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The Integrative Coronary Heart Disease (CHD) Prevention Program
Published in Mark C Houston, The Truth About Heart Disease, 2023
CoQ10 is involved in numerous body functions. It is an antioxidant and is involved in DNA synthesis, lysosomal function, gene expression, mitochondrial protein uncoupling, mitochondrial permeability, mitochondrial ETC (electron transport chain) and ATP production, membrane function, reduction of lipid peroxidation and reduction of oxLDL, apoptosis, and recycling of other micronutrients especially tocopherols and vitamin C. The ETC complex 1–4 on the inner mitochondrial membrane produces ATP via electron transport with CoQ10 involvement particularly at Complex 1 and 2 (Figure 21.4). The electron transport chain of the mitochondria and the production of ATP.
Mitochondrial Redox Regulation in Adaptation to Exercise
Published in James N. Cobley, Gareth W. Davison, Oxidative Eustress in Exercise Physiology, 2022
Christopher P. Hedges, Troy L. Merry
Skeletal muscle contraction requires energy in the form of ATP. Almost all types of exercise will require mitochondrial oxidative phosphorylation (OXPHOS) to supply at least a portion of the ATP used. Production of ATP by mitochondria is dependent on the electron transport system and oxidative phosphorylation machinery. In brief, complexes I and II, mitochondrial glycerophosphate dehydrogenase (mGPDH) and electron transferring flavoprotein dehydrogenase (ETFDH) all reduce the lipophilic mobile electron carrier ubiquinone to ubiquinol. Ubiquinol is then oxidised by complex III, which reduces cytochrome c, which is, in turn, oxidised by complex IV. Complex IV utilises electrons to bind and reduce oxygen and protons (H+) to form water (H2O). During this process, each time an electron transitions down energy states the released energy is used by complexes I, III and IV to transport H+ into the intermembrane space which is against the H+ concentration gradient (Schultz and Chan, 2001). The net result is the generation of a proton motive force, made up of a concentration gradient of H+ and an electrochemical membrane potential across the mitochondrial inner membrane. Proton motive force enables production of ATP by ATP synthase (mitochondrial complex V) simultaneous with H+ return to the mitochondrial matrix (Fillingame, 1997). Thus, ATP production is coupled to oxygen consumption in the mitochondria.
Targeted Therapy for Cancer Stem Cells
Published in Surinder K. Batra, Moorthy P. Ponnusamy, Gene Regulation and Therapeutics for Cancer, 2021
Rama Krishna Nimmakayala, Saswati Karmakar, Garima Kaushik, Sanchita Rauth, Srikanth Barkeer, Saravanakumar Marimuthu, Moorthy P. Ponnusamy
In normal or non-transformed cells, the main store of energy production is the mitochondria, where ATP is produced through the tricarboxylic acid (TCA) cycle coupled to oxidative phosphorylation. As carbon fuels such as pyruvate, glutamine, and fatty acids pass through the TCA cycle, reducing equivalents including nicotinamide adenine dinucleotide phosphate (NADH) and flavin adenine dinucleotide (FADH2) are generated that are subsequently used as electron donors for the electron transport chain (ETC). Proton motive force is generated via coupling of movement of electrons across the different complexes of the electron transport chain and is used by ATP synthase to generate ATPs.
Omentin-1 promotes mitochondrial biogenesis via PGC1α-AMPK pathway in chondrocytes
Published in Archives of Physiology and Biochemistry, 2023
Zhigang Li, Yao Zhang, Fengde Tian, Zihua Wang, Haiyang Song, Haojie Chen, Baolin Wu
The mitochondrion is the "powerhouse" in eukaryotic cells. Mitochondrial biogenesis is the process of increasing cellular metabolic capacity, featured with the synthesis of enzymes for both glycolysis and oxidative phosphorylation (Jornayvaz and Shulman 2010). An efficient mitochondrial biogenesis needs the import of nuclear protein as well as mitochondrial replication, mitochondrial fusion and fission (Nunnari and Suomalainen 2012). Mitochondria in mammalian cells contain more than 1500 proteins, but only 13 proteins are coded in mitochondrial DNA, a majority of them are synthesised from nuclear DNA coding genes. Various mitochondrial molecular markers are used to study the mitochondrial regulation in eukaryotes. Translocase of the outer membrane (TOM) complex is a membrane-bound translocator vital to import mitochondrial precursors, and TOM complex includes several subunits including TOM20, TOM40 and TOM70 and is secured by TOM5, TOM6, TOM7, etc. (Ahting et al.1999). Several subunits of mitochondrial ATP synthases are also used as the markers of functional mitochondria, including ATPA, ATP5C1, ATPD and other subunits. The electron transport chain (ETC) located within the mitochondrial inner membrane composes of four protein complexes. Succinate dehydrogenase complex iron-sulfur subunit B (SDHB) links the pathways of Krebs cycle and oxidative phosphorylation. Mitochondrial DNA encoded subunits (MTCO1, MTCO2, MTCO3) are important subunits of complex IV (Zhao et al.2019).
Protective effect and mechanism of low P50 haemoglobin oxygen carrier on isolated rat heart
Published in Artificial Cells, Nanomedicine, and Biotechnology, 2022
Wentao Zhou, Shen Li, Shasha Hao, Honghui Zhang, Tao Li, Wanjing Li, Jiaxin Liu, Hong Wang, Chengmin Yang
The inflammation score of photomicrographs of HE-stained of cardiac tissue in the low P50 HBOCs was significantly lower the control group (p < .05). The results suggest that a reasonable oxygen supply can effectively improve MI. It is most commonly thought that main cause of toxicity is not oxygen but ROS that are formed as a product of oxygen metabolism. Protons are transported across the inner mitochondrial membrane by an electron transport chain that finishes in the acceptance of electrons by molecular oxygen. Meanwhile, a small amount of these electrons are incompletely reduced to form the superoxide radical, oxygen. Superoxide can react with lipids to form lipid peroxides, and excessive superoxide can cause apoptosis and premature cell death. Thus one important implication that oxygen supply be carefully linked to energy production is that ATP production, in excess of demand, could lead to excessive accumulation of ROS. The possible reason is that the effects of ischaemic injury in the control group are similar the cause of MI of ROS generated in the body by overload of oxygen supply in high and medium P50 HBOCs, so the myocardium of rats in the high and medium P50 HBOCs group are similar to the control group, the results appear to exclude ROS as culprit of injury, and oxidative stress as a mechanism of protection for low P50 HBOCs.
Hyperglycaemia and the risk of post-surgical adhesion
Published in Archives of Physiology and Biochemistry, 2022
Gordon A. Ferns, Seyed Mahdi Hassanian, Mohammad-Hassan Arjmand
Hyperglycaemia increases superoxide production (Nishikawa et al.2000). Under hyperglycaemic conditions, there is increased glucose entering the glycolytic pathway (important biochemical pathway in the cells for glucose metabolism) that produced two molecules of pyruvate. In aerobic conditions, pyruvates are converted to acetyl-CoA by pyruvate dehydrogenase. Acetyl-CoA produced by pyruvate entered to the Krebs cycle in mitochondria. Three molecules of NADH are produced by each Krebs cycle (Sabri 1984). NADH is an electron carrier to transport electron in complex 1 of the electron transport chain in mitochondria for ATP synthesis. An excessive amount of NADH causes reductive stress by intracellular production of superoxide O2– (Liu et al.2002) (Figure 3). Superoxide is one of the most important ROS factors and can damage biomolecules and increase of inflammation (McCord 1980). Increase of ROS such as superoxide causes excessive production of proinflammatory cytokines and growth factors by immune cells which are associated with adhesion formation post-surgical (Fortin et al.2015).