Your browser doesn't support javascript.
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 81
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Aging Cell ; 18(6): e13027, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31493351

RESUMO

Aging is characterized by a progressive loss of physiological integrity, while cancer represents one of the primary pathological factors that severely threaten human lifespan and healthspan. In clinical oncology, drug resistance limits the efficacy of most anticancer treatments, and identification of major mechanisms remains a key to solve this challenging issue. Here, we highlight the multifaceted senescence-associated secretory phenotype (SASP), which comprises numerous soluble factors including amphiregulin (AREG). Production of AREG is triggered by DNA damage to stromal cells, which passively enter senescence in the tumor microenvironment (TME), a process that remarkably enhances cancer malignancy including acquired resistance mediated by EGFR. Furthermore, paracrine AREG induces programmed cell death 1 ligand (PD-L1) expression in recipient cancer cells and creates an immunosuppressive TME via immune checkpoint activation against cytotoxic lymphocytes. Targeting AREG not only minimized chemoresistance of cancer cells, but also restored immunocompetency when combined with classical chemotherapy in humanized animals. Our study underscores the potential of in vivo SASP in driving the TME-mediated drug resistance and shaping an immunosuppressive niche, and provides the proof of principle of targeting major SASP factors to improve therapeutic outcome in cancer medicine, the success of which can substantially reduce aging-related morbidity and mortality.

2.
Hepatology ; 2019 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-31469186

RESUMO

BACKGROUND AND AIMS: STAT3, a member of the signal transducer and activator of transcription (STAT) family, is strongly associated with liver injury, inflammation, regeneration, and hepatocellular carcinoma development. However, the signals that regulate STAT3 activity are not completely understood. APPROACH AND RESULTS: Here we characterize CREB/ATF bZIP transcription factor CREBZF as a critical regulator of STAT3 in the hepatocyte to repress liver regeneration. We show that CREBZF deficiency stimulates the expression of the cyclin gene family and enhances liver regeneration after partial hepatectomy. Flow cytometry analysis reveals that CREBZF regulates cell cycle progression during liver regeneration in a hepatocyte-autonomous manner. Similar results were observed in another model of liver regeneration induced by intraperitoneal injection of carbon tetrachloride (CCl4 ). Mechanistically, CREBZF potently associates with the linker domain of STAT3 and represses its dimerization and transcriptional activity in vivo and in vitro. Importantly, hepatectomy-induced hyperactivation of cyclin D1 and liver regeneration in CREBZF liver-specific knockout mice was reversed by selective STAT3 inhibitor cucurbitacin I. In contrast, adeno-associated virus-mediated overexpression of CREBZF in the liver inhibits the expression of the cyclin gene family and attenuates liver regeneration in CCl4 -treated mice. CONCLUSIONS: These results characterize CREBZF as a coregulator of STAT3 to inhibit regenerative capacity, which may represent an essential cellular signal to maintain liver mass homeostasis. Therapeutic approaches to inhibit CREBZF may benefit the compromised liver during liver transplantation.

3.
Am J Physiol Cell Physiol ; 317(3): C525-C533, 2019 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-31291142

RESUMO

p38-Regulated/activated protein kinase (PRAK) plays a critical role in modulating cellular survival and biological function. However, the function of PRAK in the regulation of myocardial ischemic injury remains unknown. This study is aimed at determining the function of PRAK in modulating myocardial ischemia-reperfusion injury and myocardial remodeling following myocardial infarction. Hearts were isolated from adult male homozygous PRAK-/- and wild-type mice and subjected to global ischemia-reperfusion injury in Langendorff isolated heart perfusion. PRAK-/- mice mitigated postischemic ventricular functional recovery and decreased coronary effluent. Moreover, the infarct size in the perfused heart was significantly increased by deletion of PRAK. Western blot showed that deletion of PRAK decreased the phosphorylation of ERK1/2. Furthermore, the effect of deletion of PRAK on myocardial function and remodeling was also examined on infarcted mice in which the left anterior descending artery was ligated. Echocardiography indicated that PRAK-/- mice had accelerated left ventricular systolic dysfunction, which was associated with increased hypertrophy in the infarcted area. Deletion of PRAK augmented interstitial fibrosis and terminal deoxynucleotidyl transferase nick-end labeling (TUNEL)-positive myocytes. Furthermore, immunostaining analysis shows that CD31-postive vascular density and α-smooth muscle actin capillary staining decreased significantly in PRAK-/- mice. These results indicate that deletion of PRAK enhances susceptibility to myocardial ischemia-reperfusion injury, attenuates cardiac performance and angiogenesis, and increases interstitial fibrosis and apoptosis in the infarcted hearts.

4.
Mol Cell ; 75(4): 823-834.e5, 2019 08 22.
Artigo em Inglês | MEDLINE | ID: mdl-31302001

RESUMO

Sirt3, as a major mitochondrial nicotinamide adenine dinucleotide (NAD)-dependent deacetylase, is required for mitochondrial metabolic adaption to various stresses. However, how to regulate Sirt3 activity responding to metabolic stress remains largely unknown. Here, we report Sirt3 as a SUMOylated protein in mitochondria. SUMOylation suppresses Sirt3 catalytic activity. SUMOylation-deficient Sirt3 shows elevated deacetylation on mitochondrial proteins and increased fatty acid oxidation. During fasting, SUMO-specific protease SENP1 is accumulated in mitochondria and quickly de-SUMOylates and activates Sirt3. SENP1 deficiency results in hyper-SUMOylation of Sirt3 and hyper-acetylation of mitochondrial proteins, which reduces mitochondrial metabolic adaption responding to fasting. Furthermore, we find that fasting induces SENP1 translocation into mitochondria to activate Sirt3. The studies on mice show that Sirt3 SUMOylation mutation reduces fat mass and antagonizes high-fat diet (HFD)-induced obesity via increasing oxidative phosphorylation and energy expenditure. Our results reveal that SENP1-Sirt3 signaling modulates Sirt3 activation and mitochondrial metabolism during metabolic stress.


Assuntos
Cisteína Endopeptidases/metabolismo , Mitocôndrias/metabolismo , Mutação , Obesidade/metabolismo , Transdução de Sinais , Sirtuína 3/metabolismo , Sumoilação , Acetilação , Animais , Cisteína Endopeptidases/genética , Gorduras na Dieta/efeitos adversos , Gorduras na Dieta/farmacologia , Células HEK293 , Humanos , Masculino , Camundongos , Camundongos Mutantes , Mitocôndrias/genética , Mitocôndrias/patologia , Obesidade/induzido quimicamente , Obesidade/genética , Obesidade/patologia , Sirtuína 3/genética
5.
Theranostics ; 9(5): 1369-1384, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30867837

RESUMO

Nuclear factor-kappa B (NF-κB) activation is critical for innate immune responses. However, cellular-intrinsic regulation of NF-κB activity during inflammatory diseases remains incompletely understood. Ubiquitin-like protein 4A (UBL4A, GdX) is a small adaptor protein involved in protein folding, biogenesis and transcription. Yet, whether GdX has a role during innate immune response is largely unknown. Methods: To investigate the involvement of GdX in innate immunity, we challenged GdX-deficient mice with lipopolysaccharides (LPS). To investigate the underlying mechanism, we performed RNA sequencing, real-time PCR, ELISA, luciferase reporter assay, immunoprecipitation and immunoblot analyses, flow cytometry, and structure analyses. To investigate whether GdX functions in inflammatory bowel disease, we generated dendritic cell (DC), macrophage (Mφ), epithelial-cell specific GdX-deficient mice and induced colitis with dextran sulfate sodium. Results: GdX enhances DC and Mφ-mediated innate immune defenses by positively regulating NF-κB signaling. GdX-deficient mice were resistant to LPS-induced endotoxin shock and DSS-induced colitis. DC- or Mφ- specific GdX-deficient mice displayed alleviated mucosal inflammation. The production of pro-inflammatory cytokines by GdX-deficient DCs and Mφ was reduced. Mechanistically, we found that tyrosine-protein phosphatase non-receptor type 2 (PTPN2, TC45) and protein phosphatase 2A (PP2A) form a complex with RelA (p65) to mediate its dephosphorylation whereas GdX interrupts the TC45/PP2A/p65 complex formation and restrict p65 dephosphorylation by trapping TC45. Conclusion: Our study provides a mechanism by which NF-κB signaling is positively regulated by an adaptor protein GdX in DC or Mφ to maintain the innate immune response. Targeting GdX could be a strategy to reduce over-activated immune response in inflammatory diseases.


Assuntos
Colite/patologia , Células Dendríticas/imunologia , Imunidade Inata , Macrófagos/imunologia , NF-kappa B/metabolismo , Transdução de Sinais , Ubiquitinas/metabolismo , Animais , Colite/induzido quimicamente , Sulfato de Dextrana/administração & dosagem , Modelos Animais de Doenças , Lipopolissacarídeos/administração & dosagem , Lipopolissacarídeos/imunologia , Camundongos , Camundongos Knockout , Ubiquitinas/deficiência
6.
Antioxid Redox Signal ; 31(5): 369-386, 2019 Aug 10.
Artigo em Inglês | MEDLINE | ID: mdl-30854870

RESUMO

Aims: Human embryonic stem cell derived-cardiovascular progenitor cells (hESC-CVPCs) are a promising cell source for cardiac repair, while the underlying mechanisms need to be elucidated. We recently observed cardioprotective effects of human pluripotent stem cell (hPSC)-CVPCs in infarcted nonhuman primates, but their effects on inflammation during early phase of myocardial infarction (MI) and the contribution of such effect to the cardioprotection are unclear. Results: Injection of hESC-CVPCs into acutely infarcted myocardium significantly ameliorated the functional worsening and scar formation, concomitantly with reduced inflammatory reactions and cardiomyocyte apoptosis as well as increased vascularization. Moreover, hESC-CVPCs modulated cardiac macrophages toward a reparative phenotype in the infarcted hearts, and such modulation was further confirmed in vitro using human cardiovascular progenitor cell (hCVPC)-conditioned medium (hCVPC-CdM) and highly contained interleukin (IL)-4/IL-13. Furthermore, signal transducer and activator of transcription 6 (STAT6) was activated in hCVPC-CdM- and IL-4/IL-13-treated macrophages in vitro and in hESC-CVPC-implanted MI hearts, resulting in the polarization of macrophages toward a reparative phenotype in the post-MI hearts. However, hESC-CVPC-mediated modulation on macrophages and cardioprotection were abolished in STAT6-deficient MI mice. Innovation: This is the first report about the immunoregulatory role played by hESC-CVPCs in the macrophage polarization in the infarcted hearts, its importance for the infarct repair, and the underlying signaling pathway. The findings provide new insight into the mechanism of microenvironmental regulation of stem cell-based therapy during acute MI. Conclusions: Implantion of hESC-CVPCs during the early phase of MI promotes infarct repair via the modulation of macrophage polarization through secreted cytokine-mediated STAT6 activation. The findings suggest a therapeutic potential by modulating macrophage polarization during acute phase of MI.

7.
EMBO J ; 38(6)2019 03 15.
Artigo em Inglês | MEDLINE | ID: mdl-30770344

RESUMO

T helper 17 (Th17)-cell differentiation triggered by interleukin-6 (IL-6) via STAT3 activation promotes inflammation in inflammatory bowel disease (IBD) patients. However, leukemia inhibitory factor (LIF), an IL-6 family cytokine, restricts inflammation by blocking Th17-cell differentiation via an unknown mechanism. Here, we report that microbiota dysregulation promotes LIF secretion by intestinal epithelial cells (IECs) in a mouse colitis model. LIF greatly activates STAT4 phosphorylation on multiple SPXX elements within the C-terminal transcription regulation domain. STAT4 and STAT3 act reciprocally on both canonical cis-inducible elements (SIEs) and noncanonical "AGG" elements at different loci. In lamina propria lymphocytes (LPLs), STAT4 activation by LIF blocks STAT3-dependent Il17a/Il17f promoter activation, whereas in IECs, LIF bypasses the extraordinarily low level of STAT4 to induce YAP gene expression via STAT3 activation. In addition, we found that the administration of LIF is sufficient to restore microbiome homeostasis. Thus, LIF effectively inhibits Th17 accumulation and promotes repair of damaged intestinal epithelium in inflamed colon, serves as a potential therapy for IBD.


Assuntos
Colite/prevenção & controle , Regulação da Expressão Gênica/efeitos dos fármacos , Inflamação/prevenção & controle , Mucosa Intestinal/efeitos dos fármacos , Fator Inibidor de Leucemia/farmacologia , Fator de Transcrição STAT3/metabolismo , Fator de Transcrição STAT4/fisiologia , Animais , Células Cultivadas , Colite/induzido quimicamente , Colite/imunologia , Inflamação/induzido quimicamente , Inflamação/imunologia , Interleucina-17/imunologia , Mucosa Intestinal/imunologia , Mucosa Intestinal/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Fosforilação , Fator de Transcrição STAT3/genética , Transdução de Sinais , Células Th17/imunologia
8.
J Cell Physiol ; 234(2): 1671-1681, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-30171682

RESUMO

Irisin, a newly identified hormone and cardiokine, is critical for modulating body metabolism. New evidence indicates that irisin protects the heart against myocardial ischemic injury. However, whether irisin enhances cardiac progenitor cell (CPC)-induced cardiac repair remains unknown. This study examines the effect of irisin on CPC-induced cardiac repair when these cells are introduced into the infarcted myocardium. Nkx2.5+ CPC stable cells were isolated from mouse embryonic stem cells. Nkx2.5 + CPCs (0.5 × 10 6 ) were reintroduced into the infarcted myocardium using PEGlylated fibrin delivery. The mouse myocardial infarction model was created by permanent ligation of the left anterior descending (LAD) artery. Nkx2.5 + CPCs were pretreated with irisin at a concentration of 5 ng/ml in vitro for 24 hr before transplantation. Myocardial functions were evaluated by echocardiographic measurement. Eight weeks after engraftment, Nkx2.5 + CPCs improved ventricular function as evident by an increase in ejection fraction and fractional shortening. These findings are concomitant with the suppression of cardiac hypertrophy and attenuation of myocardial interstitial fibrosis. Transplantation of Nkx2.5 + CPCs promoted cardiac regeneration and neovascularization, which were increased with the pretreatment of Nkx2.5 + CPCs with irisin. Furthermore, irisin treatment promoted myocyte proliferation as indicated by proliferative markers Ki67 and phosphorylated histone 3 and decreased apoptosis. Additionally, irisin resulted in a marked reduction of histone deacetylase 4 and increased p38 acetylation in cultured CPCs. These results indicate that irisin promoted Nkx2.5 + CPC-induced cardiac regeneration and functional improvement and that irisin serves as a novel therapeutic approach for stem cells in cardiac repair.


Assuntos
Fibronectinas/farmacologia , Células-Tronco Embrionárias Murinas/efeitos dos fármacos , Células-Tronco Embrionárias Murinas/transplante , Infarto do Miocárdio/cirurgia , Miócitos Cardíacos/efeitos dos fármacos , Miócitos Cardíacos/transplante , Regeneração , Transplante de Células-Tronco/métodos , Função Ventricular Esquerda , Animais , Apoptose , Proliferação de Células , Células Cultivadas , Modelos Animais de Doenças , Fibrose , Proteína Homeobox Nkx-2.5/genética , Proteína Homeobox Nkx-2.5/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos ICR , Células-Tronco Embrionárias Murinas/metabolismo , Infarto do Miocárdio/metabolismo , Infarto do Miocárdio/patologia , Infarto do Miocárdio/fisiopatologia , Miócitos Cardíacos/metabolismo , Miócitos Cardíacos/patologia , Neovascularização Fisiológica , Recuperação de Função Fisiológica , Volume Sistólico , Remodelação Ventricular
9.
Cell Death Differ ; 26(1): 196, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30185823

RESUMO

Following publication of their article "CCN2 inhibits lung cancer metastasis through promoting DAPK-dependent anoikis and inducing EGFR degradation", the authors reported an error in Fig.6b. α-Tubulin image of rCCN2 treatment  (upper panel in CL1-5) only showed eight lanes, when there should be nine.

10.
Nat Commun ; 9(1): 4315, 2018 10 17.
Artigo em Inglês | MEDLINE | ID: mdl-30333494

RESUMO

Chemotherapy and radiation not only trigger cancer cell apoptosis but also damage stromal cells in the tumour microenvironment (TME), inducing a senescence-associated secretory phenotype (SASP) characterized by chronic secretion of diverse soluble factors. Here we report serine protease inhibitor Kazal type I (SPINK1), a SASP factor produced in human stromal cells after genotoxic treatment. DNA damage causes SPINK1 expression by engaging NF-κB and C/EBP, while paracrine SPINK1 promotes cancer cell aggressiveness particularly chemoresistance. Strikingly, SPINK1 reprograms the expression profile of cancer cells, causing prominent epithelial-endothelial transition (EET), a phenotypic switch mediated by EGFR signaling but hitherto rarely reported for a SASP factor. In vivo, SPINK1 is expressed in the stroma of solid tumours and is routinely detectable in peripheral blood of cancer patients after chemotherapy. Our study substantiates SPINK1 as both a targetable SASP factor and a novel noninvasive biomarker of therapeutically damaged TME for disease control and clinical surveillance.


Assuntos
Senescência Celular , Resistencia a Medicamentos Antineoplásicos , Inibidor da Tripsina Pancreática de Kazal/metabolismo , Microambiente Tumoral , Biomarcadores/metabolismo , Linhagem Celular Tumoral , Dano ao DNA , Humanos , NF-kappa B/metabolismo , Comunicação Parácrina , Fenótipo , Transcriptoma
11.
Nat Chem Biol ; 14(12): 1118-1126, 2018 12.
Artigo em Inglês | MEDLINE | ID: mdl-30374165

RESUMO

SIRT6, a member of the SIRT deacetylase family, is responsible for deacetylation of histone H3 Nε-acetyl-lysines 9 (H3K9ac) and 56 (H3K56ac). As a tumor suppressor, SIRT6 has frequently been found to have low expression in various cancers. Here, we report the identification of MDL-800, a selective SIRT6 activator. MDL-800 increased the deacetylase activity of SIRT6 by up to 22-fold via binding to an allosteric site; this interaction led to a global decrease in H3K9ac and H3K56ac levels in human hepatocellular carcinoma (HCC) cells. Consequently, MDL-800 inhibited the proliferation of HCC cells via SIRT6-driven cell-cycle arrest and was effective in a tumor xenograft model. Together, these data demonstrate that pharmacological activation of SIRT6 is a potential therapeutic approach for the treatment of HCC. MDL-800 is a first-in-class small-molecule cellular SIRT6 activator that can be used to physiologically and pathologically investigate the roles of SIRT6 deacetylation.


Assuntos
Antineoplásicos/farmacologia , Ensaios de Triagem em Larga Escala/métodos , Sirtuínas/metabolismo , Regulação Alostérica , Sítio Alostérico , Animais , Carcinoma Hepatocelular/tratamento farmacológico , Carcinoma Hepatocelular/metabolismo , Carcinoma Hepatocelular/patologia , Linhagem Celular , Linhagem Celular Tumoral , Cristalografia por Raios X , Feminino , Humanos , Neoplasias Hepáticas/tratamento farmacológico , Neoplasias Hepáticas/metabolismo , Neoplasias Hepáticas/patologia , Camundongos Endogâmicos BALB C , Simulação de Dinâmica Molecular , Terapia de Alvo Molecular , Sirtuínas/química , Sirtuínas/genética , Ensaios Antitumorais Modelo de Xenoenxerto
12.
J Appl Physiol (1985) ; 125(6): 1968-1978, 2018 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-30284520

RESUMO

Histone deacetylases (HDACs) play a critical role in modulating cardiac function and ischemic injury. HDAC4 was found to be elevated and activated in response to injury. However, whether HDAC4 mediates cardiac function is currently unknown. In this study, we created myocyte-specific activated HDAC4 transgenic mice to examine the role of HDAC4 in mediating cardiac function during development and response to infarction. There are no differences in cardiac function and gross phenotype between wild-type and cardiomyocyte-specific HDAC4 transgenic mice at 1 mo of age. However, cardiac dysfunction and vascular growth deficiency were displayed in 6-mo-old HDAC4-transgenic mice compared with wild-type mice. Activation of HDAC4 increased heart and myocyte size, hypertrophic proteins, and interstitial fibrosis in 6-mo-old mice but not in 1-mo-old mice. To further define whether activated HDAC4 in the heart could impact myocardial function and remodeling, myocardial infarction was created in both wild-type and cardiomyocyte-specific HDAC4-transgenic mice. In myocardial infarction, the overexpression of activated HDAC4 exacerbated cardiac dysfunction and augmented cardiac remodeling and interstitial fibrosis, which was associated with the reduction of cardiokines in the heart. These results indicate the activation of HDAC4 as a crucial regulator for cardiac function in development and myocardial infarction. NEW & NOTEWORTHY We created myocyte-specific activated HDAC4-transgenic mice to examine the function of HDAC4 in mediating cardiac function. HDAC4 overexpression led to cardiac dysfunction, which was associated with increased hypertrophy and myocardial fibrosis. Furthermore, the overexpression of activated HDAC4 exacerbated cardiac dysfunction, augmented remodeling, and increased apoptosis in the infarcted heart. This is the first demonstration that transgenic overexpression of HDAC4 is crucial for modulation of cardiac function and remodeling.


Assuntos
Histona Desacetilases/metabolismo , Infarto do Miocárdio/fisiopatologia , Miocárdio/metabolismo , Proteínas Repressoras/metabolismo , Remodelação Ventricular , Animais , Vasos Coronários/patologia , Fibrose , Coração/fisiopatologia , Histona Desacetilases/genética , Hipertrofia , Camundongos Transgênicos , Miocárdio/patologia , Miócitos Cardíacos/patologia , Proteínas Repressoras/genética
13.
Mol Med ; 24(1): 37, 2018 07 17.
Artigo em Inglês | MEDLINE | ID: mdl-30134825

RESUMO

BACKGROUND: Histone deacetylases (HDACs) play a critical role in modulating myocardial protection and cardiomyocyte survivals. However, Specific HDAC isoforms in mediating myocardial ischemia/reperfusion injury remain currently unknown. We used cardiomyocyte-specific overexpression of active HDAC4 to determine the functional role of activated HDAC4 in regulating myocardial ischemia and reperfusion in isovolumetric perfused hearts. METHODS: In this study, we created myocyte-specific active HDAC4 transgenic mice to examine the functional role of active HDAC4 in mediating myocardial I/R injury. Ventricular function was determined in the isovolumetric heart, and infarct size was determined using tetrazolium chloride staining. RESULTS: Myocyte-specific overexpressing activated HDAC4 in mice promoted myocardial I/R injury, as indicated by the increases in infarct size and reduction of ventricular functional recovery following I/R injury. Notably, active HDAC4 overexpression led to an increase in LC-3 and active caspase 3 and decrease in SOD-1 in myocardium. Delivery of chemical HDAC inhibitor attenuated the detrimental effects of active HDAC4 on I/R injury, revealing the pivotal role of active HDAC4 in response to myocardial I/R injury. CONCLUSIONS: Taken together, these findings are the first to define that activated HDAC4 as a crucial regulator for myocardial ischemia and reperfusion injury.


Assuntos
Histona Desacetilases/metabolismo , Traumatismo por Reperfusão Miocárdica/metabolismo , Miócitos Cardíacos/metabolismo , Animais , Inibidores de Histona Desacetilases/farmacologia , Histona Desacetilases/genética , Masculino , Camundongos Transgênicos , Infarto do Miocárdio/metabolismo , Infarto do Miocárdio/fisiopatologia , Traumatismo por Reperfusão Miocárdica/fisiopatologia , Miócitos Cardíacos/fisiologia , Suínos , Função Ventricular Esquerda
14.
Nat Commun ; 9(1): 1723, 2018 04 30.
Artigo em Inglês | MEDLINE | ID: mdl-29712904

RESUMO

The senescence-associated secretory phenotype (SASP) can be provoked by side effects of therapeutic agents, fueling advanced complications including cancer resistance. However, the intracellular signal network supporting initiation and development of the SASP driven by treatment-induced damage remains unclear. Here we report that the transcription factor Zscan4 is elevated for expression by an ATM-TRAF6-TAK1 axis during the acute DNA damage response and enables a long term SASP in human stromal cells. Further, TAK1 activates p38 and PI3K/Akt/mTOR to support the persistent SASP signaling. As TAK1 is implicated in dual feedforward mechanisms to orchestrate the SASP development, pharmacologically targeting TAK1 deprives cancer cells of resistance acquired from treatment-damaged stromal cells in vitro and substantially promotes tumour regression in vivo. Together, our study reveals a novel network that links functionally critical molecules associated with the SASP development in therapeutic settings, thus opening new avenues to improve clinical outcomes and advance precision medicine.


Assuntos
Antineoplásicos/farmacologia , Neoplasias da Mama/tratamento farmacológico , Proteínas de Ligação a DNA/genética , Regulação Neoplásica da Expressão Gênica , Neoplasias Pulmonares/tratamento farmacológico , MAP Quinase Quinase Quinases/genética , Fatores de Transcrição/genética , Animais , Neoplasias da Mama/genética , Neoplasias da Mama/metabolismo , Neoplasias da Mama/patologia , Carcinoma Ductal/tratamento farmacológico , Carcinoma Ductal/genética , Carcinoma Ductal/metabolismo , Carcinoma Ductal/patologia , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Carcinoma Pulmonar de Células não Pequenas/genética , Carcinoma Pulmonar de Células não Pequenas/metabolismo , Carcinoma Pulmonar de Células não Pequenas/patologia , Linhagem Celular , Senescência Celular/efeitos dos fármacos , Proteínas de Ligação a DNA/antagonistas & inibidores , Proteínas de Ligação a DNA/metabolismo , Células Epiteliais/efeitos dos fármacos , Células Epiteliais/metabolismo , Células Epiteliais/patologia , Everolimo/farmacologia , Feminino , Humanos , Lactonas/farmacologia , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/metabolismo , Neoplasias Pulmonares/patologia , MAP Quinase Quinase Quinases/antagonistas & inibidores , MAP Quinase Quinase Quinases/metabolismo , Masculino , Glândulas Mamárias Humanas/efeitos dos fármacos , Glândulas Mamárias Humanas/metabolismo , Glândulas Mamárias Humanas/patologia , Camundongos , Camundongos SCID , Mitoxantrona/farmacologia , Fenótipo , Próstata/efeitos dos fármacos , Próstata/metabolismo , Próstata/patologia , Resorcinóis/farmacologia , Transdução de Sinais , Células Estromais/efeitos dos fármacos , Células Estromais/metabolismo , Células Estromais/patologia , Fatores de Transcrição/antagonistas & inibidores , Fatores de Transcrição/metabolismo , Ensaios Antitumorais Modelo de Xenoenxerto
15.
Cancer Res ; 78(11): 2825-2838, 2018 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-29531159

RESUMO

Posttranslational modifications of mammalian c-Src N-terminal and C-terminal domains regulate distinct functions. Myristoylation of G2 controls its cell membrane association and phosphorylation of Y419/Y527 controls its activation or inactivation, respectively. We provide evidence that Src-cell membrane association-dissociation and catalytic activation-inactivation are both regulated by acetylation. In EGF-treated cells, CREB binding protein (CBP) acetylates an N-terminal lysine cluster (K5, K7, and K9) of c-Src to promote dissociation from the cell membrane. CBP also acetylates the C-terminal K401, K423, and K427 of c-Src to activate intrinsic kinase activity for STAT3 recruitment and activation. N-terminal domain phosphorylation (Y14, Y45, and Y68) of STAT3 by c-Src activates transcriptionally active dimers of STAT3. Moreover, acetyl-Src translocates into nuclei, where it forms the Src-STAT3 enhanceosome for gene regulation and cancer cell proliferation. Thus, c-Src acetylation in the N-terminal and C-terminal domains play distinct roles in Src activity and regulation.Significance: CBP-mediated acetylation of lysine clusters in both the N-terminal and C-terminal regions of c-Src provides additional levels of control over STAT3 transcriptional activity. Cancer Res; 78(11); 2825-38. ©2018 AACR.


Assuntos
Carcinogênese/genética , Genes src/genética , Processamento de Proteína Pós-Traducional/genética , Fator de Transcrição STAT3/genética , Acetilação , Animais , Proteína de Ligação a CREB/genética , Linhagem Celular , Linhagem Celular Tumoral , Núcleo Celular/genética , Proliferação de Células/genética , Proteínas de Ligação a DNA/genética , Células HEK293 , Humanos , Células MCF-7 , Camundongos , Células NIH 3T3 , Proteínas Nucleares/genética , Fosforilação/genética , Proteínas Tirosina Quinases/genética , Transativadores/genética , Transcrição Genética/genética , Quinases da Família src/genética
16.
Cell Res ; 28(6): 655-669, 2018 06.
Artigo em Inglês | MEDLINE | ID: mdl-29515166

RESUMO

Glutamine metabolism plays an important role in cancer development and progression. Glutaminase C (GAC), the first enzyme in glutaminolysis, has emerged as an important target for cancer therapy and many studies have focused on the mechanism of enhanced GAC expression in cancer cells. However, little is known about the post-translational modification of GAC. Here, we report that phosphorylation is a crucial post-translational modification of GAC, which is responsible for the higher glutaminase activity in lung tumor tissues and cancer cells. We identify the key Ser314 phosphorylation site on GAC that is regulated by the NF-κB-PKCε axis. Blocking Ser314 phosphorylation by the S314A mutation in lung cancer cells inhibits the glutaminase activity, triggers genetic reprogramming, and alleviates tumor malignancy. Furthermore, we find that a high level of GAC phosphorylation correlates with poor survival rate of lung cancer patients. These findings highlight a previously unappreciated mechanism for activation of GAC by phosphorylation and demonstrate that targeting glutaminase activity can inhibit oncogenic transformation.


Assuntos
Carcinogênese/metabolismo , Carcinoma Pulmonar de Células não Pequenas/metabolismo , Glutaminase/metabolismo , Neoplasias Pulmonares/metabolismo , Proteína Quinase C-épsilon/metabolismo , Animais , Carcinogênese/patologia , Carcinoma Pulmonar de Células não Pequenas/patologia , Linhagem Celular Tumoral , Humanos , Neoplasias Pulmonares/patologia , Camundongos Endogâmicos BALB C , Camundongos Nus , Fosforilação
17.
Nat Commun ; 8(1): 1259, 2017 11 02.
Artigo em Inglês | MEDLINE | ID: mdl-29097654

RESUMO

Lysine acetylation is a post-translational modification known to regulate protein functions. Here we identify several acetylation sites of the influenza A virus nucleoprotein (NP), including the lysine residues K77, K113 and K229. Viral growth of mutant virus encoding K229R, mimicking a non-acetylated NP lysine residue, is severely impaired compared to wildtype or the mutant viruses encoding K77R or K113R. This attenuation is not the result of decreased polymerase activity, altered protein expression or disordered vRNP co-segregation but rather caused by impaired particle release. Interestingly, release deficiency is also observed mimicking constant acetylation at this site (K229Q), whereas virus encoding NP-K113Q could not be generated. However, mimicking NP hyper-acetylation at K77 and K229 severely diminishes viral polymerase activity, while mimicking NP hypo-acetylation at these sites has no effect on viral replication. These results suggest that NP acetylation at K77, K113 and K229 impacts multiple steps in viral replication of influenza A viruses.


Assuntos
Vírus da Influenza A/genética , Lisina/metabolismo , Proteínas de Ligação a RNA/genética , Proteínas do Core Viral/genética , Replicação Viral/genética , Acetilação , Animais , Cães , Células HEK293 , Humanos , Vírus da Influenza A/crescimento & desenvolvimento , Vírus da Influenza A/metabolismo , Células Madin Darby de Rim Canino , Mutação , Proteínas de Ligação a RNA/metabolismo , Proteínas do Core Viral/metabolismo
18.
EMBO Rep ; 18(12): 2131-2143, 2017 12.
Artigo em Inglês | MEDLINE | ID: mdl-28982940

RESUMO

The histone H3 N-terminal protein domain (N-tail) is regulated by multiple posttranslational modifications, including methylation, acetylation, phosphorylation, and by proteolytic cleavage. However, the mechanism underlying H3 N-tail proteolytic cleavage is largely elusive. Here, we report that JMJD5, a Jumonji C (JmjC) domain-containing protein, is a Cathepsin L-type protease that mediates histone H3 N-tail proteolytic cleavage under stress conditions that cause a DNA damage response. JMJD5 clips the H3 N-tail at the carboxyl side of monomethyl-lysine (Kme1) residues. In vitro H3 peptide digestion reveals that JMJD5 exclusively cleaves Kme1 H3 peptides, while little or no cleavage effect of JMJD5 on dimethyl-lysine (Kme2), trimethyl-lysine (Kme3), or unmethyl-lysine (Kme0) H3 peptides is observed. Although H3 Kme1 peptides of K4, K9, K27, and K36 can all be cleaved by JMJD5 in vitro, K9 of H3 is the major cleavage site in vivo, and H3.3 is the major H3 target of JMJD5 cleavage. Cleavage is enhanced at gene promoters bound and repressed by JMJD5 suggesting a role for H3 N-tail cleavage in gene expression regulation.


Assuntos
Dano ao DNA , Histona Desmetilases/genética , Histona Desmetilases/metabolismo , Histonas/metabolismo , Clivagem do RNA/genética , Células A549 , Acetilação , Regulação da Expressão Gênica , Histonas/genética , Humanos , Metilação , Fosforilação , Processamento de Proteína Pós-Traducional/genética , Proteólise
19.
Theranostics ; 7(12): 3021-3033, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28839461

RESUMO

Increased glutamine metabolism is a hallmark of cancer. Mitochondrial glutamic pyruvate transaminase (GPT2) catalyzes the reversible transamination between alanine and α-ketoglutarate (α-KG), also known as 2-oxoglutarate, to generate pyruvate and glutamate during cellular glutamine catabolism. However, the precise role of GPT2 in tumorigenesis remains elusive. Here, we report that in breast cancer tissue samples and breast cancer cell lines, GPT2 expression level was markedly elevated and correlated with the pathological grades of breast cancers. GPT2 overexpression increased the subpopulation of breast cancer stem cells in vitro and promoted tumorigenesis in mice. GPT2 reduced α-KG level in cells leading to the inhibition of proline hydroxylase 2 (PHD2) activity involved in the regulation of HIF1α stability. Accumulation of HIF1α, resulting from GPT2-α-KG-PHD2 axial, constitutively activates sonic hedgehog (Shh) signaling pathway. Overall, GPT2 promotes tumorigenesis and stemness of breast cancer cells by activating the Shh signaling, suggesting that GTP2 is a potential target for breast cancer therapy.


Assuntos
Neoplasias da Mama/patologia , Proteínas Hedgehog/análise , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Prolina Dioxigenases do Fator Induzível por Hipóxia/metabolismo , Transdução de Sinais , Transaminases/análise , Animais , Linhagem Celular Tumoral , Modelos Animais de Doenças , Feminino , Redes Reguladoras de Genes , Humanos , Ácidos Cetoglutáricos/metabolismo , Camundongos , Gradação de Tumores
20.
Stem Cell Reports ; 9(1): 231-246, 2017 07 11.
Artigo em Inglês | MEDLINE | ID: mdl-28669599

RESUMO

Although STAT3 signaling is demonstrated to regulate sensory cell differentiation and regeneration in the zebrafish, its exact role is still unclear in mammalian cochleae. Here, we report that STAT3 and its activated form are specifically expressed in hair cells during mouse cochlear development. Importantly, conditional cochlear deletion of Stat3 leads to an inhibition on hair cell differentiation in mice in vivo and in vitro. By cell fate analysis, inactivation of STAT3 signaling shifts the cell division modes from asymmetric to symmetric divisions from supporting cells. Moreover, inhibition of Notch signaling stimulates STAT3 phosphorylation, and inactivation of STAT3 signaling attenuates production of supernumerary hair cells induced by a Notch pathway inhibitor. Our findings highlight an important role of the STAT3 signaling during mouse cochlear hair cell differentiation and may have clinical implications for the recovery of hair cell loss-induced hearing impairment.


Assuntos
Diferenciação Celular , Cóclea/crescimento & desenvolvimento , Células Ciliadas Auditivas/citologia , Fator de Transcrição STAT3/metabolismo , Transdução de Sinais , Animais , Divisão Celular , Células Cultivadas , Cóclea/citologia , Cóclea/metabolismo , Deleção de Genes , Regulação da Expressão Gênica no Desenvolvimento , Células Ciliadas Auditivas/metabolismo , Camundongos , Receptores Notch/metabolismo , Fator de Transcrição STAT3/genética
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA