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1.
Mol Cell ; 80(1): 164-174.e4, 2020 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-32877642

RESUMO

SARS-CoV-2 infections are rapidly spreading around the globe. The rapid development of therapies is of major importance. However, our lack of understanding of the molecular processes and host cell signaling events underlying SARS-CoV-2 infection hinders therapy development. We use a SARS-CoV-2 infection system in permissible human cells to study signaling changes by phosphoproteomics. We identify viral protein phosphorylation and define phosphorylation-driven host cell signaling changes upon infection. Growth factor receptor (GFR) signaling and downstream pathways are activated. Drug-protein network analyses revealed GFR signaling as key pathways targetable by approved drugs. The inhibition of GFR downstream signaling by five compounds prevents SARS-CoV-2 replication in cells, assessed by cytopathic effect, viral dsRNA production, and viral RNA release into the supernatant. This study describes host cell signaling events upon SARS-CoV-2 infection and reveals GFR signaling as a central pathway essential for SARS-CoV-2 replication. It provides novel strategies for COVID-19 treatment.


Assuntos
Antivirais/uso terapêutico , Betacoronavirus/efeitos dos fármacos , Proteínas Quinases Ativadas por Mitógeno/genética , Fosfatidilinositol 3-Quinase/genética , Receptores de Fatores de Crescimento/genética , Proteínas Virais/genética , Corticosteroides/uso terapêutico , Inibidores da Enzima Conversora de Angiotensina/uso terapêutico , Anticorpos Neutralizantes/uso terapêutico , Betacoronavirus/imunologia , Betacoronavirus/patogenicidade , Células CACO-2 , Regulação da Expressão Gênica , Interações Hospedeiro-Patógeno/efeitos dos fármacos , Interações Hospedeiro-Patógeno/genética , Humanos , Proteínas Quinases Ativadas por Mitógeno/antagonistas & inibidores , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Fosfatidilinositol 3-Quinase/metabolismo , Fosfoproteínas/antagonistas & inibidores , Fosfoproteínas/genética , Fosfoproteínas/metabolismo , Fosforilação , Receptores de Fatores de Crescimento/antagonistas & inibidores , Receptores de Fatores de Crescimento/metabolismo , Transdução de Sinais , Proteínas Virais/antagonistas & inibidores , Proteínas Virais/metabolismo , Replicação Viral/efeitos dos fármacos
2.
Arch Virol ; 165(10): 2165-2176, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32740830

RESUMO

The PI3K/Akt signalling pathway is a crucial signalling cascade that regulates transcription, protein translation, cell growth, proliferation, cell survival, and metabolism. During viral infection, viruses exploit a variety of cellular pathways, including the well-known PI3K/Akt signalling pathway. Conversely, cells rely on this pathway to stimulate an antiviral response. The PI3K/Akt pathway is manipulated by a number of viruses, including DNA and RNA viruses and retroviruses. The aim of this review is to provide up-to-date information about the role of the PI3K-Akt pathway in infection with members of five different families of negative-sense ssRNA viruses. This pathway is hijacked for viral entry, regulation of endocytosis, suppression of premature apoptosis, viral protein expression, and replication. Although less common, the PI3K/Akt pathway can be downregulated as an immunomodulatory strategy or as a mechanism for inducing autophagy. Moreover, the cell activates this pathway as an antiviral strategy for interferon and cytokine production, among other strategies. Here, we present new data concerning the role of this pathway in infection with the paramyxovirus Newcastle disease virus (NDV). Our data seem to indicate that NDV uses the PI3K/Akt pathway to delay cell death and increase cell survival as a means of improving its replication. The interference of negative-sense ssRNA viruses with this essential pathway might have implications for the development of antiviral therapies.


Assuntos
Regulação da Expressão Gênica , Interações Hospedeiro-Patógeno/genética , Fosfatidilinositol 3-Quinase/genética , Proteínas Proto-Oncogênicas c-akt/genética , Infecções por Vírus de RNA/genética , Apoptose/genética , Autofagia/genética , Autofagia/imunologia , Citocinas/genética , Citocinas/imunologia , Endocitose/genética , Endocitose/imunologia , Filoviridae/genética , Filoviridae/metabolismo , Filoviridae/patogenicidade , Interações Hospedeiro-Patógeno/imunologia , Interferons/genética , Interferons/imunologia , Orthomyxoviridae/genética , Orthomyxoviridae/metabolismo , Orthomyxoviridae/patogenicidade , Paramyxoviridae/genética , Paramyxoviridae/metabolismo , Paramyxoviridae/patogenicidade , Fosfatidilinositol 3-Quinase/imunologia , Pneumovirinae/genética , Pneumovirinae/metabolismo , Pneumovirinae/patogenicidade , Biossíntese de Proteínas , Proteínas Proto-Oncogênicas c-akt/imunologia , Infecções por Vírus de RNA/imunologia , Infecções por Vírus de RNA/virologia , Rhabdoviridae/genética , Rhabdoviridae/metabolismo , Rhabdoviridae/patogenicidade , Transdução de Sinais , Proteínas Virais/genética , Proteínas Virais/imunologia , Internalização do Vírus , Replicação Viral
3.
J Virol ; 94(18)2020 08 31.
Artigo em Inglês | MEDLINE | ID: mdl-32641477

RESUMO

Positive-strand RNA [(+)RNA] viruses are important pathogens of humans, animals, and plants and replicate inside host cells by coopting numerous host factors and subcellular membranes. To gain insights into the assembly of viral replicase complexes (VRCs) and dissect the roles of various lipids and coopted host factors, we have reconstituted Tomato bushy stunt virus (TBSV) replicase using artificial giant unilamellar vesicles (GUVs). We demonstrate that reconstitution of VRCs on GUVs with endoplasmic reticulum (ER)-like phospholipid composition results in a complete cycle of replication and asymmetrical RNA synthesis, which is a hallmark of (+)RNA viruses. TBSV VRCs assembled on GUVs provide significant protection of the double-stranded RNA (dsRNA) replication intermediate against the dsRNA-specific RNase III. The lipid compositions of GUVs have pronounced effects on in vitro TBSV replication, including (-) and (+)RNA synthesis. The GUV-based assay has led to the discovery of the critical role of phosphatidylserine in TBSV replication and a novel role for phosphatidylethanolamine in asymmetrical (+)RNA synthesis. The GUV-based assay also showed stimulatory effects by phosphatidylinositol-3-phosphate [PI(3)P] and ergosterol on TBSV replication. We demonstrate that eEF1A and Hsp70 coopted replicase assembly factors, Vps34 phosphatidylinositol 3-kinase (PI3K) and the membrane-bending ESCRT factors, are required for reconstitution of the active TBSV VRCs in GUVs, further supporting that the novel GUV-based in vitro approach recapitulates critical steps and involves essential coopted cellular factors of the TBSV replication process. Taken together, this novel GUV assay will be highly suitable to dissect the functions of viral and cellular factors in TBSV replication.IMPORTANCE Understanding the mechanism of replication of positive-strand RNA viruses, which are major pathogens of plants, animals, and humans, can lead to new targets for antiviral interventions. These viruses subvert intracellular membranes for virus replication and coopt numerous host proteins, whose functions during virus replication are not yet completely defined. To dissect the roles of various host factors in Tomato bushy stunt virus (TBSV) replication, we have developed an artificial giant unilamellar vesicle (GUV)-based replication assay. The GUV-based in vitro approach recapitulates critical steps of the TBSV replication process. GUV-based reconstitution of the TBSV replicase revealed the need for a complex mixture of phospholipids, especially phosphatidylserine and phosphatidylethanolamine, in TBSV replication. The GUV-based approach will be useful to dissect the functions of essential coopted cellular factors.


Assuntos
RNA de Cadeia Dupla/genética , Tombusvirus/genética , Lipossomas Unilamelares/metabolismo , Proteínas Virais/genética , Bioensaio , Linhagem Celular , Retículo Endoplasmático/química , Complexos Endossomais de Distribuição Requeridos para Transporte/genética , Complexos Endossomais de Distribuição Requeridos para Transporte/metabolismo , Ergosterol/metabolismo , Regulação da Expressão Gênica , Proteínas de Choque Térmico HSP70/genética , Proteínas de Choque Térmico HSP70/metabolismo , Fatores de Alongamento de Peptídeos/genética , Fatores de Alongamento de Peptídeos/metabolismo , Fosfatidiletanolaminas/metabolismo , Fosfatidilinositol 3-Quinase/genética , Fosfatidilinositol 3-Quinase/metabolismo , Fosfatos de Fosfatidilinositol/metabolismo , Fosfatidilserinas/metabolismo , Células Vegetais/metabolismo , Células Vegetais/virologia , RNA de Cadeia Dupla/metabolismo , RNA Viral/genética , RNA Viral/metabolismo , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Ribonuclease III/genética , Ribonuclease III/metabolismo , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo , Tabaco/citologia , Tabaco/genética , Tabaco/metabolismo , Tabaco/virologia , Tombusvirus/metabolismo , Lipossomas Unilamelares/química , Proteínas Virais/metabolismo , Replicação Viral
4.
Int J Mol Med ; 45(3): 858-872, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31985016

RESUMO

Long non­coding RNAs (lncRNAs) have been revealed to have a marked effect in cardiovascular diseases, including during cardiac development, cardiac hypertrophy, myocardial fibrosis and myocardial ischemic injury. The mechanism of myocardial ischemia­reperfusion injury (MIRI) is very complicated. Although studies have confirmed that lncRNAs are involved, the specific mechanism remains largely unknown. The lncRNA growth arrest specific 5 (GAS5) is known as a regulator of a number of diseases, including certain cancer types. The present study aimed to investigate the function of lncRNA GAS5 in MIRI. The present study reported that the expression of lncRNA GAS5 in H9c2 cells treated with anoxia and reoxygenation was significantly upregulated compared with the control group (P<0.05). Similarly, the expression of lncRNA GAS5 in myocardial tissue obtained from rats treated with MIRI was significantly upregulated compared with the untreated controls (P<0.05). Silencing of lncRNA GAS5 was able to attenuate myocardial damage, as cell viability increased and the apoptosis rate decreased. Classical apoptotic proteins involved in MIRI, including B­cell lymphoma 2, Bcl­2­associated X protein and cleaved caspase­3, also exhibited the same trend. At the same time, when lncRNA GAS5 was silenced, microRNA (miR)­532­5p, which was originally expressed at the stage of injury, was upregulated. The luciferase reporter assay results indicated that the lncRNA GAS5 functioned as a molecular sponge of miR­532­5p. The gain­ and loss­of­function analysis of miR­532­5p indicated that it was involved in the regulation of MIRI; the trend of results following its overexpression was also consistent with the trend observed following the silencing of lncRNA GAS5. Notably, the protective effect of lncRNA GAS5 silencing on cells was attenuated by miR­532­5p inhibition. Phosphatase and tensin homolog was revealed to be a key target gene for the function of lncRNA GAS5, and its regulation was achieved via binding to miR­532­5p. In other words, silencing lncRNA GAS5 ultimately promoted the activation of the phosphoinositide­3­kinase (PI3K)/protein kinase B pathway (AKT) to reduce myocardial damage. Therefore, lncRNA GAS5 was able to regulate MIRI through the PI3K/AKT apoptosis pathway by sponging miR­532­5p.


Assuntos
MicroRNAs/metabolismo , Traumatismo por Reperfusão Miocárdica/metabolismo , Fosfatidilinositol 3-Quinase/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , RNA Longo não Codificante/metabolismo , Animais , Apoptose/genética , Apoptose/fisiologia , Western Blotting , Linhagem Celular , Masculino , MicroRNAs/genética , Traumatismo por Reperfusão Miocárdica/genética , Fosfatidilinositol 3-Quinase/genética , Proteínas Proto-Oncogênicas c-akt/genética , RNA Longo não Codificante/genética , Ratos , Ratos Wistar , Transdução de Sinais/genética , Transdução de Sinais/fisiologia
5.
Plant Physiol Biochem ; 148: 180-192, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31972387

RESUMO

Phosphatidylinositol 3-kinases (PI3Ks) are characterized by the presence of a C2 domain at the N-terminal end (class I, III); or at both the N-terminal and C-terminal ends (class II), sometimes including a Plextrin homology domain and/or a Ras domain. Plant PI3Ks are analogous to the class III mammalian PI3K. An N-terminal fragment (~170 aa) of the tomato PI3K regulatory domain including the C2 domain, was cloned and expressed in a bacterial system. This protein was purified to homogeneity and its physicochemical properties analyzed. The purified protein showed strong binding with monophosphorylated phosphatidylinositols, and the binding was dependent on calcium ion concentration and pH. In the overall tertiary structure of PI3K, C2 domain showed unique characteristics, having three antiparallel beta-sheets, hydrophobic regions, acidic as well as alkaline motifs, that can enable its membrane binding upon activation. To elucidate the functional significance of C2 domain, transgenic tobacco plants expressing the C2 domain of PI3K were generated. Transgenic plants showed defective pollen development and disrupted seed set. Flowers from the PI3K-C2 transgenic plants showed delayed wilting, and a decrease in ethylene production. It is likely that introduction of the PI3K-C2 segment may have interfered with the normal binding of PI3K to the membrane, delaying the onset of membrane lipid catabolism that lead to senescence.


Assuntos
Domínios C2 , Lycopersicon esculentum , Fosfatidilinositol 3-Quinase , Animais , Domínios C2/genética , Lycopersicon esculentum/enzimologia , Lycopersicon esculentum/genética , Fosfatidilinositol 3-Quinase/química , Fosfatidilinositol 3-Quinase/genética , Fosfatidilinositol 3-Quinase/metabolismo , Plantas Geneticamente Modificadas , Ligação Proteica , Tabaco/genética
6.
Eur Rev Med Pharmacol Sci ; 23(22): 10058-10064, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31799676

RESUMO

OBJECTIVE: The aim of this study was to investigate the influence of long non-coding ribonucleic acid (lncRNA) urothelial carcinoma associated 1 (UCA1) on glucose metabolism in rats with diabetic nephropathy (DN), and to explore its regulatory mechanism. MATERIALS AND METHODS: A total of 30 healthy Sprague-Dawley (SD) rats were selected in this study. All rats were randomly divided into three groups, including the control group, the model group, and the lncRNA UCA1 inhibitor group. The rat model of DN was successfully established via intraperitoneal injection of streptozotocin (STZ). The pathological changes in kidney tissues were detected via hematoxylin-eosin (HE) staining. The levels of blood urea nitrogen (BUN), serum creatinine (Scr), and urinary protein (UP) were detected using the biochemical method. Meanwhile, the content of serum tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) was detected via enzyme-linked immunosorbent assay (ELISA). In addition, the messenger RNA (mRNA) and protein levels of phosphatidylinositol 3-hydroxy kinase (PI3K) and protein kinase B (Akt) in kidney tissues were detected via reverse transcription-polymerase chain reaction (RT-PCR) and Western blotting, respectively. RESULTS: The model group showed severe pathological damage to the kidney, compared with the control group. Meanwhile, the levels of BUN, Scr and UP, and the content of serum TNF-α and IL-6 increased significantly in the model group. The mRNA and the protein levels of PI3K and Akt in kidney tissues of the model group were significantly up-regulated as well. LncRNA UCA1 inhibitor group exhibited relieved pathological damage to the kidney, compared with the model group. The levels of BUN, Scr and UP, and the content of serum TNF-α and IL-6 remarkably decreased in UCA1 inhibitor group. Furthermore, the mRNA and the protein levels of PI3K and Akt in kidney tissues of UCA1 inhibitor groups were significantly down-regulated. CONCLUSIONS: LncRNA UCA1 can relieve the pathological damage to the kidney, improve renal function, and alleviate inflammatory response in DN rats. The underlying mechanism may be related to the inhibition of the PI3K-Akt signaling pathway.


Assuntos
Diabetes Mellitus Experimental/complicações , Nefropatias Diabéticas/genética , Glucose/metabolismo , RNA Longo não Codificante/genética , Transdução de Sinais , Animais , Nitrogênio da Ureia Sanguínea , Creatinina/sangue , Diabetes Mellitus Experimental/genética , Diabetes Mellitus Experimental/metabolismo , Nefropatias Diabéticas/metabolismo , Modelos Animais de Doenças , Masculino , Fosfatidilinositol 3-Quinase/genética , Fosfatidilinositol 3-Quinase/metabolismo , Proteínas Proto-Oncogênicas c-akt/genética , Proteínas Proto-Oncogênicas c-akt/metabolismo , Distribuição Aleatória , Ratos , Ratos Sprague-Dawley , Estreptozocina
7.
Aging (Albany NY) ; 11(23): 10902-10922, 2019 12 05.
Artigo em Inglês | MEDLINE | ID: mdl-31808752

RESUMO

Long non-coding RNAs contribute to the development of human cancers. We compared the long non-coding RNA levels in gastric cancer (GC) and para-cancerous tissues in the Gene Expression Omnibus, and found that small nucleolar RNA host gene 12 (SNHG12) was upregulated in GC tissues. Fluorescence in situ hybridization confirmed that SNHG12 is overexpressed in GC tissues. We then used data from The Cancer Genome Atlas to assess the association of SNHG12 expression with the clinicopathological characteristics and prognosis of GC patients and found that higher SNHG12 expression was associated with a greater tumor invasion depth and poorer survival. In vitro, silencing SNHG12 suppressed GC cell proliferation, migration and invasion, but induced apoptosis and cell cycle arrest. Overexpressing SNHG12 had the opposite effects. In xenografted mice, knocking down SNHG12 reduced GC tumor growth. Taken together, cancer pathway microarray and bioinformatics analyses, RNA pulldown assays, Western blotting and immunohistochemistry revealed that SNHG12 induces GC tumorigenesis by activating the phosphatidylinositol 3-kinase/AKT pathway. SNHG12 may thus be a useful marker for predicting poor survival in GC patients.


Assuntos
Fosfatidilinositol 3-Quinase/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , RNA Longo não Codificante/metabolismo , Neoplasias Gástricas/metabolismo , Animais , Apoptose , Ciclo Celular , Linhagem Celular , Movimento Celular , Cromonas/farmacologia , Células Epiteliais , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Regulação Neoplásica da Expressão Gênica/fisiologia , Humanos , Masculino , Camundongos , Camundongos Nus , Morfolinas/farmacologia , Invasividade Neoplásica , Neoplasias Experimentais , Fosfatidilinositol 3-Quinase/genética , Proteínas Proto-Oncogênicas c-akt/genética , RNA Longo não Codificante/genética , Estômago/citologia , Transcriptoma , Regulação para Cima
8.
J Diabetes Res ; 2019: 9512406, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31886291

RESUMO

Diabetic nephropathy (DN) is the leading cause of end-stage renal disease (ESRD). The ROS-mediated PI3K/AKT pathway plays a key role in podocyte apoptosis and DN progression. Our previous study demonstrated that Baoshenfang (BSF) can decrease proteinuria and attenuate podocyte injury. However, the effects of BSF on podocyte apoptosis induced by the ROS-mediated PI3K/AKT pathway remain unclear. Herein, in vivo and in vitro studies have been performed. In our in vivo study, BSF significantly decreased 24-h urinary protein, serum creatinine, and blood urea nitrogen levels in DN mice. Meanwhile, BSF significantly inhibited oxidative stress and podocyte apoptosis in our in vivo and in vitro studies. Moreover, BSF significantly decreased the inhibition of the PI3K/AKT pathway induced by HG in DN. More importantly, the effects of BSF on podocyte apoptosis were reversed by PI3K siRNA transfection. In conclusion, BSF can decrease proteinuria and podocyte apoptosis in DN, in part through regulating the ROS-mediated PI3K/AKT pathway.


Assuntos
Antioxidantes/farmacologia , Apoptose/efeitos dos fármacos , Nefropatias Diabéticas/tratamento farmacológico , Medicamentos de Ervas Chinesas/farmacologia , Estresse Oxidativo/efeitos dos fármacos , Podócitos/efeitos dos fármacos , Proteínas Proto-Oncogênicas c-akt/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Animais , Proteínas Reguladoras de Apoptose/genética , Proteínas Reguladoras de Apoptose/metabolismo , Linhagem Celular , Nefropatias Diabéticas/enzimologia , Nefropatias Diabéticas/patologia , Modelos Animais de Doenças , Glucose/toxicidade , Masculino , Camundongos Endogâmicos C57BL , NADPH Oxidase 4/genética , NADPH Oxidase 4/metabolismo , Fosfatidilinositol 3-Quinase/genética , Fosfatidilinositol 3-Quinase/metabolismo , Fosforilação , Podócitos/enzimologia , Podócitos/patologia , Proteinúria/enzimologia , Proteinúria/patologia , Proteinúria/prevenção & controle , Ratos Sprague-Dawley , Transdução de Sinais
9.
Int J Biol Sci ; 15(12): 2561-2575, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31754329

RESUMO

Diabetes mellitus is characterized by pancreatic ß cell dysfunction. Previous studies have indicated that epidermal growth factor (EGF) and microRNA-124a (miR-124a) play opposite roles in insulin biosynthesis and secretion by beta cells. However, the underlying mechanisms remain poorly understood. In the present study, we demonstrated that EGF could inhibit miR-124a expression in beta cell lines through downstream signaling pathways, including mitogen-activated protein kinase kinase (MEK) and phosphatidylinositol 3-kinase (PI3K) cascades. Further, the transcription factor ETS2, a member of the ETS (E26 transformation-specific) family, was identified to be responsible for the EGF-mediated suppression of miR-124a expression, which was dependent on ETS2 phosphorylation at threonine 72. Activation of ETS2 decreased miR-124a promoter transcriptional activity through the putative conserved binding sites AGGAANA/TN in three miR-124a promoters located in different chromosomes. Of note, ETS2 played a positive role in regulating beta cell function-related genes, including miR-124a targets, Forkhead box a2 (FOXA2) and Neurogenic differentiation 1 (NEUROD1), which may have partly been through the inhibition of miR-124 expression. Knockdown and overexpression of ETS2 led to the prevention and promotion of insulin biosynthesis respectively, while barely affecting the secretion ability. These results suggest that EGF may induce the activation of ETS2 to inhibit miR-124a expression to maintain proper beta cell functions and that ETS2, as a novel regulator of insulin production, is a potential therapeutic target for diabetes mellitus treatment.


Assuntos
Fator de Crescimento Epidérmico/fisiologia , Células Secretoras de Insulina/metabolismo , MicroRNAs/metabolismo , Proteínas Quinases Ativadas por Mitógeno/fisiologia , Fosfatidilinositol 3-Quinase/fisiologia , Proteína Proto-Oncogênica c-ets-2/metabolismo , Animais , Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Fatores de Transcrição Hélice-Alça-Hélice Básicos/metabolismo , Sítios de Ligação , Diabetes Mellitus/genética , Diabetes Mellitus/metabolismo , Fator de Crescimento Epidérmico/genética , Fator de Crescimento Epidérmico/metabolismo , Feminino , Regulação Neoplásica da Expressão Gênica , Técnicas de Silenciamento de Genes , Fator 3-beta Nuclear de Hepatócito/genética , Fator 3-beta Nuclear de Hepatócito/metabolismo , Insulina/metabolismo , Ilhotas Pancreáticas/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , MicroRNAs/genética , Proteínas Quinases Ativadas por Mitógeno/genética , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Fosfatidilinositol 3-Quinase/genética , Fosfatidilinositol 3-Quinase/metabolismo , Fosforilação , Regiões Promotoras Genéticas , Transdução de Sinais , Treonina/metabolismo
10.
Molecules ; 24(20)2019 Oct 17.
Artigo em Inglês | MEDLINE | ID: mdl-31627430

RESUMO

Twenty new 12N-substituted matrinol derivatives were synthesized and evaluated for their inhibitory effects on collagen α1 (I) (COL1A1) promotor in human hepatic stellate LX-2 cells. The structure-activity relationship (SAR) revealed that introducing a 12N-benzeneaminoacylmethyl substitution might significantly enhance the activity. Compound 8a exhibited the highest inhibitory potency against COL1A1, and its inhibition activity against COL1A1 was further confirmed on both the mRNA and protein levels. It also effectively inhibited the expression of α smooth muscle actin (α-SMA), fibronectin and transforming growth factor ß1 (TGFß1), indicating an extensive inhibitory effect on the expression of fibrogenic genes. The primary mechanism study indicated that it might take action via the Integrin/FAK/PI3K/Akt signaling pathway. The results provided powerful information for further structure optimization, and compound 8a was selected as a novel anti-fibrogenic lead for further investigation.


Assuntos
Colágeno Tipo I/genética , Células Estreladas do Fígado/efeitos dos fármacos , Compostos Heterocíclicos de 4 ou mais Anéis/farmacologia , Transdução de Sinais/efeitos dos fármacos , Tiazóis/farmacologia , Linhagem Celular , Colágeno Tipo I/antagonistas & inibidores , Colágeno Tipo I/metabolismo , Fibrose/prevenção & controle , Quinase 1 de Adesão Focal/antagonistas & inibidores , Quinase 1 de Adesão Focal/genética , Quinase 1 de Adesão Focal/metabolismo , Regulação da Expressão Gênica , Células Estreladas do Fígado/citologia , Células Estreladas do Fígado/metabolismo , Compostos Heterocíclicos de 4 ou mais Anéis/síntese química , Humanos , Integrina alfaV/genética , Integrina alfaV/metabolismo , Modelos Biológicos , Fosfatidilinositol 3-Quinase/genética , Fosfatidilinositol 3-Quinase/metabolismo , Regiões Promotoras Genéticas , Proteínas Proto-Oncogênicas c-akt/antagonistas & inibidores , Proteínas Proto-Oncogênicas c-akt/genética , Proteínas Proto-Oncogênicas c-akt/metabolismo , RNA Mensageiro/antagonistas & inibidores , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Transdução de Sinais/genética , Relação Estrutura-Atividade , Tiazóis/síntese química
11.
PLoS Biol ; 17(10): e3000509, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31613895

RESUMO

The Hippo signalling pathway restricts cell proliferation in animal tissues by inhibiting Yes-associated protein (YAP or YAP1) and Transcriptional Activator with a PDZ domain (TAZ or WW-domain-containing transcriptional activator [WWTR1]), coactivators of the Scalloped (Sd or TEAD) DNA-binding transcription factor. Drosophila has a single YAP/TAZ homolog named Yorkie (Yki) that is regulated by Hippo pathway signalling in response to epithelial polarity and tissue mechanics during development. Here, we show that Yki translocates to the nucleus to drive Sd-mediated cell proliferation in the ovarian follicle cell epithelium in response to mechanical stretching caused by the growth of the germline. Importantly, mechanically induced Yki nuclear localisation also requires nutritionally induced insulin/insulin-like growth factor 1 (IGF-1) signalling (IIS) via phosphatidyl inositol-3-kinase (PI3K), phosphoinositide-dependent kinase 1 (PDK1 or PDPK1), and protein kinase B (Akt or PKB) in the follicular epithelium. We find similar results in the developing Drosophila wing, where Yki becomes nuclear in the mechanically stretched cells of the wing pouch during larval feeding, which induces IIS, but translocates to the cytoplasm upon cessation of feeding in the third instar stage. Inactivating Akt prevents nuclear Yki localisation in the wing disc, while ectopic activation of the insulin receptor, PI3K, or Akt/PKB is sufficient to maintain nuclear Yki in mechanically stimulated cells of the wing pouch even after feeding ceases. Finally, IIS also promotes YAP nuclear localisation in response to mechanical cues in mammalian skin epithelia. Thus, the Hippo pathway has a physiological function as an integrator of epithelial cell polarity, tissue mechanics, and nutritional cues to control cell proliferation and tissue growth in both Drosophila and mammals.


Assuntos
Proteínas de Drosophila/genética , Drosophila melanogaster/genética , Células Epiteliais/metabolismo , Peptídeos e Proteínas de Sinalização Intracelular/genética , Proteínas Nucleares/genética , Fosfatidilinositol 3-Quinase/genética , Proteínas Serina-Treonina Quinases/genética , Proteínas Proto-Oncogênicas c-akt/genética , Transativadores/genética , Proteínas Quinases Dependentes de 3-Fosfoinositídeo/genética , Proteínas Quinases Dependentes de 3-Fosfoinositídeo/metabolismo , Animais , Fenômenos Biomecânicos , Núcleo Celular/metabolismo , Núcleo Celular/ultraestrutura , Polaridade Celular , Proliferação de Células , Proteínas de Drosophila/metabolismo , Drosophila melanogaster/citologia , Drosophila melanogaster/crescimento & desenvolvimento , Drosophila melanogaster/metabolismo , Células Epiteliais/citologia , Feminino , Regulação da Expressão Gênica no Desenvolvimento , Humanos , Fator de Crescimento Insulin-Like I/genética , Fator de Crescimento Insulin-Like I/metabolismo , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Larva/citologia , Larva/genética , Larva/crescimento & desenvolvimento , Larva/metabolismo , Mecanotransdução Celular , Camundongos , Proteínas Nucleares/metabolismo , Folículo Ovariano/citologia , Folículo Ovariano/crescimento & desenvolvimento , Folículo Ovariano/metabolismo , Fosfatidilinositol 3-Quinase/metabolismo , Transporte Proteico , Proteínas Serina-Treonina Quinases/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Receptor de Insulina/genética , Receptor de Insulina/metabolismo , Transativadores/metabolismo , Asas de Animais/citologia , Asas de Animais/crescimento & desenvolvimento , Asas de Animais/metabolismo
12.
J Agric Food Chem ; 67(47): 13051-13060, 2019 Nov 27.
Artigo em Inglês | MEDLINE | ID: mdl-31609623

RESUMO

Gymnemic acid (GA) isolated from Gymnema sylvestre (Retz.) Schult. has been shown to have antihyperglycemic activity; however, the molecular mechanisms governing these effects are unclear. In this study, GA (40 and 80 mg kg-1 day-1) was evaluated by type 2 diabetes mellitus (T2DM) rats to explore its hypoglycemic activity and underlying mechanisms of action. The results indicated that GA decreased fasting blood glucose (FBG) concentrations by 26.7% and lowered insulin concentrations by 16.1% after oral administration of GA at a dose of 80 mg kg-1 day-1 for 6 weeks in T2DM rats. Our data showed that real-time polymerase chain reaction and western blot indicated that GA upregulated the level of phosphatidylinositol-3-kinase (PI3K) and glycogen synthesis (GS) and promoted the phosphorylation of protein kinase B (Akt) while downregulated the expression of glycogen synthesis kinase-3ß (GSK-3ß) in T2DM rats. In addition, key proteins involved in adenosine monophosphate (AMP)-activated protein kinase (AMPK)-mediated gluconeogenesis [such as phosphoenolpyruvate carboxy kinase (PEPCK) and glucose-6-phosphatase (G6Pase)] were downregulated in GA-treated T2DM rats. In summary, the hypoglycemic mechanisms of GA may be related to promoting insulin signal transduction and activating PI3K/Akt- and AMPK-mediated signaling pathways in T2DM rats.


Assuntos
Proteínas Quinases Ativadas por AMP/metabolismo , Diabetes Mellitus Tipo 2/tratamento farmacológico , Hipoglicemiantes/administração & dosagem , Fosfatidilinositol 3-Quinase/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Saponinas/administração & dosagem , Triterpenos/administração & dosagem , Proteínas Quinases Ativadas por AMP/genética , Animais , Diabetes Mellitus Tipo 2/enzimologia , Diabetes Mellitus Tipo 2/genética , Humanos , Insulina/metabolismo , Masculino , Fosfatidilinositol 3-Quinase/genética , Proteínas Proto-Oncogênicas c-akt/genética , Ratos , Ratos Sprague-Dawley , Transdução de Sinais/efeitos dos fármacos
13.
Mutat Res ; 846: 403076, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31585636

RESUMO

Red and processed meat consumption has been strongly related to increase the risk of colorectal cancer (CRC), although its impact is largely unknown. Hemin, an iron-containing porphyrin, is acknowledged as a putative factor of red and processed meat pro-carcinogenic effects. The aim of this study was to investigate the effects of high dietary hemin on the promotion/progression stages of 1,2-dimethylhydrazine (1,2-DMH)-induced colon carcinogenesis. Twenty-four Wistar male rats were given four subcutaneous 1,2-DMH injections and received either balanced diet or balanced diet supplemented with hemin 0.5 mmol/kg for 23 weeks. Colon specimens were analyzed for aberrant crypt foci (ACF) and tumor development. Dietary hemin significantly increased ACF number and fecal water cytotoxicity/genotoxicity in Caco-2 cells when compared to 1,2-DMH control group. However, tumor incidence, multiplicity and cell proliferation did not differ between 1,2-DMH + hemin and 1,2-DMH control group. Gene expression analysis of 91 target-genes revealed that only three genes (Figf, Pik3r5 and Tgfbr2) were down-regulated in the tumors from hemin-fed rats compared to those from 1,2-DMH control group. Therefore, the findings of this study show that high hemin intake promotes mainly DNA damage and ACF development and but does not change the number nor incidence of colon tumors induced by 1,2-DMH in male rats.


Assuntos
Focos de Criptas Aberrantes/induzido quimicamente , Neoplasias do Colo/induzido quimicamente , Dano ao DNA , Hemina/toxicidade , Lesões Pré-Cancerosas/induzido quimicamente , 1,2-Dimetilidrazina , Ração Animal , Animais , Células CACO-2 , Cocarcinogênese , Ensaio Cometa , Regulação para Baixo/efeitos dos fármacos , Fezes , Humanos , Masculino , Fosfatidilinositol 3-Quinase/genética , Ratos , Ratos Wistar , Receptor do Fator de Crescimento Transformador beta Tipo II/biossíntese , Receptor do Fator de Crescimento Transformador beta Tipo II/genética , Carne Vermelha , Fatores de Tempo , Fator D de Crescimento do Endotélio Vascular/biossíntese , Fator D de Crescimento do Endotélio Vascular/genética
14.
Mol Cancer Res ; 17(12): 2395-2409, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31548239

RESUMO

Molecular events activating the PI3K pathway are frequently detected in human tumors and the activation of PI3K signaling alters numerous cellular processes including tumor cell proliferation, survival, and motility. More recent studies have highlighted the impact of PI3K signaling on the cellular response to interferons and other immunologic processes relevant to antitumor immunity. Given the ability of IFNγ to regulate antigen processing and presentation and the pivotal role of MHC class I (MHCI) and II (MHCII) expression in T-cell-mediated antitumor immunity, we sought to determine the impact of PI3K signaling on MHCI and MHCII induction by IFNγ. We found that the induction of cell surface MHCI and MHCII molecules by IFNγ is enhanced by the clinical grade PI3K inhibitors dactolisib and pictilisib. We also found that PI3K inhibition increases STAT1 protein levels following IFNγ treatment and increases accessibility at genomic STAT1-binding motifs. Conversely, we found that pharmacologic activation of PI3K signaling can repress the induction of MHCI and MHCII molecules by IFNγ, and likewise, the loss of PTEN attenuates the induction of MHCI, MHCII, and STAT1 by IFNγ. Consistent with these in vitro studies, we found that within human head and neck squamous cell carcinomas, intratumoral regions with high phospho-AKT IHC staining had reduced MHCI IHC staining. IMPLICATIONS: Collectively, these findings demonstrate that MHC expression can be modulated by PI3K signaling and suggest that activation of PI3K signaling may promote immune escape via effects on antigen presentation.


Assuntos
Interferon gama/farmacologia , Fosfatidilinositol 3-Quinase/genética , Fator de Transcrição STAT1/genética , Carcinoma de Células Escamosas de Cabeça e Pescoço/tratamento farmacológico , Apresentação do Antígeno/genética , Apresentação do Antígeno/imunologia , Sítios de Ligação/genética , Proliferação de Células/efeitos dos fármacos , Proliferação de Células/genética , Proteínas de Ligação a DNA/genética , Regulação Neoplásica da Expressão Gênica/genética , Regulação Neoplásica da Expressão Gênica/imunologia , Genes MHC Classe I/genética , Genes MHC Classe I/imunologia , Genes MHC da Classe II/genética , Genes MHC da Classe II/imunologia , Genômica , Humanos , Interferon gama/genética , PTEN Fosfo-Hidrolase/genética , Fosfatidilinositol 3-Quinase/imunologia , Ligação Proteica/genética , Inibidores de Proteínas Quinases/farmacologia , Proteínas Proto-Oncogênicas c-akt/genética , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/imunologia , Carcinoma de Células Escamosas de Cabeça e Pescoço/genética , Carcinoma de Células Escamosas de Cabeça e Pescoço/imunologia , Carcinoma de Células Escamosas de Cabeça e Pescoço/patologia
15.
J Agric Food Chem ; 67(42): 11657-11664, 2019 Oct 23.
Artigo em Inglês | MEDLINE | ID: mdl-31549821

RESUMO

The therapeutic benefits of whole grains on diabetes mellitus have been continuously confirmed by in-depth research. To date, limited studies have investigated the effect of extruded products of whole grains on the insulin signaling pathway in vivo. This study investigated the effects of oral consumption of whole grain extrudate, including 97% brown rice and 3% defatted rice bran (w/w, BRD), on glucose metabolism and the hepatic insulin signaling pathway in C57BL/KsJ-db/db mice. BRD treatment induced a remarkable reduction in blood glucose. Moreover, glucose intolerance and insulin resistance were ameliorated in the BRD-treated group compared with those in the db/db control group. BRD also increased the hepatic glycogen content by reducing the expression and increasing the phosphorylation of glycogen synthase kinase 3ß (GSK3ß). The activities of glucose-6-phosphatase and phosphoenolpyruvate carboxylase and their respective mRNA expression levels in the liver were simultaneously decreased in the BRD-treated group. BRD also significantly upregulated the expression of phosphatidylinositol 3-kinase (PI3K) and increased the phosphorylation of insulin receptor substrate 1 (IRS1) and protein kinase B (AKT). These results indicate that BRD exhibits antidiabetic potential by activating the IRS1/PI3K/AKT signaling pathway, further regulating the expression of the FOXO1 gene and p-GSK3ß protein, thus inhibiting hepatic gluconeogenesis, increasing hepatic glycogen storage, and improving insulin resistance. Therefore, BRD could be used as a functional ingredient to alleviate the symptoms of hyperglycemia.


Assuntos
Diabetes Mellitus Tipo 2/dietoterapia , Proteínas Substratos do Receptor de Insulina/metabolismo , Insulina/metabolismo , Oryza/metabolismo , Fosfatidilinositol 3-Quinase/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Animais , Glicemia/metabolismo , Diabetes Mellitus Tipo 2/genética , Diabetes Mellitus Tipo 2/metabolismo , Teste de Tolerância a Glucose , Glicogênio Sintase Quinase 3 beta/genética , Glicogênio Sintase Quinase 3 beta/metabolismo , Humanos , Proteínas Substratos do Receptor de Insulina/genética , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Obesos , Oryza/química , Fosfatidilinositol 3-Quinase/genética , Proteínas Proto-Oncogênicas c-akt/genética , Transdução de Sinais/efeitos dos fármacos
16.
J Agric Food Chem ; 67(39): 10871-10879, 2019 Oct 02.
Artigo em Inglês | MEDLINE | ID: mdl-31517482

RESUMO

This study evaluated the effect of triterpenoids from edible mushroom Poria cocos on intestinal epithelium integrity and revealed the transcriptional regulatory pathways that underpin restorative mechanisms in the gut. Based on computational docking studies, transcriptional activation experiments and glucocorticoid receptor (GR) protein immunofluorescence localization assays in cultured cells, 16α-hydroxytrametenolic acid (HTA) was discovered as a novel GR agonist in this study. HTA ameliorates TNF-α-induced Caco-2 monolayer intestinal epithelial barrier damage and suppressed activation of phosphatidylinositol 3-kinase (PI3K) and protein kinase B (Akt), which attenuated downstream IκB and nuclear factor kappa-B (NF-κB) phosphorylation through GR activation. Moreover, HTA prevented NF-κB translocation into the nucleus and binding to its cis-element and suppressed lipopolysaccharide-induced downstream NO production and pro-inflammatory cytokines at both protein and mRNA expression levels. In conclusion, HTA from P. cocos improves intestinal barrier function through a GR-mediated PI3K/Akt/NF-κB signaling pathway and may be potentially exploited as a supportive dietary therapeutic strategy for restoring gut health.


Assuntos
Mucosa Intestinal/efeitos dos fármacos , NF-kappa B/metabolismo , Fosfatidilinositol 3-Quinase/metabolismo , Extratos Vegetais/farmacologia , Proteínas Proto-Oncogênicas c-akt/metabolismo , Receptores de Glucocorticoides/metabolismo , Triterpenos/farmacologia , Wolfiporia/química , Células CACO-2 , Humanos , Proteínas I-kappa B/genética , Proteínas I-kappa B/metabolismo , Mucosa Intestinal/metabolismo , Simulação de Acoplamento Molecular , NF-kappa B/genética , Fosfatidilinositol 3-Quinase/genética , Fosforilação , Extratos Vegetais/química , Proteínas Proto-Oncogênicas c-akt/genética , Receptores de Glucocorticoides/genética , Transdução de Sinais/efeitos dos fármacos , Triterpenos/química , Verduras/química
17.
J Food Sci ; 84(10): 3063-3068, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31524953

RESUMO

Alkylresorcinols are phenolic lipids that mainly exist in the cortex of grains, and they exhibit anticancer activity against various cancer cells in vitro. However, the underlying action mechanisms are still unclear. In our study, the influence of alkylresorcinols C19:0 and C21:0 (ARs) upon migration, invasion, and autophagy in human hepatoblastoma HepG2 cells was evaluated. Results showed that ARs at 80 and 160 µg/mL significantly suppressed cells proliferation, migration, and invasion, downregulated the expression of proteins RhoA and MMP-7 associated with migration and invasion. ARs at 160 µg/mL, the rate of LC3 puncta was appreciably increased. After autophagy was blocked by 3-MA or CQ, the expression of LC3II was significantly increased in 3-MA+ARs group and p62 was significantly decreased in CQ+ARs group. The results indicate that ARs may promote autophagic flow. ARs (80, 160 µg/mL) significantly inhibited the expression of proteins p-mTOR, p-PI3K, and p-Akt related to the PI3K/Akt pathway. The results of the present study suggest that ARs can activate autophagy and suppresses the biological behaviors of HepG2 cells by inhibiting the activation of MMP-7, Rho/Rho-associated protein kinase, and activation of the phosphatidylinositol 3-kinase/Akt signaling pathway. PRACTICAL APPLICATION: The anticancer mechanism of ARs in wheat bran was studied, which provided a basis for the development of anticancer functional auxiliary food with wheat bran as raw material. It is of great practical significance to promote the effective utilization of grain processing by-products and improve the economic benefits of the grain industry.


Assuntos
Autofagia/efeitos dos fármacos , Movimento Celular/efeitos dos fármacos , Resorcinóis/farmacologia , Apoptose/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Células Hep G2 , Humanos , Estrutura Molecular , Fosfatidilinositol 3-Quinase/genética , Fosfatidilinositol 3-Quinase/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Resorcinóis/química , Transdução de Sinais/efeitos dos fármacos , Serina-Treonina Quinases TOR/genética , Serina-Treonina Quinases TOR/metabolismo
18.
Breast Cancer Res ; 21(1): 90, 2019 08 07.
Artigo em Inglês | MEDLINE | ID: mdl-31391067

RESUMO

INTRODUCTION: The presence of tumor-infiltrating lymphocytes (TILs) is correlated with good prognosis and outcome after (immuno)therapy in triple-negative and HER2-positive breast cancer. However, the role of TILs in luminal breast cancer is less clear. Emerging evidence has now demonstrated that genetic aberrations in malignant cells influence the immune landscape of tumors. Phosphatidylinositol 3-kinase (PI3K) is the most common altered pathway in ER-positive breast cancer. It is unknown whether changes in the PI3K pathway result in a different composition of the breast tumor microenvironment. Here we present the retrospective analysis of a prospective randomized trial in ER-positive breast cancer on the prognostic and predictive value of specific tumor-associated lymphocytes in the context of PI3K alterations. METHODS: We included 563 ER-positive tumors from a multicenter trial for stage I to III postmenopausal breast cancer patients, who were randomized to tamoxifen or no adjuvant therapy. The amount of CD8-, CD4-, and FOXP3-positive cells was evaluated by immunohistochemistry and quantified by imaging-analysis software. We analyzed the associations between PIK3CA hotspot mutations, PTEN expression, phosphorylated proteins of the PI3K and MAPK pathway (p-AKT, p-ERK1/2, p-4EBP1, p-p70S6K), and recurrence-free interval after adjuvant tamoxifen or no adjuvant treatment. RESULTS: CD8-positive lymphocytes were significantly more abundant in PIK3CA-mutated tumors (OR = 1.65; 95% CI 1.03-2.68). While CD4 and FOXP3 were not significantly associated with prognosis, patients with tumors classified as CD8-high had increased risk of recurrence (HR = 1.98; 95% CI 1.14-3.41; multivariable model including PIK3CA status, treatment arm, and other standard clinicopathological variables). Lymphocytes were more often present in tumors with increased PI3K downstream phosphorylation. This was most pronounced for FOXP3-positive cells. CONCLUSION: These exploratory analyses of a prospective trial in luminal breast cancer suggest high CD8 infiltration is associated with unfavorable outcome and that PI3K pathway alterations might be associated with the composition of the tumor microenvironment.


Assuntos
Biomarcadores Tumorais , Suscetibilidade a Doenças , Neoplasias/etiologia , Neoplasias/metabolismo , Receptores Estrogênicos/metabolismo , Suscetibilidade a Doenças/imunologia , Fatores de Transcrição Forkhead/genética , Fatores de Transcrição Forkhead/metabolismo , Perfilação da Expressão Gênica , Humanos , Linfócitos do Interstício Tumoral/imunologia , Linfócitos do Interstício Tumoral/metabolismo , Linfócitos do Interstício Tumoral/patologia , Mutação , Estadiamento de Neoplasias , Neoplasias/mortalidade , Neoplasias/patologia , Fosfatidilinositol 3-Quinase/genética , Fosfatidilinositol 3-Quinase/metabolismo , Subpopulações de Linfócitos T/imunologia , Subpopulações de Linfócitos T/metabolismo , Subpopulações de Linfócitos T/patologia , Transcriptoma
19.
Eur Rev Med Pharmacol Sci ; 23(3 Suppl): 327-333, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31389593

RESUMO

OBJECTIVE: To investigate the influence of micro ribonucleic acid (miR)-126 on the rats with lower limb arteriosclerosis obliterans (ASO). MATERIALS AND METHODS: Male Sprague- Dawley rats aged 3 months old were randomly divided into Sham operation group (Control group, n=10) and Model group (n=10), and the model of lower limb ASO was established. After modeling, the expression of miR-126 in arteries was detected using quantitative Real Time-Polymerase Chain Reaction (qRT-PCR), and the change in the downstream signaling pathway was examined via Western blotting. The human umbilical vein endothelial cells (HUVECs) were induced by oxidized low-density lipoprotein (Ox-LDL) to establish the model of endothelial injury, followed by detection of miR-126 expression. Then, the Luciferase assay was performed to verify the downstream target gene of miR-126. After being cultured, HUVECs were set as Control group, Ox-LDL induction group, and Ox-LDL + miR-126 inhibitor group, and the expressions of phosphorylated-protein kinase B (p-Akt) and cleaved cysteine-aspartic protease-3 (Caspase-3) were detected in the above groups. RESULTS: After the establishment of the model, the expression level of miR-126 was raised in vessels, but the phosphatidylinositol 3-hydroxy kinase (PI3K)/Akt signals were weakened (p<0.01). Ox-LDL-induced endothelial cell apoptosis promoted the expression of miR-126, and the difference was statistically significant. The bioinformatics analysis results showed that PI3KR2 was a direct target of miR-126, which was also proven via the Luciferase assay. Moreover, the transfection with miR-126 inhibitor into endothelial cells suppressed Ox-LDL-induced cell apoptosis, thereby persistently activating the PI3K/Akt signaling pathway (p<0.01). CONCLUSIONS: In rats with lower limb arteriosclerosis obliterans (ASO), miR-126 represses the PI3K/Akt signaling pathway to accelerate endothelial cell apoptosis.


Assuntos
Arteriosclerose Obliterante/genética , Células Endoteliais da Veia Umbilical Humana/citologia , Lipoproteínas LDL/efeitos adversos , MicroRNAs/genética , Animais , Apoptose , Arteriosclerose Obliterante/metabolismo , Modelos Animais de Doenças , Células Endoteliais da Veia Umbilical Humana/efeitos dos fármacos , Células Endoteliais da Veia Umbilical Humana/metabolismo , Humanos , Extremidade Inferior , Masculino , Fosfatidilinositol 3-Quinase/genética , Fosfatidilinositol 3-Quinase/metabolismo , Proteínas Proto-Oncogênicas c-akt/genética , Proteínas Proto-Oncogênicas c-akt/metabolismo , Distribuição Aleatória , Ratos , Ratos Sprague-Dawley
20.
Nat Commun ; 10(1): 3754, 2019 08 21.
Artigo em Inglês | MEDLINE | ID: mdl-31434882

RESUMO

High resolution structural information on amyloid fibrils is crucial for the understanding of their formation mechanisms and for the rational design of amyloid inhibitors in the context of protein misfolding diseases. The Src-homology 3 domain of phosphatidyl-inositol-3-kinase (PI3K-SH3) is a model amyloid system that plays a pivotal role in our basic understanding of protein misfolding and aggregation. Here, we present the atomic model of the PI3K-SH3 amyloid fibril with a resolution determined to 3.4 Å by cryo-electron microscopy (cryo-EM). The fibril is composed of two intertwined protofilaments that create an interface spanning 13 residues from each monomer. The model comprises residues 1-77 out of 86 amino acids in total, with the missing residues located in the highly flexible C-terminus. The fibril structure allows us to rationalise the effects of chemically conservative point mutations as well as of the previously reported sequence perturbations on PI3K-SH3 fibril formation and growth.


Assuntos
Amiloide/química , Microscopia Crioeletrônica/métodos , Fosfatidilinositol 3-Quinase/química , Domínios de Homologia de src , Sequência de Aminoácidos , Sequência de Bases , Modelos Moleculares , Mutação , Fosfatidilinositol 3-Quinase/genética , Agregados Proteicos , Conformação Proteica , Domínios de Homologia de src/genética
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