VWF/ ADAMTS13 SYSTEM REGULATION BY ESTRADIOL AND HISTAMINE

POWAZNIAK Y; KEMPFER A C; CALDERAZZO JC; PAIVA J; ZAPATA VA; KELLER L; LAZZARI MA

Boston

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

Abstract: VWF and ADAMTS13 are localized in HUVEC. Studies have been conducted in normal pregnant women where levels of ADAMTS13 decrease and VWF and estradiol (E2) increase towards the end of the third trimester of pregnancy. During pregnancy there is a strong expression of histamine (H) receptors and an embryonary H-releasing factor. Objective. VWF and ADAMTS13 in HUVEC: Analysis of synthesis, storage and secretion changes caused by E2 and H. Methodology. Treatments: 1nM E2, 0.1mM H, E2 plus H or vehicle. Real-time PCR was performed for the relative quantitation of VWF and ADAMTS13 mRNAs. Culture media and cell lysates were quantified by ELISA for VWF and immunoblotting for ADAMTS13. Statistical significance: P less than 0.05 (ANOVA). Results. A significant, 9 fold, increase was observed in the VWF and ADAMTS13 mRNAs levels, when HUVECs were incubated with E2. When E2 was combined with H, there was a significant 8- and 140-fold decrease in the levels of VWF and ADAMTS13 mRNAs respectively with regard to E2. Treatment with E2 produced no increase and H induced an increase in VWF release. E2 plus H resulted in a significant decrease with regard to H. E2 and also H produced a significant 1.6- and 8- fold decrease in released ADAMTS13. Treatment with E2 plus H resulted in a significant 3-fold increase in released ADAMTS13 with regard to H. We observed a significant 8-fold increase in intracellular ADAMTS13 when HUVECs were incubated with E2, but treatment with H and E2 plus H produced no significant differences. Conclusion. For the first time we report that E2 up-regulates and E2 plus H down-regulates the expression of both genes. Treatment with E2 produced the increase of VWF mRNA, but not of VWF protein. The increased ADAMTS13 would provoke this VWF behavior. Majerus (2003) suggested that ADAMTS13 degrades VWF in the endoplasmic reticulum.