Extracellular MicroRNA-92a Mediates Endothelial Cell-Macrophage Communication

Exosomal non-coding RNAs: key regulators of inflammation-related cardiovascular disorders

Inflammation is a complex, tightly regulated process involving biochemical and cellular reactions to harmful stimuli. Often termed "the internal fire", it is crucial for protecting the body and facilitating tissue healing. While inflammation is essential for survival, chronic inflammation can be detrimental, leading to tissue damage and reduced survival. The innate immune system triggers inflammation, closely linked to the development of heart diseases, with significant consequences for individuals. Inflammation in arterial walls or the body substantially contributes to atherosclerotic disease progression, affecting the cardiovascular system. Altered lipoproteins increase the risk of excessive blood clotting, a hallmark of atherosclerotic cardiovascular disease and its complications. Integrating inflammatory biomarkers with established risk assessment techniques can enhance our ability to identify at-risk individuals, assess their risk severity, and recommend appropriate CVD prevention strategies. Exosomes, a type of extracellular vesicle, are released by various cells and mediate cell communication locally and systemically. In the past decade, exosomes have been increasingly studied for their vital roles in health maintenance and disease processes. They can transport substances like non-coding RNAs, lipids, and proteins between cells, influencing immune responses and inflammation to elicit harmful or healing effects. This study focuses on the critical role of inflammation in heart disease progression and how non-coding RNAs in exosomes modulate the inflammatory process, either exacerbating or alleviating inflammation-related damage in the cardiovascular system.

Exosomes from renal cells and macrophages: Bidirectional communication in the pathogenesis of kidney disease

Macrophages are key cells in the immune response, and their abnormal infiltration into the kidney is a common pathological feature in kidney diseases. Exosomes, acting as carriers for transporting essential proteins and genetic materials, can be derived from various cell types and are involved in a wide range of physiological and pathological processes in the kidney. As primary inflammatory immune cells, macrophages have garnered significant attention from scholars regarding the effects of their secreted exosomes on renal intrinsic cells in kidney diseases, as well as the interactive effects of exosomes derived from other cells on macrophages. This review delves into the detailed characteristics of macrophage-derived exosomes in kidney diseases, the mechanisms by which they promote damage to specific cells, and the signaling pathways involved. Additionally, it examines the reverse direction, elucidating the circulatory mechanisms of substances carried by exosomes from renal intrinsic cells that induce phenotypic transformation and inflammatory responses in macrophages, ultimately leading to further damage of renal intrinsic cells. The pathological role of exosome-macrophage interconnections in various renal diseases has received increasing attention, and understanding this mechanism can help unravel the microscopic immunoregulatory processes underlying kidney diseases. Moreover, the identification of therapeutic targets related to macrophage-related exosomes offers new strategies for the treatment of these conditions.

Natural Bioproducts with Epigenetic Properties for Treating Cardiovascular Disorders

Cardiovascular disorders (CVDs) are the leading cause of mortality worldwide, highlighting an urgent need for innovative therapeutic strategies. Recent advancements highlight the potential of naturally derived bioproducts with epigenetic properties to offer protection against CVDs. These compounds act on key epigenetic mechanisms, DNA methylation, histone modifications, and non-coding RNA regulation to modulate gene expression essential for cardiovascular health. This review explores the effects of various bioproducts, such as polyphenols, flavonoids, and other natural extracts, on these epigenetic modifications and their potential benefits in preventing and managing CVDs. We discuss recent discoveries and clinical applications, providing insights into the epigenetic regulatory mechanisms of these compounds as potential epidrugs, naturally derived agents with promising therapeutic prospects in epigenetic therapy for CVDs.

Taurine Attenuates Neuronal Ferroptosis by CSF-Derived Exosomes of GABABR Encephalitis Through GABABR/NF2/P-YAP Pathway

GABAB receptor (GABABR) encephalitis represents a rare subtype of paraneoplastic limbic encephalitis (LE), characterized by persistent seizures and cognitive impairments. Nevertheless, the precise phenotype and underlying mechanisms of neuronal dysfunction associated with intrathecal lymphocytes in GABABR encephalitis remain inadequately understood. In the present study, we demonstrate that exosomes derived from the cerebrospinal fluid (CSF) of patients with GABABR encephalitis can induce neuronal ferroptosis, oxidative stress, iron accumulation, and lipid hyperoxidation in an in vitro model of anti-GABABR encephalitis. MicroRNA (miRNA) sequencing revealed that miR-92a-3p is a differentially expressed miRNA in CSF exosomes, and its expression was positively correlated with unfavorable clinical outcomes in GABABR encephalitis patients during a 6-month follow-up period. The NF2/P-YAP signaling pathway was identified as a downstream effector of miR-92a-3p, influencing the expression of ACSL4/GPX4 and IL-6, with the expression of these genes being enhanced following taurine supplementation. Clinically, taurine levels in CSF exhibited a negative correlation with IL-6 levels, CSF cell counts, blood-CSF barrier integrity, and clinical prognosis in GABABR encephalitis. Mechanistically, taurine effectively reduced reactive oxygen species (ROS) and iron accumulation, as well as IL-6 production, while modulating the levels of NF2, P-YAP, ACSL4, and GPX4 in neurons treated with CSF-derived exosomes from GABABR encephalitis through GABABR activation. Proliferation assays indicated that extracellular taurine intake activated CD4 + T cells, CD8 + T cells, and CD19 + B cells in the CSF of patients with GABABR encephalitis. In summary, our findings reveal for the first time that intrathecal lymphocytes in GABABR encephalitis maintain an activated state by absorbing extracellular taurine and that decreased taurine levels in CSF promote neuronal ferroptosis via the miR-92a-3p-mediated NF2/P-YAP/ACSL4 pathway.

Redox imbalance driven epigenetic reprogramming and cardiovascular dysfunctions: phytocompounds for prospective epidrugs

BACKGROUND

Cardiovascular diseases (CVDs) are the major contributor to global mortality and are gaining incremental attention following the COVID-19 outbreak. Epigenetic events such as DNA methylation, histone modifications, and non-coding RNAs have a significant impact on the incidence and onset of CVDs. Altered redox status is one of the major causative factors that regulate epigenetic pathways linked to CVDs. Various bioactive phytocompounds used in alternative therapies including Traditional Chinese Medicines (TCM) regulate redox balance and epigenetic phenomena linked to CVDs. Phytocompound-based medications are in the limelight for the development of cost-effective drugs with the least side effects, which will have immense therapeutic applications.

PURPOSE

This review comprehends certain risk factors associated with CVDs and triggered by oxidative stress-driven epigenetic remodelling. Further, it critically evaluates the pharmacological efficacy of phytocompounds as inhibitors of HAT/HDAC and DNMTs as well as miRNAs regulator that lowers the incidence of CVDs, aiming for new candidates as prospective epidrugs.

METHODS

PRISMA flow approach has been adopted for systematic literature review. Different Journals, computational databases, search engines such as Google Scholar, PubMed, Science Direct, Scopus, and ResearchGate were used to collect online information for literature survey. Statistical information collected from the World Health Organization (WHO) site (https://www.who.int/news-room/fact-sheets/detail/cardiovascular-diseases-(cvds)) and the American Heart Association of Heart Disease and Stroke reported the international and national status of CVDs.

RESULTS

The meta-analysis of various studies is elucidated in the literature, shedding light on major risk factors such as socioeconomic parameters, which contribute highly to redox imbalance, epigenetic modulations, and CVDs. Going forward, redox imbalance driven epigenetic regulations include changes in DNA methylation status, histone modifications and non-coding RNAs expression pattern which further regulates global as well as promoter modification of various transcription factors leading to the onset of CVDs. Further, the role of various bioactive compounds used in herbal medicine, including TCM for redox regulation and epigenetic modifications are discussed. Pharmacological safety doses and different phases of clinical trials of these phytocompounds are elaborated on, which shed light on the acceptance of these phytocompounds as prospective drugs.

CONCLUSION

This review suggests a strong linkage between therapeutic and preventive measures against CVDs by targeting redox imbalance-driven epigenetic reprogramming using phytocompounds as prospective epidrugs. Future in-depth research is required to evaluate the possible molecular mechanisms behind the phytocompound-mediated epigenetic reprogramming and oxidative stress management during CVD progression.

Dose-responsive effects of endothelial cell-sourced exosomes on vascular cell proliferation and phenotype transition

Endothelial cell-sourced exosomes are potential participants in the process of atherosclerosis, and their function is mainly affected by concentration. By studying the effects of exosome concentrations on vascular cells, atherosclerosis can be better intervened. In this study, exosomes with concentrations of 0, 0.07, 0.35, 1.75 and 8.75 μg/mL were set to interact with endothelial cells, macrophages and smooth muscle cells respectively. The results suggested that EC-Exo altered vascular cells' proliferation, migration and nitric oxide release abilities, increasing with EC-Exo concentrate from 0 to 1.75 μg/mL and varing with cell types at 8.75 μg/mL. The effects of exosome on cells is dose-responsive，and endothelial cells-sourced exosome favors vascular repair within the concentration of 0.35-1.75 μg/mL，showing potential for atherosclerosis regulation.

Stem cell-derived exosome delivery systems for treating atherosclerosis: The new frontier of stem cell therapy

Cardiovascular diseases (CVDs) are a leading cause of mortality worldwide. As a chronic inflammatory disease with a complicated pathophysiology marked by abnormal lipid metabolism and arterial plaque formation, atherosclerosis is a major contributor to CVDs and can induce abrupt cardiac events. The discovery of exosomes' role in intercellular communication has sparked a great deal of interest in them recently. Exosomes are involved in strategic phases of the onset and development of atherosclerosis because they have been identified to control pathophysiologic pathways including inflammation, angiogenesis, or senescence. This review investigates the potential role of stem cell-derived exosomes in atherosclerosis management. We briefly introduced atherosclerosis and stem cell therapy including stem cell-derived exosomes. The biogenesis of exosomes along with their secretion and isolation have been elaborated. The design engineering of exosomes has been summarized to present how drug loading and surface modification with targeting ligands can improve the therapeutic and targeting capacity of exosomes, demonstrating atheroprotective action. Moreover, the mechanism of action (endothelial dysfunction, reduction of dyslipidemia, macrophage polarization, vascular calcification, and angiogenesis) of drug-loaded exosomes to treat atherosclerosis has been discussed in detail. In the end, a comparative and balanced viewpoint has been given regarding the current challenges and potential solutions to advance exosome engineering for cardiovascular therapeutic applications.

Lipopolysaccharide (LPS) induces sclerostin secretion by extracellular vesicle via TLR4/miR-92a-3p/PTEN/NF-κB signalling pathway in murine macrophage

BACKGROUND

Sclerostin (SOST) is traditionally regarded as an osteocyte-derived secreted glycoprotein that regulates bone mineralization. Recent studies reported that SOST is also released from non-skeletal sources, especially during inflammation. However, the cellular source and regulatory mechanisms governing SOST generation in inflammation remain unclear. This study investigated whether macrophages produce SOST in response to inflammatory stimuli and determined associated regulatory pathways.

METHODS

The effect of lipopolysaccharide (LPS)-induced inflammation in SOST generation and its underlying regulatory mechanism was examined on mouse macrophage RAW 264.7 by western blot and immunofluorescent staining. Transfection with miR-92a-3p mimic and inhibitor were used to validate its role in SOST production. The role of NF-κB and TLR4 were studied using pharmacological inhibitors BAY 11-7085 and TAK242, respectively. The involvement of NF-κB and TLR4 in LPS-induced SOST production was further validated through nuclear NF-κB p65 immunoprecipitation and TLR4 small interfering RNA (siRNA) experiments, respectively.GW4869 and manumycin A (extracellular vesicles (EV) biogenesis inhibitors) were used to examine the associated of SOST and EV. Finally, SOST expression and characteristics of the isolated EV were assessed by Western blot and nanoparticle tracking analysis (NTA).

RESULTS

LPS significantly induced SOST protein expression and secretion in RAW 264.7. MiR-92a-3p was upregulated by LPS stimulation in macrophages. Transfection of miR-92a-3p mimic increased SOST generation in RAW 264.7. Inhibition of TLR4 and NF-κB signalling pathways using pharmacological inhibitors significantly suppressed LPS-induced SOST in RAW 264.7. Similarly, TLR4 siRNA effectively suppressed LPS-induced SOST level. However, the LPS-induced upregulation of miR-92a-3p was only regulated by TLR4, but not by NF-κB. NF-κB was found to directly bind to the mouse sost promoter, thereby activating sost transcription. Additionally, SOST secretion was found predominantly associated with EV from LPS-stimulated cells, and inhibition of EV biogenesis suppressed SOST production in RAW 264.7 cells.

CONCLUSIONS

In conclusion, our study showed, for the first time, that LPS induced SOST generation and secretion via TLR4/miR-92a-3p/PTEN/NF-κB singling pathway in murine macrophage RAW 264.7 cells. Moreover, we showed that SOST is secreted from the RAW 264.7 cells in the form of extracellular vesicle. This study identified macrophage as a novel source of SOST, highlighting its potential role in inflammatory diseases.

Epigallocatechin gallate (EGCG) modulates senescent endothelial cell-monocyte communication in age-related vascular inflammation

Aging significantly affects intercellular communication between vascular endothelial cells (ECs) and hematopoietic cells, leading to vascular inflammation and age-associated diseases. This study determined how senescent ECs communicate with monocytes, whether extracellular vesicles (EVs) released from senescent ECs affect monocyte functions, and investigated the potential for epigallocatechin-3-gallate (EGCG), a flavonoid in green tea, to reverse these effects. Human umbilical vein endothelial cells (HUVECs) were treated with Etoposide (10 µM, 24 h) to induce senescence, followed by EGCG (100 µM, 24 h) treatment to evaluate its potential as a senotherapeutic agent. The interaction between ECs and monocytes was analyzed using a co-culture system and direct treatment of monocytes with EC-derived EVs. EGCG reduced senescence-associated phenotypes in ECs, as evidenced by decreased senescence-associated (SA)-β-Gal activity and reversal of Etoposide-induced senescence markers. Monocytes co-cultured with EGCG-treated senescent ECs showed decreased pro-inflammatory responses compared to those co-cultured with untreated senescent ECs. Additionally, senescent ECs produced more EVs than non-senescent ECs. EVs from senescent ECs enhanced lipopolysaccharide (LPS)-induced pro-inflammatory activation of monocytes, whereas EVs from EGCG-treated senescent ECs mitigated this activation, maintaining monocyte activation at normal levels. Our findings reveal that EGCG confers anti-senescent effects via modulation of the senescent EC secretome (including EVs) with the capacity to modify monocyte activation. These findings suggest that EGCG could act as a senotherapeutic agent to reduce vascular inflammation related to aging.

Emerging understandings of the role of exosomes in atherosclerosis

Atherosclerosis remains a major contributor to cardiovascular disease, the leading cause of global morbidity and mortality. Despite the elucidation of several molecular, biochemical, and cellular aspects that contribute to the etio-pathogenesis of atherosclerosis, much remains to be understood about the onset and progression of this disease. Emerging evidence supports a role for exosomes in the cellular basis of atherosclerosis. Indeed, exosomes of activated monocytes seem to accentuate a positive feedback loop that promotes recruitment of pro-inflammatory leukocytes. Moreover, in addition to their role in promoting proliferation and invasion of vascular smooth muscle cells, exosomes can also induce neovascularization within lesions and increase endothelial permeability, two important features of fibrous plaques. Depending on their sources and cargo, exosomes can also induce clot formation and contribute to other hallmarks of atherosclerosis. Taken together, it is becoming increasingly evident that a better understanding of exosome biology is integral to elucidating the pathogenesis of atherosclerosis, and may thus provide insight into a potentially new therapeutic target for this disease.

A review of KLF4 and inflammatory disease: Current status and future perspective

Inflammation is the response of the human body to injury, infection, or other abnormal states, which is involved in the development of many diseases. As a member of the Krüppel-like transcription factors (KLFs) family, KLF4 plays a crucial regulatory role in physiological and pathological processes due to its unique dual domain of transcriptional activation and inhibition. A growing body of evidence has demonstrated that KLF4 plays a pivotal role in the pathogenesis of various inflammatory disorders, including inflammatory bowel disease, osteoarthritis, renal inflammation, pneumonia, neuroinflammation, and so on. Consequently, KLF4 has emerged as a promising new therapeutic target for inflammatory diseases. This review systematically generalizes the molecular regulatory network, specific functions, and mechanisms of KLF4 to elucidate its complex roles in inflammatory diseases. An in-depth study on the biological function of KLF4 is anticipated to offer a novel research perspective and potential intervention strategies for inflammatory diseases.

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.

Non-coding RNAs as therapeutic targets and biomarkers in ischaemic heart disease

The adult heart is a complex, multicellular organ that is subjected to a series of regulatory stimuli and circuits and has poor reparative potential. Despite progress in our understanding of disease mechanisms and in the quality of health care, ischaemic heart disease remains the leading cause of death globally, owing to adverse cardiac remodelling, leading to ischaemic cardiomyopathy and heart failure. Therapeutic targets are urgently required for the protection and repair of the ischaemic heart. Moreover, personalized clinical biomarkers are necessary for clinical diagnosis, medical management and to inform the individual response to treatment. Non-coding RNAs (ncRNAs) deeply influence cardiovascular functions and contribute to communication between cells in the cardiac microenvironment and between the heart and other organs. As such, ncRNAs are candidates for translation into clinical practice. However, ncRNA biology has not yet been completely deciphered, given that classes and modes of action have emerged only in the past 5 years. In this Review, we discuss the latest discoveries from basic research on ncRNAs and highlight both the clinical value and the challenges underscoring the translation of these molecules as biomarkers and therapeutic regulators of the processes contributing to the initiation, progression and potentially the prevention or resolution of ischaemic heart disease and heart failure.

Exosomes based strategies for cardiovascular diseases: Opportunities and challenges

Exosomes, as nanoscale extracellular vesicles (EVs), are secreted by all types of cells to facilitate intercellular communication in living organisms. After being taken up by neighboring or distant cells, exosomes can alter the expression levels of target genes in recipient cells and thereby affect their pathophysiological outcomes depending on payloads encapsulated therein. The functions and mechanisms of exosomes in cardiovascular diseases have attracted much attention in recent years and are thought to have cardioprotective and regenerative potential. This review summarizes the biogenesis and molecular contents of exosomes and details the roles played by exosomes released from various cells in the progression and recovery of cardiovascular disease. The review also discusses the current status of traditional exosomes in cardiovascular tissue engineering and regenerative medicine, pointing out several limitations in their application. It emphasizes that some of the existing emerging industrial or bioengineering technologies are promising to compensate for these shortcomings, and the combined application of exosomes and biomaterials provides an opportunity for mutual enhancement of their performance. The integration of exosome-based cell-free diagnostic and therapeutic options will contribute to the further development of cardiovascular regenerative medicine.

Roles of extracellular vesicles on macrophages in inflammatory bone diseases

Inflammatory bone disease is a general term for a series of diseases caused by chronic inflammation, which leads to the destruction of bone homeostasis, that is, the osteolytic activity of osteoclasts increases, and the osteogenic activity of osteoblasts decreases, leading to osteolysis. Macrophages are innate immune cell with plasticity, and their polarization is related to inflammatory bone diseases. The dynamic balance of macrophages between the M1 phenotype and the M2 phenotype affects the occurrence and development of diseases. In recent years, an increasing number of studies have shown that extracellular vesicles existing in the extracellular environment can act on macrophages, affecting the progress of inflammatory diseases. This process is realized by influencing the physiological activity or functional activity of macrophages, inducing macrophages to secrete cytokines, and playing an anti-inflammatory or pro-inflammatory role. In addition, by modifying and editing extracellular vesicles, the potential of targeting macrophages can be used to provide new ideas for developing new drug carriers for inflammatory bone diseases.

Therapeutic strategies targeting mechanisms of macrophages in diabetic heart disease

Diabetic heart disease (DHD) is a serious complication in patients with diabetes. Despite numerous studies on the pathogenic mechanisms and therapeutic targets of DHD, effective means of prevention and treatment are still lacking. The pathogenic mechanisms of DHD include cardiac inflammation, insulin resistance, myocardial fibrosis, and oxidative stress. Macrophages, the primary cells of the human innate immune system, contribute significantly to these pathological processes, playing an important role in human disease and health. Therefore, drugs targeting macrophages hold great promise for the treatment of DHD. In this review, we examine how macrophages contribute to the development of DHD and which drugs could potentially be used to target macrophages in the treatment of DHD.

Neonatal adiposity is associated with microRNAs in adipocyte-derived extracellular vesicles in maternal and cord blood, a discovery analysis

BACKGROUND

Maternal body size, nutrition, and hyperglycemia contribute to neonatal body size and composition. There is little information on maternal-fetal transmission of messages which influence fetal growth. We analyzed adipocyte-derived small extracellular vesicular (ADsEV) microRNAs in maternal and cord blood to explore their adipogenic potential.

METHODS

There were 279 mother-neonate pairs with all phenotypic data (normal glucose tolerant NGT = 148, gestational diabetes mellitus GDM = 131). Neonates with adiposity were those in the highest tertile (T3) of sex-specific sum of skinfolds and those without adiposity (lean) in the lowest tertile T1 of NGT pregnancies. We studied ADsEV miRNAs in 76 and 51 neonates with and without adiposity respectively and their mothers based on power calculations (68 NGT and 59 GDM pregnancies). ADsEV miRNAs from maternal and cord blood plasma samples were profiled on Agilent 8*60 K microarray. Differential expression (DE) of ADsEV miRNAs in adipose vs. lean groups was studied before and after adjustment for maternal GDM, adiposity, and vitamin B12-folate status.

RESULTS

Multiple miRNAs were common in maternal and cord blood and positively correlated. We identified 24 maternal and 5 cord blood miRNAs differentially expressed (discovery p ≤ 0.1) in the adipose group in unadjusted, and 19 and 26, respectively, in the adjusted analyses. Even though DE miRNAs were different in maternal and cord blood, they targeted similar adipogenic pathways (e.g., the forkhead box O (FOXO) family of transcription factors, mitogen‑activated protein kinase (MAPK) pathway, transforming growth factor beta (TGF-β) pathway). Maternal GDM and adiposity were associated with many DE ADsEV miRNAs.

CONCLUSION

Our results suggest that the ADsEV miRNAs in mothers are potential regulators of fetal adiposity. The expression and functionality of miRNAs appear to be influenced by maternal adiposity, hyperglycemia, and micronutrient status during pregnancy.

Directional Endothelial Communication by Polarized Extracellular Vesicle Release

BACKGROUND

Extracellular vesicles (EVs) contain bioactive cargo including miRNAs and proteins that are released by cells during cell-cell communication. Endothelial cells (ECs) form the innermost lining of all blood vessels, interfacing with cells in the circulation and vascular wall. It is unknown whether ECs release EVs capable of governing recipient cells within these 2 separate compartments. Given their boundary location, we propose ECs use bidirectional release of distinct EV cargo in quiescent (healthy) and activated (atheroprone) states to communicate with cells within the circulation and blood vessel wall.

METHODS

EVs were isolated from primary human aortic ECs (plate and transwell grown; ±IL [interleukin]-1β activation), quantified, visualized, and analyzed by miRNA transcriptomics and proteomics. Apical and basolateral EC-EV release was determined by miRNA transfer, total internal reflection fluorescence and electron microscopy. Vascular reprogramming (RNA sequencing) and functional assays were performed on primary human monocytes or smooth muscle cells±EC-EVs.

RESULTS

Activated ECs increased EV release, with miRNA and protein cargo related to atherosclerosis. EV-treated monocytes and smooth muscle cells revealed activated EC-EV altered pathways that were proinflammatory and atherogenic. ECs released more EVs apically, which increased with activation. Apical and basolateral EV cargo contained distinct transcriptomes and proteomes that were altered by EC activation. Notably, activated basolateral EC-EVs displayed greater changes in the EV secretome, with pathways specific to atherosclerosis. In silico analysis determined compartment-specific cargo released by the apical and basolateral surfaces of ECs can reprogram monocytes and smooth muscle cells, respectively, with functional assays and in vivo imaging supporting this concept.

CONCLUSIONS

Demonstrating that ECs are capable of polarized EV cargo loading and directional EV secretion reveals a novel paradigm for endothelial communication, which may ultimately enhance the design of endothelial-based therapeutics for cardiovascular diseases such as atherosclerosis where ECs are persistently activated.

The Mechanisms of miRNAs on Target Regulation and their Recent Advances in Atherosclerosis

miRNAs are crucial regulators in a variety of physiological and pathological processes, while their regulation mechanisms were usually described as negatively regulating gene expression by targeting the 3'-untranslated region(3'-UTR) of target gene miRNAs through seed sequence in tremendous studies. However, recent evidence indicated the existence of non-canonical mechanisms mediated by binding other molecules besides mRNAs. Additionally, accumulating evidence showed that functions of intracellular and intercellular miRNAs exhibited spatiotemporal patterns. Considering that detailed knowledge of the miRNA regulating mechanism is essential for understanding the roles and further clinical applications associated with their dysfunction and dysregulation, which is complicated and not fully clarified. Based on that, we summarized the recently reported regulation mechanisms of miRNAs, including recognitions, patterns of actions, and chemical modifications. And we also highlight the novel findings of miRNAs in atherosclerosis progression researches to provide new insights for non-coding RNA-based therapy in intractable diseases.

Identification of Important Genes Associated with the Development of Atherosclerosis

Atherosclerosis is one of the most important medical problems due to its prevalence and significant contribution to the structure of temporary and permanent disability and mortality. Atherosclerosis is a complex chain of events occurring in the vascular wall over many years. Disorders of lipid metabolism, inflammation, and impaired hemodynamics are important mechanisms of atherogenesis. A growing body of evidence strengthens the understanding of the role of genetic and epigenetic factors in individual predisposition and development of atherosclerosis and its clinical outcomes. In addition, hemodynamic changes, lipid metabolism abnormalities, and inflammation are closely related and have many overlapping links in regulation. A better study of these mechanisms may improve the quality of diagnosis and management of such patients.

Extracellular vesicles in cardiovascular diseases: From pathophysiology to diagnosis and therapy

Extracellular vesicles (EVs), encompassing exosomes, microvesicles (MVs), and apoptotic bodies (ABs), are cell-derived heterogeneous nanoparticles with a pivotal role in intercellular communication. EVs are enclosed by a lipid-bilayer membrane to escape enzymatic degradation. EVs contain various functional molecules (e.g., nucleic acids, proteins, lipids and metabolites) which can be transferred from donor cells to recipient cells. EVs provide many advantages including accessibility, modifiability and easy storage, stability, biocompatibility, heterogeneity and they readily penetrate through biological barriers, making EVs ideal and promising candidates for diagnosis/prognosis biomarkers and therapeutic tools. Recently, EVs were implicated in both physiological and pathophysiological settings of cardiovascular system through regulation of cell-cell communication. Numerous studies have reported a role for EVs in the pathophysiological progression of cardiovascular diseases (CVDs) and have evaluated the utility of EVs for the diagnosis/prognosis and therapeutics of CVDs. In this review, we summarize the biology of EVs, evaluate the perceived biological function of EVs in different CVDs along with a consideration of recent progress for the application of EVs in diagnosis/prognosis and therapies of CVDs.

Extracellular vesicles and their non-coding RNA cargos: Emerging players in cardiovascular disease

Extracellular vesicles (EVs), including exosomes, microvesicles and apoptotic bodies, have recently received attention as essential mechanisms for cell-to-cell communication in cardiovascular disease. EVs can be released from different types of cells, including endothelial cells, smooth muscle cells, cardiac cells, fibroblasts, platelets, adipocytes, immune cells and stem cells. Non-coding (nc)RNAs as EV cargos have recently been investigated in the cardiovascular system. Up- or downregulated ncRNAs in EVs have been shown to play a crucial role in various cardiovascular diseases. Communication via EV-derived ncRNAs can occur between cells of the same type and between different types of cells involved in the pathophysiology of cardiovascular disease. In the present review, we highlight the important aspects of diverse cell-derived EVs and their ncRNA cargos as disease mediators and potential therapeutic targets in atherosclerosis, coronary artery disease, ischaemic heart disease and cardiac fibrosis. In addition, we summarize the potential of EV-derived ncRNAs in the treatment of cardiovascular disease. Finally, we discuss the different methods for EV isolation and characterization. A better understanding of the specific role of EVs and their ncRNA cargos in the regulation of cardiovascular (dys)function will be of importance for the development of diagnostic and therapeutic tools for cardiovascular disease.

Insight into extracellular vesicles in vascular diseases: intercellular communication role and clinical application potential

BACKGROUND

Cells have been increasingly known to release extracellular vesicles (EVs) to the extracellular environment under physiological and pathological conditions. A plethora of studies have revealed that EVs contain cell-derived biomolecules and are found in circulation, thereby implicating them in molecular trafficking between cells. Furthermore, EVs have an effect on physiological function and disease development and serve as disease biomarkers.

MAIN BODY

Given the close association  between EV circulation and vascular disease, this review aims to provide a brief introduction to EVs, with a specific focus on the EV cargoes participating in pathological mechanisms, diagnosis, engineering, and clinical potential, to highlight the emerging evidence suggesting promising targets in vascular diseases. Despite the expansion of research in this field, some noticeable limitations remain for clinical translational research.

CONCLUSION

This review makes a novel contribution to a summary of recent advances and a perspective on the future of EVs in vascular diseases. Video Abstract.

Predominantly Pro-Inflammatory Phenotype with Mixed M1/M2 Polarization of Peripheral Blood Classical Monocytes and Monocyte-Derived Macrophages among Patients with Excessive Ethanol Intake

Excessive alcohol consumption impairs the immune system, induces oxidative stress, and triggers the activation of peripheral blood (PB) monocytes, thereby contributing to alcoholic liver disease (ALD). We analyzed the M1/M2 phenotypes of circulating classical monocytes and macrophage-derived monocytes (MDMs) in excessive alcohol drinkers (EADs). PB samples from 20 EADs and 22 healthy controls were collected for isolation of CD14+ monocytes and short-term culture with LPS/IFNγ, IL4/IL13, or without stimulation. These conditions were also used to polarize MDMs into M1, M2, or M0 phenotypes. Cytokine production was assessed in the blood and culture supernatants. M1/M2-related markers were analyzed using mRNA expression and surface marker detection. Additionally, the miRNA profile of CD14+ monocytes was analyzed. PB samples from EADs exhibited increased levels of pro-inflammatory cytokines. Following short-term culture, unstimulated blood samples from EADs showed higher levels of soluble TNF-α and IL-8, whereas monocytes expressed increased levels of surface TNF-α and elevated mRNA expression of pro-inflammatory cytokines and inducible nitric oxide synthase. MDMs from EADs showed higher levels of TNF-α and CD206 surface markers and increased IL-10 production. LPS/IFNγ induced higher mRNA expression of Nrf2 only in the controls. miRNA analysis revealed a distinctive miRNA profile that is potentially associated with liver carcinogenesis and ALD through inflammation and oxidative stress. This study confirms the predominantly pro-inflammatory profile of PB monocytes among EADs and suggests immune exhaustion features in MDMs.

Atherosclerosis-associated endothelial dysfunction is promoted by miR-199a-5p/SIRT1 axis regulated by circHIF1ɑ

BACKGROUND AND AIMS

Atherosclerosis (AS) is a chronic inflammatory disease that damages the arterial wall as a result of hyperlipidemia and causes endothelial cell dysfunction, which increases the risk of atherothrombotic events. Multiple pathological conditions have shown ectopic miR-199a-5p levels to cause endothelial injury, but its role in the AS competitive endogenous RNA (CeRNA) network is still unknown.

METHODS AND RESULTS

The high-fat diet (HFD) apoE-/- mouse model was constructed in vivo, and ECs were cultured under ox-LDL treatment to induce EC injury in vitro. Immunohistochemistry and immunofluorescence staining were used to assess the effect of miR-199a-5p on the macrophage, SMC, collagen content, and endothelial coverage in the artery wall of mouse model. miR-199a-5p level was validated to be overexpression in the aorta tissue of HFD apoE-/- mice and in the ox-LDL-treated ECs, and even in the plasma EVs of the patients with cerebral AS. Silencing of miR-199a-5p significantly attenuated atherosclerotic progress in HFD apoE-/- mice, and the gain/loss-of-function assay indicated that miR-199a-5p overexpression aggravated ox-LDL-induced disabilities of endothelial proliferation, motility, and neovascularization based on cell counting kit-8 assay, transwell assay and matrigel assay. Mechanistically, miR-199a-5p prevented EC activation by activating the FOXO signaling pathway by targeting SIRT1. Additionally, circular RNA (circRNA) circHIF1ɑ was identified as having a low expression in the ox-LDL-treated EC and mediated SIRT1 expression via sponging miR-199a-5p to rescue ox-LDL-induced EC injury.

CONCLUSIONS

Our study demonstrated the vital role of miR-199a-5p/SIRT1 axis regulated by circHIF1ɑ in AS pathogenesis and provided novel effective targets for AS treatment.

Long-Term LDL-Apheresis Treatment and Dynamics of Circulating miRNAs in Patients with Severe Familial Hypercholesterolemia

Lipoprotein apheresis (LA) is a therapeutic option for patients with severe hypercholesterolemia who have persistently elevated LDL-C levels despite attempts at drug therapy. MicroRNAs (miRNAs), important posttranscriptional gene regulators, are involved in the pathogenesis of atherosclerosis. Our study aimed to monitor the dynamics of twenty preselected circulating miRNAs in patients under long-term apheresis treatment. Plasma samples from 12 FH patients (men = 50%, age = 55.3 ± 12.2 years; mean LA overall treatment time = 13.1 ± 7.8 years) were collected before each apheresis therapy every sixth month over the course of four years of treatment. Eight complete follow-up (FU) samples were measured in each patient. Dynamic changes in the relative quantity of 6 miRNAs (miR-92a, miR-21, miR-126, miR-122, miR-26a, and miR-185; all p < 0.04) during FU were identified. Overall apheresis treatment time influenced circulating miR-146a levels (p < 0.04). In LDLR mutation homozygotes (N = 5), compared to heterozygotes (N = 7), we found higher plasma levels of miR-181, miR-126, miR-155, and miR-92a (all p < 0.03). Treatment with PCSK9 inhibitors (N = 6) affected the plasma levels of 7 miRNAs (miR-126, miR-122, miR-26a, miR-155, miR-125a, miR-92a, and miR-27a; all p < 0.04). Long-term monitoring has shown that LA in patients with severe familial hypercholesterolemia influences plasma circulating miRNAs involved in endothelial dysfunction, cholesterol homeostasis, inflammation, and plaque development. The longer the treatment using LA, the better the miRNA milieu depicting the potential cardiovascular risk.

UTX deletion promotes M2 macrophage polarization by epigenetically regulating endothelial cell-macrophage crosstalk after spinal cord injury

Macrophages polarized to the M2 subtype after spinal cord injury (SCI) are beneficial for promoting neurological recovery. The crosstalk between endothelial cells (ECs) and macrophages is crucial for the imbalance between proinflammatory and pro-resolving responses caused by macrophage heterogeneity; however, this crosstalk is strengthened post-SCI, leading to inflammatory cascades and second damage. As a powerful means to regulate gene expression, epigenetic regulation of the interaction between immune cells and ECs in SCI is still largely unknown. Our previous research demonstrated that the histone demethylase UTX deletion in ECs (UTX^-/- ECs) promotes neurological recovery, while the precise mechanism is unrevealed. Here, we discovered that UTX^-/- ECs polarize macrophages toward the M2 subtype post-SCI. Macrophage deficiency could block the neurological recovery caused by the knockdown of UTX. The exosomes from UTX^-/- ECs mediate this crosstalk. In addition, we found UTX, H3K27, and miR-467b-3p/Sfmbt2 promoters forming a regulatory complex that upregulates the miR-467b-3p in UTX^-/- ECs. And then, miR-467b-3p transfers to macrophages by exosomes and activates the PI3K/AKT/mTOR signaling by decreasing PTEN expression, finally polarizing macrophage to the M2 subtype. This study reveals a mechanism by epigenetic regulation of ECs-macrophages crosstalk and identifies potential targets, which may provide opportunities for treating SCI.

Extracellular vesicles in atherosclerosis and vascular calcification: the versatile non-coding RNAs from endothelial cells and vascular smooth muscle cells

Atherosclerosis (AS) is characterized by the accumulation of lipids, fibrous elements, and calcification in the innermost layers of arteries. Vascular calcification (VC), the deposition of calcium and phosphate within the arterial wall, is an important characteristic of AS natural history. However, medial arterial calcification (MAC) differs from intimal calcification and cannot simply be explained as the consequence of AS. Endothelial cells (ECs) and vascular smooth muscle cells (VSMCs) are directly involved in AS and VC processes. Understanding the communication between ECs and VSMCs is critical in revealing mechanisms underlying AS and VC. Extracellular vesicles (EVs) are found as intercellular messengers in kinds of physiological processes and pathological progression. Non-coding RNAs (ncRNAs) encapsulated in EVs are involved in AS and VC, including microRNAs (miRNAs), long non-coding RNAs (lncRNAs), and circular RNAs (circRNAs). The effects of ncRNAs have not been comprehensively understood, especially encapsulated in EVs. Some ncRNAs have demonstrated significant roles in AS and VC, but it remains unclear the functions of the majority ncRNAs detected in EVs. In this review, we summarize ncRNAs encapsulated in EC-EVs and VSMC-EVs, and the signaling pathways that are involved in AS and VC.

Extracellular Vesicles and Intercellular Communication: Challenges for In Vivo Molecular Imaging and Tracking

Extracellular vesicles (EVs) are a heterogeneous class of cell-derived membrane vesicles released by various cell types that serve as mediators of intercellular signaling. When released into circulation, EVs may convey their cargo and serve as intermediaries for intracellular communication, reaching nearby cells and possibly also distant organs. In cardiovascular biology, EVs released by activated or apoptotic endothelial cells (EC-EVs) disseminate biological information at short and long distances, contributing to the development and progression of cardiovascular disease and related disorders. The significance of EC-EVs as mediators of cell-cell communication has advanced, but a thorough knowledge of the role that intercommunication plays in healthy and vascular disease is still lacking. Most data on EVs derive from in vitro studies, but there are still little reliable data available on biodistribution and specific homing EVs in vivo tissues. Molecular imaging techniques for EVs are crucial to monitoring in vivo biodistribution and the homing of EVs and their communication networks both in basal and pathological circumstances. This narrative review provides an overview of EC-EVs, trying to highlight their role as messengers of cell-cell interaction in vascular homeostasis and disease, and describes emerging applications of various imaging modalities for EVs visualization in vivo.

Extracellular vesicles as biomarkers and modulators of atherosclerosis pathogenesis

Extracellular vesicles (EVs) are small, lipid bilayer-enclosed structures released by various cell types that play a critical role in intercellular communication. In atherosclerosis, EVs have been implicated in multiple pathophysiological processes, including endothelial dysfunction, inflammation, and thrombosis. This review provides an up-to-date overview of our current understanding of the roles of EVs in atherosclerosis, emphasizing their potential as diagnostic biomarkers and their roles in disease pathogenesis. We discuss the different types of EVs involved in atherosclerosis, the diverse cargoes they carry, their mechanisms of action, and the various methods employed for their isolation and analysis. Moreover, we underscore the importance of using relevant animal models and human samples to elucidate the role of EVs in disease pathogenesis. Overall, this review consolidates our current knowledge of EVs in atherosclerosis and highlights their potential as promising targets for disease diagnosis and therapy.

Epigenetic modifications as therapeutic targets in atherosclerosis: a focus on DNA methylation and non-coding RNAs

Significant progress in the diagnosis and treatment of cardiovascular disease (CVD) has been made in the past decade, yet it remains a leading cause of morbidity and mortality globally, claiming an estimated 17.9 million deaths per year. Although encompassing any condition that affects the circulatory system, including thrombotic blockage, stenosis, aneurysms, blood clots and arteriosclerosis (general hardening of the arteries), the most prevalent underlying hallmark of CVD is atherosclerosis; the plaque-associated arterial thickening. Further, distinct CVD conditions have overlapping dysregulated molecular and cellular characteristics which underlie their development and progression, suggesting some common aetiology. The identification of heritable genetic mutations associated with the development of atherosclerotic vascular disease (AVD), in particular resulting from Genome Wide Association Studies (GWAS) studies has significantly improved the ability to identify individuals at risk. However, it is increasingly recognised that environmentally-acquired, epigenetic changes are key factors associated with atherosclerosis development. Increasing evidence suggests that these epigenetic changes, most notably DNA methylation and the misexpression of non-coding, microRNAs (miRNAs) are potentially both predictive and causal in AVD development. This, together with their reversible nature, makes them both useful biomarkers for disease and attractive therapeutic targets potentially to reverse AVD progression. We consider here the association of aberrant DNA methylation and dysregulated miRNA expression with the aetiology and progression of atherosclerosis, and the potential development of novel cell-based strategies to target these epigenetic changes therapeutically.

Exosomal Non-Coding RNA Mediates Macrophage Polarization: Roles in Cardiovascular Diseases

Extracellular vesicles (EVs) or exosomes are nanosized extracellular particles that contain proteins, DNA, non-coding RNA (ncRNA) and other molecules, which are widely present in biofluids throughout the body. As a key mediator of intercellular communication, EVs transfer their cargoes to target cells and activate signaling transduction. Increasing evidence shows that ncRNA is involved in a variety of pathological and physiological processes through various pathways, particularly the inflammatory response. Macrophage, one of the body's "gatekeepers", plays a crucial role in inflammatory reactions. Generally, macrophages can be classified as pro-inflammatory type (M1) or anti-inflammatory type (M2) upon their phenotypes, a phenomenon termed macrophage polarization. Increasing evidence indicates that the polarization of macrophages plays important roles in the progression of cardiovascular diseases (CVD). However, the role of exosomal ncRNA in regulating macrophage polarization and the role of polarized macrophages as an important source of EV in CVD remains to be elucidated. In this review, we summarize the role and molecular mechanisms of exosomal-ncRNA in regulating macrophage polarization during CVD development, focusing on their cellular origins, functional cargo, and their detailed effects on macrophage polarization. We also discuss the role of polarized macrophages and their derived EV in CVD as well as the therapeutic prospects of exosomal ncRNA in the treatment of CVD.

Endothelial cells secrete small extracellular vesicles bidirectionally containing distinct cargo to uniquely reprogram vascular cells in the circulation and vessel wall

Rationale

Extracellular vesicles (EVs) contain bioactive cargo including microRNAs (miRNAs) and proteins that are released by cells as a form of cell-cell communication. Endothelial cells (ECs) form the innermost lining of all blood vessels and thereby interface with cells in the circulation as well as cells residing in the vascular wall. It is unknown whether ECs have the capacity to release EVs capable of governing recipient cells within two separate compartments, and how this is affected by endothelial activation commonly seen in atheroprone regions.

Objective

Given their boundary location, we propose that ECs utilize bidirectional release of distinct EV cargo in quiescent and activated states to communicate with cells within the circulation and blood vessel wall.

Methods and Results

EVs were isolated from primary human aortic endothelial cells (ECs) (+/-IL-1β activation), quantified, and analysed by miRNA transcriptomics and proteomics. Compared to quiescent ECs, activated ECs increased EV release, with miRNA and protein cargo that were related to atherosclerosis. RNA sequencing of EV-treated monocytes and smooth muscle cells (SMCs) revealed that EVs from activated ECs altered pathways that were pro-inflammatory and atherogenic. Apical and basolateral EV release was assessed using ECs on transwells. ECs released more EVs apically, which increased with activation. Apical and basolateral EV cargo contained distinct transcriptomes and proteomes that were altered by EC activation. Notably, basolateral EC-EVs displayed greater changes in the EV secretome, with pathways specific to atherosclerosis. In silico analysis determined that compartment-specific cargo released by the apical and basolateral surfaces of ECs can reprogram monocytes and SMCs, respectively.

Conclusions

The demonstration that ECs are capable of polarized EV cargo loading and directional EV secretion reveals a novel paradigm for endothelial communication, which may ultimately enhance our ability to design endothelial-based therapeutics for cardiovascular diseases such as atherosclerosis where ECs are persistently activated.

Vascular mechanotransduction

This review aims to survey the current state of mechanotransduction in vascular smooth muscle cells (VSMCs) and endothelial cells (ECs), including their sensing of mechanical stimuli and transduction of mechanical signals that result in the acute functional modulation and longer-term transcriptomic and epigenetic regulation of blood vessels. The mechanosensors discussed include ion channels, plasma membrane-associated structures and receptors, and junction proteins. The mechanosignaling pathways presented include the cytoskeleton, integrins, extracellular matrix, and intracellular signaling molecules. These are followed by discussions on mechanical regulation of transcriptome and epigenetics, relevance of mechanotransduction to health and disease, and interactions between VSMCs and ECs. Throughout this review, we offer suggestions for specific topics that require further understanding. In the closing section on conclusions and perspectives, we summarize what is known and point out the need to treat the vasculature as a system, including not only VSMCs and ECs but also the extracellular matrix and other types of cells such as resident macrophages and pericytes, so that we can fully understand the physiology and pathophysiology of the blood vessel as a whole, thus enhancing the comprehension, diagnosis, treatment, and prevention of vascular diseases.

Participation of Krüppel-like Factors in Atherogenesis

Atherosclerosis is an important problem in modern medicine, the keys to understanding many aspects of which are still not available to clinicians. Atherosclerosis develops as a result of a complex chain of events in which many cells of the vascular wall and peripheral blood flow are involved. Endothelial cells, which line the vascular wall in a monolayer, play an important role in vascular biology. A growing body of evidence strengthens the understanding of the multifaceted functions of endothelial cells, which not only organize the barrier between blood flow and tissues but also act as regulators of hemodynamics and play an important role in regulating the function of other cells in the vascular wall. Krüppel-like factors (KLFs) perform several biological functions in various cells of the vascular wall. The large family of KLFs in humans includes 18 members, among which KLF2 and KLF4 are at the crossroads between endothelial cell mechanobiology and immunometabolism, which play important roles in both the normal vascular wall and atherosclerosis.

Emerging role of exosomes in vascular diseases

Exosomes are biological small spherical lipid bilayer vesicles secreted by most cells in the body. Their contents include nucleic acids, proteins, and lipids. Exosomes can transfer material molecules between cells and consequently have a variety of biological functions, participating in disease development while exhibiting potential value as biomarkers and therapeutics. Growing evidence suggests that exosomes are vital mediators of vascular remodeling. Endothelial cells (ECs), vascular smooth muscle cells (VSMCs), inflammatory cells, and adventitial fibroblasts (AFs) can communicate through exosomes; such communication is associated with inflammatory responses, cell migration and proliferation, and cell metabolism, leading to changes in vascular function and structure. Essential hypertension (EH), atherosclerosis (AS), and pulmonary arterial hypertension (PAH) are the most common vascular diseases and are associated with significant vascular remodeling. This paper reviews the latest research progress on the involvement of exosomes in vascular remodeling through intercellular information exchange and provides new ideas for understanding related diseases.

Non-Coding RNAs in Cell-to-Cell Communication: Exploiting Physiological Mechanisms as Therapeutic Targets in Cardiovascular Pathologies

Cardiovascular disease, the leading cause of death worldwide, has been characterized at the molecular level by alterations in gene expression that contribute to the etiology of the disease. Such alterations have been shown to play a critical role in the development of atherosclerosis, cardiac remodeling, and age-related heart failure. Although much is now known about the cellular and molecular mechanisms in this context, the role of epigenetics in the onset of cardiovascular disease remains unclear. Epigenetics, a complex network of mechanisms that regulate gene expression independently of changes to the DNA sequence, has been highly implicated in the loss of homeostasis and the aberrant activation of a myriad of cellular pathways. More specifically, non-coding RNAs have been gaining much attention as epigenetic regulators of various pathologies. In this review, we will provide an overview of the ncRNAs involved in cell-to-cell communication in cardiovascular disease, namely atherosclerosis, cardiac remodeling, and cardiac ageing, and the potential use of epigenetic drugs as novel therapeutic targets.

microRNAs Associated with Carotid Plaque Development and Vulnerability: The Clinician's Perspective

Ischemic stroke (IS) related to atherosclerosis of large arteries is one of the leading causes of mortality and disability in developed countries. Atherosclerotic internal carotid artery stenosis (ICAS) contributes to 20% of all cerebral ischemia cases. Nowadays, atherosclerosis prevention and treatment measures aim at controlling the atherosclerosis risk factors, or at the interventional (surgical or endovascular) management of mature occlusive lesions. There is a definite lack of the established circulating biomarkers which, once modulated, could prevent development of atherosclerosis, and consequently prevent the carotid-artery-related IS. Recent studies emphasize that microRNA (miRNA) are the emerging particles that could potentially play a pivotal role in this approach. There are some research studies on the association between the expression of small non-coding microRNAs with a carotid plaque development and vulnerability. However, the data remain inconsistent. In addition, all major studies on carotid atherosclerotic plaque were conducted on cell culture or animal models; very few were conducted on humans, whereas the accumulating evidence demonstrates that it cannot be automatically extrapolated to processes in humans. Therefore, this paper aims to review the current knowledge on how miRNA participate in the process of carotid plaque formation and rupture, as well as stroke occurrence. We discuss potential target miRNA that could be used as a prognostic or therapeutic tool.

The Role of microRNAs in Inflammation

Inflammation is a biological response of the immune system to various insults, such as pathogens, toxic compounds, damaged cells, and radiation. The complex network of pro- and anti-inflammatory factors and their direction towards inflammation often leads to the development and progression of various inflammation-associated diseases. The role of small non-coding RNAs (small ncRNAs) in inflammation has gained much attention in the past two decades for their regulation of inflammatory gene expression at multiple levels and their potential to serve as biomarkers and therapeutic targets in various diseases. One group of small ncRNAs, microRNAs (miRNAs), has become a key regulator in various inflammatory disease conditions. Their fine-tuning of target gene regulation often turns out to be an important factor in controlling aberrant inflammatory reactions in the system. This review summarizes the biogenesis of miRNA and the mechanisms of miRNA-mediated gene regulation. The review also briefly discusses various pro- and anti-inflammatory miRNAs, their targets and functions, and provides a detailed discussion on the role of miR-10a in inflammation.

The expression profiling of serum miR-92a, miR-134 and miR-375 in acute ischemic stroke

Aim

To investigate the expression profile and diagnostic potentials of serum miR-92a, 134, and 375 in acute ischemic stroke (AIS) patients.

Materials & methods

Serum miRs-92a, 134, and 375 expression profiles were estimated by qRT-PCR for 70 AIS patients, age-matched with 25 control subjects. Their diagnostic potential was estimated by ROC analysis.

Results

Down-expression of miR-92a and miR-375 was found (56; 96.5%; -1.86 ± 1.36; and 53; 91.4%; -1.63 ± 1.38, respectively), while miR-134 showed a predominant upregulation (46; 79.3%; 0.853 ± 1.34). The diagnostic accuracy was the highest for miR-92a and miR-375 (area under the curve = 0.9183 and 0.898, respectively), with greater specificity for miR-375 (Sp = 96%).

Conclusion

Serum miR-92a and miR-375 could be promising early detective biomarkers of AIS.

[Effects of Krüppel-like factor 4 on inflammatory response and organ injury in septic mice]

Objective: To explore the expression characteristics and role of Krüppel-like factor 4 (KLF4) in macrophage inflammatory response and its effects on inflammatory response and organ injury in septic mice, so as to lay a theoretical foundation for targeted treatment of burns and trauma sepsis. Methods: The method of experimental research was used. Mouse RAW264.7 macrophages and primary peritoneal macrophages (PMs) isolated from 10 male C57BL/6J mice aged 6-8 weeks were used for the experiments. RAW264.7 macrophages and PMs were treated with endotoxin/lipopolysaccharide (LPS) for 0 (without treatment), 1, 2, 4, 6, 8, 12, and 24 h, respectively, to establish macrophage inflammatory response model. The mRNA expression of interleukin 1β (IL-1β), IL-6, CC chemokine ligand 2 (CCL2) and tumor necrosis factor-α (TNF-α) were detected by real-time fluorescence quantitative reverse transcription polymerase chain reaction (RT-PCR), and the LPS treatment time was determined for some of the subsequent experiments. RAW264.7 macrophages were treated with LPS for 0 and 8 h, the localization and protein expression of KLF4 were detected by immunofluorescence method, transcriptome sequencing of the cells was performed using the high-throughput sequencing technology platform, and the differently expressed genes (DEGs) between the two time points treated cells were screened by DESeq2 software. RAW264.7 macrophages and PMs were treated with LPS for 0, 1, 2, 4, 6, 8, 12, and 24 h, respectively, and the mRNA and protein expressions of KLF4 were detected by real-time fluorescence quantitative RT-PCR and Western blotting, respectively. RAW264.7 macrophages were divided into negative control (NC) group and KLF4-overexpression group according to the random number table, which were treated with LPS for 0 and 8 h respectively after transfection of corresponding plasmid. The mRNA expressions of KLF4, IL-1β, IL-6, CCL2, and TNF-α were detected by real-time fluorescence quantitative RT-PCR, while the protein expression of KLF4 was detected by Western blotting. The number of samples in aforementioned experiments was all 3. Forty male C57BL/6J mice aged 6-8 weeks were divided into KLF4-overexpression group and NC group (with 20 mice in each group) according to the random number table, and the sepsis model of cecal ligation perforation was established after the corresponding transfection injection was injected respectively. Twelve mice were selected from each of the two groups according to the random number table, and the survival status within 72 hours after modeling was observed. Eight hours after modeling, the remaining 8 mice in each of the two groups were selected, the eyeball blood samples were collected to detect the levels of IL-1β and IL-6 in serum by enzyme-linked immunosorbent assay, and the levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) in serum by dry chemical method. Subsequently, the heart, lung, and liver tissue was collected, and the injury was observed after hematoxylin-eosin staining. Data were statistically analyzed with independent sample t test, Cochran & Cox approximate t test, one-way analysis of variance, Dunnett test, Brown-Forsythe and Welch one-way analysis of variance, Dunnett T3 test, log-rank (Mantel-Cox) test. Results: Compared with that of LPS treatment for 0 h, the mRNA expressions of IL-1β in RAW264.7 macrophages treated with LPS for 6 h and 8 h, the mRNA expressions of IL-6 in RAW264.7 macrophages treated with LPS for 4-12 h, the mRNA expressions of CCL2 in RAW264.7 macrophages treated with LPS for 8 h and 12 h, and the mRNA expressions of TNF-α in RAW264.7 macrophages treated with LPS for 4-8 h were significantly up-regulated (P<0.05 or P<0.01), while the mRNA expressions of IL-1β and CCL2 in PMs treated with LPS for 4-8 h, the mRNA expressions of IL-6 in PMs treated with LPS for 2-24 h, and the mRNA expressions of TNF-α in PMs treated with LPS for 2-12 h were significantly up-regulated (P<0.05 or P<0.01). Eight hours was selected as the LPS treatment time for some of the subsequent experiments. KLF4 mainly located in the nucleus of RAW264.7 macrophages. Compared with those of LPS treatment for 0 h, the protein expression of KLF4 in RAW264.7 macrophages treated with LPS for 8 h was obviously decreased, and there were 1 470 statistically differentially expressed DEGs in RAW264.7 macrophages treated with LPS for 8 h, including KLF4 with significantly down-regulated transcriptional expression (false discovery rate<0.05, log2 (fold change)=-2.47). Compared with those of LPS treatment for 0 h, the mRNA expressions of KLF4 in RAW264.7 macrophages treated with LPS for 6-24 h, the protein expressions of KLF4 in RAW264.7 macrophages and PMs treated with LPS for 1-24 h, and the mRNA expressions of KLF4 in PM treated with LPS for 4-24 h were significantly decreased (P<0.05 or P<0.01). Compared with those in NC group, the mRNA (with t' values of 17.03 and 8.61, respectively, P<0.05 or P<0.01) and protein expressions of KLF4 in RAW264.7 macrophages treated with LPS for 0 h and 8 h in KLF4-overexpression group were significantly increased, the mRNA expressions of IL-6 and CCL2 increased significantly in RAW264.7 macrophages treated with LPS for 0 h (with t values of 6.29 and 3.40, respectively, P<0.05 or P<0.01), while the mRNA expressions of IL-1β, IL-6, CCL2, and TNF-α decreased significantly in RAW264.7 macrophages treated with LPS for 8 h (with t values of 10.52, 9.60, 4.58, and 8.58, respectively, P<0.01). The survival proportion of mice within 72 h after modeling in KLF4-overexpression group was significantly higher than that in NC group (χ2=4.01, P<0.05). Eight hours after modeling, the serum levels of IL-1β, IL-6 and ALT, AST of mice in KLF4-overexpression group were (161±63), (476±161) pg/mL and (144±24), (264±93) U/L, respectively, which were significantly lower than (257±58), (654±129) pg/mL and (196±27), (407±84) U/L (with t values of 3.16, 2.44 and 4.04, 3.24, respectively, P<0.05 or P<0.01) in NC group. Eight hours after modeling, compared with those in NC group, the disorder of tissue structure of heart, lung, and liver, inflammatory exudation, and pathological changes of organ parenchyma cells in KLF4-overexpression group were obviously alleviated. Conclusions: The expression of KLF4 is significantly down-regulated in LPS-induced macrophage inflammatory response, which significantly inhibits the macrophage inflammatory response. KLF4 significantly enhances the survival rate of septic mice and alleviates inflammatory response and sepsis-related organ injury.

Endothelial senescence mediates hypoxia-induced vascular remodeling by modulating PDGFB expression

Uncontrolled accumulation of pulmonary artery smooth muscle cells (PASMCs) to the distal pulmonary arterioles (PAs) is one of the major characteristics of pulmonary hypertension (PH). Cellular senescence contributes to aging and lung diseases associated with PH and links to PH progression. However, the mechanism by which cellular senescence controls vascular remodeling in PH is not fully understood. The levels of senescence marker, p16^INK4A and senescence-associated β-galactosidase (SA-β-gal) activity are higher in PA endothelial cells (ECs) isolated from idiopathic pulmonary arterial hypertension (IPAH) patients compared to those from healthy individuals. Hypoxia-induced accumulation of α-smooth muscle actin (αSMA)-positive cells to the PAs is attenuated in p16^fl/fl-Cdh5(PAC)-Cre^ERT2 (p16^iΔEC) mice after tamoxifen induction. We have reported that endothelial TWIST1 mediates hypoxia-induced vascular remodeling by increasing platelet-derived growth factor (PDGFB) expression. Transcriptomic analyses of IPAH patient lungs or hypoxia-induced mouse lung ECs reveal the alteration of senescence-related gene expression and their interaction with TWIST1. Knockdown of p16^INK4A attenuates the expression of PDGFB and TWIST1 in IPAH patient PAECs or hypoxia-treated mouse lungs and suppresses accumulation of αSMA–positive cells to the supplemented ECs in the gel implanted on the mouse lungs. Hypoxia-treated mouse lung EC-derived exosomes stimulate DNA synthesis and migration of PASMCs in vitro and in the gel implanted on the mouse lungs, while p16^iΔEC mouse lung EC-derived exosomes inhibit the effects. These results suggest that endothelial senescence modulates TWIST1-PDGFB signaling and controls vascular remodeling in PH.

Macrophage-derived exosomal miR-4532 promotes endothelial cells injury by targeting SP1 and NF-κB P65 signalling activation

Atherosclerosis is a complex pathological process involving macrophages, endothelial cells and vascular smooth muscle cells that can lead to ischemic heart disease; however, the mechanisms underlying cell‐to‐cell communication in atherosclerosis are poorly understood. In this study, we focused on the role of exosomal miRNAs in crosstalk between macrophages and endothelial cells and explored the rarely studied molecular mechanisms involved. Our in vitro result showed that macrophage‐derived exosomal miR‐4532 significantly disrupted human umbilical vein endothelial cells (HUVECs) function by targeting SP1 and downstream NF‐κB P65 activation. In turn, increased endothelin‐1 (ET‐1), intercellular cell adhesion molecule‐1 (ICAM‐1) and vascular cell adhesion molecule‐1 (VCAM‐1) and decreased endothelial nitric oxide synthase (eNOS) expression in HUVECs increased attraction of macrophages, exacerbating foam cell formation and transfer of exosomal miR‐4532 to HUVECs. MiR‐4532 overexpression significantly promoted endothelial injury and pretreatment with an inhibitor of miR‐4532 or GW4869 (exosome inhibitor) could reverse this injury. In conclusion, our data reveal that exosomes have a critical role in crosstalk between HUVECs and macrophages. Further, exosomal miR‐4532 transferred from macrophages to HUVECs and targeting specificity protein 1 (SP1) may be a novel therapeutic target in patients with atherosclerosis.

miR-125a-3p aggravates ox-LDL-induced HUVEC injury through BAMBI

Atherosclerosis (AS) is a chronic inflammatory disease characterized by the formation of atherosclerotic plaque in the intima of arteries. Among the known regulators of atherosclerosis, microRNAs (miRNAs) have been reported to play critical roles in lipoprotein homeostasis and plaque formation. But the roles of microRNA-125a-3p (miR-125a-3p) in the pathogenesis of AS remain unknown. Human umbilical vein endothelial cells (HUVECs) were treated with oxidized low-density lipoprotein (ox-LDL) to construct the vascular injury model of AS pathogenesis in vitro. miR-125a-3p and BMP and activin membrane-bound inhibitor (BAMBI) expression levels in HUVECs were then measured by quantitative real-time polymerase chain reaction and western blot. The viability and apoptosis of HUVECs were analyzed by Cell Counting Kit-8 assay, TUNEL assay, and flow cytometry, respectively. The relationship between BAMBI 3'-untranslated region and miR-125a-3p was validated by dual luciferase reporter gene assay. miR-125a-3p expression was raised in HUVECs induced with ox-LDL. In HUVECs, miR-125a-3p enhanced the effects of ox-LDL treatment on repressing the viability and promoting the apoptosis of cells. Additionally, BAMBI was confirmed as a direct target of miR-125a-3p and BAMBI overexpression reversed the effects of miR-125a-3p on HUVECs. miR-125a-3p aggravates the dysfunction of HUVECs induced by ox-LDL via BAMBI, which implies that miR-125a-3p is involved in the pathogenesis of AS.

Genetic and Epigenetic Regulation of Lipoxygenase Pathways and Reverse Cholesterol Transport in Atherogenesis

Atherosclerosis is one of the most important medical and social problems of modern society. Atherosclerosis causes a large number of hospitalizations, disability, and mortality. A considerable amount of evidence suggests that inflammation is one of the key links in the pathogenesis of atherosclerosis. Inflammation in the vascular wall has extensive cross-linkages with lipid metabolism, and lipid mediators act as a central link in the regulation of inflammation in the vascular wall. Data on the role of genetics and epigenetic factors in the development of atherosclerosis are of great interest. A growing body of evidence is strengthening the understanding of the significance of gene polymorphism, as well as gene expression dysregulation involved in cross-links between lipid metabolism and the innate immune system. A better understanding of the genetic basis and molecular mechanisms of disease pathogenesis is an important step towards solving the problems of its early diagnosis and treatment.

Autologous Platelet-Rich Growth Factor Reduces M1 Macrophages and Modulates Inflammatory Microenvironments to Promote Sciatic Nerve Regeneration

The failure of peripheral nerve regeneration is often associated with the inability to generate a permissive molecular and cellular microenvironment for nerve repair. Autologous therapies, such as platelet-rich plasma (PRP) or its derivative platelet-rich growth factors (PRGF), may improve peripheral nerve regeneration via unknown mechanistic roles and actions in macrophage polarization. In the current study, we hypothesize that excessive and prolonged inflammation might result in the failure of pro-inflammatory M1 macrophage transit to anti-inflammatory M2 macrophages in large nerve defects. PRGF was used in vitro at the time the unpolarized macrophages (M0) macrophages were induced to M1 macrophages to observe if PRGF altered the secretion of cytokines and resulted in a phenotypic change. PRGF was also employed in the nerve conduit of a rat sciatic nerve transection model to identify alterations in macrophages that might influence excessive inflammation and nerve regeneration. PRGF administration reduced the mRNA expression of tumor necrosis factor-α (TNFα), interleukin-1β (IL-1β), and IL-6 in M0 macrophages. Increased CD206 substantiated the shift of pro-inflammatory cytokines to the M2 regenerative macrophage. Administration of PRGF in the nerve conduit after rat sciatic nerve transection promoted nerve regeneration by improving nerve gross morphology and its targeted gastrocnemius muscle mass. The regenerative markers were increased for regrown axons (protein gene product, PGP9.5), Schwann cells (S100β), and myelin basic protein (MBP) after 6 weeks of injury. The decreased expression of TNFα, IL-1β, IL-6, and CD68⁺ M1 macrophages indicated that the inflammatory microenvironments were reduced in the PRGF-treated nerve tissue. The increase in RECA-positive cells suggested the PRGF also promoted angiogenesis during nerve regeneration. Taken together, these results indicate the potential role and clinical implication of autologous PRGF in regulating inflammatory microenvironments via macrophage polarization after nerve transection.

miRNAs from Plasma Extracellular Vesicles Are Signatory Noninvasive Prognostic Biomarkers against Atherosclerosis in LDLr-/-Mice

Circular microRNAs (miRNAs) have become central in pathophysiological conditions of atherosclerosis (AS). However, the biomarkers for diagnosis and therapeutics against AS are still unclear. The atherosclerosis models in low-density lipoprotein receptor deficiency (LDLr^−/−) mice were established with a high-fat diet (HFD). The extraction kit isolated extracellular vesicles from plasma. Total RNAs were extracted from LDLr^−/− mice in plasma extracellular vesicles. Significantly varying miRNAs were detected by employing Illumina HiSeq 2000 deep sequencing technology. Target gene predictions of miRNAs were employed by related software that include RNAhybrid, TargetScan, miRanda, and PITA. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) further analyzed the intersection points of predicted results. The results showed that the HFD group gradually formed atherosclerotic plaques in thoracic aorta compared with the control group. Out of 17, 8 upregulated and 9 downregulated miRNAs with a significant difference were found in the plasma extracellular vesicles that were further cross-examined by sequencing and bioinformatics analysis. Focal adhesion and Ras signaling pathway were found to be the most closely related pathways through GO and KEGG pathway analyses. The 8 most differentially expressed up- and downregulated miRNAs were further ascertained by TaqMan-based qRT-PCR. TaqMan-based qRT-PCR and in situ hybridization further validated the most differentially expressed miRNAs (miR-378d, miR-181b-5p, miR-146a-5p, miR-421-3p, miR-350-3p, and miR-184-3p) that were consistent with deep sequencing analysis suggesting a promising potential of utility to serve as diagnostic biomarkers against AS. The study gives a comprehensive profile of circular miRNAs in atherosclerosis and may pave the way for identifying biomarkers and novel targets for atherosclerosis.

Epigenetic regulation in cardiovascular disease: mechanisms and advances in clinical trials

Epigenetics is closely related to cardiovascular diseases. Genome-wide linkage and association analyses and candidate gene approaches illustrate the multigenic complexity of cardiovascular disease. Several epigenetic mechanisms, such as DNA methylation, histone modification, and noncoding RNA, which are of importance for cardiovascular disease development and regression. Targeting epigenetic key enzymes, especially the DNA methyltransferases, histone methyltransferases, histone acetylases, histone deacetylases and their regulated target genes, could represent an attractive new route for the diagnosis and treatment of cardiovascular diseases. Herein, we summarize the knowledge on epigenetic history and essential regulatory mechanisms in cardiovascular diseases. Furthermore, we discuss the preclinical studies and drugs that are targeted these epigenetic key enzymes for cardiovascular diseases therapy. Finally, we conclude the clinical trials that are going to target some of these processes.

Extracellular Vesicles as Drivers of Immunoinflammation in Atherothrombosis

Atherosclerotic cardiovascular disease is the leading cause of morbidity and mortality all over the world. Extracellular vesicles (EVs), small lipid-bilayer membrane vesicles released by most cellular types, exert pivotal and multifaceted roles in physiology and disease. Emerging evidence emphasizes the importance of EVs in intercellular communication processes with key effects on cell survival, endothelial homeostasis, inflammation, neoangiogenesis, and thrombosis. This review focuses on EVs as effective signaling molecules able to both derail vascular homeostasis and induce vascular dysfunction, inflammation, plaque progression, and thrombus formation as well as drive anti-inflammation, vascular repair, and atheroprotection. We provide a comprehensive and updated summary of the role of EVs in the development or regression of atherosclerotic lesions, highlighting the link between thrombosis and inflammation. Importantly, we also critically describe their potential clinical use as disease biomarkers or therapeutic agents in atherothrombosis.

Circulating miRNA Fingerprint and Endothelial Function in Myocardial Infarction: Comparison at Acute Event and One-Year Follow-Up

MicroRNAs (miRNA) are major regulators of intercellular communication and key players in the pathophysiology of cardiovascular disease. This study aimed to determine the miRNA fingerprint in a cohort of 53 patients with acute myocardial infarction (AMI) with non-ST-segment elevation (NSTEMI) relative to miRNA expression in healthy controls (n = 51). miRNA expression was initially profiled by miRNA array in the serum of patients undergoing cardiac catheterization during NSTEMI (n = 8) and 1 year past the event (follow-up, n = 8) and validated in the entire cohort. In total, 58 miRNAs were differentially expressed during AMI (p < 0.05), while 36 were modified at follow-up (Fisher’s exact test: p = 0.0138). Enrichment analyses revealed differential regulation of biological processes by miRNA at each specific time point (AMI vs. follow-up). During AMI, the miRNA profile was associated mainly with processes involved in vascular development. However, 1 year after AMI, changes in miRNA expression were partially related to the regulation of cardiac tissue morphogenesis. Linear correlation analysis of miRNA with serum levels of cytokines and chemokines revealed that let-7g-5p, let-7e-5p, and miR-26a-5p expression was inversely associated with serum levels of pro-inflammatory cytokines TNF-α, and the chemokines MCP-3 and MDC. Transient transfection of human endothelial cells (HUVEC) with let-7e-5p inhibitor or mimic demonstrated a key role for this miRNA in endothelial function regulation in terms of cell adhesion and angiogenesis capacity. HUVEC transfected with let-7e-5p mimic showed a 20% increase in adhesion capacity, whereas transfection with let-7e-5p inhibitor increased the number of tube-like structures. This study pinpoints circulating miRNA expression fingerprint in NSTEMI patients, specific to the acute event and changes at 1-year follow-up. Additionally, given its involvement in modulating endothelial cell function and vascularization, altered let-7e-5p expression may constitute a therapeutic biomarker and target for ischemic heart disease.