Apoptosis indices in liver cell mitochondria in B16/F10 melanoma growing in presence of chronic neurogenic pain

Введение. Печень по количеству, плотности митохондрий один из самых богатых органов, который также является критическим местом для множества метаболических путей. Цель исследования - изучение показателей апоптоза в митохондриях печени самок мышей линии С57ВL/6 при самостоятельном росте меланомы В16/F10 и на фоне коморбидной патологии - хронической нейрогенной боли. Методика. В эксперименте использовали мышей-самок (n=168) линии С57ВL/6. Группы: интактная (n=21); контрольная (n=21) - создание модели хронической нейрогенной боли (ХНБ), путем двусторонней перевязки седалищных нервов; группа сравнения (n=63) - подкожная трансплантация меланомы B16/F10; основная группа (ХНБ+B16/F10) (n=63) - подкожная трансплантация меланомы В16/F10 через 3 нед после моделировия ХНБ. В митохондриях печени методом ИФА определяли концентрацию: цитохрома С (нг/г белка), каспазы 9 (нг/г белка), Bcl-2 (нг/г белка), AIF (нг/г белка), кальция (Са 2+) (мМоль/г белка). Результаты. В митохондриях клеток печени через 1 нед роста меланомы относительно интактных значений фиксировали нарастание уровней AIF в 2,2 раза, цитохрома С в 1,7 раза (р<0,05) и снижение каспазы 9 в 2,0 раза; через 3 нед - падение кальция в 4,7 раза, AIF в 7,1 раза и цитохрома С в 1,7 раза (р<0,05) и накопление каспазы 9 - 1,6 раза (р<0,05). Развитие опухоли при ХНБ через 1 нед сопровождалось уменьшением концентрации AIF в 29,3 раза и цитохрома С в 2,0 раза по сравнению с контрольными значениями (ХНБ). Через 3 недели роста меланомы на фоне ХНБ фиксировали снижение уровней AIF в 6,6 раза, цитохрома С в 4,7 раза и кальция в 32,8 раза, уровень каспазы 9, напротив, повышался в 1,5 раза (р<0,05). Заключение. Наличие коморбидной патологии - ХНБ при опухолевом процессе способствует раннему возникновению нарушений в электронно-транспортной цепи митохондрий клеток печени. Background. The liver is one of the richest organs in terms of the number and density of mitochondria; it is also a critical site for many metabolic pathways. The aim of the study was to analyze indicators of apoptosis in liver mitochondria in female С57ВL/6 mice with B16/F10 melanoma growing alone and in presence of chronic neurogenic pain. Methods. Female С57ВL/6 mice (n=168) were studied. Animals were divided into groups: intact group (n=21); controls (n=21) with a model of chronic neurogenic pain (CNP) created by bilateral sciatic nerve ligation; comparison group (n=63) with subcutaneous transplantation of B16/F10 melanoma; main group (CNP+B16/F10) (n=63) with subcutaneous transplantation of B16/F10 melanoma 3 wks after modeling CNP. Cytochrome C (ng/g protein), caspase-9 (ng/g protein), Bcl-2 (ng/g protein), AIF (ng/g protein), and calcium (Ca2+) (mmol/g protein) were measured by ELISA in the liver mitochondrial fraction. Results. After 1 wk of melanoma growth, AIF increased by 2.2 times, cytochrome C increased by 1.7 times (p<0.05), and caspase-9 decreased by 2.0 times compared to the intact group values. After 3 wks, calcium decreased by 4.7 times, AIF by 7.1 times, cytochrome C by 1.7 times (p<0.05), and caspase-9 increased by 1.6 times (p<0.05). After 1 wk, tumor development in the presence of CNP was accompanied by decreases in AIF by 29.3 times and cytochrome C by 2.0 times, compared to control CNP values. After 3 wks of melanoma growth in presence of CNP, AIF decreased by 6.6 times, cytochrome C by 4.7 times, and calcium by 32.8 times. Caspase-9, on the contrary, increased by 1.5 times (p<0.05). Conclusions. The presence of CNP comorbidity during the tumor development facilitates earlier occurrence of disorders in the electron transport chain of hepatocyte mitochondria.

Profiling subcellular localization of nuclear-encoded mitochondrial gene products in zebrafish

Most mitochondrial proteins are encoded by nuclear genes, synthetized in the cytosol and targeted into the organelle. The import of some, but not all, nuclear-encoded mitochondrial proteins begins with translation of messenger RNAs (mRNAs) on the surface of mitochondria. To characterize the spatial organization of mitochondrial gene products in zebrafish (Danio rerio), we sequenced RNA from different cellular fractions. Our results confirmed the presence of nuclear-encoded mRNAs in the mitochondrial fraction, which in unperturbed conditions, are mainly transcripts encoding large proteins with specific properties, like transmembrane domains. To further explore the principles of mitochondrial protein compartmentalization in zebrafish, we quantified the transcriptomic changes for each subcellular fraction triggered by the chchd4a-/- mutation, causing the disorders in the mitochondrial protein import. Our results indicate that the proteostatic stress further restricts the population of transcripts on the mitochondrial surface, allowing only the largest and the most evolutionary conserved proteins to be synthetized there. We also show that many nuclear-encoded mitochondrial transcripts translated by the cytosolic ribosomes stay resistant to the global translation shutdown. Thus, vertebrates, in contrast to yeast, are not likely to employ localized translation to facilitate synthesis of mitochondrial proteins under proteostatic stress conditions.

Dystrophin Dp71 Subisoforms Localize to the Mitochondria of Human Cells

Duchenne muscular dystrophy (DMD) is a fatal muscle wasting disease caused by deficiency in dystrophin, a protein product encoded by the DMD gene. Mitochondrial dysfunction is now attracting much attention as a central player in DMD pathology. However, dystrophin has never been explored in human mitochondria. Here, we analyzed dystrophin in cDNAs and mitochondrial fractions of human cells. Mitochondrial fraction was obtained using a magnetic-associated cell sorting (MACS) technology. Dystrophin was analyzed by reverse transcription (RT)-PCR and western blotting using an antibody against the dystrophin C-terminal. In isolated mitochondrial fraction from HEK293 cells, dystrophin was revealed as a band corresponding to Dp71b and Dp71ab subisoforms. Additionally, in mitochondria from HeLa, SH-SY5Y, CCL-136 and HepG2 cells, signals for Dp71b and Dp71ab were revealed as well. Concomitantly, dystrophin mRNAs encoding Dp71b and Dp71ab were disclosed by RT-PCR in these cells. Primary cultured myocytes from three dystrophinopathy patients showed various levels of mitochondrial Dp71 expression. Coherently, levels of mRNA were different in all cells reflecting the protein content, which indicated predominant accumulation of Dp71. Dystrophin was demonstrated to be localized to human mitochondrial fraction, specifically as Dp71 subisoforms. Myocytes derived from dystrophinopathy patients manifested different levels of mitochondrial Dp71, with higher expression revealed in myocytes from Becker muscular dystrophy (BMD) patient-derived myocytes.

Application of Non-Destructive Methods: Biomarker Assays in Blood of White Stork (Ciconia ciconia) Nestlings

White stork (Ciconia ciconia) nestlings can provide quantitative information on the quality of the surrounding environment by indicating the presence of pollutants, as they depend on locally foraged food. This study represents the first comparison of biomarkers in two fractions of white stork nestling blood: plasma and S9 (the post-mitochondrial fraction). The aim of this study was to evaluate acetylcholinesterase (AChE), carboxylesterase (CES), glutathione S-transferase (GST), and glutathione reductase (GR), as well as to establish a novel fluorescence-based method for glutathione (GSH) and reactive oxygen species (ROS) detection in plasma and S9. Considering the enzymatic biomarkers, lower variability in plasma was detected only for AChE, as CES, GST, and GR had lower variability in S9. Enzyme activity was higher in plasma for AChE, CES, and GST, while GR had higher activity in S9. Regarding the fluorescence-based method, lower variability was detected in plasma for GSH and ROS, although higher GSH detection was reported in S9, and higher ROS was detected in plasma. The present study indicated valuable differences by successfully establishing protocols for biomarker measurement in plasma and S9 based on variability, enzyme activity, and fluorescence. For a better understanding of the environmental effects on nestlings’ physiological condition, biomarkers can be measured in plasma and S9.

Role of PITRM1 in Mitochondrial Dysfunction and Neurodegeneration

Mounting evidence shows a link between mitochondrial dysfunction and neurodegenerative disorders, including Alzheimer Disease. Increased oxidative stress, defective mitodynamics, and impaired oxidative phosphorylation leading to decreased ATP production, can determine synaptic dysfunction, apoptosis, and neurodegeneration. Furthermore, mitochondrial proteostasis and the protease-mediated quality control system, carrying out degradation of potentially toxic peptides and misfolded or damaged proteins inside mitochondria, are emerging as potential pathogenetic mechanisms. The enzyme pitrilysin metallopeptidase 1 (PITRM1) is a key player in these processes; it is responsible for degrading mitochondrial targeting sequences that are cleaved off from the imported precursor proteins and for digesting a mitochondrial fraction of amyloid beta (Aβ). In this review, we present current evidence obtained from patients with PITRM1 mutations, as well as the different cellular and animal models of PITRM1 deficiency, which points toward PITRM1 as a possible driving factor of several neurodegenerative conditions. Finally, we point out the prospect of new diagnostic and therapeutic approaches.

Activity of ROS-induced processes in the combined preconditioning with amtizol before and after cerebral ischemia in rats

Introduction: The dose-dependent effect of reactive oxygen species (ROS) in tissues in preconditioning (PreC) and oxidative stress, as well as NO-synthase participation in mitochondrial ROS production determined the study aim – to assess the impact of the neuroprotective method of combined preconditioning (CPreC) on free radical reactions (FRRs) in brain in normoxia and in cerebral ischemia, including in NO-synthase blockade. Materials and methods: The intensity of FRR by iron-induced chemiluminescence (CL), the content of lipid peroxidation products and antioxidant enzyme activity were investigated 1 hr (early period) and 48 hrs (delayed period) after CPreC (amtizol and hypobaric hypoxia) in Wistar rat brain. Some animal groups were operated (common carotid artery bilateral ligation) 1 hr and 48 hrs after CPreC, as well as with preliminary introduction of L-NAME and aminoguanidine. Results and discussion: In normoxia, CPreC led to increase the CL maximum level (Fmax) in the delayed PreC period. The amount of thiobarbituric acid reactive products (TBA-RP), activity of superoxide dismutase (SOD) and catalase in mitochondrial fraction of rat brain did not change in comparison with the intact control in both PreC periods. In cerebral ischemia, oxidative stress was observed. The CPreC use before ischemia caused a decrease in CL parameters and TBA-RP in brain, the maintenance of SOD and high catalase activity. NO-synthase inhibitors partially abolished the antioxidant effect of CPreC in ischemia. Conclusion: CPreC had no influence on FRRs in brain tissue in normoxia, but prevented their excessive activation after ischemia, especially in the delayed period. NO-synthase was involved in the CPreC neuroprotection.

N-acetylcysteine supplementation did not reverse mitochondrial oxidative stress, apoptosis, and inflammation in the salivary glands of hyperglycemic rats

Background/objectives Previous studies have shown that N-acetylcysteine (NAC) supplementation with the simultaneous inclusion of HFD prevents salivary glands from oxidative stress and mitochondrial dysfunction. In this experiment, we examined if NAC supplementation could reverse the harmful effect of HFD on mitochondrial function, reduce the severity of apoptosis, and the activity of pro-oxidative enzymes in the salivary glands of rats with confirmed hyperglycemia. Subjects/methods Wistar rats were fed the standard or high-fat (HFD) diet for 10 weeks. After 6 weeks of the experiment, HFD rats were diagnosed with hyperglycemia and for the next 4 weeks, the animals were given NAC intragastrically. In the mitochondrial fraction of the parotid (PG) and submandibular salivary glands (SMG), we assessed redox status, inflammation, and apoptosis. Results The inclusion of NAC increased the activity of mitochondrial complexes I and II + III as well as decreased the concentration of interleukin-1β, tumor necrosis factor α, and caspase-3, but only in the parotid glands of rats with hyperglycemia compared to the HFD group. However, N-acetylcysteine supplementation did not reduce the activity of caspase-9 or the Bax/Bcl-2 ratio in PG and SMG mitochondria. In both salivary glands we observed reduced activity of cytochrome c oxidase, NADPH oxidase, and xanthine oxidase, as well as hindered production of ROS and lower ADP/ATP radio, but the levels of these parameters were not comparable to the control group. Conclusions We demonstrated that NAC supplementation restores the glutathione ratio only in the mitochondria of the submandibular salivary glands. The supply of NAC did not significantly affect the other measured parameters. Our results indicate that NAC supplementation provides little protection against free radicals, apoptosis, and inflammation in the salivary gland mitochondria of HFD rats. Stimulated salivary secretion in hyperglycaemic rats supplemented with NAC seems to be closely related to mitochondrial respiratory capacity and appropriate ATP level.

Synergism of the pharmacological effect of glycine and thiotriazoline

Aim. To establish the effect of the glycine and thiotriazoline (4:1) combination on the parameters of the energy production of the mitochondria of the rat brain under the conditions of simulating an acute cerebrovascular accident. Materials and methods. The experimental part was performed on 90 male Wistar rats weighing 180–200 g. To model acute cerebrovascular accident (ACVA) by ischemic type, a classical model was used, where common carotid arteries had been ligated bilaterally. All animals were divided into 5 experimental groups: the first – intact (sham-operated rats, which during anesthesia had their common carotid arteries separated without ligation); the second – rats with ACVA (control); the third – rats with ACVA, which underwent intragastric administration of glycine at a dose of 200 mg/kg in the form of a tablet mass every day for 4 days; the fourth – rats with stroke, which every day for 4 days underwent intragastric administration of a combination of glycine and thiotriazoline (4:1) in the form of a tablet mass; the fifth – rats with ACVA, which underwent every day intragastric administration of piracetam in the form of a tablet mass at a dose of 500 mg/kg. The sampling of biological material (brain) for research was carried out on the fourth day of the experiment according to the standard method. The mitochondrial fraction was isolated by differential centrifugation in a refrigerated centrifuge. The manifestations of mitochondrial dysfunction, have been spectrophotometrically studied according to the degree of opening of the mitochondrial pore (MP) and mitochondrial transmembrane potential (Ψ). The assessment of the intensity of oxidative stress was determined by the markers of protein oxidative modification – aldehydephenylhydrazone (APH) and ketonedinitrophenylhydrazone (KPH) – spectrophotometrically. The state of energy metabolism was determined by the level of the most significant intermediates – ATP, lactate, succinate and malate. Results. In the group of animals with ACVA modeling, we noted a decrease in the level of ATP in mitochondria by 1.55 times, an increase in lactate content by 1.1 times, a decrease in SDH activity by 3.8 times and a decrease in succinate concentration by 1.1 times relative to the corresponding data of intact groups. Administration of a combination of glycine and thiotriazoline to experimental animals on the fourth day of ACVA modeling led to a 1.9-fold decrease in the opening of the mitochondrial pore and an increase in the charge of the inner mitochondrial membrane by 1.2 times, an increase in ATP in the mitochondrial fraction by 1.1 times, an increase in SDH activity by 3 times, and the activity of NAD-MDH – by 3.7 times, against the background of a decrease in the level of APH by 76.6 % and KPH by 80.7 %, relative to the group of animals with modeling of stroke by ischemic type. Conclusions. Modeling of ACVA leads to the initiation of oxidative stress and the development of an imbalance of energy metabolism intermediates in the brain mitochondria of experimental animals. Administration of a combination of glycine and thiotriazoline leads to a decrease in oxidative damage to mitochondria, increases the production of ATP due to the activation of compensatory mitochondrial-cytosolic shunts, mainly in malate-aspartate and succinate oxidase. In terms of the degree of influence on the indicators of energy metabolism, the combination of glycine and thiotriazoline reliably exceeds the similar actions of glycine and the reference drug - piracetam.