Project description:We analyzed function of DHX38 helicase in RNA splicing. We downregulated DHX38 in HEK293 cells by RNAi and compared the transcriptome of DHX38 knockdown cells with cells treated with negative control siRNA.
Project description:A Drosophila mutant for the splicing factor Prp31 was generated and characterized as a model for Retinitis pigmentosa 11. The transcriptome of the mutant was compared to the genetic control white.
Project description:Recessive retinitis pigmentosa (RP) is often caused by nonsense mutations that lead to low mRNA levels as a result of nonsense-mediated decay. Some RP genes are expressed at detectable levels in leukocytes as well as in the retina. We designed a microarray-based method to find recessive RP genes based on low lymphoblast mRNA expression levels Keywords: Recessive mutations; mRNA expression; nonsense mediated-decay; retinitis pigmentosa; lymphocyte; Affymetrix genechip Human Genome U133Plus2.0.
Project description:The goal of the study was to identify transcriptional modifications in retinal tissues from mouse model of rhodopsin mutation-associated retinitis pigmentosa (RP), Q344X compared to wild-type (WT). We implemented RNA-sequencing (RNA-seq) at poly(A) selected RNA for transcriptomic profiling. Differentially expressed genes were determined by DESeq2 using the Benjamini & Hochberg p-value adjustment and an absolute log2 fold change cutoff. The results indicate that there is specificity in transcriptional patterns in the retina from Q344x mice relative to WT, including differential expression in the potassium channel gene, Kcnv2, and differential expression in histone genes including the H1 family histone member, H1foo, the H3 histone family 3B, H3f3b, and the histone deacetylase 9, Hdac9.
Project description:Experiment to examine the miRNA profiles in the retina compared to the brain and other body regions. A comparison of a wild type C57 mouse retina versus a retina from a mouse model of retinitis pigmentosa (Pro347Ser) was under taken.
Project description:Background: Substantial progress has been made in the identification of sequence elements that control mRNA splicing and the genetic variants in these elements that alter mRNA splicing (referred to as splicing quantitative trait loci -- sQTLs). Genetic variants that affect mRNA splicing in trans are harder to identify because their effects can be more subtle and diffuse, and the variants are not co-located with their targets. We carried out a transcriptome-wide analysis of the effects of a mutation in a ubiquitous splicing factor that causes retinitis pigmentosa (RP) on mRNA splicing, using exon microarrays. Results: Exon microarray data was generated from whole blood samples obtained from four individuals with a mutation in the splicing factor PRPF8 and four sibling controls. Although the mutation has no known phenotype in blood, there was evidence of widespread differences in splicing between cases and controls (affecting between 10\% and 25\% of exons). Most probesets with significantly different inclusion (defined as the expression intensity of the exon divided by the expression of the corresponding transcript) between cases and controls had higher inclusion in cases and corresponded to exons that were shorter than average, AT-rich, located towards the 5' end of the gene and flanked by long introns. Introns flanking affected probesets were particularly depleted for the shortest category of introns, associated with splicing via intron definition. Conclusions: Our results show that a mutation in a splicing factor, with a phenotype that is restricted to retinal tissue, acts as a trans-sQTL cluster in whole blood samples. Characteristics of the affected exons suggest that they are spliced co-transcriptionally and via exon definition. Eight samples consisting of four sibling pairs were analysed. One individual in each pair harboured an RP-causing mutation on the PRPF8 gene (cases). Unaffected siblings were used as controls.
Project description:In retinitis pigmentosa mouse models inhibitors of histone modification enzymes LSD1and HDAC1 blocked rod degeneration, preserved vision and affected the expression of multiple genes including maintenance of rod-specific transcripts and downregulation those involved in inflammation, gliosis and cell death.
Project description:Mutations in pre-mRNA processing factors (PRPFs) cause autosomal dominant retinitis pigmentosa (RP), but it is unclear why mutations in ubiquitously expressed genes cause retinal disease. We have generated transcriptome profiles from RP11 (PRPF31-mutated) patient-derived retinal organoids and retinal pigment epithelium (RPE), as well as Prpf31+/- mouse tissues, which revealed that disrupted alternative splicing occurred for specific splicing programmes. Mis-splicing of genes encoding pre-mRNA splicing proteins was limited to patient-specific retinal cells and Prpf31+/- mouse retinae and RPE. Mis-splicing of genes implicated in ciliogenesis and cellular adhesion was associated with severe RPE defects that include disrupted apical-basal polarity, reduced trans-epithelial resistance and phagocytic capacity, and decreased cilia length and incidence. Disrupted cilia morphology also occurred in patient-derived photoreceptors, associated with progressive degeneration and cellular stress. In situ gene-editing of a pathogenic mutation rescued protein expression and key cellular phenotypes in RPE and photoreceptors, providing proof-of-concept for future therapeutic strategies.
Project description:Background: Substantial progress has been made in the identification of sequence elements that control mRNA splicing and the genetic variants in these elements that alter mRNA splicing (referred to as splicing quantitative trait loci -- sQTLs). Genetic variants that affect mRNA splicing in trans are harder to identify because their effects can be more subtle and diffuse, and the variants are not co-located with their targets. We carried out a transcriptome-wide analysis of the effects of a mutation in a ubiquitous splicing factor that causes retinitis pigmentosa (RP) on mRNA splicing, using exon microarrays. Results: Exon microarray data was generated from whole blood samples obtained from four individuals with a mutation in the splicing factor PRPF8 and four sibling controls. Although the mutation has no known phenotype in blood, there was evidence of widespread differences in splicing between cases and controls (affecting between 10\% and 25\% of exons). Most probesets with significantly different inclusion (defined as the expression intensity of the exon divided by the expression of the corresponding transcript) between cases and controls had higher inclusion in cases and corresponded to exons that were shorter than average, AT-rich, located towards the 5' end of the gene and flanked by long introns. Introns flanking affected probesets were particularly depleted for the shortest category of introns, associated with splicing via intron definition. Conclusions: Our results show that a mutation in a splicing factor, with a phenotype that is restricted to retinal tissue, acts as a trans-sQTL cluster in whole blood samples. Characteristics of the affected exons suggest that they are spliced co-transcriptionally and via exon definition.
Project description:Purpose: To identifiy mRNA changes in retinitis pigmentosa (RP) cone photoreceptors with Txnip overexpression treatment, which improved RP cone survival and visual acuity. Methods: two RP mouse strains, rd1 and Rho-/-, were injected with AAV-Txnip or AAV-H2BGFP control subretinally at P0. Retinas were dissected out at P21 for rd1 and P90 for Rho-/-. 1,000 H2BGFP labeled cones per retina sample were FACS sorted out, and subject for RNA-sequencing. Results: >1,400 genes in P21 rd1 and >700 genes in Rho-/- were found differentially expressed with Txnip treatment. Conclusions: 25 genes are in common between P21 rd1 and P90 Rho-/- with Txnip treatment. On this list, notably, three mitochondrial Electron Transport Chain (ETC) genes were up-regulated.