Project description:In cerebellar atrophy of 12-month-old ATM-null mice, transcriptome upregulations concern most neurotransmission and neuropeptide pathways, while downregulations affect prominently Itpr1, Usp2 and non-coding RNA In cerebellar atrophy of 12-month-old ATM-null mice, transcriptome upregulations concern most neurotransmission and neuropeptide pathways, while downregulations affect prominently Itpr1, Usp2 and non-coding RNA The autosomal recessive disorder Ataxia-Telangiectasia is caused by dysfunction of stress response protein ATM. In the nucleus of proliferating cells, ATM senses DNA double-strand breaks and coordinates their repair. This role explains T-cell dysfunction and tumor risk. However, it remains unclear whether this function is relevant for postmitotic neurons and underlies the cerebellar atrophy, since ATM is cytoplasmic in postmitotic neurons. Here, we used ATM-null mice that survived early immune deficits by bone-marrow transplantation, and reached initial neurodegeneration stages at 12 months of age. Global cerebellar transcriptomics demonstrated ATM depletion to trigger upregulations in most neurotransmission and neuropeptide systems. Downregulated transcripts were found for the ATM interactome component Usp2, many non-coding RNAs, ataxia genes Itpr1, Grid2, immediate early genes and immunity factors. Allelic splice changes affected prominently neuropeptide machinery, e.g. Oprm1. Validation experiments with stressors were performed in human neuroblastoma cells, where ATM localized only to cytoplasm, similar to brain. Effect confirmation in SH-SY5Y cells occurred better after ATM depletion and osmotic stress better than nutrient / oxidative stress, rather than ATM kinase inhibition or DNA stressor bleomycin. Overall, we provide pioneer observations from a faithful A-T mouse model, which suggest general changes in synaptic and dense-core vesicle stress adaptation.
Project description:Transcriptional profiling of mouse Extensior Digitorum Longus muscle comparing control Wilde type (WT) C57BL/6J, 4 month old female with Calsequestrin 1-null muscles of the same age and gender without any treatment
Project description:Transcriptional profiling of mouse Extensior Digitorum Longus muscle comparing control Wilde type (WT) C57BL/6J, 4 month old female with Calsequestrin 1-null muscles of the same age and gender without any treatment Two-condition experiment, KO vs. WT muscle. Biological replicates: 1 pool with 6 WT controls, 4 KO independently grown. Two replicates per array and dye swap.
Project description:To look for age-related changes in the liver, we used RNAseq gene expression analysis to characterize mRNA expression profile in livers from 1-month vs. 6-month-old mice
Project description:Cerebellar cortex expression in ataxia-telangiectasia patients and normal controls. The neurodegenerative disease known as ataxia-telangiectasia (A-T) is caused by the absence of the ATM (A-T mutated) protein. A long-standing mystery surrounding A-T is why cerebellar Purkinje cells (PCs) appear uniquely vulnerable to ATM-deficiency. Here, we present that 5-hydroxymethylcytosine (5hmC), a newly recognized epigenetic marker found at high levels in neurons, is substantially reduced in human A-T and Atm-/- mouse cerebellar PCs. TET1, an enzyme that converts 5mC to 5hmC, responds to DNA damage. Manipulation of TET1 activity directly affects neuronal cell cycle reentry and cell death after the induction of DNA damage. Quantitative, genome-wide analysis of 5hmC of samples from human cerebellum showed that in ATM-deficiency there is a remarkable genome-wide reduction of 5hmC enrichment at both proximal and distal regulatory elements. These results reveal a role of TET1-mediated 5hmC in DNA damage response, and provide insights into the basis of a PC-specific DNA demethylation alteration in ATM-deficiency. Human frozen tissue was obtained from the NICHD Brain and Tissue Bank of Developmental Disorders at the University of Maryland, Baltimore, MD. RNA was prepared and run on an Illumina Human HT-12 v4 microarray. 3 ataxia-telangiectasia (A-T) cases and 4 normal controls.
Project description:Cerebellar cortex expression in ataxia-telangiectasia patients and normal controls. The neurodegenerative disease known as ataxia-telangiectasia (A-T) is caused by the absence of the ATM (A-T mutated) protein. A long-standing mystery surrounding A-T is why cerebellar Purkinje cells (PCs) appear uniquely vulnerable to ATM-deficiency. Here, we present that 5-hydroxymethylcytosine (5hmC), a newly recognized epigenetic marker found at high levels in neurons, is substantially reduced in human A-T and Atm-/- mouse cerebellar PCs. TET1, an enzyme that converts 5mC to 5hmC, responds to DNA damage. Manipulation of TET1 activity directly affects neuronal cell cycle reentry and cell death after the induction of DNA damage. Quantitative, genome-wide analysis of 5hmC of samples from human cerebellum showed that in ATM-deficiency there is a remarkable genome-wide reduction of 5hmC enrichment at both proximal and distal regulatory elements. These results reveal a role of TET1-mediated 5hmC in DNA damage response, and provide insights into the basis of a PC-specific DNA demethylation alteration in ATM-deficiency.
Project description:A neuronal PI(3,4,5)P3-dependent program of oligodendrocyte precursor recruitment and myelination was identified in mice that conditionally lack PTEN in cerebellar granular cells (PTEN cKO) Expression analysis was performed with RNA obtained selectively from cerebellar granular cell layer of PTEN conditional null mutants and controls