lncRNA HOTAIR Protects Myocardial Infarction Rat by Sponging miR-519d-3p

lncRNA HOTAIR and Cardiovascular diseases

Cardiovascular diseases (CVDs) a major contributor to global mortality rates, with a steadily rising prevalence observed across the world. Understanding the molecular mechanisms that underlie the signaling pathways implicated in the pathogenesis of CVDs represents a salient and advantageous avenue toward the development of precision and targeted therapeutics. A recent development in CVDs research is the discovery of long non-coding RNAs (lncRNAs), which are now understood to have crucial roles in the onset and development of several pathophysiological processes. The distinct expression patterns exhibited by lncRNAs in various CVDs contexts, present a significant opportunity for their utilization as both biomarkers and targets for therapeutic intervention. Among the various identified lncRNAs, HOX antisense intergenic RNA (HOTAIR) functions as signaling molecules that are significantly implicated in the pathogenesis of cardiovascular disorders in response to risk factors. HOTAIR has been observed to circulate within the bloodstream and possesses an integral epigenetic regulatory function in the transcriptional pathways of many diseases. Recent studies have suggested that HOTAIR offers promise as a biomarker for the detection and treatment of CVDs. The investigation on HOTAIR's role in CVDs, however, is still in its early phases. The goal of the current study is to give a thorough overview of recent developments in the field of analyzing the molecular mechanism of HOTAIR in controlling the pathophysiological processes of CVDs as well as its possible therapeutic uses.

Exploring the role of non-coding RNAs in atrial septal defect pathogenesis: A systematic review

BACKGROUND

Extensive research has recognized the significant roles of non-coding RNAs (ncRNAs) in various cellular pathophysiological processes and their association with diverse diseases, including atrial septal defect (ASD), one of the most prevalent congenital heart diseases. This systematic review aims to explore the intricate involvement and significance of ncRNAs in the pathogenesis and progression of ASD.

METHODS

Four databases (PubMed, Embase, Scopus, and the Web of Science) were searched systematically up to June 19, 2023, with no year restriction. The risk of bias assessment was evaluated using the Newcastle-Ottawa scale.

RESULTS

The present systematic review included thirteen studies with a collective study population of 874 individuals diagnosed with ASD, 21 parents of ASD patients, and 22 pregnant women carrying ASD fetuses. Our analysis revealed evidence linking five long ncRNAs (STX18-AS1, HOTAIR, AA709223, BX478947, and Moshe) and several microRNAs (hsa-miR-19a, hsa-miR-19b, hsa-miR-375, hsa-miR-29c, miR-29, miR-143/145, miR-17-92, miR-106b-25, and miR-503/424, miR-9, miR-30a, miR-196a2, miR-139-5p, hsa-let-7a, hsa-let-7b, and hsa-miR-486) to ASD progression, corresponding to previous studies.

CONCLUSIONS

NcRNAs play a crucial role in unraveling the underlying mechanisms of ASD, contributing to both biomarker discovery and therapeutic advancements. This systematic review sheds light on the mechanisms of action of key ncRNAs involved in ASD progression, providing valuable insights for future research in this field.

Emerging roles of HOTAIR lncRNA in the pathogenesis and prognosis of cardiovascular diseases

Highlights HOTAIR, a long noncoding RNA, plays a role in the regulation of proteins involved in the pathogenesis of cardiovascular disease. Furthermore, it has been identified as a biomarker of this type of disease. Several factors and cells contribute to atherosclerosis, a progressive disease. However, the prognosis of HOTAIR in this disease varies depending on the path in which it plays a role. For this condition, there is no single prognosis to consider.

Mechanism of lncRNA HOTAIR in attenuating cardiomyocyte pyroptosis in mice with heart failure via the miR-17-5p/RORA axis

Heart failure (HF) is a complex clinical syndrome associated with significant morbidity and mortality. Dysregulation of long non-coding RNA (lncRNA) has been implicated in the pathogenesis of HF. The present study aims to investigate the role of lncRNA HOX transcript antisense RNA (HOTAIR) in cardiomyocyte pyroptosis in a murine HF model. A murine HF model was established through transverse aortic contraction surgery, and an in vitro HF cell model was developed by treating HL-1 cells with H2O2. HOTAIR was overexpressed in TAC mice and HL-1 cells via pcDNA3.1-HOTAIR transfection. Cardiac function was assessed in TAC mice, and myocardial changes were evaluated using HE staining. The expression of NLRP3 was examined by immunohistochemistry. Myocardial injury markers and pyroptosis-related inflammatory cytokines were quantified using ELISA. Protein levels of NLRP3, cleaved-caspase-1, and GSDMD-N were analyzed by Western blot. Dual-luciferase assays and RNA immunoprecipitation were employed to confirm the binding interactions between HOTAIR and miR-17-5p, miR-17-5p and RORA. Functional rescue experiments were conducted by overexpressing miR-17-5p or silencing RORA in HL-1 cells. HOTAIR exhibited reduced expression in TAC mice and H2O2-induced cardiomyocytes. Overexpression of HOTAIR ameliorated cardiac dysfunction, reduced myocardial pathological injury, enhanced cardiomyocyte viability, and decreased myocardial injury and pyroptosis. HOTAIR interacted with miR-17-5p to repress RORA transcription. Overexpression of miR-17-5p or silencing of RORA abolished the inhibitory effect of HOTAIR overexpression on cardiomyocyte pyroptosis. In conclusion, HOTAIR competitively bound to miR-17-5p, relieving its inhibition of RORA transcription and leading to increased RORA expression and suppressed cardiomyocyte pyroptosis in HF models.

Apoptosis and long non-coding RNAs: Focus on their roles in Heart diseases

Heart disease is one of the principal death reasons around the world and there is a growing requirement to discover novel healing targets that have the potential to avert or manage these illnesses. On the other hand, apoptosis is a strongly controlled, cell removal procedure that has a crucial part in numerous cardiac problems, such as reperfusion injury, MI (myocardial infarction), consecutive heart failure, and inflammation of myocardium. Completely comprehending the managing procedures of cell death signaling is critical as it is the primary factor that influences patient mortality and morbidity, owing to cardiomyocyte damage. Indeed, the prevention of heart cell death appears to be a viable treatment approach for heart illnesses. According to current researches, a number of long non-coding RNAs cause the heart cells death via different methods that are embroiled in controlling the activity of transcription elements, the pathways that signals transmission within cells, small miRNAs, and the constancy of proteins. When there is too much cell death in the heart, it can cause problems like reduced blood flow, heart damage after restoring blood flow, heart disease in diabetics, and changes in the heart after reduced blood flow. Therefore, studying how lncRNAs control apoptosis could help us find new treatments for heart diseases. In this review, we present recent discoveries about how lncRNAs are involved in causing cell death in different cardiovascular diseases.

HOTAIR regulates SIRT3-mediated cardiomyocyte survival after myocardial ischemia/reperfusion by interacting with FUS

BACKGROUND

Myocardial ischemia/reperfusion (I/R) contributes to serious myocardial injury and even death. Therefore, prevention and mitigation of myocardial I/R is particularly important. LncRNA HOTAIR has been reported to be implicated in myocardial I/R progression. However, the detailed molecular mechanism of HOTAIR in cardiomyocyte was explored in myocardial I/R.

METHODS

Firstly, cell model of myocardial I/R was established through hypoxia/reoxygenation (H/R). Apoptosis and cell cycle were evaluated utilizing flow cytometry. The corresponding test kits were conducted to monitor the levels of LDH, Caspase3 and Caspase9. The gene expression and protein levels were detected by qPCR and western blot, respectively. RNA pull-down and RIP were performed to verify the interaction between FUS and lncRNA HOTAIR.

RESULTS

In AC16 cardiomyocytes treated with H/R, lncRNA HOTAIR and SIRT3 expression were obviously decreased. Overexpression of HOTAIR or SIRT3 could ameliorate H/R-induced cardiomyocyte injury by promoting cell viability, lowering LDH levels, and suppressing cell apoptosis. Further, lncRNA HOTAIR upregulated the expression of SIRT3 via interacting with FUS, thereby promoting the survival of H/R-injured cardiomyocytes.

CONCLUSION

LncRNA HOTAIR can improve myocardial I/R by affecting cardiomyocyte survival through regulation of SIRT3 by binding to the RNA binding protein FUS.

New developments in non-exosomal and exosomal ncRNAs in coronary artery disease

Aim & methods: Non-exosomal and exosomal ncRNAs have been reported to be involved in the regulation of coronary artery disease (CAD). Therefore, to explore the biological effects of non-exosomal/exosomal ncRNAs in CAD, the authors searched for studies published in the last 3 years on these ncRNAs in CAD and summarized their functions and mechanisms. Results: The authors summarized 120 non-exosomal ncRNAs capable of regulating CAD progression. In clinical studies, 47 non-exosomal and nine exosomal ncRNAs were able to serve as biomarkers for the diagnosis of CAD. Conclusion: Non-exosomal/exosomal ncRNAs are not only able to serve as biomarkers for CAD diagnosis but can also regulate CAD progression through ceRNA mechanisms and are a potential target for early clinical intervention in CAD.

Bone Marrow Mesenchymal Stem Cell-Derived Exosomal microRNA-29b-3p Promotes Angiogenesis and Ventricular Remodeling in Rats with Myocardial Infarction by Targeting ADAMTS16

An increasing amount of evidence has suggested that microRNA (miR) plays a role in myocardial infarction (MI). Our study aimed to discuss the impact of exosomal miR-29b-3p in MI by regulating A Disintegrin and Metalloproteinase with Thrombospondin Motifs 16 (ADAMTS16). Exosomes were extracted from bone marrow mesenchymal stem cells (BMSCs). In a rat model of MI, myocardial angiogenesis and ventricular remodeling-related factors, as well as myocardial fibrosis, collagen volume fraction (CVF), capillary density, level of vascular endothelial growth factor (VEGF), and apoptosis of cardiomyocytes, were tested. ADAMTS16 and miR-29b-3p levels in the myocardial tissue of MI rats were tested. miR-29b-3p expression was decreased and ADAMTS16 expression was increased in the myocardial tissue of MI rats. ADAMTS16 was a target gene of miR-29b-3p. Upregulated miR-29b-3p delivered by BMSC-derived exosomes improved myocardial angiogenesis and ventricular remodeling, reduced myocardial fibrosis and CVF, increased capillary density and VEGF expression, and suppressed apoptosis of cardiomyocytes in MI rats. ADAMTS16 overexpression accelerated MI in rats, and ADAMTS16 upregulation reversed the protective effects of miR-29b-3p upregulation on MI rats. Our study provides evidence that upregulated miR-29b-3p delivered by BMSC-secreted exosomes can improve myocardial angiogenesis and ventricular remodeling in rats with MI by targeting ADAMTS16.

N, Adigal S, Lukose J, Kartha VB, Chidangil S. Cardiovascular biomarkers in body fluids: progress and prospects in optical sensors

Cardiovascular diseases (CVD) are the major causative factors for high mortality and morbidity in developing and developed nations. The biomarker detection plays a crucial role in the early diagnosis of several non-infectious and life-threatening diseases like CVD and many cancers, which in turn will help in more successful therapy, reducing the mortality rate. Biomarkers have diagnostic, prognostic and therapeutic significances. The search for novel biomarkers using proteomics, bio-sensing, micro-fluidics, and spectroscopic techniques with good sensitivity and specificity for CVD is progressing rapidly at present, in addition to the use of gold standard biomarkers like troponin. This review is dealing with the current progress and prospects in biomarker research for the diagnosis of cardiovascular diseases. Expert opinion. Fast diagnosis of cardiovascular diseases (CVDs) can help to provide rapid medical intervention, which can affect the patient's short and long-term health. Identification and detection of proper biomarkers for early diagnosis are crucial for successful therapy and prognosis of CVDs. The present review discusses the analysis of clinical samples such as whole blood, blood serum, and other body fluids using techniques like high-performance liquid chromatography-LASER/LED-induced fluorescence, Raman spectroscopy, mainly, optical methods, combined with nanotechnology and micro-fluidic technologies, to probe patterns of multiple markers (marker signatures) as compared to conventional techniques.

Exploration of the α-syn/T199678/miR-519-3p/KLF9 pathway in a PD-related α-syn pathology

BACKGROUND

Kruppel-like factor 9 (KLF9) plays a key role as an inducer of cellular oxidative stress in the modulation of cell death and in oxidant-dependent tissue injury. Our previous study indicated that lncRNA-T199678 (T199678) affected the expression of KLF9 in an α-synuclein (α-syn) induced cellular model. However, the roles of interactions among α-syn, T199678, KLF9 and related microRNAs (miRNAs) in the Parkinson's disease (PD)-related α-syn pathology are unclear and were therefore investigated in this study.

METHODS

An α-syn-injected mouse model and an α-syn exposed SY-SH5Y cellular model were used in this study. We confirmed the utility of these established models with morphological and behavioral methods. We checked how expression of T199678 and KLF9 were affected by α-syn and demonstrated their interaction by fluorescence in situ hybridization (FISH) staining and western blots. We analyzed expression in ROS+ cells by immunohistochemistry. Finally, we obtained seven miRNAs through bioinformatic analysis simultaneously affected by T199678 and α-syn and verified these with RT-PCR.

RESULTS

We found that expression of KLF9 was regulated by T199678, whereas expression of T199678 was not affected by KLF9 in the α-syn exposed SY-SH5Y cells. These findings suggest that KLF9 is the downstream gene regulated by T199678, whereas miR-519-3p may play a contributing role. We also confirmed that α-syn injection upregulated the expression of ROS, which could be downregulated by upregulation of T199678, indicating an anti-oxidative role of T199678 in the α-syn-related mechanisms.

CONCLUSIONS

Our results indicate the existence of a potential α-syn/T199678/miR-519-3p /KLF9 pathway in PD-related α-syn pathology. This pathway might explain oxidative stress processes in α-syn-related mechanisms, which requires further verification.

Non-Coding RNAs: Prevention, Diagnosis, and Treatment in Myocardial Ischemia-Reperfusion Injury

Recent knowledge concerning the role of non-coding RNAs (ncRNAs) in myocardial ischemia/reperfusion (I/R) injury provides new insight into their possible roles as specific biomarkers for early diagnosis, prognosis, and treatment. MicroRNAs (miRNAs) have fewer than 200 nucleotides, while long ncRNAs (lncRNAs) have more than 200 nucleotides. The three types of ncRNAs (miRNAs, lncRNAs, and circRNAs) act as signaling molecules strongly involved in cardiovascular disorders (CVD). I/R injury of the heart is the main CVD correlated with acute myocardial infarction (AMI), cardiac surgery, and transplantation. The expression levels of many ncRNAs and miRNAs are highly modified in the plasma of MI patients, and thus they have the potential to diagnose and treat MI. Cardiomyocyte and endothelial cell death is the major trigger for myocardial ischemia–reperfusion syndrome (MIRS). The cardioprotective effect of inflammasome activation in MIRS and the therapeutics targeting the reparative response could prevent progressive post-infarction heart failure. Moreover, the pharmacological and genetic modulation of these ncRNAs has the therapeutic potential to improve clinical outcomes in AMI patients.

Validated Impacts of N6-Methyladenosine Methylated mRNAs on Apoptosis and Angiogenesis in Myocardial Infarction Based on MeRIP-Seq Analysis

Objectives: N6-methyladenosine (m⁶A) is hypothesized to play a role in the regulation of pathogenesis of myocardial infarction (MI). This study was designed to compare m⁶A-tagged transcript profiles to identify mRNA-specific changes on pathophysiological variations after MI.

Methods: N6-methyladenosine methylated RNA immunoprecipitation sequencing (MeRIP-seq) and RNA sequencing (RNA-seq) were interacted to select m⁶A-modified mRNAs with samples collected from sham operated and MI rat models. m⁶A methylation regulated mRNAs were interacted with apoptosis/angiogenesis related genes in GeneCards. Afterwards, MeRIP-quantitative real-time PCR (MeRIP-qRT-PCR) was performed to measure m⁶A methylation level of hub mRNAs. m⁶A methylation variation was tested under different oxygen concentration or hypoxic duration in H9c2 cells and HUVECs. In addition, Western blot and qRT-PCR were employed to detect expression of hub mRNAs and relevant protein level. Flow cytometry and Tunel assay were conducted to assess apoptotic level. CCK-8, EdU, and tube formation assay were performed to measure cell proliferation and tube formation ability.

Results: Upregulation of Mettl3 was firstly observed in vivo and in vitro, followed by upregulation of m⁶A methylation level. A total of 567 significantly changed m⁶A methylation peaks were identified, including 276 upregulated and 291 downregulated peaks. A total of 576 mRNAs were upregulated and 78 were downregulated. According to combined analysis of MeRIP-seq and RNA-seq, we identified 26 significantly hypermethylated and downregulated mRNAs. Based on qRT-PCR and interactive analysis, Hadh, Kcnn1, and Tet1 were preliminarily identified as hub mRNAs associated with apoptosis/angiogenesis. MeRIP-qRT-PCR assay confirmed the results from MeRIP-seq. With the inhibition of Mettl3 in H9c2 cells and HUVECs, downregulated m⁶A methylation level of total RNA and upregulated expression of hub mRNAs were observed. Increased m⁶A level was verified in the gradient context in terms of prolonged hypoxic duration and decreased oxygen concentration. Under simulated hypoxia, roles of Kcnn1 and Tet1 in angiogenesis and Hadh, Tet1, and Kcnn1 in apoptosis were further confirmed with our validation experiments.

Conclusion: Roles of m⁶A-modified mRNA transcripts in the context of MI were preliminarily verified. In the context of m⁶A methylation, three hub mRNAs were validated to impact the process of apoptosis/angiogenesis. Our study provided theoretical basis and innovative targets for treatment of MI and paved the way for future investigations aiming at exploring upstream epigenetic mechanisms of pathogenesis after MI.

The Regulation Mechanisms and Clinical Application of MicroRNAs in Myocardial Infarction: A Review of the Recent 5 Years

Myocardial infarction (MI) is the most frequent end-point of cardiovascular pathology, leading to higher mortality worldwide. Due to the particularity of the heart tissue, patients who experience ischemic infarction of the heart, still suffered irreversible damage to the heart even if the vascular reflow by treatment, and severe ones can lead to heart failure or even death. In recent years, several studies have shown that microRNAs (miRNAs), playing a regulatory role in damaged hearts, bring light for patients to alleviate MI. In this review, we summarized the effect of miRNAs on MI with some mechanisms, such as apoptosis, autophagy, proliferation, inflammatory; the regulation of miRNAs on cardiac structural changes after MI, including angiogenesis, myocardial remodeling, fibrosis; the application of miRNAs in stem cell therapy and clinical diagnosis; other non-coding RNAs related to miRNAs in MI during the past 5 years.

Targeting Epigenetics and Non-coding RNAs in Myocardial Infarction: From Mechanisms to Therapeutics

Myocardial infarction (MI) is a complicated pathology triggered by numerous environmental and genetic factors. Understanding the effect of epigenetic regulation mechanisms on the cardiovascular disease would advance the field and promote prophylactic methods targeting epigenetic mechanisms. Genetic screening guides individualised MI therapies and surveillance. The present review reported the latest development on the epigenetic regulation of MI in terms of DNA methylation, histone modifications, and microRNA-dependent MI mechanisms and the novel therapies based on epigenetics.

Ghrelin Relieves Obesity-Induced Myocardial Injury by Regulating the Epigenetic Suppression of miR-196b Mediated by lncRNA HOTAIR

INTRODUCTION

Obesity has been believed to be closely linked with many kinds of diseases including atherosclerosis, hypertension, cerebrovascular thrombosis, and diabetes. Ghrelin and Homeobox transcript antisense RNA (HOTAIR) were believed to be involved in the regulation of myocardial injury.

METHODS

The obesity mice model was established through feeding mice (C57BL/6J, male, eight-week-old) with high-fat diet and palmitate (PA)-induced cardiomyocyte injury. RNA and protein levels were detected with Quantitative real-time PCR and Western blotting. The levels of TG, TCH, LDL, CK-MB, cTnl, and BNP in the serum or cell medium supernatant were measured using ELISA kits. The ROS level was detected with the DCFH-DA method. Binding sites between different targets were identified using detection of dual luciferase reporter assay. Cell apoptosis was analyzed by flow cytometry. RNA-binding protein immunoprecipitation and chromatin immunoprecipitation were used to detect the binding of DNMT3B with HOTAIR or miR-196b promoter.

RESULTS

The expression of HOTAIR was downregulated, and miR-196b was upregulated in the obese myocardial injury. Ghrelin attenuated PA-induced cardiomyocyte injury by increasing HOTAIR. HOTAIR regulated the expression of miR-196b by recruiting DNMT3B to induce methylation of the miR-196b gene promoter. The binding site between miR-196b and IGF-1 was identified.

DISCUSSION/CONCLUSION

We demonstrated that ghrelin attenuated PA-induced cardiomyocyte injury by regulating the HOTAIR/miR-196b/IGF-1 signaling pathway. Our findings might provide novel thought for the prevention and treatment of obesity-induced myocardial injury by targeting HOTAIR/miR-196b.

Identification of Two Long Non-Coding RNAs AC010082.1 and AC011443.1 as Biomarkers of Coronary Heart Disease Based on Logistic Stepwise Regression Prediction Model

Coronary heart disease (CHD) is a global health concern with high morbidity and mortality rates. This study aimed to identify the possible long non-coding RNA (lncRNA) biomarkers of CHD. The lncRNA- and mRNA-related data of patients with CHD were downloaded from the Gene Expression Omnibus database (GSE113079). The limma package was used to identify differentially expressed lncRNAs and mRNAs (DElncRNAs and DEmRNAs, respectively). Then, miRcode, TargetScan, miRDB, and miRTarBase databases were used to form the competing endogenous RNA (ceRNA) network. Furthermore, SPSS Modeler 18.0 was used to construct a logistic stepwise regression prediction model for CHD diagnosis based on DElncRNAs. Of the microarray data, 70% was used as a training set and 30% as a test set. Moreover, a validation cohort including 30 patients with CHD and 30 healthy controls was used to verify the hub lncRNA expression through real-time reverse transcription-quantitative PCR (RT-qPCR). A total of 185 DElncRNAs (114 upregulated and 71 downregulated) and 382 DEmRNAs (162 upregulated and 220 downregulated) between CHD and healthy controls were identified from the microarray data. Furthermore, through bioinformatics prediction, a 38 lncRNA-21miRNA-40 mRNA ceRNA network was constructed. Next, by constructing a logistic stepwise regression prediction model for 38 DElncRNAs, we screened two hub lncRNAs AC010082.1 and AC011443.1 (p < 0.05). The sensitivity, specificity, and area under the curve were 98.41%, 100%, and 0.995, respectively, for the training set and 93.33%, 91.67%, and 0.983, respectively, for the test set. We further verified the significant upregulation of AC010082.1 (p < 0.01) and AC011443.1 (p < 0.05) in patients with CHD using RT-qPCR in the validation cohort. Our results suggest that lncRNA AC010082.1 and AC011443.1 are potential biomarkers of CHD. Their pathological mechanism in CHD requires further validation.

Roles and functions of antisense lncRNA in vascular aging

Vascular aging is a major cause of morbidity and mortality in the elderly population. Endothelial cells (ECs) and vascular smooth muscle cells (VSMCs), forming the intima and media layers of the vessel wall respectively, are closely associated with the process of vascular aging and vascular aging-related diseases. Numerous studies have revealed the pathophysiologic mechanism through which lncRNA contributes to vascular aging, hence more attention is now paid to the role played by antisense long non-coding RNA (AS-lncRNA) in the pathogenesis of vascular aging. Nonetheless, only a small number of studies focus on the specific mechanism through which AS-lncRNA mediates vascular aging. In this review, we summarize the roles and functions of AS-lncRNA with regards to the development of vascular aging and vascular aging-related disease. We also aim to deepen our understanding of this process and provide alternative therapeutic modalities for vascular aging-related diseases.

LncRNA H19 abrogates the protective effects of curcumin on rat carotid balloon injury via activating Wnt/β-catenin signaling pathway

Intimal hyperplasia-induced restenosis is a common response to vascular endothelial damage caused by mechanical force or other stimulation, and is closely linked to vascular remodeling. Curcumin, a traditional Chinese medicine, exhibits potent protective effects in cardiovascular diseases; for example, it attenuates vascular remodeling. Although the suppressive effects of curcumin on diseases caused by vascular narrowing have been investigated, the underlying mechanisms remain unknown. Long non-coding RNAs (lncRNAs) regulate various pathological processes and affect the action of drugs. In the present study, we found that the curcumin remarkably downregulated the expression of lncRNA H19 and thereby inhibited intimal hyperplasia-induced vascular restenosis. Furthermore, the inhibition of the expression of H19 by curcumin resulted in the inactivation of the Wnt/β-catenin signaling. Overall, we show that curcumin suppresses intimal hyperplasia via the H19/Wnt/β-catenin pathway, implying that H19 is a critical molecule in the suppression of intimal hyperplasia after balloon injury by curcumin. These insights should be useful for potential application of curcumin as a therapeutic intervention in vascular stenosis.

LncRNA RP11-400K9.4 Aggravates Cardiomyocytes Apoptosis After Hypoxia/Reperfusion Injury by Targeting miR-423

Our study was aimed at exploring the roles of lncRNA RP11-400K9.4 (RP11-400K9.4) on hypoxia/reoxygenation (H/R) -induced cardiomyocytes apoptosis. H/R model was constructed in rat primary cardiomyocytes (PC) and H9c2 cells. In this study, the results showed that H/R significantly induced the apoptosis of PC and H9c2 cells. The expression of RP11-400K9.4 was upregulated in H/R-induced PC and H9c2 cells, but miR-423 expression was downregulated. Silencing RP11-400K9.4 could attenuate H/R-induced apoptosis in PC and H9c2 cells. We also found that miR-423 was a potential target of RP11-400K9.4. The effect of silencing RP11-400K9.4 on H/R-induced apoptosis of PC and H9c2 cells was significantly reversed by miR-423 inhibitor transfection. Furthermore, our data confirmed that silencing RP11-400K9.4 promoted the activation of phosphatidylinositol 3-kinase/protein kinase B (PI3K/AKT) and mitogen-activated protein kinase/extracellular signal-regulated kinase (MEK) /extracellular signal-regulated kinase (ERK) pathways and these phenomena can be reversed by miR-423 inhibitor transfection. In conclusion, our study demonstrated that silencing RP11-400K9.4 could alleviate H/R-induced cardiomyocytes damages via suppressing apoptosis by targeting miR-423 with the activation of PI3K/AKT and MEK/ERK signaling pathways.

Downregulation of Hotair or LSD1 Impaired Heart Regeneration in the Neonatal Mouse

Previous studies have shown that lysine-specific demethylase 1 (LSD1) could regulate cell cycle progression through demethylation. The 3'domain of HOX transcript antisense RNA (Hotair) combined with the LSD1/CoREST/REST complex helps LSD1 target the corresponding gene. However, its role in mice's myocardial regeneration is still unclear. The heart from neonatal mice shows strong myocardial regeneration ability, but this ability disappears 7 days after birth. Our study shows that the myocardial tissue highly expresses Hotair and Lsd1 within 1 week after birth, consistent with the myocardial regeneration time window. Knockdown Lsd1 or Hotair expression by RNA interference could inhibit myocardial regeneration and cardiomyocyte proliferation. Our results suggest that Hotair-mediated demethylation of LSD1 may play an important role in myocardial regeneration in neonatal mice.

Circ_0093887 upregulates CCND2 and SUCNR1 to inhibit the ox-LDL-induced endothelial dysfunction in atherosclerosis by functioning as a miR-876-3p sponge

Circular RNAs (circRNAs) are widely expressed in mammals and act as regulatory targets in the atherogenesis. The objective of this study was to research the biological role and molecular mechanism of circ_0093887 in oxidized low-density lipoprotein (ox-LDL)-induced atherosclerosis (AS) of human aortic endothelial cells (HAECs). Cell viability detection was performed by CCK-8 assay. Inflammatory molecules were examined using ELISA. Flow cytometry was used to measure cell-cycle progression and cell apoptotic rate. Caspase 3 activity was determined using caspase 3 activity assay. The expression levels of circ_0093887, miR-876-3p, CCND2 and SUCNR1 were assayed by quantitative real-time polymerase chain reaction (qRT-PCR). Dual-luciferase reporter, RNA immunoprecipitation (RIP) and RNA pull-down assays were used for the target analysis. EdU assay, wound healing assay/transwell assay and tube formation assay were, respectively, used to assess the effects of circ_0093887/miR-876-3p axis on cell proliferation, migration and tube formation. Oxidized low-density lipoprotein inhibited cell viability and cell-cycle progression but induced the inflammatory response and cell apoptosis. Circ_0093887 was downregulated and miR-876-3p was upregulated in AS patients and ox-LDL-treated HAECs. Functionally, the overexpression of circ_0093887 abrogated the cell injury of HAEC exposed to ox-LDL. For the functional mechanism, we found that circ_0093887 was a sponge for miR-876-3p and miR-876 targeted CCND2 or SUCNR1. The reverted experiment indicated that the function of circ_0093887 was achieved by sponging miR-876-3p. Meanwhile, miR-876-3p inhibitor relieved the inhibitory regulation of circ_0093887 knockdown in cell proliferation, migration and tube formation. Downregulation of miR-876-3p also alleviated the ox-LDL-induced cell injury by upregulating the expression of CCND2 or SUCNR1. Furthermore, circ_0093887 was validated to regulate the levels of CCND2 and SUCNR1 via the sponge effect on miR-876-3p. The protective effects of circ_0093887 on HAECs from ox-LDL were also ​alleviated by repressing the CCND2 and SUCNR1 levels. These findings suggested that circ_0093887 protected HAEC against the ox-LDL-induced inflammatory and apoptotic damages by targeting the miR-876-3p/CCND2 or miR-876/SUCNRA axis. Circ_0093887 could act as a potential therapeutic biomarker for AS patients.

The Novel Non-coding Transcriptional Regulator Gm18840 Drives Cardiomyocyte Apoptosis in Myocardial Infarction Post Ischemia/Reperfusion

BACKGROUND

Ischemia/reperfusion-mediated myocardial infarction (MIRI) is a major pathological factor implicated in the progression of ischemic heart disease, but the key factors dysregulated during MIRI have not been fully elucidated, especially those essential non-coding factors required for cardiovascular development.

METHODS

A murine MIRI model and RNA sequencing (RNA-seq) were used to identify key lncRNAs after myocardial infarction. qRT-PCR was used to validate expression in cardiac muscle tissues and myocardial cells. The role of Gm18840 in HL-1 cell growth was determined by flow cytometry experiments in vitro. Full-length Gm18840 was identified by using a rapid amplification of cDNA ends (RACE) assay. The subcellular distribution of Gm18840 was examined by nuclear/cytoplasmic RNA fractionation and qRT-PCR. RNA pulldown and RNA immunoprecipitation (RIP)-qPCR assays were performed to identify Gm18840-interacting proteins. Chromatin isolation by RNA purification (ChIRP)-seq (chromatin isolation by RNA purification) was used to identify the genome-wide binding of Gm18840 to chromatin. The regulatory activity of Gm18840 in transcriptional regulation was examined by a luciferase reporter assay and qRT-PCR.

RESULTS

Gm18840 was upregulated after myocardial infarction in both in vivo and in vitro MIRI models. Gm18840 was 1,471 nt in length and localized in both the cytoplasm and the nucleus of HL-1 cells. Functional studies showed that the knockdown of Gm18840 promoted the apoptosis of HL-1 cells. Gm18840 directly interacts with histones, including H2B, highlighting a potential function in transcriptional regulation. Further ChIRP-seq and RNA-seq analyses showed that Gm18840 is directly bound to the cis-regulatory regions of genes involved in developmental processes, such as Junb, Rras2, and Bcl3.

CONCLUSION

Gm18840, a novel transcriptional regulator, promoted the apoptosis of myocardial cells via direct transcriptional regulation of essential genes and might serve as a novel therapeutic target for MIRI.

CircJARID2 Regulates Hypoxia-Induced Injury in H9c2 Cells by Affecting miR-9-5p-Mediated BNIP3

ABSTRACT

Myocardial infarction (MI) is a common cardiovascular disease, and many circular RNAs (circRNAs) have been found to participate in the pathological process. This study was to research circRNA jumonji and AT-rich interaction domain containing 2 (circJARID2) in MI. MI cell model was established by hypoxia treatment in H9c2 cells. CircJARID2 and microRNA-9-5p (miR-9-5p) levels were examined using real-time polymerase chain reaction. Cell viability detection was performed by Cell Counting Kit-8 (CCK-8) and 5-ethynyl-2'-deoxyuridine (Edu) assays. Cell apoptosis was evaluated by flow cytometry and caspase-3 activity assay. Apoptotic markers and B-cell lymphoma-2 (Bcl-2) interacting protein 3 (BNIP3) were quantified by western blot. Inflammatory cytokines were determined via enzyme-linked immunosorbent assay. The genic interaction was analyzed through dual-luciferase reporter and RNA immunoprecipitation assays. Hypoxia induced the upregulation of circJARID2 expression in H9c2 cells. The hypoxia-induced cell viability inhibition, apoptosis promotion, and inflammatory response were all counterbalanced by knockdown of circJARID2. CircJARID2 interacted with miR-9-5p, and its function in regulating the hypoxia-induced cell injury was also dependent on targeting miR-9-5p. BNIP3 acted as a target gene of miR-9-5p, and circJARID2 had positive effect on BNIP3 expression by binding to miR-9-5p. MiR-9-5p played a protective role for H9c2 cells against the hypoxia-induced injury via targeting BNIP3. CircJARID2 overexpression contributed to the hypoxia-induced H9c2 cell injury by sponging miR-9-5p to upregulate BNIP3 expression, showing a novel molecular network of MI pathomechanism.

Association between HOTAIR lncRNA Polymorphisms and Coronary Artery Disease Susceptibility

Coronary artery disease (CAD), one of the most frequent causes of mortality, is the most common type of cardiovascular disease. This condition is characterized by the accumulation of plaques in the coronary artery, leading to blockage of blood flow to the heart. The main symptom of CAD is chest pain caused by blockage of the coronary artery and shortness of breath. HOX transcript antisense RNA gene (HOTAIR) is a long non-coding RNA which is well-known as an oncogene involved in various cancers, such as lung, breast, colorectal, and gastric cancer. We selected six single nucleotide polymorphisms, rs4759314 A>G, rs1899663 G>T, rs920778 T>C, rs7958904 G>C, rs12826786 C>T, and rs874945 C>T, for genotype frequency analysis and assessed the frequency of HOTAIR gene polymorphisms in 442 CAD patients and 418 randomly selected control subjects. To analyze the differences between these two populations, we performed a Student's t-test, adjusted odds ratio (AOR), 95% confidence intervals (CIs), and ANOVA analysis. According to our baseline characteristic analysis, control subjects and CAD patients were significantly different in hypertension and diabetes mellitus. We also found that the rs4759314 A>G, rs1899663 G>T, and rs12826786 C>T genotypes were strongly associated with CAD susceptibility (AA vs. AG+GG: AOR = 0.608, 95% CI = 0.393-0.940, p = 0.025; GG vs. TT: AOR = 2.276, 95% CI = 1.125-4.607, p = 0.022; CC vs. CT+TT: AOR = 1.366, 95% CI = 1.027-1.818, p = 0.032, respectively). Our data also demonstrated that the genotype of HOTAIR polymorphisms, genotype combination, and haplotype analysis affect disease occurrence. Moreover, these polymorphisms are linked to clinical factors that contribute to disease susceptibility. In conclusion, results from our study suggest that HOTAIR polymorphisms may be useful novel biomarkers for diagnosing CAD.

SCD leads to the development and progression of acute myocardial infarction through the AMPK signaling pathway

Background

Acute myocardial infarction (AMI) is myocardial necrosis caused by acute coronary ischemia and hypoxia. It can be complicated by arrhythmia, shock, heart failure and other symptoms that can be life-threatening. A multi-regulator driven dysfunction module for AMI was constructed. It is intended to explore the pathogenesis and functional pathways regulation of acute myocardial infarction.

Methods

Combining differential expression analysis, co-expression analysis, and the functional enrichment analysis, a set of expression disorder modules related to AMI was obtained. Hypergeometric test was performed to calculate the potential regulatory effects of multiple factors on the module, identifying a range of non-coding RNA and transcription factors.

Results

A total of 4551 differentially expressed genes for AMI and seven co-expression modules were obtained. These modules are primarily involved in the metabolic processes of prostaglandin transport processes, regulating DNA recombination and AMPK signal transduction. Based on this set of functional modules, 3 of 24 transcription factors (TFs) including NFKB1, MECP2 and SIRT1, and 3 of 782 non-coding RNA including miR-519D-3P, TUG1 and miR-93-5p were obtained. These core regulators are thought to be involved in the progression of AMI disease. Through the AMPK signal transduction, the critical gene stearoyl-CoA desaturase (SCD) can lead to the occurrence and development of AMI.

Conclusions

In this study, a dysfunction module was used to explore the pathogenesis of multifactorial mediated AMI and provided new methods and ideas for subsequent research. It helps researchers to have a deeper understanding of its potential pathogenesis. The conclusion provides a theoretical basis for biologists to design further experiments related to AMI.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12872-021-02011-8.

Roles of noncoding RNAs in the initiation and progression of myocardial ischemia-reperfusion injury

The morbidity and mortality of myocardial ischemia-reperfusion injury (MIRI) have increased in modern society. Noncoding RNAs (ncRNAs), including lncRNAs, circRNAs, piRNAs and miRNAs, have been reported in a variety of studies to be involved in pathological initiation and developments of MIRI. Hence this review focuses on the current research regarding these ncRNAs in MIRI. We comprehensively introduce the important features of lncRNAs, circRNAs, piRNA and miRNAs and then summarize the published studies of ncRNAs in MIRI. A clarification of lncRNA-miRNA-mRNA, lncRNA-transcription factor-mRNA and circRNA-miRNA-mRNA axes in MIRI follows, to further elucidate the crucial roles of ncRNAs in MIRI. Bioinformatics analysis has revealed the biological correlation of mRNAs with MIRI. We provide a comprehensive perspective for the roles of these ncRNAs and their related networks in MIRI, providing a theoretical basis for preclinical and clinical studies on ncRNA-based gene therapy for MIRI treatment.

Long Noncoding RNAs in Myocardial Ischemia-Reperfusion Injury

Following an acute myocardial infarction, reperfusion therapy is currently the most effective way to save the ischemic myocardium; however, restoring blood flow may lead to a myocardial ischemia-reperfusion injury (MIRI). Recent studies have confirmed that long-chain noncoding RNAs (LncRNAs) play important roles in the pathophysiology of MIRIs. These LncRNA-mediated roles include cardiomyocyte apoptosis, autophagy, necrosis, oxidative stress, inflammation, mitochondrial dysfunction, and calcium overload, which are regulated through the expression of target genes. Thus, LncRNAs may be used as clinical diagnostic markers and therapeutic targets to treat or prevent MIRI. This review evaluates the research on LncRNAs involved in MIRIs and provides new ideas for preventing and treating this type of injury.

miR-22 Host Gene Enhances Nuclear Factor-kappa B Activation to Aggravate Hypoxia-induced Injury in AC16 Cardiomyocytes

Myocardial infarction (MI) is a severe life-threatening disease caused by acute and persistent ischemia and hypoxia and eventually leads to heart failure and sudden death. Long noncoding RNAs (lncRNAs) play significant roles in the pathology, diagnosis, and development of various cardiovascular diseases, including MI. This study aimed to explore the effect and molecular mechanism of lncRNA miR-22 host gene (MIR22HG) on hypoxia-induced injury in AC16 cardiomyocytes. The expression of MIR22HG and miR-24 in hypoxia-treated AC16 cardiomyocytes was detected by quantitative real-time polymerase chain reaction. Cell viability, lactate dehydrogenase release, levels of aspartate aminotransferase (AST) and creatine kinase-MB (CK-MB), and apoptosis were detected by Cell Counting Kit-8, lactate dehydrogenase (LDH) release assay, commercial enzyme-linked immune sorbent assay kits, and flow cytometry analysis, respectively. The protein levels of nuclear factor-kappa B (NF-κB) p65 and cytoplasmic inhibitor of kappa B alpha (IκBα) and phosphorylated IκBα were detected by western blot. Results showed that hypoxia treatment decreased viability and increased MIR22HG expression in AC16 cardiomyocytes. MIR22HG overexpression aggravated hypoxia-induced viability reduction, leakage of myocardial injury markers LDH, AST, and CK-MB, and apoptosis in AC16 cardiomyocytes, while MIR22HG knockdown elicited the reverse effects. MIR22HG overexpression enhanced NF-κB activation in hypoxia-treated AC16 cardiomyocytes. Inhibition of NF-κB pathway impaired the effects of MIR22HG overexpression on hypoxia-induced injury in AC16 cardiomyocytes. Moreover, MIR22HG knockdown inhibited the NF-κB pathway by upregulating miR-24 in AC16 cardiomyocytes. Inhibition of miR-24 resisted the effects of MIR22HG silencing on hypoxia-induced injury in AC16 cardiomyocytes. In conclusion, MIR22HG overexpression aggravated hypoxia-induced injury in AC16 cardiomyocytes via enhancing NF-κB activation by targeting miR-24.

Functional Interaction among lncRNA HOTAIR and MicroRNAs in Cancer and Other Human Diseases

Simple Summary

This review aimed to describe the contribution of functional interaction between the lncRNA HOTAIR and microRNAs in human diseases, including cancer. HOTAIR/miRNAs complexes interfere with different cellular processes during carcinogenesis, mainly deregulating a series of oncogenic signaling pathways. A great number of ncRNAs-related databases have been established, supported by bioinformatics technologies, to identify the ncRNA-mediated sponge regulatory network. These approaches need experimental validation through cells and animal models studies. The optimization of systems to interfere with HOTAIR/miRNAs interplay could represent a new tool for the definition of diagnostic therapeutics in cancer patients.

Abstract

LncRNAs are a class of non-coding RNAs mostly involved in regulation of cancer initiation, metastatic progression, and drug resistance, through participation in post-transcription regulatory processes by interacting with different miRNAs. LncRNAs are able to compete with endogenous RNAs by binding and sequestering miRNAs and thereby regulating the expression of their target genes, often represented by oncogenes. The lncRNA HOX transcript antisense RNA (HOTAIR) represents a diagnostic, prognostic, and predictive biomarker in many human cancers, and its functional interaction with miRNAs has been described as crucial in the modulation of different cellular processes during cancer development. The aim of this review is to highlight the relation between lncRNA HOTAIR and different microRNAs in human diseases, discussing the contribution of these functional interactions, especially in cancer development and progression.

Investigating the effect of lncRNA HOTAIR on apoptosis induced by myocardial ischemia-reperfusion injury

The present study aimed to investigate the effect of the long non‑coding ribonucleic acid (lncRNA) HOX transcript antisense intergenic RNA (HOTAIR) on apoptosis induced by ischemia‑reperfusion injury. Differential lncRNAs in myocardial ischemia rats were screened by a lncRNA microarray and the expression levels of lncRNA HOTAIR and microRNA (miR)‑130a‑3p were analyzed using reverse transcription‑quantitative polymerase chain reaction in hypoxia‑induced cardiomyocytes. The mechanism of lncRNA HOTAIR in cardiotoxicity was investigated using cell transfection, lncRNA knockdown, Cell Counting Kit‑8, flow cytometry, western blotting, dual luciferase reporter assays and RNA immunoprecipitation. The expression level of lncRNA HOTAIR was significantly downregulated in the ischemic myocardium of rats. Overexpression of HOTAIR in H9c2 (rat cardiomyocyte line) cells could inhibit the apoptosis induced by H2O2. A direct interaction was found between HOTAIR and miR‑130a‑3p, and mouse double minute 4 (MDM4) was also found to be a potential target of miR‑130a‑3p. The overexpression of MDM4 in H9c2 cells transfected with miR‑130a‑3p mimics increased apoptosis, and miR‑130a‑3p targeted inhibition of MDM4 promoted H2O2‑induced apoptosis of H9c2 cells. Overall, HOTAIR was found to inhibit the apoptosis of H9c2 cells induced by H2O2 through the miR‑130a‑3p/MDM4 axis.

Knockdown of Long Non-Coding RNA AFAP1-AS1 Promoted Viability and Suppressed Death of Cardiomyocytes in Response to I/R In Vitro and In Vivo

Long non-coding RNA (lncRNA) plays a pivotal role in the development of myocardial infarction (MI). The aim of this study was to investigate the effects of lncRNA actin filament-associated protein 1 antisense RNA 1 (AFAP1-AS1) on cell cycle, proliferation, and apoptosis. RT-qPCR was used to detect the expression levels of AFAP1-AS1, miR-512-3p, and reticulon 3 (RTN3) in rat model of I/R. The simulated MI environment was constructed. MTT assay and flow cytometry were used to detect changes in cardiomyocyte viability and cell cycle/apoptosis after MI by AFAP1-AS1 silencing or RTN3 silencing. The targeting relationship of miR-512-3p and AFAP1-AS1 and RTN3 in cardiomyocytes was verified by dual luciferase reporter assay. The expression levels of AFAP1-AS1 and RTN3 were significantly upregulated in a rat model of LAD ligation (or MI) ligation, while the expression level of miR-512-3p was significantly reduced. Overexpressed AFAP1-AS1 and RTN3 promoted cardiomyocyte apoptosis and inhibited cardiomyocyte proliferation. MiR-512-3p was a direct target of AFAP1-AS1, and RTN3 was a direct target of miR-512-3p. AFAP1-AS1 promoted the progression of MI by targeting miR-512-3p. AFAP1-AS1 promoted the progression of MI by modulating the miR-512-3p/RTN3 axis. AFAP1-AS1 may be a potential therapy target for MI. Graphical Abstract The role of AFAP1-AS1 in regulating MI injury in vivo. (A) Effect of AFAP1-AS1 in MI injury in vivo. (B) The mRNA level of RTN3 in MI injury in vivo. (C) The protein level of RTN3 in MI injury in vivo. (D) Effect of miR-512-3p in MI model group. (E) TUNEL assay. *P < 0.05, **P < 0.01 vs the sham group; #P < 0.05, ##P < 0.01 vs the MI group.

Long Noncoding RNA HOTAIR Functions as a Competitive Endogenous RNA to Regulate Connexin43 Remodeling in Atrial Fibrillation by Sponging MicroRNA-613

Several studies have indicated that long noncoding RNAs (lncRNAs)-HOX transcript antisense RNA (HOTAIR) is involved in some cardiovascular diseases by regulating gene expression as a competitive endogenous RNA (ceRNA). GJA1 encoding Cx43 is one potential target gene of microRNA-613 (miR-613). Meanwhile, there is a potential target regulatory relationship between HOTAIR and miR-613. The present study is aimed at investigating whether HOTAIR functions as a ceRNA to regulate the Cx43 expression in atrial fibrillation (AF) by sponging miR-613. The expressions of HOTAIR, miR-613, and Cx43 were detected in the right atrial appendages of 45 patients with heart valve disease, including 23 patients with chronic AF. The HOTAIR overexpressed and underexpressed HL-1 cell model were constructed to confirm the effect of HOTAIR on Cx43. Then, the Cx43 expression was detected to testify the interplay between HOTAIR and miR-613 after cotransfecting HOTAIR and miR-613. Furthermore, luciferase assays were performed to verify that HOTAIR could regulate Cx43 remolding as a ceRNA by sponging miR-613. The expression of HOTAIR and Cx43 was significantly downregulated in chronic AF group. HOTAIR regulated positively the Cx43 expression in HL-1 cells. The upregulated effect of HOTAIR on the Cx43 expression could be remarkably attenuated by miR-613. Moreover, the inhibitory effect of miR-613 on the Cx43 expression could be obviously mitigated by HOTAIR. At last, luciferase assays confirmed HOTAIR functioned as a ceRNA in the Cx43 expression by sponging miR-613. Our study suggests that HOTAIR, functioning as a ceRNA by sponging miR-613, is an important contributor to Cx43 remolding in AF.

Functional characterization of long noncoding RNAs

PURPOSE OF REVIEW

Mounting evidence suggests that long noncoding RNAs (lncRNAs) are essential regulators of gene expression. Although few lncRNAs have been the subject of detailed molecular and functional characterization, it is believed that lncRNAs play an important role in tissue homeostasis and development. In fact, gene expression profiling studies reveal lncRNAs are developmentally regulated in a tissue-type and cell-type specific manner. Such findings have brought significant attention to their potential contribution to disease cause. The current review summarizes recent studies of lncRNAs in the heart.

RECENT FINDINGS

lncRNA discovery has largely been driven by the implementation of next generation sequencing technologies. To date, such technologies have contributed to the identification of tens of thousands of distinct lncRNAs in humans -- accounting for a large majority of all RNA sequences transcribed across the human genome. Although the functions of these lncRNAs remain largely unknown, gain-of-function and loss-of-function studies (in vivo and in vitro) have uncovered a number of mechanisms by which lncRNAs regulate gene expression and protein function. Such mechanisms have been stratified according to three major functional categories: RNA sponges (RNA-mediated sequestration of free miRNAs; e.g. H19, MEG3, and MALAT1); transcription-modulating lncRNAs (RNA influences regulatory factor recruitment by binding to histone modifiers or transcription factors; e.g. CAIF, MANTIS, and NEAT1); and translation-modulating lncRNAs (RNA modifies protein function via directly interacting with a protein itself or binding partners; e.g. Airn, CCRR, and ZFAS1).

SUMMARY

Recent studies strongly suggest that lncRNAs function via binding to macromolecules (e.g. genomic DNA, miRNAs, or proteins). Thus, lncRNAs constitute an additional mode by which cells regulate gene expression.

Identification of mitochondrial function-associated lncRNAs in septic mice myocardium

The present study aimed to analyze long noncoding RNA (lncRNA) and messenger RNA (mRNA) expression profiles in septic mice heart and to identify potential lncRNAs and mRNAs that be responsible for cardiac mitochondrial dysfunction during sepsis. Mice were treated with 10 mg/kg of lipopolysaccharides to induce sepsis. LncRNAs and mRNAs expression were evaluated by using lncRNA and mRNA microarray or real-time polymerase chain reaction technique. LncRNA-mRNA coexpression network assay, Gene Ontology (GO) analysis, Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis were performed. The results showed that 1275 lncRNAs were differentially expressed in septic myocardium compared with those in the control group. A total of 2769 mRNAs were dysregulated in septic mice heart, most of which are mainly related to the process of inflammation, mitochondrial metabolism, oxidative stress, and apoptosis. Coexpression network analysis showed that 14 lncRNAs were highly correlated with 11 mitochondria-related differentially expressed mRNA. Among all lncRNAs and their cis-acting mRNAs, 41 lncRNAs-mRNA pairs (such as NONMMUG004378 and Apaf1 gene) were enriched in GO terms and KEGG pathways. In summary, we gained some specific lncRNAs and their potential target mRNAs that might be involved in mitochondrial dysfunction in septic myocardium. These findings provide a panoramic view of lncRNA and might allow developing new treatment strategies for sepsis.

Microarray analysis of long non-coding RNA expression profiles in low high-density lipoprotein cholesterol disease

Background

Low high-density lipoprotein cholesterol (HDL-C) disease with unknown etiology has a high prevalence in the Xinjiang Kazak population. In this study, long noncoding RNAs (lncRNAs) that might play a role in low HDL-C disease were identified.

Methods

Plasma samples from 10 eligible individuals with low HDL disease and 10 individuals with normal HDL-C levels were collected. The lncRNA profiles for 20 Xinjiang Kazak individuals were measured using microarray analysis.

Results

Differentially expressed lncRNAs and mRNAs with fold-change values not less than 1.5 and FDR-adjusted P-values less than 0.05 were screened. Bioinformatic analyses, including Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG), and network analyses, were used to determine relevant signaling pathways and predict potential target genes. In total, 381 lncRNAs and 370 mRNAs were differentially expressed based on microarray analysis. Compared with those in healthy individuals, several lncRNAs were upregulated or downregulated in patients with low HDL-C disease, among which TCONS_00006679 was most significantly upregulated and TCONS_00011823 was most significantly downregulated. GO and KEGG pathway analyses as well as co-expression networks of lncRNAs and mRNAs revealed that the platelet activation pathway and cardiovascular disease were associated with low HDL-C disease.

Conclusions

Potential target genes integrin beta-3 (ITGB3) and thromboxane A2 receptor (TBXA2R) were regulated by the lncRNAs AP001033.3–201 and AC068234.2–202, respectively. Both genes were associated with cardiovascular disease and were involved in the platelet activation pathway. AP001033.3–201 and AC068234.2–202 were associated with low HDL-C disease and could play a role in platelet activation in cardiovascular disease. These results reveal the potential etiology of dyslipidemia in the Xinjiang Kazakh population and lay the foundation for further validation using large sample sizes.

Non-coding RNAs in Physiological Cardiac Hypertrophy

Non-coding RNA (ncRNA) is a class of RNAs that are not act as translational protein templates. They are involved in the regulation of gene transcription, RNA maturation and protein translation, participating in a variety of physiological and physiological processes. NcRNAs have important functions, and are recently one of the hotspots in biomedical research. Cardiac hypertrophy is classified into physiological cardiac hypertrophy and pathological cardiac hypertrophy. Different from pathological cardiac hypertrophy, physiological cardiac hypertrophy usually developed during exercise, pregnancy, normal postnatal growth, accompanied with preservation or improvement of systolic function, while no cardiac fibrosis. In this chapter, we will briefly introduce the definition, characteristics, and functions of ncRNAs, including miRNAs, lncRNAs, and circRNAs, as well as a summary of the existing bioinformatics online databases which commonly used in the study of ncRNAs. Specially, this chapter will be focused on the characteristics and the underlying mechanisms about physiological cardiac hypertrophy. Furthermore, the regulatory mechanism of ncRNAs in physiological hypertrophy and the latest research progress will be summarized. Taken together, exploring physiologic cardiac hypertrophy-specific ncRNAs might be a unique research perspective that provides new point of view for interventions in heart failure and other cardiovascular diseases.

The Predicted Key Molecules, Functions, and Pathways That Bridge Mild Cognitive Impairment (MCI) and Alzheimer's Disease (AD)

To elucidate the key molecules, functions, and pathways that bridge mild cognitive impairment (MCI) and Alzheimer's disease (AD), we investigated open gene expression data sets. Differential gene expression profiles were analyzed and combined with potential MCI- and AD-related gene expression profiles in public databases. Then, weighted gene co-expression network analysis was performed to identify the gene co-expression modules. One module was significantly negatively associated with MCI samples, in which gene ontology function and Kyoto Encyclopedia of Genes and Genomes pathway enrichment analysis showed that these genes were related to cytosolic ribosome, ribosomal structure, oxidative phosphorylation, AD, and metabolic pathway. The other two modules correlated significantly with AD samples, in which functional and pathway enrichment analysis revealed strong relationships of these genes with cytoplasmic ribosome, protein binding, AD, cancer, and apoptosis. In addition, we regarded the core genes in the module network closely related to MCI and AD as bridge genes and submitted them to protein interaction network analysis to screen for major pathogenic genes according to the connectivity information. Among them, small nuclear ribonucleoprotein D2 polypeptide (SNRPD2), ribosomal protein S3a (RPS3A), S100 calcium binding protein A8 (S100A8), small nuclear ribonucleoprotein polypeptide G (SNRPG), U6 snRNA-associated Sm-like protein LSm3 (LSM3), ribosomal protein S27a (RPS27A), and ATP synthase F1 subunit gamma (ATP5C1) were not only major pathogenic genes of MCI, but also bridge genes. In addition, SNRPD2, RPS3A, S100A8, SNRPG, LSM3, thioredoxin (TXN), proteasome 20S subunit alpha 4 (PSMA4), annexin A1 (ANXA1), DnaJ heat shock protein family member A1 (DNAJA1), and prefoldin subunit 5 (PFDN5) were not only major pathogenic genes of AD, but also bridge genes. Next, we screened for differentially expressed microRNAs (miRNAs) to predict the miRNAs and transcription factors related the MCI and AD modules, respectively. The significance score of miRNAs in each module was calculated using a hypergeometric test to obtain the miRNApivot-Module interaction pair. Thirty-four bridge regulators were analyzed, among which hsa-miR-519d-3p was recognized as the bridge regulator between MCI and AD. Our study contributed to a better understanding of the pathogenic mechanisms of MCI and AD, and might lead to the development of a new strategy for clinical diagnosis and treatment.

The Long Noncoding RNA Hotair Regulates Oxidative Stress and Cardiac Myocyte Apoptosis during Ischemia-Reperfusion Injury

Oxidative stress and subsequent cardiac myocyte apoptosis play central roles in the initiation and progression of myocardial ischemia-reperfusion (I/R) injury. Homeobox transcript antisense intergenic RNA (Hotair) was previously implicated in various heart diseases, yet its role in myocardial I/R injury has not been clearly demonstrated. Mice with cardiac-restricted knockdown or overexpression of Hotair were exposed to I/R surgery. H9c2 cells were cultured and subjected to hypoxia/reoxygenation (H/R) stimulation to further verify the role and underlying mechanisms of Hotair in vitro. Histological examination, molecular detection, and functional parameters were determined in vivo and in vitro. In response to I/R or H/R treatment, Hotair expression was increased in a bromodomain-containing protein 4-dependent manner. Cardiac-restricted knockdown of Hotair exacerbated, whereas Hotair overexpression prevented I/R-induced oxidative stress, cardiac myocyte apoptosis, and cardiac dysfunction. Mechanistically, we observed that Hotair exerted its beneficial effects via activating AMP-activated protein kinase alpha (AMPKα). Further detection revealed that Hotair activated AMPKα through regulating the enhancer of zeste homolog 2/microRNA-451/calcium-binding protein 39 (EZH2/miR-451/Cab39) axis. We provide the evidence that endogenous lncRNA Hotair is an essential negative regulator for oxidative stress and cardiac myocyte apoptosis in myocardial I/R injury, which is dependent on AMPKα activation via the EZH2/miR-451/Cab39 axis.

Insight into long noncoding RNA-miRNA-mRNA axes in myocardial ischemia-reperfusion injury: the implications for mechanism and therapy

Emerging evidence has demonstrated that regulatory noncoding RNAs (ncRNAs), such as long noncoding RNAs (lncRNAs) and miRNAs, play crucial roles in the initiation and progress of myocardial ischemia-reperfusion injury (MIRI), which is associated with autophagy, apoptosis and necrosis of cardiomyocytes, as well as oxidative stress, inflammation and mitochondrial dysfunction. LncRNAs serve as a precursor or host of miRNAs and directly/indirectly affecting miRNAs via competitive binding or sponge effects. Simultaneously, miRNAs post-transcriptionally regulate the expression of genes by targeting various mRNA sequences due to their imperfect pairing with mRNAs. This review summarizes the potential regulatory role of lncRNA-miRNA-mRNA axes in MIRI and related molecular mechanisms of cardiac disorders, also provides insight into the potential therapies for MIRI-induced diseases.

Long noncoding RNA/circular noncoding RNA-miRNA-mRNA axes in cardiovascular diseases

Cardiovascular diseases (CVDs) are the leading cause of death worldwide. Non-coding RNAs including long non-coding RNAs (lncRNAs), circular RNAs (circRNAs) and microRNAs (miRNAs) have been reported to participate in pathological developments of CVDs through various mechanisms. Among them, the networks among lncRNAs/circRNAs, miRNAs, and mRNAs have recently attracted attention. Understanding the molecular mechanism could aid the discovery of therapeutic targets or strategies in CVDs including atherosclerosis, myocardial infarction (MI), hypertrophy, heart failure (HF) and cardiomyopathy. In this review, we summarize the latest research involving the lncRNA/circRNA-miRNA-mRNA axis in CVDs, with emphasis on the molecular mechanism.