Burcu Bayoglu

Evaluation of association between common genetic variants on chromosome 9p21 and coronary artery disease in Turkish population

Objective: Coronary artery disease (CAD), which develops from complex interactions between genetic and enviromental factors, is a leading cause of death worldwide. Based on genome-wide association studies (GWAS), the chromosomal region 9p21 has been identified as the most relevant locus presenting a strong association with CAD in different populations. The aim of the present study was to investigate the association of two SNPs on chromosome 9p21 on susceptibility to CAD and the effect of these SNPs along with cardiovascular risk factors on the severity of CAD in the Turkish population. Methods: This study had an observational case-control design. We genotyped 460 subjects, aged 30-65 years, to investigate the association of 2 SNPs (rs1333049, rs2383207) on chromosome 9p21 and CAD risk in Turkish population. Real-time polymerase chain reaction (RT-PCR) was used to analyze the 2 SNPs in CAD patients and healthy controls. The genotype and allelic variations of these SNPs with the severity of CAD was also assessed using semi-quantitative methods such as the Gensini score. Student’s t test and multiple regression analysis were used for statistical analysis. Results: The SNPs rs1333049 and rs2383207 were found to be associated with CAD with an adjusted OR of 1.81 (95% Cl 1.05-3.12) and 2.12 (95% CI 1.19-4.10) respectively. After adjustment of CAD risk factors such as smoking, family history of CAD and diabetes, the homozygous AA genotype for rs2383207 increased the CAD risk with an OR 3.69. Also a very strong association was found between rs1333049 and rs2383207 and Gensini scores representing the severity of CAD (p<0.001). Conclusion: The rs2383207 and rs1333049 SNPs on 9p21 chromosome were significantly associated with the risk and severity of CAD in the Turkish population.

Polymorphisms in the long non-coding RNA CDKN2B-AS1 may contribute to higher systolic blood pressure levels in hypertensive patients

OBJECTIVES Hypertension (HT) is a complex disorder influenced by both genetic and environmental factors. Recent genome-wide association studies have identified a major risk locus for atherosclerosis on chromosome 9p21.3. SNPs within the coding sequences of CDKN2A/B and the long non-coding RNA CDKN2B-AS1 could potentially contribute to HT development. Thus, this study aimed to investigate whether the frequency of four SNPs on chromosome 9p21.3 affects blood pressure (BP) levels in Turkish HT patients, and to examine correlations between these SNPs, specific SNP haplotypes, and HT. DESIGN AND METHODS This is a case-control study comparing HT patients and healthy controls. Real-time polymerase chain reaction (RT-PCR) analysis was utilized to detect SNPs rs10757274, rs2383207, rs10757278, and rs1333049 in 170 HT patients and 180 healthy controls. RESULTS Each SNP was detected at significantly higher frequencies in HT patients than in controls (p values 0.001); however, there was no significant link between rs10757274, rs2383207, rs10757278, and rs1333049 SNPs and HT grades. Furthermore, there was a significant association between elevated systolic BP levels and rs1333049 GG genotype (p=0.047), while weight gain and increased fasting glucose levels were significantly associated with rs2383207 AA genotype (p=0.020 and p=0.009, respectively). Lastly, we detected a correlation between GG, GA, and AG haplotypes in block 1 (rs10757274, rs2383207) and GC and AG haplotypes in block 2 (rs10757278, rs1333049) and HT. CONCLUSIONS Our findings suggest that SNPs rs10757274, rs2383207, rs10757278, and rs1333049, particularly those within the CDKN2B-AS1 gene, and related haplotypes may confer increased susceptibility to HT development.

Genetic polymorphism of angiotensin I-converting enzyme (ACE), but not angiotensin II type I receptor (ATr1), has a gender-specific role in panic disorder

Aims:  Angiotensins were shown to have some role in the development of panic disorder (PD). In this study, we aimed to determine the frequency of polymorphisms in two angiotensin‐related genes, angiotensin I‐converting enzyme (ACE) and angiotensin II type I receptor (ATr1), in a sample of Turkish patients with PD and to evaluate their association with PD development.

Pro198Leu polymorphism in the oxidative stress gene, glutathione peroxidase-1, is associated with a gender-specific risk for panic disorder.

Abstract Objective. Panic disorder (PD) is an anxiety disorder characterized by sudden attacks of intense fear. Biochemical studies suggest that oxidative stress (OS) index is significantly higher in PD, and OS genes may participate in development of anxiety-like behavioral phenotypes. We aimed to investigate role of polymorphisms in OS gene, glutathione peroxidase-1 (GPX1), and DNA repair enzyme gene, 8-oxoguanine glycosylase-1 (OGG1), in PD patients. Methods. GPX1 Pro198Leu (rs1050450) and OGG1 Ser326Cys (rs1052133) polymorphisms of 127 patients with PD and 151 disease-free controls were analyzed with real-time polymerase chain reaction. Severity of PD symptoms was assessed by Panic and Agoraphobia Scale (PAS). Results. No significant relationship was found in genotype distributions of OGG1 Ser326Cys and GPX1 Pro198Leu polymorphisms between PD and control groups (p > 0.05). There was no significant relationship between OGG1 or GPX1 polymorphisms, and age of onset, agoraphobia, or PAS scores in PD group (p > 0.05). However, in GPX1 Pro198Leu polymorphism, C allele (Pro) was found to be more frequent in female subgroup of PD patients compared with that in males (p = 0.027). Conclusions. GPX1 Pro198Leu and OGG1 Ser326Cys polymorphisms were not associated with PD risk in Turkish patients. However, a gender-specific effect of GPX1 Pro198Leu C allele may be associated with PD development.

Serotonin-2a receptor and catechol-O-methyltransferase polymorphisms in panic disorder

Catechol-O-methyltransferase (COMT) and serotonin receptor 2A (5HTR2A) polymorphisms have been investigated for their possible role in panic disorder (PD). The aim of this study was to investigate the genotype distribution of the COMT val158met and 5HTR2A 102T/C polymorphisms in PD. COMT val158met is a polymorphism at codon 158 that results in variations in COMT enzymatic activity with high- (H) and low-activity (L) alleles. The 5HTR2A 102T/C polymorphism comprises a T-to-C mutation at position 102. The effects of symptom severity, gender, and age of onset were also investigated. The participants were 105 outpatients with PD and 130 controls. The severity of the symptoms of PD was assessed by the Panic and Agoraphobia Scale (PAS). Polymorphisms of the 5HTR2A and COMT genes were identified using polymerase chain reaction and restriction fragment length polymorphism analysis. A significant relationship was found between the COMT Val158Met polymorphism and PD. No significant differences were found in genotype distributions or allele frequencies of the 5HTR2A polymorphisms between the PD and control groups. There were no significant relationships between the COMT and 5HTR2A polymorphisms and age of onset, gender, presence of agoraphobia, or PAS scores in the PD group (p>0.05).

Genetic variants rs1994016 and rs3825807 in ADAMTS7 affect its mRNA expression in atherosclerotic occlusive peripheral arterial disease

Peripheral artery disease (PAD) is a vascular disease affecting peripheral circulation. Recently, genome‐wide association studies revealed a relationship between single nucleotide polymorphisms (SNPs) in ADAMTS7 (a disintegrin and metalloprotease with thrombospondin motif 7) and atherosclerosis. In this study, we aimed to determine ADAMTS7 expression in peripheral blood mononuclear cells (PBMCs) and the frequency of ADAMTS7 rs1994016 and rs3825807 polymorphisms in a sample of Turkish patients with PAD, and to evaluate the association of matrix metalloproteinase (MMP) levels with PAD development.

Increased Expression of Interleukin-18 mRNA is Associated with Carotid Artery Stenosis

Background: Carotid artery stenosis is the atherosclerotic narrowing of the proximal internal carotid artery and one of the primary causes of stroke. Elevated expression of the pleiotropic proinflammatory cytokine interleukin-18 has been demonstrated in human atherosclerotic plaques. Aims: To investigate whether the mRNA expression levels of interleukin-18 and interleukin-18-binding protein and interleukin-18 −137 G/C (rs187238) variants are associated with carotid artery stenosis development. Study Design: Case-control study. Methods: The mRNA expression levels of interleukin-18 and interleukin-18-binding protein and interleukin-18 rs187238 variants were evaluated by quantitative real-time polymerase chain reaction and real-time polymerase chain reaction, respectively, in the peripheral blood mononuclear cells of 70 patients with carotid artery stenosis (36 symptomatic, 34 asymptomatic) and 75 healthy controls. Results: Interleukin-18 mRNA expression was significantly increased in carotid artery stenosis patients compared to that in healthy controls (p=0.01). However, no significant difference was observed between interleukin-18-binding protein mRNA expression levels in patients with carotid artery stenosis and those in controls (p=0.101). Internal carotid artery stenosis severity was significantly higher in symptomatic patients than that in asymptomatic patients (p<0.001). A significant relationship was identified between interleukin-18 expression and internal carotid artery stenosis severity in patients with carotid artery stenosis (p=0.051). Interleukin-18 rs187238 polymorphism genotype frequencies did not significantly differ between patients with carotid artery stenosis and controls (p=0.246). A significant difference was identified between interleukin-18-binding protein gene expression and symptomatic and asymptomatic patients (p=0.026), but there was no difference in interleukin-18 expression between the symptomatic and asymptomatic subgroups (p=0.397). Conclusion: Interleukin-18 mRNA expression may affect carotid artery stenosis etiopathogenesis and internal carotid artery stenosis severity and also may play a mechanistic role in the pathogenesis of carotid artery stenosis, influencing the appearance of symptoms.

Upregulation of OLR1 and IL17A genes and their association with blood glucose and lipid levels in femoropopliteal artery disease

Oxidized low-density lipoprotein receptor 1 (OLR1) and interleukin 17A (IL17A) have pro-inflammatory roles in the development of cardiovascular disorders. The present study evaluated the association of OLR1 and IL17A and their polymorphisms with the development of femoropopliteal (FP) artery disease. The mRNA expression of OLR1 and IL17A in peripheral blood mononuclear cells as well as the frequency of OLR1 rs11053646 and IL17A rs8193037 and rs3819025 polymorphisms were assessed by polymerase chain reaction in 70 patients with FP artery disease and 80 age-matched disease-free controls. Furthermore, the levels of plasma cytokines were assessed by multiplex immunoassay. OLR1 and IL17A mRNA expression was significantly higher in patients with FP artery disease compared with that in controls (P<0.001). No significant difference was observed in the genotypic frequencies of OLR1 rs11053646 (P=0.87) or in IL17A rs8193037 and rs3819025 (P=0.80 and 0.92, respectively) polymorphisms between patients with FP artery disease and controls. Plasma IL4, -6, -10, -22, -31 and -33 as well as soluble cluster of differentiation 40 ligand and tumor necrosis factor-α levels were significantly increased among FP artery disease patients compared with controls (P<0.05). Furthermore, OLR1 expression was positively correlated with triglyceride (r=0.463, P<0.001), low-density lipoprotein cholesterol (r=0.507, P<0.001) and total cholesterol levels (r=0.357, P=0.006) in patients with FP artery disease. To the best of our knowledge, the present study was the first to identify an association between OLR1 and IL17A genes and FP artery disease. OLR1 and IL17A mRNA transcripts may be associated with blood lipid parameters and with the development of FP artery disease.

The Roles of the Long Non-Coding RNA Transcripts in Cardiovascular Diseases

For many years, proteins have been known be the major regulators in biological processes such as transcription and translation. However, in recent years, with the advent of high-throughput sequencing technology, a high-resolution map of the human transcriptome was made and a large number of non-protein coding RNA genes were discovered. Non-protein coding RNA genes (ncRNAs) are classified according to their size. Long non-coding RNAs (lncRNAs) are a group of ncRNAs that are >200 nucleotides long. LncRNAs are involved in many biological processes. Expression levels of and genetic variations in lncRNAs contribute to in vivo and in vitro pathophysiological processes and have been associated with many diseases. In recent years, numerous lncRNAs, which are associated with cardiovascular disease (CVD), have been identified. One of the major causes of CVD is atherosclerosis. The molecular processes involved in the formation and progression of atherosclerosis in vascular smooth muscle cells, endothelial cells, and monocytes/macrophages play an important role in the development of CVD. In the future, a better understanding of the biological functions of lncRNAs with their ever-increasing importance in the formation and development of atherosclerosis will shed light on the development of novel therapeutic approaches for CVD.

Association between MTHFR C677T polymorphism and folate, vitamin B12, homocysteine, and DNA fragmentation in patients with ovarian cancer

Abstract Objective: Methylenetetrahydrofolate reductase (MTHFR) is an important enzyme that regulates the metabolism of methionine and folate. MTHFR C677T polymorphism was reported to be associated with breast and ovarian cancer. The aim of this study was to evaluate the association between the MTHFR C677T (rs1801133) polymorphism and homocysteine, vitamin B12, and folate levels, and DNA fragmentation in patients with ovarian cancer and healthy controls. Materials and methods: This case-control study was conducted in Istanbul University Cerrahpasa Medical Faculty. We studied 50 ovarian cancer patients and 54 healthy controls. The MTHFR C677T polymorphism was determined by PCR followed by restriction fragment length polymorphism (RFLP) and agarose gel electrophoresis. DNA fragmentation was assessed by the comet assay. Homocysteine levels were measured by ELISA, whereas vitamin B12 and folate levels were measured by chemiluminescence methods. Results: We found no correlation between the MTHFR C677T polymorphism and ovarian cancer. No significant difference was found in homocysteine, folate, and vitamin B12 levels between patient and control groups. Increased DNA fragmentation was detected in patients with ovarian cancer. Conclusion: Our findings suggest that MTHFR C677T polymorphism, as well as homocysteine, folic acid, and vitamin B12 levels, are not associated with an increased risk for ovarian cancer.