Leukocyte Mitochondria Research Articles

Leukocyte as an adequate model for studying changes in energy metabolism in heart cells under the influence of cardiocytoprotectors in myocardial ischemia

The aim of this study was to determine the possibility of studying the nature of the influence of cardiocytoprotectors on energy metabolism in cardiomyocytes using a model of human peripheral blood leukocytes.Materials and methods. Sixty Wistar rats were divided into groups: 1) intact rats; 2) rats with experimental myocardial ischemia; 3) rats with myocardial ischemia, which were injected with cardiocytoprotector – trimetazidine, 4) meldonium, 5) cytoflavin and 6) ethoxydol. Animals were taken out of the experiment 10 days after the administration of drugs by decapitation. The activities of pyruvate dehydrogenase and citrate synthase were determined in mitochondria of myocardial homogenates and in mitochondria of leukocytes by spectrophotometric methods.Results. The decrease in pyruvate dehydrogenase and citrate synthase activity in cardiomyocytes and in leukocytes were revealed in case of myocardial ischemia modeling. The introduction of cardiocytoprotectors led to the activation of these enzymes both in heart cells and in blood leukocytes. Direct positive correlations were obtained between the activity of pyruvate dehydrogenase in the mitochondria of cardiomyocytes and in the mitochondria of leukocytes (r = 0.811; p < 0.0001); between citrate synthase activity in the mitochondria of cardiomyocytes and in the mitochondria of leukocytes (r = 0.909; p < 0.0001).Conclusion. Changes in energy metabolism in blood leukocytes under the influence of cytoprotectors reflect similar changes occurring in heart cells.

Investigation of mitochondrial oxidative phosforylation enzymes in hematological cancers

It is known that cancerous cells are different from normal cells in their structure and functions. It is aimed to determine whether there is a change in the activities of mitochondrial oxidative phosphorylation (OXPOS) respiratory enzymes, the main energy production site of cells, in various haematological cancers and to use the obtained data for therapeutic purposes. In this study, leukocyte mitochondria were isolated from blood samples obtained from patients with non-hodgkin lymphoma (NHL), hodgkin lemphoma (HL), chronic lymphocytic leukaemia (CLL), acute myelogenic leukaemia (AML), acute lymphocytic leukaemia (ALL), chronic myeloid leukaemia (CML), multiple myeloma and myelodysplastic syndrome (MDS) and controls. The enzyme activities of oxidative phosphorylation complexes I, II and IV were measured by spectrophotometric method. Enzyme activity results were statistically evaluated according to various criteria. Enzyme activities were evaluated according to gender, chemotherapy or not and disease groups. As a result of these statistical evaluations, no correlation was found between the type of haematological cancer and gender (p>0.05). The difference in mitochondrial oxidative complex enzyme activities between patients receiving chemotherapy and those not receiving chemotherapy was insignificant (p>0.05). When the enzyme activities of the control group and all haematological cancer cells studied were compared, the difference was found to be statistically significant (p<0.05). As a result, changes in the activities of OXPOS respiratory enzymes were found in various haematological cancers. The large number of therapies that specifically target mitochondria, the altered metabolic functions and dynamics of mitochondria in cancer cells make it a target for cancer therapeutics.

Peculiarities of the Functional State of Mitochondria of Peripheral Blood Leukocytes in Patients with Acute Myocardial Infarction.

We studied the rate of oxygen consumption by mitochondria isolated from peripheral blood leukocytes of patients with acute myocardial infarction and healthy volunteers. It was found that leukocyte mitochondria in patients with acute myocardial infarction were characterized by significantly lower rate of oxygen consumption and lower level of coupling of oxidation and phosphorylation processes in comparison with mitochondria from healthy volunteers.

Ответная реакция митохондрий тромбоцитов и лейкоцитов здоровых людей на воздействие микрочастиц атмосферного воздуха

The influence of atmospheric microparticles on the state of human platelet and leukocyte mitochondria in healthy residents of the city of Vladivostok was studied. The state of mitochondria was assessed by changing the composition of membrane fatty acids and the inner mitochondrial membrane potential (∆Ψmito). The observation groups included 62 residents of Vladivostok and the Russian Islands at the age of 28 to 54 years. Vladivostok is taken as a territory with a high content of toxicants in the air of the micrometer range, island Russky - as the territory is most favorable for the environmental situation and the absence of air polluting microparticles. The fatty acid spectrum was studied by gas-liquid chromatography. The level of ∆Ψmito was studied ex tempore on flow cytofluorimeter. It was found that influence of atmospheric microparticles the accumulation of saturated fatty acids (12: 0, 14: 0, 16: 0, 18: 0) and n-6 polyunsaturated fatty acids (20: 3n-6, 20: 4n-6, 22: 4n-6), a decrease in n-3 polyunsaturated fatty acids and ∆Ψmito. The observed changes in the architecture of the inner mitochondrial membrane and its functional activity testify, on the one size, of the formation of compensatory reactions aimed at strengthening the lipid matrix of the membrane and reducing its permeability, on the other - on the development of mitochondrial dysfunction, the predisposition of cells to apoptotic changes. Identification of the spectrum of mitochondrial fatty acids membranes is an early indication of the disruption of cell functioning.

Uptake and immunomodulatory role of bixin in dogs.

Carotenoids are readily absorbed from the diet and distributed in blood leukocyte subcellular organelles. Bixin, a potent bioactive found in the seed of the Annatto plant, , possesses antioxidant and anti-inflammatory properties. The purpose of this study was to determine the uptake of bixin by plasma, lipoproteins, and leukocytes in domestic dogs and to examine immunoprotective properties. To determine uptake kinetics, female Beagle dogs (2 yr; 9.1 ± 0.1 kg BW) were first fed a single dose by oral gavage of 0, 5, 10, 20, or 40 mg bixin, with blood collected at 0 to 16 h after administration ( = 6/treatment), and then fed daily with 0, 5, 10, 20, or 40 mg bixin/d, with blood collected at 0, 1, 2, 4, 6, 10, and 14 d. In a consecutive experiment, cell-mediated and humoral responses as well as oxidative biomarkers were measured following 16 wk of dietary supplementation with 0, 5, 10, or 20 mg bixin/d. Maximal absorption in plasma occurred by 0.5 h with an elimination half-life of 2.6 to 3.3 h after a single dose of bixin. Steady-state plasma concentrations were 0.053 μ after 14 d of 40 mg bixin/d. The majority of subcellular bixin was found in the leukocyte mitochondria and was associated with the high-density lipoprotein and low-density lipoprotein fractions of lipoproteins. Specific (vaccine) response increased ( < 0.05) but nonspecific mitogen response was unchanged after 12 wk of dietary bixin, as assessed by a delayed-type hypersensitivity assay. Both B cell plasma leukocyte subpopulations at 6 and 16 wk and IgG plasma concentration at 12 wk in the 10-mg treatment group increased ( < 0.05), although IgM production and other cell populations were unaffected. In addition, 8-oxo-2'-deoxyguanosine (8-OHdG), a DNA damage biomarker, was substantially reduced ( < 0.05) in all treatment groups by wk 16, and C-reactive protein (CRP) was suppressed at wk 12 ( < 0.05). Dietary supplementation with bixin showed no changes in lymphoproliferation in response to in vitro mitogenic challenge and had no effect in enhancing natural killer cell activity. In conclusion, bixin was readily absorbed in a dose-dependent manner in blood following oral administration and was then taken up by leukocytes, where it was primarily distributed to mitochondria but in other subcellular organelles as well. Bixin also appeared to stimulate immune response, as seen with cell-mediated responses, and exerted anti-inflammatory (reduced CRP) as well as antioxidative (reduced 8-OHdG) effects in dogs.

Enhanced mitochondrial radical production in patients which rheumatoid arthritis correlates with elevated levels of tumor necrosis factor alpha in plasma.

Mitochondrial dysfunction contributes to cell damage in a number of human diseases. One significant mechanism by which mitochondria damage cells is by producing reactive oxygen species from the respiratory chain. In this study we measured the production of reactive oxygen species by leukocyte mitochondria in blood from rheumatoid arthritis patients. To do this we used the chemiluminescence of lucigenin, which is accumulated by mitochondria within cells and reacts with superoxide to form a chemiluminescent product. By using specific inhibitors we could distinguish between the production of reactive oxygen species by mitochondria and by NADPH oxidase. There was a five-fold increase in mitochondrial reactive oxygen species production in whole blood and monocytes from patients with rheumatoid arthritis, when compared to healthy subjects or patients with non-rheumatic diseases. There was no increases in mitochondrial reactive oxygen species production by neutrophils from rheumatoid arthritis patients. The enhanced mitochondrial radical production in rheumatoid arthritis patients correlated significantly with increased levels of tumor necrosis factor alpha in plasma (p < 0.0001). As tumor necrosis factor alpha is known to increase mitochondrial reactive oxygen species production the elevated mitochondrial radical formation seen in rheumatoid arthritis patients may be due to activation of the mitochondrial radical production. These data suggest that elevated mitochondrial oxidative stress contributes to the pathology of rheumatoid arthritis.

Production of ATP in leukocyte mitochondria from hyperthyroid patients before and after treatment with a beta-adrenergic blocker and antithyroid drugs.

ABSTRACT The aerobic production of adenosine-triphosphate in leukocyte mitochondria from hyperthyroid patients was measured with an enzymatic method to detect firstly differences between normal and hyperthyroid subjects, and secondly differences between non-treated and treated hyperthyroid patients. The treatment consisted of either a β-adrenergic blocker or an antithyroid drug. Adenosine-triphosphate production is significantly decreased in hyperthyroidism and increases after treatment but does not reach the normal levels.

Leukocyte Energy Metabolism III. Anaerobic and Aerobic ATP Production and Related Enzymes

We have measured anaerobic and aerobic energy metabolism in leukocytes from human and animal blood, using several methods. We have taken special care to correct our results for an unavoidable contamination with thrombocytes, which has been neglected in all previous work. White cells were isolated by a method combining sedimentation through Dextran with low speed centrifugations. A pellet of thrombocytes was prepared in parallel from the same blood. Mitochondria were isolated by differential centrifugation in 0.25 M sucrose. Firstly, we have specially studied two cytosolic glycolytic enzymes, phosphoglycerate kinase and pyruvate kinase, both of which catalyze a reaction producing ATP. These two enzymes are very active in leukocytes. Other nucleotides, such as CDP, GDP and UDP can also be phosphorylated. Secondly, we have measured the activity of several mitochondrial enzymes, the most active being α-glycerophosphate oxidase. Using an enzymatic test, we have measured the amount of ATP produced in oxidative phosphorylation; in these experiments it was necessary to consider the activity of adenylate kinase as well as correcting for thrombocyte contamination. Several metabolites in direct or indirect relation with the Krebs cycle were used as oxidizable substrates: glutamate, succinate and α-glycerophosphate gave the best results. Except for amytal, inhibitors of oxidative phosphorylation also inhibit ATP production in leukocyte mitochondria. In conclusion, it can be said that oxidative phosphorylation exists in leukocytes, but that the phosphorylation steps in glycolysis produce 1,000 to 10,000 times more ATP than aerobic energy metabolism.

Studies on the isolation of granules and mitochondria of leukocytes; with a preliminary note on the nature of the Nadi oxidase reaction.

Studies on the isolation of granules and mitochondria of leukocytes; with a preliminary note on the nature of the Nadi oxidase reaction.