Synergistic stimulation of alkaline phosphatase activity in bovine aortic endothelial cells grown in the presence of retinoids and glucocorticoids

While cigarette smoking has beenimplicated in the development of cardiovascular diseases, it has been reported to increase fibrinolytic activity in vivo. However, no data is available regarding the underlying mechanism of action. The present investigation was carried out to evaluate the effects of nicotine and its major metabolite, cotinine, on the seretion of plasminogen activator (PA) and PA inhibitor (PAI) by cultured bovine aortic endothelial cells. PA activity was determined by the fibrin plate method, and individual molecular species with PA and PAI activities were separated and visualized using SDS-PAGE with zymography and reverse fibrin autography. Both nicotine and cotinine increased PA secretion in a time- and dose-dependent manner. A maximum stimulation in PA secretion after 24-hour incubation was observed for nicotine at 10-8 M and for cotinine at 10-7> M, which corresponded to 2.5- and 2.7-foldincreases over control, respectively. These concentrations are in the range observed after cigarette smoking. The pharmacological stimulation of PA activity required both RNA and protein synthesis, as evidencedby its inhibition by cycloheximide and actinomycin D. Both control cells and cells treated with nicotine and cotinine produced multiple forms of PA and a single form of PAI. The PAI was mainly of the latent form as no quenching effect was observed on standard tissue plasminogen activator (tPA) and urokinase (UK) after they were mixed with the conditioned culture medium. The PAs werefound to consist of both tPA and UK,and the corresponding complexes with PAI, however, the UK bands were wider than the tPA bands. Both species were enhanced by nicotine and cotinine. Although activities of all species of PA were enhanced by nicotine and cotinine, these compounds had no apparent quantitative or qualitative effects on the release ofPAI. These results thus suggest that the mechanism underlying the enhanced fibrinolytic activity after cigarette smoking may be due to nicotine- and cotinine-induced stimulation of PA synthesis and subsequent release.

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Correlation of HSP70 Expression and Cell Viability Following Thermal Stimulation of Bovine Aortic Endothelial Cells

Journal of Biomechanical Engineering ◽

10.1115/1.1993661 ◽

2005 ◽

Vol 127 (5) ◽

pp. 751-757 ◽

Cited By ~ 26

Author(s):

Marissa Nichole Rylander ◽

Kenneth R. Diller ◽

Sihong Wang ◽

Shanti J. Aggarwal

Keyword(s):

Endothelial Cells ◽

Cell Viability ◽

Guideline Development ◽

Cardiac Cells ◽

Thermal Stimulation ◽

Hsp70 Expression ◽

Aortic Endothelial Cells ◽

Bovine Aortic Endothelial Cells ◽

Stimulation Of ◽

Aortic Endothelial

Thermal preconditioning protocols for cardiac cells were identified which produce elevated HSP70 levels while maintaining high cell viability. Bovine aortic endothelial cells were heated with a water bath at temperatures ranging from 44to50°C for periods of 1-30min. Thermal stimulation protocols were determined which induce HSP70 expression levels ranging from 2.3 to 3.6 times the control while maintaining cell viabilities greater than 90%. An Arrhenius injury model fit to the cell damage data yielded values of A=1.4×1066s−1 and Ea=4.1×105J∕mol. Knowledge of the injury parameters and HSP70 kinetics will enhance dosimetry guideline development for thermal stimulation of heat shock proteins expression in cardiac tissue.

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Dual regulation of PLA2 and PGI2 production by G proteins in bovine aortic endothelial cells

AJP Cell Physiology ◽

10.1152/ajpcell.1996.271.2.c555 ◽

1996 ◽

Vol 271 (2) ◽

pp. C555-C562 ◽

Cited By ~ 16

Author(s):

M. Rosenstock ◽

A. Danon ◽

G. Rimon

Keyword(s):

Endothelial Cells ◽

G Proteins ◽

Specific Inhibitor ◽

Inhibitory Effect ◽

Aortic Endothelial Cells ◽

Biphasic Pattern ◽

Bovine Aortic Endothelial Cells ◽

Phenylisopropyl Adenosine ◽

Stimulation Of ◽

Aortic Endothelial

NaF, a nonselective activator of heterotrimeric guanine nucleotide-binding proteins (G proteins), increased the release of arachidonic acid (AA) and prostacyclin (PGI2) production in bovine aortic endothelial cells (BAEC) at low concentrations (40-60 mM). On the other hand, higher concentrations (100 mM) inhibited phospholipase A2 (PLA2) compared with the basal activity. Intracellular Ca2+ levels did not rise after treatment with stimulatory concentrations of NaF, and, moreover, neither neomycin nor Ca(2+)-free medium affected the biphasic pattern of PGI2 synthesis in response to NaF. CGP-43187, an inhibitor of the 14-kDa secretory PLA2, did not affect NaF-induced AA release. However, AACOCF3, a specific inhibitor of the cytosolic 85-kDa PLA2 (cPLA2), abrogated AA release and PGI2 production in response to 60 mM NaF. A biphasic pattern of PGI2 production was also obtained with the guanosine 5'-triphosphate analogues guanosine 5'-O-(3-thiotriphosphate) and guanylylimidodiphosphate in permeabilized BAEC. Pretreatment of the cells with guanosine 5'-O-(2-thiodiphosphate) suppressed the inhibition and the stimulation of AA release induced by guanylylimidodiphosphate. In addition, phenylisopropyl adenosine inhibited the release of AA and PGI2, whereas ATP and bradykinin increased PGI2. Pertussis toxin not only inhibited ATP- and bradykinin-stimulated PGI2 release, it also reversed the inhibitory effect of phenylisopropyl adenosine, resulting in a significant stimulation. These findings strongly suggest that, in BAEC, cPLA2 is coupled with more than one G protein that are involved in inhibition and stimulation of cPLA2 activity.

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