Regulatory effect of miRNA enfolded in microparticles on endothelial cells

Endothelial cells are the cells lining the inner surfaces of blood vessels. They build up a single cell layer and play an important role in the regulation of vascular functions and the maintenance of homeostasis. The activation or injury of endothelial cells is associated with multiple diseases, including hypertension, atherosclerosis, cancer, diabetes, etc. Recent studies have found that microparticles are involved in the process of endothelial cell injury, thus playing a part in the development of many diseases. miRNAs enfolded in the microparticles have become importance in recent years. Moreover, recent studies also found that the concentration of the miRNAs enfolded in the microvesicles is higher than that of the miRNAs in the plasma, which means that the microparticles are the main form of miRNAs present in peripheral circulatory system. This article is to review the recent research progress in microparticle-encapsulated miRNAs and their regulatory effect on endothelial cell injury.     

Norepinephrine attenuates injury of vascular endothelial cells induced by LPS

AIM: To investigate the effects of norepinephrine (NE) on vascular endothelial cell damage induced by lipopolysaccharides (LPS). METHODS: Human umbilical vein endothelial cells (HUVEC-12) were cultured with LPS at 100 mg/L to establish the cell damage model. Real-time PCR and Western blot were used to determine the expressions of VE-cadherin at mRNA and protein levels. The levels of TNF-α, IL-1β, IL-2 and IL-10 in culture supernatant were measured by ELISA. The reactive oxygen species (ROS) production in the endothelial cells was detected by ROS assay kit. RESULTS: LPS decreased both mRNA and protein levels of VE-cadherin accompanied by increased levels of TNF-α, IL-1β, IL-2 and intracellular ROS, and decreased level of IL-10 in the endothelial cells. NE reversed the expression of VE-cadherin at mRNA and protein levels under the condition of LPS treatment in a dose-dependent manner, and also alleviated the intracellular oxidative stress. CONCLUSION: NE reverses the endothelial damage induced by LPS, which may be related to the up-regulation of VE-cadherin level and the decreases in oxidative stress and inflamatory mediators.     

Progress in function of HDL-eNOS signaling pathway in cardiovascular system and it's influencing factors

High-density lipoprotein (HDL) is negatively related to the risk of cardiovascular diseases such as atherosclerosis. Recent studies have shown that HDL activates a variety of target cells, such as vascular endothelial cells and macrophages, and activates the related cell signaling pathway to exert an anti-atherosclerosis role. HDL is a complex substance which composes of multiple particles. The changes of many factors affect the characteristics and functions of HDL, and then affect the activation of endothelial nitric oxide synthase (eNOS).This paper summarizes the recent correlation studies, and expounds the related factors that affect the HDL-eNOS signaling pathway.     

Role of endothelial cell glucose metabolism in vascular development

As an important organ in the body, blood vessels transport oxygen and nutrients to the tissues of the body. Endothelial cells are layers of cells lined with blood vessels whose metabolism is involved in regulating multiple links of vascular development and vascular diseases. Glucose metabolism provides the main energy for endothelial cells, and changes in glucose metabolism regulation affect vascular development and even lead to various diseases. Recently, strategies have been proposed to target endothelial cell metabolism for the treatment of vascular diseases. This article reviews the role of endothelial cell glucose metabolism in vascular development and vascular diseases in recent years.     

Ca2+-activated Cl- channels and pulmonary hypertension induced by high pulmonary blood flow

Pulmonary hypertension induced by high pulmonary blood flow involves a variety of complex mechanisms, including endothelial damage, pulmonary artery smooth muscle relaxation-contraction disorder and vascular remodeling. Besides, the factor of ion channels in pulmonary artery smooth muscle cells is also highly correlated to vasoconstriction. In recent years, many studies have shown that activation of Ca²⁺-activated Cl^- channels is responsible for the membrane depolarization of pulmonary artery smooth muscle cells, and plays an important role in the regulation of vascular tone and vasoconstriction. This article reviews the biophysical and pharmacological characteristics of Ca²⁺-activated Cl^- channels as well as the influence of Ca²⁺-activated Cl^- channels in high pulmonary blood flow-induced pulmonary hypertension.     

Intravenous transfusion of endothelial progenitor cells reduces neointima formation

AIM: To investigate the feasibility of transplanting endothelial progenitor cells (EPCs) obtained from spleen in vascular endothelium repairmen after vascular injury. METHODS: EPCs were isolated by using a Ficoll density gradient centrifugation, and were cultured in plate. The endothelial characteristics of EPCs were identified by immunochemical staining and fluorescent labeling. Dil-Ac-LDL labeled spleen-derived EPCs were transplanted into the rats by intravenous injection directly after induction of arterial injury and again 24 hours later. Rats received FITC-labeled lectin intravenously before euthanasia. The distribution of fluorescent labeled EPCs was traced. The morphology of arterial intima and media was studied by optical microscopy and image analysing system. RESULTS: The adherent cells were considered EPCs that showed spindle shape and form blood-siland-like structures during development. The adherent cells had many endothelial characteristics. Fluorescent labeling showed that the intravenously injected EPCs specifically restricted to the vascular injury site, and lectin binding confirmed the endothelial phenotype. The ratio of neointimal/media area in EPCs transplantation group was obviously reduced than that in injury group and M199 group (0.82±0.09 vs 1.52±0.21, 1.48±0.19, P<0.01). The PCNA positive expression cells were evidently decreased compared with injury group and M199 group (19.25±3.96 vs 31.42±5.23, 29.37±3.16, P<0.05). CONCLUSION: EPCs incorporate into the process of injured carotid reendothelialization. EPCs transplantation induces an increase in the circulating EPCs, accelerates the process of endothelial repairmen and reduces neointima formation.     

Progress of STIM1, a dynamic calcium signal transducer, #br# in cardiovascular diseases

Stromal interaction molecule 1 (STIM1) is a transmembrane protein of the endoplasmic reticulum (ER), a Ca²⁺ transducer in ER that activates the store-operated calcium channel. Through Orai1 protein, STIM1 adjusts the intracellular and extracellular calcium concentration. This way is called a store-operated Ca²⁺ entry. STIM1 plays a key role in phenotypic transformation of vascular smooth muscle cells, proliferation of endothelial cells, myocardial hypertrophy and myocardial fibrosis to regulate lots of cardiovascular diseases, such as atherosclerosis, congestive heart failure and systemic hypertension. STIM1 is closely related to cardiovascular diseases through calcium signal. The research progress of STIM1 in cardiovascular diseases is mainly discussed in this article.     

BYHWD promotes endothelial progenitor cells to repair damaged vascular endothelium

AIM: To investigate the role of Buyanghuanwu decoction (BYHWD) in promoting endothelial progenitor cells (EPCs)-induced recovery of damaged vascular endothelium. METHODS: The endothelial damaged rats were lavaged with BYHWD and injected with EPCs through vena caudalis. The repaired situation of damaged endothelium was observed. RESULTS: Compared with EPCs group and BYHWD group, the endothelial thickness was reduced, the levels of calcium, triglycerides and total cholesterol were decreased, but the high density lipoprotein levels were increased. In addition, the protein expression of vascular endothelial nitric oxide synthase and vascular stromal cell-drived factor-1 was sig-nificantly increased, but the expression of CXC chemokine receptor-4 was significantly reduced in BYHWD+EPC group. CONCLUSION: BYHWD promotes EPCs repairing damaged endothelium, the mechanism may be related to improve the internal environment and promotes the EPCs homing.     

Promoting angiogenesis of protein kinase D1 in vitro and in vivo

AIM: To explore the effect of protein kinase D1 (PKD1) on promoting angiogenesis in vitro and in vivo, and to furnish a new idea on targeting PKD1 for the treatment of ischemic heart disease such as myocardial infarction. METHODS: The culture, isolation and identification of endothelial progenitor cells (EPCs) were performed in vitro. The effects of PKD1 and its specific blocking agent CID755673 on expression levels of vascular endothelial growth factor (VEGF) and kinase insert domain receptor (KDR) in EPCs were determined. The rat model of myocardial infarction was established, the intervention effects of PKD1 and CID755673 on morphology, changes of microvessels and endothelial cells, and the expression of VEGF and KDR in the impaired myocardial tissue were analyzed. RESULTS: PKD1 significantly upregulated the expression of VEGF and KDR in EPCs in vitro. Meanwhile, the structure of myocardial tissue was more regular and clear, the cytomembrane of endothelial cells were more smooth and integrity, the pericytes were visible, and the expression of VEGF and KDR was significantly increased in PKD1 treatment group in vivo.CONCLUSION: PKD1 has the ability of angiogenesis obviously, which might be mediated by VEGF.     

Pathogenesis of endothelial-mesenchymal transition in pulmonary arterial hypertension

Endothelial-mesenchymal transition (EndMT) is a biological process through which endothelial cells change their endothelial phenotype into a mesenchymal or myofibroblastic phenotype with the expression of mesenchymal markers such as α-smooth muscle actin (α-SMA) and vimentin. When the pulmonary vascular endothelial cells are exposed to hypoxia and inflammatory stimulation, vascular smooth muscle cells in the outer and middle membrane accumulate through EndMT process, leading to pulmonary vascular remodeling and pulmonary arterial hypertension (PAH). Transforming growth factor β (TGF-β)/bone morphogentic protein (BMP) signaling pathways promote EndMT process by bone morphogentic protein receptor 2 (BMPR2) gene mutation which up-regulates high mobility group protein A1 (HMGA1) gene and contributes to protein expression such as Slug and Snail, thus resulting in PAH. In brief, TGF-β/BMP signaling pathways and related regulators play an important role in pulmonary vascular reconstruction and the formation of PAH.     

Progress in expression and function of tricellular tight junction protein tricellulin

Tricellulin is a novel tight junction protein that is specially expressed in tricellular contacts. Tricellulin is expressed in multiple epithelial and endothelial cells and plays an important role in regulating the paracellular transport of substances and maintaining the integrity of tight junction complexes. The abnormal expression and dysfunction of tricellulin are closely related to the occurrence and development of deafness, inflammatory bowel disease, bacterial infection diseases, tumors and damage to the blood-brain barrier and the blood-retinal barrier. In this review, the research progress on the molecular structure, expression and distribution of tricellulin, the relationship between tricellulin function and diseases as well as the relevant regulatory mechanisms are presented.     

Microparticles and acute coronary syndrome

Coronary heart disease (CHD) is an important cause of death in the world. Among them, acute coronary syndrome (ACS) is a type of CHD that has a high mortality rate. Microparticles (MPs) are tiny particles formed in the process of cell activation and apoptosis, carrying specific markers of their mother cells. There is more and more evidence that MPs derived from endothelial cells, platelets, white blood cells and other cells are closely related to the formation of ACS. Through a variety of pathways, they take part in endothelial cell damage, vascular dysfunction, plaque erosion and rupture, and thrombosis. The findings of MPs enrich our knowledge about ACS, and may provide a new approach to the treatment of ACS.     

Effect of monocyte-secreted VEGF induced by electrical burn serum on monocyte-endothelial cell adhesion

AIM: To observe the level of vascular endothelial growth factor (VEGF) secreted by monocytes cultured with electrical burn serum, and to explore the effect of VEGF on monocyte-endothelial cell adhesion.METHODS: The electrical burn serum of the rat was prepared. The normal serum from the rats without treating electric current was also collected for control. The contents of VEGF and its soluble receptor sFlt-1 in electrical burn group were determined by double-antibody sandwich ELISA. THP-1 cells were randomly divided into normal serum group and electrical burn serum group. The contents of VEGF and sFlt-1 in the culture supernatants were measured by double-antibody sandwich ELISA. THP-1 cells were also randomly divided into another 4 groups:normal serum group, electrical burn serum group, normal serum+inhibitor group and electrical burn serum+inhibitor group. THP-1 cells, which were incubated with the serum for 3 h and 6 h, were labeled with calcein-AM and then were added into the well with monolayer of endothelial cell line EA.hy926 to detect monocyte-endothelial cell adhesion.RESULTS: The levels of serum VEGF of the rats with electrical burns were significantly increased, the levels of serum sFlt-1 were significantly decreased as compared with the controls. The levels of VEGF secreted by THP-1 cells cultured with electrical burn serum were significantly increased, the levels of sFlt-1 were decreased correspondingly. Electrical burn serum enhanced monocyte-endothelial cell adhesion, sFlt-1 inhibited the adhesion between monocytes and endothelial cells.CONCLUSION: The monocytes exposed to the electrical burn serum secrete VEGF, which enhance the adhesion between monocytes and endothelial cells. Blockage of VEGF activity may effectively inhibit monocyte-endothelial cell adhesion.     

Discovery of 20-HETE receptor and its effects on hypertension

20-Hydroxyeicosatetraenoic acid (20-HETE) is a potent vasoactive eicosanoid discovered in recent years, which has multiple vascular effects including stimulation of smooth muscle contractility, migration, and proliferation, as well as endothelial cell dysfunction and inflammation. Clinical and experimental research suggests that 20-HETE is an important mediator of cardiovascular function, and plays a critical role in the pathogenesis of hypertension, stroke, myocardial infarction and vascular diseases. Recently, G-protein-coupled receptor 75 (GPR75) was identified as a 20-HETE receptor and mediated the development of 20-HETE-dependent hypertension. The discovery of 20-HETE-GPR75 pairing provides the molecular basis for the signaling and pathophysiological functions mediated by 20-HETE in hypertension and cardiovascular diseases. In this brief review, we discuss the recent findings related to the effects of 20-HETE in the pathogenesis of hypertension and the discovery and effects of GPR75.     

Role of nitric oxide in proliferation and secretion effect of vascular endothelial cells induced by vascular endothelial growth factor

AIM: To investigate the role of nitric oxide in proliferation and secretion of vascular endothelial cells induced by vascular endothelial growth factorr (VEGF). METHODS: The in vitro cultured vascular endothelial cells of rabbit aorta were divided into control group, VEGF-treated group and VEGF+L-NAME treated group, the absorbance (A) value of vascular endothelial cells, endothelin-1(ET-1) and von Willebrand factor (vWF) in the supernatant were examined by WST-1 assay, radioimmunoassay and ELISA. RESULTS: The A value in VEGF and VEGF+L-NAME treated group were higher than that in control group (P＜0.01). A value in VEGF group was higher than that in VEGF+L-NAME group the ET-1 and vWF were markedly decreased in VEGF group compared with the control and VEGF+L-NAME treated group (P＜0.05, P＜0.01). These results indicated that VEGF promoted the proliferation and inhibited the secretion of ET-1 and vWF in vascular endothelial cells, and L-NAME inhibited the effect of VEGF. CONCLUSION:Nitric oxide is an important mediator in the process of stimulating proliferation and regulating secretion of vascular endothelial cells by VEGF.     

Effects of atovastatin calcium on vascular endothelial cells in hypertensive rats

AIM: To investigate the effects of atorvastatin calcium on vascular endothelial cells and circulating endothelial progenitor cells (CEPCs) in hypertensive rats. METHODS: Renal hypertension rat model was constructed with two-kidney-one-clip technique. Twenty-four male SD rats were randomized into hypertension group, statins group and sham-operated group (n=8 each). On the 4th week, the animals in statins group were injected with 20 mg·kg-1·d-1 atorvastatin calcium intra-abdominally for 8 weeks. Blood pressure and blood lipid were measured at 4th and 12th week post-operation. On the 12th week, scanning electron microscopy was used to observe the damage of aortic endothelial cells. The circulatory endothelial cell count, CEPCs count, CEPCs proliferation ability, CEPCs adhesion ability and CEPCs apoptosis were also measured. RESULTS: The injury of endothelial cells in statins group was observed, milder than that in hypertension group, but worsen than that in sham-operated group. The numbers of circulatory endothelial cells in hypertension group, statin treatment group and sham-operated group were 5.9×106, 3.9×106 and 2.0×106 respectively, and the CEPCs apoptosis rate was 22.1%±2.1%, 13.4%±1.6 %and 7.4%±1.3%, respectively. Meanwhile, the numbers of CEPCs were 21.63±2.33, 40.38±6.00 and 65.38±2.97, respectively, the proliferative abilities of CEPCs were 0.13±0.01, 0.17±0.01 and 0.29±0.03, respectively, and the adhesion of CEPCs was 12.25±2.49, 21.50±2.20 and 28.88±2.85, respectively. CONCLUSION: (1) The severity of vascular endothelial cell injury is related to hypertension states. (2) Atorvastatin calcium has direct protective effects on endothelial cells, possibly through increasing CEPCs count, reducing CEPCs apoptosis and markedly enhancing reparation ability of CEPCs to endothelial cells.     

Vascular endothelial growth factor on function of endothelial progenitor cells from peripheral blood

AIM: To investigate the effect of vascular endothelial growth factor(VEGF) on the biological function of peripheral endothelial progenitor cells (EPCs) and to find the suitable concentration to promote the growth of EPCs.METHODS: Total mononuclear cells (MNCs) were isolated from peripheral blood by density gradient centrifugation,and then the cells were plated on fibronectin-coated culture dishes.After culture for 4 days,attached cells were incubated with VEGF in a series of concentrations (0,10,20 and 50 μg/L) for 72 h,then attached cells were characterized with immunohistochemistry.EPC proliferation and migration activity were assayed with MTT assay and modified Boyden chamber assay,respectively.EPC adhesion assay was performed by replating MNCs on fibronectin-coated dishes,and then the adherent cells were counted.RESULTS: The EPCs from MNCs were successfully isolated and were differentiated to endothelial cells (ECs).Incubation of isolated human MNCs with VEGF increased the proliferative,migratory and adhesive capacities of EPCs,and this effect was most prominent when the concentration of VEGF was 20 μg/L after 72 hours.At the same concentration of VEGF,the functions of EPCs from patients with masculine coronary arteriography were lower than those of EPCs from patients with negative coronary arteriography.CONCLUSION: Functional activities of EPCs are decreased in patients with masculine coronary arteriography.The results suggest that the low concentration of VEGF may improve functional activities of EPCs.     

The vascular endothelial progenitor cells and angiogenesis in ischemic cardiovascular diseases

The vascular endothelial progenitor cells are a population of functional endothelial precursors in circulating blood, which are derived from bone marrow or cord blood. CD34⁺, Flk-1⁺ and ACl33⁺ are their molecular markers. In this review, the functional characterization of vascular endothelial progenitor cells is introduced and the relationship between vascular endothelial progenitor cells and angiogenesis in is chemic cardiovascular diseases is discussed. These data may offer a foundation for the development of therapeutic angiogenesis for the prevention and treatment of ischemic cardiovascular diseases by transplantation of vascular endothelial progenitor cells.