Tag Archives: apoptosis

Disturbance of the transmembrane phosphatidylserine asymmetry in hepatocytes as an apoptosis marker under the action of xenobiotics on rats

O. A. Nakonechna, L. A. Babijchuk, A. I. Bezrodna

Kharkiv National Medical University, Kharkiv, Ukraine;
e-mail: bezrodnaya.ai@gmail.com

It has been reported that unfavorable chemical environmental factors affect the functional state of liver, activate free radical processes against the background of the reduced antioxidant activity, change physico-chemical properties and membrane phospholipid composition of  hepatocytes. The aim of our research was to estimate phosphatidylserine distribution in the phospholipid bilayer of hepatocyte membranes and apoptosis stages in hepatocytes of rats under the influence of surfactants: ethyleneglycol (EG), polyethyleneglycol 400, (PEG-400) and polypropyleneglycol (PPG) at a dose of 1/10 DL50. It was found in the  subacute toxicological experiment on rats that the investigated xenobiotics EG, PEG-400 and PPG at a dose of 1/10 DL50 caused phosphatidylserine translocation to the outer membrane in the phospholipid bilayer of hepatocytes. This is a specific signal for macrophages aiming at recognition and elimination of apoptotic cells. Analysis of cell death modes under the influence of the investigated xenobiotics at a dose of 1/10 DL50 revealed that the intake of xenobiotics was associated with  an increase in the amount of apoptotic/necrotic hepatocytes.

Biochemical aspects of the combined use of taxanes, irradiation and other antineoplastic agents for the treatment of anaplastic thyroid carcinoma

V. M. Pushkarev, O. I. Kovzun, V. V. Pushkarev, B. B. Guda, M. D. Tronko

SI V. P. Komisarenko Institute of Endocrinology and Metabolism, NAMS of Ukraine, Kyiv;
e-mail: pushkarev.vm@gmail.com

The review summarizes the results of the cycle of own research and literature data on biochemical mechanisms of combined action of taxanes with γ-irradiation and other antineoplastic agents on one of the most aggressive types of human cancer – anaplastic thyroid carcinoma. Antagonistic interplay between taxanes and irradiation at the level of apoptotic mechanisms and regulators of the cell cycle are discussed. The effectiveness and prospects of using low concentrations of taxanes and low doses of fractional γ-irradiation are substantiated. Attention is paid to the role of inflammation and its key factor – NF-κB in the genesis of thyroid carcinomas and their treatment. Directions for further research are outlined.

Biochemical mechanism of the o,p’-DDD effect on the adrenal cortex

A. S. Mikosha, O. I. Kovzun

V. P. Komisarenko Institute of Endocrinology and Metabolism, National Academy of Medical Sciences of Ukraine, Kyiv;
e-mail: asmikosha@gmail.com

o,p’-Dichlorodiphenyldichloroethane (o,p’-DDD, mitotane) is used in the treatment of adrenocortical cancer and Cushing’s disease. This medicine induces numerous biochemical changes in the adrenal cortex, as well as disorder in the mitochondrial structure. Therewith, the level of produced corticosteroid hormones is significantly reduced. One of the possible causes can be a decrease in the NADPH level due to inhibition of the activity of its reduction system and increased NADPH consumption during the glutathione reduction catalyzed by glutathione reductase. o,p’-DDD is partially metabolized in the adrenal glands, and   the main metabolite (in terms of quantity) is o,p’-dichlorodiphenylacetic acid. However, attempts to find a physiologically active component among metabolites were unsuccessful. The most pronounced changes caused by o,p’-DDD were found in the mitochondria of the adrenal cortex. The respiration at the level of IV and I complexes is suppressed, the protein content of these complexes decreases. The phospholipid composition of the tissue altered and the concentration of diphosphatidylglycerol, the most important component of mitochondrial membranes, decreased. In our opinion, o,p’-DDD, owing to its high lipophilicity, accumulates in the mitochondria membranes and causes conformational disorder followed by disorder in mitochondrial functions. It was shown that o,p’-DDD acts as an inhibitor of acyl-CoA-cholesterol acyltransferase (ACAT, SOAT1). Therefore, adenocorticocytes accumulate free cholesterol, causing endoplasmic reticulum stress, mitochondrial swelling and caspases activation. Increased apoptosis leads to a decline in adrenal function and to a decrease in weight of adrenal glands.

Prednisolone and vitamin D(3) modulate oxidative metabolism and cell death pathways in blood and bone marrow mononuclear cells

I. O. Shymanskyy, O. O. Lisakovska, A. O. Mazanova,
D. O. Labudzynskyi, A. V. Khomenko, M. M. Veliky

Palladin Institute of Biochemistry, National Academy of Sciences of Ukraine, Kyiv;
e-mail: ishymansk@inbox.ru

The study was designed to evaluate reactive oxygen species (ROS)/nitric oxide (NO) formation and apoptotic/necrotic cell death elicited by prednisolone in peripheral blood and bone marrow mononuclear cells and to define the efficacy of vitamin D3 to counter glucocorticoid (GC)-induced changes. It was shown that prednisolone (5 mg per kg of female Wistar rat’s body weight for 30 days) evoked ROS and NO overproduction by blood mononuclear cells (monocytes and lymphocytes) that correlated with increased cell apoptosis and necrosis. In contrast, prednisolone did not affect ROS/NO levels in bone marrow mononuclear cells that corresponded to lower level of cell death than in the control. Alterations of prooxidant processes revealed in mononuclear cells and associated with GC action were accompanied by vitamin D3 deficiency in animals, which was assessed by the decreased level of blood serum 25-hydroxivitamin D3 (25OHD3). Vitamin D3 administration (100 IU per rat daily for 30 days, concurrently with prednisolone administration) completely restored 25OHD3 content to the control values and significantly reversed ROS and NO formation in blood mononuclear cells, thus leading to decreased apoptosis. In bone marrow, vitamin D3 activated ROS/NO production and protein nitration that may play a role in prevention of prednisolone-elicited increase in bone resorption. We conclude that vitamin D3 shows a profound protection against GC-associated cellular damage through regulating intracellular ROS/NO formation and cell death pathways.

Modulation of temozolomide action towards rat and human glioblastoma cells in vitro by its combination with doxorubicin and immobilization with nanoscale polymeric carrier

N. S. Finiuk1, J. V. Senkiv1, A. O. Riabtseva2,
N. Y. Mitina2, N. I. Molochii1, M. O. Kitsera1,
S. S. Avdieiev3, O. S. Zaichenko2, R. S. Stoika1

1Institute of Cell Biology, National Academy of Science of Ukraine, Lviv;
2Lviv National Polytechnic University, Ukraine;
3Institute of Molecular Biology and Genetics, National Academy
of Science of Ukraine, Ukraine;
е-mail: stoika@cellbiol.lviv.ua

Malignant gliomas (glioblastoma multiforme and anaplastic astrocytoma) occur more frequently than other types of primary central nervous system tumors, having a combined incidence of 5–8/100,000 population. Even with aggressive treatment using surgery, radiation, and chemotherapy, median reported survival is less than one year. Alkylating agents, such as temozolomide (TMZ), are among the most effective cytotoxic agents used for malignant gliomas, however, the responses still remain poor. Here, we present data about an enhancement of TMZ treatment effect towards rat and human glioma cells in vitro by immobilizing this drug with a new nanoscale polymeric-phospholipidic delivery system. It is a water-soluble comb-like poly(PM-co-GMA)-graft-PEG polymer consisting of a backbone that is a copolymer of 5-tert-butyl-peroxy-5-methyl-l-hexene-3-yne (PM) and glycidyl methacrylate (GMA) and polyethylene glycol (PEG) side chains. The molecular weight of the carrier was 94,000 g/mol. Conjugation of TMZ with a novel polymeric carrier functionalized with phosphatidylcholine resulted in approximately 2 times enhancement of anticancer activity of TMZ. Combining of TMZ with doxorubicin (50 nM) resulted in further enhancement by 23% of the anti-proliferative effect of TMZ. TMZ caused apoptosis in glioma cells via activation of MAPK signaling pathway, inhibition of STAT3, and affected a transition through G2/M phase of cell cycle. These features make the novel nano-formulation of TMZ a perspective strategy for further development of this drug.

Metabolic changes in living cells under electromagnetic radiation of mobile communication systems

I. L. Yakymenko1,2, E. P. Sidorik1, O. S. Tsybulin2

1R.E.Kavetsty Institute of Experimental Pathology, Oncology
and Radiobiology, National Academy of Sciences of Ukraine, Kyiv;
2Bila Tserkva National Agrarian University, Ukraine;
e-mail: iyakymen@gmail.com

Review is devoted to the analysis of biological effects of microwaves. The results of last years’ researches indicated the potential risks of long-term low-level microwaves exposure for human health. The analysis of metabolic changes in living cells under the exposure of microwaves from mobile communication systems indicates that this factor is stressful for cells. Among the reproducible effects of low-level microwave radiation are overexpression of heat shock proteins, an increase of reactive oxygen species level, an increase of intracellular Ca2+, damage of DNA, inhibition of DNA reparation, and induction of apoptosis. Extracellular-signal-regulated kinases ERK and stress-related kinases p38MAPK are involved in metabolic changes. Analysis of current data suggests that the concept of exceptionally thermal mechanism of biological effects of microwaves is not correct. In turn, this raises the question of the need to revaluation of modern electromagnetic standards based on thermal effects of non-ionizing radiation on biological systems.

Folate-related processes in human placenta: gene expression, aminothiols, proliferation and apoptosis

M. Yu. Obolenskaya, R. R. Rodriges, O. P. Martsenyuk

Institute of Molecular Biology and Genetic, National Academy of Sciences of Ukraine, Kyiv;
e-mail: m.obolenska@gmail.com

The paper contains short information concerning the role of folate-related processes in cell metabolism and multiple diseases which are characterized by hyperhomocysteinemia. The authors represent more detailed information about the folate-related processes in human placenta, namely about the content of aminothiols at different allelic variants of placental methylenetetrahydrofolate reductase during the course of physiological pregnancy and preeclampsia. The existing data concerning the expression and catalytic activi­ty of corresponding enzymes are corroborated by the authors’ own results that proved for the first time the functional activity of transsulfuration pathway in human placenta. This pathway is activated in placental explants in parallel with down-regulation of proliferation and up-regulation of apoptosis when hyperhomocystei­nemia is imitated by high concentration of homocysteine in culture medium. On the whole the presented data point to the importance of placental folate-related processes for its normal function.

Effects of α-tocopherol and its anologues on rat thymocytes programmed death induced by protein kinase inhibitors

G. V. Petrova, N. V. Delemenchuk, G. V. Donchenko

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

It is established that α-tocopherol (α-ТPh) shows cytoprotective effect at the induction of rats’ thymocytes apoptosis by endocellular protein kinase inhibitors – staurosporine and phorbol ether in high concentration, and also on necrosis of the cells caused by sphyngosine. The effect of α-ТPh on thymocytes death caused by protein phosphatase type 2А inhibitor ocadaic acid is much less expressed. The obtained data testify that the known ability of α-ТPh to the inhibition of PKC and to the activation of protein phosphatase type 2А is not the main mechanism of its cytoprotective action. Partial reproduction of α-ТPh effects by its analogue α-tocopheryl acetate which is not capable to enter in redox reactions, and the absence of influence on the studied processes of an antioxidant of N-acetyl-L-cysteine do not confirm the antioxidant mechanism of α-ТPh action in this case. The inhibition by α-ТPh of the release of cytochrome c in the cytosol of cells testifies to the implementation of its cytoprotective effect at the level of mitochondrial membranes. We assume the existence of the universal mechanism of α-ТPh cytoprotective action that does not depend on the nature of apoptogenes and realized on the general for the majority of them stage of the cells death induction. The prevention by α-ТPh of mitochondria dysfunction by stabilizing mitochondrial membranes and reduction of their permeabilization is supposed as that.

Photoactivated fullerene C(60) induces store-operated Ca(2+) entry and cytochrome c release in Jurkat cells

S. M. Grebinyk1, K. O. Palyvoda2, S. V. Prylutska1, I. I. Grynyuk1,
A. A. Samoylenko2, L. B. Drobot2, O. P. Matyshevska1

1Taras Shevchenko Kyiv National University, Ukraine;
2Palladin Institute of Biochemistry, National Academy of Sciences of Ukraine, Kyiv;
e-mail: matysh@yahoo.com

The values of endoplasmic reticulum Ca2+-pool and store-operated Ca2+ entry (SOCE) were estimated in rat thymocytes and Jurkat cells loaded with indo-1 and treated with thapsigargin. It was shown that the relative value of SOCE in thymocytes was substantially lower than in Jurkat cells. Significant increase of SOCE in Jurkat cells preincubated with 10-5 M C60 and exposed to uv/visible light irradiation was detected at 1-3 h after exposure. At this time FCCP-induced Ca2+-release from mitochondria was shown to be reduced, while cytochrome c level into the cytoplasm of Jurkat cells, detected by Western blot analysis, to be increased. It is supposed that Ca2+ flux remodulation induced by photoexcited fullerene C60 in Jurkat cells might be involved in the initiation of signalling events leading to cell apoptosis.

Effect of N-stearoylethanolamine on the DNA fragmentation intensity in tumour and extratumoral tissues of the human adrenal cortex

N. I. Levchuk1, V. M. Pushkarev1, O. I. Kovzun1,
A. S. Mikosha1, N. M. Gula2, M. D. Tronko1

1State Institution V. P. Komisarenko Institute of Endocrinology and Metabolism,
National Academy of Medical Sciences of Ukraine, Kyiv;
2Palladin Institute of Biochemistry, National Academy of Sciences of Ukraine, Kyiv;
e-mail: levnataly@meta.ua

The effect of different concentrations of N-stearoylethanolamine (NSE 18:0) on fragmentation of DNA in the tumoural and extratumour tissues of the adrenal glands in vitro was studied. In this work the following types of tissue were investigated­: extratumoural tissue from patients with hormonally active tumours, benign tumour tissue (hormonally active and hormonally inactive), tissue of malignant tumours and hyperplasic tissue of the adrenal glands (Itsenko-Cushing disease). It has been established that the NSE increases the intensity of DNA fragmentation only in the tissue of hormonally inactive tumours. Benign hormonally active tumours, malignant tumours and hyperplastic tissue of the adrenal glands were resistant to the NSE. The possible mechanisms of resistance to the drug are discussed.