Transforming Growth Factor-beta1 Gene Research Articles

Transforming Growth Factor Beta 1 Is a Novel Susceptibility Gene for Adolescent Idiopathic Scoliosis

A genetic association study of the transforming growth factor beta 1 (TGFB1) gene with adolescent idiopathic scoliosis (AIS) in Russian population. To determine whether common genetic polymorphisms C-509T (rs1800469) and Arg25Pro (rs1800471) of the TGFB1 gene are associated with susceptibility to AIS. An importance of growth factors for the pathogenesis of AIS has been demonstrated by the findings of abnormal expression of these proteins in the spine and surrounding tissues in patients with AIS. However, no studies have been performed to investigate the relationship between genetic polymorphisms of the TGFB1 gene and susceptibility to AIS. A total of 600 unrelated adolescents from Central Russia (Moscow) were recruited in this study, including 300 patients with AIS and 300 age- and sex-matched healthy adolescents. The polymorphisms were genotyped by polymerase chain reaction-restriction fragment length polymorphism. The allele -509T and genotype -509TT of the TGFB1 gene were significantly associated with the increased risk of idiopathic scoliosis in both females and males (P < 0.01). Logistic regression analysis has revealed a recessive model of the genetic association between polymorphism C-509T of the TGFB1 gene and AIS. Moreover, we found sexual dimorphisms in the relationships of SNP C-509T of the TGFB1 gene with both the age of disease onset and curve severity: the polymorphism was found to determine both an early onset of scoliosis and the severity of curvature in females but not in males (P < 0.05). This study, for the first time, highlights the importance of TGFB1 gene for the development and progress of AIS. We hypothesize several mechanisms by which the TGFB1 gene may contribute to spinal deformity in patients with AIS.

Association between single nucleotide polymorphisms of the transforming growth factor-beta1 gene and overall survival in unresectable locally advanced non-small-cell lung cancer patients treated with radio(chemo)therapy in a Chinese population

The outcome is variable for unresectable locally advanced non-small-cell lung cancer (ULANSCLC) patients treated with radio(chemo)therapy. The aim of this study is to investigate whether single-nucleotide polymorphisms (SNPs) in the transforming growth factor-beta1 (TGF-β1) gene are associated with overall survival (OS) in ULANSCLC patients treated with definitive radio(chemo)therapy. A total of 109 patients who had available blood samples and complete clinical and follow-up information were enrolled. DNA from blood was genotyped for two SNPs: TGF-β1 C-509T and T+869C. Kaplan-Meier survival analysis, log-rank test, and Cox's proportional hazard model were used to evaluate associations between genotypes and OS. Log-rank test showed that TGF-β1 C-509T significantly correlated with OS (pooled P = 0.017). Both univariate and multivariate analyses showed that TGF-β1 C-509T CC genotype was significantly associated with better OS than CT or TT genotypes. These results indicate that TGF-β1 C-509T CC genotype is significantly associated with better OS in ULANSCLC patients treated with radio(chemo)therapy as a potential independent survival predictor.

A Transforming Growth Factor Beta-1 Gene Single Nucleotide Polymorphism May Influence Phenotype in Pediatric Eosinophilic Esophagitis

S U N D A Y 474 Key Function of Cadherin-Like 26 in Eosinophilic Gastrointestinal Disorders Julie M. Caldwell, PhD, Margaret Collins, MD, Carine Blanchard, PhD, Emily Stucke, BA, Katherine Kemme, BS, Lissa Amin, BA, Philip Putnam,MD, James Franciosi, MD, Juan Pablo Pablo Abonia, MD, Marc E. Rothenberg, MD, PhD, FAAAAI; Cincinnati Children’s Hospital Medical Center, Cincinnati, OH, Cincinnati Childrens’ Hospital Medical Center, Cincinnati, OH, Cincinnati Children Hospital, Cincinnati, OH, Nemours Children’s Hospital, Orlando, FL. RATIONALE: Cadherin-like 26 (CDH26) is markedly overexpressed in the affected tissue of eosinophilic gastritis (EG) and eosinophilic esophagitis (EoE) patients. We aimed to understand the expression pattern and function of CDH26 in eosinophilic gastrointestinal disorders. METHODS: Characterization of CDH26 expression patterns was undertaken through RT-PCR, immunohistochemistry, and western blot analysis. Protein interactions were examined using transient transfection and immunoprecipitation analysis. CDH26 function in mediating calciumdependent cell aggregation was tested. The impact of CDH26 on eosinophil transmigration through 293T cells was investigated. RESULTS: CDH26 was highly expressed in the gastric and esophageal epithelium of patients with EG or EoE, respectively. This molecule exhibited homotypic interaction and additionally interacted with betacatenin, alpha-catenin, and delta-catenin (p120) when expressed ectopically in 293T cells. Furthermore, cells expressing high levels of CDH26 exhibited calcium-dependent aggregation. Interestingly, CDH26 protein expression was observed in human peripheral blood eosinophils, and eosinophil transmigration through 293T cells overexpressing CDH26 was enhanced compared to transmigration through control cells. CONCLUSIONS: CDH26 interacts with catenin proteins, which link cadherin molecules to the actin cytoskeleton. Furthermore, CDH26 exhibits homotypic interaction and promotes calcium-dependent cell aggregation, consistent with a function in cell adhesion. A greater number of eosinophils migrated to eotaxin through CDH26-overexpressing cells compared to control cells. SinceCDH26 protein expressionwas detected in eosinophils, engagement between CDH26 molecules on epithelial cells and eosinophils may impact cell signaling and localization. As such, we propose that CDH26 is a major cadherin expressed in allergic GI tissue and may have a key role in various aspects of disease pathogenesis and diagnosis.

Meta-analysis of association of tumor necrosis factor alpha and transforming growth factor beta gene polymorphisms with pneumoconiosis

To evaluate the relationship between tumor necrosis factor-alpha-238, transforming growth factor beta (509 and 869) gene polymorphisms and pneumoconiosis susceptibility. We searched published full-text from foreign language databases including Elsevier, PubMed, Wiley Online Library, EMCC, Web of Science, chinese databases containing CNKI, VIP, Wanfang, CBM and Cochrane library to collect case-control or cohort study on gene gene polymorphisms said above with pneumoconiosis susceptibility from the year January1988 to August 2011. 28 relevant articles were selected and 20 of them met the criteria. The correlated index was extracted for aggregate analysis in RevMan 4.2. Among the 20 studies, 10 articles on TNF-α238 polymorphism (including 2232 pneumoconiosis cases and 1985 control subjects), 4 articles on TGF-β509 polymorphism (including 693 pneumoconiosis cases and 663 control subjects), and 6 articles on TGF-β869 polymorphism (including 1450 pneumoconiosis cases and 1101 control subjects) were included in the current study. Meta-analysis results showed that there was a significant association between TNF-α238 polymorphism and pneumoconiosis: the population with GA and AA genotypes of TNF-α238 had higher risks to pneumoconiosis (OR = 1.53, 95%CI: 1.25 ∼ 1.88) comparing to GG genotype, and the population with A allele had higher risks to pneumoconiosis comparing to allele G (OR = 1.64, 95%CI: 1.17 ∼ 2.30). The stratified analysis showed that the people with GA and AA genotypes and A allele who were silicosis, Asian or exposed to dust had higher risks to pneumoconiosis (OR = 2.14, 95%CI: 1.20 ∼ 3.82; OR = 2.16, 95%CI: 1.20 ∼ 3.88; OR = 1.78, 95%CI: 1.01 ∼ 3.11; OR = 1.83, 95%CI: 1.04 ∼ 3.22; OR = 1.80, 95%CI: 1.21 ∼ 2.66; OR = 1.50, 95%CI: 1.23 ∼ 1.83). No significant association was found between TGF-β (509 and 869) gene polymorphisms with pneumoconiosis: In contrast to the CC genotype, the population who had CT and TT genotypes had no higher risks to pneumoconiosis (OR = 1.56, 95%CI: 0.81 ∼ 3.01; OR = 0.96, 95%CI: 0.79 ∼ 1.18); The population who had T allele had no higher risks to pneumoconiosis in contrast to the C allele (OR = 1.35, 95%CI: 0.86 ∼ 2.13; OR = 1.02, 95%CI: 0.91 ∼ 1.15). Significant association was found between TNFα238 gene polymorphism and pneumoconiosis; and TGF-β (509 and 869) were not.

Correlation of transforming growth factor beta-1 gene polymorphisms C-509T and aplastic anemia

Autoreactive cytotoxic T cells play a key role in the pathogenesis of aplastic anemia (AA) by myelosuppressive cytokines including interferon gamma, tumor necrosis factor alpha, and transforming growth factor beta. As an important cytokine that modulates the cell cycle, the involvement of transforming growth factor beta-1 (TGF-β1) in AA has been studied. The purpose of our study was to investigate the role of (TGF-β1/2509) gene polymorphisms in patients with acquired AA and to assess whether genotype was associated with higher or lower production and compare it with established control populations. Thirty-one patients with acquired aplastic anemia and 30 age- and sex-matched healthy controls were analyzed consecutively using PCR–restriction fragment length polymorphism (PCR-RFLP). TGF-β1 polymorphism C-509T was identified using PCR-RFLP. Significantly different distributions of the gene were demonstrated between the case and the control. The frequencies of −509CT and −509TT genotypes (74.2 versus 30 % and 16.2 versus 3.3 %, respectively) were significantly higher in cases than in controls (P < 0.001), while the frequency of the −509 CC genotype is higher in the control than in cases (66.7 versus 9.6 %, P < 0.001). Our data showed a genotypic profile associated with high TGF-β production in patients with bone marrow failure and suggest that the genetic regulation of inflammatory and T cell-mediated immunological pathways could be involved in the pathogenesis of bone marrow failure, reinforcing the view that AA are organ-specific autoimmune disorders.

Genetic polymorphisms located in TGFB1, AGTR1, and VEGFA genes are associated to chronic renal allograft dysfunction

BackgroundPersistent inflammation and fibrosis have been related to active progression of renal deterioration and reduced survival of kidney transplant. The aim of this study was to determine the impact of single-nucleotide polymorphisms (SNPs) located in regions related to inflammatory and immune processes on the development of chronic renal allograft dysfunction (CRAD). MethodsA retrospective study was carried out on 276 patients who received kidney transplant (KT). SNPs were genotyped via the SNPlex platform. Statistical analysis was performed with SNPstat and regression logistic analyses were adjusted by age and gender of recipients and donors, cold ischemia time and the number of human leukocyte antigen (HLA) mismatches. ResultsFrom 276 patients with KT, 118 were non-CRAD and 158 were CRAD. Three SNPs showed significant associations with CRAD development: rs1800471 in transforming growth factor beta 1 (TGFB1), rs5186 in angiotensin II receptor type 1 (AGTR1), and rs699947 in vascular endothelial growth factor A (VEGFA). GC genotype of rs1800471 was associated with increased odds of CRAD compared to GG genotype (OR=2.65 (95% confidence interval (CI)=1.09; 6.47), p=0.025), as well as AC and AA genotype of rs699947 assuming a dominant model (OR=1.80 (95% CI=1.02; 3.20), p=0.044). Besides, AC and CC genotypes of rs5186 were associated with reduced odds of CRAD assuming a dominant model (OR=0.56 (95% CI=0.33; 0.96), p=0.033). ConclusionOur findings suggest that three genes related to immunity and inflammation (rs1800471, rs5186 and rs699947) are associated to susceptibility or protection to CRAD, and might have diagnostic utility in predicting the likelihood of developing CRAD.

Pharmacogenomics of multiple sclerosis: Association of immune response gene polymorphisms with copaxone treatment efficacy

Complex association analysis of copaxone (glatiramer acetate) immunotherapy efficacy with allelic polymorphism in the number of immune response genes, which encode interferone beta (IFNB1), transforming growth factor beta1 (TGFB1), interferone gamma (IFNG), tumor necrosis factor (TNF), interferon alpha/beta receptor 1 (IFNAR1), CC chemokine receptor 5 (CCR5), interleukin 7 receptor alpha subunit (IL7RA), cytotoxic T-lymphocyte antigen 4 (CTLA4) and HLA class II histocompatibility antigen beta chain (DRB1) was performed with APSampler algorithm for 285 multiple sclerosis patients of Russian ethnicity. The results show evidence for the contribution of polymorphic variants in CCRS, DRB1, IFNG, TGFB1, IFNAR1, IL7RA and, probably, TNF and CTLA4 genes to copaxone treatment response. Single alleles of CCR5 and DRB1 genes are reliably associated with treatment efficacy. Carriage of allelic variants of other above mentioned genes contribute with reliable effect to copaxone treatment response as part of bi- and three-allelic combinations only. Present investigation may support basis toward the future possibility of prognostic test realization, which can provide a personal choice of immunomodulatory treatment for a patient with multiple sclerosis.

Krüppel-like factor 6 regulates transforming growth factor-β gene expression during human respiratory syncytial virus infection

BackgroundHuman respiratory syncytial virus (RSV) infection is associated with airway remodeling and subsequent asthma development. Transforming growth factor-beta (TGF) plays a crucial role in asthma development. The mechanism regulating TGF gene expression during RSV infection is not known. Kruppel-like factor family of transcription factors are critical regulators of cellular/tissue homeostasis. Previous studies have shown that Kruppel-like factor 6 (KLF6) could function as a trans-activator of TGF gene; however, whether KLF members play a role during infection is unknown. In the current study we have evaluated the role of KLF6 during TGF expression in RSV infected cells.FindingsSilencing KLF6 expression by shRNA led to drastic inhibition in TGF production during RSV infection, as assessed by ELISA analysis of medium supernatants. RT-PCR analysis revealed loss of TGF expression in KLF6 silenced cells. Chromatin-immunoprecipitation assay conducted with RSV infected cells showed binding of KLF6 protein to the TGF promoter during RSV infection. We further observed reduced RSV infectivity in KLF6 silenced cells and in cells incubated with TGF neutralizing antibody. In contrast, enhanced RSV infection was noted in cells incubated with purified TGF.ConclusionWe have identified KLF6 as a key transcription factor required for trans-activation of TGF gene during RSV infection. Moreover, TGF production is required for efficient RSV infection and thus, KLF6 is also required for efficient RSV infection by virtue of KLF6 dependent TGF production during infection.

Contrasting roles of donor and recipient TGFB1 and IFNG gene polymorphic variants in chronic kidney transplant rejection.

To assess the long-term impact (minimum of 3 years follow-up) of polymorphisms in cytokine genes in donor:recipient pairs on the results of the transplant. We compared genetic cytokine polymorphisms and the primary factors of risk for the development of chronic rejection in paired groups of renal transplant patients with and without chronic allograft nephropathy [CAN]. Multivariate analysis indicated that the presence of the high-production TT genotype (codon 10) of the transforming growth factor beta-1 (TGFB1) was protective in receptors (p=0.017), contrasting with the increased risk when present in donor samples (p=0.049). On the other hand, in the case of the gamma interferon studied, the greater frequency of the high production allele was protective in the analysis of the donor group (p=0.013), increasing the risk of chronic nephropathy of the allograft when present in the recipients (p=0.036). Our results highlight the importance of TGFB1 genotyping in donors, and indicate that polymorphisms in the gene of this cytokine in donor cells might contribute to the development of chronic allograft nephropathy.

Evaluation of Transforming Growth Factor Beta-1 Gene 869T/C Polymorphism with Hypertension: A Meta-Analysis

Association between transforming growth factor beta-1 gene (TGFB1) 869T/C polymorphism and hypertension has been widely evaluated, yet with conflicting results. As meta-analysis is a reliable way to resolve discrepancies; I aimed to evaluate this association. Data were available from 9 study populations involving 6151 subjects. Overall, comparison of allele 869C with 869T generated a significant 30% increased hypertension risk (95% confidence interval [95% CI]: 1.11–1.51; P = 0.001), which was strengthened for homozygous comparison (869CC versus 869TT) with odds ratio (OR) doubled to 1.62 (95% CI: 1.23–2.14; P = 0.001). Stratified analysis by study design demonstrated stronger associations in population-based studies than in hospital-based studies with OR, except in the dominant model, being increased by 7.94–18.61%. Likewise, ethnicity-based analysis exhibited a contradictory association between Asians and Whites. Conclusively, these findings support the notion that TGFB1 gene 869T/C polymorphism may influence the risk of hypertension, especially in Asian populations.

Association of advanced vasculopathy and transforming growth factor-beta1 gene expression with immunoglobulin A nephropathy progression

The mechanism of IgA nephropathy (IgAN) progression remains ill-defined. In this prospective study, the prognostic role of clinical, histological and molecular markers over a 2-year follow-up was evaluated. Fifty-one patients with biopsy-proven IgAN were followed for 24months. Besides routine histology, the intrarenal gene expressions of cytokines and chemokines were quantified by reverse transcription quantitative real-time polymerase chain reaction, and the presence of lymphocytes and macrophages were immunohistochemically examined. Higher transforming growth factor-β1 and severe chronic vasculopathy (but not glomerulosclerosis, interstitial fibrosis or lymphocyte infiltrate) were associated with the IgAN progression 24months after biopsy. The gene expression of chemokine (C-C motif) ligands 2 and 5, hepatocyte growth factor, bone morphogenic protein-7 and transforming growth factor-β1 and the interstitial infiltrate of T and B lymphocytes and macrophages were significantly associated with serum creatinine and glomerular filtration rate at the time of biopsy. The intrarenal chemokine (C-C motif) ligand 2 and hepatocyte growth factor gene expression were associated with the proteinuria. Besides the known risk factors for chronic kidney disease, advanced vasculopathy and molecular signatures of fibrogenesis were associated with the IgAN progression.

Reply of the Authors: Transforming growth factor β1 gene -509 C/T polymorphism and endometriosis

My colleagues and I have read the comment by Romano et al. (1Romano A. van Kaam K.J.A.F. Dunselman G.A.J. Transforming growth factor b1 gene -509 C/T polymorphism and endometriosis.Fertil Steril. 2010; (DOI:10.1016/j.fertnstert.2010.06.022.)Abstract Full Text Full Text PDF Scopus (1) Google Scholar) directed to our article (2Kim J.J. Choi Y.M. Choung S.H. et al.Analysis of the transforming growth factor beta1 gene -509 C/T polymorphism in patients with advanced-stage endometriosis.Fertil Steril. 2010; 93: 2121-2124Abstract Full Text Full Text PDF PubMed Scopus (9) Google Scholar) entitled “Analysis of the transforming growth factor -β1 gene -509 C/T polymorphism in patients with advanced-stage endometriosis.” I would like to thank Romano et al. (1Romano A. van Kaam K.J.A.F. Dunselman G.A.J. Transforming growth factor b1 gene -509 C/T polymorphism and endometriosis.Fertil Steril. 2010; (DOI:10.1016/j.fertnstert.2010.06.022.)Abstract Full Text Full Text PDF Scopus (1) Google Scholar) for notifying us our mistake. We stated that, to the best of our knowledge, our study (2Kim J.J. Choi Y.M. Choung S.H. et al.Analysis of the transforming growth factor beta1 gene -509 C/T polymorphism in patients with advanced-stage endometriosis.Fertil Steril. 2010; 93: 2121-2124Abstract Full Text Full Text PDF PubMed Scopus (9) Google Scholar) is the second article assessing the transforming growth factor β1 (TGF-β1)-509 C/T gene polymorphism and endometriosis after the study by Hsieh et al. (3Hsieh Y.Y. Chang C.C. Tsai F.J. Peng C.T. Yeh L.S. Lin C.C. Polymorphism for transforming growth factor beta1-509 (TGF-β1-509): association with endometriosis.Biochem Genet. 2005; 43: 203-210Crossref PubMed Scopus (36) Google Scholar), but as soon as we received this comment, we searched the pubmed and reviewed the article by van Kaam et al. (4van Kaam K.J. Romano A. Dunselman G.A. Groothuis P.G. Transforming growth factor beta1 gene polymorphism 509C/T in deep infiltrating endometriosis.Reprod Sci. 2007; 14: 367-373Crossref PubMed Scopus (10) Google Scholar) entitled “Transforming growth factor beta1 gene polymorphism 509C/T in deep infiltrating endometriosis.” We also agree that this is the second study assessing this issue (date of publication of the article by Romano et al. was May, 2007, and the date of submission of our article was March 20, 2008.) Interestingly, both studies share a common conclusion indicating that TGF-β1-509 C/T gene polymorphism plays no role in endometriosis, and therefore contradicts the Chinese investigation. Transforming growth factor β1 gene -509 C/T polymorphism and endometriosisFertility and SterilityVol. 94Issue 4PreviewTo the Editor: Full-Text PDF

Gene Polymorphisms in Renal Transplantation

A vast majority of gene polymorphism studies in renal transplantation focus on short-term outcomes such as acute rejection. The main purpose of this article is to review the literature available and studies that have examined the association between the gene polymorphisms and long-term renal allograft functions. In this review, we focus on commonly reported genes in the renin angiotensin system, transforming growth factor-beta gene, and metalloproteinases on the incidence and progression of chronic renal allograft dysfunction.

Nifedipine inhibits advanced glycation end products (AGEs) and their receptor (RAGE) interaction-mediated proximal tubular cell injury via peroxisome proliferator-activated receptor-gamma activation

There is a growing body of evidence that advanced glycation end products (AGEs) and their receptor (RAGE) interaction evokes oxidative stress generation and subsequently elicits inflammatory and fibrogenic reactions, thereby contributing to the development and progression of diabetic nephropathy. We have previously found that nifedipine, a calcium-channel blocker (CCB), inhibits the AGE-induced mesangial cell damage in vitro. However, effects of nifedipine on proximal tubular cell injury remain unknown. We examined here whether and how nifedipine blocked the AGE-induced tubular cell damage. Nifedipine, but not amlodipine, a control CCB, inhibited the AGE-induced up-regulation of RAGE mRNA levels in tubular cells, which was prevented by the simultaneous treatment of GW9662, an inhibitor of peroxisome proliferator-activated receptor-γ (PPARγ). GW9662 treatment alone was found to increase RAGE mRNA levels in tubular cells. Further, nifedipine inhibited the AGE-induced reactive oxygen species generation, NF-κB activation and increases in intercellular adhesion molecule-1 and transforming growth factor-beta gene expression in tubular cells, all of which were blocked by GW9662. Our present study provides a unique beneficial aspect of nifedipine on diabetic nephropathy; it could work as an anti-oxidative and anti-inflammatory agent against AGEs in tubular cells by suppressing RAGE expression via PPARγ activation.

Transforming Growth Factor β Promotes Complexes between Smad Proteins and the CCCTC-binding Factor on the H19 Imprinting Control Region Chromatin

Whether signal transduction pathways regulate epigenetic states in response to environmental cues remains poorly understood. We demonstrate here that Smad3, signaling downstream of transforming growth factor β, interacts with the zinc finger domain of CCCTC-binding factor (CTCF), a nuclear protein known to act as “the master weaver of the genome.” This interaction occurs via the Mad homology 1 domain of Smad3. Although Smad2 and Smad4 fail to interact, an alternatively spliced form of Smad2 lacking exon 3 interacts with CTCF. CTCF does not perturb well established transforming growth factor β gene responses. However, Smads and CTCF co-localize to the H19 imprinting control region (ICR), which emerges as an insulator in cis and regulator of transcription and replication in trans via direct CTCF binding to the ICR. Smad recruitment to the ICR requires intact CTCF binding to this locus. Smad2/3 binding to the ICR requires Smad4, which potentially provides stability to the complex. Because the CTCF-Smad complex is not essential for the chromatin insulator function of the H19 ICR, we propose that it can play a role in chromatin cross-talk organized by the H19 ICR.

Analysis of Correlation between the Process of Thyroid Fibrosis and TGFB1 Gene Expression Level in Fine-needle Aspiration Biopsy (FNAB) Thyroid Specimens Collected from Patients with Hashimoto's Thyroiditis and Non-toxic Goitre

Transforming growth factor beta 1 (TGFB1) stimulates the production of various extracellular matrix components; at the same time, it inhibits matrix degradation. These actions of TGFB1 contribute to tissue repair, however, an altered expression of TGFB1 can be a causative factor of fibrosis processes, including thyroid fibrosis which follows chronic thyroiditis. The aim of our study was to examine a potential correlation between TGFB1 gene expression level in fine-needle aspiration biopsy (FNAB) thyroid specimens and fibrosis of the thyroid gland in two types of thyroid lesions. Fibrosis of the thyroid tissue was assessed, based on the expression levels of fibrosis-associated genes (COL1A1 and COL3A1) in thyroid FNAB samples, on the FNAB specimen cellularity and other features of the tissue fibrosis assessed during cytological examination, as well as on the size of thyroid gland and its function. Following routine cytological examination, 63 thyroid FNAB specimens, received from patients with Hashimoto's thyroiditis (HT, n=30) and non-toxic goitre (NTG, n=33), were quantitatively evaluated regarding TGFB1, COL1A1 and COL3A1 expression level by real-time PCR in the ABI PRISM 7500 Sequence Detection System. The obtained results showed statistically significant differences regarding the expression level (RQ) of TGFB1 and of COL1A1 genes between the groups with HT and with NTG (higher expression in HT group). No significant differences, concerning the expression level of COL3A1 gene, were observed for the studied groups (HT vs. NTG). In HT group statistically significant correlation was found between TGFB1 gene and COL3A1 gene expression levels (p<0.05). The correlation in question might suggest excessive extracellular matrix deposition and could--possibly--contribute to thyroid fibrosis mechanism in the course of chronic thyroiditis.

The C-509T Promoter Polymorphism of the Transforming Growth Factor Beta-1 Gene Is Associated with Levels of Total and Specific IgE in a Colombian Population

Background: The C-509T polymorphism of the transforming growth factor beta-1 (TGFB1) gene has been associated with asthma and asthma-related phenotypes, but its influence on total and specific IgE levels is controversial. Objective: To investigate the association between C-509T and asthma, as well as total IgE and specific IgE against Blomia tropicalis and Dermatophagoides pteronyssinus, in a Colombian population. Methods: The study population consisted of 417 asthmatics, 390 controls and 116 nuclear families. The C-509T polymorphism was genotyped using single-base extension minisequencing or Taq Man probes. IgE and TGFβ1 levels were measured by ELISA. Regression analysis and family-based association tests were performed in cases/controls and families. Associations were corrected by population structure using a panel of 52 ancestry informative markers in the case-control dataset. Results: There was no association between C-509T and asthma. In asthmatics, the CC genotype was associated with higher total IgE levels compared with the other genotypes [mean IgE: 2.81 ± 0.42 vs. 2.71 ± 0.45 log IU/ml; p = 0.016, corrected p value (p_c) = 0.019]. When only atopic asthmatics were included, the significance remained (p = 0.02, p_c = 0.03). In the family-based analyses, the C allele was associated with higher total IgE levels (p = 0.02) and the CC genotype with specific IgE to D. pteronyssinus (p = 0.01). Conclusions: C-509T is associated with total IgE levels and specific IgE to D. pteronyssinus in asthmatic patients. In contrast to other studies, we found the CC genotype to be associated with higher levels of total and specific IgE. Differences in the frequency of this allele among populations could alter its effects as a risk factor for asthma-associated phenotypes.

Endogenous transforming growth factor (TGF) beta1 promotes differentiation of smooth muscle cells from embryonic stem cells: stable plasmid-based siRNA silencing of TGF beta1 gene expression

Transforming growth factor (TGF) beta1 has been shown to promote differentiation of smooth muscle cells (SMC) from some precursor cells. Whether endogenous TGF beta1 also contributes to SMC differentiation during embryogenesis, however, remains unclear. In this study, a plasmid-based TGF beta1 RNA interference embryonic stem (ES) cell line was constructed. Morphological observation showed that TGF beta1 knockdown significantly prevented differentiated cells from outgrowing from ES cells-derived embryoid bodies (EBs). Immunofluorescence staining indicated that SM alpha-actin-positive cells were confluent and dense in the control group but dispersed in the TGF beta1 knockdown group. RT-PCR and western blot suggested that TGF beta1 knockdown resulted in a decrease in the expression of early SMC markers SM alpha-actin and myocardin in EBs. Both the retarded extension of cell outgrowth and the decrease in SM alpha-actin and myocardin expression could not be rescued by addition of exogenous TGF beta1. These data suggest that endogenous TGF beta1 promotes differentiation of SMC from ES cells.

Novel strategy to identify genetic risk factors for COPD severity: a genetic isolate

Studies using genetic isolates with limited genetic variation may be useful in chronic obstructive pulmonary disease (COPD) genetics, but are thus far lacking. The associations between single nucleotide polymorphisms (SNPs) in candidate genes and lung function in COPD were studied in a genetic isolate. In 91 subjects with Global Initiative for Chronic Obstructive Lung Disease (GOLD) stage >or=1 COPD, who were members of an extended pedigree including 6,175 people from the Genetic Research in Isolated Populations study, 32 SNPs were analysed in 13 candidate genes: a disintegrin and metalloprotease domain 33 gene (ADAM33), transforming growth factor-beta1 gene ( TGFB1), matrix metalloprotease-1 gene (MMP1), MMP2, MMP9, MMP12, tissue inhibitor of metalloprotease-1 gene (TIMP1), surfactant protein A1 gene (SFTPA1 ), SFTPA2, SFTPB, SFTPD, glutathione S-transferase P1 gene (GSTP1), and haem oxygenase 1 gene ( HMOX1). Their relation to forced expiratory volume in 1 s (FEV( 1)), inspiratory vital capacity (IVC) and FEV(1)/IVC were studied using restricted maximum likelihood linear mixed modelling, accounting for pedigree structure. Significant associations were replicated in the general Vlagtwedde/Vlaardingen study. Six SNPs in TGFB1, SFTPA1, SFTPA2 and SFTPD were significantly associated with FEV(1)/IVC in subjects with GOLD stage >or=1 COPD. Two SNPs in TGFB1 (C to T substitution at nucleotide -509 and substitution of leucine 10 with proline (Leu10Pro)), Leu50Val in SFTPA1 and Ala160Thr in SFTPD showed evidence suggestive of association with FEV(1)/IVC in subjects with GOLD stage >or=2 COPD. The TGFB1 associations were replicated in GOLD stage >or=2 patients from the Vlagtwedde/Vlaardingen population, with similar effect sizes. It was shown that a genetic isolate can be used to determine the genetics of lung function, which can be replicated in COPD patients from an independent population.

Functional impact of sequence variation in the promoter region of TGFB1

Pathological deregulation of the transforming growth factor, beta 1 (TGFB1) pathway has been implicated in the development of several major diseases, including cancers. Regulatory variation in the TGFB1 gene may lead to altered TGFB1 expression and activity, and thus, modulate an individual's susceptibility to disease. Here, we performed a study of the functional relevance of cis-acting regulatory variation in the proximal promoter region of the TGFB1 gene. In a previous study, 9 promoter polymorphisms were identified in the 2kb region upstream of the transcription start site and 9 distinct promoter haplotypes were inferred from a panel of individuals from 5 distinct continental population groups. Following experimental validation, we found that the 2 major haplotypes significantly influenced TGFB1 transcriptional activity in an allele-specific manner and that 3 of the SNPs (-1886G>A, -509C>T and -1550DEL/AGG) altered DNA-protein complex formation. Though the biological relevance of these findings remains to be verified, our study suggests that polymorphisms in the TGFB1 promoter could indeed influence gene expression and potentially contribute to the pathogenesis of TGFB1 related diseases.