Protein Kinase C and the Stimulation of Tissue Plasminogen Activator Release from Human Endothelial Cells

Abstract Trans retinoic acid (t-RA) stimulated the production of tissue plasminogen activator (tPA) in HeLa-S3 and human umbilical vein endothelial cells (huvecs) in a dose-dependent manner with maximal release (four to five times control) at 40 nmol/L and 40 mumol/L, respectively. In endothelial cells, the stimulation of tPA production by phorbol 12-myristate 13-acetate (PMA) was potentiated 1.9-fold by 10 mumol/L t-RA, or 1.8 times the additive effect. In HeLa cells, total tPA secretion with 10 nmol/L PMA was increased from 43 ng/mL to 96 ng/mL by 40 nmol/L t-RA, which was two times the additive effect. Higher concentrations of t-RA (400 nmol/L) depressed tPA secretion by itself and also suppressed PMA-induced tPA production by 50%. Histamine and thrombin also synergized with t-RA. t-RA (40 nmol/L) and 10 micrograms/mL histamine or 10 U/mL thrombin combined to induce tPA production 3.4 and 1.3 times the additive effect in HeLa cells. Cyclic adenosine monophosphate (cAMP) levels were not significantly affected by 10 nmol/L to 10 mumol/L t-RA. Nor did 10 nmol/L PMA and 40 nmol/L t- RA together affect cAMP levels, suggesting that t-RA-mediated potentiation of PMA-induced tPA production occurred via a mechanism that was independent of cAMP levels. Downregulation of protein kinase C (PKC) by pretreatment of huvecs with 100 nmol/L PMA completely blocked a secondary response to PMA, but did not have a significant effect on t- RA induction. Pretreatment with 10 mumol/L t-RA, on the other hand, did not significantly affect a secondary stimulus by 100 nmol/L PMA, but completely suppressed a secondary stimulation by 10 mumol/L t-RA alone. These studies suggest that the mechanism mediating t-RA stimulation of tPA production interacts with the PKC pathway, resulting in synergism.

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Lysophosphatidylcholine stimulation of CGMP production in human endothelial cells involves tyrosine kinases, heterotrimeric GTP binding proteins, phosphatidylinositol 3-kinase and protein kinase C

Vascular Pharmacology ◽

10.1016/j.vph.2006.08.374 ◽

2006 ◽

Vol 45 (3) ◽

pp. e142-e143

Author(s):

J.L. Whatmore ◽

O. Konopatskaya ◽

A.C. Shore

Keyword(s):

Endothelial Cells ◽

Protein Kinase C ◽

Protein Kinase ◽

Tyrosine Kinases ◽

Phosphatidylinositol 3 Kinase ◽

Human Endothelial Cells ◽

Cgmp Production ◽

Kinase C ◽

Gtp Binding ◽

Stimulation Of

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Stimulation of tissue plasminogen activator production by retinoic acid: synergistic effect on protein kinase C-mediated activation

Blood ◽

10.1182/blood.v80.4.981.bloodjournal804981 ◽

1992 ◽

Vol 80 (4) ◽

pp. 981-987 ◽

Cited By ~ 21

Author(s):

RD Medh ◽

L Santell ◽

EG Levin

Keyword(s):

Endothelial Cells ◽

Protein Kinase C ◽

Retinoic Acid ◽

Protein Kinase ◽

Hela Cells ◽

Additive Effect ◽

Kinase C ◽

Tissue Plasminogen ◽

Camp Levels ◽

Stimulation Of

Trans retinoic acid (t-RA) stimulated the production of tissue plasminogen activator (tPA) in HeLa-S3 and human umbilical vein endothelial cells (huvecs) in a dose-dependent manner with maximal release (four to five times control) at 40 nmol/L and 40 mumol/L, respectively. In endothelial cells, the stimulation of tPA production by phorbol 12-myristate 13-acetate (PMA) was potentiated 1.9-fold by 10 mumol/L t-RA, or 1.8 times the additive effect. In HeLa cells, total tPA secretion with 10 nmol/L PMA was increased from 43 ng/mL to 96 ng/mL by 40 nmol/L t-RA, which was two times the additive effect. Higher concentrations of t-RA (400 nmol/L) depressed tPA secretion by itself and also suppressed PMA-induced tPA production by 50%. Histamine and thrombin also synergized with t-RA. t-RA (40 nmol/L) and 10 micrograms/mL histamine or 10 U/mL thrombin combined to induce tPA production 3.4 and 1.3 times the additive effect in HeLa cells. Cyclic adenosine monophosphate (cAMP) levels were not significantly affected by 10 nmol/L to 10 mumol/L t-RA. Nor did 10 nmol/L PMA and 40 nmol/L t- RA together affect cAMP levels, suggesting that t-RA-mediated potentiation of PMA-induced tPA production occurred via a mechanism that was independent of cAMP levels. Downregulation of protein kinase C (PKC) by pretreatment of huvecs with 100 nmol/L PMA completely blocked a secondary response to PMA, but did not have a significant effect on t- RA induction. Pretreatment with 10 mumol/L t-RA, on the other hand, did not significantly affect a secondary stimulus by 100 nmol/L PMA, but completely suppressed a secondary stimulation by 10 mumol/L t-RA alone. These studies suggest that the mechanism mediating t-RA stimulation of tPA production interacts with the PKC pathway, resulting in synergism.

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Specificity of the Thrombin-Induced Release of Tissue Plasminogen Activator from Cultured Human Endothelial Cells

Thrombosis and Haemostasis ◽

10.1055/s-0038-1661622 ◽

1986 ◽

Vol 56 (02) ◽

pp. 115-119 ◽

Cited By ~ 43

Author(s):

Eugene G Levin ◽

David M Stern ◽

Peter P Nawroth ◽

Richard A Marlar ◽

Daryl S Fair ◽

...

Keyword(s):

Endothelial Cells ◽

Plasminogen Activator ◽

Tissue Plasminogen Activator ◽

Protein C ◽

Primary Cultures ◽

Activated Protein C ◽

Specific Inhibitor ◽

Factor Xa ◽

Human Endothelial Cells ◽

Tissue Plasminogen

SummaryThe addition of thrombin (9 nM) to primary cultures of human endothelial cells induces a 6- to 7-fold increase in the rate of release of tissue plasminogen activator (tPA). Several other serine proteases which specifically interact with endothelial cells were also analyzed for their effect on tPA release. Gamma-thrombin, an autocatalytic product of α-thrombin, promoted tPA release but was less effective than α-thrombin. A maximum increase of 5.5-fold was observed, although a concentration of γ-thrombin 20 times greater than α-thrombin was required. The response to Factor Xa was similar to α-thrombin, although the stimulation was significantly reduced by the addition of hirudin or DAPA suggesting that prothrombin activation was occurring. The simultaneous addition of prothrombin with Factor Xa resulted in enhanced tPA release equal to that observed with an equimolar concentration of active α-thrombin. Thus, under these conditions, Factor Xa-cell surface mediated activation of prothrombin can lead to a secondary effect resulting from cell-thrombin interaction. Activated protein C, which has been implicated as a profibrinolytic agent, was also tested. No change in tPA release occurred after the addition of up to 325 nM activated protein C in the presence or absence of proteins. Factor IXa and plasmin were also ineffective. The effect of thrombin on the endothelial cell derived plasminogen activator specific inhibitor was also studied. Thrombin produced a small but variable release of the inhibitor with an increase of less than twice that of non-thrombin treated controls.

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