LncRNA TINCR attenuates cardiac hypertrophy by epigenetically silencing CaMKII

Chrom-seq identifies RNAs at chromatin marks

Chromatin marks are associated with transcriptional regulatory activities. However, very few lncRNAs have been characterized with the role in regulating epigenetic marks, largely due to the technical difficulty in identifying chromatin-associating RNA. Current methods are largely limited by the availability of ChIP-grade antibody and the crosslinking, which generates high noise. Here, we developed a method termed Chrom-seq to efficiently capture RNAs associated with various chromatin marks in living cells. Chrom-seq jointly applies highly specific chromatin mark reader with APEX2, which catalyzes the oxidation of biotin-aniline to label the adjacent RNAs for isolation by streptavidin-coated beads. Using the readers of mCBX7/dPC, mCBX1, and mTAF3, we detected RNA species significantly associated with H3K27me3, H3K9me3, and H3K4me3, respectively. We demonstrated that Chrom-seq outperformed other equivalent methods in terms of sensitivity, efficiency, and cost of practice. It provides an antibody-free approach to systematically map RNAs at chromatin marks with potential regulatory roles in epigenetic events.

Unveiling the role of CaMKII in retinal degeneration: from biological mechanism to therapeutic strategies

Ca2+/calmodulin-dependent protein kinase II (CaMKII) is a family of broad substrate specificity serine (Ser)/threonine (Thr) protein kinases that play a crucial role in the Ca2+-dependent signaling pathways. Its significance as an intracellular Ca2+ sensor has garnered abundant research interest in the domain of neurodegeneration. Accumulating evidences suggest that CaMKII is implicated in the pathology of degenerative retinopathies such as diabetic retinopathy (DR), age-related macular degeneration (AMD), retinitis pigmentosa (RP) and glaucoma optic neuropathy. CaMKII can induce the aberrant proliferation of retinal blood vessels, influence the synaptic signaling, and exert dual effects on the survival of retinal ganglion cells and pigment epithelial cells. Researchers have put forth multiple therapeutic agents, encompassing small molecules, peptides, and nucleotides that possess the capability to modulate CaMKII activity. Due to its broad range isoforms and splice variants therapeutic strategies seek to inhibit specifically the CaMKII are confronted with considerable challenges. Therefore, it becomes crucial to discern the detrimental and advantageous aspects of CaMKII, thereby facilitating the development of efficacious treatment. In this review, we summarize recent research findings on the cellular and molecular biology of CaMKII, with special emphasis on its metabolic and regulatory mechanisms. We delve into the involvement of CaMKII in the retinal signal transduction pathways and discuss the correlation between CaMKII and calcium overload. Furthermore, we elaborate the therapeutic trials targeting CaMKII, and introduce recent developments in the zone of CaMKII inhibitors. These findings would enrich our knowledge of CaMKII, and shed light on the development of a therapeutic target for degenerative retinopathy.

The Role of Long Non-Coding RNAs in Cardiovascular Diseases

Long non-coding RNAs (lncRNAs) are non-coding RNA molecules longer than 200 nucleotides that regulate gene expression at the transcriptional, post-transcriptional, and translational levels. Abnormal expression of lncRNAs has been identified in many human diseases. Future improvements in diagnostic, prognostic, and therapeutic techniques will be facilitated by a deeper understanding of disease etiology. Cardiovascular diseases (CVDs) are the main cause of death globally. Cardiac development involves lncRNAs, and their abnormalities are linked to many CVDs. This review examines the relationship and function of lncRNA in a variety of CVDs, including atherosclerosis, myocardial infarction, myocardial hypertrophy, and heart failure. Therein, the potential utilization of lncRNAs in clinical diagnostic, prognostic, and therapeutic applications will also be discussed.

The regulation of circRNA and lncRNAprotein binding in cardiovascular diseases: Emerging therapeutic targets

Noncoding ribonucleic acids (ncRNAs) are a class of ribonucleic acids (RNAs) that carry cellular information and perform essential functions. This class encompasses various RNAs, such as small nuclear ribonucleic acids (snRNA), small interfering ribonucleic acids (siRNA) and many other kinds of RNA. Of these, circular ribonucleic acids (circRNAs) and long noncoding ribonucleic acids (lncRNAs) are two types of ncRNAs that regulate crucial physiological and pathological processes, including binding, in several organs through interactions with other RNAs or proteins. Recent studies indicate that these RNAs interact with various proteins, including protein 53, nuclear factor-kappa B, vascular endothelial growth factor, and fused in sarcoma/translocated in liposarcoma, to regulate both the histological and electrophysiological aspects of cardiac development as well as cardiovascular pathogenesis, ultimately leading to a variety of genetic heart diseases, coronary heart disease, myocardial infarction, rheumatic heart disease and cardiomyopathies. This paper presents a thorough review of recent studies on circRNA and lncRNAprotein binding within cardiac and vascular cells. It offers insight into the molecular mechanisms involved and emphasizes potential implications for treating cardiovascular diseases.

The potential roles of lncRNA TINCR in triple negative breast cancer

Triple negative breast cancer (TNBC) is the most aggressive intrinsic breast cancer subtype characterized by the lack of estrogen receptor (ER), progesterone receptor (PR), and low levels of human epidermal growth factor receptor 2 (HER2). The complex nature of TNBC has resulted in little therapeutic progress for the past several decades. The standard of care remains the FEC cocktail (5-fluorouracil (5-FU), epirubicin and cyclophosphamide). However, early relapse and metastasis in TNBC patients persists in causing dismal clinical outcomes. Due to complex heterogeneity features of TNBC, identifying the biomarker associated to the chemoresistance remains a challenge. The emergence of the long non-coding RNA (lncRNA) as a potential signature may have proven to be a new deterrent to diagnostic and treatment options. Previous studies unveiled the associations of lncRNA in the development of TNBCs whereby the aggressiveness and response to therapies may be associated by the abrogation of the molecular mechanism lncRNA. Terminal differentiation induced ncRNA (TINCR) is a lncRNA which have been linked with many cancers including TNBC. The expression and behavior of TINCR may exert unfavorable outcome in TNBCs. Nevertheless, the underlying molecular mechanism of TINCR in driving chemoresistance in TNBC is not well understood. This review will highlight the potential molecular mechanisms of TINCR in TNBC chemoresistance and how it can serve as a future potential prognostic and therapeutic target for a better treatment intervention.

SLC26A4-AS1 Aggravates AngII-induced Cardiac Hypertrophy by Enhancing SLC26A4 Expression

BACKGROUND

It has been reported that solute carrier family 26 members 4 antisense RNA 1 (SLC26A4-AS1) is highly related to cardiac hypertrophy.

OBJECTIVE

This research aims to investigate the role and specific mechanism of SLC26A4-AS1 in cardiac hypertrophy, providing a novel marker for cardiac hypertrophy treatment.

METHODS

Angiotensin II (AngII) was infused into neonatal mouse ventricular cardiomyocytes (NMVCs) to induce cardiac hypertrophy. Gene expression was detected by quantitative real-time PCR (RT-qPCR). Protein levels were evaluated via western blot. Functional assays analyzed the role of SLC26A4-AS1. The mechanism of SLC26A4-AS1 was assessed by RNA-binding protein immunoprecipitation (RIP), RNA pull-down, and luciferase reporter assays. The P value <0.05 was identified as statistical significance. Student's t-test evaluated the two-group comparison. The difference between different groups was analyzed by one-way analysis of variance (ANOVA).

RESULTS

SLC26A4-AS1 is upregulated in AngII-treated NMVCs and promotes AngII-induced cardiac hypertrophy. SLC26A4-AS1 regulates its nearby gene solute carrier family 26 members 4 (SLC26A4) via functioning as a competing endogenous RNA (ceRNA) to modulate the microRNA (miR)-301a-3p and miR-301b-3p in NMVCs. SLC26A4-AS1 promotes AngII-induced cardiac hypertrophy via upregulating SLC26A4 or sponging miR-301a-3p/miR-301b-3p.

CONCLUSION

SLC26A4-AS1 aggravates AngII-induced cardiac hypertrophy via sponging miR-301a-3p or miR-301b-3p to enhance SLC26A4 expression.

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.

Comparative Analysis of Non-Coding RNA Transcriptomics in Heart Failure

Heart failure constitutes a clinical complex syndrome with different symptomatic characteristics depending on age, sex, race and ethnicity, among others, which has become a major public health issue with an increasing prevalence. One of the most interesting tools seeking to improve prevention, diagnosis, treatment and prognosis of this pathology has focused on finding new molecular biomarkers since heart failure relies on deficient cardiac homeostasis, which is regulated by a strict gene expression. Therefore, currently, analyses of non-coding RNA transcriptomics have been oriented towards human samples. The present review develops a comparative study emphasizing the relevance of microRNAs, long non-coding RNAs and circular RNAs as potential biomarkers in heart failure. Significantly, further studies in this field of research are fundamental to supporting their widespread clinical use. In this sense, the various methodologies used by the authors should be standardized, including larger cohorts, homogeneity of the samples and uniformity of the bioinformatic pipelines used to reach stratification and statistical significance of the results. These basic adjustments could provide promising steps to designing novel strategies for clinical management of patients with heart failure.

Illuminating the Molecular Intricacies of Exosomes and ncRNAs in Cardiovascular Diseases: Prospective Therapeutic and Biomarker Potential

Cardiovascular diseases (CVDs) are one of the leading causes of death worldwide. Accumulating evidences have highlighted the importance of exosomes and non-coding RNAs (ncRNAs) in cardiac physiology and pathology. It is in general consensus that exosomes and ncRNAs play a crucial role in the maintenance of normal cellular function; and interestingly it is envisaged that their potential as prospective therapeutic candidates and biomarkers are increasing rapidly. Considering all these aspects, this review provides a comprehensive overview of the recent understanding of exosomes and ncRNAs in CVDs. We provide a great deal of discussion regarding their role in the cardiovascular system, together with providing a glimpse of ideas regarding strategies exploited to harness their potential as a therapeutic intervention and prospective biomarker against CVDs. Thus, it could be envisaged that a thorough understanding of the intricacies related to exosomes and ncRNA would seemingly allow their full exploration and may lead clinical settings to become a reality in near future.

LncRNA Gm43843 Promotes Cardiac Hypertrophy via miR-153-3p/Cacna1c Axis

Long noncoding RNAs (lncRNAs) have been reported to engage in many human diseases, including cardiac hypertrophy. Cardiac hypertrophy was mainly caused by excessive pressure load, which can eventually lead to a decline in myocardial contractility. Gm43843, a novel lncRNA, has not been well explored in cardiac hypertrophy so far. Herein, we are going to search the function and the underlying molecular mechanism of Gm43843 in cardiac hypertrophy. Gm43843 levels were measured via qRT-PCR in mouse myocardial cells when they are treated with angiogenin II (Ang II) or transfected with different plasmids. Western blot assay was implemented to detect the cardiac hypertrophy-related protein markers, while the cell was analyzed via immunofluorescence (IF) assay to evaluate the hypertrophy. Meanwhile, the binding of Gm43843 and the putative targets was examined based on mechanistic assay results. We found that Gm43843 expression was increased with the elevated concentration of Ang II. Inhibited Gm43843 was detected to reduce the hypertrophy of mouse myocardial cells. Meanwhile, Gm43843/miR-153-3p/Cacna1c axis was found to modulate cardiac hypertrophy. In short, Gm43843 promotes cardiac hypertrophy via miR-153-3p/Cacna1c axis.

Downregulation of lncRNA MALAT1 Inhibits Angiotensin II-induced Hypertrophic Effects of Cardiomyocytes by Regulating SIRT4 via miR-93-5p

Cardiac hypertrophy is a leading risk for heart failure and sudden death. Long non-coding RNAs (lncRNAs) have been implicated in a variety of human diseases, including cardiac hypertrophy. We aimed to investigate the potential role and functional mechanism of lncRNA metastasis-associated in lung adenocarcinoma transcript 1 (MALAT1) in cardiac hypertrophy. C57BL/6 mice underwent transverse aortic constriction (TAC) to induce cardiac hypertrophy in vivo. The expression of MALAT1, miR-93-5p, and sirtuin 4 (SIRT4) mRNA was detected using a quantitative real-time polymerase chain reaction. The protein levels of cardiac hypertrophy-related markers, including atrial natriuretic peptide (ANP), B-type natriuretic peptide (BNP) and β-myosin heavy chain (β-MHC), and SIRT4 were measured via western blotting. The putative interaction between miR-93-5p and MALAT1 or SIRT4 was verified using a dual-luciferase reporter assay, RNA immunoprecipitation assay, or pull-down assay. Consequently, the expression of MALAT1 and SIRT4 was increased in TAC-treated mouse heart and angiotensin II (Ang-II)-induced cardiomyocytes, whereas the expression of miR-93-5p was decreased. Ang-II promoted the expression of ANP, BNP, and β-MHC and the surface area of cardiomyocytes, whereas MALAT1 downregulation impaired their expression and cell area. MiR-93-5p was a target of MALAT1, and its inhibition reversed the effects of MALAT1 downregulation. More importantly, MALAT1 modulated SIRT4 expression by degrading miR-93-5p. The expression of ANP, BNP, and β-MHC suppressed by miR-93-5p restoration was recovered by SIRT4 promotion. Overall, MALAT1 knockdown ameliorated cardiac hypertrophy partly by regulating the miR-93-5p/SIRT4 network, indicating that MALAT1 was a substantial indicator of cardiac hypertrophy.

Non-Coding RNAs in the Therapeutic Landscape of Pathological Cardiac Hypertrophy

Cardiovascular diseases are a major health problem, and long-term survival for people diagnosed with heart failure is, still, unrealistic. Pathological cardiac hypertrophy largely contributes to morbidity and mortality, as effective therapeutic approaches are lacking. Non-coding RNAs (ncRNAs) arise as active regulators of the signaling pathways and mechanisms that govern this pathology, and their therapeutic potential has received great attention in the last decades. Preclinical studies in large animal models have been successful in ameliorating cardiac hypertrophy, and an antisense drug for the treatment of heart failure has, already, entered clinical trials. In this review, we provide an overview of the molecular mechanisms underlying cardiac hypertrophy, the involvement of ncRNAs, and the current therapeutic landscape of oligonucleotides targeting these regulators. Strategies to improve the delivery of such therapeutics and overcome the actual challenges are, also, defined and discussed. With the fast advance in the improvement of oligonucleotide drug delivery, the inclusion of ncRNAs-targeting therapies for cardiac hypertrophy seems, increasingly, a closer reality.

Association of the Genetic Variation in the Long Non-Coding RNA FENDRR with the Risk of Developing Hypertrophic Cardiomyopathy

Background: In around 40−60% of Hypertrophic Cardiomyopathy (HCM) cases pathogenic variants are not identified. Our aim was to evaluate the possible association of lncRNAs with the risk of developing HCM. Methods: We sequenced 10 lncRNAs coding genes that have been associated with cardiovascular disease in a discovery cohort (238 HCM patients and 212 controls) by NGS, and genotyped rs74035787 G>A and rs1424019 A>G polymorphism in a validation cohort (962 HCM patients and 923 controls). Finally, we sequenced the FENDRR promoter by Sanger sequencing. Results: We observed by NGS that FENDRR rs39527, rs39529 and rs40384 polymorphisms were significantly associated with HCM in our cohort (p = 0.0284; OR: 0.24, 95%CI: 0.07−0.86). NGS results were confirmed by genotyping rs74035787 polymorphism (p = 0.001; OR:0.38, 95%CI: 0.21−0.66). Moreover, it is also associated when stratification by sex (p = 0.003; OR:0.20, 95%CI: 0.06−0.53), and age (≥50 years old p = 0.001, OR:0.33, 95%CI: 0.16−0.63) Moreover, the risk of HCM in the carriers of the GG genotype of the rs1424019 polymorphism was significantly higher than that of the AA/AG genotypes carriers in the elderly subjects (p = 0.045, OR:1.24, 95%CI: 1.01−1.53). On the other hand, we observed significant differences in the rs74035787 A/rs1424019 G haplotype frequency (p = 0.0035; OR: 0.20, 95%CI: 0.07−0.59). Conclusions: Our study suggested a significant association between FENDRR gene variants and HCM.

lncRNA NBR2 attenuates angiotensin II-induced myocardial hypertrophy through repressing ER stress via activating LKB1/AMPK/Sirt1 pathway

Myocardial hypertrophy leads to heart failure (HF), and emerging researchers have illustrated that long noncoding RNAs (lncRNAs) modulate myocardial hypertrophy. Here, we explored the role and mechanism of a novel lncRNA, NBR2, in modulating angiotensin II (Ang II)-induced myocardial hypertrophy. First, we examined plasma NBR2 levels in 25 patients with HF and myocardial hypertrophy and ten healthy donors and analyzed the correlation between NBR2 profiles and patients’ clinical indicators. In addition, the overexpression experiment of NBR2 was carried out to probe the influence of NBR2 on myocardial hypertrophy. lncRNA NBR2 was down-regulated in plasma of patients with HF and myocardial hypertrophy (vs. healthy controls), and its level was negatively correlated with cardiac function (represented by left ventricular end-diastolic diameter and left ventricular ejection fraction) and degree of myocardial hypertrophy. Besides, Ang II treatment intensified the hypertrophy of human myocardial cell lines (HCM and AC16) and curbed the NBR2 expression. Overexpressing lncRNA NBR2 alleviated Angiotension II–induced myocardial hypertrophy and declined the profiles of hypertrophic markers. Moreover, up-regulating lncRNA NBR2 weakened Ang II-mediated endoplasmic reticulum (ER) stress and activated the LKB1/AMPK/Sirt1 pathway. Interfering with the LKB1/AMPK/Sirt1 axis abated the lncRNA NBR2-mediated inhibitory effect on myocardial hypertrophy and ER stress. This study confirmed that lncRNA NBR2 dampened myocardial hypertrophy and ER stress by modulating the LKB1/AMPK/Sirt1 pathway. Our study provides the first evidence that lncRNA NBR2 is positively associated with myocardial hypertrophy.

Long Non-Coding RNAs in Cardiac Hypertrophy

Heart disease represents one of the main challenges in modern medicine with insufficient treatment options. Whole genome sequencing allowed for the discovery of several classes of non-coding RNA (ncRNA) and widened our understanding of disease regulatory circuits. The intrinsic ability of long ncRNAs (lncRNAs) and circular RNAs (circRNAs) to regulate gene expression by a plethora of mechanisms make them candidates for conceptually new treatment options. However, important questions remain to be addressed before we can fully exploit the therapeutic potential of these molecules. Increasing our knowledge of their mechanisms of action and refining the approaches for modulating lncRNAs expression are just a few of the challenges we face. The accurate identification of novel lncRNAs is hampered by their relatively poor cross-species sequence conservation and their low and context-dependent expression pattern. Nevertheless, progress has been made in their annotation in recent years, while a few experimental studies have confirmed the value of lncRNAs as new mechanisms in the development of cardiac hypertrophy and other cardiovascular diseases. Here, we explore cardiac lncRNA biology and the evidence that this class of molecules has therapeutic benefit to treat cardiac hypertrophy.

LncRNA TINCR improves cardiac hypertrophy by regulating the miR-211-3p-VEGFB-SDF-1α-CXCR4 pathway

Cardiac hypertrophy is a common cardiovascular disease that is found worldwide and is characterized by heart enlargement, eventually resulting in heart failure. Exploring the regulatory mechanism of cardiac hypertrophy is beneficial for understanding its pathogenesis and treatment. In our study, we have showed TINCR was downregulated and miR-211-3p was upregulated in TAC- or Ang II-induced models of cardiac hypertrophy. Dual luciferase and RIP assays revealed that TINCR served as a competitive endogenous RNA (ceRNA) for miR-211-3p. Then, we observed that knockdown of miR-211-3p alleviated TAC- or Ang II-induced cardiac hypertrophy both in vivo and in vitro. Mechanistically, we demonstrated that miR-211-3p directly targeted VEGFB and thus regulated the expression of SDF-1α and CXCR4. Rescue assays further confirmed that TINCR suppressed the progression of cardiac hypertrophy by competitively binding to miR-211-3p, thereby enhancing the expression of VEGFB and activating the VEGFB-SDF-1α- CXCR4 signal. Furthermore, overexpression of TINCR suppressed TAC-induced cardiac hypertrophy in vivo by targeting miR-211-3p-VEGFB-SDF-1α- CXCR4 signalling. In conclusion, our research suggests that LncRNA TINCR improves cardiac hypertrophy by targeting miR-211-3p, thus relieving its suppressive effects on the VEGFB-SDF-1α-CXCR4 signalling axis. TINCR and miR-211-3p might act as therapeutic targets for the treatment of cardiac hypertrophy.

Reconnoitering the Role of Long-Noncoding RNAs in Hypertrophic Cardiomyopathy: A Descriptive Review

Hypertrophic cardiomyopathy (HCM) is the most common form of hereditary cardiomyopathy. It is characterized by an unexplained non-dilated hypertrophy of the left ventricle with a conserved or elevated ejection fraction. It is a genetically heterogeneous disease largely caused by variants of genes encoding for cardiac sarcomere proteins, including MYH7, MYBPC3, ACTC1, TPM1, MYL2, MYL3, TNNI3, and TNNT23. Preclinical evidence indicates that the enhanced calcium sensitivity of the myofilaments plays a key role in the pathophysiology of HCM. Notably, this is not always a direct consequence of sarcomeric variations but may also result from secondary mutation-driven alterations. Long non-coding RNAs (lncRNAs) are a large class of transcripts ≥200 nucleotides in length that do not encode proteins. Compared to coding mRNAs, most lncRNAs are not as well-annotated and their functions are greatly unexplored. Nevertheless, increasing evidence shows that lncRNAs are involved in a variety of biological processes and diseases including HCM. Accumulating evidence has indicated that lncRNAs are dysregulated in HCM, and closely related to sarcomere construction, calcium channeling and homeostasis of mitochondria. In this review, we have summarized the known regulatory and functional roles of lncRNAs in HCM.

Role of acetylation in doxorubicin-induced cardiotoxicity

As a potent chemotherapeutic agent, doxorubicin (DOX) is widely used for the treatment of a variety of cancers However, its clinical utility is limited by dose-dependent cardiotoxicity, and pathogenesis has traditionally been attributed to the formation of reactive oxygen species (ROS). Accordingly, the prevention of DOX-induced cardiotoxicity is an indispensable goal to optimize therapeutic regimens and reduce morbidity. Acetylation is an emerging and important epigenetic modification regulated by histone deacetylases (HDACs) and histone acetyltransferases (HATs). Despite extensive studies of the molecular basis and biological functions of acetylation, the application of acetylation as a therapeutic target for cardiotoxicity is in the initial stage, and further studies are required to clarify the complex acetylation network and improve the clinical management of cardiotoxicity. In this review, we summarize the pivotal functions of HDACs and HATs in DOX-induced oxidative stress, the underlying mechanisms, the contributions of noncoding RNAs (ncRNAs) and exercise-mediated deacetylases to cardiotoxicity. Furthermore, we describe research progress related to several important SIRT activators and HDAC inhibitors with potential clinical value for chemotherapy and cardiotoxicity. Collectively, a comprehensive understanding of specific roles and recent developments of acetylation in doxorubicin-induced cardiotoxicity will provide a basis for improved treatment outcomes in cancer and cardiovascular diseases.

Long non-coding RNAs in cardiac hypertrophy

Cardiac hypertrophy (CH) is generally considered adaptive responses that may occur after myocardial infarction, pressure overload, volume overload, inflammatory heart muscle disease, or idiopathic dilated cardiomyopathy, whereas long-term stimulation eventually leads to heart failure (HF). However, the current molecular mechanisms involved in CH are unclear. Recently, increasing evidences reveal that long non-coding RNAs (lncRNAs) play vital roles in CH. Different lncRNAs can promote or inhibit the pathological process of CH by different mechanisms, while the regulation of lncRNAs expression can improve CH. Thus, CH-related lncRNAs may become a novel field of research on CH.

Role of long non-coding RNAs in adipogenesis: State of the art and implications in obesity and obesity-associated diseases

Obesity is an evolutionary, chronic, and relapsing disease that consists of a pathological accumulation of adipose tissue able to increase morbidity for high blood pressure, type 2 diabetes, metabolic syndrome, and obstructive sleep apnea in adults, children, and adolescents. Despite intense research over the last 20 years, obesity remains today a disease with a complex and multifactorial etiology. Recently, long non-coding RNAs (lncRNAs) are emerging as interesting new regulators as different lncRNAs have been found to play a role in early and late phases of adipogenesis and to be implicated in obesity-associated complications onset. In this review, we discuss the most recent advances on the role of lncRNAs in adipocyte biology and in obesity-associated complications. Indeed, more and more researchers are focusing on investigating the underlying roles that these molecular modulators could play. Even if a significant number of evidence is correlation-based, with lncRNAs being differentially expressed in a specific disease, recent works are now focused on deeply analyzing how lncRNAs can effectively modulate the disease pathogenesis onset and progression. LncRNAs possibly represent new molecular markers useful in the future for both the early diagnosis and a prompt clinical management of patients with obesity.

Function of histone methylation and acetylation modifiers in cardiac hypertrophy

Cardiac hypertrophy is an adaptive response of the heart to increased workload induced by various physiological or pathological stimuli. It is a common pathological process in multiple cardiovascular diseases, and it ultimately leads to heart failure. The development of cardiac hypertrophy is accompanied by gene expression reprogramming, a process that is largely dependent on epigenetic regulation. Histone modifications such as methylation and acetylation are dynamically regulated under cardiac stress. These consequently contribute to the pathogenesis of cardiac hypertrophy via compensatory or maladaptive transcriptome reprogramming. Histone methylation and acetylation modifiers play crucial roles in epigenetic remodeling during the pathogenesis of cardiac hypertrophy. Regulation of histone methylation and acetylation modifiers serves as a bridge between signal transduction and downstream gene reprogramming. Exploring the role of histone modifiers in cardiac hypertrophy provides novel therapeutic strategies to treat cardiac hypertrophy and heart failure. In this review, we summarize the recent advancements in functional histone methylation and acetylation modifiers in cardiac hypertrophy, with an emphasis on the underlying mechanisms and the therapeutic potential.

Epigenetic Regulation of Autophagy in Cardiovascular Pathobiology

Cardiovascular diseases (CVDs) are the number one cause of debilitation and mortality worldwide, with a need for cost-effective therapeutics. Autophagy is a highly conserved catabolic recycling pathway triggered by various intra- or extracellular stimuli to play an essential role in development and pathologies, including CVDs. Accordingly, there is great interest in identifying mechanisms that govern autophagic regulation. Autophagic regulation is very complex and multifactorial that includes epigenetic pathways, such as histone modifications to regulate autophagy-related gene expression, decapping-associated mRNA degradation, microRNAs, and long non-coding RNAs; pathways are also known to play roles in CVDs. Molecular understanding of epigenetic-based pathways involved in autophagy and CVDs not only will enhance the understanding of CVDs, but may also provide novel therapeutic targets and biomarkers for CVDs.

NLRP3 Inflammasome: A Promising Therapeutic Target for Drug-Induced Toxicity

Drug-induced toxicity, which impairs human organ function, is a serious problem during drug development that hinders the clinical use of many marketed drugs, and the underlying mechanisms are complicated. As a sensor of infections and external stimuli, nucleotide-binding oligomerization domain (NOD)-like receptor family pyrin domain containing 3 (NLRP3) inflammasome plays a key role in the pathological process of various diseases. In this review, we specifically focused on the role of NLRP3 inflammasome in drug-induced diverse organ toxicities, especially the hepatotoxicity, nephrotoxicity, and cardiotoxicity. NLRP3 inflammasome is involved in the initiation and deterioration of drug-induced toxicity through multiple signaling pathways. Therapeutic strategies via inhibiting NLRP3 inflammasome for drug-induced toxicity have made significant progress, especially in the protective effects of the phytochemicals. Growing evidence collected in this review indicates that NLRP3 is a promising therapeutic target for drug-induced toxicity.

LncRNAs in Cardiomyocyte Maturation: New Window for Cardiac Regenerative Medicine

Cardiomyocyte (CM) maturation, which is characterized by structural, functional, and metabolic specializations, is the last phase of CM development that prepares the cells for efficient and forceful contraction throughout life. Over the past decades, CM maturation has gained increased attention due to the fact that pluripotent stem cell-derived CMs are structurally, transcriptionally, and functionally immature and embryonic-like, which causes a defect in cell replacement therapy. The current challenge is to discover and understand the molecular mechanisms, which control the CM maturation process. Currently, emerging shreds of evidence emphasize the role of long noncoding RNAs (lncRNAs) in regulating different aspects of CM maturation, including myofibril maturation, electrophysiology, and Ca²⁺ handling maturation, metabolic maturation and proliferation to hypertrophy transition. Here, we describe the structural and functional characteristics of mature CMs. Furthermore, this review highlights the lncRNAs as crucial regulators of different aspects in CM maturation, which have the potential to be used for mature CM production. With the current advances in oligonucleotide delivery; lncRNAs may serve as putative therapeutic targets to produce highly mature CMs for research and regenerative medicine.

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.

LncRNA Tincr regulates PKCɛ expression in a miR-31-5p-dependent manner in cardiomyocyte hypertrophy

Cardiomyocyte hypertrophy is a fatal factor in heart disease resulting in heart failure and even mortality. Although many studies have been focusing on the pathogenesis of cardiomyocyte hypertrophy, the exact molecular mechanisms are still unexclusive. In this study, we first found that the expression level of lncRNA Tincr was significantly decreased in the myocardial tissues of TAC mouse models of cardiomyocyte hypertrophy, and this result was further confirmed in H9C2 cells, a widely used rat myoblast cell lines. More intriguingly, we demonstrated that the aberration of Tincr is essential to the pathogenesis of cardiomyocyte hypertrophy, indicated by the re-induction of Tincr improving the heart functions of hypertrophic mice. In mechanism, we identified miR-31-5p as a direct target of Tincr using a widely used online bioinformatics tool StarBase, and this result was further experimentally validated using dual-luciferase reporter assay and real-time PCR. Also, we identified PRKCE as a direct target of miR-31-5p, and loss function of miR-31-5p significantly blocks the positive regulatory effect of Tincr on PRKCE expression in H9C2 cells. The knockdown of Tincr resulted in increased cardiomyocyte size, and, however, inhibition of miR-31-5p or overexpression of PRKCE significantly reversed the increased cardiomyocyte size. Taken together, our study showed that a novel Tincr-miR-31-5p axis targeting PRKCE was involved in cardiomyocyte hypertrophy, indicating that it may provide potential therapy in cardiomyocyte hypertrophy.

Morphine post-conditioning-induced up-regulation of lncRNA TINCR protects cardiomyocytes from ischemia-reperfusion injury via inhibiting degradation and ubiquitination of FGF1

BACKGROUND

Our previous study has demonstrated that morphine post-conditioning (MpostC) protects cardiomyocytes from ischemia/reperfusion (I/R) injury partly through activating protein kinase-epsilon (PKCε) signaling pathway and subsequently inhibiting mitochondrial permeability transition pore (mPTP) opening.

AIM

In this study, we aim to investigate the relationship between long non-coding RNA TINCR and PKCε in cardiomyocytes under MpostC-treated I/R injury.

DESIGN

The myocardial I/R rat model was established by the ligation of lower anterior descending coronary artery for 45 min followed by the reperfusion for 1 h, and MpostC was performed before the reperfusion.

METHOD

H/R and MpostC were performed in the rat cardiomyocyte cell line (H9C2), and the Cytochrome-c release in cytosol and mPTP opening were determined. Cell viability was detected by using Cell Counting Kit-8, and cell apoptosis was determined by using flow cytometry or TUNEL assay.

RESULTS

The results indicated that MpostC restored the expression of TINCR in I/R rat myocardial tissues. In cardiomyocytes, the therapeutic effect of MpostC, including reduced mPTP opening, reduced Cytochrome-c expression, increased cell viability and reduced cell apoptosis, was dramatically negated by interfering TINCR. The expression of fibroblast growth factor 1 (FGF1), a protein that activates PKCε signaling pathway, was positively correlated with TINCR. The RNA immunoprecipitation and RNA pull-down assay further confirmed the binding between FGF1 and TINCR. Furthermore, TINCR was demonstrated to inhibit the degradation and ubiquitination of FGF1 in cardiomyocytes using the cycloheximide experiment and the ubiquitination assay. The TINCR/FGF1/PKCε axis was revealed to mediate the protective effect of MpostC against hypoxia/reoxygenation injury both in vitro and in vivo.

CONCLUSION

In conclusion, our findings demonstrated that MpostC-induced up-regulation of TINCR protects cardiomyocytes from I/R injury via inhibiting degradation and ubiquitination of FGF1, and subsequently activating PKCε signaling pathway, which provides a novel insight in the mechanism of TINCR and PKCε during MpostC treatment of I/R injury.

Long noncoding RNAs: Potential therapeutic targets in cardiocerebrovascular diseases

Cardiocerebrovascular disease is a collective term for cardiovascular and cerebrovascular diseases. Because of the complex mechanisms involved in cardiocerebrovascular diseases, limited effective treatments have been developed. With advancements in precision medicine, studies have focused on long noncoding RNAs (lncRNAs) in cerebrovascular diseases. LncRNAs, which are over 200 nucleotides long, regulate gene expression at epigenetic, transcriptional, and post-transcriptional levels. Moreover, lncRNAs play pivotal roles in the progression of cardiocerebrovascular diseases. For example, recent studies suggested that abnormal expression of lncRNAs are closely related to the occurrence and progression of these diseases. LncRNAs regulate gene expression by specifically binding to mRNA to modulate disease progression, serving as biomarkers for the diagnosis and prognosis of cardiocerebrovascular diseases. In this review, we discuss the roles, mechanisms, and clinical value of lncRNAs in cardiocerebrovascular diseases, providing a new perspective for the diagnosis and treatment of the diseases.

Knockdown of KCNQ1OT1 attenuates cardiac hypertrophy through modulation of the miR-2054/AKT3 axis

Background

Persistent cardiac hypertrophy threatens health worldwide. Long non-coding RNAs (lncRNAs) attracted lots of attention in cardiac diseases such as cardiac hypertrophy. In this study, we aimed to study the function of KCNQ1OT1 in cardiac hypertrophy.

Methods

We first used qRT-PCR to detect the expression of KCNQ1OT1 in Ang-II-induced cardiomyocytes and mouse cardiac hypertrophy models. The function of KCNQ1OT1 was investigated by a loss-of-function test. Analysis of the luciferase reporter gene and RNA pulldown confirmed the interaction between KCNQ1OT1 and miR-2054. The target gene of miR-2054 was predicted by bioinformatics analysis and confirmed by luciferase reporter gene detection. Rescue experiments were performed to evaluate the role of miR-2054/AKT3 in the function of KCNQ1OT1.

Results

Our results suggested that KCNQ1OT1 was up-regulated in Ang-II-induced cardiomyocytes and transverse aortic constriction (TAC) mice. Knocking down of KCNQ1OT1 can reduce cell size and downregulate the expression of ANF, BNP and α-MHC in response to Ang-II. KCNQ1OT1 has been shown to compete competitively with miR-2054 and has a negative correlation with its expression. The combination of miR-2054 can reverse the effect of the KCNQ1OT1 combination in Ang-II-induced cardiomyocytes. In addition, AKT3 is a target of miR-2054 and mediates its effect on Ang-II-induced cardiomyocytes.

Conclusions

Knockdown of KCNQ1OT1 could attenuate cardiac hypertrophy through modulation of the miR-2054/AKT3 axis.

Role of the Epigenome in Heart Failure

Gene expression is needed for the maintenance of heart function under normal conditions and in response to stress. Each cell type of the heart has a specific program controlling transcription. Different types of stress induce modifications of these programs and, if prolonged, can lead to altered cardiac phenotype and, eventually, to heart failure. The transcriptional status of a gene is regulated by the epigenome, a complex network of DNA and histone modifications. Until a few years ago, our understanding of the role of the epigenome in heart disease was limited to that played by histone deacetylation. But over the last decade, the consequences for the maintenance of homeostasis in the heart and for the development of cardiac hypertrophy of a number of other modifications, including DNA methylation and hydroxymethylation, histone methylation and acetylation, and changes in chromatin architecture, have become better understood. Indeed, it is now clear that many levels of regulation contribute to defining the epigenetic landscape required for correct cardiomyocyte function, and that their perturbation is responsible for cardiac hypertrophy and fibrosis. Here, we review these aspects and draw a picture of what epigenetic modification may imply at the therapeutic level for heart failure.

lncRNA ZEB2-AS1 stimulates cardiac hypertrophy by downregulating PTEN

Cardiac hypertrophy (CH) is closely related to a range of cardiovascular diseases, including heart failure and sudden cardiac death. The present study aimed to elucidate the role of long non-coding RNA (lncRNA) ZEB2 antisense RNA 1 (ZEB2-AS1) in regulating the hypertrophic process of cardiomyocytes and the potential underlying mechanism. An in vivo CH mouse model was established by performing transverse aortic constriction procedures. An in vitro CH model was established in primary cardiomyocytes isolated from mice by phenylephrine (PE) treatment. The relative protein levels of BNP, ANP and PTEN in cells with different groups (CH group and control group) were determined by western blotting. Relative expression levels of ZEB2-AS1, natriuretic peptide A (ANP) and brain natriuretic peptide (BNP) were determined in both in vivo and in vitro CH models. The regulatory effects of ZEB2-AS1/phosphatase and tensin homolog (PTEN) on cell surface area, and the relative expression levels of ANP and BNP were explored. ZEB2-AS1, ANP and BNP expression levels were increased in both in vivo and in vitro CH models compared with the sham and negative control groups, respectively. ZEB2-AS1 knockdown decreased cell surface area, and downregulated ANP and BNP expression levels in PE-treated primary cardiomyocytes. Similarly, PTEN overexpression reduced cell surface area, and downregulated ANP and BNP expression levels in PE-treated primary cardiomyocytes. Moreover, PTEN reversed the regulatory effects of ZEB2-AS1 on hypertrophic cardiomyocytes. Therefore, the present study suggested that lncRNA ZEB2-AS1 may influence the progression of CH by downregulating PTEN.

LncRNAs in cardiac hypertrophy: From basic science to clinical application

Cardiac hypertrophy is a typical pathological phenotype of cardiomyopathy and a result from pathological remodelling of cardiomyocytes in humans. At present, emerging evidence demonstrated the roles of long non‐coding RNAs (lncRNAs) in regulating the pathophysiological process of cardiac hypertrophy. Herein, we would like to review the recent researches on this issue and try to analysis the potential therapeutic targets on lncRNA sites. Studies have revealed both genetic mutations related hypertrophic cardiomyopathy and the compensative cardiac hypertrophy due to pressure overload, inflammation, endocrine issues and other external stimulations, share a common molecular mechanism of ventricular hypertrophy. The emerging evidence identified the abnormal expression of lncRNAs would leading to the impairment the function of sarcomere, intracellular calcium handling and mitochondrial metabolisms. Several researches proved the therapeutic role of lncRNAs in preventing or reversing cardiac hypertrophy. With the development of delivery system for small pieces of oligonucleotide, clinicians could design gene therapy approaches to terminate the process of cardiac hypertrophy to provide better prognosis.

An Overview of the Role of Calcium/Calmodulin-Dependent Protein Kinase in Cardiorenal Syndrome

Calcium/calmodulin-dependent protein kinases (CaMKs) are key regulators of calcium signaling in health and disease. CaMKII is the most abundant isoform in the heart; although classically described as a regulator of excitation–contraction coupling, recent studies show that it can also mediate inflammation in cardiovascular diseases (CVDs). Among CVDs, cardiorenal syndrome (CRS) represents a pressing issue to be addressed, considering the growing incidence of kidney diseases worldwide. In this review, we aimed to discuss the role of CaMK as an inflammatory mediator in heart and kidney interaction by conducting an extensive literature review using the database PubMed. Here, we summarize the role and regulating mechanisms of CaMKII present in several quality studies, providing a better understanding for future investigations of CamKII in CVDs. Surprisingly, despite the obvious importance of CaMKII in the heart, very little is known about CaMKII in CRS. In conclusion, more studies are necessary to further understand the role of CaMKII in CRS.

Regulatory RNAs in Heart Failure

Cardiovascular disease is an enormous socioeconomic burden worldwide and remains a leading cause of mortality and disability despite significant efforts to improve treatments and personalize healthcare. Heart failure is the main manifestation of cardiovascular disease and has reached epidemic proportions. Heart failure follows a loss of cardiac homeostasis, which relies on a tight regulation of gene expression. This regulation is under the control of multiple types of RNA molecules, some encoding proteins (the so-called messenger RNAs) and others lacking protein-coding potential, named noncoding RNAs. In this review article, we aim to revisit the notion of regulatory RNA, which has been thus far mainly confined to noncoding RNA. Regulatory RNA, which we propose to abbreviate as regRNA, can include both protein-coding RNAs and noncoding RNAs, as long as they contribute, directly or indirectly, to the regulation of gene expression. We will address the regulation and functional role of messenger RNAs, microRNAs, long noncoding RNAs, and circular RNAs (ie, regRNAs) in heart failure. We will debate the utility of regRNAs to diagnose, prognosticate, and treat heart failure, and we will provide directions for future work.

Non-coding RNAs and Pathological Cardiac Hypertrophy

Cardiovascular disease (CVD) is a common disease which poses a serious threat to human health and it is characterized by high prevalence, high disability and high mortality. Myocardial hypertrophy (MH) is a common pathological process of various cardiovascular diseases and is considered as an independent risk factor for increased cardiovascular morbidity and mortality. Therefore, it is particularly important to understand its pathological mechanism and treatment. In recent years, it has been found that many non-coding RNAs (ncRNAs) play key regulatory roles in humans' various pathophysiological processes. Abnormal expression of ncRNAs in different types of cardiac cells is associated with pathological cardiac hypertrophy. Understanding the relationship between various ncRNAs and intercellular communication through extracellular vesicles (EV) can identify the key ncRNAs which are the accurate targets of precise therapy in this network of action, it also can potentially be a marker for clinical disease diagnosis, which will reflect the progress of the disease earlier and more accurately. There are many factors that regulate the occurrence and development of cardiac hypertrophy, ncRNAs are only a part of them. There are also mutual promotion or inhibition between ncRNAs and other molecules. It will be helpful for us to comprehend the mechanism of cardiac hypertrophy better and provide a sufficient theoretical basis for clinical diagnosis and treatment by defining these relationships.

Non-coding RNAs as Epigenetic Gene Regulators in Cardiovascular Diseases

Epigenetic gene regulations can be considered as de-novo initiation of abnormal molecular signaling events whose regulation is otherwise required during normal or specific developmental stages of the organisms. Primarily, three different mechanisms have been identified to participate in epigenetic gene regulations which include, DNA methylation, non-coding RNA species (microRNAs [miRNA], and long non-coding RNAs [LNC-RNA]) and histone modifications. These de-novo epigenetic mechanisms have been associated with altered normal cellular functions which eventually facilitate normal cells to transition into an abnormal phenotype. Among the three modes of regulation, RNA species which are usually considered to be less stable, can be speculated to initiate instant alterations in gene expression compared to DNA methylation or histone modifications. However, LNC-RNAs appear to be more stable in the cells than the other RNA species. Moreover, there is increasing literature which clearly suggests that a single specific LNC-RNA can regulate multiple mechanisms and disease phenotypes. With specific focus on cardiovascular diseases, here we attempt to provide UpToDate information on the functional role of miRNAs and LNC-RNAs. Here we discuss the role of these epigenetic mediators in different components of cardiovascular disease which include physiopathological heart development, athersclerosis, retenosis, diabetic hearts, myocardial infarction, ischemia-reperfusion, heart valve disease, aortic aneurysm, osteogenesis, angiogenesis and hypoxia in the heart. While there is abundant literature support that shows the involvement of many LNC-RNAs and miRNAs in cardiovascular diseases, very few RNA species have been identified which regulate epigenetic mechanisms which is the current focus in this article. Understanding the role of these RNA species in regulating epigenetic mechanisms in different cell types causing cardiovascular disease, would advance the field and promote disease prevention approaches that are aimed to target epigenetic mechanisms.

Long Noncoding RNA FTX Reduces Hypertrophy of Neonatal Mouse Cardiac Myocytes and Regulates the PTEN/PI3K/Akt Signaling Pathway by Sponging MicroRNA-22

BACKGROUND Cardiac myocyte hypertrophy results from clinical conditions that include hypertension and valvular heart disease, and can result in heart failure. This study aimed to investigate the expression and role of the long noncoding RNA FTX (lnc-FTX), an X-inactive-specific transcript (XIST) regulator transcribed from the X chromosome, in hypertrophy of neonatal mouse cardiac myocytes induced by angiotensin II (Ang II) in vitro. MATERIAL AND METHODS Cardiac myocytes were isolated from neonatal mice and cultured with and without Ang II. Immunofluorescence, with localization of an antibody to alpha-smooth muscle actin (alpha-SMA), was used to identify the neonatal mouse cardiac myocytes. Quantitative real-time polymerase chain reaction (qRT-PCR) measured gene expression levels. The cell counting kit-8 (CCK-8) assay was used to determine cell viability, and Western blot measured protein expression. StarBase v2.0 bioinformatics software was used for target gene prediction and was confirmed with the luciferase reporter assay. RESULTS The expression of lnc-FTX was reduced in mouse cardiac myocytes treated with Ang II. Overexpression of lnc-FTX reduced cell apoptosis, cardiomyocyte contractility, and the expression of c-Jun, A-type natriuretic peptide (ANP), and B-type natriuretic peptide (BNP) induced by Ang II. The target of lnc-FTX was micro-RNA 22 (miRNA-22). The mechanism of action of lnc-FTX in neonatal mouse cardiac myocytes was through suppression of the PI3K/Akt signaling pathway by promoting the release of PTEN by sponging miRNA-22. CONCLUSIONS The expression of lnc-FTX was associated with reduced hypertrophy of neonatal mouse cardiac myocytes and regulated the PTEN/PI3K/Akt signaling pathway by sponging miRNA-22.

Sp1-induced LncRNA CTBP1-AS2 is a novel regulator in cardiomyocyte hypertrophy by interacting with FUS to stabilize TLR4

Cardiomyocyte hypertrophy is a heart response adapting to increasing cardiac load. Prolonged cardiomyocyte hypertrophy indicates a higher risk of heart failure or even cardiac death. Long noncoding RNAs have been largely reported to modulate human diseases. CTPB1-AS2 is a newly discovered lncRNA reported as an oncogene in papillary thyroid cancer, but its function in cardiomyocyte hypertrophy has never been probed. Toll-like receptor 4 (TLR4) is recognized to play important roles in cardiomyocyte hypertrophy. The present study aimed to investigate the role of CTBP1-AS2 in cardiomyocyte hypertrophy. First, we discovered the low expression of CTBP1-AS2 in normal heart tissues in GETx database. Then, we established cardiomyocyte hypertrophy models on mice and cardiomyocytes through transverse aortic constriction surgery and Ang II treatment. We revealed the up-regulation of CTBP1-AS2 and TLR4 in cardiomyocyte hypertrophy models. Also, we confirmed the positive correlation between CTBP1-AS2 and TLR4 expressions in cardiomyocyte hypertrophy tissues. Loss-of-function assays confirmed that inhibiting CTBP1-AS2 attenuated the Ang II-induced cardiomyocyte hypertrophy. Mechanism research showed that CTBP1-AS2 stabilized TLR4 mRNA by recruiting FUS. Rescue assays certified that CTBP1-AS2 regulated cardiomyocyte hypertrophy through TLR4. Finally, we found Sp1 as an upstream activator for CTBP1-AS2 expression. In conclusion, our study uncovered CTBP1-AS2 as a novel regulator of cardiomyocyte hypertrophy through regulating TLR4, providing a new potential treatment target for cardiomyocyte hypertrophy.

Doxorubicin induces cardiomyocyte pyroptosis via the TINCR-mediated posttranscriptional stabilization of NLR family pyrin domain containing 3

AIMS

Doxorubicin (DOX), a widely used powerful chemotherapeutic component for cancer treatment, can give rise to severe cardiotoxicity that limits its clinical use. Pyroptosis is characterized by proinflammation and has been defined as a new type of programmed cell death in recent years. However, whether the DOX-induced cardiotoxicity is related to pyroptosis, and if so, which genes are involved in this process is largely unknown. In this study, we sought to identify the effect of DOX on cardiomyocyte pyroptosis and further reveal the underlying regulatory mechanism.

METHODS AND RESULTS

In vitro and in vivo experiments showed that DOX treatment induced cardiomyocyte pyroptosis as evidenced by increased cell death and upregulated expression levels of NLR family pyrin domain containing 3 (NLRP3), caspase-3, IL-1β, IL-18 and GMDSD-N. Inhibition of NLRP3 rescued the DOX-induced pyroptosis. qRT-PCR showed that TINCR lncRNA was upregulated by DOX treatment and knockdown of TINCR reversed the DOX-induced pyroptosis both in vitro and in vivo. Mechanistic investigations revealed that TINCR increased NLRP3 level via recruiting IGF2BP1 to enhance NLRP3 mRNA. And the effect of TINCR on cardiomyocyte pyroptosis was attenuated by the inhibition of NLRP3 or IGF2BP1. Finally, TINCR was not involved in DOX-induced pyroptosis in cancer cells.

CONCLUSION

TINCR mediates the DOX-induced cardiotoxicity and pyroptosis in an IGF2BP1-dependent manner. Therefore, TINCR may serve as a promising therapeutic target to overcome the cardiotoxicity of chemotherapy for cancer therapy.

The lncRNA Hand2os1/Uph locus orchestrates heart development through regulation of precise expression of Hand2

Exploration and dissection of potential actions and effects of long noncoding RNA (lncRNA) in animals remain challenging. Here, using multiple knockout mouse models and single cell RNA sequencing, we demonstrate that the divergent lncRNA Hand2os1/Uph has a key complex modulatory effect on the expression of its neighboring gene HAND2 and subsequently on heart development and function. Short deletion of the Hand2os1 promoter in mouse diminishes Hand2os1 transcription to ∼8-32%, but fails to affect HAND2 expression and yields no discernable heart phenotypes. Interestingly, full-length deletion of Hand2os1 in mouse causes moderate yet prevalent upregulation of HAND2 in hundreds of cardiac cells, leading to profound biological consequences, including dysregulated cardiac gene programs, congenital heart defects and perinatal lethality. We propose that the Hand2os1 locus dampens HAND2 expression to restrain cardiomyocyte proliferation, thereby orchestrating a balanced development of cardiac cell lineages. This study highlights the regulatory complexity of the lncRNA Hand2os1 on HAND2 expression, emphasizing the need for complementary genetic and single cell approaches to delineate the function and primary molecular effects of an lncRNA in animals.

Exploring the Continuum of Hypertrophic Cardiomyopathy-From DNA to Clinical Expression

The concepts underlying hypertrophic cardiomyopathy (HCM) pathogenesis have evolved greatly over the last 60 years since the pioneering work of the British pathologist Donald Teare, presenting the autopsy findings of “asymmetric hypertrophy of the heart in young adults”. Advances in human genome analysis and cardiac imaging techniques have enriched our understanding of the complex architecture of the malady and shaped the way we perceive the illness continuum. Presently, HCM is acknowledged as “a disease of the sarcomere”, where the relationship between genotype and phenotype is not straightforward but subject to various genetic and nongenetic influences. The focus of this review is to discuss key aspects related to molecular mechanisms and imaging aspects that have prompted genotype–phenotype correlations, which will hopefully empower patient-tailored health interventions.

Long noncoding RNA MAGI1-IT1 regulates cardiac hypertrophy by modulating miR-302e/DKK1/Wnt/beta-catenin signaling pathway

Cardiac hypertrophy (CH) is an adaptive cardiac response to overload whose decompensation eventually leads to heart failure or sudden death. Recently, accumulating studies have indicated the implication of long noncoding RNAs (lncRNAs) in CH progression. MAGI1-IT1 is a newly-identified lncRNA that is highly associated with CH, while its specific role in CH progression remains masked. In this study, we uncovered that MAGI1-IT1 was distinctly downregulated in angiotensin (Ang) II-induced hypertrophic H9c2 cells. Also, MAGI1-IT1 overexpression in Ang II-treated H9c2 cells strikingly abolished the enlarged surface area and the enhanced levels of hypertrophic markers such as ANP, BNP, and β-MHC. Mechanically, we found MAGI1-IT1 sponged miR-302e which was identified as a hypertrophy-facilitator here, and that miR-302e upregulation countervailed the inhibition of MAGI1-IT1 overexpression on hypertrophic cells. Moreover, it was confirmed that MAGI1-IT1 boosted DKK1 expression by absorbing miR-302e. Subsequently, we also illustrated that MAGI1-IT1 inactivated Wnt/beta-catenin signaling through a DKK1-dependent pathway. Finally, both the DKK1 inhibition and LiCI (Wnt activator) supplement abrogated the hypertrophy-suppressive impact of MAGI1-IT1 on Ang II-simulated hypertrophic H9c2 cells. Jointly, our findings disclosed that MAGI1-IT1 functioned as a negative regulator in CH through inactivating Wnt/beta-catenin pathway via targeting miR-302e/DKK1 axis, revealing a novel road for CH treatment.

LncRNA TUG1 contributes to cardiac hypertrophy via regulating miR-29b-3p

Cardiac hypertrophy with maladjusted cardiac remodeling is the leading cause of heart failure. In the past decades, long non-coding RNAs (lncRNAs) and microRNAs (miRNAs) have been proved to exert multiple functions in cellular biological behaviors; however, their role in cardiac hypertrophy remains largely unclear. Presently, we first obtained hypertrophic H9c2 cells by treating with angiotensin II (Ang II) and uncovered upregulation of lncRNA taurine upregulated gene 1 (TUG1) in such H9c2 cells. Then, we demonstrated that silencing TUG1 attenuated Ang II-induced cardiac hypertrophy. Besides, a strong interactivity of TUG1 with miR-29b-3p at the putative sites was validated, suggesting that TUG1 was an endogenous sponge of miR-29b-3p in H9c2 cells. Additionally, the expression of miR-29b-3p was strikingly reduced by TUG1 upregulation and also inhibited under Ang II treatment, whereas it was restored after silencing TUG1 in hypertrophic cells. Also, we proved miR-29b-3p as a negative regulator in cardiac hypertrophy. Finally, miR-29b-3p inhibition abolished the anti-hypertrophy effect of TUG1 depletion in Ang II-treated H9c2 cells. Collectively, our findings confirmed that TUG1 functioned as a positive modulator of cardiac hypertrophy via sponging miR-29b-3p, indicating that TUG1 might serve as a potential target for the treatment of cardiac hypertrophy and even heart failure.

Silencing of Long Noncoding RNA Nespas Aggravates Microglial Cell Death and Neuroinflammation in Ischemic Stroke

Background and Purpose- Ischemic stroke is one of the leading causes of morbidity and mortality worldwide and a major cause of long-term disability. Recently, long noncoding RNAs have been revealed, which are tightly associated with several human diseases. However, the functions of long noncoding RNAs in ischemic stroke still remain largely unknown. In the current study, for the first time, we investigated the role of long noncoding RNA Nespas in ischemic stroke. Methods- We used in vivo models of middle cerebral artery occlusion and in vitro models of oxygen-glucose deprivation to illustrate the effect of long noncoding RNA Nespas on ischemic stroke. Results- We found expression of Nespas was significantly increased in ischemic cerebral tissues and oxygen-glucose deprivation-treated BV2 cells in a time-dependent manner. Silencing of Nespas aggravated middle cerebral artery occlusion operation-induced IR injury and cell death. In addition, proinflammatory cytokine production and NF-κB (nuclear factor-κB) signaling activation were inhibited by Nespas overexpression. TAK1 (transforming growth factor-β-activated kinase 1) was found to directly interact with Nespas, and TAK1 activation was significantly suppressed by Nespas. At last, we found Nespas-inhibited TRIM8 (tripartite motif 8)-induced K63-linked polyubiquitination of TAK1. Conclusions- We showed that Nespas played anti-inflammatory and antiapoptotic roles in cultured microglial cells after oxygen-glucose deprivation stimulation and in mice after ischemic stroke by inhibiting TRIM8-related K63-linked polyubiquitination of TAK1.