Inhibition of the Cardiac Fibroblast–Enriched lncRNA Meg3 Prevents Cardiac Fibrosis and Diastolic Dysfunction

ANRIL upregulates TGFBR1 to promote idiopathic pulmonary fibrosis in TGF-β1-treated lung fibroblasts via sequestering let-7d-5p

Idiopathic pulmonary fibrosis (IPF) is a progressive and life-threatening respiratory disease characterized by worsening lung function due to excessive scarring. The objective of this study was to investigate the role of the long non-coding RNA ANRIL (antisense non-coding RNA in the INK4 locus) in the development of IPF. Our research revealed a significant increase in ANRIL expression in pulmonary fibrosis, consistent with prior studies indicating elevated ANRIL levels in fibrotic tissues. In vitro experiments demonstrated that elevated ANRIL expression promoted fibroblast activation, as evidenced by the upregulation of fibrosis-related markers. Mechanistically, we found that ANRIL interacts with let-7d-5p, a microRNA involved in gene regulation, acting as a sponge for let-7d-5p. Functional experiments confirmed a potential influence of let-7d-5p on fibroblast activation through direct interaction with ANRIL. Furthermore, our investigation identified TGFBR1 as a potential mediator of ANRIL's fibrogenic effects. Silence of TGFBR1 mitigated the fibrotic phenotype induced by ANRIL overexpression. Collectively, these results suggest that ANRIL promotes fibroblast activation and fibrosis development, possibly through the let-7d-5p/TGFBR1 axis, indicating that ANRIL could be a potential therapeutic target for pulmonary fibrosis.

Myocardial fibrosis from the perspective of the extracellular matrix: Mechanisms to clinical impact

Fibrosis is defined by the excessive accumulation of extracellular matrix (ECM) and constitutes a central pathophysiological process that underlies tissue dysfunction, across organs, in multiple chronic diseases and during aging. Myocardial fibrosis is a key contributor to dysfunction and failure in numerous diseases of the heart and is a strong predictor of poor clinical outcome and mortality. The excess structural and matricellular ECM proteins deposited by cardiac fibroblasts, is found between cardiomyocytes (interstitial fibrosis), in focal areas where cardiomyocytes have died (replacement fibrosis), and around vessels (perivascular fibrosis). Although myocardial fibrosis has important clinical prognostic value, access to cardiac tissue biopsies for histological evaluation is limited. Despite challenges with sensitivity and specificity, cardiac magnetic resonance imaging (CMR) is the most applicable diagnostic tool in the clinic, and the scientific community is currently actively searching for blood biomarkers reflecting myocardial fibrosis, to complement the imaging techniques. The lack of mechanistic insights into specific pro- and anti-fibrotic molecular pathways has hampered the development of effective treatments to prevent or reverse myocardial fibrosis. Development and implementation of anti-fibrotic therapies is expected to improve patient outcomes and is an urgent medical need. Here, we discuss the importance of the ECM in the heart, the central role of fibrosis in heart disease, and mechanistic pathways likely to impact clinical practice with regards to diagnostics of myocardial fibrosis, risk stratification of patients, and anti-fibrotic therapy.

LINC00707 inhibits myocardial fibrosis and immune disorder in rheumatic heart disease by regulating miR-145-5p/S1PR1

LINC00707 is a lncRNA that can regulate a variety of diseases. This study mainly investigated that the expression of LINC00707 in rheumatic heart disease (RHD) and LINC00707 regulates S1PR1 by targeting miR-145-5p to inhibit myocardial fibrosis and immune disorder in RHD. A rat model of RHD induced by inactivated group A β-hemolytic streptococcus (GSA) was established. Sixty female Lewis rats (8 weeks of age) were randomly divided into six groups, including control (Con), RHD, RHD+NC, RHD+LINC00707, RHD+miR-145-5p and RHD+LINC00707+miR-145-5p. The mRNA expression was detected by Quantitative Real-time polymerase chain reaction (qRT-PCR). Protein expression of S1PR1 was detected by western blot. The levels of myocardial damage markers (CK-MB, cTnl) and inflammatory immune markers (IL-6, IL-17 and IL-21) were measured by enzyme linked immunosorbent assay (ELISA). The Collagen III/I(COLIII/I) ratio, mRNA expression of COLIIIα1 and FSP1 of rat heart valve tissue in the RHD group was observably higher by comparison with the CON group. The expression of LINC00707 was observably lower in the RHD group. LINC00707 inhibited myocardial fibrosis and immune disorder in RHD. MiR-145-5p was the target gene of LINC00707 via Targetscan prediction. Luciferase reporter experiment confirmed that miR-145-5p was directly regulated by LINC00707. The expression of miR-145-5p in the RHD group was observably higher by comparison with the CON group and LINC00707 observably decreased the expression of miR-145-5p. miR-145-5p mimic reversed the inhibiting effect of LINC00707 on myocardial fibrosis and immune disorder. Furthermore, S1PR1 was confirmed to be downstream gene of miR-145-5p and low expressed in the RHD model. LINC00707 could inhibit myocardial fibrosis and immune disorder in RHD by regulating miR-145-5p/S1PR1.

LRRK2 G2019S Mutated iPSC-Derived Endothelial Cells Exhibit Increased α-Synuclein, Mitochondrial Impairment, and Altered Inflammatory Responses

The blood-brain barrier (BBB) serves as an interface between the bloodstream and the central nervous system. It limits the movement of molecules and immune cells, regulates the entry of nutrients, and removes waste products from the brain. The dysfunction of the BBB has been identified in Parkinson's disease (PD) but the role of the BBB and endothelial cells (ECs) has not been well studied. LRRK2 G2019S mutation is the most common PD causing mutation with similar pathophysiology than in sporadic cases. How the mutation affects EC function has not been investigated previously in patient cells. In the study, we used iPSC-derived ECs from PD patients with the LRRK2 mutation as well as cells from healthy individuals. We report that PD patients' ECs have higher levels of α-synuclein and an decreased maximal and ATP-linked respiration and altered response to inflammatory exposure, especially to TNFα. In addition, transcriptomic analysis showed upregulation of fatty-acid-synthesis-related pathways in PD patients' ECs and the downregulation of lncRNA MEG3, both of which have been associated with PD. Altogether, PD patients' ECs manifest some of the PD-related hallmarks and are likely to contribute to the pathogenesis of PD.

Current concepts in the epigenetic regulation of cardiac fibrosis

Cardiac fibrosis is a significant driver of congestive heart failure, a syndrome that continues to affect a growing patient population globally. Cardiac fibrosis results from a constellation of complex processes at the transcription, receptor, and signaling axes levels. Various mediators and signaling cascades, such as the transformation growth factor-beta pathway, have been implicated in the pathophysiology of cardiac tissue fibrosis. Our understanding of these markers and pathways has improved in recent years as more advanced technologies and assays have been developed, allowing for better delineation of the crosstalk between specific factors. There is mounting evidence suggesting that epigenetic modulation plays a pivotal role in the progression of cardiac fibrosis. Transcriptional regulation of key pro- and antifibrotic pathways can accentuate or blunt the rate and extent of fibrosis at the tissue level. Exosomes, micro-RNAs, and long noncoding RNAs all belong to factors that can impact the epigenetic signature in cardiac fibrosis. Herein, we comprehensively review the latest literature about exosomes, their contents, and cardiac fibrosis. In doing so, we highlight the specific transcriptional factors with pro- or antifibrotic properties. We also assimilate the data supporting these mediators' potential utility as diagnostic or prognostic biomarkers. Finally, we offer insight into where further work can be done to fill existing gaps to translate preclinical findings better and improve clinical outcomes.

LncRNA MEG3 regulates ferroptosis of lens epithelial cells via PTBP1/GPX4 axis to participate in age-related cataract

Age-related cataract (ARC) is regarded as the principal cause of vision impairment among the aged. The regulatory role of long noncoding RNAs (LncRNAs) in ARC remains unclear. The lncRNA maternally expressed gene 3 (MEG3) has been reported to promote ARC progression, and the underlying mechanism was further investigated in this study. Lens epithelium samples were collected to verify the expression of MEG3. Lens epithelial cells (LECs) were treated with H2O2 to mimic microenvironment of ARC in vitro. Cell viability, reactive oxygen species, and ferroptosis were evaluated during the in viro experiments. In the present work, lncRNA MEG3 was highly expressed in ARC group, compared with normal group. MEG3 was induced, cell viability and glutathione peroxidase 4 (GPX4) level were inhibited, and ferroptosis was promoted in H2O2 treated LECs. LncRNA MEG3 silence reversed the effects of H2O2 on viability and ferroptosis in LECs. Thereafter, lncRNA MEG3 was found to bind to PTBP1 for GPX4 degradation. Silencing of GPX4 reversed the regulation of lncRNA MEG3 inhibition in H2O2-treated LECs. To sum up, lncRNA MEG3 exhibited high expression in ARC. In H2O2-induced LECs, inhibition of lncRNA MEG3 accelerated cell viability and repressed ferroptosis by interaction with PTBP1 for GPX4 messenger RNA decay. Targeting lncRNA MEG3 may be a novel treatment of ARC.

Mitophagy deficiency activates stimulator of interferon genes activation and aggravates pathogenetic cardiac remodeling

Stimulator of interferon genes (STING) has recently been found to play a crucial role in cardiac sterile inflammation and dysfunction. The role of stimulator of interferon genes (STING) in cardiac sterile inflammation and dysfunction has been recently discovered. This study aims to examine the involvement of STING in pathological cardiac remodeling and the mechanisms that govern the activation of the STING pathway. To investigate this, transverse aortic constriction (TAC) was performed on STING knockout mice to induce pressure overload-induced cardiac remodeling. Subsequently, cardiac function, remodeling, and inflammation levels were evaluated. The STING pathway was found to be activated in the pressure overload-stressed heart and angiotensin II (Ang II)-stimulated cardiac fibroblasts. Loss of STING expression led to a significant reduction in inflammatory responses, mitochondrial fragmentation, and oxidative stress in the heart, resulting in attenuated cardiac remodeling and dysfunction. Furthermore, the exacerbation of pressure overload-induced STING-mediated inflammation and pathological cardiac remodeling was observed when mitophagy was suppressed through the silencing of Parkin, an E3 ubiquitin ligase. Taken together, these findings indicate that STING represents a newly identified and significant molecule implicated in the process of pathological cardiac remodeling and that mitophagy is an upstream mechanism that regulates STING activation. Targeting STING may therefore provide a novel therapeutic strategy for pathological cardiac remodeling and heart failure.

Epigenetic Regulation in Myocardial Fibroblasts and Its Impact on Cardiovascular Diseases

Myocardial fibroblasts play a crucial role in heart structure and function. In recent years, significant progress has been made in understanding the epigenetic regulation of myocardial fibroblasts, which is essential for cardiac development, homeostasis, and disease progression. In healthy hearts, cardiac fibroblasts (CFs) play a crucial role in synthesizing the extracellular matrix (ECM) when in a dormant state. However, under pathological and environmental stress, CFs transform into activated fibroblasts known as myofibroblasts. These myofibroblasts produce an excess of ECM, which promotes cardiac fibrosis. Although multiple molecular mechanisms are associated with CF activation and myocardial dysfunction, emerging evidence highlights the significant involvement of epigenetic regulation in this process. Epigenetics refers to the heritable changes in gene expression that occur without altering the DNA sequence. These mechanisms have emerged as key regulators of myocardial fibroblast function. This review focuses on recent advancements in the understanding of the role of epigenetic regulation and emphasizes the impact of epigenetic modifications on CF activation. Furthermore, we present perspectives and prospects for future research on epigenetic modifications and their implications for myocardial fibroblasts.

Long noncoding RNA MEG3: an active player in fibrosis

Fibrosis, characterized by excess accumulation of extracellular matrix components, disrupts normal tissue structure and causes organ dysfunction. Long noncoding RNAs (lncRNAs) are a subset of RNAs longer than 200 nucleotides that are not converted into proteins. The increasing research indicated that lncRNA maternally expressed gene 3 (MEG3) was dysregulated in the pathologic process of fibrosis in several tissues. LncRNA MEG3 was revealed to regulate the expression of target proteins or serve as a miRNAs sponge to control the development of fibrosis, which was involved in NF-ҡB, PI3K/AKT, JAK2/STAT3, Wnt/β-catenin, ERK/p38, and Hh pathway. Importantly, the interference of MEG3 level ameliorated fibrosis. The present review summarized available studies of lncRNA MEG3 in fibrosis, which is helpful for a deeper understanding of the roles of MEG3 in fibrosis.

The novel lnc-HZ12 suppresses autophagy degradation of BBC3 by preventing its interactions with HSPA8 to induce trophoblast cell apoptosis

Abnormal expression of long non-coding RNAs (lncRNAs) is associated with the dysfunctions of human trophoblast cells and the occurrence of miscarriage (abnormal early embryo loss). BBC3/PUMA (BCL2 binding component 3) plays significant roles in regulation of cell apoptosis. However, whether specific lncRNAs might regulate BBC3 in trophoblast cells and further induce apoptosis and miscarriage remains completely unclear. Through screening, we identified a novel lnc-HZ12, which was significantly highly expressed in villous tissues of recurrent miscarriage (RM) patients relative to their healthy control (HC) group. Lnc-HZ12 suppressed chaperone-mediated autophagy (CMA) degradation of BBC3, promoted trophoblast cell apoptosis, and was associated with miscarriage. In mechanism, lnc-HZ12 downregulated the expression levels of chaperone molecules HSPA8 and LAMP2A in trophoblast cells. Meanwhile, lnc-HZ12 (mainly lnc-HZ12-SO2 region in F2 fragment) and HSPA8 competitively bound with the 169RVLYNL174 patch on BBC3, which prevented BBC3 from interactions with HSPA8 and impaired the formation of BBC3-HSPA8-LAMP2A complex for CMA degradation of BBC3. Thus, lnc-HZ12 upregulated the BBC3-CASP9-CASP3 pathway and induced trophoblast cell apoptosis. In villous tissues, lnc-HZ12 was highly expressed, CMA degradation of BBC3 was suppressed, and the apoptosis levels were higher in RM vs HC villous tissues, all of which were associated with miscarriage. Interestingly, knockdown of murine Bbc3 could efficiently suppress placental apoptosis and alleviate miscarriage in a mouse miscarriage model. Taken together, our results indicated that lnc-HZ12 and BBC3 played important roles in trophoblast cell apoptosis and miscarriage and might act as attractive targets for miscarriage treatment.Abbreviation: 7-AAD: 7-aminoactinomycin D; BaP: benzopyrene; BBC3/PUMA: BCL2 binding component 3; ChIP: chromatin immunoprecipitation; CHX: cycloheximide; CMA: chaperone-mediated autophagy; CQ: chloroquine; DMSO: dimethyl sulfoxide; GAPDH: glyceraldehyde-3-phosphate dehydrogenase; HC: healthy control; HSPA8: heat shock protein family A (Hsp70) member 8; IP: immunoprecipitation; LAMP2A: lysosomal associated membrane protein 2; LncRNA: long non-coding RNA; mRNA: messenger RNA; MT: mutant-type; NC: negative control; NSO: nonspecific oligonucleotide; PARP1: poly(ADP-ribose) polymerase 1; RIP: RNA immunoprecipitation; RM: recurrent miscarriage; TBP: TATA-box binding protein; WT: wild-type.

Profiling Long Noncoding RNA in Psoriatic Skin Using Single-Cell RNA Sequencing

The expressions of long noncoding RNAs (lncRNAs) and their roles in epidermal differentiation have been previously defined using bulk RNA sequencing. Despite their tissue-specific expression profiles, most lncRNAs are not well-annotated at the single-cell level. In this study, we evaluated the use of single-cell RNA sequencing to profile and characterize lncRNAs using data from 6 patients with psoriasis with paired uninvolved and lesional psoriatic skin. Despite their overall lower expression, we were able to detect >7000 skin-expressing lncRNAs and their cellular sources. Differential gene expression analysis revealed 137 differentially expressed lncRNAs in lesional psoriasis skin and identified 169 cell-type-specific lncRNAs. Keratinocytes had the highest number of differentially expressed lncRNA in psoriatic skin, which we validated using spatial transcriptomic data. We further showed that expression of the keratinocyte-specific lncRNA, AC020916.1, upregulated in lesional skin, is significantly correlated with expressions of genes participating in cell proliferation/epidermal differentiation, including SPRR2E and transcription factor ZFP36, particularly in the psoriatic skin. Our study highlights the potential for using single-cell RNA sequencing to profile skin-expressing lncRNA transcripts and to infer their cellular origins, providing a crucial approach that can be applied to the study of other inflammatory skin conditions.

LncRNA DCRT Protects Against Dilated Cardiomyopathy by Preventing NDUFS2 Alternative Splicing by Binding to PTBP1

BACKGROUND

Dilated cardiomyopathy is characterized by left ventricular dilation and continuous systolic dysfunction. Mitochondrial impairment is critical in dilated cardiomyopathy; however, the underlying mechanisms remain unclear. Here, we explored the cardioprotective role of a heart-enriched long noncoding RNA, the dilated cardiomyopathy repressive transcript (DCRT), in maintaining mitochondrial function.

METHODS

The DCRT knockout (DCRT-/-) mice and DCRT knockout cells were developed using CRISPR-Cas9 technology. Cardiac-specific DCRT transgenic mice were generated using α-myosin heavy chain promoter. Chromatin coimmunoprecipitation, RNA immunoprecipitation, Western blot, and isoform sequencing were performed to investigate the underlying mechanisms.

RESULTS

We found that the long noncoding RNA DCRT was highly enriched in the normal heart tissues and that its expression was significantly downregulated in the myocardium of patients with dilated cardiomyopathy. DCRT-/- mice spontaneously developed cardiac dysfunction and enlargement with mitochondrial impairment. DCRT transgene or overexpression with the recombinant adeno-associated virus system in mice attenuated cardiac dysfunction induced by transverse aortic constriction treatment. Mechanistically, DCRT inhibited the third exon skipping of NDUFS2 (NADH dehydrogenase ubiquinone iron-sulfur protein 2) by directly binding to PTBP1 (polypyrimidine tract binding protein 1) in the nucleus of cardiomyocytes. Skipping of the third exon of NDUFS2 induced mitochondrial dysfunction by competitively inhibiting mitochondrial complex I activity and binding to PRDX5 (peroxiredoxin 5) and suppressing its antioxidant activity. Furthermore, coenzyme Q10 partially alleviated mitochondrial dysfunction in cardiomyocytes caused by DCRT reduction.

CONCLUSIONS

Our study revealed that the loss of DCRT contributed to PTBP1-mediated exon skipping of NDUFS2, thereby inducing cardiac mitochondrial dysfunction during dilated cardiomyopathy development, which could be partially treated with coenzyme Q10 supplementation.

Endothelial derived, secreted long non-coding RNAs Gadlor1 and Gadlor2 aggravate cardiac remodeling

Pathological cardiac remodeling predisposes individuals to developing heart failure. Here, we investigated two co-regulated long non-coding RNAs (lncRNAs), termed Gadlor1 and Gadlor2, which are upregulated in failing hearts of patients and mice. Cardiac overexpression of Gadlor1 and Gadlor2 aggravated myocardial dysfunction and enhanced hypertrophic and fibrotic remodeling in mice exposed to pressure overload. Compound Gadlor1/2 knockout (KO) mice showed markedly reduced myocardial hypertrophy, fibrosis, and dysfunction, while exhibiting increased angiogenesis during short and prolonged periods of pressure overload. Paradoxically, Gadlor1/2 KO mice suffered from sudden death during prolonged overload, possibly due to cardiac arrhythmia. Gadlor1 and Gadlor2, which are mainly expressed in endothelial cells (ECs) in the heart, where they inhibit pro-angiogenic gene expression, are strongly secreted within extracellular vesicles (EVs). These EVs transfer Gadlor lncRNAs to cardiomyocytes, where they bind and activate calmodulin-dependent kinase II, and impact pro-hypertrophic gene expression and calcium homeostasis. Therefore, we reveal a crucial lncRNA-based mechanism of EC-cardiomyocyte crosstalk during heart failure, which could be specifically modified in the future for therapeutic purposes.

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.

LncRNAs in the Dlk1-Dio3 Domain Are Essential for Mid-Embryonic Heart Development

The Dlk1-Dio3 domain is important for normal embryonic growth and development. The heart is the earliest developing and functioning organ of the embryo. In this study, we constructed a transcriptional termination model by inserting termination sequences and clarified that the lack of long non-coding RNA (lncRNA) expression in the Dlk1-Dio3 domain caused the death of maternal insertion mutant (MKI) and homozygous mutant (HOMO) mice starting from E13.5. Parental insertion mutants (PKI) can be born and grow normally. Macroscopically, dying MKI and HOMO embryos showed phenomena such as embryonic edema and reduced heart rate. Hematoxylin and eosin (H.E.) staining showed thinning of the myocardium in MKI and HOMO embryos. In situ hybridization (IHC) and quantitative reverse-transcription polymerase chain reaction (qRT-PCR) showed downregulation of lncGtl2, Rian, and Mirg expression in MKI and HOMO hearts. The results of single-cell RNA sequencing (scRNA-Seq) analysis indicated that the lack of lncRNA expression in the Dlk1-Dio3 domain led to reduced proliferation of epicardial cells and may be an important cause of cardiac dysplasia. In conclusion, this study demonstrates that Dlk1-Dio3 domain lncRNAs play an integral role in ventricular development.

The role of long noncoding RNA MEG3 in fibrosis diseases

Fibrosis is a prevalent pathological condition observed in various organs and tissues. It primarily arises from the excessive and abnormal accumulation of the extracellular matrix, resulting in the structural and functional impairment of tissues and organs, which can culminate in death. Many forms of fibrosis, including liver, cardiac, pulmonary, and renal fibrosis, are considered irreversible. Maternally expressed gene 3 (MEG3) is an imprinted RNA gene. Historically, the downregulation of MEG3 has been linked to tumor pathogenesis. However, recent studies indicate an emerging association of MEG3 with fibrotic diseases. In this review, we delve into the current understanding of MEG3's role in fibrosis, aiming to shed light on the molecular mechanisms of fibrosis and the potential of MEG3 as a novel therapeutic target.

The role of lncRNAKCNQ1OT1/miR-301b/Tcf7 axis in cardiac hypertrophy

OBJECTIVE

Cardiac hypertrophy, acting as a pathologic process of chronic hypertension and coronary disease, and its underlying mechanisms still need to be explored. Long non-coding RNA (LncRNA) potassium voltage-gated channel subfamily Q member 1 Transcript 1 (KCNQ1OT1) has been implicated in myocardial infarction. However, its role in cardiac hypertrophy remains reported.

METHOD

To explore the regulated effect of lncRNAKCNQ1OT1 and miR-301b in cardiac hypertrophy, gain-and-lose function assays were tested. The expression of lncRNAKCNQ1OT1 and miR-301b were tested by quantitative real time polymerase chain reaction (qRT-PCR). The levels of transcription factor 7 (Tcf7), Proto-oncogene c-myc (c-myc), Brainnatriureticpeptide (BNP) and β-myosin heavy chain (β-MHC) were detected by Western blot. Additionally, luciferase analysis revealed interaction between lncRNAKCNQ1OT1, BNPβ-MHCmiR-301b, and Tcf7.

RESULT

LncRNAKCNQ1OT1 overexpression significantly induced cardiac hypertrophy. Furthermore, lncRNAKCNQ1OT1 acts as a sponge for microRNA-301b, which exhibited lower expression in cardiac hypertrophy model, indicating an anti-hypertrophic role. Furthermore, the BNP and β-MHC expression increased, as well as cardiomyocyte surface area, with Ang II treatment, while the effect was repealed by miR-301b. Moreover, the protein expression of Tcf7 was inversely regulated by miR-301b and Antisense miRNA oligonucleotides (AMO)-301b.

CONCLUSION

Our study has shown that overexpression of lncRNAKCNQ1OT1 could promote the development of cardiac hypertrophy by regulating miR-301b and Tcf7. Therefore, inhibition of lncRNAKCNQ1OT1 might be a potential therapeutic strategy for cardiac hypertrophy.

Long non-coding RNAs in cardiac hypertrophy and heart failure: functions, mechanisms and clinical prospects

The surge in reports describing non-coding RNAs (ncRNAs) has focused attention on their possible biological roles and effects on development and disease. ncRNAs have been touted as previously uncharacterized regulators of gene expression and cellular processes, possibly working to fine-tune these functions. The sheer number of ncRNAs identified has outpaced the capacity to characterize each molecule thoroughly and to reliably establish its clinical relevance; it has, nonetheless, created excitement about their potential as molecular targets for novel therapeutic approaches to treat human disease. In this Review, we focus on one category of ncRNAs - long non-coding RNAs - and their expression, functions and molecular mechanisms in cardiac hypertrophy and heart failure. We further discuss the prospects for this specific class of ncRNAs as novel targets for the diagnosis and treatment of these conditions.

Long non-coding RNA H19 mediates osteogenic differentiation of bone marrow mesenchymal stem cells through the miR-29b-3p/DKK1 axis

Single immobilization theory cannot fully account for the extensive bone loss observed after spinal cord injury (SCI). Bone marrow mesenchymal stem cells (BMSCs) are crucial in bone homeostasis because they possess self-renewal capabilities and various types of differentiation potential. This study aimed to explore the molecular mechanism of long non-coding RNA H19 in osteoporosis after SCI and provide new research directions for existing prevention strategies. We used small interfering RNA to knockdown H19 expression and regulated miR-29b-2p expression using miR-29b-3p mimetics and inhibitors. Western blotting, real-time fluorescence quantitative PCR, Alizarin red staining, alkaline phosphatase staining and double-luciferase reporter gene assays were used to assess gene expression, osteogenic ability and binding sites. lncRNA H19 was upregulated in BMSCs from the osteoporosis group, whereas miR-29b-3p was downregulated. We identified the binding sites between miR-29b-3p and lncRNAs H19 and DKK1. H19 knockdown promoted BMSCs' osteogenic differentiation, whereas miR-29b-3p inhibition attenuated this effect. We discovered potential binding sites for miR-29b-3p in lncRNAs H19 and DKK1. Our findings suggest that long non-coding RNA H19 mediates BMSCs' osteogenic differentiation in osteoporosis after SCI through the miR-29b-3p/DKK1 axis and by directly inhibiting the β-catenin signalling pathway.

Unlocking the dark matter: noncoding RNAs and RNA modifications in cardiac aging

Cardiac aging is a multifaceted process that encompasses structural and functional alterations culminating in heart failure. As the elderly population continues to expand, there is a growing urgent need for interventions to combat age-related cardiac functional decline. Noncoding RNAs have emerged as critical regulators of cellular and biochemical processes underlying cardiac disease. This review summarizes our current understanding of how noncoding RNAs function in the heart during aging, with particular emphasis on mechanisms of RNA modification that control their activity. Targeting noncoding RNAs as potential novel therapeutics in cardiac aging is also discussed.

Non-coding RNAs: targets for Chinese herbal medicine in treating myocardial fibrosis

Cardiovascular diseases have become the leading cause of death in urban and rural areas. Myocardial fibrosis is a common pathological manifestation at the adaptive and repair stage of cardiovascular diseases, easily predisposing to cardiac death. Non-coding RNAs (ncRNAs), RNA molecules with no coding potential, can regulate gene expression in the occurrence and development of myocardial fibrosis. Recent studies have suggested that Chinese herbal medicine can relieve myocardial fibrosis through targeting various ncRNAs, mainly including microRNAs (miRNAs), long non-coding RNAs (lncRNAs), and circular RNAs (circRNAs). Thus, ncRNAs are novel drug targets for Chinese herbal medicine. Herein, we summarized the current understanding of ncRNAs in the pathogenesis of myocardial fibrosis, and highlighted the contribution of ncRNAs to the therapeutic effect of Chinese herbal medicine on myocardial fibrosis. Further, we discussed the future directions regarding the potential applications of ncRNA-based drug screening platform to screen drugs for myocardial fibrosis.

LncRNA CHKB-DT Downregulation Enhances Dilated Cardiomyopathy Through ALDH2

BACKGROUND

Human cardiac long noncoding RNA (lncRNA) profiles in patients with dilated cardiomyopathy (DCM) were previously analyzed, and the long noncoding RNA CHKB (choline kinase beta) divergent transcript (CHKB-DT) levels were found to be mostly downregulated in the heart. In this study, the function of CHKB-DT in DCM was determined.

METHODS

Long noncoding RNA expression levels in the human heart tissues were measured via quantitative reverse transcription-polymerase chain reaction and in situ hybridization assays. A CHKB-DT heterozygous or homozygous knockout mouse model was generated using the clustered regularly interspaced palindromic repeat (CRISPR)/CRISPR-associated protein 9 system, and the adeno-associated virus with a cardiac-specific promoter was used to deliver the RNA in vivo. Sarcomere shortening was performed to assess the primary cardiomyocyte contractility. The Seahorse XF cell mitochondrial stress test was performed to determine the energy metabolism and ATP production. Furthermore, the underlying mechanisms were explored using quantitative proteomics, ribosome profiling, RNA antisense purification assays, mass spectrometry, RNA pull-down, luciferase assay, RNA-fluorescence in situ hybridization, and Western blotting.

RESULTS

CHKB-DT levels were remarkably decreased in patients with DCM and mice with transverse aortic constriction-induced heart failure. Heterozygous knockout of CHKB-DT in cardiomyocytes caused cardiac dilation and dysfunction and reduced the contractility of primary cardiomyocytes. Moreover, CHKB-DT heterozygous knockout impaired mitochondrial function and decreased ATP production as well as cardiac energy metabolism. Mechanistically, ALDH2 (aldehyde dehydrogenase 2) was a direct target of CHKB-DT. CHKB-DT physically interacted with the mRNA of ALDH2 and fused in sarcoma (FUS) through the GGUG motif. CHKB-DT knockdown aggravated ALDH2 mRNA degradation and 4-HNE (4-hydroxy-2-nonenal) production, whereas overexpression of CHKB-DT reversed these molecular changes. Furthermore, restoring ALDH2 expression in CHKB-DT+/- mice alleviated cardiac dilation and dysfunction.

CONCLUSIONS

CHKB-DT is significantly downregulated in DCM. CHKB-DT acts as an energy metabolism-associated long noncoding RNA and represents a promising therapeutic target against DCM.

Long noncoding RNA lncPostn links TGF-β and p53 signaling pathways to transcriptional regulation of cardiac fibrosis

Cardiac fibroblasts are essential for the homeostasis of the extracellular matrix, whose remodeling in many cardiovascular diseases leads to fibrosis. Long noncoding RNAs (lncRNAs) are associated with cardiac pathologies, but their functions in cardiac fibroblasts and contributions to cardiac fibrosis remain unclear. Here, we aimed to identify fibroblast-enriched lncRNAs essential in myocardial infarction (MI)-induced fibrosis and explore the molecular mechanisms responsible for their functions. Global lncRNA profiling was performed in post-MI mouse heart ventricles and transforming growth factor-β (TGF-β)-treated primary cardiac fibroblasts and confirmed in published data sets. We identified the cardiac fibroblast-enriched lncPostn, whose expression is stimulated in cardiac fibrosis induced by MI and the extracellular growth factor TGF-β. The promoter of lncPostn contains a functional TGF-β response element, and lncPostn knockdown suppresses TGF-β-stimulated cardiac fibroblast activation and improves cardiac functions post-MI. LncPostn stabilizes and recruits EP300 to the profibrotic periostin's promoter, representing a major mechanism for its transcriptional activation. Moreover, both MI and TGF-β enhance lncPostn expression while suppressing the cellular growth gatekeeper p53. TGF-β and p53 knockdown-induced profibrotic gene expression and fibrosis occur mainly through lncPostn and show additive effects. Finally, levels of serum lncPostn are significantly increased in patients' postacute MI and show a strong correlation with fibrosis markers, revealing a potential biomarker of cardiac fibrosis. Our findings identify the fibroblast-enriched lncPostn as a potent profibrotic factor, providing a transcriptional link between TGF-β and p53 signaling pathways to regulate fibrosis in cardiac fibroblasts.NEW & NOTEWORTHY Cardiac fibroblasts are essential for the homeostasis of the extracellular matrix, whose remodeling in many cardiovascular diseases leads to fibrosis. Long noncoding RNAs are functional and contribute to the biological processes of cardiovascular development and disorders. Our findings identify the fibroblast-enriched lncPostn as a potent profibrotic factor and demonstrate that serum lncPostn level may serve as a potential biomarker of human cardiac fibrosis postacute myocardial infarction.

TAX1BP1 downregulation by STAT3 in cardiac fibroblasts contributes to diabetes-induced heart failure with preserved ejection fraction

Heart failure (HF) with preserved ejection fraction (HFpEF) is now the most common form of HF and has been reported to be closely related to diabetes. Accumulating evidence suggests that HFpEF patients exhibit cardiac fibrosis. This study investigates whether direct targeted inhibition of the activation of cardiac fibroblasts (CFs), the main effector cells in cardiac fibrosis, improves diabetes-induced HFpEF and elucidates the underlying mechanisms. Twenty-week-old db/db mice exhibited HFpEF, as confirmed by echocardiography and hemodynamic measurements. Proteomics was performed on CFs isolated from the hearts of 20-week-old C57BL/6 and db/db mice. Bioinformatic prediction was used to identify target proteins. Experimental validation was performed in both high glucose (HG)-treated neonatal mouse CFs (NMCFs) and diabetic hearts. TAX1 binding protein 1 (TAX1BP1) was identified as the most significantly differentially expressed protein between 20-week-old C57BL/6 and db/db mice. TAX1BP1 mRNA and protein were markedly downregulated in CFs from diabetic hearts and HG-cultured NMCFs. Overexpression of TAX1BP1 profoundly inhibited HG/diabetes-induced NF-κB nuclear translocation and collagen synthesis in CFs, improved cardiac fibrosis, hypertrophy, inflammation and HFpEF in diabetic mice. Mechanistically, signal transducer and activator of transcription 3 (STAT3), which is phosphorylated and translocated from the cytoplasm into the nucleus under hyperglycemic conditions, bound to TAX1BP1 promoter and blocked TAX1BP1 transcriptional activity, consequently promoting NF-κB nuclear translocation and collagen synthesis in CFs, aggravating cardiac fibrosis, hypertrophy and inflammation, leading to HFpEF in db/db mice. Taken together, our findings demonstrate that targeting regulation of STAT3-TAX1BP1-NF-κB signaling in CFs may be a promising therapeutic approach for diabetes-induced HFpEF.

Non-coding RNAs in the pathophysiology of heart failure with preserved ejection fraction

Heart failure with preserved ejection fraction (HFpEF) is the largest unmet clinical need in cardiovascular medicine. Despite decades of research, the treatment option for HFpEF is still limited, indicating our ongoing incomplete understanding on the underlying molecular mechanisms. Non-coding RNAs, comprising of microRNAs (miRNAs), long non-coding RNAs (lncRNAs) and circular RNAs (circRNAs), are non-protein coding RNA transcripts, which are implicated in various cardiovascular diseases. However, their role in the pathogenesis of HFpEF is unknown. Here, we discuss the role of miRNAs, lncRNAs and circRNAs that are involved in the pathophysiology of HFpEF, namely microvascular dysfunction, inflammation, diastolic dysfunction and cardiac fibrosis. We interrogated clinical evidence and dissected the molecular mechanisms of the ncRNAs by looking at the relevant in vivo and in vitro models that mimic the co-morbidities in patients with HFpEF. Finally, we discuss the potential of ncRNAs as biomarkers and potential novel therapeutic targets for future HFpEF treatment.

The lncRNA MEG3/miRNA-21/P38MAPK axis inhibits coxsackievirus 3 replication in acute viral myocarditis

Evidence is emerging on the roles of long noncoding RNAs (lncRNAs) as regulatory factors in a variety of viral infection processes, but the mechanisms underlying their functions in coxsackievirus group B type3 (CVB3)-induced acute viral myocarditis have not been explicitly delineated. We previously demonstrated that CVB3 infection decreases miRNA-21 expression; however, lncRNAs that regulate the miRNA-21-dependent CVB3 disease process have yet to be identified. To evaluate lncRNAs upstream of miRNA-21, differentially expressed lncRNAs in CVB3-infected mouse hearts were identified by microarray analysis and lncRNA/miRNA-21 interactions were predicted bioinformatically. MEG3 was identified as a candidate miRNA-21-interacting lncRNA upregulated in CVB3-infected mouse hearts. MEG3 expression was verified to be upregulated in HeLa cells 48 h post CVB3 infection and to act as a competitive endogenous RNA of miRNA-21. MEG3 knockdown resulted in the upregulation of miRNA-21, which inhibited CVB3 replication by attenuating P38-MAPK signaling in vitro and in vivo. Knockdown of MEG3 expression before CVB3 infection inhibited viral replication in mouse hearts and alleviated cardiac injury, which improved survival. Furthermore, the knockdown of CREB5, which was predicted bioinformatically to function upstream of MEG3, was demonstrated to decrease MEG3 expression and CVB3 viral replication. This study identifies the function of the lncRNA MEG3/miRNA-21/P38 MAPK axis in the process of CVB3 replication, for which CREB5 could serve as an upstream modulator.

High hydrostatic pressure participates in atrial fibrosis through the p300/p53/Smad3 pathway

As an independent risk factor of atrial fibrillation (AF), hypertension (HTN) can induce atrial fibrosis through cyclic stretch and hydrostatic pressure. The mechanism by which high hydrostatic pressure promotes atrial fibrosis is unclear yet. p300 and p53/Smad3 play important roles in the process of atrial fibrosis. This study investigated whether high hydrostatic pressure promotes atrial fibrosis by activating the p300/p53/Smad3 pathway. Biochemical experiments were used to study the expression of p300/p53/Smad3 pathway in left atrial appendage (LAA) tissues of patients with sinus rhythm (SR), AF, AF + HTN, and C57/BL6 mice, hypertensive C57/BL6 mice and atrial fibroblasts of mice. To investigate the roles of p300 and p53 in the process of atrial fibrosis, p300 and p53 in mice atrial fibroblasts were knocked in or knocked down, respectively. The expression of p300/p53/Smad3 and fibrotic factors was higher in patients with AF and AF + HTN than those with SR only. The expressions of p300/p53/Smad3 and fibrotic factors increased in hypertensive mice. Curcumin (Cur) and knocking down of p300 reversed the expressions of these factors. 40 mmHg hydrostatic pressure/overexpression of p300 upregulated the expressions of p300/p53/Smad3 and fibrotic factors in mice LAA fibroblasts. While Cur or knocking down p300 reversed these changes. Knocking down/overexpression of p53, the expressions of p53/Smad3 and fibrotic factors also decreased/increased, correspondingly. High hydrostatic pressure promotes atrial fibrosis by activating the p300/p53/Smad3 pathway, which further increases the susceptibility to AF.

LncRNA MEG3: Targeting the Molecular Mechanisms and Pathogenic causes of Metabolic Diseases

BACKGROUND

Non-coding RNA is a type of RNA that does not encode proteins, distributed among rRNA, tRNA, snRNA, snoRNA, microRNA and other RNAs with identified functions, where the Long non-coding RNA (lncRNA) displays a nucleotide length over 200. LncRNAs enable multiple biological processes in the human body, including cancer cell invasion and metastasis, apoptosis, cell autophagy, inflammation, etc. Recently, a growing body of studies has demonstrated the association of lncRNAs with obesity and obesity-induced insulin resistance and NAFLD, where MEG3 is related to glucose metabolism, such as insulin resistance. In addition, MEG3 has been demonstrated in the pathological processes of various cancers, such as mediating inflammation, cardiovascular disease, liver disease and other metabolic diseases.

OBJECTIVE

To explore the regulatory role of lncRNA MEG3 in metabolic diseases. It provides new ideas for clinical treatment or experimental research.

METHODS

In this paper, in order to obtain enough data, we integrate and analyze the data in the PubMed database.

RESULTS

LncRNA MEG3 can regulate many metabolic diseases, such as insulin resistance, NAFLD, inflammation and so on.

CONCLUSION

LncRNA MEG3 has a regulatory role in a variety of metabolic diseases, which are currently difficult to be completely cured, and MEG3 is a potential target for the treatment of these diseases. Here, we review the role of lncRNA MEG3 in mechanisms of action and biological functions in human metabolic diseases.

Epigenetic signatures in cardiac fibrosis: Focusing on noncoding RNA regulators as the gatekeepers of cardiac fibroblast identity

Cardiac fibroblasts play a pivotal role in cardiac fibrosis by transformation of fibroblasts into myofibroblasts, which synthesis and secrete a large number of extracellular matrix proteins. Ultimately, this will lead to cardiac wall stiffness and impaired cardiac performance. The epigenetic regulation and fate reprogramming of cardiac fibroblasts has been advanced considerably in recent decades. Non coding RNAs (microRNAs, lncRNAs, circRNAs) regulate the functions and behaviors of cardiac fibroblasts, including proliferation, migration, phenotypic transformation, inflammation, pyroptosis, apoptosis, autophagy, which can provide the basis for novel targeted therapeutic treatments that abrogate activation and inflammation of cardiac fibroblasts, induce different death pathways in cardiac fibroblasts, or make it sensitive to established pathogenic cells targeted cytotoxic agents and biotherapy. This review summarizes our current knowledge in this field of ncRNAs function in epigenetic regulation and fate determination of cardiac fibroblasts as well as the details of signaling pathways contribute to cardiac fibrosis. Moreover, we will comment on the emerging landscape of lncRNAs and circRNAs function in regulating signal transduction pathways, gene translation processes and post-translational regulation of gene expression in cardiac fibroblast. In the end, the prospect of cardiac fibroblasts targeted therapy for cardiac fibrosis based on ncRNAs is discussed.

Long Non-Coding RNAs (lncRNAs) in Heart Failure: A Comprehensive Review

Heart failure (HF) is a widespread cardiovascular condition that poses significant risks to a wide spectrum of age groups and leads to terminal illness. Although our understanding of the underlying mechanisms of HF has improved, the available treatments still remain inadequate. Recently, long non-coding RNAs (lncRNAs) have emerged as crucial players in cardiac function, showing possibilities as potential targets for HF therapy. These versatile molecules interact with chromatin, proteins, RNA, and DNA, influencing gene regulation. Notable lncRNAs like Fendrr, Trpm3, and Scarb2 have demonstrated therapeutic potential in HF cases. Additionally, utilizing lncRNAs to forecast survival rates in HF patients and distinguish various cardiac remodeling conditions holds great promise, offering significant benefits in managing cardiovascular disease and addressing its far-reaching societal and economic impacts. This underscores the pivotal role of lncRNAs in the context of HF research and treatment.

Single-cell transcriptional landscape of long non-coding RNAs orchestrating mouse heart development

Long non-coding RNAs (lncRNAs) comprise the most representative transcriptional units of the mammalian genome. They are associated with organ development linked with the emergence of cardiovascular diseases. We used bioinformatic approaches, machine learning algorithms, systems biology analyses, and statistical techniques to define co-expression modules linked to heart development and cardiovascular diseases. We also uncovered differentially expressed transcripts in subpopulations of cardiomyocytes. Finally, from this work, we were able to identify eight cardiac cell-types; several new coding, lncRNA, and pcRNA markers; two cardiomyocyte subpopulations at four different time points (ventricle E9.5, left ventricle E11.5, right ventricle E14.5 and left atrium P0) that harbored co-expressed gene modules enriched in mitochondrial, heart development and cardiovascular diseases. Our results evidence the role of particular lncRNAs in heart development and highlight the usage of co-expression modular approaches in the cell-type functional definition.

Epigallocatechin gallate prevents cardiomyocytes from pyroptosis through lncRNA MEG3/TAF15/AIM2 axis in myocardial infarction

BACKGROUND

( -)-Epigallocatechin-3-gallate (EGCG), a bioactive polyphenol isolated from green tea, has recently garnered attention for its potential protective role against acute myocardial infarction (MI) via inhibiting inflammation. Herein, we tested whether EGCG participates in modulating cardiac ischemia reperfusion-induced injury and elucidate its potential mechanisms.

METHODS

To induce MI in mice, we employed coronary artery ligation, while cell models utilized oxygen glucose deprivation/re-oxygenation (OGD/R)-treated HL-1 cells. TTC, HE and Massion staining evaluated the pathological changes of heart tissues. Besides, RNA-pull down and RIP assays analyzed the interactions of MEG3/TAF15 and AIM2 mRNA/TAF15. FISH associated with immunofiuorescence (IF) double staining was conducted to measure the co-localization of MEG3 and TAF15.

RESULTS

In vitro and in vivo evidence supported that EGCG treatment improved cardiomyocytes viability while inhibiting the expressions of AIM2, C-caspase-1, ASC, GSDMD-N, IL-18 and IL-1β. Knockdown of MEG3 intensified EGCG's therapeutic effects both in vitro and in vivo. LncRNA MEG3 and AIM2 mRNA interacted with TAF15, and MEG3, in turn, promoted the stability of AIM2 mRNA through regulating TAF15. Overexpression of TAF15 reversed the promoting effect of EGCG and MEG3 knockdown on cell viability, and the inhibiting effect on cell pyroptosis.

CONCLUSION

EGCG protected cardiomyocytes from pyroptosis by the MEG3/TAF15/AIM2 axis, indicating EGCG as a potential novel therapeutic strategy for managing MI.

LncRNA Fendrr: involvement in the protective role of nucleolin against H2O2-induced injury in cardiomyocytes

Background: Nucleolin is a multifunctional nucleolar protein with RNA-binding properties. Increased nucleolin expression protects cells from H2O2-induced damage, but the mechanism remains unknown. Long noncoding RNAs (lncRNAs) play crucial roles in cardiovascular diseases. However, the biological functions and underlying mechanisms of lncRNAs in myocardial injury remain unclear.Methods: In a nucleolin-overexpressing cardiac cell line, high-throughput technology was used to identify lncRNAs controlled by nucleolin. Cell counting kit-8 assay was used to determine cell viability, lactate dehydrogenase (LDH) assay to detect cell death, caspase activity assay and propidium iodide staining to confirm cell apoptosis, and RNA immunoprecipitation to examine the interaction between Fendrr and nucleolin.Results: We found that Fendrr expression was significantly downregulated in mouse hearts subjected to myocardial ischemia-reperfusion (MI/R) injury. High Fendrr expression abrogated H2O2-mediated injury in cardiomyocytes as evidenced by increased cell viability and decreased cell apoptosis. Conversely, Fendrr knockdown exacerbated the cardiomyocytes injury. Also, nucleolin overexpression inhibits Fendrr downregulation in H2O2-induced cardiomyocyte injury. Fendrr overexpression significantly reversed the role of the suppression of nucleolin expression in H2O2-induced cardiomyocytes.Conclusion: LncRNA Fendrr is involved in the cardioprotective effect of nucleolin against H2O2-induced injury and may be a potential therapeutic target for oxidative stress-induced myocardial injury.

Long non-coding RNAs and pancreatic cancer: A multifaceted view

Pancreatic cancer (PC) is a highly malignant disease with a 5-year survival rate of only 10%. Families with PC are at greater risk, as are type 2 diabetes, pancreatitis, and other factors. Insufficient early detection methods make this cancer have a poor prognosis. Additionally, the molecular mechanisms underlying PC development remain unclear. Increasing evidence suggests that long non-coding RNAs (lncRNAs) contribute to PC pathology,which may control gene expression by recruiting histone modification complexes to chromatin and interacting with proteins and RNAs. In recent studies, abnormal regulation of lncRNAs has been implicated in PC proliferation, metastasis, invasion, angiogenesis, apoptosis, and chemotherapy resistance suggesting potential clinical implications. The paper reviews the progress of lncRNA research in PC about diabetes mellitus, pancreatitis, cancer metastasis, tumor microenvironment regulation, and chemoresistance. Furthermore, lncRNAs may serve as potential therapeutic targets and biomarkers for PC diagnosis and prognosis. This will help improve PC patients' survival rate from a lncRNA perspective.

The role and medical prospects of long non-coding RNAs in cardiovascular disease

Cardiovascular disease (CVD) has reached epidemic proportions and is a leading cause of death worldwide. One of the long-standing goals of scientists is to repair heart tissue damaged by various forms of CVD such as cardiac hypertrophy, dilated cardiomyopathy, myocardial infarction, heart fibrosis, and genetic and developmental heart defects such as heart valve deformities. Damaged or defective heart tissue has limited regenerative capacity and results in a loss of functioning myocardium. Advances in transcriptomic profiling technology have revealed that long noncoding RNA (lncRNA) is transcribed from what was once considered "junk DNA." It has since been discovered that lncRNAs play a critical role in the pathogenesis of various CVDs and in myocardial regeneration. This review will explore how lncRNAs impact various forms of CVD as well as those involved in cardiomyocyte regeneration. Further, we discuss the potential of lncRNAs as a therapeutic modality for treating CVD.

The complex role of MEG3: An emerging long non-coding RNA in breast cancer

MEG3, a significant long non-coding RNA (lncRNA), substantially functions in diverse biological processes, particularly breast cancer (BC) development. Within the imprinting DLK-MEG3 region on human chromosomal region 14q32.3, MEG3 spans 35 kb and encompasses ten exons. It exerts regulatory effects through intricate interactions with miRNAs, proteins, and epigenetic modifications. MEG3's multifaceted function in BC is evident in gene expression modulation, osteogenic tissue differentiation, and involvement in bone-related conditions. Its role as a tumor suppressor is highlighted by its influence on miR-182 and miRNA-29 expression in BC. Additionally, MEG3 is implicated in acute myocardial infarction and endothelial cell function, emphasising cell-specific regulatory mechanisms. MEG3's impact on gene activity encompasses transcriptional and post-translational adjustments, including DNA methylation, histone modifications, and interactions with transcription factors. MEG3 dysregulation is linked to unfavourable outcomes and drug resistance. Notably, higher MEG3 expression is associated with enhanced survival in BC patients. Overcoming challenges such as unravelling context-specific interactions, understanding epigenetic control, and translating findings into clinical applications is imperative. Prospective endeavours involve elucidating underlying mechanisms, exploring epigenetic alterations, and advancing MEG3-based diagnostic and therapeutic approaches. A comprehensive investigation into broader signaling networks and rigorous clinical trials are pivotal. Rigorous validation through functional and molecular analyses will shed light on MEG3's intricate contribution to BC progression.

Astragaloside IV derivative HHQ16 ameliorates infarction-induced hypertrophy and heart failure through degradation of lncRNA4012/9456

Reversing ventricular remodeling represents a promising treatment for the post-myocardial infarction (MI) heart failure (HF). Here, we report a novel small molecule HHQ16, an optimized derivative of astragaloside IV, which effectively reversed infarction-induced myocardial remodeling and improved cardiac function by directly acting on the cardiomyocyte to reverse hypertrophy. The effect of HHQ16 was associated with a strong inhibition of a newly discovered Egr2-affiliated transcript lnc9456 in the heart. While minimally expressed in normal mouse heart, lnc9456 was dramatically upregulated in the heart subjected to left anterior descending coronary artery ligation (LADL) and in cardiomyocytes subjected to hypertrophic stimulation. The critical role of lnc9456 in cardiomyocyte hypertrophy was confirmed by specific overexpression and knockout in vitro. A physical interaction between lnc9456 and G3BP2 increased NF-κB nuclear translocation, triggering hypertrophy-related cascades. HHQ16 physically bound to lnc9456 with a high-affinity and induced its degradation. Cardiomyocyte-specific lnc9456 overexpression induced, but knockout prevented LADL-induced, cardiac hypertrophy and dysfunction. HHQ16 reversed the effect of lnc9456 overexpression while lost its protective role when lnc9456 was deleted, further confirming lnc9456 as the bona fide target of HHQ16. We further identified the human ortholog of lnc9456, also an Egr2-affiliated transcript, lnc4012. Similarly, lnc4012 was significantly upregulated in hypertrophied failing hearts of patients with dilated cardiomyopathy. HHQ16 also specifically bound to lnc4012 and caused its degradation and antagonized its hypertrophic effects. Targeted degradation of pathological increased lnc4012/lnc9456 by small molecules might serve as a novel promising strategy to regress infarction-induced cardiac hypertrophy and HF.

Cardiac Fibrosis in heart failure: Focus on non-invasive diagnosis and emerging therapeutic strategies

Heart failure is a leading cause of mortality and hospitalization worldwide. Cardiac fibrosis, resulting from the excessive deposition of collagen fibers, is a common feature across the spectrum of conditions converging in heart failure. Eventually, either reparative or reactive in nature, in the long-term cardiac fibrosis contributes to heart failure development and progression and is associated with poor clinical outcomes. Despite this, specific cardiac antifibrotic therapies are lacking, making cardiac fibrosis an urgent unmet medical need. In this context, a better patient phenotyping is needed to characterize the heterogenous features of cardiac fibrosis to advance toward its personalized management. In this review, we will describe the different phenotypes associated with cardiac fibrosis in heart failure and we will focus on the potential usefulness of imaging techniques and circulating biomarkers for the non-invasive characterization and phenotyping of this condition and for tracking its clinical impact. We will also recapitulate the cardiac antifibrotic effects of existing heart failure and non-heart failure drugs and we will discuss potential strategies under preclinical development targeting the activation of cardiac fibroblasts at different levels, as well as targeting additional extracardiac processes.

Long non-coding RNAs: The hidden players in diabetes mellitus-related complications

BACKGROUND AND AIM

Long non-coding RNAs (lncRNAs) have been recognized as important regulators of gene expression in various human diseases. Diabetes mellitus (DM) is a long-term metabolic disorder associated with serious macro and microvascular complications. This review discusses the potential lncRNAs involved in DM-related complications such as dysfunction of pancreatic beta islets, nephropathy, retinopathy, cardiomyopathy, and peripheral neuropathy.

METHODS

An extensive literature search was conducted in the Scopus database to find information from reputed biomedical articles published on lncRNAs and diabetic complications from 2014 to 2023. All review articles were collected and statistically analyzed, and the findings were summarized. In addition, the potential lncRNAs involved in DM-related complications, molecular mechanisms, and gene targets were discussed in detail.

RESULTS

The lncRNAs ANRIL, E33, MALAT1, PVT1, Erbb4-IR, Gm4419, Gm5524, MIAT, MEG3, KNCQ1OT1, Uc.48+, BC168687, HOTAIR, and NONRATT021972 were upregulated in several diabetic complications. However, βlinc1, H19, PLUTO, MEG3, GAS5, uc.322, HOTAIR, MIAT, TUG1, CASC2, CYP4B1-PS1-001, SOX2OT, and Crnde were downregulated. Remarkably, lncRNAs MALAT1, ANRIL, MIAT, MEG3, H19, and HOTAIR were overlapping in more than one diabetic complication and were considered potential lncRNAs.

CONCLUSION

Several lncRNAs are identified as regulators of DM-related complications. The expression of lncRNAs is up or downregulated depending on the disease context, target genes, and regulatory partners. However, most lncRNAs target oxidative stress, inflammation, apoptosis, fibrosis, and angiogenesis pathways to mediate their protective/pathogenic mechanism of action and contribute to DM-related complications.

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.

CVD-associated SNPs with regulatory potential reveal novel non-coding disease genes

BACKGROUND

Cardiovascular diseases (CVDs) are the leading cause of death worldwide. Genome-wide association studies (GWAS) have identified many single nucleotide polymorphisms (SNPs) appearing in non-coding genomic regions in CVDs. The SNPs may alter gene expression by modifying transcription factor (TF) binding sites and lead to functional consequences in cardiovascular traits or diseases. To understand the underlying molecular mechanisms, it is crucial to identify which variations are involved and how they affect TF binding.

METHODS

The SNEEP (SNP exploration and analysis using epigenomics data) pipeline was used to identify regulatory SNPs, which alter the binding behavior of TFs and link GWAS SNPs to their potential target genes for six CVDs. The human-induced pluripotent stem cells derived cardiomyocytes (hiPSC-CMs), monoculture cardiac organoids (MCOs) and self-organized cardiac organoids (SCOs) were used in the study. Gene expression, cardiomyocyte size and cardiac contractility were assessed.

RESULTS

By using our integrative computational pipeline, we identified 1905 regulatory SNPs in CVD GWAS data. These were associated with hundreds of genes, half of them non-coding RNAs (ncRNAs), suggesting novel CVD genes. We experimentally tested 40 CVD-associated non-coding RNAs, among them RP11-98F14.11, RPL23AP92, IGBP1P1, and CTD-2383I20.1, which were upregulated in hiPSC-CMs, MCOs and SCOs under hypoxic conditions. Further experiments showed that IGBP1P1 depletion rescued expression of hypertrophic marker genes, reduced hypoxia-induced cardiomyocyte size and improved hypoxia-reduced cardiac contractility in hiPSC-CMs and MCOs.

CONCLUSIONS

IGBP1P1 is a novel ncRNA with key regulatory functions in modulating cardiomyocyte size and cardiac function in our disease models. Our data suggest ncRNA IGBP1P1 as a potential therapeutic target to improve cardiac function in CVDs.

Bioactive Compounds and Cardiac Fibrosis: Current Insight and Future Prospect

Cardiac fibrosis is a pathological condition characterized by excessive deposition of collagen and other extracellular matrix components in the heart. It is recognized as a major contributor to the development and progression of heart failure. Despite significant research efforts in characterizing and identifying key molecular mechanisms associated with myocardial fibrosis, effective treatment for this condition is still out of sight. In this regard, bioactive compounds have emerged as potential therapeutic antifibrotic agents due to their anti-inflammatory and antioxidant properties. These compounds exhibit the ability to modulate fibrogenic processes by inhibiting the production of extracellular matrix proteins involved in fibroblast to myofibroblast differentiation, or by promoting their breakdown. Extensive investigation of these bioactive compounds offers new possibilities for preventing or reducing cardiac fibrosis and its detrimental consequences. This comprehensive review aims to provide a thorough overview of the mechanisms underlying cardiac fibrosis, address the limitations of current treatment strategies, and specifically explore the potential of bioactive compounds as therapeutic interventions for the treatment and/or prevention of cardiac fibrosis.

Endothelial microRNAs and long noncoding RNAs in cardiovascular ageing

Atherosclerosis and numerous other cardiovascular diseases develop in an age-dependent manner. The endothelial cells that line the vessel walls play an important role in the development of atherosclerosis. Non-coding RNA like microRNAs and long non-coding RNAs are known to play an important role in endothelial function and are implicated in the disease progression. Here, we summarize several microRNAs and long non-coding RNAs that are known to have an altered expression with endothelial aging and discuss their role in endothelial cell function and senescence. These processes contribute to aging-induced atherosclerosis development and by targeting the non-coding RNAs controlling endothelial cell function and senescence, atherosclerosis can potentially be attenuated.

SIRT3 Deficiency Enhances Ferroptosis and Promotes Cardiac Fibrosis via p53 Acetylation

Cardiac fibrosis plays an essential role in the development of diastolic dysfunction and contributes to heart failure with preserved ejection fraction (HFpEF). Our previous studies suggested Sirtuin 3 (SIRT3) as a potential target for cardiac fibrosis and heart failure. In the present study, we explored the role of SIRT3 in cardiac ferroptosis and its contribution to cardiac fibrosis. Our data showed that knockout of SIRT3 resulted in a significant increase in ferroptosis, with increased levels of 4-hydroxynonenal (4-HNE) and downregulation of glutathione peroxidase 4 (GPX-4) in the mouse hearts. Overexpression of SIRT3 significantly blunted ferroptosis in response to erastin, a known ferroptosis inducer, in H9c2 myofibroblasts. Knockout of SIRT3 resulted in a significant increase in p53 acetylation. Inhibition of p53 acetylation by C646 significantly alleviated ferroptosis in H9c2 myofibroblasts. To further explore the involvement of p53 acetylation in SIRT3-mediated ferroptosis, we crossed acetylated p53 mutant (p534KR) mice, which cannot activate ferroptosis, with SIRT3KO mice. SIRT3KO/p534KR mice exhibited a significant reduction in ferroptosis and less cardiac fibrosis compared to SIRT3KO mice. Furthermore, cardiomyocyte-specific knockout of SIRT3 (SIRT3-cKO) in mice resulted in a significant increase in ferroptosis and cardiac fibrosis. Treatment of SIRT3-cKO mice with the ferroptosis inhibitor ferrostatin-1 (Fer-1) led to a significant reduction in ferroptosis and cardiac fibrosis. We concluded that SIRT3-mediated cardiac fibrosis was partly through a mechanism involving p53 acetylation-induced ferroptosis in myofibroblasts.

Non-coding RNA mediates endoplasmic reticulum stress-induced apoptosis in heart disease

Apoptosis is a complex and highly self-regulating form of cell death, which is an important cause of the continuous decline in ventricular function and is widely involved in the occurrence and development of heart failure, myocardial infarction, and myocarditis. Endoplasmic reticulum stress plays a crucial role in apoptosis-inducing. Accumulation of misfolded or unfolded proteins causes cells to undergo a stress response called unfolded protein response (UPR). UPR initially has a cardioprotective effect. Nevertheless, prolonged and severe ER stress will lead up to apoptosis of stressed cells. Non-coding RNA is a type of RNA that does not code proteins. An ever-increasing number of studies have shown that non-coding RNAs are involved in regulating endoplasmic reticulum stress-induced cardiomyocyte injury and apoptosis. In this study, the effects of miRNA and LncRNA on endoplasmic reticulum stress in various heart diseases were mainly discussed to clarify their protective effects and potential therapeutic strategies for apoptosis.

Prolonged exposure to the herbicide atrazine promotes kidney fibrosis by activating Wnt/β-catenin signaling in rats

Exposure to atrazine (ATR), a widely-used herbicide, is a potential harmful to human health due to its long-term environmental persistence and bioaccumulation. The effects of chronic exposure to ATR on renal function in rats were evaluated in this research. Female Sprague-Dawley rats at 4 weeks of age were treated with different concentrations of ATR for 6 months. No significant differences  in terms of renal functions were observed after ATR treatment. In histopathological examination of the kidney, Hematoxylin-Eosin staining indicated the development of degenerative changes in a dose-dependent manner. The results revealed that ATR exposure leads to renal fibrosis and that activation of the Wnt/β-catenin pathway plays a potential role in ATR-related renal fibrosis. Levels of transforming growth factor (TGF)-β and TGF-β1 levels and the reactive oxygen species were significantly upregulated after ATR treatment. In conclusion, long-term exposure to ATR could cause kidney fibrosis, which is the result of epithelial-mesenchymal transition caused by inflammation and oxidative stress.

Differential effects of CMV infection on the viability of cardiac cells

Cytomegalovirus (CMV) is a widely prevalent herpesvirus that reaches seroprevalence rates of up to 95% in several parts of the world. The majority of CMV infections are asymptomatic, albeit they have severe detrimental effects on immunocompromised individuals. Congenital CMV infection is a leading cause of developmental abnormalities in the USA. CMV infection is a significant risk factor for cardiovascular diseases in individuals of all ages. Like other herpesviruses, CMV regulates cell death for its replication and establishes and maintains a latent state in the host. Although CMV-mediated regulation of cell death is reported by several groups, it is unknown how CMV infection affects necroptosis and apoptosis in cardiac cells. Here, we infected primary cardiomyocytes, the contractile cells in the heart, and primary cardiac fibroblasts with wild-type and cell-death suppressor deficient mutant CMVs to determine how CMV regulates necroptosis and apoptosis in cardiac cells. Our results reveal that CMV infection prevents TNF-induced necroptosis in cardiomyocytes; however, the opposite phenotype is observed in cardiac fibroblasts. CMV infection also suppresses inflammation, reactive oxygen species (ROS) generation, and apoptosis in cardiomyocytes. Furthermore, CMV infection improves mitochondrial biogenesis and viability in cardiomyocytes. We conclude that CMV infection differentially affects the viability of cardiac cells.

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.

Single-cell transcriptomes in the heart: when every epigenome counts

The response of an organ to stimuli emerges from the actions of individual cells. Recent cardiac single-cell RNA-sequencing studies of development, injury, and reprogramming have uncovered heterogeneous populations even among previously well-defined cell types, raising questions about what level of experimental resolution corresponds to disease-relevant, tissue-level phenotypes. In this review, we explore the biological meaning behind this cellular heterogeneity by undertaking an exhaustive analysis of single-cell transcriptomics in the heart (including a comprehensive, annotated compendium of studies published to date) and evaluating new models for the cardiac function that have emerged from these studies (including discussion and schematics that depict new hypotheses in the field). We evaluate the evidence to support the biological actions of newly identified cell populations and debate questions related to the role of cell-to-cell variability in development and disease. Finally, we present emerging epigenomic approaches that, when combined with single-cell RNA-sequencing, can resolve basic mechanisms of gene regulation and variability in cell phenotype.