Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 23
Filtrar
1.
Cell Rep ; 42(11): 113371, 2023 11 28.
Artículo en Inglés | MEDLINE | ID: mdl-37938972

RESUMEN

Senescent cells are a major contributor to age-dependent cardiovascular tissue dysfunction, but knowledge of their in vivo cell markers and tissue context is lacking. To reveal tissue-relevant senescence biology, we integrate the transcriptomes of 10 experimental senescence cell models with a 224 multi-tissue gene co-expression network based on RNA-seq data of seven tissues biopsies from ∼600 coronary artery disease (CAD) patients. We identify 56 senescence-associated modules, many enriched in CAD GWAS genes and correlated with cardiometabolic traits-which supports universality of senescence gene programs across tissues and in CAD. Cross-tissue network analyses reveal 86 candidate senescence-associated secretory phenotype (SASP) factors, including COL6A3. Experimental knockdown of COL6A3 induces transcriptional changes that overlap the majority of the experimental senescence models, with cell-cycle arrest linked to modulation of DREAM complex-targeted genes. We provide a transcriptomic resource for cellular senescence and identify candidate biomarkers, SASP factors, and potential drivers of senescence in human tissues.


Asunto(s)
Senescencia Celular , Transcriptoma , Humanos , Transcriptoma/genética , Senescencia Celular/genética , Fenotipo , Biomarcadores , Colágeno , Colágeno Tipo VI/genética
2.
Science ; 374(6567): eabb3420, 2021 Oct 29.
Artículo en Inglés | MEDLINE | ID: mdl-34709885

RESUMEN

Immune cells identify and destroy damaged cells to prevent them from causing cancer or other pathologies by mechanisms that remain poorly understood. Here, we report that the cell-cycle inhibitor p21 places cells under immunosurveillance to establish a biological timer mechanism that controls cell fate. p21 activates retinoblastoma protein (Rb)­dependent transcription at select gene promoters to generate a complex bioactive secretome, termed p21-activated secretory phenotype (PASP). The PASP includes the chemokine CXCL14, which promptly attracts macrophages. These macrophages disengage if cells normalize p21 within 4 days, but if p21 induction persists, they polarize toward an M1 phenotype and lymphocytes mount a cytotoxic T cell response to eliminate target cells, including preneoplastic cells. Thus, p21 concurrently induces proliferative arrest and immunosurveillance of cells under duress.


Asunto(s)
Senescencia Celular , Inhibidor p21 de las Quinasas Dependientes de la Ciclina/metabolismo , Vigilancia Inmunológica , Animales , Puntos de Control del Ciclo Celular , Línea Celular , Quimiocinas CXC/metabolismo , Inhibidor p16 de la Quinasa Dependiente de Ciclina/genética , Inhibidor p16 de la Quinasa Dependiente de Ciclina/metabolismo , Inhibidor p21 de las Quinasas Dependientes de la Ciclina/genética , Genes ras , Hepatocitos/inmunología , Hepatocitos/metabolismo , Humanos , Macrófagos/inmunología , Macrófagos/metabolismo , Ratones , Ratones Transgénicos , Proteínas Proto-Oncogénicas p21(ras)/metabolismo , Proteína de Retinoblastoma/metabolismo , Estrés Fisiológico , Linfocitos T Citotóxicos/inmunología , Transcripción Genética
3.
Aging (Albany NY) ; 13(10): 13380-13392, 2021 05 25.
Artículo en Inglés | MEDLINE | ID: mdl-34035185

RESUMEN

Cellular senescence is a cell fate response characterized by a permanent cell cycle arrest driven primarily the by cell cycle inhibitor and tumor suppressor proteins p16Ink4a and p21Cip1/Waf1. In mice, the p21Cip1/Waf1 encoding locus, Cdkn1a, is known to generate two transcripts that produce identical proteins, but one of these transcript variants is poorly characterized. We show that the Cdkn1a transcript variant 2, but not the better-studied variant 1, is selectively elevated during natural aging across multiple mouse tissues. Importantly, mouse cells induced to senescence in culture by genotoxic stress (ionizing radiation or doxorubicin) upregulated both transcripts, but with different temporal dynamics: variant 1 responded nearly immediately to genotoxic stress, whereas variant 2 increased much more slowly as cells acquired senescent characteristics. Upon treating mice systemically with doxorubicin, which induces widespread cellular senescence in vivo, variant 2 increased to a larger extent than variant 1. Variant 2 levels were also more sensitive to the senolytic drug ABT-263 in naturally aged mice. Thus, variant 2 is a novel and more sensitive marker than variant 1 or total p21Cip1/Waf1 protein for assessing the senescent cell burden and clearance in mice.


Asunto(s)
Envejecimiento/genética , Envejecimiento/patología , Senescencia Celular/genética , Inhibidor p21 de las Quinasas Dependientes de la Ciclina/genética , Compuestos de Anilina/farmacología , Animales , Biomarcadores/metabolismo , Senescencia Celular/efectos de los fármacos , Ritmo Circadiano/efectos de los fármacos , Ritmo Circadiano/genética , Inhibidor p21 de las Quinasas Dependientes de la Ciclina/metabolismo , Doxorrubicina/farmacología , Femenino , Masculino , Ratones Endogámicos C57BL , Isoformas de Proteínas/genética , Isoformas de Proteínas/metabolismo , Estabilidad Proteica/efectos de los fármacos , Sulfonamidas/farmacología , Proteína p53 Supresora de Tumor/metabolismo , Regulación hacia Arriba/efectos de los fármacos , Regulación hacia Arriba/genética
5.
Sci Rep ; 10(1): 10868, 2020 07 02.
Artículo en Inglés | MEDLINE | ID: mdl-32616761

RESUMEN

We elucidated the molecular cross-talk between cartilage and synovium in osteoarthritis, the most widespread arthritis in the world, using the powerful tool of single-cell RNA-sequencing. Multiple cell types were identified based on profiling of 10,640 synoviocytes and 26,192 chondrocytes: 12 distinct synovial cell types and 7 distinct articular chondrocyte phenotypes from matched tissues. Intact cartilage was enriched for homeostatic and hypertrophic chondrocytes, while damaged cartilage was enriched for prefibro- and fibro-, regulatory, reparative and prehypertrophic chondrocytes. A total of 61 cytokines and growth factors were predicted to regulate the 7 chondrocyte cell phenotypes. Based on production by > 1% of cells, 55% of the cytokines were produced by synovial cells (39% exclusive to synoviocytes and not expressed by chondrocytes) and their presence in osteoarthritic synovial fluid confirmed. The synoviocytes producing IL-1beta (a classic pathogenic cytokine in osteoarthritis), mainly inflammatory macrophages and dendritic cells, were characterized by co-expression of surface proteins corresponding to HLA-DQA1, HLA-DQA2, OLR1 or TLR2. Strategies to deplete these pathogenic intra-articular cell subpopulations could be a therapeutic option for human osteoarthritis.


Asunto(s)
Biomarcadores/metabolismo , Cartílago Articular/metabolismo , Osteoartritis/patología , RNA-Seq/métodos , Sinoviocitos/metabolismo , Anciano , Cartílago Articular/patología , Estudios de Casos y Controles , Células Cultivadas , Femenino , Humanos , Masculino , Osteoartritis/genética , Osteoartritis/metabolismo , Sinoviocitos/patología
6.
Aging Cell ; 17(4): e12780, 2018 08.
Artículo en Inglés | MEDLINE | ID: mdl-29766639

RESUMEN

The selective depletion of senescent cells (SCs) by small molecules, termed senolytic agents, is a promising therapeutic approach for treating age-related diseases and chemotherapy- and radiotherapy-induced side effects. Piperlongumine (PL) was recently identified as a novel senolytic agent. However, its mechanism of action and molecular targets in SCs was unknown and thus was investigated. Specifically, we used a PL-based chemical probe to pull-down PL-binding proteins from live cells and then mass spectrometry-based proteomic analysis to identify potential molecular targets of PL in SCs. One prominent target was oxidation resistance 1 (OXR1), an important antioxidant protein that regulates the expression of a variety of antioxidant enzymes. We found that OXR1 was upregulated in senescent human WI38 fibroblasts. PL bound to OXR1 directly and induced its degradation through the ubiquitin-proteasome system in an SC-specific manner. The knockdown of OXR1 expression by RNA interference significantly increased the production of reactive oxygen species in SCs in conjunction with the downregulation of antioxidant enzymes such as heme oxygenase 1, glutathione peroxidase 2, and catalase, but these effects were much less significant when OXR1 was knocked down in non-SCs. More importantly, knocking down OXR1 selectively induced apoptosis in SCs and sensitized the cells to oxidative stress caused by hydrogen peroxide. These findings provide new insights into the mechanism by which SCs are highly resistant to oxidative stress and suggest that OXR1 is a novel senolytic target that can be further exploited for the development of new senolytic agents.


Asunto(s)
Proteínas/metabolismo , Apoptosis/genética , Supervivencia Celular/genética , Células Cultivadas , Cromatografía Liquida , Humanos , Proteínas Mitocondriales , Proteínas/antagonistas & inhibidores , Proteínas/genética , ARN Interferente Pequeño/genética , Especies Reactivas de Oxígeno/análisis , Especies Reactivas de Oxígeno/metabolismo , Proteínas Recombinantes/análisis , Proteínas Recombinantes/metabolismo , Espectrometría de Masas en Tándem
7.
Nat Rev Drug Discov ; 16(10): 718-735, 2017 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-28729727

RESUMEN

Chronological age represents the single greatest risk factor for human disease. One plausible explanation for this correlation is that mechanisms that drive ageing might also promote age-related diseases. Cellular senescence, which is a permanent state of cell cycle arrest induced by cellular stress, has recently emerged as a fundamental ageing mechanism that also contributes to diseases of late life, including cancer, atherosclerosis and osteoarthritis. Therapeutic strategies that safely interfere with the detrimental effects of cellular senescence, such as the selective elimination of senescent cells (SNCs) or the disruption of the SNC secretome, are gaining significant attention, with several programmes now nearing human clinical studies.


Asunto(s)
Envejecimiento/patología , Envejecimiento/fisiología , Proliferación Celular/fisiología , Senescencia Celular/fisiología , Animales , Aterosclerosis/metabolismo , Aterosclerosis/patología , Puntos de Control del Ciclo Celular/fisiología , Humanos , Neoplasias/metabolismo , Neoplasias/patología
8.
Nat Med ; 23(6): 775-781, 2017 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-28436958

RESUMEN

Senescent cells (SnCs) accumulate in many vertebrate tissues with age and contribute to age-related pathologies, presumably through their secretion of factors contributing to the senescence-associated secretory phenotype (SASP). Removal of SnCs delays several pathologies and increases healthy lifespan. Aging and trauma are risk factors for the development of osteoarthritis (OA), a chronic disease characterized by degeneration of articular cartilage leading to pain and physical disability. Senescent chondrocytes are found in cartilage tissue isolated from patients undergoing joint replacement surgery, yet their role in disease pathogenesis is unknown. To test the idea that SnCs might play a causative role in OA, we used the p16-3MR transgenic mouse, which harbors a p16INK4a (Cdkn2a) promoter driving the expression of a fusion protein containing synthetic Renilla luciferase and monomeric red fluorescent protein domains, as well as a truncated form of herpes simplex virus 1 thymidine kinase (HSV-TK). This mouse strain allowed us to selectively follow and remove SnCs after anterior cruciate ligament transection (ACLT). We found that SnCs accumulated in the articular cartilage and synovium after ACLT, and selective elimination of these cells attenuated the development of post-traumatic OA, reduced pain and increased cartilage development. Intra-articular injection of a senolytic molecule that selectively killed SnCs validated these results in transgenic, non-transgenic and aged mice. Selective removal of the SnCs from in vitro cultures of chondrocytes isolated from patients with OA undergoing total knee replacement decreased expression of senescent and inflammatory markers while also increasing expression of cartilage tissue extracellular matrix proteins. Collectively, these findings support the use of SnCs as a therapeutic target for treating degenerative joint disease.


Asunto(s)
Senescencia Celular/genética , Condrocitos/metabolismo , Osteoartritis de la Rodilla/genética , Regeneración/genética , Animales , Ligamento Cruzado Anterior/cirugía , Lesiones del Ligamento Cruzado Anterior/complicaciones , Antivirales/farmacología , Cartílago Articular/metabolismo , Inhibidor p16 de la Quinasa Dependiente de Ciclina/genética , Inhibidor p16 de la Quinasa Dependiente de Ciclina/metabolismo , Proteínas de la Matriz Extracelular/genética , Proteínas de la Matriz Extracelular/metabolismo , Técnica del Anticuerpo Fluorescente , Ganciclovir/farmacología , Glicosaminoglicanos/metabolismo , Humanos , Immunoblotting , Inmunohistoquímica , Técnicas In Vitro , Ratones , Ratones Transgénicos , Osteoartritis de la Rodilla/etiología , Osteoartritis de la Rodilla/metabolismo , Reacción en Cadena en Tiempo Real de la Polimerasa , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Soporte de Peso
9.
Nat Med ; 22(1): 78-83, 2016 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-26657143

RESUMEN

Senescent cells (SCs) accumulate with age and after genotoxic stress, such as total-body irradiation (TBI). Clearance of SCs in a progeroid mouse model using a transgenic approach delays several age-associated disorders, suggesting that SCs play a causative role in certain age-related pathologies. Thus, a 'senolytic' pharmacological agent that can selectively kill SCs holds promise for rejuvenating tissue stem cells and extending health span. To test this idea, we screened a collection of compounds and identified ABT263 (a specific inhibitor of the anti-apoptotic proteins BCL-2 and BCL-xL) as a potent senolytic drug. We show that ABT263 selectively kills SCs in culture in a cell type- and species-independent manner by inducing apoptosis. Oral administration of ABT263 to either sublethally irradiated or normally aged mice effectively depleted SCs, including senescent bone marrow hematopoietic stem cells (HSCs) and senescent muscle stem cells (MuSCs). Notably, this depletion mitigated TBI-induced premature aging of the hematopoietic system and rejuvenated the aged HSCs and MuSCs in normally aged mice. Our results demonstrate that selective clearance of SCs by a pharmacological agent is beneficial in part through its rejuvenation of aged tissue stem cells. Thus, senolytic drugs may represent a new class of radiation mitigators and anti-aging agents.


Asunto(s)
Compuestos de Anilina/farmacología , Antineoplásicos/farmacología , Apoptosis/efectos de los fármacos , Senescencia Celular , Células Madre Hematopoyéticas/efectos de los fármacos , Mioblastos/efectos de los fármacos , ARN Mensajero/efectos de los fármacos , Sulfonamidas/farmacología , Animales , Antivirales/farmacología , Linfocitos B/efectos de los fármacos , Western Blotting , Ciclo Celular , Línea Celular , Supervivencia Celular/efectos de los fármacos , Ensayo de Unidades Formadoras de Colonias , Inhibidor p16 de la Quinasa Dependiente de Ciclina/efectos de los fármacos , Inhibidor p16 de la Quinasa Dependiente de Ciclina/genética , Inhibidor p16 de la Quinasa Dependiente de Ciclina/metabolismo , Daño del ADN , Ganciclovir/farmacología , Técnicas de Silenciamiento del Gen , Células Madre Hematopoyéticas/patología , Humanos , Ratones , Microscopía , Músculo Esquelético/citología , Mioblastos/patología , Proteínas Proto-Oncogénicas c-bcl-2/genética , ARN Mensajero/metabolismo , Rejuvenecimiento , Irradiación Corporal Total , Proteína bcl-X/genética
10.
Nat Cell Biol ; 17(8): 1049-61, 2015 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-26147250

RESUMEN

The TOR (target of rapamycin) kinase limits longevity by poorly understood mechanisms. Rapamycin suppresses the mammalian TORC1 complex, which regulates translation, and extends lifespan in diverse species, including mice. We show that rapamycin selectively blunts the pro-inflammatory phenotype of senescent cells. Cellular senescence suppresses cancer by preventing cell proliferation. However, as senescent cells accumulate with age, the senescence-associated secretory phenotype (SASP) can disrupt tissues and contribute to age-related pathologies, including cancer. MTOR inhibition suppressed the secretion of inflammatory cytokines by senescent cells. Rapamycin reduced IL6 and other cytokine mRNA levels, but selectively suppressed translation of the membrane-bound cytokine IL1A. Reduced IL1A diminished NF-κB transcriptional activity, which controls much of the SASP; exogenous IL1A restored IL6 secretion to rapamycin-treated cells. Importantly, rapamycin suppressed the ability of senescent fibroblasts to stimulate prostate tumour growth in mice. Thus, rapamycin might ameliorate age-related pathologies, including late-life cancer, by suppressing senescence-associated inflammation.


Asunto(s)
Interleucina-1alfa/metabolismo , Neoplasias de la Próstata/enzimología , Serina-Treonina Quinasas TOR/metabolismo , Animales , Antiinflamatorios/farmacología , Antineoplásicos/farmacología , Línea Celular Tumoral , Proliferación Celular , Senescencia Celular , Relación Dosis-Respuesta a Droga , Fibroblastos/efectos de los fármacos , Fibroblastos/enzimología , Regulación Neoplásica de la Expresión Génica , Humanos , Mediadores de Inflamación/metabolismo , Interleucina-1alfa/genética , Interleucina-6/metabolismo , Masculino , Ratones SCID , Mitoxantrona/farmacología , FN-kappa B/metabolismo , Fenotipo , Neoplasias de la Próstata/tratamiento farmacológico , Neoplasias de la Próstata/genética , Neoplasias de la Próstata/inmunología , Neoplasias de la Próstata/metabolismo , Neoplasias de la Próstata/patología , Interferencia de ARN , ARN Mensajero/metabolismo , Sirolimus/metabolismo , Sirolimus/farmacología , Serina-Treonina Quinasas TOR/antagonistas & inhibidores , Serina-Treonina Quinasas TOR/genética , Factores de Tiempo , Transcripción Genética , Transfección , Carga Tumoral , Regulación hacia Arriba , Ensayos Antitumor por Modelo de Xenoinjerto
11.
Curr Top Med Chem ; 15(21): 2139-51, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-26059360

RESUMEN

With the global aging population, Alzheimer's disease, Parkinson's disease and mild cognition impairment are increasing in prevalence. The success of rapamycin as an agent to extend lifespan in various organisms, including mice, brings hope that chronic mTOR inhibition could also refrain age-related neurodegeneration. Here we review the evidence suggesting that mTOR inhibition - mainly with rapamycin - is a valid intervention to delay age-related neurodegeneration. We discuss the potential mechanisms by which rapamycin may facilitate neurodegeneration prevention or restoration of cognitive function. We also discuss the known side effects of rapamycin and provide evidence to alleviate exaggerated concerns regarding its wider clinical use. We explore the small molecule alternatives to rapamycin and propose future directions for their development, mainly by exploring the possibility of targeting the downstream effectors of mTOR: S6K1 and especially S6K2. Finally, we discuss the strengths and weaknesses of the models used to determine intervention efficacy for neurodegeneration. We address the difficulties of interpreting data using the common way of investigating the efficacy of interventions to delay/prevent neurodegeneration by observing animal behavior while these animals are under treatment. We propose an experimental design that should isolate the variable of aging in the experimental design and resolve the ambiguity present in recent literature.


Asunto(s)
Terapia Molecular Dirigida/métodos , Enfermedades Neurodegenerativas/prevención & control , Serina-Treonina Quinasas TOR/antagonistas & inhibidores , Envejecimiento/efectos de los fármacos , Envejecimiento/fisiología , Animales , Cognición/efectos de los fármacos , Modelos Animales de Enfermedad , Humanos , Ratones , Proteínas Quinasas S6 Ribosómicas 70-kDa/metabolismo , Sirolimus/efectos adversos , Sirolimus/farmacología , Serina-Treonina Quinasas TOR/metabolismo
12.
Nat Commun ; 6: 6790, 2015 Apr 10.
Artículo en Inglés | MEDLINE | ID: mdl-25858675

RESUMEN

DNA damage has been implicated in ageing, but direct evidence for a causal relationship is lacking, owing to the difficulty of inducing defined DNA lesions in cells and tissues without simultaneously damaging other biomolecules and cellular structures. Here we directly test whether highly toxic DNA double-strand breaks (DSBs) alone can drive an ageing phenotype using an adenovirus-based system based on tetracycline-controlled expression of the SacI restriction enzyme. We deliver the adenovirus to mice and compare molecular and cellular end points in the liver with normally aged animals. Treated, 3-month-old mice display many, but not all signs of normal liver ageing as early as 1 month after treatment, including ageing pathologies, markers of senescence, fused mitochondria and alterations in gene expression profiles. These results, showing that DSBs alone can cause distinct ageing phenotypes in mouse liver, provide new insights in the role of DNA damage as a driver of tissue ageing.


Asunto(s)
Adenoviridae/genética , Envejecimiento/genética , Roturas del ADN de Doble Cadena , Reparación del ADN , ADN/genética , Envejecimiento/patología , Animales , Biomarcadores/metabolismo , ADN/química , Desoxirribonucleasas de Localización Especificada Tipo II/genética , Desoxirribonucleasas de Localización Especificada Tipo II/metabolismo , Perfilación de la Expresión Génica , Regulación de la Expresión Génica/efectos de los fármacos , Vectores Genéticos , Hígado/crecimiento & desarrollo , Hígado/metabolismo , Hígado/patología , Masculino , Ratones , Ratones Endogámicos BALB C , Tetraciclina/farmacología , Transgenes
13.
Dev Cell ; 31(6): 722-33, 2014 Dec 22.
Artículo en Inglés | MEDLINE | ID: mdl-25499914

RESUMEN

Cellular senescence suppresses cancer by halting the growth of premalignant cells, yet the accumulation of senescent cells is thought to drive age-related pathology through a senescence-associated secretory phenotype (SASP), the function of which is unclear. To understand the physiological role(s) of the complex senescent phenotype, we generated a mouse model in which senescent cells can be visualized and eliminated in living animals. We show that senescent fibroblasts and endothelial cells appear very early in response to a cutaneous wound, where they accelerate wound closure by inducing myofibroblast differentiation through the secretion of platelet-derived growth factor AA (PDGF-AA). In two mouse models, topical treatment of senescence-free wounds with recombinant PDGF-AA rescued the delayed wound closure and lack of myofibroblast differentiation. These findings define a beneficial role for the SASP in tissue repair and help to explain why the SASP evolved.


Asunto(s)
Senescencia Celular , Células Endoteliales/citología , Mesodermo/citología , Factor de Crecimiento Derivado de Plaquetas/metabolismo , Cicatrización de Heridas , Animales , Apoptosis , Diferenciación Celular , Femenino , Fibroblastos/metabolismo , Luminiscencia , Masculino , Ratones , Ratones Transgénicos , Miofibroblastos/metabolismo , Factor de Crecimiento Derivado de Plaquetas/química , Transgenes
14.
Biochem Biophys Res Commun ; 447(4): 574-9, 2014 May 16.
Artículo en Inglés | MEDLINE | ID: mdl-24747077

RESUMEN

The overexpression of P-glycoprotein (P-gp, ABCB1) in cancer cells often leads to multidrug resistance (MDR) through reduced drug accumulation. However, certain P-gp-positive cells display hypersensitivity, or collateral sensitivity, to certain compounds that are believed to induce Pgp-dependent oxidative stress. We have previously reported that MDR P-gp-positive CHO cells are collaterally sensitive to verapamil (VRP; Laberge et al. (2009) [1]). In this report we extend our previous findings and show that drug resistant CHO cells are also collaterally sensitive to physiologic levels of progesterone (PRO) and deoxycorticosterone (DOC). Both PRO and DOC collateral sensitivities in CH(R)C5 cells are dependent on P-gp-expression and ATPase, as knockdown of P-gp expression with siRNA or inhibition of P-gp-ATPase with PSC833 reverses PRO- and DOC-induced collateral sensitivity. Moreover, the mitochondrial complexes I and III inhibitors (antimycin-A and rotenone, respectively) synergize with PRO and DOC-induced collateral sensitivity. We also show that VRP inhibits PRO and DOC collateral sensitivity, consistent with earlier findings relating to the VRP's modulation of PRO and DOC-stimulation of P-gp ATPase. The findings of this study demonstrate a P-gp-dependent collateral sensitivity of MDR cells in the presence of physiologically achievable concentrations of progesterone and deoxycorticosterone.


Asunto(s)
Miembro 1 de la Subfamilia B de Casetes de Unión a ATP/metabolismo , Desoxicorticosterona/farmacología , Resistencia a Múltiples Medicamentos/efectos de los fármacos , Resistencia a Múltiples Medicamentos/fisiología , Progesterona/farmacología , Miembro 1 de la Subfamilia B de Casetes de Unión a ATP/antagonistas & inhibidores , Miembro 1 de la Subfamilia B de Casetes de Unión a ATP/genética , Adenosina Trifosfatasas/antagonistas & inhibidores , Adenosina Trifosfatasas/metabolismo , Animales , Antimicina A/administración & dosificación , Antimicina A/farmacología , Células CHO , Cricetinae , Cricetulus , Ciclosporinas/farmacología , Desoxicorticosterona/administración & dosificación , Sinergismo Farmacológico , Proteínas del Complejo de Cadena de Transporte de Electrón/antagonistas & inhibidores , Técnicas de Silenciamiento del Gen , Progesterona/administración & dosificación , ARN Interferente Pequeño/genética , Especies Reactivas de Oxígeno/metabolismo , Rotenona/administración & dosificación , Rotenona/farmacología , Verapamilo/farmacología
15.
Elife ; 2: e00762, 2013 Jul 23.
Artículo en Inglés | MEDLINE | ID: mdl-23898399

RESUMEN

Pseudogenes are thought to be inactive gene sequences, but recent evidence of extensive pseudogene transcription raised the question of potential function. Here we discover and characterize the sets of mouse lncRNAs induced by inflammatory signaling via TNFα. TNFα regulates hundreds of lncRNAs, including 54 pseudogene lncRNAs, several of which show exquisitely selective expression in response to specific cytokines and microbial components in a NF-κB-dependent manner. Lethe, a pseudogene lncRNA, is selectively induced by proinflammatory cytokines via NF-κB or glucocorticoid receptor agonist, and functions in negative feedback signaling to NF-κB. Lethe interacts with NF-κB subunit RelA to inhibit RelA DNA binding and target gene activation. Lethe level decreases with organismal age, a physiological state associated with increased NF-κB activity. These findings suggest that expression of pseudogenes lncRNAs are actively regulated and constitute functional regulators of inflammatory signaling. DOI:http://dx.doi.org/10.7554/eLife.00762.001.


Asunto(s)
Antiinflamatorios/uso terapéutico , Inflamación/genética , Seudogenes , ARN Largo no Codificante/genética , Animales , Factor de Necrosis Tumoral alfa/farmacología
16.
Mol Biol Cell ; 23(11): 2066-75, 2012 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-22496421

RESUMEN

Cellular senescence is a potent tumor-suppressive mechanism that arrests cell proliferation and has been linked to aging. However, studies of senescence have been impeded by the lack of simple, exclusive biomarkers of the senescent state. Senescent cells develop characteristic morphological changes, which include enlarged and often irregular nuclei and chromatin reorganization. Because alterations to the nuclear lamina can affect both nuclear morphology and gene expression, we examined the nuclear lamina of senescent cells. We show here than lamin B1 is lost from primary human and murine cell strains when they are induced to senesce by DNA damage, replicative exhaustion, or oncogene expression. Lamin B1 loss did not depend on the p38 mitogen-activated protein kinase, nuclear factor-κB, ataxia telangiectasia-mutated kinase, or reactive oxygen species signaling pathways, which are positive regulators of senescent phenotypes. However, activation of either the p53 or pRB tumor suppressor pathway was sufficient to induce lamin B1 loss. Lamin B1 declined at the mRNA level via a decrease in mRNA stability rather than by the caspase-mediated degradation seen during apoptosis. Last, lamin B1 protein and mRNA declined in mouse tissue after senescence was induced by irradiation. Our findings suggest that lamin B1 loss can serve as biomarker of senescence both in culture and in vivo.


Asunto(s)
Senescencia Celular , Lamina Tipo B/deficiencia , Animales , Proteínas de la Ataxia Telangiectasia Mutada , Biomarcadores/metabolismo , Proteínas de Ciclo Celular/metabolismo , Línea Celular , Senescencia Celular/efectos de la radiación , Inhibidor p16 de la Quinasa Dependiente de Ciclina/metabolismo , Daño del ADN , Proteínas de Unión al ADN/metabolismo , Relación Dosis-Respuesta en la Radiación , Regulación de la Expresión Génica/efectos de la radiación , Humanos , Lamina Tipo B/metabolismo , Ratones , FN-kappa B/metabolismo , Proteínas Serina-Treonina Quinasas/metabolismo , ARN Mensajero/genética , ARN Mensajero/metabolismo , Radiación Ionizante , Especies Reactivas de Oxígeno/metabolismo , Proteína de Retinoblastoma/metabolismo , Transducción de Señal/efectos de la radiación , Proteína p53 Supresora de Tumor/metabolismo , Proteínas Supresoras de Tumor/metabolismo , Proteínas Quinasas p38 Activadas por Mitógenos/metabolismo
17.
Aging Cell ; 11(4): 569-78, 2012 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-22404905

RESUMEN

Cellular senescence suppresses cancer by arresting the proliferation of cells at risk for malignant transformation. Recently, senescent cells were shown to secrete numerous cytokines, growth factors, and proteases that can alter the tissue microenvironment and may promote age-related pathology. To identify small molecules that suppress the senescence-associated secretory phenotype (SASP), we developed a screening protocol using normal human fibroblasts and a library of compounds that are approved for human use. Among the promising library constituents was the glucocorticoid corticosterone. Both corticosterone and the related glucocorticoid cortisol decreased the production and secretion of selected SASP components, including several pro-inflammatory cytokines. Importantly, the glucocorticoids suppressed the SASP without reverting the tumor suppressive growth arrest and were efficacious whether cells were induced to senesce by ionizing radiation or strong mitogenic signals delivered by oncogenic RAS or MAP kinase kinase 6 overexpression. Suppression of the prototypical SASP component IL-6 required the glucocorticoid receptor, which, in the presence of ligand, inhibited IL-1α signaling and NF-κB transactivation activity. Accordingly, co-treatments combining glucocorticoids with the glucocorticoid antagonist RU-486 or recombinant IL-1α efficiently reestablished NF-κB transcriptional activity and IL-6 secretion. Our findings demonstrate feasibility of screening for compounds that inhibit the effects of senescent cells. They further show that glucocorticoids inhibit selected components of the SASP and suggest that corticosterone and cortisol, two FDA-approved drugs, might exert their effects in part by suppressing senescence-associated inflammation.


Asunto(s)
Senescencia Celular/efectos de los fármacos , Senescencia Celular/fisiología , Glucocorticoides/farmacología , Línea Celular , Transformación Celular Neoplásica/efectos de los fármacos , Corticosterona/farmacología , Fibroblastos/efectos de los fármacos , Fibroblastos/fisiología , Humanos , Hidrocortisona/farmacología , Interleucina-1alfa/biosíntesis , Interleucina-6/biosíntesis , FN-kappa B/metabolismo , Invasividad Neoplásica/prevención & control , Fenotipo , Receptores de Glucocorticoides/metabolismo , Transducción de Señal/efectos de los fármacos
18.
Cancer Microenviron ; 5(1): 39-44, 2012 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-21706180

RESUMEN

Depending on the cell type and tissue environment, epithelial and mesenchymal cell phenotypes are not static and can be highly dynamic. Epithelial-mesenchymal transitions (EMTs) and reverse EMTs provide flexibility during embryogenesis. While EMTs are a critical normal process during development and wound healing, properties of the EMT have been implicated in human pathology, particularly cancer metastasis. A normal undamaged epithelium does not typically exhibit features of an EMT. However, particularly under the influence of the surrounding microenvironment, cancer cells may reactivate developmental phenotypes out of context in the adult. This reactivation, such as the EMT, can facilitate tumor cell invasion and metastasis, and therefore is a major mechanism of tumor progression. Conversely, cellular senescence, which is associated with aging, is a process by which cells enter a state of permanent cell cycle arrest, thereby constituting a potent tumor suppressive mechanism. However, accumulating evidence shows that senescent cells can have deleterious effects on the tissue microenvironment. The most significant of these effects is the acquisition of a senescence-associated secretory phenotype (SASP) that turns senescent fibroblasts into pro-inflammatory cells having the ability to promote tumor progression, in part by inducing an EMT in nearby epithelial cells. Here, we summarize the potential impacts of SASP factors, particularly interleukins, on tissue microenvironments and their ability to stimulate tumor progression through induction of an EMT.

20.
Arch Biochem Biophys ; 491(1-2): 53-60, 2009 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-19772851

RESUMEN

P-glycoprotein (or P-gp1, ABCB1) expression in tumor cells is causative of multidrug resistance through the active efflux of drugs across the cell membrane. However, the over-expression of P-glycoprotein in some tumor cells has been associated with increased sensitivity, or "collateral sensitivity", of multidrug resistant cells to specific drugs, including the calcium channel blocker verapamil. We previously demonstrated that collateral sensitivity to verapamil correlates with the effect of this drug on P-gp1 ATPase, and is reversed by inhibitors of P-gp1 ATPase (e.g., PSC 833 and Ivermectin). In this report, we expand on our earlier study and demonstrate that P-gp1 expression in drug-resistant cells modulates collateral sensitivity. Using P-gp1-specific siRNA, P-gp1 expression in the multidrug resistant CH(R)C5 cells was significantly down-regulated beginning on day 2 post-transfection of siRNA. Furthermore, down-regulation of P-gp1 led to increased sensitivity of CH(R)C5 cells to paclitaxel and doxorubicin, but not to cis-platinum, due to inhibition of P-gp1 drug efflux pump. Down-regulation of P-gp1 expression completely reversed collateral sensitivity to verapamil. Moreover, known inhibitors of ETC, rotenone and antimycin A which cause an increase in reactive oxygen species, synergized with verapamil-induced collateral sensitivity leading to increased cell death as determined by MTT cell survival assay. Similarly, the addition of hydrogen peroxide also synergized with verapamil. Taken together, the results of this study demonstrate a direct link between P-gp1 expression and collateral sensitivity of drug-resistant cells, possibly due to an increase in reactive oxygen species.


Asunto(s)
Miembro 1 de la Subfamilia B de Casetes de Unión a ATP/metabolismo , Resistencia a Múltiples Medicamentos , Verapamilo/farmacología , Miembro 1 de la Subfamilia B de Casetes de Unión a ATP/genética , Adenosina Trifosfatasas/metabolismo , Adenosina Trifosfato/biosíntesis , Animales , Antineoplásicos/farmacología , Secuencia de Bases , Línea Celular , Supervivencia Celular/efectos de los fármacos , Cricetinae , Resistencia a Múltiples Medicamentos/efectos de los fármacos , Regulación Neoplásica de la Expresión Génica , Humanos , Oxidación-Reducción , Fosforilación , Interferencia de ARN , ARN Interferente Pequeño/genética
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA