Ryu Juhee, Kwon Duk-Hwa, Choe Nakwon, Shin Sera, Jeong Geon, Lim Yeong-Hwan, Kim Jaetaek, Park Woo Jin, Kook Hyun, Kim Young-Kook
Basic Research Laboratory for Vascular Remodeling, Chonnam National University Medical School, Jeollanam-do, Republic of Korea; Department of Biomedical Sciences, Center for Creative Biomedical Scientists at Chonnam National University, Jeollanam-do, Republic of Korea; Department of Biochemistry, Chonnam National University Medical School, Jeollanam-do, Republic of Korea; Department of Pharmacology, Chonnam National University Medical School, Jeollanam-do, Republic of Korea.
Basic Research Laboratory for Vascular Remodeling, Chonnam National University Medical School, Jeollanam-do, Republic of Korea; Department of Pharmacology, Chonnam National University Medical School, Jeollanam-do, Republic of Korea.
Mol Ther Nucleic Acids. 2020 Mar 6;19:31-41. doi: 10.1016/j.omtn.2019.11.001. Epub 2019 Nov 14.
Circular RNAs (circRNAs) are generally formed by back splicing and are expressed in various cells. Vascular calcification (VC), a common complication of chronic kidney disease (CKD), is often associated with cardiovascular disease. The relationship between circRNAs and VC has not yet been studied. Inorganic phosphate (Pi) was used to treat rat vascular smooth muscle cells to induce VC. circRNAs were identified by analyzing RNA sequencing (RNA-seq) data, and their expression change during VC was validated. The selected circRNAs, including circSamd4a, circSmoc1-1, circMettl9, and circUxs1, were resistant to RNase R digestion and mostly localized in the cytoplasm. While silencing circSamd4a promoted VC, overexpressing it reduced VC in calcium assay and Alizarin red S (ARS) staining. In addition, microRNA (miRNA) microarray, luciferase reporter assay, and calcium assay suggested that circSamd4a could act as a miRNA suppressor. Our data show that circSamd4a has an anti-calcification role by functioning as a miRNA sponge. Moreover, mRNAs that can interact with miRNAs were predicted from RNA-seq and bioinformatics analysis, and the circSamd4a-miRNA-mRNA axis involved in VC was verified by luciferase reporter assay and calcium assay. Since circSamd4a is conserved in humans, it can serve as a novel therapeutic target in resolving VC.
环状RNA（circRNAs）一般通过反向剪接形成，并在多种细胞中表达。血管钙化（VC）是慢性肾脏病（CKD）的常见并发症，常与心血管疾病相关。circRNAs与VC之间的关系尚未得到研究。使用无机磷酸盐（Pi）处理大鼠血管平滑肌细胞以诱导VC。通过分析RNA测序（RNA-seq）数据鉴定circRNAs，并验证其在VC过程中的表达变化。所选的circRNAs，包括circSamd4a、circSmoc1-1、circMettl9和circUxs1，对RNase R消化具有抗性，且大多定位于细胞质中。在钙测定和茜素红S（ARS）染色中，沉默circSamd4a促进VC，而过表达circSamd4a则减少VC。此外，微小RNA（miRNA）微阵列、荧光素酶报告基因检测和钙测定表明，circSamd4a可作为miRNA的抑制因子。我们的数据表明，circSamd4a通过充当miRNA海绵发挥抗钙化作用。此外，通过RNA-seq和生物信息学分析预测了可与miRNAs相互作用的mRNA，并通过荧光素酶报告基因检测和钙测定验证了参与VC的circSamd4a-miRNA-mRNA轴。由于circSamd4a在人类中具有保守性，它可作为解决VC的新型治疗靶点。
