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: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:Zygotic genome activation (ZGA) is essential for early embryonic development. However, the regulation of ZGA remains elusive in mammals. Here we report that a maternal factor TDP-43, a nuclear transactive response DNA-binding protein, regulates ZGA through RNA Pol II and is essential for mouse early embryogenesis. Maternal TDP-43 translocates from the cytoplasm into the nucleus at the early two-cell stage when minor to major ZGA transition occurs. Genetic deletion of maternal TDP-43 results in mouse early embryos arrested at late two-cell stage and female infertile. TDP-43 co-occupies with RNA Pol II as large foci in the nucleus and also at the promoters of ZGA genes at the late two-cell stage. Biochemical evidence indicates that TDP-43 binds Polr2a and Cyclin T1. Depletion of maternal TDP-43 caused the loss of Pol II foci and reduced Pol II binding on chromatin at major ZGA genes, accompanied by defective ZGA. Collectively, our results suggest that maternal TDP-43 is critical for mouse early embryonic development, in part through facilitating the correct RNA Pol II configuration and zygotic genome activation.
Project description:Maintaining cholesterol homeostasis is essential for health of all animal cells. Because of blood-brain barrier, de novo cholesetrol biosynthesis and intercellular cholesterol transport is thought to maintain cholesterol homeostasis within the central nervous system (CNS). Here, we showed that TDP-43, the pathological signature protein for amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD), regulates SREBF2-mediated cholesterol metabolism in the central nervous system (CNS). Unbiased transcriptomic analysis of mice with oligodendroglial TDP-43 deletion revealed a progressive and pathway-wide disruption in the cholesterol metabolism correlating with reduced myelination and cholesterol level. Molecularly, TDP-43 binds directly to mRNA of SREBF2, the master transcription regulator for cholesterol metabolism, and multiple mRNAs encoding proteins in the cholesterol biosynthesis and uptake, including HMGCR, HMGCS1, and LDLR. Depletion of TDP-43 leads to reduced SREBF2 and cholesterol level in vitro and in vivo. The cholesterol reduction can be rescued by reintroducing either the nuclear portion of SREBF2 or LDLR, the latter of which is the receptor for cholesterol-containing low-density lipoproteins (LDLs). Furthermore, LDLR are observed to co-aggregate with pathological TDP-43 in oligodendrocytes of FTD patients and motor neurons of sporadic ALS patients. Taken together, our data indicates that TDP-43 is required to maintain SREBF2-dependent cholesterol homeostasis in the CNS, and disturbance of cholesterol metabolism may be involved in ALS, FTD and TDP-43 proteinopathies-related disease.
Project description:Loss of the nuclear RNA binding protein TAR DNA binding protein-43 (TDP-43) into cytoplasmic aggregates is the strongest correlate to neurodegeneration in amyotrophic lateral sclerosis and frontotemporal degeneration. The molecular changes associated with the loss of nuclear TDP-43 in human tissues are not entirely known. Using a novel subcellular fractionation and fluorescent activated cell sorting method to enrich for diseased neuronal nuclei without TDP-43 from post-mortem FTD-ALS human brain, we characterized the effects of TDP-43 loss on the transcriptome and chromatin accessibility. Nuclear TDP-43 loss is associated with gene expression changes that affect RNA processing, nucleocytoplasmic transport, histone processing and DNA damage. Loss of nuclear TDP-43 was also associated with chromatin decondensation around long interspersed nuclear elements (LINEs) and increased LINE1 DNA content. Moreover, loss of TDP-43 leads to increased retrotransposition that can be inhibited with antiretroviral drugs, suggesting that TDP-43 neuropathology is associated with altered chromatin structure including decondensation of LINEs.
Project description:Loss of the nuclear RNA binding protein TAR DNA binding protein-43 (TDP-43) into cytoplasmic aggregates is the strongest correlate to neurodegeneration in amyotrophic lateral sclerosis and frontotemporal degeneration. The molecular changes associated with the loss of nuclear TDP-43 in human tissues are not entirely known. Using a novel subcellular fractionation and fluorescent activated cell sorting method to enrich for diseased neuronal nuclei without TDP-43 from post-mortem FTD-ALS human brain, we characterized the effects of TDP-43 loss on the transcriptome and chromatin accessibility. Nuclear TDP-43 loss is associated with gene expression changes that affect RNA processing, nucleocytoplasmic transport, histone processing and DNA damage. Loss of nuclear TDP-43 was also associated with chromatin decondensation around long interspersed nuclear elements (LINEs) and increased LINE1 DNA content. Moreover, loss of TDP-43 leads to increased retrotransposition that can be inhibited with antiretroviral drugs, suggesting that TDP-43 neuropathology is associated with altered chromatin structure including decondensation of LINEs.
Project description:The aim of this study is to understand the mechanisms of TDP-43 neurotoxicity. Here, we perform a RNA-Seq analysis in TDP-43 gain-of-fucntion (GOF) , TDP-43 loss-of-function and wild-type late pupae heads (73-90 hours APF) and perform TDP-43 GOF vs wild type and TDP-43 LOF vs wild-type differential expression analysis to show that both mechanisms presents defects in ecdysone receptor (ECR)-dependeint transcriptional program switching, and strongly deregulate expression from the neuronal microtubule associated protien Map205.
Project description:The aim of this study is to understand the mechanisms of TDP-43 neurotoxicity. Here, we perform a RNA-Seq analysis in TDP-43 gain-of-fucntion (GOF) , TDP-43 loss-of-function and wild-type late pupae heads (73-90 hours APF) and perform TDP-43 GOF vs wild type and TDP-43 LOF vs wild-type differential expression analysis to show that both mechanisms presents defects in ecdysone receptor (ECR)-dependeint transcriptional program switching, and strongly deregulate expression from the neuronal microtubule associated protien Map205. RNA-seq was performed in two wild-type D.melanogaster biological replicates (Canton S, w1118 ), four biological replicates for TDP-43 (LOF) with two distinct genotypes (dTDP-43Δ142/Df(2R)106,dTDP-43Δ23/Δ142 ) and two TDP-43 GOF biological replicates (act5c>dTDP-43 ).
Project description:TDP-43 is an important RNA binding protein. To better understand its binding targets in human neurons, we performed TDP-43 iCLIP on SHSY5Y cells.