RESUMEN
Medical assistance in dying (MAiD) is an evolving practice in Canada, with requests and outcomes increasing each year, and yet controversy is present-with a vast spectrum of ethical positions on its permissibility. International research indicates that family members who experience disagreement over their loved one's decision to have MAiD are less likely to be actively involved in supporting patients through the practical aspects of the dying process. Family members with passive involvement in the assisted dying process may also experience more significant moral dilemmas and challenging grief experiences than those who supported the decision. Given these previous findings, we designed this study to explore the factors complicating family members' experiences with MAiD in Canada and to understand how these complicating factors impact family members' bereavement in the months and years following MAiD. We conducted narrative interviews with 12 MAiD-bereaved family members who experienced disagreements, family conflicts, or differences in understanding about MAiD. Documenting and analyzing participants' experiences through storytelling allowed us to appreciate the complexity of family members' experiences and understand their values. The analysis generated five factors that can complicate the MAiD process and bereavement for family members: family discordance, internal conflict, legislative and eligibility concerns, logistical challenges, and managing disclosure and negative reactions. To our knowledge, this is the first Canadian study that explores how family discordance can impact bereavement following MAiD. Future bereavement services and resources should consider how these complicating factors may impact bereavement and ensure that Canadians with diverse MAiD experiences can access appropriate support.
Asunto(s)
Aflicción , Suicidio Asistido , Humanos , Canadá , Pesar , Asistencia MédicaRESUMEN
Stroke is a leading cause of disability and death, and people with type 2 diabetes (T2D) have a greater risk of stroke and death or disability from stroke. The underlying pathophysiology associating stroke and T2D is complicated by the association of risk factors for stroke frequently seen in people with T2D. Treatments to reduce the excess risk of new-onset stroke or to improve outcomes in people with T2D following stroke would be of major clinical interest. In practice, the focus of care in people with T2D remains treating risk factors for stroke, such as lifestyle and pharmacological interventions for hypertension, dyslipidemia, obesity, and glycemic control. More recently, cardiovascular outcome trials primarily designed to assess the cardiovascular safety of GLP-1RAs (glucagon-like peptide-1 receptor analogues) have consistently observed a reduced stroke risk in people with T2D. This is supported by several meta-analyses of cardiovascular outcome trials observing clinically important risk reductions in stroke. Moreover, phase II trials have described reductions in poststroke hyperglycemia in people with acute ischemic stroke suggestive of improved outcomes following admission to hospital with acute stroke. In this review, we discuss the increased risk of stroke in people with T2D and outline the key associated mechanisms responsible. We discuss the evidence from cardiovascular outcome trials exploring GLP-1RA use and highlight areas of potential interest for future work in this rapidly developing area of clinical research.
Asunto(s)
Enfermedades Cardiovasculares , Diabetes Mellitus Tipo 2 , Accidente Cerebrovascular Isquémico , Humanos , Diabetes Mellitus Tipo 2/complicaciones , Péptido 1 Similar al Glucagón/uso terapéutico , Hipoglucemiantes/efectos adversos , Accidente Cerebrovascular Isquémico/tratamiento farmacológico , Factores de Riesgo , Enfermedades Cardiovasculares/prevención & controlRESUMEN
Engagement in recreation can positively impact the physical and mental health of those experiencing mental health challenges; however, the impact of engaging in other aspects of such recreation, such as volunteering, remain largely unexplored in this population. Volunteering is known to have a wealth of health and wellbeing benefits among the general population; therefore, the impact of recreational-based volunteering for those with mental health conditions deserves to be explored. The current study sought to examine the health, social and wellbeing impacts of parkrun engagement among runners and volunteers living with a mental health condition. Participants with a mental health condition (N = 1661, M(SD)age = 43.4 (12.8) years, 66% female) completed self-reported questionnaires. A MANOVA was conducted to examine the differences in health and wellbeing impacts between those who run/walk vs. those who run/walk and volunteer, while chi-square analyses examined variables of perceived social inclusion. Findings suggest that there was a statistically significant multivariate effect of participation type on perceived parkrun impact (F (10, 1470) = 7.13; p < 0.001; Wilk's Λ = 0.954, partial η2 = 0.046). It was also found that for those who run/walk and volunteer, compared to those who only run/walk, parkrun made them more feel part of a community (56% v 29% respectively, X2(1) = 116.70, p < 0.001) and facilitated them meeting new people (60% v 24% respectively, X2 (1) = 206.67, p < 0.001). These results suggest that the health, wellbeing, and social inclusion benefits of parkrun participation are different for those who run and volunteer, compared to those who only run. These findings may have public health implications and clinical implications for mental health treatment, as they convey that it is not simply the physical engagement in recreation that may play a role in one's recovery, but also the volunteer aspect.
Asunto(s)
Trastornos Mentales , Salud Mental , Humanos , Femenino , Adulto , Masculino , Inclusión Social , Caminata , Voluntarios/psicologíaRESUMEN
Reliable data on the effects of chronic prenatal exposure to low dose (LD) of ionizing radiation in humans are missing. There are concerns about adverse long-term effects that may persist throughout postnatal life of the offspring. Due to their slow cell cycle kinetics and life-long residence time in the organism, mesenchymal stem cells (MSCs) are more susceptible to low level genotoxic stress caused by extrinsic multiple LD events. The aim of this study was to investigate the effect of chronic, prenatal LD gamma irradiation to the biology of MSCs later in life. C3H mice were exposed in utero to chronic prenatal irradiation of 10 mGy/day over a period of 3 weeks. Two years later, MSCs were isolated from the bone marrow and analyzed in vitro for their radiosensitivity, for cellular senescence and for DNA double-strand break recognition after a second acute gamma-irradiation. In addition to these cellular assays, changes in protein expression were measured using HPLC-MS/MS and dysregulated molecular signaling pathways identified using bioinformatics. We observed radiation-induced proteomic changes in MSCs from the offspring of in utero irradiated mice (leading to ~ 9.4% of all detected proteins being either up- or downregulated) as compared to non-irradiated controls. The proteomic changes map to regulation pathways involved in the extracellular matrix, the response to oxidative stress, and the Wnt signaling pathway. In addition, chronic prenatal LD irradiation lead to an increased rate of in vitro radiation-induced senescence later in life and to an increased number of residual DNA double-strand breaks after 4 Gy irradiation, indicating a remarkable interaction of in vivo radiation in combination with a second acute dose of in vitro radiation. This study provides the first insight into a molecular mechanism of persistent MSC damage response by ionizing radiation exposure during prenatal time and will help to predict therapeutic safety and efficacy with respect to a clinical application of stem cells.
Asunto(s)
Rayos gamma/efectos adversos , Células Madre Mesenquimatosas/efectos de la radiación , Efectos Tardíos de la Exposición Prenatal/metabolismo , Proteoma/efectos de la radiación , Animales , Bioensayo , Células Cultivadas , Senescencia Celular/efectos de la radiación , Inhibidor p16 de la Quinasa Dependiente de Ciclina/metabolismo , Reparación del ADN , Desarrollo Embrionario , Femenino , Masculino , Intercambio Materno-Fetal , Células Madre Mesenquimatosas/metabolismo , Ratones Mutantes , Embarazo , Vía de Señalización WntRESUMEN
The impact of low-dose ionizing radiation (IR) on the human brain has recently attracted attention due to the increased use of IR for diagnostic purposes. The aim of this study was to investigate low-dose radiation response in the hippocampus. Female B6C3F1 mice were exposed to total body irradiation with 0 (control), 0.063, 0.125, or 0.5 Gy. Quantitative label-free proteomic analysis of the hippocampus was performed after 24 months. CREB signaling and CREB-associated pathways were affected at all doses. The lower doses (0.063 and 0.125 Gy) induced the CREB pathway, whereas the exposure to 0.5 Gy deactivated CREB. Similarly, the lowest dose (0.063 Gy) was anti-inflammatory, reducing the number of activated microglia. In contrast, induction of activated microglia and reactive astroglia was found at 0.5 Gy, suggesting increased inflammation and astrogliosis, respectively. The apoptotic markers BAX and cleaved CASP-3 and oxidative stress markers were increased only at the highest dose. Since the activated CREB pathway plays a central role in learning and memory, these data suggest neuroprotection at the lowest dose (0.063 Gy) but neurodegeneration at 0.5 Gy. The response to 0.5 Gy resembles alterations found in healthy aging and thus may represent radiation-induced accelerated aging of the brain.
Asunto(s)
Proteína de Unión a Elemento de Respuesta al AMP Cíclico/metabolismo , Hipocampo/metabolismo , Hipocampo/efectos de la radiación , Animales , Apoptosis/efectos de la radiación , Relación Dosis-Respuesta en la Radiación , Femenino , Inflamación/etiología , Ratones Endogámicos , Plasticidad Neuronal/efectos de la radiación , Estrés Oxidativo/efectos de la radiación , Carbonilación Proteica/efectos de la radiación , Radiación Ionizante , Transducción de Señal/efectos de la radiación , Factores de Tiempo , Irradiación Corporal TotalRESUMEN
Normal tissue toxicity is a dose-limiting factor in radiation therapy. Therefore, a detailed understanding of the normal tissue response to radiation is necessary to predict the risk of normal tissue toxicity and to development strategies for tissue protection. One component of normal tissue that is continuously exposed during therapeutic irradiation is the circulating population of peripheral blood mononuclear cells (PBMC). PBMCs are highly sensitive to ionizing radiation (IR); however, little is known about how IR affects the PBMC response on a systemic level. It was the aim of this study to investigate whether IR was capable to induce changes in the composition and function of extracellular vesicles (EVs) secreted from PBMCs after radiation exposure to different doses. Therefore, whole blood samples from healthy donors were exposed to X-ray radiation in the clinically relevant doses of 0, 0.1, 2 or 6 Gy and PBMC-secreted EVs were isolated 72 h later. Proteome and miRNome analysis of EVs as well as functional studies were performed. Secreted EVs showed a dose-dependent increase in the number of significantly deregulated proteins and microRNAs. For both, proteome and microRNA data, principal component analysis showed a dose-dependent separation of control and exposed groups. Integrated pathway analysis of the radiation-regulated EV proteins and microRNAs consistently predicted an association of deregulated molecules with apoptosis, cell death and survival. Functional studies identified endothelial cells as an efficient EV recipient system, in which irradiation of recipient cells further increased the uptake. Furthermore an apoptosis suppressive effect of EVs from irradiated PBMCs in endothelial recipient cells was detected. In summary, this study demonstrates that IR modifies the communication between PBMCs and endothelial cells. EVs from irradiated PBMC donors were identified as transmitters of protective signals to irradiated endothelial cells. Thus, these data may lead to the discovery of biomarker candidates for radiation dosimetry and even more importantly, they suggest EVs as a novel systemic communication pathway between irradiated normal, non-cancer tissues.
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Vesículas Extracelulares/metabolismo , Leucocitos Mononucleares/metabolismo , Leucocitos Mononucleares/efectos de la radiación , Exposición a la Radiación , Vesículas Secretoras/metabolismo , Apoptosis/efectos de la radiación , Células Endoteliales/metabolismo , Células Endoteliales/efectos de la radiación , Humanos , MicroARNs/genética , Proteoma/metabolismo , Radiación Ionizante , Radioterapia/métodosRESUMEN
Epidemiological studies on workers employed at the Mayak plutonium enrichment plant have demonstrated an association between external gamma ray exposure and an elevated risk of ischemic heart disease (IHD). In a previous study using fresh-frozen post mortem samples of the cardiac left ventricle of Mayak workers and non-irradiated controls, we observed radiation-induced alterations in the heart proteome, mainly downregulation of mitochondrial and structural proteins. As the control group available at that time was younger than the irradiated group, we could not exclude age as a confounding factor. To address this issue, we have now expanded our study to investigate additional samples using archival formalin-fixed paraffin-embedded (FFPE) tissue. Importantly, the control group studied here is older than the occupationally exposed (>500 mGy) group. Label-free quantitative proteomics analysis showed that proteins involved in the lipid metabolism, sirtuin signaling, mitochondrial function, cytoskeletal organization, and antioxidant defense were the most affected. A histopathological analysis elucidated large foci of fibrotic tissue, myocardial lipomatosis and lymphocytic infiltrations in the irradiated samples. These data highlight the suitability of FFPE material for proteomics analysis. The study confirms the previous results emphasizing the role of adverse metabolic changes in the radiation-associated IHD. Most importantly, it excludes age at the time of death as a confounding factor.
Asunto(s)
Isquemia Miocárdica/metabolismo , Plutonio/efectos adversos , Proteoma/metabolismo , Proteoma/efectos de la radiación , Cromatografía Liquida , Citoesqueleto/metabolismo , Citoesqueleto/efectos de la radiación , Formaldehído/química , Humanos , Metabolismo de los Lípidos/efectos de la radiación , Masculino , Mitocondrias/metabolismo , Mitocondrias/efectos de la radiación , Isquemia Miocárdica/epidemiología , Isquemia Miocárdica/etiología , Isquemia Miocárdica/patología , Exposición Profesional , Adhesión en Parafina , Análisis de Componente Principal , Mapas de Interacción de Proteínas , Proteómica/métodos , Radiación Ionizante , Transducción de Señal/efectos de la radiación , Sirtuinas/metabolismo , Espectrometría de Masas en Tándem , Fijación del TejidoRESUMEN
Radiation exposure can evoke cellular stress responses. Emerging recognition that long non-coding RNAs (lncRNAs) act as regulators of gene expression has broadened the spectra of molecules controlling the genomic landscape upon alterations in environmental conditions. Knowledge of the mechanisms responding to low dose irradiation (LDR) exposure is very limited yet most likely involve subtle ancillary molecular pathways other than those protecting the cell from direct cellular damage. The discovery that transcription of the lncRNA PARTICLE (promoter of MAT2A- antisense radiation-induced circulating lncRNA; PARTICL) becomes dramatically instigated within a day after LDR exposure introduced a new gene regulator onto the biological landscape. PARTICLE affords an RNA binding platform for genomic silencers such as DNA methyltransferase 1 and histone tri-methyltransferases to reign in the expression of tumor suppressors such as its neighboring MAT2A in cis as well as WWOX in trans. In silico evidence offers scope to speculate that PARTICLE exploits the abundance of Hoogsten bonds that exist throughout mammalian genomes for triplex formation, presumably a vital feature within this RNA silencer. PARTICLE may provide a buffering riboswitch platform for S-adenosylmethionine. The correlation of PARTICLE triplex formation sites within tumor suppressor genes and their abundance throughout the genome at cancer-related hotspots offers an insight into potential avenues worth exploring in future therapeutic endeavors.
Asunto(s)
Neoplasias/genética , Interferencia de ARN/efectos de la radiación , ARN Largo no Codificante/genética , Exposición a la Radiación/efectos adversos , ADN (Citosina-5-)-Metiltransferasa 1/genética , Regulación Neoplásica de la Expresión Génica/efectos de la radiación , Genoma Humano/efectos de la radiación , Genómica , Histona Metiltransferasas/genética , Humanos , Metionina Adenosiltransferasa/genética , Neoplasias/radioterapia , Regiones Promotoras Genéticas/genética , Dosis de Radiación , Proteínas Supresoras de Tumor/genética , Oxidorreductasa que Contiene Dominios WW/genéticaRESUMEN
Extracellular vesicles (EVs) are cell-derived membrane-bound organelles that have generated interest as they reflect the physiological condition of their source. Mass spectrometric (MS) analyses of protein cargo of EVs may lead to the discovery of biomarkers for diseases. However, for a comprehensive MS-based proteomics analysis, an optimal lysis of the EVs is required. Six methods for the protein extraction from EVs secreted by the head and neck cell line BHY were compared. Commercial radioimmunoprecipitation assay (RIPA) buffer outperformed the other buffers investigated in this study (Tris-SDS, Tris-Triton, GuHCl, urea-thiourea, and commercial Cell-lysis buffer). Following lysis with RIPA buffer, 310 proteins and 1469 peptides were identified using LTQ OrbitrapXL mass spectrometer. Among these, 86% of proteins and 72% of peptides were identified in all three replicates. In the case of other buffers, Tris-Triton identified on average 277 proteins, Cell-lysis buffer 257 proteins, and Tris-SDS, GuHCl and urea-thiourea each 267 proteins. In total, 399 proteins including 74 of the top EV markers (Exocarta) were identified, the most of the latter (73) using RIPA. The proteins exclusively identified using RIPA represented all Gene Ontology cell compartments. This study suggests that RIPA is an optimal lysis buffer for EVs in combination with MS.
Asunto(s)
Fraccionamiento Químico/métodos , Vesículas Extracelulares/metabolismo , Espectrometría de Masas , Proteoma/aislamiento & purificación , Proteoma/metabolismo , Proteómica , Tampones (Química) , Línea Celular Tumoral , HumanosRESUMEN
Pancreatic cancer has a poor prognosis. New treatment options are urgently required to improve patient outcomes. One promising new class of anticancer drugs are synthetic histone deacetylase inhibitors (HDACi) which modulate chromatin structure and gene expression by blocking histone deacetylation. In this study, we aimed at comparing the in vitro capacities of the HDACi SAHA and CUDC-101 to increase radiosensitivity of human pancreatic tumor cell lines. Therefore, three pancreatic cancer cell lines (Su.86.86, MIA Paca-2, T3M-4) were treated with SAHA (1.5-5 µM) or CUDC-101 (0.25-3 µM) and after 24 h irradiated. Cell proliferation, clonogenic survival and apoptosis was determined. Additionally, cell lysates were investigated for the expression of apoptosis-related proteins. CUDC-101 and SAHA increased the radiation sensitivity of pancreatic tumor cell lines in a dose-dependent manner. This was evidenced by cell proliferation and clonogenic survival. Furthermore, enhanced radiation sensitivity after CUDC-101 or SAHA treatment was confirmed for Su.86.86 and T3M-4 cells in a 3-D microtissue approach. Increased amounts of subG1 cells and diminished full length PARP-1 suggest increased radiation-induced apoptosis after SAHA or CUDC-101 treatment. The comparison of both inhibitors in these assays manifested CUDC-101 as more potent radiosensitizer than SAHA. In line, western blot quantification of the apoptosis-inhibitory proteins XIAP and survivin showed a stronger down-regulation in response to CUDC-101 treatment than after SAHA application. These proteins may contribute to the synergy between HDAC inhibition and radiation response. In conclusion, these preclinical results suggest that treatment with the HDAC inhibitors CUDC-101 or SAHA can enhance radiation-induced cytotoxicity in human pancreatic cells. However, comparison of both inhibitors identified the multi target inhibitor CUDC-101 as more potent radiosensitizer than the HDAC inhibitor SAHA.
Asunto(s)
Inhibidores de Histona Desacetilasas/farmacología , Ácidos Hidroxámicos/farmacología , Neoplasias Pancreáticas/tratamiento farmacológico , Quinazolinas/farmacología , Fármacos Sensibilizantes a Radiaciones/farmacología , Apoptosis/efectos de los fármacos , Apoptosis/efectos de la radiación , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Proliferación Celular/efectos de la radiación , Humanos , Neoplasias Pancreáticas/patología , Neoplasias Pancreáticas/radioterapiaRESUMEN
Chronic exposure to low-dose ionizing radiation is associated with an increased risk of cardiovascular disease. Alteration in energy metabolism has been suggested to contribute to radiation-induced heart pathology, mitochondrial dysfunction being a hallmark of this disease. The goal of this study was to investigate the regulatory role of acetylation in heart mitochondria in the long-term response to chronic radiation. ApoE-deficient C57Bl/6J mice were exposed to low-dose-rate (20 mGy/day) gamma radiation for 300 days, resulting in a cumulative total body dose of 6.0 Gy. Heart mitochondria were isolated and analyzed using quantitative proteomics. Radiation-induced proteome and acetylome alterations were further validated using immunoblotting, enzyme activity assays, and ELISA. In total, 71 proteins showed peptides with a changed acetylation status following irradiation. The great majority (94%) of the hyperacetylated proteins were involved in the TCA cycle, fatty acid oxidation, oxidative stress response and sirtuin pathway. The elevated acetylation patterns coincided with reduced activity of mitochondrial sirtuins, increased the level of Acetyl-CoA, and were accompanied by inactivation of major cardiac metabolic regulators PGC-1 alpha and PPAR alpha. These observations suggest that the changes in mitochondrial acetylation after irradiation is associated with impairment of heart metabolism. We propose a novel mechanism involved in the development of late cardiac damage following chronic irradiation.
Asunto(s)
Proteínas Mitocondriales/metabolismo , Miocitos Cardíacos/metabolismo , Procesamiento Proteico-Postraduccional , Sirtuinas/genética , Irradiación Corporal Total/efectos adversos , Acetilación , Animales , Apolipoproteínas E/deficiencia , Apolipoproteínas E/genética , Regulación hacia Abajo , Femenino , Ratones , Ratones Endogámicos C57BL , Mitocondrias Cardíacas/metabolismo , Mitocondrias Cardíacas/efectos de la radiación , Proteínas Mitocondriales/efectos de la radiación , Miocitos Cardíacos/efectos de la radiación , PPAR alfa/metabolismo , Coactivador 1-alfa del Receptor Activado por Proliferadores de Peroxisomas gamma/metabolismoRESUMEN
In children, ketamine sedation is often used during radiological procedures. Combined exposure of ketamine and radiation at doses that alone did not affect learning and memory induced permanent cognitive impairment in mice. The aim of this study was to elucidate the mechanism behind this adverse outcome. Neonatal male NMRI mice were administered ketamine (7.5 mg kg-1) and irradiated (whole-body, 100 mGy or 200 mGy, 137Cs) one hour after ketamine exposure on postnatal day 10. The control mice were injected with saline and sham-irradiated. The hippocampi were analyzed using label-free proteomics, immunoblotting, and Golgi staining of CA1 neurons six months after treatment. Mice co-exposed to ketamine and low-dose radiation showed alterations in hippocampal proteins related to neuronal shaping and synaptic plasticity. The expression of brain-derived neurotrophic factor, activity-regulated cytoskeleton-associated protein, and postsynaptic density protein 95 were significantly altered only after the combined treatment (100 mGy or 200 mGy combined with ketamine, respectively). Increased numbers of basal dendrites and branching were observed only after the co-exposure, thereby constituting a possible reason for the displayed alterations in behavior. These data suggest that the risk of radiation-induced neurotoxic effects in the pediatric population may be underestimated if based only on the radiation dose.
Asunto(s)
Región CA1 Hipocampal/patología , Ketamina/toxicidad , Neuronas/patología , Neuronas/efectos de la radiación , Radiación Ionizante , Animales , Animales Recién Nacidos , Forma de la Célula/efectos de los fármacos , Forma de la Célula/efectos de la radiación , Citoesqueleto/efectos de los fármacos , Citoesqueleto/metabolismo , Citoesqueleto/efectos de la radiación , Masculino , Ratones , Plasticidad Neuronal/efectos de los fármacos , Plasticidad Neuronal/efectos de la radiación , Neuronas/efectos de los fármacos , Proteoma/metabolismoRESUMEN
High-dose ionizing radiation is known to induce adverse effects such as inflammation and fibrosis in the heart. Transcriptional regulators PPARα and TGFß are known to be involved in this radiation response. PPARα, an anti-inflammatory transcription factor controlling cardiac energy metabolism, is inactivated by irradiation. The pro-inflammatory and pro-fibrotic TGFß is activated by irradiation via SMAD-dependent and SMAD-independent pathways. The goal of this study was to investigate how altering the level of PPARα influences the radiation response of these signaling pathways. For this purpose, we used genetically modified C57Bl/6 mice with wild type (+/+), heterozygous (+/-) or homozygous (-/-) PPARα genotype. Mice were locally irradiated to the heart using doses of 8 or 16 Gy; the controls were sham-irradiated. The heart tissue was investigated using label-free proteomics 20 weeks after the irradiation and the predicted pathways were validated using immunoblotting, ELISA, and immunohistochemistry. The heterozygous PPARα mice showed most radiation-induced changes in the cardiac proteome, whereas the homozygous PPARα mice showed the least changes. Irradiation induced SMAD-dependent TGFß signaling independently of the PPARα status, but the presence of PPARα was necessary for the activation of the SMAD-independent pathway. These data indicate a central role of PPARα in cardiac response to ionizing radiation.
Asunto(s)
Corazón/efectos de la radiación , Miocardio/metabolismo , PPAR alfa/fisiología , Factor de Crecimiento Transformador beta/metabolismo , Animales , Genotipo , Heterocigoto , Ratones , Ratones Endogámicos C57BL , Miocardio/química , PPAR alfa/genética , Proteómica , Transducción de Señal , Proteínas Smad/metabolismoRESUMEN
Because of the increasing application of ionizing radiation in medicine, quantitative data on effects of low-dose radiation are needed to optimize radiation protection, particularly with respect to cataract development. Using mice as mammalian animal model, we applied a single dose of 0, 0.063, 0.125 and 0.5 Gy at 10 weeks of age, determined lens opacities for up to 2 years and compared it with overall survival, cytogenetic alterations and cancer development. The highest dose was significantly associated with increased body weight and reduced survival rate. Chromosomal aberrations in bone marrow cells showed a dose-dependent increase 12 months after irradiation. Pathological screening indicated a dose-dependent risk for several types of tumors. Scheimpflug imaging of the lens revealed a significant dose-dependent effect of 1% of lens opacity. Comparison of different biological end points demonstrated long-term effects of low-dose irradiation for several biological end points.
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Catarata/genética , Traumatismos Experimentales por Radiación/genética , Animales , Catarata/etiología , Aberraciones Cromosómicas/efectos de la radiación , Relación Dosis-Respuesta en la Radiación , Femenino , Estimación de Kaplan-Meier , Masculino , Ratones , Traumatismos Experimentales por Radiación/etiología , Protección Radiológica , Medición de Riesgo , Telómero/efectos de la radiación , Factores de TiempoRESUMEN
Epidemiological data from patients undergoing radiotherapy for thoracic tumors clearly show the damaging effect of ionizing radiation on cardiovascular system. The long-term impairment of heart function and structure after local high-dose irradiation is associated with systemic inflammatory response, contraction impairment, microvascular damage, and cardiac fibrosis. The goal of the present study was to investigate molecular mechanisms involved in this process. C57BL/6J mice received a single X-ray dose of 16 Gy given locally to the heart at the age of 8 weeks. Radiation-induced changes in the heart transcriptome and proteome were investigated 40 weeks after the exposure. The omics data were analyzed by bioinformatics tools and validated by immunoblotting. Integrated network analysis of transcriptomics and proteomics data elucidated the signaling pathways that were similarly affected at gene and protein level. Analysis showed induction of transforming growth factor (TGF) beta signaling but inactivation of peroxisome proliferator-activated receptor (PPAR) alpha signaling in irradiated heart. The putative mediator role of mitogen-activated protein kinase cascade linking PPAR alpha and TGF beta signaling was supported by data from immunoblotting and ELISA. This study indicates that both signaling pathways are involved in radiation-induced heart fibrosis, metabolic disordering, and impaired contractility, a pathophysiological condition that is often observed in patients that received high radiation doses in thorax.
Asunto(s)
Fibrosis Endomiocárdica/genética , Corazón/efectos de la radiación , PPAR alfa/genética , Proteoma/genética , Transcriptoma , Factor de Crecimiento Transformador beta/genética , Animales , Biología Computacional , Fibrosis Endomiocárdica/etiología , Fibrosis Endomiocárdica/metabolismo , Fibrosis Endomiocárdica/patología , Rayos gamma/efectos adversos , Perfilación de la Expresión Génica , Regulación de la Expresión Génica , Corazón/fisiopatología , Masculino , Ratones , Ratones Endogámicos C57BL , Proteínas Quinasas Activadas por Mitógenos/genética , Proteínas Quinasas Activadas por Mitógenos/metabolismo , PPAR alfa/metabolismo , Proteoma/metabolismo , Transducción de Señal , Factor de Crecimiento Transformador beta/metabolismoRESUMEN
Radiation is the most common treatment of cancer. Minimizing the normal tissue injury, especially the damage to vascular endothelium, remains a challenge. This study aimed to analyze direct and indirect radiation effects on the endothelium by investigating mechanisms of signal transfer from irradiated to nonirradiated endothelial cells by means of secreted proteins. Human coronary artery endothelial cells (HCECest2) undergo radiation-induced senescence in vitro 14 days after exposure to 10 Gy X-rays. Proteomics analysis was performed on HCECest2 14 days after irradiation with X-ray doses of 0 Gy (control) or 10 Gy using label-free technology. Additionally, the proteomes of control and radiation-induced secretomes, and those of nonirradiated HCECest2 exposed for 24 h to secreted proteins of either condition were measured. Key changes identified by proteomics and bioinformatics were validated by immunoblotting, ELISA, bead-based multiplex assays, and targeted transcriptomics. The irradiated cells, their secretome, and the nonirradiated recipient cells showed similar inflammatory response, characterized by induction of interferon type I-related proteins and activation of the STAT3 pathway. These data indicate that irradiated endothelial cells may adversely affect nonirradiated surrounding cells via senescence-associated secretory phenotype. This study adds to our knowledge of the pathological background of radiation-induced cardiovascular disease.
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Inflamación/genética , Neoplasias/radioterapia , Proteoma/genética , Radioterapia/efectos adversos , Factor de Transcripción STAT3/genética , Senescencia Celular/genética , Senescencia Celular/efectos de la radiación , Vasos Coronarios/metabolismo , Vasos Coronarios/patología , Vasos Coronarios/efectos de la radiación , Relación Dosis-Respuesta en la Radiación , Células Endoteliales/metabolismo , Células Endoteliales/patología , Células Endoteliales/efectos de la radiación , Femenino , Regulación Neoplásica de la Expresión Génica/efectos de la radiación , Humanos , Inflamación/etiología , Inflamación/patología , Masculino , Neoplasias/complicaciones , Neoplasias/genética , Proteoma/efectos de la radiación , Proteómica/métodos , Transducción de Señal/efectos de la radiaciónRESUMEN
Recent epidemiological data indicate that radiation doses as low as those used in computer tomography may result in long-term neurocognitive side effects. The aim of this study was to elucidate long-term molecular alterations related to memory formation in the brain after low and moderate doses of γ radiation. Female C57BL/6J mice were irradiated on postnatal day 10 with total body doses of 0.1, 0.5, or 2.0 Gy; the control group was sham-irradiated. The proteome analysis of hippocampus, cortex, and synaptosomes isolated from these brain regions indicated changes in ephrin-related, RhoGDI, and axonal guidance signaling. Immunoblotting and miRNA-quantification demonstrated an imbalance in the synapse morphology-related Rac1-Cofilin pathway and long-term potentiation-related cAMP response element-binding protein (CREB) signaling. Proteome profiling also showed impaired oxidative phosphorylation, especially in the synaptic mitochondria. This was accompanied by an early (4 weeks) reduction of mitochondrial respiration capacity in the hippocampus. Although the respiratory capacity was restored by 24 weeks, the number of deregulated mitochondrial complex proteins was increased at this time. All observed changes were significant at doses of 0.5 and 2.0 Gy but not at 0.1 Gy. This study strongly suggests that ionizing radiation at the neonatal state triggers persistent proteomic alterations associated with synaptic impairment.
Asunto(s)
Corteza Cerebral/efectos de la radiación , Rayos gamma/efectos adversos , Hipocampo/efectos de la radiación , Potenciación a Largo Plazo/efectos de la radiación , Proteoma/genética , Transmisión Sináptica/efectos de la radiación , Factores Despolimerizantes de la Actina/genética , Factores Despolimerizantes de la Actina/metabolismo , Animales , Animales Recién Nacidos , Axones/metabolismo , Axones/efectos de la radiación , Axones/ultraestructura , Corteza Cerebral/metabolismo , Corteza Cerebral/fisiopatología , Proteína de Unión a Elemento de Respuesta al AMP Cíclico/genética , Proteína de Unión a Elemento de Respuesta al AMP Cíclico/metabolismo , Proteínas del Complejo de Cadena de Transporte de Electrón/genética , Proteínas del Complejo de Cadena de Transporte de Electrón/metabolismo , Efrinas/genética , Efrinas/metabolismo , Femenino , Hipocampo/metabolismo , Hipocampo/fisiopatología , Memoria/efectos de los fármacos , Ratones , Ratones Endogámicos C57BL , MicroARNs/genética , MicroARNs/metabolismo , Mitocondrias/metabolismo , Mitocondrias/efectos de la radiación , Neuropéptidos/genética , Neuropéptidos/metabolismo , Fosforilación Oxidativa/efectos de la radiación , Proteoma/metabolismo , Sinaptosomas/metabolismo , Sinaptosomas/efectos de la radiación , Irradiación Corporal Total , Proteína de Unión al GTP rac1/genética , Proteína de Unión al GTP rac1/metabolismo , Inhibidores de la Disociación del Nucleótido Guanina rho-Específico/genética , Inhibidores de la Disociación del Nucleótido Guanina rho-Específico/metabolismoRESUMEN
The increased use of radiation-based medical imaging methods such as computer tomography is a matter of concern due to potential radiation-induced adverse effects. Efficient protection against such detrimental effects has not been possible due to inadequate understanding of radiation-induced alterations in signaling pathways. The aim of this study was to elucidate the molecular mechanisms behind learning and memory deficits after acute low and moderate doses of ionizing radiation. Female C57BL/6J mice were irradiated on postnatal day 10 (PND10) with gamma doses of 0.1 or 0.5 Gy. This was followed by evaluation of the cellular proteome, pathway-focused transcriptome, and neurological development/disease-focused miRNAome of hippocampus and cortex 24 h postirradiation. Our analysis showed that signaling pathways related to mitochondrial and synaptic functions were changed by acute irradiation. This may lead to reduced mitochondrial function paralleled by enhanced number of dendritic spines and neurite outgrowth due to elevated long-term potentiation, triggered by increased phosphorylated CREB. This was predominately observed in the cortex at 0.1 and 0.5 Gy and in the hippocampus only at 0.5 Gy. Moreover, a radiation-induced increase in the expression of several neural miRNAs associated with synaptic plasticity was found. The early changes in signaling pathways related to memory formation may be associated with the acute neurocognitive side effects in patients after brain radiotherapy but might also contribute to late radiation-induced cognitive injury.
Asunto(s)
Corteza Cerebral/efectos de la radiación , Hipocampo/efectos de la radiación , Potenciación a Largo Plazo/efectos de la radiación , Memoria/efectos de la radiación , Mitocondrias/efectos de la radiación , Sinapsis/efectos de la radiación , Animales , Proteína de Unión a CREB/genética , Proteína de Unión a CREB/metabolismo , Corteza Cerebral/fisiología , Relación Dosis-Respuesta en la Radiación , Femenino , Rayos gamma , Expresión Génica , Hipocampo/fisiología , Humanos , Ratones , Ratones Endogámicos C57BL , Mitocondrias/metabolismo , Fosforilación , Proteoma/metabolismo , Transducción de Señal/efectos de la radiación , Sinapsis/fisiología , TranscriptomaRESUMEN
Epidemiological data from radiotherapy patients show the damaging effect of ionizing radiation on heart and vasculature. The endothelium is the main target of radiation damage and contributes essentially to the development of cardiac injury. However, the molecular mechanisms behind the radiation-induced endothelial dysfunction are not fully understood. In the present study, 10-week-old C57Bl/6 mice received local X-ray heart doses of 8 or 16 Gy and were sacrificed after 16 weeks; the controls were sham-irradiated. The cardiac microvascular endothelial cells were isolated from the heart tissue using streptavidin-CD31-coated microbeads. The cells were lysed and proteins were labeled with duplex isotope-coded protein label methodology for quantification. All samples were analyzed by LC-ESI-MS/MS and Proteome Discoverer software. The proteomics data were further studied by bioinformatics tools and validated by targeted transcriptomics, immunoblotting, immunohistochemistry, and serum profiling. Radiation-induced endothelial dysfunction was characterized by impaired energy metabolism and perturbation of the insulin/IGF-PI3K-Akt signaling pathway. The data also strongly suggested premature endothelial senescence, increased oxidative stress, decreased NO availability, and enhanced inflammation as main causes of radiation-induced long-term vascular dysfunction. Detailed data on molecular mechanisms of radiation-induced vascular injury as compiled here are essential in developing radiotherapy strategies that minimize cardiovascular complications.