Search results for "mitochondrion"

Oxidative stress in diabetic retinopathy

2020

Diabetic retinopathy (DR) is the leading cause of acquired blindness in working adults worldwide. Biochemical changes in DR contribute to both the microscopic structural and functional changes in the retina. All these alterations result in retinal damage that can be assessed by funduscopy, optical coherence tomography (OCT), and angioOCT. Reactive oxygen species (ROS) overproduction in the mitochondria is considered a causal link between elevated glucose and biochemical abnormalities in the pathophysiology of DR. Moreover, oxidative-induced pathways also seem to provide positive feedback to ROS production, resulting in a vicious cycle. ROS can directly damage lipids, proteins, and DNA, lead…

One Enzyme, Two Functions

2010

The human enzyme paraoxonase-2 (PON2) has two functions, an enzymatic lactonase activity and the reduction of intracellular oxidative stress. As a lactonase, it dominantly hydrolyzes bacterial signaling molecule 3OC12 and may contribute to the defense against pathogenic Pseudomonas aeruginosa. By its anti-oxidative effect, PON2 reduces cellular oxidative damage and influences redox signaling, which promotes cell survival. This may be appreciated but also deleterious given that high PON2 levels reduce atherosclerosis but may stabilize tumor cells. Here we addressed the unknown mechanisms and linkage of PON2 enzymatic and anti-oxidative function. We demonstrate that PON2 indirectly but specif…

Epigenetics, oxidative states and diabetes

2020

Abstract Although controlling a wide range of physiological cell functions, redox states unbalance during inflammation toward oxidative stress. Specific regions of our genome are extremely sensitive to both oxygen and reactive oxygen species, therefore modulating gene transcription in response to this specific epigenetic effect. Additional epigenetic mechanisms may include the alteration of the methylation states of DNA, protein and lipid nitration or modulation of specific microRNAs. A crucial role in finely tuning redox states is also played by mitochondria, where oxidative phosphorylation is epigenetically controlled. Diabetes, the most considerable “epigenetic” clinical disorder, exacer…

Magnesium, Oxidative Stress, and Aging Muscle

2014

Abstract Magnesium (Mg) deficiency, aside from having a negative impact on the energy production pathways required by the mitochondria to generate ATP, also reduces the threshold antioxidant capacity of the aging organism and its resistance to free-radical damage. Mg acts as an antioxidant against free radical damage of the mitochondria. Chronic Mg deficiency results in excessive production of oxygen-derived free radicals and low-grade inflammation. Chronic inflammation and oxidative stress have been identified as pathogenic factors in several age-related conditions. Aging is often associated with Mg inadequacy, muscle loss, and sarcopenia. Although the importance of magnesium as a determin…

Age-related changes in antioxidant status and oxidative damage to lipids and dna in mitochondria of rat liver

2005

To investigate the correlation between oxidative stress and mitochondrial damage with aging, antioxidant system, levels of oxidative DNA damage and as an index of the loss of plasma membrane integrity lipid peroxidation and membrane potential were studied. Results showed that the activities of antioxidant enzymes superoxide dismutase (SOD) and catalase significantly decreased during aging, however glutathione peroxidase (GSH-PX) increased in the aged mitochondria and glutathione (GSH) did not change during aging. No statistical difference was observed in the lipid peroxidation of mitochondria between young and old animals. The level of oxidative DNA damage (measured as 8oxo-dG) tended to in…

Mitochondrial Oxidative Stress in Diabetes

2014

Abstract Diabetes is a multifactorial disease associated with serious comorbidities. This condition has been related to oxidative stress and, as a consequence, to overproduction of reactive oxygen species (ROS), which are known to be produced by different sources in diabetes. Excessive production of ROS can be harmful, making antioxidant defenses of vital importance. Dietary antioxidants, such as vitamin E or vitamin C, polyphenols and flavonoids have been used to modulate the oxidative stress created in diabetes, producing contradictory results in clinical trials, perhaps as a consequence of the targets selected and/or the design of the studies in question. This chapter considers the proce…

Diabetic Retinopathy and Oxidative Stress

2014

Abstract Diabetic retinopathy (DR) is the leading cause of acquired blindness in working age adults worldwide. Biochemical changes in DR contribute to both the microscopic structural and functional changes in the retina. All these alterations result in macroscopic retinal damage that can be assessed by funduscopy. The overproduction of reactive oxygen species (ROS) in the mitochondria is considered a causal link between elevated glucose and biochemical abnormalities in the pathophysiology of DR. Moreover, oxidatively induced pathways also seem to provide positive feedback to ROS production, resulting in a vicious cycle. ROS can directly damage lipids, proteins and DNA, leading to cell death…

Evidence of an interplay between ER stress/UPR and mitochondria in human hepatic cells treated with the antiretroviral drug Efavirenz

2013

Is ER stress induced in human hepatoma cells treated with the antiretroviral drug Efavirenz mitochondria-related?

2012

Activation of Mitochondria-Driven Pathways by Artemisinin and Its Derivatives

2014

Mitochondria have recently emerged as promising agents for cancer therapy. Of particular interest and potential clinical relevance are agents that target these organelles, promoting cell death. There are literally thousands of compounds that act on mitochondria and destabilise them. Of these, naturally occurring compounds are particularly interesting, since they are often more ‘biocompatible’; besides, natural compounds can be lead drugs for the design of novel and more efficient anti-cancer agents. In this paper, we focus on the natural product artemisin and its semisynthetic derivatives, and document the molecular mechanism of their activity and their potential use as clinically relevant …