Sara Mankoč

GSTT1 Null Genotype Is a Risk Factor for Diabetic Retinopathy in Caucasians with Type 2 Diabetes, whereas GSTM1 Null Genotype Might Confer Protection against Retinopathy

Aim: Substantial data indicate that oxidative stress is involved in the development of diabetic retinopathy (DR). The aim of the present study was to investigate whether the genetic polymorphisms: polymorphic deletions of glutathione S-transferases M1 (GSTM1) and T1 (GSTT1) and Ile105Val of the GSTP1 are associated with DR in Slovenian patients with type 2 diabetes. Methods: In this cross sectional case-control study 604 unrelated Slovene subjects (Caucasians) with type 2 diabetes mellitus were enrolled: 284 patients with DR (cases) and the control group of 320 subjects with type 2 diabetes of more than 10 years’ duration who had no clinical signs of DR. Genotypes were determined by polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP). Results: In our study, the deletion of the GSTM1 was found less frequent in cases with DR than in the controls (27.5% versus 44.4%; P < 0.001), whereas the deletion of GSTT1 was found significantly more often in cases than in the controls (49.3% versus 29.7%;P < 0.001). We did not find statistically significant differences in the genotype distribution in GSTP1 (Ile105Val) polymorphism between cases and controls (40.5% versus 46.0%). Conclusions: We may conclude that individuals homozygous for the deletion of GSTT1 are at an ≈ 2-fold-greater risk of DR, whereas the GSTM1 deficiency is associated with lower frequency of DR in type 2 diabetics.

Fusion and Matrix Protein Gene Sequence Analysis of Paramyxoviruses of Type 1(PMV-1) Isolated from Pigeons in Slovenia

Paramyxoviruses of type 1 (PMV-l) isolated from pigeons were genetically analyzed. A part of the fusion and the matrix protein genes were amplified and sequenced, Typical amino acid sequences associated with virulence were determined at the fusion protein cleavage site in all PMV-1 isolates. All Slovene pigeon PMV-1 strains share high amino acid sequence similarity with other pigeon strains. In the phylogenetic tree, they are clustered together with pigeon PMV-1 isolates with moderate pathogenicity. Phylogenetic analysis obtained from the fusion and the matrix protein gene alignments showed the same branching order. Viruses circulating among pigeons were found to form quite unique lineage of virulent NDV strains.

Vascular Endothelial Growth Factor Gene Polymorphism (rs2010963) and Its Receptor, Kinase Insert Domain-Containing Receptor Gene Polymorphism (rs2071559), and Markers of Carotid Atherosclerosis in Patients with Type 2 Diabetes Mellitus.

Background. The current study was designed to reveal possible associations between the polymorphisms of the vascular endothelial growth factor (VEGF) gene (rs2010963) and its receptor, kinase insert domain-containing receptor (KDR) gene polymorphism (rs2071559), and markers of carotid atherosclerosis in patients with type 2 diabetes mellitus (T2DM). Patients and Methods. 595 T2DM subjects and 200 control subjects were enrolled. The carotid intima-media thickness (CIMT) and plaque characteristics (presence and structure) were assessed ultrasonographically. Biochemical analyses were performed using standard biochemical methods. Genotyping of VEGF/KDR polymorphisms (rs2010963, rs2071559) was performed using KASPar assays. Results. Genotype distributions and allele frequencies of the VEGF/KDR polymorphisms (rs2010963, rs2071559) were not statistically significantly different between diabetic patients and controls. In our study, we demonstrated an association between the rs2071559 of KDR and either CIMT or the sum of plaque thickness in subjects with T2DM. We did not, however, demonstrate any association between the tested polymorphism of VEGF (rs2010963) and either CIMT, the sum of plaque thickness, the number of involved segments, hsCRP, the presence of carotid plaques, or the presence of unstable carotid plaques. Conclusions. In the present study, we demonstrated minor effect of the rs2071559 of KDR on markers of carotid atherosclerosis in subjects with T2DM.

MOLECULAR CHARACTERISATION OF INFECTIOUS BURSAL DISEASE VIRUSES ISOLATED IN RECENT ACUTE OUTBREAKS IN SLOVENIA

In 2004 and then in 2006 several outbreaks of infectious bursal disease (IBD) were reported in broiler and broiler breeder flocks in Slovenia. In this report ten recently emerged IBD viruses (IBDV) were characterised by sequence analysis of the VP2 hypervariable region and compared to previous Slovene IBDV strains from 1995/1996 and to some representative serotype 1 IBDV strains of different pathotypes. On the basis of nucleotide and amino acid identities, phylogenetic analyses and the presence of very virulent IBDV (vvIBDV) conserved amino acid substitutions, all Slovene isolates from recent outbreaks were identified as vvIBDV. Although some unique nucleotide exchanges and amino acid substitutions have been observed, the results of this study indicated that recent vvIBDV isolates are closely related with those from outbreaks in the 1990s. However, acute IBD has not been reported in commercial flocks in Slovenia for some years. This could lead to the conclusion that poor biosecurity and relaxed vaccination could be responsible for the re-emergence of vvIBDV.

The joint effect of the endothelin receptor B gene (EDNRB) polymorphism rs10507875 and nitric oxide synthase 3 gene (NOS3) polymorphism rs869109213 in Slovenian patients with type 2 diabetes mellitus and diabetic retinopathy

Increasing evidence suggests that endothelin and nitric oxide synthase genes and their products exert biological effects on the vasculature via the nitric oxide or endothelin pathway. The aim of the study was to evaluate the association of rs10507875 and rs869109213 (alone or in interaction) with diabetic retinopathy (DR) in subjects with type 2 diabetes mellitus (T2DM). We genotyped the single nucleotide polymorphism rs10507875 of the endothelin receptor B gene (EDNRB) and variable number tandem repeats rs869109213 of the nitric oxide synthase 3 gene (NOS3) in 270 Slovenian patients with DR and T2DM and 256 controls with T2DM without clinical signs of DR. The genotyping was performed using either real-time polymerase chain reaction (PCR) or standard PCR. We found a significant association between the genotypes of NOS3 rs869109213 polymorphism and the risk of DR in the co-dominant model (4a4b genotype; 1.99-fold increased risk [1.09-3.65]; 95% confidence interval [CI]; p = 0.02), co-dominant model (4a4a genotype; 4.16-fold increased risk [1.03-16.74]; 95% CI; p = 0.04), and dominant model (4a4a and 4a4b genotypes; 2.22-fold increased risk [1.26-3.92]; 95% CI; p = 0.01) compared to the 4b4b genotype. Moreover, the joint effect of the two polymorphisms on DR risk was greater than the individual effect of each polymorphism in the analyzed genetic models. Additionally, adjusted odds ratio showed an increased risk in dominant × dominant (4.15-fold [1.40-12.26]; 95% CI; p = 0.01) and recessive × dominant (2.24-fold [1.25-4.01]; 95% CI; p = 0.02) genotype combinations of the two polymorphisms. In conclusion, our results indicate that NOS3 rs869109213 polymorphism alone or in a combination with EDNRB rs10507875 polymorphism may be associated with DR in Slovenian patients with T2DM.

Vascular endothelial growth factor (VEGF)-related single nucleotide polymorphisms rs10738760 and rs6921438 are not associated with diabetic retinopathy (DR) in Slovenian patients with type 2 diabetes mellitus (T2DM)

Diabetic retinopathy (DR) is a complication of diabetes characterized by vascular permeability, increased tissue ischemia, and angiogenesis. One of the most important proteins involved in angiogenesis is vascular endothelial growth factor (VEGF, also known as VEGFA). A previous study demonstrated that two single nucleotide polymorphisms (SNPs), rs6921438 and rs10738760, account for nearly half the variation in circulating VEGF levels. The aim of our study was to assess the association between rs6921438 and rs10738760 and DR in Slovenian patients with type 2 diabetes mellitus (T2DM). This case-control study enrolled 1037 unrelated Slovenian individuals (Caucasians) with T2DM. DR group included 415 T2DM patients with DR, while control group included 622 T2DM patients with no clinical signs of DR. The clinical and laboratory data were obtained from the medical records of the patients. The genotyping of rs6921438 and rs10738760 SNPs was carried out with real-time PCR assays. Significant differences were observed between patients with DR and controls in the duration of diabetes (p < 0.001), insulin therapy (p < 0.001), glycated hemoglobin (p = 0.001), body mass index (p = 0.002), total cholesterol (p = 0.002), and low-density lipoprotein cholesterol (p < 0.001). However, we did not observe significant differences in the genotype and allele distribution of the two SNPs, between DR and control group (p < 0.05). Logistic regression analysis showed that rs6921438 and rs10738760 were not independent genetic risk factors for DR in the co-dominant model adjusted for the above-mentioned clinical and laboratory data. In conclusion, VEGF-related SNPs rs10738760 and rs6921438 are not associated with DR in our group of Slovenian patients (Caucasians) with T2DM.