LncRNA AK045171 protects the heart from cardiac hypertrophy by regulating the SP1/MG53 signalling pathway

MG53/TRIM72: multi-organ repair protein and beyond

MG53, a member of the tripartite motif protein family, possesses multiple functionalities due to its classic membrane repair function, anti-inflammatory ability, and E3 ubiquitin ligase properties. Initially recognized for its crucial role in membrane repair, the therapeutic potential of MG53 has been extensively explored in various diseases including muscle injury, myocardial damage, acute lung injury, and acute kidney injury. However, further research has revealed that the E3 ubiquitin ligase characteristics of MG53 also contribute to the pathogenesis of certain conditions such as diabetic cardiomyopathy, insulin resistance, and metabolic syndrome. Moreover, recent studies have highlighted the anti-tumor effects of MG53 in different types of cancer, such as small cell lung cancer, liver cancer, and colorectal cancer; these effects are closely associated with their E3 ubiquitin ligase activities. In summary, MG53 is a multifunctional protein that participates in important physiological and pathological processes of multiple organs and is a promising therapeutic target for various human diseases. MG53 plays a multi-organ protective role due to its membrane repair function and its exertion of anti-tumor effects due to its E3 ubiquitin ligase properties. In addition, the controversial aspect of MG53's E3 ubiquitin ligase properties potentially causing insulin resistance and metabolic syndrome necessitates further cross-validation for clarity.

Advances in the Study of MG53 in Cardiovascular Disease

Cardiovascular diseases represent a global health crisis, and understanding the intricate molecular mechanisms underlying cardiac pathology is crucial for developing effective diagnostic and therapeutic strategies. Mitsugumin-53 (MG53) plays a pivotal role in cell membrane repair, has emerged as a multifaceted player in cardiovascular health. MG53, also known as TRIM72, is primarily expressed in cardiac and skeletal muscle and actively participates in membrane repair processes essential for maintaining cardiomyocyte viability. It promotes k-ion currents, ensuring action potential integrity, and actively engages in repairing myocardial and mitochondrial membranes, preserving cardiac function in the face of oxidative stress. This study discusses the dual impact of MG53 on cardiac health, highlighting its cardioprotective role during ischemia/reperfusion injury, its modulation of cardiac arrhythmias, and its influence on cardiomyopathy. MG53's regulation of metabolic pathways, such as lipid metabolism, underlines its role in diabetic cardiomyopathy, while its potential to mitigate the effects of various cardiac disorders, including those induced by antipsychotic medications and alcohol consumption, warrants further exploration. Furthermore, we examine MG53's diagnostic potential as a biomarker for cardiac injury. Research has shown that MG53 levels correlate with cardiomyocyte damage and may predict major adverse cardiovascular events, highlighting its value as a biomarker. Additionally, exogenous recombinant human MG53 (rhMG53) emerges as a promising therapeutic option, demonstrating its ability to reduce infarct size, inhibit apoptosis, and attenuate fibrotic responses. In summary, MG53's diagnostic and therapeutic potential in cardiovascular diseases presents an exciting avenue for improved patient care and outcomes.

The multifaceted biology of lncR-Meg3 in cardio-cerebrovascular diseases

Cardio-cerebrovascular disease, related to high mortality and morbidity worldwide, is a type of cardiovascular or cerebrovascular dysfunction involved in various processes. Therefore, it is imperative to conduct additional research into the pathogenesis and new therapeutic targets of cardiovascular and cerebrovascular disorders. Long non-coding RNAs (lncRNAs) have multiple functions and are involved in nearly all cellular biological processes, including translation, transcription, signal transduction, and cell cycle control. LncR-Meg3 is one of them and is becoming increasingly popular. By binding proteins or directly or competitively binding miRNAs, LncR-Meg3 is involved in apoptosis, inflammation, oxidative stress, endoplasmic reticulum stress, epithelial-mesenchymal transition, and other processes. Recent research has shown that LncR-Meg3 is associated with acute myocardial infarction and can be used to diagnose this condition. This article examines the current state of knowledge regarding the expression and regulatory function of LncR-Meg3 in relation to cardiovascular and cerebrovascular diseases. The abnormal expression of LncR-Meg3 can influence neuronal cell death, inflammation, apoptosis, smooth muscle cell proliferation, etc., thereby aggravating or promoting the disease. In addition, we review the bioactive components that target lncR-Meg3 and propose some potential delivery vectors. A comprehensive and in-depth analysis of LncR-Meg3’s role in cardiovascular disease suggests that targeting LncR-Meg3 may be an alternative therapy in the near future, providing new options for slowing the progression of cardiovascular disease.

Long noncoding RNA H19 suppresses cardiac hypertrophy through the MicroRNA-145-3p/SMAD4 axis

Sustained cardiac hypertrophy (CH) contributes to many heart diseases. Long noncoding RNAs (lncRNAs) collectively play critical roles in cardiovascular diseases (CVDs). However, the roles of lncRNA H19 in CH are still unclear. A CH model was constructed utilizing isoproterenol (ISO). We demonstrated H19 could participate in regulating ISO-induced CH development both in vivo and in vitro. The online databases DIANA and TargetScan were used to predict the targets of H19 and MicroRNA-145-3p (miR-145-3p), respectively. Luciferase reporter assay was used to verify the downstream targets. The results showed that H19 was decreased under ISO stimulation. The H19 overexpression resulted in significant decrease in mouse heart size and weight, left ventricular systolic dysfunction, left ventricular posterior wall thickness and cardiac hypertrophic growth, while promoted the increase of left ventricular ejection fraction and left ventricle fraction shortening. H19 also inhibited protein expression levels of CH markers, such as atrial natriuretic peptide (ANP), brain natriuretic peptide (BNP), and MYH7. Luciferase assays results showed that miR-145-3p was a target of H19 and SMAD4 was a target of miR-145-3p. We found that H19 regulated SMAD4 by sponging miR-145-3p. Knockout of miR-145-3p or overexpression of SMAD4 facilitated H19-induced decreases in ANP, BNP, and MYH7. Collectively, our findings have indicated that the H19/miR-145-3p/SMAD4 axis should be a negative regulator involved in CH progression.

Silencing of specificity protein 1 protects H9c2 cells against lipopolysaccharide-induced injury via binding to the promoter of chemokine CXC receptor 4 and suppressing NF-κB signaling

G protein-coupled protein receptor CXC chemokine receptor 4 (CXCR4) has been shown to be involved in the development of sepsis; however, it remains unclear whether CXCR4 participates in the septic myocardial injury. In our study, treatment with lipopolysaccharide (LPS) increased the expression of specificity protein 1 (SP1) and CXCR4 in H9c2 cells. Notably, a positive association between SP1 and CXCR4 expression was observed in LPS-treated H9c2 cells, and SP1 positively regulated CXCR4 expression in H9c2 cells. Moreover, silencing of SP1 or CXCR4 suppressed LPS-induced inflammation and cell apoptosis in H9c2 cells, as evidenced by the increase in cell viability and decrease in lactate dehydrogenase release, interleukin (IL)-6, IL-8, and tumor necrosis factor (TNF)-α levels, and caspase-3 activity. Additionally, overexpression of CXCR4 abolished the protective effects of SP1 silencing on LPS-induced injury in H9c2 cells. SP1 was also shown to enhance the promoter activity of CXCR4 by directly binding with the binding motif site – 109/–100 in CXCR4 promoter. Besides, downregulation of SP1 or CXCR4 blocked LPS-induced activation of the NF-кB signaling in H9c2 cells. Furthermore, inhibition of NF-кB signaling by DHMEQ abolished LPS-induced myocardial inflammation and apoptosis. In conclusion, silencing of SP1 protected H9c2 cells against LPS-induced injury by binding to the promoter of CXCR4 and suppressing the NF-κB signaling pathway. Hence, our findings provide evidence that manipulation of SP1 or CXCR4 may be an effective approach to promote prevention or recovery of septic myocardial injury, and thereby, may serve as a potential therapeutic strategy for sepsis.

MiR-590-5p inhibits pathological hypertrophy mediated heart failure by targeting RTN4

Heart failure (HF) is a rising epidemic and public health burden in modern society. It is of great need to find new biomarkers to ensure a timely diagnosis and to improve treatment and prognosis of the disease. The mouse model of HF was established by thoracic aortic constriction. Color Doppler ultrasound was performed to detect left ventricular end-diastolic diameter. Hematoxylin and eosin staining was conducted to observe the pathological changes of mouse myocardium. The RT-qPCR analysis was performed to detect miR-590-5p and RTN4 expression levels. Western blot was conducted to detect protein levels of the indicated genes. We found that the expression of miR-590-5p was downregulated in cardiac tissues of HF mice. Injection of AAV-miR-590-5p attenuated myocardium hypertrophy and myocyte apoptosis. Additionally, miR-590-5p overexpression promoted viability, inhibited apoptosis, and decreased ANF, BNP and beta-MHC protein levels in H9c2 cell. Mechanistically, miR-590-5p binds to RTN4 3'-untranslated region, as predicted by starBase online database and evidenced by luciferase reporter assay. Furthermore, miR-590-5p negatively regulates RTN4 mRNA expression and suppresses its translation. The final rescue experiments revealed that miR-590-5p modulated cardiomyocyte phenotypes by binding to RTN4. In conclusion, miR-590-5p modulates myocardium hypertrophy and myocyte apoptosis in HF by downregulating RTN4.

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

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

The function of LncRNA-H19 in cardiac hypertrophy

Cardiac hypertrophy, characterized by the enlargement of cardiomyocytes, is initially an adaptive response to physiological and pathological stimuli. Decompensated cardiac hypertrophy is related to fibrosis, inflammatory cytokine, maladaptive remodeling, and heart failure. Although pathological myocardial hypertrophy is the main cause of hypertrophy-related morbidity and mortality, our understanding of its mechanism is still poor. Long noncoding RNAs (lncRNAs) are noncoding RNAs that regulate various physiological and pathological processes through multiple molecular mechanisms. Recently, accumulating evidence has indicated that lncRNA-H19 is a potent regulator of the progression of cardiac hypertrophy. For the first time, this review summarizes the current studies about the role of lncRNA-H19 in cardiac hypertrophy, including its pathophysiological processes and underlying pathological mechanism, including calcium regulation, fibrosis, apoptosis, angiogenesis, inflammation, and methylation. The context within which lncRNA-H19 might be developed as a target for cardiac hypertrophy treatment is then discussed to gain better insight into the possible biological functions of lncRNA-H19 in cardiac hypertrophy.

Expression Profile of Long Noncoding RNAs and Circular RNAs in Mouse C3H10T1/2 Mesenchymal Stem Cells Undergoing Myogenic and Cardiomyogenic Differentiation

Background

Currently, a heterogeneous category of noncoding RNAs (ncRNA) that directly regulate the expression or function of protein-coding genes is shown to have an effect on the fate decision of stem cells. However, the detailed regulatory roles of ncRNAs in myogenic and cardiomyogenic differentiation of mouse C3H10T1/2 mesenchymal stem cells (MSCs) are far from clear.

Methods

In this study, 5-azacytidine- (5-AZA-) treated C3H10T1/2 cells were differentiated into myocyte-like and cardiomyocyte-like cells. Next, ncRNA associated with myogenic and cardiomyogenic differentiation was identified using high-throughput RNA sequencing (RNA-seq) data. Bioinformatics analysis was conducted to identify the differentially expressed ncRNAs and the related signaling pathways.

Results

Myotube-like structure was formed after 5-AZA treatment of C3H10T1/2 cells. In addition, myogenic and cardiomyogenic differentiation-related genes like GATA4, cTnt, MyoD, and Desmin were upregulated significantly after the 5-AZA treatment. Totally, 1538 differentially expressed lncRNAs and 3398 differentially expressed mRNAs were identified, including 1175 upregulated and 363 downregulated lncRNAs and 2429 upregulated and 969 downregulated mRNAs. In addition, 46 differentially expressed circRNAs were identified, including 25 upregulated and 21 downregulated circRNAs. Moreover, the differentially expressed mRNAs were enriched into 5 significant pathways, including those for focal adhesion, ECM-receptor interaction, PI3K-AKT signaling pathway, PPAR signaling pathway, and Tyrosine metabolism.

Conclusions

A systematic view of the expression of ncRNAs in myogenic and cardiomyogenic differentiation of MSCs was provided in the study.

The LINC01260 Functions as a Tumor Suppressor via the miR-562/CYLD/NF-κB Pathway in Non-Small Cell Lung Cancer

PURPOSE

Recently, long noncoding RNAs (lncRNAs) have been identified as novel and potential therapeutic targets in various cancer types. Nonetheless, the levels and biological effects of lncRNAs in non-small cell lung cancer (NSCLC) remain largely unknown. In this study, we aimed to identify the effects of lncRNA-LINC01260 throughout the progression of NSCLC and explore the underlying mechanism.

METHODS

Quantitative real-time PCR (qRT-PCR) and Western blot were performed to measure LINC01260, miR-562, and CYLD expression and protein levels. Luciferase reporter assay was employed to investigate the relationship between LINC01260 and miR-562, and miR-562 and CYLD, respectively. The viability and migration of cells were evaluated using CCK-8, colony formation, and transwell assays. The effects of LINC01260 were identified through tumorigenesis in vivo. ELISA was performed to detect the activity of NF-κB and p65 expression.

RESULTS

In NSCLC tissues and cell lines, LINC01260 expression was downregulated, which corresponded to a lower survival rate of patients with NSCLC. Knockdown of LINC01260 accelerated the proliferation, colony formation, and migration of NSCLC cells. Moreover, downregulation of LINC01260 inhibited apoptosis of NSCLC cells by regulating the expression of Bcl-2 and Bax proteins in vitro. In vivo, the downregulation of LINC01260 promoted tumor growth. miR-562 was identified as the target gene of LINC01260, which was upregulated in NSCLC tumors. Furthermore, CYLD was identified as the target gene of miR-562. The effects of LINC01260 were exerted by regulating CYLD via sponging miR-562. ELISA confirmed that the upregulation of CYLD inhibited NF-κB activity; however, the co-transfection of sh-LINC01260 partly reversed the inhibition. Additionally, CYLD reduced p65 expression; however, downregulation of LINC01260 slightly increased the expression level.

CONCLUSION

This study revealed a novel LINC01260/miR-562/CYLD/NF-κB pathway in the pathogenesis of NSCLC and suggested a potential therapeutic target for NSCLC.

The Pivotal Role of Mitsugumin 53 in Cardiovascular Diseases

The MG53 (also known as TRIM72) is a conserved, muscle-specific tripartite motif family protein that is abundantly expressed in cardiac or skeletal muscle and present in circulation. Recently, the MG53 had been hypothesized to serve a dual role in the heart: involving in repairing cell membranes that protect myocardial function while acting as an E3 ligase to trigger insulin resistance and cardiovascular complications. This review discusses the roles of MG53 in cardiac physiological function with emphasis on MG53 protective function in the heart and its negative impact on the myocardium due to the continuous elevation of MG53. Besides, this work reviewed the significance of MG53 as a potential therapeutic in human cardiovascular diseases. Despite the expression of MG53 being rare in the human, thus exogenous MG53 can potentially be a new treatment for human cardiovascular diseases. Notably, the specific mechanism of MG53 in cardiovascular diseases remains elusive.

MG53 Protects against Sepsis-Induced Myocardial Dysfunction by Upregulating Peroxisome Proliferator-Activated Receptor-α

Background

The heart is one of the most commonly affected organs during sepsis. Mitsugumin-53 (MG53) has attracted attention in research due to its cardioprotective function. However, the role of MG53 in sepsis-induced myocardial dysfunction (SIMD) remains unknown. The purpose of this study was to explore the underlying mechanism of MG53 in SIMD and investigate its potential relationship with peroxisome proliferator-activated receptor-α (PPARα).

Methods

The cecal ligation and puncture (CLP) model was created to induce SIMD in rats. Protein levels of MG53 and PPARα, cardiac function, cardiomyocyte injury, myocardial oxidative stress and inflammatory indicators, and cardiomyocyte apoptosis were measured at 18 h after CLP. The effects of MG53 on PPARα in SIMD were investigated via preconditioning recombinant human MG53 (rhMG53) and PPARα antagonist GW6471.

Results

The expression of MG53 and PPARα sharply decreased in the myocardium at 18 h after CLP. Compared with the sham group, cardiac function was significantly depressed, which was associated with the destructed myocardium, upregulated oxidative stress indicators and proinflammatory cytokines, and excessive cardiomyocyte apoptosis in the CLP group. Supplementation with rhMG53 enhanced myocardial MG53, increased the survival rate with improved cardiac function, and reduced oxidative stress, inflammation, and myocardial apoptosis, which were associated with PPARα upregulation. Pretreatment with GW6471 abolished the abovementioned protective effects induced by MG53.

Conclusions

Both MG53 and PPARα were downregulated after sepsis shock. MG53 supplement protects the heart against SIMD by upregulating PPARα expression. Our results provide a new treatment strategy for SIMD.

Retraction Note: Inhibition of miR-296-5p protects the heart from cardiac hypertrophy by targeting CACNG6

An amendment to this paper has been published and can be accessed via a link at the top of the paper.