420. The effect of maternal dietary protein on the expression of genes involved in TGF-β superfamily bioavailability in the bovine ovarian cortex of female offspring

Abstract

Although numerous familial studies have indicated a genetic component to polycystic ovary syndrome (PCOS), a consistent and repeatable association with any particular gene has not been definitively established. However, one genetic marker, the microsatellite D19S884, has shown repeatable and consistent association with PCOS. D19S884 maps to intron 55 of the fibrillin-3 gene. The family of fibrillin extracellular matrix proteins includes the family of latent TGF-β binding proteins which are known to have roles in ovarian function. These provide structural support to tissues and regulate TGF-β bioavailability and are candidates for involvement in clinical manifestation of PCOS. Many of the risk factors associated with PCOS including type II diabetes, heart disease, and obesity are also known to be affected by in utero experience. In addition, although diet has not been examined in the PCOS outcome of offspring, some fetal experiences including androgen exposure have been linked to PCOS outcome. We therefore investigated the effect of protein content of maternal diet on expression of fibrillins-1, –2, and –3 and LTBPs-1 and –2 in the tunica albuginea of ovaries from female offspring by QRT–PCR. Diets were either high (13% protein per total dry weight) or a low protein (5%) during the first two trimesters. All three fibrillins were expressed in the tunica albuginea with the highest level of expression observed for fibrillin-1 followed by fibrillin-2, with low levels of expression of fibrillin-3. Both LTBP-1 and LTBP-2 were expressed, with the highest expression observed for LTBP-2. No significant (P > 0.05) effects of diet upon gene expression were observed. Expression levels of all three fibrillins were positively correlated with each other, and fibrillins-1 and 2 were positively correlated with LTBP-2. This is the first demonstration of the expression of fibrillins and LTBPs in the ovary, however these were unaffected by the maternal diets examined.