Tag Archives: mitochondria

Bioenergetic functions of mitochondria in liver, pancreatic acinar cells, and sperm cells of rats fed short-term high-fat or high-fat high-sugar diets

B. V. Manko1*, N. M. Kozopas1,2, H. M. Mazur1,
A. М. Voityk1, B. O. Manko1, V. V. Manko1

1Ivan Franko National University of Lviv,
Department of Human and Animal Physiology, Lviv, Ukraine;
2Danylo Halytsky Lviv National Medical University,
Department of Clinical Laboratory Diagnostics, Lviv, Ukraine;
*e-mail: bohdan.manko.ablb@lnu.edu.ua

Received: 26 September 2023; Revised: 23 October 2023;
Accepted: 27 October 2023; Available on-line: November 2023

An unhealthy diet often is a cause of obesity, chronic inflammation, and metabolic disruption in multiple organs. However, the direct influence of elevated lipid or sugar consumption on liver, pancreatic, and sperm mitochondria is not well understood. The aim of the study was to investigate the functional activity of mitochondria of liver, pancreatic acinar cells, and sperm cells in rats on a short-term (7 weeks) diet with high fat or high fat and high sugar content. Male Wistar rats were on a basic, high-fat or high-fat high-sugar diet for 7 weeks. At the end of the experiment, visceral fat mass, blood glucose and lipids were measured. Mitochondrial functional activity was evaluated with oxygen consumption assay. In isolated pancreatic acinar cells, NAD(P)H autofluorescence and mitochondrial membrane potential were also studied. No difference in body mass was observed between the 3 groups at the end of the experiment. Visceral fat mass was slightly but significantly elevated in rats on a high-fat high-sugar diet. Both diets did not affect plasma glucose or triglyceride levels but caused a modest elevation of total plasma cholesterol. Respiration and oxidative phosphorylation of isolated liver mitochondria were not affected by any experimental diet. In pancreatic acinar cells, a high-fat diet caused a significant decrease of basal respiration by ~15%, but no effects were observed on the maximal rate of uncoupled respiration, mitochondrial membrane potential, or NAD(P)H autofluorescence. In these cells, a ketone body 3-hydroxybutyrate caused elevation of uncoupled respiration and NAD(P)H level irrespectively of the diet. Diets did not cause any change in sperm concentration, viability or motility. Surprisingly, in animals on a high-fat high-sugar diet, a significant increase in both basal and maximal respiration of sperm cells was observed. Collectively, these data show that while the elevated fat and sugar content in the diet does not cause significant obesity, no detrimental effects on mitochondria of the liver, pancreas, and sperm cells are observed.

Choline derivatives as natural ligands of mitochondrial nicotinic acetylcholine receptors

O. Lykhmus, M. Izmailov, M. Skok*

Department of Molecular Immunology, Palladin Institute of Biochemistry,
National Academy of Sciences of Ukraine, Kyiv;
*e-mail: skok@biochem.kiev.ua

Received: 16 March 2023; Revised: 28 April 2023;
Accepted: 05 June 2023; Available on-line: 20 June 2023

Nicotinic acetylcholine receptors (nAChRs) regulate mitochondria-driven apoptosis; however, their intracellular ligands are unknown. In the present paper, we show that choline and its derivatives (phosphocholine (PC), L-α-glycerophosphocholine (G-PC) and 1-palmitoyl-sn-glycero-3-phosphocholine (P-GPC)) dose-dependently influence cytochrome c release from isolated mouse liver mitochondria. Choline inhibited Ca2+-stimulated cytochrome c release, while PC attenuated wortmannin-induced cytochrome c release. Small doses of G-PC and P-GPC (up to 0.1 µM) were protective against either Ca2+ or wortmannin, while larger doses (up to 1 µM) stimulated cytochrome c release by themselves. Choline and PC disrupted interaction of VDAC1, Bax and Bcl-2 with mitochondrial α7 nAChRs and favored their interaction with α9 nAChR subunits. It is concluded that choline metabolites can regulate apoptosis by affecting mitochondrial nAChRs.

Biochemical and molecular-physiological aspects of the nitric oxide action in the utera

H. V. Danylovych, Yu. V. Danylovych

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

Received: 18 May 2021; Accepted: 12 November 2021

The sources of the nitric oxide (NO) formation in the uterus and the dynamics of changes in its content in different periods of organ functioning in human and animals are analyzed. The biochemical mechanisms of NO action on the myometrium contractile activity, the significance of NO in the physiological processes during pregnancy and labor, the importance of mitochondria as a reliable NO source in the smooth muscle and the possible ways of NO influence on Ca2+ transport and bioenergetic processes in mitochondria are considered. The authors’ data concerning ionic and membrane mechanisms of NO action on Ca2+-homeostasis of uterine myocytes, identification of nitric oxide in uterine smooth muscle mitochondria, biochemical characteristics of the NO-synthase reaction and the possible role of NO in the regulation of Ca2+ transport in these subcellular structures and in the electron transport chain functioning are presented and discussed.

Application of petri nets methodology to determine biophysicochemical parameters of mitochondria functioning

H. V. Danylovych*, A. Yu. Chunikhin, Yu. V. Danylovych, S. O. Kosterin

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

Received: 01 Nobember 2020; Accepted: 17 May 2021

With the use of Petri net methodology a mathematical simulation model able to predict simultaneous changes in biophysicochemical parameters of mitochondria functioning was developed. The model allowed to interconnect in time the changes in mitochondria hydrodynamic diameter, electronic transport chain functioning, endogenous fluorescence of adenine nucleotides, DCF fluorescence signal of ROS production and NaN3 effects. It was shown that the calculated values of the studied biophysicalchemical parameters correspond to those obtained experimentally. The model permit to link mitochondrial functional changes and their  structural representation and to optimize significantly experimental procedures.

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.