EPO Mediates Neurotrophic, Neuroprotective, Anti-Oxidant, and Anti-Apoptotic Effects via Downregulation of miR-451 and miR-885-5p in SH-SY5Y Neuron-Like Cells.

Begum Alural,Sermin Genc,Gizem Ayna Duran,Jens Allmer,Zeynep Onkal,Kursad Genc,Kemal Ugur Tufekci,Dogan Tunali

doi:10.3389/fimmu.2014.00475

Begum Alural, Sermin Genc + Show 6 more

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https://doi.org/10.3389/fimmu.2014.00475

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Abstract

Erythropoietin (EPO) is a neuroprotective cytokine, which has been applied in several animal models presenting neurological disorders. One of the proposed modes of action resulting in neuroprotection is post-transcriptional gene expression regulation. This directly brings to mind microRNAs (miRNAs), which are small non-coding RNAs that regulate gene expression at the post-transcriptional level. It has not yet been evaluated whether miRNAs participate in the biological effects of EPO or whether it, inversely, modulates specific miRNAs in neuronal cells. In this study, we employed miRNA and mRNA arrays to identify how EPO exerts its biological function. Notably, miR-451 and miR-885-5p are downregulated in EPO-treated SH-SY5Y neuronal-like cells. Accordingly, target prediction and transcriptome analysis of cells treated with EPO revealed an alteration of the expression of genes involved in apoptosis, cell survival, proliferation, and migration. Low expression of miRNAs in SH-SY5Y was correlated with high expression of their target genes, vascular endothelial growth factor A, matrix metallo peptidase 9 (MMP9), cyclin-dependent kinase 2 (CDK2), erythropoietin receptor, Mini chromosome maintenance complex 5 (MCM5), B-cell lymphoma 2 (BCL2), and Galanin (GAL). Cell viability, apoptosis, proliferation, and migration assays were carried out for functional analysis after transfection with miRNA mimics, which inhibited some biological actions of EPO such as neuroprotection, anti-oxidation, anti-apoptosis, and migratory effects. In this study, we report for the first time that EPO downregulates the expression of miRNAs (miR-451 and miR-885-5p) in SH-SY5Y neuronal-like cells. The correlation between the over-expression of miRNAs and the decrease in EPO-mediated biological effects suggests that miR-451 and miR-885-5p may play a key role in the mediation of biological function.

Highlights

Erythropoietin (EPO) is a hematopoietic cytokine that regulates erythropoiesis [1]
Analysis of the microRNA expression using microRNA arrays showed that miR-451 and miR-885-5p expression decreased in response to treatment with EPO in SHSY5Y cells according to the criteria of a fold change ≤−1.5 or ≥1.5 (P < 0.05) (Table S1 in Supplementary Material)
We found that EPO upregulates matrix metallo peptidase 9 (MMP9), Bcelllymphoma 2 (BCL2), erythropoietin receptor (EPOR), and Galanin (GAL) expression at 24 and 48 h, vascular endothelial growth factor A (VEGFA), mini chromosome maintenance complex 5 (MCM5) at 48 h, and cyclin-dependent kinase 2 (CDK2) expression at 3 h (Table 4; Figure 5)

Summary

Introduction

Erythropoietin (EPO) is a hematopoietic cytokine that regulates erythropoiesis [1]. EPO is produced by many non-hematopoietic tissues including the central nervous system (CNS). It has been well established that different cell types of the CNS (neurons, glial cells, and endothelial cells) produce EPO [2]. In addition to producing EPO, these cells express the erythropoietin receptor (EPOR) on their plasma membranes underlining the crucial role that EPO plays in the physiological function of these cells [3]. EPO exerts remarkable neuroprotection for both, in vitro and in vivo models of nervous system disorders. In vitro studies showed that EPO is directly neuroprotective in hypoxic, hypoglycemic, and excitotoxic neuronal injury models [5]. EPO is currently being under investigation in several clinical trials regarding neuropsychiatric diseases [6]

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