Jiří Vácha

Two CD14 promoter polymorphisms and atopic phenotypes in Czech patients with IgE-mediated allergy.

Background: Immunoglobulin E (IgE)‐mediated allergy belongs to common chronic disorders resulting from an interaction between both genetic and environmental factors. The gene encoding CD14 is a positional candidate gene for allergic diseases as it is localized on chromosome 5q31.1, a region that is linked to asthma and bronchial hyperresponsiveness. Recently, several polymorphisms in the promoter region of this gene have been associated with atopic phenotypes in various populations.

Polymorphisms in the RAGE gene influence susceptibility to diabetes-associated microvascular dermatoses in NIDDM

To examine genetic polymorphism in the complete sequence of the Receptor of Advanced Glycation End products (RAGE) gene and its possible associations with diabetes-associated microvascular dermatoses (DAMD). Further, to analyze the distribution of individual genotype combinations on the particular polymorphic loci in the RAGE gene. A part of the RAGE gene spanning a region from -4 to 3334 bp was analyzed on a set of 45 subjects with non-insulin dependent diabetes mellitus (NIDDM) and parallel DAMD by means of PCR with subsequent heteroduplex and single-strand conformation polymorphism (SSCP) analyses. Allele frequencies and genotype combinations of novel common polymorphisms were determined in an associations study comprising four groups of subjects (n=390). Fourteen novel polymorphisms (R77C, V89V, 718G/T, 1704G/T, 1727A1728ins, H305Q, S307C, 2117A/G, 2184A/G, 2245G/A, 2249A/G, 2741G/A, and 3089ACdel) and one described previously (G82S) were identified. Significant association with microvascular dermatoses (MD) irrespective of NIDDM were found for exon mutation 82S (P= .004, after a correction for the number of comparisons P(corr) < .05) and marginally significant for intron variant 1704T (P= .032, P(corr)> .05). Calculated odds ratios for 82S and 1704T were 4.73 (95% CI, 1.51 to 14.77) and 1.73 (95% CI, 0.93 to 3.22), respectively. Certain individual genotype combinations of G82S, 1704G/T, and 2184A/G were significantly associated with the presence of MD (P= .00647) both in diabetic and non-diabetic study populations. The two novel polymorphisms (1704G/T and 2184A/G) together with the G82S were shown to influence the susceptibility to MD independent of diabetes itself.

Promoter polymorphisms in the CD14 receptor gene and their potential association with the severity of chronic periodontitis

Periodontitis, a chronic inflammation of the tissues surrounding the teeth, is a common disease affecting all populations. The main aetiology remains a bacterial infection that leads to gingival inflammation, loss of alveolar bone, and tooth loss.1 Although the presence of pathogenic micro-organisms is required to trigger this process, the amplification and progression of the disease is believed to rely heavily on the production of host mediators in response to bacteria and/or their metabolic products.2 The CD14 molecule, described as the major endotoxin receptor, is one of the receptors which act on the recognition of lipopolysaccharides (LPS, endotoxin) and gram positive or mycobacterial cell wall components and thus can initiate the innate immune response to bacterial invasion.3–5 It is constitutively expressed primarily on the surface of monocytes, macrophages, neutrophils, and gingival fibroblasts (mCD14).6 In addition, a soluble form of CD14 (sCD14) is abundant in serum and is apparently derived both from the secretion of CD14 and from enzymatically cleaved glycosyl-phosphatidylinositol anchored mCD14.7 Besides the role of CD14 in the host defence, several other biological functions have been found. CD14 is involved in the phagocytosis of gram negative bacteria,8 LPS mediated bone resorption,9 and monocyte-endothelial cell interactions. Furthermore, changes in CD14 expression and serum sCD14 levels seem to be associated with a number of pathological states including periodontal diseases.10 CD14 production is genetically regulated. The gene for the CD14 receptor is on chromosome 5 (region q23-21), consists of ≈3900 bp organised in two exons, and encodes a protein of 375 amino acids.11 In the promoter region of the CD14 gene, a C to T transition was identified at position –159 upstream from the major transcription site, which is near to an SP1 binding site that has a major influence on the monocyte …

Polymorphism 4G/5G in the plasminogen activator inhibitor‐1 (PAI‐1) gene is associated with IgE‐mediated allergic diseases and asthma in the Czech population

Background: Plasminogen activator inhibitor type 1 (PAI‐1) is a glycoprotein that belongs to the serine protease inhibitor superfamily and has an essential role in tissue remodeling after inflammation. Recently, a single base pair deletion/insertion (4G/5G) polymorphism of the PAI‐1 gene has been associated with an increased risk of asthma in nuclear families from the UK.

TGF-beta1 gene polymorphisms

Transforming growth factor beta (TGF-beta) is a pleiotropic cytokine with significant anti-inflammatory and immunosuppressive properties. The single base pair polymorphism located at -509 (C/T) in the promoter region of the TGF-beta1 gene was previously shown to be associated with elevated total serum IgE levels. We tested the hypothesis that polymorphic alleles of the TGF-beta1 gene are associated with allergies and asthma.

Interactions of Lymphotoxin alpha (TNF-beta), Angiotensin-Converting Enzyme (ACE) and Endothelin-1 (ET-1) Gene Polymorphisms in Adult Periodontitis

BACKGROUND Adult periodontitis is a complex multifactorial disease whose etiology is not well defined. To investigate whether the genes encoded within the HLA class III region may confer susceptibility to periodontitis, polymorphisms in the ET-1 and TNF-β genes were analyzed together with the I/D polymorphism of the ACE gene. METHODS We determined allele and genotype frequencies of the NcoI bi-allelic polymorphism of the TNF-β gene, the I/D (insertion/deletion) polymorphism of the ACE gene, and the TaqI polymorphism of the ET-1 gene in 63 Caucasian patients with adult periodontitis and 95 orally healthy controls. RESULTS We found a significant difference in a 3 locus combination of genotypes between patients and controls (P <0.05). In the next analyses, no significant differences were found in allele frequencies of single genes, but we did find a significant difference in the genotype distribution between cases and controls for TNF-β (P <0.03). Differences were also observed for 2 locus combinations of ACE and TNF-β genotypes (P <0.03), and the ET-1 and TNF-β (P <0.05) genes. Evidence of deviation from Hardy-Weinberg equilibrium was observed in the periodontitis group for TNF-β, with an absence of the B1 B1 homozygotes in patients. CONCLUSIONS This study is of an exploratory nature. Considering the number of significant results, however, at least a part of the observed associations may obviously be real and our findings suggest that interactions of the TNF-β, ET-1, and ACE genes may be involved in susceptibility to adult periodontitis. J Periodontol 2001;72:85-89.

Granulocyte colony-stimulating factor and drugs elevating extracellular adenosine synergize to enhance haematopoietic reconstitution in irradiated mice

Abstract: The activation of adenosine receptors has recently been demonstrated to stimulate haematopoiesis. In the present study, we investigated the ability of drugs elevating extracellular adenosine to influence curative effects of granulocyte colony‐stimulating factor (G‐CSF) in mice exposed to a sublethal dose of 4 Gy of 60Co radiation. Elevation of extracellular adenosine in mice was induced by the combined administration of dipyridamole, a drug inhibiting the cellular uptake of adenosine, and adenosine monophosphate (AMP), an adenosine prodrug. The effects of dipyridamole plus AMP, and G‐CSF, administered either alone or in combination, were evaluated. The drugs were injected to mice in a 4‐d treatment regimen starting on d 3 after irradiation and the haematopoietic response was evaluated on d 7, 10, 14, 18 and 24 after irradiation. While the effects of G–CSF on the late maturation stages of blood cells, appearing shortly after the completion of the treatment, were not influenced by dipyridamole plus AMP, positive effects of the combination therapy occurred in the post‐irradiation recovery phase which is dependent on the repopulation of haematopoietic stem cells. This was indicated by the significant elevation of counts of granulocyte‐macrophage progenitor cells (GM‐CFC) and granulocytic cells in the bone marrow (d 14), of GM‐CFC (d 14), granulocytic and erythroid cells (d 14 and 18) in the spleen, and of neutrophils (d 18), monocytes (d 14 and 18) and platelets (d 18) in the peripheral blood. These effects suggest that the repopulation potential of the combination therapy lies in a common multilineage cell population. The results of this study implicate the promising possibility to enhance the curative effects of G–CSF under conditions of myelosuppressive states induced by radiation exposure.

Two MMP-2 promoter polymorphisms (-790T/G and -735C/T) in chronic heart failure

Abstract Remodelling of extracellular matrix by activated matrix metalloproteinases is considered to contribute to progression of ventricle remodelling during chronic heart failure. The aim of this study was to associate two promoter polymorphisms, -790T/G and -735C/T, in the gene for matrix metalloproteinase (MMP)-2 (gelatinase A) with chronic heart failure (CHF). For this purpose, 164 patients (124 men, 40 women, median age 56 years, range 21-91 years) with CHF (functional class NYHA II-IV, ejection fraction median 25%, cardiothoracic index more than 50%) were compared with 196 control subjects without clinical signs of cardiovascular disease (131 men and 65 women, median age 56 years, range 27-84 years) in -790T/G and -735C/T MMP-2 genotype distributions and allelic frequencies. The genotypes were determined by polymerase chain reaction (PCR) with restriction analyses. A significant increase of the T allele of the -790T/G MMP-2 polymorphism (p = 0.04), as well as of the C allele of the -735C/T MMP-2 gene polymorphism, in patients with CHF was proven (p = 0.04). The heterozygote CT of the 735C/T MMP-2 polymorphism exhibits a 7 times higher odds ratio (OR) for the CHF patients with lower levels of total cholesterol (less than 5 mmol/l), especially for nonhypertensive CHF men (OR = 7.28, 95% confidence interval 1.51-35.03, p = 0.006). Determination of MMP polymorphisms in the regulatory area of the gene could help us to comprehend individual susceptibility of patients with CHF to MMP inhibitors based on known risks of MMP genotypes. Clin Chem Lab Med 2003; 41(10):12991303

Drugs elevating extracellular adenosine promote regeneration of haematopoietic progenitor cells in severely myelosuppressed mice: their comparison and joint effects with the granulocyte colony-stimulating factor.

Abstract: We tested capabilities of drugs elevating extracellular adenosine and of granulocyte colony‐stimulating factor (G‐CSF) given alone or in combination to modulate regeneration from severe myelosuppression resulting from combined exposure of mice to ionizing radiation and carboplatin. Elevation of extracellular adenosine was induced by joint administration of dipyridamole (DP), a drug inhibiting the cellular uptake of adenosine, and adenosine monophosphate (AMP), serving as an adenosine prodrug. DP + AMP, G‐CSF or all these drugs in combination were administered in a 4‐d treatment regimen starting on day 3 after induction of myelosuppression. Comparable enhancements of haematopoietic regeneration due to elevation of extracellular adenosine or to action of G‐CSF were demonstrated as shown by elevated numbers of haematopoietic progenitor cells for granulocytes/macrophages (GM‐CFC) and erythrocytes (BFU‐E) in the bone marrow and spleen in early time intervals after termination of the drug treatment, i.e. on days 7 and 10 after induction of myelosuppression. Coadministration of all the drugs further potentiated the restoration of progenitor cell pools in the haematopoietic organs. The effects of the drug treatments on progenitor cells were reflected in the peripheral blood in later time intervals of days 15 and 20 after induction of myelosuppression, especially as significantly elevated numbers of granulocytes and less pronounced elevation of lymphocytes and erythrocytes. The results substantiate the potential of drugs elevating extracellular adenosine for clinical utilization in myelosuppressive states, e.g. those accompanying oncological radio‐ and chemotherapy.

C766T low-density lipoprotein receptor-related protein 1 (LRP1) gene polymorphism and susceptibility to breast cancer.

BackgroundLow-density lipoprotein receptor-related protein 1 (LRP1) is a multifunctional endocytic receptor with an important role in regulating the activity of proteinases in extracellular matrix. Several studies have also described its role in intracellular signaling. Previous studies showed that the expression of LRP1 is related to invasiveness of cancer cells. However, recent data on LRP1 suggest that this receptor can also be involved in tumor establishment and progression.MethodsWe investigated an association between the C766T polymorphism of the third exon of the LRP1 gene and breast cancer in a sample of women of Caucasian origin. Allele and genotype frequencies of this polymorphism were assessed in 164 women with breast cancer and in 183 age-compatible women without a history of any cancer disease.ResultsAn increase in LRP1 T allele frequency in subjects with breast cancer was observed compared with controls (0.21 versus 0.15, P = 0.01963). A significant excess of genotypes with the T allele (homozygotes plus heterozygotes) was also observed (odds ratio 1.743, 95% confidence interval 1.112–2.732).ConclusionThe T allele of the C766T polymorphism in the LRP1 gene is associated with an increased risk of breast cancer development in women of Caucasian origin.