PROGESTERONE AND HISTAMINE EXERT AN OPPOSITE EFFECT ON VWF/ADAMTS13 TRANSCRIPTIONAL AND PROTEIN LEVELS IN HUVEC

POWAZNIAK Y; KEMPFER A C; CALDERAZZO JC; CARRIVALE M; PAIVA J; KELLER L; LAZZARI MA

Boston

Congreso; XXII Congress of the International Society on Thrombosis and Haemostasis; 2009

Abstract: VWF and ADAMTS13 are localized in endothelial cells. ADAMTS13 has a proteolytic activity in the endoplasmic reticulum in transfected HeLa cells. Histamine (H) induces the release of VWF in a Ca2+ dependent manner through its interaction with cytochrome P450. This interaction can be inhibited by progesterone (P). Objective. VWF and ADAMTS13 in HUVEC: synthesis, storage and secretion changes caused by P and H. Treatments: 0.001mM P, 0.1mM H, P plus H or vehicle. Real-time PCR was performed for the relative quantitation of VWF mRNA and ADAMTS13 mRNA. Culture media and cell lysates were quantified by ELISA for VWF and immunoblotting for ADAMTS13. Statistical significance: P less than 0.05 (ANOVA). Treatment with P and treatment with H did not produced significant differences in the levels of both mRNA. However, P4 plus H produced a significant 6-fold and 27-fold increase in VWF and ADAMTS13 mRNA respectively, with regard to control. Treatment with P did not increase intracellular and released VWF. When HUVECs were exposed to H there was a significant 2-fold decrease in intracellular VWF with an increase in the released VWF. H plus P produced a significant decrease of released VWF (with regard to H) and a significant 2-fold decrease in the intracellular VWF (respect to control and P). No significant differences were found between control and P with respect to intracellular and released ADAMTS13. When HUVECs were incubated with P plus H, there was a significant 2-fold increase in released ADAMTS13, with regard to control. These observations strongly suggest a transcriptional synergy between P and H in: activation of the VWF and ADAMTS13 genes and the intracellular balance among VWF and ADAMTS13. Furthermore, we observed an inhibitory effect of P on H with respect to released VWF. This could be due to competition between P and H by the union with cytochrome P450 described previously by Labella (2000).