cytochrome-c-t and Cardiovascular-Diseases

Cardiolipin (CL) is a mitochondria-specific phospholipid and is critical for maintaining the integrity of mitochondrial membrane and mitochondrial function. CL also plays an active role in mitochondria-dependent apoptosis by interacting with cytochrome c (cyt c), tBid and other important Bcl-2 proteins. The unique structure of CL with four linoleic acid side chains in the same molecule and its cellular location make it extremely susceptible to free radical oxidation by reactive oxygen species including free radicals derived from peroxidase activity of cyt c/CL complex, singlet oxygen and hydroxyl radical. The free radical oxidation products of CL have been emerged as important mediators in apoptosis. In this review, we summarize the free radical chemical mechanisms that lead to CL oxidation, recent development in detection of oxidation products of CL by mass spectrometry and the implication of CL oxidation in mitochondria-mediated apoptosis, mitochondrial dysfunction and human diseases.

Topics: Aldehydes; Apoptosis; Cardiolipins; Cardiovascular Diseases; Cytochromes c; Humans; Lipid Peroxidation; Mitochondria; Neurodegenerative Diseases; Oxidation-Reduction; Oxidative Stress; Peroxidases; Proto-Oncogene Proteins c-bcl-2; Reactive Oxygen Species

Apoptosis is strictly connected to the pathogenesis of many human diseases, including neoplastic, neurodegenerative or cardiovascular diseases. It is a highly programmed cell death which can be activated by various factors. Mitochondria play a key role in the apoptotic process; their damage, which involves permeabilization of the outer mitochondrial membrane, activates a series of events that lead to cell death. Of the two proposed signaling pathways of apoptosis, i.e. the 'extrinsic' and the 'intrinsic' pathway, the latter is assumed to initiate in mitochondria. Its activation involves release of cytochrome c and other pro-apoptotic factors from the mitochondrial intermembrane space. In the cytosol, cytochrome c exerts its pro-apoptotic action. It binds to the apoptosis protease activation factor (APAf-1) and forms a complex indicated as 'apoptosome'. The complex-induced activation of pro-caspase 9 initiates an enzymatic reaction cascade leading to the execution of apoptosis in cells. This review provides an overview of the key role played by mitochondria and cytochrome c in the activation of the apoptotic process.

Topics: Apoptosis; Cardiovascular Diseases; Cytochromes c; Humans; Mitochondria; Neoplasms; Neurodegenerative Diseases

Advanced glycation end products (AGEs) by nonenzymatic glycation reactions are extremely accumulated in the diabetic vascular cells, neurons, and glia, and are confirmed to play important role in the pathogenesis of diabetes mellitus -induced cardiovascular complications. Sirt 1, known as mammalian sirtuin, has been recognized to regulate insulin secretion and protect cells against oxidative stress, which is promoted by the accumulated AGEs in cardiovascular cells. In the present study, we treated human endothelial Eahy926 cells with AGEs, and determined the apoptosis induction, caspase activation, the Sirt 1 activity, the expression and acetylation of p53. Then we manipulated Sirt 1 activity with a Sirt 1 activator, Resveratrol (RSV), and a Sirt 1 inhibitor, sirtinol, in the AGE-BSA-treated Eahy926 cells, and then re-evaluated the apoptosis induction, caspase activation, the expression and acetylation of p53. Results demonstrated that AGEs induced apoptosis in the human endothelial Eahy926 cells, by promoting the cytochrome c release, activation of caspase 9/3. Also, the AGE-BSA treatment promoted the total p53 level and acetylated (Ac) p53, but reduced the Sirt 1 level and activity. On the other hand, the Sirt 1 inhibitor/activator not only deteriorated/ameliorated the promotion to p53 level and Ac p53, but also aggravated/inhibited the AGE-induced apoptosis and the promotion to apoptosis-associated signaling molecules. In conclusion, the present study confirmed the apoptosis promotion by AGEs in endothelial Eahy926 cells, by regulating the Sirt 1 activity and p53 signaling, it also implies the protective role of Sirt 1 activator against the AGE-induced apoptosis.

Topics: Acetylation; Apoptosis; Benzamides; Cardiovascular Diseases; Caspases; Cells, Cultured; Cytochromes c; Diabetes Mellitus; Endothelial Cells; Glycation End Products, Advanced; Humans; Insulin; Insulin Secretion; Naphthols; Oxidative Stress; Resveratrol; Signal Transduction; Sirtuin 1; Stilbenes; Tumor Suppressor Protein p53

Second hand cigarette smoke is an independent risk factor for cardiovascular disease. Although a tie between smoking and cardiovascular disease is well established, the underlying mechanisms still remains elusive due to the lack of adequate animal models. This study was designed to use a mouse model of exposure to cigarette smoke, a surrogate of environmental tobacco smoke, to evaluate the impact of cardiac overexpression of heavy metal scavenger metallothionein on myocardial geometry, contractile and intracellular Ca(2+) properties and apoptosis following side-stream smoke exposure.. Adult male wild-type FVB and metallothionein transgenic mice were placed in a chamber exposed to cigarette smoke for 1 hour daily for 40 days. Echocardiographic, cardiomyocyte contractile and intracellular Ca(2+) properties, fibrosis, apoptosis and mitochondrial damage were examined.. Our data revealed that smoke exposure enlarged ventricular end systolic and diastolic diameters, reduced myocardial and cardiomyocyte contractile function, disrupted intracellular Ca(2+) homeostasis, facilitated fibrosis, apoptosis and mitochondrial damage (cytochrome C release and aconitase activity), the effects of which were attenuated or mitigated by metallothionein. In addition, side-stream smoke expose enhanced phosphorylation of Akt and GSK3β without affecting pan protein expression in the heart, the effect of which was abolished or ameliorated by metallothionein. Cigarette smoke extract interrupted cardiomyocyte contractile function and intracellular Ca(2+) properties, the effect of which was mitigated by wortmannin and NAC.. These data suggest that side-stream smoke exposure led to myocardial dysfunction, intracellular Ca(2+) mishandling, apoptosis, fibrosis and mitochondrial damage, indicating the therapeutic potential of antioxidant against in second smoking-induced cardiac defects possibly via mitochondrial damage and apoptosis.

Topics: Aconitate Hydratase; Animals; Antioxidants; Apoptosis; Apoptosis Regulatory Proteins; Calcium; Calcium Signaling; Calcium-Binding Proteins; Cardiovascular Diseases; Cells, Cultured; Cytochromes c; Fibrosis; Male; Metallothionein; Mice; Mice, Transgenic; Mitochondria, Heart; Myocardial Contraction; Myocardium; Myocytes, Cardiac; Nitric Oxide Synthase Type III; Organ Specificity; Protein Processing, Post-Translational; Reactive Oxygen Species; Sarcoplasmic Reticulum Calcium-Transporting ATPases; Smoking; Tobacco Smoke Pollution

CD31(+) T cells, or so-called "angiogenic T cells," have been shown to demonstrate vasculoprotective and neovasculogenic qualities. The influence of age on CD31(+) T-cell number and function is unclear. We tested the hypothesis that circulating CD31(+) T-cell number and migratory capacity are reduced, apoptotic susceptibility is heightened, and telomere length is shortened with advancing age in adult humans. Thirty-six healthy, sedentary men were studied: 12 young (25 ± 1 yr), 12 middle aged (46 ± 1 yr), and 12 older (64 ± 2 yr). CD31(+) T cells were isolated from peripheral blood samples by magnetic-activated cell sorting. The number of circulating CD31(+) T cells (fluorescence-activated cell sorting analysis) was lower (P < 0.01) in older (24% of CD3(+) cells) compared with middle-aged (38% of CD3(+) cells) and young (40% of CD3(+) cells) men. Migration (Boyden chamber) to both VEGF and stromal cell-derived factor-1α was markedly blunted (P < 0.05) in cells harvested from middle-aged [306.1 ± 45 and 305.6 ± 46 arbitrary units (AU), respectively] and older (231 ± 65 and 235 ± 62 AU, respectively) compared with young (525 ± 60 and 570 ± 62 AU, respectively) men. CD31(+) T cells from middle-aged and older men demonstrated greater apoptotic susceptibility, as staurosporine-stimulated intracellular caspase-3 activation was ∼ 40% higher (P < 0.05) than young. There was a progressive age-related decline in CD31(+) T-cell telomere length (young: 10,706 ± 220 bp; middle-aged: 10,179 ± 251 bp; and older: 9,324 ± 192 bp). Numerical and functional impairments in this unique T-cell subpopulation may contribute to diminished angiogenic potential and greater cardiovascular risk with advancing age.

Topics: Adult; Age Factors; Aged; Aging; Apoptosis; Cardiovascular Diseases; Caspase 3; Cell Separation; Chemokine CXCL12; Chemotaxis; Cytochromes c; Flow Cytometry; Humans; Lymphocyte Count; Male; Middle Aged; Platelet Endothelial Cell Adhesion Molecule-1; Risk Factors; T-Lymphocyte Subsets; T-Lymphocytes; Telomerase; Telomere; Vascular Endothelial Growth Factor A; Young Adult

A large number of methods devoted to the identification of apoptotic cells and the analysis of the morphological, biochemical, and molecular changes that take place during this universal biological process have been developed. Apoptotic cells are recognized on the basis of their reduced DNA content and morphological changes that include nuclear condensation and which can be detected by flow cytometry (sub-G1 DNA content), Trypan Blue, or Hoechst staining. Changes in plasma membrane composition and function are detected by the appearance of phosphatidylserine on the plasma membrane, which reacts with Annexin V-fluorochrome conjugates. Combined with propidium iodide (PI) staining, this method can distinguish between the early and late apoptotic events. The best-recognized biochemical hallmarks of apoptosis are the activation of cysteine proteases (caspases), condensation of chromatin, and fragmentation of genomic DNA into nucleosomal fragments. Recognized by a variety of assays, activated caspases cleave many cellular proteins and the resulting fragments may serve as apoptosis markers. Finally, the mitochondria and the Bcl-2 family proteins play an important role in this process that can be recognized by translocation of apoptogenic factors, such as Bax and cytochrome c, in and out of mitochondria.

Topics: Annexin A5; Apoptosis; bcl-2 Homologous Antagonist-Killer Protein; bcl-2-Associated X Protein; Bisbenzimidazole; Cardiovascular Diseases; Caspase 3; Cell Fractionation; Cell Membrane; Colorimetry; Cytochromes c; Cytological Techniques; DNA Fragmentation; Flow Cytometry; Humans; Immunoblotting; Immunohistochemistry; Mitochondria; Tetrazolium Salts; Trypan Blue

Topics: Animals; Aspartate Aminotransferases; Cardiovascular Diseases; Cytochromes; Cytochromes c; Dogs; Electron Transport Complex IV; Myocardial Infarction; Myocardium; Oxidoreductases; Transaminases

Topics: Cardiovascular Diseases; Cytochromes c; Humans