Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 3.038
Filtrar
1.
Ecotoxicol Environ Saf ; 204: 111070, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32763567

RESUMO

Silver nanoparticles (AgNPs) are widely used as antimicrobial agents and resulted in their accumulation in environment. The purpose of this study was to investigate the detailed molecular mechanisms underlying AgNP-induced lung cellular senescence which has been proposed as a pathogenic driver of chronic lung disease. Herein, we demonstrate that exposure to AgNPs elevates multiple senescence biomarkers in lung cells, with cell cycle arrest in the G2/M phase, and potently activates genes of the senescence-associated secretory phenotype (SASP) in human fetal lung fibroblast cell line MRC5. Fluorescence-based assay also reveals that apoptosis induced by AgNPs is associated with senescence. Furthermore, we show that AgNPs cause premature senescence through an increase in transcription factor nuclear factor kappa B (NF-κB), cyclooxygenase-2 (COX2) expression and over-production of prostaglandin E2 (PGE2) in lung cells. Inhibition of COX2 reduces AgNPs-induced senescence to a normal level. Moreover, AgNPs also induce upregulation of COX2 and accelerate lung cellular senescence in vivo and cause mild fibrosis in the lung tissue of mice. Taken together, our studies support a critical role of AgNPs in the induction of lung cellular senescence via the upregulation of the COX2/PGE2 intracrine pathway, and suggest the adverse effects to the human respiratory system.


Assuntos
Senescência Celular/efeitos dos fármacos , Ciclo-Oxigenase 2/metabolismo , Dinoprostona/metabolismo , Pulmão/efeitos dos fármacos , Nanopartículas Metálicas/toxicidade , Prata/toxicidade , Animais , Apoptose/efeitos dos fármacos , Linhagem Celular , Fibroblastos/efeitos dos fármacos , Fibroblastos/metabolismo , Fibroblastos/patologia , Humanos , Pulmão/metabolismo , Pulmão/patologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , NF-kappa B/metabolismo , Prata/metabolismo
2.
PLoS Biol ; 18(8): e3000808, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32817651

RESUMO

Although dysregulation of mitochondrial dynamics has been linked to cellular senescence, which contributes to advanced age-related disorders, it is unclear how Krüppel-like factor 5 (Klf5), an essential transcriptional factor of cardiovascular remodeling, mediates the link between mitochondrial dynamics and vascular smooth muscle cell (VSMC) senescence. Here, we show that Klf5 down-regulation in VSMCs is correlated with rupture of abdominal aortic aneurysm (AAA), an age-related vascular disease. Mice lacking Klf5 in VSMCs exacerbate vascular senescence and progression of angiotensin II (Ang II)-induced AAA by facilitating reactive oxygen species (ROS) formation. Klf5 knockdown enhances, while Klf5 overexpression suppresses mitochondrial fission. Mechanistically, Klf5 activates eukaryotic translation initiation factor 5a (eIF5a) transcription through binding to the promoter of eIF5a, which in turn preserves mitochondrial integrity by interacting with mitofusin 1 (Mfn1). Accordingly, decreased expression of eIF5a elicited by Klf5 down-regulation leads to mitochondrial fission and excessive ROS production. Inhibition of mitochondrial fission decreases ROS production and VSMC senescence. Our studies provide a potential therapeutic target for age-related vascular disorders.


Assuntos
Aneurisma da Aorta Abdominal/genética , Células Endoteliais/metabolismo , Fatores de Transcrição Kruppel-Like/genética , Mitocôndrias/metabolismo , Fatores de Iniciação de Peptídeos/genética , Proteínas de Ligação a RNA/genética , Idoso , Angiotensina II/genética , Angiotensina II/metabolismo , Angiotensina II/farmacologia , Animais , Aorta/diagnóstico por imagem , Aorta/metabolismo , Aorta/patologia , Aneurisma da Aorta Abdominal/diagnóstico por imagem , Aneurisma da Aorta Abdominal/metabolismo , Aneurisma da Aorta Abdominal/patologia , Senescência Celular/efeitos dos fármacos , Ecocardiografia , Células Endoteliais/patologia , Feminino , GTP Fosfo-Hidrolases/genética , GTP Fosfo-Hidrolases/metabolismo , Humanos , Fatores de Transcrição Kruppel-Like/deficiência , Masculino , Camundongos , Camundongos Knockout , Mitocôndrias/patologia , Dinâmica Mitocondrial/efeitos dos fármacos , Fatores de Iniciação de Peptídeos/deficiência , Cultura Primária de Células , Regiões Promotoras Genéticas , Ligação Proteica , Espécies Reativas de Oxigênio/metabolismo
3.
Nat Commun ; 11(1): 4289, 2020 08 27.
Artigo em Inglês | MEDLINE | ID: mdl-32855397

RESUMO

Older organs represent an untapped potential to close the gap between demand and supply in organ transplantation but are associated with age-specific responses to injury and increased immunogenicity, thereby aggravating transplant outcomes. Here we show that cell-free mitochondrial DNA (cf-mt-DNA) released by senescent cells accumulates with aging and augments immunogenicity. Ischemia reperfusion injury induces a systemic increase of cf-mt-DNA that promotes dendritic cell-mediated, age-specific inflammatory responses. Comparable events are observed clinically, with the levels of cf-mt-DNA elevated in older deceased organ donors, and with the isolated cf-mt-DNA capable of activating human dendritic cells. In experimental models, treatment of old donor animals with senolytics clear senescent cells and diminish cf-mt-DNA release, thereby dampening age-specific immune responses and prolonging the survival of old cardiac allografts comparable to young donor organs. Collectively, we identify accumulating cf-mt-DNA as a key factor in inflamm-aging and present senolytics as a potential approach to improve transplant outcomes and availability.


Assuntos
DNA Mitocondrial/efeitos adversos , Dasatinibe/farmacologia , Inflamação/prevenção & controle , Transplante de Órgãos/métodos , Quercetina/farmacologia , Adulto , Envelhecimento/fisiologia , Animais , Diferenciação Celular , Ácidos Nucleicos Livres , Senescência Celular/efeitos dos fármacos , Senescência Celular/fisiologia , Citocinas/metabolismo , DNA Mitocondrial/metabolismo , Células Dendríticas/imunologia , Células Dendríticas/fisiologia , Transplante de Coração/efeitos adversos , Transplante de Coração/métodos , Humanos , Inflamação/etiologia , Masculino , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos DBA , Pessoa de Meia-Idade , Transplante de Órgãos/efeitos adversos , Traumatismo por Reperfusão/genética , Traumatismo por Reperfusão/imunologia , Doadores de Tecidos
4.
Life Sci ; 257: 118116, 2020 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-32702447

RESUMO

Emerging evidence implicates accelerated renal tubular epithelial cell (RTEC) senescence in renal fibrosis progression. Mitophagy protects against kidney injury. However, the mechanistic interplay between cell senescence and mitophagy in RTECs is not clearly defined. The purpose of this study was to evaluate the inhibition of RTEC senescence and renal fibrosis by quercetin and explore the underlying mechanisms. We found that quercetin attenuated RTEC senescence induced by angiotensin II (AngII) in vitro and unilateral ureteral obstruction in vivo. Moreover, we demonstrated that mitochondrial abnormalities such as elevated reactive oxygen species, decreased membrane potential, and fragmentation and accumulation of mitochondrial mass, occurred in AngII-treated RTECs. Quercetin treatment reversed these effects. Furthermore, quercetin enhanced mitophagy in AngII-treated RTECs, which was markedly reduced by treatment with mitophagy-specific inhibitors. Sirtuin-1 (SIRT1) was involved in quercetin-mediated PTEN-induced kinase 1 (PINK1)/Parkin-associated mitophagy activation. Pharmacological antagonism of SIRT1 in AngII-treated RTECs blocked the effects of quercetin on mitophagy and cellular senescence. Finally, quercetin alleviated kidney fibrosis by reducing RTEC senescence via mitophagy. Collectively, the antifibrotic effect of quercetin involved inhibition of RTEC senescence, possibly through activation of SIRT1/PINK1/Parkin-mediated mitophagy. These findings suggest that pharmacological elimination of senescent cells and stimulation of mitophagy represent effective therapeutic strategies to prevent kidney fibrosis.


Assuntos
Antioxidantes/farmacologia , Senescência Celular/efeitos dos fármacos , Túbulos Renais Proximais/efeitos dos fármacos , Rim/patologia , Mitofagia/efeitos dos fármacos , Proteínas Quinases/metabolismo , Quercetina/farmacologia , Sirtuína 1/metabolismo , Animais , Antioxidantes/uso terapêutico , Linhagem Celular , Epitélio/efeitos dos fármacos , Fibrose , Citometria de Fluxo , Rim/efeitos dos fármacos , Túbulos Renais Proximais/patologia , Quercetina/uso terapêutico , Ratos
5.
Arterioscler Thromb Vasc Biol ; 40(9): 2244-2264, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32640900

RESUMO

OBJECTIVE: Nanog is expressed in adult endothelial cells (ECs) at a low-level, however, its functional significance is not known. The goal of our study was to elucidate the role of Nanog in adult ECs using a genetically engineered mouse model system. Approach and Results: Biochemical analyses showed that Nanog is expressed in both adult human and mouse tissues. Primary ECs isolated from adult mice showed detectable levels of Nanog, Tert (telomerase reverse transcriptase), and eNos (endothelial nitric oxide synthase). Wnt3a (Wnt family member 3A) increased the expression of Nanog and hTERT (human telomerase reverse transcriptase) in ECs and increased telomerase activity in these cells. In a chromatin immunoprecipitation experiment, Nanog directly bound to the hTERT and eNOS promoter/enhancer DNA elements, thereby regulating their transcription. Administration of low-dose tamoxifen to ROSAmT/mG::Nanogfl/+::Cdh5CreERT2 mice induced deletion of a single Nanog allele, simultaneously labeling ECs with green fluorescent protein and resulting in decreased Tert and eNos levels. Histological and morphometric analyses of heart tissue sections prepared from these mice revealed cell death, microvascular rarefaction, and increased fibrosis in cardiac vessels. Accordingly, EC-specific Nanog-haploinsufficiency resulted in impaired EC homeostasis and angiogenesis. Conversely, re-expression of cDNA encoding the hTERT in Nanog-depleted ECs, in part, restored the effect of loss of Nanog. CONCLUSIONS: We showed that low-level Nanog expression is required for normal EC homeostasis and angiogenesis in adulthood.


Assuntos
Proliferação de Células , Senescência Celular , Vasos Coronários/metabolismo , Células Endoteliais/metabolismo , Endotélio Vascular/metabolismo , Proteína Homeobox Nanog/metabolismo , Animais , Apoptose , Proliferação de Células/efeitos dos fármacos , Células Cultivadas , Senescência Celular/efeitos dos fármacos , Vasos Coronários/efeitos dos fármacos , Vasos Coronários/patologia , Células Endoteliais/efeitos dos fármacos , Células Endoteliais/patologia , Endotélio Vascular/efeitos dos fármacos , Endotélio Vascular/patologia , Feminino , Fibrose , Células Endoteliais da Veia Umbilical Humana/metabolismo , Humanos , Masculino , Camundongos Endogâmicos C57BL , Camundongos Knockout , Proteína Homeobox Nanog/deficiência , Proteína Homeobox Nanog/genética , Neovascularização Fisiológica , Óxido Nítrico Sintase Tipo III/genética , Óxido Nítrico Sintase Tipo III/metabolismo , Telomerase/genética , Telomerase/metabolismo , Ativação Transcricional , Via de Sinalização Wnt , Proteína Wnt3A/farmacologia
6.
Front Immunol ; 11: 1472, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32655579

RESUMO

Severe acute respiratory syndrome coronavirus 2 has spread rapidly around the globe. However, despite its high pathogenicity and transmissibility, the severity of the associated disease, COVID-19, varies widely. While the prognosis is favorable in most patients, critical illness, manifested by respiratory distress, thromboembolism, shock, and multi-organ failure, has been reported in about 5% of cases. Several studies have associated poor COVID-19 outcomes with the exhaustion of natural killer cells and cytotoxic T cells, lymphopenia, and elevated serum levels of D-dimer. In this article, we propose a common pathophysiological denominator for these negative prognostic markers, endogenous, angiotensin II toxicity. We hypothesize that, like in avian influenza, the outlook of COVID-19 is negatively correlated with the intracellular accumulation of angiotensin II promoted by the viral blockade of its degrading enzyme receptors. In this model, upregulated angiotensin II causes premature vascular senescence, leading to dysfunctional coagulation, and immunity. We further hypothesize that angiotensin II blockers and immune checkpoint inhibitors may be salutary for COVID-19 patients with critical illness by reversing both the clotting and immune defects (Graphical Abstract).


Assuntos
Angiotensina II/sangue , Betacoronavirus/metabolismo , Infecções por Coronavirus/sangue , Infecções por Coronavirus/fisiopatologia , Pneumonia Viral/sangue , Pneumonia Viral/fisiopatologia , Regulação para Cima , Fatores Etários , Antagonistas de Receptores de Angiotensina/uso terapêutico , Inibidores da Enzima Conversora de Angiotensina/uso terapêutico , Encéfalo/imunologia , Encéfalo/metabolismo , Senescência Celular/efeitos dos fármacos , Infecções por Coronavirus/tratamento farmacológico , Infecções por Coronavirus/virologia , Estado Terminal , Citocinas/metabolismo , Dopamina/metabolismo , Regulação para Baixo , Humanos , Imunoterapia/métodos , Mitocôndrias/metabolismo , Pandemias , Peptidil Dipeptidase A/metabolismo , Pneumonia Viral/tratamento farmacológico , Pneumonia Viral/virologia , Prognóstico , Sistema Renina-Angiotensina/imunologia
7.
PLoS Biol ; 18(6): e3000731, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32479501

RESUMO

The nuclear lamina protein lamin A/C is a key component of the nuclear envelope. Mutations in the lamin A/C gene (LMNA) are identified in patients with various types of laminopathy-containing diseases, which have features of accelerated aging and osteoporosis. However, the underlying mechanisms for laminopathy-associated osteoporosis remain largely unclear. Here, we provide evidence that loss of lamin A/C in skeletal muscles, but not osteoblast (OB)-lineage cells, results in not only muscle aging-like deficit but also trabecular bone loss, a feature of osteoporosis. The latter is due in large part to elevated bone resorption. Further cellular studies show an increase of osteoclast (OC) differentiation in cocultures of bone marrow macrophages/monocytes (BMMs) and OBs after treatment with the conditioned medium (CM) from lamin A/C-deficient muscle cells. Antibody array screening analysis of the CM proteins identifies interleukin (IL)-6, whose expression is markedly increased in lamin A/C-deficient muscles. Inhibition of IL-6 by its blocking antibody in BMM-OB cocultures diminishes the increase of osteoclastogenesis. Knockout (KO) of IL-6 in muscle lamin A/C-KO mice diminishes the deficits in trabecular bone mass but not muscle. Further mechanistic studies reveal an elevation of cellular senescence marked by senescence-associated beta-galactosidase (SA-ß-gal), p16Ink4a, and p53 in lamin A/C-deficient muscles and C2C12 muscle cells, and the p16Ink4a may induce senescence-associated secretory phenotype (SASP) and IL-6 expression. Taken together, these results suggest a critical role for skeletal muscle lamin A/C to prevent cellular senescence, IL-6 expression, hyperosteoclastogenesis, and trabecular bone loss, uncovering a pathological mechanism underlying the link between muscle aging/senescence and osteoporosis.


Assuntos
Envelhecimento/patologia , Lamina Tipo A/deficiência , Músculo Esquelético/patologia , Osteoporose/patologia , Animais , Anticorpos Bloqueadores/farmacologia , Fenômenos Biomecânicos , Reabsorção Óssea/complicações , Reabsorção Óssea/patologia , Osso Esponjoso/efeitos dos fármacos , Osso Esponjoso/patologia , Diferenciação Celular/efeitos dos fármacos , Senescência Celular/efeitos dos fármacos , Interleucina-6/metabolismo , Camundongos Knockout , Fibras Musculares Esqueléticas/efeitos dos fármacos , Fibras Musculares Esqueléticas/metabolismo , Músculo Esquelético/efeitos dos fármacos , Tamanho do Órgão/efeitos dos fármacos , Osteoclastos/efeitos dos fármacos , Osteoclastos/patologia , Osteogênese/efeitos dos fármacos , Osteoporose/sangue , Fenótipo
8.
Toxicology ; 441: 152525, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32540480

RESUMO

There is considerable interest in gene and environment interactions in neurodegenerative diseases. The HFE (homeostatic iron regulator) gene variant (H63D) is highly prevalent in the population and has been investigated as a disease modifier in multiple neurodegenerative diseases. We have developed a mouse model to interrogate the impact of this gene variant in a model of paraquat toxicity. Using primary astrocytes, we found that the H67D-Hfe(equivalent of the human H63D variant) astrocytes are less vulnerable than the WT-Hfe astrocytes to paraquat-induced cell death, mitochondrial damage, and cellular senescence. We hypothesized that the Hfe variant-associated protection is a result of the activation of the Nrf2 antioxidant defense system and found a significant increase in Nrf2 levels after paraquat exposure in the H67D-Hfe astrocytes than the WT-Hfe astrocytes. Moreover, decreasing Nrf2 by molecular or pharmaceutical manipulation resulted in increased vulnerability to paraquat in the H67D-Hfe astrocytes. To further elucidate the role of Hfe variant genotype in neuroprotection mediated by astrocytes, we added media from the paraquat-treated astrocytes to differentiated SH-SY5Y neuroblastoma cells and found a significantly larger reduction in the viability when treated with WT-Hfe astrocyte media than the H67D-Hfe astrocyte media possibly due to higher secretion of IL-6 observed in the WT-Hfe astrocytes. To further explore the mechanism of Nrf2 protection, we measured NQO1, the Nrf2-mediated antioxidant, in primary astrocytes and found a significantly higher NQO1 level in the H67D-Hfe astrocytes. To consider the translational potential of our findings, we utilized the PPMI (Parkinson's Progression Markers Initiative) clinical database and found that, consistent with the mouse study, H63D-HFE carriers had a significantly higher NQO1 level in the CSF than the WT-HFE carriers. Consistent with our previous reports on H63D-HFE in disease, these data further suggest that HFE genotype in the human population impacts the antioxidant defense system and can therefore alter pathogenesis.


Assuntos
Proteína da Hemocromatose/genética , Fator 2 Relacionado a NF-E2/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Animais , Astrócitos/efeitos dos fármacos , Morte Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Senescência Celular/efeitos dos fármacos , Feminino , Genótipo , Proteína da Hemocromatose/efeitos dos fármacos , Proteína da Hemocromatose/metabolismo , Humanos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Paraquat/toxicidade
9.
Life Sci ; 256: 117969, 2020 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-32553926

RESUMO

AIMS: Cannabinoids are the chemical compounds with a high affinity for cannabinoid receptors affecting the central nervous system through the release of neurotransmitters. However, the current knowledge related to the role of such compounds in the regulation of cellular aging is limited. This study aimed to investigate the effect of cannabidiol and tetrahydrocannabinol on the function of aged pancreatic islets. MAIN METHODS: The expression of p53, p38, p21, p16, and Glut2 genes and ß-galactosidase activity were measured as hallmarks of cell aging applying real-time PCR, ELISA, and immunocytochemistry techniques. Pdx1 protein expression, insulin release, and oxidative stress markers were compared between young and aged rat pancreatic islet cells. KEY FINDINGS: Upon the treatment of aged pancreatic islets cells with cannabidiol and tetrahydrocannabinol, the expression of p53, p38, p21 and the activity of ß-galactosidase were reduced. Cannabidiol and tetrahydrocannabinol increase insulin release, Pdx1, Glut2, and thiol molecules expression, while the oxidative stress parameters were decreased. The enhanced expression of Pdx1 and insulin release in aged pancreatic islet cells reflects the extension of cell healthy aging due to the significant reduction of ROS. SIGNIFICANCE: This study provides evidence for the involvement of cannabidiol and tetrahydrocannabinol in the oxidation process of cellular aging.


Assuntos
Canabinoides/farmacologia , Senescência Celular , Ilhotas Pancreáticas/citologia , Espécies Reativas de Oxigênio/metabolismo , Animais , Biomarcadores/metabolismo , Canabidiol/farmacologia , Sobrevivência Celular/efeitos dos fármacos , Senescência Celular/efeitos dos fármacos , Dronabinol/farmacologia , Proteínas de Homeodomínio/metabolismo , Secreção de Insulina/efeitos dos fármacos , Masculino , Estresse Oxidativo/efeitos dos fármacos , Ratos Wistar , Transativadores/metabolismo
10.
PLoS One ; 15(6): e0234706, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32574191

RESUMO

PURPOSE: We assessed whether mitomycin-C (MMC) has different antifibrotic mechanisms in trabeculectomy wound healing. METHODS: We identified 2 concentrations of MMC as "low-dose" by using WST-1 assay, Lactic dehydrogenase assay, and fluorescence-activated cell sorting flow cytometry. Senescence-associated ß-galactosidase (SA-ß-gal) and fibrotic gene expression was examined through immunocytochemistry, flow cytometry, real-time quantitative reverse transcription polymerase chain reaction, Western blotting, zymography, and modified scratch assay in vitro. In vivo, 0.1 mL of MMC or normal saline was injected to Tenon's capsule before trabeculectomy in a rabbit model. SA-ß-gal expression, apoptotic cell death, and collagen deposition in sites treated and not treated with MMC were evaluated using terminal dUTP nick end labeling assay and histochemical staining. Bleb function and intraocular pressure (IOP) levels were examined 3, 7, 14, 21, 28, and 35 days after trabeculectomy. RESULTS: In vitro, human Tenon's fibroblast (HTF) senescence was confirmed by observing cell morphologic change, SA-ß-gal accumulation, formation of senescence-associated heterochromatin, increased p16INK4a and p21CIP1/WAF1 expression, lower percentage of Ki-67-positive cells, and decreased COL1A1 release. Increased expression of α-SMA, COL1A1, and Smad2 signaling in TGF-ß1-induced stress fibers were passivated in senescent HTFs. In addition, cellular migration enhanced by TGF-ß1was inactivated. In vivo, histological examination indicated increased SA-ß-gal accumulation, lower apoptosis ratios, and looser collagen deposition in sites treated with 0.2 µM MMC. Low-dose MMC-induced cellular senescence prolonged trabeculectomy bleb survival and reduced IOP levels in a rabbit model. CONCLUSION: Low-dose MMC-induced cellular senescence is involved in the antifibrotic mechanism of trabeculectomy wound healing.


Assuntos
Senescência Celular/efeitos dos fármacos , Mitomicina/farmacologia , Trabeculectomia , Animais , Biomarcadores/metabolismo , Sobrevivência Celular/efeitos dos fármacos , Transdiferenciação Celular/efeitos dos fármacos , Relação Dose-Resposta a Droga , Fibrose , Miofibroblastos/citologia , Miofibroblastos/efeitos dos fármacos , Coelhos , Transdução de Sinais/efeitos dos fármacos , Proteína Smad2/metabolismo , Fator de Crescimento Transformador beta1/farmacologia , Cicatrização/efeitos dos fármacos
11.
Toxicology ; 441: 152502, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32473187

RESUMO

Cigarette smoking is a well-recognized risk factor for type 2 diabetes (T2DM), and may result in islet ß cell damage and impaired insulin secretion. However, the underlying mechanisms remain largely elusive. In the present study, we demonstrated that nicotine induced premature senescence of pancreatic ß cells in vitro and in vivo. The senescence-associated ß-galactosidase (SA-ß-Gal) assay showed that nicotine exposure induced apparent senescence phenotype of ß-TC-6 cells at an initiating dose of 100 µM and starting from 12 h. In addition, 100 and 500 µM of nicotine exposure altered the expression of senescence marker proteins, such as p16, p19 and p21. Furthermore, we uncovered that the levels of intracellular Ca2+ and reactive oxygen species (ROS) were significantly elevated in ß-TC-6 cells following exposure to 100 and 500 µM nicotine, while calcium channel blocker can reverse this effect. Furthermore, the senescence-inducing phenotype was confirmed in rat insulinoma INS-1 cells at a similar dose range, whereas blockade of nAChRs, calcium and ROS led to apparent impairment of senescence. Finally, we found that administration with 100 and 200 µg/mL nicotine in drinking water for 28 days significantly exacerbated aberrant glucose homeostasis in a mouse model of fat-induced T2DM. Of great intrigue, pancreatic ß cells exhibited significantly enhanced senescence following nicotine administration. Taken together, this study suggests that premature senescence plays a pivotal role in nicotine-triggered ß cell destruction and glucose intolerance, providing a theoretical basis for targeted prevention and treatment of smoking-induced T2DM.


Assuntos
Senescência Celular/efeitos dos fármacos , Diabetes Mellitus Tipo 2/induzido quimicamente , Células Secretoras de Insulina/efeitos dos fármacos , Nicotina/toxicidade , Animais , Western Blotting , Cálcio/metabolismo , Progressão da Doença , Relação Dose-Resposta a Droga , Ensaio de Imunoadsorção Enzimática , Glucose/metabolismo , Células Secretoras de Insulina/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Espécies Reativas de Oxigênio/metabolismo , Reação em Cadeia da Polimerase em Tempo Real , beta-Galactosidase/metabolismo
12.
Crit Rev Oncol Hematol ; 151: 102963, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32446180

RESUMO

Treatment of testicular cancer (TC) has an exceptionally high success rate compared to other cancer types; even in case of metastasized disease, 80-90 % of TC patients can be cured. Consequently, attention has been drawn to a potential downside of this treatment success: late adverse treatment effects such as the accelerated development of otherwise age-associated features like cardiovascular disease and second malignancies. Underlying mechanisms are poorly understood. Emerging data suggest that cytotoxic treatment induces cellular senescence, resulting in secretion of inflammatory factors contributing to this early ageing phenotype. Molecular and cellular characterization of this early ageing will enhance understanding the pathogenesis of TC treatment-induced morbidity and contribute to better recognition and prevention of late effects. In this review, we describe clinical manifestations of the early ageing phenotype among TC survivors, and subsequently focus on potential underlying mechanisms. We discuss the clinical implications and describe perspectives for future research and intervention strategies.


Assuntos
Antineoplásicos/uso terapêutico , Senescência Celular/efeitos dos fármacos , Neoplasias Testiculares/tratamento farmacológico , Envelhecimento , Antineoplásicos/toxicidade , Humanos , Masculino , Sobreviventes
13.
Life Sci ; 254: 117776, 2020 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-32437790

RESUMO

AIMS: Rg1 is the most active component of traditional Chinese medicine ginseng, having anti-aging and anti-oxidative stress features in multiple organs. Cellular senescence of hepatocytes is involved in the progression of a wide spectrum of chronic liver diseases. In this study, we investigated the potential benefits and mechanism of action of Rg1 on aging-driven chronic liver diseases. MATERIALS AND METHODS: A total of 40 male C57BL/6 mice were randomly divided into four groups: control group; Rg1 group; Rg1+d-gal group; and d-gal group. Blood and liver tissue samples were collected for determination of liver function, biochemical and molecular markers, as well as histopathological investigation. KEY FINDINGS: Rg1 played an anti-aging role in reversing d-galactose induced increase in senescence-associated SA-ß-gal staining and p53, p21 protein in hepatocytes of mice and sustained mitochondria homeostasis. Meanwhile, Rg1 protected livers from d-galactose caused abnormal elevation of ALT and AST in serum, hepatic steatosis, reduction in hepatic glucose production, hydrogenic degeneration, inflammatory phenomena including senescence-associated secretory phenotype (SASP) IL-1ß, IL-6, MCP-1 elevation and lymphocyte infiltration. Furthermore, Rg1 suppressed drastic elevation in FOXO1 phosphorylation resulting in maintaining FOXO1 protein level in the liver after d-galactose treatment, followed by FOXO1 targeted antioxidase SOD and CAT significant up-regulation concurrent with marked decrease in lipid peroxidation marker MDA. SIGNIFICANCE: Rg1 exerts pharmaceutic effects of maintaining FOXO1 activity in liver, which enhances anti-oxidation potential of Rg1 to ameliorate SASP and to inhibit inflammation, also promotes metabolic homeostasis, and thus protects livers from senescence induced fatty liver disease. The study provides a potential therapeutic strategy for alleviating chronic liver pathology.


Assuntos
Fígado Gorduroso/metabolismo , Fígado Gorduroso/prevenção & controle , Proteína Forkhead Box O1/metabolismo , Ginsenosídeos/farmacologia , Animais , Antioxidantes/farmacologia , Senescência Celular/efeitos dos fármacos , Modelos Animais de Doenças , Galactose/farmacologia , Peroxidação de Lipídeos/efeitos dos fármacos , Masculino , Medicina Tradicional Chinesa , Camundongos , Camundongos Endogâmicos C57BL , Estresse Oxidativo/efeitos dos fármacos , Substâncias Protetoras/farmacologia , Fatores de Transcrição/metabolismo
14.
Arterioscler Thromb Vasc Biol ; 40(6): 1479-1490, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32268785

RESUMO

OBJECTIVE: Enhanced expression of PAI-1 (plasminogen activator inhibitor-1) has been implicated in atherosclerosis formation in humans with obesity and metabolic syndrome. However, little is known about the effects of pharmacological targeting of PAI-1 on atherogenesis. This study examined the effects of pharmacological PAI-1 inhibition on atherosclerosis formation in a murine model of obesity and metabolic syndrome. Approach and Results: LDL receptor-deficient (ldlr-/-) mice were fed a Western diet high in cholesterol, fat, and sucrose to induce obesity, metabolic dysfunction, and atherosclerosis. Western diet triggered significant upregulation of PAI-1 expression compared with normal diet controls. Addition of a pharmacological PAI-1 inhibitor (either PAI-039 or MDI-2268) to Western diet significantly inhibited obesity and atherosclerosis formation for up to 24 weeks without attenuating food consumption. Pharmacological PAI-1 inhibition significantly decreased macrophage accumulation and cell senescence in atherosclerotic plaques. Recombinant PAI-1 stimulated smooth muscle cell senescence, whereas a PAI-1 mutant defective in LRP1 (LDL receptor-related protein 1) binding did not. The prosenescent effect of PAI-1 was blocked by PAI-039 and R2629, a specific anti-LRP1 antibody. PAI-039 significantly decreased visceral adipose tissue inflammation, hyperglycemia, and hepatic triglyceride content without altering plasma lipid profiles. CONCLUSIONS: Pharmacological targeting of PAI-1 inhibits atherosclerosis in mice with obesity and metabolic syndrome, while inhibiting macrophage accumulation and cell senescence in atherosclerotic plaques, as well as obesity-associated metabolic dysfunction. PAI-1 induces senescence of smooth muscle cells in an LRP1-dependent manner. These results help to define the role of PAI-1 in atherosclerosis formation and suggest a new plasma-lipid-independent strategy for inhibiting atherogenesis.


Assuntos
Aterosclerose/prevenção & controle , Síndrome Metabólica/tratamento farmacológico , Inibidor 1 de Ativador de Plasminogênio/efeitos dos fármacos , Animais , Senescência Celular/efeitos dos fármacos , Dieta Ocidental , Modelos Animais de Doenças , Ácidos Indolacéticos/administração & dosagem , Macrófagos/efeitos dos fármacos , Macrófagos/patologia , Síndrome Metabólica/patologia , Síndrome Metabólica/prevenção & controle , Camundongos , Camundongos Knockout , Obesidade/etiologia , Obesidade/prevenção & controle , Placa Aterosclerótica/patologia , Inibidor 1 de Ativador de Plasminogênio/fisiologia , Receptores de LDL/deficiência , Receptores de LDL/genética
16.
Nat Commun ; 11(1): 1996, 2020 04 24.
Artigo em Inglês | MEDLINE | ID: mdl-32332723

RESUMO

Small molecules that selectively kill senescent cells (SCs), termed senolytics, have the potential to prevent and treat various age-related diseases and extend healthspan. The use of Bcl-xl inhibitors as senolytics is largely limited by their on-target and dose-limiting platelet toxicity. Here, we report the use of proteolysis-targeting chimera (PROTAC) technology to reduce the platelet toxicity of navitoclax (also known as ABT263), a Bcl-2 and Bcl-xl dual inhibitor, by converting it into PZ15227 (PZ), a Bcl-xl PROTAC, which targets Bcl-xl to the cereblon (CRBN) E3 ligase for degradation. Compared to ABT263, PZ is less toxic to platelets, but equally or slightly more potent against SCs because CRBN is poorly expressed in platelets. PZ effectively clears SCs and rejuvenates tissue stem and progenitor cells in naturally aged mice without causing severe thrombocytopenia. With further improvement, Bcl-xl PROTACs have the potential to become safer and more potent senolytic agents than Bcl-xl inhibitors.


Assuntos
Envelhecimento/efeitos dos fármacos , Compostos de Anilina/farmacologia , Plaquetas/efeitos dos fármacos , Senescência Celular/efeitos dos fármacos , Sulfonamidas/farmacologia , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Compostos de Anilina/química , Animais , Linhagem Celular , Feminino , Humanos , Masculino , Camundongos , Camundongos Transgênicos , Modelos Animais , Cultura Primária de Células , Proteólise/efeitos dos fármacos , Sulfonamidas/química , Proteína bcl-X/antagonistas & inibidores , Proteína bcl-X/metabolismo
17.
Nat Commun ; 11(1): 1935, 2020 04 22.
Artigo em Inglês | MEDLINE | ID: mdl-32321921

RESUMO

Although cellular senescence acts primarily as a tumour suppression mechanism, the accumulation of senescent cells in vivo eventually exerts deleterious side effects through inflammatory/tumour-promoting factor secretion. Thus, the development of new drugs that cause the specific elimination of senescent cells, termed senolysis, is anticipated. Here, by an unbiased high-throughput screening of chemical compounds and a bio-functional analysis, we identify BET family protein degrader (BETd) as a promising senolytic drug. BETd provokes senolysis through two independent but integrated pathways; the attenuation of non-homologous end joining (NHEJ), and the up-regulation of autophagic gene expression. BETd treatment eliminates senescent hepatic stellate cells in obese mouse livers, accompanied by the reduction of liver cancer development. Furthermore, the elimination of chemotherapy-induced senescent cells by BETd increases the efficacy of chemotherapy against xenograft tumours in immunocompromised mice. These results reveal the vulnerability of senescent cells and open up possibilities for its control.


Assuntos
Antineoplásicos/administração & dosagem , Autofagia/efeitos dos fármacos , Senescência Celular/efeitos dos fármacos , Reparo do DNA por Junção de Extremidades/efeitos dos fármacos , Neoplasias/fisiopatologia , Animais , Proteínas de Ciclo Celular/antagonistas & inibidores , Proteínas de Ciclo Celular/genética , Proteínas de Ciclo Celular/metabolismo , Linhagem Celular Tumoral , Humanos , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Nus , Neoplasias/tratamento farmacológico , Neoplasias/genética , Neoplasias/metabolismo , Fatores de Transcrição/antagonistas & inibidores , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo
18.
Genes Dev ; 34(7-8): 489-494, 2020 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-32139422

RESUMO

Young mammals possess a limited regenerative capacity in some tissues, which is lost upon maturation. We investigated whether cellular senescence might play a role in such loss during liver regeneration. We found that following partial hepatectomy, the senescence-associated genes p21, p16Ink4a, and p19Arf become dynamically expressed in different cell types when regenerative capacity decreases, but without a full senescent response. However, we show that treatment with a senescence-inhibiting drug improves regeneration, by disrupting aberrantly prolonged p21 expression. This work suggests that senescence may initially develop from heterogeneous cellular responses, and that senotherapeutic drugs might be useful in promoting organ regeneration.


Assuntos
Compostos de Bifenilo/farmacologia , Inibidor de Quinase Dependente de Ciclina p21/genética , Regulação da Expressão Gênica/efeitos dos fármacos , Fígado/fisiologia , Nitrofenóis/farmacologia , Regeneração/efeitos dos fármacos , Sulfonamidas/farmacologia , Animais , Células Cultivadas , Senescência Celular/efeitos dos fármacos , Inibidor p16 de Quinase Dependente de Ciclina/genética , Feminino , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Modelos Animais , Piperazinas/farmacologia
19.
Psychiatry Res ; 286: 112865, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-32114208

RESUMO

Bipolar disorder (BD) may be associated with accelerated cellular aging. However, previous studies on telomere length (TL), an important biomarker of cellular aging, have yielded mixed results in BD. We aimed to evaluate the hypothesis that BD is associated with telomere shortening and whether this is counteracted by long-term lithium treatment. We also sought to determine whether long-term lithium treatment is associated with increased expression of telomerase reverse transcriptase (TERT), the catalytic subunit of telomerase. We determined TL and TERT expression in 100 BD I patients and 100 healthy controls. We also genotyped three single nucleotide polymorphisms associated with TL. TERT expression was significantly increased in BD I patients currently on lithium treatment. TERT expression was also significantly positively correlated with duration of lithium treatment in patients treated for 24 months or more. However, we did not find any significant effect of lithium treatment on TL. Neither did we find significant differences in TL between BD patients and controls. We suggest that long-term lithium treatment is associated with an increase in the expression of TERT. We hypothesize that an increase in TERT expression may contribute to lithium's mood stabilizing and neuroprotective properties by improving mitochondrial function and decreasing oxidative stress.


Assuntos
Envelhecimento/metabolismo , Antimaníacos/uso terapêutico , Transtorno Bipolar/tratamento farmacológico , Transtorno Bipolar/genética , Senescência Celular/genética , Compostos de Lítio/uso terapêutico , Lítio/uso terapêutico , Telomerase/metabolismo , Adulto , Envelhecimento/genética , Transtorno Bipolar/sangue , Senescência Celular/efeitos dos fármacos , Feminino , Humanos , Compostos de Lítio/farmacologia , Masculino , Pessoa de Meia-Idade , Mitocôndrias/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Polimorfismo de Nucleotídeo Único/genética , Reação em Cadeia da Polimerase em Tempo Real , Telomerase/efeitos dos fármacos , Telomerase/genética , Telômero/efeitos dos fármacos , Telômero/genética , Telômero/metabolismo , Homeostase do Telômero/genética , Encurtamento do Telômero/efeitos dos fármacos , Encurtamento do Telômero/genética
20.
Nat Commun ; 11(1): 1195, 2020 03 05.
Artigo em Inglês | MEDLINE | ID: mdl-32139672

RESUMO

Here, we report that the functionality of vascular progenitors (VP) generated from normal and disease-primed conventional human induced pluripotent stem cells (hiPSC) can be significantly improved by reversion to a tankyrase inhibitor-regulated human naïve epiblast-like pluripotent state. Naïve diabetic vascular progenitors (N-DVP) differentiated from patient-specific naïve diabetic hiPSC (N-DhiPSC) possessed higher vascular functionality, maintained greater genomic stability, harbored decreased lineage-primed gene expression, and were more efficient in migrating to and re-vascularizing the deep neural layers of the ischemic retina than isogenic diabetic vascular progenitors (DVP). These findings suggest that reprogramming to a stable naïve human pluripotent stem cell state may effectively erase dysfunctional epigenetic donor cell memory or disease-associated aberrations in patient-specific hiPSC. More broadly, tankyrase inhibitor-regulated naïve hiPSC (N-hiPSC) represent a class of human stem cells with high epigenetic plasticity, improved multi-lineage functionality, and potentially high impact for regenerative medicine.


Assuntos
Vasos Sanguíneos/patologia , Diabetes Mellitus/patologia , Células-Tronco Pluripotentes Induzidas/patologia , Isquemia/terapia , Retina/patologia , Células-Tronco/patologia , Tanquirases/antagonistas & inibidores , Adulto , Animais , Diferenciação Celular/efeitos dos fármacos , Linhagem Celular , Linhagem da Célula/efeitos dos fármacos , Movimento Celular/efeitos dos fármacos , Senescência Celular/efeitos dos fármacos , Dano ao DNA , Inibidores Enzimáticos/farmacologia , Epigênese Genética/efeitos dos fármacos , Fibroblastos/efeitos dos fármacos , Fibroblastos/patologia , Código das Histonas , Humanos , Células-Tronco Pluripotentes Induzidas/efeitos dos fármacos , Isquemia/patologia , Camundongos , Organoides/efeitos dos fármacos , Organoides/patologia , Inibidores de Poli(ADP-Ribose) Polimerases/farmacologia , Regiões Promotoras Genéticas/genética , Células-Tronco/efeitos dos fármacos , Células-Tronco/ultraestrutura , Tanquirases/metabolismo , Teratoma/patologia , Transcrição Genética/efeitos dos fármacos
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA