The Role of Ubiquitin-Proteasome System in the Biology of Stem Cells

Selective degradation of cellular proteins by the ubiquitin-proteasome system (UPS) is one of the key regulatory mechanisms in eukaryotic cells. A growing body of evidence indicates that UPS is involved in the regulation of fundamental processes in mammalian stem cells, including proliferation, differentiation, cell migration, aging, and programmed cell death, via proteolytic degradation of key transcription factors and cell signaling proteins and post-translational modification of target proteins with ubiquitin. Studying molecular mechanisms of proteostasis in stem cells is of great importance for the development of new therapeutic approaches aimed at the treatment of autoimmune and neurodegenerative diseases, cancer, and other socially significant pathologies. This review discusses current data on the UPS functions in stem cells.

[The Effects of the Hydrogen Sulfide Donor GYY4137 on the Proteasome Pool of Colorectal Cancer Cells]

Cancer cells are characterized by an increased level of metabolism and are highly dependent on the correct functioning of the processes that ensure homeostasis. Reactive sulfur species (RSS) are important molecular modulators of metabolic processes in both healthy and tumor cells. The effect of RSS and, in particular, H2S, on key cellular systems, including the ubiquitin-proteasome system (UPS), which provides the destruction of most intracellular proteins, has been shown. The main components of the UPS are proteasomes, multisubunit protein complexes, within which proteolysis occurs. At the same time, data on the effect of H2S directly on the pool of proteasomes in tumor cells are insufficient. Here, we studied the effect of incubation of SW620B8-mCherry colorectal adenocarcinoma cells expressing a fluorescently labeled proteasome subunit with 50, 100, and 200 μM of the hydrogen sulfide donor GYY4137. The effect of the substance on the proteasome pool was assessed 6, 24, 48, and 72 h after administration. It was shown that the chymotrypsin-like and caspase-like proteasome activity decreases in cells incubated with 200 μM of the GYY4137 for 24 h. This coincided with an increase in the expression of proteasome subunit genes. In lysates of cells incubated with 200 μM GYY4137 for 48 h an increase in the content of the constitutive β5 subunit was observed and the activity of proteasomes leveled off. Following prolonged incubation with GYY4137 (72h), an increase in the expression levels of some proteasome genes was also observed, although this did not have a significant effect on the activity and subunit composition of proteasomes. Thus, the obtained data indicate the modulation of proteasome activity by the hydrogen sulfide donor and the effect of GYY4137 on transcription and translation of proteasome genes.

[Changes in the Activities and Contents of Individual Forms of Proteasomes in Samples of the Cerebral Cortex during Pathology Development in 5xFAD Mice]

The ubiquitin-proteasome system (UPS) provides hydrolysis of most intracellular proteins in proteasomes. There are various forms of proteasomes that differ, among other things, in the set of proteolytic subunits and the presence of activators. Alzheimer's disease (AD) is characterized by disturbances in the functional state of the UPS. At the same time, an increase in the expression of certain forms of proteasomes, in particular, proteasomes containing immune subunits (nonconstitutive proteasomes), has been shown. Here, we studied dynamic changes in the expression of catalytic proteasome subunit genes and corresponding proteins in the cerebral cortex of animals using a mouse model of AD (5xFAD transgenic mice). Increases by 4 and 6 folds in transcripts of the PSMB9 and PSMB8 genes encoding immune proteasome subunits were detected, as well as a significant increase in the content of immune β-subunits (by 2.8 folds, β1i; 2.2 folds, β2i) in samples from 5xFAD mice at the age of 380 days, compared with samples from mice at 60 days of age. Moreover, the activation of both 20S and 26S proteasomes containing immune subunits were revealed in samples from 380 days old 5xFAD mice by electrophoresis in native conditions. This indicates activated synthesis of the immune subunits and assembly of nonconstitutive proteasomes at the terminal stage of pathology development. The obtained data, in combination with the available literature, indicate that the activation of nonconstitutive proteasomes is a universal phenomenon characteristic of various animal models of AD, which may reflect both the development of neuroinflammation and adaptive processes in tissues induced by the accumulation of toxic protein aggegates.

[Dynamic Changes in the Activities and Contents of Particular Proteasome Forms in the Cerebral Cortex of C57BL/6 Mice during Aging]

Proteasomes are key components of the ubiquitin-proteasome system. Various forms of proteasomes are known. During aging, disturbances in the functioning of proteasomes have been revealed, as well as increased expression of their particular forms. Considering these data, we studied the expression of genes encoding the constitutive and immune subunits of proteasomes in cerebral cortex samples from C57BL/6 mice at the ages of 60, 190, 380, and 720 days. In addition, the contents of constitutive and immune proteasome subunits, chymotrypsin-like and caspase-like activities of proteasome pools, as well as the activity of the β5i immune subunit were studied in tissue homogenates. The chymotrypsin-like activity and the activity of the β5i subunit of different forms of proteasomes separated by electrophoresis in native gel were characterized. Compared with samples from young animals, in the cerebral cortex of animals at an age of 720 days the following changes in the expression patterns of proteasome genes were revealed: a decreased expression of the PSMB5 gene encoding constitutive proteasome subunit β5; increased expression of genes encoding immune proteasome subunits β5i and β1i. In tissue homogenates of aged mice, an increase in the content of immune subunits β1i and β2i was shown. In samples from old animals, chymotrypsin-like activity was decreased and a tendency to a decrease in caspase-like activity of proteasomes as well as the β5i subunit activity was revealed. Analysis of the activity of native complexes in tissues obtained from old animals revealed decreased chymotrypsin-like activity of 26S and 20S proteasomes containing the β5i subunit. Based on the obtained data, it can be assumed that changes in the pool of nonconstitutive proteasomes reflect aging-associated adaptive processes in the mouse brain.

[Structures of the Mouse Central Nervous System Contain Different Quantities of Proteasome Gene Transcripts]

Proteasomes are multisubunit complexes that degrade most intracellular proteins. Three of the 14 subunits of the 20S proteasome, specifically β1, β2, and β5, demonstrate catalytic activity and hydrolyze peptide bonds after acidic, basic, and hydrophobic amino acids, respectively. Within proteasome, the constitutive catalytic subunits β1, β2, and β5 can be substituted by the immune βli, β2i, and β5i subunits, respectively. However, proteasomes do not always contain all the immune subunits at once; some proteasomes contain both immune and constitutive catalytic subunits simultaneously. Incorporation of immune subunits modifies the pattern of peptides produced by proteasomes. This is essential for antigen presentation and cellular response to stress as well as for a number of intracellular signaling pathways. We have developed a quantitative PCR-based system for the determination of the absolute levels of murine constitutive and immune proteasome subunits gene expression. Using the obtained system, we have estimated the expression levels of genes encoding proteasome subunits in the mouse central nervous system (CNS) tissues. We have shown that the quantity of transcripts of proteasome catalytic subunits in different CNS structures differed significantly. These data allow us to assume that the studied brain regions can be divided into two groups, with relatively "high" (cerebral cortex and spinal cord) and "low" (hippocampus and cerebellum) levels of proteasome subunit genes expression. Moreover, it was possible to distinguish structures with similar and significantly different gene expression profiles of proteasome catalytic subunits. Thus, the gene expression profiles in the cortex, spinal cord, and cerebellum were similar, but different from the expression profile in the hippocampus. Based on the obtained data, we suggest that there are differences in the proteasome pool, as well as in the functional load on the ubiquitin-proteasome system in different parts of the CNS.

[The contribution of M. N. Akhutin in field surgery (to the 75th anniversary of Victory in the Great Patriotic war)]

The article is devoted to M. N. Akhutin (1899-1848), one of the founders of the Russian military field surgery, lieutenant general of the medical service, professor, corresponding member of the USSR Academy of medical Sciences, chief of the Military medical Academy (1940-1941). M. N. Akhutin, disciple of V. A. Oppel, was active participant in the battles at the lake Hasan and the Khalkhin-Gol river (1838-1939). During the Great Patriotic War, he was the chief surgeon of the Bryansk, 2nd Baltic and 1st Ukrainian fronts. Since 1945 he was deputy chief surgeon of the Soviet Army. He is author of works on military field surgery. He was the first director of the A. V. Vishnevsky institute of surgery and the head of the department of faculty surgery of the I. M. Sechenov 1st Moscow medical Institute.

H2S counteracts proinflammatory effects of LPS through modulation of multiple pathways in human cells

BACKGROUND

Hydrogen sulfide donors reduce inflammatory signaling in vitro and in vivo. The biological effect mediated by H₂S donors depends on the kinetics of the gas release from the donor molecule. However, the molecular mechanisms of H₂S-induced immunomodulation were poorly addressed. Here, we studied the effect of two different hydrogen sulfide (H₂S)-producing agents on the generation of the LPS-induced inflammatory mediators. Importantly, we investigated the transcriptomic changes that take place in human cells after the LPS challenge, combined with the pretreatment with a slow-releasing H₂S donor-GYY4137.

METHODS

We investigated the effects of GYY4137 and sodium hydrosulfide on the release of proinflammatory molecules such as ROS, NO and TNF-α from LPS-treated human SH-SY5Y neuroblastoma and the THP-1 promonocytic cell lines. Transcriptomic and RT-qPCR studies using THP-1 cells were performed to monitor the effects of the GYY4137 on multiple signaling pathways, including various immune-related and proinflammatory genes after combined action of LPS and GYY4137.

RESULTS

The GYY4137 and sodium hydrosulfide differed in the ability to reduce the production of the LPS-evoked proinflammatory mediators. The pre-treatment with GYY4137 resulted in a drastic down-regulation of many TNF-α effectors that are induced by LPS treatment in THP-1 cells. Furthermore, GYY4137 pretreatment of LPS-exposed cells ameliorates the LPS-mediated induction of multiple pro-inflammatory genes and decreases expression of immunoproteasome genes. Besides, in these experiments we detected the up-regulation of several important pathways that are inhibited by LPS.

CONCLUSION

Based on the obtained results we believe that our transcriptomic analysis significantly contributes to the understanding of the molecular mechanisms of anti-inflammatory and cytoprotective activity of hydrogen sulfide donors, and highlights their potential against LPS challenges and other forms of inflammation.

Thermodynamic properties and lattice dynamics investigation of LuB2C: experiment and ab initio calculations

A sample of lutetium carboboride LuB2C was synthesized from a mixture of lutetium hydride, boron and carbon by annealing in argon. The temperature dependence of the heat capacity Cp(T) (2-300 K) and lattice parameters a(T), b(T), and c(T) (5-300 K) of the carboboride was experimentally determined. The experimental values of the heat capacity were fitted with the approximation Cp(T) = aT + ΣCD + CE + CTLS(T). Here the first term is the electronic contribution, the second is the sum of the Debye components, the third is the Einstein contribution, and the fourth is the contribution to the heat capacity due to the vibrations of the two-level systems which are formed in the Lu-subsystem due to the asymmetry of the B-C atomic arrangement around the Lu3+-ions and, as a consequence, the possible transition of the lutetium atoms between spatially close, but energetically non-equivalent positions. A strong anisotropy of the thermal expansion of the carboboride was revealed. Along the c axis the coefficient of thermal expansion monotonically increases; in the basal plane, the expansion is practically not observed. The temperature dependence of the unit cell volume Vu(T) has been analyzed in the Debye-Einstein approximation taking into account the electronic contribution and effect of two-level systems. The values of the Gruneisen parameters corresponding to different modes of the phonon spectrum of the carboboride have been determined. The frequencies of the lattice vibrations, determined in a Raman scattering experiment, are in satisfactory agreement with the parameters obtained from Cp(T) using the Debye-Einstein approximation. Using ab initio band theory methods and an exchange-correlation functional in the PBE form in the VASP package, it was established that the total energies of these two crystal structures differ by no more than 0.01 eV f.u.-1. Calculations of the thermodynamic properties of LuB2C yielded similar results for orthorhombic and tetragonal phases of the carboboride.

[Dynamics of the Functional Activity and Expression of Proteasome Subunits during Cellular Adaptation to Heat Shock]

The ubiquitin-proteasome system (UPS) performs proteolysis of most intracellular proteins. The key components of the UPS are the proteasomes, multi-subunit protein complexes, playing an important role in cellular adaptation to various types of stress. We analyzed the dynamics of the proteasome activity, the content of proteasome subunits, and the expression levels of genes encoding catalytic subunits of proteasomes in the human histiocytic lymphoma U937 cell line immediately, 2, 4, 6, 9, 24, and 48 h after a heat shock (HS). The initial decrease (up to 62%) in the proteasome activity in cellular lysates was revealed, then 10 h after HS the activity began to recover. The amount of proteasomal α-subunits in the cells decreased 2 h after HS, and was restored to 24-48 h after HS. Fluctuations in the levels of mRNAs encoding proteasome catalytic subunits with the maximum expression 2 h after HS and a gradual decrease to 48 h after HS were observed. The average estimated number of mRNA copies per cell ranged from 10 for weakly to 150 for highly expressed proteasome genes. Thus, the recovery efficiency of UPS functionality after HS, which reflects the important role of proteasomes in maintaining cell homeostasis, was evaluated.

Proteasomes and Several Aspects of Their Heterogeneity Relevant to Cancer

The life of every organism is dependent on the fine-tuned mechanisms of protein synthesis and breakdown. The degradation of most intracellular proteins is performed by the ubiquitin proteasome system (UPS). Proteasomes are central elements of the UPS and represent large multisubunit protein complexes directly responsible for the protein degradation. Accumulating data indicate that there is an intriguing diversity of cellular proteasomes. Different proteasome forms, containing different subunits and attached regulators have been described. In addition, proteasomes specific for a particular tissue were identified. Cancer cells are highly dependent on the proper functioning of the UPS in general, and proteasomes in particular. At the same time, the information regarding the role of different proteasome forms in cancer is limited. This review describes the functional and structural heterogeneity of proteasomes, their association with cancer as well as several established and novel proteasome-directed therapeutic strategies.

Psychometric properties of the Russian version of the Pediatric Daytime Sleepiness Scale (PDSS)

Insufficient sleep could severely impair both cognitive and learning skills. More prominent changes are found in children and adolescents. Tools used to estimate sleepiness in the adult population are commonly inappropriate for children. The objective of our study was to provide a reliable instrument to measure excessive sleepiness for upcoming studies in Russian-speaking children, applying the Russian version of Pediatric Daytime Sleepiness Scale (PDSS). The following tasks were resolved in our study: translation, validation, and analysis of psychometric properties of the Russian adaptation of the PDSS by standard tests. After the semantic validation of the instrument through a multi-stage translation process we checked its psychometric validation. A total of 552 students, consisting of N = 285 for the exploratory factor analysis (EFA), N = 267 for the confirmatory factor analysis (CFA) and N = 204 for test-retest analysis of public elementary schools located in Northern Russia completed the PDSS and Munich Chronotype Questionnaire to estimate sleep parameters in the classroom during the lessons. Response rate was 90%; excluded cases contained no data. Further, 204 of our participants completed the PDSS in a 3 months interval to check the test-retest reliability. Internal consistency was measured by Cronbach's alpha coefficients and CFA was used to test factorial validity of the tool. Concurrent validity and test-retest reliability were assessed via intra-class coefficient. Internal consistency of the PDSS scale was high (Cronbach's α = 0.8). The construct validity of the PDSS was supported by CFA (factor loadings were from 0.438 to 0.727) and the test-retest reliability demonstrated by the intra-class coefficient was 0.70. The total PDSS score was independent of sex. The mean total value of PDSS was 11.95 ± 6.24. Higher scores on PDSS were negatively correlated with sleep duration. Thus, the construct validity of the instrument remains valid and could be used for Russian-speaking youth samples in the evaluation of daytime sleepiness. It could be useful in future applications by sleep scientists and health practitioners.

Biological consequences of structural and functional proteasome diversity

Cell homeostasis and regulation of metabolic pathways are ensured by synthesis, proper folding and efficient degradation of a vast amount of proteins. Ubiquitin-proteasome system (UPS) degrades most intracellular proteins and thus, participates in regulation of cellular metabolism. Within the UPS, proteasomes are the elements that perform substrate cleavage. However, the proteasomes in the organism are diverse. Structurally different proteasomes are present not only in different types of cells, but also in a single cell. The reason for proteasome heterogeneity is not fully understood. This review briefly encompasses mammalian proteasome structure and function, and discusses biological relevance of proteasome diversity for a range of important cellular functions including internal and external signaling.

Combined Effect of Bortezomib and Menadione Sodium Bisulfite on Proteasomes of Tumor Cells: The Dramatic Decrease of Bortezomib Toxicity in a Preclinical Trial

Tumor growth is associated with elevated proteasome expression and activity. This makes proteasomes a promising target for antitumor drugs. Current antitumor drugs such as bortezomib that inhibit proteasome activity have significant side effects. The purpose of the present study was to develop effective low-toxic antitumor compositions with combined effects on proteasomes. For compositions, we used bortezomib in amounts four and ten times lower than its clinical dose, and chose menadione sodium bisulfite (MSB) as the second component. MSB is known to promote oxidation of NADH, generate superoxide radicals, and as a result damage proteasome function in cells that ensure the relevance of MSB use for the composition development. The proteasome pool was investigated by the original native gel electrophoresis method, proteasome chymotrypsin-like activity-by Suc-LLVY-AMC-hydrolysis. For the compositions, we detected 10 and 20 μM MSB doses showing stronger proteasome-suppressing and cytotoxic in cellulo effects on malignant cells than on normal ones. MSB indirectly suppressed 26S-proteasome activity in cellulo, but not in vitro. At the same time, MSB together with bortezomib displayed synergetic action on the activity of all proteasome forms in vitro as well as synergetic antitumor effects in cellulo. These findings determine the properties of the developed compositions in vivo: antitumor efficiency, higher (against hepatocellular carcinoma and mammary adenocarcinoma) or comparable to bortezomib (against Lewis lung carcinoma), and drastically reduced toxicity (LD50) relative to bortezomib. Thus, the developed compositions represent a novel generation of bortezomib-based anticancer drugs combining high efficiency, low general toxicity, and a potentially expanded range of target tumors.

Molecular Mechanisms Underlying Neuroprotective Effect of Intranasal Administration of Human Hsp70 in Mouse Model of Alzheimer's Disease

Heat shock protein 70, encoded by the HSPA1A gene in humans, is a key component of the machinery that protects neuronal cells from various stress conditions and whose production significantly declines during the course of aging and as a result of several neurodegenerative diseases. Herein, we investigated whether sub-chronic intranasal administration of exogenous Hsp70 (eHsp70) exerts a neuroprotective effect on the temporal cortex and areas of the hippocampus in transgenic 5XFAD mice, a model of Alzheimer's disease. The quantitative analysis of neuronal pathologies in the compared groups, transgenic (Tg) versus non-transgenic (nTg), revealed high level of abnormalities in the brains of transgenic mice. Treatment with human recombinant Hsp70 had profound rejuvenation effect on both neuronal morphology and functional state in the temporal cortex and hippocampal regions in transgenic mice. Hsp70 administration had a smaller, but still significant, effect on the functional state of neurons in non-transgenic mice as well. Using deep sequencing, we identified multiple differentially expressed genes (DEGs) in the hippocampus of transgenic and non-transgenic mice. Furthermore, this analysis demonstrated that eHsp70 administration strongly modulates the spectrum of DEGs in transgenic animals, reverting to a pattern similar to that observed in non-transgenic age-matched mice, which included upregulation of genes responsible for amine transport, transmission of nerve impulses and other pathways that are impaired in 5XFAD mice. Overall, our data indicate that Hsp70 treatment may be an effective therapeutic against old age diseases of the Alzheimer's type.

[Circadian rhythms of antioxidant enzyme's activity in young and adult rats under light deprivation conditions.]

We studied the age-related features of circadian rhythms of superoxide dismutase (SOD) and catalase activity in the liver of rats under light deprivation. In standard light conditions (LD), significant daily fluctuations in SOD activity with a maximum at 07:00 am was detected only in young animals (1,5 months) but catalase activity was observed in young (1,5 months) and in adults (7,5 months) with peak at 04:00 am. The daily dynamics of total and specific activity of SOD and catalase in the liver in young and adult rats differed depending on the period of ontogeny in which the impact of light deprivation began. When the females and offspring were moved to darkness after birth (group LD/DD), the circadian rhythms of SOD and catalase activitys were observed in young and were absent in adult rats. However, circadian rhythms of the antioxidant enzymes (AOE) activities were inherent only adult rats when light deprivation impacted on pregnant females (group DD/DD). Changes in circadian rhythms under light deprivation were characterized either by a phase shift of the enzymes activity (in the LD/DD group) or by a violation of their develpoment in ontogeny (in the DD/DD group). During aging significant decreasing of catalase activity was compensated by an increase in the amplitude of circadian rhythms of activity of this enzyme in animals of all groups. A distinctive feature of daily fluctuations in AOЕ activity in young rats in LD and LD/DD groups can be considered the presence of an ultradian rhythm in the general circadian cycle, which had a second peak with a smaller amplitude and shorter period.

Interplay between recombinant Hsp70 and proteasomes: proteasome activity modulation and ubiquitin-independent cleavage of Hsp70

The heat shock protein 70 (Hsp70, human HSPA1A) plays indispensable roles in cellular stress responses and protein quality control (PQC). In the framework of PQC, it cooperates with the ubiquitin-proteasome system (UPS) to clear damaged and dysfunctional proteins in the cell. Moreover, Hsp70 itself is rapidly degraded following the recovery from stress. It was demonstrated that its fast turnover is mediated via ubiquitination and subsequent degradation by the 26S proteasome. At the same time, the effect of Hsp70 on the functional state of proteasomes has been insufficiently investigated. Here, we characterized the direct effect of recombinant Hsp70 on the activity of 20S and 26S proteasomes and studied Hsp70 degradation by the 20S proteasome in vitro. We have shown that the activity of purified 20S proteasomes is decreased following incubation with recombinant human Hsp70. On the other hand, high concentrations of Hsp70 activated 26S proteasomes. Finally, we obtained evidence that in addition to previously reported ubiquitin-dependent degradation, Hsp70 could be cleaved independent of ubiquitination by the 20S proteasome. The results obtained reveal novel aspects of the interplay between Hsp70 and proteasomes.

Video-tactile pneumatic sensor for soft tissue elastic modulus estimation

Background

A new sensor for estimating elasticity of soft tissues such as a liver was developed for minimally invasive surgery application.

Methods

By measuring deformation and adjusting internal pressure of the pneumatic sensor head, the sensor can be used to do palpation (indentation) of tissues with wide range of stiffness. A video camera installed within the sensor shell is used to register the radius of the contact area. Based on finite element model simulations and the measured data, elastic modulus of the indented soft tissue can be calculated.

Results and conclusions

Three phantom materials, namely plastic, silicone and gelatin, with varied stiffness were tested. The experimental results demonstrated that the new sensor can obtain highly reliable data with error less than 5%. The new sensor might be served as an instrument in laparoscopic surgery for diagnosis of pathological tissues or internal organs.

[Heat-shock protein HSP70 decreases activity of proteasomes in human neuroblastoma cells treated by amyloid-beta 1-42 with isomerized Asp7]

Experimental evidences indicate that heat-shock protein 70 (HSP70) can serve as a prospective therapeutic agent to treat Alzheimer's disease (AD). It has demonstrated a neuroprotective effect in vivo on mice models of AD. Moreover, HSP70 decreases oxidative stress in neurons induced by amyloid-β (Aβ42) and its more toxic form with isomerized Asp7 (isoAβ42). The dysfunction of Ubiquitin-proteasome system (UPS) is observed in AD. UPS is responsible for the degradation of the majority of cellular proteins and plays an important role in protecting cells from oxidative stress. Here, we have shown that the incubation of human neuroblastoma cells SK-N-SH with isoAβ42 increases the activity of intracellular proteasomes, which are the principal elements of the UPS. On the contrary, the proteasomal activity was decreased in isoAβ42-treated cells in the presence of exogenous HSP70. These results highlight the existence of an interplay between Aβ peptides, proteasomes, and HSP70.

[Role of military medicine in delivering of health care to ministry of internal affairs staff]

Role of military medicine in delivering of health care to ministry of internal affairs staff. The article describes the creation of the Medical Service Ministry of Internal Affairs of the Russian system. Throughout its history, medical-mechanical maintenance of employees of law enforcement bodies, such as in pre-revolutionary period, and in the early years of the Soviet regime was closely linked with military medicine of the Russian Empire and the Red Army. Many police officers, and later the police received medical care in military hospitals. Start the NKVD- MVD departmental health laid in 1921 with the creation of oadmissionso to provide medical care to police officers. As part of the system of state-sensible care, the medical service of the Russian Interior Ministry system and now introduces non-assessable contribution to its development.

Effects of Geroprotectors on Age-Related Changes in Proteolytic Digestive Enzyme Activities at Different Lighting Conditions

We studied the effect of melatonin and epithalon on age-related changes in proteolytic digestive enzyme activity in the pancreas and gastric mucosa of rats kept under different lighting conditions. In rats kept under standard illumination, pepsin activity and the total proteolytic activity in the stomach and pancreas increased by the age of 12 months, but then decreased. Constant and natural lighting disturbed the age dynamics of proteolytic digestive enzyme activity. Administration of melatonin and epithalon to animals exposed to constant lighting restored age dynamics of pepsin activity and little affected total proteolytic activity.

Extended Microbiological Characterization of Göttingen Minipigs in the Context of Xenotransplantation: Detection and Vertical Transmission of Hepatitis E Virus

Xenotransplantation has been proposed as a solution to the shortage of suitable human donors. Pigs are currently favoured as donor animals for xenotransplantation of cells, including islet cells, or organs. To reduce the xenotransplantation-associated risk of infection of the recipient the pig donor should be carefully characterised. Göttingen minipigs from Ellegaard are often used for biomedical research and are regularly tested by their vendor for the presence of numerous bacteria, fungi, viruses and parasites. However, screening for some pathogens transmittable to humans had not been performed.The presence of microorganisms was examined in Göttingen Minipigs by PCR methods. Since zoonotic transmission of porcine hepatitis E virus HEV to humans has been demonstrated, extended search for HEV was considered as a priority. RNA from sera, islet and other cells from 40 minipigs were examined for HEV using different real-time reverse transcription (RT)-PCRs, among them two newly established. In addition, sera were examined by Western blot analysis using two recombinant capsid proteins of HEV as antigens. HEV RNA was not detected in pigs older than one year including gilts, but it was detected in the sera of three of ten animals younger than 1 year. Furthermore, HEV was also detected in the sera of three sows six days after delivery and their offspring, indicating vertical transmission of the virus. PCR amplicons were cloned, sequenced and the viruses were found to belong to the HEV genotype (gt) 3/4. Anti-HEV immunoglobulins G were detected in one sow and maternal antibodies in her six day old piglet. Since Göttingen minipigs were negative for many xenotransplantation-relevant microorganisms, they can now be classified as safe. HEV may be eliminated from the Ellegaard herd by selection of negative animals and/or by treatment of the animals.

[For fortieth anniversary of organization of national narcological service]

The 1975 is a year of organization in the USSR of independent service with the competence to regulate problems of alcoholism, drug addiction and toxicomania. The narcological dispensary, public narcological posts and night-time preventoriums were organized. The persons with chronic alcoholism were directed to forced treatment for preventive purpose.

The central domain of yeast transcription factor Rpn4 facilitates degradation of reporter protein in human cells

Despite high interest in the cellular degradation machinery and protein degradation signals (degrons), few degrons with universal activity along species have been identified. It has been shown that fusion of a target protein with a degradation signal from mammalian ornithine decarboxylase (ODC) induces fast proteasomal degradation of the chimera in both mammalian and yeast cells. However, no degrons from yeast-encoded proteins capable to function in mammalian cells were identified so far. Here, we demonstrate that the yeast transcription factor Rpn4 undergoes fast proteasomal degradation and its central domain can destabilize green fluorescent protein and Alpha-fetoprotein in human HEK 293T cells. Furthermore, we confirm the activity of this degron in yeast. Thus, the Rpn4 central domain is an effective interspecies degradation signal.

[From the history of health resort treatment in the Armed Forces of the Russian Federation]

The health resort treatment takes an important place in the system of treatment and prophylaxis activities aimed to conservation and restoration of the health of military personnel. It is ninety years since the foundation of the first military health resorts. During this time a unique system of resort treatment in the armed forces of the Russian Federation has been formed and is neatly functioning. It is nowadays one of the component parts of medical support of military personnel, retirees and members of their families.

Single mutations in the transmembrane envelope protein abrogate the immunosuppressive property of HIV-1

Background

The mechanism by which HIV-1 induces AIDS is still unknown. Previously, synthetic peptides corresponding to the conserved immunosuppressive (isu) domain in gp41 of HIV-1 had been shown to inhibit proliferation and to modulate cytokine expression of immune cells. The question is, whether the viral gp41 can do the same.

Results

We show for the first time that two trimeric forms of glycosylated gp41 released from transfected human cells modulated expression of cytokines and other genes in human PBMCs in the same manner, but at least seven hundred-fold stronger compared to that induced by the isu peptide. Single amino acid substitutions in the isu domain of gp41 introduced by site-directed mutagenesis abrogated this property. Furthermore, replication-competent HIV-1 with a mutation in the isu domain of gp41 did not modulate the cytokine expression, while wild-type virus did. Interestingly, most of the abrogating mutations were not reported in viral sequences derived from infected individuals, suggesting that mutated non-immunosuppressive viruses were eliminated by immune responses. Finally, immunisation of rats with gp41 mutated in the isu domain resulted in increased antibody responses compared with the non-mutated gp41. These results show that non-mutated gp41 is immunosuppressive in immunisation experiments, i.e. in vivo, and this has implications for the vaccine development.

Conclusions

These findings indicate that the isu domain of gp41 modulates cytokine expression in vitro and suppresses antibody response in vivo and therefore may contribute to the virus induced immunodeficiency.

[DNA vaccine encoding alpha-fetoprotein with fused ornithine decarboxylase degradation signal significantly suppresses hepatocellular carcinoma growth in mice]

Hepatocellular carcinoma (HCC) is among the most frequent malignancies in humans. HCC therapy is not efficient and the usual outcome is poor. In this regard, novel approaches to treat and prevent HCC are urgently needed. The Alpha-fetoprotein (AFP) is a serological marker of HCC. Recently it has been shown, that the DNA vaccines expressing AFP are capable in generating immune response against AFP. However, both, the immunization procedures and DNA vaccines used before were complex and not always very effective. We have shown that DNA vaccine encoding HIV-1 reverse transcriptase (RT) with fused ornithine decarboxylase (ODC) degradation signal induced a strong Th-1 immune response against RT in mice. Using this approach we designed a set of novel DNA vaccines bearing AFP and ODC degradation signal. Results obtained on transfected cells demonstrated efficient expression and fast proteasomal degradation of the recombinant AFP. The anti-tumor immune response stimulation was shown in immunized animals and most importantly a notable retardation of tumor growth was observed as a result of protective vaccination.

[Critical amino acids of ornitin decarboxylase degron: the presence and C-terminal arrangement is insufficient for alfa-fetoprotein degradation]

Mouse ornithine decarboxylase (ODC) degrades in proteasome in an ubiquitin-independent manner with an averagehalf-life of 2 h. The 37 amino acid long C-terminal fragment known as a degradation signal (degron) is responsible for the effective degradation of ODC. Recently, amino acids being critical for degradation in the ODC-degron have been mapped. Mutations of Cys441 and Ala442 led to protein stabilization, while a substitution of other amino acids composing ODC-degron had almost no effect on the protein turnover; whereas insertions or deletions in region between Ala442 and ODC C-terminus diminished greatly rate of protein degradation, e.g. positioning of the key amino acids from the C-terminus was shown to be crucial. Using these data we introduced both key amino acids into the alfa-fetoprotein with truncated exportation signal (deltaAFP), at the same distance from the C-terminus as they being in the ODC (deltaAFPCAG and deltaAFPLCAG). Removal of N-terminal exportation signal prevented secretion of modified proteins. Using in silico approach we demonstrated no significant difference in hydrophobicity or secondary structure between C-terminus of deltaAFP and mutated proteins. The degradation kinetics of deltaAFP, deltaAFPCAG, deltaAFPLCAG in cyloheximide-chase and proteasome inhibition assay (using MG132) was identical. Obtained results suggest that introduced substitutions are insufficient for effective recognition of mutated deltaAFP by26S proteasome. We assume thatadditional amino aci ds composing ODC-degron or their combine action could also affect degradation. Besides that, one cannot exclude that conformation of the mutated deltaAFP limits its C-terminus accessibility to proteasome.

[Aviation medicine: yesterday, today and tomorrow]

The article describes the history and current state of medical support of the Air Force. On December 1, 2009 Air Force Medical Service was renamed into the service of aviation medicine of Command Air Forces, and many of the functions of medical support of the Air Force transferred to the newly formed Air Force Center of Aviation Medicine. April 29, 2011 office of Aviation Medicine of the High Command of the Air Force has stepped 95-year milestone. The changes affected all structures entrusted with the issues of medical support of the Air Force. Today, the medical service of the Air Force faces challenges--ensuring safety, the study of flight conditions and their impact on health, job performance and psychological characteristics of flight personnel.

[Psychological and medical rehabilitation of servicemen in sanatorium-treatment institutes of the Defense Ministry of Russian Federation during the current stage of building of the Armed Forces]

Defense and promotion of health of strong and almost strong persons--is one of priorities tasks of health services, including military medicine. Federal law from the 8.11.2008 No 203-FL has made changes in federal law from 1998 No 76FL "About status of military servicemen". These changes allow, in conditions of existing of indications, effectuating psycho-medical rehabilitation less then 30 days free. To execute this federal law the Defense Ministry issued a law No 385 from 8.05.2008 "About psycho-medical rehabilitation of military servicemen of the Defense Ministry of Russian Federation". The law defines catalogue of categories of military servicemen, who are liable to psycho-medical rehabilitation and order of it's effectuating. The article is devoted to comment this law. There was examined in details the role of sanatorium stage in system of medical rehabilitation, and organization of it's effectuating in conditions of sanatorium.

[Difference in amino acid sequences of B. afzelii P66 surface-exposed loop region]

In the present work, we performed a phenotyping analysis of 45 B. afzelii 89-a.a. long amino acid sequences of 7 different allele variants, corresponding to the surface-exposed loop region of P66. 45 investigated isolates showed 5 phenotypically different variants; 2 phenotypically different variants of loop region, in particular, also showed mutations in the putative monoclonal antibody H1337 binding site; the similarity between the amino acid sequences taken from different variants is about 96.66% to 98.88%; in one natural locus up to 3 different phenotypes of P66 could circulate simultaneously.

Endogenous JSRV-like proviruses in domestic cattle: analysis of sequences and transcripts

Jaagsiekte retrovirus is an exogenous (exJSRV) beta-retrovirus with a simple genome. It causes lower airway epithelial cell tumors in small ruminants. Endogenous (enJSRV) counterparts of exJSRV are present in different copy numbers in numerous Bovidae family members. This work has focused on enJSRV in Simmental (Germany) and Limousine (France) beef breeds of domestic cattle and domestic goat. Of the enJSRV sequences in cattle, the orf-x sequences were about 99% identical, the LTR sequences were about 97% identical and the env sequences were nearly 95% identical to the corresponding endogenous sequences in sheep. A significant polymorphism of the proviral sequences between the cattle breeds was noted. Clonal analyses of the amplicons suggest two enJSRV proviruses in cattle genome. The endogenous sequences revealed in goat were closer to enzootic nasal tumor virus (ENTV) from goat rather than to enJSRV from sheep. The expression of enJSRV in cattle was partial (env only) and detected exclusively in bone marrow.

Mega-ampere submicrosecond generator GIT-32

The GIT-32 current generator was developed for experiments with current carrying pulsed plasma. The main parts of the generator are capacitor bank, multichannel multigap spark switches, low inductive current driving lines, and central load part. The generator consists of four identical sections, connected in parallel to one load. The capacitor bank is assembled from 32 IEK-100-0.17 (0.17 microF, 40 nH, 100 kV) capacitors, connected in parallel. It stores approximately 18 kJ at 80 kV charging voltage. Each two capacitors are commuted to a load by a multigap spark switch with eight parallel channels. Switches operate in ambient air at atmospheric pressure. The GIT-32 generator was tested with 10, 15, and 20 nH inductive loads. At 10 nH load and 80 kV of charging voltage it provides 1 MA of current amplitude and 490 ns rise time with 0.8 Omega damping resistors in discharge circuit of each capacitor and 1.34 MA530 ns without resistors. The net generator inductance without a load was optimized to be as low as 12 nH, which results in extremely low self-impedance of the generator ( approximately 0.05 Omega). It ensures effective energy coupling with low impedance loads like Z pinch. The generator operates reliably without any adjustments in 40-80 kV range of charging voltage. Maximum jitter (relative to a triggering pulse) at 40 kV charging voltage is about 7 ns and lower at higher charging voltages. Operation and handling are very simple, because no oil and no purified gases are required for the generator. The GIT-32 generator has dimensions of 3200 x 3200 x 400 mm(3) and total weight of about 2500 kg, thus manifesting itself as a simple, robust, and cost effective apparatus.

[A direct uretero-enteroanastomosis: a return to the past?]

The authors analyse their experience with ureter implantations into a small intestinal retaining reservoir--both direct and antireflux. From 1994 to 2004 orthotopic replacement of the urinary bladder (UB) with an ileal segment was performed in 62 patients (59 males, 3 females) for UB cancer (n = 55), microcystis (posttraumatic, radiation-induced, tuberculous) (n = 7). Orthotopic replacement of the UB was made according to VIP (vesica ileale Padovano) technique with creation of antireflux uretero-enteroanastomoses by Le Duc (group 1, 43 patients, 82 anastomoses) and Hautmann technique in modification of Lippert-Theodorescu (group 2, 14 patients, 28 direct uretero-enteroanastomoses). A direct uretero-enteroanastomosis was performed by Nesbit and Bricker technique. Five patients were withdrawn from the final analysis: 3 of them died early after the surgery because of complications, 2 patients died due to progression within 3 and 4 months after the operation. A total length of the ileac segment used for UB repair in both groups was 60 cm. Upper urinary tracts (UUT) and kidneys after the operation were assessed by the results of ultrasonic investigation of the caliceropelvic system, kidneys, UB, residual urine, serum creatinine, excretory urography, spiral CT (on demand), etc., after recovery of miction (3-4 weeks after operation), 3 and 6 (+cystography) after the operation, 12 months after the operation and annually. Comparison of the results of direct and antireflux anastomoses suggests a conclusion that a high rate of strictures due to antireflux anastomoses provoking UUT and renal dysfunction makes their benefit doubtful. Antireflux bypass ureteral surgery with neocystis of low pressure seems unjustified. In creation of capable uroreservoir of low pressure a direct implantation of the ureter into it is simple to do and less risky in respect to development of anastomotic stricture and damage to the renal function.

[Surgical treatment of acquired defects and ruptures of interventricular septum]

Surgical repair of posttraumatic ventricular septal defects, aortic-right ventricular fistulas and postinfarction ruptures of interventricular septum was carried out in 15 patients aged 18-75 years. Methods of radical correction included suturing, plastic repair with synthetic and autopericardial patches, and amputation of cardiac apex. Procedures were performed 14 days - 12 months after myocardial infarction and 1-12 months after penetrating knife wounds of the chest and the heart. Duration of follow-up was from 1 month to 9.5 years. There were no cases of defect recanalization and deaths.

[Surgical access in interventions on the kidney, adrenal gland and upper and middle third of the ureter]

The paper presents indications for, techniques and feasibility of different approaches--thoracophrenolaparotomy (TPL), vertical median and transverse subcostal laparotomy as well as anterolateral lumbotomy--in various retroperitoneal surgical conditions. TPL approach providing maximal radicality and safety in serious operations is thought basic in operative urology. The authors believe that the rest approaches are variants of abdominal part of TPL performed isolated. Thus, if one of the abdominal approaches meets with technical difficulties and a risk of serious complications, these difficulties are overcome by conversion of the approach to TPL.

[Orthotopic reconstruction of urinary bladder by intestinal flaps]

The technique of complete or partial replacement of the urinary bladder (UB) with iliac segment is discussed and principles of creation of small intestinal reservoir are validated. The authors are satisfied with the results of 17 operations for microcystis and to repair UB after radical cysto(prostat)ectomy for UB cancer. Orthotopic reconstruction of the UB is proposed as a new therapeutic standard in UB cancer and microcystis.

[Are the sequelae predictable for sectional and multiple partial nephrolithotomies of completely intrarenal coral stones? (experimental and clinical research)]

In the assessment of surgical intervention for fully intrarenal stone casts, different kinds of nephrotomies (sectional or multiple partial ones, those supplementing pyelolithotomy or performed in the kidneys with marked parenchyma) should be compared in terms of functional outcomes, severity and incidence of complications (intraoperative or postoperative bleeding from the violated kidney), postoperative urinary fistulas, aggravated renal failure and postoperative mortality. It is these milestones that have determined the scope of the present study. An experimental assessment of the degree of trauma, associated with sectional nephrolithotomy as well as its functional sequelae was made in dogs after a stone-like structure was simulated and the kidney reached the necessary degree of secretory deficiency. The comparison of pre- and postoperative renographic parameters over different spans of follow-up of animals after sectional nephrolithotomy was made to assess the latter's organ-damaging effect and, in part, functional results of surgery in a kidney with a profound functional deficiency by the time of the operation. A similar methodology was used in clinical patients, subjected to nephrolithotomy (either sectional or multiple partial procedure) for fully intrarenal coral stones. Functional results of nephrolithotomies in animals and in patients are presented in Figs 1-3. For cases where postoperative results were good or satisfactory at 1-2 months, follow-up results are presented in Tables 4-5. Postoperative complications of sectional and partial nephrolithotomies are reflected in Figs. 4-5. The incidence of paranephritis and postoperative mortality are reported in Tables 6-7. Therefore, functional results of sectional nephrolithotomy are indicative of its considerable organ-sparing effect in experimental animals. Functional outcomes of the clinical sectional and multiple partial nephrolithotomies are similar, yet partial nephrolithotomies are more detrimental to the kidney and the upper urinary tract in terms of the pattern and rate of postoperative complications, as compared to sectional nephrolithotomy. As the sequelae of sectional and partial nephrolithotomies are largely unpredictable, indications for surgical removal of intrarenal stereometrically-composite coral stones should be as limited as possible.

[Urinary enzymes induced in rats by intensive physical loading and the effect of the antioxidant potassium fenozan]

The rats subjected to repeated heavy exercises (swimming with the load equal to 10% of body weight) had an increased activity of gamma-glutamyl transpeptidase in the urine. Both the percentage of the rats with hyperenzymuria and the level of enzyme were the highest after the fifth swimming. Water-soluble antioxidant (potassium fenozan) administered intraperitoneally 30 minutes before the swimming abolished the increase of enzymuria and maintained the enzyme activity to the normal level.

[The information value of rheography and loading tests in the functional assessment of the ureter (experimental research)]

Functional tests, using electro-ureterography, ureteral rheography, electromanometry and electromagnetic flowmetry in the presence of diuretic and perfusion load tests, were performed at surgery in dogs. Ureteral rheography is shown to be a valuable method for the assessment of ureteral motility (as evidenced by ureteral volume changes), and have certain advantages over other techniques so that it can be used clinically for preoperative functional assessment of ectatic ureters. Load tests are necessary at functional tests of the upper urinary system in order to assess the pattern of ureteral wall contractility and reserves.

[Changes in the lipid levels of the liver, plasma, aorta and cholesterol esterase activity of the rat liver during exposure to tetrachloromethane]

Content of cholesterol esters was increased 2.3-fold, triglycerides--4.7-fold, phospholipids--1.5-fold in liver tissue of CCl4-treated rats. The increase in the content of cholesterol esters and triglycerides correlated with a decrease in activity of lysosomal cholesterol esterase from liver tissue. After CCl4 intoxication content of free cholesterol was decreased 2.1-fold, free fatty acids--2-fold, phospholipids--2.3-fold, triglycerides--1.75-fold in blood. In aorta an increase in content of cholesterol esters and triglycerides was found to be 2-fold as well as activation of the cytosolic cholesterol esterase was noted. The data obtained suggest that intoxication with CCl4 affected the accumulation of cholesterol esters in the arterial wall.