MicroRNA and hyperaggregability of platelets in women with sticky platelet syndrome and pregnancy complications.

AIMS: We aimed to characterize relationship between the expression profiles of platelet miR-96, miR-126 and miR-223 and platelet function examination in patients with sticky platelet syndrome (SPS) and in healthy controls. BACKGROUND: MicroRNAs (miRNA, miR) are a group of small and non-coding RNAs involved in many mechanisms as regulators of post-transcriptional protein expression in platelets. SPS is defined as platelet hyperaggregability after administration of low doses of adenosine diphosphate and/or epinephrine. Clear genetic abnormality of this syndrome is not known yet. METHODS: We examined 45 patients with SPS and 30 healthy volunteers. For functional platelet examination we used light transmission aggregometry, and qRT-PCR was used to determine the expression of the miRNAs. RESULTS: We observed no relationship of the platelet miRNA expression with functional platelet examination in the entire cohort of patients with SPS. However, in a group of patients with SPS and pregnancy complications, we found that the expression of platelet miR-96 (p = 0.009) was up-regulated. CONCLUSION: In spite of the multiple limitations of the study, it can be considered that the increased expression of platelet miR-96 found in a group of patients with SPS and pregnancy complications could be related to the hyperaggregability in these selected patients (Tab. 2, Ref. 31).

Methylation of MMP2, TIMP2, MMP9 and TIMP1 in abdominal aortic aneurysm.

OBJECTIVES: Abdominal aortic aneurysm (AAA) and its complications are among the most serious cardiovascular diseases and its occurrence has risen sharply in recent years. The aim of this pilot study is to explore the relationship between the methylation of matrix metalloproteinases and tissue inhibitors of the metalloproteinases genes' promoter region, and abdominal aortic aneurysm (AAA) through the detection of the methylation status of MMP2, TIMP2, TIMP1, and MMP9 genes in peripheral blood. METHODS: The study included 43 males with verified AAA (case group) and 34 healthy males (control group). The methylation status of the genes' promoter region was detected by methylation-specific polymerase chain reaction (MS-PCR). RESULTS: In adominal aortic aneurysm patients, the methylation ratio of MMP2 gene was positive in 9.3 % (4 cases), 2.3 % (1 case) had methylated TIMP2 gene, 7.0 % (3 cases) had methylated TIMP1 gene, while the methylation ratio of MMP9 gene was positive in 93.0 % (40 cases). In the control group, MMP2 gene was found to be methylated in 5.9 % (2 cases), 5.9 % of cases had methylated TIMP2 and TIMP1 genes (2 cases), and MMP9 gene was found to be methylated in 91.2 % (31 cases). CONCLUSION: In our pilot study, we found no association between DNA methylation of gelatinases and their tissue inhibitors, and the development of an abdominal aortic aneurysm (Tab. 2, Fig. 1, Ref. 27).

Associations of CYP1A2 Polymorphisms with the Risk Haplotypes in Lung Cancer in the Slovak Population.

Phase I enzymes, including cytochrome P450, family 1, subfamily A, and polypeptide 2 (CYP1A2), are involved in the activation of carcinogens to reactive intermediates that are capable of binding covalently to DNA to form DNA adducts, potentially initiating the carcinogenic process. The aim of present study was to investigate the association of CYP1A2 gene polymorphisms and haplotypes with lung cancer risk. A case-control study was carried out on 105 lung cancer patients and 189 controls. To investigate three CYP1A2 polymorphisms: rs2472299, rs2470890, rs11072508 we used a high resolution melting analysis. We found significant allele associations (rs2470890 and rs2422299) with lung cancer risk. We searched for meaningful associations for all variants in the dominant, recessive, and additive genetic models. Genotype associations in the recessive model were of marginal significance for the same single nucleotide polymorphisms. A haplotype analysis included five variants with the frequency higher than 1 %. The haplotype "acc", present with the highest frequency, was associated with increased lung cancer risk (38.7 % vs. 31.5 %; OR 1.38; 95 %CI 0.95-2.01). On the contrary, rare haplotype "gtc" was significantly associated with decreased lung cancer risk in the Slovak population. In conclusion, the present study identified the risk alleles and haploid genotype associations of the CYP1A2 gene in lung cancer.

Polymorphisms of Selected DNA Repair Genes and Lung Cancer in Chromium Exposure.

Chromium is a well-known mutagen and carcinogen involved in lung cancer development. DNA repair genes play an important role in the elimination of genetic changes caused by chromium exposure. In the present study, we investigated the polymorphisms of the following DNA repair genes: XRCC3, participating in the homologous recombination repair, and hMLH1 and hMSH2, functioning in the mismatch repair. We focused on the risk the polymorphisms present in the development of lung cancer regarding the exposure to chromium. We analyzed 106 individuals; 45 patients exposed to chromium with diagnosed lung cancer and 61 healthy controls. Genotypes were determined by a PCR-RFLP method. We unravelled a potential for increased risk of lung cancer development in the hMLH1 (rs1800734) AA genotype in the recessive model. In conclusion, gene polymorphisms in the DNA repair genes underscores the risk of lung cancer development in chromium exposed individuals.

Polymorphisms of DNA repair genes and lung cancer in chromium exposure.

Chromium is a well known carcinogen involved in the lung cancer development. Polymorphism of some of the DNA repair genes may be associated with elevated risk of cancerous transformation. In the present study, we investigated the polymorphisms of the following selected members of the base and nucleotide excision repair genes: XPC (Lys939Gln), XPD (Lys751Gln), XRCC1(Arg399Gln), and hOGG1(Ser326Ser), and the risk they present toward the development of lung cancer, with emphasis on the effect of chromium exposure. We analyzed 119 individuals; 50 patients exposed to chromium with diagnosed lung cancer and 69 healthy controls. Genotypes were determined by a PCR-RFLP method. We found a significantly increased risk of lung cancer development in XPD genotype Lys/Gln (OR=1.94; 95% CI=1.10-3.43; p=0.015) and in the gene combinations: XPD Lys/Gln+XPC Lys/Gln (OR=6.5; 95% CI=1.53-27.49; p=0.009) and XPD Lys/Gln+XPC Gln/Gln(OR=5.2; 95% CI=1.07-25.32; p=0.04). In conclusion, gene polymorphisms in the DNA repair genes may underscore the risk of lung cancer development in the chromium-exposed individuals.

Mismatch repair gene polymorphisms and association with lung cancer development.

hMLH1 and hMSH2 are two of the main members of the mismatch repair (MMR) genes family. Polymorphism of MMR genes is associated with a risk of developing sporadic and hereditary tumors. In the present case-control study, we investigated the promoter polymorphisms of selected mismatch repair genes: hMLH1 (rs1800734) and hMSH2 (rs2303425), and the risk they present regarding the development of lung cancer in the Slovak population. The study included 422 lung cancer cases, 511 controls for hMLH1 gene and 486 controls for hMSH2 gene. Polymorphism was investigated by a PCR-RFLP method. The risk of cancer development was evaluated in both dominant and recessive genetic models. The evaluation of rs1800734 polymorphism in patients in the dominant model showed a significantly decreased risk of lung cancer in the presence of at least one variant allele A (genotype GA and AA) (OR=1.40; 95% CI=1.08-1.82; p=0.01). These findings were equally strong expressed in women (OR=2.00; 95% CI=1.23-3.25; p=0.006). The results for rs2303425 polymorphism revealed an increased risk of lung cancer for variant genotype CC (OR=2.28; 95% CI=1.12-4.63; p=0.024) in the recessive model. A combination of rs1800734 and rs2303425 polymorphisms was shown to be risky for genotype GGCC; OR=3.08; 95% CI=1.09-8.72; p=0.03. The risk appeared even greater in female gender; (OR=11.56; 95% CI=1.33-100.36, 1.26-94.66; p=0.005. We conclude that the genotype of mismatch repair genes underscores the risk of lung cancer development in the Slovak population.

Activity of coagulation factor XI in patients with spontaneous miscarriage: the presence of risk alleles.

The aim of this study was to compare the activity of coagulation factor XI (FXI) between patients with spontaneous miscarriage versus control group with no history of miscarriage and thrombosis, and then we evaluated the occurrence of risk alleles in the relation to miscarriage. FXI activity was determined using a coagulometer (Sysmex, CA 1500, Japan). Single nucleotide polymorphisms (SNPs) of F11 and CYP4V2 genes were evaluated. We examined 55 patients versus 31 control subjects. We found significantly higher activity of FXI (p = 0.04) in patients versus control subjects. The occurrence of two SNPs (rs2289252 and rs2036914) of the F11 gene and SNP (rs13146272) of CYP4V2 gene was not significantly different between both groups. Increased activity of FXI may be a potential risk factor for miscarriage. High activity of FXI diagnosed in women with history of miscarriage is not probably caused by the presence of studied SNPs.

Cytotoxic T lymphocyte antigen 4 (CTLA-4) dimorphism in patients with systemic lupus erythematosus.

OBJECTIVE: Genetic susceptibility to systemic lupus erythematosus (SLE) is conferred not only by various genes within the major histocompatibility complex (MHC) region, but also by several other non-MHC linked genes. The negatively signalling molecule CTLA-4 is involved in establishing and maintaining of peripheral T cell tolerance, which controls T cell activation and reactivity. Its attenuating action helps to prevent an inappropriate initiation of T cell responses to self antigens and to terminate ongoing T cell responses. We tested if there was an association between CTLA-4 and SLE, a disease with B and T cell hyperreactivity and impaired peripheral T cell tolerance. METHODS: Using the polymerase chain reaction--restriction fragment length polymorphism method with Bbv I digestion, we assessed an exon 1 transition dimorphism (49 A/G) of the CTLA-4 gene in 102 SLE patients and in 76 healthy controls. RESULTS: The distribution of CTLA-4 exon 1 genotypes in the SLE group was significantly different from that in the controls (chi 2 = 6.178, p < 0.05). 17.6% of the SLE patients were G/G homozygotes compared to 5.3% of the controls; 36.3% were A/G heterozygotes vs 40.8% of controls; and 46.1% were A/A homozygotes vs 53.9% of the controls. The frequency of the G allele was significantly higher in SLE patients (35.8%) than in controls (25.7%; chi 2 = 4.142, p = 0.042). CONCLUSION: Our results indicate that the non-MHC linked CTLA-4 gene could confer susceptibility in SLE, as it does in various other autoimmune diseases (Hashimoto thyroiditis, Graves' disease, IDDM).

Association between systemic lupus erythematosus and insertion/deletion polymorphism of the angiotensin converting enzyme (ACE) gene.

OBJECTIVE: ACE takes part in the renin-angiotensin and kallikrein-kininogen systems by creating angiotensin-II and inactivating bradykinin. ACE gene insertion/deletion polymorphism is associated with the level of circulating enzymes--subjects with the DD genotype have higher levels of circulating ACE than subjects with the II genotype and show an increased tendency towards impaired vascular function and structure. Patients with systemic lupus erythematosus (SLE) suffer from differentially expressed vascular pathology. We attempted to determine whether the type of ACE polymorphism could contribute to this pathology. METHODS: 101 SLE patients fulfilling the ACR criteria were investigated. The I/D polymorphism was ascertained by PCR, followed by electrophoresis of the amplified fragments and UV visualization. RESULTS: The frequency of the D allele was higher in the SLE group (0.623) than in the controls (0.520) (chi 2 test, p < 0.025). The distribution of the ACE genotype in SLE group was different from that in the control group (p < 0.05). An association between the DD genotype and visceral damage (p < 0.006) was observed. CONCLUSION: Our results suggest that in the multifactorially determined vascular pathology of SLE, changes associated with I/D polymorphism could influence vessel wall inflammation (monocyte adhesion and activation with cytokine release, T-lymphocyte metabolism), a tendency towards vascular impairment (neointimal proliferation, vasospasm, platelet activation, myocyte proliferation) and lead to the subsequent ischemia. The ACE gene could serve as the visceral damage indicator in SLE.

[Is PLA1/A2 gene polymorphism of platelet membrane glycoprotein IIIa a risk factor for myocardial infarct?]. / Je PLA1/A2 polymorfizmus génu pre trombocytárny membránový glykoproteín IIIa rizikovým faktorom infarktu myokardu?

BACKGROUND: The PlA1/A2 polymorphism of the human platelet membrane glycoprotein IIIa gene cause T-->C transition in the exon ii (position 1565) resulting in the leucine-->proline substitution in amino-acid sequence. This polymorphism was shown to be associated with increased risk of myocardial infarction (MI). AIM: To test genetic parameters of the PlA1/A2 polymorphism in our population and to assess the relation between mutant PlA2 allele and MI. METHODS: DNA was isolated from peripheral blood, collected from 40 patients with MI and with present risk factors (hypertension, hypercholesterolaemia, diabetes, obesity, smoking...), 33 patients with MI without risk factors, 34 controls with equivalent average age to both groups of the MI-patients, 58 control probands without MI in their family history and 33 healthy controls randomly recruited. After PCR amplification the resulting 267 bp fragment was digested with the restriction endonuclease NciI and subfragments were separated electrophoretically in 12% polyacrylamide gel. RESULTS: The frequency of the PlA2 allele was 0.121 in patients with MI without risk factors, 0.205 in patients with present risk factors, 0.162 in controls of the equivalent average age to the MI-patients, 0.172 in controls without MI in their family history and 0.20 in healthy controls randomly recruited. Genotype frequencies were in all groups in genetic equilibrium. Although the groups differed significantly (p < 0.01) in serum concentrations of total cholesterol, HDL-cholesterol, LDL-cholesterol, apolipoprotein A-1, apolipoprotein B and malondialdehyde, no significant differences in the serum concentrations of these metabolites between A1/A1, A1/A2 and A2/A2 genotypes were observed. CONCLUSIONS: PLA1/A2 polymorphism is associated with MI, however not as a dominant risk factor, but as a part of environmentally influencable multigene system. There is no relation between genotypes of the PLA1/A2 polymorphism and the lipoproteins plasma concentrations. (Tab. 4, Ref. 17.)