Zsolt Nagy - Academia.edu (original) (raw)
Papers by Zsolt Nagy
Orvosi Hetilap, 2011
Women with a history of breast cancer are common at centers for cancer genetic risk all over Euro... more Women with a history of breast cancer are common at centers for cancer genetic risk all over Europe. Given limited health care resources, managing this demand, while achieving good value for money coming from health services, is generally a major challenge. This paper recapitulates and summarizes the available methods of the risk assessment of familial breast cancer. After a systematic review of the literature Gail-model, Claus-model and BOADICEA-model were selected, as well as softwares (LINKAGE software; MENDEL v3.3 software) available in the application of these algorhythms are also summarized. Comparisons were made between the models concerning their advantages and disadvantages. The really reliable methods of risk estimation of familial breast cancer are always based on the analysis of the pedigree structure and allow the estimation of the patient’s probability of carrying a susceptibility gene under a particular genetic model, given her family history. For this method the know...
BMC psychiatry, Jul 17, 2017
Marfan syndrome is a genetic disease, presenting with dysfunction of connective tissues leading t... more Marfan syndrome is a genetic disease, presenting with dysfunction of connective tissues leading to lesions in the cardiovascular and skeletal muscle system. Within these symptoms, the most typical is weakness of the connective tissue in the aorta, manifesting as aortic dilatation (aneurysm). This could, in turn, become annuloaortic ectasia, or life-threatening dissection. As a result, life-saving and preventative cardiac surgical interventions are frequent among Marfan syndrome patients. Aortic aneurysm could turn into annuloaortic ectasia or life-threatening dissection, thus life-saving and preventive cardiac surgical interventions are frequent among patients with Marfan syndrome. We hypothesized that patients with Marfan syndrome have different level of anxiety, depression and satisfaction with life compared to that of the non-clinical patient population. Patients diagnosed with Marfan syndrome were divided into 3 groups: those scheduled for prophylactic surgery, those needing acu...
Cardiology Journal, 2013
The starting point, in Marfan syndrome (MFS) appears to be the mutation of fi brillin-1 gene whos... more The starting point, in Marfan syndrome (MFS) appears to be the mutation of fi brillin-1 gene whose deconstructed protein product cannot bind transforming growth factor beta (TGF-b), leading to an increased TGF-b tissue level. The aim of this review is to review the already known features of the cellular signal transduction downstream to TGF-b and its impact on the tissue homeostasis of microfi brils, and elastic fi bers. We also investigate current data on the extracellular regulation of TGF-b level including mechanotransduction and the feedback cycles of integrin-dependent and independent activation of the latent TGF-b complex. Together these factors, by the destruction of the connective tissue fi bers, may play an important role in the development of the diverse cardiac and extracardiac manifestations of MFS and many of them could be a target of conservative treatment. We present currently investigated drugs for the treatment of the syndrome, and explore possible avenues of research into pathogenesis of MFS in order to improve understanding of the disease.
FEBS Letters, 2004
To pro¢le gene expression patterns involved in the direct myocardial e¡ect of cholesterol-enriche... more To pro¢le gene expression patterns involved in the direct myocardial e¡ect of cholesterol-enriched diet-induced hyperlipidemia, we monitored global gene expression changes by DNA microarray analysis of 3200 genes in rat hearts. Twentysix genes exhibited signi¢cant up-regulation and 25 showed down-regulation in hearts of rats fed a 2% cholesterol-enriched diet for 8 weeks as compared to age-matched controls. The expression changes of 12 selected genes were also assessed by real-time quantitative polymerase chain reaction. Genes with altered expression in the heart due to hyperlipidemia included procollagen type III, co¢lin/destrin, tensin, transcription repressor p66, synaptic vesicle protein 2B, Hsp86, chaperonin subunit 5O O, metallothionein, glutathione S-transferase, protein kinase C inhibitor, ATP synthase subunit c, creatine kinase, chloride intracellular channel 4, NADH oxidoreductase and dehydrogenase, ¢bronectin receptor L L chain, CD81 antigen, farnesyltransferase, calreticulin, disintegrin, p120 catenin, Smad7, etc. Although some of these genes have been suspected to be related to cardiovascular diseases, none of the genes has been previously shown to be involved in the mechanism of the cardiac e¡ect of hyperlipidemia.
European Journal of Obstetrics & Gynecology and Reproductive Biology, 2012
European Journal of Obstetrics & Gynecology and Reproductive Biology, 2012
BMC Cardiovascular Disorders, 2014
Background: According to previous studies, aortic diameter alone seems to be insufficient to pred... more Background: According to previous studies, aortic diameter alone seems to be insufficient to predict the event of aortic dissection in Marfan syndrome (MFS). Determining the optimal schedule for preventive aortic root replacement (ARR) aortic growth rate is of importance, as well as family history, however, none of them appear to be decisive. Thus, the aim of this study was to search for potential predictors of aortic dissection in MFS. Methods: A Marfan Biobank consisting of 79 MFS patients was established. Thirty-nine MFS patients who underwent ARR were assigned into three groups based on the indication for surgery (dissection, annuloaortic ectasia and prophylactic surgery). The prophylactic surgery group was excluded from the study. Transforming growth factor-β (TGF-β) serum levels were measured by ELISA, relative expression of c-Fos, matrix metalloproteinase 3 and 9 (MMP-3 and −9) were assessed by RT-PCR. Clinical parameters, including anthropometric variables-based on the original Ghent criteria were also analyzed. Results: Among patients with aortic dissection, TGF-β serum level was elevated (43.78 ± 6.51 vs. 31.64 ± 4.99 ng/l, p < 0.0001), MMP-3 was up-regulated (Ln2 α = 1.87, p = 0.062) and striae atrophicae were more common (92% vs. 41% p = 0.027) compared to the annuloaortic ectasia group. Conclusions: We found three easily measurable parameters (striae atrophicae, TGF-β serum level, MMP-3) that may help to predict the risk of aortic dissection in MFS. Based on these findings a new classification of MFS, that is benign or malignant is also proposed, which could be taken into consideration in determining the timing of prophylactic ARR.
Orvosi Hetilap, 2012
There is compelling evidence for a genetic contribution to physical performance. In addition, the... more There is compelling evidence for a genetic contribution to physical performance. In addition, there is an advanced scientific knowledge on the predisposition to sports-related diseases and injuries. Genetic testing of performance related polymorphisms can serve as a new opportunity for developing the process of talent selection. Sport-related genetic information may also allow for individualization of the training and improve performance. Genetic testing may also play an important role in the pre-participation screening for injuries and disease risks. Orv. Hetil., 2012, 153, 1247–1255.
Folic acid metabolism enzyme polymorphisms are believed to be responsible for the elevation of ho... more Folic acid metabolism enzyme polymorphisms are believed to be responsible for the elevation of homocysteine (HCY) concentration in the blood plasma, correlating with the pathogenesis of aortic aneurysms and aortic dissection. We studied 71 Marfan patients divided into groups based on the severity of cardiovascular involvement: no intervention required (n=27, Group A); mild involvement requiring intervention (n=17, Group B); severe involvement (n=27, Group C) subdivided into aortic dilatation (n=14, Group C1) and aortic dissection (n=13, Group C2), as well as 117 control subjects. We evaluated HCY, folate, vitamin B12 and the polymorphisms of methylenetetrahydrofolate reductase (MTHFR;c.665C>T and c.1286A>C), methionine synthase (MTR;c.2756A>G) and methionine synthase reductase (MTRR;c.66A>G). Multiple comparisons showed significantly higher levels of HCY in Group C2 compared to Groups A, B, C1 and control group (p< 0.0001, p< 0.0001, p=0.001 and p=0.003, respectively). Folate
was lower in Group C2 than in Groups A, B, C1 and control subjects (p< 0.0001, p=0.02, p< 0.0001 and p< 0.0001, respectively). Group C2 had the highest prevalence of homozygotes for all four gene polymorphisms. Multivariate logistic regression analysis revealed that HCY plasma level was an independent risk factor for severe cardiovascular
involvement (Group C; odds ratio [OR] 1.85, 95 % confidence interval [CI] 1.28–2.67, p=0.001) as well as for aortic dissection (Group C2; OR 2.49, 95 %CI 1.30–4.78, p=0.006). In conclusion, severe cardiovascular involvement in Marfan patients, and especially aortic dissection, is associated with higher HCY plasma levels and prevalence of homozygous genotypes of folic acid metabolism enzymes than mild or no cardiovascular involvement. These results suggest that impaired
folic acid metabolism has an important role in the development and remodelling of the extracellular matrix of the aorta.
We examined the gene expression profile of genes involved in bone metabolism in 23 patients with ... more We examined the gene expression profile of genes involved in bone metabolism in 23 patients with PD compared with 23 healthy controls. We found a significant overexpression of the genes of the IFN pathway along with a downregulation of tnf-alpha. Our result suggest that IFN-mediated signaling may play important roles in aberrant osteoclastogenesis of PD.
INTRODUCTION:
Paget's disease of bone (PD) is characterized by focal regions of highly exaggerated bone remodeling and aberrant osteoclastogenesis. Under physiological conditions, circulating monocytes may serve as early progenitors of osteoclasts and along with peripheral blood lymphocytes produce a wide variety of factors important in bone metabolism. Nevertheless, little is known about the roles of circulating monocytes and lymphocytes in relation to the pathological bone turnover in PD.
MATERIALS AND METHODS:
In this study, we aimed at investigating the gene expression pattern of PD using quantitative real-time PCR in monocytes and lymphocytes isolated from peripheral blood mononuclear cells (PBMCs). Fifteen genes known to be involved in osteoclastogenesis were studied in cells from 23 patients with PD and in cells from 23 healthy controls. Eight human genes including ifn-alpha (3.48-fold, p < 0.001), ifn-beta (2.68-fold, p < 0.001), ifn-gamma (1.98-fold, p = 0.002), p38 beta2 mapk (2.47-fold, p = 0.002), ifn-gammar1 (2.03-fold, p = 0.01), ifn-gammar2 (1.81-fold, p = 0.02), stat1 (1.57-fold, p = 0.037), and tnf-alpha (-2.34, p < 0.001) were found to be significantly altered in pagetic monocytes compared with monocytes of healthy controls.
RESULTS:
In pagetic lymphocytes, significant changes in the expression of ifn-alpha (2.17-fold, p < 0.001), ifn-beta (2.13-fold, p = 0.005), ifn-gamma (1.89-fold, p < 0.001), ifn-gammar1 (1.02-fold, p = 0.04), ifn-gammar2 (1.01-fold, p = 0.031), stat2 (1.79-fold, p < 0.001), and tnf-alpha (-1.49, p < 0.001) were found compared with lymphocytes of healthy controls. Furthermore, IFN-gamma protein was significantly elevated in the sera of PD patients (18.7 +/- 6.69 pg/ml) compared with healthy controls (3.87 +/- 6.48 pg/ml, p = 0.042).
CONCLUSIONS:
In conclusion, our data suggest that novel pathways mainly related to the IFN-mediated signaling may play important roles in the aberrant osteoclastogenesis of PD.
Site-directed PCR-based mutagenesis methods are widely used to generate mutations. All published ... more Site-directed PCR-based mutagenesis methods are widely used to generate mutations. All published methods work on DNA clones carrying the target sequence. However, DNA clones are not always available. We have previously published a RT-PCR-based site-directed mutagenesis method starting from total RNA to overcome this problem. In this article, we report an improvement of our previous method to facilitate introduction of multiple mutations into a target sequence. We demonstrate the efficacy and feasibility of this strategy by mutation of the human beta-actin gene. BamHI restriction endonuclease cleavage sites were generated within the gene to assist screening. Using three mutagenic primers in a single RT-PCR reaction, seven different clones were produced carrying three single and four multiple mutations. An investigation of the effect of the cycle number and elongation time of the PCR reactions revealed that both have an influence on the ratio of clones carrying single and multiple mutations. An optimized protocol was established for efficient multiple site-directed mutagenesis.
Polymorphisms of the peptidylarginine deiminase 4 (PADI4) gene encoding for the isoenzyme that co... more Polymorphisms of the peptidylarginine deiminase 4 (PADI4) gene encoding for the isoenzyme that converts arginyl into citrullyl residues have been shown to contribute to susceptibility to rheumatoid arthritis (RA), depending on the population studied. We aimed at determining whether PADI4 single nucleotide polymorphisms (SNPs) are associated with RA in a Hungarian population. The relationship between anticyclic citrullinated peptide (anti-CCP) production and HLA-DRB1 alleles encoding the shared epitope (SE) was also investigated. DNA samples were obtained from RA (n = 261) patients and from control donors (n = 120). HLA-DRB1 genotyping was carried out by polymerase chain reaction (PCR) with sequence-specific priming. PAD4_92 G/C and PAD4_104 T/C SNPs were genotyped using real-time PCR allele discrimination. Autoantibodies against CCP were detected by ELISA. All healthy controls tested anti-CCP negative, whereas 171 (66%) RA patients were anti-CCP positive. No significant difference in allele or genotype frequencies were found between RA patients and controls for any of the PADI4 SNPs. Anti-CCP seropositivity was unrelated to these two SNPs. No association was found between any of the PADI4 SNPs and HLA-DRB1 subtypes. Presence of the HLA-RB1 SE alleles was significantly associated with anti-CCP seropositivity; HLA-DRB1*0401 and HLA-DRB1*1001 carriers showed the strongest association. In conclusion, our data suggest that polymorphisms of the PADI4 gene are not associated with rheumatoid arthritis and are unlikely to be responsible for the presence of anti-CCP autoantibodies in a white Hungarian population. HLA-DRB1 SE alleles, however, may significantly contribute to the genetic determination of anti-CCP production in Hungarian patients with RA.
Systemic lupus erythematosus (SLE) is a chronic autoimmune disease characterized by B cell hyper-... more Systemic lupus erythematosus (SLE) is a chronic autoimmune disease characterized by B cell hyper-reactivity, autoantibody production, immune complex (IC) deposition, and multiple organ damage. The contribution of IC and B cell-mediated changes in the pathogenesis of SLE is well established, however, the exact role of IC-binding receptors expressed on B cells, Fcgamma receptors, and complement receptors CR1 and CR2 in these pathological processes is unclear. Development of lupus-like symptoms in mice defective for the inhibitory Fc-gammaRIIb and genetic association of certain FcgammaR genes with SLE demonstrate a significant role for these receptors but reports indicating alterations of Fcgamma or complement receptor-mediated B cell functions in human SLE are relatively few. The present review highlights a selected set of data including our own discussing the significance of animal models, genetics, and functional alterations of these IC-binding receptors in the etiopathogenesis of SLE.
Site-directed mutagenesis is of great importance for probing the structure/function relationship ... more Site-directed mutagenesis is of great importance for probing the structure/function relationship of proteins. Developing our previous method (Nagy et al. Anal Biochem 324:301-303, 2004), here we report a multiplex strategy for site-directed mutagenesis using PCR in one tube to introduce a single mutation into three or more genes at the same time. DNA fragments carrying the desired mutation can be distinguished from each other in a standard antibiotic selection step of the transformed bacteria. Due to this strategy the mutagenesis procedure for several genes can be accelerated.
Conventional approaches to target labeling for gene expression analysis using microarray technolo... more Conventional approaches to target labeling for gene expression analysis using microarray technology typically require relatively large amounts of RNA, a serious limitation when the available sample is limited. Here we describe an alternative exponential sample amplification method by using quantitative real-time polymerase chain reaction (QRT-PCR) to follow the amplification and eliminate the overamplified cDNA which could distort the quantitative ratio of the starting mRNA population. Probes generated from nonamplified, PCR-amplified, and real-time-PCR-amplified cDNA samples were generated from lipopolysaccharide-treated and nontreated mouse macrophages and hybridized to mouse cDNA microarrays. Signals obtained from the three protocols were compared. Reproducibility and reliability of the methods were determined. The Pearson correlation coefficients for replica experiments were r=0.927 and r=0.687 for QRT-PCR-amplification and PCR-overamplification protocols, respectively. Chi2 test showed that overamplification resulted in major biases in expression ratios, while these alterations could be eliminated by following the cycling status with QRT-PCR. Our exponential sample amplification protocol preserves the original expression ratios and allows unbiased gene expression analysis from minute amounts of starting material.
A mutation in the second gene in the ntrPR operon results in increased expression of nodulation (... more A mutation in the second gene in the ntrPR operon results in increased expression of nodulation (nod) and nitrogen fixation (nif) genes in Sinorhizobium meliloti. Since this pleiotropic effect is particularly pronounced in the presence of external combined nitrogen, a nitrogen regulatory function has been suggested for NtrR. To identify the complete set of protein-coding genes influenced by loss of ntrR function, microarray hybridizations were carried out to compare transcript levels in the wild type and mutant strains grown under aerobic and microaerobic conditions. Of the 6207 genes examined, representing the entire genome of S. meliloti, 7% exhibited altered expression: 4.5% of the genes are affected under oxic, 2.5% under microoxic conditions. 0.4% of all the genes are affected under both oxygen concentrations. A microoxic environment is required for the induction of genes related to symbiotic functions but results in the down-regulation of other (e.g. metabolic) functions. When the alterations in transcription levels at low oxygen concentration in the mutant strain were compared to those of the wild type, a modulating effect of the ntrR mutation was observed. For example, symbiotic nif/fix genes were induced in both strains, but the level of induction was higher in the ntrR mutant. In contrast, genes related to transcription/translation functions were down-regulated in both strains, and the effect was greater in the wild-type strain than in the ntrR mutant. A relatively wide range of functions was affected by this modulating influence, suggesting that ntrR is not a nitrogen regulatory gene. Since genes encoding various unrelated functions were affected, we propose that NtrR may either interfere with general regulatory mechanisms, such as phosphorylation/dephosphorylation, or may influence RNA stability.
Orvosi Hetilap, 2011
Women with a history of breast cancer are common at centers for cancer genetic risk all over Euro... more Women with a history of breast cancer are common at centers for cancer genetic risk all over Europe. Given limited health care resources, managing this demand, while achieving good value for money coming from health services, is generally a major challenge. This paper recapitulates and summarizes the available methods of the risk assessment of familial breast cancer. After a systematic review of the literature Gail-model, Claus-model and BOADICEA-model were selected, as well as softwares (LINKAGE software; MENDEL v3.3 software) available in the application of these algorhythms are also summarized. Comparisons were made between the models concerning their advantages and disadvantages. The really reliable methods of risk estimation of familial breast cancer are always based on the analysis of the pedigree structure and allow the estimation of the patient’s probability of carrying a susceptibility gene under a particular genetic model, given her family history. For this method the know...
BMC psychiatry, Jul 17, 2017
Marfan syndrome is a genetic disease, presenting with dysfunction of connective tissues leading t... more Marfan syndrome is a genetic disease, presenting with dysfunction of connective tissues leading to lesions in the cardiovascular and skeletal muscle system. Within these symptoms, the most typical is weakness of the connective tissue in the aorta, manifesting as aortic dilatation (aneurysm). This could, in turn, become annuloaortic ectasia, or life-threatening dissection. As a result, life-saving and preventative cardiac surgical interventions are frequent among Marfan syndrome patients. Aortic aneurysm could turn into annuloaortic ectasia or life-threatening dissection, thus life-saving and preventive cardiac surgical interventions are frequent among patients with Marfan syndrome. We hypothesized that patients with Marfan syndrome have different level of anxiety, depression and satisfaction with life compared to that of the non-clinical patient population. Patients diagnosed with Marfan syndrome were divided into 3 groups: those scheduled for prophylactic surgery, those needing acu...
Cardiology Journal, 2013
The starting point, in Marfan syndrome (MFS) appears to be the mutation of fi brillin-1 gene whos... more The starting point, in Marfan syndrome (MFS) appears to be the mutation of fi brillin-1 gene whose deconstructed protein product cannot bind transforming growth factor beta (TGF-b), leading to an increased TGF-b tissue level. The aim of this review is to review the already known features of the cellular signal transduction downstream to TGF-b and its impact on the tissue homeostasis of microfi brils, and elastic fi bers. We also investigate current data on the extracellular regulation of TGF-b level including mechanotransduction and the feedback cycles of integrin-dependent and independent activation of the latent TGF-b complex. Together these factors, by the destruction of the connective tissue fi bers, may play an important role in the development of the diverse cardiac and extracardiac manifestations of MFS and many of them could be a target of conservative treatment. We present currently investigated drugs for the treatment of the syndrome, and explore possible avenues of research into pathogenesis of MFS in order to improve understanding of the disease.
FEBS Letters, 2004
To pro¢le gene expression patterns involved in the direct myocardial e¡ect of cholesterol-enriche... more To pro¢le gene expression patterns involved in the direct myocardial e¡ect of cholesterol-enriched diet-induced hyperlipidemia, we monitored global gene expression changes by DNA microarray analysis of 3200 genes in rat hearts. Twentysix genes exhibited signi¢cant up-regulation and 25 showed down-regulation in hearts of rats fed a 2% cholesterol-enriched diet for 8 weeks as compared to age-matched controls. The expression changes of 12 selected genes were also assessed by real-time quantitative polymerase chain reaction. Genes with altered expression in the heart due to hyperlipidemia included procollagen type III, co¢lin/destrin, tensin, transcription repressor p66, synaptic vesicle protein 2B, Hsp86, chaperonin subunit 5O O, metallothionein, glutathione S-transferase, protein kinase C inhibitor, ATP synthase subunit c, creatine kinase, chloride intracellular channel 4, NADH oxidoreductase and dehydrogenase, ¢bronectin receptor L L chain, CD81 antigen, farnesyltransferase, calreticulin, disintegrin, p120 catenin, Smad7, etc. Although some of these genes have been suspected to be related to cardiovascular diseases, none of the genes has been previously shown to be involved in the mechanism of the cardiac e¡ect of hyperlipidemia.
European Journal of Obstetrics & Gynecology and Reproductive Biology, 2012
European Journal of Obstetrics & Gynecology and Reproductive Biology, 2012
BMC Cardiovascular Disorders, 2014
Background: According to previous studies, aortic diameter alone seems to be insufficient to pred... more Background: According to previous studies, aortic diameter alone seems to be insufficient to predict the event of aortic dissection in Marfan syndrome (MFS). Determining the optimal schedule for preventive aortic root replacement (ARR) aortic growth rate is of importance, as well as family history, however, none of them appear to be decisive. Thus, the aim of this study was to search for potential predictors of aortic dissection in MFS. Methods: A Marfan Biobank consisting of 79 MFS patients was established. Thirty-nine MFS patients who underwent ARR were assigned into three groups based on the indication for surgery (dissection, annuloaortic ectasia and prophylactic surgery). The prophylactic surgery group was excluded from the study. Transforming growth factor-β (TGF-β) serum levels were measured by ELISA, relative expression of c-Fos, matrix metalloproteinase 3 and 9 (MMP-3 and −9) were assessed by RT-PCR. Clinical parameters, including anthropometric variables-based on the original Ghent criteria were also analyzed. Results: Among patients with aortic dissection, TGF-β serum level was elevated (43.78 ± 6.51 vs. 31.64 ± 4.99 ng/l, p < 0.0001), MMP-3 was up-regulated (Ln2 α = 1.87, p = 0.062) and striae atrophicae were more common (92% vs. 41% p = 0.027) compared to the annuloaortic ectasia group. Conclusions: We found three easily measurable parameters (striae atrophicae, TGF-β serum level, MMP-3) that may help to predict the risk of aortic dissection in MFS. Based on these findings a new classification of MFS, that is benign or malignant is also proposed, which could be taken into consideration in determining the timing of prophylactic ARR.
Orvosi Hetilap, 2012
There is compelling evidence for a genetic contribution to physical performance. In addition, the... more There is compelling evidence for a genetic contribution to physical performance. In addition, there is an advanced scientific knowledge on the predisposition to sports-related diseases and injuries. Genetic testing of performance related polymorphisms can serve as a new opportunity for developing the process of talent selection. Sport-related genetic information may also allow for individualization of the training and improve performance. Genetic testing may also play an important role in the pre-participation screening for injuries and disease risks. Orv. Hetil., 2012, 153, 1247–1255.
Folic acid metabolism enzyme polymorphisms are believed to be responsible for the elevation of ho... more Folic acid metabolism enzyme polymorphisms are believed to be responsible for the elevation of homocysteine (HCY) concentration in the blood plasma, correlating with the pathogenesis of aortic aneurysms and aortic dissection. We studied 71 Marfan patients divided into groups based on the severity of cardiovascular involvement: no intervention required (n=27, Group A); mild involvement requiring intervention (n=17, Group B); severe involvement (n=27, Group C) subdivided into aortic dilatation (n=14, Group C1) and aortic dissection (n=13, Group C2), as well as 117 control subjects. We evaluated HCY, folate, vitamin B12 and the polymorphisms of methylenetetrahydrofolate reductase (MTHFR;c.665C>T and c.1286A>C), methionine synthase (MTR;c.2756A>G) and methionine synthase reductase (MTRR;c.66A>G). Multiple comparisons showed significantly higher levels of HCY in Group C2 compared to Groups A, B, C1 and control group (p< 0.0001, p< 0.0001, p=0.001 and p=0.003, respectively). Folate
was lower in Group C2 than in Groups A, B, C1 and control subjects (p< 0.0001, p=0.02, p< 0.0001 and p< 0.0001, respectively). Group C2 had the highest prevalence of homozygotes for all four gene polymorphisms. Multivariate logistic regression analysis revealed that HCY plasma level was an independent risk factor for severe cardiovascular
involvement (Group C; odds ratio [OR] 1.85, 95 % confidence interval [CI] 1.28–2.67, p=0.001) as well as for aortic dissection (Group C2; OR 2.49, 95 %CI 1.30–4.78, p=0.006). In conclusion, severe cardiovascular involvement in Marfan patients, and especially aortic dissection, is associated with higher HCY plasma levels and prevalence of homozygous genotypes of folic acid metabolism enzymes than mild or no cardiovascular involvement. These results suggest that impaired
folic acid metabolism has an important role in the development and remodelling of the extracellular matrix of the aorta.
We examined the gene expression profile of genes involved in bone metabolism in 23 patients with ... more We examined the gene expression profile of genes involved in bone metabolism in 23 patients with PD compared with 23 healthy controls. We found a significant overexpression of the genes of the IFN pathway along with a downregulation of tnf-alpha. Our result suggest that IFN-mediated signaling may play important roles in aberrant osteoclastogenesis of PD.
INTRODUCTION:
Paget's disease of bone (PD) is characterized by focal regions of highly exaggerated bone remodeling and aberrant osteoclastogenesis. Under physiological conditions, circulating monocytes may serve as early progenitors of osteoclasts and along with peripheral blood lymphocytes produce a wide variety of factors important in bone metabolism. Nevertheless, little is known about the roles of circulating monocytes and lymphocytes in relation to the pathological bone turnover in PD.
MATERIALS AND METHODS:
In this study, we aimed at investigating the gene expression pattern of PD using quantitative real-time PCR in monocytes and lymphocytes isolated from peripheral blood mononuclear cells (PBMCs). Fifteen genes known to be involved in osteoclastogenesis were studied in cells from 23 patients with PD and in cells from 23 healthy controls. Eight human genes including ifn-alpha (3.48-fold, p < 0.001), ifn-beta (2.68-fold, p < 0.001), ifn-gamma (1.98-fold, p = 0.002), p38 beta2 mapk (2.47-fold, p = 0.002), ifn-gammar1 (2.03-fold, p = 0.01), ifn-gammar2 (1.81-fold, p = 0.02), stat1 (1.57-fold, p = 0.037), and tnf-alpha (-2.34, p < 0.001) were found to be significantly altered in pagetic monocytes compared with monocytes of healthy controls.
RESULTS:
In pagetic lymphocytes, significant changes in the expression of ifn-alpha (2.17-fold, p < 0.001), ifn-beta (2.13-fold, p = 0.005), ifn-gamma (1.89-fold, p < 0.001), ifn-gammar1 (1.02-fold, p = 0.04), ifn-gammar2 (1.01-fold, p = 0.031), stat2 (1.79-fold, p < 0.001), and tnf-alpha (-1.49, p < 0.001) were found compared with lymphocytes of healthy controls. Furthermore, IFN-gamma protein was significantly elevated in the sera of PD patients (18.7 +/- 6.69 pg/ml) compared with healthy controls (3.87 +/- 6.48 pg/ml, p = 0.042).
CONCLUSIONS:
In conclusion, our data suggest that novel pathways mainly related to the IFN-mediated signaling may play important roles in the aberrant osteoclastogenesis of PD.
Site-directed PCR-based mutagenesis methods are widely used to generate mutations. All published ... more Site-directed PCR-based mutagenesis methods are widely used to generate mutations. All published methods work on DNA clones carrying the target sequence. However, DNA clones are not always available. We have previously published a RT-PCR-based site-directed mutagenesis method starting from total RNA to overcome this problem. In this article, we report an improvement of our previous method to facilitate introduction of multiple mutations into a target sequence. We demonstrate the efficacy and feasibility of this strategy by mutation of the human beta-actin gene. BamHI restriction endonuclease cleavage sites were generated within the gene to assist screening. Using three mutagenic primers in a single RT-PCR reaction, seven different clones were produced carrying three single and four multiple mutations. An investigation of the effect of the cycle number and elongation time of the PCR reactions revealed that both have an influence on the ratio of clones carrying single and multiple mutations. An optimized protocol was established for efficient multiple site-directed mutagenesis.
Polymorphisms of the peptidylarginine deiminase 4 (PADI4) gene encoding for the isoenzyme that co... more Polymorphisms of the peptidylarginine deiminase 4 (PADI4) gene encoding for the isoenzyme that converts arginyl into citrullyl residues have been shown to contribute to susceptibility to rheumatoid arthritis (RA), depending on the population studied. We aimed at determining whether PADI4 single nucleotide polymorphisms (SNPs) are associated with RA in a Hungarian population. The relationship between anticyclic citrullinated peptide (anti-CCP) production and HLA-DRB1 alleles encoding the shared epitope (SE) was also investigated. DNA samples were obtained from RA (n = 261) patients and from control donors (n = 120). HLA-DRB1 genotyping was carried out by polymerase chain reaction (PCR) with sequence-specific priming. PAD4_92 G/C and PAD4_104 T/C SNPs were genotyped using real-time PCR allele discrimination. Autoantibodies against CCP were detected by ELISA. All healthy controls tested anti-CCP negative, whereas 171 (66%) RA patients were anti-CCP positive. No significant difference in allele or genotype frequencies were found between RA patients and controls for any of the PADI4 SNPs. Anti-CCP seropositivity was unrelated to these two SNPs. No association was found between any of the PADI4 SNPs and HLA-DRB1 subtypes. Presence of the HLA-RB1 SE alleles was significantly associated with anti-CCP seropositivity; HLA-DRB1*0401 and HLA-DRB1*1001 carriers showed the strongest association. In conclusion, our data suggest that polymorphisms of the PADI4 gene are not associated with rheumatoid arthritis and are unlikely to be responsible for the presence of anti-CCP autoantibodies in a white Hungarian population. HLA-DRB1 SE alleles, however, may significantly contribute to the genetic determination of anti-CCP production in Hungarian patients with RA.
Systemic lupus erythematosus (SLE) is a chronic autoimmune disease characterized by B cell hyper-... more Systemic lupus erythematosus (SLE) is a chronic autoimmune disease characterized by B cell hyper-reactivity, autoantibody production, immune complex (IC) deposition, and multiple organ damage. The contribution of IC and B cell-mediated changes in the pathogenesis of SLE is well established, however, the exact role of IC-binding receptors expressed on B cells, Fcgamma receptors, and complement receptors CR1 and CR2 in these pathological processes is unclear. Development of lupus-like symptoms in mice defective for the inhibitory Fc-gammaRIIb and genetic association of certain FcgammaR genes with SLE demonstrate a significant role for these receptors but reports indicating alterations of Fcgamma or complement receptor-mediated B cell functions in human SLE are relatively few. The present review highlights a selected set of data including our own discussing the significance of animal models, genetics, and functional alterations of these IC-binding receptors in the etiopathogenesis of SLE.
Site-directed mutagenesis is of great importance for probing the structure/function relationship ... more Site-directed mutagenesis is of great importance for probing the structure/function relationship of proteins. Developing our previous method (Nagy et al. Anal Biochem 324:301-303, 2004), here we report a multiplex strategy for site-directed mutagenesis using PCR in one tube to introduce a single mutation into three or more genes at the same time. DNA fragments carrying the desired mutation can be distinguished from each other in a standard antibiotic selection step of the transformed bacteria. Due to this strategy the mutagenesis procedure for several genes can be accelerated.
Conventional approaches to target labeling for gene expression analysis using microarray technolo... more Conventional approaches to target labeling for gene expression analysis using microarray technology typically require relatively large amounts of RNA, a serious limitation when the available sample is limited. Here we describe an alternative exponential sample amplification method by using quantitative real-time polymerase chain reaction (QRT-PCR) to follow the amplification and eliminate the overamplified cDNA which could distort the quantitative ratio of the starting mRNA population. Probes generated from nonamplified, PCR-amplified, and real-time-PCR-amplified cDNA samples were generated from lipopolysaccharide-treated and nontreated mouse macrophages and hybridized to mouse cDNA microarrays. Signals obtained from the three protocols were compared. Reproducibility and reliability of the methods were determined. The Pearson correlation coefficients for replica experiments were r=0.927 and r=0.687 for QRT-PCR-amplification and PCR-overamplification protocols, respectively. Chi2 test showed that overamplification resulted in major biases in expression ratios, while these alterations could be eliminated by following the cycling status with QRT-PCR. Our exponential sample amplification protocol preserves the original expression ratios and allows unbiased gene expression analysis from minute amounts of starting material.
A mutation in the second gene in the ntrPR operon results in increased expression of nodulation (... more A mutation in the second gene in the ntrPR operon results in increased expression of nodulation (nod) and nitrogen fixation (nif) genes in Sinorhizobium meliloti. Since this pleiotropic effect is particularly pronounced in the presence of external combined nitrogen, a nitrogen regulatory function has been suggested for NtrR. To identify the complete set of protein-coding genes influenced by loss of ntrR function, microarray hybridizations were carried out to compare transcript levels in the wild type and mutant strains grown under aerobic and microaerobic conditions. Of the 6207 genes examined, representing the entire genome of S. meliloti, 7% exhibited altered expression: 4.5% of the genes are affected under oxic, 2.5% under microoxic conditions. 0.4% of all the genes are affected under both oxygen concentrations. A microoxic environment is required for the induction of genes related to symbiotic functions but results in the down-regulation of other (e.g. metabolic) functions. When the alterations in transcription levels at low oxygen concentration in the mutant strain were compared to those of the wild type, a modulating effect of the ntrR mutation was observed. For example, symbiotic nif/fix genes were induced in both strains, but the level of induction was higher in the ntrR mutant. In contrast, genes related to transcription/translation functions were down-regulated in both strains, and the effect was greater in the wild-type strain than in the ntrR mutant. A relatively wide range of functions was affected by this modulating influence, suggesting that ntrR is not a nitrogen regulatory gene. Since genes encoding various unrelated functions were affected, we propose that NtrR may either interfere with general regulatory mechanisms, such as phosphorylation/dephosphorylation, or may influence RNA stability.