Evaluation of MiR-181a as a potential therapeutic target in osteoarthritis

Yuqiang Qian,Jun Peng,Jiannong Jiang,Qiang Wang,Yixin Shen

doi:10.4314/tjpr.v16i5.14

Abstract

Purpose: To investigate microRNA-181 (miR-181) as a potential therapeutic target in osteoarthritis (OA). Methods: MiR-181 expression was evaluated in articular cartilage samples obtained from OA patients undergoing knee arthroplasty and non-OA (control) patients undergoing other orthopedic procedures. Following the isolation of total RNA, miRNA and mRNA expression was determined by real timepolymerase chain reaction (RT-PCR). Luciferase reporter assay and miRNA mimic or inhibitor were then used to establish the molecular target of miR-181 in chondrocytes. Results: miR-181 family members, namely, miR-181a, miR-181c and miR-181d were significantly upregulated in articular cartilage obtained from OA patients compared to non-OA control subjects. However, no significant difference in up-regulation of miR-181b expression. B-cell lymphoma 2 (BCL2), a putative target of the miR-181 family, was significantly down-regulated in OA patients compared to control subjects. Furthermore, luciferase reporter assay confirmed direct interaction between miR-181a and three prime untranslated region The 3’UTR of BCL2 in chondrocytes. Transfection of miR-181 mimic resulted in BCL2 suppression in chondrocytes. On the other hand, transfection of miR-181 inhibitor led to increased BCL2 expression and decreased interleukin 1-beta (IL1-β) induced apoptosis. Conclusion: miR-181 is differentially expressed in articular cartilage of OA patients and leads to downregulation of BCL2, a regulator of apoptosis. Therefore, miR-181 may be a potential therapeutic target in the treatment of OA. Keywords: MicroRNA, Osteoarthritis, Apoptosis, B-cell lymphoma 2, Transfection, Chondrocytes

Highlights

Osteoarthritis is an age-related chronic health condition [1], which affects over 20 % of the world population
B-cell lymphoma 2 (BCL2) expression in OA and non-OA cartilage was studied since it is a putative target of miR-181 family as identified by the TargetScan algorithm
Results indicated a significant down regulation of BCL2 in OA cartilage compared to non-OA cartilage (p < 0.05; Figure 2A)

Summary

Introduction

Osteoarthritis is an age-related chronic health condition [1], which affects over 20 % of the world population. It is associated with loss of mobility as well as impairment in major daily activities [2]. OA results in gradual degeneration of articular cartilage at joints thereby leading to chronic joint inflammation, followed by cartilage damage and pain. It manifests as joint stiffness and slowly develops over several years and is difficult to detect in its early stages [3]. There is an urgent need to identify therapeutic targets that are involved in the pathogenesis of OA that in turn would lead to the development of new therapeutics responsible for alteration of key biological processes underlying OA [5]

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Conclusion