Inflammation in an Animal Model of Multiple Sclerosis Leads to MicroRNA-25-3p Dysregulation Associated with Inhibition of Pten and Klf4

Ameneh  Zare-Chahoki; Meysam  Ahmadi-Zeidabadi; Saeid  Azadarmaki; Samira  Ghorbani; Farshid  Noorbakhsh

doi:10.18502/ijaai.v20i3.6337

Ameneh Zare-Chahoki Neuroscience Research Center, Institute of Neuropharmacology, Kerman University of Medical Sciences, Kerman, Iran
Meysam Ahmadi-Zeidabadi Neuroscience Research Center, Institute of Neuropharmacology, Kerman University of Medical Sciences, Kerman, Iran
Saeid Azadarmaki Clinical Laboratory, Khatam Alanbia Hospital, Tehran, Iran
Samira Ghorbani Hotchkiss Brain Institute and the Department of Clinical Neuroscience, University of Calgary, Calgary, Canada
Farshid Noorbakhsh Shefa Neuroscience Research Center, Khatam Alanbia Hospital, Tehran, Iran

DOI: https://doi.org/10.18502/ijaai.v20i3.6337

Keywords: Autoimmune diseases of the nervous system; Encephalomyelitis, Autoimmune, Experimental; MicroRNAs; Multiple sclerosis

Abstract

Perturbed expression of microRNAs (miRs) has been reported in different diseases including
autoimmune and chronic inflammatory disorders. In this study, we investigated the expression of miR25-3p and its targets in the central nervous system (CNS) tissue from mice with experimental
autoimmune encephalomyelitis (EAE). We also analyzed the expression of miR-25 and its targets in
activated macrophages and splenocytes.
EAE was induced in 12-week old female C57BL/6 mice; using myelin oligodendrocyte
glycoprotein 35-55/complete Freund's adjuvant (MOG35-55/CFA) protocol. The expression of miR25-3p and its targets, as well as the expression of inflammatory cytokines, were analyzed. We next
established primary macrophage cultures as well as splenocyte cultures and evaluated the levels of miR25-3p and its target genes in these cells following activation with lipopolysaccharide (LPS) and antiCD3/anti-CD28 antibodies, respectively.
MiR-25-3p expression showed a strong positive correlation with the expression of tumor necrosis
factor-alpha (TNF-α), interleukin (IL)-1α, and IL-6 pro-inflammatory cytokines. The expression of
phosphatase and tensin homolog (Pten) and Krüppel-like factor 4 (Klf4) was significantly reduced at the peak of
the disease. Interestingly, Pten and Klf4 expression showed a significant negative correlation with miR25-3p. Analysis of miR-25-3p expression in LPS-treated primary macrophages revealed significant
upregulation in cells treated with 100ng/ml of LPS. This was associated with suppressed levels of miR25-3p targets in these cells. However, anti-CD3/anti-CD28-stimulated splenocytes failed to show any
alterations in miR-25-3p expression compared with vehicle-treated cells.
Our results indicate that miR-25-3p expression is likely induced by inflammatory mediators during
autoimmune neuroinflammation. This upregulation is associated with decreased levels of Pten and Klf4, genes with known roles in cell cycle regulation and inflammation.