Endothelial Cells ; metabolism ; physiology ; Stem Cells ; metabolism ; physiology

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

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

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

Vascular wall-resident stem cells (VW-SCs) play a critical role in maintaining normal vascular function and regulating vascular repair. Understanding the basic functional characteristics of the VW-SCs will facilitate the study of their regulation and potential therapeutic applications. The aim of this study was to establish a stable method for the isolation, culture, and validation of the CD34⁺ VW-SCs from mice, and to provide abundant and reliable cell sources for further study of the mechanisms involved in proliferation, migration and differentiation of the VW-SCs under various physiological and pathological conditions. The vascular wall cells of mouse aortic adventitia and mesenteric artery were obtained by the method of tissue block attachment and purified by magnetic microbead sorting and flow cytometry to obtain the CD34⁺ VW-SCs. Cell immunofluorescence staining was performed to detect the stem cell markers (CD34, Flk-1, c-kit, Sca-1), smooth muscle markers (SM22, SM MHC), endothelial marker (CD31), and intranuclear division proliferation-related protein (Ki-67). To verify the multipotency of the isolated CD34⁺ VW-SCs, endothelial differentiation medium EBM-2 and fibroblast differentiation medium FM-2 were used. After culture for 7 days and 3 days respectively, endothelial cell markers and fibroblast markers of the differentiated cells were evaluated by immunofluorescence staining and q-PCR. Furthermore, the intracellular Ca²⁺ release and extracellular Ca²⁺ entry signaling were evaluated by TILLvisION system in Fura-2/AM loaded cells. The results showed that: (1) High purity (more than 90%) CD34⁺ VW-SCs from aortic adventitia and mesenteric artery of mice were harvested by means of tissue block attachment method and magnetic microbead sorting; (2) CD34⁺ VW-SCs were able to differentiate into endothelial cells and fibroblasts in vitro; (3) Caffeine and ATP significantly activated intracellular Ca²⁺ release from endoplasmic reticulum of CD34⁺ VW-SCs. Store-operated Ca²⁺ entry (SOCE) was activated by using thapsigargin (TG) applied in Ca²⁺-free/Ca²⁺ reintroduction protocol. This study successfully established a stable and efficient method for isolation, culture and validation of the CD34⁺ VW-SCs from mice, which provides an ideal VW-SCs sources for the further study of cardiovascular diseases.
Mice ; Animals ; Endothelial Cells ; Cell Differentiation/physiology* ; Stem Cells ; Adventitia ; Fibroblasts ; Cells, Cultured ; Antigens, CD34/metabolism*

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

Microcirculatory dysfunction is an important pathophysiological change of shock. In the last decade, many researches on the mechanism of microcirculatory dysfunction have been involved in areas such as the glycocalyx damage of vascular endothelial cells, macrocirculation- microcirculation discoupling, vascular hyporeactivity, and microcirculation monitoring. Accordingly, this paper discussed how these research findings can be applied to burn patients, with the aim of alerting the clinicians to improving microcirculation, and maintaining hemodynamic coordination during the treatment of burn shock and burn septic shock. In addition, with the development of accurate and reliable microcirculation monitoring techniques, it is necessary to carry out multi-center clinical trials to reveal the clinical significance of target-oriented shock resuscitation protocol combining macrocirculatory and microcirculatory parameters.
Burns/therapy* ; Endothelial Cells ; Hemodynamics/physiology* ; Humans ; Microcirculation/physiology* ; Resuscitation ; Shock ; Shock, Septic/therapy*

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

Traumatic brain injury (TBI) is a major cause of mortality and morbidity in the world. Recent clinical investigations and basic researches suggest that strategies to improve angiogenesis following TBI may provide promising opportunities to improve clinical outcomes and brain functional recovery. More and more evidences show that circulating endothelial progenitor cells (EPCs), which have been identified in the peripheral blood, may play an important role in the pathologic and physiological angiogenesis in adults. Moreover, impressive data demonstrate that EPCs are mobilized from bone marrow to blood circulation in response to traumatic or inflammatory stimulations. In this review, we discussed the role of EPCs in the repair of brain injury and the possible therapeutic implication for functional recovery of TBI in the future.
Blood-Brain Barrier ; Brain Injuries ; physiopathology ; therapy ; Endothelial Cells ; cytology ; Humans ; Neurogenesis ; Stem Cells ; physiology