Light-enabled deracemization of cyclopropanes by Al-salen photocatalysis

Privileged chiral catalysts-those that share common structural features and are enantioselective across a range of reactions-continue to transform the chemical-research landscape1. In recent years, new reactivity modes have been achieved through excited-state catalysis, processes activated by light, but it is unclear if the selectivity of ground-state privileged catalysts can be matched. Although the interception of photogenerated intermediates by ground-state cycles has partially addressed this challenge2, single, chiral photocatalysts that simultaneously regulate reactivity and selectivity are conspicuously scarce3. So far, precision donor-acceptor recognition motifs remain crucial in enantioselective photocatalyst design4. Here we show that chiral Al-salen complexes, which have well-defined photophysical properties, can be used for the efficient photochemical deracemization5 of cyclopropyl ketones (up to 98:2 enantiomeric ratio (e.r.)). Irradiation at λ = 400 nm (violet light) augments the reactivity of the commercial catalyst to enable reactivity and enantioselectivity to be regulated simultaneously. This circumvents the need for tailored catalyst-substrate recognition motifs. It is predicted that this study will stimulate a re-evaluation of many venerable (ground-state) chiral catalysts in excited-state processes, ultimately leading to the identification of candidates that may be considered 'privileged' in both reactivity models.

Helicobacter pylori regulates TIFA turnover in gastric epithelial cells

The human pathogen Helicobacter pylori induces a strong inflammatory response in gastric mucosa manifested by the recruitment of neutrophils and macrophages to the places of infection, and by changes in epithelial integrity and function. At the molecular level, this innate immune response is essentially dependent on the activation of NF-κB transcription factors regulating the expression of chemotactic factors, e.g., IL-8. Recently, it has been demonstrated that the NF-κB signaling pathway is triggered by the bacterial heptose metabolites, which activate the host ALPK1-TIFA axis. TIFA has been suggested to promote oligomerization and activity of the E3 ubiquitin ligase TRAF6, which further stimulates TAK1-IKK signaling. Here, we demonstrate that ALPK1-dependent TIFA activation in H. pylori-infected gastric epithelial cells is followed in time by a decline in TIFA levels, and that this process is impeded by inhibitors of the proteasomal and lysosomal degradation. According to our data, TRAF2, TRAF6, TAK1 or NEMO are not required for TIFA degradation. Additionally, H. pylori promotes the interaction of TIFA with free polyubiquitin as well as with optineurin, TAX1BP1 and LAMP1, which are known protein adaptors involved in intracellular trafficking to lysosomes.

Genetic Diversity of Venturia inaequalis in Latvia Revealed by Microsatellite Markers

Apple scab caused by the ascomycete Venturia inaequalis is an economically significant disease worldwide. The annual sexual reproduction of V. inaequalis leads to high variation, changes in the population's genetic structure and adaptations to the changing environment, including overcoming the host's resistance. The objective of this study is to characterise and assess the genetic diversity of V. inaequalis populations in two main apple-growing regions in Latvia. In total, 143 V. inaequalis isolates were collected from Latvia, six reference strains with known virulence were obtained from other countries, and all strains were genotyped by 12 SSR markers. The SSR markers were highly variable and informative, identifying 158 alleles that ranged from two to 29 per locus. The Bayesian clustering identified three genetic lineages among the Latvian isolates that did not correlate to the geographic origin, host genotype, organ (leaves or fruits) from which the pathogen was isolated, time of collection, and type of isolation (single conidium or ascospore). The possible relatedness to virulence was detected when reference strains with known virulence were included in the analysis. Our findings correspond with previous studies demonstrating that V. inaequalis in Europe has a high genetic diversity within populations, but low diversity among the populations.

Matrix Metalloproteinases in Helicobacter pylori-Associated Gastritis and Gastric Cancer

Gastric cancer is one of the leading causes of the cancer-related mortality worldwide. The etiology of this disease is complex and involves genetic predisposition and environmental factors, including Helicobacter pylori. Infection of the stomach with H. pylori leads to gastritis and gastric atrophy, which can progress stepwise to gastric cancer. Matrix metalloproteinases (MMPs) actively participate in the pathology development. The further progression of gastric cancer seems to be less dependent on bacteria but of intra-tumor cell dynamics. Bioinformatics data confirmed an important role of the extracellular matrix constituents and specific MMPs in stomach carcinoma invasion and metastasis, and revised their potential as predictors of the disease outcome. In this review, we describe, in detail, the impact of MMPs in H. pylori-associated gastritis and gastric cancer.

PECULIARITIES OF VASOR-REGULATING FUNCTIONS OF THE VASCULAR ENDOTHELIUM IN ADAPTATION OF THE YOUTH BODY TO SYSTEMATIC PHYSICAL LOADS

OBJECTIVE

The aim: To analyze the features of changes in the functional state of the vascular endothelium of handball players in the dynamics of the training process, at different levels of the body's hypoxic state.

PATIENTS AND METHODS

Materials and methods: Theoretical methods, the method of Corretti et al. with the use of high-resolution ultrasound, Fisher test with the calculation of the Fisher criterion and the Bland-Altman method. The study of the vasomotor function of the vascular endothelium was carried out of young men 18-20 y.o., who did not go in for sports and which were systematically played handball. The brachial artery diameter, maximum linear blood flow velocity, volumetric blood flow velocity were registered in the state of relative rest after artificially created reactive hyperemia.

RESULTS

Results: The primary results obtained showed that in the process of long-term adaptation to systematic muscular work, a pronounced vasodilation effect was observed. Subsequent analyze of changes in the functional state of the vascular endothelium of young sportsmen during the macrocycle preparation different levels of the body's hypoxic state manifested the following. The young men-athletes had more pronounced vasodilation effect, the values of the linear and volumetric blood flow velocity both in the state of relative rest and at the peak of the artificially created hyperemia were significantly higher than in the young men, who did not go in for sports.

CONCLUSION

Conclusions: Suggested that the systematic muscular work contributes to a significant intensification of the oxidation pathway of nitric oxide formation from L-arginine with the participation of endothelial NO-synthase.

TIFA has dual functions in Helicobacter pylori-induced classical and alternative NF-κB pathways

Helicobacter pylori infection constitutes one of the major risk factors for the development of gastric diseases including gastric cancer. The activation of nuclear factor‐kappa‐light‐chain‐enhancer of activated B cells (NF‐κB) via classical and alternative pathways is a hallmark of H. pylori infection leading to inflammation in gastric epithelial cells. Tumor necrosis factor receptor‐associated factor (TRAF)‐interacting protein with forkhead‐associated domain (TIFA) was previously suggested to trigger classical NF‐κB activation, but its role in alternative NF‐κB activation remains unexplored. Here, we identify TRAF6 and TRAF2 as binding partners of TIFA, contributing to the formation of TIFAsomes upon H. pylori infection. Importantly, the TIFA/TRAF6 interaction enables binding of TGFβ‐activated kinase 1 (TAK1), leading to the activation of classical NF‐κB signaling, while the TIFA/TRAF2 interaction causes the transient displacement of cellular inhibitor of apoptosis 1 (cIAP1) from TRAF2, and proteasomal degradation of cIAP1, to facilitate the activation of the alternative NF‐κB pathway. Our findings therefore establish a dual function of TIFA in the activation of classical and alternative NF‐κB signaling in H. pylori‐infected gastric epithelial cells.

Manifold role of ubiquitin in Helicobacter pylori infection and gastric cancer

Infection with H. pylori induces a strong host cellular response represented by induction of a set of molecular signaling pathways, expression of proinflammatory cytokines and changes in proliferation. Chronic infection and inflammation accompanied by secretory dysfunction can result in the development of gastric metaplasia and gastric cancer. Currently, it has been determined that the regulation of many cellular processes involves ubiquitinylation of molecular effectors. The binding of ubiquitin allows the substrate to undergo a change in function, to interact within multimolecular signaling complexes and/or to be degraded. Dysregulation of the ubiquitinylation machinery contributes to several pathologies, including cancer. It is not understood in detail how H. pylori impacts the ubiquitinylation of host substrate proteins. The aim of this review is to summarize the existing literature in this field, with an emphasis on the role of E3 ubiquitin ligases in host cell homeodynamics, gastric pathophysiology and gastric cancer.

Telemedicine Intervention to Improve Long-Term Risk Factor Control and Body Composition in Persons with High Cardiovascular Risk: Results from a Randomized Trial: Telehealth strategies may offer an advantage over standard institutional based interventions for improvement of cardiovascular risk in high-risk patients long-term

Background

Telehealth strategies are increasingly used to support people at high cardiovascular risk long-term, but is it unclear if these interventions are effective at improving cardiovascular risk.

Objective

To evaluate the effects of a telemedicine technology-based program on risk factor control and body composition in patients at high cardiovascular risk.

Methods

This is a population based randomized controlled trial. 100 patients at high and very high cardiovascular risk were randomly assigned to a telemedicine technology-based program consisting of: Comprehensive counseling on risk factors delivered by a physician; biweekly remote support via phone delivered by a trained nurse during the first three months after enrollment; and a control group receiving routine care with individual single-session counseling on patients' current risk factors without further support. The follow-up period was 1 year.

Results

Mean age of participants was 59.9 ± 4.5 years, 80% were women. Weight (-0.582; p < 0.001), waist circumference (-0.429; p = 0.01), body mass index (-0.216; p < 0.001) diastolic blood pressure (-0.881; p = 0.04), total cholesterol (-0.149; p = 0.01) and LDL cholesterol (-0.123; p = 0.003) were lower in the intervention group compared to the control group after 12-month. Body fat mass was also lower (-0.352; p = 0.01) and lean mass was higher (0.92; p = 0.03) in the intervention group. Anxiety scores (-2.5; p < 0.002) and depression scores (-2.6; p < 0.001) were also lower in the intervention group.

Conclusions

Among older people at high cardiovascular risk, the addition of telehealth strategies using remote support by phone calls over a period of 3 month resulted in small but significant improvements of cardiovascular risk factors, body composition, anxiety, and depression which are maintained long-term. Such telehealth strategies may offer an advantage over standard institution-based interventions.

Study of the Relationship between the Average Annual Temperature of Atmospheric Air and the Number of Tick-Bitten Humans in the North of European Russia

In recent decades, a considerable increase in the number of tick-bitten humans has been recorded in the north of European Russia. At the same time, significant climatic changes, such as an increase in air temperature, were noticed in this region. The northern border of the ixodidae distribution area lies in the north of European Russia, therefore the analysis of the population dynamics is of particular interest regarding the possible impact of the climate changes. Unfortunately, in such a large territory field, studies on tick abundance are very difficult. In our study, the official statistics for the number of tick-bitten humans were used. This kind of statistical analysis has been conducted in the Russian Federation for many years, and can be used for the estimation of climate change impact on tick abundance. Statistical data on tick-bitten humans have been collected in three large regions for several decades. For the same regions, the average annual air temperature was calculated and modeled. An S-shaped distribution of the number of victims depending on the average annual air temperature was established, which can be described as “Verhulst’s law”, or logistic function. However, the development of the population does not depend on time, but on the temperature of the ambient air.

CEACAMs interaction with Helicobacter pylori HopQ supports the type 4 secretion system-dependent activation of non-canonical NF-κB

Helicobacter pylori infection represents a major risk factor for the development of gastric diseases and gastric cancer. The capability of H. pylori to inject the virulence factor cytotoxin-associated gene A (CagA) depends on a type IV secretion system (T4SS) encoded by the cag pathogenicity island (cagPAI). Further, infection by H. pylori activates the nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) in a T4SS-dependent manner but CagA-independent manner. Here we investigated the role of host cell receptors carcinoembryonic antigen-related cell adhesion molecules (CEACAMs) and the bacterial adhesin HopQ in the activation of non-canonical NF-κB and CagA translocation into gastric epithelial cells. AGS cells express six of twelve CEACAMs found in humans. In HeLa cells, only CEACAM19 is expressed. We showed that deletion of hopQ attenuates the activation of non-canonical NF-κB only in AGS but not in HeLa cells. CagA translocation was in both cell lines affected by HopQ depletion, although to a much lesser extent in HeLa cells. Moreover, we observed a possible redundancy between the three HopQ-binding CEACAMs 1, 5 and 6 and their capacity to support non-canonical NF-κB activation. Our results illustrate that the interaction between HopQ and CEACAMs could promote the efficiency of the T4SS.

Physical Rehabilitation Needs in the BRICS Nations from 1990 to 2017: Cross-National Analyses Using Data from the Global Burden of Disease Study

Background: This study analyzes the current and evolving physical rehabilitation needs of BRICS nations (Brazil, Russian Federation, India, China, South Africa), a coalition of large emergent economies increasingly important for global health. Methods: Secondary, cross-national analyses of data on Years Lived with Disability (YLDs) were extracted from the Global Burden of Disease Study 2017. Total physical rehabilitation needs, and those stratified per major condition groups are analyzed for the year 2017 (current needs), and for every year since 1990 (evolution over time). ANOVAs are used to detect significant yearly changes. Results: Total physical rehabilitation needs have increased significantly from 1990 to 2017 in each of the BRICS nations, in every metric analyzed (YLD Counts, YLDs per 100,000 people, and percentage of YLDs relevant to physical rehabilitation; all p < 0.01). Musculoskeletal & pain conditions were leading cause of physical rehabilitation needs across the BRICS nations but to varying degrees: from 36% in South Africa to 60% in Brazil. Country-specific trends include: 25% of South African needs were from HIV-related conditions (no other BRICS nation had more than 1%); India had both absolute and relative growths of pediatric rehabilitation needs (p < 0.01); China had an exponential growth in the per-capita needs from neurological and neoplastic conditions (p < 0.01; r2 = 0.97); Brazil had a both absolute and relative growth of needs coming from musculoskeletal & pain conditions (p < 0.01); and the Russian Federation had the highest neurological rehabilitation needs per capita in 2017 (over than three times those of India, South Africa or Brazil). Conclusions: total physical rehabilitation needs have been increasing in each of the BRICS nations, both in absolute and relative values. Apart from the common growing trend, each of the BRICS nations had own patterns for the amount, typology, and evolution of their physical rehabilitation needs, which must be taken into account while planning for health and physical rehabilitation programs, policies and resources.

Reassessment of Paragnomonia (Sydowiellaceae, Diaporthales) and typification of Paragnomonia fragariae, the cause of strawberry root rot and petiole blight

Paragnomonia fragariae is a plant pathogenic ascomycete causing root rot and petiole blight of perennial strawberry in northern Europe. This paper provides a revised description of Paragnomonia and P. fragariae with lecto- and epitypification based on the species original description, recent collections from four European countries, examination of specimens used in the previous taxonomic studies and phylogenetic analyses of DNA sequences of LSU, ITS/5.8S and tef1-α. This study presents the first report of P. fragariae on cultivated strawberry in Finland and Lithuania. Our study on growth rate showed that P. fragariae is a cold-adapted fungus growing almost equally at 5 °C as at 20 °C and attaining maximal growth at 15 °C. New primers were designed for amplification of ca. 0.8 kb fragment of tef1-α of Sydowiella fenestrans. Additionally, newly generated sequences of tef1-α were obtained for the first time from 21 isolates of seven species belonging to five genera of Sydowiellaceae, including the type species S. fenestrans, therefore considerably contributing to the current knowledge on phylogenetic relationships of this insufficiently studied group of fungi. The phylogenetic analysis has also revealed that the recently described species "S." centaureii is genetically distant from the generic type S. fenestrans and other Sydowiella.

Crosstalk Between DNA Damage and Inflammation in the Multiple Steps of Gastric Carcinogenesis

Over the last years, intensive investigations in molecular biology and cell physiology extended tremendously the knowledge about the association of inflammation and cancer. In frame of this paradigm, the human pathogen Helicobacter pylori triggers gastritis and gastric ulcer disease, and contributes to the development of gastric cancer. Mechanisms, by which the bacteria-induced inflammation in gastric mucosa leads to intestinal metaplasia and carcinoma, are represented in this review. An altered cell-signaling response and increased production of free radicals by epithelial and immune cells account for the accumulation of DNA damage in gastric mucosa, if infection stays untreated. Host genetics and environmental factors, especially diet, can accelerate the process, which offers the opportunity of intervention based on a balanced nutrition. It is supposed that inflammation might influence stem- or progenitor cells in gastric tissue predisposing for metaplasia or tumor relapse. Herein, DNA is strongly mutated and labile, which restricts therapy options. Thus, the understanding of the mechanisms that underlie gastric carcinogenesis will be of preeminent importance for the development of strategies for screening and early detection. As most gastric cancer patients face late-stage disease with a poor overall survival, the development of multi-targeted therapeutic intervention strategies is a major challenge for the future.

Influence of eukaryotic translation initiation factor 6 on non-small cell lung cancer development and progression

Non-small cell lung cancer (NSCLC) is the leading cause of cancer-related death worldwide. Dysregulation of protein synthesis plays a major role in carcinogenesis, a process regulated at multiple levels, including translation of mRNA into proteins. Ribosome assembly requires correct association of ribosome subunits, which is ensured by eukaryotic translation initiation factors (eIFs). eIFs have become targets in cancer therapy studies, and promising data on eIF6 in various cancer entities have been reported. Therefore, we hypothesised that eIF6 represents a crossroad for pulmonary carcinogenesis. High levels of eIF6 are associated with shorter patient overall survival in adenocarcinoma (ADC), but not in squamous cell carcinoma (SQC) of the lung. We demonstrate significantly higher protein expression of eIF6 in ADC and SQC than in healthy lung tissue based on immunohistochemical data from tissue microarrays (TMAs) and on fresh frozen lung tissue. Depletion of eIF6 in ADC and SQC lung cancer cell lines inhibited cell proliferation and induced apoptosis. Knockdown of eIF6 led to pre-rRNA processing and ribosomal 60S maturation defects. Our data indicate that eIF6 is upregulated in NSCLC, suggesting an important contribution of eIF6 to the development and progression of NSCLC and a potential for new treatment strategies against NSCLC.

Determinants of the presence of human papillomaviruses in the anal canal of Russian men

Knowledge of determinants of anal human papillomavirus (HPV) infections among men is still limited as most of the studies are focused on high-risk populations and geographically narrowed. Such knowledge obtained in different populations is essential for better understanding of HPV natural history, transmission dynamics, and its role in the development and prevention of anogenital malignancies in different regions. Here we tested anal canal swab samples from 359 Russian heterosexual (323 human immunodeficiency virus [HIV]-negative and 27 HIV-positive, aged 18-67 years) men attending a sexually transmitted infection clinic 36 HPV types using a proficient Luminex assay. HPV-positivity in anal samples was common for 332 HIV-negative heterosexual men for overall HPV (15.7%, n = 52), oncogenic HPV (9.6%, n = 32), nononcogenic HPV (8.1%, n = 27), and multiple HPV infections (4.5%, n = 14). The most common anal HPV types were HPV16 (5.7%), HPV45, and HPV51 (1.8% each), HPV66, and HPV87 (1.8% each). No association was found with the number of lifetime sexual partners, age of participants at the time of the study, or their sexual debut. Although anal HPV positivity was more common among HIV-positive men, the current study provides additional evidence that anal HPV can be frequently detected in heterosexual HIV-negative men favoring further studies on transmission routes to discriminate between contamination and true HPV infection.

HopQ impacts the integrin α5β1-independent NF-κB activation by Helicobacter pylori in CEACAM expressing cells

Helicobacter pylori infection persists in more than half of the world's population and represents a risk factor for peptic ulcer disease and gastric cancer. Virulent strains of H. pylori carry a cag pathogenicity island (cagPAI), which encodes a type IV secretion system (T4SS) with the capability to inject the effector protein cytotoxin-associated gene A (CagA) into eukaryotic cells. Colonisation of the gastric epithelium by H. pylori provokes direct activation of the proinflammatory and survival factor nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB). We investigated the impact of host cell receptor integrin α5β1 and the bacterial adhesin HopQ on the NF-κB activation. We found that H. pylori induced early T4SS-dependent, but CagA-independent canonical NF-κB signalling in polarized, apical infected NCI-N87 cells. Integrin-dependent CagA translocation was hardly detectable, as integrin β1 was sparsely located at the apical surface of polarized NCI-N87 cells. Knockdown experiments indicated that integrin α5β1 and integrin linked kinase (ILK) were dispensable for NF-κB activation in H. pylori infection. Thus, there exists no common mechanism, which mediates integrin α5β1-dependent H. pylori-triggered CagA translocation and the activation of NF-κB. Further, we report that H. pylori adhesin HopQ, which binds to a specific subset of carcinoembryonic antigen-related cell adhesion molecules (CEACAMs), promotes canonical NF-κB activation in AGS and NCI-N87 cells, but not in HeLa cells, which are devoid of these CEACAMs. Noteworthy, these effects were not mediated by reduced adhesion, indicating additional functions of HopQ.

Potential and limitations of health policy to improve coronary heart disease prevention and to reduce the burden of disease: A Russian experience

Background Mortality from cardiovascular diseases is particularly high in Russia compared with the European average. The National Priority Project 'Health', launched in 2005, aimed to promote prevention of non-communicable diseases, particularly cardiovascular diseases, in primary care and to increase availability of state-of-art cardiovascular disease management. Methods This is a multiregional population based study with analysis of indicators for cardiovascular health and coronary heart disease in Moscow, St Petersburg, the Moscow region and across Russia, including a total population of 143.7 million inhabitants between 2005 and 2013. Data were collected using conventional methodology and originate from open statistical sources. Results The overall age-standardized coronary heart disease mortality decreased in 2005-2013 by 24.7% from 383.6 to 289.0 per 100000 population, but with substantial interregional differences: it declined from 306.1 to 196.9 per 100,000 in Moscow (-35.7%), from 362.1 to 258.9 per 100,000 in St Petersburg (-28.5%) and from 433.8 to 374.3 per 100,000 in the Moscow region (-13.7%). Income in Moscow exceeded the national average 2-3-fold, and Moscow had the highest availability of modern treatments and interventions. Although vegetables, fruits and fish consumption increased overall in Russia, this trend was most prominent in Moscow. Indicators for psychosocial well-being also were best in Moscow. Life expectancy in Moscow is almost six years higher than the Russian average. Conclusion Health policy interventions turned out to be successful but with substantial interregional differences. Lower coronary heart disease mortality and higher life expectancy in Moscow may be due to a more favourable socioeconomic and psychological environment, more healthy eating and greater availability of medical care.

Helicobacter pylori induces direct activation of the lymphotoxin beta receptor and non-canonical nuclear factor-kappa B signaling

The pathogen Helicobacter pylori, which infects half of the world's population, is a major risk factor for the development of gastric diseases including chronic gastritis and gastric cancer. Among H. pylori's virulence factors is the cytotoxin-associated gene pathogenicity island (cagPAI), which encodes for a type IV secretion system (T4SS). The T4SS induces fast canonical nuclear factor-kappa B (NF-κB) signaling, a major factor increasing inflammation, supressing apoptotic cell death and thereby promoting the development of neoplasia. However, H. pylori's capability to mediate fast non-canonical NF-κB signaling is unresolved, despite a contribution of non-canonical NF-κB signaling to gastric cancer has been suggested. We analyzed signaling elements within non-canonical NF-κB in response to H. pylori in epithelial cell lines by immunoprecipitation, immunoblot, electrophoretic mobility shift assay and RNA interference knockdown. In addition, tissue samples of H. pylori-infected patients were investigated by immunohistochemistry. Here, we provide evidence for a T4SS-dependent direct activation of non-canonical NF-κB signaling. We identified the lymphotoxin beta receptor (LTβR) to elicit the fast release of NF-κB inducing kinase (NIK) from the receptor complex leading to non-canonical NF-κB signaling. Further, NIK expression was increased in human biopsies of H. pylori-associated gastritis. Thus, NIK could represent a novel target to reduce Helicobacter pylori-induced gastric inflammation and pathology.

Governmental efforts for cardiovascular disease prevention efforts in the Russian Federation

Cardiovascular disease (CVD) is the leading cause of death and disability in Russia as is case with the most other countries of the world, although Russia has unique features and demographic trends. In the late 90's and early 2000's Russia has sustained a profound demographical crisis with a period of overmortality but since 2003 the mortality rates are declining. By 2013, the birth rates exceeded mortality. The reversal of the demographic crisis took place on the background of a number of comprehensive governmental efforts with focus on non-communicable diseases prevention. The National Priority Project "Health" implied enhancement of primary care along with improving availability of state-of-art care for CVD patients. The most notable activities in the field of preventive medicine were the launch of Health Centers for universal free-of-charge screening for risk factors and for preventive counseling and the Dispanserization program (a large scale health screening aiming on detection of both people with chronic conditions and of high-risk persons).

NF-κB Signaling in Gastric Cancer

Gastric cancer is a leading cause of cancer death worldwide. Diet, obesity, smoking and chronic infections, especially with Helicobacter pylori, contribute to stomach cancer development. H. pylori possesses a variety of virulence factors including encoded factors from the cytotoxin-associated gene pathogenicity island (cagPAI) or vacuolating cytotoxin A (VacA). Most of the cagPAI-encoded products form a type 4 secretion system (T4SS), a pilus-like macromolecular transporter, which translocates CagA into the cytoplasm of the host cell. Only H. pylori strains carrying the cagPAI induce the transcription factor NF-κB, but CagA and VacA are dispensable for direct NF-κB activation. NF-κB-driven gene products include cytokines/chemokines, growth factors, anti-apoptotic factors, angiogenesis regulators and metalloproteinases. Many of the genes transcribed by NF-κB promote gastric carcinogenesis. Since it has been shown that chemotherapy-caused cellular stress could elicit activation of the survival factor NF-κB, which leads to acquisition of chemoresistance, the NF-κB system is recommended for therapeutic targeting. Research is motivated for further search of predisposing conditions, diagnostic markers and efficient drugs to improve significantly the overall survival of patients. In this review, we provide an overview about mechanisms and consequences of NF-κB activation in gastric mucosa in order to understand the role of NF-κB in gastric carcinogenesis.

Prevalence of cutaneous beta and gamma human papillomaviruses in the anal canal of men who have sex with women

Background

Data regarding anal cutaneous HPV detection among HIV-positive and HIV-negative persons largely relies on studies among men who have sex with men in limited geographical settings. Understanding the distribution, determinants, and potential human health effects of anal cutaneous HPV types among men who have sex with women (MSW) is important.

Methods

Anal canal swab samples from 415 Russian MSW (384 HIV-negative and 31 HIV-positive) were tested for 43 β-HPVs and 29 γ-HPVs, using a multiplex PCR combined with Luminex technology.

Results

β-HPV was detected in 24.4% and γ-HPV in 15.9% of anal samples of all Russian MSW. In total, 34 β-HPV and 19 γ-HPV types were detected, with the most commonly detected β-HPV types being 110, 22 and 124 and the most common γ-HPV types being 95, 132 and 50. For both genera, being HIV-positive at the time of testing was a significant determinant of detection (74.2% for β-HPVs and 48.4% for γ-HPVs compared to 20.1% and 12.5% in HIV-negative MSW, respectively).

Conclusions

A wide spectrum and moderate prevalence of anal β-HPV and γ-HPV types was found in our MSW study sample, suggesting that routes other than penile-anal intercourse may be important in cutaneous HPV transmission.

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β and γ HPV types commonly colonize the anal canal of MSW, but their geographical variation in prevalence could be wide.

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HIV-positive men were more likely to have both genera of HPV types detected.

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Routes other than penile-anal intercourse may be important in cutaneous HPV transmission.

Robot-assisted surgery in complex treatment of the pulmonary tuberculosis

Surgery of pulmonary tuberculosis associated with open thoracotomy due to dense pleural and vascular adhesions. These reasons limited the use of video-assisted thoracoscopic surgery (VATS) in these cases. Robotic surgical system aimed to performing successfully minimally invasive operations for pulmonary tuberculosis. This paper showed 3-year experience of one chest center in this area. The results of this work are recommendations that facilitate the implementation of robot-assisted lung resection in complex treatment of pulmonary tuberculosis.

Structure and mechanism of mouse cyclase-associated protein (CAP1) in regulating actin dynamics

Srv2/CAP is a conserved actin-binding protein with important roles in driving cellular actin dynamics in diverse animal, fungal, and plant species. However, there have been conflicting reports about whether the activities of Srv2/CAP are conserved, particularly between yeast and mammalian homologs. Yeast Srv2 has two distinct functions in actin turnover: its hexameric N-terminal-half enhances cofilin-mediated severing of filaments, while its C-terminal-half catalyzes dissociation of cofilin from ADP-actin monomers and stimulates nucleotide exchange. Here, we dissected the structure and function of mouse CAP1 to better understand its mechanistic relationship to yeast Srv2. Although CAP1 has a shorter N-terminal oligomerization sequence compared with Srv2, we find that the N-terminal-half of CAP1 (N-CAP1) forms hexameric structures with six protrusions, similar to N-Srv2. Further, N-CAP1 autonomously binds to F-actin and decorates the sides and ends of filaments, altering F-actin structure and enhancing cofilin-mediated severing. These activities depend on conserved surface residues on the helical-folded domain. Moreover, N-CAP1 enhances yeast cofilin-mediated severing, and conversely, yeast N-Srv2 enhances human cofilin-mediated severing, highlighting the mechanistic conservation between yeast and mammals. Further, we demonstrate that the C-terminal actin-binding β-sheet domain of CAP1 is sufficient to catalyze nucleotide-exchange of ADP-actin monomers, while in the presence of cofilin this activity additionally requires the WH2 domain. Thus, the structures, activities, and mechanisms of mouse and yeast Srv2/CAP homologs are remarkably well conserved, suggesting that the same activities and mechanisms underlie many of the diverse actin-based functions ascribed to Srv2/CAP homologs in different organisms.

Helicobacter pylori promotes eukaryotic protein translation by activating phosphatidylinositol 3 kinase/mTOR

The innate immune response elicited by Helicobacter pylori in the human gastric mucosa involves a range of cellular signalling pathways, including those implicated in metabolism regulation. In this study, we analysed H. pylori-induced PI3K/Akt/mTOR signalling, which regulates glycolysis and protein synthesis and associates thereby with cellular energy- and nutrients-consuming processes such as growth and proliferation. The immunohistochemical analysis demonstrated that Akt kinase phosphorylation is abundant in gastric biopsies obtained from gastritis, gastric adenoma and adenocarcinoma patients. Infection with H. pylori led to the phosphorylation of Akt effectors mTOR and S6 in a type 4 secretion system (T4SS)-independent manner in AGS cells. We observed that the activation of these molecules was dependent on PI3K and the Src family tyrosine kinases. Furthermore, H. pylori induced the phosphorylation of 4E-BP1 and eIF4E and suppressed the phosphorylation of eEF2, which are important regulators of protein synthesis. Inhibition of PI3K and Akt kinase prevented the phosphorylation of 4E-BP1, suggesting that PI3K signalling is involved in the regulation of translation initiation during H. pylori infection. Metabolic labelling showed that infected cells had higher rates of [(35)S]methionine/cysteine incorporation, and this effect could be prevented using LY294002, an PI3K inhibitor. Thus, H. pylori activates PI3K/Akt signalling, mTOR, eIFs and protein translation, which might impact H. pylori-related gastric pathophysiology.

Tryptamine induces axonopathy and mitochondriopathy mimicking neurodegenerative diseases via tryptophanyl-tRNA deficiency

Neurodegeneration is induced by tryptamine, a human diet constituent, which easily crosses the blood/brain barrier. Tryptamine neurotoxicity, caused by tryptophanyl-tRNA synthetase (TrpRS) inhibition and downregulation leads to tryptophanyl-tRNA deficiency and synthesis of aberrant proteins. We identified axonal defects in hippocampus of tryptamine- treated mice similar to those observed in human brain of patients with Alzheimer's disease, multiple sclerosis and epilepsy using anti-TrpRS site-directed antibodies. The axonal defects are characterized by swellings that accumulate abnormal amounts of helical filaments and amyloid. Tryptamine produced a decreased density of somatic mitochondria concomitant with neuronal loss in mouse hippocampus. In addition, tryptamine evoked accumulation and clustering of small mitochondria in mouse hippocampus causing axonal swellings. Similarly, mitochondrial fission, fusion and clustering were revealed in human neuronal cells after tryptamine administration. Moreover the tryptamine-induced mitochondrial neuropathology includes electron-dense deposits comprising helical fibrils, cristae disruption, cristolysis, mitochondrial swelling and mitochondria-derived vesicles. TrpRS+ helical filamentous tangles formed in both neuronal and kidney cells following tryptamine treatment suggest a tryptamine broad cytotoxic repertoire in damaging vital organs. Tryptamine elicited vesicularization of inner and outer mitochondrial membranes, axonal and cell membranes. Ultrastructurally, fragmentation of swollen degenerated mitochondria, small mitochondria clustering and neurofibrillary tangles are associated with axonal membrane protrusions attributed as neuritic swellings at a lower magnification. TrpRS+ axonal swellings associated with neuropathology of patients and tryptamine-treated human cells suggest that under toxic concentrations, tryptamine is implicated as a causative agent in neurodegeneration resembling that defining a number of human diseases.

Rapid interaction of Helicobacter pylori with microvilli of the polar human gastric epithelial cell line NCI-N87

Infection with Helicobacter pylori results often in chronic gastritis, gastric ulcers or even gastric tumor development. Little is known about the initial interaction between gastric epithelial cells and H. pylori. The aim of the present study was to analyze the initial host contact to the bacteria. Monolayers of the human gastric epithelial cell line NCI-N87 grown on porous membranes were used and the apical side of the epithelium was exposed to the H. pylori wild-type strain P1 for 1 hr. Many epithelial cells were colonized by bacteria within the period of 60 min. Using scanning electron microscopy we detected that the bacteria were in close contact with the epithelia via microvilli. Further, transmission electron microscopy of the contact sites revealed no difference in the morphology of the microvilli in comparison to those not attached to the bacteria. The present study demonstrates the importance of microvilli on apical epithelial cells during the initial contact of the host by colonizing H. pylori. Anat Rec, 296:1800–1805, 2013. © 2013 The Authors. The Anatomical Record: Advances in Integrative Anatomy and Evolutionary Biology published by Wiley Periodicals, Inc. on behalf of the American Association of Anatomists.

Helicobacter pylori induces type 4 secretion system-dependent, but CagA-independent activation of IκBs and NF-κB/RelA at early time points

Colonization of the gastric epithelium by Helicobacter pylori induces the transcription factor nuclear factor of kappa light polypeptide gene enhancer in B-cells (NF-κB) and the innate immune response. Virulent strains of H. pylori carry a cag pathogenicity island (cagPAI), which encodes a type IV secretion system (T4SS). Recent publications have shown controversial data regarding the role of the T4SS and the effector protein cytotoxin associated gene A (CagA), which becomes translocated by the T4SS into the eukaryotic epithelial cell, in H. pylori-induced NF-κB activation. Thus, this study analyses by using three different H. pylori strains (P1, B128 and G27) whether CagA is required to initiate activation of different molecules of inhibitors of kappa B (IκB) and the NF-κB transcription factor RelA. We provide experimental evidence that H. pylori induces phosphorylation of NF-κB inhibitors IκBα, IκBβ and IκBɛ, and degradation of IκBα. Further, H. pylori stimulates phosphorylation of RelA at amino acids S536, S468 and S276, promotes DNA binding of RelA, and interleukin 8 (IL-8) gene expression in a T4SS-, but CagA-independent manner at early time points.

GMF severs actin-Arp2/3 complex branch junctions by a cofilin-like mechanism

BACKGROUND

Branched actin filament networks driving cell motility, endocytosis, and intracellular transport are assembled in seconds by the Arp2/3 complex and must be equally rapidly debranched and turned over. One of the only factors known to promote debranching of actin networks is the yeast homolog of glia maturation factor (GMF), which is structurally related to the actin filament-severing protein cofilin. However, the identity of the molecular mechanism underlying debranching and whether this activity extends to mammalian GMF have remained open questions.

RESULTS

Using scanning mutagenesis and total internal reflection fluorescence microscopy, we show that GMF depends on two separate surfaces for debranching. One is analogous to the G-actin and F-actin binding site on cofilin, but we show using fluorescence anisotropy and chemical crosslinking that it instead interacts with actin-related proteins in the Arp2/3 complex. The other is analogous to a second F-actin binding site on cofilin, which in GMF appears to contact the first actin subunit in the daughter filament. We further show that GMF binds to the Arp2/3 complex with low nanomolar affinity and promotes the open conformation. Finally, we show that this debranching activity and mechanism are conserved for mammalian GMF.

CONCLUSIONS

GMF debranches filaments by a mechanism related to cofilin-mediated severing, but in which GMF has evolved to target molecular junctions between actin-related proteins in the Arp2/3 complex and actin subunits in the daughter filament of the branch. This activity and mechanism are conserved in GMF homologs from evolutionarily distant species.

Ca2+/calmodulin-dependent kinase II contributes to inhibitor of nuclear factor-kappa B kinase complex activation in Helicobacter pylori infection

Helicobacter pylori, a class I carcinogen, induces a proinflammatory response by activating the transcription factor nuclear factor-kappa B (NF-κB) in gastric epithelial cells. This inflammatory condition could lead to chronic gastritis, which is epidemiologically and biologically linked to the development of gastric cancer. So far, there exists no clear knowledge on how H. pylori induces the NF-κB-mediated inflammatory response. In our study, we investigated the role of Ca(2+) /calmodulin-dependent kinase II (CAMKII), calmodulin, protein kinases C (PKCs) and the CARMA3-Bcl10-MALT1 (CBM) complex in conjunction with H. pylori-induced activation of NF-κB via the inhibitor of nuclear factor-kappa B kinase (IKK) complex. We use specific inhibitors and/or RNA interference to assess the contribution of these components. Our results show that CAMKII and calmodulin contribute to IKK complex activation and thus to the induction of NF-κB in response to H. pylori infection, but not in response to TNF-α. Thus, our findings are specific for H. pylori infected cells. Neither the PKCs α, δ, θ, nor the CBM complex itself is involved in the activation of NF-κB by H. pylori. The contribution of CAMKII and calmodulin, but not PKCs/CBM to the induction of an inflammatory response by H. pylori infection augment the understanding of the molecular mechanism involved and provide potential new disease markers for the diagnosis of gastric inflammatory diseases including gastric cancer.

Protein kinase C isozymes regulate matrix metalloproteinase-1 expression and cell invasion in Helicobacter pylori infection

BACKGROUND

Protein kinase C (PKC) signalling is often dysregulated in gastric cancer and therefore represents a potential target in cancer therapy. The Gram-negative bacterium Helicobacter pylori, which colonises the human stomach, plays a major role in the development of gastritis, peptic ulcer and gastric adenocarcinoma.

OBJECTIVE

To analyse the role of PKC isozymes as mediators of H pylori-induced pathogenesis.

METHODS

PKC phosphorylation was evaluated by immunoblotting and immunohistochemistry. Gene reporter assays, RT-PCR and invasion assays were performed to assess the role of PKC in the regulation of activator protein-1 (AP-1), matrix metalloproteinase-1 (MMP-1) and the invasion of H pylori-infected epithelial cells.

RESULTS

H pylori induced phosphorylation of PKC isozymes α, δ, θ in AGS cells, which was accompanied by the phosphorylation of PKC substrates, including PKCμ and myristoylated alanine-rich C kinase substrate (MARCKS), in a CagA-independent manner. Phospholipase C, phosphatidylinositol 3-kinase and Ca(2+) were crucial for PKC activation on infection; inhibition of PKC diminished AP-1 induction and, subsequently, MMP-1 expression. Invasion assays confirmed PKC involvement in H pylori-induced MMP-1 secretion. In addition, analysis of biopsies from human gastric mucosa showed increased phosphorylation of PKC in active H pylori gastritis and gastric adenocarcinoma.

CONCLUSION

The targeting of certain PKC isozymes might represent a suitable strategy to interfere with the MMP-1-dependent remodelling of infected tissue and to overcome the invasive behaviour of gastric cancer cells.

Structure and activity of full-length formin mDia1

Formins are a conserved family of actin assembly-promoting factors with essential and diverse biological roles. Most of our biochemical understanding of formin effects on actin dynamics is derived from studies using formin fragments. In addition, all structural information on formins has been limited to fragments. This has left open key questions about the structure, activity and regulation of intact formin proteins. Here, we isolated full-length mouse mDia1 (mDia1-FL) and found that it forms tightly autoinhibited dimers that can only be partially activated by RhoA. We solved the structure of autoinhibited mDia1-FL using electron microscopy and single particle analysis. Docking of crystal structures into the three dimensional reconstruction revealed that the fork-shaped N-terminal diaphanous inhibitory domain-coiled coil domain region hangs over the ring-shaped formin homology (FH)2 domain, suggesting that autoinhibition results from steric obstruction of actin binding. Deletion of the C-terminal diaphanous autoregulatory domain extended mDia1 structure and activated it for actin assembly. Using total internal reflection fluorescence microscopy, we observed that RhoA-activated mDia1-FL persistently accelerated filament elongation in the presence of profilin similar to mDia1 FH1-FH2 fragment. These observations validate the known activities of FH1-FH2 fragments as reflecting those of the intact molecule. Our results further suggest that mDia1-FL does not readily snap back into the autoinhibited conformation and dissociate from growing filament ends, and thus additional factors may be required to displace formins and restrict filament length.

43. Anal human papillomavirus prevalence in HIV-negative and HIV-infected Russian men who have sex with women

Background HPV has been found in the anal canal of heterosexual men (MSWs) but knowledge on anal HPV epidemiology among MSWs is still limited. So far, there are no such data from Russia. Methods: In total, 350 β-globin-positive anal samples from Russian MSWs (age 18–58 years; sex debut 9–23 years; 1–700 life-time sex partners) attending a urology unit of an STI clinic and HIV+ patients from a city infection hospital were collected in St Petersburg. PCR using HPV general primers with genotyping using Luminex with probes for 13 oncogenic, high-risk HPV types (16, 18, 31, 33, 35 39, 45, 51, 52, 56, 58, 59, and 68, including variants) and 23 non-oncogenic types (6, 11, 26, 30, 40, 42, 43, 53, 54, 61, 66, 67, 70, 73, 74, 81, 82, 83, 86, 87, 89, 90, and 91) was used with 11 negative controls (water) and 8 positive controls (HPV plasmid pools) run in each assay. The method was proficient in the WHO HPV LabNet global proficiency panel. Results: Overall, HPV prevalence (including oncogenic and non-oncogenic types) was 17.1%, with 15.2% in HIV– compared with 40.7% in HIV+ Russian MSW (P = 0.0022). The most commonly detected was HPV-16 (5.4%) followed by HPV-51 (2.0%), HPV-45, (1.7%) and HPV-87 (1.7%). Interestingly, neither age, nor number of sexual partners, nor age at sexual debut were associated with HPV infection. Conclusions: HPV infection is common in anal canal samples of Russian MSWs. HPV prevalence is higher among men who were HIV positive.

Srv2/cyclase-associated protein forms hexameric shurikens that directly catalyze actin filament severing by cofilin

Dual-color total internal reflection fluorescence microscopy revealed that the N-terminal half of Srv2 (N-Srv2) directly catalyzes severing of cofilin-decorated actin filaments. N-Srv2 formed novel six-bladed structures resembling ninja throwing stars (shurikens), and N-Srv2 activities were critical for actin organization in vivo and were lethal in combination with Aip1.

Actin filament severing is critical for the dynamic turnover of cellular actin networks. Cofilin severs filaments, but additional factors may be required to increase severing efficiency in vivo. Srv2/cyclase-associated protein (CAP) is a widely expressed protein with a role in binding and recycling actin monomers ascribed to domains in its C-terminus (C-Srv2). In this paper, we report a new biochemical and cellular function for Srv2/CAP in directly catalyzing cofilin-mediated severing of filaments. This function is mediated by its N-terminal half (N-Srv2), and is physically and genetically separable from C-Srv2 activities. Using dual-color total internal reflection fluorescence microscopy, we determined that N-Srv2 stimulates filament disassembly by increasing the frequency of cofilin-mediated severing without affecting cofilin binding to filaments. Structural analysis shows that N-Srv2 forms novel hexameric star-shaped structures, and disrupting oligomerization impairs N-Srv2 activities and in vivo function. Further, genetic analysis shows that the combined activities of N-Srv2 and Aip1 are essential in vivo. These observations define a novel mechanism by which the combined activities of cofilin and Srv2/CAP lead to enhanced filament severing and support an emerging view that actin disassembly is controlled not by cofilin alone, but by a more complex set of factors working in concert.

Characterization of Virulence Factors of Staphylococcus aureus: Novel Function of Known Virulence Factors That Are Implicated in Activation of Airway Epithelial Proinflammatory Response

Airway epithelial cells play a major role in initiating inflammation in response to bacterial pathogens. S. aureus is an important pathogen associated with activation of diverse types of infection characterized by inflammation dominated by polymorphonuclear leukocytes. This bacterium frequently causes lung infection, which is attributed to virulence factors. Many of virulence determinants associated with S. aureus-mediated lung infection have been known for several years. In this paper, we discuss recent advances in our understanding of known virulence factors implicated in pneumonia. We anticipate that better understanding of novel functions of known virulence factors could open the way to regulate inflammatory reactions of the epithelium and to develop effective strategies to treat S. aureus-induced airway diseases.