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1.
J Agric Food Chem ; 67(41): 11364-11372, 2019 Oct 16.
Artigo em Inglês | MEDLINE | ID: mdl-31542934

RESUMO

The extensive use of pesticide caused an amount of pressure on the environment and increased the potential human health risk. Glyphosate-based herbicide (GBH) is one of the most widely used pesticides based on a 5-enolpyruvylshikimate-3-phosphate synthase target, which does not exist in vertebrates. Here, we study autophagic effects of the most famous commercial GBH Roundup (RDP) on human A549 cells in vitro. Intracellular biochemical assay indicated opening of mitochondrial permeability transition pore, LC3-II conversion, up-regulation of beclin-1, down-regulation of p62, and the changes in the phosphorylation of AMPK and mTOR induced by RDP in A549 cells. Further experimental results indicated that all the effects induced by RDP were related to its adjuvant polyethoxylated tallow amine, not its herbicidal active ingredient glyphosate isopropylamine salt. All these results showed that RDP has the ability to induce AMPK/mTOR-mediated cell autophagy in human A549 cells. This study would provide a theoretical basis for understanding RDP's autophagic effects on human A549 cells and attract attention on the potential human health risks induced by the adjuvant.


Assuntos
Proteínas Quinases Ativadas por AMP/metabolismo , Autofagia/efeitos dos fármacos , Glicina/análogos & derivados , Herbicidas/toxicidade , Serina-Treonina Quinases TOR/metabolismo , Células A549 , Proteínas Quinases Ativadas por AMP/genética , Proteína Beclina-1/genética , Proteína Beclina-1/metabolismo , Linhagem Celular , Glicina/toxicidade , Humanos , Serina-Treonina Quinases TOR/genética
2.
J Agric Food Chem ; 67(37): 10513-10520, 2019 Sep 18.
Artigo em Inglês | MEDLINE | ID: mdl-31475823

RESUMO

Amino acids can stimulate milk fat synthesis, but the underlying molecular mechanism is still largely unknown. In this study, we studied the regulatory role and corresponding molecular mechanism of cAMP response element-binding protein-regulated transcription coactivator 2 (CRTC2) in amino acid-induced milk fat synthesis in mammary epithelial cells. We showed that leucine and methionine stimulated CRTC2 but not p-CRTC2(Ser171) expression and nuclear localization in cow mammary epithelial cells. Knockdown of CRTC2 decreased milk fat synthesis and sterol regulatory element binding protein 1c (SREBP-1c) expression and activation, whereas its overexpression had the opposite effects. Neither knockdown nor overexpression of CRTC2 affected ß-casein synthesis and phosphorylation of the machanistic target of rapamycin (mTOR), suggesting that CRTC2 only regulates milk fat synthesis. CRTC2 knockdown abolished the stimulation of leucine and methionine on SREBP-1c expression and activation. Knockdown or overexpression of CRTC2 did not affect the protein level of cAMP-response element-binding protein (CREB) and its phosphorylation but decreased or increased the binding of p-CREB to the promoter of SREBP-1c gene and its mRNA expression, respectively. Mutation of Ser171 of CRTC2 did not alter the stimulation of CRTC2 on SREBP-1c expression and activation, further suggesting that CRTC2 functions in the nucleus. mTOR inhibition by rapamycin totally blocked the stimulation of leucine and methionine on CRTC2 expression. The expression of CRTC2 was dramatically higher in the mouse mammary gland of lactation period, compared with that of the dry and puberty periods, whereas p-CRTC2(Ser171) was not changed, further supporting that CRTC2 is a key transcription coactivator for milk fat synthesis. These results uncover that CRTC2 is a key transcription coactivator of amino acid-stimulated mTOR-mediated milk fat synthesis in mammary epithelial cells.


Assuntos
Aminoácidos/metabolismo , Bovinos/metabolismo , Células Epiteliais/metabolismo , Gorduras/metabolismo , Glândulas Mamárias Animais/citologia , Leite/metabolismo , Fatores de Transcrição/metabolismo , Animais , Bovinos/genética , Feminino , Glândulas Mamárias Animais/metabolismo , Camundongos , Fosforilação , Proteína de Ligação a Elemento Regulador de Esterol 1/genética , Proteína de Ligação a Elemento Regulador de Esterol 1/metabolismo , Serina-Treonina Quinases TOR/genética , Serina-Treonina Quinases TOR/metabolismo , Fatores de Transcrição/genética
3.
Life Sci ; 233: 116748, 2019 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-31412263

RESUMO

AIMS: Resveratrol is a polyphenolic compound that has received much attention for its use in ameliorating various systemic pathological conditions. The present study was performed to investigate whether the resveratrol alleviated cardiac hypertrophy and functional remodelling by regulating autophagy. MATERIALS AND METHODS: Male rats were exposed to CIH 8 h/day for five weeks and/or intragastric administration of resveratrol daily. The morphological and echocardiography were used to evaluate the cardiac protective effects. The apoptosis was detected by TUNEL staining. The biochemical assessments were used to evaluate oxidative stress. Further, the effect of resveratrol on autophagy and PI3K/AKT/mTOR pathway was investigated. KEY FINDINGS: The CIH group exhibited increased heart weight/body weight and left ventricle weight/body weight ratios, which was accompanied by left ventricular remodelling. Echocardiography analysis showed that CIH-treated rats had significantly higher left ventricular posterior wall thickness, ejection fraction and fractional shortening than those of controls. In addition, the apoptosis index and oxidative markers were significantly elevated in the CIH group versus the control. The autophagy marker Beclin-1 was elevated, while p62 was decreased by CIH treatment. Resveratrol treatment significantly improved cardiac function and alleviated cardiac hypertrophy, oxidative stress, and apoptosis in CIH rats. Further results indicated that PI3K/AKT pathway-mediated inhibition of the mammalian target of rapamycin (mTOR) pathway played a role in the activation of autophagy by resveratrol after CIH stimulation. SIGNIFICANCE: In conclusion, resveratrol supplementation during CIH upregulates autophagy by targeting the PI3K/AKT/mTOR pathway, which appears to be beneficial for resisting cardiac hypertrophy.


Assuntos
Cardiomegalia/prevenção & controle , Regulação da Expressão Gênica/efeitos dos fármacos , Hipóxia/complicações , Fosfatidilinositol 3-Quinases/antagonistas & inibidores , Proteínas Proto-Oncogênicas c-akt/antagonistas & inibidores , Resveratrol/farmacologia , Serina-Treonina Quinases TOR/antagonistas & inibidores , Animais , Antioxidantes/farmacologia , Apoptose , Autofagia , Cardiomegalia/etiologia , Cardiomegalia/patologia , Masculino , Estresse Oxidativo/efeitos dos fármacos , Fosfatidilinositol 3-Quinases/genética , Fosfatidilinositol 3-Quinases/metabolismo , Proteínas Proto-Oncogênicas c-akt/genética , Proteínas Proto-Oncogênicas c-akt/metabolismo , Ratos , Ratos Sprague-Dawley , Transdução de Sinais , Serina-Treonina Quinases TOR/genética , Serina-Treonina Quinases TOR/metabolismo
4.
Anticancer Res ; 39(8): 4165-4170, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31366501

RESUMO

AIM: To examine the influence of hypoxia on the in vitro growth of leukaemia cells and the activity of signalling proteins to better understand the pathophysiology of leukaemia cells in human bone marrow. MATERIALS AND METHODS: Six human leukaemia cell lines were cultured under normoxic or hypoxic conditions. Cell growth, recovery of clonogenic cells, and the expression and activation of various signalling proteins were examined. RESULTS: Hypoxia suppressed cell growth and the recovery of clonogenic cells. Moreover, hypoxia up-regulated hypoxia-inducible factor (HIF) 1α and HIF2α expression while suppressing the expression and activation of NOTCH1, mechanistic target of rapamycin kinase (mTOR) activation, and nuclear factor-kappa B (NF-κB) phosphorylation. CONCLUSION: We found that hypoxia up-regulated HIF expression while it suppressed the self-renewal capacity of leukaemia cells, NOTCH activity, and expression of its down-stream signalling molecules, which differs from previous reports mentioning that HIF activates NOTCH signalling. Our findings serve to further elucidate the in vivo pathophysiology of leukaemia cells.


Assuntos
Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Subunidade alfa do Fator 1 Induzível por Hipóxia/genética , Leucemia/genética , Receptor Notch1/genética , Ciclo Celular/genética , Hipóxia Celular/genética , Linhagem Celular Tumoral , Proliferação de Células/genética , Regulação Leucêmica da Expressão Gênica/genética , Humanos , Leucemia/patologia , NF-kappa B/genética , Fosforilação , Proteínas Proto-Oncogênicas c-akt/genética , Transdução de Sinais/genética , Serina-Treonina Quinases TOR/genética
5.
J Agric Food Chem ; 67(32): 8884-8895, 2019 Aug 14.
Artigo em Inglês | MEDLINE | ID: mdl-31345029

RESUMO

Leucine is an essential amino acid in the milk production of bovine mammary glands, but the regulatory roles and molecular mechanisms of leucine are still not known well. This study investigated the roles of leucine on milk synthesis and explored the corresponding mechanism in bovine mammary epithelial cells (BMECs). Leucine (0, 0.25, 0.5, 0.75, 1.0, and 1.25 mM) was added to BMECs that were cultured in FBS-free OPTI-MEM medium. Leucine significantly promoted milk protein and milk fat synthesis and also increased phosphorylation of mTOR signaling protein and the protein expression levels of SREBP-1c, with the most significant effects at 0.75 mM concentration. Leucine increased the expression and nuclear localization of DDX59, and loss and gain of gene function experiments further reveal that DDX59 mediates the stimulation of leucine on the mRNA expression variation of mTOR and SREBP-1c genes. PI3K inhibition experiment further detected that leucine upregulated expression of DDX59 and its downstream signaling via PI3K activation. ChIP-qPCR analysis further proved the binding of DDX59 to the promoter regions of mTOR and SREBP-1c. In summary, these data prove that DDX59 positively regulates the mTOR and SREBP-1c signaling pathways leading to synthesis of milk, and leucine regulates these two signaling pathways through the PI3K-DDX59 signaling.


Assuntos
Bovinos/metabolismo , Células Epiteliais/metabolismo , Leucina/metabolismo , Glândulas Mamárias Animais/metabolismo , Leite/metabolismo , Fosfatidilinositol 3-Quinases/metabolismo , RNA Helicases/metabolismo , Animais , Bovinos/genética , Feminino , Fosfatidilinositol 3-Quinases/genética , RNA Helicases/genética , Transdução de Sinais , Proteína de Ligação a Elemento Regulador de Esterol 1/genética , Proteína de Ligação a Elemento Regulador de Esterol 1/metabolismo , Serina-Treonina Quinases TOR/genética , Serina-Treonina Quinases TOR/metabolismo
6.
Gene ; 715: 144017, 2019 Oct 05.
Artigo em Inglês | MEDLINE | ID: mdl-31357026

RESUMO

SRY-related high-mobility-group box 9 (SOX9) is a member of the SOX family of transcription factors. Accumulating evidence has shown that SOX9 plays a significant role in various malignancies. However, the role of SOX9 in nasopharyngeal carcinoma (NPC) remains unknown. In the present study, up-regulation of SOX9 was observed in both NPC tissues and different NPC cells. Overexpression of SOX9 promoted NPC cell proliferation, migration and invasion. Conversely, knock down of SOX9 inhibited NPC proliferation, colony formation, migration and invasion. Mechanistically, SOX9 bound directly to the promoter region of BMP2 and increased BMP2 expression. In addition, overexpression of SOX9 activated the mTOR pathway partly through BMP2. Collectively, these results identify a novel role for SOX9 as a potential therapeutic marker for the prevention and treatment of NPC.


Assuntos
Proteína Morfogenética Óssea 2/metabolismo , Movimento Celular , Proliferação de Células , Carcinoma Nasofaríngeo/metabolismo , Neoplasias Nasofaríngeas/metabolismo , Proteínas de Neoplasias/metabolismo , Fatores de Transcrição SOX9/metabolismo , Serina-Treonina Quinases TOR/metabolismo , Proteína Morfogenética Óssea 2/genética , Linhagem Celular Tumoral , Humanos , Carcinoma Nasofaríngeo/genética , Carcinoma Nasofaríngeo/patologia , Neoplasias Nasofaríngeas/genética , Neoplasias Nasofaríngeas/patologia , Invasividade Neoplásica , Proteínas de Neoplasias/genética , Fatores de Transcrição SOX9/genética , Serina-Treonina Quinases TOR/genética
7.
Life Sci ; 233: 116696, 2019 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-31351969

RESUMO

AIMS: To explore the mechanism of how LSD1 regulates autophagy and the correlation between LSD1 and Ox-LDL-induced inflammation. MAIN METHODS: RAW264.7 cells were used during the whole study. Firstly, the effect of Ox-LDL-stimulation on LSD1 expression was detected. Through loss-of-function assay, the associations between LSD1 interference and SESN2 expression, autophagy, NLRP3 inflammasome and inflammatory cytokines were explored. Finally, the function of LSD1 exerted on activation of PI3K/Akt/mTOR signal pathway was detected using western blotting assay. KEY FINDINGS: The expression of LSD1 was significantly elevated in Ox-LDL-treated RAW264.7 cells. Inhibition of LSD1 promoted autophagy, inhibited inflammation and activated NLRP3 inflammasome. SESN2 was elevated by LSD1 inhibition, and thus activate the PI3K/Akt/mTOR signal pathway. What' more, Knockdown of SESN2 or deactivate the PI3K/Akt/mTOR signal pathway partly reversed the effect of LSD1 inhibition on autophagy. SIGNIFICANCE: Our present study drew the finding that the knockdown of LSD1 meliorated Ox-LDL-stimulated NLRP3 activation and inflammation through promoting autophagy via SESN2-mediated PI3K/Akt/mTOR pathway.


Assuntos
Autofagia , Regulação da Expressão Gênica/efeitos dos fármacos , Histona Desmetilases/metabolismo , Inflamação/patologia , Lipoproteínas LDL/efeitos adversos , Proteína 3 que Contém Domínio de Pirina da Família NLR/metabolismo , Proteínas Nucleares/metabolismo , Animais , Células Cultivadas , Histona Desmetilases/antagonistas & inibidores , Histona Desmetilases/genética , Inflamação/etiologia , Inflamação/metabolismo , Macrófagos/efeitos dos fármacos , Macrófagos/imunologia , Macrófagos/metabolismo , Macrófagos/patologia , Camundongos , Proteína 3 que Contém Domínio de Pirina da Família NLR/genética , Proteínas Nucleares/genética , Fosfatidilinositol 3-Quinases/genética , Fosfatidilinositol 3-Quinases/metabolismo , Proteínas Proto-Oncogênicas c-akt/genética , Proteínas Proto-Oncogênicas c-akt/metabolismo , RNA Interferente Pequeno/genética , Serina-Treonina Quinases TOR/genética , Serina-Treonina Quinases TOR/metabolismo
8.
Scand J Immunol ; 90(5): e12810, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31325389

RESUMO

MicroRNAs (miRNAs) play a vital role in the occurrence and development of many human diseases, including systemic lupus erythematosus (SLE). SLE is an autoimmune disease characterized by the production of autoantibodies against nuclear antigens and multiorgan involvement. Study of miRNAs involved in SLE provides new insights into the pathogenesis of SLE and might lead to the identification of new therapeutic interventions. The aim of this study was to investigate the effect of miR-183 injection on the progression of SLE by using MRL/lpr mouse model. The expression levels of miR-183 and mTOR mRNA were detected by quantitative real-time PCR assay. The effect of miR-183 on the course of spontaneous disease progression in the MRL/lpr mice was examined by intraperitoneal injection of miR-183 into mice and followed by monitoring lifespan, anti-dsDNA antibody levels, urinary albumin levels, blood urea nitrogen (BUN) levels, and Tregs and Th17 cell population. We found that miR-183 injection resulted in reduction of anti-DNA antibody and immune complex component levels, restoration of Tregs and Th17 cell population and prolongation of survival. Our findings suggest that miR-183 injection may serve as an effective therapeutic treatment for delaying or easing pathologic features of SLE.


Assuntos
Nefrite Lúpica/terapia , MicroRNAs/genética , MicroRNAs/uso terapêutico , Serina-Treonina Quinases TOR/antagonistas & inibidores , Serina-Treonina Quinases TOR/genética , Adulto , Albuminúria/urina , Animais , Anticorpos Antinucleares/sangue , Nitrogênio da Ureia Sanguínea , Modelos Animais de Doenças , Feminino , Humanos , Nefrite Lúpica/genética , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , RNA Mensageiro/genética , Linfócitos T Reguladores/imunologia , Serina-Treonina Quinases TOR/metabolismo , Células Th17/imunologia
9.
Transplant Proc ; 51(6): 1962-1971, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31303410

RESUMO

BACKGROUND: The impact of immunosuppressive drugs in patients following liver transplantation (LT) is very individual. Despite the multiple beneficial effects of the mammalian target of rapamycin (mTOR) inhibitor everolimus (EVR) in LT recipients, some patients do not benefit from EVR administration. We investigated whether the presence of common single-nucleotide polymorphisms (SNPs) in the mTOR gene are predictive for adverse events following the introduction of EVR after LT. MATERIALS AND METHODS: The feasibility and efficacy of EVR in 127 liver transplant recipients who were converted to EVR-based immunosuppression was documented retrospectively. Blood samples of these patients were analyzed for the occurrence of 4 SNPs in the mTOR promoter region (mTOR3099/rs2295079 C>G, mTOR3162/rs2295080 A>C) and the mTOR 3' untranslated regio (mTOR8167/rs12139042 C>T, mTOR8600/rs2536 A>G); the specific allele variants were also associated with the incidence of adverse events (AEs). RESULTS: Of all patients, 21 (16.5%) did not tolerate the medication and had to discontinue. Of those patients who continued, 37% developed signs of reduced tolerance within the first 6 months, resolving after 12 months. When the cohort was divided according to genotype and allele frequency, patients with the mTOR3162/rs2295080 CC variant had a significantly higher risk (odds ratio = 5.89; 95% confidence interval = 1.48-23.40; P = .012) of developing new-onset diabetes mellitus following EVR treatment than AA or AC genotype carriers. CONCLUSION: Our results suggest that the SNP mTOR3162/rs2295080 CC genotype is associated with the development of new-onset diabetes mellitus following EVR treatment.


Assuntos
Diabetes Mellitus/induzido quimicamente , Everolimo/efeitos adversos , Imunossupressores/efeitos adversos , Transplante de Fígado/efeitos adversos , Complicações Pós-Operatórias/induzido quimicamente , Serina-Treonina Quinases TOR/genética , Diabetes Mellitus/genética , Feminino , Humanos , Imunossupressão/efeitos adversos , Imunossupressão/métodos , Masculino , Pessoa de Meia-Idade , Polimorfismo de Nucleotídeo Único , Complicações Pós-Operatórias/genética , Estudos Retrospectivos
10.
Nat Commun ; 10(1): 2865, 2019 06 28.
Artigo em Inglês | MEDLINE | ID: mdl-31253771

RESUMO

The mechanistic target of rapamycin (mTOR) kinase forms two multi-protein signaling complexes, mTORC1 and mTORC2, which are master regulators of cell growth, metabolism, survival and autophagy. Two of the subunits of these complexes are mLST8 and Raptor, ß-propeller proteins that stabilize the mTOR kinase and recruit substrates, respectively. Here we report that the eukaryotic chaperonin CCT plays a key role in mTORC assembly and signaling by folding both mLST8 and Raptor. A high resolution (4.0 Å) cryo-EM structure of the human mLST8-CCT intermediate isolated directly from cells shows mLST8 in a near-native state bound to CCT deep within the folding chamber between the two CCT rings, and interacting mainly with the disordered N- and C-termini of specific CCT subunits of both rings. These findings describe a unique function of CCT in mTORC assembly and a distinct binding site in CCT for mLST8, far from those found for similar ß-propeller proteins.


Assuntos
Chaperonina com TCP-1/fisiologia , Homólogo LST8 da Proteína Associada a MTOR/metabolismo , Proteína Regulatória Associada a mTOR/metabolismo , Serina-Treonina Quinases TOR/metabolismo , Sequência de Aminoácidos , Sítios de Ligação , Microscopia Crioeletrônica , Regulação da Expressão Gênica/fisiologia , Técnicas de Silenciamento de Genes , Células HEK293 , Células Hep G2 , Humanos , Homólogo LST8 da Proteína Associada a MTOR/genética , Espectrometria de Massas , Modelos Moleculares , Ligação Proteica , Conformação Proteica , Dobramento de Proteína , Proteína Regulatória Associada a mTOR/genética , Serina-Treonina Quinases TOR/genética
11.
Cancer Sci ; 110(8): 2368-2377, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31222863

RESUMO

Macrophages are essential inflammatory cells which regulate the features of immune reactions within tumors. Many studies have reported their regulatory roles in immunity through cytokines and cell signaling. However, relatively few studies have focused on their metabolic features and mechanisms. We aimed to determine the signaling pathway regulating cell metabolism and the mechanism related to the regulation of human tumor-associated macrophages (TAMs) in gastric cancer (GC). Tumor-infiltrated macrophages were isolated from human GC tissues using magnetic beads, gene transcription was determined by real-time PCR, protein expression was monitored using western blots, metabolites were determined using HPLC, and transcriptional regulation was analyzed by the luciferase-based reporter gene system. A significant decrease in microRNA (miR)-30c and an increase in regulated in development and DNA damage responses 1 (REDD1) were detected in human GC TAMs, the transcription of miR-30c was negatively correlated with REDD1. MicroRNA-30c expression was suppressed by hypoxia-inducible factor-1α activation and related to decreased mTOR activity as well as glycolysis in human GC TAMs. Hypoxia-regulated miR-30c downregulated REDD-1 expression by targeting its 3'UTR. Overexpression of miR-30c or restored mTOR activity in macrophages with miR-30cLow expression promoted M1 macrophage differentiation and function in TAMs. Therefore, hypoxia in the human GC microenvironment suppressed the expression of miR-30c, and decreased mTOR activity as well as glycolysis in GC TAMs, thus inhibiting M1 differentiation and function. These results provide a novel metabolic strategy for tumor microenvironment-based therapy.


Assuntos
Glicólise/genética , Hipóxia/genética , Macrófagos/patologia , MicroRNAs/genética , Neoplasias Gástricas/genética , Serina-Treonina Quinases TOR/genética , Regiões 3' não Traduzidas/genética , Diferenciação Celular , Linhagem Celular , Proliferação de Células/genética , Regulação para Baixo/genética , Feminino , Regulação Neoplásica da Expressão Gênica/genética , Humanos , Hipóxia/patologia , Subunidade alfa do Fator 1 Induzível por Hipóxia/genética , Masculino , Pessoa de Meia-Idade , Transdução de Sinais/genética , Neoplasias Gástricas/patologia , Fatores de Transcrição/genética , Transcrição Genética/genética , Microambiente Tumoral/genética
12.
J Agric Food Chem ; 67(28): 7832-7843, 2019 Jul 17.
Artigo em Inglês | MEDLINE | ID: mdl-31242723

RESUMO

Oxidative-stress-induced senescence constitutes a great risk factor for chronic diseases. Therefore, ameliorating oxidative-stress-induced senescence is expected to prevent chronic diseases. The beneficial effects of bilberry anthocyanin (BA) on healthy aging were evaluated using 12 month old, aging female SD rats in this study. The experimental results suggested that consumption of a middle-dose of BA (MBA) appreciably increased the relative liver mass by 7.34% when compared with that of the AC group. Furthermore, BA significantly increased the total antioxidant capacity, total superoxide dismutase activity, and catalase activities; decreased malondialdehyde, serum low-density lipoprotein cholesterol (LDL-C), serum total cholesterol (TC), serum triglyceride (TG), and glycated serum protein (GSP) levels; and reduced TC/high-density lipoprotein cholesterol (HDL-C) and LDL-C/HDL-C ratios. In addition, MBA decreased the activity of fecal bacterial enzymes and increased the content of fecal short-chain fatty acids. The Western blot results showed that MBA significantly upregulated the expression of OCLN, ZO-1, and autophagy-related proteins (ATP6 V0C, ATG4D, and CTSB) in aging rats. Moreover, it also showed that MBA induced the phosphorylation of AMPK and FOXO3a and inhibited the phosphorylation of mTOR, which indicated that bilberry anthocyanin induced autophagy via the AMPK-mTOR signaling pathways. This induction of autophagy further promoted oxidative stress resistance effects and intestinal epithelial barrier function of bilberry anthocyanin in aging female rats.


Assuntos
Proteínas Quinases Ativadas por AMP/metabolismo , Envelhecimento/fisiologia , Antocianinas/administração & dosagem , Autofagia/efeitos dos fármacos , Serina-Treonina Quinases TOR/metabolismo , Vaccinium myrtillus/química , Proteínas Quinases Ativadas por AMP/genética , Envelhecimento/sangue , Envelhecimento/efeitos dos fármacos , Envelhecimento/genética , Animais , Suplementos Nutricionais/análise , Feminino , Proteína Forkhead Box O3/genética , Proteína Forkhead Box O3/metabolismo , Humanos , Lipoproteínas LDL/sangue , Malondialdeído/sangue , Estresse Oxidativo/efeitos dos fármacos , Ratos , Ratos Sprague-Dawley , Transdução de Sinais/efeitos dos fármacos , Serina-Treonina Quinases TOR/genética , Triglicerídeos/sangue
13.
Int J Mol Sci ; 20(11)2019 Jun 06.
Artigo em Inglês | MEDLINE | ID: mdl-31174250

RESUMO

Aging is a physiologic/pathologic process characterized by a progressive impairment of cellular functions, supported by the alterations of several molecular pathways, leading to an increased cell susceptibility to injury. This deterioration is the primary risk factor for several major human pathologies. Numerous cellular processes, including genomic instability, telomere erosion, epigenetic alterations, loss of proteostasis, deregulated nutrient-sensing, mitochondrial dysfunction, stem cell exhaustion, and altered intercellular signal transduction represent common denominators of aging in different organisms. Mammalian target of rapamycin (mTOR) is an evolutionarily conserved nutrient sensing protein kinase that regulates growth and metabolism in all eukaryotic cells. Studies in flies, worms, yeast, and mice support the hypothesis that the mTOR signalling network plays a pivotal role in modulating aging. mTOR is emerging as the most robust mediator of the protective effects of various forms of dietary restriction, which has been shown to extend lifespan and slow the onset of age-related diseases across species. Herein we discuss the role of mTor signalling network in the development of classic age-related diseases, focused on cardiovascular system, immune response, and cancer.


Assuntos
Envelhecimento/metabolismo , Doenças Cardiovasculares/etiologia , Doenças do Sistema Imunitário/etiologia , Neoplasias/etiologia , Serina-Treonina Quinases TOR/metabolismo , Envelhecimento/genética , Animais , Evolução Molecular , Humanos , Transdução de Sinais , Serina-Treonina Quinases TOR/genética
15.
Biomed Res Int ; 2019: 6061594, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31119177

RESUMO

Aims: Abnormal regulation of autophagy participates in the development of diabetic nephropathy. mTOR is the most common negative regulator of the autophagy signaling pathway. FBW7 constitutes the SCF (Skp1-Cullin1-F-box protein) recognition subunit of E3 ubiquitin ligase, and mTOR is a substrate of FBW7 that can be modified by ubiquitination and be degraded via proteasomes. In this study, we explored the relationship between FBW7 and autophagy and examined the effects of FBW7 on the occurrence of diabetic nephropathy in vitro. Materials and Methods: We cultured mesangial cells induced by high glucose in vitro and used rapamycin as a specific mTOR inhibitor, performed FBW7 gene overexpression, and detected the expression of autophagy signal and inflammatory factors by WB, ELISA, RT-PCR, and immunofluorescence. Results: High glucose can downregulate the expression of FBW7 and activate mTOR signal, which leads to diminished autophagy in renal mesangial cells, as well as renal inflammatory cytokines and fibrotic factors. RAPA, as a specifically inhibitor of mTOR, can decrease inflammatory cytokines and fibrotic factors by inhibiting mTOR. Moreover, FBW7 gene overexpression can increase autophagy by inhibiting mTOR signal; at the same time, the inflammatory cytokines and fibrotic factors were decreased in mesangial cells. Conclusions: FBW7 was decreased in renal mesangial cells induced by high glucose, and FBW7 gene overexpression can increase autophagy by inhibiting mTOR signaling and ameliorate inflammation and fibrosis.


Assuntos
Autofagia/genética , Nefropatias Diabéticas/tratamento farmacológico , Proteína 7 com Repetições F-Box-WD/genética , Serina-Treonina Quinases TOR/genética , Autofagia/efeitos dos fármacos , Linhagem Celular , Nefropatias Diabéticas/genética , Nefropatias Diabéticas/patologia , Regulação da Expressão Gênica/efeitos dos fármacos , Glucose/metabolismo , Glucose/toxicidade , Humanos , Células Mesangiais/efeitos dos fármacos , Fosforilação/efeitos dos fármacos , Complexo de Endopeptidases do Proteassoma/efeitos dos fármacos , Complexo de Endopeptidases do Proteassoma/genética , Proteólise/efeitos dos fármacos , Transdução de Sinais/efeitos dos fármacos , Sirolimo/farmacologia , Serina-Treonina Quinases TOR/antagonistas & inibidores , Ubiquitinação/efeitos dos fármacos
16.
J Exp Clin Cancer Res ; 38(1): 184, 2019 May 03.
Artigo em Inglês | MEDLINE | ID: mdl-31053160

RESUMO

BACKGROUND: Celastrol, a triterpene compound derived from the traditional Chinese medicine Tripterygium wilfordii, has been reported to possess potential antitumor activity towards various malignancies. However, the effect of celastrol on glioma cells and the underlying molecular mechanisms remain elusive. METHODS: Glioma cells, including the U251, U87-MG and C6 cell lines and an animal model were used. The effects of celastrol on cells were evaluated by flow cytometry, confocal microscopy, reactive oxygen species production assay and immunoblotting after treatment of celastrol. Fisher's exact test, a one-way ANOVA and the Mann-Whitney U-test were used to compare differences between groups. All data were analyzed using SPSS version 21.0 software. RESULTS: Here, we found that exposure to celastrol induced G2/M phase arrest and apoptosis. Celastrol increased the formation of autophagosomes, accumulation of LC3B and the expression of p62 protein. Celastrol-treated glioma cells exhibited decreased cell viability after the use of autophagy inhibitors. Additionally, autophagy and apoptosis caused by celastrol in glioma cells inhibited each other. Furthermore, celastrol induced JNK activation and ROS production and inhibited the activities of Akt and mTOR kinases. JNK and ROS inhibitors significantly attenuated celastrol-trigged apoptosis and autophagy, while Akt and mTOR inhibitors had opposite effects. CONCLUSIONS: In conclusion, our study revealed that celastrol caused G2/M phase arrest and trigged apoptosis and autophagy by activating ROS/JNK signaling and blocking the Akt/mTOR signaling pathway.


Assuntos
Glioma/tratamento farmacológico , Proteínas Tirosina Quinases/genética , Proteínas Proto-Oncogênicas/genética , Serina-Treonina Quinases TOR/genética , Triterpenos/farmacologia , Apoptose/efeitos dos fármacos , Autofagossomos/efeitos dos fármacos , Autofagia/efeitos dos fármacos , Pontos de Checagem do Ciclo Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Glioma/genética , Glioma/patologia , Humanos , MAP Quinase Quinase 4/genética , Proteínas Associadas aos Microtúbulos/genética , Proteínas Proto-Oncogênicas c-akt/genética , Proteínas Proto-Oncogênicas c-myc/genética , Espécies Reativas de Oxigênio/metabolismo , Transdução de Sinais/efeitos dos fármacos
17.
Toxicol Lett ; 312: 11-21, 2019 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-31059759

RESUMO

Methamphetamine (METH) is a widely abused illicit psychoactive drug. Our previous study has shown that CCAAT-enhancer binding protein ß (C/EBPß) is an important regulator in METH-induced neuronal autophagy and apoptosis. However, the detailed molecular mechanisms underlying this process remain poorly understood. Previous studies have demonstrated that DNA damage-inducible transcript 4 (DDIT4), Trib3 (tribbles pseudo kinase 3), alpha-synuclein (α-syn) are involved in METH-induced dopaminergic neurotoxicity. We hypothesized that C/EBPß is involved in METH-induced DDIT4-mediated neuronal autophagy and Trib3-mediated neuronal apoptosis. We tested our hypothesis by examining the effects of silencing C/EBPß, DDIT4, Trib3 or α-syn with small interfering ribonucleic acid (siRNA) on METH-induced autophagy and apoptosis in the human neuroblastoma SH-SY5Y cells. We also measured the levels of phosphorylated tuberous sclerosis complex 2 (TSC2) protein and Parkin protein level in SH-SY5Y cells. Furthermore, we demonstrated the effect of silencing C/EBPß on METH-caused neurotoxicity in the striatum of rats by injecting LV-shC/EBPß lentivirus using a stereotaxic positioning system. The results showed that METH exposure increased C/EBPß, DDIT4 protein expression. Elevated DDIT4 expression raised up p-TSC2/TSC2 protein expression ratio, inhibited mTOR signaling pathway, activating cell autophagy. We also found that METH exposure increased the expression of Trib3, α-syn, decreased the Parkin protein expression. Lowering levels of Parkin raised up α-syn expression, which initiated mitochondrial apoptosis by down-regulating anti-apoptotic Bcl-2, followed by up-regulation of pro-apoptotic Bax, resulting in translocation of cytochrome c (cyto c), an apoptogenic factor, from the mitochondria to cytoplasm and activation of caspase-dependent pathways. These findings were supported by data showing METH-induced autophagy and apoptosis was significantly inhibited by silencing C/EBPß, DDIT4, Trib3 or α-syn, or by Parkin over-expression. Based on the present data, a novel of mechanism on METH-induced cell toxicity is proposed, METH exposure increased C/EBPß protein expression, triggered DDIT4/TSC2/mTOR signaling pathway, and evoked Trib3/Parkin/α-syn-related mitochondrial apoptotic signaling pathway. Collectively, these results suggest that C/EBPß plays an important role in METH-triggered autophagy and apoptosis and it may be a potential target for therapeutics in METH-caused neurotoxicity.


Assuntos
Apoptose/efeitos dos fármacos , Autofagia/efeitos dos fármacos , Proteína beta Intensificadora de Ligação a CCAAT/metabolismo , Estimulantes do Sistema Nervoso Central/toxicidade , Metanfetamina/toxicidade , Neurônios/efeitos dos fármacos , Animais , Proteína beta Intensificadora de Ligação a CCAAT/genética , Linhagem Celular Tumoral , Regulação da Expressão Gênica/efeitos dos fármacos , Inativação Gênica , Humanos , Masculino , Neuroblastoma , Ratos , Ratos Sprague-Dawley , Transdução de Sinais/fisiologia , Serina-Treonina Quinases TOR/genética , Serina-Treonina Quinases TOR/metabolismo , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Proteína 2 do Complexo Esclerose Tuberosa/genética , Proteína 2 do Complexo Esclerose Tuberosa/metabolismo , alfa-Sinucleína/genética , alfa-Sinucleína/metabolismo
18.
J Mol Histol ; 50(3): 273-283, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31049797

RESUMO

Recent studies have demonstrated that IGF-1 modulates the pluripotent differentiation of dental pulp stem cells (DPSCs). Although mTOR pathway activation has been showed as responsible for IGF-1 induced pluripotent differentiation, the mechanism that the IGF-1-mTOR pathway induces the neural differentiation of DPSCs is still unclear. In our research, we have demonstrated that 0-10 ng/mL IGF-1 had no obvious effect on the proliferation of DPSCs, but IGF-1 nonetheless enhances the neural differentiation of DPSCs in a dose-dependent manner. Simultaneously, we found that phosphorylated mTOR was up-regulated, which indicated the involvement of mTOR in the process. Rapamycin, an inhibitor of mTOR activity, can reverse the effect of DPSCs stimulated by IGF-1. Next, we studied the role of mTORC1 and mTORC2, two known mTOR complexes, in the neural differentiation of DPSCs. We found that inhibition of mTORC1 can severely restricts the neural differentiation of DPSCs. However, inhibition of mTORC2 has the opposite effect. This latter effect disappears when both rictor and mTOR are inhibited, showing that the mTORC2 effect is mTORC1 dependent. This study has expanded the role of mTOR in DPSCs neural differentiation regulated by IGF-1.


Assuntos
Diferenciação Celular/genética , Polpa Dentária/enzimologia , Fator de Crescimento Insulin-Like I/genética , Células-Tronco/efeitos dos fármacos , Adolescente , Adulto , Diferenciação Celular/efeitos dos fármacos , Proliferação de Células , Polpa Dentária/citologia , Polpa Dentária/efeitos dos fármacos , Polpa Dentária/crescimento & desenvolvimento , Feminino , Humanos , Fator de Crescimento Insulin-Like I/farmacologia , Masculino , Alvo Mecanístico do Complexo 1 de Rapamicina/antagonistas & inibidores , Alvo Mecanístico do Complexo 2 de Rapamicina/antagonistas & inibidores , Fosforilação/efeitos dos fármacos , Proteínas Recombinantes/farmacologia , Transdução de Sinais/efeitos dos fármacos , Sirolimo/farmacologia , Serina-Treonina Quinases TOR/antagonistas & inibidores , Serina-Treonina Quinases TOR/genética , Adulto Jovem
19.
Environ Pollut ; 252(Pt A): 14-20, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31146228

RESUMO

Various crustaceans are farmed using aquaculture, and food deprivation or fasting can occur due to changing of environmental or management strategies. However, the molecular mechanisms underlying responses to starvation in crustaceans remain unclear. To address this, 12 hepatopancreas transcriptomes were compared for oriental river prawn (Macrobrachium nipponense) from four fasting stages (0, 7, 14 and 21 d). Gene Ontology functional annotation and Kyoto Encyclopaedia of Genes and Genomes pathway enrichment analysis of differentially expressed genes were subsequently performed. During the early stages of starvation (0-7 d), drug metabolism via the cytochrome P450 pathway and metabolism of xenobiotics by the cytochrome P450 pathway were enriched, suggesting that they metabolised compounds generated under starvation stress. As starvation proceeded (7-14 d), the retinol (vitamin A) metabolism pathway was activated, based on three up-regulated genes (CYP3, ADH and UGT), along with the two p450 pathways. Meanwhile, vitamin A was gradually consumed. As acute starvation was reached (14-21 d), vitamin A deficiency decreased the mRNA expression levels of IGF-I that is involved in the mTOR signalling pathway, which ultimately affected the growth and development of M. nipponense. Our results implicate drug/xenobiotic metabolism by cytochrome P450s in adaptation to starvation stress. Furthermore, metabolic cascades (CYP and retinol pathways) and growth (mTOR signalling) pathways are clearly triggered in crustaceans during starvation. The findings expand our understanding of the genes associated with hepatopancreas functioning in M. nipponense, and the underlying molecular mechanisms that govern the responses of crustaceans to starvation stress.


Assuntos
Hepatopâncreas/fisiologia , Palaemonidae/genética , Inanição/fisiopatologia , Estresse Fisiológico/fisiologia , Transcriptoma/genética , Aclimatação , Animais , Sistema Enzimático do Citocromo P-450/genética , Sistema Enzimático do Citocromo P-450/metabolismo , Palaemonidae/fisiologia , Transdução de Sinais , Serina-Treonina Quinases TOR/genética , Serina-Treonina Quinases TOR/metabolismo , Vitamina A/metabolismo
20.
Oxid Med Cell Longev ; 2019: 2715810, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31049129

RESUMO

Background: Hyperosmotic stress is an important pathophysiologic condition in diabetes, severe trauma, dehydration, infection, and ischemia. Furthermore, brain neuronal cells face hyperosmotic stress in ageing and Alzheimer's disease. Despite the enormous importance of knowing the homeostatic mechanisms underlying the responses of nerve cells to hyperosmotic stress, this topic has been underrepresented in the literature. Recent evidence points to autophagy induction as a hallmark of hyperosmotic stress, which has been proposed to be controlled by mTOR inhibition as a consequence of AMPK activation. We previously showed that methylglyoxal induced a decrease in the antioxidant proteins thioredoxin 1 (Trx1) and glyoxalase 2 (Glo2), which was mediated by AMPK-dependent autophagy. Thus, we hypothesized that hyperosmotic stress would have the same effect. Methods: HT22 hippocampal nerve cells were treated with NaCl (37, 75, or 150 mM), and the activation of the AMPK/mTOR pathway was investigated, as well as the levels of Trx1 and Glo2. To determine if autophagy was involved, the inhibitors bafilomycin (Baf) and chloroquine (CQ), as well as ATG5 siRNA, were used. To test for AMPK involvement, AMPK-deficient mouse embryonic fibroblasts (MEFs) were used. Results: Hyperosmotic stress induced a clear increase in autophagy, which was demonstrated by a decrease in p62 and an increase in LC3 lipidation. AMPK phosphorylation, linked to a decrease in mTOR and S6 ribosomal protein phosphorylation, was also observed. Deletion of AMPK in MEFs did not prevent autophagy induction by hyperosmotic stress, as detected by decreased p62 and increased LC3 II, or mTOR inhibition, inferred by decreased phosphorylation of P70 S6 kinase and S6 ribosomal protein. These data indicating that AMPK was not involved in autophagy activation by hyperosmotic stress were supported by a decrease in pS555-ULK1, an AMPK phosphorylation site. Trx1 and Glo2 levels were decreased at 6 and 18 h after treatment with 150 mM NaCl. However, this decrease in Trx1 and Glo2 in HT22 cells was not prevented by autophagy inhibition by Baf, CQ, or ATG5 siRNA. AMPK-deficient MEFs under hyperosmotic stress presented the same Trx1 and Glo2 decrease as wild-type cells. Conclusion: Hyperosmotic stress induced AMPK activation, but this was not responsible for its effects on mTOR activity or autophagy induction. Moreover, the decrease in Trx1 and Glo2 induced by hyperosmotic stress was independent of both autophagy and AMPK activation.


Assuntos
Proteínas Quinases Ativadas por AMP/metabolismo , Autofagia , Neurônios/metabolismo , Pressão Osmótica , Transdução de Sinais , Tioléster Hidrolases/metabolismo , Tiorredoxinas/metabolismo , Proteínas Quinases Ativadas por AMP/genética , Animais , Linhagem Celular Transformada , Ativação Enzimática , Camundongos , Neurônios/citologia , Serina-Treonina Quinases TOR/genética , Serina-Treonina Quinases TOR/metabolismo , Tioléster Hidrolases/genética , Tiorredoxinas/genética
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