Ljiljana Stojković

Association of MMP-3 5A/6A gene polymorphism with susceptibility to carotid atherosclerosis

OBJECTIVES Stromelysin-1 (MMP-3) as a key member of metalloproteinase family could have an important role in atherogenesis. The 5A/6A polymorphism in the promoter of MMP-3 gene affects the level of MMP-3 gene expression. We assessed whether the MMP-3 promoter low- and high-activity genotypes are related to susceptibility for carotid atherosclerosis (CA) in Serbian population. DESIGN AND METHODS The study group of case-control design consisted of 515 participants. The 265 patients with ultrasonographic evidence of carotid plaque presence were recruited for the study. The 5A/6A polymorphism was typed by RFLP-PCR. RESULTS There was significantly higher prevalence of genotypes containing 6A allele in the patients with CA compared to controls (p<0.05). The model of inheritance with the dominant effect of 6A allele gave elevated and significant OR for carotid atherosclerosis (adjusted OR 2.35, CI=1.0-5.5, p=0.048). CONCLUSIONS Subjects carrying genotypes with 6A allele had significantly higher susceptibility to carotid atherosclerosis.

Matrix metalloproteinase-1 promoter genotypes and haplotypes are associated with carotid plaque presence.

OBJECTIVES Matrix metalloproteinase (MMP)-1 degrades fibrillar collagens suggesting important role in vascular remodeling. Data about MMP-1 promoter polymorphisms and carotid atherosclerosis (CA) are scarce. The aim of this study was to evaluate association of MMP-1 genotypes/haplotypes with carotid plaque (CP) presence in Serbian population. DESIGN AND METHODS Study enrolled a total of 702 participants: 274 controls and 428 consecutive patients with CA who underwent carotid endarterectomy. MMP-1 polymorphisms -1607 1G/2G, -519 A/G and -340 T/C were genotyped by PCR and RFLP methods. RESULTS Individuals carrying MMP-1 -1607 2G allele had significantly increased allele dose-dependent risk for CP presence (1G1G vs. 1G2G vs. 2G2G; OR=1; OR=1.87 95% CI 1.29-2.07; OR=3.49 95% CI 1.67-7.30, p=0.0009, respectively). Compared to the referent haplotype 2G(-1607)-T(-340)-A(-519), the haplotypes 1G(-1607)-T(-340)-A(-519), 1G(-1607)-T(-340)-G(-519) and 2G(-1607)-C(-340)-A(-519) had statistically significant protective effect on CP presence (OR=0.41, 95% CI 0.29-0.81, p=0.01; OR=0.56, 95% CI 0.44-0.89, p=0.01; OR=0.43, 95% CI 0.27-0.86, p=0.02, respectively). CONCLUSIONS MMP-1 -1607 G/2G polymorphism solely and specific haplotypes of three analyzed promoter polymorphisms are significantly and independently associated with occurrence of CP. Replication studies in other populations are needed.

The glutathione S-transferase T1 deletion is associated with susceptibility to multiple sclerosis

BACKGROUND Multiple sclerosis (MS) occurs as a result of interaction between genetic and environmental factors. Recent data support the view that oxidative damage is one of an early event in MS tissue injury. The safe elimination of reactive oxygen species and toxins via glutathione S-transferase (GST) pathways is required in order to protect cells against reactive oxygen-induced damage. The aim of our study was to analyze the possible association of GSTM1 and GSTT1 gene polymorphisms with the susceptibility and clinical parameters of MS, in 455 consecutive patients and 366 controls. METHODS A multiplex polymerase chain reaction (PCR) was used to detect the deletions in GSTM1 and GSTT1 genes. RESULTS Patients with MS had significantly higher frequency of GSTT1 null genotype compared to controls (37.36% vs. 21.86%, respectively, p<0.0001, adjusted OR 2.13 (1.56-2.90)), as well as double deletions (15.38% vs. 10.38%, respectively, p<0.05). The carriers of GSTM1 deletion had significantly earlier onset of MS compared to the wild-type carriers (28.31 ± 8.45 vs. 30.64 ± 9.30 years, respectively, p = 0.03). CONCLUSION This study suggests the potential pathogenic role of GSTT1 deletion on MS susceptibility. There are no similar data published so far, yet this study should be replicated in other populations.

Renin-angiotensin system gene polymorphisms as risk factors for multiple sclerosis

The components of renin-angiotensin system, such as angiotensin-converting enzyme (ACE), angiotensin II and angiotensin II receptor type 1 and 2 (AT1R and AT2R), are expressed in the central nervous system and leukocytes and proposed to be involved in the inflammation and pathogenesis of multiple sclerosis (MS). ACE I/D, AT1R 1166A/C and AT2R -1332A/G are functional polymorphisms associated with phenotypes of diverse chronic inflammatory diseases. The aim of this study was to investigate the association between ACE I/D, AT1R 1166A/C and AT2R -1332A/G gene polymorphisms and MS in Serbian population. A total of 470 MS patients and 478 controls participated in the study. Allele-specific polymerase chain reaction (PCR) was performed for genotyping of the ACE polymorphism. The AT1R and AT2R genotyping was done by duplex PCR and restriction fragment length polymorphism analysis. Both ACE homozygotes, II and DD, were significantly overrepresented in MS patients, compared to controls (χ(2) test p=0.03). Neither genotype nor allele frequencies of AT1R 1166A/C polymorphism were significantly different between patients and controls. Significant overrepresentation of AT2R -1332 AA genotype in female patients, compared to female controls, was detected (OR=1.67, 95%CI=1.13-2.49, χ(2) test p=0.01), suggesting that this genotype could be a gender-specific genetic risk factor for MS.

CXCL16 haplotypes in patients with human carotid atherosclerosis: preliminary results.

AIM Chemokine CXC ligand 16 (CXCL16) has chemoattractive, adhesive and scavenging properties and may play a role in the formation of atherosclerotic lesions. However, studies of CXCL16 polymorphisms in patients with atherosclerosis are scarce. The missense polymorphisms I123T and A181V are potentially important factors in the regulation of presentation and shedding of the CXCL16 chemokine domain. The aim of this study was to analyze the association between I123T and A181V polymorphism haplotypes and the accumulation of carotid plaque as well as the effect of the haplotype on the CXCL16 mRNA expression in carotid plaques in patients with advanced atherosclerosis. Additionally, we performed a bioinformatic prediction analysis of the impact of CXCL16 protein sequence variation on CXCL16-CXCR6 interactions and analyzed the soluble CXCL16 plasma levels according to the CXCL16 haplotype. METHODS This study evaluated a total of 733 participants, including 283 controls and 450 patients with carotid atherosclerosis (CA) undergoing endarterectomy. Analyses of the polymorphisms and the gene expression were performed using real-time PCR. The soluble CXCL16 levels were measured with ELISA. RESULTS The missense allele haplotype, T123V181, was found to be significantly and independently associated with the occurrence of CA plaque (OR=1.27;1.02-1.57, p=0.03). This haplotype was predicted to significantly change the CXCL16-CXCR6 interaction, compared to I123A181. Neither the CXCL16 mRNA expression in the human plaques nor the soluble CXCL16 plasma levels differed according to the haplotype. CONCLUSIONS These results indicate that the CXCL16 T123V181 haplotype is a moderate genetic risk factor for the development of carotid plaque. Further functional and replication studies are needed to clarify the mechanisms by which this combination of alleles promotes advanced CA and validate its impact on disease progression.

The Role of TPA I/D and PAI-1 4G/5G Polymorphisms in Multiple Sclerosis

Background. Previous studies have shown impaired fibrinolysis in multiple sclerosis (MS) and implicated extracellular proteolytic enzymes as important factors in demyelinating neuroinflammatory disorders. Tissue-type plasminogen activator (t-PA) and its inhibitor (PAI-1) are key molecules in both fibrinolysis and extracellular proteolysis. In the present study, an association of the TPA Alu I/D and PAI-1 4G/5G polymorphisms with MS was analyzed within the Genomic Network for Multiple Sclerosis (GENoMS). Methods. The GENoMS includes four populations (Croatian, Slovenian, Serbian, and Bosnian and Herzegovinian) sharing the same geographic location and a similar ethnic background. A total of 885 patients and 656 ethnically matched healthy blood donors with no history of MS in their families were genotyped using PCR-RFLP. Results. TPA DD homozygosity was protective (OR = 0.79, 95% CI 0.63–0.99, P = 0.037) and PAI 5G5G was a risk factor for MS (OR = 1.30, 95% CI 1.01–1.66, P = 0.038). A significant effect of the genotype/carrier combination was detected in 5G5G/I carriers (OR = 1.39 95% CI 1.06–1.82, P = 0.017). Conclusions. We found a significantly harmful effect of the combination of the PAI-1 5G/5G genotype and TPA I allele on MS susceptibility, which indicates the importance of gene-gene interactions in complex diseases such as MS.

Chemokines and chemokine receptors in the pathogenesis of multiple sclerosis

Multiple sclerosis (MS) is a chronic inflammatory and autoimmune, demyelinating disease of the central nervous system (CNS). Migration of autoreactive T lymphocytes into the CNS is one of the key processes that characterize the pathogenesis of MS and lead to the formation of inflammatory demyelinating CNS lesions. Chemokines represent a family of cytokines. They are low molecular weight soluble proteins, which affect target cells by binding to membrane chemokine receptors. Previous studies on experimental model of MS and experimental clinical studies confirmed that numerous chemokines and chemokine receptors, synthesized by CNS cells and various leukocyte populations, are an important component in the pathogenesis of MS. The essential role of chemokines in MS pathogenesis is to stimulate the migration of peripheral leukocytes into the CNS. In clinical pharmacological studies, it was demonstrated that the impact on expression of chemokines and chemokine receptors represents one of the mechanisms of action of pharmacological immunomodulatory agents used in the treatment of MS. It is difficult to allocate a pharmacological agent that permanently effectively suppresses the disease, and one of the reasons for that is complexity of the network of chemokines and chemokine receptors, in terms of their multitude and their variety of functions. Improved therapeutics that would be produced in the future, by acting through the individual components of complex network of chemokines and chemokine receptors, would selectively influence the migratory properties of pathogenic leukocyte populations, without compromising the functions of other components of the immune system.

Genetic Factors Underlying Susceptibility to Acute Pyelonephritis and Post-infectious Renal Damage

Symptomatic UTIs can be classified into infections limited to the lower urinary tract and in‐ fections of the upper urinary tract. Marked individual differences in susceptibility to UTIs have been known for decades. Through different molecular interactions bacteria may trigger epithelial cell responses, cause cell detachment and invade or kill cells by apoptosis. The in‐ dividual inflammatory response determines severity of acute pyelonephritis (APN) as well as differences in response to UTI among individuals. It is suggested that APN occurs more readily in high responders. Level of individual inflammatory response could be a key of enigma why some patients with APN develop renal scarring and progressive kidney dam‐ age whereas others do not.