Smooth Muscle Enriched Long Noncoding RNA (SMILR) Regulates Cell Proliferation

The role of lncRNAs in sepsis-induced acute lung injury: Molecular mechanisms and therapeutic potential

Sepsis, a life-threatening syndrome, results from a dysregulated immune and hemostatic response, contributing to acute lung injury (ALI) and its progression into acute respiratory distress syndrome (ARDS). The development of septic ALI is complex, involving excessive inflammatory mediator production that damages endothelial and epithelial cells, leading to vascular leakage, edema, and vasodilation-key factors in ALI pathogenesis. Long noncoding RNAs (lncRNAs), over 200 nucleotides in length, play critical roles in various biological processes, including sepsis regulation. They exhibit both promotive and inhibitory effects, influencing sepsis progression and resolution. Despite their significance, comprehensive reviews detailing lncRNA involvement in sepsis-induced ALI remain limited. This review aims to address this gap by summarizing the diverse functions of lncRNAs in septic ALI, emphasizing their potential in diagnosis and treatment. Furthermore, we will explore the molecular mechanisms underlying lncRNA involvement, particularly their miRNA-dependent regulatory pathways. Understanding these interactions may provide novel insights into therapeutic strategies for sepsis-induced ALI.

Functional screening identifies miRNAs with a novel function inhibiting vascular smooth muscle cell proliferation

Proliferation of vascular smooth muscle cells (vSMCs) is a crucial contributor to pathological vascular remodeling. MicroRNAs (miRNAs) are powerful gene regulators and attractive therapeutic agents. Here, we aimed to systematically identify and characterize miRNAs with therapeutic potential in targeting vSMC proliferation. Using high-throughput screening, we assessed the impact of 2,042 human miRNA mimics on vSMC proliferation and identified seven miRNAs with novel vSMC anti-proliferative function: miR-323a-3p, miR-449b-5p, miR-491-3p, miR-892b, miR-1827, miR-4774-3p, and miR-5681b. miRNA-mimic treatment affects proliferation of vSMCs from different vascular beds. Focusing on vein graft failure, where miRNA-based therapeutics can be applied to the graft ex vivo, we showed that these miRNAs reduced human saphenous vein smooth muscle cell (HSVSMC) proliferation without toxic effect. HSVSMC transcriptomics revealed a distinct set of targets for each miRNA, leading to the common downregulation of a cell-cycle gene network for all miRNAs. For miR-449b-5p, we showed that its candidate target, CCND1, contributes to HSVSMC proliferation. In contrast to HSVSMCs, miRNA overexpression in endothelial cells led to a limited response in terms of proliferation and transcriptomics. In an ex vivo vein organ model, overexpression of miR-323a-3p and miR-449b-5p reduced medial proliferation. Collectively, the results of our study show the therapeutic potential of seven miRNAs to target pathological vascular remodeling.

Long Non-Coding RNA Function in Smooth Muscle Cell Plasticity and Atherosclerosis

In the healthy mature artery, vascular cells, including endothelial cells, smooth muscle cells (SMCs), and fibroblasts are organized in different layers, performing specific functions. SMCs located in the media are in a differentiated state and exhibit a contractile phenotype. However, in response to vascular injury within the intima, stimuli from activated endothelial cells and recruited inflammatory cells reach SMCs and induce a series of remodeling events in them, known as phenotypic switching. Indeed, SMCs retain a certain degree of plasticity and are able to transdifferentiate into other cell types that are crucial for both the formation and development of atherosclerotic lesions. Because of their highly cell-specific expression profiles and their widely recognized contribution to physiological and disease-related biological processes, long non-coding RNAs have received increasing attention in atherosclerosis research. Dynamic fluctuations in their expression have been implicated in the regulation of SMC identity. Sophisticated technologies are now available to allow researchers to access single-cell transcriptomes and study long non-coding RNA function with unprecedented precision. Here, we discuss the state of the art of long non-coding RNAs regulation of SMC phenotypic switching, describing the methodologies used to approach this issue and evaluating the therapeutic perspectives of exploiting long non-coding RNAs as targets in atherosclerosis.

Non-coding RNAs to treat vascular smooth muscle cell dysfunction

Vascular smooth muscle cell (vSMC) dysfunction is a critical contributor to cardiovascular diseases, including atherosclerosis, restenosis and vein graft failure. Recent advances have unveiled a fascinating range of non-coding RNAs (ncRNAs) that play a pivotal role in regulating vSMC function. This review aims to provide an in-depth analysis of the mechanisms underlying vSMC dysfunction and the therapeutic potential of various ncRNAs in mitigating this dysfunction, either preventing or reversing it. We explore the intricate interplay of microRNAs, long-non-coding RNAs and circular RNAs, shedding light on their roles in regulating key signalling pathways associated with vSMC dysfunction. We also discuss the prospects and challenges associated with developing ncRNA-based therapies for this prevalent type of cardiovascular pathology. LINKED ARTICLES: This article is part of a themed issue Non-coding RNA Therapeutics. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v182.2/issuetoc.

Targeting noncoding RNAs to treat atherosclerosis

Noncoding RNAs (ncRNAs) are pivotal for various pathological processes, impacting disease progression. The potential for leveraging ncRNAs to prevent or treat atherosclerosis and associated cardiovascular diseases is of great significance, especially given the increasing prevalence of atherosclerosis in an ageing and sedentary population. Together, these diseases impose a substantial socio-economic burden, demanding innovative therapeutic solutions. This review explores the potential of ncRNAs in atherosclerosis treatment. We commence by examining approaches for identifying and characterizing atherosclerosis-associated ncRNAs. We then delve into the functional aspects of ncRNAs in atherosclerosis development and progression. Additionally, we review current RNA and RNA-targeting molecules in development or under approval for clinical use, offering insights into their pharmacological potential. The importance of improved ncRNA delivery strategies is highlighted. Finally, we suggest avenues for advanced research to accelerate the use of ncRNAs in treating atherosclerosis and mitigating its societal impact. LINKED ARTICLES: This article is part of a themed issue Non-coding RNA Therapeutics. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v182.2/issuetoc.

Unraveling the genetic landscape of pulmonary arterial hypertension in Indian patients: A transcriptome study

BACKGROUND

Pulmonary hypertension (PH) is the abnormal elevation of pressure in the pulmonary vascular system, with various underlying causes. A specific type of PH is pulmonary arterial hypertension (PAH), a severe condition characterized by high pulmonary arterial pressure resulting from structural changes in distal pulmonary vessels, altered arterial tone, and inflammation. This leads to right ventricular hypertrophy and heart failure. The molecular mechanisms behind PAH are not well understood. This manuscript aims to elucidate these mechanisms using the genetic tool, aiding in diagnosis and treatment selection.

METHOD

In our present study, we have obtained blood samples from both patients with pulmonary arterial hypertension (PAH) and healthy individuals. We conducted a comparative transcriptome analysis to identify genes that are either upregulated or downregulated in PAH patients when compared to the control group. Subsequently, we carried out a validation study focusing on the log2-fold downregulated genes in PAH, employing Quantitative Real-Time PCR for confirmation. Additionally, we quantified the proteins encoded by the validated genes using the ELISA technique.

RESULTS

The results of the transcriptome analysis revealed that 97 genes were significantly upregulated, and 6 genes were significantly downregulated. Among these, we chose to focus on and validate only four of the downregulated genes, as they were directly or indirectly associated with the hypertension pathway. We also conducted validation studies for the proteins encoded by these genes, and the results were consistent with those obtained in the transcriptome analysis.

CONCLUSION

In conclusion, the findings of this study indicate that the four validated genes identified in the context of PAH can be further explored as potential targets for both diagnostic and therapeutic applications.

Differentiation and Growth-Arrest-Related lncRNA (DAGAR): Initial Characterization in Human Smooth Muscle and Fibroblast Cells

Vascular smooth muscle cells (SMCs) can transition between a quiescent contractile or "differentiated" phenotype and a "proliferative-dedifferentiated" phenotype in response to environmental cues, similar to what in occurs in the wound healing process observed in fibroblasts. When dysregulated, these processes contribute to the development of various lung and cardiovascular diseases such as Chronic Obstructive Pulmonary Disease (COPD). Long non-coding RNAs (lncRNAs) have emerged as key modulators of SMC differentiation and phenotypic changes. In this study, we examined the expression of lncRNAs in primary human pulmonary artery SMCs (hPASMCs) during cell-to-cell contact-induced SMC differentiation. We discovered a novel lncRNA, which we named Differentiation And Growth Arrest-Related lncRNA (DAGAR) that was significantly upregulated in the quiescent phenotype with respect to proliferative SMCs and in cell-cycle-arrested MRC5 lung fibroblasts. We demonstrated that DAGAR expression is essential for SMC quiescence and its knockdown hinders SMC differentiation. The treatment of quiescent SMCs with the pro-inflammatory cytokine Tumor Necrosis Factor (TNF), a known inducer of SMC dedifferentiation and proliferation, elicited DAGAR downregulation. Consistent with this, we observed diminished DAGAR expression in pulmonary arteries from COPD patients compared to non-smoker controls. Through pulldown experiments followed by mass spectrometry analysis, we identified several proteins that interact with DAGAR that are related to cell differentiation, the cell cycle, cytoskeleton organization, iron metabolism, and the N-6-Methyladenosine (m6A) machinery. In conclusion, our findings highlight DAGAR as a novel lncRNA that plays a crucial role in the regulation of cell proliferation and SMC differentiation. This paper underscores the potential significance of DAGAR in SMC and fibroblast physiology in health and disease.

Novel long noncoding lncARF mediated hyperhomocysteinemia-induced atherosclerosis via autophagy inhibition in foam cells

INTRODUCTION

Homocysteine (Hcy) is well recognized to be an independent risk factor for atherosclerosis. Long non-coding RNAs (lncRNAs) are emerging regulators of pathophysiological processes including atherosclerosis, while the underlying mechanisms of its involvement in Hcy induced-atherosclerosis remain largely unknown.

OBJECTIVES

The primary aim of this study is to assess the role of lncARF (autophagy-related factor induced by Hcy) in Hcy induced-atherosclerosis and related mechanism.

METHODS

RNA sequencing of foam cells treated with Hcy revealed a novel specific long noncoding RNA called lncARF. Locked nucleic acid gapmeRs-mediated lncARF knockdown was used to explore the role of lncARF both in vivo and in vitro. Mass spectrometry, RNA pull-down and RNA immunoprecipitation (RIP) assays were employed to uncover a mechanistic role of lncARF. Mass array assay and chromatin immunoprecipitation (ChIP) were used to detect the transcriptional activation of lncARF mediated by transcription factor. Clinically, receiver operating characteristic (ROC) curve analysis was used to assess the diagnostic value of lncARF in atherosclerotic patients with hyperhomocysteinemia (HHcy).

RESULTS

We observed that the expression of lncARF was substantially upregulated in atherosclerotic plaques, and knockdown of lncARF decreased the formation of atherosclerotic lesions by promoting autophagy in foam cells. Mechanistically, lncARF physically binds to RRAGD and inhibits its ubiquitination, further activating the PI3K/Akt and MAPK signaling pathways. Moreover, in vitro experiments showed that transcription factor FosB inhibited the binding of DNMT1 at the lncARF promoter, leading to transcriptional activation through DNA hypomethylation. Clinically, lncARF expression was positively correlated with serum Hcy levels, and it could distinguish atherosclerotic patients with HHcy with a high area under the ROC curve, sensitivity and specificity.

CONCLUSIONS

Our study highlights the mechanisms of lncARF in protecting against the development of atherosclerosis involving the epigenetic modifications and RRAGD/PI3K/Akt and RRAGD/MAPK signaling pathways, which may provide novel diagnostic biomarkers to improve atherosclerosis treatment.

Non-coding RNAs as therapeutic targets and biomarkers in ischaemic heart disease

The adult heart is a complex, multicellular organ that is subjected to a series of regulatory stimuli and circuits and has poor reparative potential. Despite progress in our understanding of disease mechanisms and in the quality of health care, ischaemic heart disease remains the leading cause of death globally, owing to adverse cardiac remodelling, leading to ischaemic cardiomyopathy and heart failure. Therapeutic targets are urgently required for the protection and repair of the ischaemic heart. Moreover, personalized clinical biomarkers are necessary for clinical diagnosis, medical management and to inform the individual response to treatment. Non-coding RNAs (ncRNAs) deeply influence cardiovascular functions and contribute to communication between cells in the cardiac microenvironment and between the heart and other organs. As such, ncRNAs are candidates for translation into clinical practice. However, ncRNA biology has not yet been completely deciphered, given that classes and modes of action have emerged only in the past 5 years. In this Review, we discuss the latest discoveries from basic research on ncRNAs and highlight both the clinical value and the challenges underscoring the translation of these molecules as biomarkers and therapeutic regulators of the processes contributing to the initiation, progression and potentially the prevention or resolution of ischaemic heart disease and heart failure.

Therapeutic Potential of Natural Compounds Acting through Epigenetic Mechanisms in Cardiovascular Diseases: Current Findings and Future Directions

Cardiovascular diseases (CVDs) remain a leading global cause of morbidity and mortality. These diseases have a multifaceted nature being influenced by a multitude of biochemical, genetic, environmental, and behavioral factors. Epigenetic modifications have a crucial role in the onset and progression of CVD. Epigenetics, which regulates gene activity without altering the DNA's primary structure, can modulate cardiovascular homeostasis through DNA methylation, histone modification, and non-coding RNA regulation. The effects of environmental stimuli on CVD are mediated by epigenetic changes, which can be reversible and, hence, are susceptible to pharmacological interventions. This represents an opportunity to prevent diseases by targeting harmful epigenetic modifications. Factors such as high-fat diets or nutrient deficiencies can influence epigenetic enzymes, affecting fetal growth, metabolism, oxidative stress, inflammation, and atherosclerosis. Recent studies have shown that plant-derived bioactive compounds can modulate epigenetic regulators and inflammatory responses, contributing to the cardioprotective effects of diets. Understanding these nutriepigenetic effects and their reversibility is crucial for developing effective interventions to combat CVD. This review delves into the general mechanisms of epigenetics, its regulatory roles in CVD, and the potential of epigenetics as a CVD therapeutic strategy. It also examines the role of epigenetic natural compounds (ENCs) in CVD and their potential as intervention tools for prevention and therapy.

LncRNAs as potential prognosis/diagnosis markers and factors driving drug resistance of osteosarcoma, a review

Osteosarcoma is a common malignancy that often occurs in children, teenagers and young adults. Although the treatment strategy has improved, the results are still poor for most patients with metastatic or recurrent osteosarcomas. Therefore, it is necessary to identify new and effective prognostic biomarkers and therapeutic targets for diseases. Human genomes contain lncRNAs, transcripts with limited or insufficient capacity to encode proteins. They have been implicated in tumorigenesis, particularly regarding the onset, advancement, resistance to treatment, recurrence and remote dissemination of malignancies. Aberrant lncRNA expression in osteosarcomas has been reported by numerous researchers; lncRNAs have the potential to exhibit either oncogenic or tumor-suppressing behaviors and thus, to govern the advancement of this skeletal cancer. They are suspected to influence osteosarcoma cell growth, replication, invasion, migration, remote dissemination and programmed cell death. Additionally, they have been recognized as clinical markers, and may participate in the development of multidrug resistance. Therefore, the study of lncRNAs in the growth, metastasis, treatment and prognosis of osteosarcoma is very important for the active prevention and treatment of osteosarcoma. Consequently, this work reviews the functions of lncRNAs.

Small nucleolar RNA host gene 18 controls vascular smooth muscle cell contractile phenotype and neointimal hyperplasia

AIMS

Long non-coding RNA (LncRNA) small nucleolar RNA host gene 18 (SNHG18) has been widely implicated in cancers. However, little is known about its functional involvement in vascular diseases. Herein, we attempted to explore a role for SNHG18 in modulating vascular smooth muscle cell (VSMC) contractile phenotype and injury-induced neointima formation.

METHODS AND RESULTS

Analysis of single-cell RNA sequencing and transcriptomic datasets showed decreased levels of SNHG18 in injured and atherosclerotic murine and human arteries, which is positively associated with VSMC contractile genes. SNHG18 was upregulated in VSMCs by TGFβ1 through transcription factors Sp1 and SMAD3. SNHG18 gene gain/loss-of-function studies revealed that VSMC contractile phenotype was positively regulated by SNHG18. Mechanistic studies showed that SNHG18 promotes a contractile VSMC phenotype by up-regulating miR-22-3p. SNHG18 up-regulates miR-22 biogenesis and miR-22-3p production by competitive binding with the A-to-I RNA editing enzyme, adenosine deaminase acting on RNA-2 (ADAR2). Surprisingly, we observed that ADAR2 inhibited miR-22 biogenesis not through increasing A-to-I editing within primary miR-22, but by interfering with the binding of microprocessor complex subunit DGCR8 to primary miR-22. Importantly, perivascular SNHG18 overexpression in the injured vessels dramatically up-regulated the expression levels of miR-22-3p and VSMC contractile genes, and prevented injury-induced neointimal hyperplasia. Such modulatory effects were reverted by miR-22-3p inhibition in the injured arteries. Finally, we observed a similar regulator role for SNHG18 in human VSMCs and a decreased expression level of both SNHG18 and miR-22-3p in diseased human arteries; and we found that the expression level of SNHG18 was positively associated with that of miR-22-3p in both healthy and diseased human arteries.

CONCLUSION

We demonstrate that SNHG18 is a novel regulator in governing VSMC contractile phenotype and preventing injury-induced neointimal hyperplasia. Our findings have important implications for therapeutic targeting snhg18/miR-22-3p signalling in vascular diseases.

Nuclear Control of Vascular Smooth Muscle Cell Plasticity during Vascular Remodeling

Control of vascular smooth muscle cell (SMC) gene expression is an essential process for establishing and maintaining lineage identity, contractility, and plasticity. Most mechanisms (epigenetic, transcriptional, and post-transcriptional) implicated in gene regulation occur in the nucleus. Still, intranuclear pathways are directly impacted by modifications in the extracellular environment in conditions of adaptive or maladaptive remodeling. Integration of extracellular, cellular, and genomic information into the nucleus through epigenetic and transcriptional control of genome organization plays a major role in regulating SMC functions and phenotypic transitions during vascular remodeling and diseases. This review aims to provide a comprehensive update on nuclear mechanisms, their interactions, and their integration in controlling SMC homeostasis and dysfunction. It summarizes and discusses the main nuclear mechanisms preponderant in SMCs in the context of vascular disease, such as atherosclerosis, with an emphasis on studies employing in vivo cell-specific loss-of-function and single-cell omics approaches.

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.

Long noncoding RNA TUG1 regulates smooth muscle cell differentiation via KLF4-myocardin axis

Abdominal aortic aneurysms (AAAs) are asymptomatic vascular diseases that have life-threatening outcomes. Smooth muscle cell (SMC) dysfunction plays an important role in AAA development. The contribution of non-coding genome, specifically the role of long non-coding RNAs (lncRNAs) in SMC dysfunction, is relatively unexplored. We investigated the role of lncRNA TUG1 in SMC dysfunction. To identify potential lncRNAs relevant to SMC functionality, lncRNA profiling was performed in angiotensin-II-treated SMCs. AAA was induced by angiotensin-II treatment in mice. Transcriptional regulation of TUG1 was studied using promoter luciferase and chromatin-immuno-precipitation experiments. Gain-or-loss-of-function experiments were performed in vitro to investigate TUG1-mediated regulation of SMC function. Immunoprecipitation experiments were conducted to elucidate the mechanism underlying TUG1-mediated SMC dysfunction. TUG1 was upregulated in SMCs following angiotensin-II treatment. Similarly, TUG1 levels were elevated in abdominal aorta in a mouse model of angiotensin-II-induced AAA. Further investigations showed that angiotensin-II-induced TUG1 expression could be suppressed by inhibiting Notch-signaling pathway, both in vitro and in mouse AAA model and that TUG1 is a direct transcriptional target of the Notch pathway. In aneurysmal tissues, TUG1 expression was inversely correlated with the expression of SMC contractile genes. Overexpression of TUG1 repressed SMC differentiation in vitro, whereas siRNA/shRNA-mediated TUG1 knockdown showed an opposite effect. Mechanistically, TUG1 interacts with transcriptional repressor KLF4 and facilitates its recruitment to myocardin promoter ultimately leading to the repression of SMC differentiation. In summary, our study uncovers a novel role for the lncRNA TUG1 wherein it modulates SMC differentiation via the KLF4-myocardin axis, which may have potential implications in AAA development.NEW & NOTEWORTHY TUG1 is an angiotensin-II-induced long noncoding RNA that mediates smooth muscle cell (SMC) dysfunction through interaction with transcriptional repressor KLF4.

Vascular smooth muscle cells enhance immune/vascular interplay in a 3-cell model of vascular inflammation

Atherosclerosis is a serious cardiovascular disease that is characterised by the development of atheroma, which are lipid-laden plaques that build up within arterial walls due to chronic inflammatory processes. These lesions are fundamentally attributed to a complex cellular crosstalk between vascular smooth muscle cells (VSMCs), vascular endothelial cells (VECs) and central immune cells, such as macrophages (Mɸs), which promote vascular inflammation. The presence of VSMCs exerts both positive and negative effects during atheroma development, which can be attributed to their phenotypic plasticity. Understanding the interactions between these key cell types during the development of vascular inflammation and atheroma will enhance the scope for new therapeutic interventions. This study aims to determine the importance of VSMCs for shaping the extracellular cytokine/chemokine profile and transcriptional responses of VECs (human coronary artery endothelial cells; HCAECs) to activated lipopolysaccharide (LPS)-stimulated THP1 Mɸs, in a 3-cell model of human vascular inflammation. It is evident that within the presence of VSMCs, enhanced cytokine production was associated with up-regulation of genes associated with vascular inflammation t. Results demonstrate that the presence of VSMCs in co-culture experiments enhanced cytokine production (including CXCL1/GROα, IL-6, IL-8 and CCL2/MCP1) and inflammatory gene expression (including genes involved in JAK/STAT, Jun and NFκB signalling) in HCAECs co-cultured with LPS-stimulated THP1 Mɸs. Our results highlight the importance of VSMCs in immune/endothelial cell interplay and indicate that 3-cell, rather than 2-cell co-culture, may be more appropriate for the study of cellular crosstalk between immune and vascular compartments in response to inflammatory and atherogenic stimuli.

Probing the links: Long non-coding RNAs and NF-κB signalling in atherosclerosis

Atherosclerosis is a chronic inflammatory disease that involves the accumulation of lipids and immune cells in the arterial wall. NF-kB signaling is a key regulator of inflammation and is known to play a critical role in atherosclerosis. Recent studies have shown that lncRNAs can regulate NF-kB and contribute to the development and progression of atherosclerosis. Preliminary findings reveal significant alterations in the expression of specific lncRNAs in atherosclerotic lesions compared to healthy arterial tissue. Experimental evidence suggests that these dysregulated lncRNAs can influence the NF-kB pathway. By unravelling the crosstalk between lncRNAs and NF-kB signaling, this review aims to enhance our understanding of the molecular mechanisms underlying atherosclerosis. Identifying novel therapeutic targets and diagnostic markers may lead to developing interventions and management strategies for this prevalent cardiovascular disease. This review summarizes the current knowledge on the role of lncRNAs in NF-kB signaling in atherosclerosis and highlights their potential as therapeutic targets for this disease.

INKILN is a Novel Long Noncoding RNA Promoting Vascular Smooth Muscle Inflammation via Scaffolding MKL1 and USP10

BACKGROUND

Activation of vascular smooth muscle cell (VSMC) inflammation is vital to initiate vascular disease. The role of human-specific long noncoding RNAs in VSMC inflammation is poorly understood.

METHODS

Bulk RNA sequencing in differentiated human VSMCs revealed a novel human-specific long noncoding RNA called inflammatory MKL1 (megakaryoblastic leukemia 1) interacting long noncoding RNA (INKILN). INKILN expression was assessed in multiple in vitro and ex vivo models of VSMC phenotypic modulation as well as human atherosclerosis and abdominal aortic aneurysm. The transcriptional regulation of INKILN was verified through luciferase reporter and chromatin immunoprecipitation assays. Loss-of-function and gain-of-function studies and multiple RNA-protein and protein-protein interaction assays were used to uncover a mechanistic role of INKILN in the VSMC proinflammatory gene program. Bacterial artificial chromosome transgenic mice were used to study INKILN expression and function in ligation injury-induced neointimal formation.

RESULTS

INKILN expression is downregulated in contractile VSMCs and induced in human atherosclerosis and abdominal aortic aneurysm. INKILN is transcriptionally activated by the p65 pathway, partially through a predicted NF-κB (nuclear factor kappa B) site within its proximal promoter. INKILN activates proinflammatory gene expression in cultured human VSMCs and ex vivo cultured vessels. INKILN physically interacts with and stabilizes MKL1, a key activator of VSMC inflammation through the p65/NF-κB pathway. INKILN depletion blocks interleukin-1β-induced nuclear localization of both p65 and MKL1. Knockdown of INKILN abolishes the physical interaction between p65 and MKL1 and the luciferase activity of an NF-κB reporter. Furthermore, INKILN knockdown enhances MKL1 ubiquitination through reduced physical interaction with the deubiquitinating enzyme USP10 (ubiquitin-specific peptidase 10). INKILN is induced in injured carotid arteries and exacerbates ligation injury-induced neointimal formation in bacterial artificial chromosome transgenic mice.

CONCLUSIONS

These findings elucidate an important pathway of VSMC inflammation involving an INKILN/MKL1/USP10 regulatory axis. Human bacterial artificial chromosome transgenic mice offer a novel and physiologically relevant approach for investigating human-specific long noncoding RNAs under vascular disease conditions.

A transposable element into the human long noncoding RNA CARMEN is a switch for cardiac precursor cell specification

AIMS

The major cardiac cell types composing the adult heart arise from common multipotent precursor cells. Cardiac lineage decisions are guided by extrinsic and cell-autonomous factors, including recently discovered long noncoding RNAs (lncRNAs). The human lncRNA CARMEN, which is known to dictate specification toward the cardiomyocyte (CM) and the smooth muscle cell (SMC) fates, generates a diversity of alternatively spliced isoforms.

METHODS AND RESULTS

The CARMEN locus can be manipulated to direct human primary cardiac precursor cells (CPCs) into specific cardiovascular fates. Investigating CARMEN isoform usage in differentiating CPCs represents therefore a unique opportunity to uncover isoform-specific functions in lncRNAs. Here, we identify one CARMEN isoform, CARMEN-201, to be crucial for SMC commitment. CARMEN-201 activity is encoded within an alternatively spliced exon containing a MIRc short interspersed nuclear element. This element binds the transcriptional repressor REST (RE1 Silencing Transcription Factor), targets it to cardiogenic loci, including ISL1, IRX1, IRX5, and SFRP1, and thereby blocks the CM gene program. In turn, genes regulating SMC differentiation are induced.

CONCLUSIONS

These data show how a critical physiological switch is wired by alternative splicing and functional transposable elements in a long noncoding RNA. They further demonstrated the crucial importance of the lncRNA isoform CARMEN-201 in SMC specification during heart development.

Long non-coding RNAs: The growth controller of vascular smooth muscle cells in cardiovascular diseases

The active proliferation and migration of vascular smooth muscle cells supports the healing of vessel damage while their abnormal aggression or destitution contribute to the aberrant intima-medial structure and function in various cardiovascular diseases, so the understanding of the proliferation disorders of vascular smooth muscle cell and the related mechanism is the basis of effective intervention and control for cardiovascular diseases. Recently, long non-coding RNAs have stood out as upstream switchers for multiple proliferative signaling pathways and molecules, and many of them have been shown to conduce to the dysregulated proliferation and apoptosis of vascular smooth muscle cells under various pathogenic stimuli. This article discusses the long non-coding RNAs disclosed and linked to atherosclerosis, pulmonary hypertension, and aneurysms, and focuses upon their modulation of vascular smooth muscle cell population affecting three deadly cardiovascular diseases.

Discovery of Transacting Long Noncoding RNAs That Regulate Smooth Muscle Cell Phenotype

BACKGROUND

Smooth muscle cells (SMC), the major cell type in atherosclerotic plaques, are vital in coronary artery diseases (CADs). SMC phenotypic transition, which leads to the formation of various cell types in atherosclerotic plaques, is regulated by a network of genetic and epigenetic mechanisms and governs the risk of disease. The involvement of long noncoding RNAs (lncRNAs) has been increasingly identified in cardiovascular disease. However, SMC lncRNAs have not been comprehensively characterized, and their regulatory role in SMC state transition remains unknown.

METHODS

A discovery pipeline was constructed and applied to deeply strand-specific RNA sequencing from perturbed human coronary artery SMC with different disease-related stimuli, to allow for the detection of novel lncRNAs. The functional relevance of a select few novel lncRNAs were verified in vitro.

RESULTS

We identified 4579 known and 13 655 de novo lncRNAs in human coronary artery SMC. Consistent with previous long noncoding RNA studies, these lncRNAs overall have fewer exons, are shorter in length than protein-coding genes (pcGenes), and have relatively low expression level. Genomic location of these long noncoding RNA is disproportionately enriched near CAD-related TFs (transcription factors), genetic loci, and gene regulators of SMC identity, suggesting the importance of their function in disease. Two de novo lncRNAs, ZIPPOR (ZEB-interacting suppressor) and TNS1-AS2 (TNS1-antisense 2), were identified by our screen. Combining transcriptional data and in silico modeling along with in vitro validation, we identified CAD gene ZEB2 as a target through which these lncRNAs exert their function in SMC phenotypic transition.

CONCLUSIONS

Expression of a large and diverse set of lncRNAs in human coronary artery SMC are highly dynamic in response to CAD-related stimuli. The dynamic changes in expression of these lncRNAs correspond to alterations in transcriptional programs that are relevant to CAD, suggesting a critical role for lncRNAs in SMC phenotypic transition and human atherosclerotic disease.

Influence of FOSL1 Inhibition on Vascular Calcification and ROS Generation through Ferroptosis via P53-SLC7A11 Axis

BACKGROUND

Vascular calcification during aging is highly prevalent in patients with cardiovascular disease; however, there is still no improvement in clarifying the development of vascular calcification. FOSL1 is a transcription regulator belonging to the AP-1 family, which has a unique function in vascular senescence, but its role in vascular calcification needs to be further explored.

METHODS

Primary mouse vascular smooth muscle cells were isolated and used to construct a calcification model in vitro. Seven-week-old male C57BL/6 mice were used to build the vitD3-induced calcification model in vivo. qRT-PCR and western blot were used to verify the expression of FOSL1 and other genes expressed in vascular smooth muscle cells and aortas. The level of calcification was determined by Alizarin Red S (ARS) staining and the calcium content assay. The level of cellular GSH was detected by the GSH assay kit.

RESULTS

Here, we report that FOSL1 was up-regulated after high-calcium/phosphate treatment in both the in vivo and in vitro vascular calcification models. Functional studies have shown that the reduction of FOSL1 attenuates ferroptosis and calcification in vascular smooth muscle cells, as indicated by ARS staining, calcium content assay, and western blot. The inhibition of FOSL1 downregulated the expression of bone-related molecules including Msh Homeobox 2 (MSX2) and tumor necrosis factor receptor superfamily, member 11b/osteoprotegerin (OPG), suggesting that FOSL1 promoted osteogenic differentiation of vascular smooth muscle cells. Furthermore, we found that the ferroptosis-inducing drug erastin can significantly accelerate calcification in the aortic ring while Ferrostatin-1 (fer-1), a drug to protect cells from ferroptosis, can alleviate calcification. Further experiments have shown that inhibiting FOSL1 can promote the expression of ferroptosis-related genes and attenuate calcification. Functionally, cellular GSH levels were increased after the reduction of FOSL1.

CONCLUSIONS

In this study, we observed a significant protective effect when we reduced the expression of FOSL1 during vascular calcification, and this effect might regulate ferroptosis to a great extent.

Circulatory long noncoding RNAs (circulatory-LNC-RNAs) as novel biomarkers and therapeutic targets in cardiovascular diseases: Implications for cardiovascular diseases complications

Cardiovascular diseases (CVDs) are a group of disorders with major global health consequences. The prevalence of CVDs continues to grow due to population-aging and lifestyle modifications. Non-coding RNAs (ncRNAs) as key regulators of cell signaling pathways have gained attention in the occurrence and development of CVDs. Exosomal-lncRNAs (exos-lncRNAs) are emerging biomarkers due to their high sensitivity and specificity, stability, accuracy and accessibility in the biological fluids. Recently, circulatory and exos-based-lncRNAs are emerging and novel bio-tools in various pathogenic conditions. It is worth mentioning that dysregulation of these molecules has been found in different types of CVDs. In this regard, we aimed to discuss the knowledge gaps and suggest research priorities regarding circulatory and exos-lncRNAs as novel bio-tools and therapeutic targets for CVDs.

INKILN is a novel long noncoding RNA promoting vascular smooth muscle inflammation via scaffolding MKL1 and USP10

Background

Activation of vascular smooth muscle cells (VSMCs) inflammation is vital to initiate vascular disease. However, the role of human-specific long noncoding RNAs (lncRNAs) in VSMC inflammation is poorly understood.

Methods

Bulk RNA-seq in differentiated human VSMCs revealed a novel human-specific lncRNA called IN flammatory M K L1 I nteracting L ong N oncoding RNA ( INKILN ). INKILN expression was assessed in multiple in vitro and ex vivo models of VSMC phenotypic modulation and human atherosclerosis and abdominal aortic aneurysm (AAA) samples. The transcriptional regulation of INKILN was determined through luciferase reporter system and chromatin immunoprecipitation assay. Both loss- and gain-of-function approaches and multiple RNA-protein and protein-protein interaction assays were utilized to uncover the role of INKILN in VSMC proinflammatory gene program and underlying mechanisms. Bacterial Artificial Chromosome (BAC) transgenic (Tg) mice were utilized to study INKLIN expression and function in ligation injury-induced neointimal formation.

Results

INKILN expression is downregulated in contractile VSMCs and induced by human atherosclerosis and abdominal aortic aneurysm. INKILN is transcriptionally activated by the p65 pathway, partially through a predicted NF-κB site within its proximal promoter. INKILN activates the proinflammatory gene expression in cultured human VSMCs and ex vivo cultured vessels. Mechanistically, INKILN physically interacts with and stabilizes MKL1, a key activator of VSMC inflammation through the p65/NF-κB pathway. INKILN depletion blocks ILIβ-induced nuclear localization of both p65 and MKL1. Knockdown of INKILN abolishes the physical interaction between p65 and MKL1, and the luciferase activity of an NF-κB reporter. Further, INKILN knockdown enhances MKL1 ubiquitination, likely through the reduced physical interaction with the deubiquitinating enzyme, USP10. INKILN is induced in injured carotid arteries and exacerbates ligation injury-induced neointimal formation in BAC Tg mice.

Conclusions

These findings elucidate an important pathway of VSMC inflammation involving an INKILN /MKL1/USP10 regulatory axis. Human BAC Tg mice offer a novel and physiologically relevant approach for investigating human-specific lncRNAs under vascular disease conditions.

Noncoding RNAs in Vascular Cell Biology and Restenosis

In-stent restenosis (ISR), characterised by ≥50% re-narrowing of the target vessel, is a common complication following stent implantation and remains a significant challenge to the long-term success of angioplasty procedures. Considering the global burden of cardiovascular diseases, improving angioplasty patient outcomes remains a key priority. Noncoding RNAs (ncRNAs) including microRNA (miRNA), long noncoding RNA (lncRNA) and circular RNA (circRNA) have been extensively implicated in vascular cell biology and ISR through multiple, both distinct and overlapping, mechanisms. Vascular smooth muscle cells, endothelial cells and macrophages constitute the main cell types involved in the multifactorial pathophysiology of ISR. The identification of critical regulators exemplified by ncRNAs in all these cell types and processes makes them an exciting therapeutic target in the field of restenosis. In this review, we will comprehensively explore the potential functions and underlying molecular mechanisms of ncRNAs in vascular cell biology in the context of restenosis, with an in-depth focus on vascular cell dysfunction during restenosis development and progression. We will also discuss the diagnostic biomarker and therapeutic target potential of ncRNAs in ISR. Finally, we will discuss the current shortcomings, challenges, and perspectives toward the clinical application of ncRNAs.

Long non-coding RNAs at the crossroad of vascular smooth muscle cell phenotypic modulation in atherosclerosis and neointimal formation

Despite extraordinary advances in the comprehension of the pathophysiology of atherosclerosis and the employment of very effective treatments, cardiovascular diseases are still a major cause of mortality and represent a large share of health expenditure worldwide. Atherosclerosis is a disease affecting the medium and large arteries, which consists of a progressive accumulation of fatty substances, cellular waste products and fibrous elements, which culminates in the buildup of a plaque obstructing the blood flow. Endothelial dysfunction represents an early pathological event, favoring immune cells recruitment and triggering local inflammation. The release of inflammatory cytokines and other signaling molecules stimulates phenotypic modifications in the underlying vascular smooth muscle cells, which, in physiological conditions, are responsible for the maintenance of vessels architecture while regulating vascular tone. Vascular smooth muscle cells are highly plastic and may respond to disease stimuli by de-differentiating and losing their contractility, while increasing their synthetic, proliferative, and migratory capacity. This phenotypic switching is considered a pathological hallmark of atherogenesis and is ruled by the activation of selective gene programs. The advent of genomics and the improvement of sequencing technologies deepened our knowledge of the complex gene expression regulatory networks mediated by non-coding RNAs, and favored the rise of innovative therapeutic approaches targeting the non-coding transcriptome. In the context of atherosclerosis, long non-coding RNAs have received increasing attention as potential translational targets, due to their contribution to the molecular dynamics modulating the expression of vascular smooth muscle cells contractile/synthetic gene programs. In this review, we will focus on the most well-characterized long non-coding RNAs contributing to atherosclerosis by controlling expression of the contractile apparatus and genes activated in perturbed vascular smooth muscle cells.

Downregulation of Long Noncoding RNA Myocardial Infarction Associated Transcript Suppresses Cell Proliferation, Migration, Invasion, and Glycolysis by Regulation of miR-488-3p/IGF1R Pathway in Colorectal Cancer

Background: Colorectal cancer (CRC) is a significant public problem and the third cause of cancer-induced death all over the world. Long noncoding RNA (lncRNA) has been reported as a vital mediator in human cancer. However, the precise role of lncRNA myocardial infarction associated transcript (MIAT) in CRC is unclear. Materials and Methods: The abundance of MIAT, miR-488-3p, and the type 1 insulin-like growth factor receptor (IGF1R) was measured by real-time quantitative polymerase chain reaction assay. Western blot assay was carried out to assess the protein level in CRC samples or control group. The cell activity, abilities of migration and invasion, and glycolysis were evaluated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazol-3-ium bromide (MTT), transwell, and testing glucose consumption and lactate product, correspondingly. The target association between miR-488-3p, MIAT, or IGF1R was predicted and established by bioinformatics tools, dual-luciferase reporter, and RNA pull-down assays, correspondingly. The effects of MIAT silencing in vivo were analyzed by animal experiments. Results: LncRNA MIAT was upregulated in CRC sample and that was positively correlated with IGF1R expression. Loss-of-functional assay suggested that knockdown of MIAT impeded cell activity, migration, invasion, and glycolysis of CRC cells in vivo, along with xenograft growth in vivo. Moreover, silencing of IGF1R inhibited the progression of CRC. Therefore, overexpression of IGF1R could abolish silencing of MIAT-induced effects on CRC cells. Mechanistically, MIAT was a sponge for miR-488-3p, thereby regulating IGF1R expression in CRC. Conclusion: The present study confirmed that the "MIAT/miR-488-3p/IGF1R" pathway was involved in the development of CRC, which may be the target for developing therapeutic approaches for CRC.

The role of long non-coding RNA ANRIL in the development of atherosclerosis

Atherosclerosis is an important pathological basis of coronary heart disease, and the antisense non-coding RNA in the INK4 locus (ANRIL) is located in the genetically susceptible segment with the strongest correlation with it - the short arm 2 region 1 of chromosome 9 (Chr9p21). ANRIL can produce linear, circular and other transcripts through different transcriptional splicing methods, which can regulate the proliferation and apoptosis of related cells and closely related to the development of atherosclerotic plaques. Linear ANRIL can regulate proliferation of vascular smooth muscle cells (VSMCs) in plaques by chromatin modification, as well as affecting on proliferation and the apoptosis of macrophages at the transcriptional level; circular ANRIL can affect on proliferation and apoptosis of VSMCs by chromatin modification as well as interfering with rRNA maturation. In this review we describe the evolutionary characteristics of ANRIL, the formation and structure of transcripts, and the mechanism by which each transcript regulates the proliferation and apoptosis of vascular cells and then participates in atherosclerosis.

An overview of long noncoding RNAs: Biology, functions, therapeutics, analysis methods, and bioinformatics tools

Long noncoding RNAs (lncRNAs) are a diverse class of RNAs whose functions are widespread in all branches of life and have been the focus of attention in the last decade. While a huge number of lncRNAs have been identified, there is still much work to be done and plenty to be learned. In the current review, we begin with the biogenesis and function of lncRNAs as they are involved in the different cellular processes from regulating the architecture of chromosomes to controlling translation and post-translation modifications. Questions on how overexpression, mutations, or deficiency of lncRNAs can affect the cellular status and result in the pathogenesis of various human diseases are responded to. Besides, we allocate an overview of several studies, concerning the application of lncRNAs either as diagnostic and prognostic biomarkers or novel therapeutics. We also introduce the currently available techniques to explore details of lncRNAs such as their function, cellular localization, and structure. In the last section, as exponentially growing data in this area need to be gathered and organized in comprehensive databases, we have a particular focus on presenting general and specialized databases. Taken together, with this review, we aim to provide the latest information on different aspects of lncRNAs to highlight their importance in physiopathologic states and take a step towards helping future studies.

Tribulus terrestris L. extract ameliorates atherosclerosis by inhibition of vascular smooth muscle cell proliferation in ApoE-/- mice and A7r5 cells via suppression of Akt/MEK/ERK signaling

ETHNOPHARMACOLOGICAL RELEVANCE

Atherosclerosis (AS) is one of major threatens of death worldwide, and vascular smooth muscle cell (VSMC) proliferation is an important characteristic in the progression of AS. Tribulus terrestris L. is a well-known Chinese Materia Medica for treating skin pruritus, vertigo and cardiovascular diseases in traditional Chinese medicine. However, its anti-AS activity and inhibition effect on VSMC proliferation are not fully elucidated.

AIMS

We hypothesize that the furostanol saponins enriched extract (FSEE) of T. terrestris L. presents anti-AS effect by inhibition of VSMC proliferation. The molecular action mechanism underlying the anti-VSMC proliferation effect of FSEE is also investigated.

MATERIALS AND METHODS

Apolipoprotein-E deficient (ApoE^-/-) mice and rat thoracic smooth muscle cell A7r5 were employed as the in vivo and in vitro models respectively to evaluate the anti- AS and VSMC proliferation effects of FSEE. In ApoE^-/- mice, the amounts of total cholesterol, triglyceride, low density lipoprotein and high density lipoprotein in serum were measured by commercially available kits. The size of atherosclerotic plaque was observed by hematoxylin & eosin staining. The protein expressions of α-smooth muscle actin (α-SMA) and osteopontin (OPN) in the plaque were examined by immunohistochemistry. In A7r5 cells, the cell viability and proliferation were tested by MTT and Real Time Cell Analysis assays. The cell migration was evaluated by wound healing assay. Propidium iodide staining followed by flow cytometry was used to analyze the cell cycle progression. The expression of intracellular total and phosphorylated proteins including protein kinase B (Akt) and mitogen-activated protein kinases (MAPKs), such as mitogen-activated extracellular signal-regulated kinase (MEK), extracellular signal-regulated kinase (ERK) and c-Jun N-terminal kinase (JNK), were detected by western blotting analysis.

RESULTS

FSEE significantly reduced the area of atherosclerotic plaque in high-fat diet-fed ApoE^-/- mice. And FSEE increased the protein expression level of α-SMA and decreased the level of OPN in atherosclerotic plaque, which revealed the inhibition of VSMC phenotype switching and proliferation. In A7r5 cells, FSEE suppressed fetal bovine serum (FBS) or oxidized low density lipoprotein (oxLDL)-triggered VSMC proliferation and migration in a concentration dependent manner. FSEE protected against the elevation of cell numbers in S phase induced by FBS or oxLDL and the reduction of cell numbers in G₀/G₁ phase induced by oxLDL. Moreover, the phosphorylation of Akt and MAPKs including MEK, ERK and JNK could be facilitated by FBS or oxLDL, while co-treatment of FSEE attenuated the phosphorylation of Akt induced by oxLDL as well as the phosphorylation of MEK and ERK induced by FBS. In addition, (25R)-terrestrinin B (JL-6), which was the main ingredient of FSEE, and its potential active pharmaceutical ingredients tigogenin (Tigo) and hecogenin (Heco) also significantly attenuated FBS or oxLDL-induced VSMC proliferation in A7r5 cells.

CONCLUSION

FSEE presents potent anti- AS and VSMC proliferation activities and the underlying mechanism is likely to the suppression of Akt/MEK/ERK signaling. The active components of FSEE are JL-6 and its potential active pharmaceutical ingredients Tigo and Heco. So, FSEE and its active compounds may be potential therapeutic drug candidates for AS.

Identifying Candidate Circulating RNA Markers for Coronary Artery Disease by Deep RNA-Sequencing in Human Plasma

Advances in RNA sequencing (RNA-Seq) have facilitated transcriptomic analysis of plasma for the discovery of new diagnostic and prognostic markers for disease. We aimed to develop a short-read RNA-Seq protocol to detect mRNAs, long non-coding RNAs (lncRNAs) and circular RNAs (circRNAs) in plasma for the discovery of novel markers for coronary artery disease (CAD) and heart failure (HF). Circulating cell-free RNA from 59 patients with stable CAD (half of whom developed HF within 3 years) and 30 controls was sequenced to a median depth of 108 paired reads per sample. We identified fragments from 3986 messenger RNAs (mRNAs), 164 long non-coding RNAs (lncRNAs), 405 putative novel lncRNAs and 227 circular RNAs in plasma. Circulating levels of 160 mRNAs, 10 lncRNAs and 2 putative novel lncRNAs were altered in patients compared with controls (absolute fold change >1.2, p < 0.01 adjusted for multiple comparisons). The most differentially abundant transcripts were enriched in mRNAs encoded by the mitochondrial genome. We did not detect any differences in the plasma RNA profile between patients who developed HF compared with those who did not. In summary, we show that mRNAs, lncRNAs and circular RNAs can be reliably detected in plasma by deep RNA-Seq. Multiple coding and non-coding transcripts were altered in association with CAD, including several mitochondrial mRNAs, which may indicate underlying myocardial ischaemia and oxidative stress. If validated, circulating levels of these transcripts could potentially be used to help identify asymptomatic individuals with established CAD prior to an acute coronary event.

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.

Buffalo long non-coding RNA gene11007 promotes myoblasts proliferation

Buffalo meat is of good quality because it is lean and tender, and could bring significant cardiovascular benefits. The underlying difference in muscle development and meat quality is a complex and precisely orchestrated process which has been demonstrated to be regulated by long non-coding RNAs (lncRNAs). However, the regulatory role of lncRNAs in the growth and development of buffalo skeletal muscle is still unclear. In this study, the Ribo-Zero RNA-Seq method was used to explore the lncRNA expression profiles of buffalo myoblasts during the proliferation and differentiation phases. A specific set of 9,978 lncRNAs was found. By comparing the expression profiles of lncRNAs, it was found that there were 1,576 differentially expressed lncRNAs (DELs) during buffalo myoblast differentiation. Twelve DELs were chosen and subsequently verified in eight different buffalo tissues during fetal and adult stages by using qPCR. Gene11007 was found to be one of the most down-regulated lncRNAs during buffalo myoblasts differentiation and it was subsequently characterized. EdU, CCK-8, qPCR and western blotting assays showed that gene11007 promoted the proliferation of buffalo myoblasts but it had no effect on cell differentiation. Our research may enrich the genome annotations of buffalo and provide a new molecular target for the in-depth understanding of the regulation of lncRNAs in skeletal muscle.

Decoding microRNA drivers in Atherosclerosis

An estimated 97% of the human genome consists of non-protein-coding sequences. As our understanding of genome regulation improves, this has led to the characterization of a diverse array of non-coding RNAs (ncRNA). Among these, micro-RNAs (miRNAs) belong to the short ncRNA class (22–25 nucleotides in length), with approximately 2500 miRNA genes encoded within the human genome. From a therapeutic perspective, there is interest in exploiting miRNA as biomarkers of disease progression and response to treatments, as well as miRNA mimics/repressors as novel medicines. miRNA have emerged as an important class of RNA master regulators with important roles identified in the pathogenesis of atherosclerotic cardiovascular disease. Atherosclerosis is characterized by a chronic inflammatory build-up, driven largely by low-density lipoprotein cholesterol accumulation within the artery wall and vascular injury, including endothelial dysfunction, leukocyte recruitment and vascular remodelling. Conventional therapy focuses on lifestyle interventions, blood pressure-lowering medications, high-intensity statin therapy and antiplatelet agents. However, a significant proportion of patients remain at increased risk of cardiovascular disease. This continued cardiovascular risk is referred to as residual risk. Hence, a new drug class targeting atherosclerosis could synergise with existing therapies to optimise outcomes. Here, we review our current understanding of the role of ncRNA, with a focus on miRNA, in the development and progression of atherosclerosis, highlighting novel biological mechanisms and therapeutic avenues.

Epigenetic regulation in cardiovascular disease: mechanisms and advances in clinical trials

Epigenetics is closely related to cardiovascular diseases. Genome-wide linkage and association analyses and candidate gene approaches illustrate the multigenic complexity of cardiovascular disease. Several epigenetic mechanisms, such as DNA methylation, histone modification, and noncoding RNA, which are of importance for cardiovascular disease development and regression. Targeting epigenetic key enzymes, especially the DNA methyltransferases, histone methyltransferases, histone acetylases, histone deacetylases and their regulated target genes, could represent an attractive new route for the diagnosis and treatment of cardiovascular diseases. Herein, we summarize the knowledge on epigenetic history and essential regulatory mechanisms in cardiovascular diseases. Furthermore, we discuss the preclinical studies and drugs that are targeted these epigenetic key enzymes for cardiovascular diseases therapy. Finally, we conclude the clinical trials that are going to target some of these processes.

Utilization and Potential of RNA-Based Therapies in Cardiovascular Disease

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RNA-based therapeutics have the potential to reach previously “undruggable” pathways in cardiovascular disease

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RNA-based therapeutics constitute a vast array of technologies, including unique forms, chemistries, and modalities of delivery

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Rapid development of RNA-based vaccines was made possible by decades of foundational work

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Specificity and efficacy of targeting and determination of mechanism(s) of action remain a distinct challenge

Cardiovascular disease (CVD) remains the largest cause of mortality worldwide. The development of new effective therapeutics is a major unmet need. The current review focuses broadly on the concept of nucleic acid (NA)–based therapies, considering the use of various forms of NAs, including mRNAs, miRNAs, siRNA, and guide RNAs, the latter specifically for the purpose of CRISPR-Cas directed gene editing. We describe the current state-of-the-art of RNA target discovery and development, the status of RNA therapeutics in the context of CVD, and some of the challenges and hurdles to be overcome.

Non-coding RNA-Associated Therapeutic Strategies in Atherosclerosis

Atherosclerosis has been the main cause of disability and mortality in the world, resulting in a heavy medical burden for all countries. It is widely known to be a kind of chronic inflammatory disease in the blood walls, of which the key pathogenesis is the accumulation of immunologic cells in the lesion, foam cells formation, and eventually plaque rupture causing ischemia of various organs. Non-coding RNAs (ncRNAs) play a vital role in regulating the physiologic and pathophysiologic processes in cells. More and more studies have revealed that ncRNAs also participated in the development of atherosclerosis and regulated cellular phenotypes such as endothelial dysfunction, leukocyte recruitment, foam cells formation, and vascular smooth muscle cells phenotype-switching and apoptosis. Given the broad functions of ncRNAs in atherogenesis, they have become potential therapeutic targets. Apart from that, ncRNAs have become powerful blueprints to design new drugs. For example, RNA interference drugs were inspired by small interfering RNAs that exist in normal cellular physiologic processes and behave as negative regulators of specific proteins. For instance, inclisiran is a kind of RNAi drug targeting PCKS9 mRNA, which can lower the level of LDL-C and treat atherosclerosis. We introduce some recent research progresses on ncRNAs related to atherosclerotic pathophysiologic process and the current clinical trials of RNA drugs pointed at atherosclerosis.

The natural antisense transcript HAS2-AS1 regulates breast cancer cells aggressiveness independently from hyaluronan metabolism

Hyaluronan (HA) is a ubiquitous extracellular matrix component playing a crucial role in the regulation of cell behaviors, including cancer. Aggressive breast cancer cells tend to proliferate, migrate and metastatize. Notably, triple-negative breast cancer cells lacking the expression of estrogen receptor (ER) as well as progesterone receptor and HER2 are more aggressive than ER-positive ones. As currently no targeted therapy is available for triple-negative breast cancer, the identification of novel therapeutic targets has a high clinical priority. In ER-negative cells, tumoral behavior can be reduced by inhibiting HA synthesis or silencing the enzymes involved in its metabolism, such as HA synthase 2 (HAS2). HAS2-AS1 is a long non-coding RNA belonging to the natural antisense transcript family which is known to favor HAS2 gene expression and HA synthesis, thus bolstering malignant progression in brain, ovary, and lung tumors. As the role of HAS2-AS1 has not yet been investigated in breast cancer, in this work we report that ER-positive breast cancers had lower HAS2-AS1 expression compared to ER-negative tumors. Moreover, the survival of patients with ER-negative tumors was higher when the expression of HAS2-AS1 was elevated. Experiments with ER-negative cell lines as MDA-MB-231 and Hs 578T revealed that the overexpression of either the full-length HAS2-AS1 or its exon 2 long or short isoforms alone, strongly reduced cell viability, migration, and invasion, whereas HAS2-AS1 silencing increased cell aggressiveness. Unexpectedly, in these ER-negative cell lines, HAS2-AS1 is involved neither in the regulation of HAS2 nor in HA deposition. Finally, transcriptome analysis revealed that HAS2-AS1 modulation affected several pathways, including apoptosis, proliferation, motility, adhesion, epithelial to mesenchymal transition, and signaling, describing this long non-coding RNA as an important regulator of breast cancer cells aggressiveness.

Pathophysiology of Atherosclerosis

Atherosclerosis is the main risk factor for cardiovascular disease (CVD), which is the leading cause of mortality worldwide. Atherosclerosis is initiated by endothelium activation and, followed by a cascade of events (accumulation of lipids, fibrous elements, and calcification), triggers the vessel narrowing and activation of inflammatory pathways. The resultant atheroma plaque, along with these processes, results in cardiovascular complications. This review focuses on the different stages of atherosclerosis development, ranging from endothelial dysfunction to plaque rupture. In addition, the post-transcriptional regulation and modulation of atheroma plaque by microRNAs and lncRNAs, the role of microbiota, and the importance of sex as a crucial risk factor in atherosclerosis are covered here in order to provide a global view of the disease.

LncRNAs and Cardiovascular Disease

A novel class of RNA molecule emerged from human transcriptome sequencing studies termed long non-coding RNAs. These RNA molecules differ from other classes of non-coding RNAs such as microRNAs in their sizes, sequence motifs and structures. Studies have demonstrated that long non-coding RNAs play a prominent role in the development and progression of cardiovascular disease. They provide the cell with tiered levels of gene regulation interacting with DNA, other RNA molecules or proteins acting in various capacities to control a variety of cellular mechanisms. Cell specificity is a hallmark of lncRNA studies and they have been identified in macrophages, smooth muscle cells, endothelial cells and hepatocytes. Recent lncRNA studies have uncovered functional micropeptides encoded within lncRNA genes that can have a different function to the lncRNA. Disease associated mutations in the genome tend to occur in non-coding regions signifying the importance of non-coding genes in disease associations. There is a great deal of work to be done in the non-coding RNA field and tremendous therapeutic potential due to their cell type specificity. A better understanding of the functions and interactions of lncRNAs will inevitably have clinical implications.

PDGF regulates guanylate cyclase expression and cGMP signaling in vascular smooth muscle

The nitric oxide-cGMP (NO-cGMP) pathway is of outstanding importance for vascular homeostasis and has multiple beneficial effects in vascular disease. Neointimal hyperplasia after vascular injury is caused by increased proliferation and migration of vascular smooth muscle cells (VSMCs). However, the role of NO-cGMP signaling in human VSMCs in this process is still not fully understood. Here, we investigate the interaction between platelet derived growth factor (PDGF)-signaling, one of the major contributors to neointimal hyperplasia, and the cGMP pathway in vascular smooth muscle, focusing on NO-sensitive soluble guanylyl cyclase (sGC). We show that PDGF reduces sGC expression by activating PI3K and Rac1, which in turn alters Notch ligand signaling. These data are corroborated by gene expression analysis in human atheromas, as well as immunohistological analysis of diseased and injured arteries. Collectively, our data identify the crosstalk between PDGF and NO/sGC signaling pathway in human VSMCs as a potential target to tackle neointimal hyperplasia.

PDGF reduces expression of nitric oxide-sensitive soluble guanylyl cyclase (NO-sGC) through PI3K-P-Rex1-Rac1 signaling in vascular smooth muscle cells. These insights provide possible avenues to prevent dysregulation of NO/cGMP signaling in vascular disease.

Curcumin improves atherosclerosis by inhibiting the epigenetic repression of lncRNA MIAT to miR-124

Objectives: Atherosclerosis is a dominant cardiovascular disease. Curcumin has protective effect on atherosclerosis. However, the mechanisms remain to be explored. Methods: Atherosclerosis was induced by feeding mice with high-fat diet (HFD) and ox-low-density lipoprotein (LDL)-induced human umbilical vein endothelial cells (HUVECs) were structured. Oil Red O staining was used to evaluate the plaques in the artery. Quantitative real-time PCR (qRT-PCR) was conducted to detect the level of myocardial infarction associated transcript (MIAT), miR-124, and enhancer of zeste homolog 2 (EZH2). We performed western blotting and enzyme linked immunosorbent assay to examine the expression of EZH2 and cytokines including IL-1β, TNFα, IL-6, and IL-8, respectively. RNA immunoprecipitation and chromatin immunoprecipitation (ChIP) were used to validate the interaction between myocardial infarction associated transcript and EZH2. Flow cytometry and CCK-8 assay were used to examine cell apoptosis and proliferation, respectively. Results: Curcumin suppressed inflammation in atherosclerosis mouse model and ox-LDL-induced cell model. MIAT overexpression and miR-124 inhibition relieved the anti-inflammation effect of curcumin in ox-LDL-induced cell. MIAT regulated miR-124 by interacting with EZH2. Curcumin relieved ox-LDL-induced cell inflammation via regulating MIAT/miR-124 pathway. Conclusion: MIAT/miR-124 axis mediated the effect of curcumin on atherosclerosis and altered cell apoptosis and proliferation, both in vivo and in vitro. These data further support the application of curcumin in control of atherosclerosis advancement.

Predictive value of using plasma long non-coding RNAs ANRIL and HOXA11-AS for in-stent restenosis

In-stent restenosis (ISR) can pose serious challenges for cardiologists following coronary stent implantation. Early identification of patients at high risk of ISR is considered to be effective for its prevention. However, factors that can reliably predict the risk of ISR remain elusive at present. The present study aimed to investigate the possible association between plasma long non-coding RNA (lncRNA) levels and ISR. A total of 410 patients with single-vessel lesion who received drug-eluting stents (DES) were included in the present study. After 12-36 months of follow-up, coronary angiography was performed and ISR was defined as >50% diameter stenosis at follow-up. RT-qPCR was used to measure lncRNA expression. Expression of the lncRNA RNA antisense non-coding RNA at the INK4 locus (ANRIL) was found to be upregulated whereas the lncRNA homeobox A11 antisense (HOXA11-AS) was downregulated in the plasma of patients with ISR compared with that from patients without ISR (P<0.001). Logistic regression analysis revealed that ANRIL [odds ratio (OR)=2.95; 95% confidence interval (CI)=1.68-8.08] was an independent risk factor for ISR, whilst HOXA11-AS (OR=0.58; 95% CI=0.48-0.71) was found to be an independent protective factor for ISR. Receiver operating characteristic (ROC) analysis demonstrated that high ANRIL expression [area under the ROC (auROC)=0.755; 95% CI=0.702-0.803] and low HOXA11-AS levels (auROC=0.712; 95% CI=0.657-0.763) predicted a high risk for ISR, and the combined score of ANRIL and HOXA11-AS (auROC=0.844; 95% CI=0.798-0.884) was more efficient at predicting ISR than either ANRIL or HOXA11-AS alone (P<0.001). In conclusion, increased ANRIL and decreased HOXA11-AS expressions were associated with ISR. However, combined ANRIL and HOXA11-AS plasma levels proved to be more effective at predicting ISR compared with either ANRIL or HOXA11-AS alone, suggesting that the multiplex detection of lncRNAs could be used to predict ISR in the future.

CARMN Is an Evolutionarily Conserved Smooth Muscle Cell-Specific LncRNA That Maintains Contractile Phenotype by Binding Myocardin

BACKGROUND

Vascular homeostasis is maintained by the differentiated phenotype of vascular smooth muscle cells (VSMCs). The landscape of protein coding genes comprising the transcriptome of differentiated VSMCs has been intensively investigated but many gaps remain including the emerging roles of noncoding genes.

METHODS

We reanalyzed large-scale, publicly available bulk and single-cell RNA sequencing datasets from multiple tissues and cell types to identify VSMC-enriched long noncoding RNAs. The in vivo expression pattern of a novel smooth muscle cell (SMC)-expressed long noncoding RNA, Carmn (cardiac mesoderm enhancer-associated noncoding RNA), was investigated using a novel Carmn green fluorescent protein knock-in reporter mouse model. Bioinformatics and quantitative real-time polymerase chain reaction analysis were used to assess CARMN expression changes during VSMC phenotypic modulation in human and murine vascular disease models. In vitro, functional assays were performed by knocking down CARMN with antisense oligonucleotides and overexpressing Carmn by adenovirus in human coronary artery SMCs. Carotid artery injury was performed in SMC-specific Carmn knockout mice to assess neointima formation and the therapeutic potential of reversing CARMN loss was tested in a rat carotid artery balloon injury model. The molecular mechanisms underlying CARMN function were investigated using RNA pull-down, RNA immunoprecipitation, and luciferase reporter assays.

RESULTS

We identified CARMN, which was initially annotated as the host gene of the MIR143/145 cluster and recently reported to play a role in cardiac differentiation, as a highly abundant and conserved, SMC-specific long noncoding RNA. Analysis of the Carmn GFP knock-in mouse model confirmed that Carmn is transiently expressed in embryonic cardiomyocytes and thereafter becomes restricted to SMCs. We also found that Carmn is transcribed independently of Mir143/145. CARMN expression is dramatically decreased by vascular disease in humans and murine models and regulates the contractile phenotype of VSMCs in vitro. In vivo, SMC-specific deletion of Carmn significantly exacerbated, whereas overexpression of Carmn markedly attenuated, injury-induced neointima formation in mouse and rat, respectively. Mechanistically, we found that Carmn physically binds to the key transcriptional cofactor myocardin, facilitating its activity and thereby maintaining the contractile phenotype of VSMCs.

CONCLUSIONS

CARMN is an evolutionarily conserved SMC-specific long noncoding RNA with a previously unappreciated role in maintaining the contractile phenotype of VSMCs and is the first noncoding RNA discovered to interact with myocardin.

Microarray analysis of long non-coding RNAs related to osteogenic differentiation of human dental pulp stem cells

Background/purpose

Dental pulp stem cells (DPSCs) are candidate seed cells for bone tissue engineering, but the molecular regulation of osteogenic differentiation in DPSCs is not fully understood. Long non-coding RNAs (lncRNAs) are important regulators of gene expression, and whether they play roles in osteogenic differentiation of DPSCs requires more study.

Materials and methods

DPSCs were isolated and cultured. The mRNA and lncRNA expression profiles were compared through microarray assay between osteo-differentiated DPSCs and non-differentiated DPSCs. Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses, Gene ontology (GO) analyses, and the mRNA-lncRNA co-expression analyses were performed for functional annotation of differentially expressed RNAs. Small interfering RNA (siRNA) was used to interfere the expression of lncRNA ENST00000533992 (also named smooth muscle-induced lncRNA or SMILR), a candidate regulator, then the osteogenic differentiation potential of DPSCs was analyzed.

Results

DPSCs were isolated and cultured successfully. The expression of 273 mRNAs and 184 lncRNAs changed significantly in DPSCs after osteogenic induction. KEGG analyses and GO analyses showed that the differentially expressed RNAs were enriched in several pathways and biological processes. The mRNA-lncRNA co-expression network was constructed to reveal the potential relationships between mRNAs and lncRNAs. The osteogenic differentiation potential of DPSCs decreased when SMILR was interfered.

Conclusion

The present study provides clues for seeking for lncRNAs that participate in the regulation of osteogenic differentiation in DPSCs. LncRNA SMILR could play a role in regulating osteogenic differentiation of DPSCs.

Long Non-Coding RNAs in Cardiovascular Diseases: Potential Function as Biomarkers and Therapeutic Targets of Exercise Training

Despite advances in treatments and therapies, cardiovascular diseases (CVDs) remain one of the leading causes of death worldwide. The discovery that most of the human genome, although transcribed, does not encode proteins was crucial for focusing on the potential of long non-coding RNAs (lncRNAs) as essential regulators of cell function at the epigenetic, transcriptional, and post-transcriptional levels. This class of non-coding RNAs is related to the pathophysiology of the cardiovascular system. The different expression profiles of lncRNAs, in different contexts of CVDs, change a great potential in their use as a biomarker and targets of therapeutic intervention. Furthermore, regular physical exercise plays a protective role against CVDs; on the other hand, little is known about its underlying molecular mechanisms. In this review, we look at the accumulated knowledge on lncRNAs and their functions in the cardiovascular system, focusing on the cardiovascular pathology of arterial hypertension, coronary heart disease, acute myocardial infarction, and heart failure. We discuss the potential of these molecules as biomarkers for clinical use, their limitations, and how the manipulation of the expression profile of these transcripts through physical exercise can begin to be suggested as a strategy for the treatment of CVDs.

Angiotensin II-Induced Long Non-Coding RNA Alivec Regulates Chondrogenesis in Vascular Smooth Muscle Cells

Long non-coding RNAs (lncRNAs) play key roles in Angiotensin II (AngII) signaling but their role in chondrogenic transformation of vascular smooth muscle cells (VSMCs) is unknown. We describe a novel AngII-induced lncRNA Alivec (Angiotensin II-induced lncRNA in VSMCs eliciting chondrogenic phenotype) implicated in VSMC chondrogenesis. In rat VSMCs, Alivec and the nearby gene Acan, a chondrogenic marker, were induced by growth factors AngII and PDGF and the inflammatory cytokine TNF-α. AngII co-regulated Alivec and Acan through the activation of AngII type1 receptor signaling and Sox9, a master transcriptional regulator of chondrogenesis. Alivec knockdown with GapmeR antisense-oligonucleotides attenuated the expression of AngII-induced chondrogenic marker genes, including Acan, and inhibited the chondrogenic phenotype of VSMCs. Conversely, Alivec overexpression upregulated these genes and promoted chondrogenic transformation. RNA-pulldown coupled to mass-spectrometry identified Tropomyosin-3-alpha and hnRNPA2B1 proteins as Alivec-binding proteins in VSMCs. Furthermore, male rats with AngII-driven hypertension showed increased aortic expression of Alivec and Acan. A putative human ortholog ALIVEC, was induced by AngII in human VSMCs, and this locus was found to harbor the quantitative trait loci affecting blood pressure. Together, these findings suggest that AngII-regulated lncRNA Alivec functions, at least in part, to mediate the AngII-induced chondrogenic transformation of VSMCs implicated in vascular dysfunction and hypertension.

LncRNA-SNHG1 promotes macrophage M2-like polarization and contributes to breast cancer growth and metastasis

Breast cancer is one of the most common malignant cancers among women. Cancer cells and adjacent cells determine the development of the disease. Tumor associated macrophages (TAMs) are involved in the regulation of different stages of cancer progression. LncRNAs play an important role in tumor growth and metastasis. However, the function of lncRNA in macrophage and tumor cell interaction is poorly described. Here we reported that lncRNA SNHG1 functioned as a modulator of M2 macrophage polarization and regulated tumor growth and angiogenesis. We indicated that knockdown of SNHG1 inhibited M2 macrophage polarization by suppression of STAT6 phosphorylation. SNHG1 silencing significantly alleviated migration of MCF-7 cells and tube formation of Human Umbilical Vein Endothelial Cells (HUVEC). Furthermore, we found that implantation of cell mixture of MCF-7 cells and macrophages promoted tumor growth and angiogenesis. However, knockdown of SNHG1 in macrophages reversed that effect. Collectively, we demonstrated the important role of lncRNA SNHG1 in macrophages and breast cancer cells interaction. We highlight the essential effect of lncRNA in tumor progression and provide a new method for the prevention and treatment of breast tumor metastasis.

Long Non-Coding RNA Regulation of Epigenetics in Vascular Cells

The vascular endothelium comprises the interface between the circulation and the vessel wall and, as such, is under the dynamic regulation of vascular signalling, nutrients, and hypoxia. Understanding the molecular drivers behind endothelial cell (EC) and vascular smooth muscle cell (VSMC) function and dysfunction remains a pivotal task for further clinical progress in tackling vascular disease. A newly emerging era in vascular biology with landmark deep sequencing approaches has provided us with the means to profile diverse layers of transcriptional regulation at a single cell, chromatin, and epigenetic level. This review describes the roles of major vascular long non-coding RNA (lncRNAs) in the epigenetic regulation of EC and VSMC function and discusses the recent progress in their discovery, detection, and functional characterisation. We summarise new findings regarding lncRNA-mediated epigenetic mechanisms—often regulated by hypoxia—within the vascular endothelium and smooth muscle to control vascular homeostasis in health and disease. Furthermore, we outline novel molecular techniques being used in the field to delineate the lncRNA subcellular localisation and interaction with proteins to unravel their biological roles in the epigenetic regulation of vascular genes.

A Novel Human Long Noncoding RNA SCDAL Promotes Angiogenesis through SNF5-Mediated GDF6 Expression

Angiogenesis is essential for vascular development. The roles of regulatory long noncoding RNAs (lncRNAs) in mediating angiogenesis remain under-explored. Human embryonic stem cell-derived mesenchymal stem cells (hES-MSCs) are shown to exert more potent cardioprotective effects against cardiac ischemia than human bone marrow-derived MSCs (hBM-MSCs), associated with enhanced neovascularization. The purpose of this study is to search for angiogenic lncRNAs enriched in hES-MSCs, and investigate their roles and mechanisms. AC103746.1 is one of the most highly expressed intergenic lncRNAs detected in hES-MSCs versus hBM-MSCs, and named as SCDAL (stem cell-derived angiogenic lncRNA). SCDAL knockdown significantly reduce the angiogenic potential and reparative effects of hES-MSCs in the infarcted hearts, while overexpression of SCDAL in either hES-MSCs or hBM-MSCs exhibits augmented angiogenesis and cardiac function recovery. Mechanistically, SCDAL induces growth differentiation factor 6 (GDF6) expression via direct interaction with SNF5 at GDF6 promoter. Secreted GDF6 promotes endothelial angiogenesis via non-canonical vascular endothelial growth factor receptor 2 activation. Furthermore, SCDAL-GDF6 is expressed in human endothelial cells, and directly enhances endothelial angiogenesis in vitro and in vivo. Thus, these findings uncover a previously unknown lncRNA-dependent regulatory circuit for angiogenesis. Targeted intervention of the SCDAL-GDF6 pathway has potential as a therapy for ischemic heart diseases.