Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 1.115
Filtrar
1.
Int J Mol Sci ; 22(6)2021 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-33804169

RESUMO

Glioblastoma multiforme (GBM) is a malignant primary brain tumor with poor patient prognosis. Although the standard treatment of GBM is surgery followed by chemotherapy and radiotherapy, often a small portion of surviving tumor cells acquire therapeutic resistance and become more aggressive. Recently, altered kinase expression and activity have been shown to determine metabolic flux in tumor cells and metabolic reprogramming has emerged as a tumor progression regulatory mechanism. Here we investigated novel kinase-mediated metabolic alterations that lead to acquired GBM radioresistance and malignancy. We utilized transcriptomic analyses within a radioresistant GBM orthotopic xenograft mouse model that overexpresses the dual specificity tyrosine-phosphorylation-regulated kinase 3 (DYRK3). We find that within GBM cells, radiation exposure induces DYRK3 expression and DYRK3 regulates mammalian target of rapamycin complex 1 (mTORC1) activity through phosphorylation of proline-rich AKT1 substrate 1 (PRAS40). We also find that DYRK3 knockdown inhibits dynamin-related protein 1 (DRP1)-mediated mitochondrial fission, leading to increased oxidative phosphorylation (OXPHOS) and reduced glycolysis. Importantly, enforced DYRK3 downregulation following irradiation significantly impaired GBM cell migration and invasion. Collectively, we suggest DYRK3 suppression may be a novel strategy for preventing GBM malignancy through regulating mitochondrial metabolism.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal/genética , Dinaminas/genética , Glioblastoma/radioterapia , Proteínas Serina-Treonina Quinases/genética , Proteínas Tirosina Quinases/genética , Animais , Linhagem Celular Tumoral , Proliferação de Células/genética , Proliferação de Células/efeitos da radiação , Regulação Neoplásica da Expressão Gênica/efeitos da radiação , Glioblastoma/genética , Glioblastoma/patologia , Humanos , Camundongos , Mitocôndrias/genética , Mitocôndrias/patologia , Mitocôndrias/efeitos da radiação , Fosforilação Oxidativa/efeitos da radiação , Proteínas Proto-Oncogênicas c-akt/genética , Tolerância a Radiação/genética , Ensaios Antitumorais Modelo de Xenoenxerto
2.
Nat Commun ; 12(1): 1049, 2021 02 16.
Artigo em Inglês | MEDLINE | ID: mdl-33594064

RESUMO

Eukaryotic phytoplankton have a small global biomass but play major roles in primary production and climate. Despite improved understanding of phytoplankton diversity and evolution, we largely ignore the cellular bases of their environmental plasticity. By comparative 3D morphometric analysis across seven distant phytoplankton taxa, we observe constant volume occupancy by the main organelles and preserved volumetric ratios between plastids and mitochondria. We hypothesise that phytoplankton subcellular topology is modulated by energy-management constraints. Consistent with this, shifting the diatom Phaeodactylum from low to high light enhances photosynthesis and respiration, increases cell-volume occupancy by mitochondria and the plastid CO2-fixing pyrenoid, and boosts plastid-mitochondria contacts. Changes in organelle architectures and interactions also accompany Nannochloropsis acclimation to different trophic lifestyles, along with respiratory and photosynthetic responses. By revealing evolutionarily-conserved topologies of energy-managing organelles, and their role in phytoplankton acclimation, this work deciphers phytoplankton responses at subcellular scales.


Assuntos
Metabolismo Energético , Imageamento Tridimensional , Fitoplâncton/citologia , Fitoplâncton/fisiologia , Aclimatação/efeitos da radiação , Metabolismo Energético/efeitos da radiação , Luz , Microalgas/metabolismo , Microalgas/efeitos da radiação , Microalgas/ultraestrutura , Mitocôndrias/metabolismo , Mitocôndrias/efeitos da radiação , Mitocôndrias/ultraestrutura , Fitoplâncton/efeitos da radiação , Fitoplâncton/ultraestrutura , Plastídeos/metabolismo , Frações Subcelulares/metabolismo
3.
Sci Rep ; 10(1): 21972, 2020 12 15.
Artigo em Inglês | MEDLINE | ID: mdl-33319819

RESUMO

The effects of ultraviolet-C light (UVC) on vitamin C and phenolic compounds in acerola during postharvest storage were investigated in order to elucidate the mechanism inducing the antioxidant systems. The fruits, stored at 10 °C for 7 days after a hormetic UVC irradiation (two pulses of 0.3 J/cm2), showed significantly less degradation of vitamin C and phenolic compounds than the control without the UVC challenge. UVC activated the L-galactono-1,4-lactone dehydrogenase (GalDH), a key enzyme for vitamin C biosynthesis, and altered the composition of phenolic compounds, through phenolic biosynthesis, in acerola during postharvest storage. UVC also induced reactive oxygen species (ROS) productions at immediate (day 0) and late (day 7) times during postharvest storage through the mitochondrial electron transport chain and NADPH oxidase, respectively. Results suggest that UVC helps in the retention of vitamin C and phenolic content in acerola by altering ascorbic acid and phenolic metabolism through an increase in mitochondrial activity and a ROS-mediated mechanism. Data showed the beneficial effects of UVC on maintenance of nutraceutical quality in acerola during postharvest storage and supplied new insights into understanding the mechanism by which UVC irradiation enhance the antioxidant system in fruits.


Assuntos
Ácido Ascórbico/biossíntese , Malpighiaceae/metabolismo , Malpighiaceae/efeitos da radiação , Mitocôndrias/metabolismo , Fenóis/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Raios Ultravioleta , Ácido Ascórbico/metabolismo , Vias Biossintéticas , Catecol Oxidase/metabolismo , Flavonoides/análise , Regulação da Expressão Gênica/efeitos dos fármacos , Hidroxibenzoatos/análise , Mitocôndrias/efeitos da radiação , Modelos Biológicos , NADPH Oxidases/metabolismo , Oxirredutases/metabolismo , Fenilalanina Amônia-Liase/metabolismo
4.
Lasers Med Sci ; 35(8): 1831-1839, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32451640

RESUMO

Photobiomodulation (PBM) has been shown to improve wound healing by promoting mesenchymal stem cell migration and proliferation. However, it remains unknown whether an 808-nm diode laser can influence human gingival mesenchymal stem cells (HGMSCs), and which dose this works well. In the present study, it was found that PBM could promote the migration of HGMSCs but not the proliferation. Furthermore, PBM could activate mitochondrial ROS, which could elevate the phosphorylation levels of JNK and IKB in HGMSCs, and further activate NF-κB as the nuclear translocation of p65 is elevated. Taken together, these present results indicate that PBM might promote cell migration via the ROS/JNK/NF-κB pathway.


Assuntos
Movimento Celular/efeitos da radiação , Gengiva/fisiologia , Gengiva/efeitos da radiação , Lasers Semicondutores/uso terapêutico , Sistema de Sinalização das MAP Quinases/efeitos da radiação , Células-Tronco Mesenquimais/citologia , Cicatrização/efeitos da radiação , Gengiva/citologia , Humanos , Proteínas Quinases JNK Ativadas por Mitógeno/metabolismo , Metaloproteinase 1 da Matriz/metabolismo , Células-Tronco Mesenquimais/efeitos da radiação , Mitocôndrias/metabolismo , Mitocôndrias/efeitos da radiação , NF-kappa B/metabolismo , Fosforilação/efeitos da radiação , Espécies Reativas de Oxigênio/metabolismo
5.
Sci Rep ; 10(1): 6733, 2020 04 21.
Artigo em Inglês | MEDLINE | ID: mdl-32317708

RESUMO

Exposure Limit Values (ELV) for artificial lighting were defined in order to prevent light-induced damage to the retina. The evaluation of the lighting devices include the correction of their spectra by the B(λ) function or blue light hazard function, representing the relative spectral sensitivity of the human eye to the blue light. This weighting function peaks between 435 and 440 nm. In this study we evaluate a new generation of light emitting diode (LED), the GaN-on-GaN (gallium nitride on gallium nitride) LED, that present an emission peak in the purple part of the spectrum. Wistar rats were exposed to GaN-on-GaN and conventional diodes at different retinal doses (from 2.2 to 0.5 J/cm2). We show that GaN-on-GaN diodes are more toxic than conventional LED for the rat neural retina and the rat retinal pigment epithelium, indicating that the BLH (blue light hazard) weighting is not adapted to this type of diodes. One of the reasons of this increased toxicity is the effects of shorter wavelengths on mitochondria polarization. We also show that the threshold of phototoxic retinal dose in the rat (fixed at 11 J/cm2, BLH weighted) is overestimated, suggesting that the values used for regulations, calculated in primates using the same methods than in rats, should be revised.


Assuntos
Gálio/química , Luz/efeitos adversos , Substâncias Luminescentes/química , Mitocôndrias/efeitos da radiação , Epitélio Pigmentado da Retina/efeitos da radiação , Animais , Biomarcadores/metabolismo , Cor , Relação Dose-Resposta à Radiação , Expressão Gênica/efeitos da radiação , Proteína Glial Fibrilar Ácida/genética , Proteína Glial Fibrilar Ácida/metabolismo , Humanos , Iluminação , Masculino , Mitocôndrias/metabolismo , Mitocôndrias/patologia , Estresse Oxidativo , Primatas , Radiometria , Ratos , Ratos Wistar , Epitélio Pigmentado da Retina/metabolismo , Epitélio Pigmentado da Retina/patologia , Especificidade da Espécie , Superóxido Dismutase/genética , Superóxido Dismutase/metabolismo
6.
Sci Rep ; 10(1): 6881, 2020 04 23.
Artigo em Inglês | MEDLINE | ID: mdl-32327691

RESUMO

Triphenylamines (TPAs) were previously shown to trigger cell death under prolonged one- or two-photon illumination. Their initial subcellular localization, before prolonged illumination, is exclusively cytoplasmic and they translocate to the nucleus upon photoactivation. However, depending on their structure, they display significant differences in terms of precise initial localization and subsequent photoinduced cell death mechanism. Here, we investigated the structural features of TPAs that influence cell death by studying a series of molecules differing by the number and chemical nature of vinyl branches. All compounds triggered cell death upon one-photon excitation, however to different extents, the nature of the electron acceptor group being determinant for the overall cell death efficiency. Photobleaching susceptibility was also an important parameter for discriminating efficient/inefficient compounds in two-photon experiments. Furthermore, the number of branches, but not their chemical nature, was crucial for determining the cellular uptake mechanism of TPAs and their intracellular fate. The uptake of all TPAs is an active endocytic process but two- and three-branch compounds are taken up via distinct endocytosis pathways, clathrin-dependent or -independent (predominantly caveolae-dependent), respectively. Two-branch TPAs preferentially target mitochondria and photoinduce both apoptosis and a proper necrotic process, whereas three-branch TPAs preferentially target late endosomes and photoinduce apoptosis only.


Assuntos
Aminas/toxicidade , Endocitose/efeitos dos fármacos , Endocitose/efeitos da radiação , Espaço Intracelular/metabolismo , Luz , Aminas/química , Morte Celular/efeitos dos fármacos , Morte Celular/efeitos da radiação , Sobrevivência Celular/efeitos dos fármacos , Células HeLa , Humanos , Lisossomos/efeitos dos fármacos , Lisossomos/metabolismo , Lisossomos/efeitos da radiação , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/metabolismo , Mitocôndrias/efeitos da radiação , Espécies Reativas de Oxigênio/metabolismo , Espectrometria de Fluorescência
7.
Sci Rep ; 10(1): 6131, 2020 04 09.
Artigo em Inglês | MEDLINE | ID: mdl-32273537

RESUMO

Radiobiology is moving towards a better understanding of the intercellular signaling that occurs upon radiation and how its effects relate to the dose applied. The mitochondrial role in orchestrating this biological response needs to be further explored. Cybrids (cytoplasmic hybrids) are useful cell models for studying the involvement of mitochondria in cellular processes. In the present study we used cybrid cell lines to investigate the role of mitochondria in the response to radiation exposure. Cybrid cell lines, derived from the osteosarcoma human cell line 143B, harboring, either wild-type mitochondrial DNA (Cy143Bwt), cells with mitochondria with mutated DNA that causes mitochondrial dysfunction (Cy143Bmut), as well as cells without mitochondrial DNA (mtDNA) (143B-Rho0), were irradiated with 0.2 Gy and 2.0 Gy. Evaluation of the non-targeted (or bystander) effects in non-irradiated cells were assessed by using conditioned media from the irradiated cells. DNA double stranded breaks were assessed with the γH2AX assay. Both directly irradiated cells and cells treated with the conditioned media, showed increased DNA damage. The effect of the irradiated cells media was different according to the cell line it derived from: from Cy143Bwt cells irradiated with 0.2 Gy (low dose) and from Cy143Bmut irradiated with 2.0 Gy (high dose) induced highest DNA damage. Notably, media obtained from cells without mtDNA, the143B-Rho0 cell line, produced no effect in DNA damage. These results point to a possible role of mitochondria in the radiation-induced non-targeted effects. Furthermore, it indicates that cybrid models are valuable tools for radiobiological studies.


Assuntos
Efeito Espectador , Quebras de DNA de Cadeia Dupla , Mitocôndrias/efeitos da radiação , Radiação Ionizante , Linhagem Celular Tumoral , DNA Mitocondrial/genética , DNA Mitocondrial/efeitos da radiação , Humanos , Mitocôndrias/genética
8.
Am J Physiol Cell Physiol ; 318(5): C1005-C1017, 2020 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-32233952

RESUMO

The role of cellular senescence induced by radiation in bone loss has attracted much attention. As one of the common complications of anticancer radiotherapy, irradiation-induced bone deterioration is common and clinically significant, but the pathological mechanism has not been elucidated. This study was performed to explore the cellular senescence and senescence-associated secretory phenotype (SASP) induction of bone marrow-derived mesenchymal stem cells (BMSCs) by irradiation and its role in osteogenic differentiation dysfunction. It was observed that irradiated BMSCs lost typical fibroblast-like morphology, exhibited suppressed viability and differentiation potential accompanied with senescence phenotypes, including an increase in senescence-associated ß-galactosidase (SA-ß-gal) staining-positive cells, and upregulated senescence-related genes p53/p21, whereas no changes happened to p16. Additionally, DNA damage γ-H2AX foci, G0/G1 phase of cell cycle arrest, and cellular and mitochondrial reactive oxygen species (ROS) increased in an irradiation dose-dependent manner. Meanwhile, the JAK1/STAT3 pathway was activated and accompanied by an increase in SASP secretion, such as IL-6, IL-8, and matrix metalloproteinase-9 (MMP9), whereas 0.8 µM JAK1 inhibitor (JAKi) treatment effectively inhibited the JAK pathway and SASP production. Furthermore, conditioned medium (CM) from irradiation-induced senescent (IRIS) BMSCs exhibited a markedly reduced ability in osteogenic differentiation and marker gene expression of osteoblasts, whereas CM with JAKi intervention may effectively improve these deterioration effects. In conclusion, irradiation could provoke BMSC senescence and SASP secretion and further aggravate osteogenic differentiation dysfunction via paracrine signaling, whereas SASP targeting may be a possible intervention strategy for alleviating irradiation-induced bone loss.


Assuntos
Diferenciação Celular/genética , Senescência Celular/genética , Células-Tronco Mesenquimais/citologia , Osteogênese/genética , Reabsorção Óssea/genética , Reabsorção Óssea/terapia , Pontos de Checagem do Ciclo Celular/genética , Proliferação de Células/genética , Senescência Celular/efeitos da radiação , Dano ao DNA/efeitos da radiação , Regulação da Expressão Gênica no Desenvolvimento/efeitos da radiação , Histonas/genética , Humanos , Janus Quinase 1/genética , Células-Tronco Mesenquimais/efeitos da radiação , Mitocôndrias/genética , Mitocôndrias/efeitos da radiação , Comunicação Parácrina/genética , Radiação , Espécies Reativas de Oxigênio/metabolismo , Fator de Transcrição STAT3/genética , Transdução de Sinais/efeitos da radiação
9.
Cytogenet Genome Res ; 160(2): 100-109, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32146470

RESUMO

Chloroplasts and mitochondria are semi-autonomous organelles and have their own genomes (cytoplasmic genomes). Physical radiations (e.g., γ-rays) have been widely used in artificial mutation induction for plant germplasm enhancement and for breeding new cultivars. However, little is known at the genomic level about which kind of cytoplasmic mutations and/or characteristics could be induced in plants. The present study aimed to investigate the type, number, and distribution of inheritable cytoplasmic mutations induced by γ-rays in rice (Oryza sativa L.). Six plants were selected from the 2nd generation (M2) populations after γ-ray (137Cs) irradiation of the rice cultivar Nipponbare, 2 each for the 3 irradiation doses (150, 250, and 350 Gy), and their genomes were sequenced on an Illumina platform. Together with the whole-genome sequencing data of 3 external Nipponbare control plants, single-base substitutions (SBSs) and insertions/deletions (InDels) in chloroplast (cp) and mitochondrial (mt) genomes were identified and analyzed in-depth using bioinformatic tools. The majority of SBSs and InDels identified were background mutations in the 6 M2 plants, and the number of induced mutations varied greatly among the plants. Most induced mutations were present in a heterogeneous state, reflecting the fact that multiple cp and mt copies existed in the progenitor cells. The induced mutations were distributed in different genomic regions in the 6 M2 plants, including exonic regions, but none of them was predicted to cause nonsynonymous mutations or frameshifts. Our study thus revealed, at the genomic level, characteristics of cytoplasmic mutations induced by γ-rays in rice.


Assuntos
Raios gama/efeitos adversos , Mutação , Oryza/efeitos da radiação , Sequenciamento Completo do Genoma/métodos , Cloroplastos/genética , Cloroplastos/efeitos da radiação , Genoma de Planta/efeitos da radiação , Sequenciamento de Nucleotídeos em Larga Escala , Mitocôndrias/genética , Mitocôndrias/efeitos da radiação , Oryza/genética , Proteínas de Plantas/genética , Proteínas de Plantas/efeitos da radiação , Sementes/genética , Sementes/efeitos da radiação
10.
Oxid Med Cell Longev ; 2020: 5135893, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32190174

RESUMO

Objective: The mechanism of enhanced radiosensitivity induced by mitochondrial uncoupling protein UCP2 was investigated in HeLa cells to provide a theoretical basis as a novel target for cervical cancer treatment. Methods: HeLa cells were irradiated with 4 Gy X-radiation at 1.0 Gy/min. The expression of UCP2 mRNA and protein was assayed by real-time quantitative polymerase chain reaction and western blotting. UCP2 siRNA and negative control siRNA fragments were constructed and transfected into HeLa cells 24 h after irradiation. The effect of UCP2 silencing and irradiation on HeLa cells was determined by colony formation, CCK-8 cell viability, γH2AX immunofluorescence assay of DNA damage, Annexin V-FITC/PI apoptosis assay, and propidium iodide cell cycle assay. The effects on mitochondrial structure and function were investigated with fluorescent probes including dichlorodihydrofluorescein diacetate (DCFH-DA) assay of reactive oxygen species (ROS), rhodamine 123, and MitoTracker Green assay of mitochondrial structure and function. Results: Irradiation upregulated UCP2 expression, and UCP2 knockdown decreased the survival of irradiated HeLa cells. UCP2 silencing sensitized HeLa cells to irradiation-induced DNA damage and led to increased apoptosis, cell cycle arrest in G2/M, and increased mitochondrial ROS. Increased radiosensitivity was associated with an activation of P53, decreased Bcl-2, Bcl-xl, cyclin B, CDC2, Ku70, and Rad51 expression, and increased Apaf-1, cytochrome c, caspase-3, and caspase-9 expression. Conclusions: UCP2 inhibition augmented the radiosensitivity of cervical cancer cells, and it may be a potential target of radiotherapy of advanced cervical cancer.


Assuntos
Tolerância a Radiação , Espécies Reativas de Oxigênio/metabolismo , Proteína Desacopladora 2/antagonistas & inibidores , Neoplasias do Colo do Útero/metabolismo , Apoptose/efeitos da radiação , Autofagia/efeitos da radiação , Pontos de Checagem do Ciclo Celular/efeitos da radiação , Dano ao DNA , Reparo do DNA/efeitos da radiação , Regulação para Baixo/efeitos da radiação , Feminino , Inativação Gênica/efeitos da radiação , Células HeLa , Humanos , Potencial da Membrana Mitocondrial/efeitos da radiação , Mitocôndrias/metabolismo , Mitocôndrias/efeitos da radiação , Modelos Biológicos , Tolerância a Radiação/efeitos da radiação , Proteína Desacopladora 2/genética , Proteína Desacopladora 2/metabolismo , Neoplasias do Colo do Útero/patologia
11.
Life Sci ; 250: 117570, 2020 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-32205088

RESUMO

Accidental exposure to ionizing radiation is a serious concern to human life. Studies on the mitigation of side effects following exposure to accidental radiation events are ongoing. Recent studies have shown that radiation can activate several signaling pathways, leading to changes in the metabolism of free radicals including reactive oxygen species (ROS) and nitric oxide (NO). Cellular and molecular mechanisms show that radiation can cause disruption of normal reduction/oxidation (redox) system. Mitochondria malfunction following exposure to radiation and mutations in mitochondria DNA (mtDNA) have a key role in chronic oxidative stress. Furthermore, exposure to radiation leads to infiltration of inflammatory cells such as macrophages, lymphocytes and mast cells, which are important sources of ROS and NO. These cells generate free radicals via upregulation of some pro-oxidant enzymes such as NADPH oxidases, inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2). Epigenetic changes also have a key role in a similar way. Other mediators such as mammalian target of rapamycin (mTOR) and peroxisome proliferator-activated receptor (PPAR), which are involved in the normal metabolism of cells have also been shown to regulate cell death following exposure to radiation. These mechanisms are tissue specific. Inhibition or activation of each of these targets can be suggested for mitigation of radiation injury in a specific tissue. In the current paper, we review the cellular and molecular changes in the metabolism of cells and ROS/NO following exposure to radiation. Furthermore, the possible strategies for mitigation of radiation injury through modulation of cellular metabolism in irradiated organs will be discussed.


Assuntos
Estresse Oxidativo/efeitos da radiação , Lesões por Radiação/metabolismo , Animais , Ciclo-Oxigenase 2/metabolismo , DNA Mitocondrial/genética , Epigênese Genética , Humanos , Inflamação , Linfócitos/citologia , Mastócitos/citologia , Camundongos , Mitocôndrias/efeitos da radiação , Mutação , NADPH Oxidases/metabolismo , Óxido Nítrico/metabolismo , Óxido Nítrico Sintase Tipo II/metabolismo , Oxirredução , Radiação Ionizante , Espécies Reativas de Oxigênio/metabolismo
12.
Int J Mol Sci ; 21(4)2020 Feb 11.
Artigo em Inglês | MEDLINE | ID: mdl-32054039

RESUMO

Studies of molecular changes occurred in various brain regions after whole-body irradiation showed a significant increase in terms of the importance in gaining insight into how to slow down or prevent the development of long-term side effects such as carcinogenesis, cognitive impairment and other pathologies. We have analyzed nDNA damage and repair, changes in mitochondrial DNA (mtDNA) copy number and in the level of mtDNA heteroplasmy, and also examined changes in the expression of genes involved in the regulation of mitochondrial biogenesis and dynamics in three areas of the rat brain (hippocampus, cortex and cerebellum) after whole-body X-ray irradiation. Long amplicon quantitative polymerase chain reaction (LA-QPCR) was used to detect nDNA and mtDNA damage. The level of mtDNA heteroplasmy was estimated using Surveyor nuclease technology. The mtDNA copy numbers and expression levels of a number of genes were determined by real-time PCR. The results showed that the repair of nDNA damage in the rat brain regions occurs slowly within 24 h; in the hippocampus, this process runs much slower. The number of mtDNA copies in three regions of the rat brain increases with a simultaneous increase in mtDNA heteroplasmy. However, in the hippocampus, the copy number of mutant mtDNAs increases significantly by the time point of 24 h after radiation exposure. Our analysis shows that in the brain regions of irradiated rats, there is a decrease in the expression of genes (ND2, CytB, ATP5O) involved in ATP synthesis, although by the same time point after irradiation, an increase in transcripts of genes regulating mitochondrial biogenesis is observed. On the other hand, analysis of genes that control the dynamics of mitochondria (Mfn1, Fis1) revealed that sharp decrease in gene expression level occurred, only in the hippocampus. Consequently, the structural and functional characteristics of the hippocampus of rats exposed to whole-body radiation can be different, most significantly from those of the other brain regions.


Assuntos
Encéfalo/efeitos da radiação , Núcleo Celular/efeitos da radiação , Dano ao DNA/efeitos da radiação , Mitocôndrias/efeitos da radiação , Irradiação Corporal Total/efeitos adversos , Animais , Encéfalo/metabolismo , Núcleo Celular/genética , DNA Mitocondrial/genética , Regulação da Expressão Gênica/efeitos da radiação , Genes Mitocondriais/efeitos da radiação , Masculino , Mitocôndrias/genética , Ratos , Ratos Wistar
13.
Int J Mol Med ; 45(2): 485-496, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31894256

RESUMO

Combined androgen deprivation therapy (ADT) and radiation therapy (RT) is the standard of care treatment for non­metastatic prostate cancer (NMPC). Despite the efficacy, treatment­related symptoms including fatigue greatly reduce the quality of life of cancer patients. The goal of the study is to examine the influence of combined ADT/RT on fatigue and understand its underlying mechanisms. A total of 64 participants with NMPC were enrolled. Fatigue was assessed using the Functional Assessment of Cancer Therapy­Fatigue. Mitochondrial function parameters were measured as oxygen consumption from peripheral blood mononuclear cells (PBMCs) extracted from participants' whole blood. An ADT/RT­induced fatigue mouse model was developed, with fatigue measured as a reduction in voluntary wheel­running activity (VWRA) in 54 mice. Mitochondrial function was assessed in the ADT/RT mouse brains using western blot analysis of glucose transporter 4 (GLUT4) and transcription factor A, mitochondrial (TFAM). The results demonstrated that fatigue in the ADT group was exacerbated during RT compared with the non­ADT group. This effect was specific to fatigue, as depressive symptoms were unaffected. PBMCs of fatigued subjects exhibited decreased ATP coupling efficiency compared to non­fatigued subjects, indicative of mitochondrial dysfunction. The ADT/RT mice demonstrated the synergistic effect of ADT and RT in decreasing VWRA. Brain tissues of ADT/RT mice exhibited decreased levels of GLUT4 and TFAM suggesting that impaired neuronal metabolic homeostasis may contribute to fatigue pathogenesis. In conclusion, these findings suggest that fatigue induced by ADT/RT may be attributable to mitochondrial dysfunction both peripherally and in the central nervous system (CNS). The synergistic effect of ADT/RT is behaviorally reproducible in a mouse model and its mechanism may be related to bioenergetics in the CNS.


Assuntos
Antagonistas de Androgênios/uso terapêutico , Fadiga/etiologia , Neoplasias da Próstata/tratamento farmacológico , Neoplasias da Próstata/radioterapia , Idoso , Antagonistas de Androgênios/efeitos adversos , Animais , Terapia Combinada/efeitos adversos , Fadiga/patologia , Humanos , Masculino , Camundongos Endogâmicos C57BL , Pessoa de Meia-Idade , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/patologia , Mitocôndrias/efeitos da radiação , Neoplasias da Próstata/complicações , Neoplasias da Próstata/patologia , Qualidade de Vida
14.
Metabolism ; 103: 154025, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-31765667

RESUMO

BACKGROUND: Metabolic complications are highly prevalent in cancer survivors treated with irradiation but the underlying mechanisms remain unknown. METHODS: Chow or high fat-fed C57Bl/6J mice were irradiated (6Gy) before investigating the impact on whole-body or skeletal muscle metabolism and profiling their lipidomic signature. Using a transgenic mouse model (Tg:Pax7-nGFP), we isolated muscle progenitor cells (satellite cells) and characterised their metabolic functions. We recruited childhood cancer survivors, grouped them based on the use of total body irradiation during their treatment and established their lipidomic profile. RESULTS: In mice, irradiation delayed body weight gain and impaired fat pads and muscle weights. These changes were associated with impaired whole-body fat oxidation in chow-fed mice and altered ex vivo skeletal muscle fatty acid oxidation, potentially due to a reduction in oxidative fibres and reduced mitochondrial enzyme activity. Irradiation led to fasting hyperglycaemia and impaired glucose uptake in isolated skeletal muscles. Cultured satellite cells from irradiated mice showed decreased fatty acid oxidation and reduced glucose uptake, recapitulating the host metabolic phenotype. Irradiation resulted in a remodelling of lipid species in skeletal muscles, with the extensor digitorum longus muscle being particularly affected. A large number of lipid species were reduced, with several of these species showing a positive correlation with mitochondrial enzymes activity. In cancer survivors exposed to irradiation, we found a similar decrease in systemic levels of most lipid species, and lipid species that increased were positively correlated with insulin resistance (HOMA-IR). CONCLUSION: Irradiation leads to long-term alterations in body composition, and lipid and carbohydrate metabolism in skeletal muscle, and affects muscle progenitor cells. Such changes result in persistent impairment of metabolic functions, providing a new mechanism for the increased prevalence of metabolic diseases reported in irradiated individuals. In this context, changes in the lipidomic signature in response to irradiation could be of diagnostic value.


Assuntos
Sobreviventes de Câncer , Doenças Metabólicas/etiologia , Mitocôndrias/efeitos da radiação , Músculo Esquelético/efeitos da radiação , Neoplasias/radioterapia , Irradiação Corporal Total/efeitos adversos , Adolescente , Adulto , Animais , Criança , Pré-Escolar , Metabolismo Energético/efeitos da radiação , Feminino , Seguimentos , Humanos , Masculino , Doenças Metabólicas/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Mitocôndrias/fisiologia , Músculo Esquelético/metabolismo , Neoplasias/metabolismo , Oxirredução/efeitos da radiação , Lesões por Radiação/metabolismo , Lesões por Radiação/patologia , Irradiação Corporal Total/veterinária , Terapia por Raios X , Raios X/efeitos adversos , Adulto Jovem
15.
Cell Mol Life Sci ; 77(14): 2815-2838, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31583425

RESUMO

Biological effects of high fluence low-power (HFLP) lasers have been reported for some time, yet the molecular mechanisms procuring cellular responses remain obscure. A better understanding of the effects of HFLP lasers on living cells will be instrumental for the development of new experimental and therapeutic strategies. Therefore, we investigated sub-cellular mechanisms involved in the laser interaction with human hepatic cell lines. We show that mitochondria serve as sub-cellular "sensor" and "effector" of laser light non-specific interactions with cells. We demonstrated that despite blue and red laser irradiation results in similar apoptotic death, cellular signaling and kinetic of biochemical responses are distinct. Based on our data, we concluded that blue laser irradiation inhibited cytochrome c oxidase activity in electron transport chain of mitochondria. Contrary, red laser triggered cytochrome c oxidase excessive activation. Moreover, we showed that Bcl-2 protein inhibited laser-induced toxicity by stabilizing mitochondria membrane potential. Thus, cells that either overexpress or have elevated levels of Bcl-2 are protected from laser-induced cytotoxicity. Our findings reveal the mechanism how HFLP laser irradiation interfere with cell homeostasis and underscore that such laser irradiation permits remote control of mitochondrial function in the absence of chemical or biological agents.


Assuntos
Complexo IV da Cadeia de Transporte de Elétrons/genética , Transporte de Elétrons/efeitos da radiação , Terapia com Luz de Baixa Intensidade , Fototerapia , Apoptose/efeitos da radiação , Sobrevivência Celular/genética , Sobrevivência Celular/efeitos da radiação , Transporte de Elétrons/genética , Regulação da Expressão Gênica/efeitos da radiação , Células Hep G2 , Humanos , Potencial da Membrana Mitocondrial/genética , Potencial da Membrana Mitocondrial/efeitos da radiação , Mitocôndrias/genética , Mitocôndrias/efeitos da radiação , Membranas Mitocondriais/metabolismo , Membranas Mitocondriais/efeitos da radiação , Oxirredução/efeitos da radiação , Espécies Reativas de Oxigênio/metabolismo
16.
J Biochem ; 167(3): 303-314, 2020 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-31670806

RESUMO

Interleukin-6 (IL-6)-induced glycolysis and therapeutic resistance is reported in some cell systems; however, the mechanism of IL-6-induced glycolysis in radio-resistance is unexplored. Therefore, to investigate, we treated Raw264.7 cells with IL-6 (1 h prior to irradiation) and examined the glycolytic flux. Increased expression of mRNA and protein levels of key glycolytic enzymes was observed after IL-6 treatment, which conferred glycolysis dependent resistance from radiation-induced cell death. We further established that IL-6-induced glycolysis is activated by Akt signalling and knocking down Akt or inhibition of pan Akt phosphorylation significantly abrogated the IL-6-induced radio-resistance. Moreover, reduction of IL-6-induced pAkt level suppressed the expression of Hexokinase-2 and its translocation to the mitochondria, thereby inhibiting the glycolysis-induced resistance to radiation. IL-6-induced glycolysis also minimized the radiation-induced mitochondrial damage. These results suggest that IL-6-induced glycolysis observed in cells may be responsible for IL-6-mediated therapeutic radio-resistance in cancer cells, partly by activation of Akt signalling.


Assuntos
Glicólise/efeitos dos fármacos , Interleucina-6/farmacologia , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Tolerância a Radiação/efeitos dos fármacos , Animais , Morte Celular/efeitos dos fármacos , Morte Celular/genética , Morte Celular/efeitos da radiação , Proliferação de Células/efeitos dos fármacos , Proliferação de Células/genética , Proliferação de Células/efeitos da radiação , Sobrevivência Celular/efeitos dos fármacos , Sobrevivência Celular/genética , Sobrevivência Celular/efeitos da radiação , Técnicas de Silenciamento de Genes , Glicólise/genética , Glicólise/efeitos da radiação , Hexoquinase/genética , Hexoquinase/metabolismo , Camundongos , Mitocôndrias/patologia , Mitocôndrias/efeitos da radiação , Fosforilação , Proteínas Proto-Oncogênicas c-akt/genética , Células RAW 264.7 , RNA Interferente Pequeno , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/genética , Transdução de Sinais/efeitos da radiação
17.
Radiat Res ; 193(1): 63-72, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31714866

RESUMO

It is well known that mitochondria and the endoplasmic reticulum (ER) play important roles in radiation response, but their functions in radiation-induced bystander effect (RIBE) are largely unclear. In this study, we found that when a small portion of cells in a population of human lung fibroblast MRC-5 cells were precisely irradiated through either the nuclei or cytoplasm with counted microbeam protons, the yield of micronuclei (MN) and the levels of intracellular reactive oxygen species (ROS) in nonirradiated cells neighboring irradiated cells were significantly increased. Mito/ER-tracker staining demonstrated that the mitochondria were clearly activated after nuclear irradiation and ER mass approached a higher level after cytoplasmic irradiation. Moreover, the radiation-induced ROS was diminished by rotenone, an inhibitor of mitochondria activation, but it was not influenced by siRNA interference of BiP, an ER regulation protein. While for nuclear irradiation, rotenone-enhanced radiation-induced ER expression, and BiP siRNA eliminated radiation-induced activation of mitochondria, these phenomena were not observed for cytoplasmic irradiation. Bystander MN was reduced by rotenone but enhanced by BiP siRNA. When the cells were treated with both rotenone and BiP siRNA, the MN yield was reduced for nuclear irradiation but was enhanced for cytoplasmic irradiation. Our results suggest that the organelles of mitochondria and ER have different roles in RIBE with respect to nuclear and cytoplasmic irradiation, and the function of ER is a prerequisite for mitochondrial activation.


Assuntos
Efeito Espectador/efeitos da radiação , Retículo Endoplasmático/metabolismo , Retículo Endoplasmático/efeitos da radiação , Mitocôndrias/metabolismo , Mitocôndrias/efeitos da radiação , Prótons/efeitos adversos , Linhagem Celular , Fibroblastos/citologia , Fibroblastos/efeitos da radiação , Humanos , Espécies Reativas de Oxigênio/metabolismo
18.
Sci Rep ; 9(1): 19941, 2019 12 27.
Artigo em Inglês | MEDLINE | ID: mdl-31882895

RESUMO

Standard cytotoxic cancer treatments, such as radiation, can damage and deplete the supply of oocytes stored within the ovary, which predisposes females to infertility and premature menopause later in life. The mechanisms by which radiation induces oocyte damage have not been completely elucidated. The objective of this study was to determine if γ-irradiation changes mitochondrial characteristics in oocytes, possibly contributing to a reduction in oocyte number and quality. Immature oocytes were collected from postnatal day (PN) 9-11 C57Bl6 mice 3, 6 and 24 hours after 0.1 Gy γ-irradiation to monitor acute mitochondrial changes. Oocytes were classified as small (>20 µm) or growing (40-60 µm). Mitochondrial membrane potential was lost in 20% and 44% of small oocytes (~20 µm) at 3 and 6 hours after γ-irradiation, respectively, consistent with the induction of apoptosis. However, mitochondrial mass, distribution and membrane potential in the surviving small oocytes were similar to the non-irradiated controls at both time points. At 24 hours after γ-irradiation, all mitochondrial parameters analysed within immature oocytes were similar to untreated controls. Mitochondrial parameters within growing oocytes were also similar to untreated controls. When mice were superovulated more than 3 weeks after γ-irradiation, there was a significant reduction in the number of mature oocytes harvested compared to controls (Control 18 ± 1 vs 0.1 Gy 4 ± 1, n = 6/16 mice, p < 0.05). There was a slight reduction in mitochondrial mass in mature oocytes after γ-irradiation, though mitochondrial localization, mtDNA copy number and ATP levels were similar between groups. In summary, this study shows that γ-irradiation of pre-pubertal mice is associated with loss of mitochondrial membrane potential in a significant proportion of small immature oocytes and a reduction in the number of mature oocytes harvested from adult mice. Furthermore, these results suggest that immature oocytes that survive γ-irradiation and develop through to ovulation contain mitochondria with normal characteristics. Whether the oocytes that survive radiation and eventually undergo meiosis can support fertility remains to be determined.


Assuntos
Raios gama/efeitos adversos , Mitocôndrias/efeitos da radiação , Oócitos/efeitos da radiação , Animais , DNA Mitocondrial/genética , Feminino , Fertilidade/efeitos da radiação , Meiose , Potencial da Membrana Mitocondrial/efeitos da radiação , Camundongos , Camundongos Endogâmicos C57BL , Mitocôndrias/metabolismo , Oócitos/metabolismo , Ovário/metabolismo , Ovulação/efeitos da radiação
19.
Sci Rep ; 9(1): 18435, 2019 12 05.
Artigo em Inglês | MEDLINE | ID: mdl-31804563

RESUMO

Here at the first time we suggested that the surface plasmon-polariton phenomenon which it is well described in metallic nanostructures could also be used for explanation of the unexpectedly strong oxidative effects of the low-intensity laser irradiation in living matters (cells, tissues, organism). We demonstrated that the narrow-band laser emitting at 1265 nm could generate significant amount of the reactive oxygen species (ROS) in both HCT116 and CHO-K1 cell cultures. Such cellular ROS effects could be explained through the generation of highly localized plasmon-polaritons on the surface of mitochondrial crista. Our experimental conditions, the low-intensity irradiation, the narrow spectrum band (<4 nm) of the laser and comparably small size bio-structures (~10 µm) were shown to be sufficient for the plasmon-polariton generation and strong laser field confinement enabling the oxidative stress observed.


Assuntos
Lasers/efeitos adversos , Luz/efeitos adversos , Mitocôndrias/efeitos da radiação , Estresse Oxidativo/efeitos da radiação , Oxigênio/metabolismo , Animais , Células CHO , Cricetulus , Células HCT116 , Humanos , Mitocôndrias/metabolismo , Oxirredução/efeitos da radiação , Espécies Reativas de Oxigênio/metabolismo , Ressonância de Plasmônio de Superfície
20.
Commun Biol ; 2: 424, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31799427

RESUMO

Mitochondrial degeneration is considered one of the major causes of Parkinson's disease (PD). Improved mitochondrial functions are expected to be a promising therapeutic strategy for PD. In this study, we introduced a light-driven proton transporter, Delta-rhodopsin (dR), to Drosophila mitochondria, where the mitochondrial proton-motive force (Δp) and mitochondrial membrane potential are maintained in a light-dependent manner. The loss of the PD-associated mitochondrial gene CHCHD2 resulted in reduced ATP production, enhanced mitochondrial peroxide production and lower Ca2+-buffering activity in dopaminergic (DA) terminals in flies. These cellular defects were improved by the light-dependent activation of mitochondrion-targeted dR (mito-dR). Moreover, mito-dR reversed the pathology caused by the CHCHD2 deficiency to suppress α-synuclein aggregation, DA neuronal loss, and elevated lipid peroxidation in brain tissue, improving motor behaviors. This study suggests the enhancement of Δp by mito-dR as a therapeutic mechanism that ameliorates neurodegeneration by protecting mitochondrial functions.


Assuntos
Luz , Mitocôndrias/metabolismo , Mitocôndrias/efeitos da radiação , Doenças Mitocondriais/etiologia , Doenças Mitocondriais/metabolismo , Atividade Motora , Doença de Parkinson/etiologia , Doença de Parkinson/metabolismo , Prótons , Animais , Biomarcadores , Modelos Animais de Doenças , Suscetibilidade a Doenças , Neurônios Dopaminérgicos/metabolismo , Drosophila , Modelos Biológicos , Estresse Oxidativo , Espécies Reativas de Oxigênio/metabolismo , alfa-Sinucleína/metabolismo
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...