Monocyte chemoattractant protein-1 in schizophrenia: −2518A/G genetic variant and protein levels in Armenian population

Association between the MCP-1 -2518 A > G (rs1024611) polymorphism and susceptibility to type 2 diabetes mellitus and diabetic nephropathy: a meta-analysis

BACKGROUND

Studies evaluating the association between monocyte chemoattractant protein-1 (MCP-1) -2518 A > G (rs1024611) polymorphism and type 2 diabetes mellitus (T2DM) and diabetic nephropathy (DN) are contradictory. The present study aims to provide a comprehensive assessment and more reliable estimation of the relationship between the MCP-1 rs1024611 polymorphism and T2DM and DN risk.

METHODS

Eligible articles were retrieved from the PubMed, Web of Science, EMBASE, Cochrane, and China National Knowledge Infrastructure databases. The effect summary odds ratios (ORs) and 95% confidence intervals (CIs) were obtained to calculate the summary effect size. Heterogeneity was analyzed by subgroup analysis and meta-regression. Publication bias was tested using funnel plots and Egger's test.

RESULTS

In total, sixteen studies were included. Thirteen studies involving 2,363 patients with T2DM and 4,650 healthy controls found no significant association between the MCP-1 rs1024611 polymorphism and T2DM in the overall population. Ethnicity stratification found an association between the GG + GA genotype and decreased T2DM risk in Caucasians (OR = 0.79, 95% CI: 0.66-0.93, P = 0.006; PQ = 0.372). No significant risks were found in the Asian population for any genetic models. Seven studies found an association between the GG + GA genotype and DN risk in the Asian population (OR = 1.37, 95% CI: 1.11-1.71, P = 0.004, PQ = 0.222). No significant risks were found in the Caucasian population with any genetic models. There were no statistically significant differences in genotype distribution between patients with T2DM and DN in Asians or Caucasians. Meta-regression revealed that genotyping method was a major driver of heterogeneity in five genetic models (GG + GA vs. AA: P = 0.032; GG vs. GA + AA: P = 0.028; GG vs. AA: P = 0.035; GG vs. GA: P = 0.041; G vs. A: P = 0.041).

CONCLUSION

The MCP-1 rs1024611 polymorphism is associated with susceptibility to T2DM in Caucasians and DN in Asians. Larger, well-designed cohort studies are needed in the future to verify this association.

Chemokine Dysregulation and Neuroinflammation in Schizophrenia: A Systematic Review

Chemokines are known to be immunoregulatory proteins involved not only in lymphocyte chemotaxis to the site of inflammation, but also in neuromodulation, neurogenesis, and neurotransmission. Multiple lines of evidence suggest a peripheral proinflammatory state and neuroinflammation in at least a third of patients with schizophrenia. Therefore, chemokines can be active players in these processes. In this systematic review, we analyzed the available data on chemokine dysregulation in schizophrenia and the association of chemokines with neuroinflammation. It has been shown that there is a genetic association of chemokine and chemokine receptor gene polymorphisms in schizophrenia. Besides, the most reliable data confirmed by the results of meta-analyses showed an increase in CXCL8/IL-8, CCL2/MCP-1, CCL4/MIP-1β, CCL11/eotaxin-1 in the blood of patients with schizophrenia. An increase in CXCL8 has been found in cerebrospinal fluid, but other chemokines have been less well studied. Increased/decreased expression of genes of chemokine and their receptors have been found in different areas of the brain and peripheral immune cells. The peripheral proinflammatory state may influence the expression of chemokines since their expression is regulated by pro- and anti-inflammatory cytokines. Mouse models have shown an association of schizophrenia with dysregulation of the CX3CL1-CX3CR1 and CXCL12-CXCR4 axes. Altogether, dysregulation in chemokine expression may contribute to neuroinflammation in schizophrenia. In conclusion, this evidence indicates the involvement of chemokines in the neurobiological processes associated with schizophrenia.

Immune-Related Genomic Schizophrenic Subtyping Identified in DLPFC Transcriptome

Well-documented evidence of the physiologic, genetic, and behavioral heterogeneity of schizophrenia suggests that diagnostic subtyping may clarify the underlying pathobiology of the disorder. Recent studies have demonstrated that increased inflammation may be a prominent feature of a subset of schizophrenics. However, these findings are inconsistent, possibly due to evaluating schizophrenics as a single group. In this study, we segregated schizophrenic patients into two groups (“Type 1”, “Type 2”) by their gene expression in the dorsolateral prefrontal cortex and explored biological differences between the subgroups. The study included post-mortem tissue samples that were sequenced in multiple, publicly available gene datasets using different sequencing methods. To evaluate the role of inflammation, the expression of genes in multiple components of neuroinflammation were examined: complement cascade activation, glial cell activation, pro-inflammatory mediator secretion, blood–brain barrier (BBB) breakdown, chemokine production and peripheral immune cell infiltration. The Type 2 schizophrenics showed widespread abnormal gene expression across all the neuroinflammation components that was not observed in Type 1 schizophrenics. Our results demonstrate the importance of separating schizophrenic patients into their molecularly defined subgroups and provide supporting evidence for the involvement of the immune-related pathways in a schizophrenic subset.

The Role of CCL2/CCR2 Axis in Cerebral Ischemia-Reperfusion Injury and Treatment: From Animal Experiments to Clinical Trials

C-C motif chemokine ligand 2 (CCL2) is a member of the monocyte chemokine protein family, which binds to its receptor CCR2 to induce monocyte infiltration and mediate inflammation. The CCL2/CCR2 signaling pathway participates in the transduction of neuroinflammatory information between all types of cells in the central nervous system. Animal studies and clinical trials have shown that CCL2/CCR2 mediate the pathological process of ischemic stroke, and a higher CCL2 level in serum is associated with a higher risk of any form of stroke. In the acute phase of cerebral ischemia-reperfusion, the expression of CCL2/CCR2 is increased in the ischemic penumbra, which promotes neuroinflammation and enhances brain injury. In the later phase, it participates in the migration of neuroblasts to the ischemic area and promotes the recovery of neurological function. CCL2/CCR2 gene knockout or activity inhibition can reduce the nerve inflammation and brain injury induced by cerebral ischemia-reperfusion, suggesting that the development of drugs regulating the activity of the CCL2/CCR2 signaling pathway could be used to prevent and treat the cell injury in the acute phase and promote the recovery of neurological function in the chronic phase in ischemic stroke patients.

The Transcriptome and Methylome of the Developing and Aging Brain and Their Relations to Gliomas and Psychological Disorders

Mutually linked expression and methylation dynamics in the brain govern genome regulation over the whole lifetime with an impact on cognition, psychological disorders, and cancer. We performed a joint study of gene expression and DNA methylation of brain tissue originating from the human prefrontal cortex of individuals across the lifespan to describe changes in cellular programs and their regulation by epigenetic mechanisms. The analysis considers previous knowledge in terms of functional gene signatures and chromatin states derived from independent studies, aging profiles of a battery of chromatin modifying enzymes, and data of gliomas and neuropsychological disorders for a holistic view on the development and aging of the brain. Expression and methylation changes from babies to elderly adults decompose into different modes associated with the serial activation of (brain) developmental, learning, metabolic and inflammatory functions, where methylation in gene promoters mostly represses transcription. Expression of genes encoding methylome modifying enzymes is very diverse reflecting complex regulations during lifetime which also associates with the marked remodeling of chromatin between permissive and restrictive states. Data of brain cancer and psychotic disorders reveal footprints of pathophysiologies related to brain development and aging. Comparison of aging brains with gliomas supports the view that glioblastoma-like and astrocytoma-like tumors exhibit higher cellular plasticity activated in the developing healthy brain while oligodendrogliomas have a more stable differentiation hierarchy more resembling the aged brain. The balance and specific shifts between volatile and stable and between more irreversible and more plastic epigenomic networks govern the development and aging of healthy and diseased brain.

Quantile-specific heritability of monocyte chemoattractant protein-1, and relevance to rs1024611-disease interactions

BACKGROUND

Monocyte chemoattractant protein-1 (MCP-1) concentrations are 34% to 47% heritable. Larger -2518 G/A (rs1024611) genotypes differences are reported for: 1) MCP-1 production in stimulated vs. basal cells; and 2) MCP-1 concentrations in diseased (sepsis, brain abscess, hepatitis B virus, Alzheimer's disease, Behcet's disease, and systemic lupus erythematosus) vs. healthy patients. Those results suggest that the -2518 G/A effect size may depend on whether the phenotype is high or low relative to its distribution (quantile-dependent expressivity).

METHOD

To test whether quantile-dependent expressivity applies more broadly to genetic influences on MCP-1 concentrations, quantile-specific offspring-parent (β_OP) and full-sib regression slopes (β_FS) were estimated by applying quantile regression to the age- and sex-adjusted serum MCP-1 concentrations of Framingham Heart Study families. Quantile-specific heritabilities were calculated as h² = 2β_OP/(1 + r_spouse) and h²={(1 + 8r_spouseβ_FS)^0.5-1}/(2r_spouse)).

RESULTS

Heritability (h² ± SE) of MCP-1 concentrations increased from 0.15 ± 0.05 at the 10th percentile of the MCP-1 distribution, 0.23 ± 0.04 at the 25th, 0.32 ± 0.05 at the 50th, 0.43 ± 0.07 at the 75th, and 0.44 ± 0.07 at the 90th percentile, or an 0.0041 ± 0.0009 increase for each one-percent increment in the MCP-1 distribution (P_{linear trend} = 2.4 × 10^-5) when estimated from β_OP, and (P_{linear trend} = 7.7 × 10^-9) when estimated from β_FS. Compared to the 10th percentile, β_OP-estimated h² was 3-fold greater at the 90th percentile (P_difference = 0.0003), and 6.9-fold greater when estimated from β_FS (P_difference = 3.3 × 10^-6). Re-analysis of in vivo comparison of MCP-1 concentrations in controls vs. patients with MCP-1-elevating conditions, and in vitro studies of MCP-1 production in basal vs. stimulated cells, show rs1024611 genotypes differences that were consistent with quantile-dependent expressivity.

CONCLUSION

The heritability of circulating MCP-1 concentrations is quantile-dependent.

A pilot study of biomarkers of oxidative stress in serum and schizophrenia

Increasing evidence indicates that oxidative damage and inflammation is present in patients with schizophrenia. In this study, we investigated the association between the serum concentrations of four typical oxidative stress and inflammatory biomarkers (monocyte chemotactic protein-1, heme oxygenase-1, interleukin-8, and 8-Hydroxydeoxyguanine) and schizophrenia using a case-control study design. In total, 44 patients with schizophrenia and 45 normal controls from Shandong Province, China were recruited. Fasting blood samples were collected from all participants and the serum concentration of the four biomarkers were analyzed by Enzyme-linked immunosorbent assay. The concentrations of monocyte chemotactic protein-1 and interleukin-8 were significantly higher in the patients than in the controls, while there was no significant difference in the serum concentrations of heme oxygenase-1 and 8-Hydroxydeoxyguanine. Moreover, the serum concentrations of monocyte chemotactic protein-1 and interleukin-8 in patients were positively correlated with severity of clinical symptoms. Dose-response relationships between serum biomarker concentrations and schizophrenia were observed. This study suggests that levels of monocyte chemotactic protein-1 and interleukin-8 are increased in patients with schizophrenia and correlated with positive symptom severity.

Protective Effect of the MCP-1 Gene Haplotype against Schizophrenia

While cytokines and their genetic variants have been intensively studied in schizophrenia, little attention has been focused on chemokines in the last years. The monocyte chemoattractant protein 1 (MCP-1) is known to attract peripheral monocytes to the brain during an inflammatory reaction and to affect the T helper (Th) cell development by stimulating Th2 polarization. Owing to the neuroinflammation in schizophrenia and the variable level of MCP-1 in these patients' sera, we proposed to analyze the impact of functional genetic variants of the MCP-1 gene (MCP-1-2518A/G (rs1024611), MCP-1-362G/C (rs2857656), and MCP-1 int1del554-567 (rs3917887)) in schizophrenic patients. We conducted a case-control study on a Tunisian population composed of 200 patients and 200 controls using RFLP-PCR. Our results indicated that the minor alleles (-2518G and Del554-567) were significantly more prevalent in controls than in patients (P=0.001/adjusted OR = 0.42, P=0.04/adjusted OR = 0.64), whereas, for -362C minor allele, increased risk of schizophrenia was revealed (P=0.001, adjusted OR = 2.38). In conclusion, we have identified the haplotype combination -2581G/-362G/int1del554-567 that could mediate protection against schizophrenia (P=0.0038, OR = 0.19) and the effect could result more strongly from the MCP-1 -2582G with -362G variants, whereas the effect of int1del554-567 may in part be explained by its LD with -362.

Association between MCP-1 2518 A>G gene polymorphism and chronic kidney disease

Monocyte chemoattractant protein-1 (MCP-1) is involved in the pathogenesis of chronic kidney diseases (CKD). MCP-1 2518 A>G gene polymorphism is associated with MCP-1 status. We performed a meta-analysis to assess the association between MCP-1 2518 A>G gene polymorphism and CKD risk. The eligible studies regarding the relationship between MCP-1 2518 A>G gene polymorphism and CKD risk were searched through electronic databases. The pooled odds ratios (ORs) and its 95% confidence intervals (CIs) were calculated by using a fixed-effects model, or in the presence of heterogeneity, a random-effects model. A total of 2415 cases and 2011 controls were recruited in our investigation. A allele/GG genotype was not associated with CKD risk in overall populations, Asians, Caucasians, and Africans. AA/AG genotype was not associated with the risk of CKD in overall populations, Asians, Caucasians, and Africans. AA genotype was associated with a lower risk of CKD in Caucasians (OR 0.816, 95% CI 0.703-0.947). AG genotype was associated with a higher risk of CKD in Caucasians (OR 1.230, 95% CI 1.042-1.452). There was no marked publication bias. In conclusion, AA genotype may be a protective factor against CKD susceptibility in Caucasians. AG genotype may be a risk factor for CKD risk in Caucasians. However, more studies are needed in the future.

Profiling inflammatory signatures of schizophrenia: A cross-sectional and meta-analysis study

We aimed to profile a broad panel of inflammatory markers in patients with schizophrenia and healthy controls. Additionally, we performed a meta-analysis of chemokine alterations that have not been subjected to quantitative synthesis so far. We recruited 78 patients with schizophrenia and 78 healthy controls, and measured inflammatory markers using the Luminex technology. After adjustment for multiple testing, we found elevated levels of interleukin (IL)-1 receptor antagonist (IL-1RA), IL-6, IL-7, IL-8, IL-9, IL-10, IL-13, interferon-γ, eotaxin-1, granulocyte-macrophage colony-stimulating factor (GM-CSF), monocyte chemoattractant protein-1 (MCP-1), platelet-derived growth factor with two B subunits (PDGF-BB), macrophage inflammatory protein (MIP)-1α, MIP-1β, vascular endothelial growth factor A (VEGF-A) and RANTES in multiple-episode schizophrenia (MES) patients. These differences, except for the difference in eotaxin-1 levels, appeared to be significant after co-varying for the dosage of antipsychotics. There were no significant differences in the levels of immune markers between first-episode schizophrenia (FES) patients and controls. Our meta-analysis revealed elevated levels of MCP-1 in first-episode psychosis (FEP) patients and MES individuals. Other chemokine alterations (elevated levels of IL-8, eotaxin-1 and MIP-1β) were present only in MES patients. Our results indicate that dysregulation of immune response in schizophrenia develops with illness progression or appears as a long-term medication effect. Chemokine alterations are another example of aberrant immune response in schizophrenia patients. Elevated levels of MCP-1 might represent trait markers since these alterations were found in FEP and MES patients. Other chemokine alterations might be the markers of disease progression or might represent medication effects.

Association of CCL11 promoter polymorphisms with schizophrenia in a Korean population

BACKGROUND

Immunological alterations and dysregulation of the inflammatory response have been suggested to play a crucial role in schizophrenia pathophysiology. Growing evidence supports the involvement of chemokines in brain development, thus many chemokines have been studied in relation with schizophrenia. The C-C motif chemokine ligand 11 (CCL11) has been shown to be related with synaptic plasticity and neurogenesis. Moreover, altered levels of CCL11 have been observed in schizophrenia patients. Therefore, we examined whether single nucleotide polymorphisms (SNPs) of the CCL11 in the promoter region contribute to susceptibility to schizophrenia.

METHODS

Four promoter SNPs [rs17809012 (-384T>C), rs16969415 (-426C>T), rs17735961 (-488C>A), and rs4795896 (576G>A)] were genotyped in 254 schizophrenia patients and 405 control subjects using Fluidigm SNPtype assays.

RESULTS

The genotype frequency of CCL11 rs4795896 (-576G>A) showed significant association with schizophrenia in a recessive model (AA vs. GG/AG, p < 0.0001) and in a log-additive model (AG vs. AA vs. GG, p < 0.0001). The allele frequency of rs4795896 also showed a significant association with schizophrenia (p < 0.0001). Furthermore, haplotype analysis revealed that GCT, ACT, and GCC haplotypes containing rs4795896, rs17735961 and rs17809012 were significantly associated with schizophrenia (p = 0.0044, p < 0.0001, and p < 0.0001, respectively).

CONCLUSION

Our results suggest that CCL11 promotor polymorphism is associated with increased risk for the development of schizophrenia in a Korean population.

Cannabinoid receptors on peripheral leukocytes from patients with schizophrenia: Evidence for defective immunomodulatory mechanisms

OBJECTIVES

to evaluate cannabinoid receptors (CBRs) expression on peripheral immune cells, i.e., blood monocytes, neutrophils, lymphocytes, and NK cells, and their relationship to a wide range of serum cytokine levels in subjects with schizophrenia and controls.

METHODS

A sample of 55 people with chronic schizophrenia and 48 controls were enrolled in the study. The expression of the cannabinoid receptors CB1R and CB2R was evaluated in peripheral blood leukocytes by flow cytometry. Serum levels of cytokines/chemokines were simultaneously analyzed by cytometric bead array.

RESULTS

We found higher expression of cannabinoid receptors on cells of the innate immune system in subjects with schizophrenia when compared with controls. Serum levels of interleukin-4 (IL-4), IL-6, IL-10, IL-17, interferon (IFN-γ), and (C-X-C motif) ligand 10/interferon gamma-induced protein 10 (CXCL10/IP10) were decreased, while levels of the chemokine (C-C motif) ligand 2/monocyte chemoattractant protein-1 (CCL2/MCP-1) were increased in the schizophrenia group in comparison with controls. Patients with schizophrenia showed simpler correlation network between cytokines and CBRs expression than controls.

CONCLUSION

Patients with schizophrenia showed increased CBRs expression in cells of the innate immune system and simpler correlation network between cytokines and CBRs expression when compared with controls. These results suggest a defective endocannabinoid system-mediated immunomodulation in patients with schizophrenia.

Abnormalities in chemokine levels in schizophrenia and their clinical correlates

Chemokines are promising biomarkers of immune activation and inflammation, but evidence for chemokine abnormalities in schizophrenia and their relationship to clinical factors remains inconclusive. We aimed to understand chemokine-related diagnostic differences and clinical correlates using a comprehensive panel and studying a large, well-characterized sample of adults with and without schizophrenia. We studied 134 outpatients with schizophrenia or schizoaffective disorder and 112 healthy comparison (HC) individuals, 26 to 65years of age. Clinical measures were obtained, and plasma levels of 11 chemokines were assessed using multiplex immunoassay. Schizophrenia vs. HC differences were tested for each chemokine, adjusting for age, gender, body mass index, and current smoking status. We also examined whether age and gender relationships differed between diagnostic groups. Using logistic regression, we created a Chemokine Index (CI) and explored its clinical correlates. Levels of monocyte chemoattractant protein-1 (MCP-1/CCL2), macrophage inflammatory protein-1β (MIP-1β/CCL4), Eotaxin-1 (CCL11), thymus and activation-regulated chemokine (TARC/CCL17), and macrophage-derived chemokine (MDC/CCL22) were significantly higher in persons with schizophrenia than HCs. Group differences in TARC were reduced after adjusting for covariates. The CI, a linear combination of Eotaxin-1 and MDC levels, was positively associated with age, duration of schizophrenia, and severity of negative symptoms. Levels of chemokines with neuroimmune regulatory effects were higher in individuals with schizophrenia, particularly in older and chronic patients. Treatments aimed at normalizing chemokine levels might improve mental and physical health among schizophrenia patients as they age.

Meta-Analysis of Cytokine and Chemokine Genes in Schizophrenia

INTRODUCTION

Immune system genes, including cytokines, are associated with schizophrenia risk. Polymorphisms in cytokine genes may also impact on blood levels of cytokines, which are altered in patients with schizophrenia. We performed a meta-analysis of case-control studies of cytokine and chemokine genes in schizophrenia that have not been considered in previous quantitative reviews.

METHODS

We identified articles by systematic searches of PubMed, PsycInfo, and ISI, and the reference lists of identified studies. For each cytokine or chemokine polymorphism, we performed an allele- and genotype-wise meta-analysis, using a random effects model.

RESULTS

Twenty-one independent studies met the inclusion criteria, comprising polymorphisms for the IL1B, IL2, IL4, IL6, sIL6R, MCP1, and TGFB1 genes. For IL6, the A allele (OR=0.95, 95% CI 0.91-0.99) and AA genotype (OR=0.65, 95% CI 0.50-0.85) for the rs1800795 polymorphism, and for sIL6R, the A allele (OR=0.96 95%, CI 0.92-1.00) and AA genotype (OR=0.72, 95% CI 0.55-0.94) the rs8192284 polymorphism were associated with significantly decreased schizophrenia risk. In the genotype-wise analysis for IL1B, homozygosity for either allele (AA: OR=1.91, 95% CI 1.60-2.27; and GG: OR=0.40, 95% CI 0.33-0.49) of the rs1143627 polymorphism was also significantly associated with schizophrenia risk.

CONCLUSIONS

Associations between polymorphisms for the IL1B, IL6, and sIL6R genes and schizophrenia risk complement and extend previous findings regarding immune dysfunction in this disorder, including genome-wide association studies. Future studies of cytokine expression in schizophrenia should consider the effect of these polymorphisms. The finding of potential "protective" alleles may also be relevant for at-risk populations.

Inflammatory cytokine network in schizophrenia

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. Proinflammatory and chemotactic cytokines and their receptors may represent additional therapeutic targets for treatment of schizophrenia.

Chemokines and chemokine receptors in mood disorders, schizophrenia, and cognitive impairment: a systematic review of biomarker studies

The search for immune biomarkers in psychiatric disorders has primarily focused on pro-inflammatory cytokines. Other immune proteins including chemokines have been relatively neglected in such studies. Recent evidence has implicated chemokines in many neurobiological processes potentially relevant to psychiatric disorders, beyond their classical chemotactic functions. These may include neuromodulator effects, neurotransmitter-like effects, and direct/indirect regulation of neurogenesis. This systematic review presents the existing early evidence which supports an association of many chemokines with the psychiatric disorders: depression, bipolar disorder, schizophrenia, mild cognitive impairment and Alzheimer's disease. The non-specific association of chemokines including CXCL8 (IL-8), CCL2 (MCP-1), CCL3 (MIP-1α) and CCL5 (RANTES) with these disorders across diagnostic categories implies a generalised involvement of many chemokine systemic with psychiatric disease. Additional chemokines with great mechanistic relevance including CXCL12 (SDF-1) and CX3CL1 (fractalkine) have been rarely reported in the existing human literature and should be included in future clinical studies. The potential utility of these proteins as pathologically relevant biomarkers or therapeutic targets should be considered by future clinical and translational research.

Role of immunological factors in the pathophysiology and diagnosis of bipolar disorder: comparison with schizophrenia

Several lines of evidence point to the key role of neurobiological mechanisms and shared genetic background in schizophrenia and bipolar disorder. For both disorders, neurodevelopmental and neurodegenerative processes have been postulated to be relevant for the pathogenesis as well as dysregulation of immuno-inflammatory pathways. Inflammation is a complex biological response to harmful stimuli and it is mediated by cytokines cascades, cellular immune responses, oxidative factors and hormone regulation. Cytokines, in particular, are supposed to play a critical role in infectious and inflammatory processes, mediating the cross-talk between the brain and the immune system; they also possibly contribute to the development of the central nervous system. From this perspective, even though mixed results have been reported, it seems that both schizophrenia and bipolar disorder are associated with an imbalance in inflammatory cytokines; in fact, some of these could represent biological markers of illness and could be possible targets for pharmacological treatments. In light of these considerations, the purpose of the present paper was to provide a comprehensive and critical review of the existing literature about immunological abnormalities in bipolar disorder with particular attention to the similarities and differences with schizophrenia.

Functional genetic polymorphisms of monocyte chemoattractant protein 1 and C-C chemokine receptor type 2 in ischemic stroke

Recent findings indicated that monocyte chemoattractant protein 1 (MCP1) and its C-C chemokine receptor type 2 (CCR2) play a key role in ischemic stroke (IS) progression. This study was aimed at evaluating the potential association of the MCP1 gene (MCP1) rs1024611 (-2518 A>G) and CCR2 gene (CCR2) rs1799864 (V64I; 190 G>A) functional single nucleotide polymorphisms (SNPs) with IS in the Armenian population. For the purpose of this study, genomic DNA samples of 100 patients with the first-episode IS and 115 healthy subjects (controls) were genotyped for the selected SNPs using a polymerase chain reaction with sequence-specific primers. The results obtained demonstrated that while the CCR2 rs1799864 SNP genotypes were equally distributed among patients and controls, the frequency and carriage rate of the of the MCP1 rs1024611*G minor allele were higher in patients. While a potential association between IS and CCR2 rs1799864 SNP was evaluated for the first time, the latest finding was in agreement with the earlier data reported for some other populations. In summary, this study revealed no association of CCR2 rs1799864 SNP with IS, and a positive association between G minor allele of MCP1 rs1024611 SNP and IS in the Armenian population. Based on the present and earlier reported data, we concluded that the minor G allele of the MCP1 rs1024611 SNP might be considered a risk factor for IS.