P. White et al. / Free Radical Biology and Medicine 75 (2014) S21–S53
as cell proliferation, differentiation, and apoptosis. In the present study, we showed that Insulin-like growth factor-1(IGF-1) modulates SKOV-3 ovarian cancer cell by regulation of generation of ROS. Akt mediates cellular signaling pathways in association with mammalian target of rapamycin complex (mTOR) and Rac small G protein. Insulin-like growth factor-1 (IGF-1)-induced generation of ROS was completely abolished by phosphatidylinositol 3-kinase (PI3K) (LY294002, 10 μM) or Akt inhibitors (SH-5, 50 μM), whereas inhibition of extracellular-regulated kinase by an ERK inhibitor (PD98059, 10 μM) or inhibition of mammalian target of rapamycin complex 1 (mTORC1) by an mTORC1 inhibitor (Rapamycin, 100 nM) did not affect IGF-1-induced generation of ROS. Inactivation of mTORC2 by silencing Rapamycin-insensitive companion of mTOR (Rictor), abolished IGF-1-induced SKOV-3 cell migration as well as activation of Akt. However, inactivation of mTORC1 by silencing of Raptor had no effect. Silencing of Akt1 but not Akt2 attenuated IGF-1-induced generation of ROS. Expression of PIP3-dependent Rac exchanger1 (P-Rex1), a Rac guanosine exchange factor and a component of the mTOR complex. Silencing of P-Rex1 abolished IGF-1-induced generation of ROS. Finally, inhibition of NADPH oxidase system completely blunted IGF-1-induced generation of ROS, whereas inhibition of xanthine oxiase,cyclooxygenase, and mitochondrial respiratory chain complex was not effective. Given these results, we suggest that IGF-1 induces ROS generation through the PI3K/Akt/ mTOR2/NADPH oxidase signaling axis.
http://dx.doi.org/10.1016/j.freeradbiomed.2014.10.773
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Heat shock proteins and proteasomal degradation in normal and tumor cells Karademir Betula, Bozaykut Perinurb, Kartal Ozer Nesrinc a
Marmara University (Genetic and Metabolic Diseases Research and Investigation Center), Department of Biochemistry, Turkey b Marmara University (Genetic and Metabolic Diseases Research and Investigation Center), Department of Biochemistry, Turkey c Marmara University (Genetic and Metabolic Diseases Research and Investigation Center), Department of Biochemistry, Turkey
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The modified proteins in erythrocytes at hemodialysis patients Klyuyev Dmitriy, Muravlyova Larissa, Molotov-Luchanskiy Vilen, Ponamareva Olga, Kolesnikova Yevgeniya, Demidchik Ludmila, Beynikova Irina Karaganda State Medical University (faculty of General Medidcine), Biological chemistry, Kazakhstan
Abstract The main goal of our research was to study the modified proteins and activity of integral band 3 protein in erythrocytes of patients with endstage renal failure during hemodialysis. Depending on the starting nosological variant 2 groups were formed. The first group included 27 patients with end-stage renal failurein the outcome of chronic pyelonephritis, the second – 20 patients with end-stage renal failure, developed on a background of chronic glomerulonephritis. The control group consisted of 15 healthy subjects. The patients of 1-th and 2-nd groups were treated with hemodialysis. The concentration of reactive protein carbonyl derivates, membrane-binding hemoglobin were detected in erythrocytes. Activity of band 3 protein was detected following the protocol of I. Mindukshev et al. (2010). Comparison the results obtained was performed using non-parametric Mann-Whitney U-test (for independent variables). Before hemodialysis the significant increasing of concentration of reactive protein carbonyl derivates and membrane-binding hemoglobin in erythrocytes of both group patients in comparison with healthy ones was observed. During hemodialysis the further augmentation of modified proteins in erythrocytes took place. Different changes in the activity of the protein band 3 in erythrocytes of patients during hemodialysis were found. The similar type of protein band 3 activity changing was determined in erythrocytes of 1-th group patients. There was positive pair correlation between concentration of the reactive protein carbonyl derivates and protein band 3 activity (r ¼ 0,31, po 0,05). Two different types of protein band 3 activity changing were determined in erythrocytes of 2-th group patients. Thus, the differences in modified proteins concentration and protein band 3 activity that occurred in the erythrocytes of patients during hemodialysis were established.
http://dx.doi.org/10.1016/j.freeradbiomed.2014.10.775
Abstract Proteasomal degradation of oxidized proteins is a crucial mechanism to prevent the accumulation of cellular damage. The removal of the damage is generally a required process for healthy organisms to keep the integrity while in cancer cells the situation may be different. In normal conditions, cancer cells have higher proteasome activity compared to normal cells. During cancer treatment, cellular damage by chemotherapy is an expected process to be able to kill the tumor cells. And the accumulation of this damage accompanied by the decrease in protein repair and removal systems may increase the efficacy of the cancer therapy. Heat shock proteins (Hsp) as molecular chaperones are involved in the folding, activation and assembly of a variety of proteins. Among these Hsp40, Hsp70 and Hsp90 are believed to act as a chaperone system to regulate the proteasomal degradation. In this study, we tested the role of heat stress response on the proteasomal degradation of oxidized proteins. We used two different cell lines to observe the difference in normal and tumor cells. First the effect of heat stress (42 1C, 1 h) were tested in terms of protein oxidation tested by protein carbonyl formation and proteasomal degradation. The results were extremely different in normal fibroblast cells and hippocampal tumor cells. In the same direction, the expressions of Hsp40, Hsp70 and Hsp90 were affected in a different manner in two cell lines, will be discussed in detail. Supported by TUBITAK COST-CM1001-110S281.
http://dx.doi.org/10.1016/j.freeradbiomed.2014.10.774
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Characteristic of oxidative metabolism in patients with chronic kidney disease depending on etiological nosology Kolesnikova Yevgeniya, Demidchik Lyudmila, Muravlyova Larissa, Molotov-Luchanskiy Vilen, Klyuyev Dmitriy, Beinikova Irina Karaganda State Medical University (Faculty of General Medicine), Department of Biochemistry, Kazakhstan
Abstract Development of chronic kidney disease (CKD) is accompanied by change in the oxidative metabolism. The aim of the study was to assess the parameters of oxidative stress in erythrocytes and plasma of patients with CKD 1 and 2 stages depending on the etiological nosology.