Critical roles of miRNA-mediated regulation of TGFβ signalling during mouse cardiogenesis

Inhibition of TGF-β1/Smad3 signaling by compound 5aa: A potential treatment for idiopathic pulmonary fibrosis

The incidence of idiopathic pulmonary fibrosis (IPF) has been steadily increasing each year, posing significant challenges in its treatment. In this study, we conducted the design and synthesis of 23 new inhibitors that specifically target the TGF-β1/Smad3 pathway. Initially, we employed a cell model of TGF-β-induced pulmonary fibrosis, using cell survival rate and HYP expression as indicators to identify the potent ingredient 5aa, which demonstrated significant anti-pulmonary fibrosis activity. Subsequently, we induced mice with bleomycin (BLM) to establish an experimental animal model of pulmonary fibrosis, and evaluated the pharmacodynamics of 5aa in vivo against pulmonary fibrosis. The alterations in HYP and collagen levels in BLM-induced pulmonary fibrosis mice were analyzed using ELISA and immunohistochemistry techniques. The results indicated that compound 5aa effectively suppressed the fibrotic response induced by TGF-β1, inhibited the expression of the fibrotic marker α-SMA, and hindered the EMT process in NIH3T3 cells. Additionally, oral administration of 5aa demonstrated significant therapeutic effects in a mouse model of IPF, comparable to the established drug Nintedanib. Moreover, compound 5aa exhibited higher bioavailability in vivo compared to Nintedanib. These collective outcomes suggest that 5aa holds promise as a potential inhibitor of TGF-β1/Smad3 signaling for the treatment of IPF.

Differential requirement for DICER1 activity during the development of mitral and tricuspid valves

Mitral and tricuspid valves are essential for unidirectional blood flow in the heart. They are derived from similar cell sources, and yet congenital dysplasia affecting both valves is clinically rare, suggesting the presence of differential regulatory mechanisms underlying their development. Here, we specifically inactivated Dicer1 in the endocardium during cardiogenesis and found that Dicer1 deletion caused congenital mitral valve stenosis and regurgitation, whereas it had no impact on other valves. We showed that hyperplastic mitral valves were caused by abnormal condensation and extracellular matrix (ECM) remodeling. Our single-cell RNA sequencing analysis revealed impaired maturation of mesenchymal cells and abnormal expression of ECM genes in mutant mitral valves. Furthermore, expression of a set of miRNAs that target ECM genes was significantly lower in tricuspid valves compared to mitral valves, consistent with the idea that the miRNAs are differentially required for mitral and tricuspid valve development. We thus reveal miRNA-mediated gene regulation as a novel molecular mechanism that differentially regulates mitral and tricuspid valve development, thereby enhancing our understanding of the non-association of inborn mitral and tricuspid dysplasia observed clinically.

In vitro CSC-derived cardiomyocytes exhibit the typical microRNA-mRNA blueprint of endogenous cardiomyocytes

miRNAs modulate cardiomyocyte specification by targeting mRNAs of cell cycle regulators and acting in cardiac muscle lineage gene regulatory loops. It is unknown if or to-what-extent these miRNA/mRNA networks are operative during cardiomyocyte differentiation of adult cardiac stem/progenitor cells (CSCs). Clonally-derived mouse CSCs differentiated into contracting cardiomyocytes in vitro (iCMs). Comparison of "CSCs vs. iCMs" mRNome and microRNome showed a balanced up-regulation of CM-related mRNAs together with a down-regulation of cell cycle and DNA replication mRNAs. The down-regulation of cell cycle genes and the up-regulation of the mature myofilament genes in iCMs reached intermediate levels between those of fetal and neonatal cardiomyocytes. Cardiomyo-miRs were up-regulated in iCMs. The specific networks of miRNA/mRNAs operative in iCMs closely resembled those of adult CMs (aCMs). miR-1 and miR-499 enhanced myogenic commitment toward terminal differentiation of iCMs. In conclusions, CSC specification/differentiation into contracting iCMs follows known cardiomyo-MiR-dependent developmental cardiomyocyte differentiation trajectories and iCMs transcriptome/miRNome resembles that of CMs.

Circulatory microRNA expression profile for coronary artery calcification in chronic kidney disease patients

BACKGROUND & AIM

Coronary artery disease (CAD) is the primary cause of mortality in patients with end stage renal disease (ESRD). MicroRNA profiling is proven as a powerful tool in the diagnosis of any disease at the molecular level. Hence, the present study aimed to profile the microRNA expression for CAD especially coronary artery calcification in CKD patients.

MATERIALS AND METHODS

Two hundread patients with CKD stages 3 to 5 without dialysis and healthy controls were included in this study. All two hundred patients underwent 1024 multi sliceardiac computed tomography (CT) scan for calcium scoring. The calcium scoring more than 100 have been included in the study. We performed miRNA microarray analysis from serum samples of seven high calcium scored with CKD patients and one control patients.

RESULTS

Seven patients have observed circulating miRNAs has significantly upregulated and downregulated when compared with control patients. mir21, mir 67, mir 390, mir 56, mir 250, mir 65 and mir 13 were up regulated and mir235, mir256, mir226, mir207, mir255, mir193 were downregulated. There was no significant difference in left ventricle function.

CONCLUSION

13 microRNAs play a potential role in coronary artery calcification in CKD patients.

Protective effect of microRNA‑381 against inflammatory damage of endothelial cells during coronary heart disease by targeting CXCR4

Coronary heart disease (CHD) is the leading cause of human morbidity and mortality worldwide. MicroRNA (miRNA) profiling is an innovative method of identifying biomarkers for many diseases and may be a powerful tool in the diagnosis and treatment of CHD. The present study aimed to analyze the effects of miRNA (miR)‑381 on the inflammatory damage of endothelial cells during CHD. A total of 21 patients with CHD and 21 healthy control patients were enrolled in this study. Reverse transcription‑quantitative PCR, western blotting and immunofluorescence assays were conducted to examine the expression levels of miR‑381, C‑X‑C chemokine receptor type 4 (CXCR4), Bcl‑2, Bax, Cleaved‑Caspases‑3 and ‑9, p38, ERK1/2 and JNK. Cell Counting Kit‑8, EdU and flow cytometry experiments were performed to evaluate cell proliferation and apoptosis. An ELISA was adopted to determine the expressions of inflammatory factors (interleukins‑8, ‑6 and ‑1β, and tumor necrosis factor‑α). In addition, a dual‑luciferase reporter assay was used to determine the relationship between miR‑381 and CXCR4. Decreased miR‑381 expression and increased CXCR4 expression in the plasma were observed in the CHD group compared with the normal group, which indicated a negative relationship between miR‑381 and CXCR4. Overexpression of miR‑381 significantly promoted the proliferation and inhibited the apoptosis of oxidized low‑density lipoprotein (OX‑LDL)‑induced human umbilical vein endothelial cells (HUVECs) through mitogen‑activated protein kinase pathway by targeting and inhibiting CXCR4. Furthermore, overexpression of miR‑381 reduced the release of inflammatory factors in OX‑LDL‑induced HUVECs. By contrast, reduced expression of miR‑381 exerted the opposite effects, which were subsequently reversed by silencing CXCR4 expression. Results from the present study indicated that miR‑381 was a CHD‑related factor that may serve as a potential molecular target for CHD treatment.

Circulating MicroRNA Expression Profiles in Patients with Stable and Unstable Angina

OBJECTIVES

High incidence and case fatality of unstable angina (UA) is, to a large extent, a consequence of the lack of highly sensitive and specific non-invasive markers. Circulating microRNAs (miRNAs) have been widely recommended as potential biomarkers for numerous diseases. In the present study, we characterized distinctive miRNA expression profiles in patients with stable angina (SA), UA, and normal coronary arteries (NCA), and identified promising candidates for UA diagnosis.

METHODS

Serum was collected from patients with SA, UA, and NCA who visited the Department of Cardiovascular Diseases of the Meizhou People's Hospital. Small RNA sequencing was carried out on an Illumina HiSeq 2500 platform. miRNA expression in different groups of patients was profiled and then confirmed based on that in an independent set of patients. Functions of differentially expressed miRNAs were predicted using gene ontology classification and Kyoto Encyclopedia of Genes and Genomes pathway analysis.

RESULTS

Our results indicated that circulating miRNA expression profiles differed between SA, UA, and NCA patients. A total of 36 and 161 miRNAs were dysregulated in SA and UA patients, respectively. miRNA expression was validated by reverse transcription quantitative polymerase chain reaction.

CONCLUSION

The results suggest that circulating miRNAs are potential biomarkers of UA.

SEMA6D regulates perinatal cardiomyocyte proliferation and maturation in mice

Cardiomyocytes undergo dramatic changes during the fetal to neonatal transition stage to adapt to the new environment. The molecular and genetic mechanisms regulating these changes remain elusive. In this study, we showed Sema6D as a novel signaling molecule regulating perinatal cardiomyocyte proliferation and maturation. SEMA6D is a member of the Semaphorin family of signaling molecules. To reveal its function during cardiogenesis, we specifically inactivated Sema6D in embryonic cardiomyocytes using a conditional gene deletion approach. All mutant animals showed hypoplastic myocardial walls in neonatal hearts due to reduced cell proliferation. We further revealed that expression of MYCN and its downstream cell cycle regulators is impaired in late fetal hearts in which Sema6D is deleted, suggesting that SEMA6D acts through MYCN to regulate cardiomyocyte proliferation. In early postnatal mutant hearts, expression of adult forms of sarcomeric proteins is increased, while expression of embryonic forms is decreased. These data collectively suggest that SEMA6D is required to maintain late fetal/early neonatal cardiomyocytes at a proliferative and less mature status. Deletion of Sema6D in cardiomyocytes led to reduced proliferation and accelerated maturation. We further examined the consequence of these defects through echocardiographic analysis. Embryonic heart deletion of Sema6D significantly impaired the cardiac contraction of male adult hearts, while having a minor effect on female mutant hearts, suggesting that the effect of Sema6D-deletion in adult hearts is sex dependent.

TrkC-miR2 regulates TGFβ signaling pathway through targeting of SMAD3 transcript

TrkC, neurotrophin receptor, functions inside and outside of the nervous system and has a crucial effect on the regulation of cardiovascular formation. Recently, we introduced TrkC-miR2 as a novel microRNA located in TrkC gene, which is a regulator of the Wnt signaling pathway. Here, we presented a lot of evidence showing that TrkC-miR2 also regulates the transforming growth factor-beta (TGFβ) signaling pathway. Bioinformatics studies predicted SMAD3 as one of the bona fide TrkC-miR2 target genes. Quantitative reverse transcription PCR (RT-qPCR), Western blot analysis, and dual luciferase assay analysis confirmed that SMAD3 is targeted by TrkC-miR2. On the other hand, overexpression of TrkC-miR2 in cardiosphere-derived cells (CDCs) rendered downregulation of TGFβR1, TGFβR2, and SMAD7 detected by RT-qPCR. Consistently, an inverse correlation of expression between TrkC-miR2 and SMAD3 genes was detected during the course of CDC differentiation, and also during the course of human embryonic stem cells differentiation to cardiomyocytes. Overall, we conclude that TrkC-miR2 downregulates the expression of SMAD3 and potentially regulates the TGFβ signaling pathway. Knowing its approved effect on Wnt signaling, TrkC-miR2 here is introduced as a common regulator of both the Wnt and TGFβ signaling pathways. Therefore, it may be a potential key element in controlling both of these signaling pathways in cell processes like colorectal cancer and cardiogenesis.

Circulating miRNAs as biomarkers for early diagnosis of coronary artery disease

INTRODUCTION

Coronary artery disease (CAD) contributes to a huge number of human death worldwide. The early diagnosis can arrest the development of CAD and effectively lower the mortality rate. Recently, circulating miRNAs emerged as CAD biomarkers.

AREAS COVERED

Many efforts were paid to explore early diagnostic biomarkers of CAD. Some proteins have been used as diagnostic golden standard. However, the diagnostic and prognostic value of them is limited. MicroRNAs (miRNAs), a class of small noncoding RNAs, have been illustrated to regulate gene expression. The dysfunction of miRNAs is associated with CAD. MiRNAs presenting stably in body fluids are called circulating miRNAs. The altered expression of specific circulating miRNAs has been discovered in CAD and reported to affect the pathogenesis of CAD. We reviewed the recent data about circulating miRNAs regarding their potential roles in diagnosis, prognosis and therapeutic strategies for CAD. Additionally, we also summarized the current knowledge about circulating miRNA formation and detection.

EXPERT OPINION

Compared with traditional diagnostic tools, circulating miRNAs have many strongpoints, suggesting that circulating miRNAs can serve as promising biomarkers for the early diagnosis and prognosis of CAD.

miR-941 as a promising biomarker for acute coronary syndrome

BACKGROUND

Circulating miRNAs can function as biomarkers for diagnosis, treatment, and prevention of diseases. However, it is unclear whether miRNAs can be used as biomarkers for acute coronary syndrome (ACS). To this end, we applied gene chip technology to analyze miRNA expression in patients with stable angina (SA), non-ST elevation ACS (NSTE-ACS), and ST-segment elevation myocardial infarction (STEMI).

METHODS

We enrolled patients with chest pain who underwent diagnostic coronary angiography, including five patients each with SA, NSTE-ACS, or STEMI, and five controls without coronary artery disease (CAD) but with three or more risk factors. After microarray analysis, differential miRNA expression was confirmed by quantitative real-time reverse transcription polymerase chain reaction (qRT-PCR).

RESULTS

Compared with those in patients with STEMI, differentially expressed microRNAs in controls and patients with SA or NSTE-ACS were involved in inflammation, protein phosphorylation, and cell adhesion. Pathway analysis showed that differentially expressed miRNAs were related to the mitogen-activated protein kinase signaling, calcium ion pathways, and cell adhesion pathways. Compared with their expression levels in patients with STEMI, miR-941, miR-363-3p, and miR-182-5p were significantly up-regulated (fold-change: 2.0 or more, P < 0.05) in controls and patients with SA or NSTE-ACS. Further, qRT-PCR showed that plasma miR-941 level was elevated in patients with NSTE-ACS or STEMI as compared with that in patients without CAD (fold-change: 1.65 and 2.28, respectively; P < 0.05). Additionally, miR-941 expression was significantly elevated in the STEMI group compared with that in the SA (P < 0.01) and NSTE-ACS groups (P < 0.05). Similarly, miR-941 expression was higher in patients with ACS (NSTE-ACS or STEMI) than in patients without ACS (without CAD or with SA; P < 0.01). There were no significant differences in miR-182-5p and miR-363-3p expression. The areas under the receiver operating characteristic curves were 0.896, 0.808, and 0.781 for patients in the control, SA, and NSTE-ACS groups, respectively, compared with that for patients with STEMI; that for the ACS group compared with the non-ACS group was 0.734.

CONCLUSION

miR-941 expression was relatively higher in patients with ACS and STEMI. Thus, miR-941 may be a potential biomarker of ACS or STEMI.

Pdgfrb is a direct regulatory target of TGFβ signaling in atrioventricular cushion mesenchymal cells

Cushion formation is the initial step for the development of valvuloseptal structures in mammalian hearts. TGFβ signaling plays critical roles in multiple steps of cushion morphogenesis. We used a newly developed conditional immortal atrioventricular cushion mesenchymal cell line, tsA58-AVM, to identify the TGFβ regulatory target genes through microarray analysis. Expression of ~1350 genes was significantly altered by TGFβ1 treatment. Subsequent bioinformatic analysis of TGFβ activated genes revealed that PDGF-BB signaling is the top hit as the potential upstream regulator. Among the 37 target molecules, 10 genes known to be involved in valve development and hemostasis were selected for quantitative reverse transcription polymerase chain reaction (qRT-PCR) analysis. Our results confirmed that they are all upregulated by TGFβ1 stimulation in tsA58-AVM cells and in primary atrioventricular cushion cells. We focused on examining regulation of Pdgfrb by TGFβ1, which encodes a tyrosine kinase receptor for PDGF-BB. We found that the ~150bp Pdgfrb promoter can respond to TGFβ stimulation and that this response relies on the two SP1 binding sites within the promoter. Co-immunoprecipitation analysis confirmed SP1 interacts with SMAD2 in a TGFβ-dependent fashion. Furthermore, SMAD2 is associated with the Pdgfrb promoter and this association is diminished by knocking down expression of Sp1. Our data therefore collectively suggest that upon TGFβ stimulation, SP1 recruits SMAD2 to the promoter of Pdgfrb to up-regulate its expression and thus Pdgfrb is a direct downstream target of the TGFβ/SMAD2 signaling.

Rare copy number variants in a population-based investigation of hypoplastic right heart syndrome

BACKGROUND

Hypoplastic right heart syndrome (HRHS) is a rare congenital defect characterized by underdevelopment of the right heart structures commonly accompanied by an atrial septal defect. Familial HRHS reports suggest genetic factor involvement. We examined the role of copy number variants (CNVs) in HRHS.

METHODS

We genotyped 32 HRHS cases identified from all New York State live births (1998-2005) using Illumina HumanOmni2.5 microarrays. CNVs were called with PennCNV and prioritized if they were ≥20 Kb, contained ≥10 SNPs and had minimal overlap with CNVs from in-house controls, the Database of Genomic Variants, HapMap3, and Childrens Hospital of Philadelphia database.

RESULTS

We identified 28 CNVs in 17 cases; several encompassed genes important for right heart development. One case had a 2p16-2p23 duplication spanning LBH, a limb and heart development transcription factor. Lbh mis-expression results in right ventricular hypoplasia and pulmonary valve defects. This duplication also encompassed SOS1, a factor associated with pulmonary valve stenosis in Noonan syndrome. Sos1-/- mice display thin and poorly trabeculated ventricles. In another case, we identified a 1.5 Mb deletion associated with Williams-Beuren syndrome, a disorder that includes valvular malformations. A third case had a 24 Kb deletion upstream of the TGFβ ligand ITGB8. Embryos genetically null for Itgb8, and its intracellular interactant Band 4.1B, display lethal cardiac phenotypes.

CONCLUSION

To our knowledge, this is the first study of CNVs in HRHS. We identified several rare CNVs that overlap genes related to right ventricular wall and valve development, suggesting that genetics plays a role in HRHS and providing clues for further investigation. Birth Defects Research 109:16-26, 2017. © 2016 Wiley Periodicals, Inc.

Functions of miRNAs during Mammalian Heart Development

MicroRNAs (miRNAs) play essential roles during mammalian heart development and have emerged as attractive therapeutic targets for cardiovascular diseases. The mammalian embryonic heart is mainly derived from four major cell types during development. These include cardiomyocytes, endocardial cells, epicardial cells, and neural crest cells. Recent data have identified various miRNAs as critical regulators of the proper differentiation, proliferation, and survival of these cell types. In this review, we briefly introduce the contemporary understanding of mammalian cardiac development. We also focus on recent developments in the field of cardiac miRNAs and their functions during the development of different cell types.

MicroRNAs in congenital heart disease

Congenital heart disease (CHD) is a broad term which encompasses a spectrum of pathology, the most common phenotypes include atrial septal defects (ASDs), ventricular septal defects (VSDs), patent ductus arteriosus (PAD) and tetralogy of Fallot (TOF). The impact of CHD is profound and it is estimated to be responsible for over 40% of prenatal deaths. MicroRNAs (miRs) are small, highly conserved, non-coding RNAs which have complex roles in a variety of pathophysiological states. miRs are post-transcriptional negative regulators of gene expression. Individual miRs are known to exert effects in multiple target genes, therefore the altered expression of a single miR could influence an entire gene network resulting in complex pathological states. Recent evidences suggest a role in the dysregulation of miRs in CHD. Mouse knock out models have contributed to our knowledge base revealing specific patterns of miR expression in cardiovascular physiology and pathological states. Specific miRs necessary for embryonic cardiac development have been revealed. Dysregulation of these miRs has been shown to cause structural abnormalities in the heart and vasculature, thus furthering our understanding of the processes which result in CHD. These advances have provided new insight into the signalling pathways responsible for CHD. Furthermore, this new appreciation for miRs in the development of CHD has uncovered their potential for new therapeutic targets where modulated miR activity may reduce the burden of disease. Here, we summarize current knowledge of the cause-effect relationships of miRs in CHD and consider their potential as a therapeutic targets and biomarkers in this clinical setting.

Mechanisms and therapeutic potential of microRNAs in hypertension

Hypertension is the major risk factor for the development of stroke, coronary artery disease, heart failure and renal disease. The underlying cellular and molecular mechanisms of hypertension are complex and remain largely elusive. MicroRNAs (miRNAs) are short, noncoding RNA fragments of 22-26 nucleotides and regulate protein expression post-transcriptionally by targeting the 3'-untranslated region of mRNA. A growing body of recent research indicates that miRNAs are important in the pathogenesis of arterial hypertension. Herein, we summarize the current knowledge regarding the mechanisms of miRNAs in cardiovascular remodeling, focusing specifically on hypertension. We also review recent progress of the miRNA-based therapeutics including pharmacological and nonpharmacological therapies (such as exercise training) and their potential applications in the management of hypertension.

MicroRNA biomarkers for early detection of embryonic malformations in pregnancy

Congenital birth defects, manifested in newborn infants, are formed during early embryogenesis. Targeted and individualized interventions to prevent birth defects require early detection of risk and signs of developmental abnormalities. Current diagnosis of structural anomalies largely relies on ultrasonography, which can only detect abnormities after their formation in fetuses. Biomolecules, mainly proteins, in maternal blood have been used as indicators of fetal anomalies; however, they lack adequate sensitivity for detecting embryonic malformations. Recently, cell-free microRNAs (miRNAs) have been found in blood and evaluated as biomarkers for diseases. Expression of certain miRNAs in maternal plasma has been shown to be correlated with birth defects in infants. Although their reliability and sensitivity remain to be validated, miRNAs, which can be amplified and sequenced, are potentially sensitive and specific biomarkers for early embryonic dysmorphogenesis.

The diagnostic value of circulating microRNAs for middle-aged (40-60-year-old) coronary artery disease patients

OBJECTIVE

Circulating microRNAs have been recognized as promising biomarkers for various diseases. The present study aimed to explore the potential roles of circulating miR-149, miR-424 and miR-765 as non-invasive biomarkers for the diagnosis of coronary artery disease in middle-aged (40-60-year-old) patients.

METHODS

Sixty-five stable coronary artery disease patients (49-57 years old), 30 unstable coronary artery disease patients (49-58 years old), and 32 non-coronary artery disease patients (49--57 years old) who were matched for age, sex, smoking habits, hypertension and diabetes were enrolled in this study. Total RNA was isolated from plasma with TRIzol reagent. Circulating miRNA levels were measured by quantitative real-time polymerase chain reaction.

RESULTS

Circulating miR-149 levels were decreased 4.49-fold in stable coronary artery disease patients (1.18 ± 0.84) and 5.09-fold in unstable coronary artery disease patients (1.04 ± 0.65) compared with non-coronary artery disease patients (5.30 ± 2.57) (p<0.001). Circulating miR-424 levels were reduced 3.6-fold in stable coronary artery disease patients (1.18 ± 0.60) and 5-fold in unstable coronary artery disease patients (0.86 ± 0.54) compared with non-coronary artery disease patients (4.35 ± 2.20) (p<0.001). In contrast, circulating miR-765 levels were elevated 3.98-fold in stable coronary artery disease patients (6.09 ± 2.27) and 5.33-fold in unstable coronary artery disease patients (8.17 ± 2.77) compared with non-coronary artery disease patients (1.53 ± 0.99) (p<0.001). Receiver operating characteristic curve analysis revealed that the respective areas under the curve for circulating miR-149, miR-424 and miR-765 were 0.938, 0.919 and 0.968 in stable CAD patients and 0.951, 0.960 and 0.977 in unstable coronary artery disease patients compared with non-coronary artery disease patients.

CONCLUSION

Our results suggest that circulating miR-149, miR-424 and miR-765 might be novel, non-invasive biomarkers for the diagnosis of coronary artery disease in middle-aged patients. However, future prospective trials in large patient cohorts are necessary before reaching a solid conclusion.