Endothelial dysfunction is considered to be an early change in atherosclerosis. Endocan, also known as endothelial cell specific molecule-1, is a soluble proteoglycan mainly secreted by endothelial cells. Inflammatory factors such as IL-1β and TNF-α can up regulate the expression of endocan and then affect the expression of cell adhesion molecules, such as ICAM-1 and VCAM-1, which play an important role in promoting leukocyte migration and inflammatory response. Elevated plasma levels of endocan may reflect endothelial activation and dysfunction, and is considered to be a potential immuno-inflammatory marker that may be related to cardiovascular disease. In the case of hypertension, diabetes, angina pectoris and acute myocardial infarction, the increase or decrease of serum endocan levels is of great significance. Here, we reviewed the current research on endocan, and emphasis its possible clinical value as a prognostic marker of cardiovascular disease. Endocan may be a useful biomarker for the prognosis of cardiovascular disease, but more research is needed on its mechanism of action.
ATP-binding cassette transporter A1 (ABCA1) plays a critical role in maintaining cellular cholesterol homeostasis. The purpose of this study is to identify the molecular mechanism(s) underlying ABCA1 epigenetic modification and determine its potential impact on ABCA1 expression in macrophage-derived foam cell formation and atherosclerosis development. DNA methylation induced foam cell formation from macrophages and promoted atherosclerosis in apolipoprotein E-deficient (apoE−/−) mice. Bioinformatics analyses revealed a large CpG island (CGI) located in the promoter region of ABCA1. Histone methyltransferase enhancer of zeste homolog 2 (EZH2) downregulated ABCA1 mRNA and protein expression in THP-1 and RAW264.7 macrophage-derived foam cells. Pharmacological inhibition of DNA methyltransferase 1 (DNMT1) with 5-Aza-dC or knockdown of DNMT1 prevented the downregulation of macrophage ABCA1 expression, suggesting a role of DNA methylation in ABCA1 expression. Polycomb protein EZH2 induced DNMT1 expression and methyl-CpG-binding protein-2 (MeCP2) recruitment, and stimulated the binding of DNMT1 and MeCP2 to ABCA1 promoter, thereby promoting ABCA1 gene DNA methylation and atherosclerosis. Knockdown of DNMT1 inhibited EZH2-induced downregulation of ABCA1 in macrophages. Conversely, EZH2 overexpression stimulated DNMT1-induced ABCA1 gene promoter methylation and atherosclerosis. EZH2-induced downregulation of ABCA1 gene expression promotes foam cell formation and the development of atherosclerosis by DNA methylation of ABCA1 gene promoter.
Exosomes are a subset of extracellular vesicles that act as messengers to facilitate communication between cells. Non-coding RNAs, proteins, lipids, and microRNAs are delivered by the exosomes to target molecules (such as proteins, mRNAs, or DNA) of host cells, thereby playing a key role in the maintenance of normal brain function. However, exosomes are also involved in the occurrence, prognosis, and clinical treatment of brain diseases, such as Alzheimer's disease, Parkinson's disease, stroke, and traumatic brain injury. In this review, we have summarized novel findings that elucidate the role of exosomes in the occurrence, prognosis, and treatment of brain diseases.
1 December 2017 in Biochemical and Biophysical Research Communications