MicroRNAs hsa-miR-99b, hsa-miR-330, hsa-miR-126 and hsa-miR-30c: Potential Diagnostic Biomarkers in Natural Killer (NK) Cells of Patients with Chronic Fatigue Syndrome (CFS)/ Myalgic Encephalomyelitis (ME)

PLoS One. 2016 Mar 11;11(3):e0150904. doi: 10.1371/journal.pone.0150904. eCollection 2016.

Abstract

Background: Chronic Fatigue Syndrome (CFS/ME) is a complex multisystem disease of unknown aetiology which causes debilitating symptoms in up to 1% of the global population. Although a large cohort of genes have been shown to exhibit altered expression in CFS/ME patients, it is currently unknown whether microRNA (miRNA) molecules which regulate gene translation contribute to disease pathogenesis. We hypothesized that changes in microRNA expression in patient leukocytes contribute to CFS/ME pathology, and may therefore represent useful diagnostic biomarkers that can be detected in the peripheral blood of CFS/ME patients.

Methods: miRNA expression in peripheral blood mononuclear cells (PBMC) from CFS/ME patients and healthy controls was analysed using the Ambion Bioarray V1. miRNA demonstrating differential expression were validated by qRT-PCR and then replicated in fractionated blood leukocyte subsets from an independent patient cohort. The CFS/ME associated miRNA identified by these experiments were then transfected into primary NK cells and gene expression analyses conducted to identify their gene targets.

Results: Microarray analysis identified differential expression of 34 miRNA, all of which were up-regulated. Four of the 34 miRNA had confirmed expression changes by qRT-PCR. Fractionating PBMC samples by cell type from an independent patient cohort identified changes in miRNA expression in NK-cells, B-cells and monocytes with the most significant abnormalities occurring in NK cells. Transfecting primary NK cells with hsa-miR-99b or hsa-miR-330-3p, resulted in gene expression changes consistent with NK cell activation but diminished cytotoxicity, suggesting that defective NK cell function contributes to CFS/ME pathology.

Conclusion: This study demonstrates altered microRNA expression in the peripheral blood mononuclear cells of CFS/ME patients, which are potential diagnostic biomarkers. The greatest degree of miRNA deregulation was identified in NK cells with targets consistent with cellular activation and altered effector function.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Fatigue Syndrome, Chronic / diagnosis*
  • Fatigue Syndrome, Chronic / genetics
  • Fatigue Syndrome, Chronic / immunology
  • Gene Expression Profiling
  • Genetic Markers / genetics
  • Humans
  • Killer Cells, Natural / metabolism
  • Killer Cells, Natural / pathology
  • Lymphocyte Activation
  • MicroRNAs / genetics*
  • Oligonucleotide Array Sequence Analysis
  • Up-Regulation

Substances

  • Genetic Markers
  • MIRN126 microRNA, human
  • MIRN30b microRNA, human
  • MIRN330 microRNA, human
  • MIRN99 microRNA, human
  • MicroRNAs

Grants and funding

This work was partially funded by the chronic fatigue syndrome research foundation (CFSRF), who also funded the salary of RDP, and partially funded by ME research UK (http://www.meresearch.org.uk/). The salary of JRK was funded by Joseph Hotung. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.