Anna Boyajyan

Bio: Anna Boyajyan is an academic researcher from Armenian National Academy of Sciences. The author has contributed to research in topics: Population & Single-nucleotide polymorphism. The author has an hindex of 16, co-authored 65 publications receiving 794 citations. Previous affiliations of Anna Boyajyan include National Academy of Sciences & Yerevan State Medical University.

Serum levels of the MCP-1 chemokine in patients with ischemic stroke and myocardial infarction.

Abstract: Chemokine-driven migration of inflammatory cells has been implicated in pathogenesis of atherosclerosis-associated conditions such as ischemic stroke and myocardial infarction. In this study, a candidate chemokine, monocyte chemoattractant protein (MCP)-1, was investigated in patients with both aforementioned manifestations of atheroslerotic inflammation. MCP-1 levels in serum were determined by ELISA in 40 healthy, control subjects (C), 40 patients with ischemic stroke (IS), and in 64 patients with myocardial infarction (MI). Statistical analysis utilised Mann-Whitney test, Fisher's exact test, and Spearman's rank correlation (P < .05). In comparison to control subjects (C; median/interquartile range: 239/126 pg/mL), MCP-1 serum levels were increased in both investigated patient cohorts (IS: 384/370, P < .001; MI: 360/200, P < .002). There was a substantial variability of MCP-1 serum levels, especially in the IS group. No relationship was observed between chemokine levels and atherosclerosis risk factors (hypertension, diabetes, smoking, and alcohol consumption), and MCP-1 was also not related to age or gender. Elevation of MCP-1 in circulation of patients with atherosclerosis-associated complications implicates this CC chemokine ligand (CCL)2 in inflammatory processes, which contribute to pathogenesis of myocardial infarction and ischemic stroke. Further investigations, including patient stratification, are however necessary to evaluate if MCP-1 can be utilised for clinical management of patients with these diseases.

Interleukin-6 promoter polymorphism and plasma levels in patients with schizophrenia.

Abstract: Schizophrenia is a severe psychiatric disease with inflammatory component. Several studies indicated the increased blood levels of proinflammatory interleukin-6 cytokine in schizophrenia. However, only limited studies explored the relationship between excess production and genetic variations of this cytokine in schizophrenia, and the results were controversial. Here, we investigated possible association of the interleukin-6 gene (IL6) rs1800795 (-174G/C) polymorphism with schizophrenia and relationship between this polymorphism and interleukin-6 protein (IL-6) blood levels. This polymorphism was found by other researchers to associate with different transcription rates and different plasma levels of IL-6. A total of 208 unrelated Armenians were genotyped by polymerase chain reaction with sequence-specific primers, and IL-6 levels were assessed by enzyme-linked immunosorbent assay. The IL6 rs1800795 alleles and genotypes in both groups were in Hardy-Weinberg (H-W) equilibrium. We found that rs1800795*C allele [38% vs 24%, P = 0.002, odds ratio (OR) = 1.95, 95% confidence interval (CI): 1.18-2.14] and its carriers (62% vs 42%, P = 0.003, OR = 2.28, 95% CI: 1.13-1.94) were more frequent in patients than in controls. IL-6 in patients was 1.5-fold higher than in controls (mean ± SD: 6.41 ± 2.47 pg/ml vs 4.15 ± 1.42 pg/ml, P = 1.9E-19). In both groups, higher IL-6 in rs1800795 GG compared to rs1800795*C allele carriers was observed (GG vs GC + CC, patients: 7.02 ± 2.83 pg/ml vs 5.39 ± 1.2 pg/ml, P = 0.0006; controls: 5.21 ± 1.17 pg/ml vs 3.38 ± 1.03 pg/ml, P = 1.6E-15). In conclusion, we report an association of IL6 rs1800795 and higher IL-6 with schizophrenia. We also conclude that IL6 rs1800795*C allele is linked to increased IL-6 blood levels and may be a risk factor for schizophrenia development at least in Armenian population.

Inflammatory cytokine network in schizophrenia

Abstract: Objectives. The purpose of this review is to analyse, sum up and discuss the available literature on the role of inflammation and inflammatory cytokines in the pathogenesis of schizophrenia. Methods. An electronic literature search of peer-reviewed English language articles using Pubmed was undertaken. These articles together with those published by us provided the background for the present review. Results. An overview of the available literature on this issue clearly demonstrated the alterations in mRNA and protein expression levels of several proinflammatory and chemotactic cytokines in patients with schizophrenia. Importantly, some of these changes are genetically determined. It was noteworthy that, depending on the study population, some variations of the data obtained are detected. Conclusions. Altered inflammatory cytokine production, both genetically and environmentally determined, is implicated in schizophrenia and contributes to disease-associated low-grade systemic inflammation. Proinfl...

Complement: a key system for immune surveillance and homeostasis

Abstract: Nearly a century after the significance of the human complement system was recognized, we have come to realize that its functions extend far beyond the elimination of microbes. Complement acts as a rapid and efficient immune surveillance system that has distinct effects on healthy and altered host cells and foreign intruders. By eliminating cellular debris and infectious microbes, orchestrating immune responses and sending 'danger' signals, complement contributes substantially to homeostasis, but it can also take action against healthy cells if not properly controlled. This review describes our updated view of the function, structure and dynamics of the complement network, highlights its interconnection with immunity at large and with other endogenous pathways, and illustrates its multiple roles in homeostasis and disease.

Schizophrenia risk from complex variation of complement component 4

Abstract: Schizophrenia is a heritable brain illness with unknown pathogenic mechanisms. Schizophrenia's strongest genetic association at a population level involves variation in the major histocompatibility complex (MHC) locus, but the genes and molecular mechanisms accounting for this have been challenging to identify. Here we show that this association arises in part from many structurally diverse alleles of the complement component 4 (C4) genes. We found that these alleles generated widely varying levels of C4A and C4B expression in the brain, with each common C4 allele associating with schizophrenia in proportion to its tendency to generate greater expression of C4A. Human C4 protein localized to neuronal synapses, dendrites, axons, and cell bodies. In mice, C4 mediated synapse elimination during postnatal development. These results implicate excessive complement activity in the development of schizophrenia and may help explain the reduced numbers of synapses in the brains of individuals with schizophrenia.

Relative Quantification of Proteins in Human Cerebrospinal Fluids by MS/MS Using 6-Plex Isobaric Tags

Abstract: A new 6-plex isobaric mass tagging technology is presented, and proof of principle studies are carried out using standard protein mixtures and human cerebrospinal fluid (CSF) samples. The Tandem Mass Tags (TMT) comprise a set of structurally identical tags which label peptides on free amino-terminus and epsilon-amino functions of lysine residues. During MS/MS fragmentation, quantification information is obtained through the losses of the reporter ions. After evaluation of the relative quantification with the 6-plex version of the TMT on a model protein mixture at various concentrations, the quantification of proteins in CSF samples was performed using shotgun methods. Human postmortem (PM) CSF was taken as a model of massive brain injury and comparison was carried out with antemortem (AM) CSF. After immunoaffinity depletion, triplicates of AM and PM CSF pooled samples were reduced, alkylated, digested by trypsin, and labeled, respectively, with the six isobaric variants of the TMT (with reporter ions from...

Increased inflammatory markers identified in the dorsolateral prefrontal cortex of individuals with schizophrenia

Abstract: Upregulation of the immune response may be involved in the pathogenesis of schizophrenia with changes occurring in both peripheral blood and brain tissue. To date, microarray technology has provided a limited view of specific inflammatory transcripts in brain perhaps due to sensitivity issues. Here we used SOLiD Next Generation Sequencing to quantify neuroimmune mRNA expression levels in the dorsolateral prefrontal cortex of 20 individuals with schizophrenia and their matched controls. We detected 798 differentially regulated transcripts present in people with schizophrenia compared with controls. Ingenuity pathway analysis identified the inflammatory response as a key change. Using quantitative real-time PCR we confirmed the changes in candidate cytokines and immune modulators, including interleukin (IL)-6, IL-8, IL-1β and SERPINA3. The density of major histocompatibility complex-II-positive cells morphologically resembling microglia was significantly increased in schizophrenia and correlated with IL-1β expression. A group of individuals, most of whom had schizophrenia, were found to have increased inflammatory mRNA expression. In summary, we have demonstrated changes in an inflammatory response pathway that are present in ∼40% of people diagnosed with schizophrenia. This suggests that therapies aimed at immune system attenuation in schizophrenia may be of direct benefit in the brain.