Reciprocal regulation of endothelial-mesenchymal transition by MAPK7 and EZH2 in intimal hyperplasia and coronary artery disease

Interplay between epigenetic mechanisms and transcription factors in atherosclerosis

Cardiovascular diseases (CVD), including coronary heart disease and stroke, comprise the number one cause of mortality worldwide. A major contributor to CVD is atherosclerosis, which is a low-grade inflammatory disease of vasculature that involves a pathological build-up of plaque within the arterial walls. Studies have shown that regulation of gene expression via transcription factors and epigenetic mechanisms play a fundamental role in transcriptomic changes linked to the development of atherosclerosis. Chromatin remodeling is a reversible phenomenon and studies have supported the clinical application of chromatin-modifying agents for the prevention and treatment of CVD. In addition, pre-clinical studies have identified multiple transcription factors as potential therapeutic targets in combating atherosclerotic CVD. Although interaction between transcription factors and epigenetic mechanisms facilitate gene regulation, a limited number of studies appreciate this crosstalk in the context of CVD. Here, we reviewed this gene regulatory mechanism underappreciated in atherosclerosis, which will highlight the mechanisms underlying novel therapeutics targeting epigenetic modifiers and transcription factors in atherosclerosis.

H3K27Me3 abundance increases fibrogenesis during endothelial-to-mesenchymal transition via the silencing of microRNA-29c

Objective

Endothelial-to-mesenchymal transition (EndMT) is a transdifferentiation process in which endothelial cells (ECs) adopt a mesenchymal-like phenotype. Over the past few years, it became clear that EndMT can contribute to several cardiovascular pathologies. However, the molecular pathways underlying the development of EndMT remain incompletely understood. Since the epigenetic enzyme Enhancer of Zeste Homolog 2 (EZH2) and its concomitant mark H3K27Me3 have been shown to be elevated in many cardiovascular diseases that associate with EndMT, we hypothesized that H3K27Me3 is a determinant for the susceptibility of EndMT.

Methods

To study the association between H3K27Me3 and EndMT, a knockdown model of EZH2 in human endothelial cells (HUVEC) was utilized to reduce H3K27Me3 abundance, followed by induction of EndMT using TGFβ1. The expression of molecular markers of EndMT and fibrogenesis were analysed.

Results

In cultured HUVECs, a reduction of H3K27Me3 abundance facilitates EndMT but mitigates fibrogenesis as shown by a decreased expression of collagen I and III. In HUVEC, H3K27Me3 abundance directly affects the expression of miR29c, a collagen-targeting miRNA. Additionally, knockdown of miR-29c in HUVEC with low H3K27Me3 abundance partly restored the expression of collagen I and III. Expectedly, in rats with perivascular fibrosis an increased abundance of H3K27Me3 associated with a decreased expression of miR-29c.

Conclusion

our data shows that endothelial fibrogenesis underlies an epigenetic regulatory pathway and we demonstrate that a decreased abundance of H3K27Me3 in ECs blunts fibrogenesis in part in a miR-29c dependent manner. Therefore, a reduction of H3K27Me3 could serve as a novel therapeutical strategy to mitigate fibrogenesis and may prove to be beneficial in fibrogenic diseases including atherosclerosis, cardiac fibrosis, and PAH.

The beneficial health effects of puerarin in the treatment of cardiovascular diseases: from mechanisms to therapeutics

Cardiovascular diseases (CVDs) are the leading causes of death globally that seriously threaten human health. Although novel western medicines have continued to be discovered over the past few decades to inhibit the progression of CVDs, new drug research and development for treating CVDs with less side effects and adverse reactions are continuously being desired. Puerarin is a natural product found in a variety of medicinal plants belonging to the flavonoid family with potent biological and pharmacological activities. Abundant research findings in the literature have suggested that puerarin possesses a promising prospect in treating CVDs. In recent years, numerous new molecular mechanisms of puerarin have been explored in experimental and clinical studies, providing new evidence for this plant metabolite to protect against CVDs. This article systematically introduces the history of use, bioavailability, and various dosage forms of puerarin and further summarizes recently published data on the major research advances and their underlying therapeutic mechanisms in treating CVDs. It may provide references for researchers in the fields of pharmacology, natural products, and internal medicine.

Bone and Extracellular Signal-Related Kinase 5 (ERK5)

Bones are vital for anchoring muscles, tendons, and ligaments, serving as a fundamental element of the human skeletal structure. However, our understanding of bone development mechanisms and the maintenance of bone homeostasis is still limited. Extracellular signal-related kinase 5 (ERK5), a recently identified member of the mitogen-activated protein kinase (MAPK) family, plays a critical role in the pathogenesis and progression of various diseases, especially neoplasms. Recent studies have highlighted ERK5's significant role in both bone development and bone-associated pathologies. This review offers a detailed examination of the latest research on ERK5 in different tissues and diseases, with a particular focus on its implications for bone health. It also examines therapeutic strategies and future research avenues targeting ERK5.

Endothelial dysfunction in vascular complications of diabetes: a comprehensive review of mechanisms and implications

Diabetic vascular complications are prevalent and severe among diabetic patients, profoundly affecting both their quality of life and long-term prospects. These complications can be classified into macrovascular and microvascular complications. Under the impact of risk factors such as elevated blood glucose, blood pressure, and cholesterol lipids, the vascular endothelium undergoes endothelial dysfunction, characterized by increased inflammation and oxidative stress, decreased NO biosynthesis, endothelial-mesenchymal transition, senescence, and even cell death. These processes will ultimately lead to macrovascular and microvascular diseases, with macrovascular diseases mainly characterized by atherosclerosis (AS) and microvascular diseases mainly characterized by thickening of the basement membrane. It further indicates a primary contributor to the elevated morbidity and mortality observed in individuals with diabetes. In this review, we will delve into the intricate mechanisms that drive endothelial dysfunction during diabetes progression and its associated vascular complications. Furthermore, we will outline various pharmacotherapies targeting diabetic endothelial dysfunction in the hope of accelerating effective therapeutic drug discovery for early control of diabetes and its vascular complications.

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.

LIM Homeobox 2 Increases Adhesion-Regulating Molecule 1 Transcription to Facilitate the Pathological Progression of Oxidized Low-Density Lipoprotein-Stimulated Atherosclerotic Cell Models

Endothelial-mesenchymal transition (EndMT) and endothelial cell apoptosis have been documented to have a role in atherosclerosis (AS) progression. To deepen knowledge in this aspect, our study investigated the effect of LIM homeobox 2 (LHX2) and adhesion-regulating molecule 1 (ADRM1) on EndMT and endothelial cell apoptosis in the oxidized low-density lipoprotein (ox-LDL) -stimulated AS cell model.Ox-LDL was utilized to treat human umbilical vein endothelial cells (HUVECs) for constructing an AS model in vitro, followed by measurement of LHX2 and ADRM1 expressions. Afterward, gain- and loss-of-function assays were performed in HUVECs, followed by detection of cell viability, invasion, migration, and apoptosis and the expression of inflammatory factors [tumor necrosis factor (TNF) -α, interleukin (IL) -1β, and IL-6], EndMT-related proteins [CD31, vascular epithelium (VE) -cadherin, vimentin, α-smooth muscle actin (SMA), Snai1, Snai2, and Twist1], and the apoptotic protein cleaved caspase-3. Interactions between LHX2 and ADRM1 were analyzed with dual-luciferase reporter gene and chromatin immunoprecipitation assays.High levels of LHX2 and ADRM1 were observed in ox-LDL-induced HUVECs. In ox-LDL-treated HUVECs, LHX2, or ADRM1 knockdown promoted CD31 and VE-cadherin levels, viability, invasion, and migration and reduced apoptosis and the expressions of TNF-α, IL-1β, IL-6, vimentin, α-SMA, Snai1, Snai2, Twist1, and cleaved caspase-3. Mechanistically, LHX2 bound to the ADRM1 promoter to promote ADRM1 transcription. Overexpression of ADRM1 annulled the aforementioned effects of LHX2 knockdown on ox-LDL-induced HUVECs.LHX2 facilitates the pathological progression of ox-LDL-stimulated AS cell models by increasing ADRM1 transcription.

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.

miRNA/mRNA co-profiling identifies the miR-200 family as a central regulator of SMC quiescence

miRNAs are versatile regulators of smooth muscle cell (SMC) fate and behavior in vascular development and disease. Targeted loss-of-function studies have established the relevance of specific miRNAs in controlling SMC differentiation or mediating phenotypic modulation. Our goal was to characterize SMC miRNAome and its contribution to transcriptome changes during phenotypic modulation. Small RNA sequencing revealed that dedifferentiation led to the differential expression of over 50 miRNAs in cultured SMC. miRNA/mRNA comparison predicted that over a third of SMC transcript expression was regulated by differentially expressed miRNAs. Our screen identified the miR-200 cluster as highly downregulated during dedifferentiation. miR-200 maintains SMC quiescence and represses proliferation, migration, and neointima formation, in part by targeting Quaking, a central SMC phenotypic switching mediator. Our study unraveled the substantial contribution of miRNAs in regulating the SMC transcriptome and identified the miR-200 cluster as a pro-quiescence mechanism and a potential inhibitor of vascular restenosis.