A large novel deletion downstream of PAX6 gene in a Chinese family with coloboma of iris
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ABSTRACT:
ORGANISM(S): Homo sapiens
PROVIDER: GSE50577 | GEO | 2013/09/05
SECONDARY ACCESSION(S): PRJNA217974
REPOSITORIES: GEO
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Project description:The paired box gene 6 (PAX6) is an essential transcription factor for eye formation. Genetic alterations in PAX6 can lead to various ocular malformations including aniridia. The purpose of this study was to identify genetic defects as the underlying cause of familial coloboma of iris in a large Chinese family. After linkage analysis was carried out in this family, all exons of PAX6 in the proband were sequenced by the Sanger sequencing technique. Then the genome of the proband was evaluated by a microarray-based comparative genomic hybridization (aCGH). Quantitative real-time PCR was applied to verify the abnormal aCGH findings. All patients presented bilateral partial coloboma of iris, severe congenital nystagmus, hyperpresbyopia and congenital posterior polar cataracts. Two-point linkage analysis in the autosomal dominant family showed loss of heterozygosity at the D11S914 locus. There was no pathogenic mutation in the exons of PAX6. The aCGH analysis revealed a 681 kb heterozygous deletion on chromosome 11p13. Quantitative real-time PCR verified the deletion in the patients and further confirmed this deletion cosegregation with the coloboma of iris phenotype in the family. The 681 kb large deletion of chromosome 11p13 downstream of PAX6 is the genetic cause of the familial coloboma of ocular in this large Chinese family. aCGH should be applied if there is a negative result for the mutation detection of PAX6 in patients with aniridia. One Case sample and one control sample
2013-09-05 | E-GEOD-50577 | biostudies-arrayexpress
Project description:A large novel deletion downstream of PAX6 gene in a Chinese family with coloboma of iris
| PRJNA217974 | ENA
Project description:PAX6-related Aniridia is a sight-threatening disease due to progression of secondary glaucoma and aniridia associated keratopathy (AAK). Changes or loss of limbal epithelial progenitors causes the epithelial surfaces defects. We analyzed how PAX6 contribute to this with a two-step approach. 1) mRNA Sequencing of limbal epithelial cells isolated from controls and aniridia patients. 2) confirming the bioinformatical and literature-based result list on a siRNA based primary aniridia cell model (PAX6- knockdown). With this approach genes which are directly influenced by PAX6 should be distinguishable from genes secondary affected by AAK disease state. Therefore epithelial cells were isolated from the limbus region of two patients with aniridia and cultured in KSFM medium. Normal cells were obtained from limbus region of cadaveric control patients. For the siRNA based anridia cell model cells were transfected with lipofectamine and 5 nM siRNA against PAX6 or scrambled control. All cells were lysed to obtain DNA, RNA and protein. Reduction of PAX6 protein was controlled by Western Blot. Aniridia and Control Poly-A enriched RNA-librarys were subjected to Next Generation Sequencing. The differential analysis was a combination of quantification with RSEM and differential tests with edgeR. Gene lists were filtered by comparing to NCBI GEO Datasets, annotation with DAVID and manually annotation using literature search. For the resulting filtered gene list qPCR primer were ordered and postulated changes were verified with qPCR on siRNA based aniridia- cell model (Namely: TP63, ABCG2, ADH7, ALDH1A1, PITX1, DKK1, DSG1, K12, K3, K13, SPINK6, SPINK7, CTSV, SPERPINB1). We could identify genes which might be regulated by PAX6. We could show that SPINK7 mRNA coding for a protease inhibitor is downregulated in patients as well as in our primary aniridia cell model. ALDH1A1 and AHD7 mRNAs were reduced in limbal epithelial cells of aniridia patients (AN-LEC). Both transcripts were downregulated upon PAX6 knockdown in our cell model.Our siRNA-based aniridia cell model is a tool to proof identified PAX6 affected genes which might drive AAK pathogenesis. We could demonstrate, that this is the fact for transcripts coding for retinol converting enzymes. This provides evidence that PAX6 might drive corneal epithelial differentiation process by direct or indirect controlling retinoic acid signaling processes.
2018-10-24 | GSE113008 | GEO
Project description:Nonsense and missense mutations in the transcription factor PAX6 cause a wide range of eye development defects, including aniridia, microphthalmia and coloboma. To understand how changes of PAX6:DNA binding cause these phenotypes, we combined saturation mutagenesis of the paired domain of PAX6 with a yeast one-hybrid (Y1H) assay in which expression of a PAX6-GAL4 fusion gene drives antibiotic resistance. We quantified binding of more than 2,700 single amino-acid variants to two DNA sequence elements. Mutations in DNA-facing residues of the N-terminal subdomain and linker region were most detrimental, as were mutations to prolines and to negatively charged residues. Many variants caused sequence-specific molecular gain-of-function effects, including variants in position Ile71 that increased binding to the LE9 enhancer but decreased binding to a SELEX-derived binding site. In the absence of antibiotic selection, variants that retained DNA binding slowed yeast growth, likely because such variants perturbed the yeast transcriptome. Benchmarking against known patient variants and applying ACMG/AMP guidelines to variant classification, we obtained supporting to moderate evidence to suggest that 1,306 variants are likely benign, and 977, likely pathogenic. Our analysis shows that most pathogenic mutations in the paired domain of PAX6 can be explained simply by the effects of these mutations on PAX6:DNA association, and establishes Y1H as a generalisable assay for the interpretation of variant effects in transcription factors.
2024-03-21 | GSE253580 | GEO
Project description:Heterozygous PAX6 gene mutations leading to haploinsufficiency are the main cause of congenital aniridia, a rare and progressive panocular disease characterized by reduced visual acuity. Up to 90% of patients suffer from aniridia-related keratopathy (ARK), caused by a combination of factors including limbal epithelial stem-cell (LSC) deficiency, impaired healing response and abnormal differentiation. It usually begins in the first decade of life, resulting in recurrent corneal erosions, sub-epithelial fibrosis and corneal opacification. Unfortunately, there are currently no efficient treatments available for these patients and no in vitro model for this pathology. We used CRISPR/Cas9 technology to introduce into the PAX6 gene of LSCs a heterozygous nonsense mutation found in ARK patients. Nine clones carrying a p.E109X mutation on one allele were obtained with no off-target mutations. Compared to the parental WT-LSCs, heterozygous mutant LSCs displayed reduced expression of PAX6 and marked slow-down of cell proliferation, migration and detachment. Remarkably, addition to the culture medium of recombinant PAX6 protein fused to a cell penetrating peptide was able to activate the endogenous PAX6 gene and to rescue phenotypic defects of mutant LSCs, suggesting that administration of such recombinant PAX6 protein could be a promising therapeutic approach of congenital aniridia. More generally, our results demonstrate that introduction of disease mutations into LSCs by CRISPR/Cas9 genome editing allows creating relevant cellular models of ocular disease that should greatly facilitate screening of novel therapeutic approaches.
2019-10-22 | GSE139221 | GEO
Project description:We identified a novel homozygous 15q13.3 microdeletion in a young boy with a complex neurodevelopmental disorder characterized by severe cerebral visual impairment with additional signs of congenital stationary night blindness (CSNB), congenital hypotonia with areflexia, profound intellectual disability, and refractory epilepsy. The mechanisms by which the genes in the deleted region exert their effect are unclear. In this paper we probed the role of downstream effects of the deletions as a contributing mechanism to the molecular basis of the observed phenotype. We analyzed gene expression of lymphoblastoid cells derived from peripheral blood of the proband and his relatives to ascertain the relative effects of the homozygous and heterozygous deletions. The proband with 15q13.3 homozygous deletion and his parents with 15q13.3 heterozygous deletions described in our previous report 15 were evaluated using Affymetrix aCGH-244K arrays (build hg18). The aCGH data were validated by qPCR using primers specific to CHRNA7 as previously described. 15 The extended family and comparison subjects were also screened using the CHRNA7 primers. Immortalized lymphoblastoid lines were created from the proband, his mother, father, a paternal half sister, a paternal half brother, a paternal grandmother and two paternal great uncles. Three lymphoblastoid lines from age- and sex- matched normally developing comparison subjects with normal chromosomes were obtained from the Coriell cell repository [(AG14724 (8 yo), AG14948 (10 yo), AG14980 (9 yo)] were used for gene expression comparison with the proband. The samples from the father, mother and paternal grandmother with heterozygous 15q13.3 deletions were compared to samples from lymphoblastoid cells from adult male and female subjects respectively (normal copy number for 15q13.3 determined by qPCR).
2013-02-17 | E-GEOD-43583 | biostudies-arrayexpress
Project description:Purpose: To evaluate conjunctival cell microRNA and mRNA expression in relation to observed phenotype and genotype of aniridia-associated keratopathy (AAK) in a cohort of subjects with congenital aniridia. Methods: Using impression cytology, bulbar conjunctival cells were sampled from 20 subjects with congenital aniridia and 20 age and sex-matched healthy control subjects. RNA was extracted and microRNA and mRNA analysis was performed using microarrays. Results were related to the presence and severity of AAK determined by a standardized clinical grading scale and to the genotype (PAX6 mutation?) determined by clinical genetics. Results: Of the 2549 microRNAs analyzed, 21 were differentially expressed relative to controls. Among these miR-204-5p, an inhibitor of corneal neovascularization, was downregulated 26.8-fold, while miR-5787 and miR-224-5p were upregulated 2.8 and 2.4-fold relative to controls, respectively. At the mRNA level, 539 transcripts were differentially expressed, among these FOSB and FOS were upregulated 17.5 and 9.7-fold respectively, and JUN by 2.9-fold, all components of the AP-1 transcription factor complex. Pathway analysis revealed dysregulation of several enriched pathways including PI3K-Akt, MAPK, and Ras signaling pathways in aniridia. For several microRNAs and transcripts, expression levels aligned with AAK severity, while in very mild cases with missense or non-PAX6 coding mutations, gene expression was only minimally altered. Conclusion: In aniridia, specific factors and pathways are strongly dysregulated in conjunctival cells, suggesting that the conjunctiva in aniridia is abnormally maintained in a pro-angiogenic and proliferative state, promoting the aggressivity of AAK in a mutation-dependent manner. Transcriptional profiling of conjunctival cells at the microRNA and mRNA levels presents a powerful, minimally-invasive means to assess the regulation of cell dysfunction at the ocular surface.
2020-06-05 | GSE137996 | GEO
Project description:Purpose: To evaluate conjunctival cell microRNA and mRNA expression in relation to observed phenotype and genotype of aniridia-associated keratopathy (AAK) in a cohort of subjects with congenital aniridia. Methods: Using impression cytology, bulbar conjunctival cells were sampled from 20 subjects with congenital aniridia and 20 age and sex-matched healthy control subjects. RNA was extracted and microRNA and mRNA analysis was performed using microarrays. Results were related to the presence and severity of AAK determined by a standardized clinical grading scale and to the genotype (PAX6 mutation?) determined by clinical genetics. Results: Of the 2549 microRNAs analyzed, 21 were differentially expressed relative to controls. Among these miR-204-5p, an inhibitor of corneal neovascularization, was downregulated 26.8-fold, while miR-5787 and miR-224-5p were upregulated 2.8 and 2.4-fold relative to controls, respectively. At the mRNA level, 539 transcripts were differentially expressed, among these FOSB and FOS were upregulated 17.5 and 9.7-fold respectively, and JUN by 2.9-fold, all components of the AP-1 transcription factor complex. Pathway analysis revealed dysregulation of several enriched pathways including PI3K-Akt, MAPK, and Ras signaling pathways in aniridia. For several microRNAs and transcripts, expression levels aligned with AAK severity, while in very mild cases with missense or non-PAX6 coding mutations, gene expression was only minimally altered. Conclusion: In aniridia, specific factors and pathways are strongly dysregulated in conjunctival cells, suggesting that the conjunctiva in aniridia is abnormally maintained in a pro-angiogenic and proliferative state, promoting the aggressivity of AAK in a mutation-dependent manner. Transcriptional profiling of conjunctival cells at the microRNA and mRNA levels presents a powerful, minimally-invasive means to assess the regulation of cell dysfunction at the ocular surface.
2020-06-05 | GSE137995 | GEO
Project description:Purpose: To evaluate conjunctival cell microRNA and mRNA expression in relation to observed phenotype and genotype of aniridia-associated keratopathy (AAK) in a cohort of subjects with congenital aniridia. Methods: Using impression cytology, bulbar conjunctival cells were sampled from 20 subjects with congenital aniridia and 20 age and sex-matched healthy control subjects. RNA was extracted and microRNA and mRNA analysis was performed using microarrays. Results were related to the presence and severity of AAK determined by a standardized clinical grading scale and to the genotype (PAX6 mutation?) determined by clinical genetics. Results: Of the 2549 microRNAs analyzed, 21 were differentially expressed relative to controls. Among these miR-204-5p, an inhibitor of corneal neovascularization, was downregulated 26.8-fold, while miR-5787 and miR-224-5p were upregulated 2.8 and 2.4-fold relative to controls, respectively. At the mRNA level, 539 transcripts were differentially expressed, among these FOSB and FOS were upregulated 17.5 and 9.7-fold respectively, and JUN by 2.9-fold, all components of the AP-1 transcription factor complex. Pathway analysis revealed dysregulation of several enriched pathways including PI3K-Akt, MAPK, and Ras signaling pathways in aniridia. For several microRNAs and transcripts, expression levels aligned with AAK severity, while in very mild cases with missense or non-PAX6 coding mutations, gene expression was only minimally altered. Conclusion: In aniridia, specific factors and pathways are strongly dysregulated in conjunctival cells, suggesting that the conjunctiva in aniridia is abnormally maintained in a pro-angiogenic and proliferative state, promoting the aggressivity of AAK in a mutation-dependent manner. Transcriptional profiling of conjunctival cells at the microRNA and mRNA levels presents a powerful, minimally-invasive means to assess the regulation of cell dysfunction at the ocular surface.
2022-07-20 | GSE204838 | GEO
Project description:Purpose: To evaluate conjunctival cell microRNA and mRNA expression in relation to observed phenotype and genotype of aniridia-associated keratopathy (AAK) in a cohort of subjects with congenital aniridia. Methods: Using impression cytology, bulbar conjunctival cells were sampled from 20 subjects with congenital aniridia and 20 age and sex-matched healthy control subjects. RNA was extracted and microRNA and mRNA analysis was performed using microarrays. Results were related to the presence and severity of AAK determined by a standardized clinical grading scale and to the genotype (PAX6 mutation?) determined by clinical genetics. Results: Of the 2549 microRNAs analyzed, 21 were differentially expressed relative to controls. Among these miR-204-5p, an inhibitor of corneal neovascularization, was downregulated 26.8-fold, while miR-5787 and miR-224-5p were upregulated 2.8 and 2.4-fold relative to controls, respectively. At the mRNA level, 539 transcripts were differentially expressed, among these FOSB and FOS were upregulated 17.5 and 9.7-fold respectively, and JUN by 2.9-fold, all components of the AP-1 transcription factor complex. Pathway analysis revealed dysregulation of several enriched pathways including PI3K-Akt, MAPK, and Ras signaling pathways in aniridia. For several microRNAs and transcripts, expression levels aligned with AAK severity, while in very mild cases with missense or non-PAX6 coding mutations, gene expression was only minimally altered. Conclusion: In aniridia, specific factors and pathways are strongly dysregulated in conjunctival cells, suggesting that the conjunctiva in aniridia is abnormally maintained in a pro-angiogenic and proliferative state, promoting the aggressivity of AAK in a mutation-dependent manner. Transcriptional profiling of conjunctival cells at the microRNA and mRNA levels presents a powerful, minimally-invasive means to assess the regulation of cell dysfunction at the ocular surface.
2022-07-20 | GSE204791 | GEO