Identification of novel MicroRNA signatures linked to experimental autoimmune myasthenia gravis pathogenesis: down-regulated miR-145 promotes pathogenetic Th17 cell response

J Neuroimmune Pharmacol. 2013 Dec;8(5):1287-302. doi: 10.1007/s11481-013-9498-9. Epub 2013 Sep 17.

Abstract

Emerging evidence demonstrates that miRNAs, a new family of key mRNA regulatory molecules, have crucial roles in controlling and modulating immunity. Their contribution to myasthenia gravis (MG), a T cell-dependent, antibody-mediated nervous system autoimmune disease, has not been thoroughly investigated. In the present study, using a highly sensitive microarray-based approach, we identified 11 miRNAs with differential expression between Peripheral Blood Mononuclear Cells (PBMC) from experimental autoimmune MG (EAMG) rats and control rats. miR-145 is one of the most significantly down-regulated miRNAs in PBMC from EAMG rats. Down-regulation of miR-145 expression was confirmed in PBMC and CD4+CD25- T cells (T effector cells) from both EAMG rats and MG patients by real-time PCR. Bioinformatics target prediction identified two crucial immune-related molecules-CD28 and NFATc1, as putative targets of miR-145. Furthermore, miR-145 inhibited CD28 and NFATc1 expression by directly targeting their 3'-UTRs, which was abolished by mutation of the miR-145 and CD28/NFATc1 binding sites. In vitro up-regulation of miR-145 in CD4+ T cells can significantly reduce CD28 protein levels accompanied by decreased proliferative response. In a dendritic cell (DC)-T cell coculture system, overexpression of miR-145 in AChR-specific CD4+ T cells suppresses NFATc1 expression and T Helper 17 cells level. Finally, we observed that administration of lentiviral-miR-145 decreased the severity of ongoing, established EAMG with decreased IL-17 production, and also decreased serum anti-AChR IgG levels. Our studies provide an important new insight into the pathogenesis of EAMG and MG, which may open a new perspective for the development of effective gene therapy for EAMG/MG.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Animals
  • Base Sequence
  • Blotting, Western
  • CD28 Antigens / genetics
  • CD28 Antigens / metabolism
  • Enzyme-Linked Immunosorbent Assay
  • Female
  • Flow Cytometry
  • Humans
  • Male
  • MicroRNAs / genetics*
  • MicroRNAs / immunology
  • Middle Aged
  • Myasthenia Gravis / genetics*
  • Myasthenia Gravis / immunology
  • Myasthenia Gravis / metabolism
  • Myasthenia Gravis, Autoimmune, Experimental / genetics*
  • Myasthenia Gravis, Autoimmune, Experimental / immunology
  • Myasthenia Gravis, Autoimmune, Experimental / metabolism
  • NFATC Transcription Factors / biosynthesis
  • NFATC Transcription Factors / genetics
  • Oligonucleotide Array Sequence Analysis
  • Rats
  • Rats, Inbred Lew
  • Real-Time Polymerase Chain Reaction
  • Th17 Cells / immunology*
  • Transcriptome
  • Transfection

Substances

  • CD28 Antigens
  • MIRN145 microRNA, rat
  • MicroRNAs
  • NFATC Transcription Factors