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.
Project description:Purpose: To identifiy mRNA changes in wt cone photoreceptors with Txnip overexpression treatment, which improved retinitis pigmentosa (RP) cone survival and visual acuity. Methods: two wt mouse strains, BALB/c and C57BL/6J were injected with AAV-Txnip or AAV-H2BGFP control subretinally at P0. Retinas were dissected out at P21 for BALB/c and P35 for C57BL/6J. 1,000 H2BGFP labeled cones per retina sample were FACS sorted out, and subject for RNA-sequencing. Results: only ~70 genes in P21 BALB/c and 1 genes in C57BL/6J were found differentially expressed with Txnip treatment. Only 1 genes (i.e. Txnip) were in commonly upregulated between the two lists. Conclusions: Txnip seems to be not changing RNA expression much in wt cones. Instead, its major function to rescue RP cones may lay in protein-protein interactions.
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:Cone photoreceptor cell death in inherited retinal diseases, such as Retinitis Pigmentosa (RP), leads to the loss of accurate and color vision and ultimately blindness. In RP, a vast number of mutations are affecting the structure and function of rod photoreceptors while cones remain mutation-free. Once majority of rods have degenerated cones are dying secondarily due to the increased oxidative stress, inflammation and loss of structural and nutritional support normally provided by rods. Here we demonstrated that secondary cone cell death in animal models for RP is governed by an increased activity of histone deacetylates (HDACs). A single intravitreal injection of an HDAC inhibitor at a late stage of the disease, when majority of rods have already degenerated, is sufficient to delay cone death and support long-term cone survival. Surviving cones are retaining functionality and are mediating light-driven ganglion cell responses. RNA-seq analysis of surviving cones demonstrated that HDAC inhibition affords multi-level protection trough regulation of different prosurvival pathways including MAPK, PI3K-AKT and autophagy. These study suggest a unique possibility for targeted pharmacological protection of both primary degenerating rods and mutation-free secondary dying cones and creates hope to maintain vision in RP patients independent of the disease stage.
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: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: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: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.