MiR-18a-5p inhibits endothelial-mesenchymal transition and cardiac fibrosis through the Notch2 pathway

Pathophysiology in Brain Arteriovenous Malformations: Focus on Endothelial Dysfunctions and Endothelial-to-Mesenchymal Transition

Brain arteriovenous malformations (bAVMs) substantially increase the risk for intracerebral hemorrhage (ICH), which is associated with significant morbidity and mortality. However, the treatment options for bAVMs are severely limited, primarily relying on invasive methods that carry their own risks for intraoperative hemorrhage or even death. Currently, there are no pharmaceutical agents shown to treat this condition, primarily due to a poor understanding of bAVM pathophysiology. For the last decade, bAVM research has made significant advances, including the identification of novel genetic mutations and relevant signaling in bAVM development. However, bAVM pathophysiology is still largely unclear. Further investigation is required to understand the detailed cellular and molecular mechanisms involved, which will enable the development of safer and more effective treatment options. Endothelial cells (ECs), the cells that line the vascular lumen, are integral to the pathogenesis of bAVMs. Understanding the fundamental role of ECs in pathological conditions is crucial to unraveling bAVM pathophysiology. This review focuses on the current knowledge of bAVM-relevant signaling pathways and dysfunctions in ECs, particularly the endothelial-to-mesenchymal transition (EndMT).

Roles of non-coding RNA in diabetic cardiomyopathy

In recent years, the incidence of diabetes has been increasing rapidly, posing a serious threat to human health. Diabetic cardiomyopathy (DCM) is characterized by cardiomyocyte hypertrophy, myocardial fibrosis, apoptosis, ventricular remodeling, and cardiac dysfunction in individuals with diabetes, ultimately leading to heart failure and mortality. However, the underlying mechanisms contributing to DCM remain incompletely understood. With advancements in molecular biology technology, accumulating evidence has shown that numerous non-coding RNAs (ncRNAs) crucial roles in the development and progression of DCM. This review aims to summarize recent studies on the involvement of three types of ncRNAs (micro RNA, long ncRNA and circular RNA) in the pathophysiology of DCM, with the goal of providing innovative strategies for the prevention and treatment of DCM.

Unraveling the Cardiac Matrix: From Diabetes to Heart Failure, Exploring Pathways and Potential Medications

Myocardial infarction (MI) often leads to heart failure (HF) through acute or chronic maladaptive remodeling processes. This establishes coronary artery disease (CAD) and HF as significant contributors to cardiovascular illness and death. Therefore, treatment strategies for patients with CAD primarily focus on preventing MI and lessening the impact of HF after an MI event. Myocardial fibrosis, characterized by abnormal extracellular matrix (ECM) deposition, is central to cardiac remodeling. Understanding these processes is key to identifying new treatment targets. Recent studies highlight SGLT2 inhibitors (SGLT2i) and GLP-1 receptor agonists (GLP1-RAs) as favorable options in managing type 2 diabetes due to their low hypoglycemic risk and cardiovascular benefits. This review explores inflammation's role in cardiac fibrosis and evaluates emerging anti-diabetic medications' effectiveness, such as SGLT2i, GLP1-RAs, and dipeptidyl peptidase-4 inhibitors (DPP4i), in preventing fibrosis in patients with diabetes post-acute MI. Recent studies were analyzed to identify effective medications in reducing fibrosis risk in these patients. By addressing these areas, we can advance our understanding of the potential benefits of anti-diabetic medications in reducing cardiac fibrosis post-MI and improve patient outcomes in individuals with diabetes at risk of HF.

Experimental Models to Study Endothelial to Mesenchymal Transition in Myocardial Fibrosis and Cardiovascular Diseases

Fibrosis is a common feature of cardiovascular diseases and targets multiple organs, such as the heart and vessels. Endothelial to mesenchymal transition is a complex, vital process that occurs during embryonic formation and plays a crucial role in cardiac development. It is also a fundamental process implicated in cardiac fibrosis and repair, but also in other organs. Indeed, in numerous cardiovascular diseases, the endothelial-to-mesenchymal transition has been shown to be involved in the generation of fibroblasts that are able to produce extracellular matrix proteins such as type I collagen. This massive deposition results in tissue stiffening and organ dysfunction. To advance our understanding of this process for the development of new specific diagnostic and therapeutic strategies, it is essential to develop relevant cellular and animal models of this process. In this review, our aim was to gain an in-depth insight into existing in vitro and in vivo models of endothelial to mesenchymal transition in cardiovascular diseases with a focus on cardiac fibrosis. We discuss important parameters impacting endothelial to mesenchymal transition, and we give perspectives for the development of relevant models to decipher the underlying mechanisms and ultimately find new treatments specific to fibrosis happening in cardiovascular diseases.

Prognostic significance of serum miR-18a-5p in severe COVID-19 Egyptian patients

BACKGROUND

The identification of miRNAs as well as characterization of miRNA-mRNA interactions in SARS-CoV-2 infection is important to understand their role in disease pathogenesis. Therefore the aim of the present study was to measure the expression levels of hsa-mir-18a-5p in the sera of severe COVID-19 Egyptian patients admitted to ICU to investigate its roles in the pathogenesis and severity of COVID-19 disease.

METHODS

A total of 180 unvaccinated severe COVID-19 patients were enrolled in our study. Besides the routine laboratory work, the expression level of hsa-mir-18a-5p was done using reverse transcription quantitative real-time PCR (RTqPCR) technique. Also, target genes of hsa-mir-18a-5p were explored by using online bioinformatics databases.

RESULTS

The expression level of hsa-mir-18a-5p decreased in nonsurvival severe COVID-19 patients (0.38 ± 0.26) when compared to the survival ones (0.84 ± 0.23). While as a prognostic tool for the prediction of bad prognosis and mortality among severe COVID-19 patients, our results showed that the serum hsa-mir-18a-5p expression level is a good sensitive and specific marker. By using bioinformatics tools, our results revealed that the decreased hsa-mir-18a-5p expression level may have a crucial role in COVID-19 pathogenesis and severity through decreased immunological responses (interpreted as lymphopenia) or increased inflammation (interpreted as increased serum levels of IL-6, CRP, LDH).

CONCLUSION

Taken together, the decreased expression level of hsa-mir-18a-5p could be a bad prognostic marker and therapeutic overexpression of hsa-mir-18a-5p could be a novel approach in the treatment of COVID-19 disease.

Central role of cardiac fibroblasts in myocardial fibrosis of diabetic cardiomyopathy

Diabetic cardiomyopathy (DCM), a main cardiovascular complication of diabetes, can eventually develop into heart failure and affect the prognosis of patients. Myocardial fibrosis is the main factor causing ventricular wall stiffness and heart failure in DCM. Early control of myocardial fibrosis in DCM is of great significance to prevent or postpone the progression of DCM to heart failure. A growing body of evidence suggests that cardiomyocytes, immunocytes, and endothelial cells involve fibrogenic actions, however, cardiac fibroblasts, the main participants in collagen production, are situated in the most central position in cardiac fibrosis. In this review, we systematically elaborate the source and physiological role of myocardial fibroblasts in the context of DCM, and we also discuss the potential action and mechanism of cardiac fibroblasts in promoting fibrosis, so as to provide guidance for formulating strategies for prevention and treatment of cardiac fibrosis in DCM.

Low expression of RBP4 in the vitreous humour of patients with proliferative diabetic retinopathy who underwent Conbercept intravitreal injection

Intravitreal injection of anti-VEGF antibodies has been widely used in the treatment of proliferative diabetic retinopathy (PDR). However, anti-VEGF drugs can exacerbate fibrosis and eventually lead to retinal detachment. To explore proteins closely related to fibrosis, we conducted proteomic analysis of human vitreous humour collected from PDR patients who have or have not intravitreal Conbercept (IVC) injection. Sixteen vitreous humour samples from PDR patients with preoperative IVC and 20 samples from those without preoperative IVC were examined. An immunodepletion kit was used to remove high-abundance vitreous proteins. Conbercept-induced changes were determined using a tandem mass tag-based quantitative proteomic strategy. Enzyme-linked immunosorbent assays were performed to confirm the concentrations of selected proteins and validate the proteomic results. Based on a false discovery rate between 0.05% and -0.05% and a fold-change > 1.5, 97 proteins were altered (49 higher levels and 48 lower levels) in response to IVC. Differentially expressed proteins were found in the extracellular and intracellular regions and were found to be involved in VEGF binding and VEGF-activated receptor activity. Protein-protein interactions indicated associations with fibrosis, neovascularisation and inflammatory signalling pathways. We found the low levels of RBP4 in the vitreous humour of PDR patients with IVC injection, as revealed by ELISA and proteomic profiling. Moreover, RBP4 significantly restored the mitochondrial function of HRMECs induced by AGEs and down regulated the level of glycolysis. Our study is the first to report that RBP4 decreases in the vitreous humour of PDR patients who underwent Conbercept treatment, thereby verifying the role of RBP4 in glucose metabolism. Results provide evidence for the potential mechanism underlying Conbercept-related fibrosis.

miR-409-3p Regulated by GATA2 Promotes Cardiac Fibrosis through Targeting Gpd1

Cardiac fibrosis is a hallmark of numerous chronic cardiovascular diseases that leads to heart failure. However, there is no validated therapy for it. Dysregulation of microRNAs has been confirmed to be involved in cardiac fibrosis development. However, the regulatory network was not well explored. This study was the first to highlight the role and molecular mechanism of miR-409-3p in cardiac fibrosis. We found that miR-409-3p was consistently increased in three fibrotic models, including heart tissues of postmyocardial infarction (MI) mice and neonatal rat cardiac fibroblasts treated with angiotensin II (Ang II) or transforming growth factor-β (TGF-β). Furthermore, myocardial infarction surgery-induced cardiac fibrosis and dysfunction were attenuated by systemic delivery of miR-409-3p antagomir. Notably, transfection with miR-409-3p mimics promoted the proliferation of cardiac fibroblasts and fibroblast-to-myofibroblast differentiation, accompanied by upregulated expression of Col1a1, Col3a1, and α-SMA. On the contrary, the miR-409-3p inhibitor exhibited the opposite effect. Following this, we verified Gpd1 as a direct target of miR-409-3p. Gpd1 siRNA abolished the antifibrotic effect of miR-409-3p inhibitor in neonatal rat cardiac fibroblasts, suggesting that miR-409-3p promotes cardiac fibrosis at least partially through Gpd1. Moreover, GATA2 was identified as a cardiac fibrosis-associated upstream positive transcription factor of miR-409-3p. Finally, these findings suggest that modulating miR-409-3p could be a potential therapeutic method for cardiac fibrosis.

Comparative Analysis of miRNA Expression Profiles in Skeletal Muscle of Bian Chickens at Different Embryonic Ages

MicroRNAs (miRNAs) are widely involved in the growth and development of skeletal muscle through the negative regulation of target genes. In order to screen out the differentially expressed miRNAs (DEMs) associated with skeletal muscle development of Bian chickens at different embryonic ages, we used the leg muscles of fast-growing and slow-growing Bian chickens at the 14th and 20th embryonic ages (F14, F20, S14 and S20) for RNA-seq. A total of 836 known miRNAs were identified, and 121 novel miRNAs were predicted. In the F14 vs. F20 comparison group, 127 DEMs were screened, targeting a total of 2871 genes, with 61 miRNAs significantly upregulated and 66 miRNAs significantly downregulated. In the S14 vs. S20 comparison group, 131 DEMs were screened, targeting a total of 3236 genes, with 60 miRNAs significantly upregulated and 71 miRNAs significantly downregulated. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis showed that the predicted target genes were significantly enriched in 706 GO terms and 6 KEGG pathways in the F14 vs. F20 group and 677 GO terms and 5 KEGG pathways in the S14 vs. S20 group. According to the interaction network analysis, we screened five coexpressed DEMs (gga-miR-146a-3p, gga-miR-2954, gga-miR-34a-5p, gga-miR-1625-5p and gga-miR-18b-3p) with the highest connectivity degree with predicted target genes between the two comparison groups, and five hub genes (HSPA5, PKM2, Notch1, Notch2 and RBPJ) related to muscle development were obtained as well. Subsequently, we further identified nine DEMs (gga-let-7g-3p, gga-miR-490-3p, gga-miR-6660-3p, gga-miR-12223-5p, novel-miR-327, gga-miR-18a-5p, gga-miR-18b-5p, gga-miR-34a-5p and gga-miR-1677-3p) with a targeting relationship to the hub genes, suggesting that they may play important roles in the muscle development of Bian chickens. This study reveals the miRNA differences in skeletal muscle development between 14- and 20-day embryos of Bian chickens from fast- and slow-growing groups and provides a miRNA database for further studies on the molecular mechanisms of the skeletal muscle development in Bian chickens.

Cellular interplay between cardiomyocytes and non-myocytes in diabetic cardiomyopathy

Patients with Type 2 diabetes mellitus (T2DM) frequently exhibit a distinctive cardiac phenotype known as diabetic cardiomyopathy. Cardiac complications associated with T2DM include cardiac inflammation, hypertrophy, fibrosis and diastolic dysfunction in the early stages of the disease, which can progress to systolic dysfunction and heart failure. Effective therapeutic options for diabetic cardiomyopathy are limited and often have conflicting results. The lack of effective treatments for diabetic cardiomyopathy is due in part, to our poor understanding of the disease development and progression, as well as a lack of robust and valid preclinical human models that can accurately recapitulate the pathophysiology of the human heart. In addition to cardiomyocytes, the heart contains a heterogeneous population of non-myocytes including fibroblasts, vascular cells, autonomic neurons and immune cells. These cardiac non-myocytes play important roles in cardiac homeostasis and disease, yet the effect of hyperglycaemia and hyperlipidaemia on these cell types are often overlooked in preclinical models of diabetic cardiomyopathy. The advent of human induced pluripotent stem cells provides a new paradigm in which to model diabetic cardiomyopathy as they can be differentiated into all cell types in the human heart. This review will discuss the roles of cardiac non-myocytes and their dynamic intercellular interactions in the pathogenesis of diabetic cardiomyopathy. We will also discuss the use of sodium-glucose cotransporter 2 inhibitors as a therapy for diabetic cardiomyopathy and their known impacts on non-myocytes. These developments will no doubt facilitate the discovery of novel treatment targets for preventing the onset and progression of diabetic cardiomyopathy.

Diagnostic and Predictive Values of Circulating Extracellular Vesicle-Carried microRNAs in Ischemic Heart Disease Patients With Type 2 Diabetes Mellitus

Ischemic heart disease patients with diabetes mellitus (IHD-DM) have a higher risk of cardiovascular events than those without DM. Rapid identification of IHD-DM can enable early access to medical treatment and reduce the occurrence of cardiovascular adverse events. In the present study, we identified and examined extracellular vesicle (EV)-carried microRNAs (miRNAs) as the possible diagnostic biomarkers of IHD-DM. Small RNA sequencing was performed to analyze the EV-carried miRNAs spectrum, and differentially expressed miRNAs were further confirmed by quantitative real-time polymerase chain reaction (qRT-PCR). Through small RNA sequencing, we identified 138 differentially expressed EV-carried miRNAs between IHD-DM patients and healthy controls. Furthermore, we identified that five EV-carried miRNAs (miR-15a-3p, miR-18a-5p, miR-133a-3p, miR-155-5p, and miR-210-3p) were significantly down-regulated and one (miR-19a-3p) was significantly up-regulated in the IHD-DM patients compared to healthy controls. The receiver–operating characteristic curve analysis showed that the above six EV-carried miRNAs have excellent diagnostic efficacy of IHD-DM. Our findings indicated that the circulating EV-miRNAs might be promising biomarkers for the convenient and rapid diagnosis of IHD-DM.

Signaling Pathways Related to Oxidative Stress in Diabetic Cardiomyopathy

Diabetes is a chronic metabolic disease that is increasing in prevalence and causes many complications. Diabetic cardiomyopathy (DCM) is a complication of diabetes that is associated with high mortality, but it is not well defined. Nevertheless, it is generally accepted that DCM refers to a clinical disease that occurs in patients with diabetes and involves ventricular dysfunction, in the absence of other cardiovascular diseases, such as coronary atherosclerotic heart disease, hypertension, or valvular heart disease. However, it is currently uncertain whether the pathogenesis of DCM is directly attributable to metabolic dysfunction or secondary to diabetic microangiopathy. Oxidative stress (OS) is considered to be a key component of its pathogenesis. The production of reactive oxygen species (ROS) in cardiomyocytes is a vicious circle, resulting in further production of ROS, mitochondrial DNA damage, lipid peroxidation, and the post-translational modification of proteins, as well as inflammation, cardiac hypertrophy and fibrosis, ultimately leading to cell death and cardiac dysfunction. ROS have been shown to affect various signaling pathways involved in the development of DCM. For instance, OS causes metabolic disorders by affecting the regulation of PPARα, AMPK/mTOR, and SIRT3/FOXO3a. Furthermore, OS participates in inflammation mediated by the NF-κB pathway, NLRP3 inflammasome, and the TLR4 pathway. OS also promotes TGF-β-, Rho-ROCK-, and Notch-mediated cardiac remodeling, and is involved in the regulation of calcium homeostasis, which impairs ATP production and causes ROS overproduction. In this review, we summarize the signaling pathways that link OS to DCM, with the intention of identifying appropriate targets and new antioxidant therapies for DCM.

MicroRNA targets and biomarker validation for diabetes-associated cardiac fibrosis

Cardiac fibrosis is one of the main characteristics of diabetic cardiomyopathy and manifests excessive accumulation of extracellular matrix proteins in the heart. Several signaling pathways have been proposed for pathogenesis of cardiac fibrosis in the diabetic heart. TGF-β/Smad2/3-dependent or independent pathway is the major signaling molecule core in the pathogenesis of cardiac fibrosis. MicroRNAs (miRNAs, miR) are ~22-nuceotide regulatory RNAs that are involved in gene silencing through the degradation of post-transcriptional mRNA or suppression of the expressed proteins. Hyperglycemia in the diabetic heart regulates expression of some miRNAs. Target molecules of miRNAs can be identified through biocomputational database initial screening and dual luciferase assay validation. miR-21, miR-150-5p, miR-155, miR-216a-3p, miR-221-3p, miR-223, and miR-451 were up-regulated in the diabetic heart and promoted cardiac fibrosis through targeting signaling pathways in cardiac fibroblasts, endothelial cells, and cardiac myocytes. miR-15a/-15b, miR-18a-5p, miR-20a-5p, miR-26b-5p, miR-29, miR-133a, miR-141, miR-146, miR-200b, miR-203, miR-222, and miR-551b-5p were down-regulated in the diabetic heart and exhibited anti-fibrosis when they were overexpressed. miRNAs are stable molecules and may reflect the pathological changes of organs. Some miRNAs have been detected in the plasma or serum in patients with diabetes mellitus or heart failure. Exploration of targets and biomarkers of miRNA may provide additional information on pathogenesis and diagnosis of cardiac fibrosis and novel targets to tackle diabetic cardiomyopathy.

CDKN2B-AS1 participates in high glucose-induced apoptosis and fibrosis via NOTCH2 through functioning as a miR-98-5p decoy in human podocytes and renal tubular cells

BACKGROUND

Diabetic nephropathy (DN) is the most common causes of end-stage renal disease. Long non-coding RNA cyclin-dependent kinase inhibitor 2B antisense RNA 1 (CDKN2B-AS1) is connected with the development of DN, but the role of CDKN2B-AS1 in DN has not been entirely elucidated.

METHODS

Quantitative real-time polymerase chain reaction (qRT-PCR) was carried out to measure CDKN2B-AS1 and miR-98-5p levels. Cell viability, proliferation, and apoptosis were analyzed with 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) or flow cytometry assays. Protein levels were measured by western blotting. The relationship between CDKN2B-AS1 or notch homolog 2 (NOTCH2) and miR-98-5p was verified via dual-luciferase reporter assay.

RESULTS

CDKN2B-AS1 and NOTCH2 were upregulated in the serum of DN patients and high glucose-disposed human podocytes (HPCs) and human renal tubular cells (HK-2), whereas miR-98-5p was downregulated. High glucose repressed viability and accelerated apoptosis of HPCs and HK-2 cells. CDKN2B-AS1 knockdown impaired high glucose-induced apoptosis and fibrosis of HPCs and HK-2 cells. Mechanistically, CDKN2B-AS1 sponged miR-98-5p to regulate NOTCH2 expression. Also, CDKN2B-AS1 inhibition-mediated effects on apoptosis and fibrosis of high glucose-disposed HPCs and HK-2 cells were weakened by miR-98-5p inhibitor. Also, NOTCH2 knockdown partly reversed miR-98-5p inhibitor-mediated impacts on apoptosis and fibrosis of high glucose-disposed HPCs and HK-2 cells.

CONCLUSION

High glucose-induced CDKN2B-AS1 promoted apoptosis and fibrosis via the TGF-β1 signaling mediated by the miR-98-5p/NOTCH2 axis in HPCs and HK-2 cells.

MicroRNA-18a-5p represses scar fibroblast proliferation and extracellular matrix deposition through regulating Smad2 expression

The aim of the present study was to investigate the expression and role of microRNA-18a-5p (miR-18a-5p) during the formation of hypertrophic scar (HS), and to further explore the molecular mechanisms involved. Downregulation of miR-18a-5p in HS tissues and human HS fibroblasts (hHSFs) was detected by reverse transcription-quantitative polymerase chain reaction. The binding sites between miR-18a-5p and the 3'-untranslated region of SMAD family member 2 (Smad2) were predicted by TargetScan and confirmed by dual-luciferase reporter assay. To investigate the role of miR-18a-5p in HS formation, the effects of miR-18a-5p downregulation or upregulation on hHSFs were subsequently determined. Cell proliferation was detected by an MTT assay, while cell apoptosis was measured by flow cytometry. In addition, the protein expression levels of Smad2, Collagen I (Col I) and Col III were examined by western blot assay. The findings indicated that miR-18a-5p downregulation in hHSFs significantly promoted the cell proliferation, decreased cell apoptosis and enhanced the expression levels of Smad2, Col I and Col III protein and mRNA, whereas miR-18a-5p upregulation in hHSFs exerted opposite effects. Notably, the effects of miR-18a-5p upregulation on hHSFs were eliminated by Smad2 upregulation. In conclusion, the data indicated that miR-18a-5p was downregulated during HS formation, and its upregulation repressed scar fibroblast proliferation and extracellular matrix deposition by targeting Smad2. Therefore, miR-18a-5p may serve as a novel therapeutic target for the treatment of HS.

EndMT Regulation by Small RNAs in Diabetes-Associated Fibrotic Conditions: Potential Link With Oxidative Stress

Diabetes-associated complications, such as retinopathy, nephropathy, cardiomyopathy, and atherosclerosis, the main consequences of long-term hyperglycemia, often lead to organ dysfunction, disability, and increased mortality. A common denominator of these complications is the myofibroblast-driven excessive deposition of extracellular matrix proteins. Although fibroblast appears to be the primary source of myofibroblasts, other cells, including endothelial cells, can generate myofibroblasts through a process known as endothelial to mesenchymal transition (EndMT). During EndMT, endothelial cells lose their typical phenotype to acquire mesenchymal features, characterized by the development of invasive and migratory abilities as well as the expression of typical mesenchymal products such as α-smooth muscle actin and type I collagen. EndMT is involved in many chronic and fibrotic diseases and appears to be regulated by complex molecular mechanisms and different signaling pathways. Recent evidence suggests that small RNAs, in particular microRNAs (miRNAs) and long non-coding RNAs (lncRNAs), are crucial mediators of EndMT. Furthermore, EndMT and miRNAs are both affected by oxidative stress, another key player in the pathophysiology of diabetic fibrotic complications. In this review, we provide an overview of the primary redox signals underpinning the diabetic-associated fibrotic process. Then, we discuss the current knowledge on the role of small RNAs in the regulation of EndMT in diabetic retinopathy, nephropathy, cardiomyopathy, and atherosclerosis and highlight potential links between oxidative stress and the dyad small RNAs-EndMT in driving these pathological states.

Lung-specific distant enhancer cis regulates expression of FOXF1 and lncRNA FENDRR

The FOXF1 gene, causative for a neonatal lethal lung developmental disorder alveolar capillary dysplasia with misalignment of pulmonary veins (ACDMPV), maps 1.7 kb away from the long noncoding RNA gene FENDRR on the opposite strand, suggesting they may be coregulated. Using RNA sequencing in lung tissue from ACDMPV patients with heterozygous deletions of the FOXF1 distant enhancer located 286 kb upstream, leaving FOXF1 and FENDRR intact, we have found that the FENDRR and FOXF1 expressions were reduced by approximately 75% and 50%, respectively, and were monoallelic from the intact chromosome 16q24.1. In contrast, ACDMPV patients with FOXF1 SNVs had biallelic FENDRR expression reduced by 66%-82%. Corroboratively, depletion of FOXF1 by small interfering RNA in lung fibroblasts resulted in a 50% decrease of FENDRR expression. These data indicate that FENDRR expression in the lungs is regulated both in cis by the FOXF1 distant enhancer and in trans by FOXF1. Our findings are compatible with the involvement of FENDRR in FOXF1-related disorders, including ACDMPV.

The crosstalk of HDAC3, microRNA-18a and ADRB3 in the progression of heart failure

BACKGROUND

Heart failure (HF) is a clinical syndrome characterized by left ventricular dysfunction or elevated intracardiac pressures. Research supports that microRNAs (miRs) participate in HF by regulating  targeted genes. Hence, the current study set out to study the role of HDAC3-medaited miR-18a in HF by targeting ADRB3.

METHODS

Firstly, HF mouse models were established by ligation of the left coronary artery at the lower edge of the left atrial appendage, and HF cell models were generated in the cardiomyocytes, followed by ectopic expression and silencing experiments. Numerous parameters including left ventricular posterior wall dimension (LVPWD), interventricular septal dimension (IVSD), left ventricular end diastolic diameter (LVEDD), left ventricular end systolic diameter (LVESD), left ventricular ejection fraction (LVEF), left ventricular fractional shortening (LVFS), left ventricular systolic pressure (LVSP), left ventricular end diastolic pressure (LEVDP), heart rate (HR), left ventricular pressure rise rate (+ dp/dt) and left ventricular pressure drop rate (-dp/dt) were measured in the mice. In addition, apoptosis in the mice was detected by means of TUNEL staining, while RT-qPCR and Western blot analysis were performed to detect miR-18a, HDAC3, ADRB3, cMyb, MMP-9, Collagen 1 and TGF-β1 expression patterns. Dual luciferase reporter assay validated the targeting relationship between ADRB3 and miR-18a. Cardiomyocyte apoptosis was determined by means of flow cytometry.

RESULTS

HDAC3 and ADRB3 were up-regulated and miR-18a was down-regulated in HF mice and cardiomyocytes. In addition, HDAC3 could reduce the miR-18a expression, and ADRB3 was negatively-targeted by miR-18a. After down-regulation of HDAC3 or ADRB3 or over-expression of miR-18a, IVSD, LVEDD, LVESD and LEVDP were found to be decreased but LVPWD, LVEF, LVFS, LVSP, + dp/dt, and -dp/dt were all increased in the HF mice, whereas fibrosis, hypertrophy and apoptosis of HF cardiomyocytes were declined.

CONCLUSION

Collectively, our findings indicate that HDAC3 silencing confers protection against HF by inhibiting miR-18a-targeted ADRB3.

Calcium-Sensing Receptor Participates in High Glucose-Induced EndMT in Primary Human Aortic Endothelial Cells

Objective

Previous studies have shown that high glucose (HG) induces endothelial cell (EC) damage via endothelial-to-mesenchymal transition (EndMT). Although the underlying mechanisms are still unclear, recent studies have demonstrated the role of calcium-sensing receptor (CaSR) in mediating EC damage. Therefore, the aim of our study was to investigate whether CaSR mediates HG-induced EndMT and to determine the underlying mechanism.

Methods

Bioinformatics analysis of microarray profiles (GSE30780) and protein-protein interaction (PPI) analyses were performed to select the hub genes. As for in vitro research, the human aortic ECs (HAECs) were exposed to HG to induce EndMT. The expression of CaSR and β-catenin was determined, as well as their effects on EndMT (endothelial marker CD31, mesenchymal marker FSP1, and α-SMA).

Results

The bioinformatics analysis indicated CaSR was significantly increased in HG-treated HAECs and was one of the hub genes. The in vitro results showed that HG significantly inhibited the expression of CD31 and increased FSP1 and α-SMA in a concentration- and time-dependent manner. Moreover, CaSR was increased in HAECs after HG treatment. The CaSR antagonist attenuated HG-induced expression of EndMT-related markers. Furthermore, HG treatment increased the nuclear translocation of β-catenin in HAECs. In contrast, blocking the nuclear translocation of β-catenin by DKK1 could attenuate HG-induced EndMT (increased the protein expression of CD31 by 30% and decreased the protein expression of FSP1 by 15% and α-SMA by 25%). CaSR siRNA further inhibited the HG-induced nuclear translocation of β-catenin in HAECs.

Conclusion

Our research demonstrated that HG-induced EndMT in HAECs might be mediated by CaSR and the downstream nuclear translocation of β-catenin.

Long Non-Coding RNA FENDRR: Gene Structure, Expression, and Biological Relevance

The FOXF1 Adjacent Noncoding Developmental Regulatory RNA (Fendrr) plays an important role in the control of gene expression in mammals. It is transcribed in the opposite direction to the neighboring Foxf1 gene with which it shares a region containing promoters. In humans, FENDRR is located on chromosome 16q24.1, and is positively regulated both by the FOXF1 distant lung-specific cis-acting enhancer and by trans-acting FOXF1. Fendrr has been shown to function as a competing endogenous RNA, sponging microRNAs and protein factors that control stability of mRNAs, and as an epigenetic modifier of chromatin structure around gene promoters and other regulatory sites, targeting them with histone methyltrasferase complexes. In mice, Fendrr is essential for development of the heart, lungs, and gastrointestinal system; its homozygous loss causes embryonic or perinatal lethality. Importantly, deregulation of FENDRR expression has been causatively linked also to tumorigenesis, resistance to chemotherapy, fibrosis, and inflammatory diseases. Here, we review the current knowledge on the FENDRR structure, expression, and involvement in development and tissue maintenance.

Noncoding RNAs as Promising Diagnostic Biomarkers and Therapeutic Targets in Intestinal Fibrosis of Crohn's Disease: The Path From Bench to Bedside

Fibrosis is a major pathway to organ injury and failure, accounting for more than one-third of deaths worldwide. Intestinal fibrosis causes irreversible and serious clinical complications, such as strictures and obstruction, secondary to a complex pathogenesis. Under the stimulation of profibrotic soluble factors, excessive activation of mesenchymal cells causes extracellular matrix deposition via canonical transforming growth factor-β/Smads signaling or other pathways (eg, epithelial-to-mesenchymal transition and endothelial-to-mesenchymal transition) in intestinal fibrogenesis. In recent studies, the importance of noncoding RNAs (ncRNAs) stands out in fibrotic diseases in that ncRNAs exhibit a remarkable variety of biological functions in modulating the aforementioned fibrogenic responses. In this review, we summarize the role of ncRNAs, including the emerging long ncRNAs and circular RNAs, in intestinal fibrogenesis. Notably, the translational potential of ncRNAs as diagnostic biomarkers and therapeutic targets in the management of intestinal fibrosis is discussed based on clinical trials from fibrotic diseases in other organs. The main points of this review include the following: • Characteristics of ncRNAs and mechanisms of intestinal fibrogenesis • Wide participation of ncRNAs (especially the emerging long ncRNAs and circular RNAs) in intestinal fibrosis, including transforming growth factor-β signaling, epithelial-to-mesenchymal transition/endothelial-to-mesenchymal transition, and extracellular matrix remodeling • Translational potential of ncRNAs in the diagnosis and treatment of intestinal fibrosis based on clinical trials from fibrotic diseases in other organs.

Differential epigenetic factors in the prediction of cardiovascular risk in diabetic patients

Hyperglycaemia can strongly alter the epigenetic signatures in many types of human vascular cells providing persistent perturbations of protein–protein interactions both in micro- and macro-domains. The establishment of these epigenetic changes may precede cardiovascular (CV) complications and help us to predict vascular lesions in diabetic patients. Importantly, these epigenetic marks may be transmitted across several generations (transgenerational effect) and increase the individual risk of disease. Aberrant DNA methylation and imbalance of histone modifications, mainly acetylation and methylation of H3, represent key determinants of vascular lesions and, thus, putative useful biomarkers for prevention and diagnosis of CV risk in diabetics. Moreover, a differential expression of some micro-RNAs (miRNAs), mainly miR-126, may be a useful prognostic biomarker for atherosclerosis development in asymptomatic subjects. Recently, also environmental-induced chemical perturbations in mRNA (epitranscriptome), mainly the N⁶-methyladenosine, have been associated with obesity and diabetes. Importantly, reversal of epigenetic changes by modulation of lifestyle and use of metformin, statins, fenofibrate, and apabetalone may offer useful therapeutic options to prevent or delay CV events in diabetics increasing the opportunity for personalized therapy. Network medicine is a promising molecular-bioinformatic approach to identify the signalling pathways underlying the pathogenesis of CV lesions in diabetic patients. Moreover, machine learning tools combined with tomography are advancing the individualized assessment of CV risk in these patients. We remark the need for combining epigenetics and advanced bioinformatic platforms to improve the prediction of vascular lesions in diabetics increasing the opportunity for CV precision medicine.

ALK-1 to ALK-5 ratio dictated by the Akt1-β-catenin pathway regulates TGFβ-induced endothelial-to-mesenchymal transition

Endothelial-to-mesenchymal transition (EndMT) indispensable in embryogenesis also occurs in several human pathologies. Although transforming growth factor-β (TGFβ) has been demonstrated to induce EndMT, the type-I receptors (ALK-1 and ALK-5) responsible for TGFβ-induced EndMT is unclear. In the current study, we investigated the role of the Akt1 pathway in ALK1 and ALK5 expression regulation in response to TGFβ1 and TGFβ2 in human microvascular endothelial cells (HMECs). Whereas treatment with TGFβ1 and TGFβ2 or Akt1 gene silencing promoted EndMT accompanied by increased ALK5 expression and reduced ALK1 expression accompanied by increased expression of N-cadherin and reduced expression of eNOS in HMECs, treatment with ALK-5 inhibitor (SB431542) blunted these effects. Importantly, the inhibitor of β-catenin (ICG-001) suppressed TGFβ1- and TGFβ2-induced ALK5 expression in both normal and Akt1 deficient HMECs indicating the integral role of Akt1-β-catenin pathway in the regulation of ALK5 expression promoting EndMT.

Roles of Biomarkers in Myocardial Fibrosis

Myocardial fibrosis is observed in various cardiovascular diseases and plays a key role in the impairment of cardiac function. Endomyocardial biopsy, as the gold standard for the diagnosis of myocardial fibrosis, has limitations in terms of clinical application. Therefore, biomarkers have been recommended for noninvasive assessment of myocardial fibrosis. This review discusses the role of biomarkers in myocardial fibrosis from the perspective of collagen.

Endothelial-to-Mesenchymal Transition: Role in Cardiac Fibrosis

Endothelial-to-mesenchymal transition (EndMT) is a complex biological process by which endothelial cells lose their endothelial cell characteristics and acquire mesenchymal cell properties under certain physiological or pathological conditions. Recently, it has been found that EndMT plays an important role in the occurrence and development of fibrotic cardiovascular diseases. In this review, we first summarize the main induction pathways involved in EndMT process. In addition, we discuss the role of EndMT in fibrotic cardiovascular diseases and its potential implication in new therapeutic interventions.

Increased miR-7641 Levels in Peritoneal Hyalinizing Vasculopathy in Long-Term Peritoneal Dialysis Patients

Peritoneal hyalinizing vasculopathy (PHV) represents the cornerstone of long-term peritoneal dialysis (PD), and especially characterizes patients associated with encapsulating peritoneal sclerosis. However, the mechanisms of PHV development remain unknown. A cross sectional study was performed in 100 non-selected peritoneal biopsies of PD patients. Clinical data were collected and lesions were evaluated by immunohistochemistry. In selected biopsies a microRNA (miRNA)-sequencing analysis was performed. Only fifteen patients (15%) showed PHV at different degrees. PHV prevalence was significantly lower among patients using PD fluids containing low glucose degradation products (GDP) (5.9% vs. 24.5%), angiotensin converting enzyme inhibitors (ACEIs) (7.5% vs. 23.4%), statins (6.5% vs. 22.6%) or presenting residual renal function, suggesting the existence of several PHV protective factors. Peritoneal biopsies from PHV samples showed loss of endothelial markers and induction of mesenchymal proteins, associated with collagen IV accumulation and wide reduplication of the basement membrane. Moreover, co-expression of endothelial and mesenchymal markers, as well as TGF-β1/Smad3 signaling activation were found in PHV biopsies. These findings suggest that an endothelial-to-mesenchymal transition (EndMT) process was taking place. Additionally, significantly higher levels of miR-7641 were observed in severe PHV compared to non-PHV peritoneal biopsies. Peritoneal damage by GDPs induce miRNA deregulation and an EndMT process in submesothelial vessels, which could contribute to collagen IV accumulation and PHV.

Good or not good: Role of miR-18a in cancer biology

miR-18a is a member of primary transcript called miR-17-92a (C13orf25 or MIR17HG) which also contains five other miRNAs: miR-17, miR-19a, miR-20a, miR-19b and miR-92a. This cluster as a whole shows specific characteristics, where miR-18a seems to be unique. In contrast to the other members, the expression of miR-18a is additionally controlled and probably functions as its own internal controller of the cluster. miR-18a regulates many genes involved in proliferation, cell cycle, apoptosis, response to different kinds of stress, autophagy and differentiation. The disturbances of miR-18a expression are observed in cancer as well as in different diseases or pathological states. The miR-17-92a cluster is commonly described as oncogenic and it is known as 'oncomiR-1', but this statement is a simplification because miR-18a can act both as an oncogene and a suppressor. In this review we summarize the current knowledge about miR-18a focusing on its regulation, role in cancer biology and utility as a potential biomarker.

Circulating miRNAs as molecular markers of occupational grain dust exposure

Dust from grain and feed production may cause adverse health effects in exposed workers. In this study we explored circulating miRNAs as potential biomarkers of occupational grain dust exposure. Twenty-two serum miRNAs were analyzed in 44 grain dust exposed workers and 22 controls. Exposed workers had significantly upregulated miR-18a-5p, miR-124-3p and miR-574-3p, and downregulated miR-19b-3p and miR-146a-5p, compared to controls. Putative target genes for the differentially expressed miRNAs were involved in a range of Kyoto Encyclopedia of Genes and Genomes signaling pathways, and ‘Pathways in cancer’ and ‘Wnt signaling pathway’ were common for all the five miRNAs. MiRNA-diseases association analysis showed a link between the five identified miRNAs and several lung diseases terms. A positive correlation between miR-124-3p, miR-18a-5p, and miR-574-3p and IL-6 protein level was shown, while miR-19b-3p was inversely correlated with CC-16 and sCD40L protein levels. Receiver-operating characteristic analysis of the five miRNA showed that three miRNAs (miR-574-3p, miR-124-3p and miR-18a-5p) could distinguish the grain dust exposed group from the control group, with miR-574-3p as the strongest predictor of grain dust exposure. In conclusion, this study identified five signature miRNAs as potential novel biomarkers of grain dust exposure that may have potential as early disease markers.

Non-coding RNA in endothelial-to-mesenchymal transition

Endothelial-to-mesenchymal transition (EndMT) is the process wherein endothelial cells lose their typical endothelial cell markers and functions and adopt a mesenchymal-like phenotype. EndMT is required for development of the cardiac valves, the pulmonary and dorsal aorta, and arterial maturation, but activation of the EndMT programme during adulthood is believed to contribute to several pathologies including organ fibrosis, cardiovascular disease, and cancer. Non-coding RNAs, including microRNAs, long non-coding RNAs, and circular RNAs, modulate EndMT during development and disease. Here, we review the mechanisms by which non-coding RNAs facilitate or inhibit EndMT during development and disease and provide a perspective on the therapeutic application of non-coding RNAs to treat fibroproliferative cardiovascular disease.

MiR-18a-5p contributes to enhanced proliferation and migration of PASMCs via targeting Notch2 in pulmonary arterial hypertension

AIM

This study is undertaken to investigate the role and molecular mechanisms of miR-18a-5p in regulating pulmonary arterial hypertension (PAH) pathogenesis.

METHODS

Gene expression and protein levels were determined by qRT-PCR and western blot, respectively; Cell counting kti-8 and Transwell migration assays were used to determine the biological functions of miR-18a-5p in pulmonary arterial smooth muscle cells (PASMCs); bioinformatics analysis, luciferase reporter assays were used to elucidate the mechanisms of miR-18a-5p.

RESULTS

MiR-18a-5p was up-regulated in the clinical samples from PAH patients. PASMCs treated with hypoxia exhibited enhanced proliferative ability and upregulated miR-18a-5p expression. Knockdown of miR-18a-5p attenuated hypoxia-induced hyper-proliferation and enhanced migratory potential of PASMCs; while miR-18a-5p overexpression promoted PASMC proliferation and migration. Further mechanistic studies showed that Notch2 was a direct target of miR-18a-5p and was repressed by miR-18a-5p overexpression. The rescue studies indicated that Notch2 overexpression counteracted the enhanced proliferation and migration induced by miR-18a-5p mimics in PASMCs. Similarly, Notch2 overexpression also block the effects caused by hypoxia in PASMCs. Moreover, Notch2 expression was down-regulated in the PAH patients and was negatively correlated with miR-18a-5p expression. In vivo animal studies further revealed the up-regulation of miR-18a-5p and the down-regulation of Notch2 in the PAH rats.

CONCLUSIONS

Collectively, this study identified the up-regulated miR-18a-5p in the PAH patients; our data suggest that miR-18a-5p contributes to the enhanced proliferation and migration of PASMCs via repressing Notch2 expression.

Endothelial-to-mesenchymal transition in anticancer therapy and normal tissue damage

Endothelial-to-mesenchymal transition (EndMT) involves the phenotypic conversion of endothelial-to-mesenchymal cells, and was first discovered in association with embryonic heart development. EndMT can regulate various processes, such as tissue fibrosis and cancer. Recent findings have shown that EndMT is related to resistance to cancer therapy, such as chemotherapy, antiangiogenic therapy, and radiation therapy. Based on the known effects of EndMT on the cardiac toxicity of anticancer therapy and tissue damage of radiation therapy, we propose that EndMT can be targeted as a strategy for overcoming tumor resistance while reducing complications, such as tissue damage. In this review, we discuss EndMT and its roles in damaging cardiac and lung tissues, as well as EndMT-related effects on tumor vasculature and resistance in anticancer therapy. Modulating EndMT in radioresistant tumors and radiation-induced tissue fibrosis can especially increase the efficacy of radiation therapy. In addition, we review the role of hypoxia and reactive oxygen species as the main stimulating factors of tissue damage due to vascular damage and EndMT. We consider drugs that may be clinically useful for regulating EndMT in various diseases. Finally, we argue the importance of EndMT as a therapeutic target in anticancer therapy for reducing tissue damage.

A process of cellular conversion known as endothelial-to-mesenchymal transition (EndMT) may offer a valuable target for treating cancer and other diseases. In EndMT, the cells lining blood vessels undergo a striking change in shape and physiology, acquiring features of cells called fibroblasts. Fibroblasts form the body’s connective tissue, but also produce scar tissue that impairs organ function. Researchers led by Yoon-Jin Lee of the Korea Institute of Radiological & Medical Sciences in Seoul, South Korea, have reviewed the impact of this transformation on human disease. EndMT is seen as a prelude to heart failure, in lung tissue affected by pulmonary fibrosis, and within tumors, where the process recruits cells that further stimulate cancer progression. The authors highlight the potential of using drugs that target EndMT to bolster the efficacy and safety of tumor therapy.

EOFAZ inhibits endothelial‑to‑mesenchymal transition through downregulation of KLF4

Essential oil from Alpinia zerumbet rhizome (EOFAZ), which is termed Yan shanjiang in China, is extensively used as an herbal medicine in the Guizhou area and has been shown to protect against the damaging effects of cardiovascular injury in vitro and in vivo. In the present study, it was hypothesized that the protective effects of EOFAZ on transforming growth factor (TGF)-β1-induced endothelial-to-mesenchymal transition (EndMT) in human umbilical vein endothelial cells (HUVECs) were mediated by inhibition of Krüppel-like factor 4 (KLF4). Cell motility was assessed using wound healing and Transwell assays. The expression of endothelial markers and mesenchymal markers were determined by reverse transcription-quantitative PCR, immunofluorescence staining and western blotting, and additionally, phosphorylated NF-κB p65 expression was determined by western blotting. Furthermore, the involvement of KLF4 in EndMT was determined using RNA interference to knockdown the expression of KLF4. TGF-β1 treatment significantly promoted EndMT, as evidenced by downregu-lation of vascular endothelial-cadherin and upregulation of α-smooth muscle actin in HUVECs, and by enhancing cell migration. Small interfering RNA-mediated knockdown of KLF4 reversed TGF-β1-induced EndMT. Additionally, treatment with EOFAZ inhibited TGF-β1-induced EndMT in a dose-dependent manner. These results suggest that TGF-β1 may induce EndMT through upregulation of KLF4, and this may be reversed by EOFAZ. Therefore, EOFAZ was shown to inhibit TGF-β1-induced EndMT through regulation of KLF4.

Aberrant expression of miR-29b-3p influences heart development and cardiomyocyte proliferation by targeting NOTCH2

Objectives

microRNA‐29 (miR‐29) family have shown different expression patterns in cardiovascular diseases. Our study aims to explore the effect and mechanism of miR‐29 family on cardiac development.

Materials and methods

A total of 13 patients with congenital heart disease (CHD) and 7 controls were included in our study. Tissues were obtained from the right ventricular outflow tract (RVOT) after surgical resection or autopsy. The next‐generation sequencing was applied to screen the microRNA expression profiles of CHD. Quantitative RT‐PCR and Western blot were employed to measure genes expression. Tg Cmlc2: GFP reporter zebrafish embryos were injected with microRNA (miRNA) to explore its role in cardiac development in vivo. Dual‐luciferase reporter assay was designed to validate the target gene of miRNAs. CCK‐8 and EdU incorporation assays were performed to evaluate cardiomyocyte proliferation.

Results

Our study showed miR‐29b‐3p expression was significantly increased in the RVOT of the CHD patients. Injection of miR‐29b‐3p into zebrafish embryos induced higher mortality and malformation rates, developmental delay, cardiac malformation and dysfunction. miR‐29b‐3p inhibited cardiomyocyte proliferation, and its inhibitor promoted cardiomyocyte proliferation in vitro and in vivo. Furthermore, we identified that miR‐29b‐3p influenced cardiomyocyte proliferation by targeting NOTCH2, which was down‐regulated in the RVOT of the CHD patients.

Conclusion

This study reveals that miR‐29b‐3p functions as a novel regulator of cardiac development and inhibits cardiomyocyte proliferation via NOTCH2, which provides novel insights into the aetiology and potential treatment of CHD.

When Wounds Are Good for You: The Regenerative Capacity of Fractional Resurfacing and Potential Utility in Chronic Wound Prevention

Significance: Fractional resurfacing involves producing arrays of microinjuries on the skin, by thermal or mechanical means, to trigger tissue regeneration. Originally developed for cosmetic enhancement, fractional resurfacing induces a broad array of improvements in the structural and functional qualities of the treated skin and is especially effective at returning defective skin to a more normal state. In addition to fascinating questions about the nature of this remarkable regenerative capacity, there may be potential utility in ulcer prevention by halting or even reversing the progressive decline in overall skin quality that usually precedes chronic wound development. Recent Advances: Photoaging and scarring are the two skin defects most commonly treated by fractional resurfacing, and the treatment produces profound and long-lasting improvements in skin quality, both clinically and at the cellular/histologic level. Chronic wounds usually occur in skin that is compromised by various pathologic factors, and many of the defects found in this ulcer-prone skin are similar to those that have seen improvements after fractional resurfacing. Critical Issues: The mechanisms responsible for the regenerative capacity of fractional resurfacing are mostly unknown, as is how ulcer-prone skin, which is usually afflicted by stressors external to the skin tissue itself, would respond to fractional resurfacing. Future Directions: Better understanding of the cellular and molecular mechanisms underlying the unique healing response to fractional resurfacing could reveal fundamental information about adult tissue regeneration, lead to improvements in current applications, as well as new therapies in other pathologic conditions.

rhBMP‑7 suppresses TGF‑β1‑induced endothelial to mesenchymal transition in circulating endothelial cells by regulating Smad5

Endothelial to mesenchymal transition (EndMT) has been confirmed to participate in several cardiovascular diseases. In addition, EndMT of circulating endothelial cells (CECs) contributes to the pathology of musculoskeletal injury. However, little is known about the molecular mechanism of CECs undergoing EndMT. In the present study, human CECs were isolated and identified using anti‑CD146‑coupled magnetic beads. CECs were exposed to transforming growth factor (TGF)‑β1 or TGF‑β1 + recombinant human bone morphogenetic protein 7 (rhBMP‑7) or TGF‑β1 + rhBMP‑7 + Smad5 antagonist Jun activation domain‑binding protein 1. Vascular endothelial (VE)‑cadherin and vimentin expression were detected by immunofluorescence staining in TGF‑β1‑treated CECs. The expression levels of von Willebrand factor (vWF), E‑selectin, VE‑cadherin, vimentin, fibronectin, α smooth muscle actin (α‑SMA) and Smad2/3 were detected by reverse transcription‑quantitative PCR or western blot analysis. It was identified that rhBMP‑7 attenuated TGF‑β1‑induced endothelial cell injury. TGF‑β1 could induce the EndMT process in CECs, as confirmed by the co‑expression of VE‑cadherin and vimentin. TGF‑β1 significantly reduced the expression of VE‑cadherin, and induced the expression of vimentin, fibronectin and α‑SMA. rhBMP‑7 reversed the effects of TGF‑β1 on the expression of these genes. Additionally, Smad5 antagonist reversed the effects of rhBMP‑7 on TGF‑β1‑induced EndMT, and upregulated rhBMP‑7‑inhibited Smad2/3 expression. In conclusion, TGF‑β1 could induce EndMT in CECs and rhBMP‑7 may suppress this process by regulating Smad5.

Inhibition of microRNA-150-5p alleviates cardiac inflammation and fibrosis via targeting Smad7 in high glucose-treated cardiac fibroblasts

Hyperglycemia-induced cardiac fibrosis is a prominent characteristic of diabetic cardiomyopathy. Changes in proinflammatory cytokines have been shown to lead to cardiac fibrosis in patients with diabetes mellitus. This study aimed to investigate the role of miR-150-5p in mediating cardiac inflammation and fibrosis in cardiac fibroblasts (CFs). Herein, we found that high-glucose (HG) treatment significantly induced cardiac inflammation, as manifested by increased proinflammatory cytokine production (IL-1β) and NF-κB activity in CFs. Moreover, HG markedly aggravated cardiac fibrosis and increased levels of fibrotic markers (CTGF, FN, α-SMA) and extracellular matrix proteins (Col-I, Col-III) in CFs. At the same time, HG disturbed the TGF-β1/Smad signaling pathway, as evidenced by increases in TGF-β1 and p-Smad2/3 levels and decreases in Smad7 levels in CFs. Furthermore, we found that miR-150-5p was upregulated by HG, which negatively regulated Smad7 expression at the posttranscription level. Further study demonstrated that cardiac inflammation and fibrosis in CFs were corrected following miR-150-5p knockdown, but exacerbated by miR-150-5p overexpression. These data indicated that miR-150-5p inhibition could ameliorate NF-κB-related inflammation and TGF-β1/Smad-induced cardiac fibrosis through targeting Smad7. Thus, miR-150-5p may be a novel promising target for treating diabetic cardiomyopathy.

Role of microRNA in the pathogenesis of systemic sclerosis tissue fibrosis and vasculopathy

Systemic Sclerosis (SSc) pathogenesis involves multiple immunological, vascular and fibroproliferative abnormalities that contribute to a severe and complex clinical picture. Vasculopathy and fibroproliferative alterations are two hallmark pathological processes in SSc that are responsible for the most severe clinical manifestations of the disease and determine its clinical outcome and mortality. However, the pathogenesis of SSc vasculopathy and of the uncontrolled SSc fibrotic process remain incompletely understood. Recent investigations into the molecular pathways involved in these processes have identified an important role for epigenetic processes that contribute to overall disease progression and have emphasized microRNAs (miRNAs) as crucial epigenetic regulators. MiRNAs hold unique potential for elucidating SSc pathogenesis, improving diagnosis and developing effective targeted therapies for the disease. This review examines the important role that miRNAs play in the development and regulation of vascular and fibroproliferative alterations associated with SSc pathogenesis and their possible participation in the establishment of pathogenetic connections between these two processes. This review also emphasizes that further understanding of the involvement of miRNA in SSc fibrosis and vasculopathy will very likely provide novel future research directions and allow for the identification of groundbreaking therapeutic interventions within these processes. MiR-21, miR- 31, and miR-155 are of particular interest owing to their important involvement in both SSc vasculopathy and fibroproliferative alterations.

Regulation of Endothelial-to-Mesenchymal Transition by MicroRNAs in Chronic Allograft Dysfunction

Fibrosis is a universal finding in chronic allograft dysfunction, and it is characterized by an accumulation of extracellular matrix. The precise source of the myofibroblasts responsible for matrix deposition is not understood, and pharmacological strategies for prevention or treatment of fibrosis remain limited. One source of myofibroblasts in fibrosis is an endothelial-to-mesenchymal transition (EndMT), a process first described in heart development and involving endothelial cells undergoing a phenotypic change to become more like mesenchymal cells. Recently, lineage tracing of endothelial cells in mouse models allowed studies of EndMT in vivo and reported 27% to 35% of myofibroblasts involved in cardiac fibrosis and 16% of isolated fibroblasts in bleomycin-induced pulmonary fibrosis to be of endothelial origin. Over the past decade, mature microRNAs (miRNAs) have increasingly been described as key regulators of biological processes through repression or degradation of targeted mRNA. The stability and abundance of miRNAs in body fluids make them attractive as potential biomarkers, and progress is being made in developing miRNA targeted therapeutics. In this review, we will discuss the evidence of miRNA regulation of EndMT from in vitro and in vivo studies and the potential relevance of this to heart, lung, and kidney allograft dysfunction.

Three miRNAs cooperate with host genes involved in human cardiovascular disease

Background

Understanding the roles of miRNAs in cardiovascular disease remains a challenge. Genomic linkage indicates a functional relationship between intronic miRNAs and their host genes. However, few studies have shown functional association between intronic miRNAs and their host coding genes that are genetically associated with cardiovascular disease.

Methods

In this study, we investigated functional relationship between three protein-coding genes genetically associated with cardiovascular disease, i.e., CDH13, SLC12A3, and CKAP5, and their intronic miRNAs using a data-driven approach.

Results

We found that the three protein-coding genes functionally interact with targets of their intronic miRNAs, i.e., miR-3182, miR-6863, and miR-5582, in a tissue-specific pattern. The intronic miRNAs preferentially impact important genes for the three host genes in the network, indicating their roles in maintaining the integrity of the interactome where the host genes are involved. Targets of the intronic miRNAs display functional similarity to the host genes. We furthermore present sets of target genes for future investigation on the possible miRNA-target interactions that potentially contribute to cardiovascular diseases.

Conclusions

Our work provides new insight into the regulatory network of the cardiovascular-associated pathways and opens the possibility for future experimental research.

Electronic supplementary material

The online version of this article (10.1186/s40246-019-0232-4) contains supplementary material, which is available to authorized users.

Connecting sex differences, estrogen signaling, and microRNAs in cardiac fibrosis

Sex differences are evident in the pathophysiology of heart failure (HF). Progression of HF is promoted by cardiac fibrosis and no fibrosis-specific therapies are currently available. The fibrotic response is mediated by cardiac fibroblasts (CFs), and a central event is their phenotypic transition to pro-fibrotic myofibroblasts. These myofibroblasts may arise from various cellular origins including resident CFs and epicardial and endothelial cells. Both female subjects in clinical studies and female animals in experimental studies generally present less cardiac fibrosis compared with males. This difference is at least partially considered attributable to the ovarian hormone 17β-estradiol (E2). E2 signals via estrogen receptors to regulate genes are involved in the fibrotic response and myofibroblast transition. Besides protein-coding genes, E2 also regulates transcription of microRNA that modulate cardiac fibrosis. Sex dimorphism, E2, and miRNAs form multi-level regulatory networks in the pathophysiology of cardiac fibrosis, and the mechanism of these networks is not yet fully deciphered. Therefore, this review is aimed at summarizing current knowledge on sex differences, E2, and estrogen receptors in cardiac fibrosis, emphasizing on microRNAs and myofibroblast origins. KEY MESSAGES: • E2 and ERs regulate cardiac fibroblast function. • E2 and ERs may distinctly affect male and female cardiac fibrosis pathophysiology. • Sex, E2, and miRNAs form multi-level regulatory networks in cardiac fibrosis. • Sex-dimorphic and E2-regulated miRNAs affect mesenchymal transition.

Endothelial to Mesenchymal Transition: Role in Physiology and in the Pathogenesis of Human Diseases

Numerous studies have demonstrated that endothelial cells are capable of undergoing endothelial to mesenchymal transition (EndMT), a newly recognized type of cellular transdifferentiation. EndMT is a complex biological process in which endothelial cells adopt a mesenchymal phenotype displaying typical mesenchymal cell morphology and functions, including the acquisition of cellular motility and contractile properties. Endothelial cells undergoing EndMT lose the expression of endothelial cell-specific proteins such as CD31/platelet-endothelial cell adhesion molecule, von Willebrand factor, and vascular-endothelial cadherin and initiate the expression of mesenchymal cell-specific genes and the production of their encoded proteins including α-smooth muscle actin, extra domain A fibronectin, N-cadherin, vimentin, fibroblast specific protein-1, also known as S100A4 protein, and fibrillar type I and type III collagens. Transforming growth factor-β1 is considered the main EndMT inducer. However, EndMT involves numerous molecular and signaling pathways that are triggered and modulated by multiple and often redundant mechanisms depending on the specific cellular context and on the physiological or pathological status of the cells. EndMT participates in highly important embryonic development processes, as well as in the pathogenesis of numerous genetically determined and acquired human diseases including malignant, vascular, inflammatory, and fibrotic disorders. Despite intensive investigation, many aspects of EndMT remain to be elucidated. The identification of molecules and regulatory pathways involved in EndMT and the discovery of specific EndMT inhibitors should provide novel therapeutic approaches for various human disorders mediated by EndMT.

miR-29a/b cluster suppresses high glucose-induced endothelial-mesenchymal transition in human retinal microvascular endothelial cells by targeting Notch2

Several studies have previously reported that endothelial cells contributed to pathological fibrosis in proliferative diabetic retinopathy (PDR) through endothelial-mesenchymal transition (EndMT); however, the precise mechanism of this interaction has not been completely elucidated. The present study investigated the expression of microRNA (miR)-29a/b cluster in human retinal microvascular endothelial cells (HRMECs) and examined its functional role in high glucose (HG)-induced EndMT. HRMECs were exposed to glucose at concentrations of 5, 15, 30 and 50 mM for 7 days and reverse transcription-quantitative polymerase chain reaction, western blotting and immunofluorescence were conducted to determine the expression of genes associated with miR-29a/b and EndMT. A luciferase reporter gene assay was also performed to confirm the association between miR-29a/b and neurogenic locus notch homolog protein 2 (Notch2). The expression levels of miR-29a/b, and endothelial markers vascular endothelial cadherin and cluster of differentiation 31 were decreased, whereas the expression levels of Notch2 and mesenchymal markers, including α-smooth muscle actin, fibroblast-specific protein 1 (also named S100 calcium binding protein A4, S100A4), fibronectin and SNAI1 were increased in HRMECs under HG (30 nM) conditions. In addition, Notch2 was identified as a target of miR-29a and miR-29b. Overexpression of miR-29a/b downregulated the expression of Notch2 and subsequently suppressed HG-induced EndMT. Taken together, the results of the present study revealed that the miR-29/Notch2 signaling pathway may participate in the regulation of HG-induced EndMT, and may serve as a potential molecular target during fibrosis in PDR.

LncRNAs and miRs as epigenetic signatures in diabetic cardiac fibrosis: new advances and perspectives

PURPOSE

Diabetic cardiomyopathy (DCM) is a serious cardiac complication of diabetes, which further lead to heartfailure. It is known that diabetes-induced cardiac fibrosis is a key pathogenic factor contributing topathological changes in DCM. However, pathogenetic mechanisms underlying diabetes cardiac fibrosis arestill elusive. Recent studies have indicated that noncoding RNAs (ncRNAs) play a key role in diabetescardiac fibrosis. The increasing complexity of epigenetic regulator poses great challenges to ourconventional conceptions regarding how ncRNAs regulate diabetes cardiac fibrosis.

METHODS

We searched PubMed, Web of Science, and Scopus for manuscripts published prior to April 2018 using keywords "Diabetic cardiomyopathy" AND " diabetes cardiac fibrosis " OR " noncoding RNAs " OR " longnoncoding RNAs " OR " microRNAs " OR "epigenetic". Manuscripts were collated, studied and carriedforward for discussion where appropriate.

RESULTS

Based on the view that during diabetic cardiac fibrosis, ncRNAs are able to regulate diabetic cardiac fibrosisby targeting genes involved in epigenetic pathways. Many studies have focused on ncRNAs, an epigeneticregulator deregulating protein-coding genes in diabetic cardiac fibrosis, to identify potential therapeutictargets. Recent advances and new perspectives have found that long noncoding RNAs and microRNAs,exert their own effects on the progression of diabetic cardiac fibrosis.

CONCLUSION

We firstly examine the growing role of ncRNAs characteristics and ncRNAs-regulated genes involved indiabetic cardiac fibrosis. Then, we provide several possible therapeutic strategies and highlight the potentialof molecular mechanisms in which targeting epigenetic regulators are considered as an effective means of treating diabetic cardiac fibrosis.

MicroRNAs as critical regulators of the endothelial to mesenchymal transition in vascular biology

The endothelial to mesenchymal transition (EndMT) is a newly recognized, fundamental biological process involved in development and tissue regeneration, as well as pathological processes such as the complications of diabetes, fibrosis and pulmonary arterial hypertension. The EndMT process is tightly controlled by diverse signaling networks, similar to the epithelial to mesenchymal transition. Accumulating evidence suggests that microRNAs (miRNAs) are key regulators of this network, with the capacity to target multiple messenger RNAs involved in the EndMT process as well as in the regulation of disease progression. Thus, it is highly important to understand the molecular basis of miRNA control of EndMT. This review highlights the current fund of knowledge regarding the known links between miRNAs and the EndMT process, with a focus on the mechanism that regulates associated signaling pathways and discusses the potential for the EndMT as a therapeutic target to treat many diseases.

MiR-18a regulates myoblasts proliferation by targeting Fgf1

MiRNAs play an important role in cell proliferation, apoptosis, and differentiation. MiR-18a is increasingly being recognized as a regulator of cancer pathogenesis. Here, we discovered that miR-18a participates in myoblasts proliferation. Expression of miR-18a was downregulated with the differentiation of C2C12 myoblasts. Overexpression of miR-18a affected the proliferation of C2C12 cells, primary myoblasts and RD cells. MiR-18a influenced the expression of cell cycle-related genes. Using TargetScan 6.2, we found that the 3’ untranslated region (UTR) of the mouse Fgf1 gene contains complementary sequences to miR-18a. Using a siRNA, we confirmed that the reduction in the Fgf1 levels inhibited proliferation of C2C12 cells. Therefore, our results show that miR-18a participates in the regulation of proliferation by partly decreasing the expression of Fgf1.

MicroRNA Control of TGF-β Signaling

Transcriptional and post-transcriptional regulation shapes the transcriptome and proteome changes induced by various cellular signaling cascades. MicroRNAs (miRNAs) are small regulatory RNAs that are approximately 22 nucleotides long, which direct the post-transcriptional regulation of diverse target genes and control cell states. Transforming growth factor (TGF)-β family is a multifunctional cytokine family, which plays many regulatory roles in the development and pathogenesis of diverse diseases, including fibrotic disease, cardiovascular disease and cancer. Previous studies have shown that the TGF-β pathway includes the miRNA pathway as an important component of its downstream signaling cascades. Multiple studies of epithelial–mesenchymal transition (EMT)-related miRNAs have highlighted that miRNAs constitute the intrinsic bistable molecular switches of cell states by forming double negative feedback loops with EMT-inducing transcription factors. This may be important for understanding the reversibility of EMT at the single-cell level, the presence of distinct EMT transition states and the intra- and inter-tumor heterogeneity of cancer cell phenotypes. In the present review, I summarize the connection between TGF-β signaling and the miRNA pathway, placing particular emphasis on the regulation of miRNA expression by TGF-β signaling, the modulation of TGF-β signaling by miRNAs, the miRNA-mediated modulation of EMT and endothelial–mesenchymal transition as well as the crosstalk between miRNA and TGF-β pathways in the tumor microenvironment.

MicroRNA-495 inhibits the high glucose-induced inflammation, differentiation and extracellular matrix accumulation of cardiac fibroblasts through downregulation of NOD1

Background

MicroRNAs (miRNAs) have physiological and pathophysiological functions that are involved in the regulation of cardiac fibrosis. This study aimed to investigate the effects of miR-495 on high glucose-induced cardiac fibrosis in human cardiac fibroblasts (CFs) and to establish the mechanism underlying these effects.

Methods

Human CFs were transfected with an miR-495 inhibitor or mimic and incubated with high glucose. The levels of NOD1 and miR-495 were then determined via quantitative RT-PCR. Pro-inflammatory cytokine levels, cell differentiation and extracellular matrix accumulation were respectively detected using ELISA, quantitative RT-PCR and western blot assays. The luciferase reporter assay, quantitative RT-PCR and western blot were used to explore whether NOD1 was a target of miR-495. The effects of miR-495 on the NF-κB and TGF-β1/Smad signaling pathways were also detected via western blot.

Results

Our results show that high glucose can significantly increase the expression of NOD1 in a time-dependent manner. Upregulation of miR-495 significantly alleviated the high glucose-induced increases in cell differentiation and collagen accumulation of CFs. Moreover, the bioinformatics analysis predicted that NOD1 was a potential target gene for miR-495. The luciferase reporter assay showed that miR-495 can directly target NOD1. The introduction of miR-495 could significantly inhibit the high glucose-activated NF-κB and TGF-β1/Smad signaling pathways.

Conclusion

Upregulation of miR-495 ameliorates the high glucose-induced inflammatory, cell differentiation and extracellular matrix accumulation of human CFs by modulating both the NF-κB and TGF-β1/Smad signaling pathways through downregulation of NOD1 expression. These results provide further evidence for the protective effect of miR-495 overexpression in cases of high glucose-induced cardiac fibrosis.

lncRNA PFAL promotes lung fibrosis through CTGF by competitively binding miR-18a

Idiopathic pulmonary fibrosis (IPF) is a chronic, progressive, fibrotic parenchymal lung disease of unknown etiology and lacks an effective intervention. Long noncoding RNAs (lncRNAs) participate in organ fibrosis and various pulmonary diseases, but the role of lncRNAs in lung fibrosis is not fully understood. In the present study, we identified that lncRNA NONMMUT021928, designated as pulmonary fibrosis-associated lncRNA (PFAL), was up-regulated in the lungs of mice with experimental lung fibrosis, and in TGF-β1-induced fibrotic lung fibroblasts. Further study showed that overexpression of PFAL promoted cell proliferation, migration, and fibroblast-myofibroblast transition. Overexpression further resulted in extracellular matrix deposition and fibrogenesis in lung fibroblasts through regulation of microRNA-18a (miR-18a). Importantly, knockdown of PFAL alleviated lung fibrosis both in vitro and in vivo. Mechanistically, our study showed that PFAL promoted lung-fibroblast activation and fibrogenesis by acting as a competing endogenous RNA for miR-18a: forced expression of PFAL inhibited the expression and activity of miR-18a, whereas silencing of PFAL had the opposite effect. Furthermore, we found that miR-18a was decreased during lung fibrosis in vitro and in vivo, as well as in patients with IPF. Moreover, knockdown of miR-18a led to fibrogenesis in lung fibroblasts, whereas enhanced expression of miR-18a attenuated TGF-β1-induced lung fibrosis by directly targeting the regulation of connecting tissue growth factor. Taken together, these results revealed the effect and mechanism of lncRNA PFAL in pulmonary fibrosis and suggested that PFAL depletion may provide a novel strategy for the treatment of lung fibrosis.-Li, X., Yu, T., Shan, H., Jiang, H., Sun, J., Zhao, X., Su, W., Yang, L., Shan, H., Liang, H. lncRNA PFAL promotes lung fibrosis through CTGF by competitively binding miR-18a.

Long non-coding RNA FENDRR reduces prostate cancer malignancy by competitively binding miR-18a-5p with RUNX1

CONTEXT

Prostate cancer (PCa) is one of the most commonly diagnosed malignancy in men in the western world.

OBJECTIVE

We aim to investigate the biological role of long non-coding RNA FENDRR and its mechanism in PCa.

MATERIALS AND METHODS

We determined the expression of FENDRR and miR-18a-5p in PCa tissues and examined the regulatory mechanism in PCa cell lines.

RESULTS

FENDRR transcripts in human PCa tissues were significantly decreased compared with the normal controls. Reduced expression of FENDRR was correlated with the increase of pathological degree and poor prognosis in PCa patients. Upregulation of FENDRR inhibited cell proliferation, increased apoptosis and decreased invasion and migration ability, which was inhibited by miR-18a-5p mimic. Knockdown of FENDRR resulted in a significant increase of PCa cell proliferation and decrease of apoptosis and this effect was inhibited miR-18a-5p inhibitor. FENDRR and RUNX1 contain potential target sites for miR-18a-5p. miR-18a-5p mimic inhibited RUNX1 expression and luciferase activity. FENDRR could increase RUNX1 expression, which was inhibited by miR-18a-5p. The effect of FENDRR on cell proliferation, apoptosis and invasion and migration ability was suppressed by silence of RUNX1.

DISCUSSION AND CONCLUSION

These results position FENDRR/miR-18a-5p/RUNX1 as a potential therapeutic target and biomarker for PCa.