Endothelial cells (ECs) with a variety of functions are vulnerable to attack by various risk factors. These risk factors of vascular pathology lead to endothelial dysfunction (ED). However, the present methods of evaluating ED have their limitations. Atomic force microscope (AFM), which can offer the information on the surface images and the mechanical properties of the single cell at nanometer scale, will become a new technical approach to ED evaluation. This review focuses on the recent progress in the application of AFM to assess ED.
Endothelial Cells ; cytology ; physiology ; Humans ; Microscopy, Atomic Force ; methods

OBJECTIVEReduced arterial elasticity is a hallmark of aging in healthy humans independently of diseases and endothelial-cell injury and dysfunction may be responsible for this fall in arterial elasticity. We hypothesized that circulating endothelial progenitor cells (EPCs) are involved in endothelial repair and that lack of EPCs contributes to impaired arterial elasticity.

METHODSA total of 56 healthy male volunteers were divided into young (n = 26) and elderly (n = 30) groups. Large and small artery elasticity indices were non-invasively assessed by using pulse wave analysis. Flow cytometer was used to count the number of circulating CD34(+) mononuclear cells (MNCs), which were isolated from peripheral blood by Ficoll density gradient centrifugation, and then the cells were plated on fibronectin-coated culture dishes. EPCs were characterized as adherent cells double positive staining for DiI-acLDL uptake and lectin binding with using fluorescent microscope.

RESULTSC(1) (large artery elasticity index) and C(2) (small artery elasticity index) were significantly reduced in the elderly group compared with those in the young group (11.73 +/- 1.45 vs 16.89 +/- 1.69 ml/mm Hg x 10, P < 0.001; 8.40 +/- 1.45 vs 10.58 +/- 1.18 ml/mm Hg x 100, P < 0.001 respectively). In parallel, the number of circulating EPCs was significantly reduced in the elderly group compared with the young group (0.13 +/- 0.02 vs 0.17 +/- 0.04%, P < 0.05). The number of circulating EPCs correlated with C(1) large and C(2) small artery elasticity indices (r = 0.47, P < 0.01; r = 0.4, P < 0.01). Fluorescent microscope was used to identify EPCs, which were double positive staining for DiI-acLDL uptake and lectin binding.

CONCLUSIONThe present findings suggested that the fall in circulating EPCs with subsequently impaired endothelial-cell repair and function might contribute to reduced arterial elasticity in humans with aging. The decrease in circulating EPCs could serve as a surrogate biologic measure of vascular function and human age.

Adult ; Aged ; Aging ; physiology ; Arteries ; physiology ; Elasticity ; Endothelial Cells ; cytology ; physiology ; Humans ; Male ; Middle Aged ; Stem Cells ; cytology ; physiology

Bone marrow mensenchymal stem cells (BM-MSCs) are capable of supporting the survival, differentiation and migration of hematopoietic stem cell, and have a profound application prospect in transplantation and treatment of graft-versus-host disease (GVHD). This review aims to illustrate the interaction between BM-MSCs and other intra-bone marrow cells, including hematopoietic stem cells, endothelial cells and osteoblasts. The investigation of their regulating mechanism will help better understanding of the BM-MSCs' role in hematopoiesis.
Bone Marrow Cells ; cytology ; Cell Communication ; physiology ; Endothelial Cells ; cytology ; Humans ; Mesenchymal Stromal Cells ; cytology ; Osteoblasts ; cytology

The micropipette aspiration technique was improved by selecting the uniform cells in round shape (UCR) from a number of adhered cells on the testing surface so as to measure the adhesion forces during the initial adhesion stage. Silk fibroin film and silk fibroin/fucoidan film were used as testing substrates. The testing results revealed that the modified micropipette method was more rapid for testing. The tendency of cell adhesion force on different materials surface under different conditions remained unchanged. The testing results showed good reproducibility. It was easy to distinguish small differences in the adhesiveness of endothelial cell on the silk fibroin based materials, thus exhibiting the high sensitivity of the improved method.
Cell Adhesion ; physiology ; Cells, Cultured ; Endothelial Cells ; cytology ; Fibroins ; Humans ; Umbilical Veins ; cytology

Endothelial progenitor cells (EPCs) are a kind of progenitor cells with high potential of proliferation, which exist in the bone marrow, umbilical cord blood, and peripheral blood. Under certain conditions, EPCs can differentiate into mature vascular endothelial cells. Many studies have shown that EPCs could delay the onset and development of atherosclerosis by promoting the repair of the endothelium and neovascularization. EPCs have also been considered to be a biological marker for cardiovascular diseases. Recent investigations demonstrate that EPCs can mediate the effect of some anti-atherosclerosis drugs. This paper reviews the role of EPCs in atherosclerosis and the influence of drugs on EPC function. The feasibility and the problem of using EPCs as a treatment strategy are also discussed.
Atherosclerosis ; drug therapy ; pathology ; Cell Differentiation ; Endothelial Cells ; cytology ; Humans ; Stem Cells ; cytology ; physiology

BACKGROUNDHepatitis B virus (HBV) replication has been reported to be involved in many extrahepatic viral disorders; however, the mechanism by which HBV is transinfected into extrahepatic tissues such as myocardium and causes HBV associated myocarditis remains largely unknown.

METHODSIn this study, endothelial progenitor cells (EPCs) were infected by HBV and then transfused into ischemic model of mice. HBV surface and core antigen as well as mutation of HBV particles were detected by immunohistochemistry, fluorescent activated cell sorter and transmission electron microscopy in vitro and in vivo.

RESULTSHuman cord blood EPCs, but not human umbilical vein endothelial cells (HUVECs) could be effectively infected by taking up HBV in vitro. HBV envelope surface and core antigen expressions were first detectable in EPCs at day 3 after virus challenge, sustained for up to 11 days, and decreased thereafter. Similarly, the virus particles were the most abundant in EPCs in the first week observed by a transmission electron microscope, and declined in 3 weeks after HBV infection. HBV DNA but not HBV cccDNA in EPCs were detectable even 3 weeks after virus challenge, as shown by PCR analysis. Furthermore, intravenous transplantation of HBV-treated EPCs into myocardial infarction Sprague & Dawley rats model resulted in incorporation of both EPCs and HBV into injured endothelial tissues of capillaries in the ischemic border zone.

CONCLUSIONSThese results strongly support that EPCs serve as virus carrier mediating HBV trans-infection into the injured myocardial tissues. The findings might suggest a novel mechanism for HBV-associated myocarditis.

Cell Movement ; Cells, Cultured ; Endothelial Cells ; cytology ; physiology ; Heart ; virology ; Hepatitis B virus ; physiology ; Humans ; Neovascularization, Physiologic ; Stem Cells ; physiology

Endothelial progenitor cells (EPCs) are immature endothelial cells which have the capacity to proliferate, migrate and differentiate into mature endothelial cells from bone marrow to the peripheral circulation. EPCs have been shown to participate in postnatal endothelial repair and neovascularization of ischemic organs, and have been used as a new source of seeded cells in vascular tissue engineering. In this review, we focus on the origin, identification, property and function of EPCs as well as their application in vascular tissue engineering.
Animals ; Blood Vessels ; physiopathology ; Endothelial Cells ; cytology ; physiology ; Endothelium, Vascular ; pathology ; physiology ; Humans ; Neovascularization, Physiologic ; physiology ; Recovery of Function ; physiology ; Stem Cells ; cytology ; physiology ; Tissue Engineering ; methods

OBJECTIVETo investigate the relationship between aging and the number and function of bone marrow-derived endothelial progenitor cells (EPC) in rats.

METHODSThe number and function of bone marrow-derived EPC were measured in 4, 10 and 18 months old rats (n = 10 in each group). Mononuclear cells (MNC) were isolated from rat bone marrow by Ficoll density gradient centrifugation and cultured for 7 days, EPC were identified as adherent cells double positive stained for FITC-UEA-I and DiI-acLDL under laser confocal immunofluence microscopy. Boyden chamber was used to determine the migration capacity of EPC and the number of recultured EPC was counted to test the adherent function of EPC.

RESULTThe number (42.0 +/- 5.8 vs 30.8 +/- 4.7 vs 21.5 +/- 4.7 per field) and the migration and adhesion capacities of EPC were significantly reduced with aging.

CONCLUSIONThis study shows that the number and function of EPC are decreased with aging.

Age Factors ; Animals ; Bone Marrow Cells ; cytology ; Cell Count ; Cells, Cultured ; Endothelial Cells ; cytology ; Monocytes ; physiology ; Rats ; Rats, Sprague-Dawley

OBJECTIVETo examine the number and function of circulating endothelial progenitor cells (EPCs) in children with cyanotic congenital heart diseases (CHD) and study their correlation with serum levels of vascular endothelial growth factor (VEGF) and stromal cell derived factor-1 (SDF-1).

METHODSFifteen children with tetralogy of Fallot (cyanotic group) and 15 age-and sex-matched children with ventricular septal defect (control group) were enrolled. Serum levels of VEGF and SDF-1 were measured using ELISA. Mononuclear cells were isolated from peripheral blood by Ficoll density gradient centrifugation and cultured in vitro. EPCs were identified by immunofluorescence and were counted under a microscope. Modified Boyden chamber assay and the MTT assay were used to measure the migration and proliferation capacities of EPCs. EPCs adhesion ability assay was performed by replating cells on fibronectin-coated dishes, and then adherent cells were counted. The correlations of serum levels of VEGF and SDF-1 with the number and function of circulating EPCs were assessed by linear regression analysis.

RESULTSSerum levels of VEGF (201.42+/-44.74 ng/L vs 113.56+/-35.62 ng/L; P<0.05) and SDF-1 (3.45+/-1.07 ng/L vs 1.05+/-0.99 ng/L; P<0.05) in the cyanotic group were higher than those in the control group. There was a positive correlation between serum levels of VEGF and SDF-1(r=0.675, P<0.01). The number of EPCs (*200 field) in the cyanotic group significantly increased compared with that of the control group (72.2+/-9.73 vs 51.2+/-3.83; P<0.01). The functional activities of EPCs, including proliferation, migration and adhesion capacities, were augmented in the cyanotic group compared with those in the control group. The increased number and function of EPCs and the increased serum levels of VEGF and SDF-1 were consistent in the cyanotic group, with a correlation coefficient of 0.8395, 0.5491, 0.6376 and 0.7392 respectively.

CONCLUSIONSThe number and functional activity of EPCs as well as serum levels of VEGF and SDF-1 increased in children with cyanotic CHD. Serum levels of VEGF and SDF-1 were correlated to the number and functional activity of EPCs. Serum VEGF and SDF-1 together with circulating EPCs may play important roles in the pathology and physiology in these patients.

Chemokine CXCL12 ; blood ; physiology ; Cyanosis ; blood ; Endothelial Cells ; cytology ; physiology ; Heart Defects, Congenital ; blood ; Humans ; Stem Cells ; physiology ; Vascular Endothelial Growth Factor A ; blood ; physiology

OBJECTIVEA variety of inner ear disease is related to microcirculation disturbance of inner ear, but smooth muscle cells (SMC) and endothelial cells (EC) of the spiral modiolar artery (SMA), which is the main blood supply to the inner ear, physiological feature is not very clear.

METHODSIn this study, two-intracellular microelectrode recording technique and cell staining techniques to study the SMC and EC resting membrane potential characteristics and communication links between cells of SMA.

RESULTSStudy found that SMC and EC have high and low resting membrane potential state, two state of the resting membrane potential of cells to ACh and high K+ response is completely different. The different types of cells, EC-EC, SMC-SMC and SMC-EC, can simultaneously record by two-microelectrode, two cell resting membrane potential can also be a double-high RP, double-low RP and one high- and one low- RP. Experiment recorded in one high- and one low- RP are the SMC-EC types, and ECs initial membrane potential are high potential, SMCs membrane potential are low initial potential. The double-high and double-low RP can be SMC-SMC or EC-EC or SMC-EC types.

CONCLUSIONThe results show that SMC and EC in the 0.3 - 0.5 mm range, similar type of cells have very good communication, can function together to maintain good and consistent, heterogeneous cell performance is more different.

Animals ; Arteries ; cytology ; Cochlea ; blood supply ; physiology ; Endothelial Cells ; physiology ; Guinea Pigs ; Membrane Potentials ; physiology ; Myocytes, Smooth Muscle ; physiology