Mutations in PNPLA6 are linked to photoreceptor degeneration and various forms of childhood blindness
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PROVIDER: EGAS00001001013 | EGA |
REPOSITORIES: EGA
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Project description:In this work, using exome sequencing, we identified biallelic PNLPA6 mutations in patients with childhood blindness due to severe photoreceptor death and clinical features of Leber congenital amaurosis (LCA) and, interestingly, also of the rare Oliver McFarlane Syndrome
| EGAD00001001042 | EGA
Project description:Leber congenital amaurosis (LCA) includes congenital or early-onset blinding diseases, characterized by vision loss together with nystagmus and nonrecordable electroretinogram (ERG). At least 19 genes are associated with LCA. While most LCA is recessive, mutations in the homeodomain transcription factor gene CRX lead to autosomal dominant LCA. The mechanism of CRX-LCA is not understood. Here, we report a new spontaneous mouse mutant carrying a frameshift mutation in Crx (CrxRip). We show that, unlike Crx-/- mouse retina, the dominant Crx c.763del1 mutation in CrxRip results in congenital blindness with complete loss of ERG, yet the photoreceptors do not degenerate. Dominant CRX frameshift mutations associated with LCA mimic the CrxRip phenotype that can be rescued by Crx. RNA-Seq profiling reveals progressive and complete loss of rod differentiation factor Nrl in CrxRip, while residual Nrl remains in Crx-/- retina. Moreover, Nrl partially restores the rod phenotype in CrxRip/+ mice. We show that the binding of Otx2 to Nrl promoter is obliterated in CrxRip mutant, and ectopic Otx2 can rescue the rod phenotype. Therefore, Otx2 is required to maintain Nrl expression in developing rods to consolidate rod fate. Our studies provide the mechanism of congenital blindness caused by dominant CRX mutations and should assist in therapeutic design. Retinal samples were harvested from WT, CrxRip/+, CrxRip/Rip, Crx-/- and Nrl-/- retina at postnatal days 2 and 21 for whole transcriptome sequencing (RNAseq). Each sample included 2 independent frozen retina and experiments were performed in duplicates. RNA-seq transcriptome libraries were constructed from 1 ?g of total RNA.
2014-01-13 | E-GEOD-52006 | biostudies-arrayexpress
Project description:Leber congenital amaurosis (LCA) includes congenital or early-onset blinding diseases, characterized by vision loss together with nystagmus and nonrecordable electroretinogram (ERG). At least 19 genes are associated with LCA. While most LCA is recessive, mutations in the homeodomain transcription factor gene CRX lead to autosomal dominant LCA. The mechanism of CRX-LCA is not understood. Here, we report a new spontaneous mouse mutant carrying a frameshift mutation in Crx (CrxRip). We show that, unlike Crx-/- mouse retina, the dominant Crx c.763del1 mutation in CrxRip results in congenital blindness with complete loss of ERG, yet the photoreceptors do not degenerate. Dominant CRX frameshift mutations associated with LCA mimic the CrxRip phenotype that can be rescued by Crx. RNA-Seq profiling reveals progressive and complete loss of rod differentiation factor Nrl in CrxRip, while residual Nrl remains in Crx-/- retina. Moreover, Nrl partially restores the rod phenotype in CrxRip/+ mice. We show that the binding of Otx2 to Nrl promoter is obliterated in CrxRip mutant, and ectopic Otx2 can rescue the rod phenotype. Therefore, Otx2 is required to maintain Nrl expression in developing rods to consolidate rod fate. Our studies provide the mechanism of congenital blindness caused by dominant CRX mutations and should assist in therapeutic design.
2014-01-13 | GSE52006 | GEO
Project description:Our purpose was to investigate genes and molecular mechanisms involved in patients with Leber congenital amaurosis (LCA). Fibroblasts from two unrelated clinically-identified patients (Coriell) were reprogrammed to pluripotency by retroviral transduction. These human induced Pluripotent Stem Cells (hiPSCs) were differentiated into neural stem cells (NSC) that mimicked the neural tube stage and retinal pigmented epithelial (RPE) cells that could be targeted by the disease. A genome wide transcriptome analysis was performed with Affymetrix Exon Array GeneChipM-BM-., comparing LCA-hiPSCs derivatives to controls. The aim was to identify differentially expressed genes which may be associated with early developmental defect before the establishment of mature retinal circuitry. We analyzed iPSC-derived retinal pigmented epithelial (RPE) cells from LCA patient's fibroblast (n=2) and iPSC-derivedretinal pigmented epithelial (RPE) cells from healthy people fibroblast (n=2). A total of 13 samples were analyzed : 9 RPE cells derived from iPSC LCA and 4 RPE cells derived from wild-type iPSC.
2015-01-21 | E-GEOD-43926 | biostudies-arrayexpress
Project description:Our purpose was to investigate genes and molecular mechanisms involved in patients with Leber congenital amaurosis (LCA). Fibroblasts from two unrelated clinically-identified patients (Coriell) were reprogrammed to pluripotency by retroviral transduction. These human induced Pluripotent Stem Cells (hiPSCs) were differentiated into neural stem cells (NSC) that mimicked the neural tube stage and retinal pigmented epithelial (RPE) cells that could be targeted by the disease. A genome wide transcriptome analysis was performed with Affymetrix Exon Array GeneChipM-BM-., comparing LCA-hiPSCs derivatives to controls. The aim was to identify differentially expressed genes which may be associated with early developmental defect before the establishment of mature retinal circuitry. We analyzed iPSC-derived neural stem cells from LCA patient's fibroblast (n=2) and iPSC-derived neural stem cells from healthy people fibroblast (n=2). A total of 21 samples were analyzed : 9 NSC derived from iPSC LCA and 12 NSC derived from wild-type iPSC.
2015-01-21 | E-GEOD-43924 | biostudies-arrayexpress
Project description:Bariatric surgical procedures such as sleeve gastrectomy (SG) provide effective type 2 diabetes remission in human patients. Previous work demonstrated that gastrointestinal levels of the bacterial metabolite lithocholic acid (LCA) are decreased after SG in mice and humans. Here, we show that LCA worsens glucose tolerance and impairs whole body metabolism. We also show that taurodeoxycholic acid (TDCA), which was the only bile acid whose concentration was increased in the murine small intestine post-SG, suppresses the bacterial bile acid-inducible (bai) operon and production of LCA both in vitro and in vivo. Treatment of diet-induced obese (DIO) mice with TDCA reduces LCA levels and leads to microbiome-dependent improvements in host glucose handling. Moreover, TDCA abundance is decreased in small intestinal tissue from T2D patients. This work has revealed that TDCA is an endogenous inhibitor of LCA production and suggests that TDCA may contribute to the glucoregulatory effects of bariatric surgery.
2024-07-21 | GSE262065 | GEO
Project description:Mutations in IQCB1/NPHP5 gene encoding the ciliary protein Nephrocystin 5 cause early-onset blinding disease Leber congenital amaurosis (LCA), together with kidney dysfunction in Senior-Løken Syndrome. For in vitro disease modeling, we obtained dermal fibroblasts from NPHP5-LCA patients, which were reprogrammed into induced pluripotent stem cells (iPSCs) and differentiated into retinal pigment epithelium (RPE) and retinal organoids. Patient fibroblasts and RPE demonstrated aberrantly elongated ciliary axonemes. Organoids revealed impaired development of outer segment structures, which are modified primary cilia, and mislocalization of visual pigments to photoreceptor cell soma. All patient-derived cells showed reduced levels of CEP290 protein, a critical cilia transition zone component interacting with NPHP5, providing a plausible mechanism for aberrant ciliary gating and cargo transport. Disease phenotype in NPHP5-LCA retinal organoids could be rescued by AAV-mediated NPHP5 gene augmentation therapy. Our studies thus establish a human disease model and a path for treatment of NPHP5-LCA.
2022-08-26 | GSE200339 | GEO
Project description:Mutations in the cone-rod homeobox (CRX) transcription factor lead to distinct retinopathy phenotypes, including early-onset vision impairment in dominant Leber congenital amaurosis (LCA). Using induced pluripotent stem cells (iPSCs) from a patient with CRX-I138fs mutation, we established an in vitro model of CRX-LCA in retinal organoids that exhibit defective photoreceptor maturation by histology and gene profiling including diminished expression of visual opsins. Gene therapy by delivery of an additional correct CRX allele using an AAV vector partially restored photoreceptor phenotype and expression of phototransduction-related genes as revealed by single cell RNA-sequencing. Retinal organoids derived from iPSCs of a second dominant CRX-LCA patient carrying a K88N mutation revealed loss of opsin expression as a common phenotype, which could also be alleviated by AAV-mediated overexpression of CRX. Our studies provide the proof-of-concept for development of gene therapy for dominant CRX-LCA and other CRX-retinopathies.
2021-02-17 | GSE153099 | GEO
Project description:Mutations in the cone-rod homeobox (CRX) transcription factor lead to distinct retinopathy phenotypes, including early-onset vision impairment in dominant Leber congenital amaurosis (LCA). Using induced pluripotent stem cells (iPSCs) from a patient with CRX-I138fs mutation, we established an in vitro model of CRX-LCA in retinal organoids that exhibit defective photoreceptor maturation by histology and gene profiling including diminished expression of visual opsins. Gene therapy by delivery of an additional correct CRX allele using an AAV vector partially restored photoreceptor phenotype and expression of phototransduction-related genes as revealed by single cell RNA-sequencing. Retinal organoids derived from iPSCs of a second dominant CRX-LCA patient carrying a K88N mutation revealed loss of opsin expression as a common phenotype, which could also be alleviated by AAV-mediated overexpression of CRX. Our studies provide the proof-of-concept for development of gene therapy for dominant CRX-LCA and other CRX-retinopathies.
2021-02-17 | GSE152939 | GEO
Project description:Blindness due to retinal degeneration affects millions of people worldwide, but many disease-causing mutations remain unknown. PNPLA6 encodes the patatin-like phospholipase domain containing protein 6, also known as neuropathy target esterase (NTE), which is the target of toxic organophosphates that induce human paralysis due to severe axonopathy of large neurons. Mutations in PNPLA6 also cause human spastic paraplegia characterized by motor neuron degeneration. Here we identify PNPLA6 mutations in childhood blindness in seven families with retinal degeneration, including Leber congenital amaurosis and Oliver McFarlane syndrome. PNPLA6 localizes mostly at the inner segment plasma membrane in photoreceptors and mutations in Drosophila PNPLA6 lead to photoreceptor cell death. We also report that lysophosphatidylcholine and lysophosphatidic acid levels are elevated in mutant Drosophila. These findings show a role for PNPLA6 in photoreceptor survival and identify phospholipid metabolism as a potential therapeutic target for some forms of blindness.
| S-EPMC4356490 | biostudies-literature