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Tsakanova G, Stepanyan A, Arakelova E, Ayvazyan V, Tonoyan V, Arakelyan A, Hildebrandt G, Schültke E. The radioenhancement potential of Schiff base derived copper (II) compounds against lung carcinoma in vitro. PLoS One 2021; 16:e0253553. [PMID: 34143847 PMCID: PMC8213134 DOI: 10.1371/journal.pone.0253553] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2021] [Accepted: 06/07/2021] [Indexed: 11/30/2022] Open
Abstract
For the last years, copper complexes have been intensively implicated in biomedical research as components of cancer treatment. Herewith, we provide highlights of the synthesis, physical measurements, structural characterization of the newly developed Cu(II) chelates of Schiff Bases, Cu(Picolinyl-L-Tryptopahanate)2, Cu(Picolinyl-L-Tyrosinate)2, Cu(Isonicotinyl-L-Tyrosinate)2, Cu(Picolinyl-L-Phenylalaninate)2, Cu(Nicotinyl-L-Phenylalaninate)2, Cu(Isonicotinyl-L-Phenylalaninate)2, and their radioenhancement capacity at kV and MV ranges of irradiation of human lung carcinoma epithelial cells in vitro. The methods of cell growth, viability and proliferation were used. All compounds exerted very potent radioenhancer capacities in the irradiated lung carcinoma cells at both kV and MV ranges in a 100 μM concentration. At a concentration of 10 μM, only Cu(Picolinyl-L-Tyrosinate)2, Cu(Isonicotinyl-L-Tyrosinate)2, Cu(Picolinyl-L-Phenylalaninate)2 possessed radioenhancer properties at kV and MV ranges. Cu(Picolinyl-L-Tryptophanate)2 showed radioenhancer properties only at kV range. Cu(Nicotinyl-L-Phenylalaninate)2 and Cu(Isonicotinyl-L-Phenylalaninate)2 showed remarkable radioenhancer activity only at MV range. All compounds acted in dose-dependent manner at both tested energy ranges. These copper (II) compounds, in combination with 1 Gy irradiation at either 120 kV or 6 MV, are more efficient at delaying cell growth of lung cancer cells and at reducing cell viability in vitro than the irradiation administered alone. Thus, we have demonstrated that the studied copper compounds have a good potential for radioenhancement.
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Avetyan D, Chavushyan A, Ghazaryan H, Melkonyan A, Stepanyan A, Zakharyan R, Hayrapetyan V, Atshemyan S, Khachatryan G, Sirunyan T, Davitavyan S, Martirosyan G, Melik-Andreasyan G, Sargsyan S, Ghazazyan A, Aleksanyan N, Yin X, Arakelyan A. SARS-CoV-2 detection by extraction-free qRT-PCR for massive and rapid COVID-19 diagnosis during a pandemic in Armenia. J Virol Methods 2021; 295:114199. [PMID: 34091213 PMCID: PMC8175123 DOI: 10.1016/j.jviromet.2021.114199] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2021] [Revised: 05/25/2021] [Accepted: 05/25/2021] [Indexed: 12/13/2022]
Abstract
COVID-19 pandemic severely impacted the healthcare and economy on a global scale. It is widely recognized that mass testing is an efficient way to contain the spread of SARS-CoV-2 infection as well as aid in the development of informed policies for disease management. However, the current COVID-19 worldwide infection rates increased the demand for rapid and reliable screening of infection. We compared the performance of qRT-PCR in direct heat-inactivated (H), heat-inactivated and pelleted (HC) samples against RNA in a group of 74 subjects (44 positive and 30 negative). Then we compared the sensitivity of HC in a larger group of 196 COVID-19 positive samples. Our study suggests that HC samples show higher accuracy for SARS-CoV-2 detection PCR assay compared to direct H (89 % vs 83 % of the detection in RNA). The sensitivity of detection using direct samples varied depending on the sample transport and storage media as well as the viral loads (as measured by qRT-PCR Ct levels). Altogether, all the data suggest that purified RNA provides more accurate results, however, direct sample testing with qRT-PCR may help to significantly increase testing capacity. Switching to the direct sample testing is justified if the number of tests is doubled at least.
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Nersisyan L, Simonyan A, Binder H, Arakelyan A. Telomere Maintenance Pathway Activity Analysis Enables Tissue- and Gene-Level Inferences. Front Genet 2021; 12:662464. [PMID: 33897770 PMCID: PMC8058386 DOI: 10.3389/fgene.2021.662464] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2021] [Accepted: 03/16/2021] [Indexed: 12/31/2022] Open
Abstract
Telomere maintenance is one of the mechanisms ensuring indefinite divisions of cancer and stem cells. Good understanding of telomere maintenance mechanisms (TMM) is important for studying cancers and designing therapies. However, molecular factors triggering selective activation of either the telomerase dependent (TEL) or the alternative lengthening of telomeres (ALT) pathway are poorly understood. In addition, more accurate and easy-to-use methodologies are required for TMM phenotyping. In this study, we have performed literature based reconstruction of signaling pathways for the ALT and TEL TMMs. Gene expression data were used for computational assessment of TMM pathway activities and compared with experimental assays for TEL and ALT. Explicit consideration of pathway topology makes bioinformatics analysis more informative compared to computational methods based on simple summary measures of gene expression. Application to healthy human tissues showed high ALT and TEL pathway activities in testis, and identified genes and pathways that may trigger TMM activation. Our approach offers a novel option for systematic investigation of TMM activation patterns across cancers and healthy tissues for dissecting pathway-based molecular markers with diagnostic impact.
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Garikipati VNS, Arakelyan A, Blakely EA, Chang PY, Truongcao MM, Cimini M, Malaredy V, Bajpai A, Addya S, Bisserier M, Brojakowska A, Eskandari A, Khlgatian MK, Hadri L, Fish KM, Kishore R, Goukassian DA. Long-Term Effects of Very Low Dose Particle Radiation on Gene Expression in the Heart: Degenerative Disease Risks. Cells 2021; 10:cells10020387. [PMID: 33668521 PMCID: PMC7917872 DOI: 10.3390/cells10020387] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2021] [Revised: 01/27/2021] [Accepted: 02/08/2021] [Indexed: 12/13/2022] Open
Abstract
Compared to low doses of gamma irradiation (γ-IR), high-charge-and-energy (HZE) particle IR may have different biological response thresholds in cardiac tissue at lower doses, and these effects may be IR type and dose dependent. Three- to four-month-old female CB6F1/Hsd mice were exposed once to one of four different doses of the following types of radiation: γ-IR 137Cs (40-160 cGy, 0.662 MeV), 14Si-IR (4-32 cGy, 260 MeV/n), or 22Ti-IR (3-26 cGy, 1 GeV/n). At 16 months post-exposure, animals were sacrificed and hearts were harvested and archived as part of the NASA Space Radiation Tissue Sharing Forum. These heart tissue samples were used in our study for RNA isolation and microarray hybridization. Functional annotation of twofold up/down differentially expressed genes (DEGs) and bioinformatics analyses revealed the following: (i) there were no clear lower IR thresholds for HZE- or γ-IR; (ii) there were 12 common DEGs across all 3 IR types; (iii) these 12 overlapping genes predicted various degrees of cardiovascular, pulmonary, and metabolic diseases, cancer, and aging; and (iv) these 12 genes revealed an exclusive non-linear DEG pattern in 14Si- and 22Ti-IR-exposed hearts, whereas two-thirds of γ-IR-exposed hearts revealed a linear pattern of DEGs. Thus, our study may provide experimental evidence of excess relative risk (ERR) quantification of low/very low doses of full-body space-type IR-associated degenerative disease development.
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Arakelyan A, Melkonyan A, Hakobyan S, Boyarskih U, Simonyan A, Nersisyan L, Nikoghosyan M, Filipenko M, Binder H. Transcriptome Patterns of BRCA1- and BRCA2- Mutated Breast and Ovarian Cancers. Int J Mol Sci 2021; 22:1266. [PMID: 33525353 PMCID: PMC7865215 DOI: 10.3390/ijms22031266] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2020] [Revised: 01/06/2021] [Accepted: 01/07/2021] [Indexed: 02/06/2023] Open
Abstract
Mutations in the BRCA1 and BRCA2 genes are known risk factors and drivers of breast and ovarian cancers. So far, few studies have been focused on understanding the differences in transcriptome and functional landscapes associated with the disease (breast vs. ovarian cancers), gene (BRCA1 vs. BRCA2), and mutation type (germline vs. somatic). In this study, we were aimed at systemic evaluation of the association of BRCA1 and BRCA2 germline and somatic mutations with gene expression, disease clinical features, outcome, and treatment. We performed BRCA1/2 mutation centered RNA-seq data analysis of breast and ovarian cancers from the TCGA repository using transcriptome and phenotype "portrayal" with multi-layer self-organizing maps and functional annotation. The results revealed considerable differences in BRCA1- and BRCA2-dependent transcriptome landscapes in the studied cancers. Furthermore, our data indicated that somatic and germline mutations for both genes are characterized by deregulation of different biological functions and differential associations with phenotype characteristics and poly(ADP-ribose) polymerase (PARP)-inhibitor gene signatures. Overall, this study demonstrates considerable variation in transcriptomic landscapes of breast and ovarian cancers associated with the affected gene (BRCA1 vs. BRCA2), as well as the mutation type (somatic vs. germline). These results warrant further investigations with larger groups of mutation carriers aimed at refining the understanding of molecular mechanisms of breast and ovarian cancers.
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Tsakanova G, Ayvazyan V, Arakelova E, Ayvazyan A, Tatikyan S, Djavadovna L, Babayan N, Grigoryan R, Sargsyan N, Arakelyan A. Helix pomatia albumen gland water soluble protein extract as powerful antiaging agent. Exp Gerontol 2021; 146:111244. [PMID: 33454353 DOI: 10.1016/j.exger.2021.111244] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2020] [Revised: 01/09/2021] [Accepted: 01/11/2021] [Indexed: 12/01/2022]
Abstract
Accounting for increasingly developed population aging and dramatic elevation of aging-related severe disorders worldwide, search of the efficient antiaging agents is becoming one of the urgent problems of contemporary biomedical science. The aim of current study was to reveal the potential protective effects of water-soluble proteins extracted from albumen gland of snails against aging processes. We evaluated the antioxidant effect of the extract in 20 older adult rats in vivo and on 60 human blood samples ex vivo at the cellular level under physiological and oxidative stress conditions using the methods of spectrophotometric analysis, two-photon imaging and cell viability assay. The in vivo animal experiments showed significant increase in the levels of catalase and superoxide dismutase in treated older adult rats, compared to non-treated group. The ex vivo studies involving three human groups (young, middle aged and older adult), demonstrated that the extract has no effect on the cell viability, moreover significantly increases the number of erythrocytes, decreases age-related oxidative stress and the percentage of hemolysis of erythrocytes by aging. Thus, the snails albumen gland protein extract can be considered as effective natural antioxidative antiaging agent in prevention of aging-related pathological processes associated with oxidative stress.
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Schmidt M, Hopp L, Arakelyan A, Kirsten H, Engel C, Wirkner K, Krohn K, Burkhardt R, Thiery J, Loeffler M, Loeffler-Wirth H, Binder H. The Human Blood Transcriptome in a Large Population Cohort and Its Relation to Aging and Health. Front Big Data 2020; 3:548873. [PMID: 33693414 PMCID: PMC7931910 DOI: 10.3389/fdata.2020.548873] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2020] [Accepted: 09/02/2020] [Indexed: 02/06/2023] Open
Abstract
Background: The blood transcriptome is expected to provide a detailed picture of an organism's physiological state with potential outcomes for applications in medical diagnostics and molecular and epidemiological research. We here present the analysis of blood specimens of 3,388 adult individuals, together with phenotype characteristics such as disease history, medication status, lifestyle factors, and body mass index (BMI). The size and heterogeneity of this data challenges analytics in terms of dimension reduction, knowledge mining, feature extraction, and data integration. Methods: Self-organizing maps (SOM)-machine learning was applied to study transcriptional states on a population-wide scale. This method permits a detailed description and visualization of the molecular heterogeneity of transcriptomes and of their association with different phenotypic features. Results: The diversity of transcriptomes is described by personalized SOM-portraits, which specify the samples in terms of modules of co-expressed genes of different functional context. We identified two major blood transcriptome types where type 1 was found more in men, the elderly, and overweight people and it upregulated genes associated with inflammation and increased heme metabolism, while type 2 was predominantly found in women, younger, and normal weight participants and it was associated with activated immune responses, transcriptional, ribosomal, mitochondrial, and telomere-maintenance cell-functions. We find a striking overlap of signatures shared by multiple diseases, aging, and obesity driven by an underlying common pattern, which was associated with the immune response and the increase of inflammatory processes. Conclusions: Machine learning applications for large and heterogeneous omics data provide a holistic view on the diversity of the human blood transcriptome. It provides a tool for comparative analyses of transcriptional signatures and of associated phenotypes in population studies and medical applications.
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Nikoghosyan M, Schmidt M, Margaryan K, Loeffler-Wirth H, Arakelyan A, Binder H. SOMmelier-Intuitive Visualization of the Topology of Grapevine Genome Landscapes Using Artificial Neural Networks. Genes (Basel) 2020; 11:genes11070817. [PMID: 32709105 PMCID: PMC7397337 DOI: 10.3390/genes11070817] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2020] [Revised: 06/26/2020] [Accepted: 07/15/2020] [Indexed: 01/02/2023] Open
Abstract
Background: Whole-genome studies of vine cultivars have brought novel knowledge about the diversity, geographical relatedness, historical origin and dissemination, phenotype associations and genetic markers. Method: We applied SOM (self-organizing maps) portrayal, a neural network-based machine learning method, to re-analyze the genome-wide Single Nucleotide Polymorphism (SNP) data of nearly eight hundred grapevine cultivars. The method generates genome-specific data landscapes. Their topology reflects the geographical distribution of cultivars, indicates paths of cultivar dissemination in history and genome-phenotype associations about grape utilization. Results: The landscape of vine genomes resembles the geographic map of the Mediterranean world, reflecting two major dissemination paths from South Caucasus along a northern route via Balkan towards Western Europe and along a southern route via Palestine and Maghreb towards Iberian Peninsula. The Mediterranean and Black Sea, as well as the Pyrenees, constitute barriers for genetic exchange. On the coarsest level of stratification, cultivars divide into three major groups: Western Europe and Italian grapes, Iberian grapes and vine cultivars from Near East and Maghreb regions. Genetic landmarks were associated with agronomic traits, referring to their utilization as table and wine grapes. Pseudotime analysis describes the dissemination of grapevines in an East to West direction in different waves of cultivation. Conclusion: In analogy to the tasks of the wine waiter in gastronomy, the sommelier, our ‘SOMmelier’-approach supports understanding the diversity of grapevine genomes in the context of their geographic and historical background, using SOM portrayal. It offers an option to supplement vine cultivar passports by genome fingerprint portraits.
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Boyarskikh UA, Gulyaeva LF, Avdalyan AM, Kechin AA, Khrapov EA, Lazareva DG, Kushlinskii NE, Melkonyan A, Arakelyan A, Filipenko ML. Spectrum of TP53 Mutations in BRCA1/2 Associated High-Grade Serous Ovarian Cancer. Front Oncol 2020; 10:1103. [PMID: 32766142 PMCID: PMC7378769 DOI: 10.3389/fonc.2020.01103] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2020] [Accepted: 06/02/2020] [Indexed: 12/11/2022] Open
Abstract
Objective: Mutations in TP53 lead to loss of function (LOF) or gain of function (GOF) of the corresponding protein p53 and produce a different effect on the tumor. Our goal was to determine the spectrum of somatic TP53 variants in BRCA1/2 associated high-grade serous ovarian cancer (HGSOC). Methods: The population under study comprised of HGSOCs with pathogenic variants in BRCA1 (n = 78) or BRCA2 (n = 21). Only chemo-naive and platinum-sensitive patients were included in this study. The case group of the IARC database (n = 1249) with HGSOC not stratified by BRCA status was used as a reference. A custom NGS panel was used for sequencing TP53 and mutational hot-spots of other genes, and p53 expression was evaluated by immunohistochemistry for 68 cases of HGSOCs. Results: Somatic TP53 variants (95) or inhibition of wild-type p53 expression (3) were observed in 98 cases. The sample with normal p53 had CDKNA1 variants. The frequency of truncating variants was significantly higher than in the reference cohort (30.3 vs. 21.0%, p = 0.01). Most of the samples (41/68) demonstrated low (or absent) expression of p53, and 17 samples overexpressed p53. LOH was typical for TP53 nonsense variants (14/15). In total, 68/95 samples were LOH positive and showed LOH in all tumorous cells, thus indicating the driver effect of TP53 mutations. Three specimens had KRAS, BAX, APC, and CTNNB1 subclones variants. Conclusion: High frequency of TP53 truncating variants, the low expression of mutant p53, and low incidence of oncogene mutations show potential GOF properties of p53 to be poorly represented in BRCA1/2 associated HGSOC.
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Tsakanova G, Arakelova E, Ayvazyan V, Ayvazyan A, Tatikyan S, Grigoryan R, Sargsyan N, Arakelyan A. Two-photon imaging of oxidative stress in living erythrocytes as a measure for human aging. BIOMEDICAL OPTICS EXPRESS 2020; 11:3444-3454. [PMID: 33014543 PMCID: PMC7510891 DOI: 10.1364/boe.393898] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/30/2020] [Revised: 05/23/2020] [Accepted: 05/27/2020] [Indexed: 06/11/2023]
Abstract
According to the "oxidative stress theory" of aging, this process is accompanied by a progressive and irreversible accumulation of oxidative damage caused by reactive oxygen species (ROS). This, in turn, has a deleterious impact on molecular mechanisms in aging thereby altering the physiological function of the organism, increasing the risk of different aging-related diseases, as well as impacting the life span. The aim of the current study was to investigate oxidative stress in living red blood cells (RBCs) in human aging as an oxidative stress-related pathological condition. Two-photon laser scanning and light microscopy techniques were applied to analyze the oxidative stress in RBCs and the cell viability. Spectrophotometric analyzes were performed to determine the percentage of RBC hemolysis, activities of superoxide dismutase and catalase in RBCs, as well as the ferroxidase activities of ceruloplasmin in blood plasma samples. The studies included three human aging groups, young, middle-aged, and elderly. According to the results, the two-photon fluorescence of carboxy-DCFDA, indicating the intensity of oxidative stress, significantly increase in RBCs by the increase of age (P < 0.05), and these intensities are in statistically significant positive correlation with age (P < 0.001) and a strong negative correlation (P < 0.05) with the activity of catalase in RBCs and ferroxidase activity of ceruloplasmin in plasma. In conclusion, two-photon fluorescent imaging of oxidative stress in human living RBCs is a valuable and accurate method for the determination of aging processes in humans and can be suggested as a novel indicator for human aging processes in individual aging.
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Zakharyan R, Ghazaryan H, Kocourkova L, Chavushyan A, Mkrtchyan A, Zizkova V, Arakelyan A, Petrek M. Association of Genetic Variants of Dopamine and Serotonin In Schizophrenia. Arch Med Res 2020; 51:13-20. [PMID: 32086104 DOI: 10.1016/j.arcmed.2019.12.011] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2019] [Revised: 11/29/2019] [Accepted: 12/16/2019] [Indexed: 01/03/2023]
Abstract
BACKGROUND Several studies indicated that antipsychotic treatment response and side effect manifestation can be different due to inter-individual variability in genetic variations. AIM OF THE STUDY Here we perform a case-control study to explore a potential association between schizophrenia and variants within the antipsychotic drug molecular targets (DRD1, DRD2, DRD3, HTR2A, HTR6) and metabolizing enzymes (CYP2D6, COMT) genes in Armenian population including also analysis of their possible relationship with disease clinical symptoms. METHODS A total of 18 SNPs was studied in patients with schizophrenia (n = 78) and healthy control subjects (n = 77) using MassARRAY genotyping. RESULTS We found that two studied genetic variants, namely DRD2 rs4436578*C and HTR2A rs6314*A are underrepresented in the group of patients compared to healthy subjects. After the correction for multiple testing, the rs4436578*C variant remained significant while the rs6314*A reported borderline significance. No significant differences in minor allele frequencies for other studied variants were identified. Also, a relationship between the genotypes and age of onset as well as disease duration has been detected. CONCLUSIONS The DRD2 rs4436578*C genetic variant might have protective role against schizophrenia, at least in Armenians.
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Arakelyan A, Nersisyan L, Nikoghosyan M, Hakobyan S, Simonyan A, Hopp L, Loeffler-Wirth H, Binder H. Transcriptome-Guided Drug Repositioning. Pharmaceutics 2019; 11:E677. [PMID: 31842375 PMCID: PMC6969900 DOI: 10.3390/pharmaceutics11120677] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2019] [Revised: 11/17/2019] [Accepted: 12/11/2019] [Indexed: 02/06/2023] Open
Abstract
Drug repositioning can save considerable time and resources and significantly speed up the drug development process. The increasing availability of drug action and disease-associated transcriptome data makes it an attractive source for repositioning studies. Here, we have developed a transcriptome-guided approach for drug/biologics repositioning based on multi-layer self-organizing maps (ml-SOM). It allows for analyzing multiple transcriptome datasets by segmenting them into layers of drug action- and disease-associated transcriptome data. A comparison of expression changes in clusters of functionally related genes across the layers identifies "drug target" spots in disease layers and evaluates the repositioning possibility of a drug. The repositioning potential for two approved biologics drugs (infliximab and brodalumab) confirmed the drugs' action for approved diseases (ulcerative colitis and Crohn's disease for infliximab and psoriasis for brodalumab). We showed the potential efficacy of infliximab for the treatment of sarcoidosis, but not chronic obstructive pulmonary disease (COPD). Brodalumab failed to affect dysregulated functional gene clusters in Crohn's disease (CD) and systemic juvenile idiopathic arthritis (SJIA), clearly indicating that it may not be effective in the treatment of these diseases. In conclusion, ml-SOM offers a novel approach for transcriptome-guided drug repositioning that could be particularly useful for biologics drugs.
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Nersisyan L, Hopp L, Loeffler-Wirth H, Galle J, Loeffler M, Arakelyan A, Binder H. Telomere Length Maintenance and Its Transcriptional Regulation in Lynch Syndrome and Sporadic Colorectal Carcinoma. Front Oncol 2019; 9:1172. [PMID: 31750255 PMCID: PMC6848383 DOI: 10.3389/fonc.2019.01172] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2019] [Accepted: 10/18/2019] [Indexed: 12/14/2022] Open
Abstract
Background: Activation of telomere maintenance mechanisms (TMMs) is a hallmark of most cancers, and is required to prevent genome instability and to establish cellular immortality through reconstitution of capping of chromosome ends. TMM depends on the cancer type. Comparative studies linking tumor biology and TMM have potential impact for evaluating cancer onset and development. Methods: We have studied alterations of telomere length, their sequence composition and transcriptional regulation in mismatch repair deficient colorectal cancers arising in Lynch syndrome (LS-CRC) and microsatellite instable (MSI) sporadic CRC (MSI s-CRC), and for comparison, in microsatellite stable (MSS) s-CRC and in benign colon mucosa. Our study applied bioinformatics analysis of whole genome DNA and RNA sequencing data and a pathway model to study telomere length alterations and the potential effect of the "classical" telomerase (TEL-) and alternative (ALT-) TMM using transcriptomic signatures. Results: We have found progressive decrease of mean telomere length in all cancer subtypes compared with reference systems. Our results support the view that telomere attrition is an early event in tumorigenesis. TMM gets activated in all tumors studied due to concerted overexpression of a large fraction of genes with direct relation to telomere function, where only a very small fraction of them showed recurrent mutations. TEL-related transcriptional state was dominating in all CRC subtypes, showing, however, subtype-specific activation patterns; while contribution of the ALT-TMM was slightly more prominent in the hypermutated MSI s-CRC and LS-CRC. TEL-TMM is mainly activated by over-expression of DKC1 and/or TERT genes and their interaction partners, where DKC1 is more prominent in MSS than in MSI s-CRC and can serve as a transcriptomic marker of TMM activity. Conclusions: Our results suggest that transcriptional patterns are indicative for TMM pathway activation with subtle differences between TEL and ALT mechanisms in a CRC subtype-specific fashion. Sequencing data potentially provide a suited measure to study alterations of telomere length and of underlying transcriptional regulation. Further studies are needed to improve this method.
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Loeffler-Wirth H, Kreuz M, Hopp L, Arakelyan A, Haake A, Cogliatti SB, Feller AC, Hansmann ML, Lenze D, Möller P, Müller-Hermelink HK, Fortenbacher E, Willscher E, Ott G, Rosenwald A, Pott C, Schwaenen C, Trautmann H, Wessendorf S, Stein H, Szczepanowski M, Trümper L, Hummel M, Klapper W, Siebert R, Loeffler M, Binder H. A modular transcriptome map of mature B cell lymphomas. Genome Med 2019; 11:27. [PMID: 31039827 PMCID: PMC6492344 DOI: 10.1186/s13073-019-0637-7] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2018] [Accepted: 04/04/2019] [Indexed: 12/22/2022] Open
Abstract
BACKGROUND Germinal center-derived B cell lymphomas are tumors of the lymphoid tissues representing one of the most heterogeneous malignancies. Here we characterize the variety of transcriptomic phenotypes of this disease based on 873 biopsy specimens collected in the German Cancer Aid MMML (Molecular Mechanisms in Malignant Lymphoma) consortium. They include diffuse large B cell lymphoma (DLBCL), follicular lymphoma (FL), Burkitt's lymphoma, mixed FL/DLBCL lymphomas, primary mediastinal large B cell lymphoma, multiple myeloma, IRF4-rearranged large cell lymphoma, MYC-negative Burkitt-like lymphoma with chr. 11q aberration and mantle cell lymphoma. METHODS We apply self-organizing map (SOM) machine learning to microarray-derived expression data to generate a holistic view on the transcriptome landscape of lymphomas, to describe the multidimensional nature of gene regulation and to pursue a modular view on co-expression. Expression data were complemented by pathological, genetic and clinical characteristics. RESULTS We present a transcriptome map of B cell lymphomas that allows visual comparison between the SOM portraits of different lymphoma strata and individual cases. It decomposes into one dozen modules of co-expressed genes related to different functional categories, to genetic defects and to the pathogenesis of lymphomas. On a molecular level, this disease rather forms a continuum of expression states than clearly separated phenotypes. We introduced the concept of combinatorial pattern types (PATs) that stratifies the lymphomas into nine PAT groups and, on a coarser level, into five prominent cancer hallmark types with proliferation, inflammation and stroma signatures. Inflammation signatures in combination with healthy B cell and tonsil characteristics associate with better overall survival rates, while proliferation in combination with inflammation and plasma cell characteristics worsens it. A phenotypic similarity tree is presented that reveals possible progression paths along the transcriptional dimensions. Our analysis provided a novel look on the transition range between FL and DLBCL, on DLBCL with poor prognosis showing expression patterns resembling that of Burkitt's lymphoma and particularly on 'double-hit' MYC and BCL2 transformed lymphomas. CONCLUSIONS The transcriptome map provides a tool that aggregates, refines and visualizes the data collected in the MMML study and interprets them in the light of previous knowledge to provide orientation and support in current and future studies on lymphomas and on other cancer entities.
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Nikoghosyan M, Hakobyan S, Hovhannisyan A, Loeffler-Wirth H, Binder H, Arakelyan A. Population Levels Assessment of the Distribution of Disease-Associated Variants With Emphasis on Armenians - A Machine Learning Approach. Front Genet 2019; 10:394. [PMID: 31105750 PMCID: PMC6498285 DOI: 10.3389/fgene.2019.00394] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2018] [Accepted: 04/11/2019] [Indexed: 12/25/2022] Open
Abstract
Background: During the last decades a number of genome-wide association studies (GWASs) has identified numerous single nucleotide polymorphisms (SNPs) associated with different complex diseases. However, associations reported in one population are often conflicting and did not replicate when studied in other populations. One of the reasons could be that most GWAS employ a case-control design in one or a limited number of populations, but little attention was paid to the global distribution of disease-associated alleles across different populations. Moreover, the majority of GWAS have been performed on selected European, African, and Chinese populations and the considerable number of populations remains understudied. Aim: We have investigated the global distribution of so far discovered disease-associated SNPs across worldwide populations of different ancestry and geographical regions with a special focus on the understudied population of Armenians. Data and Methods: We have used genotyping data from the Human Genome Diversity Project and of Armenian population and combined them with disease-associated SNP data taken from public repositories leading to a final dataset of 44,234 markers. Their frequency distribution across 1039 individuals from 53 populations was analyzed using self-organizing maps (SOM) machine learning. Our SOM portrayal approach reduces data dimensionality, clusters SNPs with similar frequency profiles and provides two-dimensional data images which enable visual evaluation of disease-associated SNPs landscapes among human populations. Results: We find that populations from Africa, Oceania, and America show specific patterns of minor allele frequencies of disease-associated SNPs, while populations from Europe, Middle East, Central South Asia, and Armenia mostly share similar patterns. Importantly, different sets of SNPs associated with common polygenic diseases, such as cancer, diabetes, neurodegeneration in populations from different geographic regions. Armenians are characterized by a set of SNPs that are distinct from other populations from the neighboring geographical regions. Conclusion: Genetic associations of diseases considerably vary across populations which necessitates health-related genotyping efforts especially for so far understudied populations. SOM portrayal represents novel promising methods in population genetic research with special strength in visualization-based comparison of SNP data.
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Kozachenko A, Akinfiev D, Arakelyan A, Adamyan L. Combined Treatment Techniques in Women with Cervical Ectopic Pregnancy: 58 Cases. J Minim Invasive Gynecol 2018. [DOI: 10.1016/j.jmig.2018.09.131] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Margaryan S, Witkowicz A, Arakelyan A, Partyka A, Karabon L, Manukyan G. sFasL-mediated induction of neutrophil activation in patients with type 2 diabetes mellitus. PLoS One 2018; 13:e0201087. [PMID: 30024959 PMCID: PMC6053218 DOI: 10.1371/journal.pone.0201087] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2018] [Accepted: 07/09/2018] [Indexed: 12/13/2022] Open
Abstract
Fas/Fas ligand system was shown to be related to insulin resistance and type 2 diabetes mellitus (T2DM). However, the role of soluble Fas ligand (sFasL) in functioning of immune cells in type 2 diabetes mellitus (T2DM) has not been studied yet. The aim of the present study was to determine in vitro effects of sFasL on neutrophil activation and apoptosis. We demonstrate here that sFasL exhibited proinflammatory effect and induced mRNA levels of caspase-1, NF-κB, IL-1β and CD18 expression. At the same time, sFasL induced reactive oxygen species (ROS) production. Activation of caspase-1 activity abolished sFasL-dependent apoptosis, and suppressed Fas expression and mRNA levels of caspase-3 in neutrophils from T2DM patients. Collectively, our findings identify a novel proinflammatory role of sFasL in T2DM neutrophils that is dependent of caspase activity. Thus, sFasL enhances inflammatory response of neutrophils from T2DM patients without increasing apoptosis suggesting its triggering role in T2DM inflammation.
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Hopp L, Loeffler-Wirth H, Nersisyan L, Arakelyan A, Binder H. Footprints of Sepsis Framed Within Community Acquired Pneumonia in the Blood Transcriptome. Front Immunol 2018; 9:1620. [PMID: 30065722 PMCID: PMC6056630 DOI: 10.3389/fimmu.2018.01620] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2018] [Accepted: 06/29/2018] [Indexed: 12/14/2022] Open
Abstract
We analyzed the blood transcriptome of sepsis framed within community-acquired pneumonia (CAP) and characterized its molecular and cellular heterogeneity in terms of functional modules of co-regulated genes with impact for the underlying pathophysiological mechanisms. Our results showed that CAP severity is associated with immune suppression owing to T-cell exhaustion and HLA and chemokine receptor deactivation, endotoxin tolerance, macrophage polarization, and metabolic conversion from oxidative phosphorylation to glycolysis. We also found footprints of host's response to viruses and bacteria, altered levels of mRNA from erythrocytes and platelets indicating coagulopathy that parallel severity of sepsis and survival. Finally, our data demonstrated chromatin re-modeling associated with extensive transcriptional deregulation of chromatin modifying enzymes, which suggests the extensive changes of DNA methylation with potential impact for marker selection and functional characterization. Based on the molecular footprints identified, we propose a novel stratification of CAP cases into six groups differing in the transcriptomic scores of CAP severity, interferon response, and erythrocyte mRNA expression with impact for prognosis. Our analysis increases the resolution of transcriptomic footprints of CAP and reveals opportunities for selecting sets of transcriptomic markers with impact for translation of omics research in terms of patient stratification schemes and sets of signature genes.
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Stepanyan A, Zakharyan R, Simonyan A, Tsakanova G, Arakelyan A. Involvement of polymorphisms of the nerve growth factor and its receptor encoding genes in the etiopathogenesis of ischemic stroke. BMC MEDICAL GENETICS 2018; 19:33. [PMID: 29499660 PMCID: PMC5834891 DOI: 10.1186/s12881-018-0551-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/09/2017] [Accepted: 02/23/2018] [Indexed: 11/25/2022]
Abstract
Background Despite the important role of the nerve growth factor in the survival and maintenance of neurons in ischemic stroke, data regarding the relationships between variations in the encoding gene and stroke are lacking. In the present study, we evaluated the association of the functional polymorphisms in NGF (rs6330) and NGFR (rs2072446 and rs734194) genes with ischemic stroke in an Armenian population. Methods In total, 370 unrelated individuals of Armenian nationality were enrolled in this study. Genomic DNA samples of patients and healthy controls were genotyped using polymerase chain reaction with sequence-specific primers. Results The results obtained indicate that the minor allele of rs6330 (Pcorr = 2.4E-10) and rs2072446 (Pcorr = 0.02) are significantly overrepresented in stroke group, while the minor allele of rs734194 (Pcorr = 8.5E-10) was underrepresented in diseased subjects. Single nucleotide polymorphisms in NGF gene (rs6330) and NGFR gene (rs2072446 and rs734194) are associated with the disease. Furthermore, it was shown that the carriage of the NGF rs6330*T minor allele is associated with increased infarct volume and higher risk of recurrent stroke. Conclusions In conclusion, our findings suggest that the NGF rs6330*T and NGFR rs2072446*T minor alleles might be nominated as a risk factor for developing ischemic stroke and NGFR rs734194*G minor allele as a protective against this disease at least in Armenian population.
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Tsakanova G, Arakelova E, Ayvazyan V, Ayvazyan A, Tatikyan S, Aroutiounian R, Dalyan Y, Haroutiunian S, Tsakanov V, Arakelyan A. Two-photon microscopy imaging of oxidative stress in human living erythrocytes. BIOMEDICAL OPTICS EXPRESS 2017; 8:5834-5846. [PMID: 29296508 PMCID: PMC5745123 DOI: 10.1364/boe.8.005834] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/22/2017] [Revised: 11/05/2017] [Accepted: 11/20/2017] [Indexed: 06/07/2023]
Abstract
Red blood cells (RBCs) are known to be the most suitable cells to study oxidative stress, which is implicated in the etiopathology of many human diseases. The goal of the current study was to develop a new effective approach for assessing oxidative stress in human living RBCs using two-photon microscopy. To mimic oxidative stress in human living RBCs, an in vitro model was generated followed by two-photon microscopy imaging. The results revealed that oxidative stress is clearly visible on the two-photon microscopy images of RBCs under oxidative stress compared to no fluorescence in controls (P<0.0001). This novel approach for oxidative stress investigation in human living RBCs could efficiently be applied in clinical research and antioxidant compounds testing.
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Arakelyan A, Nersisyan L, Poghosyan D, Khondkaryan L, Hakobyan A, Löffler-Wirth H, Melanitou E, Binder H. Autoimmunity and autoinflammation: A systems view on signaling pathway dysregulation profiles. PLoS One 2017; 12:e0187572. [PMID: 29099860 PMCID: PMC5669448 DOI: 10.1371/journal.pone.0187572] [Citation(s) in RCA: 50] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2017] [Accepted: 10/23/2017] [Indexed: 12/20/2022] Open
Abstract
INTRODUCTION Autoinflammatory and autoimmune disorders are characterized by aberrant changes in innate and adaptive immunity that may lead from an initial inflammatory state to an organ specific damage. These disorders possess heterogeneity in terms of affected organs and clinical phenotypes. However, despite the differences in etiology and phenotypic variations, they share genetic associations, treatment responses and clinical manifestations. The mechanisms involved in their initiation and development remain poorly understood, however the existence of some clear similarities between autoimmune and autoinflammatory disorders indicates variable degrees of interaction between immune-related mechanisms. METHODS Our study aims at contributing to a holistic, pathway-centered view on the inflammatory condition of autoimmune and autoinflammatory diseases. We have evaluated similarities and specificities of pathway activity changes in twelve autoimmune and autoinflammatory disorders by performing meta-analysis of publicly available gene expression datasets generated from peripheral blood mononuclear cells, using a bioinformatics pipeline that integrates Self Organizing Maps and Pathway Signal Flow algorithms along with KEGG pathway topologies. RESULTS AND CONCLUSIONS The results reveal that clinically divergent disease groups share common pathway perturbation profiles. We identified pathways, similarly perturbed in all the studied diseases, such as PI3K-Akt, Toll-like receptor, and NF-kappa B signaling, that serve as integrators of signals guiding immune cell polarization, migration, growth, survival and differentiation. Further, two clusters of diseases were identified based on specifically dysregulated pathways: one gathering mostly autoimmune and the other mainly autoinflammatory diseases. Cluster separation was driven not only by apparent involvement of pathways implicated in adaptive immunity in one case, and inflammation in the other, but also by processes not explicitly related to immune response, but rather representing various events related to the formation of specific pathophysiological environment. Thus, our data suggest that while all of the studied diseases are affected by activation of common inflammatory processes, disease-specific variations in their relative balance are also identified.
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Binder H, Hopp L, Schweiger MR, Hoffmann S, Jühling F, Kerick M, Timmermann B, Siebert S, Grimm C, Nersisyan L, Arakelyan A, Herberg M, Buske P, Loeffler-Wirth H, Rosolowski M, Engel C, Przybilla J, Peifer M, Friedrichs N, Moeslein G, Odenthal M, Hussong M, Peters S, Holzapfel S, Nattermann J, Hueneburg R, Schmiegel W, Royer-Pokora B, Aretz S, Kloth M, Kloor M, Buettner R, Galle J, Loeffler M. Genomic and transcriptomic heterogeneity of colorectal tumours arising in Lynch syndrome. J Pathol 2017; 243:242-254. [DOI: 10.1002/path.4948] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2017] [Revised: 06/01/2017] [Accepted: 07/14/2017] [Indexed: 12/16/2022]
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Tsakanova G, Stepanyan A, Nahapetyan K, Sim RB, Arakelyan A, Boyajyan A. Serine proteases of the complement lectin pathway and their genetic variations in ischaemic stroke. J Clin Pathol 2017; 71:141-147. [PMID: 28720568 DOI: 10.1136/jclinpath-2017-204403] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2017] [Revised: 05/12/2017] [Accepted: 06/12/2017] [Indexed: 12/19/2022]
Abstract
AIMS The aim of the current study was to assess the proteolytic activities of collectin-bound MASP-1 and MASP-2 in the blood of patients with ischaemic stroke, as well as the association of their six genetic polymorphisms (rs3203210, rs28945070, rs28945073 in MASP1 gene and rs2273343, rs12711521, rs147270785 in MASP2 gene) with this pathology. METHODS In total, 250 patients and 300 healthy subjects were involved in this study. MBL-associated serine protease (MASP)-1 and MASP-2 activities were measured using in-house developed immunofluorescent and enzyme-linked immunosorbent assays, respectively. Sequence specific primer PCR was used to study the association of MASP1 and MASP2 genetic polymorphisms with ischaemic stroke. RESULTS The results obtained demonstrate that the activities of collectin-bound MASP-1 and MASP-2 in patients with ischaemic stroke are significantly higher than those in healthy subjects (p<0.001). According to the data obtained for genotyping, the rs3203210 polymorphism in the MASP1 gene and the rs147270785 polymorphism in the MASP2 gene are associated with ischaemic stroke (p<0.0001). CONCLUSIONS In conclusion we suggest that the complement lectin pathway serine proteases, MASP-1 and MASP-2, can be associated with ischaemic stroke development risk and may participate in pathological events leading to post-ischaemic brain damage. Moreover rs3203210 and rs147270785 single nucleotide polymorphisms in the MASP1 and MASP2 genes, respectively, are strongly associated with ischaemic stroke, and the minor rs3203210*C and rs147270785*A alleles of these polymorphisms may be considered as protective factors for ischameic stroke, at least in the Armenian population.
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Hovhannisyan L, Stepanyan A, Arakelyan A. Genetic variability of interleukin-1 beta as prospective factor from developing post-traumatic stress disorder. Immunogenetics 2017; 69:703-708. [PMID: 28681202 DOI: 10.1007/s00251-017-1016-4] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2017] [Accepted: 06/14/2017] [Indexed: 02/03/2023]
Abstract
Individual susceptibility to post-traumatic stress disorder (PTSD) is conditioned by genetic factors, and association between this disorder and polymorphisms of several genes have been shown. The aim of this study was to explore a potential association between single nucleotide polymorphisms (SNP) of the IL-1β gene (IL1B) and PTSD. In genomic DNA samples of PTSD-affected and healthy subjects, the rs16944, rs1143634, rs2853550, rs1143643, and rs1143633 SNPs of IL1B gene have been genotyped. The results obtained demonstrated that IL1B rs1143633*C and rs16944*A minor allele frequency were significantly lower in patients than in controls. Our results confirm that IL1B rs1143633 and rs16944 SNPs are negatively associated with PTSD which allows us to consider them as protective variants for PTSD. IL1B rs1143633*C and rs16944*A minor allele frequencies and carriage rates are significantly lower in the PTSD patients as compared to the controls. These results may provide a base to conclude that above-mentioned alleles can be protective against PTSD, and IL1B gene can be involved in the pathogenesis of this disorder.
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Khoyetsyan A, Kacimi R, Tsakanova G, Boyajyan A, Arakelyan A, Yenari MA. Activated complement protein C5a does not affect brain-derived endothelial cell viability and zonula occludens-1 levels following oxygen-glucose deprivation. Brain Circ 2017; 3:14-20. [PMID: 30276299 PMCID: PMC6126234 DOI: 10.4103/2394-8108.203258] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2016] [Revised: 12/05/2016] [Accepted: 12/19/2016] [Indexed: 02/07/2023] Open
Abstract
BACKGROUND AND PURPOSE: Ischemic brain injury induces both functional and structural disarray affecting the blood–brain barrier (BBB) which in return aggravates stroke outcomes. Complement system and its bioactive proteins are important molecular responders to ischemia. C5a protein along with its receptor C5a receptor 1 is a key component of this system with potent pro-inflammatory and chemoattractant properties. The purpose of this study is to investigate the role of C5a protein and its receptor which are believed to participate in the inflammatory response that follows ischemic insult. MATERIALS AND METHODS: To mimic an ischemic in vivo event in which C5a may contact brain endothelial cells after injury, we studied oxygen-glucose deprivation (OGD) followed by reperfusion in brain microvascular endothelial cells (b.End. 3) by only added C5a at the time of reperfusion. Cell death and viability were estimated by trypan blue and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assays, respectively. Tight junction protein zonula occluden (ZO-1) levels were analyzed by Western blot analysis, and nitric oxide (NO) was assessed using the Griess reagent. RESULTS: Brain-derived endothelial cell was susceptible to OGD-induced injury in a duration-dependent manner as was the presence of ZO-1 protein. However, the addition of C5a protein had no notable effects even when used at high concentrations up to 100 nM. While OGD led to reduction in ZO-1 protein levels, no change was seen following the addition of C5a. Finally, OGD led unexpectedly to small decreases in NO generation, but this was again unaltered by C5a. CONCLUSIONS: Our study suggests that complement system protein C5a may not have a direct role in the disruption of BBB, following brain ischemia. This is in contrary with previous literature that suggests a possible role of this protein in the inflammatory response to ischemia.
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