MicroRNA-17-5p Promotes Cardiac Hypertrophy by Targeting Mfn2 to Inhibit Autophagy

Suppression of miR-17 Alleviates Acute Respiratory Distress-associated Lung Fibrosis by Regulating Mfn2

OBJECTIVE

Acute respiratory distress syndrome (ARDS) patients currently have relatively high mortality, which is associated with early lung fibrosis. This study aimed to investigate whether miR-17 suppression could alleviate ARDS-associated lung fibrosis by regulating Mfn2.

METHODS

A mouse model of ARDS-related lung fibrosis was constructed via intratracheal instillation of bleomycin. The expression level of miR-17 in lung tissues was detected via quantitative real time polymerase chain reaction (qRT-PCR). In the ARDS mouse model of lung fibrosis, the mitigating effects of miR-17 interference were evaluated via tail vein injection of the miR negative control or the miR-17 antagomir. The pathological changes in the lung tissue were examined via HE staining and Masson's trichrome staining, and the underlying molecular mechanism was investigated via ELISA, qRT-PCR and Western blotting.

RESULTS

Bleomycin-induced pulmonary fibrosis significantly increased collagen deposition and the levels of hydroxyproline (HYP) and miR-17. Interfering with miR-17 significantly reduced the levels of HYP and miR-17 and upregulated the expression of Mfn2. The intravenous injection of the miR-17 antagomir alleviated lung inflammation and reduced collagen deposition. In addition, interference with miR-17 could upregulate LC3B expression, downregulate p62 expression, and improve mitochondrial structure.

CONCLUSION

Interfering with miR-17 can improve pulmonary fibrosis in mice by promoting mitochondrial autophagy via Mfn2.

Research Progress of miRNA in Heart Failure: Prediction and Treatment

ABSTRACT

This review summarizes the multiple roles of microRNAs (miRNAs) in the prediction and treatment of heart failure (HF), including the molecular mechanisms regulating cell apoptosis, myocardial fibrosis, cardiac hypertrophy, and ventricular remodeling, and highlights the importance of miRNAs in the prognosis of HF. In addition, the strategies for alleviating HF with miRNA intervention are discussed. On the basis of the challenges and emerging directions in the research and clinical practice of HF miRNAs, it is proposed that miRNA-based therapy could be a new approach for prevention and treatment of HF.

Changes in Circulating MicroRNA Levels as Potential Indicators of Training Adaptation in Professional Volleyball Players

The increasing demand placed on professional athletes to enhance their fitness and performance has prompted the search for new, more sensitive biomarkers of physiological ability. One such potential biomarker includes microRNA (miRNA) small regulatory RNA sequences. The study investigated the levels of the selected circulating miRNAs before and after a 10-week training cycle in 12 professional female volleyball players, as well as their association with cortisol, creatine kinase (CK), and interleukin 6 (IL-6), using the qPCR technique. Significant decreases in the miR-22 (0.40 ± 0.1 vs. 0.28 ± 0.12, p = 0.009), miR-17 (0.35 ± 0.13 vs. 0.23 ± 0.08; p = 0.039), miR-24 (0.09 ± 0.04 vs. 0.05 ± 0.02; p = 0.001), and miR-26a (0.11 ± 0.06 vs. 0.06 ± 0.04; p = 0.003) levels were observed after training, alongside reduced levels of cortisol and IL-6. The correlation analysis revealed associations between the miRNAs' relative quantity and the CK concentrations, highlighting their potential role in the muscle repair processes. The linear regression analysis indicated that miR-24 and miR-26a had the greatest impact on the CK levels. The study provides insights into the dynamic changes in the miRNA levels during training, suggesting their potential as biomarkers for monitoring the adaptive responses to exercise. Overall, the findings contribute to a better understanding of the physiological effects of exercise and the potential use of miRNAs, especially miR-24 and miR-26a, as biomarkers in sports science and medicine.

lncRNA ZNF593-AS inhibits cardiac hypertrophy and myocardial remodeling by upregulating Mfn2 expression

lncRNA ZNF593 antisense (ZNF593-AS) transcripts have been implicated in heart failure through the regulation of myocardial contractility. The decreased transcriptional activity of ZNF593-AS has also been detected in cardiac hypertrophy. However, the function of ZNF593-AS in cardiac hypertrophy remains unclear. Herein, we report that the expression of ZNF593-AS reduced in a mouse model of left ventricular hypertrophy and cardiomyocytes in response to treatment with the hypertrophic agonist phenylephrine (PE). In vivo, ZNF593-AS aggravated pressure overload-induced cardiac hypertrophy in knockout mice. By contrast, cardiomyocyte-specific transgenic mice (ZNF593-AS MHC-Tg) exhibited attenuated TAC-induced cardiac hypertrophy. In vitro, vector-based overexpression using murine or human ZNF593-AS alleviated PE-induced myocyte hypertrophy, whereas GapmeR-induced inhibition aggravated hypertrophic phenotypes. By using RNA-seq and gene set enrichment analyses, we identified a link between ZNF593-AS and oxidative phosphorylation and found that mitofusin 2 (Mfn2) is a direct target of ZNF593-AS. ZNF593-AS exerts an antihypertrophic effect by upregulating Mfn2 expression and improving mitochondrial function. Therefore, it represents a promising therapeutic target for combating pathological cardiac remodeling.

Low circulating levels of miR-17 and miR-126-3p are associated with increased mortality risk in geriatric hospitalized patients affected by cardiovascular multimorbidity

MultiMorbidity (MM), defined as the co-occurrence of two or more chronic conditions, is associated with poorer health outcomes, such as recurrent hospital readmission and mortality. As a group of conditions, cardiovascular disease (CVD) exemplifies several challenges of MM, and the identification of prognostic minimally invasive biomarkers to stratify mortality risk in patients affected by cardiovascular MM is a huge challenge. Circulating miRNAs associated to inflammaging and endothelial dysfunction, such as miR-17, miR-21-5p, and miR-126-3p, are expected to have prognostic relevance. We analyzed a composite profile of circulating biomarkers, including miR-17, miR-21-5p, and miR-126-3p, and routine laboratory biomarkers in a sample of 246 hospitalized geriatric patients selected for cardiovascular MM from the Report-AGE INRCA database and BioGER INRCA biobank, to evaluate the association with all-cause mortality during 31 days and 12 and 24 months follow-up. Circulating levels of miR-17, miR-126-3p, and some blood parameters, including neutrophil to lymphocyte ratio (NLR) and eGFR, were significantly associated with mortality in these patients. Overall, our results suggest that in a cohort of geriatric hospitalized patients affected by cardiovascular MM, lower circulating miR-17 and miR-126-3p levels could contribute to identify patients at higher risk of short- and medium-term mortality.

Role of miRNA in Cardiovascular Diseases in Children-Systematic Review

The number of children suffering from cardiovascular diseases (CVDs) is rising globally. Therefore, there is an urgent need to acquire a better understanding of the genetic factors and molecular mechanisms related to the pathogenesis of CVDs in order to develop new prevention and treatment strategies for the future. MicroRNAs (miRNAs) constitute a class of small non-coding RNA fragments that range from 17 to 25 nucleotides in length and play an essential role in regulating gene expression, controlling an abundance of biological aspects of cell life, such as proliferation, differentiation, and apoptosis, thus affecting immune response, stem cell growth, ageing and haematopoiesis. In recent years, the concept of miRNAs as diagnostic markers allowing discrimination between healthy individuals and those affected by CVDs entered the purview of academic debate. In this review, we aimed to systematise available information regarding miRNAs associated with arrhythmias, cardiomyopathies, myocarditis and congenital heart diseases in children. We focused on the targeted genes and metabolic pathways influenced by those particular miRNAs, and finally, tried to determine the future of miRNAs as novel biomarkers of CVD.

Melatonin enhances captopril mediated cardioprotective effects and improves mitochondrial dynamics in male Wistar rats with chronic heart failure

Mitochondrial dysfunction is a recent emerging research scope that proved to be involved in many cardiovascular diseases culminating in chronic heart failure (CHF), which remains one of the primary causes of morbidity and mortality. This study investigated the added cardio-protective effects of exogenous melatonin administration to conventional captopril therapy in isoproterenol (ISO) exposed rats with CHF. Five groups of Wistar rats were recruited; (I): Control group, (II): (ISO group), (III): (ISO + captopril group), (IV): (ISO + melatonin group) and (V): (ISO + melatonin/captopril group). Cardiac function parameters and some oxidant, inflammatory and fibrotic markers were investigated. Moreover; mRNA expression of mitochondrial mitophagy [parkin & PTEN induced kinase 1 (PINK1)], biogenesis [Peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α)], fusion [mitofusin 2 (Mfn2)] and fission [dynamin-related protein 1 (DRP-1)] parameters in rat's myocardium were evaluated. Rats' myocardium was histo-pathologically and immunohistochemically evaluated for Beclin1 and Sirt3 expression. The present study revealed that captopril and melatonin ameliorated cardiac injury, oxidative stress biomarkers, and pro-inflammatory cytokines in ISO-exposed rats. These protective effects could be attributed to mitochondrial dynamic proteins control (i.e. enhanced the mRNA expression of parkin, PINK1, PGC-1α and Mfn2, while reduced DRP-1 mRNA expression). Also, Beclin1 and Sirt3 cardiac immunoreactivity were improved. Combined captopril and melatonin therapy showed a better response than either agent alone. Melatonin enhanced myocardial mitochondrial dynamics and Sirt3 expression in CHF rats and may represent a promising upcoming therapy added to conventional heart failure treatment.

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.

Angiotensin II-induced calcium overload affects mitochondrial functions in cardiac hypertrophy by targeting the USP2/MFN2 axis

Ubiquitination, a common type of post-translational modification, is known to affect various diseases, including cardiac hypertrophy. Ubiquitin-specific peptidase 2 (USP2) plays a crucial role in regulating cell functions, but its role in cardiac functions remains elusive. The present study aims to investigate the mechanism of USP2 in cardiac hypertrophy. Animal and cell models of cardiac hypertrophy were established using Angiotensin II (Ang II) induction. Our experiments revealed that Ang II induced USP2 downregulation in the in vitro and in vivo models. USP2 overexpression suppressed the degree of cardiac hypertrophy (decreased ANP, BNP, and β-MHC mRNA levels, cell surface area, and ratio of protein/DNA), calcium overload (decreased Ca²⁺ concentration and t-CaMKⅡ and p-CaMKⅡ, and increased SERCA2), and mitochondrial dysfunction (decreased MDA and ROS and increased MFN1, ATP, MMP, and complex Ⅰ and II) both in vitro and in vivo. Mechanically, USP2 interacted with MFN2 and improved the protein level of MFN2 through deubiquitination. Rescue experiments confirmed that MFN2 downregulation neutralized the protective role of USP2 overexpression in cardiac hypertrophy. Overall, our findings suggested that USP2 overexpression mediated deubiquitination to upregulate MFN2, thus alleviating calcium overload-induced mitochondrial dysfunction and cardiac hypertrophy.

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

BACKGROUND

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSION

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

Protective effect of bone marrow mesenchymal stem cell-derived exosomes on cardiomyoblast hypoxia-reperfusion injury through the HAND2-AS1/miR-17-5p/Mfn2 axis

BACKGROUND

The exosomes (exos) of bone marrow mesenchymal stem cells (BMSCs) play an important therapeutic role in repairing myocardial injury. The purpose of this study was to explore how the exos of BMSCs can alleviate the myocardial cell injury caused by hypoxia/reoxygenation (H/R) through HAND2-AS1/miR-17-5p/Mfn 2 pathway.

METHODS

Cardiomyocytes H9c2 were damaged by H/R to mimic myocardial damage. Exos were gained from BMSC. The content of HAND2-AS1 and miR-17-5p was assessed by RT-qPCR. Cell survival rate and apoptosis were estimated by MTT assay and flow cytometry. Western blotting was used to detect the expression of protein. The contents of LDH, SOD, and MDA in the cell culture were detected by commercial kits. The luciferase reporter gene method confirmed the targeted relationships.

RESULTS

In H9c2 cells induced by H/R, the level of HAND2-AS1 declined and the expression of miR-17-5p was elevated, but their expression was reversed after exo treatment. Exos improved the cell viability, declined cell apoptosis, controlled the oxidative stress, and repressed inflammation, thus attenuating the damage of H9c2 induced by H/R, whereas, the knockdown of HAND2-AS1 partly alleviated the impacts of exos. MiR-17-5p played the opposite role to HAND2-AS1 on H/R-injured myocardial cells.

CONCLUSION

Exos derived from BMSC could alleviate H/R-induced myocardial injury by activating HAND2-AS1/miR-17-5p/Mfn2 pathway.

Mitophagy: A Potential Target for Pressure Overload-Induced Cardiac Remodelling

The pathological mechanisms underlying cardiac remodelling and cardiac dysfunction caused by pressure overload are poorly understood. Mitochondrial damage and functional dysfunction, including mitochondrial bioenergetic disorder, oxidative stress, and mtDNA damage, contribute to heart injury caused by pressure overload. Mitophagy, an important regulator of mitochondrial homeostasis and function, is triggered by mitochondrial damage and participates in the pathological process of cardiovascular diseases. Recent studies indicate that mitophagy plays a critical role in the pressure overload model, but evidence on the causal relationship between mitophagy abnormality and pressure overload-induced heart injury is inconclusive. This review summarises the mechanism, role, and regulation of mitophagy in the pressure overload model. It also pays special attention to active compounds that may regulate mitophagy in pressure overload, which provide clues for possible clinical applications.

The Role of the miR-17-92 Cluster in Autophagy and Atherosclerosis Supports Its Link to Lysosomal Storage Diseases

Establishing the role of non-coding RNA (ncRNA), especially microRNAs (miRNAs), in the regulation of cell function constitutes a current research challenge. Two to six miRNAs can act in clusters; particularly, the miR-17-92 family, composed of miR-17, miR-18a, miR-19a, miR-20a, miR-19b-1, and miR-92a is well-characterized. This cluster functions during embryonic development in cell differentiation, growth, development, and morphogenesis and is an established oncogenic cluster. However, its role in the regulation of cellular metabolism, mainly in lipid metabolism and autophagy, has received less attention. Here, we argue that the miR-17-92 cluster is highly relevant for these two processes, and thus, could be involved in the study of pathologies derived from lysosomal deficiencies. Lysosomes are related to both processes, as they control cholesterol flux and regulate autophagy. Accordingly, we compiled, analyzed, and discussed current evidence that highlights the cluster's fundamental role in regulating cellular energetic metabolism (mainly lipid and cholesterol flux) and atherosclerosis, as well as its critical participation in autophagy regulation. Because these processes are closely related to lysosomes, we also provide experimental data from the literature to support our proposal that the miR-17-92 cluster could be involved in the pathogenesis and effects of lysosomal storage diseases (LSD).

MicroRNA-17-5p Protects against Propofol Anesthesia-Induced Neurotoxicity and Autophagy Impairment via Targeting BCL2L11

Background. Propofol (PPF) has been shown in studies to cause cognitive impairment and neuronal cell death in developing animals. PPF has been demonstrated to decrease the expression of microRNA-17-5p (miR-17-5p) in a recent study. Nonetheless, the function of miR-17-5p in PPF-induced neurotoxicity and related mechanisms is uncharacterized. Methods. After the induction of neurotoxicity by treating the SH-SY5Y cells with PPF, qRT-PCR was conducted to evaluate the level of miR-17-5p. Using MTT and flow cytometry, cell viability and apoptosis rate were assessed, respectively. Interaction between miR-17-5p and BCL2 like 11 was (BCL2L11) studied using a Luciferase reporter assay. With the help of western blot analysis, we determined the level of proteins of apoptosis-related genes and autophagy-related markers. Results. In SH-SY5Y cells, PPF treatment induced neurotoxicity and downregulated miR-17-5p expression. In SH-SY5Y cells post-PPF exposure, overexpression of miR-17-5p increased cell viability and decreased apoptosis. Consistently, miR-17-5p mimics mitigated PPF-generated autophagy via inhibition of Atg5, Beclin1, and LC3II/I level and elevation of p62 protein expression. In addition, BCL2L11, which was highly expressed in PPF-treated SH-SY5Y cells, was directly targeted by miR-17-5p. Further, in PPF-treated SH-SY5Y cells, overexpressed BCL2L11 counteracted the suppressing behavior of miR-17-5p elevation on PPF-induced apoptosis. Conclusion. Overexpressed miR-17-5p alleviates PPF exposure-induced neurotoxicity and autophagy in SH-SY5Y cells via binding to BCL2L11, suggesting the possibility that miR-17-5p can serve as a candidate in the treatment of neurotoxicity (caused by PPF).

Cell death regulation by MAMs: from molecular mechanisms to therapeutic implications in cardiovascular diseases

The endoplasmic reticulum (ER) and mitochondria are interconnected intracellular organelles with vital roles in the regulation of cell signaling and function. While the ER participates in a number of biological processes including lipid biosynthesis, Ca2+ storage and protein folding and processing, mitochondria are highly dynamic organelles governing ATP synthesis, free radical production, innate immunity and apoptosis. Interplay between the ER and mitochondria plays a crucial role in regulating energy metabolism and cell fate control under stress. The mitochondria-associated membranes (MAMs) denote physical contact sites between ER and mitochondria that mediate bidirectional communications between the two organelles. Although Ca2+ transport from ER to mitochondria is vital for mitochondrial homeostasis and energy metabolism, unrestrained Ca2+ transfer may result in mitochondrial Ca2+ overload, mitochondrial damage and cell death. Here we summarize the roles of MAMs in cell physiology and its impact in pathological conditions with a focus on cardiovascular disease. The possibility of manipulating ER-mitochondria contacts as potential therapeutic approaches is also discussed.

MicroRNAs in hypertrophic cardiomyopathy: pathogenesis, diagnosis, treatment potential and roles as clinical biomarkers

Hypertrophic cardiomyopathy (HCM) is the most common heritable cardiomyopathy and is characterized by increased left ventricular wall thickness, but existing diagnostic and treatment approaches face limitations. MicroRNAs (miRNAs) are type of noncoding RNA molecule that plays crucial roles in the pathological process of cardiac remodelling. Accordingly, miRNAs related to HCM may represent potential novel therapeutic targets. In this review, we first discuss the different roles of miRNAs in the development of HCM. We then summarize the roles of common miRNAs as diagnostic and clinical biomarkers in HCM. Finally, we outline current and future challenges and potential new directions for miRNA-based therapeutics for HCM.

MicroRNA-Related Strategies to Improve Cardiac Function in Heart Failure

Heart failure (HF) describes a group of manifestations caused by the failure of heart function as a pump that supports blood flow through the body. MicroRNAs (miRNAs), as one type of non-coding RNA molecule, have crucial roles in the etiology of HF. Accordingly, miRNAs related to HF may represent potential novel therapeutic targets. In this review, we first discuss the different roles of miRNAs in the development and diseases of the heart. We then outline commonly used miRNA chemical modifications and delivery systems. Further, we summarize the opportunities and challenges for HF-related miRNA therapeutics targets, and discuss the first clinical trial of an antisense drug (CDR132L) in patients with HF. Finally, we outline current and future challenges and potential new directions for miRNA-based therapeutics for HF.