Ahmet Arman

Interleukin-1 receptor antagonist gene VNTR polymorphism is associated with coronary artery disease.

BACKGROUND Coronary Artery Disease (CAD) is the atherosclerosis of coronary arteries that carry blood to the heart muscle. Atherosclerosis is an inflammatory disease. Cytokine gene variations such as those associated with the IL1 family are involved in the pathogenesis of atherosclerosis. OBJECTIVE The purpose of this study was to determine the relationship between IL1 family polymorphisms (IL1RN VNTR, IL1B positions -511 and +3953) and CAD in Turkish population. METHODS 427 individuals were submitted to coronary angiography and were grouped as 170 control subjects and 257 CAD patients. The CAD subjects were divided into two subgroups: 91 Single Vessel Disease (SVD) and 166 Multiple Vessel Disease (MVD) subjects. The genotypes of IL1RN and of IL1B (-511, +3953) were determined by polymerase chain reaction (PCR) followed by restriction digestion analysis. RESULTS No significant difference was found in IL1RN and IL1B (-511 and +3953) genotype distributions between CAD and control subjects or MVD and control subjects. However, significant association was seen in IL1RN 2/2 genotype between SVD and control subjects (P= 0.016, x2: 10.289, OR: 2.94, 95% CI: 1.183-7.229). Similarly, no statistically significant difference was found in IL1RN and IL1B (-511 and +3953) allele frequencies between CAD and control subjects, MVD and control subjects or SVD and control subjects. CONCLUSION No association was found in either allele frequency or genotype distribution of IL1RN and IL1B polymorphisms between CAD and the control groups. However; IL1RN 2/2 genotype may be a risk factor for SVD in the Turkish population.

Lack of association between IL‐1 and IL‐6 gene polymorphisms and myocardial infarction in Turkish population

Inflammation and genetics play a key role in the pathogenesis of atherosclerosis and its clinical result myocardial infarction (MI). Proinflammatory cytokines, IL‐1 and IL‐6, have been shown to play essential roles in developmental stages of coronary artery plaque formation. The aim of this study was to determine the association between IL‐1 [IL‐1RN, IL‐1β (−511, +3953)], IL‐6 [−174, −572, −597] gene polymorphisms and MI in Turkish population. A total of 402 people were participated; 235 healthy control subjects and 167 MI patients (MI < 40, n: 72; MI > 40, n: 95). Polymerase chain reaction (PCR) was used to determine the genotype of IL‐1RN, whereas the genotypes of IL‐1β (−511, +3953) and IL‐6 (−174, −572, −597) were determined using PCR followed with restriction digestion analysis. There was no significant difference between MI and controls for IL‐1RN, IL‐1β−511, +3953 (P: 0.875, 0.608, 0.442) and IL‐6 −174, −572, −597 (P: 0.977, 0.632, 0.584) gene polymorphisms. Lack of association was observed between MI at younger age (MI < 40) and either IL‐1RN VNTR, IL‐1β−511, +3953 (P: 0.878, 0.732, 0.978) or IL‐6 −174, −572, −597 (P: 0.313, 0.654, 0.552) gene polymorphisms. This study demonstrated that there was not any association between IL‐1, IL‐6 gene variants and MI in Turkish population. In addition, IL‐1 and IL‐6 gene polymorphisms did not affect MI at younger age (MI < 40) or older age (MI > 40). Thus, IL‐1 and IL‐6 single nucleotide polymorphisms may not be a risk factor for susceptibility to MI in Turkish population.

Association between sporadic Parkinson disease and interleukin-1β -511 gene polymorphisms in the Turkish population

The pathogenesis of Parkinson Disease (PD) remains poorly understood; however, inflammation is thought to play an important role in disease progression. Recent reports suggest that IL-1, a major proinflammatory cytokine, might play a role in PD progression. The purpose of this study was to determine the relationship between IL-1 gene family polymorphisms [IL-1 alpha (-889), IL-1Ra (VNTR) and IL-1 beta (-511, +3953)] and PD in the Turkish population. In this study, we examined the genotypes of IL-1 gene family polymorphisms in 365 individuals, of which 199 were healthy control subjects and 166 were PD patients. No significant differences were found in the genotype distribution or in the allele frequencies of IL-1 alpha (-889), IL-1Ra (VNTR) and IL-1 beta (+3953) between PD cases and control subjects. However, distribution of the IL-1 beta -511 2/2 (T/T) genotype was found to be significantly lower in PD patients than in healthy controls (p = 0.018, x2: 8.242, OR: 2.211, 95% CI: 1.261-3.877). In addition, the IL-1 beta -511 allele 1 (C) frequency was significantly elevated in PD patients versus controls (p = 0.048, x2: 3.87, OR: 1.178, 95% CI: 0.999-1.388). These results suggest that IL-1 alpha (-889), IL-1Ra and IL-1 beta (+3953) gene polymorphisms have no association with PD, while allele 1 (C) of IL-1 beta (-511) is associated with PD and may provide a susceptibility factor for this disease in the Turkish population. Furthermore, the 2/2 (T/T) genotype of IL-1 beta (-511) may protect individuals from PD.

Multiple sclerosis: association with the interleukin-1 gene family polymorphisms in the Turkish population

Background: Multiple Sclerosis (MS) is a neurodegenerative disease. It involves inflammation and demyelination. Since cytokines play an important role in the development of MS, genes encoding cytokines such as the Interleukin (IL)-1 family are candidate genes for MS susceptibility. Objective: To determine the relationship between IL-1 gene family and MS in the Turkish population. Methods: A total of 409 MS patients and 256 healthy controls were included in the study. IL-1A −889 (rs1800587), IL-1 RN variable number tandom repeat (VNTR), IL-1B −511 (rs 16944) and IL-1B +3953 (rs 1143634) polymorphisms were investigated from the genomic DNA, obtained via blood samples. Results: No association was found between IL-1A and IL-1RN polymorphisms and susceptibility to MS. However, we have found significantly decreased frequency of IL-1B −511 genotype (p = 0.004) in MS patients compared to controls. In addition, there was a significant association between IL-1B −511 (1/2) genotype and early onset MS (EOMS) (p = 0.0001). Conclusions: Individuals with the 2/2 genotype of IL-1B −511 have significantly decreased incidence of MS, suggesting a protective role for this genotype in the Turkish population. Additionally, IL-1B −511 (1/2) genotype was determined as a possible risk factor for EOMS.

Novel Splice Site Mutation in the Growth Hormone Receptor Gene in Turkish Patients with Laron-type Dwarfism

Growth hormone (GH) is involved in growth, and fat and carbohydrate metabolism. Interaction of GH with the GH receptor (GHR) is necessary for systemic and local production of insulin-like growth factor-I (IGF-I) which mediates GH actions. Mutations in the GHR cause severe postnatal growth failure; the disorder is an autosomal recessive genetic disease resulting in GH insensitivity, called Laron syndrome. It is characterized by dwarfism with elevated serum GH and low levels of IGF-I. We analyzed the GHR gene for mutations and polymorphisms in eight patients with Laron-type dwarfism from six families. We found three missense mutations (S40L, V125A, I526L), one nonsense mutation (W157X), and one splice site mutation in the extracellular domain of GHR. Furthermore, G168G and exon 3 deletion polymorphisms were detected in patients with Laron syndrome. The splice site mutation, which is a novel mutation, was located at the donor splice site of exon 2/ intron 2 within GHR. Although this mutation changed the highly conserved donor splice site consensus sequence GT to GGT by insertion of a G residue, the intron splicing between exon 2 and exon 3 was detected in the patient. These results imply that the splicing occurs arthe GT site in intron 2, leaving the extra inserted G residue at the end of exon 2, thus changing the open reading frame of GHR resulting in a premature termination codon in exon 3.

Interleukin-1B (-511) gene polymorphism is associated with acute coronary syndrome in the Turkish population

OBJECTIVES acute coronary syndrome (ACS) is defined as an inflammatory disease associated with development of atherosclerosis and instability. IL-1 is a candidate inflammatory cytokine that is thought to trigger ACS. The purpose of this study was to determine the relationship between IL-1 gene family polymorphisms (IL-1RN, IL-1B in positions -511 and +3953) and ACS in the Turkish population. METHODS a total of 381 people participated in the study, with 117 control subjects and 264 ACS patients. Of the 264 ACS patients, 112 were diagnosed with stable angina pectoris (SAP) and 152 were diagnosed with unstable angina pectoris (USAP). The polymerase chain reaction (PCR) was used to determine the genotype of IL-1RN. The genotypes of IL-1B (-511 and +3953) were determined by PCR, followed by restriction enzyme digestion of the PCR products. RESULTS there were no significant differences in both IL-1RN, IL-1B (-511 and +3953) genotype distributions and IL-1RN allele frequencies between ACS patients and the control subjects. In addition, no association was observed in the allele frequency of IL-1B (-511 and +3953) between ACS patients and controls (p = 0.113 and p = 0.859, respectively), or between SAP patients and controls (p = 0.575 and p = 0.359, respectively). However, IL-1B allele 1 (C) (-511) polymorphism in USAP patients was found to be significantly different from that of control subjects (p = 0.041, OR: 2.01; 95% CI: 1.985-3.933). A significant difference was also observed between USAP and SAP patients for IL-1B (+3953) allele 1 (C) polymorphism; (p = 0.043, OR: 1.522; 95% CI: 1.012-2.88). CONCLUSION these results show that IL-1RN gene polymorphism has no association with ACS. However, the allele 1 (C) of IL-1B (-511) may be a risk factor for susceptibility to USAP in the Turkish population.

Interleukin 1 (IL-1) induces the activation of Stat3.

Interleukin-1 (IL-1) is involved in a variety of immune system activities, such as acute phase response, fever and cartilage breakdown. The acute phase response is a result of injury, virus or bacterial infection, all of which induce acute phase protein synthesis. Expression of the acute phase proteins is predominantly regulated by IL-1 and IL-6; however, the liver centrally regulates the acute-phase response by inducing the release of acute phase reactants (APRs). There are two classes of these acute phase reactants. IL-1 induces class 1 acute phase proteins, such as serum amyloid A and 1acid glycoprotein, synergistically, with or without IL-6. However, class 2 APRs, including various anti-proteases and 2-macroglobin, are induced only by IL-6. The promoters of some of the acute phase genes contain regulatory respond elements called acute phase response elements (APRE). APRE bind to transcription factors termed acute-phase response factor (AFRF) or to the signal transducer and activator of transcription 3, (Stat3). Additional types of regulatory elements found in promoters of APRs are CCAAT enhancer-binding protein (C/EBP) and nuclear factor-N3 (NF-NB) binding elements that bind to C/EBP family of transcription factors such as NF-IL6, C/EBPI and NF-NB respectively. IL-1 only activates NF-A8 and C/EBP transcription factors; however, IL-6 activates Stat3 molecules.

Novel growth hormone receptor gene mutation in a patient with Laron syndrome.

ABSTRACT Growth Hormone (GH) is a 22 kDa protein that has effects on growth and glucose and fat metabolisms. These effects are initiated by binding of growth hormone (GH) to growth hormone receptors (GHR) expressed in target cells. Mutations or deletions in the growth hormone receptor cause an autosomal disorder called Laron-type dwarfism (LS) characterized by high circulating levels of serum GH and low levels of insulin like growth factor-1 (IGF-1). We analyzed the GHR gene for genetic defect in seven patients identified as Laron type dwarfism. We identified two missense mutations (S40L and W104R), and four polymorphisms (S473S, L526I, G168G and exon 3 deletion). We are reporting a mutation (W104R) at exon 5 of GHR gene that is not previously reported, and it is a novel mutation.

Novel Growth Hormone-Releasing Hormone Receptor Gene Mutations in Turkish Children with Isolated Growth Hormone Deficiency

Objective: Isolated growth hormone deficiency (IGHD) is defined as a medical condition associated with growth failure due to insufficient production of GH or lack of GH action. Mutations in the gene encoding for GH-releasing hormone receptor (GHRHR) have been detected in patients with IGHD type IB. However, genetic defects on GHRHR causing IGHD in the Turkish population have not yet been reported. To identify mutations on GHRHR gene in a population of Turkish children with IGHD. Methods: Ninety-six Turkish children with IGHD were included in this study. Exon1-13 and exon/intron boundaries of GHRHR were amplified by suitable primers. The polymerase chain reaction products for GHRHR gene were sequenced with primers. Results: We analyzed the GHRHR gene for mutations in ninety-six patients with IGHD based on sequence results. We identified novel p.K264E, p.S317T, p.S330L, p.G369V, p.T257A and C base insertion on position 380 (c.380inserC) mutations. In 5 of the patients, the mutation was homozygote and in 1-heterozygote (p.S317T). Conclusion: Six new missense mutations and one first case of insertion mutations for the GHRHR gene are reported.

Vitreoscilla hemoglobin renders Enterobacter aerogenes highly susceptible to heavy metals.

When expressed in heterologous microorganisms Vitreoscilla hemoglobin (VHb) acts as oxygen storage and causes a higher oxygen uptake. In this study, the effect of this protein on growth, sensitivity and antioxidant properties of Enterobacter aerogenes exposed to metal stress was investigated. The strain expressing VHb was more sensitive to mercury and cadmium as the minimal inhibitory concentration (MIC) for these metals was up to 2-fold lower in this strain than the host and the recombinant strain carrying a comparable plasmid. At lower concentrations than MIC, the metals partially limited growth and caused an inhibition proportional to metal concentration applied. The growth pattern of VHb expressing strain was also distinctly different from other two non-hemoglobin strains. The hemoglobin containing strain showed substantially higher superoxide dismuates (SOD) activity than the non-hemoglobin strains, while catalase levels were similar in all strains. All strains exposed to copper, however, showed similar MIC values, growth patterns, and SOD and catalase levels.