26 research outputs found
The ETS Family Member TEL Binds to Nuclear Receptors RAR and RXR and Represses Gene Activation
Retinoic acid receptor (RAR) signaling is important for regulating transcriptional activity of genes involved in growth, differentiation, metabolism and reproduction. Defects in RAR signaling have been implicated in cancer. TEL, a member of the ETS family of transcription factors, is a DNA-binding transcriptional repressor. Here, we identify TEL as a transcriptional repressor of RAR signaling by its direct binding to both RAR and its dimerisation partner, the retinoid x receptor (RXR) in a ligand-independent fashion. TEL is found in two isoforms, created by the use of an alternative startcodon at amino acid 43. Although both isoforms bind to RAR and RXR in vitro and in vivo, the shorter form of TEL represses RAR signaling much more efficiently. Binding studies revealed that TEL binds closely to the DNA binding domain of RAR and that both Helix Loop Helix (HLH) and DNA binding domains of TEL are mandatory for interaction. We have shown that repression by TEL does not involve recruitment of histone deacetylases and suggest that polycomb group proteins participate in the process
Increased High Density Lipoprotein-levels associated with Age-related Macular degeneration. Evidence from the EYE-RISK and E3 Consortia
Purpose
Genetic and epidemiologic studies have shown that lipid genes and high-density lipoproteins (HDLs) are implicated in age-related macular degeneration (AMD). We studied circulating lipid levels in relationship to AMD in a large European dataset.
Design
Pooled analysis of cross-sectional data.
Participants
Individuals (N = 30 953) aged 50 years or older participating in the European Eye Epidemiology (E3) consortium and 1530 individuals from the Rotterdam Study with lipid subfraction data.
Methods
AMD features were graded on fundus photographs using the Rotterdam classification. Routine blood lipid measurements, genetics, medication, and potential confounders were extracted from the E3 database. In a subgroup of the Rotterdam Study, lipid subfractions were identified by the Nightingale biomarker platform. Random-intercepts mixed-effects models incorporating confounders and study site as a random effect were used to estimate associations.
Main Outcome Measures
AMD features and stage; lipid measurements.
Results
HDL was associated with an increased risk of AMD (odds ratio [OR], 1.21 per 1-mmol/l increase; 95% confidence interval [CI], 1.14–1.29), whereas triglycerides were associated with a decreased risk (OR, 0.94 per 1-mmol/l increase; 95% CI, 0.91–0.97). Both were associated with drusen size. Higher HDL raised the odds of larger drusen, whereas higher triglycerides decreases the odds. LDL cholesterol reached statistical significance only in the association with early AMD (P = 0.045). Regarding lipid subfractions, the concentration of extra-large HDL particles showed the most prominent association with AMD (OR, 1.24; 95% CI, 1.10–1.40). The cholesteryl ester transfer protein risk variant (rs17231506) for AMD was in line with increased HDL levels (P = 7.7 × 10–7), but lipase C risk variants (rs2043085, rs2070895) were associated in an opposite way (P = 1.0 × 10–6 and P = 1.6 × 10–4).
Conclusions
Our study suggested that HDL cholesterol is associated with increased risk of AMD and that triglycerides are negatively associated. Both show the strongest association with early AMD and drusen. Extra-large HDL subfractions seem to be drivers in the relationship with AMD, and variants in lipid genes play a more ambiguous role in this association. Whether systemic lipids directly influence AMD or represent lipid metabolism in the retina remains to be answered.</p
Microdeletion del(22)(q12.2) encompassing the facial development-associated gene, MN1 (meningioma 1) in a child with Pierre-Robin sequence (including cleft palate) and neurofibromatosis 2 (NF2): a case report and review of the literature
<p>Abstract</p> <p>Background</p> <p>Pierre-Robin sequence (PRS) is defined by micro- and/or retrognathia, glossoptosis and cleft soft palate, either caused by deformational defect or part of a malformation syndrome. Neurofibromatosis type 2 (NF2) is an autosomal dominant syndrome caused by mutations in the <it>NF2 </it>gene on chromosome 22q12.2. NF2 is characterized by bilateral vestibular schwannomas, spinal cord schwannomas, meningiomas and ependymomas, and juvenile cataracts. To date, NF2 and PRS have not been described together in the same patient.</p> <p>Case presentation</p> <p>We report a female with PRS (micrognathia, cleft palate), microcephaly, ocular hypertelorism, mental retardation and bilateral hearing loss, who at age 15 was also diagnosed with severe NF2 (bilateral cerebellopontine schwannomas and multiple extramedullary/intradural spine tumors). This is the first published report of an individual with both diagnosed PRS and NF2. High resolution karyotype revealed 46, XX, del(22)(q12.1q12.3), FISH confirmed a deletion encompassing <it>NF2</it>, and chromosomal microarray identified a 3,693 kb deletion encompassing multiple genes including <it>NF2 </it>and <it>MN1 </it>(meningioma 1).</p> <p>Five additional patients with craniofacial dysmorphism and deletion in chromosome 22-adjacent-to or containing <it>NF2 </it>were identified in PubMed and the DECIPHER clinical chromosomal database. Their shared chromosomal deletion encompassed <it>MN1</it>, <it>PITPNB </it>and <it>TTC28</it>. <it>MN1</it>, initially cloned from a patient with meningioma, is an oncogene in murine hematopoiesis and participates as a fusion gene (<it>TEL</it>/<it>MN1</it>) in human myeloid leukemias. Interestingly, <it>Mn1</it>-haploinsufficient mice have abnormal skull development and secondary cleft palate. Additionally, <it>Mn1 </it>regulates maturation and function of calvarial osteoblasts and is an upstream regulator of <it>Tbx22</it>, a gene associated with murine and human cleft palate. This suggests that deletion of <it>MN1 </it>in the six patients we describe may be causally linked to their cleft palates and/or craniofacial abnormalities.</p> <p>Conclusions</p> <p>Thus, our report describes a <it>NF2</it>-adjacent chromosome 22q12.2 deletion syndrome and is the first to report association of <it>MN1 </it>deletion with abnormal craniofacial development and/or cleft palate in humans.</p
CITED2 and NCOR2 in anti-oestrogen resistance and progression of breast cancer
Background:Endocrine therapies of breast cancer are effective but ultimately fail because of the development of treatment resistance. We have previously revealed several genes leading to tamoxifen resistance in vitro by retroviral insertion mutagenesis. To understand the manner in which these genes yield tamoxifen resistance, their effects on global gene expression were studied and those genes resulting in a distinct gene expression profile were further investigated for their clinical relevance.Methods:Gene expression profiles of 69 human breast cancer cell lines that were made tamoxifen resistant through retroviral insertion mutagenesis were obtained using oligonucleotide arrays and analysed with bioinformatic tools. mRNA levels of NCOR2 and CITED2 in oestrogen receptor-positive breast tumours were determined by quantitative RT-PCR. mRNA levels were evaluated for association with metastasis-free survival (MFS) in 620 patients with lymph node-negative primary breast cancer who did not receive systemic adjuvant therapy, and with clinical benefit in 296 patients receiving tamoxifen therapy for recurrent breast cancer.Results:mRNA expression profiles of most tamoxifen-resistant cell lines were strikingly similar, except for the subgroups of cell lines in which NCOR2 or CITED2 were targeted by the retrovirus. Both NCOR2 and CITED2 mRNA levels were associated with MFS, that is, tumour aggressiveness, independently of traditional prognostic factors. In addition, high CITED2 mRNA levels were predictive for a clinical benefit from first-line tamoxifen treatment in patients with advanced disease.Conclusions: Most retrovirally targeted genes yielding tamoxifen resistance in our cell lines do not impose a distinctive expressi
IMI - Myopia Genetics Report
The knowledge on the genetic background of refractive error and myopia has expanded
dramatically in the past few years. This white paper aims to provide a concise summary of
current genetic findings and defines the direction where development is needed.
We performed an extensive literature search and conducted informal discussions with key
stakeholders. Specific topics reviewed included common refractive error, any and high
myopia, and myopia related to syndromes.
To date, almost 200 genetic loci have been identified for refractive error and myopia, and risk
variants mostly carry low risk but are highly prevalent in the general population. Several
genes for secondary syndromic myopia overlap with those for common myopia. Polygenic
risk scores show overrepresentation of high myopia in the higher deciles of risk. Annotated
genes have a wide variety of functions, and all retinal layers appear to be sites of expression.
The current genetic findings offer a world of new molecules involved in myopiagenesis. As
the missing heritability is still large, further genetic advances are needed. This Committee
recommends expanding large-scale, in-depth genetic studies using complementary big data
analytics, consideration of gene-environment effects by thorough measurement of environmental exposures, and focus on subgroups with extreme phenotypes and high familial
occurrence. Functional characterization of associated variants is simultaneously needed to
bridge the knowledge gap between sequence variance and consequence for eye growth
IMI - Myopia Genetics Report
The knowledge on the genetic background of refractive error and myopia has expanded dramatically in the past few years. This white paper aims to provide a concise summary of current genetic findings and defines the direction where development is needed.We performed an extensive literature search and conducted informal discussions with key stakeholders. Specific topics reviewed included common refractive error, any and high myopia, and myopia related to syndromes.To date, almost 200 genetic loci have been identified for refractive error and myopia, and risk variants mostly carry low risk but are highly prevalent in the general population. Several genes for secondary syndromic myopia overlap with those for common myopia. Polygenic risk scores show overrepresentation of high myopia in the higher deciles of risk. Annotated genes have a wide variety of functions, and all retinal layers appear to be sites of expression.The current genetic findings offer a world of new molecules involved in myopiagenesis. As the missing heritability is still large, further genetic advances are needed. This Committee recommends expanding large-scale, in-depth genetic studies using complementary big data analytics, consideration of gene-environment effects by thorough measurement of environmental exposures, and focus on subgroups with extreme phenotypes and high familial occurrence. Functional characterization of associated variants is simultaneously needed to bridge the knowledge gap between sequence variance and consequence for eye growth
Increased High Density Lipoprotein-levels associated with Age-related Macular degeneration. Evidence from the EYE-RISK and E3 Consortia
Purpose
Genetic and epidemiologic studies have shown that lipid genes and high-density lipoproteins (HDLs) are implicated in age-related macular degeneration (AMD). We studied circulating lipid levels in relationship to AMD in a large European dataset.
Design
Pooled analysis of cross-sectional data.
Participants
Individuals (N = 30 953) aged 50 years or older participating in the European Eye Epidemiology (E3) consortium and 1530 individuals from the Rotterdam Study with lipid subfraction data.
Methods
AMD features were graded on fundus photographs using the Rotterdam classification. Routine blood lipid measurements, genetics, medication, and potential confounders were extracted from the E3 database. In a subgroup of the Rotterdam Study, lipid subfractions were identified by the Nightingale biomarker platform. Random-intercepts mixed-effects models incorporating confounders and study site as a random effect were used to estimate associations.
Main Outcome Measures
AMD features and stage; lipid measurements.
Results
HDL was associated with an increased risk of AMD (odds ratio [OR], 1.21 per 1-mmol/l increase; 95% confidence interval [CI], 1.14–1.29), whereas triglycerides were associated with a decreased risk (OR, 0.94 per 1-mmol/l increase; 95% CI, 0.91–0.97). Both were associated with drusen size. Higher HDL raised the odds of larger drusen, whereas higher triglycerides decreases the odds. LDL cholesterol reached statistical significance only in the association with early AMD (P = 0.045). Regarding lipid subfractions, the concentration of extra-large HDL particles showed the most prominent association with AMD (OR, 1.24; 95% CI, 1.10–1.40). The cholesteryl ester transfer protein risk variant (rs17231506) for AMD was in line with increased HDL levels (P = 7.7 × 10–7), but lipase C risk variants (rs2043085, rs2070895) were associated in an opposite way (P = 1.0 × 10–6 and P = 1.6 × 10–4).
Conclusions
Our study suggested that HDL cholesterol is associated with increased risk of AMD and that triglycerides are negatively associated. Both show the strongest association with early AMD and drusen. Extra-large HDL subfractions seem to be drivers in the relationship with AMD, and variants in lipid genes play a more ambiguous role in this association. Whether systemic lipids directly influence AMD or represent lipid metabolism in the retina remains to be answered.</p
Integrating metabolomics, genomics and disease pathways in age-related macular degeneration: The EYE-RISK Consortium
Objective
In the current study we aimed to identify metabolites associated with age-related macular degeneration (AMD) by performing the largest metabolome association analysis in AMD to date. In addition, we aimed to determine the effect of AMD-associated genetic variants on metabolite levels, and aimed to investigate associations between the identified metabolites and activity of the complement system, one of the main AMD-associated disease pathways.
Design
Case-control assocation analysis of metabolomics data.
Subjects
2,267 AMD cases and 4,266 controls from five European cohorts.
Methods
Metabolomics was performed using a high-throughput H-NMR metabolomics platform, which allows the quantification of 146 metabolite measurements and 79 derivative values. Metabolome-AMD associations were studied using univariate logistic regression analyses. The effect of 52 AMD-associated genetic variants on the identified metabolites was investigated using linear regression. In addition, associations between the identified metabolites and activity of the complement pathway (defined by the C3d/C3 ratio) were investigated using linear regression.
Main Outcome Measures
Metabolites associated with AMD
Results
We identified 60 metabolites that were significantly associated with AMD, including increased levels of large and extra-large HDL subclasses and decreased levels of VLDL, amino acids and citrate. Out of 52 AMD-associated genetic variants, seven variants were significantly associated with 34 of the identified metabolites. The strongest associations were identified for genetic variants located in or near genes involved in lipid metabolism (ABCA1, CETP, APOE, LIPC) with metabolites belonging to the large and extra-large HDL subclasses. In addition, 57 out of 60 metabolites were significantly associated with complement activation levels, and these associations were independent of AMD status. Increased large and extra-large HDL levels and decreased VLDL and amino acid levels were associated with increased complement activation.
Conclusions
Lipoprotein levels were associated with AMD-associated genetic variants, while decreased essential amino acids may point to nutritional deficiencies in AMD. We observed strong associations between the vast majority of the AMD-associated metabolites and systemic complement activation levels, independent of AMD status. This may indicate biological interactions between the main AMD disease pathways, and suggests that multiple pathways may need to be targeted simultaneously for successful treatment of AMD.
Abbreviations
AMDAge-related macular degenerationGWASGenome-wide association studyHDLHigh density lipoproteinVLDLVery low density lipoproteinNMRNuclear magnetic resonanceACMEAverage casual effect estimatesOROdds ratiopFDRFalse discovery rate corrected p-valueCIConfindence intervalCVDCardiovascular diseasesPCAPrincipal component analysisSDStandard deviationBMIBody mass indexFDRFalse discovery rateEUGENDAEuropean Genetic DatabaseRSRotterdam StudyALIENORAntioxydants, LIpides Essentiels, Nutrition et maladies OculaiResCORRBICombined Ophthalmic Research Rotterdam BiobankMARSMünster Age and Retina Study. For all metabolite abbreviations please see supplementary table