Tag Archives: mitochondria

Effects of thiazole derivatives on intracellular structure and functions in murine lymphoma cells

V. P. Hreniukh1, N. S. Finiuk1,2, Ya. R. Shalai1, B. O. Manko1,
B. V. Manko1, Yu. V. Ostapiuk1, O. R. Kulachkovskyy1,
M. D. Obushak1, R. S. Stoika1,2, A. M. Babsky1*

1Ivan Franko National University of Lviv, Ukraine;
2Institute of Cell Biology, Nationl Academy of Sciences of Ukraine, Lviv;
*e-mail: andriy.babsky@gmail.com

Received: 22 December 2019; Accepted: 27 March 2020

Thiazole derivatives have cytotoxic effects towards tumor cells, such as glioblastoma, melanoma, leukemia and lymphoma. However, the intracellular mechanism of this action is not clear. The aim of our study was to investigate the action of N-(5-benzyl-1,3-thiazol-2-yl)-3,5-dimethyl-1-benzofuran-2-carboxamide (BF1) and 7-benzyl-8-methyl-2-propylpyrazolo[4,3-e]thiazolo[3,2-a]pyrimidin-4(2H)-one (PP2) on cellular structure, and bioenergetic functions of mitochondria in Nemeth-Kellner lymphoma cells (NK/Ly). The structure of treated NK/Ly cells and their mitochondria was examined using electron microscopy. The rate of oxygen uptake by isolated mitochondria was recorded by a polarographic method using a Clark electrode. The mitochondrial potential relative values were registered using fluorescence dye rhodamine 123. In the short-term (15 min), incubation with BF1 and PP2 in 10 and 50 µM concentrations induced apoptotic and necrotic changes in the structure of NK/Ly cells, such as fragmentation and disintegration of the nucleus, destruction of the plasma membrane, and an increase in numbers of lysosomes and mitochondria. A polarographic method did not show significant metabolic shifts in lymphoma mitochondria, in either in vitro or ex vivo actions of the thiazole derivatives. However, fluorescent microscopy showed a significant decrease in mitochondria potential, following a 15 min incubation of cells with 50 µM of PP2. Thus, the electron and fluorescent microscopy data suggest that mitochondria are involved in the mechanism of cytotoxic action of the studied thiazole derivatives.

Exogenous hydrogen sulfide for the treatment of mesenteric damage associated with fructose-induced malfunctions via inhibition of oxidative stress

O. Revenko1*, N. Zaichko2, J. Wallace3, O. Zayachkivska1

1Department of Physiology, Danylo Halytskyy Lviv National Medical University, Ukraine;
2Department of Biochemistry and General Chemistry,
National Pirogov Memorial Medical University, Vinnytsia, Ukraine;
3Department of Physiology and Pharmacology, University of Calgary, Canada;
*e-mail: wersus35@gmail.com

Received: 30 December 2019; Accepted: 27 March 2020

Remodeling of adipocytes in mesentery (AM) associated with nutritional overload from high fructose diet (HFD) is a source of several comorbidities. However, its pathogenesis is still unclear and there are no specific effective drugs for AM remodeling. Recently hydrogen sulfide (H2S) demonstrated potent cytoprotective actions. The purpose of this study was to investigate the effects and underlying mechanisms of AM remodeling in rats fed HFD and with H2S pre-treatment. Adult male rats on standard diet (SD, control group) or HFD that underwent acute water-immersion restraint stress (WIS) were evaluated for subcellular AM adaptive responses by electron microscopy. The effects on AM of exogenous sodium hydrosulfide (NaHS, 5.6 mg/kg/day for 9 days) and the Н2S-releasing aspirin (ASA) derivative (H2S-ASA [ATB-340], 17.5 mg/kg/day) vs conventional ASA (10 mg/kg/day) vs vehicle were investigated. Serum glucose level, thiobarbituric acid reactive substances (TBARS), and activities of cystathionine γ-lyase (CSE) and cystathionine β-synthase (CBS) were examined biochemically using spectrophotometry. In the HFD groups, treatment with NaHS protected AM, as mesenteric microvascular endothelial and sub-endothelial structures were observed vs the vehicle-treated group that had signs of endothelial dysfunction, AM damage and dysfunctional mitochondria. The effect of H2S-ASA was characterized by protection of AM against HFD and WIS-induced injury, with lower TBARS blood level and increased CSE and CBS activities. Carbohydrate overload for 4 weeks is sufficient to cause AM oxidative damage, mitochondrial dysfunction and endothelial changes. H2S plays an important role in mesenteric adipocyte cellular survival against HFD-induced oxidative stress by decreasing overproduction of TBARS and mitochondrial dysfunction. The use of H2S could lead to a novel approach for anti-obesity treatment.

Sources and regulation of nitric oxide synthesis in uterus smooth muscle cells

H. V. Danylovych, Yu. V. Danylovych, T. V. Bohach,
V. T. Hurska, S. O. Kosterin

Palladin Institute of Biochemistry, National Academy of Sciences of Ukraine, Kyiv;
e-mail: danylovych@biochem.kiev.ua

Received: 28 February 2019; Accepted: 17 May 2019

It was proved that NO synthesis in isolated mitochondria of rat uterus smooth muscle depended on the entry of exogenous Ca2+ to mitochondria (inhibited by 1-10 mM Mg2+ in the absence of ATP and by 10 μM ruthenium red) and was suppressed by calmodulin antagonists (0.1-10 μM calmidazolium and 1-100 μM trifluoperazine). It was blocked by NG-nitro-L-arginine, a known antagonist of the constitutive NO-synthase, with a half-maximal inhibition effect at about 25 μM. Moderate deholesterinization of the plasma membrane of myocytes after processing with 0.01% digitonin was followed by increased nitric oxide biosynthesis by cells. The data obtained suggested that mitochondria and plasmalemma is a possible source of NO synthesis in uterine myocytes.

Сalix[4]arene chalcone amides effects on myometrium mitochondria

S. G. Shlykov1, A. M. Kushnarova-Vakal1, A. V. Sylenko1,
L. G. Babich1, О. Yu. Chunikhin1, O. A. Yesypenko2,
V. I. Kalchenko2, S. O. Kosterin1

1Palladin Institute of Biochemistry, National Academy of Sciences of Ukraine, Kyiv;
e-mail: sshlykov@biochem.kiev.ua;
2Institute of Organic Chemistry, National Academy of Sciences of Ukraine, Kyiv

Received: 19 November 2018; Accepted: 14 March 2019

Mitochondria are a key player in a wide range of the most important functions of the cell. Calixarenes are supramolecular compounds that have been widely used in bioorganic chemistry and biochemistry. The aim of this work was to study the effects of calix[4]arenes with two (С-1012, С-1021), three (С-1023, С-1024) and four (С-1011) chalcone amide groups on the myometrial mitochondria membranes polarization, Ca2+ concentration in the matrix of these organelles ([Ca2+]m ) and on the average hydrodynamic diameter of mitochondria. It was shown that permeabilized myometrium cells incubation with calix[4]arenes containing two or more chalcone amide groups, was accompanied by an increased level of myometrial mitochondria membranes polarization. All studied calix[4]arenes increased [Ca2+]m values in the absence and in the presence of exogenous Ca2+. The values of [Ca2+]m in the absence of exogenous Ca2+ were higher at mitochondria incubation in Mg2+-containing, than in Mg2+,ATP-containing medium. Incubation of isolated mitochondria with the studied calix[4]arenes resulted in changes of mitochondria volume: at incubation with С-1012, С-1021, C-1023 the average hydrodynamic diameter was decreased, while with С-1011 it was increased. Thus, we have shown that a short-term (5 min) incubation of mitochondria in the presence of 10 µM calix[4]arenes, which contain from two to four chalcone amide groups, increased the level of mitochondria membranes polarization, ionized Ca concentration in the matrix and had different effects on the mitochondrial volume.

Adaptive respiratory response of rat pancreatic acinar cells to mitochondrial membrane depolarization

B. O. Manko, O. O. Bilonoha, V. V. Manko

Ivan Franko National University of Lviv, Ukraine;
e-mail: bohdan.manko@lnu.edu.ua

Received: 06 December 2018; Accepted: 14 March 2019

The dependence of uncoupled respiratory capacity of intact pancreatic acini on oxidative substrate supply and functional cell state has not yet been studied in detail. In this study, the respiratory responses of isolated pancreatic acini to FCCP were measured with Clark electrode and mitochondrial membrane potential was assessed with rhodamine123 fluorescence. The response of acini to FCCP was characteri­zed with maximal uncoupled respiration rate, optimal FCCP concentration, respiration acceleration and decele­ration. Maximal uncoupled respiration rate substantially increased upon the oxidation of glucose + glutamine (3.03 ± 0.54 r.u.), glucose + glutamine + pyruvate (2.82 ± 0.51 r.u.), glucose + isocitrate (2.71 ± 0.33 r.u.), glucose + malate (2.75 ± 0.38 r.u.), glucose + monomethyl-succinate (2.64 ± 0.42 r.u.) or glucose + dimethyl-α-ketoglutarate (2.36 ± 0.33 r.u.) comparing to glucose alone (1.73–2.02 r.u.) or no substrate (1.76 ± 0.33 r.u.). The optimal FCCP concentration was the highest (1.75 μM) upon glucose + glutamine + pyruvate combination and the lowest (0.5 μM) upon glutamate, combinations of glucose with isocitrate, malate, succinate or α-ketoglutarate. Respiration acceleration after FCCP application was the highest with dimethyl-α-ketoglutarate. Following the peak respiration, time-dependent deceleration was observed. It increased with FCCP concentration and depended on oxidative substrate type. Deceleration was the highest upon malate or isocitrate oxidation but was not observed in case of glutamine or dimethyl-α-ketoglutarate oxidation. Pyruvate alone or in combination with glutamine and glucose significantly decreased the depolarizing effect of FCCP on mitochondrial membrane potential and increased respiration elasticity coefficient with respect to the membrane potential change. Thus, in pancreatic acinar cells, the combination of pyruvate, glutamine and glucose enables the optimal adaptive respiratory response to membrane depolarization.

Glutathione influence on energy metabolism in rat liver mitochondria under experimental nephropathy

Ye. O. Ferenchuk, I. V. Gerush

Higher State Educational Establishment of Ukraine “Bukovinian State Medical University”, Chernivtsi;
e-mail: yelena_f@ukr.net

Received: 17 October 2018; Accepted: 14 March 2019

Mitochondrial oxidative damage and disorders of energy metabolism contribute to a wide range of pathologies and disease progression. In our work, the effect of glutathione on the activity of respiratory chain enzymes and the content of free SH-groups in rat liver mitochondria was examined with the use of folic acid-induced nephropathy model. Mitochondria were isolated by differential centrifugation, NADH-dehydrogenase, succinate dehydrogenase, cytochrome oxidase and H+-ATPase activity were determined. The activity of these enzymes and the content of the free SH-groups in the liver were shown to be decreased under conditions of nephropathy, evidently due to the intensification of the free radical processes. The introduction of glutathione increased the content of SH-groups and the activity of the Complexes II and V enzymes of mitochondrial respiratory chain but did not change the activity of cytochrome oxidase in mitochondria isolated from the liver of rats under experimental nephropathy. The results obtained demonstrate a positive effect of glutathione on mitochondrial succinate dehydrogenase and H+-ATPase activity normalization in the liver of rats with nephropathy. These findings may help to extend the understanding of mitochondrial energy metabolism under development of kidney diseases.

The relationship between the ionized Ca concentration and mitochondrial functions

L. G. Babich1, S. G. Shlykov1, A. M. Kushnarova-Vakal1, N. I. Kupynyak2, V. V. Manko2, V. P. Fomin3, S. O. Kosterin1

1Palladin Institute of Biochemistry, National Academy of Sciences of Ukraine, Kyiv;
e-mail: babich@biochem.kiev.ua;
2Ivan Franko National University of Lviv, Ukraine;
3University of Delaware, Newark, USA

The aim of the study was to show the relationships between ionized Ca concentration ([Ca2+]m) in the mitochondria matrix and functional activity of this organelle. [Ca2+]m was determined using the fluorescent probe Fluo-4, AM. Total level of Ca2+ accumulation in mitochondria was monitored using 45Ca2+ as radioactive tracer. It was shown that incubation of myometrium mitochondria with 3 mM Mg2+ resulted in the low level of [Ca2+]m. Subsequent addition of 100 µM Ca2+ resulted in 8 times increase of [Ca2+]m but in low level of total calcium accumulation. Normalized fluorescence of Ca2+-sensitive probe Fluo-4 in response to the Ca2+ addition was higher than 2.5. At the same time, [Ca2+]m was considerably higher in the medium containing­ 3 mМ АТР and 3 mМ Mg2+. Subsequent addition of 100 µM Ca2+ to the incubation medium resulted in only 2.4 times increase of [Ca2+]m but considerably higher level of total calcium accumulation was observed. Normali­zed fluorescence of Fluo-4 in response to the Ca2+ addition was lower than 1.3. In liver mitochondria higher rate of oxygen consumption was detected in the presence of an oxidative substrate succinate than of pyruvate or α-ketoglutarate. At the presence of an oxidative substrate succinate normalized fluorescence of Fluo-4 in liver mitochondria in response to the Ca2+ addition was lower than 1.3. It was concluded that low level of [Ca2+]m was correlated with low functional activity of this organelle and, vise versa, high level of [Ca2+]m was correlated with high functional activity. It was suggested that normalized fluorescence changes in response to the Са2+ addition could be used as a test of the mitochondrial functional activity: lower normalized fluorescence values − higher functional activity.

Activity of the mitochondrial isoenzymes of endogenous aldehydes catabolism under the conditions of acetaminophen-induced hepatitis

O. M. Voloshchuk, G. P. Kopylchuk, Y. I. Mishyna

Yuriy Fedkovych Chernivtsi National University, Institute of Biology, Chemistry and Natural Resources, Ukraine;
e-mail: o.voloschuk@chnu.edu.ua

The research deals with the determination of the activity of aldehyde dehydrogenase (EC 1.2.1.3), aldehyde reductase (EC 1.1.1.21) as well as the content of TBA reactive substances and protein carbonyl derivates in the rat liver  cytosolic fraction under the conditions of acetaminophen-induced hepatitis and protein deficiency. The most pronounced decrease in the activity of enzymes utilizing endogenous aldehydes is observed in the liver cytosolic fraction of animals with toxic liver injury maintained under the conditions of alimentary protein deficiency. Meanwhile, the accumulation of TBA reactive substances and protein carbonyl-derivates in the liver cytosolic fraction of animals of this experimental group was established. The accumulation of aldehyde products of lipid and protein oxidative damage on the background of the reduction in the activity of enzymes providing aldehyde catabolism may be considered as a possible mechanism underlying hepatocyte dysfunction under the conditions of toxic damage in protein-deficient animals.

Cаlіx[4]аrene С-956 is effective inhibitor of Н(+)-Сa(2+)-exchanger in smooth muscle mitochondria

G. V. Danylovych1, О. V. Kоlomiets1, Yu. V. Danylovych1, R. V. Rodik2, V. I. Kаlchenko2, S. О. Kоsterin1

1Palladin Institute of Biochemistry, National Academy of Science of Ukraine, Kyiv;
e-mail: danylovych@biochem.kiev.ua;
2Institute of Organic Chemistry, National Academy of Science of Ukraine, Kyiv

It was shown that calix[4]arene C-956 exhibited a pronounced concentration-dependent (10-100 μM) inhibitory effect on the H+-Ca2+-exchanger of the inner mitochondrial membrane of rat uterine myocytes (Ki 35.1 ± 7.9 μM). The inhibitory effect of calix[4]arene C-956 was accompanied by a decrease in the initial rate (V0) and an increase in the magnitude of the characteristic time (τ1/2) of the ΔрН-induced Са2+ release. At the same time, it did not affect the potential-dependent accumulation of Ca2+ in mitochondria. Thus, the action of calix[4]arene C-956 might be directed on increasing the concentration of Ca ions in the mitochondrial matrix. The calculation of basic kinetic parameters of the Ca2+ transport from isolated organelles (in the case of its non-zero stationary level), based on changes in fluorescence of Ca2+-sensitive dye Fluo-4 AM in mitochondria was performed. The proposed approach can be used for the kinetic analysis of the exponential decrease of the fluorescence response of any probes under the same experimental conditions.

The biosynthesis of nitric oxide from L-arginine. Nitric oxide formation features and its functional role in mitochondria

G. V. Danylovych, T. V. Bohach, Yu. V. Danylovych

Palladin Institute of Biochemistry, National Academy of Sciences of Ukraine, Kyiv;
e-mail: danylovych@biochem.kiev.ua

Modern data on biochemical patterns of nitric oxide biosynthesis in mammal cells from L-arginine in normoxic conditions is described.  The attention of the authors is given to the results of the recent years on the structure and regulation features isoforms of NO-synthase. The emphasis is put on the latest conception of the compartmentalization of certain isoforms of these enzymes in cells and on the possibility of the directed transport of nitric oxide in the vascular wall. The central place in the review is devoted to issues on the endogenous formation of NO in mitochondria and its potential physiological significance. Our own results on the identification of NO in mitochondria of the uterine smooth muscle, biochemical characteristics of this process and NO possible role in Са2+ transport regulation by organelles are presented and discussed.