Long Noncoding RNAs in Atherosclerosis

MiR-193-3p inhibits the malignant progression of atherosclerosis by targeting WDR5

BACKGROUND

The aberrantly increased proliferation and migration of vascular smooth muscle cells (VSMCs) was critically associated with atherosclerosis (AS) progression. MiR-197-3p has been confirmed to regulate various biological processes, such as tumorigenesis; however, whether miR-197-3p is involved with the pathological development of AS remains largely unknown.

METHODS

The serum levels of miR-197-3p in AS patients and healthy donors were determined by polymerase chain reaction (PCR) assay. The transfection efficacies of miR-197-3p mimic or inhibitor in VSMCs were evaluated by PCR assay. The effects of miR-197-3p on VSMC proliferation and migration were determined by EdU cell proliferation and Traswell migration assays. Western blotting was conducted to evaluate the effect of miR-197-3p on WDR5 expression in VSMCs.

RESULTS

In the present study, we found that the expression of miR-197-3p was decreased in the serum of AS patients compared to healthy donors. Overexpression of miR-197-3p inhibited the proliferation and migration of VSMCs, while silencing miR-197-3p showed opposite effects. Mechanistical study revealed that WD Repeat Domain 5 (WDR5) was a target of miR-197-3p. Moreover, miR-197-3p was downregulated in VSMCs upon IL6 treatment and inhibited IL6-induced proliferation and migration in VSMCs.

CONCLUSIONS

These findings indicate that miR-197-3p could serve as a promising diagnostic marker for AS and that targeting IL6/miR-197-3p/WDR5 axis might be a potential approach to treat AS.

Long non-coding RNAs: Modulators of phenotypic transformation in vascular smooth muscle cells

Long non-coding RNA (lncRNAs) are longer than 200 nucleotides and cannot encode proteins but can regulate the expression of genes through epigenetic, transcriptional, and post-transcriptional modifications. The pathophysiology of smooth muscle cells can lead to many vascular diseases, and studies have shown that lncRNAs can regulate the phenotypic conversion of smooth muscle cells so that smooth muscle cells proliferate, migrate, and undergo apoptosis, thereby affecting the development and prognosis of vascular diseases. This review discusses the molecular mechanisms of lncRNA as a signal, bait, stent, guide, and other functions to regulate the phenotypic conversion of vascular smooth muscle cells, and summarizes the role of lncRNAs in regulating vascular smooth muscle cells in atherosclerosis, hypertension, aortic dissection, vascular restenosis, and aneurysms, providing new ideas for the diagnosis and treatment of vascular diseases.

DOCK9 antisense RNA2 interacts with LIN28B to stabilize Wnt5a and boosts proliferation and migration of oxidized low densitylipoprotein-induced vascular smooth muscle cells

Study has suggested that long non-coding RNA DOCK9 antisense RNA2 (LncRNA DOCK9-AS2) may play an important role in atherosclerosis, but the specific role is unclear. In this article, we aim to explore the role and mechanism of DOCK9-AS2 in the proliferation and migration of vascular smooth muscle cells (VSMCs) in atherosclerosis. VSMCs were treated with oxidized low densitylipoprotein (ox-LDL) for 24 h to establish the model of atherosclerosis in vitro. Gain- and loss-of function experiments were conducted. Cell Counting Kit-8 (CCK-8) assay and Ki67 staining were used to evaluate the ability cell proliferation. Transwell assay and immunofluorescence staining of N-Cadherin and E-cadherin were carried out to detect cell migration. RNA immunoprecipitation (RIP) experiment, pull down assay and mRNA stability analysis were used to assess the relationship of DOCK9-AS2, Wnt5a and LIN28B. Western blot analysis was used to measure the protein expression levels. The results showed that DOCK9-AS2 knockdown inhibited the proliferation and migration of ox-LDL-induced VSMCs. Further study on the interaction between DOCK9-AS2, Wnt5a and LIN28B revealed that LIN28B could both directly interact with DOCK9-AS2 and Wnt5a, and DOCK9-AS2 regulated Wnt5a by targeting LIN28B. In addition, Overexpression of Wnt5a partly abolished the inhibitory effects of LIN28B knockdown or DOCK9-AS2 knockdown on cell proliferation and migration induced by in ox-LDL-induced proliferation and migration. In conclusion, the results showed that DOCK9-AS2 promoted the proliferation and migration of vascular smooth muscle cells in atherosclerosis through regulating Wnt5a by targeting LIN28B.

Association between lncRNA genetic variants and susceptibility to large artery atherosclerotic stroke

Studies have already illustrated the role of long non-coding RNAs (lncRNAs) in the progression of atherosclerosis, while the potential role of lncRNA gene variation in susceptibility to large artery atherosclerotic stroke (LAAS) remains controversial. We therefore conducted this study to explore and verify the gene expression modules of LAAS. Differentially expressed genes (DEGs) in atherosclerosis were screened in 3 patients with LAAS, and 3 healthy control patients. A further 31 individuals were used to screen DEGs, and MALAT1, MEG3, or SENCR were identified. Real-time PCR and western blotting were used to assess the difference in DEGs between the atherosclerotic and the non-atherosclerotic artery models. A total of 454 DEGs were detected from the initial screening step, and MALAT1, MEG3, or SENCR were applied to predict the risk of LAAS. The AUC of MALAT1, MEG3, and SENCR in predicting the risk of LAAS was 0.746 (95% CI: 0.398-0.753; P = 0.005), 0.575 (95% CI: 0.398-0.753; P = 0.389), and 0.629 (95% CI: 0.449- .808; P = 0.141), respectively. Moreover, there were significant differences between the atherosclerotic and non-atherosclerotic artery models for the expression of MALAT1, GCNT1, VEGFA, and VCAM-1. This study found that the MALAT1 contributes to LAAS susceptibility, and might play an important role in the progression of LAAS.

LncRNA MIAT Mediates ox-LDL-Induced Endothelial Cell Injury Via miR-206/RAB22A Axis

BACKGROUND

Long non-coding RNA myocardial infarction associated transcript (MIAT) has exerted significant effects on atherosclerosis (AS). The biological roles of MIAT in endothelial cell dysfunction are not thoroughly elucidated.

METHODS

The expression of MIAT, microRNA (miR)-206 and Ras-related protein Rab-22A (RAB22A) was detected by quantitative real-time polymerase chain reaction and western blot. The injury of human umbilical vein endothelial cells (HUVECs) was evaluated by testing cell viability, invasion, migration, apoptosis, epithelial-mesenchymal transition capacities and inflammatory response using cell counting kit-8, transwell, wound healing assays, flow cytometry, western blot and enzyme-linked immunosorbent assay, respectively. The binding interaction between miR-206 and MIAT or RAB22A was confirmed by dual-luciferase reporter and RNA immunoprecipitation assays.

RESULTS

The expression of MIAT was up-regulated in ox-LDL-treated HUVECs, and knockdown of MIAT in ox-LDL-treated HUVECs remarkably promoted cell viability, invasion, migration, and epithelial-mesenchymal transition (EMT), as well as suppressed cell apoptosis and the levels of interleukin (IL)-1β, tumor necrosis factor (TNF)-α and endothelial nitric oxide synthase (eNOS). In a mechanical study, MIAT directly targeted miR-206, and miR-206 inhibition attenuated the protective effects of MIAT knockdown on ox-LDL-triggered HUVEC injury. Besides that, RAB22A was a target of miR-206, and RAB22A overexpression reversed the biological effects of miR-206 on ox-LDL-treated HUVECs. Additionally, we also proved MIAT could regulate RAB22A via miR-206 in HUVECs.

CONCLUSION

MIAT knockdown impaired ox-LDL-induced HUVEC injury via regulating miR-206/RAB22A axis, suggesting the potential impacts of MIAT on AS occurrence, which revealed a potential therapeutic strategy for future clinic intervention in AS.

GAS5 knockdown suppresses inflammation and oxidative stress induced by oxidized low-density lipoprotein in macrophages by sponging miR-135a

A large number of long non-coding RNAs have been confirmed to play vital roles in regulating various biological processes. Abnormal expression of growth arrest-specific transcript 5 (GAS5) is reported to be involved in the development of atherosclerosis (AS). This work is to explore the detailed mechanism underling how GAS5 regulates AS progression. We found that the abundance of GAS5 was markedly increased, and miR-135a was decreased in AS patient serums and ox-LDL-induced human THP-1 cells dose and time dependently. Interference of GAS5 suppressed inflammation and oxidative stress induced by ox-LDL in THP-1 cells. Mechanistically, GAS5 acted as a molecular sponge of microRNA-135a (miR-135a). Rescue assays indicated that knockdown of miR-135a partially rescued small interference RNA for GAS5-inhibited inflammatory cytokines release and oxidative stress in ox-LDL-triggered THP-1 cells. In conclusion, the absence of GAS5-inhibited inflammatory response and oxidative stress induced by ox-LDL in THP-1 cells via sponging miR-135a, providing a deep insight into the molecular target for AS treatment.

Downregulation of lncRNA H19 alleviates atherosclerosis through inducing the apoptosis of vascular smooth muscle cells

Aberrant proliferation and apoptosis of vascular smooth muscle cells (VSMCs) serve a dominant role in the pathogenesis of atherosclerosis (AS). Long non‑coding (lnc)RNA H19 is reported to accelerate the progression of AS by inhibiting the apoptosis of VSMCs, whereas p53 is identified as promoting VSMC apoptosis. The present study aimed to explore the effects of H19/p53 on the pathogenesis of AS. Apolipoprotein E knockout (ApoE‑/‑) mice fed a high‑fat diet were used as in vivo AS models. Reverse transcription‑quantitative PCR and western blot were used to detect mRNA and protein expression levels, respectively. VSMC proliferation and apoptosis were respectively assessed by CCK‑8 and flow cytometry. Compared with the control group, mouse weight and plaque area were all increased in the AS model group, as was the expression of H19. Knockdown of H19 reduced the proliferation and induced apoptosis of VSMCs, and increased the expression of p53, cleaved caspase3 (c‑caspase3) and p53 upregulated modulator of apoptosis, as well as enhancing the interaction between Bax and p53 proteins. Downregulation of H19 reduced the plaque area and promoted the expression of c‑caspase3 in mouse aortic tissues in vivo, as well as enhancing the effects of simvastatin, a drug used for AS treatment. Results from the present study indicated that knockdown of H19 may prevent AS deterioration through increased p53‑mediated VSMC apoptosis.

Long non-coding RNA LINC00299 knockdown inhibits ox-LDL-induced T/G HAVSMC injury by regulating miR-135a-5p/XBP1 axis in atherosclerosis

BACKGROUND

Atherosclerosis (AS) is a highly relevant social problem. Long noncoding RNA (lncRNA) long intergenic non-coding00299 (LINC00299) participates in the regulation of AS development. Therefore, this study was to explore the potential role and mechanism of LINC00299 in AS.

METHODS

Human aortic vascular smooth muscle cells (T/G HA-VSMCs) were treated with oxidized low-density lipoprotein (ox-LDL). Cell viability and migration were measured by 3-(4, 5-dimethyl-2-thiazolyl)-2, 5-diphenyl-2-H-tetrazolium bromide (MTT) and transwell assays, severally. The activities of SOD and MDA were detected by total superoxide dismutase assay kit and malondialdehyde assay kit. The protein levels of ki67, matrix metalloproteinase 9 (MMP9) and X-box binding protein 1 (XBP1) were detected by western blot assay. The expression levels of LINC00299, microRNA-135a-5p (miR-135a-5p) and XBP1 were detected by real-time quantitative polymerase chain reaction (RT-qPCR). The binding relationship between miR-135a-5p and LINC00299 or XBP1 was predicted by miRcode and Starbase3.0 then verified by the dual-luciferase reporter assay.

RESULTS

Ox-LDL induced cell viability, oxidative damage and migration of T/G HA-VSMCs. LINC00299 knockdown weakened ox-LDL-induced T/G HA-VSMCs injury. Mechanical analysis confirmed that LINC00299 improved XBP1 expression by interacting with miR-135a-5p. Furthermore, rescue assays showed that LINC00299 regulated ox-LDL-induced T/G HA-VSMCs injury through the miR-135a-5p/XBP1 axis.

CONCLUSIONS

Our studies revealed the regulatory function of LINC00299/miR-135a-5p/XBP1 axis in AS development, suggesting a potential therapeutic strategy for AS treatment.

Macrophage Long Non-Coding RNAs in Pathogenesis of Cardiovascular Disease

Chronic inflammation is inextricably linked to cardiovascular disease (CVD). Macrophages themselves play important roles in atherosclerosis, as well as acute and chronic heart failure. Although the role of macrophages in CVD pathophysiology is well-recognized, little is known regarding the precise mechanisms influencing their function in these contexts. Long non-coding RNAs (lncRNAs) have emerged as significant regulators of macrophage function; as such, there is rising interest in understanding how these nucleic acids influence macrophage signaling, cell fate decisions, and activity in health and disease. In this review, we summarize current knowledge regarding lncRNAs in directing various aspects of macrophage function in CVD. These include foam cell formation, Toll-like receptor (TLR) and NF-kβ signaling, and macrophage phenotype switching. This review will provide a comprehensive understanding concerning previous, ongoing, and future studies of lncRNAs in macrophage functions and their importance in CVD.

Long Noncoding RNA TUG1 Promotes the Function in ox-LDL-Treated HA-VSMCs via miR-141-3p/ROR2 Axis

Background

Atherosclerosis (AS) is a common severe disease around the world. The merging paper reported that long noncoding RNAs (lncRNAs) took part in diversified pathological processes of AS, although the mechanism remains unknown. This study is aimed at uncovering the profile of lncRNA taurine-upregulated gene 1 (TUG1), which has biological function, and potential mechanism in AS progression in vitro.

Methods

Oxidized low-density lipoprotein (ox-LDL) was used for AS model construction in vitro. Levels of lncRNA TUG1, miR-141-3p, and receptor tyrosine kinase-like orphan receptor 2 (ROR2) were detected by quantitative real-time polymerase chain reaction (qRT-PCR) in AS tissues or in ox-LDL-treated vascular smooth muscle cells (HA-VSMCs). The biofunctional effects were examined by 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide (MTT) and transwell assays. The expression of proliferation-related proteins (CyclinD1, Ki-67) and metastasis-associated proteins (β-catenin, Vimentin) and ROR2 in cells was determined by western blot analysis. The potential binding sites were predicted by starBase software online and confirmed by dual-luciferase reporter analysis.

Results

The expression of TUG1 and ROR2 was promoted in AS tissues and ox-LDL-treated HA-VSMCs. While the low expression of miR-141-3p negatively correlated with that of TUG1 or ROR2 in AS tissues. Silencing of TUG1 inhibited the proliferation, migration, invasion, and metastasis in ox-LDL-treated HA-VSMCs. Moreover, the putative binding sites between miR-141-3p and TUG1 or ROR2 were predicted by starBase software online. Also, miR-141-3p deletion reversed the positive effects of TUG1 knockdown on cells. Besides, downregulation of miR-141-3p disrupted the biofunctional results from ROR2 silencing.

Conclusion

TUG1 enhanced the progression of AS in vitro by regulating the miR-141-3p/ROR2 axis.

Long non-coding RNA CDKN2B-AS1 contributes to atherosclerotic plaque formation by forming RNA-DNA triplex in the CDKN2B promoter

BACKGROUND

Atherosclerosis involves a slow process of plaque formation on the walls of arteries, and comprises a leading cause of cardiovascular disease. Long non-coding RNAs (lncRNAs) have been implicated in the pathogenesis of atherosclerosis. In this study, we aim to explore the possible involvement of lncRNA 'cyclin-dependent kinase inhibitor 2B antisense noncoding RNA' (CDKN2B-AS1) and CDKN2B in the progression of atherosclerosis.

METHODS

Initially, we quantified the expression of CDKN2B-AS1 in atherosclerotic plaque tissues and, in THP-1 macrophage-derived, and human primary macrophage (HPM)-derived foam cells. Next, we established a mouse model of atherosclerosis using apolipoprotein E knockout (ApoE-/-) mice, where lipid uptake, lipid accumulation, and macrophage reverse cholesterol transport (mRCT) were assessed, in order to explore the contributory role of CDKN2B-AS1 to the progression of atherosclerosis. RIP and ChIP assays were used to identify interactions between CDKN2B-AS1, CCCTC-binding factor (CTCF), enhancer of zeste homologue 2 (EZH2), and CDKN2B. Triplex formation was determined by RNA-DNA pull-down and capture assay as well as EMSA experiment.

FINDINGS

CDKN2B-AS1 showed high expression levels in atherosclerosis, whereas CDKN2B showed low expression levels. CDKN2B-AS1 accelerated lipid uptake and intracellular lipid accumulation whilst attenuating mRCT in THP-1 macrophage-derived foam cells, HPM-derived foam cells, and in the mouse model. EZH2 and CTCF were found to bind to the CDKN2B promoter region. An RNA-DNA triplex formed by CDKN2B-AS1 and CDKN2B promoter was found to recruit EZH2 and CTCF in the CDKN2B promoter region and consequently inhibit CDKN2B transcription by accelerating histone methylation.

INTERPRETATION

The results demonstrated that CDKN2B-AS1 promotes atherosclerotic plaque formation and inhibits mRCT in atherosclerosis by regulating CDKN2B promoter, and thereby could be a potential therapeutic target for atherosclerosis.

Potential Role of mRNAs and LncRNAs in Chronic Intermittent Hypoxia Exposure-Aggravated Atherosclerosis

Atherosclerosis is the pathological basis of cardiovascular disease. Obstructive sleep apnea (OSA) aggravates atherosclerosis, and chronic intermittent hypoxia (CIH) as a prominent feature of OSA plays an important role during the process of atherosclerosis. The mechanisms of CIH in the development of atherosclerosis remain unclear. In the current study, we used microarray to investigate differentially expressed mRNAs and long non-coding RNAs (lncRNAs) in aorta from five groups of ApoE^–/– mice fed with a high-fat diet and exposed to various conditions: normoxia for 8 weeks, CIH for 8 weeks, normoxia for 12 weeks, CIH for 12 weeks, or CIH for 8 weeks followed by normoxia for 4 weeks. Selected transcripts were validated in aorta tissues and RT-qPCR analysis showed correlation with the microarray data. Gene Ontology analysis and pathway enrichment analysis were performed to explore the mRNA function. Bioinformatic analysis indicated that short-term CIH induced up-regulated mRNAs involved in inflammatory response. Pathway enrichment analysis of lncRNA co-localized mRNAs and lncRNA co-expressed mRNAs were performed to explore lncRNA functions. The up-regulated mRNAs, lncRNA co-localized mRNAs and lncRNA co-expressed mRNAs were significantly associated with protein processing in endoplasmic reticulum pathway in atherosclerotic vascular tissue with long-term CIH exposure, suggesting that differentially expressed mRNAs and lncRNAs play important roles in this pathway. Moreover, a mRNA-lncRNA co-expression network with 380 lncRNAs, 508 mRNAs and 3238 relationships was constructed based on the correlation analysis between the differentially expressed mRNAs and lncRNAs. In summary, our study provided a systematic perspective on the potential function of mRNAs and lncRNAs in CIH-aggravated atherosclerosis, and may provide novel molecular candidates for future investigation on atherosclerosis exposed to CIH.

Inhibition of ZEB1-AS1 confers cisplatin sensitivity in breast cancer by promoting microRNA-129-5p-dependent ZEB1 downregulation

Background

Breast cancer is the leading cause of cancer-related mortality in women worldwide. Long non-coding RNAs (lncRNAs) are of critical importance in tumor drug resistance. Herein, this study aims to determine the roles of lncRNA ZEB1-AS1 in drug resistance of breast cancer involving microRNA-129-5p (miR-129-5p) and ZEB1.

Methods

Microarray-based gene expression profiling of breast cancer was conducted to identify the differentially expressed lncRNAs. ZEB1 expression was measured in adjacent and cancerous tissues. Next, MCF-7 and MDA-MB-231 cells were treated with a series of inhibitor, mimic or siRNA to clarify the roles of lncRNA ZEB1-AS1 and miR-129-5p in drug resistance of breast cancer. Then the target relationship of miR-129-5p with lncRNA ZEB1-AS1 and ZEB1 was verified. The expression patterns of miR-129-5p, lncRNA ZEB1-AS1, Bcl-2, MDR-1, ZEB1 and corresponding proteins were evaluated. Moreover, the apoptosis and drug resistance of MCF-7 cell were detected by CCK-8 and flow cytometry respectively.

Results

LncRNA ZEB1-AS1 was observed to be an upregulated lncRNA in breast cancer, and ZEB1 overexpression was noted in breast cancerous tissues. MiR-129-5p was revealed to specifically bind to both ZEB1 and lncRNA ZEB1-AS1. Moreover, the expression levels of ZEB1-AS1, ZEB1, Bcl-2, MDR-1, and corresponding proteins were decreased, but the expression of miR-129-5p was increased with transfection of miR-129-5p mimic and lncRNA ZEB1-AS1 siRNA. Besides, drug resistance to cisplatin was inhibited, and cell apoptosis was promoted in breast cancer after transfection of miR-129-5p mimic, lncRNA ZEB1-AS1 siRNA, and ZEB1 siRNA.

Conclusion

In conclusion, the study provides evidence that lncRNA ZEB1-AS1 silencing protects against drug resistance in breast cancer by promoting miR-129-5p-dependent ZEB1 downregulation. It may serve as a novel therapeutic target in breast cancer treatment.

Association of long non-coding RNA MIAT and MALAT1 expression profiles in peripheral blood of coronary artery disease patients with previous cardiac events

Long non-coding RNAs (lncRNAs) are implicated in various cellular and pathological processes. Two lncRNAs, myocardial infarction-associated transcript (MIAT) and metastasis-associated lung adenocarcinoma transcript 1 (MALAT1), may be involved in the pathogenesis of coronary artery disease (CAD). Here, we aimed to determine the relative circulating levels of MIAT and MALAT1 in 110 stable CAD patients and 117 controls and to correlate their levels with the clinical and laboratory data. Peripheral blood expression levels were quantified by Real-Time qPCR. The median MIAT expression level in CAD patients was significantly 12-fold higher than controls (p<0.001). Otherwise, the median MALAT1 expression level was comparable in patient and control groups. Both lncRNAs showed significantly higher relative expression levels in patients with positive history of previous cardiac ischemic events, and MIAT showed significantly higher expression in diabetic CAD patients. The area under the curve of MIAT (0.888 ± 0.02 with sensitivity 95.5% and specificity 72.7%), was significantly larger than that of MALAT1 (0.601 ± 0.04 with sensitivity 50% and specificity 63.6%) for detecting the presence of significant CAD. The current findings suggest that lncRNA MIAT could have a diagnostic significance in CAD patients. MALAT1 levels, however, are not sufficiently reliable to have much clinical use in our cases.

Interfering with long chain noncoding RNA ANRIL expression reduces heart failure in rats with diabetes by inhibiting myocardial oxidative stress

This study is performed to elucidate whether long-chain noncoding RNA ANRIL has an effect on diabetes, and further explore the mechanism of ANRIL in diabetes. The rat model of diabetes was established via intraperitoneal injection of streptozotocin. The modeled rats were grouped into normal, diabetes, siRNA-NC, and ANRIL siRNA groups. Besides, the expression of ANRIL, cardiac function, inflammatory factor levels, cardiomyocyte apoptosis, and levels of oxidative stress index were all determined. Upregulated ANRIL was found in myocardial tissue of diabetic rats. Downregulated ANRIL improved cardiac function index and the expression of inflammatory factors, improved the pathological state of myocardial tissue and myocardial remodeling, decreased myocardial collagen deposition area and cardiomyocyte apoptosis and reduced the oxidative level of myocardial tissue in diabetic rats. This present study suggests that upregulated ANRIL is found in myocardial tissue of diabetic rats. Additionally, silencing of ANRIL reduces myocardial injury in diabetes by inhibiting myocardial oxidative stress.

Identification of Key lncRNAs Associated With Atherosclerosis Progression Based on Public Datasets

Atherosclerosis is one of the most common type of cardiovascular disease and the prime cause of mortality in the aging population worldwide. However, the detail mechanisms and special biomarkers of atherosclerosis remain to be further investigated. Lately, long non-coding RNAs (lncRNAs) has attracted much more attention than other types of ncRNAs. In our work, we found and confirmed differently expressed lncRNAs and mRNAs in atherosclerosis by analyzing GSE28829. We performed the weighted gene co-expression network analysis (WGCNA) by analyzing GSE40231 to confirm highly correlated genes. Gene Ontology (GO) analysis were utilized to assess the potential functions of differential expressed lncRNAs in atherosclerosis. Co-expression networks were also constructed to confirm hub lncRNAs in atherosclerosis. A total of 5784 mRNAs and 654 lncRNAs were found to be dysregulated in the progression of atherosclerosis. A total of 15 lncRNA-mRNA co-expression modules were identified in this study based on WGCNA analysis. Moreover, a few lncRNAs, such as ZFAS1, LOC100506730, LOC100506691, DOCK9-AS2, RP11-6I2.3, LOC100130219, were confirmed as important lncRNAs in atherosclerosis. Taken together, bioinformatics analysis revealed these lncRNAs were involved in regulating the leukotriene biosynthetic process, gene expression, actin filament organization, t-circle formation, antigen processing, and presentation, interferon-gamma-mediated signaling pathway, and activation of GTPase activity. We believed that this study would provide potential novel therapeutic and prognostic targets for atherosclerosis.

Linc00299/miR-490-3p/AURKA axis regulates cell growth and migration in atherosclerosis

Long non-coding RNA (lncRNA) plays a crucial role in regulating various cellular processes in atherosclerosis. The present study identified the regulation of Linc00299, via miR-490-3p targeting Aurora kinase A (AURKA), on migration and proliferation of endothelial cells and vascular smooth muscle cells (VSMCs) during atherosclerosis. The expression of RNAs was assessed by real-time PCR. The proliferation, apoptosis and migration were detected using MTT assay, Annexin V/PI staining and Transwell system, respectively. Bindings of Linc00299/miR-490-3p and subsequent miR-490-3p/AURKA were verified by luciferase and biotin pull-down assays. The protein expression of AURKA was detected by Western blotting. Expressions of Linc00299 and miR-490-3p were upregulated and downregulated in atherosclerosis patients, respectively. Both Linc00299 knockdown and miR-490-3p overexpression suppressed cell proliferation, increased apoptosis and inhibited migration of VSMCs and HUVECs. Linc00299 directly bound to miR-490-3p which targeted AURKA. The regulation of Linc00299 on expression of AURKA and proliferation and migration of VSMCs were dependent on miR-490-3p. Atherosclerosis-increased Linc00299 acts as a sponge of miR-490-3p to upregulate AURKA, and as a result increases proliferation and migration in VSMCs and HUVECs. Our study reveals an important effect of Linc00299/miR-490-3p/AURKA axis on regulating cell proliferation and migration in atherosclerosis.

LncRNA UCA1 sponges miR-206 to exacerbate oxidative stress and apoptosis induced by ox-LDL in human macrophages

Long noncoding RNA UCA1 has exerted a significant effect in cardiovascular disease. The biological role of UCA1 in atherosclerosis is unclear. Our study was to identify the potential mechanisms in the progression of atherosclerosis. Here, we observed that ox-LDL increased UCA1 expression greatly in THP-1 cells. Knockdown of UCA1 greatly inhibited CD36 expression, a crucial biomarker in atherosclerosis. Meanwhile, 20 μg/ml ox-LDL induced foam cell formation, which can be reversed by downregulation of UCA1. In addition, TC and TG levels induced by ox-LDL was rescued by UCA1 small interfering RNA. Accumulating studies have indicated that oxidative stress contributes to atherosclerosis progression. Here, we also found that reactive oxygen species, MDA, and THP-1 cell apoptosis were restrained by decreased of UCA1 with an increase of the superoxide dismutase activity. Moreover, miR-206 was predicted as a target of UCA1 and knockdown of UCA1 was able to repress miR-206 expression. Furthermore, overexpression of miR-206 inhibited oxidative stress process and it was reversed by UCA1 upregulation in vitro. In conclusion, we indicated that UCA1 sponged miR-206 to exacerbate atherosclerosis events induced by ox-LDL in THP-1 cells.

Long noncoding RNA ATB participates in the development of renal cell carcinoma by downregulating p53 via binding to DNMT1

Long noncoding RNA (lncRNA) exerts an essential role in the pathological processes of many diseases. Our previous study found that lncRNA ATB was highly expressed in renal cell carcinoma (RCC). Cell Counting Kit-8 (CCK-8), 5-ethynyl-2'-deoxyuridine (EdU), and migration-related assays were conducted to access the regulatory effects of lncRNA ATB on proliferative and migratory capacities of RCC cells. Flow cytometry was carried out to determine cell cycle and apoptosis influenced by lncRNA ATB. The interaction among lncRNA ATB, DNMT1, and p53 was evaluated through RNA immunoprecipitation (RIP), chromatin immunoprecipitation (ChIP), and western blot analyses. The results showed that lncRNA ATB knockdown in RCC cell line ACHN inhibited proliferative and migratory capacities and promoted apoptosis. Meanwhile, overexpression of lncRNA ATB in RCC cell line A-498 promoted proliferative and migratory capacities but inhibited apoptosis. RIP and ChIP assays confirmed that lncRNA ATB can bind to DNMT1 and stabilize its expression; meanwhile, it can promote the binding of DNMT1 to p53. Overexpression of p53 partially reversed the proliferative and migratory changes caused by lncRNA ATB. To sum up, our study revealed that high expression of lncRNA ATB could accelerate the proliferative and migratory rates of RCC cells and inhibit cell apoptosis through downregulating p53 via binding to DNMT1.

The suppression of ox-LDL-induced inflammatory cytokine release and apoptosis of HCAECs by long non-coding RNA-MALAT1 via regulating microRNA-155/SOCS1 pathway

BACKGROUND

Atherosclerosis is a chronic inflammatory disease. Accumulating evidence suggests that long non-coding RNAs (lncRNAs) and microRNAs have emerged as critical regulators of atherosclerosis; however, whether they have crosstalk on this issue remains elusive. Here, we investigated the potential associations between lncRNA-MALAT1 and miR-155 on the regulation of atherosclerosis.

METHODS

Quantitative real-time PCR was employed to assess the expression of MALAT1, IL-6 and IL-8. ELISA was performed to measure the secretion of IL-6 and IL-8. MTT assay was used to determine the proliferation of Human Coronary Artery Endothelial Cells (HCAECs). Flow cytometry was used to measure the cell apoptosis. Western blot was used to assess the expression of apoptosis-related proteins and the phosphorylation of STAT1 and STAT3.

RESULTS

We found that the pro-inflammatory cytokine release and the apoptosis of HCAECs were elevated upon ox-LDL treatment, while MALAT1 expression was also up regulated. Knocking down of MALAT1 boosted ox-LDL-induced cytokine release and apoptosis of HCAECs. The binding site of miR-155 in MALAT1 sequence was confirmed by dual luciferase assay. Furthermore, miR-155 inhibition significantly repressed ox-LDL mediated inflammation and apoptosis of HCAECs via SOCS1. At last, we found that MALAT1 could suppress the inflammatory cytokine release and cell apoptosis via sponging miR-155 to increase SOCS1 level, which in turn restrained JAK-STAT pathway.

CONCLUSION

In summary, this study revealed the mechanisms by which MALAT1 worked as a putative atherosclerosis suppressor via miR-155 and SOCS1. Therefore, modulation of MALAT1/miR-155/SOCS1 axis might alleviate the inflammation persisted in atherosclerosis.

Long non-coding RNA H19 and MALAT1 gene variants in patients with ischemic stroke in a northern Chinese Han population

Objectives Long non-coding RNAs (lncRNAs) have been identified as key regulators in the development of atherosclerosis, which is a major cause of ischemic stroke. However, to date, there are no reports on the association between lncRNA gene variation and the risk of ischemic stroke. Therefore, we assessed the association between H19 and MALAT1 gene polymorphisms and susceptibility to ischemic stroke in a northern Chinese Han population. Methods In our study, we genotyped four genetic variations in lncRNA-H19 and -MALAT1 (rs217727, rs2251375, rs619586, and rs3200401) in a case-control study of 567 ischemic stroke patients and 552 control subjects. Results We found that the TT genotype of the rs217727 polymorphism within H19 was significantly associated with increased risk of ischemic stroke in our northern Chinese Han population (odds ration (OR) = 1.519, 95% confidence interval (CI) = 1.072-2.152, p = 0.018). Stratified analysis based on stroke subtype revealed that the increased risk was more evident in small vessel ischemic stroke (OR = 1.941, 95% CI = 1.260-2.992, p = 0.02). Individuals with the TT genotype had a 1.941 times higher risk of small vessel ischemic stroke when compared with the subjects of CC + CT. These correlations remained after adjusting for confounding risk factors of stroke (OR = 1.913, 95% CI = 1.221-2.998, p = 0.005). However, there was no significant association between H19 rs2251375 or MALAT1 rs3200401 and ischemic stroke in either total population analysis or subgroup analysis. Conclusion In conclusion, our findings suggest that the H19 rs217727 gene polymorphism contributes to small vessel ischemic stroke susceptibility in the Chinese Han population and may serve as a potential indicator for ischemic stroke susceptibility.

Flow-dependent epigenetic regulation of IGFBP5 expression by H3K27me3 contributes to endothelial anti-inflammatory effects

Rationale: Atherosclerosis is a chronic inflammatory and epigenetic disease that is influenced by different patterns of blood flow. However, the epigenetic mechanism whereby atheroprotective flow controls endothelial gene programming remains elusive. Here, we investigated the possibility that flow alters endothelial gene expression through epigenetic mechanisms. Methods: En face staining and western blot were used to detect protein expression. Real-time PCR was used to determine relative gene expression. RNA-sequencing of human umbilical vein endothelial cells treated with siRNA of enhancer of zeste homolog 2 (EZH2) or laminar flow was used for transcriptional profiling. Results: We found that trimethylation of histone 3 lysine 27 (H3K27me3), a repressive epigenetic mark that orchestrates gene repression, was reduced in laminar flow areas of mouse aorta and flow-treated human endothelial cells. The decrease of H3K27me3 paralleled a reduction in the epigenetic "writer"-EZH2, the catalytic subunit of the polycomb repressive complex 2 (PRC2). Moreover, laminar flow decreased expression of EZH2 via mechanosensitive miR101. Genome-wide transcriptome profiling studies in endothelial cells treated with EZH2 siRNA and flow revealed the upregulation of novel mechanosensitive gene IGFBP5 (insulin-like growth factor-binding protein 5), which is epigenetically silenced by H3K27me3. Functionally, inhibition of H3K27me3 by EZH2 siRNA or GSK126 (a specific EZH2 inhibitor) reduced H3K27me3 levels and monocyte adhesion to endothelial cells. Adenoviral overexpression of IGFBP5 also recapitulated the anti-inflammatory effects of H3K27me3 inhibition. More importantly, we observed EZH2 upregulation, and IGFBP5 downregulation, in advanced atherosclerotic plaques from human patients. Conclusion: Taken together, our findings reveal that atheroprotective flow reduces H3K27me3 as a chromatin-based mechanism to augment the expression of genes that confer an anti-inflammatory response in the endothelium. Our study exemplifies flow-dependent epigenetic regulation of endothelial gene expression, and also suggests that targeting the EZH2/H3K27me3/IGFBP5 pathway may offer novel therapeutics for inflammatory disorders such as atherosclerosis.

Linking diabetic vascular complications with LncRNAs

Diabetes leads to markedly accelerated rates of many associated macrovascular complications like hypertension and atherosclerosis, and microvascular complications like nephropathy and retinopathy. High glucose, the hallmark of diabetes, drives changes in vascular and inflammatory cells that promote the development of these complications. Understanding the molecular processes involved in the development of diabetes and its debilitating complications can lead to much needed newer clinical therapies. Recently, long-noncoding RNAs (lncRNAs) have been shown to be important in the biology of vascular cells and there is growing evidence that lncRNAs are also involved in the cell biology relevant to diabetic vascular complications. In this review, we provide an overview of lncRNAs that function in vascular cells, and those that have been linked to diabetic complications.

TUG1 knockdown ameliorates atherosclerosis via up-regulating the expression of miR-133a target gene FGF1

BACKGROUND

Long non-coding RNAs (lncRNAs) have been revealed to participate in the pathological events associated with atherosclerosis. However, the exact role of lncRNA taurine-up-regulated gene 1 (TUG1) and its possible molecular mechanism in atherosclerosis remain unidentified.

METHODS

High-fat diet (HFD)-treated ApoE^-/- mice were used as an in vivo model of atherosclerosis. Ox-LDL-induced macrophages and vascular smooth muscle cells (VSMCs) were employed as cell models of atherosclerosis. qRT-PCR was performed to detect the expression of TUG1 and miR-133a. Serum levels of total cholesterol (TC), triglyceride (TG), low-density lipoprotein cholesterol (LDL-C), and high-density lipoprotein cholesterol (HDL-C) were analyzed by commercially available enzyme kits. Oil red O and hematoxylin and eosin (H&E) staining were conducted to examine atherosclerotic lesion. Luciferase reporter assay combined with RNA immunoprecipitation (RIP) was applied to confirm the interaction between TUG1, miR-133a and FGF1. Cell proliferation ability was determined by Cell Counting Kit-8 (CCK-8) assay and trypan blue dye exclusion test. Cell apoptosis was evaluated with TUNEL assay. Expression and production of inflammatory cytokines was measured with western blot and ELISA analysis.

RESULTS

TUG1 expression was up-regulated in HFD-treated ApoE^-/- mice, as well as in ox-LDL-induced RAW264.7 and MOVAS cells. TUG1 knockdown inhibited hyperlipidemia, decreased inflammatory response, and attenuated atherosclerotic lesion in HFD-treated ApoE^-/- mice. TUG1 could function as a molecular sponge of miR-133a to suppress its expression. TUG1 overexpression accelerated cell growth, improved inflammatory factor expression, and inhibited apoptosis in ox-LDL-stimulated RAW264.7 and MOVAS cells, while this effect was abated after transfection with miR-133 mimic. Moreover, fibroblast growth factor 1 (FGF1) was identified as a direct target of miR-133a. Restored expression of FGF1 overturned the effect of miR-133a on cell proliferation, inflammatory factor secretion and apoptosis in ox-LDL-treated RAW264.7 and MOVAS cells. Finally, TUG1 was revealed to up-regulate FGF1 expression by sponging miR-133a.

CONCLUSION

TUG1 knockdown ameliorates atherosclerosis by modulating FGF1 via miR-133a, raising the possibility of targeting TUG1 as an atheroprotective therapeutic strategy.