Enhancer of zeste homolog-2 (EZH2) methyltransferase regulates transgelin/smooth muscle-22α expression in endothelial cells in response to interleukin-1β and transforming growth factor-β2

Navigating tumor angiogenesis: therapeutic perspectives and myeloid cell regulation mechanism

Sustained angiogenesis stands as a hallmark of cancer. The intricate vascular tumor microenvironment fuels cancer progression and metastasis, fosters therapy resistance, and facilitates immune evasion. Therapeutic strategies targeting tumor vasculature have emerged as transformative for cancer treatment, encompassing anti-angiogenesis, vessel normalization, and endothelial reprogramming. Growing evidence suggests the dynamic regulation of tumor angiogenesis by infiltrating myeloid cells, such as macrophages, myeloid-derived suppressor cells (MDSCs), and neutrophils. Understanding these regulatory mechanisms is pivotal in paving the way for successful vasculature-targeted cancer treatments. Therapeutic interventions aimed to disrupt myeloid cell-mediated tumor angiogenesis may reshape tumor microenvironment and overcome tumor resistance to radio/chemotherapy and immunotherapy.

Beyond VICs: Shedding light on the overlooked VECs in calcific aortic valve disease

Calcific aortic valve disease (CAVD) is prevalent in developed nations and has emerged as a pressing global public health concern due to population aging. The precise etiology of this disease remains uncertain, and recent research has primarily focused on examining the role of valvular interstitial cells (VICs) in the development of CAVD. The predominant treatment options currently available involve open surgery and minimally invasive interventional surgery, with no efficacious pharmacological treatment. This article seeks to provide a comprehensive understanding of valvular endothelial cells (VECs) from the aspects of valvular endothelium-derived nitric oxide (NO), valvular endothelial mechanotransduction, valvular endothelial injury, valvular endothelial-mesenchymal transition (EndMT), and valvular neovascularization, which have received less attention, and aims to establish their role and interaction with VICs in CAVD. The ultimate goal is to provide new perspectives for the investigation of non-invasive treatment options for this disease.

Epigallocatechin-3-gallate attenuates arsenic-induced fibrogenic changes in human kidney epithelial cells through reversal of epigenetic aberrations and antioxidant activities

Renal fibrosis is a pathogenic intermediate stage of chronic kidney disease (CKD). Nephrotoxicants including arsenic can cause kidney fibrosis through induction of oxidative stress and epigenetic aberrations. Epigallocatechin-3-gallate (EGCG), a green tea polyphenol, is known to have antioxidant and epigenetic modulation properties. Whether EGCG, through its antioxidant and epigenetic modulating activities, can attenuate fibrogenesis is not known. Therefore, the objective of this study was to determine whether EGCG can attenuate arsenic-induced acute injury and long-term exposure associated fibrogenicity in kidney epithelial cells. To address this question, two human kidney epithelial cell lines Caki-1 and HK-2 exposed to arsenic for both acute and long-term durations were treated with EGCG. The protective effect of EGCG on arsenic-induced cytotoxicity and fibrogenicity were evaluated by measuring the cell growth, reactive oxygen species (ROS) production, genes expression, and epigenetic changes in histone marks. Results revealed that EGCG has a protective effect in arsenic-induced acute cytotoxicity in these cells. EGCG scavenges the increased levels of ROS in arsenic exposed cells. Aberrant expression of fibrogenic genes in arsenic exposed cells were restored by EGCG. Abrogation of arsenic-induced fibrogenic changes was also associated with EGCG-mediated restoration of arsenic-induced aberrant expression of epigenetic regulatory proteins and histone marks. Novel findings of this study suggest that EGCG, through its antioxidant and epigenetic modulation capacities, has protective effects against arsenic-induced cytotoxicity and fibrogenic changes in kidney epithelial cells.

Endothelial to mesenchymal transition: at the axis of cardiovascular health and disease

Endothelial cells (ECs) line the luminal surface of blood vessels and play a major role in vascular (patho)-physiology by acting as a barrier, sensing circulating factors and intrinsic/extrinsic signals. ECs have the capacity to undergo endothelial-to-mesenchymal transition (EndMT), a complex differentiation process with key roles both during embryonic development and in adulthood. EndMT can contribute to EC activation and dysfunctional alterations associated with maladaptive tissue responses in human disease. During EndMT, ECs progressively undergo changes leading to expression of mesenchymal markers while repressing EC lineage-specific traits. This phenotypic and functional switch is considered to largely exist in a continuum, being characterized by a gradation of transitioning stages. In this report, we discuss process plasticity and potential reversibility and the hypothesis that different EndMT-derived cell populations may play a different role in disease progression or resolution. In addition, we review advancements in the EndMT field, current technical challenges, as well as therapeutic options and opportunities in the context of cardiovascular biology.

Single-Cell RNA-Seq Reveals Coronary Heterogeneity and Identifies CD133+TRPV4high Endothelial Subpopulation in Regulating Flow-Induced Vascular Tone in Mice

BACKGROUND

Single-cell RNA-Seq analysis can determine the heterogeneity of cells between different tissues at a single-cell level. Coronary artery endothelial cells (ECs) are important to coronary blood flow. However, little is known about the heterogeneity of coronary artery ECs, and cellular identity responses to flow. Identifying endothelial subpopulations will contribute to the precise localization of vascular endothelial subpopulations, thus enabling the precision of vascular injury treatment.

METHODS

Here, we performed a single-cell RNA sequencing of 31 962 cells and functional assays of 3 branches of the coronary arteries (right coronary artery/circumflex left coronary artery/anterior descending left coronary artery) in wild-type mice.

RESULTS

We found a compendium of 7 distinct cell types in mouse coronary arteries, mainly ECs, granulocytes, cardiac myocytes, smooth muscle cells, lymphocytes, myeloid cells, and fibroblast cells, and showed spatial heterogeneity between arterial branches. Furthermore, we revealed a subpopulation of coronary artery ECs, CD133+TRPV4high ECs. TRPV4 (transient receptor potential vanilloid 4) in CD133+TRPV4high ECs is important for regulating vasodilation and coronary blood flow.

CONCLUSIONS

Our study elucidates the nature and range of coronary arterial cell diversity and highlights the importance of coronary CD133+TRPV4high ECs in regulating coronary vascular tone.

Diverse WGBS profiles of longissimus dorsi muscle in Hainan black goats and hybrid goats

BACKGROUND

Goat products have played a crucial role in meeting the dietary demands of people since the Neolithic era, giving rise to a multitude of goat breeds globally with varying characteristics and meat qualities. The primary objective of this study is to pinpoint the pivotal genes and their functions responsible for regulating muscle fiber growth in the longissimus dorsi muscle (LDM) through DNA methylation modifications in Hainan black goats and hybrid goats.

METHODS

Whole-genome bisulfite sequencing (WGBS) was employed to scrutinize the impact of methylation on LDM growth. This was accomplished by comparing methylation differences, gene expression, and their associations with growth-related traits.

RESULTS

In this study, we identified a total of 3,269 genes from differentially methylated regions (DMR), and detected 189 differentially expressed genes (DEGs) through RNA-seq analysis. Hypo DMR genes were primarily enriched in KEGG terms associated with muscle development, such as MAPK and PI3K-Akt signaling pathways. We selected 11 hub genes from the network that intersected the gene sets within DMR and DEGs, and nine genes exhibited significant correlation with one or more of the three LDM growth traits, namely area, height, and weight of loin eye muscle. Particularly, PRKG1 demonstrated a negative correlation with all three traits. The top five most crucial genes played vital roles in muscle fiber growth: FOXO3 safeguarded the myofiber's immune environment, FOXO6 was involved in myotube development and differentiation, and PRKG1 facilitated vasodilatation to release more glucose. This, in turn, accelerated the transfer of glucose from blood vessels to myofibers, regulated by ADCY5 and AKT2, ultimately ensuring glycogen storage and energy provision in muscle fibers.

CONCLUSION

This study delved into the diverse methylation modifications affecting critical genes, which collectively contribute to the maintenance of glycogen storage around myofibers, ultimately supporting muscle fiber growth.

Vascular calcification: from the perspective of crosstalk

Vascular calcification (VC) is highly correlated with cardiovascular disease morbidity and mortality, but anti-VC treatment remains an area to be tackled due to the ill-defined molecular mechanisms. Regardless of the type of VC, it does not depend on a single cell but involves multi-cells/organs to form a complex cellular communication network through the vascular microenvironment to participate in the occurrence and development of VC. Therefore, focusing only on the direct effect of pathological factors on vascular smooth muscle cells (VSMCs) tends to overlook the combined effect of other cells and VSMCs, including VSMCs-VSMCs, ECs-VMSCs, Macrophages-VSMCs, etc. Extracellular vesicles (EVs) are a collective term for tiny vesicles with a membrane structure that are actively secreted by cells, and almost all cells secrete EVs. EVs docked on the surface of receptor cells can directly mediate signal transduction or transfer their contents into the cell to elicit a functional response from the receptor cells. They have been proven to participate in the VC process and have also shown attractive therapeutic prospects. Based on the advantages of EVs and the ability to be detected in body fluids, they may become a novel therapeutic agent, drug delivery vehicle, diagnostic and prognostic biomarker, and potential therapeutic target in the future. This review focuses on the new insight into VC molecular mechanisms from the perspective of crosstalk, summarizes how multi-cells/organs interactions communicate via EVs to regulate VC and the emerging potential of EVs as therapeutic methods in VC. We also summarize preclinical experiments on crosstalk-based and the current state of clinical studies on VC-related measures.

EZH2 can be used as a therapeutic agent for inhibiting endothelial dysfunction

Enhancer of zeste homolog 2 (EZH2) is a catalytic subunit of polycomb repressor complex 2 and plays important roles in endothelial cell homeostasis. EZH2 functionally methylates lysine 27 of histone H3 and represses gene expression through chromatin compaction. EZH2 mediates the effects of environmental stimuli by regulating endothelial functions, such as angiogenesis, endothelial barrier integrity, inflammatory signaling, and endothelial mesenchymal transition. Numerous studies have been conducted to determine the significance of EZH2 in endothelial function. The aim of this review is to provide a concise summary of the roles EZH2 plays in endothelial function and elucidate its therapeutic potential in cardiovascular diseases.

Molecular mechanisms of endothelial remodeling under doxorubicin treatment

Doxorubicin (DOX) is an effective antineoplastic agent used to treat various types of cancers. However, its use is limited by the development of cardiotoxicity, which may result in heart failure. The exact mechanisms underlying DOX-induced cardiotoxicity are not fully understood, but recent studies have shown that endothelial-mesenchymal transition (EndMT) and endothelial damage play a crucial role in this process. EndMT is a biological process in which endothelial cells lose their characteristics and transform into mesenchymal cells, which have a fibroblast-like phenotype. This process has been shown to contribute to tissue fibrosis and remodeling in various diseases, including cancer and cardiovascular diseases. DOX-induced cardiotoxicity has been demonstrated to increase the expression of EndMT markers, suggesting that EndMT may play a critical role in the development of this condition. Furthermore, DOX-induced cardiotoxicity has been shown to cause endothelial damage, leading to the disruption of the endothelial barrier function and increased vascular permeability. This can result in the leakage of plasma proteins, leading to tissue edema and inflammation. Moreover, DOX can impair the production of nitric oxide, endothelin-1, neuregulin, thrombomodulin, thromboxane B2 etc. by endothelial cells, leading to vasoconstriction, thrombosis and further impairing cardiac function. In this regard, this review is devoted to the generalization and structuring of information about the known molecular mechanisms of endothelial remodeling under the action of DOX.

Single-Cell Profiling Uncovers the Roles of Endometrial Fibrosis and Microenvironmental Changes in Adenomyosis

Purpose

Adenomyosis (AM) is a common benign uterine disorder that has deleterious effects on women's health. However, the pathogenesis of AM is not clearly understood. We aimed to investigate the pathophysiological changes and molecular mechanism in AM.

Methods

Single-cell RNA sequencing (scRNA-seq) was employed to construct a transcriptomic atlas of various cell subsets from the ectopic endometrium (EC) and eutopic endometrium (EM) of one AM patient and evaluate differential expression. The Cell Ranger software pipeline (version 4.0.0) was applied to conduct sample demultiplexing, barcode processing and mapping reads to the reference genome (human GRCh38). Different cell types were classified with markers with the "FindAllMarkers" function, and differential gene expression analysis was performed with Seurat software in R. The findings were confirmed by Reverse Transcription Real-Time PCR using samples from three AM patients.

Results

We identified nine cell types: endothelial cells, epithelial cells, myoepithelial cells, smooth muscle cells, fibroblasts, lymphocytes, mast cells, macrophages and unknown cells. A number of differentially expressed genes, including CLO4A1, MMP1, TPM2 and CXCL8, were identified from all cell types. Functional enrichment showed that aberrant gene expression in fibroblasts and immune cells was related to fibrosis-associated terms, such as extracellular matrix dysregulation, focal adhesion and the PI3K-Akt signaling pathway. We also identified fibroblast subtypes and determined a potential developmental trajectory related to AM. In addition, we identified increased cell-cell communication patterns in EC, highlighting the imbalanced microenvironment in AM progression.

Conclusion

Our results support the theory of endometrial-myometrial interface disruption for AM, and repeated tissue injury and repair could lead to increased fibrosis in the endometrium. Therefore, the present study reveals the association between fibrosis, the microenvironment, and AM pathogenesis. This study provides insight into the molecular mechanisms regulating AM progression.

Integration of epigenetic regulatory mechanisms in heart failure

The number of "omics" approaches is continuously growing. Among others, epigenetics has appeared as an attractive area of investigation by the cardiovascular research community, notably considering its association with disease development. Complex diseases such as cardiovascular diseases have to be tackled using methods integrating different omics levels, so called "multi-omics" approaches. These approaches combine and co-analyze different levels of disease regulation. In this review, we present and discuss the role of epigenetic mechanisms in regulating gene expression and provide an integrated view of how these mechanisms are interlinked and regulate the development of cardiac disease, with a particular attention to heart failure. We focus on DNA, histone, and RNA modifications, and discuss the current methods and tools used for data integration and analysis. Enhancing the knowledge of these regulatory mechanisms may lead to novel therapeutic approaches and biomarkers for precision healthcare and improved clinical outcomes.

Epigenetics as a versatile regulator of fibrosis

Fibrosis, a process caused by excessive deposition of extracellular matrix (ECM), is a common cause and outcome of organ failure and even death. Researchers have made many efforts to understand the mechanism of fibrogenesis and to develop therapeutic strategies; yet, the outcome remains unsatisfactory. In recent years, advances in epigenetics, including chromatin remodeling, histone modification, DNA methylation, and noncoding RNA (ncRNA), have provided more insights into the fibrotic process and have suggested the possibility of novel therapy for organ fibrosis. In this review, we summarize the current research on the epigenetic mechanisms involved in organ fibrosis and their possible clinical applications.

Histone modification of endothelial-mesenchymal transition in cardiovascular diseases

Endothelial-mesenchymal transition (EndMT) is a differentiation process in which endothelial cells lose their own characteristics and acquire mesenchymal-like characteristics, which contributes to the formation and development of atherosclerotic plaques. Until now, there is still a lack of effective measures to treat atherosclerosis (AS), so there is an urgent need to understand the underlying mechanisms of AS. In addition, although various studies have shown that EndMT is involved in the pathological stages of cardiovascular diseases, such as myocardial fibrosis, myocardial hypertrophy, and hypertension, the specific molecular mechanisms driving EndMT are still in the exploratory stage. In this review, we review the role of histone modifications (methylation, demethylation and acetylation, deacetylation) on EndMT in cardiovascular disease, aiming to target histone-modifying enzymes to guide cardiovascular disease therapy.

Transforming growth factor-β-induced secretion of extracellular vesicles from oral cancer cells evokes endothelial barrier instability via endothelial-mesenchymal transition

Background

During metastasis, cancer cells undergo epithelial-mesenchymal transition (EMT) in response to transforming growth factor-β (TGF-β), which is abundant in the tumor microenvironment, and acquire invasive and metastatic potentials. Metastasis to distant organs requires intravascular invasion and extravasation of cancer cells, which is accompanied by the disruption of the adhesion between vascular endothelial cells. Cancer cell-derived extracellular vesicles (EVs) have been suggested to induce the destabilization of normal blood vessels at the metastatic sites. However, the roles of EVs secreted from cancer cells that have undergone EMT in the destabilization of blood vessels remain to be elucidated. In the present study, we characterized EVs secreted by oral cancer cells undergoing TGF-β-induced EMT and elucidated their effects on the characteristics of vascular endothelial cells.

Methods

Induction of EMT by TGF-β in human oral cancer cells was assessed using quantitative RT-PCR (qRT-PCR) and immunocytochemistry. Oral cancer cell-derived EVs were isolated from the conditioned media of oral cancer cells that were treated with or without TGF-β using ultracentrifugation, and characterized using nanoparticle tracking analysis and immunoblotting. The effects of EVs on human umbilical artery endothelial cells were examined by qRT-PCR, cellular staining, and permeability assay. The significant differences between means were determined using a t-test or one-way analysis of variance with Tukey’s multiple comparisons test.

Results

Oral cancer cells underwent EMT in response to TGF-β as revealed by changes in the expression of epithelial and mesenchymal cell markers at both the RNA and protein levels. Oral cancer cells treated with TGF-β showed increased EV production and altered EV composition when compared with untreated cells. The EVs that originated from cells that underwent EMT by TGF-β induced endothelial-mesenchymal transition, which was characterized by the decreased and increased expression of endothelial and mesenchymal cell markers, respectively. EVs derived from oral cancer cells also induced intercellular gap formation which led to the loss of endothelial cell barrier stability.

Conclusions

EVs released from oral cancer cells that underwent TGF-β-induced EMT target endothelial cells to induce vascular destabilization. Detailed characterization of oral cancer-derived EVs and factors responsible for EV-mediated vascular instability will lead to the development of agents targeting metastasis.

Supplementary Information

The online version contains supplementary material available at 10.1186/s41232-022-00225-7.

Engineering bioactive nanoparticles to rejuvenate vascular progenitor cells

Fetal exposure to gestational diabetes mellitus (GDM) predisposes children to future health complications including type-2 diabetes mellitus, hypertension, and cardiovascular disease. A key mechanism by which these complications occur is through stress-induced dysfunction of endothelial progenitor cells (EPCs), including endothelial colony-forming cells (ECFCs). Although several approaches have been previously explored to restore endothelial function, their widespread adoption remains tampered by systemic side effects of adjuvant drugs and unintended immune response of gene therapies. Here, we report a strategy to rejuvenate circulating vascular progenitor cells by conjugation of drug-loaded liposomal nanoparticles directly to the surface of GDM-exposed ECFCs (GDM-ECFCs). Bioactive nanoparticles can be robustly conjugated to the surface of ECFCs without altering cell viability and key progenitor phenotypes. Moreover, controlled delivery of therapeutic drugs to GDM-ECFCs is able to normalize transgelin (TAGLN) expression and improve cell migration, which is a critical key step in establishing functional vascular networks. More importantly, sustained pseudo-autocrine stimulation with bioactive nanoparticles is able to improve in vitro and in vivo vasculogenesis of GDM-ECFCs. Collectively, these findings highlight a simple, yet promising strategy to rejuvenate GDM-ECFCs and improve their therapeutic potential. Promising results from this study warrant future investigations on the prospect of the proposed strategy to improve dysfunctional vascular progenitor cells in the context of other chronic diseases, which has broad implications for addressing various cardiovascular complications, as well as advancing tissue repair and regenerative medicine.

Drug-loaded liposomal nanoparticles conjugated to endothelial colony-forming cells can improve the vasculogenic potential of vascular progenitor cells exposed to gestational diabetes mellitus.

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.

Elevated H3K4me3 Through MLL2-WDR82 upon Hyperglycemia Causes Jagged Ligand Dependent Notch Activation to Interplay with Differentiation State of Endothelial Cells

Endothelial-to-mesenchymal transition (EndMT) is a hallmark of diabetes-associated vascular complications. Epigenetic mechanisms emerged as one of the key pathways to regulate diabetes-associated complications. In the current study, we aimed to determine how abrupt changes in histone 3 lysine 4 tri-methylation (H3K4me3) upon hyperglycemia exposure reprograms endothelial cells to undergo EndMT. Through in vitro studies, we first establish that intermittent high-glucose exposure to EC most potently induced partial mesenchyme-like characteristics compared with transient or constant high-glucose-challenged endothelial cells. In addition, glomerular endothelial cells of BTBR Ob/Ob mice also exhibited mesenchymal-like characteristics. Intermittent hyperglycemia-dependent induction of partial mesenchyme-like phenotype of endothelial cells coincided with an increase in H3K4me3 level in both macro- and micro-vascular EC due to selective increase in MLL2 and WDR82 protein of SET1/COMPASS complex. Such an endothelial-specific heightened H3K4me3 level was also detected in intermittent high-glucose-exposed rat aorta and in kidney glomeruli of Ob/Ob mice. Elevated H3K4me3 enriched in the promoter regions of Notch ligands Jagged1 and Jagged2, thus causing abrupt expression of these ligands and concomitant activation of Notch signaling upon intermittent hyperglycemia challenge. Pharmacological inhibition and/or knockdown of MLL2 in cells in vitro or in tissues ex vivo normalized intermittent high-glucose-mediated increase in H3K4me3 level and further reversed Jagged1 and Jagged2 expression, Notch activation and further attenuated acquisition of partial mesenchyme-like phenotype of endothelial cells. In summary, the present study identifies a crucial role of histone methylation in hyperglycemia-dependent reprograming of endothelial cells to undergo mesenchymal transition and indicated that epigenetic pathways contribute to diabetes-associated vascular complications.

Histone Lysine Methylation Modification and Its Role in Vascular Calcification

Histone methylation is an epigenetic change mediated by histone methyltransferase, and has been connected to the beginning and progression of several diseases. The most common ailments that affect the elderly are cardiovascular and cerebrovascular disorders. They are the leading causes of death, and their incidence is linked to vascular calcification (VC). The key mechanism of VC is the transformation of vascular smooth muscle cells (VSMCs) into osteoblast-like phenotypes, which is a highly adjustable process involving a variety of complex pathophysiological processes, such as metabolic abnormalities, apoptosis, oxidative stress and signalling pathways. Many researchers have investigated the mechanism of VC and related targets for the prevention and treatment of cardiovascular and cerebrovascular diseases. Their findings revealed that histone lysine methylation modification may play a key role in the various stages of VC. As a result, a thorough examination of the role and mechanism of lysine methylation modification in physiological and pathological states is critical, not only for identifying specific molecular markers of VC and new therapeutic targets, but also for directing the development of new related drugs. Finally, we provide this review to discover the association between histone methylation modification and VC, as well as diverse approaches with which to investigate the pathophysiology of VC and prospective treatment possibilities.

Novel application of live imaging to determine the functional cell biology of endothelial-to-mesenchymal transition (EndMT) within a liver-on-a-chip platform

Objective

Imaging endothelial cell behaviour under physiological conditions, particularly those associated with chronic fibrotic pathologies, is an incredibly challenging endeavour. While short-term assessments (hours) can be achieved with techniques such as intravital microscopy, vascular changes often occur over days and weeks which is unfeasible with current imaging techniques. These challenges are exemplified within the liver where liver sinusoidal endothelial cells (LSECs) are known to undergo dramatic changes termed endothelial-to-mesenchymal transition (EndMT) during fibrotic liver disease. Despite the established presence of EndMT in liver disease, the inaccessibility of viable liver tissue, and simplicity of 2D culture techniques has meant, the role of EndMT during disease progression remains largely undetermined. This study describes the development of novel fluorescent EndMT reporters to identify, track, and characterise the migratory behaviour of EndMT cells. We show that liver-on-a-chip (LOAC) platforms provide a flexible, optically accessible, and physiologically relevant microenvironment to study the vascular dynamics of EndMT during liver disease.

Methods

Identification, creation, and application of an EndMT-specific fluorescent reporter construct (EndMT-Rep). Transduction of EC using lentiviral packaged CNN1-eGFP construct as an inducible EndMT-Rep (CNN1-Rep) to 2D, 3D, and 4D imaging techniques for fixed and live cell imaging. Combined application of live and fixed imaging technologies to measure EndMT using CNN1-Rep on LOAC platform under physiological conditions. Demonstration of the high-resolution single-cell EndMT tracking by live cell time-lapse microscopy and with post-acquisition processing to perform a comparative study of CNN1-Rep and healthy LSECs within a NASH-like LOAC microenvironment.

Conclusions

LOAC enables prolonged, multi-platform imaging of endothelial cell sub-populations such as those undergoing EndMT in 2D and 3D cultures. Our study highlights the application of EndMT reporters, such as CNN1-Rep, to provide high-resolution imaging of EndMT behaviour for the first time under physiologically relevant liver microenvironment. Overall, these methods reveal the adaptability and impact of live-cell imaging on uncovering vascular behaviours, such as EndMT, that are unattainable in viable tissue or conventional 2D in vitro experiments.

Supplementary Information

The online version contains supplementary material available at 10.1007/s44164-022-00034-9.

Regulation of Partial and Reversible Endothelial-to-Mesenchymal Transition in Angiogenesis

During development and in several diseases, endothelial cells (EC) can undergo complete endothelial-to-mesenchymal transition (EndoMT or EndMT) to generate endothelial-derived mesenchymal cells. Emerging evidence suggests that ECs can also undergo a partial EndoMT to generate cells with intermediate endothelial- and mesenchymal-character. This partial EndoMT event is transient, reversible, and supports both developmental and pathological angiogenesis. Here, we discuss possible regulatory mechanisms that may control the EndoMT program to dictate whether cells undergo complete or partial mesenchymal transition, and we further consider how these pathways might be targeted therapeutically in cancer.

RETRACTED: Tumor cell-secreted exosomal miR-22-3p inhibits transgelin and induces vascular abnormalization to promote tumor budding

This article has been retracted: please see Elsevier Policy on Article Withdrawal (http://www.elsevier.com/locate/withdrawalpolicy). This article has been retracted at the request of the editor-in-chief. The editor-in-chief was informed of evidence for image duplication in identical or altered fashion in Figures 3A and 8D, as well as undisclosed reuse of an image in Figure 5B from a previous article in Cell Death & Disease (https://doi.org/10.1038/s41419-018-0902-5), in a PubPeer thread: https://pubpeer.com/publications/F5B591481C516F4CE42C7925AC48E9. Image analysis performed by the journal's editorial office confirmed these findings. This reuse (and in part misrepresentation) of data without appropriate attribution represents a severe abuse of the scientific publishing system.

Mesenchymal stem cells-derived extracellular vesicles carrying microRNA-17 inhibits macrophage apoptosis in lipopolysaccharide-induced sepsis

OBJECTIVE

Sepsis, as a disease affecting the microcirculation and tissue perfusion, results in tissue hypoxia and multiple organ dysfunctions. Bone mesenchymal stem cell (BMSC)-derived extracellular vesicles (EVs) have been demonstrated to transfer trivial molecules (proteins/peptides, mRNA, microRNA and lipids) to alleviate sepsis. We sought to define the function of microRNA (miR)-17 carried in BMSC-EVs in sepsis.

METHODS

The purity of the extracted BMSCs was identified and confirmed by detection of the surface markers by flow cytometry, followed by osteoblastic, adipogenic, and chondrocyte differentiation experiments. Subsequently, EVs were collected from the medium of BMSCs. The uptake of PKH-67-labeled BMSC-EVs or EVs carrying cy3-miR-17 by RAW264.7 cells was observed under laser confocal microscopy. Furthermore, a series of gain- and loss-of-function approaches were conducted to test the effects of LPS, miR-17 and BRD4 on the inflammatory factors (IL-1β, IL-6 and TNF-α), number of M1 macrophages and M2 macrophages, inflammatory-related signal pathway factors (EZH2, c-MYC and TRAIL), macrophage proliferation, and apoptosis in sepsis. The survival rates were measured in vivo.

RESULTS

BMSC-EVs was internalized by the RAW264.7 cells. BDR4 was verified as a target of miR-17, while the expression pattern of miR-17 was upregulated in BMSC-EVs. MiR-17 carried by BMSC-EVs inhibited LPS-induced inflammation and apoptosis of RAW264.7 cells, but improved the viability of RAW264.7 cells. Next, in vitro experiments supported that miR-17 inhibited LPS-induced inflammation in RAW264.7 cells through BRD4/EZH2/TRAIL axis. BRD4 overexpression reversed the effects of miR-17. Moreover, the therapeutic function of BMSC-EVs carried miR-17 was verified by in vivo experiments.

CONCLUSIONS

MiR-17 derived from BMSCs-EVs regulates BRD4-mediated EZH2/TRAIL axis to essentially inhibit LPS-induced macrophages inflammation.

The Effect of EZH2 Inhibition through DZNep on Epithelial-Mesenchymal Transition Mechanism

Although the molecular pathogenesis of hepatocellular carcinoma (HCC) is uncertain, it is known that the epithelial-mesenchymal transition (EMT) mechanism and epigenetic changes have an important role. This study was focused on evaluating the relationship of 3-Deazaneplanocin A (DZNep) with the EMT mechanism, which is a histone methyltransferase inhibitor on HCC and is also known as an enhancer of zeste homolog 2 (EZH2) inhibitor. Cell viability of HepG2 cells (HCC cell line) assessed for DZNep over 72 hours with 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Additionally, colony-forming assay, apoptosis assay, RNA isolation, cDNA synthesis, and real-time PCR (RT-PCR) were performed to see the effect of DZNep on HepG2 cells. DZNep reduced cell proliferation for 72 hours, also significantly reduced colony formation in addition it increased the total apoptosis. DZNep on EZH2, E-cadherin, N-cadherin, and Vimentin (Vim) gene expressions was given different results by either decreasing or increasing the expressions. In this study, we observed a positive effect of DZNep on apoptosis and TIMP3 expression level and decreased colony formation. However, it gave complicated results with the level of gene expression E-cadherin and TIMP2, increase the level of Vim and MMP2 expression. Therefore, we think that further studies are necessary to clarify the role of DZNep.

MFGE8 is down-regulated in cardiac fibrosis and attenuates endothelial-mesenchymal transition through Smad2/3-Snail signalling pathway

Endothelial‐mesenchymal transition (EndMT) is a major source of transformed cardiac fibroblasts, which is reported to play a key role in cardiac fibrosis (CF), a pathogenesis of cardiovascular diseases such as heart failure, myocardial infarction and atrial fibrillation. Nonetheless, the specific mechanism underlying the progression of EndMT to CF is still largely unknown. In this study, we aimed to investigate the role of milk fat globule‐EGF factor 8 (MFGE8), a kind of soluble glycoprotein, in TGF‐β1‐induced EndMT. In animal experiments, the expression of MFGE8 was found down‐regulated in the left ventricle and aorta of rats after transverse aortic constriction (TAC) compared with the sham group, especially in endothelial cells (ECs). In in vitro cultured ECs, silencing MFGE8 with small interfering RNA (siRNA) was found to promote the process of TGF‐β1‐induced EndMT, whereas administration of recombinant human MFGE8 (rh‐MFGE8) attenuated the process. Moreover, activated Smad2/3 signalling pathway after TGF‐β1 treatment and EndMT‐related transcription factors, such as Snail, Twist and Slug, was potentiated by MFGE8 knock‐down but inhibited by rh‐MFGE8. In conclusion, our experiments indicate that MFGE8 might play a protective role in TGF‐β1‐induced EndMT and might be a potential therapeutic target for cardiac fibrosis.

Endothelial-to-Mesenchymal Transition in Cancer

Cancer is one of the most important causes of morbidity and mortality worldwide. Tumor cells grow in a complex microenvironment constituted of immune, stromal, and vascular cells that supports growth, angiogenesis, and metastasis. Endothelial cells (ECs) are major components of the vascular microenvironment. These cells have been described for their plasticity and potential to transdifferentiate into mesenchymal cells through a process known as endothelial-to-mesenchymal transition (EndMT). This complex process is controlled by various factors, by which ECs convert into a phenotype characterized by mesenchymal protein expression and motile, contractile morphology. Initially described in normal heart development, EndMT is now identified in several pathologies, and especially in cancer. In this review, we highlight the process of EndMT in the context of cancer and we discuss it as an important adaptive process of the tumor microenvironment that favors tumor growth and dissemination but also resistance to treatment. Thus, we underline targeting of EndMT as a potential therapeutic strategy.

Endothelial to mesenchymal transition (EndMT) and vascular remodeling in pulmonary hypertension and idiopathic pulmonary fibrosis

INTRODUCTION

Idiopathic pulmonary fibrosis (IPF) is a chronic, progressive, and irreversible fibrotic disease associated with respiratory failure. The disease remains idiopathic, but repeated alveolar epithelium injury, disruption of alveolar-capillary integrity, abnormal vascular repair, and pulmonary vascular remodeling are considered possible pathogenic mechanisms. Also, the development of comorbidities such as pulmonary hypertension (PH) could further impact disease outcome, quality of life and survival rates in IPF.

AREAS COVERED

The current review provides a comprehensive literature survey of the mechanisms involved in the development and manifestations of IPF and their links to PH pathology. This review also provides the current understanding of molecular mechanisms that link the two pathologies and will specifically decipher the role of endothelial to mesenchymal transition (EndMT) along with the possible triggers of EndMT. The possibility of targeting EndMT as a therapeutic option in IPF is discussed.

EXPERT OPINION

With a steady increase in prevalence and mortality, IPF is no longer considered a rare disease. Thus, it is of utmost importance and urgency that the underlying profibrotic pathways and mechanisms are fully understood, to enable the development of novel therapeutic strategies.

Dual roles of chromatin remodeling protein BRG1 in angiotensin II-induced endothelial-mesenchymal transition

Endothelial–mesenchymal transition (EndMT) is considered one of the processes underlying tissue fibrosis by contributing to the pool of myofibroblasts. In the present study, we investigated the epigenetic mechanism whereby angiotensin II (Ang II) regulates EndMT to promote cardiac fibrosis focusing on the role of chromatin remodeling protein BRG1. BRG1 knockdown or inhibition attenuated Ang II-induced EndMT, as evidenced by down-regulation of CDH5, an endothelial marker, and up-regulation of COL1A2, a mesenchymal marker, in cultured vascular endothelial cells. On the one hand, BRG1 interacted with and was recruited by Sp1 to the SNAI2 (encoding SLUG) promoter to activate SNAI2 transcription in response to Ang II stimulation. Once activated, SLUG bound to the CDH5 promoter to repress CDH5 transcription. On the other hand, BRG1 interacted with and was recruited by SRF to the COL1A2 promoter to activate COL1A2 transcription. Mechanistically, BRG1 evicted histones from the target promoters to facilitate the bindings of Sp1 and SRF. Finally, endothelial conditional BRG1 knockout mice (CKO) exhibited a reduction in cardiac fibrosis, compared to the wild type (WT) littermates, in response to chronic Ang II infusion. In conclusion, our data demonstrate that BRG1 is a key transcriptional coordinator programming Ang II-induced EndMT to contribute to cardiac fibrosis.

Non-coding RNA in endothelial-to-mesenchymal transition

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

Puromycin aminonucleoside-induced podocyte injury is ameliorated by the Smad3 inhibitor SIS3

Smad3 signaling and transgelin expression are often activated during puromycin aminonucleoside (PAN)‐induced podocyte injury. Here, we investigated whether the Smad3 inhibitor SIS3 can ameliorate damage to injured podocytes. A model of PAN‐induced podocyte injury was constructed using the MPC5 cell line. The effects of SIS3 on the expression of the podocyte cytoskeletal proteins transgelin, p15^INK4B, phosphor‐smad3, phosphor‐JAK/stat3, the apoptotic marker cleaved caspase 3, and c‐myc were investigated using western blot. The distribution of F‐actin in PAN‐induced podocyte injury was observed under an immunofluorescence microscope. PAN‐induced podocyte injury altered the distribution of F‐actin and transgelin, and colocalization of these two proteins was observed. Transgelin expression and Smad3 phosphorylation were increased in the MPC5 cell line with prolonged PAN treatment. In addition, c‐myc expression, p15^INK4B, and JAK phosphorylation were all increased after treatment with PAN. Treatment with the Smad3 inhibitor SIS3 reversed these phenomena and protected against PAN‐induced podocyte injury. Moreover, stimulating podocytes directly with TGFβ‐1 also led to enhanced expression of transgelin or phosphor‐JAK/stat3, and this could be inhibited by SIS3. In conclusion, transgelin expression was induced through the Smad3 signaling pathway during PAN‐induced podocyte injury, and the resulting abnormal distribution of F‐actin and the enhanced expression of transgelin could be reversed by blockade of this pathway.

Inhibition of EZH2 attenuates inhibitory synaptic transmission via the pro-inflammatory pathway in rats

Enhancer of zeste homolog 2 (EZH2), a subunit of the polycomb repressive complex 2 (PRC2), is associated with seizure development and epileptogenesis, however, the underlying mechanism of the process remains to be elucidated. This study focused on exploring whether EZH2 regulated gamma-aminobutyric acid (GABA)-mediated neurotransmission during seizure generation. Hyperthermia-induced seizures were generated in Sprague-Dawley (SD) rats using a hot (43.5 °C) bath method, and seizure severity was evaluated according to the Racine scale. The effect of treatment with the EZH2 pharmacological inhibitor GSK 126 on the GABA and pro-inflammatory cytokine levels was tested using enzyme-linked immunosorbent assay (ELISA). Miniature inhibitory postsynaptic currents (mIPSCs) were recorded using whole-cell patch clamp. In this study, our results showed that intracerebroventricular (i.c.v) injection of the EZH2 pharmacological inhibitor GSK 126 (10 nM) increased seizure severity and shortened seizure latency in a rat model of FS, and these effects were accompanied by reduced GABA content. Furthermore, GSK 126 (1 μM) treatment decreased the mean amplitude and frequency of the mIPSCs in cultured hippocampal neurons subjected to hyperthermia. Importantly, the same results were also obtained in cultured neurons infected with lentivirus carrying EZH2 shRNA. In addition, a significant increase in the pro-inflammatory cytokine (IL-1β and TNF-α) levels was observed in rats after GSK 126 treatment, and IL-1β administration increased seizure severity, suggesting that the inflammatory response was involved in the regulation of seizure development by EZH2. This study helps clarify the role of EZH2 in FS and supports EZH2 administration as an effective target for the management of seizure generation.

Fibronectin has multifunctional roles in posterior capsular opacification (PCO)

Fibrotic posterior capsular opacification (PCO), one of the major complications of cataract surgery, occurs when lens epithelial cells (LCs) left behind post cataract surgery (PCS) undergo epithelial to mesenchymal transition, migrate into the optical axis and produce opaque scar tissue. LCs left behind PCS robustly produce fibronectin, although its roles in fibrotic PCO are not known. In order to determine the function of fibronectin in PCO pathogenesis, we created mice lacking the fibronectin gene (FN conditional knock out -FNcKO) from the lens. While animals from this line have normal lenses, upon lens fiber cell removal which models cataract surgery, FNcKO LCs exhibit a greatly attenuated fibrotic response from 3 days PCS onward as assessed by a reduction in surgery-induced cell proliferation, and fibrotic extracellular matrix (ECM) production and deposition. This is correlated with less upregulation of Transforming Growth Factor β (TGFβ) and integrin signaling in FNcKO LCs PCS concomitant with sustained Bone Morphogenetic Protein (BMP) signaling and elevation of the epithelial cell marker E cadherin. Although the initial fibrotic response of FNcKO LCs was qualitatively normal at 48 h PCS as measured by the upregulation of fibrotic marker protein αSMA, RNA sequencing revealed that the fibrotic response was already quantitatively attenuated at this time, as measured by the upregulation of mRNAs encoding molecules that control, and are controlled by, TGFβ signaling, including many known markers of fibrosis. Most notably, gremlin-1, a known regulator of TGFβ superfamily signaling, was upregulated sharply in WT LCs PCS, while this response was attenuated in FNcKO LCs. As exogenous administration of either active TGFβ1 or gremlin-1 to FNcKO lens capsular bags rescued the attenuated fibrotic response of fibronectin null LCs PCS including the loss of SMAD2/3 phosphorylation, this suggests that fibronectin plays multifunctional roles in fibrotic PCO development.

Smad3 signalling affects high glucose-induced podocyte injury via regulation of the cytoskeletal protein transgelin

Aim

The aim of the present study was to characterize the role of Smad3 signalling on high glucose‐induced podocyte injury.

Methods

Synchronized conditionally immortalized mouse podocyte cell line (MPC5) cells were treated with either D‐glucose alone or D‐glucose plus the Smad3 inhibitor SIS3. The distribution of F‐actin and transgelin in a high glucose‐induced model of podocyte injury were examined by immunofluorescence. Levels of transgelin and Smad3 signalling proteins in MPC5 cells were determined by Western blot.

Results

A disordered distribution of F‐actin, as well as co‐localization of F‐actin and transgelin, was observed in podocytes exposed to high glucose. Increased levels of transgelin were first observed 10 minutes after treatment with glucose, suggesting that this protein is sensitive to hyperglycaemic injury. Levels of phosphorylated Smad3 and cleaved caspase 3 increased significantly with glucose stimulation. Moreover, expression of the downstream protein c‐Myc, but not JAK1/STAT3, was induced in conditions of high glucose. The Smad3‐specific inhibitor SIS3 prevented the effects of high glucose on Smad3 phosphorylation, expression of transgelin and c‐Myc, caspase 3 cleavage and cytoskeletal organization. Expression of the tumour suppressor protein p15^INK4B increased after podocyte injury but was unaffected by Smad3 inhibition, suggesting that Smad3 regulation of high glucose‐induced podocyte injury occurs through a p15^INK4B‐independent mechanism.

Conclusion

Smad3 signalling plays a critical role in the modulation of hyperglycaemic injury. Targeted inhibition of the Smad3 pathway may offer a novel route for treatment of podocyte damage, especially in cases of diabetic nephropathy.

Podocyte damage is characteristic of diabetic kidney disease. This study showed that inhibition of Smad‐3 signalling using the specific inhibitor SIS3 in vitro, could alleviate podocyte abnormalities induced by high glucose including actin cytoskeletal rearrangement and actviation of cell death pathways.

The histone demethylase JMJD2B regulates endothelial-to-mesenchymal transition

Here we show that the histone demethylase JMJD2B is induced in endothelial cells by EndMT provoking stimuli and thereby contributes to the acquirement of a mesenchymal/smooth muscle phenotype. Silencing of JMJD2B inhibited EndMT in vitro and reduced the induction of EndMT after myocardial infarction in vivo. Inhibition of JMJD2B prevents the demethylation of repressive trimethylated histone H3 at lysine 9 (H3K9me3) at promoters of mesenchymal and EndMT-controlling genes, thereby reducing EndMT. Together, our study reports a crucial role for JMJD2B in controlling histone modifications during the transition of endothelial cells toward a mesenchymal phenotype.

Endothelial cells play an important role in maintenance of the vascular system and the repair after injury. Under proinflammatory conditions, endothelial cells can acquire a mesenchymal phenotype by a process named endothelial-to-mesenchymal transition (EndMT), which affects the functional properties of endothelial cells. Here, we investigated the epigenetic control of EndMT. We show that the histone demethylase JMJD2B is induced by EndMT-promoting, proinflammatory, and hypoxic conditions. Silencing of JMJD2B reduced TGF-β2-induced expression of mesenchymal genes, prevented the alterations in endothelial morphology and impaired endothelial barrier function. Endothelial-specific deletion of JMJD2B in vivo confirmed a reduction of EndMT after myocardial infarction. EndMT did not affect global H3K9me3 levels but induced a site-specific reduction of repressive H3K9me3 marks at promoters of mesenchymal genes, such as Calponin (CNN1), and genes involved in TGF-β signaling, such as AKT Serine/Threonine Kinase 3 (AKT3) and Sulfatase 1 (SULF1). Silencing of JMJD2B prevented the EndMT-induced reduction of H3K9me3 marks at these promotors and further repressed these EndMT-related genes. Our study reveals that endothelial identity and function is critically controlled by the histone demethylase JMJD2B, which is induced by EndMT-promoting, proinflammatory, and hypoxic conditions, and supports the acquirement of a mesenchymal phenotype.

EZH2 Regulates Intestinal Inflammation and Necroptosis Through the JNK Signaling Pathway in Intestinal Epithelial Cells

BACKGROUND

Inflammatory bowel disease (IBD) is a common disorder of chronic intestinal inflammation that can be caused by the disruption of intestinal immune homeostasis.

AIM

We aimed to evaluate the role of enhancer of zeste homolog 2 (EZH2) in the inflammatory response and explore the association between EZH2 and necroptosis in human epithelial colorectal adenocarcinoma cell lines.

METHODS

In both in vitro and in vivo models, expression of EZH2 in intestinal tissues was verified by histology. The expression of inflammatory cytokines in cell lines treated with EZH2 siRNA with or without stimulus was analyzed by quantitative real-time polymerase chain reaction. An intestinal necroptosis cell model was established to elucidate whether EZH2 is involved in necroptosis.

RESULTS

Our present data indicated that EZH2 expression was decreased in in vitro and in vivo models and in patients with inflammatory bowel disease. EZH2 downregulation increased the expression of inflammatory factors, including TNF-α, IL-8, IL-17, CCL5, and CCL20 in a Caco-2 cell model. The JNK pathway was activated with the reduction of EZH2. In the necroptosis model, downregulation of EZH2 was detected with the upregulation of necroptotic markers RIP1 and RIP3. In addition, EZH2 knockdown with siRNA increased p-JNK and p-c-Jun.

CONCLUSION

Our data suggest that EZH2 plays an important role in the development of intestinal inflammation and necroptosis. Hence, EZH2 could be a potential therapeutic target for IBD.

miR-181b-5p inhibits endothelial-mesenchymal transition in monocrotaline-induced pulmonary arterial hypertension by targeting endocan and TGFBR1

Endothelial-mesenchymal transition (EndMT) is a frequent event in endothelial dysfunction, which is associated with pulmonary arterial hypertension (PAH). MiR-181 family members exert diverse effects in multiple biological processes. However, the relationships between miR-181b-5p (miR-181b) and EndMT in PAH are not well understood. In this study, Sprague-Dawley (SD) rats were injected with monocrotaline (MCT) to establish PAH model, and primary rat pulmonary arterial endothelial cells (rPAECs) were treated with TNF-α, TGFβ1 and IL-1β in combination to induce EndMT (I-EndMT). Then we explored miR-181b expression and examined its functional role in PAH. Our data showed that miR-181b was down-expressed in PAH, and its overexpression attenuated the hemodynamics, pulmonary vascular hypertrophy, right ventricular remodeling and EndMT process in MCT-induced PAH rats. In I-EndMT rPAECs, we observed that inducing miR-181b reversed the decrease of endothelial markers and increase of mesenchymal markers. However, knockdown of miR-181b induced similar effects to EndMT. In addition, endocan and TGFBR1 levels were also increased in EndMT, which were negatively regulated by miR-181b. Luciferase activity results indicated that endocan and TGFBR1 were direct target genes of miR-181b. In summary, our findings firstly demonstrate that the beneficial effect of miR-181b on PAH may be associated with endocan/TGFBR1-mediated EndMT, providing a new insight into the diagnosis and treatment of PAH.

Adipose tissue-derived stromal cells' conditioned medium modulates endothelial-mesenchymal transition induced by IL-1β/TGF-β2 but does not restore endothelial function

Objectives

Endothelial cells undergo TGF‐β–driven endothelial‐mesenchymal transition (EndMT), representing up to 25% of cardiac myofibroblasts in ischaemic hearts. Previous research showed that conditioned medium of adipose tissue–derived stromal cells (ASC‐CMed) blocks the activation of fibroblasts into fibrotic myofibroblasts. We tested the hypothesis that ASC‐CMed abrogates EndMT and prevents the formation of adverse myofibroblasts.

Materials and methods

Human umbilical vein endothelial cells (HUVEC) were treated with IL‐1β and TGF‐β2 to induce EndMT, and the influence of ASC‐CMed was assessed. As controls, non‐treated HUVEC or HUVEC treated only with IL‐1β in the absence or presence of ASC‐CMed were used. Gene expression of inflammatory, endothelial, mesenchymal and extracellular matrix markers, transcription factors and cell receptors was analysed by RT‐qPCR. The protein expression of endothelial and mesenchymal markers was evaluated by immunofluorescence microscopy and immunoblotting. Endothelial cell function was measured by sprouting assay.

Results

IL‐1β/TGF‐β2 treatment induced EndMT, as evidenced by the change in HUVEC morphology and an increase in mesenchymal markers. ASC‐CMed blocked the EndMT‐related fibrotic processes, as observed by reduced expression of mesenchymal markers TAGLN (P = 0.0008) and CNN1 (P = 0.0573), as well as SM22α (P = 0.0501). The angiogenesis potential was impaired in HUVEC undergoing EndMT and could not be restored by ASC‐CMed.

Conclusions

We demonstrated that ASC‐CMed reduces IL‐1β/TGF‐β2‐induced EndMT as observed by the loss of mesenchymal markers. The present study supports the anti‐fibrotic effects of ASC‐CMed through the modulation of the EndMT process.

TGF-β-induced transgelin promotes bladder cancer metastasis by regulating epithelial-mesenchymal transition and invadopodia formation

Background

Metastatic bladder cancer (BLCA) is a lethal disease with an unmet need for study. Transgelin (TAGLN) is an actin-binding protein that affects the dynamics of the actin cytoskeleton indicating its robust potential as a metastasis initiator. Here, we sought to explore the expression pattern of TAGLN and elucidate its specific functioning and mechanisms in BLCA.

Methods

A comprehensive assessment of TAGLN expression in BLCA was performed in three cohorts with a total of 847 patients. The potential effects of TAGLN on BLCA were further determined using clinical genomic analyses that guided the subsequent functional and mechanistic studies. In vitro migration, invasion assays and in vivo metastatic mouse model were performed to explore the biological functions of TAGLN in BLCA cells. Immunofluorescence, western blot and correlation analysis were used to investigate the molecular mechanisms of TAGLN.

Findings

TAGLN was highly expressed in BLCA and correlated with advanced prognostic features. TAGLN promoted cell colony formation and cell migration and invasion both in vitro and in vivo by inducing invadopodia formation and epithelial-mesenchymal transition, during which a significant correlation between TAGLN and Slug was observed. The progression-dependent correlation between TGF-β and TAGLN was analysed at both the cellular and tissue levels, while TGF-β-mediated migration was abolished by the suppression of TAGLN.

Interpretation

Overall, TAGLN is a promising novel prognosis biomarker of BLCA, and its metastatic mechanisms indicate that TAGLN may represent a novel target agent that can be utilized for the clinical management of invasive and metastatic BLCA.

Fund

This work was supported by the National Natural Science Foundation of China [81772703, 81672546, 81602253]; the Natural Science Foundation of Beijing [71772219, 7152146]. and Innovative Fund for Doctoral Students of Peking University Health Science Center (BUM2018BSS002). Funders had no role in the design of the study, data collection, data analysis, interpretation, or the writing of this report.

Epigenetic Regulation of Endothelial-to-Mesenchymal Transition in Chronic Heart Disease

Endothelial-to-mesenchymal transition (EndMT) is a process in which endothelial cells lose their properties and transform into fibroblast-like cells. This transition process contributes to cardiac fibrosis, a common feature of patients with chronic heart failure. To date, no specific therapies to halt or reverse cardiac fibrosis are available, so knowledge of the underlying mechanisms of cardiac fibrosis is urgently needed. In addition, EndMT contributes to other cardiovascular pathologies such as atherosclerosis and pulmonary hypertension, but also to cancer and organ fibrosis. Remarkably, the molecular mechanisms driving EndMT are largely unknown. Epigenetics play an important role in regulating gene transcription and translation and have been implicated in the EndMT process. Therefore, epigenetics might be the missing link in unraveling the underlying mechanisms of EndMT. Here, we review the involvement of epigenetic regulators during EndMT in the context of cardiac fibrosis. The role of DNA methylation, histone modifications (acetylation and methylation), and noncoding RNAs (microRNAs, long noncoding RNAs, and circular RNAs) in the facilitation and inhibition of EndMT are discussed, and potential therapeutic epigenetic targets will be highlighted.

HiPS-Cardiac Trilineage Cell Generation and Transplantation: a Novel Therapy for Myocardial Infarction

Despite primary percutaneous coronary intervention (PPCI) and the availability of optimal medications, including dual antiplatelet therapy (DAPT), most patients still experience major adverse cardiovascular events (MACEs) due to frequent recurrence of thrombotic complications and myocardial infarction (MI). MI occurs secondary to a massive loss of endothelial cells (ECs), vascular smooth muscle cells (VSMCs), and cardiomyocytes (CMs). The adult cardiovascular system gradually loses the ability to spontaneously and regularly regenerate ECs, VSMCs, and CMs. However, human cells can be induced by cytokines and growth factors to regenerate human-induced pluripotent stem cells (hiPSCs), which progress to produce cardiac trilineage cells (CTCs) such as ECs, VSMCs, and CMs, replacing lost cells and inducing myocardial repair. Nevertheless, the processes and pathways involved in hiPSC-CTC generation and their potential therapeutic effects remain unknown. Herein, we provide evidence of in vitro CTC generation, the pathways involved, in vivo transplantation, and its therapeutic effect, which may provide novel targets in regenerative medicine for the treatment of cardiovascular diseases (CVDs).

Endothelial to Mesenchymal Transition in Cardiovascular Disease: JACC State-of-the-Art Review

Endothelial to mesenchymal transition (EndMT) is a process whereby an endothelial cell undergoes a series of molecular events that lead to a change in phenotype toward a mesenchymal cell (e.g., myofibroblast, smooth muscle cell). EndMT plays a fundamental role during development, and mounting evidence indicates that EndMT is involved in adult cardiovascular diseases (CVDs), including atherosclerosis, pulmonary hypertension, valvular disease, and fibroelastosis. Therefore, the targeting of EndMT may hold therapeutic promise for treating CVD. However, the field faces a number of challenges, including the lack of a precise functional and molecular definition, a lack of understanding of the causative pathological role of EndMT in CVDs (versus being a "bystander-phenomenon"), and a lack of robust human data corroborating the extent and causality of EndMT in adult CVDs. Here, we review this emerging but exciting field, and propose a framework for its systematic advancement at the molecular and translational levels.

Suppression of TGFβ-mediated conversion of endothelial cells and fibroblasts into cancer associated (myo)fibroblasts via HDAC inhibition

Background

Cancer-associated fibroblasts (CAFs) support tumour progression and invasion, and they secrete abundant extracellular matrix (ECM) that may shield tumour cells from immune checkpoint or kinase inhibitors. Targeting CAFs using drugs that revert their differentiation, or inhibit their tumour-supportive functions, has been considered as an anti-cancer strategy.

Methods

We have used human and murine cell culture models, atomic force microscopy (AFM), microarray analyses, CAF/tumour cell spheroid co-cultures and transgenic fibroblast reporter mice to study how targeting HDACs using small molecule inhibitors or siRNAs re-directs CAF differentiation and function in vitro and in vivo.

Results

From a small molecule screen, we identified Scriptaid, a selective inhibitor of HDACs 1/3/8, as a repressor of TGFβ-mediated CAF differentiation. Scriptaid inhibits ECM secretion, reduces cellular contraction and stiffness, and impairs collective cell invasion in CAF/tumour cell spheroid co-cultures. Scriptaid also reduces CAF abundance and delays tumour growth in vivo.

Conclusions

Scriptaid is a well-tolerated and effective HDACi that reverses many of the functional and phenotypic properties of CAFs. Impeding or reversing CAF activation/function by altering the cellular epigenetic regulatory machinery could control tumour growth and invasion, and be beneficial in combination with additional therapies that target cancer cells or immune cells directly.

Epigenetic modulation of vascular diseases: Assessing the evidence and exploring the opportunities

Vascular adaptations to either physiological or pathophysiological conditions commonly require gene expression modifications in the most represented cellular elements of the vessel wall, i.e. endothelial and smooth muscle cells. In addition to transcription factors, a number of mechanisms contribute to the regulation of gene expression in these cells including noncoding RNAs, histone and DNA modifications, collectively indicated as epigenetic modifications. Here, we summarize the state of art regarding the role of epigenetic changes in major vascular diseases, and discuss the potential diagnostic and therapeutic applications of epigenetic modulation in this context.

EZH2 inhibition promotes epithelial-to-mesenchymal transition in ovarian cancer cells

Cancer cells acquire essential characteristics for metastatic dissemination through the process of epithelial-to-mesenchymal transition (EMT), which is regulated by gene expression and chromatin remodeling changes. The enhancer of zeste homolog 2 (EZH2), the catalytic subunit of the polycomb repressive complex 2 (PRC2), catalyzes trimethylation of lysine 27 of histone H3 (H3K27me3) to repress gene transcription. Here we report the functional roles of EZH2-catalyzed H3K27me3 during EMT in ovarian cancer (OC) cells. TGF-β-induced EMT in SKOV3 OC cells was associated with decreased levels of EZH2 and H3K27me3 (P<0.05). These effects were delayed (~72 h relative to EMT initiation) and coincided with increased (>15-fold) expression of EMT-associated transcription factors ZEB2 and SNAI2. EZH2 knockdown (using siRNA) or enzymatic inhibition (by GSK126) induced EMT-like changes in OC cells. The EMT regulator ZEB2 was upregulated in cells treated with either approach. Furthermore, TGF-β enhanced expression of ZEB2 in EZH2 siRNA- or GSK126-treated cells (P<0.01), suggesting that H3K27me3 plays a role in TGF-β-stimulated ZEB2 induction. Chromatin immunoprecipitation assays confirmed that TGF-β treatment decreased binding of EZH2 and H3K27me3 to the ZEB2 promoter (P<0.05). In all, these results demonstrate that EZH2, by repressing ZEB2, is required for the maintenance of an epithelial phenotype in OC cells.

Endothelial to Mesenchymal Transition Represents a Key Link in the Interaction between Inflammation and Endothelial Dysfunction

Endothelial cells that line the inner walls of blood vessels are in direct contact with blood and display remarkable heterogeneity in their response to exogenous stimuli. These ECs have unique location-dependent properties determined by the corresponding vascular beds and play an important role in regulating the homeostasis of the vascular system. Evidence suggests that vascular endothelial cells exposed to various environments undergo dynamic phenotypic switching, a key biological program in the context of endothelial heterogeneity, but that might result in EC dysfunction and, in turn, cause a variety of human diseases. Emerging studies show the importance of endothelial to mesenchymal transition (EndMT) in endothelial dysfunction during inflammation. EndMT is a complex biological process in which ECs lose their endothelial characteristics, acquire mesenchymal phenotypes, and express mesenchymal cell markers, such as alpha smooth muscle actin and fibroblast-specific protein 1. EndMT is induced by inflammatory responses, leading to pathological states, including tissue fibrosis, pulmonary arterial hypertension, and atherosclerosis, via dysfunction of the vascular system. Although the mechanisms associated with inflammation-induced EndMT have been identified, unraveling the specific role of this phenotypic switching in vascular dysfunction remains a challenge. Here, we review the current understanding on the interactions between inflammatory processes, EndMT, and endothelial dysfunction, with a focus on the mechanisms that regulate essential signaling pathways. Identification of such mechanisms will guide future research and could provide novel therapeutic targets for the treatment of vascular diseases.

FGFR1 is critical for the anti-endothelial mesenchymal transition effect of N-acetyl-seryl-aspartyl-lysyl-proline via induction of the MAP4K4 pathway

Endothelial-to-mesenchymal transition (EndMT) has been shown to contribute to organ fibrogenesis, and we have reported that the anti-EndMT effect of N-acetyl-seryl-aspartyl-lysyl-proline (AcSDKP) is associated with restoring expression of diabetes-suppressed fibroblast growth factor receptor (FGFR), the key anti-EndMT molecule. FGFR1 is the key inhibitor of EndMT via the suppression of the transforming growth factor β (TGFβ) signaling pathway, and mitogen-activated protein kinase kinase kinase kinase 4 (MAP4K4) inhibits integrin β1, a key factor in activating TGFβ signaling and EndMT. Here, we showed that the close proximity between AcSDKP and FGFR1 was essential for the suppression of TGFβ/smad signaling and EndMT associated with MAP4K4 phosphorylation (P-MAP4K4) in endothelial cells. In cultured human dermal microvascular endothelial cells (HMVECs), the anti-EndMT and anti-TGFβ/smad effects of AcSDKP were lost following treatment with a neutralizing FGFR1 antibody (N-FGFR1) or transfection of FRS2 siRNA. The physical interaction between FGFR1 and P-MAP4K4 in HMVECs was confirmed by proximity ligation analysis and an immunoprecipitation assay. AcSDKP induced P-MAP4K4 in HMVECs, which was significantly inhibited by treatment with either N-FGFR1 or FRS2 siRNA. Furthermore, MAP4K4 knockdown using specific siRNAs induced smad3 phosphorylation and EndMT in HMVECs, which was not suppressed by AcSDKP. Streptozotocin-induced diabetic CD-1 mice exhibited suppression of both FGFR1 and P-MAP4K4 expression levels associated with the induction of TGFβ/smad3 signaling and EndMT in their hearts and kidneys; those were restored by AcSDKP treatment. These data demonstrate that the AcSDKP-FGFR1-MAP4K4 axis has an important role in combating EndMT-associated fibrotic disorders.

Endothelial to mesenchymal transition in the cardiovascular system

Endothelial to mesenchymal transition (EndMT) is a special type of epithelial to mesenchymal transition. It is a process that is characterized by the loss of features of endothelial cells and acquisition of specific markers of mesenchymal cells. A variety of stimuli, such as inflammation, growth factors, and hypoxia, regulate EndMT through various signaling pathways and intracellular transcription factors. It has been demonstrated that epigenetic modifications are also involved in this process. Recent studies have identified the essential role of EndMT in the cardiovascular system. EndMT contributes to steps in cardiovascular development, such as cardiac valve formation and septation, as well as the pathogenesis of various cardiovascular disorders, such as congenital heart disease, myocardial fibrosis, myocardial infarction and pulmonary arterial hypertension. Thus, comprehensive understanding of the underlying mechanisms of EndMT will provide novel therapeutic strategies to overcome congenital heart disease due to abnormal development and other cardiovascular diseases. This review will focus on summarizing the currently understood signaling pathways and epigenetic modifications involved in the regulation of EndMT and the role of EndMT in pathophysiological conditions of the cardiovascular system.

Integrative analysis for the role of long non-coding RNAs in radiation-induced mouse thymocytes responses

Long non-coding RNAs (lncRNAs) are a critical class of regulatory molecules involved in a variety of biological functions; however, their role in immune cells response to radiation is unknown. Therefore, in this study we used integrative analysis to determine the expression profile of lncRNAs in mouse thymocytes and the potential functions of lncRNAs in response to radiation. Microarray data profiling indicated that 53 lncRNAs (36 up-regulated and 17 down-regulated) and 74 coding genes (39 up-regulated and 35 down-regulated) were highly differentially expressed in the high dose radiation (HDR) group compared with the control group. In the low dose radiation (LDR) group, only one lncRNA was down-regulated. Moreover, as compared with the control group, 109 lncRNA pathways in the HDR group and 14 lncRNA pathways in the LDR group were differentially expressed. Our data revealed the expression pattern of lncRNAs in mouse thymocytes and predicted their potential functions in response to LDR and HDR. In the HDR group, GO analysis showed that the role of lncRNAs in damage responses of thymocytes to HDR mainly involved chromatin organization and cell death. These findings might improve our understanding of the role of lncRNAs in LDR- and HDR-induced immune cells and provide a new experimental basis for further investigation.