NovelmiRNA-25 inhibits AMPD2 in peripheral blood mononuclear cells of patients with systemic lupus erythematosus and represents a promising novel biomarker

Gangqiang Guo,Kai Wu,Lele Ye,Sisi Ye,Kangmin Lin,Baoqing Li,Xinyu Shi,Huijing Wang,Xiangyang Xue,Shuang Ye,Chaosheng Chen,Huidi Zhang,Qiaoai Lin

doi:10.1186/s12967-018-1739-5

Abstract

BackgroundSystemic lupus erythematosus (SLE) is a multisystemic autoimmune disease with various clinical manifestations. MicroRNAs (miRNAs) and immunometabolism are recognized as key elements in SLE pathogenesis; however, the relationship between miRNAs in peripheral blood mononuclear cells (PBMCs) and metabolism in SLE remains unclear.MethodsWe detected PBMC miRNA and mRNA profiles from 3 pooled SLE patients and 3 healthy controls (HCs) using next-generation sequencing, predicted miRNA targets in dysregulated mRNAs, predicted functions and interactions of differentially expressed genes using bioinformatics analysis, validated candidate miRNAs using qRT-PCR, and investigated the association between the expression of candidate miRNAs and SLE clinical characteristics. Moreover, we validated the direct and transcriptional regulatory effect of NovelmiRNA-25 on adenosine monophosphate deaminase 2 (AMPD2) using a dual-luciferase reporter assay and western blot and confirmed AMPD2 mRNA and protein expression in PBMCs using qRT-PCR and western blot, respectively.ResultsMultilayer integrative analysis of microRNA and mRNA regulation showed that 10 miRNAs were down-regulated and 19 miRNAs were up-regulated in SLE patient PBMCs compared with HCs. Bioinformatics analysis of regulatory networks between miRNAs and mRNAs showed that 19 miRNAs were related to metabolic processes. Two candidate miRNAs, NovelmiRNA-25 and miR-1273h-5p, which were significantly increased in the PBMCs of SLE patients (P < 0.05), represented diagnostic biomarkers with sensitivities of 94.74% and 89.47%, respectively (area under the curve = 0.574 and 0.788, respectively). NovelmiRNA-25 expression in PBMCs was associated with disease activity in SLE patients, in both active and stable groups (P < 0.05). NovelmiRNA-25 overexpression downregulated AMPD2 expression in HEK293T cells through direct targeting of the AMPD2 3ʹUTR (P < 0.01), while inhibition of NovelmiRNA-25 activity led to increased AMPD2 expression (P < 0.01). NovelmiRNA-25 overexpression also downregulated AMPD2 protein expression in HEK293T cells; AMPD2 protein expression in SLE patient PBMCs was decreased. Our results show that differentially expressed miRNAs play an important role in SLE.ConclusionsOur data demonstrate a novel mechanism in SLE development that involves the targeting of AMPD2 expression by NovelmiRNA-25. miRNAs may serve as novel biomarkers for the diagnosis and evaluation of disease activity of SLE and represent potential therapeutic targets for this disease.

Highlights

Systemic lupus erythematosus (SLE) is a multisystemic autoimmune disease with various clinical manifestations
Our data demonstrate a novel mechanism in SLE development that involves the targeting of adenosine monophosphate deaminase 2 (AMPD2) expression by NovelmiRNA-25. miRNAs may serve as novel biomarkers for the diagnosis and evaluation of disease activity of SLE and represent potential therapeutic targets for this disease
Overview of RNA‐seq data for SLE patients and healthy controls In order to investigate miRNA and mRNA interactions, the expression profiles of miRNAs and mRNAs in peripheral blood mononuclear cells (PBMCs) from three SLE patients and three HCs were analyzed

Summary

Introduction

Systemic lupus erythematosus (SLE) is a multisystemic autoimmune disease with various clinical manifestations. MicroRNAs (miRNAs) and immunometabolism are recognized as key elements in SLE pathogenesis; the relationship between miRNAs in peripheral blood mononuclear cells (PBMCs) and metabolism in SLE remains unclear. Systemic lupus erythematosus (SLE), an autoimmune disease mediated by pathogenic autoantibodies, presents with severe clinical manifestations such as nephritis, multisystem organ failure, or central nervous system disease [1]. As the pathogenesis of SLE remains unclear, treatment, which mainly consists of glucocorticoid-antimalarial drugs and non-steroidal antiinflammatory drugs (NSAIDs), often focuses on immune suppression to prevent and control disease progression, but flare still occurs [3, 4]. The mortality rate of SLE remains high owing to the severity of the disease and the resulting organ damage [1]. A proof-of-concept trial found a reduction in clinical flare-ups following metformin add-on treatment in mild or moderate SLE [11], thereby demonstrating that drugs involved in metabolic regulation may be used as add-on treatment in autoimmune diseases

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