Effect of conditioned medium of vascular endothelial cells on the epithelial-mesenchymal transition of hepatocellular carcinoma cells / 生物医学工程学杂志

This study aims to investigate the effect of substances secreted or metabolized by vascular endothelial cells on epithelial-mesenchymal transition (EMT) of hepatocellular carcinoma cells under indirect co-culture condition. Human hepatocellular carcinoma cell line QGY-7703 was cultured , and then was co-cultured with conditioned medium of human umbilical vein endothelial cells (HUVEC). The morphological changes of QGY-7703 cells were observed by inverted phase contrast microscopy. The migration ability of QGY-7703 cells was analyzed by scratch-wound assays. The effect of conditioned medium on the expression and distribution of EMT related proteins was detected by Western blot and immunofluorescence assays, respectively. The results showed that the QGY-7703 cells gradually changed from polygonal to spindle shape, the migration ability promoted significantly, and both the expression and distribution of EMT related marker changed in a time-dependent manner after co-culturing. The results confirm that vascular endothelial cells can induce EMT in hepatocellular carcinoma cells under indirect co-culture condition.

Effects of arsenic trioxide on migration, invasion and apoptosis of hepatocellular carcinoma HepG2 cells / 生物医学工程学杂志

The article aims to explore the optimal concentration of arsenic trioxide (As O ) on HepG2 of liver cancer cells, and the effect of As O on the migration, invasion and apoptosis of HepG2 cells. In this study, the activity of HepG2 cells treated with 0, 1, 2, 4, 8, 16, 32 μmol/L As O was tested by CCK-8 method, the semi-inhibitory concentration (IC50) was calculated, and the morphological changes of HepG2 cells were observed after the action of As O at IC50 concentration for 12, 24, 48 h. The effect of As O on cell migration and invasion ability was verified by wound healing experiment and Transwell invasion experiment. Western blot and qRT-PCR were used to detect the effects of As O on the gene and protein expression levels related to cell migration, invasion and apoptosis. The results showed that, compared with the control group, the activity of HepG2 cells decreased with the increase of the concentration of As O treatment, showing a dose-dependent effect, and its IC50 was 7.3 μmol/L. After 24 hours' treatment with 8 μmol/L As O , HepG2 cells underwent significant apoptosis, and its migration and invasion abilities were significantly reduced. In addition, the protein expression levels of RhoA, Cdc42, Rac1 and matrix metalloproteinase-9 (MMP-9) were down-regulated, the protein and mRNA expression levels of anti-apoptotic gene Bcl-2 were significantly down-regulated, and the protein and mRNA expression levels of pro-apoptotic genes Bax and Caspase-3 were significantly up-regulated. The above results indicate that certain concentration of As O can inhibit the migration and invasion of hepatocellular carcinoma cells and promote the apoptosis of hepatocellular carcinoma cells.

Role of cytoskeleton in autophagy / 生物医学工程学杂志

Cell autophagy plays a key role in maintaining intracellular nutritional homeostasis during starvation through elimination of aberrant or obsolete cellular structures. The cellular cytoskeleton has a crucial role in multiple processes involving membrane rearrangements and vesicle-mediated events. Autophagy is mediated by both microtubules and actin networks: microtubules promote the synthesis of autophagosome and are related to the movement of autophagosome; actin networks have been implicated in structurally supporting the expanding of phagophore, moving autophagosomes and enabling their efficient fusion with the lysosome; non-muscle myosinⅡoperates in the early stages of autophagy during the initiation and expansion of the phagophore, whereas myosinⅥ and myosin 1C are involved in the late stages of autophagosome maturation and fusion with the lysosome, respectively. This review summarizes the multiple regulation of cytoskeleton on autophagy and focuses on the regulation of autophagy by actin and myosin, providing a new approach for the study of pathogenesis and innovative therapies of autophagy related diseases.

Advances in Research on Reendothelialization after Intervention in Artery / 生物医学工程学杂志

Coronary heart disease is a kind of heart disease that is caused by atherosclerosis. The lipid deposition in the vessel wall results in occlusion of coronary artery and stenosis, which could induce myocardial ischemia and oxygen deficiency. Intervention therapies like percutaneous coronary intervention (PCI) and coronary stent improve myocardial perfusion using catheter angioplasty to reduce stenosis and occlusion of coronary artery lumen. Accordingly, intervention therapies are widely applied in clinic to treat ischemic cardiovascular disease, arterial intima hyperplasia and other heart diseases, which could save the patients' life rapidly and effectively. However, these interventions also damage the original endothelium, promote acute and subacute thrombosis and intimal hyperplasia, and thus induce in-stent restenosis (ISR) eventually. Studies indicated that the rapid reendothelialization of damaged section determined postoperative effects. In this review, reendothelialization of implants after intervention therapy is discussed, including the resource of cells contributed on injured artery, the influences of implanted stents on hemodynamic, and the effects of damaged degree on reendothelialization.

Role of vascular endothelial glycocalyx in inflammation / 国际生物医学工程杂志

Luminal surface of vascular endothelium is decorated with a variety of polysaccharide-protein complexes,which constitute the glycocalyx.It has been demonstrated that vascular endothelial glycocalyx plays an important role in modulation of selective permeability of vessels,mediation of the blood cell-endothelial cell interactions and the release of nitric oxide induced by fluid shear stress under physiological condition.In inflammation condition,sheding of glycocalyx due to inflammation mediator leads to its functional weakening in vessel protection.At the same time,heparan sulfate as a major constituent of vascular endothelial glycocalyx could be involved in regulating the evolution of inflammation.Heparan sulfate interacts with L-selectin to mediating leukocyte rolling,presents chemokines on luminal surfaces of endothelial cells to mediate leukocyte crawling and firm adhesion,participates in transcytosis of chemokines from tissue to luminal side of endothelial cells during inflammation.Various risk factors of atherosclerosis,as an inflammatory disease,are closely associated with vascular endothelial glycocalyx.This paper is aimed to review the role of vascular endothelial glycocalyx in inflammation and atherosclerosis.

Effect of Gold (Au) Nanoparticles Modified by Surface Chemistry on the Proliferation and Migration of Hepatocellular Carcinoma Cells in Vitro / 生物医学工程学杂志

Due to the good tumor-targeting and excellent biocompatibility, the drug-loading nanoparticles (NPs) has been widely applied in the diagnosis and treatment of cancer. However, after the NPs are recognized and internalized by cancer cells, the effects of NPs on cell migration behavior were unclear. In the present study, the self-assembly techniques (SAMs) was used to modify gold (Au) nanoparticles (Au NPs) with different chemical functional groups (CH3, OH, COOH and NH2) as model NPs. The dispersion of these groups in solution and the distribution in cells were studied by transmission electron microscope (TEM), respectively, and the proliferation was examined by MTT assay in vitro. The wound-healing and the Transwell assay were used to examine the effect of internalized Au-NPs on HepG2 cells migration. The results showed that different Au-NPs mainly distributed at the edge of the vesicle membrane and the gap between cells. The Au-NPs resulted in decreased cell viability in a concentration-depended manner. In addition, the results of wound-healing and Transwells assay indicated that the internalization of the NH2-NPs and OH-NPs would inhibit cell migration compared with those in the control group.

Influence of Tumor Microenvironment of Hepatocellular Carcinoma on the Proliferation of Vascular Endothelial Cells and Vascular Angiogenesis Ability / 生物医学工程学杂志

To study the potential molecular mechanism of tumor angiogenesis in its microenvironment, we investigated the effects of HepG2 conditioned medium on the proliferation of vascular endothelial cell and vascular angiogenesis in our laboratory. Human umbilical vein endothelial EA. hy926 cells were co-cultured with HepG2 conditioned medium in vitro. The proliferation and the tubulogenesis of EA. hy926 cells were detected by teramethylazo salt azole (MTT) and tube formation assay, respectively. The results showed that the survival rate of the EA. hy926 cells was significantly increased under the co-culture condition. HepG2 conditioned medium also enhanced the angiogenesis ability of EA. hy926 cells. In addition, the expressions of intracellular VEGF and extracellular VEGFR (Flk-1) were regulated upward in a time-dependent manner. In conclusion, the proliferation of vascular endothelial cells and Vascula angiogenesis were improved under the condition of indirect co-culture.

Integrins mediate the migration of HepG2 cells induced by low shear stress / 生物医学工程学杂志

Low shear stress is a component of the tumor microenvironment in vivo and plays a key role in regulating cancer cell migration and invasion. The integrin, as a mechano-sensors mediating and integrating mechanical and chemical signals, induce the adhesion between cells and extracellular matrix (ECM). The purpose of this study is to investigate the effect of low shear stress (1.4 dyn/cm2)on the migration of HepG2 cells and the expression of integrin. Scratch wound migration assay was performed to examine the effect of low shear stress on the migration of HepG2 cells at 0 h, 1 h, 2 h and 4 h, respectively. F-actin staining was used to detect the expression of F-actin in HepG2 cells treated with low shear stress at 2 h and 4 h. Western blot analysis was carried out to determine the effect of low shear stress on the expression of integrin at different durations. The results showed that the migrated distance of HepG2 cells and the expression of F-actin increased significantly compared with the controls. The integrin alpha subunits showed a different time-dependent expression, suggesting that various subunits of integrin exhibit different effects in low shear stress regulating cancer cells migration.

Study on FAK regulation of migration of vascular endothelial cells depending upon focal adhesion proteins / 生物医学工程学杂志

Tumor angiogenesis induced by vascular endothelial cells (VECs) migration is a necessary condition for tumor growth and metastasis. The purpose of this study is to investigate the effect of focal adhesion kinase (FAK) inhibitor (50nmol/mL) on the adhesion and migration of endothelial cells(ECs) and the expression of focal adhesion proteins vinculin, talin and paxillin. Scratch wound migration assay was performed to examine the effect of FAK inhibitor with 50nmol/mL on ECs migration at 0, 5, 10, 30, 60 and 120min, respectively. And immunofluorescence analysis was performed to detect the expression of F-actin in ECs treated with FAK inhibitor within 2h. Western blot was carried out to determine the effect of FAK inhibitor on expression of vinculin, talin and paxillin proteins. The results showed that the migration distance and the expression of F-actin in ECs treated with FAK inhibitor decreased significantly compared with that of the controls, and the level of vinculin showed no significant difference with increasing of treated time of FAK inhibitor. However, the talin and paxillin showed an identical decreasing tendency in 5-10min, but slowly going up in 30min and then after subsequently decreasing. The results of this study proved that blocking phosphorylation of FAK could inhibit VECs adhesion and migration by downregulating focal adhesion proteins so that it may inhibit tumor angiogenesis. This may provide a new approach for tumor therapy.

Advances of research of hydrophilic/hydrophobic surface effect on cell biologic behaviors in vitro / 生物医学工程学杂志

Hydrophilicity/hydrophobicity, the same as chemical signals and mechanical stimuli, is an important characteristic of material surface, induces a cascade events of intercelluar proteins and genes, and determines cells biologic behaviors in vitro eventually. In this review, we summarize the available reports to review the methods of hydrophilic/hydrophobic surface modification, and its effects on protein adsorption and cells biologic behaviors.

Effects of IL-8 on the tight junction of vascular endothelial cells / 国际生物医学工程杂志

Objective To investigate the influence of IL-8 on the tight junction of vascular endothelial cells.Methods Immunofluorescence was used to observe the modality and the distribution of three tight junction proteins (occludin,claudin-5 and ZO-1) of the EA.hy926 cells treated with IL-8 under different concentrations and different times.RT-PCR was used to measure the mRNA expression of these three proteins.Results The results demonstrated that IL-8 could change the distribution of occludin,claudin-5 and ZO-1 in EA.hy926 cells,and the mRNA expression of occludin,claudin-5 and ZO-1 decreased with the increase of IL-8 concentration and treated time.Conclusion The effects of IL-8 on the distribution and the expression of occludin,claudin-5 and ZO-1 are dose and time-dependent.

Numerical simulation of the distribution of shear stress on the bottom of parallel plate flow chamber under different inlet velocity conditions / 生物医学工程学杂志

The distribution of shear stress on the bottom of the parallel plate flow chamber under different inlet velocities was analyzed by numerical simulation. In the present experimental study, the projection planes of the relative errors at 0.7% level were obtained, and then the efficient region and the actual entrance length were further corrected by introducing the concept of relative error. The results showed that the efficient region of the chamber increased with the direction of length while the inlet velocity was increased, and the actual entrance length was much greater than that of the theoretical entrance length. Therefore, in accordance to the needed range of shear stress in experiment and to the needed efficient region area, the optimum design of the flow chamber is necessary.

The role of CXCR1/2 in shear stress-induced endothelial cell migration / 生物医学工程学杂志

CXCR1 and CXCR2 are important receptors in regulating vascular endothelial cell activities. In order to elucidate the role of CXCR1/2 in shear stress-induced endothelial cell migration, we have investigated the expression levels of CXCR1 and CXCR2 in the endothelial cells exposed to shear stress. In the experiment, anti-IL8RA and anti-IL8RB were used to antagonize CXCR1 and CXCR2. Different shear stresses were generated in a flow chamber; scratch test was carried out to compare endothelial cell migration in the control group and the receptor-antagonized groups. The results indicated that the migration of endothelial cells was restrained effectively after CXCR1 and CXCR2 were antagonized by anti-IL8RA and anti-IL8RB. And anti-IL8RA showed a stronger inhibitive effect than did anti-IL8RB (P<0.05). In the group with both receptor antagonisms, the migration was further inhibited. These results suggest that both CXCR1 and CXCR2 are important factors in mediating the migration of endothelial cells induced by shear stress, and CXCR1 fulfills a more important role.

Activated protein C ameliorates TNF-alpha-induced inflammatory response of endothelium via the endothelial protein C receptor / 生物医学工程学杂志

It has been demonstrated that the activated protein C (APC) plays an important role in the inhibition of inflammation. The activation of protein C can be significantly enhanced by the endothelial cell protein C receptor (EPCR). Previous studies proposed that the APC regulates the inflammatory response in endothelial cells by suppressing the expression of adhesion molecules and the secretion of chemokines and cytokines. However, the precise mechanism of the inhibitory effect of APC on inflammation is still poorly understood. In the present study, we evaluated the anti-inflammatory effect of recombinant human APC (rhAPC) and whether its inhibitory effect is conducted through the EPCR-dependent mechanism on human umbilical vein endothelial cells (HUVECs). By exposing HUVECs to: (1) TNF-alpha; (2) rhAPC plus TNF-alpha; (3) anti EPCR antibody that prevents rhAPC interaction with EPCR; (4) TNF-alpha plus anti EPCR antibody; (5) rhAPC plus TNF-alpha in the presence of anti EPCR antibody, we found that APC was able to significantly inhibit the TNF-alpha-induced secretion of cytokines such as IL-1beta and IL-8, as well as the expression of adhesion molecules such as ICAM-1, VCAM-1 and E-selction in HUVECs. These results reveal a novel pathway by which APC protects endothelial cells from inflammatory mediators through an EPCR-dependent mechanism.

Shear stress-regulated vascular endothelial permeability is mediated by Rho GTPases / 国际生物医学工程杂志

Dysfunctions of vascular endothelial permeability are related to a number of human diseases such as atherosclerosis, high blood pressure, stroke, inflammation, cancer, diabetes-induced retinopathy, macular edema and so on. Shear stress is an important mechanical force that affects vascular endothelial cells. It plays a particular role in permeability regulation. Rho GTPases is a family of small G proteins which act as cell signal molecules. They are assumed to mediate the regulation of the permeability of vascular endothelial cells. In this paper review is given on how shear stress regulates the permeability of vascular endothehal cells as well as the in-fluence of Rho GTPases on the role in molecular mechanism. It is suggested that shear stress-regulated vascular endothelial permeability is mediated by Rho GTPases.

Rac1 mediates the migration of endothelial cells induced by IL-8 / 生物医学工程学杂志

This study sought to elucidate whether Rac1 mediates the migration of endothelial cell induced by IL-8. The Transwell chamber motility assay was conducted to disclose the effect of different matrigel dilution and different time of IL-8 treatment on the migration of endothelial cells. The mRNA of Rac1 was detected by RT-PCR. The results demonstrated that when the concentration of Matrigel was 1:2, there is significant difference on the amounts of migration cells than that of the concentration of 1:3 or 1:8; When the dilution of Matrigel was 1:4, 1:5 or 1:6, there is no significant difference on the amounts of migration cells than that of other dilution groups. So we choose the Matrigel concentration as 1:4. With the increase of IL-8 stimulation time, the cells which migrated from upper reservoirs to lower reservoirs progressively increased. After six hours stimulation by IL-8, the expression of Rac1 mRNA in migrated cells was increased, compared with that of other groups. The results suggest that Rac1 may mediate the migration of endothelial cells induced by IL-8. It can also be the foundation for further investigation on the role of Rac1 in the migration of endothelial cells induced by IL-8.

Effects of laminar shear stress on the expression of IL-8 receptor CXCR1 in endothelial cells / 生物医学工程学杂志

This study was conducted to elucidate the effects of different fluid shear stress on the expression of IL-8 receptors CXCR1 in endothelial cells. The HUVEC cell lines, EA. Hy926 cells, were cultured in vitro, exposed to 5.56, 10.02, and 15.27 dyn/cm2 laminar shear stress, respectively, and then the shear stress grous were each investigated at the time-points of 0h, 1h, 2h, 4h and 8h. Western blotting was used for detecting the expression of IL-8 receptor CXCR1 at the time-points. The results showed that, under 5.56 dyn/cm2 shear stress, the expression of CXCR1 increased with time significantly (P < 0.01). The maximum expression of CXCR1 appeared at 4 h and was 2.2 times that of the control. When exposed to 10.02 dyn/cm2, the expression of CXCR1 increased gradually with time and finally remained at a constant higher level. When exposed to 15.27 dyn/cm2, CXCR1 expression decreased significantly with time (P < 0.01). The minimum CXCR1 expression appeared at 8 h and was 62. 59 percent of that of the control. These results indicate that the expression of CXCR1 in endothelial cell is regulated by laminar shear stress.

Effects of fluid shear stress on the expression of IL-8 receptor mRNA in EA. Hy926 cells / 生物医学工程学杂志

This study was conducted to elucidate the effects of different fluid shear stress on the expression of IL-8 receptors CXCR1 and CXCR2 mRNA in endothelial cells, EA. Hy926 cells. The HUVEC cell lines were cultured in vitro and then exposed to 5.56, 10.02, and 15.27 dyn/cm2 fluid shear stress respectively for 5 min, 10 min, 15 min, 20 min, 25 min, 30 min, 1 h, 2 h, 4 h and 8 h. Semi-quantitative reversal transcription-polymerase chain reaction (RT-PCR) was used for detecting IL-8 receptors mRNA expression at different times. The results showed that, under 5. 56 dyn/cm2 shear stress, both the expression of CXCR1 and CXCR2 mRNA increased significantly with time (P<0.05). When exposed to 10. 02 dyn/cm2, the expression of CXCR1 mRNA was down-regulated with time on every occasion. CXCR2 mRNA increased temporally at 30 min, then it decreased gradually with time and finally went on at a constant lower level. When exposed to 15.27 dyn/cm2, both CXCR1 and CXCR2 mRNA expression decreased significantly with time (P<0.01). These data indicate that the expression of CXCR1 and CXCR2 mRNA of endothelial cell is regulated by fluid shear stress.

Mechano-chemical Signal Pathway of Endothelial Cells Migration Induced by Fluid Shear Stress / 航天医学与医学工程

The migration of endothelial cell induced by fluid shear stress is related to many physiological and pathological responses in organism.The redistribution of membrane receptors and proteins,caused by shear stress,is a vital step for cell migration,followed by chemical reactions and signal transduction.Then cell morphological changes are induced,such as polarity,protrusion,and adhesion,which lead to the migration of endothelial cell at last.The goal of this paper is to review what is known about the mechanical models of endothelial cell migration and the responses of cells to fluid flow.It is helpful for better understanding the intrinsic mechanism of mechano-chemical signal pathway of the migration of endothelial cells induced by fluid shear stress.

Experimental study on the migration of vascular endothelial cells stimulated by IL-8 / 生物医学工程学杂志

To investigate the influence of different concentrations of IL-8 on the migration of vascular endothelial cells and find out the best IL-8 concentration, the transwell chamber motility assay and the scrape motility assay were applied to observe the migration of vascular endothelial cells induced by IL-8. The results demonstrated that the migration of vascular endothelial cells was increased significantly under different IL-8 concentrations, while the best effect occurred when IL-8 concentration was 100 ng/ml.