Inhibition of miR‑155‑5p attenuates the valvular damage induced by rheumatic heart disease

Emerging role of sphingolipids and extracellular vesicles in development and therapeutics of cardiovascular diseases

Sphingolipids are eighteen carbon alcohol lipids synthesized from non-sphingolipid precursors in the endoplasmic reticulum (ER). The sphingolipids serve as precursors for a vast range of moieties found in our cells that play a critical role in various cellular processes, including cell division, senescence, migration, differentiation, apoptosis, pyroptosis, autophagy, nutrition intake, metabolism, and protein synthesis. In CVDs, different subclasses of sphingolipids and other derived molecules such as sphingomyelin (SM), ceramides (CERs), and sphingosine-1-phosphate (S1P) are directly related to diabetic cardiomyopathy, dilated cardiomyopathy, myocarditis, ischemic heart disease (IHD), hypertension, and atherogenesis. Several genome-wide association studies showed an association between genetic variations in sphingolipid pathway genes and the risk of CVDs. The sphingolipid pathway plays an important role in the biogenesis and secretion of exosomes. Small extracellular vesicles (sEVs)/ exosomes have recently been found as possible indicators for the onset of CVDs, linking various cellular signaling pathways that contribute to the disease progression. Important features of EVs like biocompatibility, and crossing of biological barriers can improve the pharmacokinetics of drugs and will be exploited to develop next-generation drug delivery systems. In this review, we have comprehensively discussed the role of sphingolipids, and sphingolipid metabolites in the development of CVDs. In addition, concise deliberations were laid to discuss the role of sEVs/exosomes in regulating the pathophysiological processes of CVDs and the exosomes as therapeutic targets.

Anti-IL-17 Inhibits PINK1/Parkin Autophagy and M1 Macrophage Polarization in Rheumatic Heart Disease

Rheumatic heart disease (RHD) is an important and preventable cause of cardiovascular death and disability, but the lack of clarity about its exact mechanisms makes it more difficult to find alternative methods or prevention and treatment. We previously demonstrated that increased IL-17 expression plays a crucial role in the development of RHD-related valvular inflammatory injury. Macrophage autophagy/polarization may be a pro-survival strategy in the initiation and resolution of the inflammatory process. This study investigated the mechanism by which IL-17 regulates autophagy/polarization activation in macrophages. A RHD rat model was generated, and the effects of anti-IL-17 and 3-methyladenine (3-MA) were analyzed. The molecular mechanisms underlying IL-17-induced macrophage autophagy/polarization were investigated via in vitro experiments. In our established RHD rat model, the activation of the macrophage PINK1/Parkin autophagic pathway in valve tissue was accompanied by M1 macrophage infiltration, and anti-IL-17 treatment inhibited autophagy and reversed macrophage inflammatory infiltration, thereby attenuating endothelial-mesenchymal transition (EndMT) in the valve tissue. The efficacy of 3-MA treatment was similar to that of anti-IL-17 treatment. Furthermore, in THP-1 cells, the pharmacological promotion of autophagy by IL-17 induced M1-type polarization, whereas the inhibition of autophagy by 3-MA reversed this process. Mechanistically, silencing PINK1 in THP-1 blocked autophagic flux. Moreover, IL-17-induced M1-polarized macrophages promoted EndMT in HUVECs. This study revealed that IL-17 plays an important role in EndMT in RHD via the PINK1/Parkin autophagic pathway and macrophage polarization, providing a potential therapeutic target.

Challenges and promise of targeting miRNA in rheumatic diseases: a computational approach to identify miRNA association with cell types, cytokines, and disease mechanisms

MicroRNAs (miRNAs) are small non-coding RNAs that alter the expression of target genes at the post-transcriptional level, influencing diverse outcomes in metabolism, cell differentiation, proliferation, cell survival, and cell death. Dysregulated miRNA expression is implicated in various rheumatic conditions, including ankylosing spondylitis (AS), gout, juvenile idiopathic arthritis (JIA), osteoarthritis (OA), psoriatic arthritis, rheumatoid arthritis (RA), Sjogren's syndrome, systemic lupus erythematosus (SLE) and systemic sclerosis. For this review, we used an open-source programming language- PowerShell, to scan the massive number of existing primary research publications on PubMed on miRNAs in these nine diseases to identify and count unique co-occurrences of individual miRNAs and the disease name. These counts were used to rank the top seven most relevant immuno-miRs based on their research volume in each rheumatic disease. Individual miRNAs were also screened for publication with the names of immune cells, cytokines, and pathological processes involved in rheumatic diseases. These occurrences were tabulated into matrices to identify hotspots for research relevance. Based on this information, we summarize the basic and clinical findings for the top three miRNAs - miR-146, miR-155, and miR-21 - whose relevance spans across multiple rheumatic diseases. Furthermore, we highlight some unique miRNAs for each disease and why some rheumatic conditions lack research in this emerging epigenetics field. With the overwhelming number of publications on miRNAs in rheumatic diseases, this review serves as a 'relevance finder' to guide researchers in selecting miRNAs based on the compiled existing knowledge of their involvement in disease pathogenesis. This approach applies to other disease contexts with the end goal of developing miRNA-based therapeutics.

Detection and management of latent rheumatic heart disease: a narrative review

Rheumatic heart disease (RHD) is a public health concern in many developing nations around the world. Early detection of latent or subclinical RHD can help in reversing mild lesions, retarding disease progression, reducing morbidity and mortality, and improving the quality of life of patients. Echocardiography is the gold-standard method for screening and confirming latent RHD cases. The rates and determinants of progression of latent RHD cases as assessed by echocardiography have been found to be variable through studies. Even though latent RHD has a slow rate of progression, the rate of progression of its subtype, 'definite' RHD, is substantial. A brief training of nonexpert operators on the use of handheld echocardiography with a simplified protocol is an important strategy to scale up the screening program to detect latent cases. Newer advancements in screening, such as deep-learning digital stethoscopes and telehealth services, have provided an opportunity to expand screening programs even in resource-constrained settings. Newer studies have established the efficacy and safety profile of secondary antibiotic prophylaxis in latent RHD. The concerned authorities in endemic regions of the world should work on improving the availability and accessibility of antibiotic prophylaxis.

Inhibition of miR-143-3p alleviates myocardial ischemia reperfusion injury via limiting mitochondria-mediated apoptosis

MicroRNA (miR)-143-3p is a potential regulatory molecule in myocardial ischemia/reperfusion injury (MI/RI), wherein its expression and pathological effects remains controversial. Thus, a mouse MI/RI and cell hypoxia/reoxygenation (H/R) models were built for clarifying the miR-143-3p's role in MI/RI. Following myocardial ischemia for 30 min, mice underwent reperfusion for 3, 6, 12 and 24 h. It was found miR-143-3p increased in the ischemic heart tissue over time after reperfusion. Cardiomyocytes transfected with miR-143-3p were more susceptible to apoptosis. Mechanistically, miR-143-3p targeted B cell lymphoma 2 (bcl-2). And miR-143-3p inhibition reduced cardiomyocytes apoptosis upon H/R, whereas it was reversed by a specific bcl-2 inhibitor ABT-737. Of note, miR-143-3p inhibition upregulated bcl-2 with better mitochondrial membrane potential (Δψm), reduced cytoplasmic cytochrome c (cyto-c) and caspase proteins, and minimized infarction area in mice upon I/R. Collectively, inhibition of miR-143-3p might alleviate MI/RI via targeting bcl-2 to limit mitochondria-mediated apoptosis. To our knowledge, this study further clarifies the miR-143-3p's pathological role in the early stages of MI/RI, and inhibiting miR-143-3p could be an effective treatment for ischemic myocardial disease.

Non-coding RNA mediates endoplasmic reticulum stress-induced apoptosis in heart disease

Apoptosis is a complex and highly self-regulating form of cell death, which is an important cause of the continuous decline in ventricular function and is widely involved in the occurrence and development of heart failure, myocardial infarction, and myocarditis. Endoplasmic reticulum stress plays a crucial role in apoptosis-inducing. Accumulation of misfolded or unfolded proteins causes cells to undergo a stress response called unfolded protein response (UPR). UPR initially has a cardioprotective effect. Nevertheless, prolonged and severe ER stress will lead up to apoptosis of stressed cells. Non-coding RNA is a type of RNA that does not code proteins. An ever-increasing number of studies have shown that non-coding RNAs are involved in regulating endoplasmic reticulum stress-induced cardiomyocyte injury and apoptosis. In this study, the effects of miRNA and LncRNA on endoplasmic reticulum stress in various heart diseases were mainly discussed to clarify their protective effects and potential therapeutic strategies for apoptosis.

Exploration and validation of the influence of angiogenesis-related factors in aortic valve calcification

Over the years, bioinformatics tools have been used to identify functional genes. In the present study, bioinformatics analyses were conducted to explore the underlying molecular mechanisms of angiogenic factors in calcific aortic valve disease (CAVD). The raw gene expression profiles were from datasets GSE153555, GSE83453, and GSE51472, and the angiogenesis-related gene set was from the Gene Set Enrichment Analysis database (GSEA). In this study, R was used to screen for differentially expressed genes (DEGs) and co-expressed genes. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genome (KEGG) Pathway enrichment analysis were performed on DEGs and validated in clinical samples. DEGs in CAVD were significantly enriched in numerous immune response pathways, inflammatory response pathways and angiogenesis-related pathways. Nine highly expressed angiogenesis-related genes were identified, of which secretogranin II (SCG2) was the most critical gene. MiRNA and transcription factors (TFs) networks were established centered on five DEGs, and zinc finger E-box binding homeobox 1 (ZEB1) was the most important transcription factor, verified by PCR, immunohistochemical staining and western blotting experiments. Overall, this study identified key genes and TFs that may be involved in the pathogenesis of CAVD and may have promising applications in the treatment of CAVD.

Mir155 regulates osteogenesis and bone mass phenotype via targeting S1pr1 gene

MicroRNA-155 (miR155) is overexpressed in various inflammatory diseases and cancer, in which bone resorption and osteolysis are frequently observed. However, the role of miR155 on osteogenesis and bone mass phenotype is still unknown. Here, we report a low bone mass phenotype in the long bone of Mir155-Tg mice compared with wild-type mice. In contrast, Mir155-KO mice showed a high bone mass phenotype and protective effect against inflammation-induced bone loss. Mir155-KO mice showed robust bone regeneration in the ectopic and orthotopic model, but Mir155-Tg mice showed compromised bone regeneration compared with the wild-type mice. Similarly, the osteogenic differentiation potential of bone marrow stromal stem cells (BMSCs) from Mir155-KO mice was robust and Mir155-Tg was compromised compared with that of wild-type mice. Moreover, Mir155 knockdown in BMSCs from wild-type mice showed higher osteogenic differentiation potential, supporting the results from Mir155-KO mice. TargetScan analysis predicted sphingosine 1-phosphate receptor-1 (S1pr1) as a target gene of Mir155, which was further confirmed by luciferase assay and Mir155 knockdown. S1pr1 overexpression in BMSCs robustly promoted osteogenic differentiation without affecting cell viability and proliferation. Furthermore, osteoclastogenic differentiation of Mir155-Tg bone marrow-derived macrophages was inhibited compared with that of wild-type mice. Thus, Mir155 showed a catabolic effect on osteogenesis and bone mass phenotype via interaction with the S1pr1 gene, suggesting inhibition of Mir155 as a potential strategy for bone regeneration and bone defect healing.

Analysis of the Research Hotspot of Exosomes in Cardiovascular Disease: A Bibliometric-based Literature Review

OBJECTIVE

To investigate the current status and development trend of research on exosomes in cardiovascular disease (CVD) using bibliometric analysis and to elucidate trending research topics.

METHODS

Research articles on exosomes in CVD published up to April 2022 were retrieved from the Web of Science database. Data were organized using Microsoft Office Excel 2019. CiteSpace 6.1 and VOSviewer 1.6.18 were used for bibliometric analysis and result visualization.

RESULTS

Overall, 256 original research publications containing 190 fundamental research publications and 66 clinical research publications were included. "Extracellular vesicle" was the most frequent research keyword, followed by "microrna," "apoptosis," and "angiogenesis." Most publications were from China (187, 73.05%), followed by the United States (57, 22.27%), the United Kingdom (7, 2.73%), and Japan (7, 2.73%). A systematic review of the publications revealed that myocardial infarction and stroke were the most popular topics and that exosomes and their contents, such as microRNAs (miRNAs), play positive roles in neuroprotection, inhibition of autophagy and apoptosis, promotion of angiogenesis, and protection of cardiomyocytes.

CONCLUSION

Research on exosomes in CVD has attracted considerable attention, with China having the most published studies. Fundamental research has focused on CVD pathogenesis; exosomes regulate the progression of CVD through biological processes, such as the inflammatory response, autophagy, and apoptosis. Clinical research has focused on biomarkers for CVD; studies on using miRNAs in exosomes as disease markers for diagnosis could become a future trend.

Circulating exosome-derived miR-122-5p is a novel biomarker for prediction of postoperative atrial fibrillation

Postoperative atrial fibrillation (POAF) is a frequent complication associated with increased periprocedural mortality and morbidity after cardiac surgery. Our study aimed to identify the difference in exosomal miRNA and further explore its role in the diagnosis of POAF. First, the differentially expressed miRNAs (DEMs) were obtained by high-throughput RNA sequencing. Second, the DEMs target genes were put into gene ontology (GO) and KEGG pathway analysis. Third, real-time quantification PCR (RT-qPCR) was used to verify the DEMs. Finally, we revealed 23 DEMs in POAF patients. Furthermore, analysis of gene function revealed that DEMs may affect atrial structure through many signaling pathways. We also found that miR-122-5p was up-regulated in POAF patients, but there are no significant changes in miR-191-5p, miR-181a-5p, miR-155-5p and miR-151a-5p. Our study revealed that exosomal miRNAs exert enormous potential in evaluating the severity or prognostic of POAF.

Alpha-1-antitrypsin in serum exosomes and pericardial fluid exosomes is associated with severity of rheumatic heart disease

Rheumatic heart disease (RHD) is an autoimmune sequel of pharyngitis and rheumatic fever that leads to permanent heart valve damage, especially the mitral valves. The mitral valves, which are responsible for the binding of auto-antibodies during immune response generation, lead to valve scarring and eventually valves dysfunction. Recently, exosomes (EXOs), the nano-sized vesicles, which range in size from 30 to 150 nm, are reported in various cardiovascular physiological and pathological processes. These vesicles are found in several body fluids such as plasma, serum, and also in cell culture media. Exosomal cargo contains proteins, which are taken up by the recipient cells and modulate the cellular characteristics. The role of exosomal proteins in RHD is still obscure. Hence, the present study has been designed to unveil the exosomal proteins in disease severity during RHD. In this study, the exosomes were isolated from biological fluids (serum and pericardial fluid) of RHD patients as well as from their respective controls. Protein profiling of these isolated exosomes revealed that alpha-1 antitrypsin is up-regulated in the biological fluids of RHD patients. The enhanced levels of exosomal alpha-1 antitrypsin, were further, validated in biological samples and mitral valve tissues of RHD patients, to correlate with the disease severity. These findings suggest an association of increased levels of exosomal alpha-1 antitrypsin with the RHD pathogenesis.

The crosstalk between STAT3 and microRNA in cardiac diseases and protection

Signal transducer and activator of transcription 3 (STAT3), an important transcription factor and signaling molecule, play an important role in cardiac disease and protection. As a transcription factor, STAT3 upregulates anti-oxidative and anti-apoptotic genes but suppresses anti-inflammatory and anti-fibrotic genes in cardiac disease and protection. As a signaling molecule, STAT3 is the downstream or upstream of other molecules for signaling transduction, also activated in cardiac disease and protection. MicroRNAs (miRNAs) are endogenous short non-coding RNAs that regulate mRNA expression at the transcriptional level and prevent protein translation. Recently, STAT3 is reported to be not only the target of miRNA but also the inhibitor or inducer of miRNA to modify the mRNA expression profiles in cardiomyocytes resulting in different effects on cardiac disease and protection. We summarize the current knowledge on STAT3 regulation of individual miRNAs and the modulation of STAT3 by miRNAs in cardiac diseases and protection.

MiR-186-5p Downregulates NAMPT and Functions as a Potential Therapeutic Target for Sepsis-Induced Coagulation Disorders

Purpose

Present study is aimed to explore the role of miR-186-5p in sepsis-induced coagulation disorders and molecular mechanisms.

Methods

Thirty-four sepsis patients and 34 respiratory infection/pneumonia patients were selected in the present study. Polymicrobial sepsis model was created by cecal ligation and puncture (CLP). The mRNA expression was detected by qRT-PCR. Western blot was utilized to measure protein expression. Thromborel S Reagent was applied to measure the prothrombin time (PT). Platelet count of blood was measured via LH 780. ELISA kits were utilized to evaluate the fibrinogen and PAI-1 concentration.

Results

MiR-186-5p expression was lower and nicotinamide phosphoribosyltransferase (NAMPT) mRNA expression was higher in sepsis patients in contrast to control group. Coagulation time was markedly prolonged and platelet count was markedly decreased in CLP mice. In addition, fibrinogen concentration was obviously lower and PAI-1 concentration was obviously higher in CLP mice. MiR-186-5p mimic obviously decreased coagulation time and PAI-1 concentration, while raised platelet count and fibrinogen concentration. Targetscan predicted miR-186-5p might directly regulates NAMPT, and luciferase reporter assay verified this prediction. In addition, miR-186-5p mimic obviously inhibited the mRNA expression of NAMPT. Knockdown of NAMPT improved coagulation dysfunction in sepsis. Overexpression of NAMPT reversed the improvement effect of miR-186-5p on coagulation dysfunction. MiR-186-5p mimic markedly inhibited NF-κB pathway.

Conclusion

MiR-186-5p inhibited sepsis-induced coagulation disorders via targeting NAMPT and inactivating NF-κB pathway.

Exosomes and Exosomal Non-coding RNAs Are Novel Promises for the Mechanism-Based Diagnosis and Treatments of Atrial Fibrillation

Atrial fibrillation (AF) is the most common arrhythmia worldwide and has a significant impact on human health and substantial costs. Currently, there is a lack of accurate biomarkers for the diagnosis and prognosis of AF. Moreover, the long-term efficacy of the catheter ablation in the AF is unsatisfactory. Therefore, it is necessary to explore new biomarkers and treatment strategies for the mechanism-based AF. Exosomes are nano-sized biovesicles released by nearly all types of cells. Since the AF would be linked to the changes of the atrial cells and their microenvironment, and the AF would strictly influence the exosomal non-coding RNAs (exo-ncRNAs) expression, which makes them as attractive diagnostic and prognostic biomarkers for the AF. Simultaneously, the exo-ncRNAs have been found to play an important role in the mechanisms of the AF and have potential therapeutic prospects. Although the role of the exo-ncRNAs in the AF is being actively investigated, the evidence is still limited. Furthermore, there is a lack of consensus regarding the most appropriate approach for exosome isolation and characterization. In this article, we reviewed the new methodologies available for exosomes biogenesis, isolation, and characterization, and then discussed the mechanism of the AF and various levels and types of exosomes relevant to the AF, with the special emphasis on the exo-ncRNAs in the diagnosis, prognosis, and treatment of the mechanism-based AF.

MicroRNAs in Valvular Heart Diseases: Biological Regulators, Prognostic Markers and Therapeutical Targets

miRNAs have recently attracted investigators’ interest as regulators of valvular diseases pathogenesis, diagnostic biomarkers, and therapeutical targets. Evidence from in-vivo and in-vitro studies demonstrated stimulatory or inhibitory roles in mitral valve prolapse development, aortic leaflet fusion, and calcification pathways, specifically osteoblastic differentiation and transcription factors modulation. Tissue expression assessment and comparison between physiological and pathological phenotypes of different disease entities, including mitral valve prolapse and mitral chordae tendineae rupture, emerged as the best strategies to address miRNAs over or under-representation and thus, their impact on pathogeneses. In this review, we discuss the fundamental intra- and intercellular signals regulated by miRNAs leading to defects in mitral and aortic valves, congenital heart diseases, and the possible therapeutic strategies targeting them. These miRNAs inhibitors are comprised of antisense oligonucleotides and sponge vectors. The miRNA mimics, miRNA expression vectors, and small molecules are instead possible practical strategies to increase specific miRNA activity. Advantages and technical limitations of these new drugs, including instability and complex pharmacokinetics, are also presented. Novel delivery strategies, such as nanoparticles and liposomes, are described to improve knowledge on future personalized treatment directions.

Interference with the expression of S1PR1 or STAT3 attenuates valvular damage due to rheumatic heart disease

Rheumatic heart disease (RHD) affects numerous individuals annually; however, its pathogenesis remains unclear. The sphingosine 1‑phosphate receptor 1 (S1PR1) and signal transducer and activator of transcription 3 (STAT3) have recently been shown to be involved in valvular damage via the promotion of the differentiation of T helper 17 (Th17) cells during the development of RHD‑induced valvular damage. The present study investigated whether altering the expression of S1PR1 or STAT3 attenuates valvular damage due to RHD. Inactivated group A streptococcus (GAS) was used to establish a rat model of RHD. Recombinant adeno‑associated viral vectors carrying an S1PR1 overexpression sequence were used to overexpress S1PR1. STAT3 small interfering RNA (STAT3‑siRNA) was used to inhibit STAT3 expression. Reverse transcription‑quantitative PCR (RT‑qPCR) was performed to detect the mRNA expression of S1PR1, STAT3, collagen type III α1 chain (Col3a1) and fibroblast‑specific protein 1. Western blotting (WB) and immunohistochemistry were used to detect the levels of S1PR1, STAT3, phosphorylated (p‑) STAT3, and retinoic acid‑related orphan receptor γT (RORγt) proteins. Enzyme‑linked immunosorbent assays (ELISAs) and immunohistochemistry were used to detect the levels of interleukin (IL)‑6 and IL‑17. Hematoxylin and eosin (H&E) staining and Sirius Red staining were performed to evaluate the degree of inflammation and fibrosis in the valvular tissues. S1PR1 expression was decreased in the valvular tissues of the rats with RHD. The levels of IL‑6, IL‑17 and p‑STAT3 in the rats with RHD were increased. The degree of valvular inflammation and fibrosis in the rats with RHD was also increased. The overexpression of S1PR1 and the inhibition of STAT3 reduced the total p‑STAT3 level, resulting in decreased levels of IL‑6, IL‑17 and RORγt, and a reduced degree of valvular inflammation and fibrosis. These results suggest that the expression of S1PR1 and STAT3 may be involved in valvular tissue damage due to RHD. Thus, strategies designed to interfere with the expression of S1PR1 or STAT3 may affect the expression of Th17 cell‑related cytokines and may thus attenuate valvular damage due to RHD.

S1P Increases VEGF Production in Osteoblasts and Facilitates Endothelial Progenitor Cell Angiogenesis by Inhibiting miR-16-5p Expression via the c-Src/FAK Signaling Pathway in Rheumatoid Arthritis

Angiogenesis is a critical process in the formation of new capillaries and a key participant in rheumatoid arthritis (RA) pathogenesis. Vascular endothelial growth factor (VEGF) stimulation of endothelial progenitor cells (EPCs) facilitates angiogenesis and the progression of RA. Phosphorylation of sphingosine kinase 1 (SphK1) produces sphingosine-1-phosphate (S1P), which increases inflammatory cytokine production, although the role of S1P in RA angiogenesis is unclear. In this study, we evaluated the impact of S1P treatment on VEGF-dependent angiogenesis in osteoblast-like cells (MG-63 cells) and the significance of SphK1 short hairpin RNA (shRNA) on S1P production in an in vivo model. We found significantly higher levels of S1P and VEGF expression in synovial fluid from RA patients compared with those with osteoarthritis by ELISA analysis. Treating MG-63 cells with S1P increased VEGF production, while focal adhesion kinase (FAK) and Src siRNAs and inhibitors decreased VEGF production in S1P-treated MG-63 cells. Conditioned medium from S1P-treated osteoblasts significantly increased EPC tube formation and migration by inhibiting miR-16-5p synthesis via proto-oncogene tyrosine-protein kinase src (c-Src) and FAK signaling in chick chorioallantoic membrane (CAM) and Matrigel plug assays. Infection with SphK1 shRNA reduced angiogenesis, articular swelling and cartilage erosion in the ankle joints of mice with collagen-induced arthritis (CIA). S1P appears to have therapeutic potential in RA treatment.

Functional Role of miR-155 in the Pathogenesis of Diabetes Mellitus and Its Complications

Substantial evidence indicates that microRNA-155 (miR-155) plays a crucial role in the pathogenesis of diabetes mellitus (DM) and its complications. A number of clinical studies reported low serum levels of miR-155 in patients with type 2 diabetes (T2D). Preclinical studies revealed that miR-155 partakes in the phenotypic switch of cells within the islets of Langerhans under metabolic stress. Moreover, miR-155 was shown to regulate insulin sensitivity in liver, adipose tissue, and skeletal muscle. Dysregulation of miR-155 expression was also shown to predict the development of nephropathy, neuropathy, and retinopathy in DM. Here, we systematically describe the reports investigating the role of miR-155 in DM and its complications. We also discuss the recent results from in vivo and in vitro models of type 1 diabetes (T1D) and T2D, discussing the differences between clinical and preclinical studies and shedding light on the molecular pathways mediated by miR-155 in different tissues affected by DM.

Hsa-miR-155 regulates the cell cycle and barrier function of corneal endothelial cells through E2F2

This study was aimed to determine the role of has-miR-155 and E2F2 on corneal endothelial cells. Real-time quantitative PCR and Western blot assays were carried out to determine the levels of has-miR-155 and E2F2, and Flow cytometry assay was conducted to detect cell cycle. In addition, Targetscan7.2 was adopted to analyze the internal connection between hsa-miR-155 and E2F2, and a dual luciferase reporter gene assay to determine predicted site between has-miR-155 and E2F2. Increased hsa-miR-155 resulted in decreased E2F2, while decreased hsa-miR-155 increased the level of E2F2. In addition, both increased hsa-miR-155 and decreased E2F2 led to an increase in S-phase cells and a decrease in G1-phase cells. Also, they induced an increase in the activity of barrier-related proteins MLCK and ZO-1, an up-regulation of Cyclin D1 and Cyclin E1, and a down-regulation of apoptosis proteins (Caspase 3/Bax/Bim/Bid) whereas decreased hsa-miR-155 led to an opposite change in cells, and decreased E2F2 could offset cell changes caused by increased has-miR-155. In conclusion, Has-miR-155 regulates the cell cycle of corneal endothelial cells and improves their barrier function by down regulating E2F2.

Toward the Effective Bioengineering of a Pathological Tissue for Cardiovascular Disease Modeling: Old Strategies and New Frontiers for Prevention, Diagnosis, and Therapy

Cardiovascular diseases (CVDs) still represent the primary cause of mortality worldwide. Preclinical modeling by recapitulating human pathophysiology is fundamental to advance the comprehension of these diseases and propose effective strategies for their prevention, diagnosis, and treatment. In silico, in vivo, and in vitro models have been applied to dissect many cardiovascular pathologies. Computational and bioinformatic simulations allow developing algorithmic disease models considering all known variables and severity degrees of disease. In vivo studies based on small or large animals have a long tradition and largely contribute to the current treatment and management of CVDs. In vitro investigation with two-dimensional cell culture demonstrates its suitability to analyze the behavior of single, diseased cellular types. The introduction of induced pluripotent stem cell technology and the application of bioengineering principles raised the bar toward in vitro three-dimensional modeling by enabling the development of pathological tissue equivalents. This review article intends to describe the advantages and disadvantages of past and present modeling approaches applied to provide insights on some of the most relevant congenital and acquired CVDs, such as rhythm disturbances, bicuspid aortic valve, cardiac infections and autoimmunity, cardiovascular fibrosis, atherosclerosis, and calcific aortic valve stenosis.

Myocardial ischemia-reperfusion induced cardiac extracellular vesicles harbour proinflammatory features and aggravate heart injury

Extracellular vesicles (EVs) curb important biological functions. We previously disclosed that ischemia-reperfusion (IR) induces increased release of EVs (IR-EVs) in the heart. However, the role of IR-EVs in IR pathological process remains poorly understood. Here we found that adoptive transfer of IR-EVs aggravated IR induced heart injury, and EV inhibition by GW4869 reduced the IR injury. Our in vivo and in vitro investigations substantiated that IR-EVs facilitated M1-like polarization of macrophages with increased expression of proinflammatory cytokines. Further, we disclosed the miRNA profile in cardiac EVs and confirmed the enrichment of miRNAs, such as miR-155-5p in IR-EVs compared to EVs from the sham heart (S-EVs). In particular, IR-EVs transferred miR-155-5p to macrophages and enhanced the inflammatory response through activating JAK2/STAT1 pathway. Interestingly, IR-EVs not only boosted the local inflammation in the heart, but even triggered systemic inflammation in distant organs. Taken together, we newly identify an IR-EVs-miR-155-5p-M1 polarization axis in the heart post IR. The EVs derived from IR-injured heart contribute to both local and systemic inflammation. Importantly, EV inhibition by GW4869 is supposed to be a promising therapeutic strategy for IR injury.

The Role of Exosomes and Exosomal MicroRNA in Cardiovascular Disease

Exosomes are small vesicles (30–150 nm in diameter) enclosed by a lipid membrane bilayer, secreted by most cells in the body. They carry various molecules, including proteins, lipids, mRNA, and other RNA species, such as long non-coding RNA, circular RNA, and microRNA (miRNA). miRNAs are the most numerous cargo molecules in the exosome. They are endogenous non-coding RNA molecules, approximately 19–22-nt-long, and important regulators of protein biosynthesis. Exosomes can be taken up by neighboring or distant cells, where they play a role in post-transcriptional regulation of gene expression by targeting mRNA. Exosomal miRNAs have diverse functions, such as participation in inflammatory reactions, cell migration, proliferation, apoptosis, autophagy, and epithelial–mesenchymal transition. There is increasing evidence that exosomal miRNAs play an important role in cardiovascular health. Exosomal miRNAs are widely involved in the occurrence and development of cardiovascular diseases, such as atherosclerosis, acute coronary syndrome, heart failure (HF), myocardial ischemia reperfusion injury, and pulmonary hypertension. In this review, we present a systematic overview of the research progress into the role of exosomal miRNAs in cardiovascular diseases, and present new ideas for the diagnosis and treatment of cardiovascular diseases.

Experimental Rodent Models of Cardiovascular Diseases

Cardiovascular diseases, as the most common non-communicable disease in the world, cause a high mortality rate today and bring a serious medical burden to countries worldwide, especially in low- and middle-income countries. Experimental rodent models are widely used for cardiovascular diseases researches due to the effective simulation of human cardiovascular diseases, strong reproductive ability, and easy detection. Herein, we will summarize the pathological manifestations of common cardiovascular diseases and illustrate the establishment of corresponding experimental rodent models in detail.

Signalling pathways implicated in the pathogenesis of rheumatic heart disease (Review)

Rheumatic heart disease (RHD) is frequently encountered in underdeveloped areas and primarily affects patients under the age of 40 years old. The pathogenesis of RHD has yet to be fully elucidated and surgical treatment remains the only option, which is expensive and technically demanding for patients in less developed areas. Signalling pathways are crucial for the occurrence and development of several diseases, and researchers worldwide have made progress in elucidating the signalling pathways associated with the pathogenesis of RHD. The aim of the present review was to discuss 6 signalling pathways implicated in the pathogenesis of RHD, summarize the methods and progress of these studies and propose future research directions. Important information on the pathogenesis of RHD according to the current progress of signalling pathway studies was also summarized, in the hope that this review may serve as a reference for future research on the signalling pathways involved in the pathogenesis of RHD.

Activation of activin/Smad2 and 3 signaling pathway and the potential involvement of endothelial‑mesenchymal transition in the valvular damage due to rheumatic heart disease

Rheumatic heart disease (RHD) is an autoimmune disease caused by rheumatic fever following group A hemolytic streptococcal infection and primarily affects the mitral valve. RHD is currently a major global health problem. However, the exact pathological mechanisms associated with RHD-induced cardiac valve damage remain to be elucidated. The endothelial-mesenchymal transition (EndMT) serves a key role in a number of diseases with an important role in cardiac fibrosis and the activin/Smad2 and 3 signaling pathway is involved in regulating the EndMT. Nevertheless, there are no studies to date, to the best of the authors' knowledge, investigating the association between RHD and EndMT. Thus, the aim of the current study was to investigate the potential role of EndMT in cardiac valve damage and assess whether activin/Smad2 and 3 signaling was activated during RHD-induced valvular injury in a rat model of RHD induced by inactivated Group A streptococci and complete Freund's adjuvant. Inflammation and fibrosis were assessed by hematoxylin and eosin and Sirius red staining. Serum cytokine and rheumatoid factor levels were measured using ELISA kits. Expression levels of activin/Smad2 and 3 signaling pathway-related factors [activin A, Smad2, Smad3, phosphorylated (p-)Smad2 and p-Smad3], EndMT-related factors [lymphoid enhancer factor-1 (LEF-1), Snail1, TWIST, zinc finger E-box-binding homeobox (ZEB)1, ZEB2, α smooth muscle actin (α-SMA) and type I collagen α 1 (COL1A1)], apoptosis-related markers (BAX and cleaved caspase-3) and valvular inflammation markers (NF-κB and p-NF-κB) were detected using reverse transcription-quantitative PCR and western blot analyses. Compared with the control group, the degree of valvular inflammation and fibrosis, serum levels of IL-6, IL-17, TNF-α and expression of apoptosis-related markers (BAX and cleaved caspase-3) and valvular inflammation marker (p-NF-κB), activin/Smad2 and 3 signaling pathway-related factors (activin A, p-Smad2 and p-Smad3), EndMT-related factors (LEF-1, Snail1, TWIST, ZEB 1, ZEB2, α-SMA and COL1A1) were significantly increased in the RHD group. These results suggested that the activin/Smad2 and 3 signaling pathway was activated during the development of valvular damage caused by RHD and that the EndMT is involved in RHD-induced cardiac valve damage.