Long non-coding RNA and alternative splicing modulations in Parkinson's leukocytes identified by RNA sequencing

PLoS Comput Biol. 2014 Mar 20;10(3):e1003517. doi: 10.1371/journal.pcbi.1003517. eCollection 2014 Mar.

Abstract

The continuously prolonged human lifespan is accompanied by increase in neurodegenerative diseases incidence, calling for the development of inexpensive blood-based diagnostics. Analyzing blood cell transcripts by RNA-Seq is a robust means to identify novel biomarkers that rapidly becomes a commonplace. However, there is lack of tools to discover novel exons, junctions and splicing events and to precisely and sensitively assess differential splicing through RNA-Seq data analysis and across RNA-Seq platforms. Here, we present a new and comprehensive computational workflow for whole-transcriptome RNA-Seq analysis, using an updated version of the software AltAnalyze, to identify both known and novel high-confidence alternative splicing events, and to integrate them with both protein-domains and microRNA binding annotations. We applied the novel workflow on RNA-Seq data from Parkinson's disease (PD) patients' leukocytes pre- and post- Deep Brain Stimulation (DBS) treatment and compared to healthy controls. Disease-mediated changes included decreased usage of alternative promoters and N-termini, 5'-end variations and mutually-exclusive exons. The PD regulated FUS and HNRNP A/B included prion-like domains regulated regions. We also present here a workflow to identify and analyze long non-coding RNAs (lncRNAs) via RNA-Seq data. We identified reduced lncRNA expression and selective PD-induced changes in 13 of over 6,000 detected leukocyte lncRNAs, four of which were inversely altered post-DBS. These included the U1 spliceosomal lncRNA and RP11-462G22.1, each entailing sequence complementarity to numerous microRNAs. Analysis of RNA-Seq from PD and unaffected controls brains revealed over 7,000 brain-expressed lncRNAs, of which 3,495 were co-expressed in the leukocytes including U1, which showed both leukocyte and brain increases. Furthermore, qRT-PCR validations confirmed these co-increases in PD leukocytes and two brain regions, the amygdala and substantia-nigra, compared to controls. This novel workflow allows deep multi-level inspection of RNA-Seq datasets and provides a comprehensive new resource for understanding disease transcriptome modifications in PD and other neurodegenerative diseases.

MeSH terms

  • Alternative Splicing*
  • Amygdala / metabolism
  • Brain Mapping / methods
  • Deep Brain Stimulation
  • Female
  • Gene Expression Profiling
  • Humans
  • Leukocytes / metabolism*
  • Male
  • MicroRNAs
  • Oligonucleotide Array Sequence Analysis
  • Parkinson Disease / blood*
  • RNA, Long Noncoding*
  • Sequence Analysis, RNA / methods*
  • Substantia Nigra / metabolism

Substances

  • MicroRNAs
  • RNA, Long Noncoding

Associated data

  • GEO/GSE42608

Grants and funding

This work was supported by the Israeli Chief Scientist (http://www.matimop.org.il/ocs.html) to HB, the Thyssen Foundation (http://www.fritz-thyssen-stiftung.de/?L=1) and an Infrastructure Award of the Israeli Ministry of Science (http://most.gov.il/english/research/Pages/default.aspx) to HS and HB, ELSC (http://elsc.huji.ac.il/) and the Rosetrees foundation (http://www.rosetreestrust.co.uk/) to HS and the European Network of excellence on alternative splicing (EURASNET, http://www.eurasnet.info/, LSH-2004-1.1.5-3) to HS, the Edmond and Lilly Safra Center for Brain Sciences (ELSC, http://elsc.huji.ac.il/) to HS and HB. LS thanks HUJI sources (http://new.huji.ac.il/) for PhD fellowship support. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.