Search results for "MITOCHONDRION"

Mitochondrial disruption and apoptosis in lymphocytes of an HIV infected patient affected by lactic acidosis after treatment with highly active antir…

2003

Aims: Highly active antiretroviral therapy (HAART) can induce an increase in lactic acid concentrations that seems to be caused by mitochondrial dysfunction induced by the interaction of nucleoside reverse transcriptase inhibitors (NRTIs) with DNA polymerase γ in the mitochondria. Mitochondrial alterations have been described in liver and muscle cells of NRTI treated human immunodeficiency virus (HIV) infected patients. Because lymphocytes are the main target for HIV and because mitochondria are involved in apoptosis, we studied mitochondrial morphology and apoptosis in the lymphocytes of an HIV infected patient with severe lactic acidosis after treatment with stavudine, didanosine, and ind…

Effects of metformin on mitochondrial function of leukocytes from polycystic ovary syndrome patients with insulin resistance.

2015

ObjectiveOxidative stress and mitochondrial dysfunction are implicated in polycystic ovary syndrome (PCOS). The present study assesses the effect of metformin treatment on mitochondrial function in polymorphonuclear cells from PCOS subjects. Additionally, we evaluate endocrine parameters and levels of interleukin 6 (IL6) and tumour necrosis factor alpha (TNFα).Design and methodsOur study population was comprised of 35 women of reproductive age diagnosed with PCOS and treated with metformin for 12 weeks, and their corresponding controls (n=41), adjusted by age and BMI. We evaluated the alteration of endocrinological and anthropometrical parameters and androgen levels. Mitochondrial O2 consum…

Mitochondrial transcriptional study of the effect of aflatoxins, enniatins and carotenoids in vitro in a blood brain barrier model

2020

C. maxima (var. Delica), a variety of pumpkin, is well known for its high concentration on carotenoids, possessing dietary benefits and antioxidant properties. Aflatoxins and enniatins are common mycotoxins present in food and feed with an extended toxicity profile in humans and animals. Both types of substances reach a wide range of tissues and organs and have the capability to penetrate the blood brain barrier. Since carotenoids and mycotoxins have been reported to modify diverse mitochondrial processes individually, transcriptional in vitro studies on human epithelial cells ECV 304 were conducted to analyze the relative expression of 13 mitochondria related genes. ECV 304 cells were diff…

Oxidative Stress in Neurodegenerative Diseases: From a Mitochondrial Point of View

2019

Age is the main risk factor for a number of human diseases, including neurodegenerative disorders such as Alzheimer’s disease, Parkinson’s disease, and amyotrophic lateral sclerosis, which increasing numbers of elderly individuals suffer. These pathological conditions are characterized by progressive loss of neuron cells, compromised motor or cognitive functions, and accumulation of abnormally aggregated proteins. Mitochondrial dysfunction is one of the main features of the aging process, particularly in organs requiring a high-energy source such as the heart, muscles, brain, or liver. Neurons rely almost exclusively on the mitochondria, which produce the energy required for most of the cel…

Respiratory chain cysteine and methionine usage indicate a causal role for thiyl radicals in aging

2011

The identification of longevity-related structural adaptations in biological macromolecules may yield relevant insights into the molecular mechanisms of aging. In screening fully sequenced animal proteomes for signals associated with longevity, it was found that cysteine depletion in respiratory chain complexes was the by far strongest predictor on the amino acid usage level to co-vary with lifespan. This association was though restricted to aerobic animals, whereas anaerobic animals showed variable cysteine accumulation. By contrast, methionine accumulation, a prominent feature of mitochondrially encoded proteins affording competitive antioxidant protection, was not predictive of longevity…

Induction of Mitochondrial Changes Associated with Oxidative Stress on Very Long Chain Fatty Acids (C22:0, C24:0, or C26:0)-Treated Human Neuronal Ce…

2012

In Alzheimer's disease, lipid alterations point towards peroxisomal dysfunctions. Indeed, a cortical accumulation of saturated very long chain fatty acids (VLCFAs: C22:0, C24:0, C26:0), substrates for peroxisomalβ-oxidation, has been found in Alzheimer patients. This study was realized to investigate the effects of VLCFAs at the mitochondrial level since mitochondrial dysfunctions play crucial roles in neurodegeneration. On human neuronal SK-NB-E cells treated with C22:0, C24:0, or C26:0 (0.1–20 μM; 48 h), an inhibition of cell growth and mitochondrial dysfunctions were observed by cell counting with trypan blue, MTT assay, and measurement of mitochondrial transmembrane potential (Δψm) with…

Mitochondrial oxidative stress plays a key role in aging and apoptosis

2000

Harman first suggested in 1972 that mitochondria might be the biological clock in aging, noting that the rate of oxygen consumption should determine the rate of accumulation of mitochondrial damage produced by free radical reactions. Later in 1980 Miquel and coworkers proposed the mitochondrial theory of cell aging. Mitochondria from postmitotic cells use O2 at a high rate, hence releasing oxygen radicals that exceed the cellular antioxidant defences. The key role of mitochondria in cell aging has been outlined by the degeneration induced in cells microinjected with mitochondria isolated from fibroblasts of old rats, especially by the inverse relationship reported between the rate of mitoch…

Mitochondria, oxidative stress and aging

2000

In the eighties, Miquel and Fleming suggested that mitochondria play a key role in cellular aging. Mitochondria, and specially mitochondrial DNA (mtDNA), are major targets of free radical attack. At present, it is well established that mitochondrial deficits accumulate upon aging due to oxidative damage. Thus, oxidative lesions to mtDNA accumulate with age in human and rodent tissues. Furthermore, levels of oxidative damage to mtDNA are several times higher than those of nuclear DNA. Mitochondrial size increases whereas mitochondrial membrane potential decreases with age in brain and liver. Recently, we have shown that treatment with certain antioxidants, such as sulphur-containing antioxid…

Humanin: A mitochondria-derived peptide with emerging properties.

2020

Glutathione, oxidative stress and aging

1996

The free radical theory of aging proposes that the impairment in physiological performance associated with aging is caused by the detrimental effects of oxygen free radicals. This is interesting because it provides us with a theoretical framework to understand aging and because it suggests a rationale for intervention, i.e., antioxidant administration. Thus, the study of antioxidant systems of the cell may be very important in gerontological studies. Glutathione is one of the main nonprotein antioxidants in the cell which, together with its related enzymes, constitute the “glutathione system.” The involvement of glutathione in aging has been known since the early seventies. Several studies …