Project description:HEK293 FlpIn T-Rex cells were maintained in Dulbeccos Modified Eagle Medium (DMEM) with 10% fetal bovine serum (FBS), supplemented with 3 g/ml blasticidine and 50 g/ml zeocin. For the siRNA-induced knockdown of TDP-43, 20 nM of TDP-43 stealth siRNA was mixed with 10 L of RNAiMAX following the manufacturers reverse transfection protocol and added to a 10 cm dish of HEK FlpIn cells. For the non-targeting siRNA also 20 nM was used, to distinguish off-target effects from biologically relevant ones. After the first 24 hrs of transfection, the medium was replaced with DMEM with 10% FBS and after an additional 24 hrs, the cells were collected for analysis. RNA was extracted using the Direct-zol RNA kit and an in-column DNase digestion step was performed at room temperature for 15 minutes. The poly(A)seq libraries for samples, that were transfected with either non-targeting siRNA or TARDBP siRNA, were generated using the reverse QuantSeq 3mRNA-Seq kit. Libraries were prepared from 500 ng of total RNA. In the protocol one fragment per transcript was generated, which resulted in extremely accurate gene expression values. For the initial step of this kit, oligodT priming, including Illumina-compatible linker sequences, was carried out. The second strand synthesis was followed by purification with magnetic beads. Barcodes were introduced during the PCR amplification step as standard external barcodes. Single-end sequencing (60 nts) was performed on a Illumina GA-2 with a Rapid Run flow-cell. This kit makes use of a custom sequencing primer that anneals to a linker sequence previously introduced in the oligo(dT) priming step for reverse transcription.
Project description:QuantSeq-Rev method to generate highly strand-specific next-generation sequencing (NGS) libraries enabling transcript quantification and identification of the 3'end of polyadenylated RNAs
Project description:A stable HEK293 FlpIn T-Rex cells expressing TDP-43 with an N-terminal eGFP-tag was generated that allowed inducible physiological expression of the protein (Ling et al. 2010). Duplicate iCLIP experiments were performed using an antibody targeting eGFP (Abcam ab290). Crosslinked RNA-protein complexes were isolated by immuno-precipitation and cDNAs were generated to allow preparation of Illumina compatible DNA libraries as described in Huppertz et al. (2014).
Project description:Mutations in TDP-43 (an RNA binding protein) are known to cause amyotrophic lateral sclerosis (ALS). Previously, our group and several other studies showed that TDP-43 binds to several RNA targets in the mammalian CNS. ALS causing mutations in the C-terminal region of TDP-43 that is involved in splicing regulation may lead to aberrant splicing of several RNA transcripts. The main aim of this study is to identify the effect of an ALS causing mutation on the splicing regulation of previously known targets of TDP-43. Mice overexpressing a mutant human TDP-43 (hTDP-43) gene were obtained from The Jackson Laboratory (strain name - B6;CB-Tg(Prnp-TARDBP*A315T) 95Balo/J; Stock no:010700). Mutant hTDP43 was expressed under the control of a prion protein promoter that drives the expression mainly in the mouse CNS and the male transgenic mice developed symptoms around 12 weeks of age while the female mice develop symptoms approximately 20 weeks of age. Therefore, Tg animals that are 50 days old were considered pre-symptomatic and 100 days old (Tg) animals were considered to be in the post-symptomatic stages of the disease for exon array experiments. Age and sex matched pre and post-symptomatic transgenic animals and their wild type littermates were euthanised by cervical dislocation and tissues (brain and spinal cord) were harvested immediately for total RNA isolation experiments (n=3 per group). 200 ng of total RNA from transgenic TDP-43 mice and wild type animals was converted to cDNA and then amplified using the Applause WT-Amp Plus ST kit (NuGEN). Amplified cDNA was then fragmented and biotin labeled using the Encore Biotin Module kit (NuGEN) according to the manufacturer's instruction manual. Labelled cDNA was then hybridised onto Affymetrix GeneChip Exon 1.0 ST arrays in a hybridisation oven at 45 degrees C for 20 hours at 60rpm. After hybridization, washing and staining of the arrays were carried out using Affymetrix fluidics station 450 followed by scanning using GeneChip scanner. GeneChip Command Console Software (AGCC) controlled both the fluidics station and the scanner. CEL files generated by AGCC were uploaded onto Partek software and the data analysis was carried out using the exon array analysis workflow. Exon 1.0 ST arrays contain many more probes, which are classified into three major types based on their source. They are Core, extended and full probe set annotation. Core annotation refers the probe sets that are the most reliable of the three and is derived based on evidences from Refseq and GenBank. Extended annotations refer to probe sets that are generated based on EST sequences, ENSEMBL gene collections and other databases including those used for generating core probe sets. The full annotation refers to probe sets that are purely based on computational predictions. Core probe set annotation, unlike the extended or full annotation excludes the speculative probes reducing the incidence of false positives and was employed for exon array analysis. Alt-splice Anova, a statistical tool available in Partek was used for identifying novel alternative splicing events.
Project description:MicroRNAs (miRNAs) play important roles in a wide range of cellular processes. Aberrant regulation of miRNA genes contributes to human diseases, including cancer. The TAR DNA binding protein 43 (TDP-43), a DNA/RNA binding protein associated with neurodegeneration, is involved in miRNA biogenesis. Here, we systematically examined miRNAs whose expression levels are regulated by TDP-43 using RNA-Seq coupled with siRNA-mediated knockdown approach. TDP-43 knocking down affected the expression of a number of miRNAs. Alterations in isomiR patterns and miRNA arm selection after TDP-43 knockdown suggest a role of TDP-43 in miRNA editing. We examined correlation of selected TDP-43 associated miRNAs and their candidate target genes in human cancers. Our data reveal highly complex roles of TDP-43 in regulating different miRNAs and their target genes. Our results suggest that TDP-43 may promote migration of lung cancer cells by regulating miR-423-3p expression. On the other hand, TDP-43 increases miR-500a-3p expression and binds to the mature miR-500a-3p sequence. Low expression of miR-500a-3p was associated with poor survival of lung cancer patients, suggesting that TDP-43 may have a suppressive role in cancer by regulating miR-500a-3p. Our experiments reveal that cancer-associated genes LIF and PAPPA may be targets of miR-500a-3p. Together with other studies, our work suggests that TDP-43-regulated miRNAs may play multi-facet roles in the pathogenesis of cancer. small RNA seq in SH-SY-5Y, SNB-19 and HT22 (TDP-43 siRNA VS Control siRNA)
Project description:We performed mRNA 3'end sequencing experiments on three biological replicates of HeLa cells depleted of MATR3, PTBP1/2, controls, or combined depletion of MATR3/PTBP1/2. Cells were fractionated into cytoplasmic and nuclear RNAn and only the nuclear RNA was used. Library preparation was done with the QuantSeq library kit (Lexogen) according to manufacturer’s recommendations. Replicates 1 and 2 were prepared with the QuantSeq forward library kit, replicates 3 and 4 with the QuantSeq reverse library kit. All libraries were sequenced on Illumina HiSeq2 machines in a single-end manner with a read length of 100 nt.
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: firstname.lastname@example.org 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:In recent times, high throughput screening analyses have broadly defined the RNA cellular targets of TDP-43, a nuclear factor involved in neurodegeneration. A common outcome of all these studies is that changing the expression levels of this protein can alter the expression of several hundred RNAs within cells. What still remains to be clarified is which changes represent direct cellular targets of TDP-43 or just secondary variations due to the general role played by this protein in RNA metabolism. Using a HTS-based splicing junction analysis we have now identified 162 splicing events that are consistent with being directly controlled by TDP-43. Validation of the data, both in neuronal and non-neuronal cell lines demonstrated that TDP-43 substantially alters the levels of isoform expression in four genes potentially important for neuropathology: MADD/IG20, STAG2, FNIP1, and BRD8. Most importantly, for MADD/IG20 and STAG2 these changes could also be confirmed at the protein level. These alterations were also observed in a cellular model that successfully mimics TDP-43 loss of function effects following its aggregation. These novel splicing events may represent potential biomarkers to predict disease onset, progression, and to test the efficacy of novel therapeutic agents to recover TDP-43 functional properties. We have performed an HTS-based splicing junction analysis of a series of stable cell lines that lack TDP-43, overexpress this factor, or express an RNA-binding mutant, in order to find splicing events, potentially associated with neurodegenerativce diseases, regulated by this splicing factor. Samples were analyzed in triplicate from: The following samples were analyzed in triplicate: wild-type HEK-293 cells, siTDP43-treated HEK-293 cells, siTDP43-treated HEK-293 cells overexpressing a flagged-wildtype TDP-43, siTDP43-treated HEK-293 cells overexpressing a RNA-binding deficient mutant.