Long noncoding RNA NEXN-AS1 mitigates atherosclerosis by regulating the actin-binding protein NEXN

Atorvastatin inhibits pyroptosis through the lncRNA NEXN-AS1/NEXN pathway in human vascular endothelial cells

BACKGROUND AND AIMS

Many clinical trials have demonstrated that statins convey protective effects against atherosclerosis independent of cholesterol-lowering capacities. Other evidence indicates that pyroptosis, a type of programmed cell death, is likely involved in atherosclerosis, but the effects and mechanisms of statins on pyroptosis must be further revealed.

METHODS

Here, we explored the effects and mechanisms of atorvastatin on pyroptosis in human vascular endothelial cells by quantitative real-time polymerase chain reaction and Western blot analyses.

RESULTS

Atorvastatin upregulated long non-coding RNA (lncRNA) NEXN-AS1 and the expression of NEXN at both the mRNA and protein levels in a concentration- and time-dependent manner. Atorvastatin inhibited pyroptosis by decreasing the expression levels of the canonical inflammasome pathway biomarkers NLRP3, caspase-1, GSDMD, IL-1β, and IL-18 at both the mRNA and protein levels. The promotion effects of atorvastatin on NEXN-AS1 and NEXN expression could be significantly abolished by knockdown of lncRNA NEXN-AS1 or NEXN, and its inhibitory effects on pyroptosis were also markedly offset by knock-down of lncRNA NEXN-AS1 or interference of NEXN.

CONCLUSIONS

These results demonstrated that atorvastatin regulated pyroptosis via the lncRNA NEXN-AS1-NEXN pathway, which provides a new insight into the mechanism of how atorvastatin promotes non-lipid-lower effects against the development of atherosclerosis and gives new directions on how to reverse atherosclerosis.

Microarray profiling analysis and validation of novel long noncoding RNAs and mRNAs as potential biomarkers and their functions in atherosclerosis

Long noncoding (lnc)RNAs have been implicated in the development and progression of atherosclerosis. However, the expression and mechanism of action of lncRNAs in atherosclerosis are still unclear. We implemented microarray analysis in human advanced atherosclerotic plaques and normal arterial intimae to detect the lncRNA and mRNA expression profile. Gene Ontology functional enrichment and pathway analyses were applied to explore the potential functions and pathways involved in the pathogenesis of atherosclerosis. A total of 236 lncRNAs and 488 mRNAs were selected for further Ingenuity Pathway Analysis. Moreover, quantitative RT-PCR tests of most selected lncRNAs and mRNAs with high fold changes were consistent with the microarray data. We also performed ELISA to investigate the corresponding proteins levels of selected genes and showed that serum levels of SPP1, CD36, ATP6V0D2, CHI3L1, MYH11, and BDNF were differentially expressed in patients with coronary heart disease compared with healthy subjects. These proteins correlated with some biochemical parameters used in the diagnosis of cardiovascular diseases. Furthermore, receiver operating characteristic analysis showed a favorable diagnostic performance. The microarray profiling analysis and validation of differentially-expressed lncRNAs and mRNAs in atherosclerosis not only provide new insights into the pathogenesis of this disease but may also reveal new biomarkers for its diagnosis and treatment.

Long non-coding RNAs and pyroptosis

Long noncoding RNAs (lncRNAs) are defined as transcripts longer than 200 nucleotides that have no or only a low coding potential. They are involved in the progression of multiple diseases by the regulation of mechanisms related to epigenetic modifications and transcriptional and posttranscriptional processing. Recent studies have revealed an important function of lncRNAs in the regulation of pyroptosis, a type of programmed cell death associated with inflammatory responses that plays a critical role in many diseases. Through direct or indirect action on proteins related to the pyroptosis signaling pathway, lncRNAs are involved in the pathological processes related to cardiovascular diseases, kidney diseases, immune diseases and other diseases. Based on the expression characteristics of lncRNAs, this paper reviews the role of lncRNAs in regulating pyroptosis, aiming to provide new ideas for the research of lncRNAs regulating pyroptosis and treating pyroptosis-related diseases.

Multi-Omics Approaches to Study Long Non-coding RNA Function in Atherosclerosis

Atherosclerosis is a complex inflammatory disease of the vessel wall involving the interplay of multiple cell types including vascular smooth muscle cells, endothelial cells, and macrophages. Large-scale genome-wide association studies (GWAS) and the advancement of next generation sequencing technologies have rapidly expanded the number of long non-coding RNA (lncRNA) transcripts predicted to play critical roles in the pathogenesis of the disease. In this review, we highlight several lncRNAs whose functional role in atherosclerosis is well-documented through traditional biochemical approaches as well as those identified through RNA-sequencing and other high-throughput assays. We describe novel genomics approaches to study both evolutionarily conserved and divergent lncRNA functions and interactions with DNA, RNA, and proteins. We also highlight assays to resolve the complex spatial and temporal regulation of lncRNAs. Finally, we summarize the latest suite of computational tools designed to improve genomic and functional annotation of these transcripts in the human genome. Deep characterization of lncRNAs is fundamental to unravel coronary atherosclerosis and other cardiovascular diseases, as these regulatory molecules represent a new class of potential therapeutic targets and/or diagnostic markers to mitigate both genetic and environmental risk factors.

LncRNA NEXN-AS1 attenuates proliferation and migration of vascular smooth muscle cells through sponging miR-33a/b

Non-protein-coding RNAs (lncRNAs) are emerging as important regulators in disease pathogenesis, including atherosclerosis (AS). Here, we investigated the role and underlying mechanisms of nexilin F-actin binding protein antisense RNA 1 (NEXN-AS1) on the proliferation and migration of vascular smooth muscle cells (VSMCs). Our data revealed that ox-LDL treatment resulted in decreased NEXN-AS1 expression and increased miR-33a/b levels in human aorta VSMCs (HA-VSMCs) in dose- and time-dependent manners. Overexpression of NEXN-AS1 mitigated the proliferation and migration of HA-VSMCs under ox-LDL stimulation using CCK-8 and wound-healing assays. Moreover, dual-luciferase reporter and RNA immunoprecipitation assays verified that NEXN-AS1 acted as molecular sponges of miR-33a and miR-33b in HA-VSMCs. MiR-33a or miR-33b silencing attenuated the proliferation and migration of ox-LDL-treated HA-VSMCs. Furthermore, miR-33a or miR-33b mediated the inhibitory effects of NEXN-AS1 overexpression on the proliferation and migration of ox-LDL-treated HA-VSMCs. Our study suggested that high level of NEXN-AS1 mitigated VSMC proliferation and migration under ox-LDL stimulation at least partly through sponging miR-33a and miR-33b, illuminating NEXN-AS1 as a novel therapeutic approach for AS treatment.

Non-protein-coding RNAs (lncRNAs) are emerging as important regulators in disease pathogenesis, including atherosclerosis (AS).