Long noncoding RNAs in vascular smooth muscle cells regulate vascular calcification

Geon Jeong,Juhee Ryu,Duk-Hwa Kwon,Sera Shin,Yeong-Hwan Lim,Young-Kook Kim,Nakwon Choe,Woo Jin Park,Hyun Kook,Jaetaek Kim

doi:10.1038/s41598-019-42283-x

Abstract

Vascular calcification is characterized by the accumulation of hydroxyapatite crystals, which is a result of aberrant mineral metabolism. Although many clinical studies have reported its adverse effects on cardiovascular morbidity, the molecular mechanism of vascular calcification, especially the involvement of long noncoding RNAs (lncRNAs), is not yet reported. From the transcriptomic analysis, we discovered hundreds of lncRNAs differentially expressed in rat vascular smooth muscle cells (VSMCs) treated with inorganic phosphate, which mimics vascular calcification. We focused on Lrrc75a-as1 and elucidated its transcript structure and confirmed its cytoplasmic localization. Our results showed that calcium deposition was elevated after knockdown of Lrrc75a-as1, while its overexpression inhibited calcium accumulation in A10 cells. In addition, Lrrc75a-as1 attenuated VSMCs calcification by decreasing the expression of osteoblast-related factors. These findings suggest that Lrrc75a-as1 acts as a negative regulator of vascular calcification, and may serve as a possible therapeutic target in vascular calcification.

Highlights

Vascular calcification is caused by an imbalance of mineral metabolism, especially calcium phosphate metabolism[1]
To identify the long noncoding RNAs (lncRNAs) involved in vascular calcification, we utilized primary-cultured vascular smooth muscle cells (VSMCs)
The pathway analysis for the decreased mRNAs after Pi treatment showed that the genes involved in the VSMC contractions were most highly decreased[22,23], suggesting that the phenotype of VSMCs was successfully changed in our experimental condition (Supplementary Fig. 1)

Summary

Introduction

Vascular calcification is caused by an imbalance of mineral metabolism, especially calcium phosphate metabolism[1]. It was reported that smooth muscle and endothelial cell enriched migration/differentiation-associated lncRNA (SENCR) and myocardin-induced smooth muscle lncRNA, inducer of differentiation (MYOSLID) lncRNAs control the phenotypic switching of VSMCs to maintain their contractile phenotype[18,19] Another lncRNA, taurine up-regulated gene 1, was shown to upregulate the expression of Runx[2] through sponging miR-204-5p, and increase osteoblast differentiation of aortic valve interstitial cells[20]. We identified diverse lncRNAs that are differentially expressed in VSMCs during vascular calcification through RNA sequencing. Subsequent functional studies showed that among the selected lncRNAs, Lrrc75a-as[1] regulated calcium deposition in VSMCs. our study revealed that Lrrc75a-as[1] can be considered as a possible therapeutic target for the treatment of diverse diseases related with vascular calcification

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Results

Conclusion