Institute of Life Science, School of Medicine, Swansea University, Singleton Park, Swansea SA2 8PP, United Kingdom.
Endocrinology. 2011 Dec;152(12):5029-40. doi: 10.1210/en.2011-1124. Epub 2011 Oct 11.
Infections of the reproductive tract or mammary gland with Gram-negative bacteria perturb ovarian function, follicular growth, and fecundity in cattle. We hypothesized that lipopolysaccharide (LPS) from Gram-negative bacteria stimulates an inflammatory response by ovarian granulosa cells that is mediated by Toll-like receptor (TLR) 4. The present study tested the capacity of bovine ovarian granulosa cells to initiate an inflammatory response to pathogen-associated molecular patterns and determined subsequent effects on the in vitro maturation of oocytes. Granulosa cells elicited an inflammatory response to pathogen-associated molecular patterns (LPS, lipoteichoic acid, peptidoglycan, or Pam3CSK4) with accumulation of the cytokine IL-6, and the chemokine IL-8, in a time- and dose-dependent manner. Granulosa cells responded acutely to LPS with rapid phosphorylation of TLR signaling components, p38 and ERK, and increased expression of IL6 and IL8 mRNA, although nuclear translocation of p65 was not evident. Targeting TLR4 with small interfering RNA attenuated granulosa cell accumulation of IL-6 in response to LPS. Endocrine function of granulosa cells is regulated by FSH, but here, FSH also enhanced responsiveness to LPS, increasing IL-6 and IL-8 accumulation. Furthermore, LPS stimulated IL-6 secretion and expansion by cumulus-oocyte complexes and increased rates of meiotic arrest and germinal vesicle breakdown failure. In conclusion, bovine granulosa cells initiate an innate immune response to LPS via the TLR4 pathway, leading to inflammation and to perturbation of meiotic competence.
生殖道或乳腺的革兰氏阴性菌感染会扰乱牛的卵巢功能、卵泡生长和生育能力。我们假设革兰氏阴性菌的脂多糖（LPS）通过卵巢颗粒细胞中的 Toll 样受体（TLR）4 刺激炎症反应。本研究检测了牛卵巢颗粒细胞对病原体相关分子模式产生炎症反应的能力，并确定了随后对卵母细胞体外成熟的影响。颗粒细胞以时间和剂量依赖的方式对病原体相关分子模式（LPS、脂磷壁酸、肽聚糖或 Pam3CSK4）产生炎症反应，细胞因子 IL-6 和趋化因子 IL-8 积累。颗粒细胞对 LPS 表现出急性反应，TLR 信号成分 p38 和 ERK 迅速磷酸化，并增加 IL6 和 IL8 mRNA 的表达，尽管核转位 p65 不明显。用小干扰 RNA 靶向 TLR4 可减弱 LPS 对颗粒细胞 IL-6 积累的作用。FSH 调节颗粒细胞的内分泌功能，但在这里，FSH 也增强了对 LPS 的反应性，增加了 IL-6 和 IL-8 的积累。此外，LPS 刺激了卵丘-卵母细胞复合物的 IL-6 分泌和扩张，并增加了减数分裂阻滞和生发泡破裂失败的比率。总之，牛颗粒细胞通过 TLR4 途径对 LPS 产生先天免疫反应，导致炎症和减数分裂能力受到干扰。
