Changes in the Proliferation/Apoptosis Balance in the Bovine Ovary: A Key Early Event in Follicular Persistence

BELOTTI, E. MATÍAS; STASSI, ANTONELA F.; VELÁZQUEZ, MELISA M.L.; DÍAZ, PABLO U.; MARELLI, BELKIS E.; REY, FLORENCIA; NOTARO, ULISES S.; ORTEGA, HUGO H.; SALVETTI, NATALIA R.

CELLS TISSUES ORGANS

KARGER

Año: 2017

1422-6405

The objective of thiswork was to evaluate proliferation and apoptosis in the bovine ovary in a modelof follicular persistence induced by low levels of progesterone to detectincipient changes during cystic ovarian disease development on the expected dayof ovulation (day 0) and after 5, 10, and 15 days of follicular persistence. Weanalyzed cell proliferation by evaluating the expression of Ki-67 and apoptosisby evaluating caspase-3, BAX, and BCL2 expression. Proliferation was similar inthe granulosa and theca cells of antral follicles in the P0 group (treated withprogesterone up to the expected day of ovulation) and in the control group. Adecrease in cell proliferation was detected after 5 days of persistence (P5) inrelation to P0 ( p <0.05). Similar changes were found in the granulosa cells of the persistentfollicles in relation to the control group ( p < 0.05). Caspase-3expression was similar in granulosa cells of antral follicles at early stages ofpersistence, with an increase after 15 days of persistence ( p < 0.05). In thegranulosa cells of group P10 (10 days of per-sistence), caspase-3 expressionwas reduced relative to that of antral follicles from the control group ( p < 0.05). BCL2expression was higher in granulosa cells of the persistent follicles of groupP0 relative to the control follicles, with no changes in BAX expression, whichwas increased in persistent follicles of group P15 ( p < 0.05). Similarresults were observed in theca cells at initial stages of persistence. Theresults show that, initially, proliferation is maintained with low apoptosisand an increase in cell survival.