido Aspártico Endopeptidases/genética , Linhagem Celular Tumoral , Receptor beta de Estrogênio/genética , Células HEK293 , Humanos , NF-kappa B/genética , Transdução de Sinais/genética
15.
Chem Biol Interact ; 316: 108927, 2020 Jan 25.
Artigo em Inglês | MEDLINE | ID: mdl-31843630

RESUMO

Environmental pollutant, Lead (Pb) is known to induce neurotoxicity in human. The central nervous system is the most vulnerable to the minute levels of Pb induced toxicity. Pb has been linked to Alzheimer's disease (AD) as a probable risk factor, as it shows epigenetic and developmental link associated with Alzheimer's disease-like pathology. Beta amyloid peptides were considered as the crucial factors in the beta amyloid plaque formation in Alzheimer's disease brain. In this context, we investigated the molecular mechanism involved in the development of Pb induced Alzheimer's disease in in vitro. Previous data from our studies have reported that Pb in the presence of beta Amyloid peptide (1-40) and (25-35) induces more apoptosis than individual exposures. Here, to further evaluate the molecular mechanism underlying Pb induced Alzheimer's disease; we focussed on the involvement of calcium signalling in inducing cell death. Our experimental observations suggesting that Pb in the presence of beta amyloid peptide alters intracellular calcium levels, which leads to the increased beta-secretase activity, which further promotes the generation of beta amyloid peptides. It also showed depression in the levels of GAP-43 expression, inhibition of PKC activity and altering synaptic activity further leads to cell death.


Assuntos
Peptídeos beta-Amiloides/toxicidade , Cálcio/metabolismo , Proteína GAP-43/metabolismo , Regulação da Expressão Gênica/efeitos dos fármacos , Chumbo/toxicidade , Secretases da Proteína Precursora do Amiloide/genética , Secretases da Proteína Precursora do Amiloide/metabolismo , Ácido Aspártico Endopeptidases/genética , Ácido Aspártico Endopeptidases/metabolismo , Diferenciação Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Proteína GAP-43/genética , Humanos , Proteína Quinase C/genética , Proteína Quinase C/metabolismo , Sinaptofisina/genética , Sinaptofisina/metabolismo
16.
PLoS One ; 14(12): e0226368, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31830091

RESUMO

It has been revealed that ß-amyloid (Aß) is generated and released from the presynaptic terminals in activity-dependent manner. However, molecules modulating the presynaptic Aß generation remain elusive. Here we test the hypothesis that Synapsin 1 (Syn1) may acts as a modulator of the Aß production. Using biochemical and Förster resonance energy transfer (FRET)-based imaging approaches we have found that Syn1 knock down decreases, whereas (over)expression of Syn1 in cells increases the Aß levels. Mechanistically, Syn1 does not seem to affect the activity of Presenilin 1 (PS1)/γ-secretase, PS1 conformation, or the proximity between PS1 and amyloid precursor protein (APP). However, we found that Syn1 is involved in up-regulation of the ß-site APP cleaving enzyme 1 (BACE1)/ß-secretase activity and increases the APP/BACE1 interaction. Therefore, we conclude that Syn1 may promote Aß production via the modulation of BACE1.


Assuntos
Secretases da Proteína Precursora do Amiloide/metabolismo , Peptídeos beta-Amiloides/metabolismo , Ácido Aspártico Endopeptidases/metabolismo , Regulação da Expressão Gênica , Presenilina-1/metabolismo , Sinapsinas/metabolismo , Secretases da Proteína Precursora do Amiloide/genética , Animais , Ácido Aspártico Endopeptidases/genética , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Presenilina-1/genética , Sinapsinas/genética
17.
J Enzyme Inhib Med Chem ; 34(1): 712-727, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31852270

RESUMO

The design of multi-target directed ligands (MTDLs) is a valid approach for obtaining effective drugs for complex pathologies. MTDLs that combine neuro-repair properties and block the first steps of neurotoxic cascades could be the so long wanted remedies to treat neurodegenerative diseases (NDs). By linking two privileged scaffolds with well-known activities in ND-targets, the flavonoid and the N,N-dibenzyl(N-methyl)amine (DBMA) fragments, new CNS-permeable flavonoid - DBMA hybrids (1-13) were obtained. They were subjected to biological evaluation in a battery of targets involved in Alzheimer's disease (AD) and other NDs, namely human cholinesterases (hAChE/hBuChE), ß-secretase (hBACE-1), monoamine oxidases (hMAO-A/B), lipoxygenase-5 (hLOX-5) and sigma receptors (σ1R/σ2R). After a funnel-type screening, 6,7-dimethoxychromone - DBMA (6) was highlighted due to its neurogenic properties and an interesting MTD-profile in hAChE, hLOX-5, hBACE-1 and σ1R. Molecular dynamic simulations showed the most relevant drug-protein interactions of hybrid 6, which could synergistically contribute to neuronal regeneration and block neurodegeneration.


Assuntos
Doença de Alzheimer/tratamento farmacológico , Inibidores Enzimáticos/farmacologia , Flavonoides/farmacologia , Metilaminas/farmacologia , Regeneração Nervosa/efeitos dos fármacos , Fármacos Neuroprotetores/farmacologia , Acetilcolinesterase/metabolismo , Doença de Alzheimer/metabolismo , Secretases da Proteína Precursora do Amiloide/antagonistas & inibidores , Secretases da Proteína Precursora do Amiloide/metabolismo , Animais , Araquidonato 5-Lipoxigenase/metabolismo , Ácido Aspártico Endopeptidases/antagonistas & inibidores , Ácido Aspártico Endopeptidases/metabolismo , Barreira Hematoencefálica/efeitos dos fármacos , Barreira Hematoencefálica/metabolismo , Butirilcolinesterase/metabolismo , Inibidores Enzimáticos/síntese química , Inibidores Enzimáticos/química , Flavonoides/química , Humanos , Masculino , Metilaminas/química , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Modelos Moleculares , Estrutura Molecular , Monoaminoxidase/metabolismo , Fármacos Neuroprotetores/síntese química , Fármacos Neuroprotetores/química
18.
Cell Rep ; 29(12): 3796-3806.e4, 2019 12 17.
Artigo em Inglês | MEDLINE | ID: mdl-31851913

RESUMO

Plasmodium falciparum gametocytes infect mosquitoes and are responsible for malaria transmission. New interventions that block transmission could accelerate malaria elimination. Gametocytes develop within erythrocytes and activate protein export pathways that remodel the host cell. Plasmepsin V (PMV) is an aspartyl protease that is required for protein export in asexual parasites, but its function and essentiality in gametocytes has not been definitively proven, nor has PMV been assessed as a transmission-blocking drug target. Here, we show that PMV is expressed and can be inhibited specifically in P. falciparum stage I-II gametocytes. PMV inhibitors block processing and export of gametocyte effector proteins and inhibit development of stage II-V gametocytes. Gametocytogenesis in the presence of sublethal inhibitor concentrations results in stage V gametocytes that fail to infect mosquitoes. Therefore, PMV primes gametocyte effectors for export, which is essential for the development and fitness of gametocytes for transmission to mosquitoes.


Assuntos
Ácido Aspártico Endopeptidases/antagonistas & inibidores , Culicidae/crescimento & desenvolvimento , Inibidores Enzimáticos/farmacologia , Gametogênese/efeitos dos fármacos , Malária Falciparum/prevenção & controle , Plasmodium falciparum/crescimento & desenvolvimento , Proteínas de Protozoários/antagonistas & inibidores , Animais , Ácido Aspártico Endopeptidases/metabolismo , Culicidae/efeitos dos fármacos , Culicidae/parasitologia , Eritrócitos/efeitos dos fármacos , Eritrócitos/parasitologia , Humanos , Estágios do Ciclo de Vida , Malária Falciparum/enzimologia , Malária Falciparum/parasitologia , Malária Falciparum/transmissão , Plasmodium falciparum/efeitos dos fármacos , Plasmodium falciparum/enzimologia , Proteínas de Protozoários/metabolismo
19.
Nutrients ; 11(11)2019 Nov 07.
Artigo em Inglês | MEDLINE | ID: mdl-31703329

RESUMO

One of the major neurodegenerative features of Alzheimer's disease (AD) is the presence of neurotoxic amyloid plaques composed of amyloid beta peptide (Aß). ß-Secretase (BACE1) and acetylcholinesterase (AChE), which promote Aß fibril formation, have become attractive therapeutic targets for AD. P-glycoprotein (P-gp), the major efflux pump of the blood-brain barrier (BBB), plays a critical role in limiting therapeutic molecules. In pursuit of discovering a natural anti-AD candidate, the bioactivity, physicochemical, drug-likeness, and molecular docking properties of baicalein, a major compound from Scutellaria baicalensis, was investigated. Baicalein exhibited strong BACE1 and AChE inhibitory properties (IC50 23.71 ± 1.91 µM and 45.95 ± 3.44 µM, respectively) and reacted in non-competitive and competitive manners with substrates, respectively. in Silico docking analysis was in full agreement with the in vitro results, demonstrating that the compound exhibited powerful binding interaction with target enzymes. Particularly, three continuous hydroxyl groups on the A ring demonstrated strong H-bond binding properties. It is also noteworthy that baicalein complied with all requirements of Lipinski's rule of five by its optimal physicochemical properties for both oral bioavailability and blood-brain barrier permeability. Overall, the present study strongly demonstrated the possibility of baicalein having in vivo pharmacological efficacy for specific targets in the prevention and/or treatment of AD.


Assuntos
Acetilcolinesterase , Secretases da Proteína Precursora do Amiloide , Ácido Aspártico Endopeptidases , Inibidores da Colinesterase , Flavanonas , Membro 1 da Subfamília B de Cassetes de Ligação de ATP/química , Membro 1 da Subfamília B de Cassetes de Ligação de ATP/metabolismo , Acetilcolinesterase/química , Acetilcolinesterase/metabolismo , Doença de Alzheimer , Secretases da Proteína Precursora do Amiloide/antagonistas & inibidores , Secretases da Proteína Precursora do Amiloide/química , Secretases da Proteína Precursora do Amiloide/metabolismo , Ácido Aspártico Endopeptidases/antagonistas & inibidores , Ácido Aspártico Endopeptidases/química , Ácido Aspártico Endopeptidases/metabolismo , Inibidores da Colinesterase/química , Inibidores da Colinesterase/metabolismo , Inibidores da Colinesterase/farmacologia , Flavanonas/química , Flavanonas/metabolismo , Flavanonas/farmacologia , Humanos , Simulação de Acoplamento Molecular , Proteínas Recombinantes/química , Proteínas Recombinantes/metabolismo , Scutellaria baicalensis
20.
EMBO J ; 38(23): e102345, 2019 12 02.
Artigo em Inglês | MEDLINE | ID: mdl-31701556

RESUMO

In Alzheimer's disease, BACE1 protease initiates the amyloidogenic processing of amyloid precursor protein (APP) that eventually results in synthesis of ß-amyloid (Aß) peptide. Aß deposition in turn causes accumulation of BACE1 in plaque-associated dystrophic neurites, thereby potentiating progressive Aß deposition once initiated. Since systemic pharmacological BACE inhibition causes adverse effects in humans, it is important to identify strategies that specifically normalize overt BACE1 activity around plaques. The microtubule-associated protein tau regulates axonal transport of proteins, and tau deletion rescues Aß-induced transport deficits in vitro. In the current study, long-term in vivo two-photon microscopy and immunohistochemistry were performed in tau-deficient APPPS1 mice. Tau deletion reduced plaque-associated axonal pathology and BACE1 accumulation without affecting physiological BACE1 expression distant from plaques. Thereby, tau deletion effectively decelerated formation of new plaques and reduced plaque compactness. The data revealed that tau reinforces Aß deposition, presumably by contributing to accumulation of BACE1 in plaque-associated dystrophies. Targeting tau-dependent mechanisms could become a suitable strategy to specifically reduce overt BACE1 activity around plaques, thereby avoiding adverse effects of systemic BACE inhibition.


Assuntos
Doença de Alzheimer/prevenção & controle , Secretases da Proteína Precursora do Amiloide/fisiologia , Ácido Aspártico Endopeptidases/antagonistas & inibidores , Regulação da Expressão Gênica , Placa Amiloide/prevenção & controle , Proteínas tau/antagonistas & inibidores , Doença de Alzheimer/etiologia , Doença de Alzheimer/metabolismo , Doença de Alzheimer/patologia , Secretases da Proteína Precursora do Amiloide/antagonistas & inibidores , Secretases da Proteína Precursora do Amiloide/genética , Secretases da Proteína Precursora do Amiloide/metabolismo , Animais , Ácido Aspártico Endopeptidases/genética , Ácido Aspártico Endopeptidases/metabolismo , Encéfalo/metabolismo , Encéfalo/patologia , Modelos Animais de Doenças , Feminino , Humanos , Masculino , Camundongos , Camundongos Transgênicos , Placa Amiloide/etiologia , Placa Amiloide/metabolismo , Placa Amiloide/patologia
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