Magata F, Horiuchi M, Miyamoto A, Shimizu T
Graduate School of Animal and Food Hygiene, Obihiro University of Agriculture and Veterinary Medicine, 0808555 Obihiro, Japan.
Toxicol In Vitro. 2014 Aug;28(5):961-7. doi: 10.1016/j.tiv.2014.04.005. Epub 2014 Apr 13.
Uterine bacterial infection perturbs uterine and ovarian functions in postpartum dairy cows. Peptidoglycan (PGN) produced by gram-positive bacteria has been shown to disrupt the ovarian function in ewes. The aim of this study was to determine the effect of PGN on steroid production in bovine theca cells at different stages of follicular development. Bovine theca cells isolated from pre- and post-selection ovarian follicles (<8.5mm and >8.5mm in diameter, respectively) were cultured in vitro and challenged with PGN. Steroid production was evaluated by measuring progesterone (P4) and androstenedione (A4) concentration in culture media after 48 h or 96 h of culture. Bovine theca cells expressed PGN receptors including Toll-like receptor 2 and nucleotide-binding oligomerization domain 1 and 2. Treatment with PGN (1, 10, or 50 μg/ml) led to a decrease in P4 and A4 production by theca cells in both pre- and post-selection follicles. The mRNA expression of steroidogenic enzymes were decreased by PGN treatment. Moreover, A4 production was further suppressed when theca cells of post-selection follicles were simultaneously treated by PGN and lipopolysaccharide (0.1, 1, or 10 μg/ml). These findings indicate that bacterial toxins may act locally on ovarian steroidogenic cells and compromise follicular development in postpartum dairy cows.
子宫细菌感染会扰乱产后奶牛的子宫和卵巢功能。革兰氏阳性菌产生的肽聚糖（PGN）已被证明会破坏母羊的卵巢功能。本研究的目的是确定PGN对卵泡发育不同阶段的牛卵泡膜细胞类固醇生成的影响。从选择前和选择后的卵巢卵泡（直径分别<8.5mm和>8.5mm）中分离出的牛卵泡膜细胞进行体外培养，并用PGN进行刺激。在培养48小时或96小时后，通过测量培养基中孕酮（P4）和雄烯二酮（A4）的浓度来评估类固醇生成。牛卵泡膜细胞表达包括Toll样受体2以及核苷酸结合寡聚化结构域1和2在内的PGN受体。用PGN（1、10或50μg/ml）处理导致选择前和选择后的卵泡中的卵泡膜细胞产生的P4和A4减少。PGN处理使类固醇生成酶的mRNA表达降低。此外，当选择后的卵泡的卵泡膜细胞同时用PGN和脂多糖（0.1、1或10μg/ml）处理时，A4的产生进一步受到抑制。这些发现表明细菌毒素可能局部作用于卵巢类固醇生成细胞，并损害产后奶牛的卵泡发育。
