scholarly journals Prolonged α-Tocopherol Deficiency Decreases Oxidative Stress and Unmasks α-Tocopherol-dependent Regulation of Mitochondrial Function in the Brain

2008 ◽  
Vol 283 (11) ◽  
pp. 6915-6924 ◽  
Author(s):  
Sarah L. Cuddihy ◽  
Sameh S. Ali ◽  
Erik S. Musiek ◽  
Jacinta Lucero ◽  
Sarah J. Kopp ◽  
...  
2014 ◽  
Vol 2014 ◽  
pp. 1-12 ◽  
Author(s):  
Heshan Peiris ◽  
Daphne Dubach ◽  
Claire F. Jessup ◽  
Petra Unterweger ◽  
Ravinarayan Raghupathi ◽  
...  

Mitochondria are the primary site of cellular energy generation and reactive oxygen species (ROS) accumulation. Elevated ROS levels are detrimental to normal cell function and have been linked to the pathogenesis of neurodegenerative disorders such as Down's syndrome (DS) and Alzheimer’s disease (AD). RCAN1 is abundantly expressed in the brain and overexpressed in brain of DS and AD patients. Data from nonmammalian species indicates that increased RCAN1 expression results in altered mitochondrial function and that RCAN1 may itself regulate neuronal ROS production. In this study, we have utilized mice overexpressing RCAN1RCAN1oxand demonstrate an increased susceptibility of neurons from these mice to oxidative stress. Mitochondria from these mice are more numerous and smaller, indicative of mitochondrial dysfunction, and mitochondrial membrane potential is altered under conditions of oxidative stress. We also generated a PC12 cell line overexpressing RCAN1PC12RCAN1. Similar toRCAN1oxneurons,PC12RCAN1cells have an increased susceptibility to oxidative stress and produce more mitochondrial ROS. This study demonstrates that increasing RCAN1 expression alters mitochondrial function and increases the susceptibility of neurons to oxidative stress in mammalian cells. These findings further contribute to our understanding of RCAN1 and its potential role in the pathogenesis of neurodegenerative disorders such as AD and DS.


2019 ◽  
Vol 57 (3) ◽  
pp. 1317-1331 ◽  
Author(s):  
Gavin Pharaoh ◽  
Daniel Owen ◽  
Alexander Yeganeh ◽  
Pavithra Premkumar ◽  
Julie Farley ◽  
...  

AbstractAge-related decline in circulating levels of insulin-like growth factor (IGF)-1 is associated with reduced cognitive function, neuronal aging, and neurodegeneration. Decreased mitochondrial function along with increased reactive oxygen species (ROS) and accumulation of damaged macromolecules are hallmarks of cellular aging. Based on numerous studies indicating pleiotropic effects of IGF-1 during aging, we compared the central and peripheral effects of circulating IGF-1 deficiency on tissue mitochondrial function using an inducible liver IGF-1 knockout (LID). Circulating levels of IGF-1 (~ 75%) were depleted in adult male Igf1f/f mice via AAV-mediated knockdown of hepatic IGF-1 at 5 months of age. Cognitive function was evaluated at 18 months using the radial arm water maze and glucose and insulin tolerance assessed. Mitochondrial function was analyzed in hippocampus, muscle, and visceral fat tissues using high-resolution respirometry O2K as well as redox status and oxidative stress in the cortex. Peripherally, IGF-1 deficiency did not significantly impact muscle mass or mitochondrial function. Aged LID mice were insulin resistant and exhibited ~ 60% less adipose tissue but increased fat mitochondrial respiration (20%). The effects on fat metabolism were attributed to increases in growth hormone. Centrally, IGF-1 deficiency impaired hippocampal-dependent spatial acquisition as well as reversal learning in male mice. Hippocampal mitochondrial OXPHOS coupling efficiency and cortex ATP levels (~ 50%) were decreased and hippocampal oxidative stress (protein carbonylation and F2-isoprostanes) was increased. These data suggest that IGF-1 is critical for regulating mitochondrial function, redox status, and spatial learning in the central nervous system but has limited impact on peripheral (liver and muscle) metabolism with age. Therefore, IGF-1 deficiency with age may increase sensitivity to damage in the brain and propensity for cognitive deficits. Targeting mitochondrial function in the brain may be an avenue for therapy of age-related impairment of cognitive function. Regulation of mitochondrial function and redox status by IGF-1 is essential to maintain brain function and coordinate hippocampal-dependent spatial learning. While a decline in IGF-1 in the periphery may be beneficial to avert cancer progression, diminished central IGF-1 signaling may mediate, in part, age-related cognitive dysfunction and cognitive pathologies potentially by decreasing mitochondrial function.


2015 ◽  
Vol 40 (10) ◽  
pp. 1078-1081 ◽  
Author(s):  
Yoswaris Semaming ◽  
Jirapas Sripetchwandee ◽  
Piangkwan Sa-nguanmoo ◽  
Hiranya Pintana ◽  
Patchareewan Pannangpetch ◽  
...  

Brain mitochondrial dysfunction has been demonstrated in diabetic animals with neurodegeneration. Protocatechuic acid (PCA), a major metabolite of anthocyanin, has been shown to exert glycemic control and oxidative stress reduction in the heart. However, its effects on oxidative stress and mitochondrial function in the brain under diabetic condition have never been investigated. We found that PCA exerted glycemic control, attenuates brain mitochondrial dysfunction, and contributes to the prevention of brain oxidative stress in diabetic rats.


2015 ◽  
Vol 113 (11) ◽  
pp. 1667-1676 ◽  
Author(s):  
Adi Zheng ◽  
Hao Li ◽  
Jie Xu ◽  
Ke Cao ◽  
Hua Li ◽  
...  

Hydroxytyrosol (HT) is a major polyphenolic compound found in olive oil with reported anti-cancer and anti-inflammatory activities. However, the neuroprotective effect of HT on type 2 diabetes remains unknown. In the present study, db/db mice and SH-SY-5Y neuroblastoma cells were used to evaluate the neuroprotective effects of HT. After 8 weeks of HT administration at doses of 10 and 50 mg/kg, expression levels of the mitochondrial respiratory chain complexes I/II/IV and the activity of complex I were significantly elevated in the brain of db/db mice. Likewise, targets of the antioxidative transcription factor nuclear factor erythroid 2 related factor 2 including p62 (sequestosome-1), haeme oxygenase 1 (HO-1), and superoxide dismutases 1 and 2 increased, and protein oxidation significantly decreased. HT treatment was also found to activate AMP-activated protein kinase (AMPK), sirtuin 1 and PPARγ coactivator-1α, which constitute an energy-sensing protein network known to regulate mitochondrial function and oxidative stress responses. Meanwhile, neuronal survival indicated by neuron marker expression levels including activity-regulated cytoskeleton-associated protein, N-methyl-d-aspartate receptor and nerve growth factor was significantly improved by HT administration. Additionally, in a high glucose-induced neuronal cell damage model, HT effectively increased mitochondrial complex IV and HO-1 expression through activating AMPK pathway, followed by the prevention of high glucose-induced production of reactive oxygen species and declines of cell viability and VO2 capacity. Our observations suggest that HT improves mitochondrial function and reduces oxidative stress potentially through activation of the AMPK pathway in the brain of db/db mice.


2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Abayomi Ololade Adelaja ◽  
Oluwafemi Gabriel Oluwole ◽  
Oritoke Modupe. Aluko ◽  
Solomon Umukoro

AbstractObjectivesRepeated exposure to anoxic stress damages the brain through cortisol-mediated increases in oxidative stress and cellular-antioxidants depletion. Thus, compounds with antioxidant property might confer protection against anoxic stress-induced brain injuries. In this study, we further examined the protective effect of methyl jasmonate (MJ), a potent anti-stress agent against anoxic stress-induced convulsions in mice.MethodsThirty-six male Swiss mice randomized into six groups (n=6) were given MJ (25, 50 and 100 mg/kg, i.p.) or vehicle (10 mL/kg, i.p.) 30 min before 15 min daily exposure to anoxic stress for 7 days. The latency(s) to anoxic convulsion was recorded on day 7. The blood glucose and serum corticosterone levels were measured afterwards. The brains were also processed for the determination of malondialdehyde, nitrite, and glutathione levels.ResultsMethyl jasmonate (MJ) delayed the latency to anoxic convulsion and reduced the blood glucose and serum corticosterone levels. The increased malondialdehyde and nitrite contents accompanied by decreased glutathione concentrations in mice with anoxic stress were significantly attenuated by MJ.ConclusionsThese findings further showed that MJ possesses anti-stress property via mechanisms relating to the reduction of serum contents of corticosterone and normalization of brain biomarker levels of oxidative stress in mice with anoxic stress.


2021 ◽  
Vol 22 (3) ◽  
pp. 1059
Author(s):  
Bodo C. Melnik

Epidemiological studies associate milk consumption with an increased risk of Parkinson’s disease (PD) and type 2 diabetes mellitus (T2D). PD is an α-synucleinopathy associated with mitochondrial dysfunction, oxidative stress, deficient lysosomal clearance of α-synuclein (α-syn) and aggregation of misfolded α-syn. In T2D, α-syn promotes co-aggregation with islet amyloid polypeptide in pancreatic β-cells. Prion-like vagal nerve-mediated propagation of exosomal α-syn from the gut to the brain and pancreatic islets apparently link both pathologies. Exosomes are critical transmitters of α-syn from cell to cell especially under conditions of compromised autophagy. This review provides translational evidence that milk exosomes (MEX) disturb α-syn homeostasis. MEX are taken up by intestinal epithelial cells and accumulate in the brain after oral administration to mice. The potential uptake of MEX miRNA-148a and miRNA-21 by enteroendocrine cells in the gut, dopaminergic neurons in substantia nigra and pancreatic β-cells may enhance miRNA-148a/DNMT1-dependent overexpression of α-syn and impair miRNA-148a/PPARGC1A- and miRNA-21/LAMP2A-dependent autophagy driving both diseases. MiRNA-148a- and galactose-induced mitochondrial oxidative stress activate c-Abl-mediated aggregation of α-syn which is exported by exosome release. Via the vagal nerve and/or systemic exosomes, toxic α-syn may spread to dopaminergic neurons and pancreatic β-cells linking the pathogenesis of PD and T2D.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Danilo Reymão Moreira ◽  
Ana Carolina Musa Gonçalves Uberti ◽  
Antonio Rafael Quadros Gomes ◽  
Michelli Erica Souza Ferreira ◽  
Aline da Silva Barbosa ◽  
...  

AbstractThe present study aimed to evaluate the effects of dexamethasone on the redox status, parasitemia evolution, and survival rate of Plasmodium berghei-infected mice. Two-hundred and twenty-five mice were infected with Plasmodium berghei and subjected to stimulation or inhibition of NO synthesis. The stimulation of NO synthesis was performed through the administration of L-arginine, while its inhibition was made by the administration of dexamethasone. Inducible NO synthase (iNOS) inhibition by dexamethasone promoted an increase in the survival rate of P. berghei-infected mice, and the data suggested the participation of oxidative stress in the brain as a result of plasmodial infection, as well as the inhibition of brain NO synthesis, which promoted the survival rate of almost 90% of the animals until the 15th day of infection, with possible direct interference of ischemia and reperfusion syndrome, as seen by increased levels of uric acid. Inhibition of brain iNOS by dexamethasone caused a decrease in parasitemia and increased the survival rate of infected animals, suggesting that NO synthesis may stimulate a series of compensatory redox effects that, if overstimulated, may be responsible for the onset of severe forms of malaria.


Author(s):  
Sicong Yu ◽  
Lepeng Gao ◽  
Yang Song ◽  
Xin Ma ◽  
Shuang Liang ◽  
...  

Abstract Mitochondria play an important role in controlling oocyte developmental competence. Our previous studies showed that glycine can regulate mitochondrial function and improve oocyte maturation in vitro. However, the mechanisms by which glycine affects mitochondrial function during oocyte maturation in vitro have not been fully investigated. In this study, we induced a mitochondrial damage model in oocytes with the Bcl-2-specific antagonist ABT-199. We investigated whether glycine could reverse the mitochondrial dysfunction induced by ABT-199 exposure and whether it is related to calcium regulation. Our results showed that ABT-199 inhibited cumulus expansion, decreased the oocyte maturation rate and the intracellular glutathione (GSH) level, caused mitochondrial dysfunction, induced oxidative stress, which was confirmed by decreased mitochondrial membrane potential (Δ⍦m) and the expression of mitochondrial function-related genes (PGC-1α), and increased reactive oxygen species (ROS) levels and the expression of apoptosis-associated genes (Bax, caspase-3, CytC). More importantly, ABT-199-treated oocytes showed an increase in the intracellular free calcium concentration ([Ca 2+]i) and had impaired cortical type 1 inositol 1,4,5-trisphosphate receptors (IP3R1) distribution. Nevertheless, treatment with glycine significantly ameliorated mitochondrial dysfunction, oxidative stress and apoptosis, glycine also regulated [Ca 2+]i levels and IP3R1 cellular distribution, which further protects oocyte maturation in ABT-199-induced porcine oocytes. Taken together, our results indicate that glycine has a protective action against ABT-199-induced mitochondrial dysfunction in porcine oocytes.


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