Vasopressin-induced von Willebrand factor secretion from endothelial cells involves V2 receptors and cAMP
Jocelyne E. Kaufmann, Alexander Oksche, Claes B. Wollheim, Gabriele Günther, Walter Rosenthal, Ulrich M. Vischer
Jocelyne E. Kaufmann, Alexander Oksche, Claes B. Wollheim, Gabriele Günther, Walter Rosenthal, Ulrich M. Vischer
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Vasopressin-induced von Willebrand factor secretion from endothelial cells involves V2 receptors and cAMP

Abstract

Vasopressin and its analogue 1-deamino-8-D-arginine vasopressin (DDAVP) are known to raise plasma von Willebrand factor (vWF) levels. DDAVP is used as a hemostatic agent for the treatment of von Willebrand’s disease. However, its cellular mechanisms of action have not been elucidated. DDAVP, a specific agonist for the vasopressin V2 receptor (V2R), exerts its antidiuretic effect via a rise in cAMP in kidney collecting ducts. We tested the hypothesis that DDAVP induces vWF secretion by binding to V2R and activating cAMP-mediated signaling in endothelial cells. vWF secretion from human umbilical vein endothelial cells (HUVECs) can be mediated by cAMP, but DDAVP is ineffective, presumably due to the absence of V2R. We report that DDAVP stimulates vWF secretion in a cAMP-dependent manner in HUVECs after transfection of the V2R. In addition, vasopressin and DDAVP induce vWF secretion in human lung microvascular endothelial cells (HMVEC-L). These cells (but not HUVECs) express endogenous V2R, as shown by RT-PCR. Vasopressin-induced vWF secretion is mimicked by DDAVP and inhibited by the selective V2R antagonist SR121463B. It is mediated by cAMP, since it is inhibited by the protein kinase A inhibitor Rp-8CPT-cAMPS. These results indicate that vasopressin induces cAMP-mediated vWF secretion by a direct effect on endothelial cells. They also demonstrate functional expression of V2R in endothelial cells, and provide a cellular mechanism for the hemostatic effects of DDAVP.

Authors

Jocelyne E. Kaufmann, Alexander Oksche, Claes B. Wollheim, Gabriele Günther, Walter Rosenthal, Ulrich M. Vischer

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DDAVP mediates vWF secretion by an increase in [cAMP]i in cells expressi...
DDAVP mediates vWF secretion by an increase in [cAMP]i in cells expressing V2R.EGFP. (a) DDAVP-mediated increase in [cAMP]i in cells expressing V2R.EGFP. HUVECs transfected with V2R were handled as in Figure 2. Sorted EGFP-negative cells were used as controls. At the end of the incubations (with 100 μM IBMX, alone [open bars], in the presence of 0.1 μM DDAVP [shaded bars], or of 10 μM forskolin [filled bars]) cAMP was extracted and quantified by radioimmunoassay. The results are shown as a percentage of the [cAMP]i in basal conditions (IBMX alone). The data are means ± SEM for four independent experiments. (AP < 0.05; BP < 0.01 by Student’s paired t test). (b) Inhibition of DDAVP-mediated vWF secretion from cells expressing V2R.EGFP by the PKA inhibitor Rp-8CPT-cAMPS. Seventy-two hours after FACS sorting, V2R.EGFP-positive cells were preincubated for 30 minutes in the absence (filled bars) or presence (shaded bars) of 0.5 mM Rp-8CPT-cAMPS in KRBH. They were then incubated for 1 hour in the presence of 100 μM IBMX alone or together with either 0.1 μM DDAVP or 10 μM forskolin (as in Figure 2). Then, vWF in the media was measured by ELISA. The results are shown as a percentage of the vWF secreted in basal conditions (IBMX alone). The data are means ± SEM for five independent experiments. (AP < 0.05 by Student’s paired t test).