MiRNAs as potential molecular targets in heart failure

Correlations of circulating miR-26b level with left ventricular hypertrophy and cardiac function in elderly patients with hypertension

Objectives:

To study the correlations of circulating miR-26b level with left ventricular hypertrophy (LVH) and cardiac function in elderly patients with hypertension.

Methods:

A total of 132 eligible patients were divided into low and high miR-26b level groups. Their baseline clinical data and biochemical indices were compared. The correlations between miR-26b level and echocardiographic parameters were studied by Pearson’s analysis. Factors affecting LVH were explored by multivariate logistic regression analysis. The role of miR-26b in diagnosing LVH was predicted by receiver operating characteristic curve.

Results:

The relative expression level of miR-26b was 4.56-16.93, with a median of 7.62. The two groups had similar baseline clinical data and biochemical indices (P>0.05). Compared with high miR-26b level group, interventricular septal thickness (IVST), left ventricular posterior wall thickness (LVPWT), left ventricular mass index (LVMI) and number of LVH cases in low miR-26b level group significantly increased (P<0.05), and mitral ratio of peak early to late diastolic filling velocity (E/A) decreased (P<0.05). Circulating miR-26b level was negatively correlated with IVST, LVPWT and LVMI (P<0.0001), and positively correlated with E/A (P<0.0001). The proportion of cardiac hypofunction cases in low miR-26b level group significantly exceeded that of high miR-26b level group (P<0.05). Age and increased IVST, LVPWT and LVMI were independent risk factors for LVH (P<0.05), and elevated miR-26b level was a protective factor (P<0.05). AUC was 0.836, and the optimal cutoff value was 8.83, with high sensitivity and specificity.

Conclusions:

MiR-26b level is negatively correlated with LVH and positively correlated with left ventricular diastolic function in elderly hypertensive patients. It is a protective factor for LVH complicated with diastolic dysfunction and a potential biomarker for diagnosis.

The miRNA199a/SIRT1/P300/Yy1/sST2 signaling axis regulates adverse cardiac remodeling following MI

Left ventricular remodeling following myocardial infarction (MI) is related to adverse outcome. It has been shown that an up-regulation of plasma soluble ST2 (sST2) levels are associated with lower pre-discharge left ventricular (LV) ejection fraction, adverse cardiovascular outcomes and mortality outcome after MI. The mechanisms involved in its modulation are unknown and there is not specific treatment capable of lowering plasma sST2 levels in acute-stage HF. We recently identified Yin-yang 1 (Yy1) as a transcription factor related to circulating soluble ST2 isoform (sST2) expression in infarcted myocardium. However, the underlying mechanisms involved in this process have not been thoroughly elucidated. This study aimed to evaluate the pathophysiological implication of miR-199a-5p in cardiac remodeling and the expression of the soluble ST2 isoform. Myocardial infarction (MI) was induced by permanent ligation of the left anterior coronary artery in C57BL6/J mice that randomly received antimiR199a therapy, antimiR-Ctrl or saline. A model of biomechanical stretching was also used to characterize the underlying mechanisms involved in the activation of Yy1/sST2 axis. Our results show that the significant upregulation of miR-199a-5p after myocardial infarction increases pathological cardiac hypertrophy by upregulating circulating soluble sST2 levels. AntimiR199a therapy up-regulates Sirt1 and inactivates the co-activator P300 protein, thus leading to Yy1 inhibition which decreases both expression and release of circulating sST2 by cardiomyocytes after myocardial infarction. Pharmacological inhibition of miR-199a rescues cardiac hypertrophy and heart failure in mice, offering a potential therapeutic approach for cardiac failure.

MicroRNA-24-3p inhibition prevents cell growth of vascular smooth muscle cells by targeting Bcl-2-like protein 11

Numerous reports have shown that dysfunction of vascular smooth muscle cells (VSMCs) serves a critical function in the development of cardiovascular disease, including coronary heart disease (CHD). microRNAs (miRNAs/miRs) have been reported to play important roles in regulating the function of VSMCs. The present study aimed to determine the role of miR-24-3p in VSMCs and to uncover the underlying mechanism. The expression of miR-24-3p in the peripheral blood samples of CHD patients was measured by reverse transcription-quantitative (RT-q)PCR. It was found that the level of miR-24-3p in the peripheral blood of patients with CHD was significantly upregulated compared with that in healthy controls. A dual luciferase reporter assay was performed to determine whether Bcl-2-like protein 11 (Bcl-2L11) was a target gene of miR-24-3p, and it was identified that Bcl-2L11 was a direct target of miR-24-3p. The mRNA level and protein expression of Bcl-2L11 in the peripheral blood of patients with CHD were measured by RT-qPCR and western blotting, respectively. The findings suggested that Bcl-2L11 was downregulated in the peripheral blood of patients with CHD. In addition, it was found that downregulation of miR-24-3p suppressed VSMC proliferation and promoted VSMC apoptosis, while the effects of the miR-24-3p inhibitor on cell viability and apoptosis were reversed by Bcl-2L11-small interfering (si)RNA. Additionally, downregulation of miR-24-3p increased the levels of Bcl-2L11, caspase-3 and Bax, and decreased Bcl-2 expression in VSMCs; these changes were abolished by Bcl-2L11-siRNA. In conclusion, the aforementioned results indicated that miR-24-3p was an important regulator in VSMC proliferation and apoptosis by targeting Bcl-2L11, which suggested that miR-24-3p might be a potential therapeutic target for the treatment of CHD.

miRNA transfection via poly(amidoamine)-based delivery vector prevents hypoxia/reperfusion-induced cardiomyocyte apoptosis

Aim: Myocardial infarction is a tissue injury that leads to apoptosis of cardiomyocytes. This can be prevented by using miRNAs, but its delivery to cardiomyocytes is a major hurdle. We aimed to deliver miRNAs using poly(amidoamine)-histidine (PAMAM-His) nanocarriers to prevent apoptosis. Materials & methods: The PAMAM-His nanoparticles were synthesized and assessed for their transfection efficiency of miRNAs to prevent apoptosis in hypoxia/reperfusion-induced H9c2 as well as primary cultured cardiomyocytes. Results & conclusion: miRNAs-nanoparticle complexes exerted a significant antiapoptotic effect on the H9c2 and primary rat ventricular cardiomyocytes. Enhanced expression of antiapoptotic genes and decreased expression of proapoptotic genes were observed. PAMAM-His nanoparticles effectively delivered miRNAs to the cardiomyocytes and prevented the hypoxia/reperfusion-induced apoptosis critical in myocardial infarctions.

Identification of serum microRNAs as potential biomarkers in Pompe disease

OBJECTIVE

To analyze the microRNA profile in serum of patients with Adult Onset Pompe disease (AOPD).

METHODS

We analyzed the expression of 185 microRNAs in serum of 15 AOPD patients and five controls using microRNA PCR Panels. The expression levels of microRNAs that were deregulated were further studied in 35 AOPD patients and 10 controls using Real-Time PCR. Additionally, the skeletal muscle expression of microRNAs which showed significant increase levels in serum samples was also studied. Correlations between microRNA serum levels and muscle function test, spirometry, and quantitative muscle MRI were performed (these data correspond to the study NCT01914536 at ClinicalTrials.gov).

RESULTS

We identified 14 microRNAs that showed different expression levels in serum samples of AOPD patients compared to controls. We validated these results in a larger cohort of patients and we found increased levels of three microRNAs, the so called dystromirs: miR-1-3p, miR-133a-3p, and miR-206. These microRNAs are involved in muscle regeneration and the expression of these was increased in patients' muscle biopsies. Significant correlations between microRNA levels and muscle function test were found.

INTERPRETATION

Serum expression levels of dystromirs may represent additional biomarkers for the follow-up of AOPD patients.

MiR-1a-3p mitigates isoproterenol-induced heart failure by enhancing the expression of mitochondrial ND1 and COX1

MicroRNAs (miRNAs) have become potential targets for the treatment of heart failure (HF). It has been shown that miR-1 can reverse cardiac hypertrophy during the compensatory phase of HF development, but it is unknown whether miR-1 can still reverse cardiac dysfunction and improve cardiac remodeling after HF progresses to the decompensation stage. We established a mouse model of isoproterenol-induced HF and then injected miR-1a-3p agomir (agomir-1) into the tail vein. Echocardiography showed that the mice treated with agomir-1 had significantly increased ejection fraction and fractional shortening. These mice also showed a decrease in the N-terminal pro-B type natriuretic peptide (NT-proBNP) levels, but this remained higher than in controls. Cardiac hypertrophy, myocardial fibrosis, apoptosis, and glycogen deposition were reduced in mice treated with agomir-1. Furthermore, we found that supplementation of agomir-1 increased the expression of two mitochondrial DNA-encoded proteins, mitochondrially encoded NADH dehydrogenase 1 (ND1) and mitochondrially encoded cytochrome c oxidase I (COX1). In conclusion, our study found that miR-1a-3p alleviated the symptoms of ISO-induced HF in mice by enhancing mitochondrial ND1 and COX1. The results of this work may provide new therapeutic strategies for the treatment of HF patients.

Potential biomarkers for heart failure

In this study, we identified candidate biomarkers for heart failure (HF). The gene expression profile GSE57338, containing 117 ischemic cardiomyopathic HF and 136 control samples, was downloaded and analyzed using various bioinformatics approaches. In total, 376 differentially expressed genes (DEGs) were identified, and four modules were explored in protein-protein interaction networks. DEGs (including ankyrin repeat and SOCS box-containing 14 [ASB14]) in the modules were mainly categorized by the function. Several relationships including interferon regulatory factor 1 (IRF1)-C-C motif chemokine ligand 5 (CCL5) were revealed in the transcription factor microRNA target gene regulatory network. Gene-drug analysis revealed 11 DEGs (such as the cluster of differentiation 163 [CD163]) for the target drugs. Data verification analysis identified 118 overlapping DEGs including ASB14, CD163, and CCL5. ASB14 may be involved in HF progression via protein ubiquitination and CCL5 may be involved in HF via the IRF1-CCL5 interaction. Genes including CD163 are potential biomarkers for HF.

Rescuing infusion of miRNA-1 prevents cardiac remodeling in a heart-selective miRNA deficient mouse

OBJECTIVE

The decreased expression of muscle-specific microRNA-1 (miR-1) has been found in many cardiovascular diseases and is considered to contribute to heart failure (HF). Here we investigated the role of miR-1 in myocardium protection by infusion of miR-1 in a cardiac global miRNA-deficient mouse.

METHODS

We generated a cardiac-selective miRNA-deficient mouse by crossing Dicerflox/flox mice with mice expressing tamoxifen-inducible Cre recombinase under the control of a mouse αMHC promoter. When Dicer gene was removed following tamoxifen injection, the mice were treated with micrONTM mmu-miR-1a-3p agomir (agomir-1). The mice were subjected to echocardiography measurement, and the heart tissue specimens were stained with hematoxylin and eosin (H&E) and Sirius red. Terminal deoxynucleotidyl transferase-mediated dUTP nickend labeling assay and Ki67 immunofluorescence were used to determine apoptosis and proliferation.

RESULTS

Dicer deletion resulted in extensive decrease in cardiac miRNAs in the mice. In echocardiography, the mice developed rapid and dramatic left ventricular enlargement. In histology, apparent cardiomyocyte hypertrophy, myofiber disarray, ventricular fibrosis, inflammatory infiltration, and severe ventricular remodeling were exhibited. When the mice were treated with agomir-1, they did not show any significant abnormalities in heart structure and histology in response to Dicer ablation.

CONCLUSION

The proper expression of miRNAs plays vital roles in the maintenance of heart histology and function. Among these miRNAs, miR-1 is critical to inhibit myocyte hypertrophy and extracellular matrix deposition, thereby preventing cardiac remodeling in cardiac-selective Dicer deficient mice.

Short‑term vagus nerve stimulation reduces myocardial apoptosis by downregulating microRNA‑205 in rats with chronic heart failure

Previous studies have reported that short-term vagus nerve stimulation (VNS) improves cardiac function in rats with chronic heart failure (CHF). The molecular mechanisms are unclear. The potential effect of microRNA (miR)-205 in apoptosis of short-term VNS was examined. A total of 3 weeks after inducing CHF, the rats were divided into three groups: Sham stimulation in sham operated rats, sham stimulation in CHF rats (CHF-SS), and treated with VNS in CHF rats (CHF-VNS). The right vagus nerve of the neck was stimulated for 72 h in CHF rats with rectangular pulses of 40 msec duration at 1 Hz and 5 V. miR-205 was focused on, which exhibited differential expression in the miRNA microarray analysis of CHF rats, and the effects of VNS on apoptosis were examined. It was verified that the expression level of miR-205 in the CHF-SS group was increased, and the expression was reduced in the CHF-VNS group. Furthermore, mimics or inhibitor of miR-205 was transfected into H9c2 to investigate its function on apoptosis. Baculoviral IAP repeat-containing protein 2 (Birc2) was confirmed a target of miR-205 through a dual luciferase reporter assay and western blotting. It was demonstrated that downregulated miR-205 decreased apoptosis in H9c2 cells. The apoptosis-associated proteins were further detected in H9c2 cells and rat tissue. The mRNA and protein expression levels of caspase-3 and Bcl-2-associated X protein were decreased in the CHF-VNS group, the expression of Birc2 and B-cell lymphoma 2 were increased. The results were consistent with the in vitro study in the miR-205 inhibitor group. The present study demonstrated that short-term VNS decreased apoptosis by downregulating miR-205 in rats with CHF. Therefore, the results of the present study provide basic evidence for short-term VNS in the clinical treatment of CHF.

Novel Biomarkers of Heart Failure

Although substantial improvements have been made in majority of cardiac disorders, heart failure (HF) remains a major health problem, with both increasing incidence and prevalence over the past decades. For that reason, the number of potential biomarkers that could contribute to diagnosis and treatment of HF patients is, almost exponentially, increasing over the recent years. The biomarkers that are, at the moment, more or less ready for use in everyday clinical practice, reflect different pathophysiological processes present in HF. In this review, seven groups of biomarkers associated to myocardial stretch (mid-regional proatrial natriuretic peptide, MR-proANP), myocyte injury (high-sensitive troponins, hs-cTn; heart-type fatty acid-binding protein, H-FABP; glutathione transferase P1, GSTP1), matrix remodeling (galectin-3; soluble isoform of suppression of tumorigenicity 2, sST2), inflammation (growth differentiation factor-15, GDF-15), renal dysfunction (neutrophil gelatinase-associated lipocalin, NGAL; kidney injury molecule-1, KIM-1), neurohumoral activation (adrenomedullin, MR-proADM; copeptin), and oxidative stress (ceruloplasmin; myeloperoxidase, MPO; 8-hydroxy-2'-deoxyguanosine, 8-OHdG; thioredoxin 1, Trx1) in HF will be overviewed. It is important to note that clinical value of individual biomarkers within the single time points in both diagnosis and outcome prediction in HF is limited. Hence, the future of biomarker application in HF lies in the multimarker panel strategy, which would include specific combination of biomarkers that reflect different pathophysiological processes underlying HF.

Diagnostic and prognostic value of circulating microRNAs in heart failure with preserved and reduced ejection fraction

microRNAs (miRNAs) are powerful regulators of posttranscriptional gene expression and play an important role in pathophysiological processes. Circulating miRNAs can be quantified in body liquids and are promising biomarkers in numerous diseases. In cardiovascular disease miRNAs have been proven to be reliable diagnostic biomarkers for different disease entities. In cardiac fibrosis (CF) and heart failure (HF) dysregulated circulating miRNAs have been identified, indicating their promising applicability as diagnostic biomarkers. Some miRNAs were successfully tested in risk stratification of HF implementing their potential use as prognostic biomarkers. In this respect miRNAs might soon be implemented in diagnostic clinical routine. In the young field of miRNA based research advances have been made in identifying miRNAs as potential targets for the treatment of experimental CF and HF. Promising study results suggest their potential future application as therapeutic agents in treatment of cardiovascular disease. This article summarizes the current state of the various aspects of miRNA research in the field of CF and HF with reduced ejection fraction as well as preserved ejection fraction. The review provides an overview of the application of circulating miRNAs as biomarkers in CF and HF and current approaches to therapeutically utilize miRNAs in this field of cardiovascular disease.

miRNA therapeutics: a new class of drugs with potential therapeutic applications in the heart

miRNAs are small non-coding RNAs (ncRNAs), which regulate gene expression. Here, the authors describe the contribution of miRNAs to cardiac biology and disease. They discuss various strategies for manipulating miRNA activity including antisense oligonucleotides (antimiRs, blockmiRs), mimics, miRNA sponges, Tough Decoys and miRNA mowers. They review developments in chemistries (e.g., locked nucleic acid) and modifications (sugar, 'ZEN', peptide nucleic acids) and miRNA delivery tools (viral vectors, liposomes, nanoparticles, pHLIP). They summarize potential miRNA therapeutic targets for heart disease based on preclinical studies. Finally, the authors review current progress of miRNA therapeutics in clinical development for HCV and cancer, and discuss challenges that will need to be overcome for similar therapies to enter the clinic for patients with cardiac disease.