RESUMO
OBJECTIVE: We report the prevalence, characteristics and clinical outcomes of women with sexually transmitted infections (STIs) in pregnancy in the Western Sydney Local Health District (WSLHD) serving a large culturally and socio-economically diverse community in New South Wales (NSW), Australia, over the last 10 years. METHODS: A retrospective cohort study of all pregnant women booked for antenatal care at three hospitals in WSLHD between September 2012 and August 2022 inclusive. Characteristics and birth outcomes associated with STIs diagnosed in pregnancy (chlamydia, gonorrhea, and syphilis) are reported using multivariable logistic regression adjusting for relevant confounders. RESULTS: During 2012-2022, there were 102 905 births and 451 women (0.44%) with an STI diagnosis during pregnancy. The number of women with a history of chlamydia prior to their current pregnancy has increased over the last 10 years (P < 0.001). STIs in pregnancy were more common in younger women aged <20 years (adjusted odds ratio [aOR] 7.30, 95% confidence interval [CI] 5.04-10.57), 20-24 years (aOR 3.12, 95% CI 2.46-3.96), and >40 years (adj OR 1.67, 95% CI 1.07-2.59), in women with body mass index >30 (aOR 1.73, 95%CI 1.37-2.19), and those who smoked (aOR 2.24, 95% CI 1.71-2.94) and consumed alcohol (aOR 3.14, 95% CI 1.88-5.23) and illicit drugs (aOR 2.10, 95% CI 1.31-3.36). STIs in pregnancy were borderline associated with stillbirth (aOR 2.19 95% CI 0.90-5.36) but did not have a significant impact on preterm birth (aOR 1.21, 95% CI 0.87-1.68), admission to neonatal intensive care unit (NICU) (aOR 1.02, 95% CI 0.77-1.34), or having a small-for-gestational-age (SGA) baby (aOR 0.97, 95% CI 0.74-1.27). CONCLUSIONS: Sociodemographic factors such as age, weight, smoking, and alcohol and drug use, were associated with the STI incidence in pregnancy. While the latter did not have an impact on preterm birth, NICU admission, and SGA in our cohort, there was a borderline association with stillbirth. Future research should identify barriers and facilitators to testing in a multicultural population and understanding the drivers of higher rates of STIs in certain population groups.
Assuntos
Complicações Infecciosas na Gravidez , Resultado da Gravidez , Infecções Sexualmente Transmissíveis , Humanos , Feminino , Gravidez , Adulto , Estudos Retrospectivos , Prevalência , Complicações Infecciosas na Gravidez/epidemiologia , New South Wales/epidemiologia , Adulto Jovem , Infecções Sexualmente Transmissíveis/epidemiologia , Resultado da Gravidez/epidemiologia , Infecções por Chlamydia/epidemiologia , Modelos Logísticos , Gonorreia/epidemiologia , Sífilis/epidemiologia , Cuidado Pré-Natal/estatística & dados numéricos , Nascimento Prematuro/epidemiologia , Adolescente , Fatores de Risco , Natimorto/epidemiologia , Recém-NascidoRESUMO
BACKGROUND: Microphthalmia and anophthalmia are rare congenital fetal abnormalities. The combined incidence is estimated at 1 in 10,000 births. These two conditions arise from complex and incompletely understood genetic and/or environmental causes. Prenatal diagnosis is neither frequent nor easy and relies on precise, high-quality ultrasonography. Current antenatal ultrasound protocols for imaging of the fetal eye are inconsistent and inadequate to screen for the spectrum of ocular malformations, and there are no clear guidelines on detection of these rare abnormalities. Our study of two cases highlights the importance of early detection, and we review current practice and suggest a definitive fetal imaging protocol. CASE PRESENTATION: We present two antenatal cases, one each of microphthalmia and anophthalmia, both diagnosed at the morphology scan at our tertiary fetal medicine unit. In both cases, the parents (a 36-year-old woman of Mauritanian ethnicity and a non-consanguineous partner of Nepalese descent, and a 31-year-old Caucasian woman and non-consanguineous Caucasian partner) elected to terminate their pregnancies and made unremarkable recoveries. Subsequent fetal autopsy confirmed the ultrasound scan findings. CONCLUSIONS: We recommend that antenatal ultrasound guidelines are updated to specify use of a curvilinear transducer (2-9 MHz) to image both orbits in the axial and coronal planes, aided by use of a transvaginal probe when the transabdominal approach is inadequate to generate these images. When applicable, three-dimensional reverse-face imaging should be obtained to aid the diagnosis. The presence, absence, or non-visualization of lenses and hyaloid arteries should be documented in reports and these cases referred for a tertiary-level ultrasound scan and fetal medicine review. Imaging of the orbits should occur from 12 weeks' gestation. Magnetic resonance imaging and amniocentesis with chromosome microarray testing may provide additional genetic and structural information that may affect the overall morbidity associated with a diagnosis of microphthalmia or anophthalmia.
Assuntos
Anoftalmia/diagnóstico por imagem , Microftalmia/diagnóstico por imagem , Adulto , Anoftalmia/genética , Feminino , Aconselhamento Genético , Humanos , Masculino , Microftalmia/genética , Gravidez , Ultrassonografia Pré-NatalRESUMO
We used cDNA microarrays to screen for differentially expressed genes during recovery from exercise-induced muscle damage in humans. Male subjects (n = 4) performed 300 maximal eccentric contractions, and skeletal muscle biopsy samples were analyzed at 3 h and 48 h after exercise. In total, 113 genes increased 3 h postexercise, and 34 decreased. At 48 h postexercise, 59 genes increased and 29 decreased. On the basis of these data, we chose 19 gene changes and conducted secondary analyses using real-time RT-PCR from muscle biopsy samples taken from 11 additional subjects who performed an identical bout of exercise. Real-time RT-PCR analyses confirmed that exercise-induced muscle damage led to a rapid (3 h) increase in sterol response element binding protein 2 (SREBP-2), followed by a delayed (48 h) increase in the SREBP-2 gene targets Acyl CoA:cholesterol acyltransferase (ACAT)-2 and insulin-induced gene 1 (insig-1). The expression of the IL-1 receptor, a known regulator of SREBP-2, was also elevated after exercise. Taken together, these expression changes suggest a transcriptional program for increasing cholesterol and lipid synthesis and/or modification. Additionally, damaging exercise induced the expression of protein kinase H11, capping protein Z alpha (capZalpha), and modulatory calcineurin-interacting protein 1 (MCIP1), as well as cardiac ankryin repeat protein 1 (CARP1), DNAJB2, c-myc, and junD, each of which are likely involved in skeletal muscle growth, remodeling, and stress management. In summary, using DNA microarrays and RT-PCR, we have identified novel genes that respond to skeletal muscle damage, which, given the known biological functions, are likely involved in recovery from and/or adaptation to damaging exercise.
Assuntos
Exercício Físico/fisiologia , Perfilação da Expressão Gênica , Músculo Esquelético/metabolismo , Adulto , Proteínas Reguladoras de Apoptose , Biópsia , Proteína de Capeamento de Actina CapZ/metabolismo , Proteínas de Transporte/metabolismo , Proteínas de Ciclo Celular , Proteínas de Ligação a DNA , Proteínas de Choque Térmico HSP40/metabolismo , Humanos , Inflamação/metabolismo , Inflamação/fisiopatologia , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Masculino , Chaperonas Moleculares/metabolismo , Proteínas Musculares/metabolismo , Músculo Esquelético/patologia , Análise de Sequência com Séries de Oligonucleotídeos , Proteínas Proto-Oncogênicas c-jun/metabolismo , Proteínas Proto-Oncogênicas c-myc/metabolismo , Receptores de Interleucina-1/metabolismo , Proteína de Ligação a Elemento Regulador de Esterol 2/metabolismoRESUMO
Aging is generally defined and studied as a population phenomenon. However, there is great interest, especially when discussing human aging, in the identification of factors that influence the life span of an individual organism. The nematode Caenorhabditis elegans provides an excellent model system for the study of aging at the level of the individual, since young nematodes are essentially clonal yet experience a large range of individual life spans. We are conducting gene expression profiling of individual nematodes, with the aim of discovering genes that vary stochastically in expression between individuals of the same age. Such genes are candidates to modulate the ultimate life span achieved by each individual. We here present statistical analysis of gene expression profiles of individual nematodes from two different microarray platforms, examining the issue of technical vs. biological variance as it pertains to uncovering genes of interest in this paradigm of individual aging.
Assuntos
Envelhecimento/genética , Caenorhabditis elegans/genética , Análise de Sequência com Séries de Oligonucleotídeos/métodos , Animais , Biomarcadores/análise , Expressão Gênica/genética , Perfilação da Expressão Gênica/métodos , Genes de Helmintos/genética , Variação Genética/genética , Proteínas de Fluorescência Verde/análise , Humanos , Substâncias Luminescentes/análise , Modelos Animais , Processos EstocásticosRESUMO
To search for novel transcriptional pathways that are activated in skeletal muscle after endurance exercise, we used cDNA microarrays to measure global mRNA expression after an exhaustive bout of high-intensity cycling (approximately 75 min). Healthy, young, sedentary males performed the cycling bout, and skeletal muscle biopsies were taken from the vastus lateralis before, and at 3 and 48 h after exercise. We examined mRNA expression in individual muscle samples from four subjects using cDNA microarrays, used repeated-measures significance analysis of microarray (SAM) to determine statistically significant expression changes, and confirmed selected results using real-time RT-PCR. In total, the expression of 118 genes significantly increased 3 h postcycling and 8 decreased. At 48 h, the expression of 29 genes significantly increased and 5 decreased. Many of these are potentially important novel genes involved in exercise recovery and adaptation, including several involved in 1) metabolism and mitochondrial biogenesis (FOXO1, PPARdelta, PPARgamma, nuclear receptor binding protein 2, IL-6 receptor, ribosomal protein L2, aminolevulinate delta-synthase 2); 2) the oxidant stress response (metalothioneins 1B, 1F, 1G, 1H, 1L, 2A, 3, interferon regulatory factor 1); and 3) electrolyte transport across membranes [Na+-K+-ATPase (beta3), SERCA3, chloride channel 4]. Others include genes involved in cell stress, proteolysis, apoptosis, growth, differentiation, and transcriptional activation, as well as all three nuclear receptor subfamily 4A family members (Nur77, Nurr1, and Nor1). This study is the first to characterize global mRNA expression during recovery from endurance exercise, and the results provide potential insight into 1) the transcriptional contributions to homeostatic recovery in human skeletal muscle after endurance exercise, and 2) the transcriptional contributions from a single bout of endurance exercise to the adaptive processes that occur after a period of endurance exercise training.
Assuntos
Exercício Físico , Músculo Esquelético/metabolismo , RNA Mensageiro/análise , Adulto , Apoptose , Proteínas de Ligação a DNA/genética , Transporte de Elétrons , Proteína Forkhead Box O1 , Fatores de Transcrição Forkhead/genética , Humanos , Masculino , Mitocôndrias/metabolismo , Proteínas do Tecido Nervoso/genética , Análise de Sequência com Séries de Oligonucleotídeos , Estresse Oxidativo , PPAR gama/genética , PPAR gama/fisiologia , Resistência Física , Receptores de Interleucina-6/genética , Receptores de Esteroides/genética , Receptores dos Hormônios Tireóideos/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Transdução de Sinais , ATPase Trocadora de Sódio-Potássio/genéticaRESUMO
Reactive oxygen species are an inevitable by-product of mitochondrial respiration. It has been estimated that between 0.4 and 4% of molecular oxygen is converted to the radical superoxide (O2*-) and this level is significantly influenced by the functional status of the mitochondria. It is well established that exogenous oxidative stress and high doses of mitochondrial poisons such as paraquat and carbonyl cyanide 4 (trifluoromethoxy) phenylhydrazone (FCCP) can lead to genomic instability. In this report we show for the first time that endogenous mitochondrial oxidative stress in standard cell culture conditions results in nuclear genomic instability in primary mouse embryonic fibroblasts (MEFs). We show that lack of mitochondrial superoxide dismutase in MEFs leads to a severe increase of double strand breaks, end-to-end fusions, chromosomal translocations, and loss of cell viability and proliferative capacity. Our results predict that endogenous mitochondrial oxidative stress can induce genomic instability, and therefore may have a profound effect in cancer and aging.
Assuntos
Instabilidade Cromossômica , Fibroblastos/ultraestrutura , Mitocôndrias/enzimologia , Estresse Oxidativo , Animais , Apoptose , Caspase 3 , Caspases/metabolismo , Divisão Celular , Transformação Celular Neoplásica/genética , Transformação Celular Neoplásica/metabolismo , Células Cultivadas , Embrião de Mamíferos/citologia , Feminino , Fibroblastos/citologia , Fibroblastos/metabolismo , Camundongos , Oxigênio/fisiologia , Gravidez , Superóxido Dismutase/biossíntese , Superóxido Dismutase/genética , Superóxido Dismutase/fisiologia , Translocação GenéticaRESUMO
Superoxide is produced as a result of normal energy metabolism within the mitochondria and is scavenged by the mitochondrial form of superoxide dismutase (sod2). Mice with inactivated SOD2 (sod2 nullizygous mice) die prematurely, exhibiting several metabolic and mitochondrial defects and severe tissue pathologies, including a lethal spongiform neurodegenerative disorder (Li et al., 1995; Melov et al., 1998, 1999). We show that treatment of sod2 nullizygous mice with synthetic superoxide dismutase (SOD)-catalase mimetics extends their lifespan by threefold, rescues the spongiform encephalopathy, and attenuates mitochondrial defects. This class of antioxidant compounds has been shown previously to extend lifespan in the nematode Caenorhabditis elegans (Melov et al., 2000). These new findings in mice suggest novel therapeutic approaches to neurodegenerative diseases associated with oxidative stress such as Friedreich ataxia, spongiform encephalopathies, and Alzheimer's and Parkinson's diseases, in which chronic oxidative damage to the brain has been implicated.
Assuntos
Antioxidantes/administração & dosagem , Sequestradores de Radicais Livres/administração & dosagem , Doenças Neurodegenerativas/tratamento farmacológico , Doenças Neurodegenerativas/enzimologia , Superóxido Dismutase/deficiência , Animais , Antioxidantes/química , Catalase , Catálise , Progressão da Doença , Relação Dose-Resposta a Droga , Esquema de Medicação , Etilenodiaminas/administração & dosagem , Etilenodiaminas/química , Sequestradores de Radicais Livres/química , Injeções Intraperitoneais , Lipídeos/química , Metaloporfirinas/administração & dosagem , Camundongos , Camundongos Knockout , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/patologia , Doenças Neurodegenerativas/genética , Doenças Neurodegenerativas/patologia , Compostos Organometálicos/administração & dosagem , Compostos Organometálicos/química , Estresse Oxidativo/efeitos dos fármacos , Fenótipo , Salicilatos/administração & dosagem , Salicilatos/química , Superóxido Dismutase/genética , Taxa de SobrevidaRESUMO
Advances in understanding of mitochondrial physiology and genetics in relation to pathology have exploded in the last decade. Paralleling this increase has been an active debate about the role of mitochondrial oxidative stress with regard to mitochondrial DNA mutations, aging, and disease. We discuss in a historical context the rapid progress in our understanding of the role of mitochondrial DNA mutations in disease, mitochondrial oxidative stress in aging, and the potential interplay between these two phenomena.
Assuntos
Envelhecimento/genética , DNA Mitocondrial/fisiologia , Mutação , Estresse Oxidativo/fisiologia , Animais , Predisposição Genética para Doença/genética , HumanosAssuntos
Academias e Institutos , Envelhecimento , Idoso , California , Docentes , Humanos , PesquisaRESUMO
We tested the theory that reactive oxygen species cause aging. We augmented the natural antioxidant systems of Caenorhabditis elegans with small synthetic superoxide dismutase/catalase mimetics. Treatment of wild-type worms increased their mean life-span by a mean of 44 percent, and treatment of prematurely aging worms resulted in normalization of their life-span (a 67 percent increase). It appears that oxidative stress is a major determinant of life-span and that it can be counteracted by pharmacological intervention.
Assuntos
Envelhecimento/efeitos dos fármacos , Antioxidantes/farmacologia , Caenorhabditis elegans/fisiologia , Catalase/metabolismo , Superóxido Dismutase/metabolismo , Animais , Caenorhabditis elegans/efeitos dos fármacos , Transtornos do Desenvolvimento Sexual , Fertilidade/efeitos dos fármacos , Longevidade/efeitos dos fármacos , Mimetismo Molecular , Estresse Oxidativo , Espécies Reativas de Oxigênio/metabolismoRESUMO
During the last 10 years, the theory known as the "free radical theory of aging" has achieved prominence as one of the most compelling explanations for many of the degenerative changes associated with aging. Although its appeal derives from a long-standing body of supporting correlative data, the theory was only recently more rigorously tested. Ongoing researches in the study of free radical biochemistry and the genetics of aging have been at the forefront of this work. First, transgenic approaches in invertebrate models with candidate genes such as superoxide dismutase (SOD) involved in the detoxification of reactive oxygen species (ROS) have shown that the endogenous production of ROS due to normal physiologic processes is a major limiter of life span. Genes involved in ROS detoxification are highly conserved among eukaryotes; hence, the physiologic processes that limit life span in invertebrates are likely to be similar in higher eukaryotes. Secondly, transgenic mice deficient in the antioxidant enzyme mitochondrial superoxide dismutase (SOD2) die within their first week of life, demonstrating the importance of limiting endogenous mitochondrial free radicals in mammals. Together, data from studies using transgenic invertebrates and those using sod2 mutant mice demonstrate that modulation of metabolic ROS can have a profound effect on life span. We show here that the effects of mitochondrial ROS can be modulated through appropriate catalytic antioxidant intervention. These catalytic antioxidants are discussed in the context of mitochondrial oxidative stress and their potential role in intervening in mitochondrial oxidative stress and aging.
Assuntos
Envelhecimento/fisiologia , Mitocôndrias/fisiologia , Estresse Oxidativo/fisiologia , Envelhecimento/metabolismo , Animais , Antioxidantes/metabolismo , Catálise , Expectativa de Vida , Camundongos , Camundongos Mutantes , Superóxido Dismutase/genéticaRESUMO
During the course of normal respiration, reactive oxygen species are produced which are particularly detrimental to mitochondrial function. This is shown by recent studies with a mouse that lacks the mitochondrial form of superoxide dismutase (Sod2). Tissues that are heavily dependent on mitochondrial function such as the brain and heart are most severely affected in the Sod2 mutant mouse. Recent work with a mouse mutant for the heart/muscle specific isoform of the mitochondrial adenine nuclear translocator (Ant1) demonstrates a potential link between mitochondrial oxidative stress and mitochondrial DNA mutations. These mutations can be detected by Long-extension PCR, a method for detecting a wide variety of mutations of the mitochondrial genome. Such mutations have also been observed in the mitochondrial genome with senescence regardless of the mean or maximal lifespan of the organism being studied. Mutations have been detected with age in Caenorhabditis elegans, mice, chimpanzees, and humans. This implies that a causal relationship may exist between mitochondrial reactive oxygen species production, and the senescence specific occurrence of mitochondrial DNA mutations.
Assuntos
DNA Mitocondrial , Modelos Animais de Doenças , Estresse Oxidativo , Envelhecimento , Animais , Encéfalo/metabolismo , Complexo IV da Cadeia de Transporte de Elétrons/metabolismo , Humanos , Camundongos , Miocárdio/metabolismo , Pan troglodytes/genética , Espécies Reativas de Oxigênio/metabolismo , Succinato Desidrogenase/metabolismo , Transcrição GênicaRESUMO
It has been hypothesized that a major factor in the progression of mitochondrial disease resulting from defects in oxidative phosphorylation (OXPHOS) is the stimulation of the mitochondrial production of reactive oxygen species (ROS) and the resulting damage to the mtDNA. To test this hypothesis, we examined the mitochondria from mice lacking the heart/muscle isoform of the adenine nucleotide translocator (Ant1), designated Ant1(tm2Mgr) (-/-) mice. The absence of Ant1 blocks the exchange of ADP and ATP across the mitochondrial inner membrane, thus inhibiting OXPHOS. Consistent with Ant1 expression, mitochondria isolated from skeletal muscle, heart, and brain of the Ant1-deficient mice produced markedly increased amounts of the ROS hydrogen peroxide, whereas liver mitochondria, which express a different Ant isoform, produced normally low levels of hydrogen peroxide. The increased production of ROS by the skeletal muscle and heart was associated with a dramatic increase in the ROS detoxification enzyme manganese superoxide dismutase (Sod2, also known as MnSod) in muscle tissue and muscle mitochondria, a modest increase in Sod2 in heart tissue, and no increase in heart mitochondria. The level of glutathione peroxidase-1 (Gpx1), a second ROS detoxifying enzyme, was increased moderately in the mitochondria of both tissues. Consistent with the lower antioxidant defenses in heart, the heart mtDNAs of the Ant1-deficient mice showed a striking increase in the accumulation of mtDNA rearrangements, whereas skeletal muscle, with higher antioxidant defenses, had fewer mtDNA rearrangements. Hence, inhibition of OXPHOS does increase mitochondrial ROS production, eliciting antioxidant defenses. If the antioxidant defenses are insufficient to detoxify the ROS, then an increased mtDNA mutation rate can result.
Assuntos
Dano ao DNA , Translocases Mitocondriais de ADP e ATP/deficiência , Encefalomiopatias Mitocondriais/metabolismo , Estresse Oxidativo , Espécies Reativas de Oxigênio/metabolismo , Animais , Encéfalo/metabolismo , DNA Mitocondrial/genética , Camundongos , Mitocôndrias/genética , Mitocôndrias/metabolismo , Mitocôndrias Cardíacas/genética , Mitocôndrias Cardíacas/metabolismo , Translocases Mitocondriais de ADP e ATP/genética , Encefalomiopatias Mitocondriais/genética , Músculo Esquelético/metabolismo , Miocárdio/metabolismo , Isoformas de Proteínas/genética , Isoformas de Proteínas/metabolismoRESUMO
Oxidative stress has been implicated in many diseases. The chief source of reactive oxygen species within the cell is the mitochondrion. We have characterized a variety of the biochemical and metabolic effects of inactivation of the mouse gene for the mitochondrial superoxide dismutase (CD1-Sod2(tm1Cje)). The Sod2 mutant mice exhibit a tissue-specific inhibition of the respiratory chain enzymes NADH-dehydrogenase (complex I) and succinate dehydrogenase (complex II), inactivation of the tricarboxylic acid cycle enzyme aconitase, development of a urine organic aciduria in conjunction with a partial defect in 3-hydroxy-3-methylglutaryl-CoA lyase, and accumulation of oxidative DNA damage. These results indicate that the increase in mitochondrial reactive oxygen species can result in biochemical aberrations with features reminiscent of mitochondrial myopathy, Friedreich ataxia, and 3-hydroxy-3-methylglutaryl-CoA lyase deficiency.
Assuntos
Mitocôndrias Cardíacas/metabolismo , Mitocôndrias Musculares/metabolismo , Miopatias Mitocondriais/genética , Fosforilação Oxidativa , Superóxido Dismutase/deficiência , Superóxido Dismutase/genética , Aconitato Hidratase/deficiência , Aconitato Hidratase/metabolismo , Animais , Encéfalo/metabolismo , Ácidos Carboxílicos/metabolismo , Ácidos Carboxílicos/urina , Cruzamentos Genéticos , Dano ao DNA , Feminino , Fumarato Hidratase/metabolismo , Masculino , Camundongos , Camundongos Mutantes , Mitocôndrias/metabolismo , Miopatias Mitocondriais/enzimologia , Oxo-Ácido-Liases/deficiência , Oxo-Ácido-Liases/metabolismo , Espécies Reativas de Oxigênio/metabolismoRESUMO
Deletions of the mitochondrial DNA (mtDNA) have been shown to accumulate with age in a variety of species regardless of mean or maximal life span. This implies that such mutations are either a molecular biomarker of senescence or that they are more causally linked to senescence itself. One assay that can be used to detect these mtDNA mutations is the long-extension polymerase chain reaction assay. This assay amplifies approximately 16 kb of the mtDNA in mammalian mitochondria and preferentially amplifies mtDNAs that are either deleted or duplicated. We have applied this assay to the aging human brain and found a heterogeneous array of rearranged mtDNAs. In addition, we have developed in situ polymerase chain reaction to detect mtDNA within individual cells of both the mouse and the human brain as a first step in identifying and enumerating cells containing mutant mtDNAs in situ.
Assuntos
Envelhecimento/genética , DNA Mitocondrial/genética , Rearranjo Gênico , Mitocôndrias/enzimologia , Idoso , Animais , Cerebelo/metabolismo , Primers do DNA , Metabolismo Energético/fisiologia , Feminino , Lobo Frontal/metabolismo , Deleção de Genes , Humanos , Camundongos , Camundongos Endogâmicos C57BL , Mitocôndrias/genética , Translocases Mitocondriais de ADP e ATP/genética , Translocases Mitocondriais de ADP e ATP/metabolismo , Estresse Oxidativo/fisiologia , Reação em Cadeia da Polimerase/métodos , Superóxido Dismutase/genética , Superóxido Dismutase/metabolismo , Superóxidos/metabolismoAssuntos
Longevidade , Neurônios Motores/enzimologia , Superóxido Dismutase/fisiologia , Envelhecimento/genética , Envelhecimento/fisiologia , Animais , Drosophila , Genótipo , Humanos , Longevidade/genética , Longevidade/fisiologia , Neurônios Motores/fisiologia , Estresse Oxidativo/genética , Estresse Oxidativo/fisiologia , Espécies Reativas de Oxigênio , Superóxido Dismutase/biossíntese , Superóxido Dismutase/genética , Superóxido Dismutase-1 , TransfecçãoRESUMO
Reactive oxygen species (ROS) have been implicated in a wide range of degenerative processes including amyotrophic lateral sclerosis, ischemic heart disease, Alzheimer disease, Parkinson disease and aging. ROS are generated by mitochondria as the toxic by-products of oxidative phosphorylation, their energy generating pathway. Genetic inactivation of the mitochondrial form of superoxide dismutase in mice results in dilated cardiomyopathy, hepatic lipid accumulation and early neonatal death. We report that treatment with the superoxide dismutase (SOD) mimetic Manganese 5, 10, 15, 20-tetrakis (4-benzoic acid) porphyrin (MnTBAP) rescues these Sod2tm1Cje(-/-) mutant mice from this systemic pathology and dramatically prolongs their survival. The animals instead develop a pronounced movement disorder progressing to total debilitation by three weeks of age. Neuropathologic evaluation reveals a striking spongiform degeneration of the cortex and specific brain stem nuclei associated with gliosis and intramyelinic vacuolization similar to that observed in cytotoxic edema and disorders associated with mitochondrial abnormalities such as Leighs disease and Canavans disease. We believe that due to the failure of MnTBAP to cross the blood brain barrier progressive neuropathology is caused by excessive mitochondrial production of ROS. Consequently, MnTBAP-treated Sod2tm1Cje(-/-) mice may provide an excellent model for examining the relationship between free radicals and neurodegenerative diseases and for screening new drugs to treat these disorders.
Assuntos
DNA Mitocondrial/genética , Metaloporfirinas/farmacologia , Doenças Neurodegenerativas/genética , Superóxido Dismutase/deficiência , Superóxido Dismutase/genética , Animais , Encéfalo/patologia , Tronco Encefálico/patologia , Tronco Encefálico/ultraestrutura , Córtex Cerebral/patologia , Córtex Cerebral/ultraestrutura , Sequestradores de Radicais Livres/farmacologia , Humanos , Metabolismo dos Lipídeos , Fígado/metabolismo , Camundongos , Camundongos Knockout , Mitocôndrias/enzimologia , Doenças Neurodegenerativas/tratamento farmacológico , Doenças Neurodegenerativas/patologia , Neurônios/patologia , Taxa de Sobrevida , Núcleos do Trigêmeo/patologia , Núcleos do Trigêmeo/ultraestrutura , Vacúolos/patologia , Vacúolos/ultraestruturaRESUMO
Mitochondrial DNA (mtDNA) rearrangements have been shown to accumulate with age in the post-mitotic tissues of a variety of animals and have been hypothesized to result in the age-related decline of mitochondrial bioenergetics leading to tissue and organ failure. Caloric restriction in rodents has been shown to extend life span supporting an association between bioenergetics and senescence. In the present study, we use full length mtDNA amplification by long-extension polymerase chain reaction (LX-PCR) to demonstrate that mice accumulate a wide variety of mtDNA rearrangements with age in post mitotic tissues. Similarly, using an alternative PCR strategy, we have found that 2-4 kb minicircles containing the origin of heavy-strand replication accumulate with age in heart but not brain. Analysis of mtDNA structure and conformation by Southern blots of unrestricted DNA resolved by field inversion gel electrophoresis have revealed that the brain mtDNAs of young animals contain the traditional linear, nicked, and supercoiled mtDNAs while old animals accumulate substantial levels of a slower migrating species we designate age-specific mtDNAs. In old caloric restricted animals, a wide variety of rearranged mtDNAs can be detected by LX-PCR in post mitotic tissues, but Southern blots of unrestricted DNA reveals a marked reduction in the levels of the age- specific mtDNA species. These observations confirm that mtDNA mutations accumulate with age in mice and suggest that caloric restriction impedes this progress.
Assuntos
Envelhecimento/genética , DNA Mitocondrial/genética , Ingestão de Energia , Rearranjo Gênico , Animais , Southern Blotting , Feminino , Privação de Alimentos , Camundongos , Camundongos Endogâmicos C57BL , Reação em Cadeia da PolimeraseRESUMO
The Sod2 gene for Mn-superoxide dismutase (MnSOD), an intramitochondrial free radical scavenging enzyme that is the first line of defense against superoxide produced as a byproduct of oxidative phosphorylation, was inactivated by homologous recombination. Homozygous mutant mice die within the first 10 days of life with a dilated cardiomyopathy, accumulation of lipid in liver and skeletal muscle, and metabolic acidosis. Cytochemical analysis revealed a severe reduction in succinate dehydrogenase (complex II) and aconitase (a TCA cycle enzyme) activities in the heart and, to a lesser extent, in other organs. These findings indicate that MnSOD is required for normal biological function of tissues by maintaining the integrity of mitochondrial enzymes susceptible to direct inactivation by superoxide.