TESTOSTERONE INDUCES PHOSPHORYLATION OF P38 AND JNK IN HUVEC

POWAZNIAK Y; KEMPFER A C; FARIAS CE; KELLER L; DOMINGUEZ M P; CALDERAZZO JC; LAZZARI MA

Ginebra

Congreso; XXIst ISTH Congress; 2007

International Society on Thrombosis and Haemostasis

Introduction: Effects of sexual hormones on the apoptotic/proliferate process in HUVEC are in current study. We hypothesize that ERK1/2, p38, and JNK play an important role as mediators in these functions. Methods: HUVEC were isolated from human umbilical veins (Jaffe EA., 1973), and treated with 10% normal male plasma (NMP), normal female plasma (NFP), NFP pregnant, 17 beta-estradiol (E2) and testosterone (T). We used flutamide (F) and fulvestrant (Fu) as inhibitors of T and E2 respectively. Phosphorylation of ERK1/2, p38 and JNK, by SDS- PAGE 12% was analyzed by densitometric scanning. Apoptosis by annexin V-FITC and PI was detected by FACScan flow cytometer. The relative number of viable cells was estimated by MTS measurement. Results: The increase of phosphorylation of ERK2 was statistically significant in E2 (1nM) treated HUVEC, and reverted with the addition of Fu (10nM). NMP and T (60nM) induced phosphorylation of p38, reverted with the addition of F (1mM), but only T (120-600nM) treatment resulted in JNK phosphorylation. Treatment with T (120-600nM) and TNF-alpha; (40ng/ml) provoked apoptosis of HUVEC, 10 and 25% respectively. Exposure to T (120-1200nM) for 24 h resulted in the death of 20-30% of cells, as revealed by MTS. Conclusions: E2 in physiological doses promoted cell survival and induced the phosphorylation of ERK2. NMP increased phosphorylation of p38. T was able to phosphorilate JNK and promotes cell death and apoptosis when it was used in a dose two fold higher of physiological levels. This effect appears to be mediated by the activation of p-38 and JNK pathways in HUVEC. Treatment of HUVEC by sex hormones was found to influence cell proliferation (estrogens) and apoptosis (androgens).