Project description:Parental imprinting is a form of epigenetic regulation that results in parent-of-origin differential gene expression. To study Prader-Willi syndrome (PWS), a developmental imprinting disorder, we generated patient-derived induced pluripotent stem cells (iPSCs) harboring distinct deletions in the affected region on chromosome 15. Studying PWS-iPSCs and human parthenogenetic iPSCs unexpectedly revealed substantial upregulation of virtually all maternally expressed genes (MEGs) in the imprinted DLK1-DIO3 locus on chromosome 14. Subsequently, we identified IPW, a long noncoding RNA in the critical region of the PWS locus, as a regulator of the DLK1-DIO3 region, as its over-expression in PWS and parthenogenetic iPSCs results in downregulation of the MEGs in this locus. We further show that gene expression changes in the DLK1-DIO3 region coincide with chromatin modifications, rather than DNA methylation levels. Our results suggest that a subset of PWS phenotypes may arise from dysregulation of an imprinted locus distinct from the PWS region. Gene expression analysis was performed on a total of 4 human cell lines, including 3 Prader-Willi Syndrome indcued pluripotent stem cell lines - derived from 3 affected individuals and one of their parental fibroblast cell line.
Project description:Transcriptional analysis of brain tissue from people with molecularly defined causes of obesity may highlight novel disease mechanisms and therapeutic targets. Prader-Willi syndrome (PWS) is a genetic obesity syndrome characterised by severe hyperphagia. We performed RNA sequencing of the hypothalamus from 4 individuals with PWS and 4 age-matched controls.
Project description:Prader-Willi syndrome (PWS) is a genetic disorder caused by deficiency of imprinted gene expression from the paternal chromosome 15q11-15q13 and clinically characterized by neonatal hypotonia, short stature, cognitive impairment, hypogonadism, hyperphagia, morbid obesity and diabetes. Previous clinical studies suggest that a defect in energy metabolism may be involved in the pathogenesis of PWS. Assessment of enzyme activities of mitochondrial oxidative phosphorylation (OXPHOS) complexes in the brain, heart, liver and muscle were assessed. We used microarrays to detail the global programme of gene expression underlyingthe PWS and identified distinct classes of disregulated genes during this process. Skeletal (quadriceps) muscle Vastus Lateralis and whole brain samples from the mutant mice and their wild-type age-matched littermates were analyzed by microarray technology using the Mouse Genome 430 2.0 arrays (Affymetrix).
Project description:Prader-Willi syndrome (PWS) is a genetic disorder caused by deficiency of imprinted gene expression from the paternal chromosome 15q11-15q13 and clinically characterized by neonatal hypotonia, short stature, cognitive impairment, hypogonadism, hyperphagia, morbid obesity and diabetes. Previous clinical studies suggest that a defect in energy metabolism may be involved in the pathogenesis of PWS. Assessment of enzyme activities of mitochondrial oxidative phosphorylation (OXPHOS) complexes in the brain, heart, liver and muscle were assessed. We used microarrays to detail the global programme of gene expression underlyingthe PWS and identified distinct classes of disregulated genes during this process.
Project description:We generated knockdowns (KD) of long non-coding RNAs (lncRNAs) arising from locus 15q11-q13, deletions in which result in Prader-Willi syndrome, in induced pluripotent stem cells. We extracted chromatin-associated RNA (chRNA) and total RNA and sequenced those using Illumina platform. There were four conditions for chRNA: control, KD of sno-lncRNAs, KD of SPA-lncRNAs, KD of both sno/SPA-lncRNAs, in biological duplicate. There were only two conditions for the total RNA seq: control and sno/SPA-lncRNAs. We found differential expression of genes relating to neurodevelopment and cell death between control and sno/SPA-lncRNAs only in chRNA samples.
Project description:Prader-Willi syndrome (PWS), a genetic cause of childhood obesity, is characterized by intellectual disabilities and sleep abnormalities. PWS-causing deletions include a neuronal long, non-coding RNA (lncRNA) processed into small nucleolar RNAs and a spliced lncRNA,116HG. We show that 116HG forms a subnuclear RNA cloud that co-purifies with the transcriptional activator RBBP5 and active metabolic genes, remains tethered to the site of its transcription and increases in size in postnatal neurons. Snord116del mice lacking 116HG exhibited increased energy expenditure corresponding to dysregulation of diurnally expressed Mtor and circadian genes Clock, Cry1, and Per2. Genomic and metabolic analyses demonstrate altered diurnal energy regulation in the Snord116del mouse cortex and link the loss of 116HG to the energy imbalance observed in PWS.
