Project description:To investigate the presence of piRNAs and their potential functions in human brain and neurodegenerations, we performed the genomic profiling in Healthy Brain (HB) sample as well as Alzheimer-affected brain (AD) sample by adopting Next-Gen small RNA sequencing technology. Using deep sequencing of small RNAs, we identified an extensive catalogue of 564 and 451 mature piRNAs in HB and AD respectively. The piRNAs from each sample exhibited varied length distribution between 26-32 nts and are originated from different genomic locations. We found 149 piRNAs to be differentially expressed in Alzheimer’s disease which comprises of 146 up-regulated and 3 down-regulated piRNAs. Ours is the first study that reported the presence of piRNAs in healthy as well as Alzheimer’s disease-affected human brain. The extensive catalogue of human piRNAs detected in this study provides a useful resource for decrypting the involvement of piRNAs in neurological functions as well as neurodegenerations.
Project description:FASTQ Sequencing files of 5 healthy pancreas tissues and 6 pancreatic ductal adenocarcinoma (PDAC) tissues. Analysis of data is presented in the manuscript: Next generation sequencing reveals novel differentially regulated mRNAs, lncRNAs, miRNAs, sdRNAs and a piRNA in pancreatic cancer in BMC Molecular Cancer.
Project description:Transcribed regions in adult temporal lobe, hippocampus and frontal lobe were assesed by strand specific next generation sequencing of polyA RNA. Strand specific mRNA expression profiles of three human adult brain regions were generated by next generation sequencing using Illumina GAIIx
Project description:Extracellular vesicles (EVs) are tiny membranous structures capable of mediating intercellular communication. In the brain, the role(s) of EVs have been extensively studied in the context of neurological diseases, but their potential implications in the neuropathology underlying human mental disorders remain largely unexplored. Here, we investigated the potential role(s) of brain EVs in schizophrenia (SZ) by analyzing these vesicles from the three post-mortem anatomical brain regions: prefrontal cortex (PFC), hippocampus (HC) and caudate (CAU), using next-generation discovery-driven proteomics. Our results indicate that EVs from SZ-affected brains present region-specific proteins associated with abnormal GABAergic and glutamatergic transmission, as well as alterations in proteins involved in synaptic decay, abnormal brain immunity, neuronal structural imbalances and impaired cell homeostasis. Our findings also provide the first evidence that molecular exchange networks are potentially active and mediated by EVs in cognitively healthy brains. These EV-mediated networks were partially reversed and largely disrupted in brains affected by SZ.
Project description:To investigate why dipeptides accumulate in immature CML cells, we examined upstream gene expression patterns. We isolated the most primitive long-term stem cells, short-term stem cells, and KLS- progenitor cells from healthy littermate control and CML-affected mice and performed gene expression profiling using next-generation RNA-sequencing. Gene expression profiles of the most primitive long-term (LT) stem cells (CD150+CD48-CD135-KLS+ cells), short-term (ST) stem cells (CD150-CD48-CD135- KLS+ cells), and KLS- progenitor cells from healthy littermate control and CML-affected mice
Project description:Transposable elements, known colloquially as “jumping genes,” constitute approximately 45% of the human genome. Cells utilize epigenetic defenses to limit transposable element jumping, including formation of silencing heterochromatin and generation of piwi-interacting RNAs (piRNAs), small RNAs that facilitate clearance of transposable element transcripts. Here we identify transposable element activation as a key mediator of neuronal death in tauopathies, a group of neurodegenerative disorders, including Alzheimer’s disease, that are pathologically characterized by deposits of tau protein in the brain. Mechanistically, we find that heterochromatin decondensation and reduction of piwi/piRNAs drive transposable element activation in tauopathy. Using genetic and pharmacological approaches in a Drosophila melanogaster model of tauopathy, we provide evidence for a causal relationship between pathogenic tau-induced heterochromatin decondensation, piwi/piRNA depletion, active transposable element obilization, and neurodegeneration. We further report a significant increase in transcripts of the endogenous retrovirus class of transposable elements in human Alzheimer’s disease and progressive supranuclear palsy, suggesting that transposable element dysregulation is conserved in human tauopathy. Taken together, our data identify heterochromatin decondensation, piwi/piRNA depletion and consequent transposable element activation as a novel, pharmacologically targetable, mechanistic driver of neurodegeneration in tauopathy.
Project description:Small non-coding RNAs that associate with Piwi proteins, called piRNAs, serve as guides for repression of diverse transposable elements in germ cells of Metazoa. In Drosophila, the genomic regions that give rise to piRNAs, the so-called piRNA clusters, are transcribed to generate long precursor molecules that are processed into mature piRNAs. How genomic regions that give rise to piRNA precursor transcripts are differentiated from the rest of the genome and how these transcripts are specifically channeled into the piRNA biogenesis pathway are not known. We found that trans-generationally inherited piRNAs provide the critical trigger for piRNA production from homologous genomic regions in the next generation by two different mechanisms. First, inherited piRNAs enhance processing of homologous transcripts into mature piRNAs by initiating the ping-pong cycle in the cytoplasm. Second, inherited piRNAs induce installment of the H3K9me3 mark on genomic piRNA cluster sequences. The HP1 homolog Rhino binds to the H3K9me3 mark through its chromodomain and is enriched over piRNA clusters. Rhino recruits the piRNA biogenesis factor Cutoff to piRNA clusters and is required for efficient transcription of piRNA precursors. We propose that trans-generationally inherited piRNAs act as an epigenetic memory for identification of substrates for piRNA biogenesis on two levels, by inducing a permissive chromatin environment for piRNA precursor synthesis and by enhancing processing of these precursors. sequencing of argonaute-bound and total small RNAs from ovaries of different fly crosses: maternal deposition (MD) crosses, in which piRNAs from the P1152 locus are transmitted into the next generation through the mother. No maternak deposition (NMD) crosses, which are reciprocal to the MD crosses. Subsequently, no piRNAs from the P1152 locus are transmitted into the next generation. The strain P-1152, that carries insertion of P{lArB} construct in telomeric sequences of X chromosome (site 1A) is described in (Roche and Rio 1998). The strain BC69 that has insertion of P{A92} construct at a euchromatic location on chromosome 2L (site 35B10-35C1) is described in (Lemaitre et al. 1993).Both stocks were a generous gift from S. Ronsseray.
Project description:23-29 nt Piwi-interacting RNAs (piRNAs) are crucial components of the ribonucleoprotein complexes which silence the most abundant class of mobile genetic elements in human genome, retrotransposons, in germline (germ) cells. In these cells, antisense piRNAs serve as RNA guides for Piwi proteins, base pairing with transposon RNAs which are subsequently cleaved by Piwi proteins. Germ cells belong to special class of stem cells which ultimately give rise to eggs and sperm and therefore, to next generations. Therefore, piRNAs protect next-generation genomes from devastating mutations caused by transposon insertions. Although, role of piRNAs in germ cells has been studied, functions of piRNAs and their associated proteins in somatic cells are not well understood. Importantly, Piwi proteins are expressed in the fruit fly Drosophila brain and are required for the silencing of transposable elements there, clearly indicating that Piwi-associated piRNAs are involved in this process in the brain. Furthermore, piRNAs have been implicated in the memory formation mechanisms in Aplysia brain. In addition to Piwi proteins, their associated partner, molecular scaffold Tudor protein, participates in piRNA biogenesis in germ cells and it is absolutely required for germline development. However, although tudor gene is expressed in the fly brain, its role in the central nervous system is not understood. In this study, we look at the role of Tudor as an essential player in piRNA biogenesis in Drosophila brain.
Project description:The study aimed to investigate molecular signatures in peripheral blood of individuals affected by metabolic syndrome (MetS) and different degrees of obesity. Metabolic health of 1204 individuals was assessed, and 32 subjects were recruited to four study groups: MetS lean, MetS obese, “healthy obese” and healthy lean. Whole-blood transcriptome next generation sequencing with functional data analysis was carried out.