Long non-coding RNA UCA1 relieves cardiomyocytes H9c2 injury aroused by oxygen-glucose deprivation via declining miR-122

LncRNA UCA1 enhances NRF2 expression through the m6A pathway to mitigate oxidative stress and ferroptosis in aging cardiomyocytes

To explore the regulatory mechanism of lncRNA UCA1 and NRF2 in cardiomyocyte aging. In this study, we explored how lncRNA UCA1 regulates NRF2 and its effect on cardiomyocyte aging. H9c2 cardiomyocytes were cultured and treated with H2O2 to simulate cardiomyocyte aging in vitro. The expression levels of lncRNA UCA1 and NRF2 in cells were detected using qRT-PCR. Cell viability was assessed using the CCK8 assay, and cell aging was detected via Sa-β-gal staining. The levels of oxidative stress markers (SOD, MDA, ROS) and the expressions of ferroptosis-related proteins (ACSL4, TFR1, FTH1, GPX4) were measured. The regulatory mechanism between UCA1 and NRF2 was investigated using RIP-qPCR. Additionally, changes in m6A modification levels and the expression of m6A modification-related proteins in cells after UCA1 overexpression were analyzed by western blot. Our results indicate that H2O2 treatment significantly downregulated the expression of lncRNA UCA1 and NRF2. UCA1 overexpression promoted H9c2 cell proliferation, inhibited cell aging, increased SOD activity and the expression of FTH1 and GPX4 proteins, and decreased MDA and ROS content as well as ACSL4 and TFR1 protein expression. RIP-qPCR verified that UCA1 can promote the expression of NRF2 in cells. Overexpression of UCA1 significantly increased the expression of the demethylase FTO, leading to a reduction in m6A modification levels. Furthermore, there was significant enrichment between FTO and NRF2, and overexpression of FTO improved the expression of NRF2 protein in cells. Taken together, lncRNA UCA1 inhibits oxidative stress and ferroptosis, thereby preventing cardiomyocyte aging. This protective effect is likely mediated by increasing the expression of demethylase FTO and reducing m6A modification, which promotes the expression of NRF2.

microRNAs as Biomarkers of Endothelial Dysfunction and Therapeutic Target in the Pathogenesis of Atrial Fibrillation

The pathophysiology of atrial fibrillation (AF) may involve atrial fibrosis/remodeling and dysfunctional endothelial activities. Despite the currently available treatment approaches, the progression of AF, its recurrence rate, and the high mortality risk of related complications underlay the need for more advanced prognostic and therapeutic strategies. There is increasing attention on the molecular mechanisms controlling AF onset and progression points to the complex cell to cell interplay that triggers fibroblasts, immune cells and myofibroblasts, enhancing atrial fibrosis. In this scenario, endothelial cell dysfunction (ED) might play an unexpected but significant role. microRNAs (miRNAs) regulate gene expression at the post-transcriptional level. In the cardiovascular compartment, both free circulating and exosomal miRNAs entail the control of plaque formation, lipid metabolism, inflammation and angiogenesis, cardiomyocyte growth and contractility, and even the maintenance of cardiac rhythm. Abnormal miRNAs levels may indicate the activation state of circulating cells, and thus represent a specific read-out of cardiac tissue changes. Although several unresolved questions still limit their clinical use, the ease of accessibility in biofluids and their prognostic and diagnostic properties make them novel and attractive biomarker candidates in AF. This article summarizes the most recent features of AF associated with miRNAs and relates them to potentially underlying mechanisms.

Circulating exosome-derived miR-122-5p is a novel biomarker for prediction of postoperative atrial fibrillation

Postoperative atrial fibrillation (POAF) is a frequent complication associated with increased periprocedural mortality and morbidity after cardiac surgery. Our study aimed to identify the difference in exosomal miRNA and further explore its role in the diagnosis of POAF. First, the differentially expressed miRNAs (DEMs) were obtained by high-throughput RNA sequencing. Second, the DEMs target genes were put into gene ontology (GO) and KEGG pathway analysis. Third, real-time quantification PCR (RT-qPCR) was used to verify the DEMs. Finally, we revealed 23 DEMs in POAF patients. Furthermore, analysis of gene function revealed that DEMs may affect atrial structure through many signaling pathways. We also found that miR-122-5p was up-regulated in POAF patients, but there are no significant changes in miR-191-5p, miR-181a-5p, miR-155-5p and miR-151a-5p. Our study revealed that exosomal miRNAs exert enormous potential in evaluating the severity or prognostic of POAF.

The Coordination of mTOR Signaling and Non-Coding RNA in Regulating Epileptic Neuroinflammation

Epilepsy accounts for a significant proportion of the burden of neurological disorders. Neuroinflammation acting as the inflammatory response to epileptic seizures is characterized by aberrant regulation of inflammatory cells and molecules, and has been regarded as a key process in epilepsy where mTOR signaling serves as a pivotal modulator. Meanwhile, accumulating evidence has revealed that non-coding RNAs (ncRNAs) interfering with mTOR signaling are involved in neuroinflammation and therefore articipate in the development and progression of epilepsy. In this review, we highlight recent advances in the regulation of mTOR on neuroinflammatory cells and mediators, and feature the progresses of the interaction between ncRNAs and mTOR in epileptic neuroinflammation.

LncRNA UCA1 epigenetically suppresses APAF1 expression to mediate the protective effect of sevoflurane against myocardial ischemia-reperfusion injury

Myocardial ischemia-reperfusion injury (MI/RI) is a leading cause of death globally. Whereas some long noncoding RNAs (lncRNAs) are known to participate in the progression of MI/RI, the role of urothelial carcinoma associated 1 (UCA1) in conjunction with sevoflurane treatment remains largely unknown. H9C2 cardiomyocytes were subjected to hypoxia/reoxygenation (H/R) to establish an in vitro MI/RI model, and sevoflurane was then added. Cell viability, apoptosis, SOD activity, and MDA levels were measured. Levels of inflammatory cytokines and methylation of apoptosis protease-activating factor 1 (APAF1) were determined. Interactions among lncRNA UCA1, enhancer of zeste homologue 2 (EZH2), DNA methyltransferase-1 (DNMT1), and APAF1 were analyzed. After H/R treatment, the viability of H9C2 cardiomyocytes decreased and apoptosis rate, oxidative stress factor levels, inflammatory cytokine levels, and apoptosis-related protein levels all increased. Sevoflurane treatment reversed these changes. LncRNA UCA1 knockdown attenuated the therapeutic effect of sevoflurane on H/R-treated cardiomyocytes, and silencing of APAF1 reversed this role of UCA1 knockdown. Moreover, lncRNA UCA1 recruited DNMT1 through EZH2, thus promoting methylation of the APAF1 promoter region. LncRNA UCA1 recruits DNMT1 to promote methylation of the APAF1 promoter through EZH2, thus strengthening the protective effect of sevoflurane on H/R-induced cardiomyocyte injury.

Insight into the Role of the PI3K/Akt Pathway in Ischemic Injury and Post-Infarct Left Ventricular Remodeling in Normal and Diabetic Heart

Despite the significant decline in mortality, cardiovascular diseases are still the leading cause of death worldwide. Among them, myocardial infarction (MI) seems to be the most important. A further decline in the death rate may be achieved by the introduction of molecularly targeted drugs. It seems that the components of the PI3K/Akt signaling pathway are good candidates for this. The PI3K/Akt pathway plays a key role in the regulation of the growth and survival of cells, such as cardiomyocytes. In addition, it has been shown that the activation of the PI3K/Akt pathway results in the alleviation of the negative post-infarct changes in the myocardium and is impaired in the state of diabetes. In this article, the role of this pathway was described in each step of ischemia and subsequent left ventricular remodeling. In addition, we point out the most promising substances which need more investigation before introduction into clinical practice. Moreover, we present the impact of diabetes and widely used cardiac and antidiabetic drugs on the PI3K/Akt pathway and discuss the molecular mechanism of its effects on myocardial ischemia and left ventricular remodeling.

Signaling pathways and targeted therapy for myocardial infarction

Although the treatment of myocardial infarction (MI) has improved considerably, it is still a worldwide disease with high morbidity and high mortality. Whilst there is still a long way to go for discovering ideal treatments, therapeutic strategies committed to cardioprotection and cardiac repair following cardiac ischemia are emerging. Evidence of pathological characteristics in MI illustrates cell signaling pathways that participate in the survival, proliferation, apoptosis, autophagy of cardiomyocytes, endothelial cells, fibroblasts, monocytes, and stem cells. These signaling pathways include the key players in inflammation response, e.g., NLRP3/caspase-1 and TLR4/MyD88/NF-κB; the crucial mediators in oxidative stress and apoptosis, for instance, Notch, Hippo/YAP, RhoA/ROCK, Nrf2/HO-1, and Sonic hedgehog; the controller of myocardial fibrosis such as TGF-β/SMADs and Wnt/β-catenin; and the main regulator of angiogenesis, PI3K/Akt, MAPK, JAK/STAT, Sonic hedgehog, etc. Since signaling pathways play an important role in administering the process of MI, aiming at targeting these aberrant signaling pathways and improving the pathological manifestations in MI is indispensable and promising. Hence, drug therapy, gene therapy, protein therapy, cell therapy, and exosome therapy have been emerging and are known as novel therapies. In this review, we summarize the therapeutic strategies for MI by regulating these associated pathways, which contribute to inhibiting cardiomyocytes death, attenuating inflammation, enhancing angiogenesis, etc. so as to repair and re-functionalize damaged hearts.

Long non-coding RNAs and microRNAs as crucial regulators in cardio-oncology

Cancer is one of the leading causes of morbidity and mortality worldwide. Significant improvements in the modern era of anticancer therapeutic strategies have increased the survival rate of cancer patients. Unfortunately, cancer survivors have an increased risk of cardiovascular diseases, which is believed to result from anticancer therapies. The emergence of cardiovascular diseases among cancer survivors has served as the basis for establishing a novel field termed cardio-oncology. Cardio-oncology primarily focuses on investigating the underlying molecular mechanisms by which anticancer treatments lead to cardiovascular dysfunction and the development of novel cardioprotective strategies to counteract cardiotoxic effects of cancer therapies. Advances in genome biology have revealed that most of the genome is transcribed into non-coding RNAs (ncRNAs), which are recognized as being instrumental in cancer, cardiovascular health, and disease. Emerging studies have demonstrated that alterations of these ncRNAs have pathophysiological roles in multiple diseases in humans. As it relates to cardio-oncology, though, there is limited knowledge of the role of ncRNAs. In the present review, we summarize the up-to-date knowledge regarding the roles of long non-coding RNAs (lncRNAs) and microRNAs (miRNAs) in cancer therapy-induced cardiotoxicities. Moreover, we also discuss prospective therapeutic strategies and the translational relevance of these ncRNAs.

Inhibition of extracellular vesicle-associated MMP2 abrogates intercellular hepatic miR-122 transfer to liver macrophages and curtails inflammation

Hepatic miRNA, miR-122, plays an important role in controlling metabolic homeostasis in mammalian liver. Intercellular transfer of miR-122 was found to play a role in controlling tissue inflammation. miR-122, as part of extracellular vesicles released by lipid-exposed hepatic cells, are taken up by tissue macrophages to activate them and produce inflammatory cytokines. Matrix metalloprotease 2 or MMP2 was found to be essential for transfer of extracellular vesicles and their miRNA content from hepatic to non-hepatic cells. MMP2 was found to increase the movement of the extracellular vesicles along the extracellular matrix to enhance their uptake in recipient cells. Inhibition of MMP2 restricts functional transfer of hepatic miRNAs across the hepatic and non-hepatic cell boundaries, and by targeting MMP2, we could reduce the innate immune response in mammalian liver by preventing intra-tissue miR-122 transfer. MMP2 thus could be a useful target to restrict high-fat-diet-induced obesity-related metaflammation.

•

Hepatocytes on exposure to high lipid export proinflammatory miR-122 in mouse liver

•

Uptake of extracellular miR-122 induces inflammatory signals in liver macrophages

•

MMP2 on extracellular vesicles is essential for intercellular transfer of miRNA

•

Inhibition of MMP2 prevents miR-122 transfer and stops activation of macrophages

Impact of the Main Cardiovascular Risk Factors on Plasma Extracellular Vesicles and Their Influence on the Heart's Vulnerability to Ischemia-Reperfusion Injury

The majority of cardiovascular deaths are associated with acute coronary syndrome, especially ST-elevation myocardial infarction. Therapeutic reperfusion alone can contribute up to 40 percent of total infarct size following coronary artery occlusion, which is called ischemia-reperfusion injury (IRI). Its size depends on many factors, including the main risk factors of cardiovascular mortality, such as age, sex, systolic blood pressure, smoking, and total cholesterol level as well as obesity, diabetes, and physical effort. Extracellular vesicles (EVs) are membrane-coated particles released by every type of cell, which can carry content that affects the functioning of other tissues. Their role is essential in the communication between healthy and dysfunctional cells. In this article, data on the variability of the content of EVs in patients with the most prevalent cardiovascular risk factors is presented, and their influence on IRI is discussed.

M1 Bone Marrow-Derived Macrophage-Derived Extracellular Vesicles Inhibit Angiogenesis and Myocardial Regeneration Following Myocardial Infarction via the MALAT1/MicroRNA-25-3p/CDC42 Axis

Myocardial infarction (MI) is a severe cardiovascular disease. Some M1 macrophage-derived extracellular vesicles (EVs) are involved in the inhibition of angiogenesis and acceleration dysfunction during MI. However, the potential mechanism of M1 phenotype bone marrow-derived macrophages- (BMMs-) EVs (M1-BMMs-EVs) in MI is largely unknown. This study sought to investigate whether M1-BMMs-EVs increased CDC42 expression and activated the MEK/ERK pathway by carrying lncRNA MALAT1 and competitively binding to miR-25-3p, thus inhibiting angiogenesis and myocardial regeneration after MI. After EV treatment, the cardiac function, infarct size, fibrosis, angiogenesis, and myocardial regeneration of MI mice and the viability, proliferation and angiogenesis of oxygen-glucose deprivation- (OGD-) treated myocardial microvascular endothelial cells (MMECs) were assessed. MALAT1 expression in MI mice, cells, and EVs was detected. MALAT1 downstream microRNAs (miRs), genes, and pathways were predicted and verified. MALAT1 and miR-25-3p were intervened to evaluate EV effects on OGD-treated cells. In MI mice, EV treatment aggravated MI and inhibited angiogenesis and myocardial regeneration. In OGD-treated cells, EV treatment suppressed cell viability, proliferation, and angiogenesis. MALAT1 was highly expressed in MI mice, OGD-treated MMECs, M1-BMMs, and EVs. Silencing MALAT1 weakened the inhibition of EV treatment on OGD-treated cells. MALAT1 sponged miR-25-3p to upregulate CDC42. miR-25-3p overexpression promoted OGD-treated cell viability, proliferation, and angiogenesis. The MEK/ERK pathway was activated after EV treatment. Collectively, M1-BMMs-EVs inhibited angiogenesis and myocardial regeneration following MI via the MALAT1/miR-25-3p/CDC42 axis and the MEK/ERK pathway activation.

Regulatory role of long non-coding RNA UCA1 in signaling pathways and its clinical applications

Long non-coding RNA metastasis-associated urothelial carcinoma associated 1 (UCA1) plays a pivotal role in various human diseases. Its gene expression is regulated by several factors, including transcription factors, chromatin remodeling and epigenetic modification. UCA1 is involved in the regulation of the PI3K/AKT, Wnt/β-catenin, MAPK, NF-κB and JAK/STAT signaling pathways, affecting a series of cellular biological functions, such as cell proliferation, apoptosis, migration, invasion and tumor drug resistance. Furthermore, UCA1 is used as a novel potential biomarker for disease diagnosis and prognosis, as well as a target for clinical gene therapy. The present review systematically summarizes and elucidates the mechanisms of upstream transcriptional regulation of UCA1, the regulatory role of UCA1 in multiple signaling pathways in the occurrence and development of several diseases, and its potential applications in clinical treatment.

Transfer of lncRNA UCA1 by hUCMSCs-derived exosomes protects against hypoxia/reoxygenation injury through impairing miR-143-targeted degradation of Bcl-2

Ischemia results in neuronal damage via alterations in gene transcription and protein expression. Long noncoding RNAs (LncRNAs) are pivotal in the regulation of target protein expression in hypoxia/reoxygenation (H/R). In this study, we observed the function of exosomes-carried lncRNA UCA1 in H/R-induced injury of cardiac microvascular endothelial cells (CMECs). In H/R cell model, CMECs were co-cultured with human umbilical cord mesenchymal stem cell-derived exosomes (hUCMSC-ex). The loss-of-function experiments were conducted to assess the effect of lncRNA UCA1 on H/R injury by assessing the biological behaviors of CMECs. The relationship among lncRNA UCA1, miR-143 and Bcl-2 were verified. An ischemia-reperfusion (I/R) rat model was established. Then hUCMSC-ex was injected into I/R rats to identify its effects on apoptosis and autophagy. Functional rescue experiments were performed to verify the sponge system. In vitro and in vivo experiments showed that hUCMSC-ex protected I/R rats and H/R CMECs against injury. Silencing UCA1 in hUCMSC-ex or miR-143 overexpression aggravated H/R injury in CMECs. LncRNA UCA1 competitively bound to miR-143 to upregulate Bcl-2. And hUCMSCs-ex/si-UCA1+inhi-miR-143 treatment protected CMECs against H/R injury and inhibited hyperautophagy. Together, hUCMSC-ex-derived lncRNA UCA1 alleviates H/R injury through the miR-143/Bcl-2/Beclin-1 axis. Hence, this study highlights a stem cell-based approach against I/R injury.

Proteomic Analysis Reveals the Effect of Trichostatin A and Bone Marrow-Derived Dendritic Cells on the Fatty Acid Metabolism of NIH3T3 Cells under Oxygen-Glucose Deprivation Conditions

Fibroblasts mediate acute wound healing and long-term tissue remodeling with scarring after tissue injury. Following myocardial infarction (MI), necrotized cardiomyocytes become replaced by secreted extracellular matrix proteins produced by fibroblasts. Dendritic cells (DCs) can migrate from the bone marrow to the infarct areas and infarct border areas to mediate collagen accumulation after MI. Trichostatin A (TSA) is known to regulate apoptosis and proliferation in fibroblasts and affect the functions of DCs under oxygen-glucose deprivation (OGD) conditions. In this study, we used label-free quantitative proteomics to investigate the effects of TSA and bone marrow-derived dendritic cells (BMDCs) on NIH3T3 fibroblasts under OGD conditions. The results showed that the fatty acid degradation pathway was significantly upregulated in NIH3T3 cells under OGD conditions and that the fatty acid synthesis pathway was significantly downregulated in NIH3T3 cells treated with conditioned media (CM) from BMDCs treated with TSA under OGD conditions [BMDCs-CM(TSA)]. In addition, BMDCs-CM(TSA) significantly decreased the levels of triglycerides and free fatty acids and mediated fatty acid metabolism-related proteins in NIH3T3 cells under OGD conditions. In summary, this proteomics analysis showed that TSA and BMDCs affect fatty acid metabolism in NIH3T3 cells under OGD conditions.

Roles of MicroRNA-122 in Cardiovascular Fibrosis and Related Diseases

Fibrotic diseases cause annually more than 800,000 deaths worldwide, where of the majority accounts for cardiovascular fibrosis, which is characterized by endothelial dysfunction, myocardial stiffening and reduced dispensability. MicroRNAs (miRs), small noncoding RNAs, play critical roles in cardiovascular dysfunction and related disorders. Intriguingly, there is a critical link among miR-122, cardiovascular fibrosis, sirtuin 6 (SIRT6) and angiotensin-converting enzyme 2 (ACE2), which was recently identified as a coreceptor for SARS-CoV2 and a negative regulator of the rennin-angiotensin system. MiR-122 overexpression appears to exacerbate the angiotensin II-mediated loss of autophagy and increased inflammation, apoptosis, extracellular matrix deposition, cardiovascular fibrosis and dysfunction by modulating the SIRT6-Elabela-ACE2, LGR4-β-catenin, TGFβ-CTGF and PTEN-PI3K-Akt signaling pathways. More importantly, the inhibition of miR-122 has proautophagic, antioxidant, anti-inflammatory, anti-apoptotic and antifibrotic effects. Clinical and experimental studies clearly demonstrate that miR-122 functions as a crucial hallmark of fibrogenesis, cardiovascular injury and dysfunction. Additionally, the miR-122 level is related to the severity of hypertension, atherosclerosis, atrial fibrillation, acute myocardial infarction and heart failure, and miR-122 expression is a risk factor for these diseases. The miR-122 level has emerged as an early-warning biomarker cardiovascular fibrosis, and targeting miR-122 is a novel therapeutic approach against progression of cardiovascular dysfunction. Therefore, an increased understanding of the cardiovascular roles of miR-122 will help the development of effective interventions. This review summarizes the biogenesis of miR-122; regulatory effects and underlying mechanisms of miR-122 on cardiovascular fibrosis and related diseases; and its function as a potential specific biomarker for cardiovascular dysfunction.

LncRNA Kcnq1ot1 renders cardiomyocytes apoptosis in acute myocardial infarction model by up-regulating Tead1

Acute myocardial infarction (AMI) is a major cardiovascular disease with high mortality worldwide. Hypoxia is a key inducing factor for AMI. We aimed to examine the expression and functions of Kcnq1ot1 (KCNQ1 overlapping transcript 1) in hypoxia-induced cardiomyocytes in the process of AMI. The left anterior descending coronary artery ligation (LAD) was used for inducing in-vivo AMI model and the primary cardiomyocytes were extracted; in-vitro H9c2 cell model was simulated by hypoxia treatment. TUNEL, flow cytometry and JC-1 assay were carried out to evaluate cell apoptosis. Mechanism assays including luciferase reporter assay and RIP assay revealed interplays between RNAs. To begin with, Kcnq1ot1 was revealed to be conspicuously upregulated in myocardium infracted zone and border zone within 2 days since establishment of the model. Moreover, inhibition of Kcnq1ot1 protected cardiomyocytes against hypoxia-triggered cell apoptosis during the process of AMI. Then, miR-466k and miR-466i-5p were proved to bind with Kcnq1ot1 and participated in Kcnq1ot1-mediated cardiomyocyte injury under hypoxia. Subsequently, Kcnq1ot1 was found to elevate Tead1 (TEA domain transcription factor 1) expression via sponging miR-466k and miR-466i-5p. Finally, it was verified that Kcnq1ot1 regulated hypoxia-induced cardiomyocyte injury dependent on Tead1. In conclusion, Kcnq1ot1 sponged miR-466k and miR-466i-5p to up-regulate Tead1, thus triggering cardiomyocyte injury in the process of AMI.