RESUMO
Pathogenic variants in the WDR45 (OMIM: 300,526) gene on chromosome Xp11 are the genetic cause of a rare neurological disorder characterized by increased iron deposition in the basal ganglia. As WDR45 encodes a beta-propeller scaffold protein with a putative role in autophagy, the disease has been named Beta-Propeller Protein-Associated Neurodegeneration (BPAN). BPAN represents one of the four most common forms of Neurodegeneration with Brain Iron Accumulation (NBIA). In the current study, we generated and characterized a whole-body Wdr45 knock-out (KO) mouse model. The model, developed using TALENs, presents a 20-bp deletion in exon 2 of Wdr45. Homozygous females and hemizygous males are viable, proving that systemic depletion of Wdr45 does not impair viability and male fertility in mice. The in-depth phenotypic characterization of the mouse model revealed neuropathology signs at four months of age, neurodegeneration progressing with ageing, hearing and visual impairment, specific haematological alterations, but no brain iron accumulation. Biochemically, Wdr45 KO mice presented with decreased complex I (CI) activity in the brain, suggesting that mitochondrial dysfunction accompanies Wdr45 deficiency. Overall, the systemic Wdr45 KO described here complements the two mouse models previously reported in the literature (PMIDs: 26,000,824, 31,204,559) and represents an additional robust model to investigate the pathophysiology of BPAN and to test therapeutic strategies for the disease.
Assuntos
Proteínas de Transporte/genética , Animais , Feminino , Masculino , Camundongos , Camundongos Knockout , FenótipoRESUMO
Glutathione peroxidase 4 (GPX4) is unique as it is the only enzyme that can prevent detrimental lipid peroxidation in vivo by reducing lipid peroxides to the respective alcohols thereby stabilizing oxidation products of unsaturated fatty acids. During reticulocyte maturation, lipid peroxidation mediated by 15-lipoxygenase in humans and rabbits and by 12/15-lipoxygenase (ALOX15) in mice was considered the initiating event for the elimination of mitochondria but is now known to occur through mitophagy. Yet, genetic ablation of the Alox15 gene in mice failed to provide evidence for this hypothesis. We designed a different genetic approach to tackle this open conundrum. Since either other lipoxygenases or non-enzymatic autooxidative mechanisms may compensate for the loss of Alox15, we asked whether ablation of Gpx4 in the hematopoietic system would result in the perturbation of reticulocyte maturation. Quantitative assessment of erythropoiesis indices in the blood, bone marrow (BM) and spleen of chimeric mice with Gpx4 ablated in hematopoietic cells revealed anemia with an increase in the fraction of erythroid precursor cells and reticulocytes. Additional dietary vitamin E depletion strongly aggravated the anemic phenotype. Despite strong extramedullary erythropoiesis reticulocytes failed to mature and accumulated large autophagosomes with engulfed mitochondria. Gpx4-deficiency in hematopoietic cells led to systemic hepatic iron overload and simultaneous severe iron demand in the erythroid system. Despite extremely high erythropoietin and erythroferrone levels in the plasma, hepcidin expression remained unchanged. Conclusively, perturbed reticulocyte maturation in response to Gpx4 loss in hematopoietic cells thus causes ineffective erythropoiesis, a phenotype partially masked by dietary vitamin E supplementation.
Assuntos
Eritropoese , Ferro , Fosfolipídeo Hidroperóxido Glutationa Peroxidase/genética , Reticulócitos , Vitamina E , Animais , Homeostase , Camundongos , CoelhosRESUMO
Animal welfare requires the adequate housing of animals to ensure health and well-being. The application of environmental enrichment is a way to improve the well-being of laboratory animals. However, it is important to know whether these enrichment items can be incorporated in experimental mouse husbandry without creating a divide between past and future experimental results. Previous small-scale studies have been inconsistent throughout the literature, and it is not yet completely understood whether and how enrichment might endanger comparability of results of scientific experiments. Here, we measured the effect on means and variability of 164 physiological parameters in 3 conditions: with nesting material with or without a shelter, comparing these 2 conditions to a "barren" regime without any enrichments. We studied a total of 360 mice from each of 2 mouse strains (C57BL/6NTac and DBA/2NCrl) and both sexes for each of the 3 conditions. Our study indicates that enrichment affects the mean values of some of the 164 parameters with no consistent effects on variability. However, the influence of enrichment appears negligible compared to the effects of other influencing factors. Therefore, nesting material and shelters may be used to improve animal welfare without impairment of experimental outcome or loss of comparability to previous data collected under barren housing conditions.
Assuntos
Bem-Estar do Animal/ética , Ambiente Controlado , Comportamento de Nidação/fisiologia , Bem-Estar do Animal/economia , Animais , Metabolismo Energético/fisiologia , Feminino , Testes de Função Cardíaca/métodos , Masculino , Aprendizagem em Labirinto/fisiologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos DBA , Nociceptividade/fisiologiaRESUMO
The formation of amyloid fibrils by human islet amyloid polypeptide protein (hIAPP) has been implicated in pancreas dysfunction and diabetes. However, efficient treatment options to reduce amyloid fibrils in vivo are still lacking. Therefore, we tested the effect of epigallocatechin gallate (EGCG) on fibril formation in vitro and in vivo. To determine the binding of hIAPP and EGCG, in vitro interaction studies were performed. To inhibit amyloid plaque formation in vivo, homozygous (tg/tg), hemizygous (wt/tg), and control mice (wt/wt) were treated with EGCG. EGCG bound to hIAPP in vitro and induced formation of amorphous aggregates instead of amyloid fibrils. Amyloid fibrils were detected in the pancreatic islets of tg/tg mice, which was associated with disrupted islet structure and diabetes. Although pancreatic amyloid fibrils could be detected in wt/tg mice, these animals were non-diabetic. EGCG application decreased amyloid fibril intensity in wt/tg mice, however it was ineffective in tg/tg animals. Our data indicate that EGCG inhibits amyloid fibril formation in vitro and reduces fibril intensity in non-diabetic wt/tg mice. These results demonstrate a possible in vivo effectiveness of EGCG on amyloid formation and suggest an early therapeutical application.
Assuntos
Amiloide/metabolismo , Amiloidose/metabolismo , Catequina/análogos & derivados , Polipeptídeo Amiloide das Ilhotas Pancreáticas/genética , Fármacos Neuroprotetores/farmacologia , Pâncreas/metabolismo , Amiloide/química , Amiloidose/patologia , Animais , Biomarcadores , Catequina/química , Catequina/metabolismo , Catequina/farmacologia , Humanos , Polipeptídeo Amiloide das Ilhotas Pancreáticas/metabolismo , Camundongos , Camundongos Transgênicos , Modelos Moleculares , Conformação Molecular , Fármacos Neuroprotetores/química , Fármacos Neuroprotetores/metabolismo , Pâncreas/patologia , Pâncreas/ultraestrutura , Ligação ProteicaRESUMO
Dietary restriction regimes extend lifespan in various animal models. Here we show that longevity in male C57BL/6J mice subjected to every-other-day feeding is associated with a delayed onset of neoplastic disease that naturally limits lifespan in these animals. We compare more than 200 phenotypes in over 20 tissues in aged animals fed with a lifelong every-other-day feeding or ad libitum access to food diet to determine whether molecular, cellular, physiological and histopathological aging features develop more slowly in every-other-day feeding mice than in controls. We also analyze the effects of every-other-day feeding on young mice on shorter-term every-other-day feeding or ad libitum to account for possible aging-independent restriction effects. Our large-scale analysis reveals overall only limited evidence for a retardation of the aging rate in every-other-day feeding mice. The data indicate that every-other-day feeding-induced longevity is sufficiently explained by delays in life-limiting neoplastic disorders and is not associated with a more general slowing of the aging process in mice.Dietary restriction can extend the life of various model organisms. Here, Xie et al. show that intermittent periods of fasting achieved through every-other-day feeding protect mice against neoplastic disease but do not broadly delay organismal aging in animals.
Assuntos
Envelhecimento , Privação de Alimentos , Longevidade , Animais , Masculino , Camundongos , Camundongos Endogâmicos C57BLRESUMO
Aging is associated with an increased risk of cardiovascular disease and death. Here we show that oral supplementation of the natural polyamine spermidine extends the lifespan of mice and exerts cardioprotective effects, reducing cardiac hypertrophy and preserving diastolic function in old mice. Spermidine feeding enhanced cardiac autophagy, mitophagy and mitochondrial respiration, and it also improved the mechano-elastical properties of cardiomyocytes in vivo, coinciding with increased titin phosphorylation and suppressed subclinical inflammation. Spermidine feeding failed to provide cardioprotection in mice that lack the autophagy-related protein Atg5 in cardiomyocytes. In Dahl salt-sensitive rats that were fed a high-salt diet, a model for hypertension-induced congestive heart failure, spermidine feeding reduced systemic blood pressure, increased titin phosphorylation and prevented cardiac hypertrophy and a decline in diastolic function, thus delaying the progression to heart failure. In humans, high levels of dietary spermidine, as assessed from food questionnaires, correlated with reduced blood pressure and a lower incidence of cardiovascular disease. Our results suggest a new and feasible strategy for protection against cardiovascular disease.
Assuntos
Envelhecimento/efeitos dos fármacos , Autofagia/efeitos dos fármacos , Pressão Sanguínea/efeitos dos fármacos , Coração/efeitos dos fármacos , Longevidade/efeitos dos fármacos , Mitocôndrias Cardíacas/efeitos dos fármacos , Mitofagia/efeitos dos fármacos , Miócitos Cardíacos/efeitos dos fármacos , Espermidina/farmacologia , Adulto , Idoso , Envelhecimento/imunologia , Envelhecimento/metabolismo , Animais , Proteína 5 Relacionada à Autofagia/genética , Cardiomegalia/diagnóstico por imagem , Cardiotônicos/farmacologia , Doenças Cardiovasculares/epidemiologia , Cromatografia Líquida de Alta Pressão , Conectina/efeitos dos fármacos , Conectina/metabolismo , Citocinas/efeitos dos fármacos , Citocinas/imunologia , Diástole , Dieta/estatística & dados numéricos , Ecocardiografia , Feminino , Expressão Gênica/efeitos dos fármacos , Teste de Tolerância a Glucose , Coração/diagnóstico por imagem , Insuficiência Cardíaca , Humanos , Immunoblotting , Inflamação , Masculino , Espectrometria de Massas , Camundongos , Pessoa de Meia-Idade , Mitocôndrias Cardíacas/metabolismo , Fosforilação/efeitos dos fármacos , Estudos Prospectivos , Ratos , Ratos Endogâmicos Dahl , Inquéritos e QuestionáriosRESUMO
Accruing data indicate that radiation-induced consequences resemble pathologies of neurodegenerative diseases such as Alzheimer´s. The aim of this study was to elucidate the effect on hippocampus of chronic low-dose-rate radiation exposure (1 mGy/day or 20 mGy/day) given over 300 days with cumulative doses of 0.3 Gy and 6.0 Gy, respectively. ApoE deficient mutant C57Bl/6 mouse was used as an Alzheimer´s model. Using mass spectrometry, a marked alteration in the phosphoproteome was found at both dose rates. The radiation-induced changes in the phosphoproteome were associated with the control of synaptic plasticity, calcium-dependent signalling and brain metabolism. An inhibition of CREB signalling was found at both dose rates whereas Rac1-Cofilin signalling was found activated only at the lower dose rate. Similarly, the reduction in the number of activated microglia in the molecular layer of hippocampus that paralleled with reduced levels of TNFα expression and lipid peroxidation was significant only at the lower dose rate. Adult neurogenesis, investigated by Ki67, GFAP and NeuN staining, and cell death (activated caspase-3) were not influenced at any dose or dose rate. This study shows that several molecular targets induced by chronic low-dose-rate radiation overlap with those of Alzheimer´s pathology. It may suggest that ionising radiation functions as a contributing risk factor to this neurodegenerative disease.
Assuntos
Doença de Alzheimer/etiologia , Apolipoproteínas E/fisiologia , Hipocampo/efeitos da radiação , Proteoma , Doença de Alzheimer/metabolismo , Animais , Proteína de Ligação ao Elemento de Resposta ao AMP Cíclico/fisiologia , Modelos Animais de Doenças , Feminino , Hipocampo/metabolismo , Peroxidação de Lipídeos/efeitos da radiação , Camundongos , Camundongos Endogâmicos C57BL , Neurogênese/efeitos da radiação , Plasticidade Neuronal/efeitos da radiação , Fosforilação , Doses de Radiação , Radiação Ionizante , Transdução de SinaisRESUMO
In Wilson disease (WD), functional loss of ATPase copper-transporting ß (ATP7B) impairs biliary copper excretion, leading to excessive copper accumulation in the liver and fulminant hepatitis. Current US Food and Drug Administration- and European Medicines Agency-approved pharmacological treatments usually fail to restore copper homeostasis in patients with WD who have progressed to acute liver failure, leaving liver transplantation as the only viable treatment option. Here, we investigated the therapeutic utility of methanobactin (MB), a peptide produced by Methylosinus trichosporium OB3b, which has an exceptionally high affinity for copper. We demonstrated that ATP7B-deficient rats recapitulate WD-associated phenotypes, including hepatic copper accumulation, liver damage, and mitochondrial impairment. Short-term treatment of these rats with MB efficiently reversed mitochondrial impairment and liver damage in the acute stages of liver copper accumulation compared with that seen in untreated ATP7B-deficient rats. This beneficial effect was associated with depletion of copper from hepatocyte mitochondria. Moreover, MB treatment prevented hepatocyte death, subsequent liver failure, and death in the rodent model. These results suggest that MB has potential as a therapeutic agent for the treatment of acute WD.
Assuntos
Degeneração Hepatolenticular/tratamento farmacológico , Imidazóis/farmacologia , Falência Hepática Aguda/tratamento farmacológico , Oligopeptídeos/farmacologia , Adenosina Trifosfatases/metabolismo , Animais , Bile/química , Proteínas de Transporte de Cátions/metabolismo , Quelantes/química , Cobre/química , ATPases Transportadoras de Cobre , Modelos Animais de Doenças , Hepatócitos/metabolismo , Humanos , Fígado/efeitos dos fármacos , Mitocôndrias/efeitos dos fármacos , Fenótipo , RatosRESUMO
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.
Assuntos
Córtex Cerebral/efeitos da radiação , Raios gama/efeitos adversos , Hipocampo/efeitos da radiação , Potenciação de Longa Duração/efeitos da radiação , Proteoma/genética , Transmissão Sináptica/efeitos da radiação , Fatores de Despolimerização de Actina/genética , Fatores de Despolimerização de Actina/metabolismo , Animais , Animais Recém-Nascidos , Axônios/metabolismo , Axônios/efeitos da radiação , Axônios/ultraestrutura , Córtex Cerebral/metabolismo , Córtex Cerebral/fisiopatologia , Proteína de Ligação ao Elemento de Resposta ao AMP Cíclico/genética , Proteína de Ligação ao Elemento de Resposta ao AMP Cíclico/metabolismo , Complexo de Proteínas da Cadeia de Transporte de Elétrons/genética , Complexo de Proteínas da Cadeia de Transporte de Elétrons/metabolismo , Efrinas/genética , Efrinas/metabolismo , Feminino , Hipocampo/metabolismo , Hipocampo/fisiopatologia , Memória/efeitos dos fármacos , Camundongos , Camundongos Endogâmicos C57BL , MicroRNAs/genética , MicroRNAs/metabolismo , Mitocôndrias/metabolismo , Mitocôndrias/efeitos da radiação , Neuropeptídeos/genética , Neuropeptídeos/metabolismo , Fosforilação Oxidativa/efeitos da radiação , Proteoma/metabolismo , Sinaptossomos/metabolismo , Sinaptossomos/efeitos da radiação , Irradiação Corporal Total , Proteínas rac1 de Ligação ao GTP/genética , Proteínas rac1 de Ligação ao GTP/metabolismo , Inibidores da Dissociação do Nucleotídeo Guanina rho-Específico/genética , Inibidores da Dissociação do Nucleotídeo Guanina rho-Específico/metabolismoRESUMO
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.
Assuntos
Vasos Sanguíneos/efeitos da radiação , Proteômica , Transcriptoma , Animais , Vasos Sanguíneos/citologia , Vasos Sanguíneos/fisiopatologia , Cromatografia Líquida , Perfilação da Expressão Gênica , Camundongos , Camundongos Endogâmicos C57BL , Espectrometria de Massas por Ionização por Electrospray , Espectrometria de Massas em TandemRESUMO
Recently, mutations in the mitochondrial translation optimization factor 1 gene (MTO1) were identified as causative in children with hypertrophic cardiomyopathy, lactic acidosis and respiratory chain defect. Here, we describe an MTO1-deficient mouse model generated by gene trap mutagenesis that mirrors the human phenotype remarkably well. As in patients, the most prominent signs and symptoms were cardiovascular and included bradycardia and cardiomyopathy. In addition, the mutant mice showed a marked worsening of arrhythmias during induction and reversal of anaesthesia. The detailed morphological and biochemical workup of murine hearts indicated that the myocardial damage was due to complex I deficiency and mitochondrial dysfunction. In contrast, neurological examination was largely normal in Mto1-deficient mice. A translational consequence of this mouse model may be to caution against anaesthesia-related cardiac arrhythmias which may be fatal in patients.
Assuntos
Cardiomiopatias/genética , Cardiomiopatias/fisiopatologia , Proteínas de Transporte/genética , Técnicas de Silenciamento de Genes , Coração/fisiopatologia , Miocárdio/patologia , Animais , Cardiomiopatias/patologia , DNA Mitocondrial/genética , Modelos Animais de Doenças , Complexo I de Transporte de Elétrons/genética , Feminino , Dosagem de Genes , Genes Mitocondriais , Humanos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Mitocôndrias/metabolismo , Mitocôndrias/patologia , Proteínas Mitocondriais , Fosforilação Oxidativa , Proteínas de Ligação a RNARESUMO
BACKGROUND/PURPOSE OF THE STUDY: Epidemiological evidence suggests that low doses of ionising radiation (≤1.0 Gy) produce persistent alterations in cognition if the exposure occurs at a young age. The mechanisms underlying such alterations are unknown. We investigated the long-term effects of low doses of total body gamma radiation on neonatally exposed NMRI mice on the molecular and cellular level to elucidate neurodegeneration. RESULTS: Significant alterations in spontaneous behaviour were observed at 2 and 4 months following a single 0.5 or 1.0 Gy exposure. Alterations in the brain proteome, transcriptome, and several miRNAs were analysed 6-7 months post-irradiation in the hippocampus, dentate gyrus (DG) and cortex. Signalling pathways related to synaptic actin remodelling such as the Rac1-Cofilin pathway were altered in the cortex and hippocampus. Further, synaptic proteins MAP-2 and PSD-95 were increased in the DG and hippocampus (1.0 Gy). The expression of synaptic plasticity genes Arc, c-Fos and CREB was persistently reduced at 1.0 Gy in the hippocampus and cortex. These changes were coupled to epigenetic modulation via increased levels of microRNAs (miR-132/miR-212, miR-134). Astrogliosis, activation of insulin-growth factor/insulin signalling and increased level of microglial cytokine TNFα indicated radiation-induced neuroinflammation. In addition, adult neurogenesis within the DG was persistently negatively affected after irradiation, particularly at 1.0 Gy. CONCLUSION: These data suggest that neurocognitive disorders may be induced in adults when exposed at a young age to low and moderate cranial doses of radiation. This raises concerns about radiation safety standards and regulatory practices.
Assuntos
Encéfalo/efeitos da radiação , Cognição/efeitos da radiação , Neurogênese/efeitos da radiação , Plasticidade Neuronal/efeitos da radiação , Lesões Experimentais por Radiação , Animais , Animais Recém-Nascidos , Comportamento Animal/efeitos da radiação , Imunofluorescência , Immunoblotting , Imuno-Histoquímica , Masculino , Camundongos , Transdução de Sinais/efeitos da radiaçãoRESUMO
UNLABELLED: Vector-borne flaviviruses, such as tick-borne encephalitis virus (TBEV), West Nile virus, and dengue virus, cause millions of infections in humans. TBEV causes a broad range of pathological symptoms, ranging from meningitis to severe encephalitis or even hemorrhagic fever, with high mortality. Despite the availability of an effective vaccine, the incidence of TBEV infections is increasing. Not much is known about the role of the innate immune system in the control of TBEV infections. Here, we show that the type I interferon (IFN) system is essential for protection against TBEV and Langat virus (LGTV) in mice. In the absence of a functional IFN system, mice rapidly develop neurological symptoms and succumb to LGTV and TBEV infections. Type I IFN system deficiency results in severe neuroinflammation in LGTV-infected mice, characterized by breakdown of the blood-brain barrier and infiltration of macrophages into the central nervous system (CNS). Using mice with tissue-specific IFN receptor deletions, we show that coordinated activation of the type I IFN system in peripheral tissues as well as in the CNS is indispensable for viral control and protection against virus induced inflammation and fatal encephalitis. IMPORTANCE: The type I interferon (IFN) system is important to control viral infections; however, the interactions between tick-borne encephalitis virus (TBEV) and the type I IFN system are poorly characterized. TBEV causes severe infections in humans that are characterized by fever and debilitating encephalitis, which can progress to chronic illness or death. No treatment options are available. An improved understanding of antiviral innate immune responses is pivotal for the development of effective therapeutics. We show that type I IFN, an effector molecule of the innate immune system, is responsible for the extended survival of TBEV and Langat virus (LGTV), an attenuated member of the TBE serogroup. IFN production and signaling appeared to be essential in two different phases during infection. The first phase is in the periphery, by reducing systemic LGTV replication and spreading into the central nervous system (CNS). In the second phase, the local IFN response in the CNS prevents virus-induced inflammation and the development of encephalitis.
Assuntos
Vírus da Encefalite Transmitidos por Carrapatos/imunologia , Encefalite Transmitida por Carrapatos/imunologia , Encefalite Transmitida por Carrapatos/mortalidade , Interferon Tipo I/imunologia , Animais , Camundongos Endogâmicos C57BL , Camundongos Knockout , Receptores de Interferon/deficiência , Análise de SobrevidaRESUMO
BACKGROUND INFORMATION: Ewing's sarcoma (ES) is the second most common bone-associated malignancy in children and is driven by the fusion oncogene EWS/FLI1 and characterised by rapid growth and early metastasis. Here, we explored the role of the Zyxin-related protein thyroid receptor interacting protein 6 (TRIP6) in ES. The Zyxin family comprises seven homologous proteins involved in migration and proliferation of many cell types of which Zyxin has been described as a tumour suppressor in ES. RESULTS: By interrogation of published microarray data (n = 1254), we observed that of all Zyxin proteins, only TRIP6 is highly overexpressed in primary ES compared with normal tissues. Re-analysis of published EWS/FLI1 gain- and loss-of-function microarray experiments as well as chromatin-immunoprecipitation assays revealed that TRIP6 overexpression is not mediated by EWS/FLI1. Microarray and subsequent gene-set enrichment analyses of ES cells with and without RNA interference-mediated TRIP6 knockdown demonstrated that TRIP6 expression confers a pro-proliferative and pro-invasive transcriptional signature to ES cells. While short-term proliferation was not considerably affected by TRIP6 knockdown, silencing of the protein significantly reduced migration, invasion, long-term proliferation and clonogenicity of ES cells in vitro as well as tumourigenicity in vivo. CONCLUSIONS: Taken together, our data indicate that TRIP6 acts, in contrast to Zyxin, as an oncogene that partially accounts for the autonomous migratory, invasive and proliferative properties of ES cells independent of EWS/FLI1.
Assuntos
Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Movimento Celular , Proteínas com Domínio LIM/metabolismo , Sarcoma de Ewing/patologia , Fatores de Transcrição/metabolismo , ATPases Associadas a Diversas Atividades Celulares , Animais , Carcinogênese/genética , Carcinogênese/patologia , Linhagem Celular Tumoral , Proliferação de Células , Células Clonais , Perfilação da Expressão Gênica , Regulação Neoplásica da Expressão Gênica , Técnicas de Silenciamento de Genes , Células HEK293 , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Invasividade Neoplásica , Complexo de Endopeptidases do Proteassoma , Sarcoma de Ewing/genéticaRESUMO
Radiation exposure of the thorax is associated with a markedly increased risk of cardiac morbidity and mortality with a latency period of decades. Although many studies have confirmed the damaging effect of ionizing radiation on the myocardium and cardiac endothelial structure and function, the molecular mechanism behind this damage is not yet elucidated. Peroxisome proliferator-activated receptor alpha (PPAR alpha), a transcriptional regulator of lipid metabolism in heart tissue, has recently received great attention in the development of cardiovascular disease. The goal of this study was to investigate radiation-induced cardiac damage in general and the role of PPAR alpha in this process in particular. C57BL/6 mice received local heart irradiation with X-ray doses of 8 and 16 gray (Gy) at the age of 8 weeks. The mice were sacrificed 16 weeks later. Radiation-induced changes in the cardiac proteome were quantified using the Isotope Coded Protein Label (ICPL) method followed by mass spectrometry and software analysis. Significant alterations were observed in proteins involved in lipid metabolism and oxidative phosphorylation. Ionizing radiation markedly changed the phosphorylation and ubiquitination status of PPAR alpha. This was reflected as decreased expression of its target genes involved in energy metabolism and mitochondrial respiratory chain confirming the proteomics data. This study suggests that persistent alteration of cardiac metabolism due to impaired PPAR alpha activity contributes to the heart pathology after radiation.
Assuntos
Coração/efeitos da radiação , Metabolismo dos Lipídeos/efeitos da radiação , Mitocôndrias Cardíacas/efeitos da radiação , PPAR alfa/genética , Animais , Expressão Gênica/efeitos da radiação , Coração/fisiopatologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Mitocôndrias Cardíacas/metabolismo , Fosforilação Oxidativa/efeitos da radiação , PPAR alfa/metabolismo , Mapeamento de Interação de Proteínas , Proteômica , Transdução de Sinais , Espectrometria de Massas por Ionização por Electrospray , Espectrometria de Massas em Tandem , Raios XRESUMO
Morphological lesions in kidneys and brain are all too often considered diagnostic for confirmation of encephalitozoonosis in rabbits. The current study evaluated the diagnostic value of histology versus other etiological tests, including immunohistochemistry and real-time polymerase chain reaction (PCR) for Encephalitozoon cuniculi infection diagnosis. Samples of brain, heart, lungs, intestine, liver, and kidneys from 81 rabbits were examined for morphological lesions attributed to E. cuniculi infection as well as for the presence of spores and E. cuniculi antigen. Of these, 55 rabbits were tested for E. cuniculi DNA. Histological changes consistent with E. cuniculi infection were seen in 33 rabbits (41%, 33/81) representing 87% (33/38) of all rabbits with confirmed E. cuniculi infection. Brains of these rabbits displayed 6 different types of focal lesions corresponding to the stage of infection and specific tissue response. In 5 rabbits that were tested positive, histology was either inconclusive or inconspicuous. Etiological diagnosis was based on histological spore detection in 16% (6/38) of infected rabbits. Immunohistochemistry was more sensitive (42%, 16/38) than histological spore detection, and real-time PCR proved to be the most sensitive of all investigated methods (30/35, 86% of the examined rabbits with E. cuniculi infection). Encephalitozoon cuniculi infection rarely occurs without characteristic kidney and brain lesions. However, the spectrum of brain changes is wider than previously reported. Based on these findings, confirmation of pathogenic E. cuniculi infection should include standard histology of the predilection sites and a specific etiological assay, preferably real-time PCR.
Assuntos
Encephalitozoon cuniculi/isolamento & purificação , Encefalitozoonose/veterinária , Coelhos/microbiologia , Animais , Encéfalo/microbiologia , DNA Fúngico/química , DNA Fúngico/genética , Encephalitozoon cuniculi/genética , Encefalitozoonose/diagnóstico , Encefalitozoonose/microbiologia , Feminino , Imuno-Histoquímica/veterinária , Rim/microbiologia , Masculino , Reação em Cadeia da Polimerase em Tempo Real/veterináriaRESUMO
Under the label of the German Mouse Clinic (GMC), a concept has been developed and implemented that allows the better understanding of human diseases on the pathophysiological and molecular level. This includes better understanding of the crosstalk between different organs, pleiotropy of genes, and the systemic impact of envirotypes and drugs. In the GMC, experts from various fields of mouse genetics and physiology, in close collaboration with clinicians, work side by side under one roof. The GMC is an open-access platform for the scientific community by providing phenotypic analysis in bilateral collaborations ("bottom-up projects") and as a partner and driver in international large-scale biology projects ("top-down projects"). Furthermore, technology development is a major topic in the GMC. Innovative techniques for primary and secondary screens are developed and implemented into the phenotyping pipelines (e.g., detection of volatile organic compounds, VOCs).
Assuntos
Modelos Animais , Animais , Alemanha , Camundongos , FenótipoAssuntos
Furões/microbiologia , Infecções por Mycobacterium/veterinária , Mycobacterium/classificação , Animais , Meios de Cultura , Pulmão/microbiologia , Pulmão/patologia , Masculino , Mycobacterium/genética , Mycobacterium/isolamento & purificação , Infecções por Mycobacterium/microbiologia , Reação em Cadeia da Polimerase/métodosRESUMO
A widespread, severe outbreak of canine distemper encephalitis was observed in wildlife in Southern Bavaria in the spring and summer of 2008. The haemagglutinin (HA) genes of six representative canine distemper virus (CDV) samples originating from five red foxes and one badger during this outbreak had a Y549H amino acid substitution in the HA protein compared to sequences from two captive domesticated ferrets which succumbed to CDV in the same area 2 years earlier. As this specific substitution at the receptor-binding site has been hypothesised to contribute to the emergence of CDV and its spread to novel hosts, the outbreak in wildlife in Southern Bavaria might, directly or indirectly, be associated with a Y549H amino acid exchange.
Assuntos
Substituição de Aminoácidos , Vírus da Cinomose Canina/genética , Cinomose/epidemiologia , Cinomose/virologia , Hemaglutininas/genética , Animais , Animais Selvagens , Doenças Transmissíveis Emergentes/epidemiologia , Doenças Transmissíveis Emergentes/veterinária , Doenças Transmissíveis Emergentes/virologia , Vírus da Cinomose Canina/isolamento & purificação , Cães , Feminino , Raposas/virologia , Variação Genética , Alemanha/epidemiologia , Masculino , Mustelidae/virologiaRESUMO
In the mouse Pax6 function is critical in a dose-dependent manner for proper eye development. Pax6 contiguous gene deletions were shown to be homozygous lethal at an early embryonic stage. Heterozygotes express belly spotting and extreme microphthalmia. The eye phenotype is more severe than in heterozygous Pax6 intragenic null mutants, raising the possibility that deletions are functionally different from intragenic null mutations or that a region distinct from Pax6 included in the deletions affects eye phenotype. We recovered and identified the exact regions deleted in three new Pax6 deletions. All are homozygous lethal at an early embryonic stage. None express belly spotting. One expresses extreme microphthalmia and two express the milder eye phenotype similar to Pax6 intragenic null mutants. Analysis of Pax6 expression levels and the major isoforms excluded the hypothesis that the deletions expressing extreme microphthalmia are directly due to the action of Pax6 and functionally different from intragenic null mutations. A region distinct from Pax6 containing eight genes was identified for belly spotting. A second region containing one gene (Rcn1) was identified for the extreme microphthalmia phenotype. Rcn1 is a Ca(+2)-binding protein, resident in the endoplasmic reticulum, participates in the secretory pathway and expressed in the eye. Our results suggest that deletion of Rcn1 directly or indirectly contributes to the eye phenotype in Pax6 contiguous gene deletions.