1
|
Shin H, Shannon CP, Fishbane N, Ruan J, Zhou M, Balshaw R, Wilson-McManus JE, Ng RT, McManus BM, Tebbutt SJ. Variation in RNA-Seq transcriptome profiles of peripheral whole blood from healthy individuals with and without globin depletion. PLoS One 2014; 9:e91041. [PMID: 24608128 PMCID: PMC3946641 DOI: 10.1371/journal.pone.0091041] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2013] [Accepted: 02/08/2014] [Indexed: 12/21/2022] Open
Abstract
Background The molecular profile of circulating blood can reflect physiological and pathological events occurring in other tissues and organs of the body and delivers a comprehensive view of the status of the immune system. Blood has been useful in studying the pathobiology of many diseases. It is accessible and easily collected making it ideally suited to the development of diagnostic biomarker tests. The blood transcriptome has a high complement of globin RNA that could potentially saturate next-generation sequencing platforms, masking lower abundance transcripts. Methods to deplete globin mRNA are available, but their effect has not been comprehensively studied in peripheral whole blood RNA-Seq data. In this study we aimed to assess technical variability associated with globin depletion in addition to assessing general technical variability in RNA-Seq from whole blood derived samples. Results We compared technical and biological replicates having undergone globin depletion or not and found that the experimental globin depletion protocol employed removed approximately 80% of globin transcripts, improved the correlation of technical replicates, allowed for reliable detection of thousands of additional transcripts and generally increased transcript abundance measures. Differential expression analysis revealed thousands of genes significantly up-regulated as a result of globin depletion. In addition, globin depletion resulted in the down-regulation of genes involved in both iron and zinc metal ion bonding. Conclusions Globin depletion appears to meaningfully improve the quality of peripheral whole blood RNA-Seq data, and may improve our ability to detect true biological variation. Some concerns remain, however. Key amongst them the significant reduction in RNA yields following globin depletion. More generally, our investigation of technical and biological variation with and without globin depletion finds that high-throughput sequencing by RNA-Seq is highly reproducible within a large dynamic range of detection and provides an accurate estimation of RNA concentration in peripheral whole blood. High-throughput sequencing is thus a promising technology for whole blood transcriptomics and biomarker discovery.
Collapse
Affiliation(s)
- Heesun Shin
- NCE CECR PROOF Centre of Excellence, Vancouver, British Columbia, Canada
- UBC Department of Medicine (Division of Respiratory Medicine), University of British Columbia, Vancouver, British Columbia, Canada
- UBC James Hogg Research Centre & Institute for HEART + LUNG Health, University of British Columbia, Vancouver, British Columbia, Canada
| | - Casey P. Shannon
- NCE CECR PROOF Centre of Excellence, Vancouver, British Columbia, Canada
| | - Nick Fishbane
- NCE CECR PROOF Centre of Excellence, Vancouver, British Columbia, Canada
- UBC Department of Statistics, University of British Columbia, Vancouver, British Columbia, Canada
| | - Jian Ruan
- NCE CECR PROOF Centre of Excellence, Vancouver, British Columbia, Canada
- UBC James Hogg Research Centre & Institute for HEART + LUNG Health, University of British Columbia, Vancouver, British Columbia, Canada
| | - Mi Zhou
- NCE CECR PROOF Centre of Excellence, Vancouver, British Columbia, Canada
| | - Robert Balshaw
- NCE CECR PROOF Centre of Excellence, Vancouver, British Columbia, Canada
- UBC Department of Statistics, University of British Columbia, Vancouver, British Columbia, Canada
| | | | - Raymond T. Ng
- NCE CECR PROOF Centre of Excellence, Vancouver, British Columbia, Canada
- UBC Department of Computer Science, University of British Columbia, Vancouver, British Columbia, Canada
| | - Bruce M. McManus
- NCE CECR PROOF Centre of Excellence, Vancouver, British Columbia, Canada
- UBC Department of Pathology and Laboratory Medicine, University of British Columbia, Vancouver, British Columbia, Canada
- UBC James Hogg Research Centre & Institute for HEART + LUNG Health, University of British Columbia, Vancouver, British Columbia, Canada
| | - Scott J. Tebbutt
- NCE CECR PROOF Centre of Excellence, Vancouver, British Columbia, Canada
- UBC Department of Medicine (Division of Respiratory Medicine), University of British Columbia, Vancouver, British Columbia, Canada
- UBC James Hogg Research Centre & Institute for HEART + LUNG Health, University of British Columbia, Vancouver, British Columbia, Canada
- * E-mail:
| | | |
Collapse
|