Dysregulation of miR-342-3p in plasma exosomes derived from convalescent AMI patients and its consequences on cardiac repair

The Role of Cardiac Troponin and Other Emerging Biomarkers Among Athletes and Beyond: Underlying Mechanisms, Differential Diagnosis, and Guide for Interpretation

Cardiovascular (CV) disease remains the leading cause of morbidity and mortality worldwide, highlighting the necessity of understanding its underlying molecular and pathophysiological pathways. Conversely, physical activity (PA) and exercise are key strategies in reducing CV event risks. Detecting latent CV conditions in apparently healthy individuals, such as athletes, presents a unique challenge. The early identification and treatment of CV disorders are vital for long-term health and patient survival. Cardiac troponin is currently the most commonly used biomarker for assessing CV changes in both athletes and the general population. However, there remains considerable debate surrounding the mechanisms underlying exercise-induced troponin elevations and its release in non-ischemic contexts. Thus, there is a pressing need to identify and implement more sensitive and specific biomarkers for CV disorders in clinical practice. Indeed, research continues to explore reliable biomarkers for evaluating the health of athletes and the effectiveness of physical exercise. It is essential to analyze current evidence on troponin release in non-ischemic conditions, post-strenuous exercise, and the complex biological pathways that influence its detection. Furthermore, this study summarizes current research on cytokines and exosomes, including their physiological roles and their relevance in various CV conditions, especially in athletes. In addition, this paper gives special attention to underlying mechanisms, potential biomarkers, and future perspectives.

MIAT promotes myofibroblastic activities and transformation in oral submucous fibrosis through sponging the miR-342-3p/SOX6 axis

Oral submucous fibrosis (OSF) is an oral potentially malignant disorder that is closely related to the habit of areca nut chewing. Long non-coding RNA (lncRNA) myocardial infarction-associated transcript (MIAT) has been identified as an essential regulator in the fibrosis progression. However, the role of MIAT in the development of OSF remains unknown. The transcriptomic profile showed that MIAT is significantly overexpressed in the OSF cohort, with a positive correlation to fibrotic markers. The silencing of MIAT expression in primary buccal mucosal fibroblasts (BMFs) markedly inhibited arecoline-induced myofibroblast transformation. Mechanistically, MIAT functioned as a miR-342-3p sponge and suppressed the inhibitory effect of miR-342-3p on SOX6 mRNA, thereby reinstating SOX6 expression. Subsequent RNA expression rescue experiments confirmed that MIAT enhanced resistance to apoptosis and facilitated myofibroblastic properties such as cell mobility and collagen gel contraction by regulating the miR-342-3p/SOX6 axis. Taken together, these results suggest that the abnormal upregulation of MIAT is important in contributing persistent activation of myofibroblasts in fibrotic tissue, which may result from prolonged exposure to the constituents of areca nut. Furthermore, our findings demonstrated that therapeutic avenues that target the MIAT/miR-342-3p/SOX6 axis may be a promising approach for OSF treatments.

Research progress of exosomes from different sources in myocardial ischemia

Ischemic heart disease refers to the imbalance between the supply and demand of myocardial blood; it has various causes and results in a class of clinical diseases characterized by myocardial ischemia (MI). In recent years, the incidence of cardiovascular disease has become higher and higher, and the number of patients with ischemic heart disease has also increased year by year. Traditional treatment methods include drug therapy and surgical treatment, both of which have limitations. The former maybe develop risks of drug resistance and has more significant side effects, while the latter may damage blood vessels and risk infection. At this stage, a new cell-free treatment method needs to be explored. Many research results have shown that exosomes from different cell sources can protect the ischemic myocardium via intercellular action methods, such as promoting angiogenesis, inhibiting myocardial fibrosis, apoptosis and pyroptosis, and providing a new basis for the treatment of MI. In this review, we briefly introduce the formation and consequences of myocardial ischemia and the biology of exosomes, and then focus on the role and mechanism of exosomes from different sources in MI. We also discuss the role and mechanism of exosomes pretreated with Chinese and Western medicines on myocardial ischemia. We also discuss the potential of exosomes as diagnostic markers and therapeutic drug for MI.

Circulating extracellular vesicles as biomarkers in the diagnosis, prognosis and therapy of cardiovascular diseases

Cardiovascular disease (CVD) ranks among the primary contributors to worldwide mortality. Hence, the importance of constant research on new circulating biomarkers for the improvement of early diagnosis and prognostication of different CVDs and the development and refinement of therapeutic measures is critical. Extracellular vesicles (EV) have a great potential as diagnostic and prognostic markers, as they represent their parent cell by enclosing cell-specific molecules, which can differ in quality and quantity based on cell state. Assuming that all cell types of the cardiovascular system are capable of releasing EV into circulation, an emerging body of evidence has investigated the potential role of serum- or plasma-derived EV in CVD. Comprehensive research has unveiled alterations in EV quantity and EV-bound cargo in the form of RNA, proteins and lipids in the context of common CVDs such as coronary artery disease, atrial fibrillation, heart failure or inflammatory heart diseases, highlighting their diagnostic and prognostic relevance. In numerous in vitro and in vivo models, EV also showed promising therapeutic potential. However, translation of EV studies to a preclinical or clinical setting has proven to be challenging. This review is intended to provide an overview of the most relevant studies in the field of serum or plasma-derived EV.

miR-24-3p and miR-484 are potential biomarkers for neurodegeneration in multiple sclerosis

Multiple sclerosis (MS) is a complex, neurodegenerative chronic disorder. Circulating diagnostic biomarkers for MS have remained elusive, and those proposed so far have limited sensitivity and specificity to MS. Plasma-circulating microRNAs (miRNAs) have advantageous biochemical and physiological attributes that can be utilized in clinical testing and disease monitoring. MS miRNA expression microarray datasets analysis resulted in four candidate miRNAs that were assessed for their expression in a separate MS case-control study. Only miR-24-3p was downregulated in all MS patients compared to healthy controls. MiR-484 was significantly upregulated in relapsing-remitting MS (RRMS) patients compared to healthy controls. Mir-146-5p and miR-484 were significantly downregulated in secondary-progressive MS (SPMS) compared to RRMS. MiR-484 downregulation was associated with worsening disability and increased lipocalin-2 levels. Mir-342-3p and miR-24-3p downregulation were associated with increased semaphorin-3A levels in MS and RRMS patients. In conclusion, mir-24-3p downregulation is diagnostic of MS, and mir-484 upregulation and downregulation are potential biomarkers for RRMS and SPMS conversion, respectively. The differential expression of miR-146a-3p in MS subtypes suggests its potential as an SPMS transition biomarker. The association of downregulated mir-24-3p and mir-484 with increased neurodegeneration biomarkers suggests they play a role in MS pathogenesis and neurodegeneration.

CircTAOK1 regulates high glucose induced inflammation, oxidative stress, ECM accumulation, and apoptosis in diabetic nephropathy via targeting miR-142-3p/SOX6 axis

BACKGROUND

Diabetic nephropathy (DN) is a complication caused by diabetes. Circular RNAs (circRNAs) are a kind of RNA with a closed circular structure, which has high stability and is involved in many disease-related processes. The mechanism of circRNA TAO kinase 1 (circTAOK1) in the pathogenesis and development of DN is unclear.

METHODS

CircTAOK1, microRNA (miR)-142-3p, and sex-determining region Y-box transcription factor 6 (SOX6) mRNA levels were analyzed by real-time quantitative polymerase chain reaction (RT-qPCR). Cell counting kit-8 (CCK8) and 5-ethynyl-2'-deoxyuridine (EdU) assays were used to analyze cell proliferation. Cell cycle distribution was detected by flow cytometry. Western blot assay was performed to test B-cell lymphoma 2 (Bcl-2), Bcl-2 associated X (Bax), cleaved-caspase 3, and fibronectin (FN), collagen I (Col I), and collagen IV (Col IV) protein levels. ELISA assay was used to measure interleukin 1β (IL-1β), interleukin 6 (IL-6), and tumor necrosis factor (TNF-α) levels. The reactive oxygen species (ROS) and malondialdehyde (MDA) levels and the superoxide dismutase (SOD) activity were assessed by the corresponding kits. And the correlation between miR-142-3p and circTAOK1 or SOX6 was confirmed by dual luciferase reporter assay, RNA immunoprecipitation assay and RNA pull down assay.

RESULTS

CircTAOK1 and SOX6 expression levels were up-regulated, while miR-142-3p expression was down-regulated in DN serum and HG-treated HK-2 cells. Knockdown of circTAOK1 could inhibit cell injury of HG-induced HK-2 cells. The inhibitory effect of circTAOK1 knockdown on HG-induced HK-2 cell injury was restored by miR-142-3p downregulation. CircTAOK1 acted as a sponge for miR-142-3p, and SOX6 was targeted by miR-142-3p. The overexpression of SOX6 could recover the effect of miR-142-3p overexpression on HG-induced HK-2 cell injury. CircTAOK1 regulated the expression of SOX6 by targeting miR-142-3p.

CONCLUSION

CircTAOK1 knockdown inhibited HG-induced HK-2 cell damage in DN by the miR-142-3p/SOX6 axis.

Unraveling the Signaling Dynamics of Small Extracellular Vesicles in Cardiac Diseases

Effective intercellular communication is essential for cellular and tissue balance maintenance and response to challenges. Cellular communication methods involve direct cell contact or the release of biological molecules to cover short and long distances. However, a recent discovery in this communication network is the involvement of extracellular vesicles that host biological contents such as proteins, nucleic acids, and lipids, influencing neighboring cells. These extracellular vesicles are found in body fluids; thus, they are considered as potential disease biomarkers. Cardiovascular diseases are significant contributors to global morbidity and mortality, encompassing conditions such as ischemic heart disease, cardiomyopathies, electrical heart diseases, and heart failure. Recent studies reveal the release of extracellular vesicles by cardiovascular cells, influencing normal cardiac function and structure. However, under pathological conditions, extracellular vesicles composition changes, contributing to the development of cardiovascular diseases. Investigating the loading of molecular cargo in these extracellular vesicles is essential for understanding their role in disease development. This review consolidates the latest insights into the role of extracellular vesicles in diagnosis and prognosis of cardiovascular diseases, exploring the potential applications of extracellular vesicles in personalized therapies, shedding light on the evolving landscape of cardiovascular medicine.

Mechanisms and therapeutic strategies of extracellular vesicles in cardiovascular diseases

Cardiovascular disease (CVD) significantly impacts global society since it is the leading cause of death and disability worldwide, and extracellular vesicle (EV)-based therapies have been extensively investigated. EV delivery is involved in mediating the progression of CVDs and has great potential to be biomarker and therapeutic molecular carrier. Besides, EVs from stem cells and cardiac cells can effectively protect the heart from various pathologic conditions, and then serve as an alternative treatment for CVDs. Moreover, the research of using EVs as delivery carriers of therapeutic molecules, membrane engineering modification of EVs, or combining EVs with biomaterials further improves the application potential of EVs in clinical treatment. However, currently there are only a few articles summarizing the application of EVs in CVDs. This review provides an overview of the role of EVs in the pathogenesis and diagnosis of CVDs. It also focuses on how EVs promote the repair of myocardial injury and therapeutic methods of CVDs. In conclusion, it is of great significance to review the research on the application of EVs in the treatment of CVDs, which lays a foundation for further exploration of the role of EVs, and clarifies the prospect of EVs in the treatment of myocardial injury.

Tenogenic differentiation of human tendon-derived stem cells induced by long non-coding RNA LINCMD1 via miR-342-3p/EGR1 axis

BACKGROUND

Tendon-derived stem cells (TDSCs) are proposed as a potential cell-seed for the treatment of tendon injury due to their tenogenic differentiation potential. In this work, we defined the action of long non-coding RNA (lncRNA) muscle differentiation 1 (LINCMD1) in tenogenic differentiation of human TDSCs (hTDSCs).

METHODS

Quantitative real-time PCR (qRT-PCR) was used to assess the levels of LINCMD1, microRNA (miR)-342-3p, and early growth response-1 (EGR1) mRNA. Cell proliferation was detected by the XTT colorimetric assay. Protein expression was quantified by western blot. hTDSCs were grown in an osteogenic medium to induce osteogenic differentiation, and the extent of osteogenic differentiation was assessed by Alizarin Red Staining (ARS). The activity of alkaline phosphatase (ALP) was measured by the ALP Activity Assay Kit. Dual-luciferase reporter and RNA immunoprecipitation (RIP) assays were used to evaluate the direct relationship between miR-342-3p and LINCMD1 or EGR1.

RESULTS

Our results showed that enforced expression of LINCMD1 or suppression of miR-342-3p accelerated the proliferation and tenogenic differentiation and reduced osteogenic differentiation of hTDSCs. LINCMD1 regulated miR-342-3p expression by binding to miR-342-3p. EGR1 was identified as a direct and functional target of miR-342-3p, and knockdown of EGR1 reversed the effects of miR-342-3p suppression on cell proliferation and tenogenic and osteogenic differentiation. Furthermore, the miR-342-3p/EGR1 axis mediated the regulation of LINCMD1 on hTDSC proliferation and tenogenic and osteogenic differentiation.

CONCLUSION

Our study suggests the induction of LINCMD1 in tenogenic differentiation of hTDSCs through miR-342-3p/EGR1 axis.

Plasma exosomes from patients with acute myocardial infarction alleviate myocardial injury by inhibiting ferroptosis through miR-26b-5p/SLC7A11 axis

AIMS

Ferroptosis promotes myocardial injury in acute myocardial infarction (AMI). Increasing evidence suggests the crucial role of exosomes in post-AMI pathophysiological regulation. We aimed to investigate the effects and underlying mechanisms of plasma exosomes derived from patients with AMI in inhibiting ferroptosis after AMI.

METHODS

Plasma exosomes were isolated from controls (Con-Exo) and patients with AMI (MI-Exo). These exosomes were incubated with hypoxic cardiomyocytes or intramyocardially injected into the AMI mice. Histopathological changes, cell viability, and cell death were measured to evaluate the myocardial injury. For the ferroptosis evaluation, iron particle deposition, Fe²⁺, ROS, MDA, GSH, and GPX4 levels were detected. Exosomal miR-26b-5p expression was detected by qRT-PCR, and the targeting relationship between miR-26b-5p and SLC7A11 was confirmed by dual luciferase reporter gene assay. The role of the miR-26b-5p/SLC7A11 axis in the regulation of ferroptosis was validated by rescue experiments in cardiomyocytes.

FINDINGS

Hypoxia-treatment induced ferroptosis and injury in H9C2 cells and primary cardiomyocytes. MI-Exo performed better than Con-Exo in inhibiting hypoxia-induced ferroptosis. miR-26b-5p expression was downregulated in MI-Exo, and miR-26b-5p overexpression significantly eliminated the inhibitory effect of MI-Exo on ferroptosis. Mechanistically, knockdown of miR-26b-5p upregulated SLC7A11/GSH/GPX4 expressions by directly targeting SLC7A11. Moreover, SLC7A11 silencing also reversed the inhibitory effect of MI-Exo on hypoxia-induced ferroptosis. In vivo, MI-Exo significantly inhibited ferroptosis, reduced myocardial injury, and improved the cardiac function of AMI mice.

SIGNIFICANCE

Our findings revealed a novel mechanism of myocardial protection that downregulation of miR-26b-5p in MI-Exo notably upregulated SLC7A11 expression, thereby inhibiting post-AMI ferroptosis and alleviating myocardial injury.

Idebenone attenuates ferroptosis by inhibiting excessive autophagy via the ROS-AMPK-mTOR pathway to preserve cardiac function after myocardial infarction

Cardiovascular diseases (CVDs) are the leading causes of mortality worldwide. As a type of CVDs, myocardial infarction (MI) induces ischemia hypoxia, which leads to excessive reactive oxygen species (ROS), resulting in multiple cell deaths and contributing to the subsequent development of heart failure or premature death. Recent evidence indicates that ROS-induced lipid peroxidation promotes autophagy and ferroptosis, leading to the loss of healthy myocardium and resulting in the dysfunction of cardiac tissue. Theoretically, cardiac function would be preserved after MI by inhibiting autophagy and ferroptosis. As an analog of coenzyme Q10 (CoQ10) and a clinically approved drug, idebenone would be used to inhibit ferroptosis and preserve cardiac function due to its capacity to improve mitochondrial physiology with antioxidant and anti-inflammatory properties. Here, we confirmed that the addition of idebenone inhibited H₂O₂-induced and RSL3-induced ferroptosis. Furthermore, the ROS-AMPK-mTOR pathway axis was identified as the signaling pathway that idebenone stimulated to prevent excessive autophagy and consequent ferroptosis. In the MI animal model, idebenone demonstrated a cardioprotective role by regulating ROS-dependent autophagy and inhibiting ferroptosis, which paves the way for the future clinical translation of idebenone in MI management.

Prioritization of microRNA biomarkers for a prospective evaluation in a cohort of myocardial infarction patients based on their mechanistic role using public datasets

Background

MicroRNAs (miR) have proven to be promising biomarkers for several diseases due to their diverse functions, stability and tissue/organ-specific nature. Identification of new markers with high sensitivity and specificity will help in risk reduction in acute myocardial infarction (AMI) patients with chest pain and also prevent future adverse outcomes. Hence the aim of this study was to perform a detailed in silico analysis for identifying the mechanistic role of miRs involved in the pathogenesis/prognosis of AMI for prospective evaluation in AMI patients.

Methods

miR profiling data was extracted from GSE148153 and GSE24591 datasets using the GEO2R gene expression omnibus repository and analyzed using limma algorithm. Differentially expressed miRs were obtained by comparing MI patients with corresponding controls after multiple testing corrections. Data mining for identifying candidate miRs from published literature was also performed. Target prediction and gene enrichment was done using standard bioinformatics tools. Disease specific analysis was performed to identify target genes specific for AMI using open targets platform. Protein-protein interaction and pathway analysis was done using STRING database and Cytoscape platform.

Results and conclusion

The analysis revealed significant miRs like let-7b-5p, let-7c-5p, miR-4505, and miR-342-3p in important functions/pathways including phosphatidylinositol-3-kinase/AKT and the mammalian target of rapamycin, advanced glycation end products and its receptor and renin–angiotensin–aldosterone system by directly targeting angiotensin II receptor type 1, forkhead box protein O1, etc. With this approach we were able to prioritize the miR candidates for a prospective clinical association study in AMI patients of south Indian origin.

The regulatory mechanism and therapeutic potential of transcription factor EB in neurodegenerative diseases

The autophagy-lysosomal pathway (ALP) is involved in the degradation of protein aggregates and damaged organelles. Transcription factor EB (TFEB), a major regulator of ALP, has emerged as a leading factor in addressing neurodegenerative disease pathology, including Alzheimer's disease (AD), Parkinson's disease (PD), PolyQ diseases, and Amyotrophic lateral sclerosis (ALS). In this review, we delineate the regulation of TFEB expression and its functions in ALP. Dysfunctions of TFEB and its role in the pathogenesis of several neurodegenerative diseases are reviewed. We summarize the protective effects and molecular mechanisms of some TFEB-targeted agonists in neurodegenerative diseases. We also offer our perspective on analyzing the pros and cons of these agonists in the treatment of neurodegenerative diseases from the perspective of drug development. More studies on the regulatory mechanisms of TFEB in other biological processes will aid our understanding of the application of TFEB-targeted therapy in neurodegeneration.

Type 2 alveolar epithelial cell-derived circulating extracellular vesicle-encapsulated surfactant protein C as a mediator of cardiac inflammation in COVID-19

Among the countless endeavours made at elucidating the pathogenesis of COVID-19, those aimed at the histopathological alterations of type 2 alveolar epithelial cells (AT2) are of outstanding relevance to the field of lung physiology, as they are the building blocks of the pulmonary alveoli. A merit of high regenerative and proliferative capacity, exocytotic activity resulting in the release of extracellular vesicles (EVs) is particularly high in AT2 cells, especially in those infected with SARS-CoV-2. These AT2 cell-derived EVs, containing the genetic material of the virus, might enter the bloodstream and make their way into the cardiovascular system, where they may infect cardiomyocytes and bring about a series of events leading to heart failure. As surfactant protein C, a marker of AT2 cell activity and a constituent of the lung surfactant complex, occurs abundantly inside the AT2-derived EVs released during the inflammatory stage of COVID-19, it could potentially be used as a biomarker for predicting impending heart failure in those patients with a history of cardiovascular disease.

Inhibition of miR-218-5p reduces myocardial ischemia-reperfusion injury in a Sprague-Dawley rat model by reducing oxidative stress and inflammation through MEF2C/NF-κB pathway

Following myocardial ischemia, myocardial reperfusion injury causes oxidative stress (OS) and inflammation, leading to myocardial cell apoptosis and necrosis. Recently, emerging studies have shown that microRNAs (miRNAs) contribute to the pathophysiology associated with myocardial ischemia-reperfusion (I/R). In this study, we conducted both in-vitro and in-vivo experiments to explore the role of miR-218-5p in ischemia-reperfusion (I/R)- or oxygen and glucose deprivation/reperfusion (OGD/R)-mediated cardiomyocyte injury. A total 44 Sprague-Dawley (SD) rats were used, and randomly divided into four groups, control group (n = 11), miR-218-5p-in group (n = 11), I/R group (n = 11), I/R + miR-218-5p-in group (n = 11). Our data showed that miR-218-5p was overexpressed in H9C2 cardiomyocytes under OGD/R treatment. miR-218-5p inhibition reduced the lactate dehydrogenase (LDH) activity and the levels of reactive oxygen species (ROS), malondialdehyde (MDA) and superoxide dismutase (SOD), as well as the expression of tumor necrosis factor alpha (TNF-α), interleukin (IL-1β), and IL-6. Oppositely, miR-218-5p overexpression aggravated OGD/R-mediated damage on H9C2 cells, whereas nuclear factor kappa B (NF-κB) pathway inhibition or myocyte enhancer factor 2C (MEF2C) upregulation reversed miR-218-5p mimics-mediated effects. Bioinformatics analysis predicted that miR-218-5p targeted and dampened its expression, which was testified by the dual-luciferase reporter assay and RNA pull-down assay. In vivo, inhibiting miR-218-5p declined LDH activities and ROS, MDA and SOD levels in rat myocardial tissues under I/R injury, alleviated myocardial fibrosis and inflammatory reactions, and reduced myocardial infarction area. Overall, inhibition of miR-218-5p choked oxidative stress and inflammation in myocardial I/R injury via targeting MEF2C/NF-κB axis, thus relieving the disease progression.