MicroRNA-505 is involved in the regulation of osteogenic differentiation of MC3T3-E1 cells partially by targeting RUNX2

Weihua Li,Xiao Wang,Chuanqi Cai,Zhenyu Shi,Gunjun Li,Zongchao Chen

doi:10.1186/s13018-020-01645-2

Abstract

ObjectiveEvidence suggests that microRNAs (miRNAs) regulate the expression of genes involved in bone metabolism. This study aimed to investigate the role of miR-505 in the osteogenic differentiation of MC3T3-E1 cells.MethodsWe performed miRNA sequencing to identify differentially expressed miRNAs between MC3T3-E1 cells treated with osteogenic induction medium (OIM) and control cells. Bioinformatics analysis was performed by using the TargetScan and miRDB databases. The expression of miR-505 in MC3T3-E1 cells was detected during osteogenic differentiation. After transfection with miR-505 mimic or miR-505 inhibitor, MC3T3-E1 cells were induced to differentiate into osteoblasts, and the expression of osteogenic differentiation markers (Runt-related transcription factor 2 (RUNX2), alkaline phosphatase (ALP), osteopontin (OPN), osteocalcin (OCN), and osterix (OSX)) was detected.ResultsmiR-505 was the most downregulated miRNA among the differentially expressed miRNAs. The RUNX2 gene was identified as a potential target of miR-505 using the target prediction program. miR-505 expression was downregulated during osteogenic differentiation of MC3T3-E1 cells. The expression of osteogenic marker genes was inhibited in MC3T3-E1 cells after transfection with miR-505. However, the expression of osteogenic marker genes was upregulated after transfection with miR-505 inhibitor.ConclusionThis study is the first to report miR-505 could bind to the RUNX2 gene and thus regulate partly the dysfunction of osteoblasts differentiation, which is expected to be targets for the treatment of osteoporosis.

Highlights

Osteoporosis is a chronic systemic bone disease manifesting as lower bone mass, which eventually contributes to increased risk of fractures [1, 2]
Preliminary screening by miRNA array chip We used volcano plot to show the inter-relationships between differentially expressed mRNAs in MC3T3-E1 cells in the control (Con) and osteogenic induction medium (OIM) groups (Fig. 1a)
We found that the predicted genes were most enriched in multicellular organism growth (Fig. 3a, biological process), and nucleoplasm (Fig. 3b, cellular component) and transcription factor binding (Fig. 3c, molecular function)

Summary

Introduction

Osteoporosis is a chronic systemic bone disease manifesting as lower bone mass, which eventually contributes to increased risk of fractures [1, 2]. Several interacting factors contribute to the risk of osteoporosis and fracture, including hormones, cytokines, transcription factors, and genetic variables. MiRNAs are a class of multifunctional noncoding small RNAs that regulate cell functions and signaling pathways by inhibiting the expression of target mRNAs [6, 7]. MiRNAs could regulate gene expression at the post-. Several experiments have shown that miRNAs can regulate the function of osteoblasts [9, 10]. Feng et al [11] reported that miR-152 influences osteoporosis through the regulation of osteoblast differentiation by targeting RICTOR. Yin et al [12] revealed that miR-135-5p promotes osteoblast differentiation by targeting hypoxia-inducible factor 1 α inhibitor (HIF1AN) in MC3T3-E1 cells. Exploring the expression of other miRNAs to identify additional targets for osteogenic differentiation could be useful

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Discussion

Conclusion