Thrombin induces Contraction And increased 51-Cr Release from Cultured Human Endothelial Cells

1979 ◽  
Author(s):  
K.S. Galdal ◽  
S.A. Evensen

Injury to human endothelial cells(EC) in primary culture was evaluated by a 51-Cr release assay, phase contrast microscopy and the trypan blue exclusion test. Normal integrity of EC, was maintained and 51-Cr release showed a slow linear increase during 24h incubation with either RPMI 1640 supplemented with 20% foetal calf serum, glutamine and antibiotics(SCM) or normal human serum(NHS). Thrombin in a concentration as low as 0.1 IU/ml induced obvious contraction of EC incubated in SCM, but the cells remained fixed to the bottom of the wells. Cell contraction was maximal after 15min and disappeared within 4h. 51-Cr release increased 2-3 fold within a few minutes and remained increased during an incubation period of 4h. The injurious effect of thrombin was inhibited in SCM containing hirudin(l.7 u/ml) or in NHS. ADP(10-5 M), endotoxin (0.1mg/ml) and 5 vasoactive agents adrenalin 5.5 10-5, noradrenalin 5.9 10-5 M, histamine 9.10-4 M, bradykinin 7.5 10-7 M and serotonin 10-5 M) did not cause cellular injury. Cultured human EC are injured by thrombin. The other tested agents do not appear to induce direct injury in vitro, but may interact with cellular elements in the blood to produce the endothelial injury previously observed in vivo.

1993 ◽  
Vol 292 (3) ◽  
pp. 759-765 ◽  
Author(s):  
P Raynal ◽  
F Hullin ◽  
J M F Ragab-Thomas ◽  
J Fauvel ◽  
H Chap

In vitro phosphorylation of annexin 1 by purified rat brain protein kinase C (PKC) has been studied in the presence of annexin 5, which is not a substrate for PKC. Annexin 5 promoted a dose-dependent inhibition of annexin 1 phosphorylation, which could be overcome by increasing the concentration of phosphatidylserine (PtdSer). In addition, a close relationship was found between the amount of PtdSer uncovered by annexin 5 and the residual phosphorylation of annexin 1. These data fit with the ‘surface depletion model’ explaining the antiphospholipase activity of annexins. In order to check the possibility that the in vitro effect of annexin 5 could be of some physiological relevance, annexins 1, 2, and 5, as well as the light chain of calpactin 1 (p11), have been quantified in human endothelial cells by measuring the radioactivity bound to the proteins after Western blotting with specific antibodies and 125I-labelled secondary antibody. Our data indicate that annexins 1 and 5, PKC and PtdSer are present in human endothelial cells in relative amounts very similar to those used in vitro under conditions permitting the detection of the inhibitory effect of annexin 5. Since annexin 1 remained refractory to PKC-dependent phosphorylation in intact cells, we suggest that annexin 5 might exert its inhibitory effect towards PKC in vivo, provided that its binding to phospholipids can occur at physiological (micromolar) concentrations of Ca2+. This was previously shown to occur in vitro using phosphatidylethanolamine/phosphatidic acid vesicles [Blackwood and Ernst (1990) Biochem. J. 266, 195-200]. Using identical assay conditions, which also allowed expression of PKC activity, annexin 5 again inhibited annexin 1 phosphorylation without interfering with PKC autophosphorylation. These data suggest that annexins 1 and 5 might interact with each other on the lipid surface, resulting in a specific inhibition of annexin 1 phosphorylation by PKC. Whether a similar mechanism also occurs in vivo remains to be determined.


1977 ◽  
Vol 25 (1) ◽  
pp. 265-277
Author(s):  
M.A. Surani

The influence of extracellular environmental factors on preimplantation rat blastocysts was tested by determining the number of embryos which escaped from their zonae pellucidae, followed by attachment and outgrowth of trophoblast giant cells, after 72 h in culture Uterine luminal ocmponents from individual females, or hormones, were included in Dulbecco's medium which contained 4 mg/ml bovine serum albumin. In about 20% of cases, uterine fluids were embryotonic. However, uterine fluids from day-5 pregnant females, the day of implantation in the rat, were more potent in these tests than uterine fluids obtained from ovariectomized females treated with progesterone alone. The potency of a mixture of the 2 fluids was also high. Uterine fluids obtained at 14 h after an injection of oestradiol and progesterone to the ovariectomized females, were also effective in these tests. Rat serum and foetal calf serum were effective too, but steroids or insulin alone in the medium had no detectable influence on embryos. Serum or uterine luminal proteins appear to be essential for maintaining the viability of the blastocysts and for inducing the responses observed here. In the uterine fluids, some proteins released into the lumen after treatment of females with oestradiol and progesterone appear to be the biologically active components. Differences in the responses of blastocysts in vitro are compared with those in vivo.


Development ◽  
1997 ◽  
Vol 124 (12) ◽  
pp. 2345-2354 ◽  
Author(s):  
C. Neophytou ◽  
A.B. Vernallis ◽  
A. Smith ◽  
M.C. Raff

In the present study, we examine rod photoreceptor development in dissociated-cell cultures of neonatal mouse retina. We show that, although very few rhodopsin+ rods develop in the presence of 10% foetal calf serum (FCS), large numbers develop in the absence of serum, but only if the cell density in the cultures is high. The rods all develop from nondividing rhodopsin- cells, and new rods continue to develop from rhodopsin- cells for at least 6–8 days, indicating that there can be a long delay between when a precursor cell withdraws from the cell cycle and when it becomes a rhodopsin+ rod. We show that FCS arrests rod development in these cultures at a postmitotic, rhodopsin-, pre-rod stage. We present evidence that FCS acts indirectly by stimulating the proliferation of Muller cells, which arrest rod differentiation by releasing leukaemia inhibitory factor (LIF). These findings identify an inhibitory cell-cell interaction, which may help to explain the long delay that can occur both in vitro and in vivo between cell-cycle withdrawal and rhodopsin expression during rod development.


1991 ◽  
Vol 99 (1) ◽  
pp. 131-139
Author(s):  
J.H. Bennett ◽  
C.J. Joyner ◽  
J.T. Triffitt ◽  
M.E. Owen

Stromal colonies with fibroblastic morphology grown from rabbit marrow cells in culture supplemented with foetal calf serum. In this study the same marrow cells cultured with autologous rabbit plasma and hydrocortisone form colonies of a single lineage that express the adipocytic phenotype. A comparison of the potential for differentiation of cloned cell populations grown from fibroblastic and adipocytic colonies has been made using an in vivo diffusion chamber assay. The adipocytic colonies differentiated and grew to a limited size in medium with rabbit plasma and hydrocortisone, but attempts to isolate them and expand them in this medium failed. When the serum supplement was changed to foetal calf serum at day 10 the cells in the adipocytic colonies acquired a less differentiated morphology, there was a large increase in colony growth and cells were produced in sufficient numbers for the diffusion chamber assay. Thirty one fibroblastic colonies and twenty one adipocytic colonies were isolated either by limiting dilution or ring cloning and then expanded. Of these, eleven fibroblastic and eight adipocytic colonies provided enough cells (2 × 10(5) to 2 × 10(6] for implantation and culture in the chambers. Four of the eleven fibroblastic and three of the eight adipocytic colonies formed an osteogenic tissue in the chambers. It was concluded that cells that have differentiated in an adipocytic direction are able to revert to a more proliferative stage and subsequently to differentiate along the osteogenic pathway. Adipocytic and fibroblastic cells cultured in vitro from marrow have, with osteogenic cells, a common precursor in adult marrow.


PLoS ONE ◽  
2010 ◽  
Vol 5 (4) ◽  
pp. e10091 ◽  
Author(s):  
Verónica Azcutia ◽  
May Abu-Taha ◽  
Tania Romacho ◽  
Marta Vázquez-Bella ◽  
Nuria Matesanz ◽  
...  

1977 ◽  
Author(s):  
E. G. D. Tuddenham ◽  
L. W. Hoyer

In vivo studies have shown that many stimuli such as epinephrine, exercise and pregnancy lead to a rise in factor VIII levels. However, the physiologic mechanisms controlling factor VIII levels are poorly, if at all, understood. Since endothelial cells synthesize factor VIII related protein (FVIII:RP) and can be grown in tissue culture, they provide a suitable in vitro model to study synthesis and release of FVIII:RP. Endothelial cells were harvested by collagenase digestion from human umbilical cords and grown in medium 199 supplemented with 20 to 30% pooled human serum. Confluent cultures were washed and then maintained in medium 199 supplemented with 20% fetal calf serum. Release of FVIII:RP into the medium was measured by immunoradiometric assay. Labeled amino acids were added to the medium for studies of FVIII:RP synthesis. Incorporation of radioactive label into FVIII:RP was measured in binding studies using a specific immunoadsorbent. Epinephrine in concentrations from 1 ng to 10 ug per ml had no effect on rate of release of FVIII:RP from cultured endothelial cells, suggesting that the in vivo effect of epinephrine is not due to a direct action on endothelial cells. In a separate experiment,exogenous FVIII:RP was added to the culture medium at a high concentration (2 units FVIII:RP per ml) along with 3H Leucine. A control without exogenous VIII:RP incorporated as much radioactivity into VIII:RP as did the culture with added FVIII:RP. This result suggests that there is no end product inhibition of FVIII:RP synthesis which operates on the endothelial cell.


2017 ◽  
Vol 114 (12) ◽  
pp. 2920-2930 ◽  
Author(s):  
Sorour Nemati ◽  
Aysa Rezabakhsh ◽  
Ali Baradar Khoshfetrat ◽  
Alireza Nourazarian ◽  
Çığır Biray Avci ◽  
...  

2001 ◽  
Vol 85 (5) ◽  
pp. 615-620 ◽  
Author(s):  
Chingwen Ying ◽  
Jih-Tay Hsu ◽  
Show-Chi Shieh

This study examined the growth regulatory effects of a phyto-oestrogen, biochanin A, on a transformed human endothelial cell line ECV304 in vitro. Biochanin A was found to inhibit cell proliferation in a dose-dependent fashion and this effect was influenced by the concentration of serum present in the culture medium. In the absence of serum, the calculated IC50 of biochanin A was 0.18 ± 0.1 μM COMPARED TO AN IC50 OF 35±5 Μm at 10 % serum. At low cell density, the growth inhibitory effects of biochanin A were more evident than at high cell density. Co-administration of a synthetic oestrogen diethylstilboestrol with biochanin A did not suppress the growth regulatory effects of biochanin A treatment. We conclude that biochanin A inhibits the cell proliferation of human endothelial cells at concentrations that are physiologically achievable in vivo and that this effect may play an important role in the cancer-preventing activity of the phyto-oestrogens.


1986 ◽  
Vol 82 (1) ◽  
pp. 263-280
Author(s):  
R.A. Clark ◽  
J.M. Folkvord ◽  
L.D. Nielsen

Recently, we have presented evidence that proliferating blood vessels produce and deposit fibronectin in situ during the angiogenesis of wound repair. This report extends these observations by demonstrating that human endothelial cells from both large and small vessels depend on fibronectin for their adherence in vitro. Endothelial cells were grown from human umbilical veins (HUVEC) by the method of Gimbrone and from the microvasculature of human omentum by the method of Kern, Knedler and Eckel. Second-passage cells were plated into microtitre wells that had been coated with 100 micrograms ml-1 of fibronectin, types I and III collagen, type IV collagen or laminin. After a 3-h incubation, adherent cells were solubilized with Zap-Isoton and quantified on a Coulter Counter. Under normal culture conditions HUVEC showed no preference for fibronectin substrates while microvascular cells always demonstrated a striking preference for fibronectin substrates. However, when HUVEC were exposed to 2.5 or 25 micrograms ml-1 of cycloheximide for 4 h before and during the adherence assays, the adherence to fibronectin was 50–200% greater than to types I and III collagen. Immunofluorescence studies showed that while HUVEC expressed a large quantity of surface fibronectin, microvascular cells expressed very little. Metabolic labelling studies confirmed that HUVEC cultures had substantial quantities of fibronectin in their cell layer while microvascular cells did not. In antibody blocking experiments, preincubation of fibronectin-coated surfaces with anti-fibronectin antibodies totally blocked microvascular cell adhesion but only abrogated HUVEC adherence by 50%, presumably since these latter cells were able to deposit additional fibronectin onto the surface during the 3 h assay period. In the presence of cycloheximide anti-fibronectin antibodies totally blocked HUVEC adherence. These results demonstrate that both endothelial cell types rely, at least in part, on fibronectin for adherence in vitro. HUVEC can synthesize, secrete and deposit enough fibronectin for their adherence in vitro, while microvascular cells rely on an exogenous source of fibronectin under these culture conditions. Thus, the increased blood vessel fibronectin observed during angiogenesis in vivo may mediate adherence of the proliferating and migrating endothelial cells.


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