Project description:Through splicing analysis of a publicly available RNA-Seq dataset, we discovered TDP-43 represses a cryptic exon splicing event in UNC13A, a gene that had been associated with FTD/ALS through GWA studies. To confirm the sequences of the cryptic exons, we used shRNA to reduce TDP-43 levels in iPSC-derived motor neurons (iPSC-MNs) and by amplicon sequencing the RT-PCR product, we observed the insertion in cells with TDP-43 depletion but not in control shRNA-treated cells. Through sequence alignment, we verified the sequences of the cryptic exons.
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.
Project description:TAR DNA binding protein of 43 kDa (TDP-43; gene name: Tardbp), a ubiquitously expressed evolutionarily conserved protein, is highly expressed in the preleptotene and pachytene spermatocytes. TDP-43 is linked to several human neurodegenerative disorders. Exploring its functional requirement for spermatogenesis for the first time, we show here that conditional knockout (cKO) of Tardbp in male germ cells of mice leads to failure of meiosis and arrest of spermatogenesis. Fertility trials indicated severe subfertility. Spermatocytes of cKO mice showed failure to complete prophase I of meiosis with arrest at mid-pachytene stage. Our work reveals a crucial role for TDP-43 in male meiosis and suggests that some forms of meiotic arrest seen in infertile men may result from loss of function of TDP-43. In order to identify putative direct genes of TDP-43, we performed RNA-seq using testes from postnatal day 12 (PND12) wild type (control) and cKO (experimental) mice.
Project description:Sporadic amyotrophic lateral sclerosis (sALS) is the most common (~90%) form of ALS. There are no animal models of sALS and exact molecular mechanisms remain elusive. Here, we elucidate gene-expression profiles in laser capture microdissected enriched surviving motor neurons (MNs) from sALS lumbar spinal cords in patients who had rostral onset and caudal progression. A strong signature was detected and immunological signals were computationally filtered. The filtered dataset showed clustering groups that were significantly explained by levels of phosphorylated TDP-43 (pTDP-43). Transcriptome-pathology correlations and enhanced crosslinking and immunoprecipitation combined with sequencing (eCLIP-seq) identified that Casein kinase 1ε (CSNK1E) had the highest correlation with pTDP-43 status and TDP-43 binding in its 3’UTR. Furthermore, CSNK1E interacted with TDP-43 on protein level and its overexpression lead to increased cytoplasmic pTDP-43 accumulations in iPSC-MNs, suggesting CSNK1E directly mediates TDP-43 phosphorylation. Therefore, we report an essential framework for molecular disease classification and transcriptome – pathology correlation in sALS to identify candidate genes for elucidating disease mechanisms and potential therapeutic interventions.
Project description:This study aims to investigate whether the passage of human chromosome 21 through the mouse male germline results in changes in the transcriptional deployment of the exogenous chromosome in the offspring generation. We used the Tc1 mouse model that stably carries almost an entire copy of human chromosome 21 and profiled the genome-wide pattern of non-methylated DNA using BioCAP-sequencing (doi: 10.1093/nar/gkr1207) in the livers of male- and female-germline derived Tc1 mice. This dataset contains only the samples for male-germline derived animals, BioCAP-Seq data for female-germline derived animals have already been deposited in Gene Expression Omnibus with the accession number GSE72208.
Project description:TDP-43 is a nuclear protein involved in pivotal processes, extensively studied for its implication in neurodegenerative disorders. TDP-43 cytosolic inclusions are a common neuropathologic hallmark in amyotrophic lateral sclerosis (ALS) and related diseases, and it is now established that TDP-43 misfolding and aggregation play a key role in their etiopathology. TDP-43 neurotoxic mechanisms are not yet clarified, but the identification of proteins able to modulate TDP-43-mediated damage may be promising therapeutic targets for TDP-43 proteinopathies. Here we show by the use of refined yeast models that the nucleolar protein nucleolin (NCL) acts as a potent suppressor of TDP-43 toxicity, restoring cell viability. We provide evidence that NCL co-expression is able to alleviate TDP-43-induced damage also in human cells, further supporting its beneficial effects in a more consistent pathophysiological context. Presented data suggest that NCL could promote TDP-43 nuclear retention, reducing the formation of toxic cytosolic TDP-43 aggregates.
Project description:Purpose: The goal of this stuydy was to apply transcriptome profiling (RNA-seq) to human cells that either express or which lack the TDP-43 protein. Methods: mRNA profiles of TDP-43 KO HeLa cells and "rescued" TDP-43 KO cells wherein a wildtype TDP-43 transgene was re-expressed at endogenous levels were generated by deep sequencing, in triplicate, on Illumina’s HiSeq 2500 using 2x70bp paired-end reads, generating 104.4-128.2 million reads (52.2-64.1 million pairs) per sample. . The sequence reads that passed quality filters were analyzed at the transcript isoform level with TopHat2 followed by Cufflinks Cuffmerge and Cuffdiff to define transcripts and establish their abundance and finally to perform differential gene expression analysis, using the assembled known plus novel transcripts . Results: Using an optimized data analysis workflow, we mapped approximately 50-60 million reads per sample to the human genome (build hg19) and identified transcripts whose abundance differed between the TDP-43 KO versus "rescued" conditions. Conclusions: Our study presents a detailed analysis of the impact of the knockout of TDP-43 on the transcriptome of a human cell line. The results reported here should provide a framework for defining transcripts whose abundnace and splicing are regulated by TDP-43.
Project description:TAR DNA-binding protein 43 (TDP-43) is the major protein component of neuronal inclusions characterizing the adult-onset neurodegenerative diseases amyotrophic lateral sclerosis (ALS) and frontotemporal lobar degeneration with ubiquitinated inclusions (FTLD-TDP). Whereas TDP-43 was originally identified as a DNA-binding protein that bound the HIV-1 trans-activation response (TAR) DNA element, recent work elucidating its role in neurodegenerative disease pathogenesis has largely focused on TDP-43’s role as an RNA-binding protein. Here, we demonstrate that in human cells, TDP-43 binds DNA genome-wide, with strong enrichment at small nuclear RNA (snRNA) genes. Moreover, TDP-43 binding to snRNA genes is not dependent on RNA, and the snRNA products of TDP-43-bound sites are incorporated into Smith antigen-containing snRNPs. Furthermore, TDP-43 knockdown increases expression of bound snRNA genes, supporting a role for TDP-43 in the negative regulation of snRNA biogenesis. Finally, ALS-associated missense mutations in the gene encoding TDP-43, TARDBP, reduce binding to snRNA genes. Together, our data suggest that the DNA-binding role of TDP-43 is important in health and in disease, and aberrant TDP-43 binding to snRNA gene loci may alter splicing function in ALS and FTLD-TDP.
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)