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Mutations in coiled-coil-helix-coiled-coil-helix-domain containing 10 (CHCHD10), a mitochondrial twin CX9C protein whose function is still unknown, cause myopathy, motor neuron disease, frontotemporal dementia, and Parkinson's disease. Here, we investigate CHCHD10 topology and its protein interactome, as well as the effects of CHCHD10 depletion or expression of disease-associated mutations in wild-type cells. We find that CHCHD10 associates with membranes in the mitochondrial intermembrane space, where it interacts with a closely related protein, CHCHD2. Furthermore, both CHCHD10 and CHCHD2 interact with p32/GC1QR, a protein with various intra and extra-mitochondrial functions. CHCHD10 and CHCHD2 have short half-lives, suggesting regulatory rather than structural functions. Cell lines with CHCHD10 knockdown do not display bioenergetic defects, but, unexpectedly, accumulate excessive intramitochondrial iron. In mice, CHCHD10 is expressed in many tissues, most abundantly in heart, skeletal muscle, liver, and in specific CNS regions, notably the dopaminergic neurons of the substantia nigra and spinal cord neurons, which is consistent with the pathology associated with CHCHD10 mutations. Homozygote CHCHD10 knockout mice are viable, have no gross phenotypes, no bioenergetic defects or ultrastructural mitochondrial abnormalities in brain, heart or skeletal muscle, indicating that functional redundancy or compensatory mechanisms for CHCHD10 loss occur in vivo. Instead, cells expressing S59L or R15L mutant versions of CHCHD10, but not WT, have impaired mitochondrial energy metabolism. Taken together, the evidence obtained from our in vitro and in vivo studies suggest that CHCHD10 mutants cause disease through a gain of toxic function mechanism, rather than a loss of function.
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Proteínas Mitocondriais/genética , Proteínas Mitocondriais/metabolismo , Esclerose Lateral Amiotrófica/genética , Esclerose Lateral Amiotrófica/metabolismo , Animais , Proteínas de Transporte , Proteínas de Ligação a DNA , Demência Frontotemporal/genética , Estudos de Associação Genética , Células HEK293 , Células HeLa , Humanos , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Mitocôndrias/genética , Mitocôndrias/metabolismo , Proteínas Mitocondriais/química , Modelos Moleculares , Mutação , Domínios e Motivos de Interação entre Proteínas , Mapeamento de Interação de Proteínas , Elementos Estruturais de Proteínas , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismoRESUMO
Pelvic floor rehabilitation is frequently recommended for defecation disorders, in both constipation and fecal incontinence. However, the lack of patient selection, together with the variety of rehabilitation methods and protocols, often jeopardize the results of this approach, causing difficulty in evaluating outcomes and addressing proper management, and above all, in obtaining scientific evidence for the efficacy of these methods for specific indications. The authors represent different gastroenterological and surgical scientific societies in Italy, and their aim was to identify the indications and agree on treatment protocols for pelvic floor rehabilitation of patients with defecation disorders. This was achieved by means of a modified Delphi method, utilizing a working team (10 members) which developed the statements and a consensus group (15 members, different from the previous ones) which voted twice also suggesting modifications of the statements.
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Constipação Intestinal/reabilitação , Incontinência Fecal/reabilitação , Gastroenterologia/normas , Guias de Prática Clínica como Assunto/normas , Sociedades Médicas/normas , Defecação , Técnica Delphi , Humanos , Itália , Diafragma da PelveRESUMO
Iron released by steel corrosion was found to be a key impurity in reactions with dissolved oxygen in liquid lead-bismuth eutectic alloys. The iron-oxygen-magnetite equilibrium was characterized, allowing the quantification of phenomena that are important for long-term operation of lead-alloy based installations such as corrosion rate control and management of precipitates.
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PROBLEM: It's well known that iv. immunoglobulins may be useful to overcome habitual abortions, but the mechanisms at the base of a successful outcome and the likelihoods are still unknown. METHOD OF STUDY: In one hundred and sixty women with habitual abortions and one hundred and sixty healthy mothers, we evaluated blood IgG subclasses; among the patients, sixteen merely showed IgG subclass deficiency, after leaving out any autoimmunity and/or coagulation disorders. All the patients (100%) showed IgG3, twelve (75%) IgG1, eight (50%) IgG4 and six (37,5%) IgG2 deficiency; healthy control people's IgG subclasses fell in normal range in 156 women, but just four women showed IgG2 and IgG4 deficiency with neither immune deficiency's clinical marks nor increased vulnerability to infections. All the patients were treated with whole immunoglobulins iv. infusion (200 mg/kg/monthly) all over the pregnancy. RESULTS: The successful pregnancy rate is very high (>90%): 100% out of women showing IgG1 (12/12), 87,5% of IgG3 (14/16), 75% of IgG4 (6/8) and 66% of IgG2 deficiency (4/6) had successful pregnancies. The Odd's Ratio between IgG subclass deficiency and recurrent abortions is 4,33 with confidence interval of 95%; chi square value is 7.68 (p<0.025). CONCLUSIONS: Low dose immunoglobulin infusion is the only effective way to reach successful pregnancy, despite previous habitual abortions in patients suffering from IgG subclass deficiency without autoimmunity and/or coagulation disorders, likely restoring idiotype-antiidiotype network; showing evidence of IgG subclasses deficiency (mostly IgG1 and IgG3) may help identify patients who can benefit from iv. immunoglobulin treatment.
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Aborto Habitual/prevenção & controle , Deficiência de IgG/tratamento farmacológico , Imunoglobulina G/sangue , Imunoglobulinas Intravenosas/administração & dosagem , Aborto Habitual/sangue , Aborto Habitual/diagnóstico , Aborto Habitual/imunologia , Biomarcadores/sangue , Estudos de Casos e Controles , Feminino , Humanos , Deficiência de IgG/sangue , Deficiência de IgG/diagnóstico , Deficiência de IgG/imunologia , Imunoglobulina G/classificação , Infusões Intravenosas , Nascido Vivo , Razão de Chances , Gravidez , Fatores de Risco , Resultado do TratamentoRESUMO
The most prevalent genetic cause of both amyotrophic lateral sclerosis and frontotemporal dementia is a (GGGGCC)n nucleotide repeat expansion (NRE) occurring in the first intron of the C9orf72 gene (C9). Brain glucose hypometabolism is consistently observed in C9-NRE carriers, even at pre-symptomatic stages, although its potential role in disease pathogenesis is unknown. Here, we identified alterations in glucose metabolic pathways and ATP levels in the brain of asymptomatic C9-BAC mice. We found that, through activation of the GCN2 kinase, glucose hypometabolism drives the production of dipeptide repeat proteins (DPRs), impairs the survival of C9 patient-derived neurons, and triggers motor dysfunction in C9-BAC mice. We also found that one of the arginine-rich DPRs (PR) can directly contribute to glucose metabolism and metabolic stress. These findings provide a mechanistic link between energy imbalances and C9-ALS/FTD pathogenesis and support a feedforward loop model that opens several opportunities for therapeutic intervention.
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Mutations in the mitochondrial DNA (mtDNA) encoded subunit 6 of ATPase (ATP6) are associated with variable disease expression, ranging from adult onset neuropathy, ataxia and retinitis pigmentosa (NARP) to fatal childhood maternally inherited Leigh's syndrome (MILS). Phenotypical variations have largely been attributed to mtDNA heteroplasmy. However, there is often a discrepancy between the levels of mutant mtDNA and disease severity. Therefore, the correlation among genetic defect, bioenergetic impairment and clinical outcome in NARP/MILS remains to be elucidated. We investigated the bioenergetics of cybrids from five patients carrying different ATP6 mutations: three harboring the T8993G, one with the T8993C and one with the T9176G mutation. The bioenergetic defects varied dramatically, not only among different ATP6 mutants, but also among lines carrying the same T8993G mutation. Mutants with the most severe ATP synthesis impairment showed defective respiration and disassembly of respiratory chain complexes. This indicates that respiratory chain defects modulate the bioenergetic impairment in NARP/MILS cells. Sequencing of the entire mtDNA from the different mutant cell lines identified variations in structural genes, resulting in amino acid changes that destabilize the respiratory chain. Taken together, these results indicate that the mtDNA background plays an important role in modulating the biochemical defects and clinical outcome in NARP/MILS.
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DNA Mitocondrial/genética , Metabolismo Energético , Doença de Leigh/enzimologia , ATPases Mitocondriais Próton-Translocadoras/genética , Mutação , Retinose Pigmentar/enzimologia , Respiração Celular , Células Cultivadas , DNA Mitocondrial/metabolismo , Humanos , Doença de Leigh/genética , Doença de Leigh/metabolismo , ATPases Mitocondriais Próton-Translocadoras/metabolismo , Dados de Sequência Molecular , Retinose Pigmentar/genética , Retinose Pigmentar/metabolismoRESUMO
Retinal dystrophies such as Retinitis pigmentosa are among the most prevalent causes of inherited legal blindness, for which treatments are in demand. Retinal prostheses have been developed to stimulate the inner retinal network that, initially spared by degeneration, deteriorates in the late stages of the disease. We recently reported that conjugated polymer nanoparticles persistently rescue visual activities after a single subretinal injection in the Royal College of Surgeons rat model of Retinitis pigmentosa. Here we demonstrate that conjugated polymer nanoparticles can reinstate physiological signals at the cortical level and visually driven activities when microinjected in 10-months-old Royal College of Surgeons rats bearing fully light-insensitive retinas. The extent of visual restoration positively correlates with the nanoparticle density and hybrid contacts with second-order retinal neurons. The results establish the functional role of organic photovoltaic nanoparticles in restoring visual activities in fully degenerate retinas with intense inner retina rewiring, a stage of the disease in which patients are subjected to prosthetic interventions.
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Nanopartículas , Retinose Pigmentar , Próteses Visuais , Animais , Modelos Animais de Doenças , Humanos , Polímeros , Ratos , Retinose Pigmentar/terapiaRESUMO
Hereditary haemorrhagic telangiectasia (HHT) is a complex, multisystemic vascular dysplasia affecting approximately 85,000 European Citizens. In 2016, eight founding centres operating within 6 countries, set up a working group dedicated to HHT within what became the European Reference Network on Rare Multisystemic Vascular Diseases. By launch, combined experience exceeded 10,000 HHT patients, and Chairs representing 7 separate specialties provided a median of 24 years' experience in HHT. Integrated were expert patients who focused discussions on the patient experience. Following a 2016-2017 survey to capture priorities, and underpinned by more than 40 monthly meetings, and new data acquisitions, VASCERN HHT generated position statements that distinguish expert HHT care from non-expert HHT practice. Leadership was by specialists in the relevant sub-discipline(s), and 100% consensus was required amongst all clinicians before statements were published or disseminated. One major set of outputs targeted all healthcare professionals and their HHT patients, and include the new Orphanet definition; Do's and Don'ts for common situations; Outcome Measures suitable for all consultations; COVID-19; and anticoagulation. The second output set span aspects of vascular pathophysiology where greater understanding will assist organ-specific specialist clinicians to provide more informed care to HHT patients. These cover cerebral vascular malformations and screening; mucocutaneous telangiectasia and differential diagnosis; anti-angiogenic therapies; circulatory interplays between anaemia and arteriovenous malformations; and microbiological strategies to counteract loss of normal pulmonary capillary function. Overall, the integrated outputs, and documented current practices, provide frameworks for approaches that augment the health and safety of HHT patients in diverse health-care settings.
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Telangiectasia Hemorrágica Hereditária/terapia , Gerenciamento Clínico , Europa (Continente) , Humanos , Guias de Prática Clínica como Assunto , Doenças Raras , Telangiectasia Hemorrágica Hereditária/diagnósticoRESUMO
The usage of magnetic nanoparticles (NPs) in applications necessitates a precise mastering of their properties at the single nanoparticle level. There has been a lot of progress in the understanding of the magnetic properties of NPs, but incomparably less when interparticle interactions govern the overall magnetic response. Here, we present a quantitative investigation of magnetic fields generated by small clusters of NPs assembled on a dielectric non-magnetic surface. Structures ranging from individual NPs to fifth-fold particulate clusters are investigated in their magnetization saturation state by magnetic force microscopy and numerical calculations. It is found that the magnetic stray field does not increase proportionally with the number of NPs in the cluster. Both measured and calculated magnetic force fields underline the great importance of the exact spatial arrangement of NPs, shedding light on the magnetic force field distribution of particulate clusters, which is relevant for the quantitative evaluation of their magnetization and perceptibly for many applications.
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AIMS: To evaluate diagnostic accuracy of contrast echocardiography (CE) as compared with CT, for the screening of pulmonary arteriovenous malformations (PAVMs) in hereditary haemorrhagic telangiectasia (HHT); to evaluate the clinical significance of semi-quantitative analysis of a shunt on CE. METHODS AND RESULTS: A blinded prospective study was conducted in 190 consecutive subjects at risk of HHT who underwent screening for PAVMs, including clinical evaluation, pulse oximetry, standard and CE, and chest multirow CT without contrast medium. A semi-quantitative analysis of the shunt size was performed according to the contrast echo opacification of the left-sided chambers: Grade 0, no bubbles; 1, occasional filling with <20 bubbles; 2, moderate filling; 3, complete opacification. The first 100 patients were compared with 100 controls. A total of 119 (63%) patients had positive CE (32.2% Grade 1, 13.1% Grade 2, 11% Grade 3, 6.3% with patent foramen ovale). The overall diagnostic performance of CE was sensitivity 1.00, specificity 0.49, positive predictive value (PPV) 0.32, negative predictive value (NPV) 1.00. The PPV for the different grades was 0.00 for Grade 1, 0.56 for Grade 2, 1.00 for Grade 3; the NPV of Grade 0 was 1.00. A significant correlation was found between the CE grading and the number of PAVM, and complications (P < 0.0001). CONCLUSION: CE is an extremely sensitive procedure for the detection of PAVMs with substantial clinical impact.
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Malformações Arteriovenosas/diagnóstico por imagem , Ecocardiografia/métodos , Artéria Pulmonar/anormalidades , Veias Pulmonares/anormalidades , Telangiectasia Hemorrágica Hereditária/complicações , Tomografia Computadorizada por Raios X/métodos , Adolescente , Adulto , Idoso , Malformações Arteriovenosas/diagnóstico , Malformações Arteriovenosas/etiologia , Estudos de Casos e Controles , Distribuição de Qui-Quadrado , Criança , Pré-Escolar , Embolização Terapêutica , Feminino , Predisposição Genética para Doença , Humanos , Masculino , Microbolhas , Pessoa de Meia-Idade , Oximetria , Estudos Prospectivos , Artéria Pulmonar/diagnóstico por imagem , Veias Pulmonares/diagnóstico por imagem , Sensibilidade e Especificidade , Método Simples-Cego , Adulto JovemRESUMO
OBJECTIVE: The aim of this study was to evaluate the roles of personality and affective temperament traits in the prediction of suicide risk in mood disorders. METHODS: The participants were 147 psychiatric inpatients with bipolar disorders I and II and major depressive disorder. Patients undertook the Temperament Evaluation of Memphis, Pisa, Paris, and San Diego self-rating questionnaire, the Minnesota Multiphasic Personality Inventory-2 (MMPI-2), and the Beck Hopelessness Scale. RESULTS: Sixty-four subjects were diagnosed with increased suicidal risk based on the Mini International Neuropsychiatric Interview (MINI). Logistic regression analysis resulted in two models predictive of MINI-based suicidal risk: irritable temperament and the MMPI-2 scale. Multiple regression analysis further indicated that higher hyperthymic values are protective against hopelessness, while MINI-based suicidal intent is a predictor of hopelessness. CONCLUSIONS: Personality and affective temperament traits may have a role in the prediction of suicide.
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Transtorno Bipolar/epidemiologia , Transtorno Bipolar/psicologia , Depressão/epidemiologia , Depressão/psicologia , Determinação da Personalidade , Personalidade , Suicídio/psicologia , Suicídio/estatística & dados numéricos , Adulto , Comorbidade , Feminino , Humanos , Internacionalidade , Masculino , Medição de Risco/métodos , Fatores de Risco , Estatística como Assunto , TemperamentoRESUMO
BACKGROUND: Hereditary hemorrhagic telangiectasia (HHT) is a rare vascular dysplasia resulting in visceral arteriovenous malformations and smaller mucocutaneous telangiectasia. Most patients experience recurrent nosebleeds and become anemic without iron supplementation. However, thousands may require anticoagulation for conditions such as venous thromboembolism and/or atrial fibrillation. Over decades, tolerance data has been published for almost 200 HHT-affected users of warfarin and heparins, but there are no published data for the newer direct oral anticoagulants (DOACs) in HHT. METHODS: To provide such data, a retrospective audit was conducted across the eight HHT centres of the European Reference Network for Rare Multisystemic Vascular Diseases (VASCERN), in Denmark, France, Germany, Italy, the Netherlands and the UK. RESULTS: Although HHT Centres had not specifically recommended the use of DOACs, 32 treatment episodes had been initiated by other clinicians in 28 patients reviewed at the Centres, at median age 65 years (range 30-84). Indications were for atrial fibrillation (16 treatment episodes) and venous thromboembolism (16 episodes). The 32 treatment episodes used Apixaban (n = 15), Rivaroxaban (n = 14), and Dabigatran (n = 3). HHT nosebleeds increased in severity in 24/32 treatment episodes (75%), leading to treatment discontinuation in 11 (34.4%). Treatment discontinuation was required for 4/15 (26.7%) Apixaban episodes and 7/14 (50%) Rivaroxaban episodes. By a 4 point scale of increasing severity, there was a trend for Rivaroxaban to be associated with a greater bleeding risk both including and excluding patients who had used more than one agent (age-adjusted coefficients 0.61 (95% confidence intervals 0.11, 1.20) and 0.74 (95% confidence intervals 0.12, 1.36) respectively. Associations were maintained after adjustment for gender and treatment indication. Extreme hemorrhagic responses, worse than anything experienced previously, with individual nosebleeds lasting hours requiring hospital admissions, blood transfusions and in all cases treatment discontinuation, occurred in 5/14 (35.7%) Rivaroxaban episodes compared to 3/15 (20%) Apixaban episodes and published rates of ~ 5% for warfarin and heparin. CONCLUSIONS: Currently, conventional heparin and warfarin remain first choice anticoagulants in HHT. If newer anticoagulants are considered, although study numbers are small, at this stage Apixaban appears to be associated with lesser bleeding risk than Rivaroxaban.
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Anticoagulantes/administração & dosagem , Anticoagulantes/efeitos adversos , Telangiectasia Hemorrágica Hereditária/tratamento farmacológico , Administração Oral , Idoso , Idoso de 80 Anos ou mais , Anticoagulantes/uso terapêutico , Fibrilação Atrial/tratamento farmacológico , Dabigatrana/administração & dosagem , Dabigatrana/efeitos adversos , Dabigatrana/uso terapêutico , Epistaxe/tratamento farmacológico , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Embolia Pulmonar/tratamento farmacológico , Pirazóis/administração & dosagem , Pirazóis/efeitos adversos , Pirazóis/uso terapêutico , Piridonas/administração & dosagem , Piridonas/efeitos adversos , Piridonas/uso terapêutico , Estudos Retrospectivos , Rivaroxabana/administração & dosagem , Rivaroxabana/efeitos adversos , Rivaroxabana/uso terapêutico , Tromboembolia Venosa , Varfarina/administração & dosagem , Varfarina/efeitos adversos , Varfarina/uso terapêuticoRESUMO
Of all ethical issues in clinical trial designs, only placebo use is dealt with acrimony and unwarranted, rhetoric emphasis. Many misconceptions are biased and may hamper research in the mechanisms of healing and recovery if placebo is banned from clinical trials, as some influential ethicists propose. Current treatments in psychiatry are by no means optimal and may vary in their effect across studies, rendering difficult to find the best available therapeutic method with which to compare new drugs. Because drugs possess specific mechanisms, it is not possible to compare drugs with different mechanisms as to their relevance in the pathophysiology of a given disorder. Placebo acts through non-specific mechanisms and is the ideal control for any disorder whose pathophysiology is relatively unknown and its treatment is still suboptimal. Sticking to short-term patient benefit in a trial reflects an individualistically oriented thinking in contemporary ethics and is likely to limit further research and efforts to better understand the mechanisms of disease and drug action, but also those related to general body reactance and self-healing, which are enhanced by placebo administration. Because in history ethics are swinging between two opposed views, it is possible that in the near future, the balance will move towards communitarianism, which is more likely to better serve long-term patient needs. Ethicists should also consider some other aspects of human experimentation, such as the consistency of research lines and the trend to substitute older drugs with their metabolites or enantiomers.
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Ensaios Clínicos como Assunto/normas , Ética Médica , Transtornos Mentais/tratamento farmacológico , Placebos/normas , Psicofarmacologia/ética , Humanos , Publicações Periódicas como Assunto , EditoraçãoRESUMO
AIM: The aim of this study was to test the possibility of enhancing blood calcium levels in totally thyroidectomized patients by supplementation with 1 L/d carbonate-bicarbonate-high-calcium mineral water. METHODS: This study enrolled 95 outpatients, totally thyroidectomized four months earlier, and hence treated with oral calcium and vitamin-D. At recruitment, ionized blood calcium was either below (Group A; N. 55) or above (Group B; N. 40, randomly divided in Group B1 [N. 20] and Group B2 [N.20]) the lower limit of the normal range (1.12 mmol/L). For one month, Group A was treated with 1 L/d high-calcium (483 mg/L) mineral water and continued the usual therapy with Ca and vitamin-D. In contrast, Group B1 and Group B2 substituted their Ca and vitamin-D therapy with 1 L/d high-calcium mineral water (Group B1) or 1 L/d of placebo mineral water (Ca:80 mg/L) (Group B2). RESULTS: After one month, a significant 7.5% increase in blood ionized-calcium levels was observed in Group A, no change in Group B1 and a significant drop below normality in Group B2 (Group B2 vs Group B1, P<0.001). Thereafter, 1 L/d of the high-calcium mineral water, given to Group B2 instead of placebo for an additional month, significantly enhanced ionized-calcium levels above the lower limit of normality (Group B2 vs Group B1, NS). CONCLUSION: These experiments show that calcium supplementation as 1 L/d of a high-calcium mineral water may efficaciously enhance blood calcium levels in thyroidectomized patients. This complementary treatment might at least in part contribute to the prevention and/or treatment of hypocalcemia and substitute vitamin-D and calcium therapies after thyroidectomy.
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Cálcio/uso terapêutico , Hipocalcemia/tratamento farmacológico , Águas Minerais/uso terapêutico , Tireoidectomia/efeitos adversos , Adulto , Calcitriol/administração & dosagem , Calcitriol/uso terapêutico , Cálcio/administração & dosagem , Cálcio/sangue , Compostos de Cálcio/administração & dosagem , Compostos de Cálcio/uso terapêutico , Carbonatos/administração & dosagem , Carbonatos/uso terapêutico , Estudos Cross-Over , Relação Dose-Resposta a Droga , Feminino , Bócio/cirurgia , Humanos , Hipocalcemia/sangue , Hipocalcemia/etiologia , Hipoparatireoidismo/sangue , Hipoparatireoidismo/etiologia , Lactatos/administração & dosagem , Lactatos/uso terapêutico , Masculino , Águas Minerais/análise , Hormônio Paratireóideo/sangue , Hormônios Tireóideos/sangue , Tireotropina/sangue , Tiroxina/uso terapêuticoRESUMO
The quasilinear theory of the Wigner-Poisson system in one spatial dimension is examined. Conservation laws and properties of the stationary solutions are determined. Quantum effects are shown to manifest themselves in transient periodic oscillations of the averaged Wigner function in velocity space. The quantum quasilinear theory is checked against numerical simulations of the bump-on-tail and two-stream instabilities. The predicted wavelength of the oscillations in velocity space agrees well with the numerical results.
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Colloidal nanocrystals attract considerable attention in the field of light emitting devices thanks to their high fluorescence quantum yield, low amplified spontaneous emission (ASE) threshold, and spectral tunability via electronic structure engineering and surface functionalization. Combining polymer microcavities with colloidal nanocrystals as gain material promises a solution-based fabrication route to plastic laser cavities as well as applications in the field of smart flexible large area light sources and sensors. Here we demonstrate lasing from polymer microcavities embedding solution processable dot-in-rod (DiR) CdSe/CdS nanocrystals. Two highly reflective polymer dielectric mirrors are prepared by spin-coating of alternated layers of polyacrylic acid and poly(N-vinyl carbazole), with their photonic band gap tailored to the emission of the DiRs. The DiRs are enclosed in the polymer microcavity by drop-cast deposition on one mirror, followed by pressing the mirrors onto each other. We obtain excellent overlap of the ASE band of the DiRs with the photonic band gap of the cavity and observe optically pumped lasing at 640 nm with a threshold of about 50 µJ cm-2.
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Large-scale rearrangements of mitochondrial DNA (mtDNA; i.e., partial duplications [dup-mtDNAs] and deletions [Delta-mtDNAs]) coexist in tissues in a subset of patients with sporadic mitochondrial disorders. In order to study the dynamic relationship among rearranged and wild-type mtDNA (wt-mtDNA) species, we created transmitochondrial cell lines harboring various proportions of wt-, Delta-, and dup-mtDNAs from two patients. After prolonged culture in nonselective media, cells that contained initially 100% dup-mtDNAs became heteroplasmic, containing both wild-type and rearranged mtDNAs, likely generated via intramolecular recombination events. However, in cells that contained initially a mixture of both wt- and Delta-mtDNAs, we did not observe any dup-mtDNAs or other new forms of rearranged mtDNAs, perhaps because the two species were physically separated and were therefore unable to recombine. The ratio of wt-mtDNA to Delta-mtDNAs remained stable in all cells examined, suggesting that there was no replicative advantage for the smaller deleted molecules. Finally, in cells containing a mixture of monomeric and dimeric forms of a specific Delta-mtDNA, we found that the mtDNA population shifted towards homoplasmic dimers, suggesting that there may be circumstances under which the cells favor molecules with multiple replication origins, independent of the size of the molecule.
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DNA Mitocondrial , Síndrome de Kearns-Sayre/genética , Doenças Musculares/genética , Recombinação Genética , Técnicas de Cultura de Células/métodos , Linhagem Celular , Deleção de Genes , Duplicação Gênica , Rearranjo Gênico , Humanos , Fatores de TempoRESUMO
By causing mitochondrial DNA (mtDNA) mutations and oxidation of mitochondrial proteins, reactive oxygen species (ROS) leads to perturbations in mitochondrial proteostasis. Several studies have linked mtDNA mutations to metastasis of cancer cells but the nature of the mtDNA species involved remains unclear. Our data suggests that no common mtDNA mutation identifies metastatic cells; rather the metastatic potential of several ROS-generating mutations is largely determined by their mtDNA genomic landscapes, which can act either as an enhancer or repressor of metastasis. However, mtDNA landscapes of all metastatic cells are characterized by activation of the SIRT/FOXO/SOD2 axis of the mitochondrial unfolded protein response (UPRmt). The UPRmt promotes a complex transcription program ultimately increasing mitochondrial integrity and fitness in response to oxidative proteotoxic stress. Using SOD2 as a surrogate marker of the UPRmt, we found that in primary breast cancers, SOD2 is significantly increased in metastatic lesions. We propose that the ability of selected mtDNA species to activate the UPRmt is a process that is exploited by cancer cells to maintain mitochondrial fitness and facilitate metastasis.
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DNA Mitocondrial/fisiologia , Metástase Neoplásica , Sirtuína 3/fisiologia , Resposta a Proteínas não Dobradas/fisiologia , Neoplasias da Mama/patologia , Linhagem Celular Tumoral , Feminino , Proteína Forkhead Box O3/fisiologia , Humanos , Mitocôndrias/patologia , Superóxido Dismutase/fisiologiaRESUMO
The use of PCR to identify mtDNAs containing a partial duplication (dup-mtDNA) in the presence of a heteroplasmic population of mtDNAs harboring the corresponding deletion (delta-mtDNA) leads to ambiguous results: when the primers anneal in the duplicated portion of the dup-mtDNA (which is also the non-deleted region of the delta-mtDNA) and point towards the abnormal breakpoint junction, both templates are amplified indiscriminately. We have developed two different 'long PCR' approaches to amplify dup-mtDNA even in the presence of delta-mtDNA and wild-type mtDNA (wt-mtDNA). Long PCR with two primers annealing in the non-duplicated region in dup-mtDNA (equivalent to the region missing in delta-mtDNA) and whose 3' ends pointed towards the duplicated area amplified both dup-mtDNA and coexisting wt-mtDNA. We observed, however, a preferential amplification of the wt-mtDNA over that of the longer dup-mtDNAs. This problem was partly overcome by modifying the PCR conditions (extension time, amplicon length, amount of template). In order to overcome the problem of co-amplification, we developed a novel PCR method to amplify specifically dup-mtDNAs. A forward primer annealing across the breakpoint junction was used in conjunction with a backward primer annealing in the non-duplicated region. For those duplication breakpoints flanked by direct repeats, we designed a 'breakpoint loop-out' primer whose sequence omitted the repeated region, in order to avoid the annealing of this primer to wt-mtDNA. This second approach was able to amplify specifically and efficiently the dup-mtDNA in all samples analyzed, irrespective of the size of the duplication or its proportion in the samples.
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DNA Mitocondrial/genética , Miopatias Mitocondriais/genética , Família Multigênica , Reação em Cadeia da Polimerase/métodos , Sequência de Bases , Southern Blotting , Grupo dos Citocromos b/genética , Primers do DNA , Complexo I de Transporte de Elétrons , Complexo IV da Cadeia de Transporte de Elétrons/genética , Humanos , Síndrome de Kearns-Sayre/enzimologia , Síndrome de Kearns-Sayre/genética , Miopatias Mitocondriais/enzimologia , Dados de Sequência Molecular , NADH NADPH Oxirredutases/genética , Oftalmoplegia/enzimologia , Oftalmoplegia/genética , Deleção de SequênciaRESUMO
To 106 14-56 year-old allergic people (30 monosensitized, 24 sensitized to 2 pollens, 52 polysensitized) we have evaluated the Global Immune Competence Status (GICS). That's a compound score, made of ten parameters, six regarding cell-mediated immunity (WBC/mmc, Gr/mmc, Ly/mmc, Ly CD3+/mmc, Ly CD4+/mmc, CD4/CD8 Ratio), four regarding nutritional status and humoral immunity (Tot. Protein mg/dl, Albumin mg/dl, Gammaglobulins mg/dl, IgG mg/dl). Each parameter is brought on a grid including 4 worth scores worsening from 4 to 1, related to different ranges of values; this way quickly leads to characterize type and grade of immune deficiency. So doing we found that in 30 monosensitized people 27 (90%) show a complete immune competence, while just 3 people (10%) have impaired GICS: in these 1 (3%) regards cell-mediated immunity, while 2 (7%) regard humoral immunity. In 24 patients sensitized to 2 allergenes, 18 (75%) showed complete immune competence, while 6 (25%) a GICS impairment regarding cell-mediated immunity. In leaving 52 polysensitized patients, 30 people showed complete immune competence (58%), while 20 (38%) showed a GICS impairment regarding cell-mediated immunity and 2 (4%) impaired humoral immunity. This work shows that the higher the number of sensitizations is, the stronger the cell-mediated immunity impairment in allergic people become.