Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:1.9.3.1 (cytochrome oxidase)
 8,822 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Homogenates of control and diet-induced atherosclerotic aortas of rabbit were prepared and the levels of DNA, protein, free and esterified cholesterol, and six enzymes known to be associated with various subcellular organelles [N-acetyl-beta-glucosaminidase, beta-galactosidase (lysosomes); cytochrome oxidase (mitochondria); neutral alpha-glucosidase (endoplasmic reticulum); 5'-nucleotidase (plasma membrane); catalase (peroxisomes)] were compared between control and atherosclerotic preparations. The levels of prostaglandins I2, E2, and F2 alpha, based on DNA, also were measured by radioimmunoassay. Atherosclerotic aortas were significantly enriched in catalase activity (440%) and in each of the acid hydrolases (395 and 630%), based on DNA, as well as in free (630%) and esterified cholesterol (930%), based on tissue wet weight, compared to control aortas. The control level of prostaglandin I2 was 10-fold higher than that of prostaglandin E2, which was 3-fold higher than that of prostaglandin F 2 alpha. Prostaglandin I2 doubled in amount with advanced atherosclerosis, while prostaglandin E2 increased over 10-fold, resulting in twice the amount of prostaglandin I2 than E2 in advanced atherosclerosis; the level of prostaglandin F2 alpha did not appear to change significantly with atherosclerosis. Increased levels of prostaglandins I2 and E2 were correlated significantly with increased aortic total cholesterol content (based on DNA) but not increased serum cholesterol levels. N-Acetyl-beta-glucosaminidase activity also was correlated significantly to aortic total cholesterol content and beta-galactosidase activity, as well as to the level of prostaglandin I2; in contrast, N-acetyl-beta-glucosaminidase was not significantly correlated to prostaglandin E2. The association of prostaglandins I2 and E2 with aortic total cholesterol suggests the participation of prostaglandins in the response of arterial cells to lipid accumulation in atherosclerosis. The specific association of aortic prostaglandin I2 level and N-acetyl-beta-glucosaminidase activity further suggests a possible role for this prostaglandin during arterial intralysosomal cholesterol accumulation.
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PMID:Arterial prostaglandins and lysosomal function during atherogenesis. I. Homogenates of diet-induced atherosclerotic aortas of rabbit. 389 3

A detailed histochemical study of the macrophage involvement during experimental atherogenesis in rhesus and cynomolgus monkeys was performed. Aortic, carotid, and femoral artery lesions were examined in both species after 4, 8, and 12 months of atherogenic diet feeding. Macrophages were identified and quantified in the atherosclerotic lesions using acid lipase, acid esterase, beta-galactosidase, and cytochrome oxidase histochemical procedures. Morphometric quantitation revealed that the cynomolgus monkey arterial lesions were larger and consistently demonstrated a greater number of cells with characteristics of macrophages in the intimal, medial, and adventitial portion of the arteries when compared to the primarily intimal rhesus monkey lesions. Biochemical assays of aortic samples for acid lipase and acid esterase activity also showed consistently higher activities in the cynomolgus samples when compared to the rhesus samples. Average serum cholesterol levels were higher in the cynomolgus monkeys than in the rhesus monkeys, but the differences in the arterial lesions still existed when animals with overlapping cholesterol levels were compared. Macrophages and their associated activities predominated in experimental cynomolgus monkey atherosclerosis when it was compared to the rhesus disease process, which may be an explanation for some of the differences in atherogenesis reported in these two species.
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PMID:Histochemical detection and quantification of macrophages in rhesus and cynomolgus monkey atherosclerotic lesions. 650 64

Chlamydia pneumoniae, a respiratory pathogen implicated in the development and progress of atherosclerosis, is known to infect and survive in macrophages, despite macrophage producing reactive oxygen species (ROS). To gain insight into ROS generation in macrophages infected with C. pneumoniae and to explore factors accounting for their final levels and effect, we investigated the role of NADPH oxidase and cytochrome oxidase pathways in the production and modulation of ROS. We also determined the operational role of Ca2+ signaling in the process. Macrophages stimulated with C. pneumoniae exhibit early release of ROS via up-regulation of NADPH oxidase and cytochrome c oxidase activities. Increasing the dose of C. pneumoniae led to an increase in the expression of these enzymes gene production, which was accompanied by a significant up-regulation of their gene products, implying a probable activation of transcriptional and translational processes, respectively. The change in levels of free Ca2+, influx across plasma membrane and efflux from intracellular store into cytosol all exhibited a significant regulatory role on the ROS generation pathways in macrophages. The observed events were shown to be dependent on binding of C. pneumoniae to CD14 receptors of macrophages. The data reported here imply that macrophages infected with C. pneumoniae produce ROS through membrane-associated NADPH oxidase with oxidative phosphorylation levels depending on Ca2+ influx signals.
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PMID:Elicitation of reactive oxygen species in Chlamydia pneumoniae-stimulated macrophages: a Ca2+-dependent process involving simultaneous activation of NADPH oxidase and cytochrome oxidase genes. 1519 88

Atherosclerotic cardiovascular disease is the leading cause of mortality in the Western world. Dysfunction of the mitochondrial respiratory chain and overproduction of reactive oxygen species (ROS) are associated with atherosclerosis and cardiovascular disease. Oxidation increases the atherogenecity of LDL. Oxidized LDL may be apoptotic or nonapoptotic for vascular endothelial cells (EC), depending on the intensity of oxidation. A previous study demonstrated that nonapoptotic oxidized LDL increased activity of mitochondrial complex I in human umbilical vein EC. The present study examined the impact of extensively oxidized LDL (eoLDL) on oxygen consumption and the activities of key enzymes in the mitochondrial respiratory chain of cultured porcine aortic EC. Oxygraphy detected that eoLDL significantly reduced oxygen consumption in various mitochondrial complexes. Treatment with eoLDL significantly decreased NADH-ubiquinone dehydrogenase (complex I), succinate cytochrome c reductase (complex II/III), ubiquinone cytochrome c reductase (complex III), and cytochrome c oxidase (complex IV) activities and the NAD+-to-NADH ratio in EC compared with mildly oxidized LDL, LDL, or vehicle. Butylated hydroxytoluene, a potent antioxidant, normalized eoLDL-induced reductions in complex I and III enzyme activity in EC. Mitochondria-associated intracellular ROS and release of ROS from EC were significantly increased after eoLDL treatment. These findings suggest that eoLDL impairs enzyme activity in mitochondrial respiratory chain complexes and increases ROS generation from mitochondria of arterial EC. Collectively, these effects could contribute to vascular injury and atherogenesis under conditions of hypercholesterolemia and oxidative stress.
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PMID:Effects of extensively oxidized low-density lipoprotein on mitochondrial function and reactive oxygen species in porcine aortic endothelial cells. 1984 72

Hyperglycemia-induced reactive oxygen species production can cause diabetes and its complications, including atherosclerosis. The role of mitochondrial DNA variants and mitochondrial copy number in the pathogenesis of diabetic atherogenesis is not well understood. We examined 36 diabetic patients who had undergone amputation for diabetic foot and seven non-diabetic patients who had undergone amputation after traumatic injury. Mitochondrial DNA was extracted and used for sequencing. Single nucleotide polymorphisms (SNPs) relative to the Cambridge reference sequence were analyzed. Mitochondrial DNA copy number was quantified by real-time PCR. Twenty-one novel variants were detected in 29 diabetic patients with arterial stenosis; six of the variants were heteroplasmic, and most occurred in highly evolutionarily conserved residues. These variants were more prevalent in patients with arterial stenosis than in those without stenosis. The novel variants included four in complex I (ND1: C3477A/C, A3523A/G; ND5: C13028A/C, C13060A/C), one in complex IV (COX1: T6090A/T), and one in rRNA (12srRNA: G857G/T). Compared with non-diabetic patients, the diabetic patients had significantly less mitochondrial DNA. Furthermore, among diabetic patients with arterial stenosis, there was a significant positive correlation between mitochondrial DNA copy number and the number of total SNPs. In conclusion, we identified six novel heteroplasmic mitochondrial DNA variants among diabetic patients with arterial stenosis, and we found that diabetic atherogenesis is associated with decreased amounts of mitochondrial DNA.
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PMID:Role of mitochondrial DNA variants and copy number in diabetic atherogenesis. 2307 27

The aim of this study was to identify potential markers of atherosclerosis development in familial hypercholesterolemia (FH) patients. GSE13985 microarray data, generated using blood samples from 5 FH patients and 5 matched controls, was downloaded from the Gene Expression Omnibus. Differentially expressed genes (DEGs) between FH and controls were identified and a protein-protein interaction (PPI) network was constructed. Module and hub proteins were screened in this network. The module genes were subjected to a gene ontology (GO) analysis, and a Kyoto Encyclopedia of Genes and Genomes enrichment analysis was also performed. A total of 394 genes, including 125 up- and 269 down-regulated genes, were differentially expressed. Ribosomal proteins L9 (RPL9), L35 (RPL35), and S7 (RPS7) were designated as hub nodes in the PPI network. The DEGs were found to be significantly enriched in ribosomal and oxidative phosphorylation pathways. Ribosomal protein genes were found to be involved in the ribosomal pathway. The cytochrome-c oxidase (COX) genes COX subunit VIIa polypeptide 2 (COX7A2), COX subunit VIIb (COX7B), COX subunit VIIc (COX7C), and COX subunit VIc (COX6C) were enriched in the oxidative phosphorylation pathway. Module analysis and GO enrichment analysis identified ribosomal proteins as important regulators of FH. Ribosomal and oxidative phosphorylation pathways may be closely associated with atherosclerosis development. Ribosomal protein genes and cytochrome-coxidase genes may be potential therapeutic targets for atherosclerosis.
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PMID:Prediction of genetic risk factors of atherosclerosis using various bioinformatic tools. 2717 80

A high level of circulating free fatty acids (FFAs) is known to be an important trigger for macrophage apoptosis during the development of atherosclerosis. However, the underlying mechanism by which FFAs result in macrophage apoptosis is not well understood. In cultured human macrophage Thp-1 cells, we showed that palmitate (PA), the most abundant FFA in circulation, induced excessive reactive oxidative substance production, increased malondialdehyde concentration, and decreased adenosine triphosphate levels. Furthermore, PA treatment also led to mitochondrial dysfunction, including the decrease of mitochondrial number, the impairment of respiratory complex IV and succinate dehydrogenase activity, and the reduction of mitochondrial membrane potential. Mitochondrial apoptosis was also detected after PA treatment, indicated by a decrease in cytochrome c release, downregulation of Bcl-2, upregulation of Bax, and increased caspase-3 activity. PA treatment upregulated the expression of adipocyte fatty acid-binding protein (A-FABP), a critical regulator of fatty acid trafficking and lipid metabolism. Inhibition of A-FABP with BMS309403, a small-molecule A-FABP inhibitor, almost reversed all of these indexes. Thus, this study suggested that PA-mediated macrophage apoptosis through A-FABP upregulation, which subsequently resulted in mitochondrial dysfunction and reactive oxidative stress. Inhibition of A-FABP may be a potential therapeutic target for macrophage apoptosis and to delay the progress of atherosclerosis.
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PMID:Adipocyte Fatty Acid-Binding Protein Promotes Palmitate-Induced Mitochondrial Dysfunction and Apoptosis in Macrophages. 2944 Oct 65