Project description:To clarify the functional properties of Tdp-43, we established the differentially expressed alternative exons in Tdp-43-silenced primary cortical neurons by using exon-sensitive microarray technology. We analyzed total RNA of primary motor neuron infected with lentivirus expressing shRNA against mouse Tdp-43 or control. RNA was harvested 11 days after transfection.
Project description:To clarify the functional properties of Tdp-43, we established the differentially expressed alternative exons in Tdp-43-silenced primary cortical neurons by using exon-sensitive microarray technology.
Project description:Mutation in TDP-43 is causative to amyotrophic lateral sclerosis (ALS). TDP-43 is a multifunctional ribonucleoprotein and is reproted to regulate thousands of genes in neurons, but how astrocytes contribute to TDP-43 pathogenesis is not known. This study examined how mutant TDP-43 in astrocytes kills motor neurons and causes ALS phenotypes. Primary astrocytes were isolated from transgenic rats expressing mutant TDP-43 or from control rats without mutant TDP-43 expression. Cultured astrocytes were induced to express mutant human TDP-43 and their gene expression profiles were determined by microarray assays. Microarray analysis revealed that hundreds of genes were altered in astrocytes in response to mutant TDP-43 expression.
Project description:We generated total mRNA libraries and ribosome footprint libraries from motor neuron-like cells (MN1) and primary cortical neurons expressing GFPor pure wild type cells as control, human TDP-43 wild type and mutant proteins to identify translational targets of human TDP-43 mutant protein
Project description:We identify the RNA targets of TAR DNA-binding protein 43 (TDP-43) from cortical neurons by RNA immunoprecipitation followed by deep sequencing (RIP-seq). We identify 4352 highly enriched RNA targets of TDP-43. We determined that the canonical TDP-43 binding site (TG)n was 55.1-fold enriched in our TDP-43 library. Moreover, our analysis shows there is often an adenine in the middle of the motif, (TG)nTA(TG)m. TDP-43 RNA targets are particularly enriched for Gene Ontology terms related to RNA metabolism, neuronal development, and synaptic function. Examination of TDP-43 RNA targets in rat cortical neurons by RIP-seq. Chantelle F. Sephton isolated the TDP-43:RNA complexes and generated the cDNA library for deep sequencing. Email: chantelle.sephton@utsouthwestern.edu Phone: 214-648-4119 Fax: 214-648-1801 ULR: http://www8.utsouthwestern.edu/utsw/cda/dept120915/files/151135.html Organization name: University of Texas Southwestern Medical Center at Dallas Department: Neuroscience Lab: Gang Yu lab Street: 6000 Harry Hines Blvd. City: Dallas State: Texas ZIP: 75390 Country: USA
Project description:Mutation in TDP-43 is causative to amyotrophic lateral sclerosis (ALS). TDP-43 is a multifunctional ribonucleoprotein and is reproted to regulate thousands of genes in neurons, but how astrocytes contribute to TDP-43 pathogenesis is not known. This study examined how mutant TDP-43 in astrocytes kills motor neurons and causes ALS phenotypes. Primary astrocytes were isolated from transgenic rats expressing mutant TDP-43 or from control rats without mutant TDP-43 expression. Cultured astrocytes were induced to express mutant human TDP-43 and their gene expression profiles were determined by microarray assays. Microarray analysis revealed that hundreds of genes were altered in astrocytes in response to mutant TDP-43 expression. As mutant TDP-43 transgene is under the control of tetracycline-regulated pomoter elements (TRE), mutant TDP-43 expression is subjected to Doxycline regulation. Astrocytes isolated from GFAP-tTA/TRE-TDP43M337V rats were desiginated as M337V groups and astrocytes isolated from GFAP-tTA single transgenic rats were desiginated as tTA control groups. Total RNA was isolated from cultured astrocytes at varying times (3, 4, or 6 days after Dox withdrawal) after mutant TDP-43 was induced in astrocytes. Upon mutant TDP-43 induction in astroyctes, gene expression profiles in astroyctes were determined by Illumina Direct Hybridization Assay and compared between tTA and M337V groups at the varying time points of mutant TDP-43 induction.
Project description:Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease characterized by spinal and cortical motor neuron loss and progressive neuromuscular decline. When ALS pathology involves the primary motor cortex (PMC), cortical excitability is often disrupted, yet how these alterations map onto motor deficits during symptomatic ALS remains unclear. To investigate this, we examined the neuromuscular function, cortico-muscular output, and neuronal excitability of symptomatic 4-month-old TDP-43Q331K mice. TDP-43 mice exhibited reduced neuromuscular excitability and impaired strength compared to WT mice. Cranial motor evoked potentials were significantly reduced in TDP-43 mice, indicating decreased cortical output to muscle. Compared to WT mice, whole-cell patch-clamp recordings from TDP-43 PMC layer V pyramidal neurons revealed intrinsic hypoexcitability, diminished persistent inward currents (PICs), and decreased excitatory synaptic activity. Corroborating PIC findings, immunohistochemical analysis showed reduced colocalization of the PIC-associated proteins Nav1.6 and 5-HT2C with PMC layer V neurons. Bulk RNA-seq of the cortex showed distinct transcriptional profiles in TDP-43 mice, with enrichment analysis indicating altered pathways relating to ion transport, synaptic signaling, and neuronal excitability. These results suggest that cortex-wide transcriptional changes may reflect broader and additional molecular mechanisms underlying cortical hypoexcitability in ALS. Together, our results demonstrate that symptomatic TDP-43Q331K mice exhibit a reduction in cortico-muscular output and PMC neuron excitability, accompanied by reduced PICs and PIC-associated proteins within these neurons. These findings identify cortical hypoexcitability as a defining feature of the TDP-43Q331k ALS mouse model and establish multi-level associations between cortical cellular-level dysfunction and impaired motor systems output.