MicroRNA-19a/b-3p protect the heart from hypertension-induced pathological cardiac hypertrophy through PDE5A

Holistic expression of miR-17-92 cluster in obesity, kidney diseases, cardiovascular diseases, and diabetes

miR-17-92 cluster encodes six micro RNAs (miRNAs) and plays a crucial role in the regulation of various cellular processes. Aberrant expression of this cluster may result in the onset of several diseases. Initially, the role of miR-17-92 cluster in tumorigenesis was discovered but recent research has also uncovered its role in other diseases. Members of the cluster may serve as potential biomarkers in the prognosis, diagnosis, and treatment of several diseases and their complications. In this article, we have reviewed the recent research carried out on the expression pattern of miR-17-92 cluster in non-communicable diseases i.e., obesity, cardiovascular diseases (CVD), kidney diseases (KD) and diabetes mellitus (DM). We examined miR-17-92 role in pathological processes and their potential importance as biomarkers. Each member of the cluster miR-17-92 was upregulated in obesity. miR-18a, miR-19b-3p, miR20a, and miR92a were significantly upregulated in CVD. An equal fraction of the cluster was dysregulated (upregulated and downregulated) in diabetes; however, miR-17-92 was downregulated in most studies on CKD.

Clinical Significance of MicroRNAs, Long Non-Coding RNAs, and CircRNAs in Cardiovascular Diseases

Based on recent research, the non-coding genome is essential for controlling genes and genetic programming during development, as well as for health and cardiovascular diseases (CVDs). The microRNAs (miRNAs), lncRNAs (long ncRNAs), and circRNAs (circular RNAs) with significant regulatory and structural roles make up approximately 99% of the human genome, which does not contain proteins. Non-coding RNAs (ncRNA) have been discovered to be essential novel regulators of cardiovascular risk factors and cellular processes, making them significant prospects for advanced diagnostics and prognosis evaluation. Cases of CVDs are rising due to limitations in the current therapeutic approach; most of the treatment options are based on the coding transcripts that encode proteins. Recently, various investigations have shown the role of nc-RNA in the early diagnosis and treatment of CVDs. Furthermore, the development of novel diagnoses and treatments based on miRNAs, lncRNAs, and circRNAs could be more helpful in the clinical management of patients with CVDs. CVDs are classified into various types of heart diseases, including cardiac hypertrophy (CH), heart failure (HF), rheumatic heart disease (RHD), acute coronary syndrome (ACS), myocardial infarction (MI), atherosclerosis (AS), myocardial fibrosis (MF), arrhythmia (ARR), and pulmonary arterial hypertension (PAH). Here, we discuss the biological and clinical importance of miRNAs, lncRNAs, and circRNAs and their expression profiles and manipulation of non-coding transcripts in CVDs, which will deliver an in-depth knowledge of the role of ncRNAs in CVDs for progressing new clinical diagnosis and treatment.

Analysis of hsa-miR-19a-3p and hsa-miR-19b-3p modulation and phosphodiesterase type 5 expression in the vaginal epithelium of premenopausal women with genital arousal disorder

BACKGROUND

Few studies have investigated the role of the phosphodiesterase type 5A (PDE5A) isoenzyme in female genital tissue disorders, exclusively taken from cadavers, as well as the epigenetic mechanisms responsible for the regulation of PDE5A levels.

AIM

The aim was to study the in vivo association between microRNA (miRNA) expression and the expression levels of PDE5A in women with female genital arousal disorder (FGAD) compared with healthy women.

METHODS

Premenopausal women affected by FGAD (cases) and sexually healthy women (control group) underwent microbiopsy of the periclitoral anterior vaginal wall for the collection of tissue samples. Computational analyses were preliminarily performed in order to identify miRNAs involved in the modulation of PDE5A by using miRNA-messenger RNA interaction prediction tools. Differences in the expression levels of miRNAs and PDE5A were finally investigated in cases and control subjects by using the droplet digital polymerase chain reaction amplification system and stratifying women considering their age, number of pregnancies, and body mass index.

OUTCOMES

Expression levels of miRNAs were able to target PDE5A and the tissue expression in women with FGAD compared with healthy women.

RESULTS

The experimental analyses were performed on 22 (43.1%) cases and 29 (56.9%) control subjects. Two miRNAs with the highest interaction levels with PDE5A, hsa-miR-19a-3p (miR-19a) and hsa-miR-19b-3p (miR-19b), were identified and selected for validation analyses. A reduction of the expression levels of both miRNAs was observed in women with FGAD compared with the control subjects (P < .05). Moreover, PDE5A expression levels were higher in women with FGAD and lower in women without sexual dysfunctions (P < .05). Finally, a correlation between body mass index and the expression levels of miR-19a was found (P < .01).

CLINICAL IMPLICATIONS

Women with FGAD had higher levels of PDE5 compared with control subjects; therefore, the administration of PDE5 inhibitors (PDE5 inhibitors) could be useful in women with FGAD.

STRENGTHS AND LIMITATIONS

The strength of the current study was to analyze genital tissue obtained in vivo from premenopausal women. A limitation was to not investigate other factors, including endothelial nitric oxide synthetases, nitric oxide, and cyclic guanosine monophosphate.

CONCLUSION

The results of the present study indicate that the modulation of selected miRNAs could influence PDE5A expression in genital tissues in healthy women or in those with FGAD. Such findings further suggest that treatment with PDE5 inhibitors, as a modulator of PDE5A expression, could be indicated for women with FGAD.

MicroRNA sequencing in patients with coronary artery disease – considerations for use as biomarker for thrombotic risk

MicroRNAs (miRNAs) are small RNAs integral in the regulation of gene expression. Analysis of circulating miRNA levels may identify patients with coronary artery disease (CAD) at risk for recurrent myocardial infarction (MI) after percutaneous coronary interventions (PCIs). Subjects with CAD were selected from the GENCATH cardiac catheterization biobank. Subjects with recurrent MI after PCI were compared with those without recurrent MI during follow‐up in the initial (n = 48) and replication cohort (n = 67). Next generation MiRNA sequencing was performed on plasma samples and whole blood samples fixed with PAXGENE tubes upon collection. Overall, 164 miRNAs derived from whole blood were differentially expressed in the replication cohort between subjects with and without recurrent MI events (p < 0.05), with 69 remaining significant after false‐discovery rate (FDR) correction. None of the miRNAs in plasma was significantly different by FDR among subjects with and without MI. Overall, correlation between direction of effects between plasma and whole blood assays was variable, and only two miRNAs were concordant and significant in both. Associations of miRNA with vascular disease, MI, and thrombosis were further explored. MiRNA profiling has potential as the future biomarker for disease prognosis and treatment response marker in secondary treatment of patients with CAD after PCI. Whole blood may be the preferred sample source as compared to plasma.

Endoplasmic reticulum stress mediates homocysteine-induced hypertrophy of cardiac cells through activation of cyclic nucleotide phosphodiesterase 1C

Although the association of elevated homocysteine level with cardiac hypertrophy has been reported, the molecular mechanisms by which homocysteine induces cardiac hypertrophy remain inadequately understood. In this study we aim to uncover the roles of cyclic nucleotide phosphodiesterase 1 (PDE1) and endoplasmic reticulum (ER) stress and their relationship to advance the mechanistic understanding of homocysteine-induced cardiac cell hypertrophy. H9c2 cells and primary neonatal rat cardiomyocytes are exposed to homocysteine with or without ER stress inhibitor TUDCA or PDE1-specific inhibitor Lu AF58027, or transfected with siRNAs targeting PDE1 isoforms prior to homocysteine-exposure. Cell surface area is measured and ultrastructure is examined by transmission electron microscopy. Hypertrophic markers, PDE1 isoforms, and ER stress molecules are detected by q-PCR and western blot analysis. Intracellular cGMP and cAMP are measured by ELISA. The results show that homocysteine causes the enlargement of H9c2 cells, increases the expressions of hypertrophic markers β-MHC and ANP, upregulates PDE1A and PDE1C, promotes the expressions of ER stress molecules, and causes ER dilatation and degranulation. TUDCA and Lu AF58027 downregulate β-MHC and ANP, and alleviate cell enlargement. TUDCA decreases PDE1A and PDE1C levels. Silencing of PDE1C inhibits homocysteine-induced hypertrophy, whereas PDE1A knockdown has minor effect. Both cAMP and cGMP are decreased after homocysteine-exposure, while only cAMP is restored by Lu AF58027 and TUDCA. TUDCA and Lu AF58027 also inhibit cell enlargement, downregulate ANP, β-MHC and PDE1C, and enhance cAMP level in homocysteine-exposed primary cardiomyocytes. ER stress mediates homocysteine-induced hypertrophy of cardiac cells via upregulating PDE1C expression Cyclic nucleotide, especially cAMP, is the downstream mediator of the ER stress-PDE1C signaling axis in homocysteine-induced cell hypertrophy.

MicroRNAs Regulating Renin-Angiotensin-Aldosterone System, Sympathetic Nervous System and Left Ventricular Hypertrophy in Systemic Arterial Hypertension

MicroRNAs are small non-coding RNAs that regulate gene and protein expression. MicroRNAs also regulate several cellular processes such as proliferation, differentiation, cell cycle, apoptosis, among others. In this context, they play important roles in the human body and in the pathogenesis of diseases such as cancer, diabetes, obesity and hypertension. In hypertension, microRNAs act on the renin-angiotensin-aldosterone system, sympathetic nervous system and left ventricular hypertrophy, however the signaling pathways that interact in these processes and are regulated by microRNAs inducing hypertension and the worsening of the disease still need to be elucidated. Thus, the aim of this review is to analyze the pattern of expression of microRNAs in these processes and the possible associated signaling pathways.

Epigenetic Regulation of Cardiac Troponin Genes in Pediatric Patients with Heart Failure Supported by Ventricular Assist Device

Ventricular Assist Device (VAD) therapy is considered as a part of standard care for end-stage Heart Failure (HF) children unresponsive to medical management, but the potential role of miRNAs in response to VAD therapy on molecular pathways underlying LV remodeling and cardiac function in HF is unknown. The aims of this study were to evaluate the effects of VAD on miRNA expression profile in cardiac tissue obtained from HF children, to determine the putative miRNA targets by an in-silico analysis as well as to verify the changes of predicated miRNA target in the same cardiac samples. The regulatory role of selected miRNAs on predicted targets was evaluated by a dedicated in vitro study. miRNA profile was determined in cardiac samples obtained from 13 HF children [median: 29 months; 19 LVEF%; 9 Kg] by NGS before VAD implant (pre-VAD) and at the moment of heart transplant (Post-VAD). Only hsa-miR-199b-5p, hsa-miR-19a-3p, hsa-miR-1246 were differentially expressed at post-VAD when compared to pre-VAD, and validated by real-time PCR. Putative targets of the selected miRNAs were involved in regulation of sarcomere genes, such as cardiac troponin (cTns) complex. The expression levels of fetal ad adult isoforms of cTns resulted significantly higher after VAD in cardiac tissue of HF pediatric patients when compared with HF adults. An in vitro study confirmed a down-regulatory effect of hsa-miR-19a-3p on cTnC expression. The effect of VAD on sarcomere organization through cTn isoform expression may be epigenetically regulated, suggesting for miRNAs a potential role as therapeutic targets to improve heart function in HF pediatric patients.

MicroRNAs-The Heart of Post-Myocardial Infarction Remodeling

Myocardial infarction (MI) is one of the most frequent cardiac emergencies, with significant potential for mortality. One of the major challenges of the post-MI healing response is that replacement fibrosis could lead to left ventricular remodeling (LVR) and heart failure (HF). This process involves canonical and non-canonical transforming growth factor-beta (TGF-β) signaling pathways translating into an intricate activation of cardiac fibroblasts and disproportionate collagen synthesis. Accumulating evidence has indicated that microRNAs (miRNAs) significantly contribute to the modulation of these signaling pathways. This review summarizes the recent updates regarding the molecular mechanisms underlying the role of the over 30 miRNAs involved in post-MI LVR. In addition, we compare the contradictory roles of several multifunctional miRNAs and highlight their potential use in pressure overload and ischemia-induced fibrosis. Finally, we discuss their attractive role as prognostic biomarkers for HF, highlighting the most relevant human trials involving these miRNAs.

Reveals of candidate active ingredients in Justicia and its anti-thrombotic action of mechanism based on network pharmacology approach and experimental validation

Thrombotic diseases seriously threaten human life. Justicia, as a common Chinese medicine, is usually used for anti-inflammatory treatment, and further studies have found that it has an inhibitory effect on platelet aggregation. Therefore, it can be inferred that Justicia can be used as a therapeutic drug for thrombosis. This work aims to reveal the pharmacological mechanism of the anti-thrombotic effect of Justicia through network pharmacology combined with wet experimental verification. During the analysis, 461 compound targets were predicted from various databases and 881 thrombus-related targets were collected. Then, herb-compound-target network and protein-protein interaction network of disease and prediction targets were constructed and cluster analysis was applied to further explore the connection between the targets. In addition, Gene Ontology (GO) and pathway (KEGG) enrichment were used to further determine the association between target proteins and diseases. Finally, the expression of hub target proteins of the core component and the anti-thrombotic effect of Justicia's core compounds were verified by experiments. In conclusion, the core bioactive components, especially justicidin D, can reduce thrombosis by regulating F2, MMP9, CXCL12, MET, RAC1, PDE5A, and ABCB1. The combination of network pharmacology and the experimental research strategies proposed in this paper provides a comprehensive method for systematically exploring the therapeutic mechanism of multi-component medicine.

Isoflurane and low-level carbon monoxide exposures increase expression of pro-survival miRNA in neonatal mouse heart

Anesthetics such as isoflurane are known to cause apoptosis in the developing mammalian brain. However, isoflurane may have protective effects on the heart via relieving ischemia and downregulating genes related to apoptosis. Ischemic preconditioning, e.g. through the use of low levels of carbon monoxide (CO), has promise in preventing ischemia-reperfusion injury and cell death. However, it is still unclear how it either triggers the stress response in neonatal hearts. For this reason, thirty-three microRNAs (miRNAs) known to be differentially expressed following anesthesia and/or ischemic or hypoxic heart damage were investigated in the hearts from neonatal mice exposed to isoflurane or low level of CO, using an air-exposed control group. Only miR-93-5p increased with isoflurane exposure, which may be associated with the suppression of cell death, autophagy, and inflammation. By contrast, twelve miRNAs were differentially expressed in the heart following CO treatment. Many miRNAs previously shown to be responsible for suppressing cell death, autophagy, and myocardial hypertrophy were upregulated (e.g., 125b-3p, 19-3p, and 21a-5p). Finally, some miRNAs (miR-103-3p, miR-1a-3p, miR-199a-1-5p) which have been implicated in regulating energy balance and cardiac contraction were also differentially expressed. Overall, this study demonstrated that CO-mediated miRNA regulation may promote ischemic preconditioning and cardioprotection based on the putative protective roles of the differentially expressed miRNAs explored herein and the consistency of these results with those that have shown positive effects of CO on heart viability following anesthesia and ischemia-reperfusion stress.

The Impact of microRNAs in Renin-Angiotensin-System-Induced Cardiac Remodelling

Current knowledge on the renin-angiotensin system (RAS) indicates its central role in the pathogenesis of cardiovascular remodelling via both hemodynamic alterations and direct growth and the proliferation effects of angiotensin II or aldosterone resulting in the hypertrophy of cardiomyocytes, the proliferation of fibroblasts, and inflammatory immune cell activation. The noncoding regulatory microRNAs has recently emerged as a completely novel approach to the study of the RAS. A growing number of microRNAs serve as mediators and/or regulators of RAS-induced cardiac remodelling by directly targeting RAS enzymes, receptors, signalling molecules, or inhibitors of signalling pathways. Specifically, microRNAs that directly modulate pro-hypertrophic, pro-fibrotic and pro-inflammatory signalling initiated by angiotensin II receptor type 1 (AT1R) stimulation are of particular relevance in mediating the cardiovascular effects of the RAS. The aim of this review is to summarize the current knowledge in the field that is still in the early stage of preclinical investigation with occasionally conflicting reports. Understanding the big picture of microRNAs not only aids in the improved understanding of cardiac response to injury but also leads to better therapeutic strategies utilizing microRNAs as biomarkers, therapeutic agents and pharmacological targets.

Inhibited histone deacetylase 3 ameliorates myocardial ischemia-reperfusion injury in a rat model by elevating microRNA-19a-3p and reducing cyclin-dependent kinase 2

OBJECTIVE

Over the years, the roles of microRNAs (miRNAs) and histone deacetylase 3 (HDAC3) in human diseases have been investigated. This study focused on the effect of miR-19a-3p and HDAC3 in myocardial ischemia-reperfusion (I/R) injury (MIRI) by targeting cyclin-dependent kinase 2 (CDK2).

METHODS

The I/R rat models were established by coronary artery ligation, which were then treated with RGFP966 (an inhibitor of HDAC3), miR-19a-3p agomir or antagomir, or silenced CDK2 to explore their roles in the cardiac function, pathological changes of myocardial tissues, myocardial infarction area, inflammatory factors and oxidative stress factors in rats with MIRI. The expression of miR-19a-3p, HDAC3, and CDK2 was determined by RT-qPCR and western blot assay, and the interaction among which was also verified by online prediction, luciferase activity assay and ChIP assay.

RESULTS

The results indicated that HDAC3 and CDK2 were upregulated while miR-19a-3p was downregulated in myocardial tissues of I/R rats. The inhibited HDAC3/CDK2 or elevated miR-19a-3p could promote cardiac function, attenuate pathological changes, inflammatory reaction, oxidative stress, myocardial infarction area and apoptosis of myocardial tissues. HDAC3 mediates miR-19a-3p and CDK2 is targeted by miR-19a-3p.

CONCLUSION

Inhibited HDAC3 ameliorates MIRI in a rat model by elevating miR-19a-3p and reducing CDK2, which may contribute to the treatment of MIRI.

miR-19a/19b-loaded exosomes in combination with mesenchymal stem cell transplantation in a preclinical model of myocardial infarction

Aim: We aimed to investigate the protection of exogenous miR-19a/19b with bone marrow-derived mesenchymal stem cell (BM-MSC) transplantation on cardiac function and inhibition of fibrosis in myocardial infarction (MI). Materials & methods: BM-MSC-derived exosomes were used to deliver miR-19a/19b (exo/miR-19a/19b) to the cultured cardiac HL-1 cells, and the apoptosis of cells were evaluated. Exo/miR-19a/19b and BM-MSCs were also transplanted to an in vivo MI mouse model. The recovery of cardiac function was assessed and the level of cardiac fibrosis was determined. Results: Exo/miR-19a/19b and MSCs reduced the area of cardiac fibrosis in the heart tissue in the mouse MI model. Using BM-MSC-derived exosomes as a vehicle, miR-19a/19b significantly suppressed the apoptosis of cardiac HL-1 cells. The combination of Exo/miR-19a/19b and MSC transplantation significantly enhanced the recovery of cardiac function and reduced cardiac fibrosis in the MI model. Conclusion: Our study provides an effective regenerative intervention strategy to attenuate the damage of MI.

Circulating microRNAs differentiate Kawasaki Disease from infectious febrile illnesses in childhood

BACKGROUND

Kawasaki Disease (KD) is an acute vasculitis of unknown etiology in children that can lead to coronary artery lesions (CAL) in 25% of untreated patients. There is currently no diagnostic test for KD, and the clinical presentation is often difficult to differentiate from other febrile childhood illnesses. Circulating microRNAs (miRNAs) are small noncoding RNA molecules that control gene expression by inducing transcript degradation or by blocking translation. We hypothesize that the expression of circulating miRNAs will differentiate KD from non-KD febrile illnesses in children.

METHODS

Circulating miRNA profiles from 84 KD patients and 29 non-KD febrile controls (7 viral and 22 bacterial infections) were evaluated. 3 ul of serum from each subject was submitted to 3 freeze/heat cycles to ensure miRNA release from microvesicles or interaction with serum proteins. miRNAs were reverse transcribed using a pool of primers specific for each miRNA. Real-time PCR reactions were performed in a 384 well plate containing sequence-specific primers and TaqMan probes in the ABI7900. '.

RESULTS

KD patients (3.6 ± 2.2 yrs., 58% male) were found to have a unique circulating miRNA profile, including upregulation of miRNA-210-3p, -184, and -19a-3p (p < .0001), compared to non-KD febrile controls (8.5 ± 6.1 yrs., 72% male).

CONCLUSIONS

Circulating miRNAs can differentiate KD from infectious febrile childhood diseases, supporting their potential as a diagnostic biomarker for KD.

Molecular miR-19a in Acute Myocardial Infarction: Novel Potential Indicators of Prognosis and Early Diagnosis

OBJECTIVE

Due to the increasing annual incidence rate of disability and mortality in patients with acute myocardial infarction (AMI), the need for an appropriate diagnostic tool has become a crucial urgent issue. An increase in biomarkers and protein levels in response to AMI can be used as a predictive biomarker with different sensitivities and specificities. This study aimed at investigating the role of miR-19a as a biomarker with acceptable sensitivity and specificity for early diagnosis of AMI.

METHODS

We studied 175 patients with AMI admitted within 12 h of symptom onset and 90 healthy subjects as control group. Patients were divided into two groups, including group I (normal vessels and no significant artery stenosis) and primary percutaneous coronary intervention (PCI) group II (patients with more than 50% stenosis in vessels and severe atherosclerosis) diagnosed by angiography. The expression level of miR-19a was evaluated by the real-time polymerase chain reaction and other serum chemistries were also analyzed.

RESULTS

The results demonstrated that circulating miR-19a levels were significantly increased in patient groups compared to the control group (2.88 ± 1.06 vs. 5.93 ± 1.28, P<0.0001). We also found that miR-19a levels were higher in group II (134.62-fold) than group I (15.42-fold). The upper levels of miR-19a were significantly correlated with the increased serum levels of CK-MB (ρ=0.29, P<0.0001), CTn I (ρ=0.4, P<0.0001) and creatinine (ρ=0.27, P<0.0001). In addition, Receiver Operating Characteristic (ROC) analysis revealed that circulating miR-19a had considerable diagnostic accuracy for the patients with normal vessel with an AUC of 0.930 (95% CI: 0.697-0.765) and for PCI patients with an AUC of 0.966 (95% CI: 0.748-0.784).

CONCLUSION

Circulating miR-19a possibly has prognostic value to be used as a promising molecular target for early diagnosis and prognosis of AMI.

Regulatory RNAs in Heart Failure

Cardiovascular disease is an enormous socioeconomic burden worldwide and remains a leading cause of mortality and disability despite significant efforts to improve treatments and personalize healthcare. Heart failure is the main manifestation of cardiovascular disease and has reached epidemic proportions. Heart failure follows a loss of cardiac homeostasis, which relies on a tight regulation of gene expression. This regulation is under the control of multiple types of RNA molecules, some encoding proteins (the so-called messenger RNAs) and others lacking protein-coding potential, named noncoding RNAs. In this review article, we aim to revisit the notion of regulatory RNA, which has been thus far mainly confined to noncoding RNA. Regulatory RNA, which we propose to abbreviate as regRNA, can include both protein-coding RNAs and noncoding RNAs, as long as they contribute, directly or indirectly, to the regulation of gene expression. We will address the regulation and functional role of messenger RNAs, microRNAs, long noncoding RNAs, and circular RNAs (ie, regRNAs) in heart failure. We will debate the utility of regRNAs to diagnose, prognosticate, and treat heart failure, and we will provide directions for future work.

Human umbilical cord mesenchymal stem cells-derived exosomes transfers microRNA-19a to protect cardiomyocytes from acute myocardial infarction by targeting SOX6

Exosomes secreted by human umbilical cord mesenchymal stem cells (hucMSCs) protect cardiomyocytes from anoxia-reoxygenation injury. But the mechanism of hucMSC-exo-microRNA (miR)-19a in acute myocardial infarction (AMI) remains unclear. For this study, cardiac function related indicators, inflammatory factors and markers of myocardial injury, cardiomyocyte injury, infarct size, and apoptosis were detected in vivo experiments. The gain-and loss-of function was performed to evaluate the effects of hucMSC-exo with down/upregulated miR-19a on AMI rats and hypoxic H9C2 cells. Western blot analysis was used to detect levels of AKT/JNK3/caspase-3 axis-related proteins. Consequently, hucMSC-exo alleviated AMI and inhibited cardiomyocyte apoptosis. miR-19a was downregulated in AMI tissues and cells, and increased after hucMSC-exo treatment. miR-19a knockdown in hucMSC-exo impaired the protective role of hucMSC-exo alone in the AMI damage. SOX6 is a target gene of miR-19a and its inhibition lightened hypoxic damage of H9C2 cells. SOX6 knockdown together with miR-19a inhibition in hucMSC-exo activated AKT and inhibited JNK3/caspase-3 axis. Taken together, hucMSC-exo protected cardiomyocytes from AMI injury by transferring miR-19a, targeting SOX6, activating AKT, and inhibiting JNK3/caspase-3 activation. This study may provide new understanding for AMI treatment.

miR-762 modulates thyroxine-induced cardiomyocyte hypertrophy by inhibiting Beclin-1

PURPOSE

Whether autophagy plays a key role in thyroxine-induced cardiomyocyte hypertrophy, and whether the role of autophagy in thyroxine-induced cardiomyocyte hypertrophy is related to targeting of Beclin-1 by miR-762 remains unclear. This research focused on testing these two hypotheses. Importantly, the results of this study will help us better understand the molecular mechanisms of thyroxine-induced cardiomyocyte hypertrophy.

METHODS

In vivo and in vitro, RT-PCR, western blot, and dual luciferase reporter assay were performed to understand the molecular mechanism of thyroxine-induced cardiomyocyte hypertrophy. HE staining, Masson staining, transmission electron microscopy, and immunofluorescence were used to observe intuitively changes of hearts and cardiomyocytes.

RESULTS

Our results showed that in vivo, serum TT3, TT4, and heart rate were significantly upregulated in the T4 group compared with the control group. Moreover, the surface area of cardiomyocytes was significantly increased in the T4 group, and the structural disorder was accompanied by obvious hyperplasia of collagen fibers. The expression of ANP, and β-MHC was significantly upregulated in the T4 group. In addition, LC3 II/LC3 I, Beclin-1 and the count of autophagic vacuoles were significantly upregulated, but miR-762 was significantly downregulated in the T4 group compared to the control group. Subsequently, a dual luciferase reporter assay suggested that Beclin-1 was the target gene of miR-762. In vitro, the results for the T3 group were consistent with the results for the T4 group. Furthermore, cardiomyocyte hypertrophy and autophagic activity were attenuated in the T3 + miR-762 mimic group compared with the T3 group. In contrast, cardiomyocyte hypertrophy and autophagic activity were aggravated in the T3 + miR-762 inhibitor group compared with the T3 group.

CONCLUSIONS

miR-762 modulates thyroxine-induced cardiomyocyte hypertrophy by inhibiting Beclin-1.

α-synuclein accumulation in SH-SY5Y cell impairs autophagy in microglia by exosomes overloading miR-19a-3p

Aims: To reveal whether miRNAs in exosomes from α-synuclein transgenic SH-SY5Y cells are able to regulate autophagy in recipient microglia. Materials & methods: Microarray analysis and experimental verification were adopted to assess the significance of autophagy-associated miRNAs in exosomes from neuronal model of α-synucleinopathies. Results: We found that miR-19a-3p increased remarkably in the exosomes from α-synuclein gene transgenic SH-SY5Y cells. Further study inferred that α-synuclein gene transgenic SH-SY5Y cell-derived exosomes and miR-19a-3p mimic consistently inhibited the expression of phosphatase and tensin homolog and increased the phosphorylation of AKT and mTOR, both of which ultimately lead to the dysfunction of autophagy in recipient microglia. Conclusion: The data suggested that enhanced expression of miR-19a-3p in exosomes suppress autophagy in recipient microglia by targeting the phosphatase and tensin homolog/AKT/mTOR signaling pathway.

MicroRNA-200a-3p Is a Positive Regulator in Cardiac Hypertrophy Through Directly Targeting WDR1 as Well as Modulating PTEN/PI3K/AKT/CREB/WDR1 Signaling

Cardiac hypertrophy is an adaptive expansion of the myocardium due to the overloaded stress of heart. Recently, emerging studies have drawn a conclusion that microRNAs (miRNAs) are involved in myocardial hypertrophy and even heart failure. To figure out the role of microRNA-200a-3p (miR-200a-3p) in cardiac hypertrophy, the in vitro cardiac hypertrophy model was established in H9c2 cells using angiotensin II (Ang-II) as previously described. First of all, we observed a significant increase of miR-200a-3p expression in Ang-II-induced hypertrophic H9c2 cells. Moreover, inhibition of miR-200a-3p dramatically reversed the Ang-II-upregulated expression of hypertrophic markers (atrial natriuretic peptide, brain natriuretic peptide, and β-MHC) and the expanded cell surface area in H9c2 cells. In addition, our results indicated that miR-200a-3p directly targeted both WDR1 and phosphatase and tensin homolog (PTEN). In this regard, miR-200a-3p further activated PI3K/AKT/CREB pathway so as to intensify its negative regulation on WDR1. At length, WDR1 silence, PTEN inhibitor, and PI3K activator recovered the repressive effect of miR-200a-3p suppression on the development of cardiac hypertrophy. Jointly, our study suggested that miR-200a-3p facilitated cardiac hypertrophy by not only directly targeting WDR1 but also through modulating PTEN/PI3K/AKT/CREB/WDR1 signaling, therefore proving novel downstream molecular pathway of miR-200a-3p in cardiac hypertrophy.

miR-19 family: A promising biomarker and therapeutic target in heart, vessels and neurons

The miR-19 family, including miR-19a, miR-19b-1 and miR-19b-2, arises from two different paralogous clusters miR-17-92 and miR-106a-363. Although it is identified as oncogenic miRNA, the miR-19 family has also been found to play important roles in regulating normal tissue development. The precise control of miR-19 family level is essential for keeping tissue homeostasis and normal development of organisms. Its dysregulation leads to dysplasia, disease and even cancer. Therefore, this review focuses on the roles of miR-19 family in the development and disease of heart, vessels and neurons to estimate the potential value of miR-19 family as diagnostic biomarker or therapeutic target of cardiac, neurological, and vascular diseases.

The low expression of circulating microRNA-19a represents an additional mortality risk in stable patients with vascular disease

BACKGROUND

Secondary prevention of atherosclerotic vascular diseases represents a cascade of procedures to reduce the risk of future fatal and non-fatal cardiovascular events. We sought to determine whether the expression of selected microRNAs influenced mortality of stable chronic cardiovascular patients.

METHODS

The plasma concentrations of five selected microRNAs (miR-1, miR-19, miR-126, miR-133 and miR-223) were quantified in 826 patients (mean age 65.2 years) with stable vascular disease (6-36 months after acute coronary syndrome, coronary revascularization or first-ever ischemic stroke). All-cause and cardiovascular mortality rates were followed during our prospective study.

RESULTS

Low expression (bottom quartile) of all five miRNAs was associated with a significant increase in five-year all-cause death, even when adjusted for conventional risk factors, treatment, raised troponin I and brain natriuretic protein levels [hazard risk ratios (HRRs) were as follows: miR-1, 1.65 (95% CI: 1.16-2.35); miR-19a, 2.27 (95% CI: 1.59-3.23); miR-126, 1.64 (95% CI: 1.15-2.33); miR-133a, 1.46 (95% CI: 1.01-2.12) and miR-223, 2.05 (95% CI: 1.45-2.91)]. Nearly similar results were found if using five-year cardiovascular mortality as the outcome. However, if entering all five miRNAs (along with other covariates) into a single regression model, only low miR-19a remained a significant mortality predictor; and only in patients with coronary artery disease [3.00 (95% CI: 1.77-5.08)], but not in post-stroke patients [1.63 (95% CI: 0.94-2.86)].

CONCLUSIONS

In stable chronic coronary artery disease patients, low miR-19a expression was associated with a substantial increase in mortality risk independently of other conventional cardiovascular risk factors.

The Impact of Cardiac Lipotoxicity on Cardiac Function and Mirnas Signature in Obese and Non-Obese Rats with Myocardial Infarction

Cardiac lipotoxicity is involved in the cardiac functional consequences associated with obesity. Therefore, the aim of this study was to explore whether changes in the mitochondrial lipid cardiac profile could reflect differences in cardiac function and structure in obese and non-obese rats with myocardial infarction (MI). Whether these changes can also be reflected in a specific plasma miRNA signature as markers of cardiac damage was also evaluated. Rats were fed with either standard (3.5% fat) or high fat diet (35% fat) for 6 weeks before the induction of MI and sacrificed 4 weeks later. MI showed cardiac lipotoxicity independently of the presence of obesity, although obese and non-obese rats did not present the same cardiac lipid profile at mitochondrial level. Several cardiac lipid species in mitochondria, including cardiolipins and triglycerides, were associated with myocardial fibrosis, with mitochondrial triglyceride levels being independently associated with it; this supports that lipotoxicity can affect cardiac function. MI down-regulated plasma levels of miRNA 15b-5p and 194-5p in obese and non-obese animals, which were associated with cardiac function, mitochondrial lipids and myocardial fibrosis, with miRNA 15b-5p levels being independently associated with cardiac fibrosis. This could support that lipotoxicity could affect heart function by modulating plasma miRNAs.