Репозиторий Университета

Репликативный полипротеин 1а вируса желтухи свеклы (ВЖС) содержит консервативные домены лидерной папаин-подобной протеиназы (РСР), метилтрансферазы (MTR) и РНК хеликазы (HEL). Центральный район (central region, CR) между MTR и HEL ранее считали «вариабельным». Нами проведен компьютерный анализ CR, который позволил выявить новый консервативный домен между позициями 1287-1390 (здесь и далее приводится нумерация аминокислотных остатков белка 1а вируса желтухи свеклы, BYV), сохраняющийся у всех представителей рода Closterovirus. Этот домен содержит 4 предсказанных альфа-спиральных участка (альфа А – D) и три строго консервативные позиции – глютамат-1291, пролин-1380 и аргинин-1384. Кроме того, биоинформатический анализ позволил предсказать амфипатическую спираль в позициях 1368-1380 (входящую в состав участка альфа D). Гидрофобный домен CR-2 (позиции 1305-1494 белка 1а), вызывающий при экспрессии в растениях реструктуризацию эндоплазматического ретикулюма и образование подвижных глобул диаметром ~1 мкм, включает участки альфа В, С и D. Установлено, что экспрессия в растениях слитных белков CR-2:GFP и GFP:CR-2 вызывает сходный «глобулообразующий» фенотип, т.е. N-концевое или C-концевое положение маркера GFP в слитном белке не влияет на переформатирование мембран эндоплазматического ретикулюма. Проведен делеционный анализ CR-2 BYV. Показано, что делеционные варианты 1355-1494 и 1325-1484 сохраняют фенотип дикого типа (образование глобул и реструктуризация ЭР вокруг ядра клетки). Варианты 1375-1484, 1368-1484 и 1368-1432 индуцировали образование глобул, но утрачивали способность к реструктуризации ЭР. Внесение замен гидрофобных аминокислотных остатков на остатки серина и глицина в «минимальном» делеционном мутанте 1368-1432 блокировало образование глобул. Предложена рабочая гипотеза о влиянии консервативной амфипатической спирали 1368-1385 в белке 1а BYV на ремоделирование мембран ЭР растительной клетки и создание репликативных платформ при клостеровирусной инфекции.

Human B-cell receptor-associated protein BAP31 (HsBAP31) is the endoplasmic reticulum-resident protein involved in protein sorting and transport as well as pro-apoptotic signaling. Plant orthologs of HsBAP31 termed 'plant BAP-like proteins' (PBL proteins) have thus far remained unstudied. Recently, the PBL protein from Nicotiana tabacum (NtPBL) was identified as an interactor of Nt-4/1, a plant protein known to interact with plant virus movement proteins and affect the long-distance transport of potato spindle tuber viroid (PSTVd) via the phloem. Here, we have compared the sequences of PBL proteins and studied the biochemical properties of NtPBL. Analysis of a number of fully sequenced plant genomes revealed that PBL-encoding genes represent a small multigene family with up to six members per genome. Two conserved motifs were identified in the C-terminal region of PBL proteins. The NtPBL C-terminal hydrophilic region (NtPBL-C) was expressed in bacterial cells, purified, and used for analysis of its RNA binding properties in vitro. In gel shift experiments, NtPBL-C was found to bind several tested RNAs, showing the most efficient binding to microRNA precursors (pre-miRNA) and less efficient interaction with PSTVd. Mutational analysis suggested that NtPBL-C has a composite RNA-binding site, with two conserved lysine residues in the most C-terminal protein region being involved in binding of pre-miRNA but not PSTVd RNA. Virus-mediated transient expression of NtPBL-C in plants resulted in stunting and leaf malformation, developmental abnormalities similar to those described previously for blockage of miRNA biogenesis/function. We hypothesize that the NtPBL protein represents a previously undiscovered component of the miRNA pathway.

Main conclusion: The plant-specific 4/1 protein interacts, both in yeast two-hybrid system and in vitro, and co-localizes in plant cells with plant BAP-like protein, the orthologue of human protein BAP31. In yeast two-hybrid system, we identified a number of Nicotiana benthamiana protein interactors of Nt-4/1, the protein known to affect systemic transport of potato spindle tuber viroid. For one of these interactors, an orthologue of human B-cell receptor-associated protein 31 (BAP31) termed plant BAP-like protein (PBL), the ability to interact with Nt-4/1 was studied in greater detail. Analyses of purified proteins expressed in bacterial cells carried out in vitro with the surface plasmon resonance (SPR) spectroscopy revealed that the N. tabacum PBL (NtPBL) was able to interact with Nt-4/1 with high-affinity, and that their complex can form at physiologically relevant concentrations of both proteins. Subcellular localization studies of 4/1-GFP and NtPBL-mRFP transiently co-expressed in plant cells revealed the co-localization of the two fusion proteins in endoplasmic reticulum-associated bodies, suggesting their interaction in vivo. The N-terminal region of the Nt-4/1 protein was found to be required for the specific subcellular targeting of the protein, presumably due to a predicted amphipathic helix mediating association of the Nt-4/1 protein with cell membranes. Additionally, this region was found to contain a trans-activator domain responsible for the Nt-4/1 ability to activate transcription of a reporter gene in yeast.

(PDF) Plant-specific 4/1 polypeptide interacts with an endoplasmic reticulum protein related to human BAP31. Available from: https://www.researchgate.net/publication/308925365_Plant-specific_41_polypeptide_interacts_with_an_endoplasmic_reticulum_protein_related_to_human_BAP31 [accessed Dec 14 2018].

The outcomes in patients with anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis have improved significantly over the past decades, although a significant proportion of them still reach end-stage renal disease (ESRD). Renal replacement therapy (RRT) is associated with a relatively low risk of relapsing vasculitis as a result of anti-rejection treatment after kidney transplantation or quiescence of the autoimmune process in haemodialysis patients, but a flare of vasculitis in the latter setting presents a challenge because the treatment is poorly tolerated. There are benefits of rituximab in haemodialysed patients, as it is more steroid sparing in the treatment of extrarenal disease. More favourable outcomes of kidney transplantation compared with haemodialysis support its use as a preferable method of RRT in patients with vasculitis remission or low disease activity.

Celiac disease (CD) is an autoimmune enteropathy triggered by the ingestion of dietary gluten from some cereals mainly in individuals carrying the HLA-DQ2 and/or HLA-DQ8 haplotypes. As an autoimmune disease, CD is manifested in the small intestine in the form of a progressive and reversible inflammatory lesion due to immune response to self-antigens. Indeed, CD is one of the most challenging medicosocial problems in current gastroenterology. At present, the global CD prevalence is estimated at approximately 1% based on data sent from different locations and available CD screening strategies used. However, it is impossible to estimate global CD prevalence without all the data from the world, including Russia. In this review, we summarize the data on the incidence and prevalence of CD across geographically distinct regions of Russia, which are mostly present in local Russian scientific sources. Our conclusion is that the situation of CD prevalence in Russia is higher than is commonly believed and follows global tendencies that correspond to the epidemiologic situation in Europe, America, and Southwest Asia.

Near complete rabies virus N gene sequences (1,110 nt) were determined for 82 isolates obtained from different regions of Russia between 2008 and 2016. These sequences were analyzed together with 108 representative GenBank sequences from 1977–2016 using the Bayesian coalescent approach. The timing of the major evolutionary events was estimated. Most of the isolates represented the steppe rabies virus group C, which was found over a vast geographic region from Central Russia to Mongolia and split into three groups (C0-C2) with discrete geographic prevalence. A single strain of the steppe rabies virus lineage was isolated in the far eastern part of Russia (Primorsky Krai), likely as a result of a recent anthropogenic introduction. For the first time the polar rabies virus group A2, previously reported in Alaska, was described in the northern part of European Russia and at the Franz Josef Land. Phylogenetic analysis suggested that all currently circulating rabies virus groups in the Russian Federation were introduced within the few last centuries, with most of the groups spreading in the 20 th century. The dating of evolutionary events was highly con-cordant with the historical epidemiological data.

We read with great interest the article by Saadoun et al1 who investigated the efficacy and safety of a 24-week treatment with sofosbuvir and ribavirin in a small, open-label and uncontrolled study of patients with hepatitis C virus (HCV)-associated cryoglobulinemia vasculitis. However, the limitations of the VASCUVALDIC study diminish the validity of the conclusions, although we agree with the authors that it would be unethical to delay effective antiviral therapy given the established role of HCV in the development of cryoglobulinemia vasculitis and its unfavourable prognosis. As expected, the rate of sustained virological response (SVR) was higher (74%) than in previous trials of interferon-based antiviral treatment in patients with HCV-associated cryoglobulinemia vasculitis.2 ,3 However, this looks relatively moderate in light of the current efficacy of the interferon-free, all-oral antiviral regimens (up to 95%–100%). Nonetheless, the SVR rate was comparable with that identified in the previous phase III sofosbuvir plus ribavirin trial in patients with HCV infection.4 We can also assume that the proportion of virological responders among patients with HCV-associated cryoglobulinemia vasculitis will increase further due to the use of other available and emerging direct-acting antivirals. Moreover, ribavirin-free regimen may improve the safety of antiviral treatment, given a high rate of anaemia (25%) in this study. Over 24 months, almost 90% of patients achieved a complete clinical response that was defined by an improvement in all vasculitis manifestations and the absence of clinical relapse. In the majority of responders, the clinical and virological effects were rapid and apparent within the first 12 weeks of treatment. Approximately 30% of patients received treatment with immunomodulatory or immunosuppressive therapy (including rituximab) that may contribute to, but could not explain, the impressive results of the VASCUVALDIC study. Notably, SVR12 was achieved in all three patients who received a rituximab infusion 1 month prior to the antiviral therapy. Rituximab did not seem to impair the antiviral activity of sofosbuvir plus ribavirin and it can be used concomitantly with direct-acting antivirals. These reassuring findings are important, as antiviral treatment does not eliminate the need for immunosuppression in patients with severe cryoglobulinemia glomerulonephritis or nervous system disease. http://dx.doi.org/10.1136/annrheumdis-2016-210636

BACKGROUND Trauma-induced coagulopathy (TIC) is commonly seen among patients with severe injury. The dynamic process of TIC is characterized by variability of the features of the disease.

METHODS A model of TIC was created. Hemodilution was produced by mixing the blood with 40% Tris/saline solution, fibrinolysis by treating the blood with 160 ng/mL tPA, acidosis by adding 1.2 mg/mL lactic acid achieving pH 7.0 to 7.1, and hypothermia by running the assay at 31°C. Intact blood tested at 37°C served as control. Clot formation was evaluated using rotation thromboelastometry. Platelet adhesion and aggregation were assayed at a shear rate of 1800 s−1 using Impact-R device.

RESULTS Clotting time was not affected by any of the TIC constituents used. Clotting initiation was reduced by hemodilution and further reduced by additive hypothermia. The propagation phase of blood clotting was reduced by hemodilution, further reduced by additive hypothermia, and maximally reduced if additionally combined with fibrinolysis. No effect of fibrinolysis on clot propagation was observed at 37°C. Maximum clot firmness was reduced by hemodilution, further reduced by additive fibrinolysis, and maximally reduced if additionally combined with hypothermia. No effect of hypothermia on clot strength was observed in the absence of fibrinolysis. Platelet adhesion (percentage of surface coverage) and aggregation (aggregate size) under flow condition were reduced by hemodilution and further reduced by additive acidosis. Introduction of tPA to diluted blood had no effect on platelet function.

CONCLUSION The study revealed a differential effect of TIC constituents—hemodilution, hypothermia, fibrinolysis, and acidosis—on clot formation and platelet function. The effect of one factor may influence that of another factor. These data may be helpful to better understand the pathogenesis of TIC and to elaborate an individually tailored treatment strategy.

LEVEL Of EVIDENCE A new model of TIC is created. Contribution of various constituents to pathogenesis of TIC and their interactions are evaluated.

The transient receptor potential ankyrin-repeat 1 (TRPA1) is an important player in pain and inflammatory pathways. It is a promising target for novel drug development for the treatment of a number of pathological states. A novel peptide producing a significant potentiating effect on allyl isothiocyanate (AITC)- and diclofenac-induced currents of TRPA1 was isolated from the venom of sea anemone Metridium senile. It is a 35-amino-acid peptide cross-linked by two disulfide bridges, named τ-AnmTX Ms 9a-1 (short name Ms 9a-1) according to a structure similar to other sea anemone peptides belonging to structural group 9a. The structures of the two genes encoding the different precursor proteins of Ms 9a-1 were determined. Peptide Ms 9a-1 acted as a positive modulator of TRPA1 in vitro but did not cause pain or thermal hyperalgesia when injected into the hind paw of mice. Intravenous injection of Ms 9a-1 (0.3 mg/kg) produced a significant decrease in the nociceptive and inflammatory response to AITC (the agonist of TRPA1) and reversed CFA-induced inflammation and thermal hyperalgesia. Taken together, these data support the hypothesis that Ms 9a-1 potentiates the response of TRPA1 to endogenous agonists followed by persistent functional loss of TRPA1-expressing neurons. We can conclude that TRPA1 potentiating may be useful as a therapeutic approach since Ms 9a-1 produces significant analgesic and anti-inflammatory effects in mice models of pain.

While deficient brain plasticity is a well-established pathophysiologic feature of depression, little is known about disorder-associated enhanced cognitive processing. Here, we studied a novel mouse paradigm that potentially models augmented learning of adverse memories during development of a depressive-like state. We used a modification of the classic two-day protocol of a mouse Porsolt test with an additional session occurring on Day 5 following the initial exposure. Unexpectedly, floating behaviour and brain glycogen synthase kinase-3 beta (GSK-3beta) mRNA levels, a factor of synaptic plasticity as well as a marker of distress and depression, were increased during the additional swimming session that was prevented by imipramine. Observed increases of GSK-3beta mRNA in prefrontal cortex during delayed testing session correlated with individual parameters of behavioural despair that was not found in the classic Porsolt test. Repeated swim exposure was accompanied by a lower pGSK-3beta/GSK-3beta ratio. A replacement of the second or the final swim sessions with exposure to the context of testing resulted in increased GSK-3beta mRNA level similar to the effects of swimming, while exclusion of the second testing prevented these changes. Together, our findings implicate the activation of brain GSK-3beta expression in enhanced contextual conditioning of adverse memories, which is associated with an individual susceptibility to a depressive syndrome.

Thiamine (vitamin B1) deficiency in the brain has been implicated in the development of dementia and symptoms of depression. Indirect evidence suggests that thiamine may contribute to these pathologies by controlling the activities of glycogen synthase kinase (GSK)-3β. While decreased GSK-3β activity appears to impair memory, increased GSK-3β activity is associated with the distressed/depressed state. However, hitherto direct evidence for the effects of thiamine on GSK-3β function has not been reported. Here, we administered thiamine or, the more bioavailable precursor, benfotiamine at 200 mg/kg/day for 2 weeks to C57BL/6J mice, to determine whether treatment might affect behaviours that are known to be sensitive to GSK-3β activity and whether such administration impacts on GSK-3β expression within the brain. The mice were tested in models of contextual conditioning and extinction, a 5-day rat exposure stress test, and a modified swim test with repeated testing. The tricyclic antidepressant imipramine (7.5 mg/kg/day), was administered as a positive control for the effects of thiamine or benfotiamine. As for imipramine, both compounds inhibited the upregulation of GSK-3β induced by predator stress or repeated swimming, and reduced floating scores and the predator stress-induced behavioural changes in anxiety and exploration. Coincident, thiamine and benfotiamine improved learning and extinction of contextual fear, and the acquisition of the step-down avoidance task. Our data indicate that thiamine and benfotiamine have antidepressant/anti-stress effects in naïve animals that are associated with reduced GSK-3β expression and conditioning of adverse memories. Thus thiamine and benfotiamine may modulate GSK-3β functions in a manner that is dependent on whether the contextual conditioning is adaptive or maladaptive.

Излагаются результаты анализа и систематизации интернет-ресурсов, используемых при подготовке врачей-специалистов по авиационной и космической медицине в системе высшего медицинского образования Российской Федерации. Представленный материал направлен на обеспечение успешности обучения с учетом требований, установленных Федеральным государственным образовательным стандартом по данной специальности.

Marine sponges contain a variety of low-molecular-weight compounds including guanidine alkaloids possessing different biological activities. Monanchomycalin B and urupocidin A were isolated from the marine sponge Monanchora pulchra. We found that they act as inhibitors of the TRPV1, TRPV2, and TRPV3 channels, but are inactive against the TRPA1 receptor. Monanchomycalin B is the most active among all published marine alkaloids (EC50 6.02, 2.84, and 3.25 μM for TRPV1, TRPV2, and TRPV3, correspondingly). Moreover, monanchomycalin B and urupocidin A are the first samples of marine alkaloids affecting the TRPV2 receptor. Two semi-synthetic urupocidin A derivatives were also obtained and tested against TRP (Transient Receptor Potential) receptors that allowed us to collect some data concerning the structure-activity relationship in this series of compounds. We showed that the removal of one of three side chains or double bonds in the other side chains in urupocidin A led to a decrease of the inhibitory activities. New ligands specific to the TRPV subfamily may be useful for the design of medicines as in the study of TRP channels biology.

1) Отделение сосудистой хирургии, Российский научный центр хирургии им. академика Б.В. Петровского,
2) Кафедра сердечно-сосудистой хирургии №1 им. академика Б.В. Петровского, Первый московский государственный медицинский университет им. И.М. Сеченова Минздрава РФ, Москва, Россия

Представлен обзор литературы, посвященный проблеме хирургического лечения больных с гемодинамически значимым стенозом внутренней сонной артерии и контрлатеральной окклюзией. Проведен обзор исследований, сравнивающих периоперационные и ранние послеоперационные исходы каротидной эндартерэктомии у пациентов с данной нозологией. Поиск литературы осуществлен с помощью баз данных Scopus, WebofScience, MedLine, РИНЦ.

This chapter focuses on large vessel vasculitis (LVV), encompassing Giant Cell Arteritis (GCA), Takayasu’s Arteritis (TA) and aortitis defined by the 2012 Revised International Chapel Hill Consensus Conference Nomenclature of Vasculitides [1]. We include Polymyalgia Rheumatica (PMR), which can occur with GCA and aortitis. Glucocorticoids (GC) are the mainstay treatment of large vessel vasculitides and PMR [2- 4]. However, the majority will have flares (>50%), remaining on GC for a minimum of 1- 3 years with their cumulative dose often resulting in side effects [5]. Furthermore, steroid resistance has been frequently recorded in a subset of patients. Relapse remains common despite use of GC and synthetic immunomodulators. We explore the use of biologic therapies and address the unmet need of patients who are resistant or intolerant to GC therapy, along with their use as steroid sparing agents. Having reviewed current literature and clinical trials we will focus our attention on when best to commence biologic therapy and who is most likely to benefit.

Abstract

Background and Aim

Non‐invasive markers are essential to assess the progression of chronic liver diseases to fibrosis/ cirrhosis and the effectiveness of therapeutic strategies. The aim of this study was to evaluate the ability of non‐invasive markers to identify significant fibrosis, severe fibrosis, and cirrhosis in patients with autoimmune hepatitis (AIH).

Methods

Seventy‐six patients with AIH were enrolled in the study and analyzed for the following parameters of liver fibrosis: Fibrosis 4 score (FIB‐4), aspartate aminotransferase (AST) to alanine aminotransferase (ALT) ratio (AAR), AST to platelet count ratio (APRI), and platelet count to spleen diameter (PC/SD) ratio. All patients underwent liver biopsy. The diagnostic accuracy of tests was evaluated by the area under the receiver operating characteristic curve (AUROC).

Results

Among the 76 AIH patients, 55 (72.3%) had significant fibrosis (≥ F2), 37 (48.7%) had severe fibrosis (≥ F3), and 29 (38.2%) had cirrhosis (F4). PC/SD ratio (AUROC = 0.840) was superior to AAR (AUROC = 0.756), FIB‐4 (AUROC = 0.702), and APRI (AUROC = 0.626) in discriminating between mild and significant fibrosis (≥ F2). The AUROCs of PC/SD ratio, FIB‐4, AAR, and APRI were 0.884, 0.742, 0.731, and 0.707, respectively, for severe fibrosis (≥ F3); 0.968, 0.795, 0.744, and 0.723, respectively, for cirrhosis (F4). PC/SD ratio correctly identified 85.1% of patients with severe fibrosis, and 89.6% of patients with cirrhosis.

Conclusions

PC/SD ratio proved to be a simple non‐invasive tool to correctly identify AIH patients with severe fibrosis and cirrhosis, thereby reducing the need for a liver biopsy in these patients.

Background

The PGC-1α/PPAR axis has been proposed as a potential therapeutic target for several metabolic disorders. The aim was to evaluate the efficacy of the pan-PPAR agonist, bezafibrate, in tafazzin knockdown mice (TazKD), a mouse model of Barth syndrome that exhibits age-dependent dilated cardiomyopathy with left ventricular (LV) dysfunction.

Results

The effect of bezafibrate on cardiac function was evaluated by echocardiography in TazKD mice with or without beta-adrenergic stress. Adrenergic stress by chronic isoproterenol infusion exacerbates the cardiac phenotype in TazKD mice, significantly depressing LV systolic function by 4.5 months of age. Bezafibrate intake over 2 months substantially ameliorates the development of LV systolic dysfunction in isoproterenol-stressed TazKD mice. Without beta-adrenergic stress, TazKD mice develop dilated cardiomyopathy by 7 months of age. Prolonged treatment with suprapharmacological dose of bezafibrate (0.5% in rodent diet) over a 4-month period effectively prevented LV dilation in mice isoproterenol treatment. Bezafibrate increased mitochondrial biogenesis, however also promoted oxidative stress in cardiomyocytes. Surprisingly, improvement of systolic function in bezafibrate-treated mice was accompanied with simultaneous reduction of cardiolipin content and increase of monolysocardiolipin levels in cardiac muscle.

Conclusions

Thus, we demonstrate that bezafibrate has a potent therapeutic effect on preventing cardiac dysfunction in a mouse model of Barth syndrome with obvious implications for treating the human disease. Additional studies are needed to assess the potential benefits of PPAR agonists in humans with Barth syndrome.