Expression status and clinical significance of lncRNA APPAT in the progression of atherosclerosis

Crosstalk between ubiquitin ligases and ncRNAs drives cardiovascular disease progression

Cardiovascular diseases (CVDs) are multifactorial chronic diseases and have the highest rates of morbidity and mortality worldwide. The ubiquitin-proteasome system (UPS) plays a crucial role in posttranslational modification and quality control of proteins, maintaining intracellular homeostasis via degradation of misfolded, short-lived, or nonfunctional regulatory proteins. Noncoding RNAs (ncRNAs, such as microRNAs, long noncoding RNAs, circular RNAs and small interfering RNAs) serve as epigenetic factors and directly or indirectly participate in various physiological and pathological processes. NcRNAs that regulate ubiquitination or are regulated by the UPS are involved in the execution of target protein stability. The cross-linked relationship between the UPS, ncRNAs and CVDs has drawn researchers' attention. Herein, we provide an update on recent developments and perspectives on how the crosstalk of the UPS and ncRNAs affects the pathological mechanisms of CVDs, particularly myocardial ischemia/reperfusion injury, myocardial infarction, cardiomyopathy, heart failure, atherosclerosis, hypertension, and ischemic stroke. In addition, we further envision that RNA interference or ncRNA mimics or inhibitors targeting the UPS can potentially be used as therapeutic tools and strategies.

The Lnc-RNA APPAT Suppresses Human Aortic Smooth Muscle Cell Proliferation and Migration by Interacting With MiR-647 and FGF5 in Atherosclerosis

PURPOSE

LncRNA-Atherosclerotic plaque pathogenesis-associated transcript (APPAT) could be detected in circulating blood and has been demonstrated to correlate with the development of atherosclerosis in our previous work. It could be a potential noninvasive biomarker for earlier diagnoses of clinical cardiovascular disease. Moreover, the expression of miR-647 increased in ox-LDL-treated vascular smooth muscle cells and peripheral blood of patients with coronary heart disease. A negative correlation between APPAT and miR-647 was confirmed, and FGF5 was screened as molecular target of miR-647. However, it is largely unclear how APPAT, miR-647, and FGF5 interact and function in disease development. Here, we aim to explore the underlying molecular mechanism in this progression.

MATERIALS AND METHODS

APPAT, miR-647, and FGF5 expression levels were detected by quantitative reverse transcription polymerase chain reaction; cell proliferation was detected by EdU incorporation assay; cell migration was detected by wound-healing assay; the molecular interaction of APPAT/FGF5 with miR-647 was verified by dual-luciferase reporter assay; the western blot was performed to determine the gene expression at protein levels; subcellular localizations of APPAT and miR-647 were observed by fluorescence in situ hybridization; cytosolic and nucleus fractionation assay was performed to further detect the distribution of miR-647.

RESULTS

APPAT and miR-647 have inverse effects on human aortic smooth muscle cells' (HASMCs) proliferation and migration. APPAT negatively regulated the cell activity, whereas miR-647 did it in a positive way (p<0.05). Three pairs of molecular interplay were found: mutual negative regulation between APPAT and miR-647, APPAT downregulated FGF5, miR-647 regulation on FGF5 (p<0.05). Subcellular location assay confirmed the molecular interaction of APPAT and miR-647.

CONCLUSIONS

APPAT could suppress the migration and proliferation of ox-LDL-treated HASMCs via interacting with miR-647 and FGF5. We revealed a nontypical competing endogenous RNA mechanism of long noncoding RNA in the progression of atherosclerosis.

Inhibition of ox‐LDL‐induced endothelial cell injury by LINC02381 knockdown through the microRNA‐491‐5p/transcription factor 7 axis

Atherosclerosis (AS) is a complex multifactorial and chronic inflammatory vascular disease that contributes to the development of cardiovascular diseases. Abnormal cellular proliferation in human umbilical vein endothelial cells (HUVECs) is a crucial element in AS development. In this study, we investigated the potential role of the long noncoding RNA LINC02381/microRNA (miR)‐491‐5p/transcription factor 7 (TCF7) axis in regulating HUVEC injury in 30 participants suffering from AS and 30 healthy control participants. We established an in vitro model of AS in HUVECs using oxidized low‐density lipoprotein (ox‐LDL), and measured cellular mRNA and protein levels of LINC02381, miR‐491‐5p, and TCF7 in serum samples using reverse transcription‐quantitative polymerase chain reaction and Western blotting assays. We evaluated cell viability, apoptosis, and inflammation using Cell Counting Kit‐8, flow cytometry, and enzyme‐linked immunosorbent assays, respectively. Moreover, we analyzed apoptosis‐related protein expression using western blotting analysis and determined the association between miR‐491‐5p and LINC02381 or TCF7 using dual‐luciferase reporter assay, RNA pull‐down, and rescue experiments. We observed that LINC02381 was elevated, while miR‐491‐5p was downregulated in serum samples from participants with AS and in ox‐LDL‐treated HUVECs. LINC02381 knockdown was protective against HUVEC injury via miR‐491‐5p inhibition, which is its downstream target. Rescue experiments further demonstrated that miR‐491‐5p alleviated HUVEC injury by modulating TCF7. Thus, LINC02381 knockdown ameliorated HUVEC injury by regulating the miR‐491‐5p/TCF7 axis, which provides new insights into AS treatment strategies.

Research advances on circulating Long noncoding RNAs as biomarkers of cardiovascular diseases

Cardiovascular diseases (CVD) such as myocardial ischemia, myocardial infarction, heart failure, atherosclerosis, hypertension, arrhythmia, and their complications diseases are associated with increased morbidity and mortality, it is necessary to develop new diagnostic markers for CVD. LncRNAs have become a new class of biomarkers in CVD with good development prospects. Numerous studies have confirmed lncRNAs feasibility as diagnostic, prognostic and predictive tools for different types of CVD. In this review, we summarized the available knowledge regarding the clinical application value and pathophysiological mechanism of circulating lncRNA as potential biomarkers of cardiovascular disease. We reviewed the scope of application and changes of circulating lncRNAs such as ZFAS1, CDR1AS, CHAST, UCA1, HOTAIR, MIAT, NEAT1, LIPCAR, H19, NRF, NRON, MHRT, PVT1, Heat2, CASC7, GAS5, MALAT1, APPAT, HIF1A-AS1, KCNQ1OT1, NEXN in different kinds of CVD and discussed their clinical application potential as biomarker, which can help us better understand the mechanism of CVD.

The Transient Receptor Potential Channel Yvc1 Deletion Recovers the Growth Defect of Calcineurin Mutant Under Endoplasmic Reticulum Stress in Candida albicans

Transient receptor potential (TRP) channel Yvc1 was related with hyphal growth, oxidative stress response, and pathogenicity. Calcineurin subunit Cnb1 was activated immediately in yeasts when exposed to severe stimulation. However, the relationship between Yvc1 and Cnb1-governed calcium ions and endoplasmic reticulum (ER) stress response remains unrevealed. In this study, we found that the mutant cnb1Δ/Δ was sensitive to TN, which was related with the overexpression of membrane calcium ion channels that could increase the cytosol calcium concentration. However, the growth of the cnb1Δ/Δyvc1Δ/Δ mutant was recovered and its cell vitality was better than the cnb1Δ/Δ strain. Meanwhile, the cellular calcium concentration was decreased and its fluctuation was weakened under ER stress in the cnb1Δ/Δyvc1Δ/Δ strain. To verify the regulation role of Yvc1 in the calcium concentration, we found that the addition of CaCl2 led to the worse viability, while the growth state was relieved under the treatment of EGTA in the cnb1Δ/Δ strain. In conclusion, the deletion of YVC1 could reduce the cellular calcium and relieve the ER stress sensitivity of the cnb1Δ/Δ strain. Thereby, our findings shed a novel light on the relationship between the Yvc1-governed cellular calcium concentration and ER stress response in C. albicans.

LncRNA Miat knockdown alleviates endothelial cell injury through regulation of miR-214-3p/Caspase-1 signalling during atherogenesis

Atherosclerosis is a common problem in healthy people around the world. Long noncoding RNAs (lncRNAs) play important roles in atherosclerosis. Myocardial infarction-associated transcript (Miat) is a cardiovascular disease-associated lncRNA. Its role and mechanism in atherosclerosis is still not fully clarified. Our study aims to explore the role and mechanism of lncRNA Miat in atherosclerosis. The atherosclerosis models were established both in vitro and in vivo. Real-time PCR was used to measure the expression of lncRNA Miat, miR-214, Caspase-1 and IL-1β. Western blot was performed to detect the protein expression of Caspase-1. CCK-8 assay, Tunel staining, and flow cytometry analysis were conducted to detect proliferation and apoptosis of human aortic endothelial cells (HAECs), respectively. Oil red O staining and HE staining were used to evaluated the histological changes of the aorta. The results found that lncRNA Miat was upregulated in ox-LDL-induced atherosclerosis model in vitro. The inhibition of lncRNA Miat protects against ox-LDL-induced HAEC injury, presented as increased cell viability and decreased apoptosis. LncRNA Miat and miR-214 has binding site, and CASP1, which encodes Caspase-1, is a target of miR-214. The downregulation of lncRNA Miat increased the expression of miR-214-3p and decreased the expression of Caspase-1, as well as its downstream molecule IL-1β in HAECs. However, the inhibition of miR-214-3p attenuated the effect of lncRNA Miat downregulation on HAECs. Furthermore, the downregulation of lncRNA Miat alleviated atherosclerosis in ApoE-deficient mice. Correspondingly, the expression of miR-214-3p was upregulated and Caspase-1 was downregulated after knockdown of lncRNA Miat. In conclusion, downregulation of lncRNA Miat exerts a protective effect against atherosclerosis through the regulation miR-214-3p/Caspase-1 signalling pathway. Therefore, the inhibition of lncRNA Miat expression may be an effective strategy in the treatment of atherosclerosis.

Foxc2 Alleviates Ox-LDL-Induced Lipid Accumulation, Inflammation, and Apoptosis of Macrophage via Regulating the Expression of Angptl2

The present study aimed to investigate the role of Forkhead box protein C2 (Foxc2) in oxidized low-density lipoprotein (ox-LDL)-induced macrophages and identify the potential mechanisms. RAW264.7 cells, the murine macrophage cell line, were stimulated by ox-LDL, and cell proliferation was examined. The levels of inflammation- and oxidative stress-related markers were detected using kits after induction with ox-LDL. Subsequently, the expression of Foxc2 was measured using Western blotting. After transfection with Foxc2 pcDNA3.1, intracellular lipid droplets were examined using oil red O staining. The levels of total cholesterol (TC), free cholesterol (FC), inflammatory cytokines, and oxidative stress markers were determined. Moreover, apoptosis of RAW264.7 cells was detected using flow cytometry, and apoptosis-related proteins were measured using Western blotting. Angiopoietin-like protein 2 (Angptl2) was predicted as a target gene of Foxc2. Therefore, the expression of Angptl2 was examined after Foxc2 overexpression in ox-LDL-induced RAW264.7 cells. Then, the changes of intracellular lipid droplets, TC, FC, inflammatory cytokines, oxidative stress factors, and cell apoptosis were detected after Angptl2 overexpression or co-transfection with Foxc2 and Angptl2 pcDNA3.1. The results revealed that ox-LDL induction inhibited proliferation of RAW264.7 cells and promoted the release of inflammatory factors. Importantly, the expression of Foxc2 was obviously decreased after stimulation by ox-LDL. Foxc2 overexpression suppressed lipid accumulation, TC, FC levels, inflammation, oxidative stress, and apoptosis induced by ox-LDL, whereas these inhibitory effects were relieved after co-transfection with Angptl2 pcDNA3.1. These findings demonstrated that Foxc2 can alleviate ox-LDL-induced lipid accumulation, inflammation, and apoptosis of macrophage via regulating the expression of Angptl2.

Silencing lncRNA AK136714 reduces endothelial cell damage and inhibits atherosclerosis

Atherosclerosis correlates with ischemic cardio-cerebrovascular diseases such as coronary heart disease. Long non-coding RNAs (lncRNAs) can promote atherosclerosis. We investigated the role of the lncRNA AK136714 in atherosclerosis. Compared with the healthy group, lncRNA AK136714 expression was elevated in the plaque and plasma of the atherosclerosis patients in a GEO dataset. AK136714 silencing inhibited atherosclerosis formation in ApoE-/- mice. AK136714 silencing also protected the endothelial barrier and inhibited endothelial cell inflammation. In vitro assays showed that knockdown of AK136714 suppressed the inflammatory response and apoptosis in human umbilical vein endothelial cells (HUVECs). Moreover, AK136714 was found to bind directly to HuR to increase the mRNA stability of TNF-α, IL-1β and IL-6 mRNAs. In addition, AK136714 promoted the transcription of Bim. This study expands our understanding of the role of lncRNA AK136714 in atherosclerosis and provides potential drug targets for the treatment of atherosclerosis.

Effect of Long Non-Coding RNA Small Nucleolar RNA Host Gene 14 Targeting miR-93-5p on Oxidized Low-Density Lipoprotein-Induced Endothelial Cell Injury and Its Mechanism

To explore the influence and mechanism of lncRNA SNHG14 on oxidized low-density lipoprotein (oxLDL)-induced vascular endothelial cell injury, cellular levels of SNHG14 and miRNA-93-5p were detected in oxLDL-induced vascular endothelial cells by RT-qPCR, and the levels of MDA, SOD and GSH-Px were detected by ELISA. Flow cytometry was used to detect cellular apoptosis, and western blot analysis was used to determine the abundance of Bcl-2 and Bax proteins. SNHG14 small interfering RNA or miRNA-93-5p mimics were transfected into vascular endothelial cells to interfere with SNHG14 expression or overexpress miRNA-93-5p. To study the effects of interfering with SNHG14 expression or overexpression of miRNA-93-5p, the levels of MDA, SOD and GSH-Px, apoptosis and the levels of Bcl-2 and Bax protein were studied in oxLDL-induced endothelial cells with either altered SNHG14 expression or overexpressed miRNA-93-5p. A dual-luciferase reporter gene experiment verified the regulatory connection between SNHG14 and miRNA-93-5p. After oxLDL acted on vascular endothelial cells, the expression levels of SNHG14 were significantly increased, while the expression levels of miRNA-93-5p were significantly reduced, MDA levels were increased, and SOD and GSH-Px activities were reduced. Both the apoptosis rate and Bax protein levels were significantly increased, and Bcl-2 expression was reduced. Interference with SNHG14 expression or overexpression of miRNA-93-5p can reduce the MDA content in oxLDL-induced vascular endothelial cells, increase the activity of SOD and GSH-Px, and reduce the apoptosis rate and Bax protein levels, and promote Bcl-2 expression. SNHG14 targeted to negatively regulate miRNA-93-5p expression, inhibited miRNA-93-5p expression and reversed the interference of SNHG14 expression with oxLDL-induced variation in MDA, SOD and GSH-Px levels, apoptosis rate, and Bax and Bcl-2 protein levels. Interference of SNHG14 expression may reduce oxidative stress and apoptosis of vascular endothelial cells induced by oxLDL by negatively regulating the expression of miRNA-93-5p.

Long Non-Coding RNAs (lncRNAs) in Cardiovascular Disease Complication of Type 2 Diabetes

The discovery of non-coding RNAs (ncRNAs) has opened a new paradigm to use ncRNAs as biomarkers to detect disease progression. Long non-coding RNAs (lncRNA) have garnered the most attention due to their specific cell-origin and their existence in biological fluids. Type 2 diabetes patients will develop cardiovascular disease (CVD) complications, and CVD remains the top risk factor for mortality. Understanding the lncRNA roles in T2D and CVD conditions will allow the future use of lncRNAs to detect CVD complications before the symptoms appear. This review aimed to discuss the roles of lncRNAs in T2D and CVD conditions and their diagnostic potential as molecular biomarkers for CVD complications in T2D.

Epigenetic mechanisms underlying the benefits of flavonoids in cardiovascular health and diseases: are long non-coding RNAs rising stars?

Cardiovascular diseases (CVDs) rank as the first leading cause of death globally. High dietary polyphenol (especially flavonoids) intake has strongly been associated with low incidence of the primary outcome, overall mortality, blood pressure, inflammatory biomarkers, onset of new-onset type 2 diabetes mellitus (T2DM), and obesity. Phytogenic flavonoids affect the physiological and pathological processes of CVDs by modulating various biochemical signaling pathways. Non-coding RNAs (ncRNAs) have attracted increasing attention as fundamental regulator of gene expression involved in CVDs. Among the different ncRNA subgroups, long ncRNAs (lncRNAs) have recently emerged as regulatory eukaryotic transcripts and therapeutic targets with important and diverse functions in health and diseases. lncRNAs may be associated with the initiation, development and progression of CVDs by modulating acute and chronic inflammation, adipogenesis and lipid metabolism, and cellular physiology. This review summarizes this research on the modulatory effects of lncRNAs and their roles in mediating cellular processes. The mechanisms of action of flavonoids underlying their therapeutic effects on CVDs are also discussed. Based on our review, flavonoids might facilitate a significant epigenetic modification as part (if not full) of their tissue-/cell-related biological effects. This finding may be attributed to their interaction with cellular signaling pathways involved in chronic diseases. Certain lncRNAs might be the target of specific flavonoids, and some critical signaling processes involved in the intervention of CVDs might mediate the therapeutic roles of flavonoids.

Phenotype-genotype network construction and characterization: a case study of cardiovascular diseases and associated non-coding RNAs

The phenotype–genotype relationship is a key for personalized and precision medicine for complex diseases. To unravel the complexity of the clinical phenotype–genotype network, we used cardiovascular diseases (CVDs) and associated non-coding RNAs (ncRNAs) (i.e. miRNAs, long ncRNAs, etc.) as the case for the study of CVDs at a systems or network level. We first integrated a database of CVDs and ncRNAs (CVDncR, http://sysbio.org.cn/cvdncr/) to construct CVD–ncRNA networks and annotate their clinical associations. To characterize the networks, we then separated the miRNAs into two groups, i.e. universal miRNAs associated with at least two types of CVDs and specific miRNAs related only to one type of CVD. Our analyses indicated two interesting patterns in these CVD–ncRNA networks. First, scale-free features were present within both CVD–miRNA and CVD–lncRNA networks; second, universal miRNAs were more likely to be CVDs biomarkers. These results were confirmed by computational functional analyses. The findings offer theoretical guidance for decoding CVD–ncRNA associations and will facilitate the screening of CVD ncRNA biomarkers.

Database URL: http://sysbio.org.cn/cvdncr/

Definition and review on a category of long non-coding RNA: Atherosclerosis-associated circulating lncRNA (ASCLncRNA)

Atherosclerosis (AS) is one of the most common cardiovascular system diseases which seriously affects public health in modern society. Finding potential biomarkers in the complicated pathological progression of AS is of great significance for the prevention and treatment of AS. Studies have shown that long noncoding RNAs (lncRNAs) can be widely involved in the regulation of many physiological processes, and have important roles in different stages of AS formation. LncRNAs can be secreted into the circulatory system through exosomes, microvesicles, and apoptotic bodies. Recently, increasing studies have been focused on the relationships between circulating lncRNAs and AS development. The lncRNAs in circulating blood are expected to be new non-invasive diagnostic markers for monitoring the progression of AS. We briefly reviewed the previously reported lncRNA transcripts which related to AS development and detectable in circulating blood, including ANRIL, SENCR, CoroMarker, LIPCAR, HIF1α-AS1, LncRNA H19, APPAT, KCNQ1OT1, LncPPARδ, LincRNA-p21, MALAT1, MIAT, and UCA1. Further researches and a definition of atherosclerosis-associated circulating lncRNA (ASCLncRNA) were also discussed.

LncRNA HCG11 regulates proliferation and apoptosis of vascular smooth muscle cell through targeting miR-144-3p/FOXF1 axis in atherosclerosis

BACKGROUND

Atherosclerosis (AS) is the main pathological basis of coronary heart disease, cerebral infarction and peripheral vascular disease, which seriously endanger people's life and health. In recent years, long non-coding RNA (lncRNA) has been found to be involved in gene expression regulation, but the research on AS is still in the initial stage. In this study, we mainly studied the role of HCG11 in patients with AS. Quantitative Real-time Polymerase Chain Reaction (QRT-PCR) was used to detect the expression of HCG11 and miR-144 in the serum of AS patients and healthy volunteers. Oxidation Low Lipoprotein (Ox-LDL), interleukin-6 (IL-6) and tumor necrosis factor α (TNF α) radiation were used to establish human vascular smooth muscle cells (VSMCs) in vitro model. Cell proliferation was determined by Cell Counting Kit-8 (CCK-8) assay. The apoptosis rate was determined by flow cytometry (FACS) and terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling assay (TUNEL) staining. The expression levels of Forkhead box protein F1 (FOXF1), B cell lymphoma-2 (Bcl-2) and BCL2-Associated X (Bax) were detected by qRT-PCR. Luciferase gene reporter and RNA pull down experiments confirmed the relationship between HCG11 and miR-144, miR-144 and FOXF1.

RESULTS

This study showed that HCG11 was significantly upregulated in patients with AS, while miR-144 was down-regulated in patients with AS. Ox-LDL and IL-6 in VSMCs induced up-regulation of HCG11 and down-regulation of miR-144. Overexpression of HCG11 promoted the proliferation and inhibited apoptosis of VSMCs. Luciferase gene reporter gene assay showed that HCG11 could bind to miR-144, and miR-144 could bind to FOXF1. Overexpression of miR-144 reversed the effect of HCG11 on VSMCs.

CONCLUSIONS

LncRNA HCG11 regulates proliferation and apoptosis of vascular smooth muscle cell through targeting miR-144-3p/FOXF1 axis.

Study and Characterization of Long Non-coding RUNX1-IT1 among Large Artery Atherosclerosis Stroke Patients Based on the ceRNA Hypothesis

Recent studies have shed light on the involvement of long non-coding RNAs (lncRNAs) in the initiation and development of stroke. However, the regulatory function of many lncRNAs in large artery atherosclerosis (LAA) has not been fully elucidated. Based on the competing endogenous RNA (ceRNA) hypothesis recently proposed by Pandolfi, the present study was conducted using experimental techniques and bioinformatics to investigate the expression and regulatory function of a lncRNA involved in the development of LAA. The lncRNAs differentially expressed in stroke were obtained using meta-analysis, and one lncRNA was selected for experimental studies on patients with LAA (n = 100) and healthy controls (n = 100) using quantitative real-time polymerase chain reaction (qRT-PCR). The patients were also evaluated through meta-analysis to identify the function of the selected lncRNA, miRNAs, and mRNAs with altered expression in stroke. Finally, the experimental results and meta-analysis findings were integrated, and different functional groups were assigned. The results indicated that the level of lncRNA-RUNX1-IT1 was significantly lower in the patients with LAA compared to the healthy control subjects (p > 0.05). Logistic regression analyses revealed that the expression of lncRNA-RUNX1-IT1 was inversely correlated with LAA (P = 009, OR = 0.871, 95% CI: 0.786-0.965). In addition, a network of differentially expressed genes (DE genes) was created for miRNAs and mRNAs based on their association with lncRNA-RUNX1-IT1. Functional analysis showed that the DE genes in the network are involved in the apoptosis and alternative splicing of RNAs. The findings of the present study suggest that the downregulation of lncRNA-RUNX1-IT1 is associated with LAA development by interrupting the regulatory network of cells. The results of network analysis demonstrated that the lncRNA-RUNX1-IT1 could influence the expression of mRNAs and miRNAs involved in the apoptosis and alternative splicing of RNAs.

The Long Non-Coding RNA Landscape of Atherosclerotic Plaques

Currently, cardiovascular diseases continue to be the leading cause of death worldwide; therefore, atherosclerosis remains one of the most crucial public health problems. This chronic and complex disease is considered to be a result of aberrant lipid homeostasis and inflammation of the inner wall of arteries that leads to plaque development. In recent years, a specific class of non-coding RNAs that are characterised by transcript lengths longer than 200 nucleotides, called long non-coding RNAs (lncRNAs), has emerged. Moreover, a growing body of evidence indicates that deregulation of lncRNA expression may contribute to the development of many diseases. Despite continuous efforts in deciphering the molecular basis of atherosclerotic plaque (AP) formation, many aspects of this process remain elusive. Therefore, continuing efforts in this area should remain the highest priority in the coming years. Establishment of a standardised experimental pipeline and validation of lncRNAs as possible relevant biomarkers for cardiovascular disease would enable the translation of gathered findings into clinical practice.

Long noncoding RNA NEAT1 is involved in the protective effect of Klotho on renal tubular epithelial cells in diabetic kidney disease through the ERK1/2 signaling pathway

Klotho, an antiaging protein, has been shown to play a protective role in renal tubular epithelial-mesenchymal transition (EMT) during the development of diabetic kidney disease (DKD). Long noncoding RNAs (lncRNAs) participate in the progression of EMT in many diseases. However, the effect of Klotho on lncRNAs during the development of DKD is still unknown. In this study, we found that Klotho overexpression in high-fat diet (HFD)- and streptozotocin (STZ)-induced DKD mice significantly inhibited the expression of lncRNA nuclear-enriched abundant transcript 1 (Neat1). We demonstrated that NEAT1 was significantly upregulated in both bovine serum albumin (BSA)-stimulated HK2 cells and mice with HFD- and STZ-induced diabetes. In addition, we observed that Klotho displays colocalization with NEAT1. Furthermore, overexpression of Klotho can inhibit the high expression of NEAT1 in BSA-stimulated HK2 cells, while silencing Klotho can further upregulate the expression of NEAT1. Silencing NEAT1 in HK2 cells resulted in inhibition of the EMT-related markers alpha smooth muscle actin (α-SMA) and vimentin (VIM) and the renal fibrosis-related markers transforming growth factor-β1 (TGF-β1) and connective tissue growth factor (CTGF). The effect of NEAT1 on DKD was partly mediated by regulation of the ERK1/2 signaling pathway. Finally, we found that silencing NEAT1 can reverse the activation of EMT and fibrosis caused by Klotho silencing in a manner dependent on the ERK1/2 signaling pathway. These findings reveal a new regulatory pathway by which Klotho regulates ERK1/2 signaling via NEAT1 to protect against EMT and renal fibrosis, suggesting that NEAT1 is a potential therapeutic target for DKD.

An anti-ageing protein called Klotho helps protect against kidney failure in mice and human cells by silencing a long non-coding RNA molecule. The regulatory RNA involved, known as NEAT1, promotes cellular transformations associated with the disease process. A team led by Yao-Ming Xue from Southern Medical University in Guangdong, China, showed that levels of NEAT1 are elevated in mouse models of diabetic kidney disease and in injured human kidney calls. The identification of NEAT1 in kidney disease thus provides a novel therapeutic target. After demonstrating that Klotho and NEAT1 interact directly with each other in cells, they experimentally boosted Klotho expression and observed suppressed levels of NEAT1. As a consequence, the cells displayed lower levels of the proteins linked to the progressive deposition of fibrosis in the kidneys.

Long Noncoding RNAs in Pathological Cardiac Remodeling: A Review of the Update Literature

Cardiac remodeling is a self-regulatory response of the myocardium and vasculature under the stressful condition. Cardiomyocytes (CMs), vascular smooth muscle cells (VSMCs), endothelial cells (ECs), and cardiac fibroblasts (CFs) are all involved in this process, characterized by change of morphological structures and mechanical/chemical activities as well as metabolic patterns. Despite current development of consciousness, the control of cardiac remodeling remains unsatisfactory, and to further explore the underlying mechanism and seek the optimal therapeutic targets is still the urgent need in clinical practice. It is now emerging that long noncoding RNAs (lncRNAs) play key regulatory roles in these adverse responses: lncRNA TUG1, AK098656, TRPV1, GAS5, Giver, and Lnc-Ang362 have been indicated in hypertension-related vascular remodeling, H19, TUG1, UCA1, MEG3, APPAT, and lincRNA-p21 in atherosclerosis (AS), and HIF1A-AS1 and Lnc-HLTF-5 in aortic aneurysm (AA). In addition, Neat1, AK139328, APF, CAIF, AK088388, CARL, MALAT1, HOTAIR, XIST, and NRF are involved in postischemia myocardial remodeling, while Mhrt, Chast, CHRF, ROR, H19, Plscr4, and MIAT are involved in myocardial hypertrophy, and MALAT1, wisper, MEG3, and H19 are involved in extracellular matrix (ECM) reconstitution. Signaling to specific miRNAs by acting as endogenous sponge (ceRNA) was the main form that regulates the target gene expression during cardiac remodeling. This review will underline the updates of lncRNAs and lncRNA-miRNA interactions in maladaptive remodeling and also cast light on their potential roles as therapeutic targets, hoping to provide supportive background for following research.

lncRNA 430945 promotes the proliferation and migration of vascular smooth muscle cells via the ROR2/RhoA signaling pathway in atherosclerosis

The proliferation and migration of vascular smooth muscle cells (VSMCs) are major cellular events in hypertension‑induced vascular remodeling, which is closely involved in the progression of atherosclerosis (AS). Although long non‑coding RNAs (lncRNAs) are gaining recognition as novel regulators of VSMCs, their functioning and role in AS remain to be elucidated. In the present study, the role of lncRNA ENST00000430945 (lncRNA 430945) in AS was investigated. VSMCs transfected with a small interfering RNA (siRNA; si‑430945) and a negative control (si‑NC) were used. Cell Counting Kit‑8, wound‑healing and Transwell migration arrays were performed to determine whether lncRNA 430945 influenced VSMC proliferation and migration. Furthermore, the study examined whether a correlation exists between lncRNA 430945 and the receptor tyrosine kinase‑like orphan receptor 2 (ROR2) signaling pathway. It was found that the expression of lncRNA 430945 was high in human AS tissues, which in turn promoted angiotensin II (AngII)‑induced VSMC proliferation. Reverse transcription‑quantitative polymerase chain reaction (RT‑qPCR) and western blot analyses showed that lncRNA 430945 mediated the AngII‑induced upregulation of ROR2. In addition, the microarray and RT‑qPCR results showed that the expression of lncRNA 430945 was increased considerably in AS tissues. The downregulation of lncRNA 430945 significantly suppressed AngII‑induced VSMC proliferation and migration. In addition, ROR2 levels in VSMCs transfected with si‑430945 were markedly lower than those cells transfected with si‑NC. Additionally, western blotting showed that lncRNA 430945 activated the signaling pathways associated with ROR2 and Ras homolog gene family member A (RhoA). The upregulation of lncRNA 430945 in AS promoted the proliferation and migration of VSMCs via activation of the ROR2/RhoA signaling pathway. Therefore, targeting ROR2 or RhoA may be a promising technique in developing therapeutic strategies for treating AS.

TGF‑β1 upregulates the expression of lncRNA‑ATB to promote atherosclerosis

Transforming growth factor (TGF)-β1 is reported to be associated with the occurrence of atherosclerosis, although the mechanism remains unclear. Therefore, the present study aimed to investigate the involvement of TGF-β1 signaling in atherosclerosis. A total of 56 patients with atherosclerosis and 44 healthy volunteers were involved in this study. Serum expression of TGF-β1 and long non-coding RNA-ATB was detected by ELISA and quantitative polymerase chain reaction (qPCR). Receiver operating characteristic curve analysis was performed to analyze the diagnostic value of serum TGF-β1 and lncRNA-ATB for atherosclerosis. A human umbilical vein endothelial cell (HUVEC) line overexpressing lncRNA-ATB was constructed. The effects of TGF-β1 treatment and lncRNA-ATB overexpression on HUVEC cell proliferation and viability was detected with Cell Counting Kit-8 and MTT assays, respectively. Expression of TGF-β1 and pro-apoptotic Caspase-3 in lncRNA-ATB-overexpressing HUVECs was detected by western blotting. In addition, the expression of lncRNA-ATB in TGF-β1-treated HUVECs was detected by qPCR. It was demonstrated that serum TGF-β1 and lncRNA-ATB expression was significantly higher in atherosclerosis patients, compared with controls, and could be used to effectively distinguish patients from healthy individuals. TGF-β1 treatment and lncRNA-ATB overexpression reduced HUVEC viability and proliferation. TGF-β1 treatment increased the expression of lncRNA-ATB in HUVECs, while lncRNA-ATB overexpression had no significant effect on TGF-β1 expression. LncRNA-ATB silencing with small interfering RNA significantly reduced the effects of TGF-β1 treatment on the proliferation and viability of HUVECs. Furthermore, LncRNA-ATB overexpression upregulated the expression of caspase-3 in HUVECs. Therefore, it was concluded that TGF-β1 may have upregulated the expression of lncRNA-ATB to promote atherosclerosis, and lncRNA-ATB may serve as a potential therapeutic target for atherosclerosis. However, the mechanism remains to be further investigated.

Role of flow-sensitive microRNAs and long noncoding RNAs in vascular dysfunction and atherosclerosis

Atherosclerosis is the primary underlying cause of myocardial infarction, ischemic stroke, and peripheral artery disease. The disease preferentially occurs in arterial regions exposed to disturbed blood flow, in part, by altering expression of flow-sensitive coding- and non-coding genes. In this review, we summarize the role of noncoding RNAs, [microRNAs (miRNAs) and long noncoding RNAs(lncRNAs)], as regulators of gene expression and outline their relationship to the pathogenesis of atherosclerosis. While miRNAs are small noncoding genes that post-transcriptionally regulate gene expression by targeting mRNA transcripts, the lncRNAs regulate gene expression by diverse mechanisms, which are still emerging and incompletely understood. We focused on multiple flow-sensitive miRNAs such as, miR-10a, -19a, -23b, -17~92, -21, -663, -92a, -143/145, -101, -126, -712, -205, and -155 that play a critical role in endothelial function and atherosclerosis by targeting inflammation, cell cycle, proliferation, migration, apoptosis, and nitric oxide signaling. Flow-dependent regulation of lncRNAs is just emerging, and their role in vascular dysfunction and atherosclerosis is unknown. Here, we discuss the flow-sensitive lncRNA STEEL along with other lncRNAs studied in the context of vascular pathophysiology and atherosclerosis such as MALAT1, MIAT1, ANRIL, MYOSLID, MEG3, SENCR, SMILR, LISPR1, and H19. Also discussed is the use of these noncoding RNAs as potential biomarkers and therapeutics to reduce and regress atherosclerosis.

Long Noncoding RNA-H19 Contributes to Atherosclerosis and Induces Ischemic Stroke via the Upregulation of Acid Phosphatase 5

Objective: Atherosclerosis is closely associated with ischemic stroke, and long noncoding RNA-H19 (lncRNA-H19) might be a potential target for treating atherosclerosis. The present study aimed to investigate the function of lncRNA-H19 in atherosclerosis and to explore a novel therapeutic strategy for ischemic stroke. Methods: Differentially expressed genes (DEGs) in atherosclerosis were screened by searching public database. In combination with the lncRNA-H19-knockout database, potential lncRNA-H19-mediated gene was retrieved and their relationship was identified. In order to assess the detailed regulatory mechanism of lncRNA-H19, we used a lentivirus packaging system to upregulate Acp5 (Acid phosphatase 5) expression in vascular smooth muscle cells (VSMC) and human umbilical vein endothelial cells (HUVECs). The expression of ACP5 was determined by Western Blot, and evaluations of cell proliferation and apoptosis were detected. An ischemic stroke mouse model was established. Atherosclerosis was measured by using plaque area size. The effects H19 on the expression of ACP5 were explored by the overexpression or silence of H19. Results: H19 and ACP5 were associated with Acute Stroke Treatment (TOAST) subtypes of atherosclerotic patients. The target prediction program and dual-luciferase reporter confirmed ACP5 as a direct target of H19. Lentivirus-mediated H19-forced expression upregulated ACP5 protein levels, promoted cell proliferation and suppressed the apoptosis. The plaque area size was larger in ischemic models than controls. The overexpression or silence of H19 increased or reduced the plaque size. The overexpression or silence of H19 resulted in the expression or inhibition of ACP5. Conclusion: IncRNA-H19 promoting ACP5 protein expression contributed to atherosclerosis and increased the risk of ischemic stroke.

Diagnostic potential of circulating LncRNAs in human cardiovascular disease: a meta-analysis

Cardiovascular disease (CVD) is a major killer of the human population around the world. Identifying effective diagnostic biomarkers for CVDs is particularly important in order to guide optimizing treatment. Accumulating evidence on aberrantly regulated circulating long non-coding RNAs (LncRNAs) promise to serve as a diagnostic or prognostic biomarker for various types of CVDs. We summarized studies to identify the potential diagnostic values of LncRNAs in CVD patients. We included articles reporting on the association between LncRNAs and diagnosis in CVDs. We calculated sensitivities, specificities, and area under the curves of LncRNAs. The pooled overall sensitivity and specificity for LncRNAs expression profile in differentiating CVD patients from controls (non-CVDs or healthy subjects) were 0.74 (95%CI 0.68–0.80) and 0.81 (95%CI 0.76–0.85), respectively; the overall positive likelihood ratio, 3.9 (95%CI 3.1–4.9); the negative likelihood ratio, 0.32 (95%CI 0.25–0.40); corresponding to an area under curve of 0.85 (95%CI 0.82–0.88) and overall diagnostic odds ratio 12 (95%CI 9–18). Subgroup analysis showed that the detection of LncRNAs expression in plasma substantially improved the diagnostic accuracy. Likewise, meta-regression analysis indicated that the detection method and sample size were the main source of heterogeneity. All these results suggested a relatively good reference value of LncRNAs as auxiliary biomarkers for CVDs, and should be considered in cases where the diagnosis is uncertain. Population-based prospective cohort studies are warranted to confirm our findings.

Endothelial dysfunction in diabetes and hypertension: Role of microRNAs and long non-coding RNAs

The vascular endothelium acts as a barrier between the blood flow and the inner lining of the vessel wall, and it functions as a filtering machinery to filter out any unwanted transfer of materials from both sides (i.e. the blood and the surrounding tissues). It is evident that diseases such as diabetes, obesity, and hypertension disturb the normal endothelial functions in humans and lead to endothelial dysfunction, which may further precede to the development of atherosclerosis. Long non-coding RNAs and micro RNAs both are types of non-coding RNAs which, in the recent years, have increasingly been studied in the pathophysiology of many diseases including diabetes, obesity, cardiovascular diseases, neurological diseases, and others. Recent findings have pointed out important aspects on their relevance to endothelial function as well as dysfunction of the system which may arise from presence of diseases such as diabetes and hypertension. Diabetes or hypertension-mediated endothelial dysfunction show characteristics such as reduced nitric oxide synthesis through suppression of endothelial nitric oxide synthase activity in endothelial cells, reduced sensitivity of nitric oxide in smooth muscle cells, and inflammation - all of which have been either shown to be directly caused by gene regulatory mechanisms of non-coding RNAs or shown to be having a correlation with them. In this review, we aim to discuss such findings on the role of these non-coding RNAs in diabetes or hypertension-associated endothelial dysfunction and the related mechanisms that may pave the way for alleviating endothelial dysfunction and its related complications such as atherosclerosis.

Angiogenic lncRNAs: A potential therapeutic target for ischaemic heart disease

Long noncoding RNAs (LncRNAs) are involved in biological processes and the pathology of diseases and represent an important biomarker or therapeutic target for disease. Emerging evidence has suggested that lncRNAs modulate angiogenesis by regulating the angiogenic cell process-including vascular endothelial cells (VECs); stem cells, particularly bone marrow-derived stem cells, endothelial progenitor cells (EPCs) and mesenchymal stem cells (MSCs); and vascular smooth muscle cells (VSMCs)-and participating in ischaemic heart disease (IHD). Therapeutic angiogenesis as an alternative therapy to promote coronary collateral circulation has been demonstrated to significantly improve the prognosis and quality of life of patients with IHD in past decades. Therefore, lncRNAs are likely to represent a novel therapeutic target for IHD through regulation of the angiogenesis process. This review summarizes the classification and functions of lncRNAs and their roles in regulating angiogenesis and in IHD, in the context of an overview of therapeutic angiogenesis in clinical trials.