MiR-181a mediates Ang II-induced myocardial hypertrophy by mediating autophagy

Circ_ZNF512-Mediated miR-181d-5p Inhibition Limits Cardiomyocyte Autophagy and Promotes Myocardial Ischemia/Reperfusion Injury through an EGR1/mTORC1/TFEB-Based Mechanism

Studies have shown that circRNAs are important regulatory molecules involved in cell physiology and pathology. Herein, we analyzed the role of circ_ZNF512 in cardiomyocyte autophagy of myocardial ischemia/reperfusion (I/R) injury. A mouse model was induced by ligation of the left anterior descending artery followed by reperfusion. An in vitro model was also developed in cultured cardiomyocytes following hypoxia/reoxygenation (H/R) injury. It was established that EGR1 expression was increased in myocardial tissues of I/R mice and H/R-induced cardiomyocytes. Silencing of circ_ZNF512 attenuated its binding to miR-181d-5p, which in turn impaired the EGR1 expression by targeting its 3'-UTR, thus promoting the autophagy of cardiomyocytes and suppressing cell apoptosis to alleviate myocardial tissue injury. Additionally, the circ_ZNF512/miR-181d-5p/EGR1 crosstalk activated the mTORC1/TFEB signaling pathway, increasing mTORC1 expression while suppressing TFEB expression. Together, circ_ZNF512 knockdown protects against myocardial I/R injury, which may be a potential therapeutic approach for preventing myocardial I/R injury.

Role of Known Transient Receptor Potential Vanilloid Channels in Modulating Cardiac Mechanobiology

The transient receptor potential (TRP) channels have been described in almost every mammalian cell type. Several members of the Vanilloid (TRPV) subtype have been found to play important roles in modulating cardiac structure and function through Ca²⁺ handling in response to systemic and local mechanobiological cues. In this review, we will consider the most studied TRPV channels in the cardiovascular field; transient receptor potential vanilloid 1 as a modulator of cardiac hypertrophy; transient receptor potential vanilloid 2 as a structural and functional protein; transient receptor potential vanilloid 3 in the development of hypertrophy and myocardial fibrosis; and transient receptor potential vanilloid 4 in its roles modulating the fibrotic and functional responses of the heart to pressure overload. Lastly, we will also review the potential overlapping roles of these channels with other TRP proteins as well as the advances in translational and clinical arenas associated with TRPV channels.

MiR-181a-5p inhibits goose granulosa cell viability by targeting SIRT1

1. Granulosa cells (GCs) are involved in folliculogenesis, follicular development, and atresia. Previous studies have shown that microRNA-181a-5p (miR-181a-5p) and sirtuin 1 (SIRT1) are involved in GC proliferation and apoptosis, and SIRT1 has been predicted as one target of miR-181a-5p. However, there are few studies with poultry.2. Quantitative real-time PCR (qRT-PCR) was used to detect the expression level of miR-181a-5p in granulosa layers during geese ovarian follicular development. A methyl thiazolyl tetrazolium (MTT) assay was performed to assess the viability of geese granulosa cells treated with miR-181a-5p mimic or inhibitor. The binding sites between the SIRT1 3'-UTR region and miR-181a-5p were evaluated using a luciferase reporter assay system. SIRT1 mRNA levels were detected using qRT-PCR after transfection with miR-181a-5p mimic and inhibitor.3. The miR-181a-5p suppressed geese GC viability and regulated the mRNA expression of viability-related genes in geese GCs. SIRT1 was a target gene of miR-181a-5p and miR-181a-5p suppressed its mRNA expression.4. The miR-181a-5p may target and inhibit SIRT1 expression, thus suppressing GC viability by regulating viability-related key genes.

MiR-26a-5p inhibits GSK3β expression and promotes cardiac hypertrophy in vitro

Background

The role of miR-26a-5p expression in cardiac hypertrophy remains unclear. Herein, the effect of miR-26a-5p on cardiac hypertrophy was investigated using phenylephrine (PE)-induced cardiac hypertrophy in vitro and in a rat model of hypertension-induced hypertrophy in vivo.

Methods

The PE-induced cardiac hypertrophy models in vitro and vivo were established. To investigate the effect of miR-26a-5p activation on autophagy, the protein expression of autophagosome marker (LC3) and p62 was detected by western blot analysis. To explore the effect of miR-26a-5p activation on cardiac hypertrophy, the relative mRNA expression of cardiac hypertrophy related mark GSK3β was detected by qRT-PCR in vitro and vivo. In addition, immunofluorescence staining was used to detect cardiac hypertrophy related mark α-actinin. The cell surface area was measured by immunofluorescence staining. The direct target relationship between miR-26a-5p and GSK3β was confirmed by dual luciferase report.

Results

MiR-26a-5p was highly expressed in PE-induced cardiac hypertrophy. MiR-26a-5p promoted LC3II and decreased p62 expression in PE-induced cardiac hypertrophy in the presence or absence of lysosomal inhibitor. Furthermore, miR-26a-5p significantly inhibited GSK3β expression in vitro and in vivo. Dual luciferase report results confirmed that miR-26a-5p could directly target GSK3β. GSK3β overexpression significantly reversed the expression of cardiac hypertrophy-related markers including ANP, ACTA1 and MYH7. Immunofluorescence staining results demonstrated that miR-26a-5p promoted cardiac hypertrophy related protein α-actinin expression, and increased cell surface area in vitro and in vivo.

Conclusion

Our study revealed that miR-26a-5p promotes myocardial cell autophagy activation and cardiac hypertrophy by regulating GSK3β, which needs further research.

Autophagy in cardiovascular diseases: role of noncoding RNAs

Cardiovascular diseases (CVDs) remain the world's leading cause of death. Cardiomyocyte autophagy helps maintain normal metabolism and functioning of the heart. Importantly, mounting evidence has revealed that autophagy plays a dual role in CVD pathology. Under physiological conditions, moderate autophagy maintains cell metabolic balance by degrading and recycling damaged organelles and proteins, and it promotes myocardial survival, but excessive or insufficient autophagy is equally deleterious and contributes to disease progression. Noncoding RNAs (ncRNAs) are a class of RNAs transcribed from the genome, but most ncRNAs do not code for functional proteins. In recent years, increasingly, various ncRNAs have been identified, and they play important regulatory roles in the physiological and pathological processes of organisms, as well as in autophagy. Thus, determining whether ncRNA-regulated autophagy plays a protective role in CVDs or promotes their progression can help us to develop ncRNAs as therapeutic targets in autophagy-related CVDs. In this review, we briefly summarize the regulatory roles of several important ncRNAs, including microRNAs (miRNAs), long ncRNAs (lncRNAs), and circular RNAs (circRNAs), in the autophagy of various CVDs to provide a theoretical basis for the etiology and pathogenesis of CVDs and develop novel therapies to treat CVDs.

Reprogramming of miR-181a/DNA methylation patterns contribute to the maternal nicotine exposure-induced fetal programming of cardiac ischemia-sensitive phenotype in postnatal life

Background: E-cigarette and other novel electronic nicotine delivery systems (ENDS) have recently entered the market at a rapid pace. The community desperately needs answers about the health effects of ENDS. The present study tested the hypothesis that perinatal nicotine exposure (PNE) causes a gender-dependent increase in vulnerability of the heart to ischemia-reperfusion (I/R) injury and cardiac dysfunction in male rat offspring via reprogramming of the miRNA-181a (miR-181a)-mediated signaling pathway and that miR-181a antisense could rescue this phenotype. Methods: Nicotine or saline was administered to pregnant rats via subcutaneous osmotic minipumps from gestational day 4 until postnatal day 10. Cardiac function and molecular biological experiments were conducted in ~3- month-old offspring. Results: PNE enhanced I/R-induced cardiac dysfunction and infarction in adult male but not in female offspring, which was associated with miR-181a over-expression in left ventricle tissues. In addition, PNE enhanced offspring cardiac angiotensin receptor (ATR) expressions via specific CpG hypomethylation of AT₁R/AT₂R promoter. Furthermore, PNE attenuated cardiac lncRNA H19 levels, but up-regulated cardiac TGF-β/Smads family proteins and consequently up-regulated autophagy-related protein (Atg-5, beclin-1, LC3 II, p62) expression in the male offspring. Of importance, treatment with miR-181a antisense eliminated the PNE's effect on miR-181a expression/H19 levels and reversed PNE-mediated I/R-induced cardiac infarction and dysfunction in male offspring. Furthermore, miR-181a antisense also attenuated the effect of PNE on AT₁R/AT₂R/TGF-β/Smads/autophagy-related biomarkers in the male offspring. Conclusion: Our data suggest that PNE could induce a reprogramming of cardiac miR-181a expression/DNA methylation pattern, which epigenetically modulates ATR/TGF-β/autophagy signaling pathways, leading to gender-dependent development of ischemia-sensitive phenotype in postnatal life. Furthermore, miR-181a could severe as a potential therapeutic target for rescuing this phenotype.

MicroRNA-363-3p serves as a diagnostic biomarker of acute myocardial infarction and regulates vascular endothelial injury by targeting KLF2

Background

Acute myocardial infarction (AMI) is a serious cardiovascular disease. This study aimed to investigate the diagnostic value of microRNA-363-3p (miR-363-3p) in AMI patients and explore the effects of miR-363-3p on vascular endothelial injury in an AMI rat model.

Methods

The Expression of miR-363-3p was measured by quantitative real-time PCR. A receiver operating characteristic (ROC) curve was plotted to evaluate the diagnostic value of miR-363-3p in AMI patients. The biomarkers of endothelial injury were estimated using enzyme-linked immunosorbent assays, and the correlation of miR-363-3p with these markers was assessed. AMI rat model was constructed using coronary artery ligation, and the effects of miR-363-3p on endothelial injury and endothelial cell proliferation were analyzed.

Results

Serum expression of miR-363-3p was upregulated in the AMI patients compared with healthy controls. The increased serum miR-363-3p serves a candidate diagnostic biomarker of AMI. The correlation analysis indicated that serum miR-363-3p expression was positively correlated with the concentration of endothelial injury biomarkers in AMI patients. Furthermore, the increased endothelial injury biomarkers in AMI rats were all inhibited by the knockdown of miR-363-3p, and the cell proliferation of human umbilical vein endothelial cells was obviously enhanced by the reduction of miR-363-3p. The prediction results shown that Kruppel-like factor 2 (KLF2) is a target of miR-363-3p, and their interaction was proved using a luciferase reporter assay.

Conclusions

Collectively, overexpression of miR-363-3p acts as a diagnostic biomarker for patients with AMI, and the downregulation of miR-363-3p improves AMI-associated endothelial injury by targeting KLF2, which indicated that miR-363-3p has a potential to develop the treatment of AMI.

Pregnancy-associated cardiac dysfunction and the regulatory role of microRNAs

Many crucial cardiovascular adaptations occur in the body during pregnancy to ensure successful gestation. Maladaptation of the cardiovascular system during pregnancy can lead to complications that promote cardiac dysfunction and may lead to heart failure (HF). About 12% of pregnancy-related deaths in the USA have been attributed to HF and the detrimental effects of cardiovascular complications on the heart can be long-lasting, pre-disposing the mother to HF later in life. Indeed, cardiovascular complications such as gestational diabetes mellitus, preeclampsia, gestational hypertension, and peripartum cardiomyopathy have been shown to induce cardiac metabolic dysfunction, oxidative stress, fibrosis, apoptosis, and diastolic and systolic dysfunction in the hearts of pregnant women, all of which are hallmarks of HF. The exact etiology and cardiac pathophysiology of pregnancy-related complications is not yet fully deciphered. Furthermore, diagnosis of cardiac dysfunction in pregnancy is often made only after clinical symptoms are already present, thus necessitating the need for novel diagnostic and prognostic biomarkers. Mounting data demonstrates an altered expression of maternal circulating miRNAs during pregnancy affected by cardiovascular complications. Throughout the past decade, miRNAs have become of growing interest as modulators and biomarkers of pathophysiology, diagnosis, and prognosis in cardiac dysfunction. While the association between pregnancy-related cardiovascular complications and cardiac dysfunction or HF is becoming increasingly evident, the roles of miRNA-mediated regulation herein remain poorly understood. Therefore, this review will summarize current reports on pregnancy-related cardiovascular complications that may lead to cardiac dysfunction and HF during and after pregnancy in previously healthy women, with a focus on the pathophysiological role of miRNAs.

Clinical significance of miR-181a in patients with neonatal sepsis and its regulatory role in the lipopolysaccharide-induced inflammatory response

Neonatal sepsis (NS) poses a serious threat to the health of neonates worldwide. The present study aimed to investigate the diagnostic value of microRNA (miR)-181a in patients with NS and the regulatory role of miR-181a in lipopolysaccharide (LPS)-induced inflammation. A total of 102 neonates with NS and 50 neonates without sepsis were enrolled in the present study. The serum levels of miR-181a were estimated using reverse transcription-quantitative PCR. Receiver operating characteristic (ROC) analysis was performed to evaluate the diagnostic value of miR-181a for NS. The effect of miR-181a on the expression of Toll-like receptor (TLR)4 was assessed after modification of the expression of miR-181a in monocytes isolated from the blood of neonates in vitro. An ELISA was used to measure the concentration of inflammatory cytokines tumor necrosis factor (TNF)-α and interleukin (IL)-8 in the supernatant of monocytes. The serum levels of miR-181a were decreased in patients with NS compared with those in the controls. The area under the ROC curve of miR-181a was 0.893 with a sensitivity of 83.3% and a specificity of 84.0%. LPS stimulation in monocytes also led to a decrease in the expression of miR-181a. TLR4 was proven to be a direct target gene of miR-181a, according to the results of a luciferase reporter assay, and overexpression of miR-181a suppressed TLR4 expression in monocytes. Regarding LPS-induced inflammation, it was revealed that the upregulated levels of TNF-α and IL-8 induced by LPS were reduced by overexpression of miR-181a in monocytes. In conclusion, decreased serum levels of miR-181a may serve as a diagnostic biomarker in patients with NS and overexpression of miR-181a inhibits the LPS-induced inflammatory response at least partially by targeting TLR4. Aberrant miR-181a may be a non-invasive biomarker for NS patients, and provide a novel insight into the pathologic mechanisms of action behind the development of NS.

MiR-103 inhibiting cardiac hypertrophy through inactivation of myocardial cell autophagy via targeting TRPV3 channel in rat hearts

Cardiac hypertrophy is a common pathological change frequently accompanied by chronic hypertension and myocardial infarction. Nevertheless, the pathophysiological mechanisms of cardiac hypertrophy have never been elucidated. Recent studies indicated that miR-103 expression was significantly decreased in heart failure patients. However, less is known about the role of miR-103 in cardiac hypertrophy. The present study was designed to investigate the relationship between miR-103 and the mechanism of pressure overload-induced cardiac hypertrophy. TRPV3 protein, cardiac hypertrophy marker proteins (BNP and β-MHC) and autophagy associated proteins (Beclin-1 and LC3-II) were up-regulated, as well as, miR-103 expression and autophagy associated proteins (p62) were down-regulated in cardiac hypertrophy models in vivo and in vitro respectively. Further results indicated that silencing TRPV3 or forcing overexpression of miR-103 could dramatically inhibit cell surface area, relative fluorescence intensity of Ca2+ signal and the expressions of BNP, β-MHC, Beclin-1 and LC3-II, but promote p62 expression. Moreover, TRPV3 protein was decreased in neonatal rat ventricular myocyte transfected with miR-103, but increased by AMO-103. Co-transfection of the miR-103 with the luciferase reporter vector into HEK293 cells caused a sharp decrease in luciferase activity compared with transfection of the luciferase vector alone. The miR-103-induced depression of luciferase activity was rescued by an AMO-103. These findings suggested that TRPV3 was a direct target of miR-103. In conclusion, miR-103 could attenuate cardiomyocyte hypertrophy partly by reducing cardiac autophagy activity through the targeted inhibition of TRPV3 signalling in the pressure-overloaded rat hearts.