Long-term hyperthermia impairs activity of both photosystems.

This is the first study to perform a simultaneous analysis of the activity of photosystem 1 and photosystem 2 after long-term exposure to elevated temperature. It was found that the quantum yield of photochemical reactions decreases in both photosystems. It is shown that, in photosystem 2, the regulated nonphotochemical quenching decreases whereas the unregulated non-photochemical quenching increases. In photosystem 1, limitation on both acceptor and donor sides increases.

Signaling targets of alcoholic intoxication in human skeletal muscle.

Intracellular signaling pathways were investigated in skeletal muscle cells at the early stages of alcohol addiction manifestations. No muscle fiber atrophy was observed in m. vastus lateralis of male patients. No significant changes in the signaling mechanisms that control protein degradation were detected as well. However, the concentration of the insulin-like growth factor (IGF-1) in blood plasma as well as the content of markers of intracellular signaling pathways regulating protein synthesis were significantly reduced compared to the control group.

[Effect of Combined Aerobic and Strength Exercise on Regulation of Mitochondrial Biogenesis, Protein Synthesis and Degradation in Human Skeletal Muscle.]

We tested the hypothesis that strength exercise after intermittent aerobice exercise might activate signalling pathways related to mitochondrial biogenesis (phosphorylation level of AMPK, p38; expression of PGC-1a, NT-PGC-la, TFAM, VEGFA), to protein synthesis (phosphorylation level of p70S6Kl(Thr389) eEF2(Thr56) expression of IGF-lEa, IGF-lEc (MGF), REDDl) and to proteolysis (phosphorylation level of FOXOl(Ser256) and expression of MURFl, MAFbx, Myostatin) in trained skeletal muscle. Nine amateur endurance-trained athletes performed 70-Min bicycle intermittent exercise with both legs (E), followed by one-leg strength exercise (ES: 4 bouts of knee extensions at 75% MVC till exhaustion). Gene expression and protein level were evaluated in samples from m. vastus lateralis before, 40 min, 5 and 22 h after the aerobic exercise. The phosphorylation level of the ACC(Ser79/222)(an endogenous marker of AMPK activity) and expression of PGC-la-related TFAM - marker of mitochondrial biogenesis were increased after E exercise and did not changed after ES. Expression of PGC-lα and truncated isoform NT- PGC-lα was increased in both legs as well. Insulin concentration in blood was dramatically, 7.5-fold diminished after intermittent aerobic exercise. Phosphorylation of FOXO(Ser256) - regulator of ubiquitin-related proteolysis - was decreased after both E and ES exercise, it means it was activated in both cases, while expression of E3-ubiquitin ligase MURFl was increased only after E exercise. Both aerobic and combined exercise did not affect regulation of protein synthesis: neither expression of IGF-lEa and IGF-Ec (MGF) mRNA isoforms nor phosphorylation levels of markers of protein synthesis p70S6Kl(Thr389) and eEF2(Thr56) were changed. Thus effects of aerobic exercise in trained muscles are noticeably suppressed by performing strength exercise immediately after endurance one. In particular, the activity of signalling cascades and expression of genes regulating mitochondrial biogenesis are lessened, but protein synthesis regulation is not affected. And at last strength exercise suppresses induced by aerobic exercise expression of MURF1 gene - marker of ubiquitin proteasome system. It means that strength exercise just after intermittent aerobic exercise might have a negative effect on aerobic performance if used chronically.

[The Effect of Single Aerobic Training on the Regulation of Mitochondrial Biogenesis in Skeletal Muscles of Trained Men: a Time-Course Study].

Adaptation of skeletal muscles to physical training depends on intensity and duration of exercise sessions. The purpose of this study was to investigate the effect of the duration of moderately intensive single aerobic exercise session (60% V(O2max)) on the activation of signalling kinases which regulate PGC-1α gene expression and on the expression of regulatory genes of mitochondrial biogenesis and muscle catabolism. Nine athletes (V(O2max)) 59 mL/min/kg) performed 30-, 60-, and 90-min cycling sessions. An exercise-induced increase in PGC-1α gene expression was proved to occur without activation of AM PK, p38 MAPK and CAMKII. It was found that 60- and 90-min sessions result in comparable increases of PGC-lα gene expression, while VEGFA gene expression increased only after 90-min session. Even 90-min exercise did not induce the activation of FOXO1-E3 ubiquitin ligase pathway and did not result in an increase of expression of exercise-induced catabolic genes.

[Effect of branched-chain amino acids mixture on repair of atrophied rats' skeletal muscles].

Loss of muscle mass (atrophy) is a regular consequence of gravitational unloading. In hypogravity, muscle atrophy ensues from depression of protein synthesis and increase of its degradation. Both of these processes underlie also atrophy caused by muscle immobilization, cancer cachexia, cardiomyopathy and age-related sarcopenia. At the same time, atrophy of skeletal muscles due to chronic alcohol intoxication is the outcome of protein synthesis depression primarily. The study was part of a program aimed to develop a technique for atrophied muscle recovery by activation of anabolic signal pathways. A similar approach is applied to correct hypogravity-induced atrophy; however, analysis of effectiveness of this approach to the treatment of alcoholic muscle atrophy will be more "pure", as proteolytic processes in intoxicated animals are on the level typical of the intact ones. The issue in hand was whether injection of branched-chain amino acids (BCAA) would facilitate repair of m. gastrocnemius medialis in rats in the period of 30 days after 16-week alcoholic intoxication. BCAA was shown to enhance regain size by fast muscular fibers, full recovery of phosphorylated p90RSK concentrations without consequential effects on general proliferative processes and myonuclear number in rat's m. gastrocnemius medialis.

[Regional differences in the level of ERK1/2 phosphorylation and expression of the myogenic regulatory factors following electrostimulation with different mechanic and metabolic action on the gastrocnemius muscle].

Effect of high-frequency electrical stimulation of the sciatic nerve on ERK1/2 kinase phosphorylation and mRNA expression in MyoD (myogenic regulation factor) and myogenin in the red (RGM) and white (WGM) parts of the medial head in rat's m. gastrocnemius was studied. Two stimulation regimes were equalized both lengthwise and in total effort but differed in duration and number of contractions and, therefore, in mechanic and metabolic effects on the muscle. It was shown that growth of the number of phosphorylated ERK1/2 was particularly high in WCM due to application of the protocol for multiple short-time contractions. Whatever the stimulation regime, MyoD mRNA expression in RGM and WGM increases to the same extent, whereas myogenin mRNA expression does not change. Consequently, the regime with the predominantly mechanic effect is favorable to activation of the ERK signaling pathway in glycolytic myofibers.

[The study of intron containing pre-mRNA and spliced mRNA in maize chloroplasts with the use of RT-PCR].

The study of chloroplast RNA splicing is usually performed by such complicated methods as Northern blot hybridization, RNAse protection or primer extension. An application of simpler RT-PCR technique may lead to underestimation of unspliced pre-mRNA. We used five protein coding genes from maize plastome to analyze factors that can reduce a pool ofintron containing transcripts as compared to a mature RNA. We revealed that a mode of DNAse inactivation, a temperature of cDNA synthesis, and a type of DNA polymerase used are important for the proper detection of unspliced RNA level. The increase in a number of PCR cycles was accompanied with a concomitant decrease in the proportion of unspliced RNA for a one gene only. We demonstrated that after PCR intron containing and intron free strands of amplicons are able to form heteroduplexes. The information obtained let us to introduce the simple and effective method for the investigation of a chloroplast spliced mRNA and unspliced pre-mRNA.

[Proteolytic signaling mechanisms in skeletal muscles in patients with alcohol-induced muscle disease].

Chronic alcoholic myopathy is one of most numerous and profound manifestations of chronic alcohol intoxication. This disease is characterized by the pronounced atrophy of the locomotor muscles, which involves predominantly those fibers expressing myosin isoforms of the I "fast" type. In early experiments with alcohol-fed rats and studies of patients it was shown the impairment of the anabolic intracellular signaling pathways and decrease in protein synthesis rate. We were the first to analyze the signaling pathways involved in the pathogenesis of alcoholic myopathy with different fiber atrophy levels. At the early stages of the pathogenesis we observed also the sufficient increase of mRNA of E3 ubiquitin ligases. However the ubiquitinylation level was not altered in patients as compared to the control subjects. This phenomenon could be associated with the increased expression of the heat-shock proteins, known for their protective action.

[Optimization of training: development of a new partial load mode of strength training].

Hypertrophic effect of strength training is known to originate from mechanical and metabolic stimuli. During exercise with restricted blood supply ofworking muscles, that is under conditions of intensified metabolic shifts, training effect may be achieved with much lower external loads (20% of one repetition maximum (1 RM)). The aim of the study was to compare the effects of 8 wks high-intensity (80-85% MVC) strength training and low-intensity (50% 1 RM) training without relaxation. The high-intensity strength training leads to somewhat higher increments in strength and size of trained muscles than training without relaxation. During high-intensity training an increase of area occupied by type II fibers at muscle cross section prevails while during training without relaxation - an increase of area occupied by type I fibers takes place. An exercise session without relaxation leads to a more pronounced increase in secretion of growth hormone, IGF-1 and cortisol. Expression of gene regulating myogenesis (Myostatin) is changed in different ways after high-intensity strength exercise session and after exercise session without relaxation. Low-intensity strength training (50% 1 RM) without relaxation is an effective way for inducing increases of strength and size of trained muscles. This low intensive type of training may be used in restorative medicine, sports and physical culture.

Role of NO-synthase in regulation of protein metabolism of stretched rat m. soleus muscle during functional unloading.

Gravitational unloading causes atrophy of muscle fibers and can lead to destruction of cytoskeletal and contractile proteins. Along with the atrophic changes, unloaded muscle frequently demonstrates significant shifts in the ratio of muscle fibers expressing fast and slow myosin heavy chain isoforms. Stretching of the m. soleus during hindlimb suspension prevents its atrophy. We supposed that neuronal NO-synthase (NOS) (which is attached to membrane dystrophin-sarcoglycan complex) can contribute to maintenance of protein metabolism in the muscle and prevent its atrophy when m. soleus is stretched. To test this hypothesis, we used Wistar rats (56 animals) in experiments with hindlimb suspension during 14 days. The group of hindlimb suspended rats with stretched m. soleus was injected with L-NAME to block NOS activity. We found that m. soleus mass and its protein content in hindlimb-suspended rats with stretched m. soleus were preserved due to prevention of protein degradation. NOS is involved in maintenance of expression of some muscle proteins. Proliferation of satellite cells in stretched m. soleus may be due to nNOS activity, but maintenance of muscle mass upon stretching is regulated not by NOS alone.

Protective effect of L-Arginine administration on proteins of unloaded m. soleus.

Cytoskeletal and contractile proteins degenerate during functional unloading of muscle. The ratio of myosin heavy chain (MHC) expression changes simultaneously. We have supposed that NO can be a signal molecule related to the regulation of protein metabolism upon muscle unloading. To test this hypothesis, Wistar rats underwent functional unloading for 14 days without and with peroral administration of L-arginine (500 mg/kg) as NO precursor. Significant decreases in m. soleus mass, NO, nNOS, dystrophin, Hsp90, p-S6K, and type I MHC mRNA contents were found in the group of animals with unloading without preparation compared to those in control and in the group with unloading and administration of L-arginine; at the same time, increased contents of atrogin-1/MAFbx and MuRF-1 (p < 0.05) were found. No difference in the IGF-1 mRNA content between all three groups was found. Atrophy was significantly less pronounced in the group with unloading and L-arginine administration compared to that without the amino acid, and no destruction of cytoskeletal proteins was observed. We conclude that administration of L-arginine upon functional unloading decreases the extent of m. soleus atrophy, prevents the decrease in it of type I MHC mRNA, and blocks destructive changes in some cytoskeletal proteins. Such effect can be due to the absence of increase in this group of the content of some ubiquitin ligases and decreased intensity of the p70S6 kinase synthesis marker.

EPR spin probe study of polymer associative systems.

Molecular dynamics of polyacrylamide gels, polymeric micelles and hydrogel of polyacrylic acid and macrodiisocyanate was investigated by the ESR spectroscopy of spin probes. The local mobility in network junction of polyacrylamide gels is found to be essentially slower than that in the micelles created by the low molecular weight detergents and does not depend on the amount and length of hydrophobic groups (C9 or C12) in the polymer chain. The immersion of 10-30 mol.% of ionic monomers into the polymer chain (sodium acrylate) influences insufficiently on the local mobility of network junctions. In aqueous solutions, polystyrene-block-poly-(N-ethyl-4-vinylpyridinium bromide) block copolymers create polymeric micelles. The local mobility in the polystyrene core of the micelles is about twice as much as that in the solid polystyrene. Partially swellable polymer network in aqueous solutions was synthesized from polyacrylic acid and macrodiisocyanate. The local mobility in hydrophobic regions of the gel is substantially lower than that in the hydrophilic regions. It was concluded that the hydrophobic and hydrophilic regions and the local dynamics of them dictate practical application of the polymer associative systems.

[The role of TLR4 receptor in the stress response of lymphocytes].

In vitro effects of low-level electromagnetic waves (8.18 GHz, frequency swings within 1 s, intensity 1 microW/cm, exposure for 1 h) and low-energy laser light (He-Ne laser with 632.8 nm, 0.2 mW/cm, dose 1.2 x 10(-2) J/cm2) on the expression of receptor protein TLR4, which is known as a part of the system for microbal toxin recognition, were studied in mouse lymphocytes. In addition, TLR4 expression was examined in situations when stress responses to low-level nonionizing radiation were modified by the antibiotic geldanamycin, which suppresses the activity of the heat shock protein Hsp90. It was found that low-level microwaves significantly raised the amount of TLR4; in contrast, laser light decreased the expression of the receptor in lymphocytes. In cells pretreated with geldanamycin, the TLR4 expression in irradiated cells was reduced to minimum levels, much lower than control values. The results showed that TLR4, which is involved in specific binding of toxin from gram-negative bacteria, can regulate cell responses to signals of other origin, in particular to nonionizig radiation, including low-level microwaves and laser light.

[Effect of thymopentin on production of cytokines, heat shock proteins, and NF-kappaB signaling proteins].

In vivo effects of thymopentin, an active fragment of the naturally occurring thymic hormone thymopoietin, on the production of cytokines, nitric oxide, heat shock proteins, and signal proteins NF-kappaB, phNF-kappaB, and IkappaB-alpha in lymphoid cells of male NMRI mice was studied. Activation of production of several cytokines (IL-1alpha, IL-2, IL-6, IL-10, and IFN-gamma), nitric oxide, and heat shock proteins (HSP70 and HSP90) was observed in peritoneal macrophages and spleen lymphocytes of mice that received intraperitoneal injections of thymopentin (15 microg per 100 g body weight). Thymopentin apparently produces stress-like rather than damaging effects. A probable action mechanism of this hormone is activation of the NF-kappaB signaling pathway, which is most pronounced at the NF-kappaA phosphorylation stage.

[The role of transcription factors in the response of mouse lymphocytes to low-level electromagnetic and laser radiations].

The effects of low-intensity laser radiation (LILR, 632.8 nm, 0.2 mW/cm2) and low-intensity electromagnetic waves (LIEW, 8.15 - 18 GHz, 1 MW/cm2) on the production of transcription factors in lymphocytes from NMRI male mice were examined. The total level of NF-KB and its phosphorylated metabolite Phospho-NF-kappaB, as well as the regulatory protein IkappaB-alpha were determined in spleen lymphocytes subjected to laser or microwave radiations. The proteins were determined by immunoblotting. Laser light induced a lowering in the level of NF-kappaB and IkappaB-alpha. By contrast, irradiation with electromagnetic waves resulted in a significant increase in the amount of NF-kappaB and IkappaB-alpha. The phosphorylated form of NF-kappaB did not noticeably change under either of the two kinds of radiation. The results showed that electromagnetic waves activate the production of both NF-kappaB and the regulatory protein IkappaB-alpha and these data confirm the stress character of the response of spleen lymphocytes to low-level microwaves of the centimeter range.

[Plastid RNA polymerases].

Plastids have a very interesting transcription apparatus that gives us an opportunity to investigate mono- and multisubunut RNA polymerase interaction under conditions of complex biogenesis of the organelles and the necessity to coordinate the expression of genes located in different cell compartments. The last decade has been a breakthrough in the study of chloroplast RNA polymerases. The most important advances are the discovery of nucleus-encoded RNA polymerase and nuclear gene family for sigma subunits of plastid-encoded RNA polymerase, the obtaining of knockout-mutants on the subunits of plastid-encoded RNA polymerase, and the revelation of this RNA polymerase reorganization during plastid biogenesis. The hypothesis concerning labor division between two plastid RNA polymerases has been proposed. The review focuses on the analysis of modern information about organization, function and evolution of plastid RNA polymerases.

Regulation of PGC-1α Isoform Expression in Skeletal Muscles.

The coactivator PGC-1α is the key regulator of mitochondrial biogenesis in skeletal muscle. Skeletal muscle expresses several PGC-1α isoforms. This review covers the functional role of PGC-1α isoforms and the regulation of their exercise-associated expression in skeletal muscle. The patterns of PGC-1α mRNA expression may markedly differ at rest and after muscle activity. Different signaling pathways are activated by different physiological stimuli, which regulate the expression of the PGC-1α gene from the canonical and alternative promoters: expression from a canonical (proximal) promoter is regulated by activation of the AMPK; expression from an alternative promoter, via a ß2-adrenergic receptor. All transcripts from both promoters are subject to alternative splicing. As a result, truncated isoforms that possess different properties are translated: truncated isoforms are more stable and predominantly activate angiogenesis, whereas full-length isoforms manly regulate mitochondrial biogenesis. The existence of several isoforms partially explains the broad-spectrum function of this protein and allows the organism to adapt to different physiological stimuli. Regulation of the PGC-1α gene expression by different signaling pathways provides ample opportunity for pharmacological influence on the expression of this gene. Those opportunities might be important for the treatment and prevention of various diseases, such as metabolic syndrome and diabetes mellitus. Elucidation of the regulatory mechanisms of the PGC-1α gene expression and their functional role may provide an opportunity to control the expression of different isoforms through exercise and/or pharmacological intervention.

[THE INDICATORS OF GROWTH AND MYOGENESIS IN THE GLYCOLYTIC AND OXIDATIVE MUSCLES OF THE RAT AFTER INDIRECT ELECTROSTIMULATION].

A comparative analysis of the signaling pathways activity and gene expression in the red (RG) and white (WG) parts of the gastrocnemius muscle of rat after a series of short (1 s) tetanic contractions induced by motor nerve stimulation at a frequency of 100 Hz and with an amplitude that provides activation of all motor units of the muscle. WG compared to RG demonstrated a marked increase in the phosphorylation level of ERK1/2, although the increase in the phosphorylation of AMPK was not different in two muscles 2 h after the stimulation. Along with that, content of MyoD and myogenin mRNA in WG increased much higher than in RG, whereas the effect of stimulation on IGF-1, MaFbx and MuRF genes expression was weak and comparable in WG and RG. There was an increase of myostatin mRNA in RG. Thus, glycolytic muscle fibers of WG exhibit more pronounced regulatory shifts of hypertrophic character than oxidative muscle fibers of RG.