Department of Animal Genetics, Faculty of Veterinary Medicine, Kastamonu University, Kastamonu, Turkey.
Department of Obstetrics and Gynecology, Faculty of Veterinary Medicine, Dicle University, Diyarbakır, Turkey.
Anim Reprod Sci. 2022 May;240:106988. doi: 10.1016/j.anireprosci.2022.106988. Epub 2022 May 5.
The aim was to evaluate the expression of genes of steroidogenic, cholesterol uptake, and liver X receptor (LXR) mediated cholesterol efflux pathway in ovine corpus luteum (CL) during natural and prostaglandin F2α (PGF2α) induced luteolysis and early pregnancy. For this study, two experiments were carried out 1); ewes were grouped into two sub-groups as cyclic 12 (C12, n = 4) and 16 (C16, n = 4) and pregnant 12 (P12, n = 4), 16 (P16, n = 4), and 22 (P22, n = 4). Additionally, 2) ewes were grouped into four groups following treatment of PGF2α, the duration of PGF2α challenge at 1 (PG1, n = 4), 4 (PG4, n = 4), and 16 (PG16, n = 4) hours on day 12 of the cycle was compared with 0 h. The corpus luteum tissue samples were collected on the corresponding estrus cycle and pregnancy days, and RNA was extracted using Trizol. mRNA expression levels of the steroidogenic (StAR, CYP11A1, and HSD3B1) and cholesterol uptake receptors (SCARB1 and LDLR) and LXR pathway (NR1H3, NR1H2, ABCA1, and ABCG1) were assessed using quantitative PCR (qPCR), and protein of LXR pathway was investigated using western blot. In-situ hybridization was used to detect mRNA localization. Steroidogenic and cholesterol uptake mRNAs were decreased in C16, while NR1H2 and ABCG1 were increased in C16, compared to C12. Steroidogenic and cholesterol uptake mRNA was greater in P16 than in C16. NR1H2 and ABCA1 protein expression were higher in P16 than in C16. LDLR mRNA was higher in P22 than in P12, while SCARB1 was higher in P16 than in P12. NR1H2 mRNA was greater in P22 than in P12. Steroidogenic and cholesterol uptake mRNA were decreased in PGF2α-induced luteolysis groups against C12. ABCG1 mRNA was higher in PG16 than in PG4 and PG1. The reduction of lipoprotein receptors rather than LXR-mediated reverse transport may contribute to the decline in progesterone (P4) in natural and functional luteolysis.
目的是评估绵羊黄体（CL）中类固醇生成、胆固醇摄取以及肝 X 受体（LXR）介导的胆固醇外排途径的基因表达在自然和前列腺素 F2α（PGF2α）诱导的黄体溶解和早孕期间的变化。为此，进行了两项实验：1）将绵羊分为两组，即周期 12 天（C12，n=4）和 16 天（C16，n=4）以及妊娠 12 天（P12，n=4）、16 天（P16，n=4）和 22 天（P22，n=4）；2）在 PGF2α 处理后，将绵羊分为四组，在周期第 12 天分别处理 1（PG1，n=4）、4（PG4，n=4）和 16 小时（PG16，n=4）PGF2α，并与 0 小时进行比较。在相应的发情周期和妊娠天数采集黄体组织样本，使用 Trizol 提取 RNA。采用定量 PCR（qPCR）评估类固醇生成（StAR、CYP11A1 和 HSD3B1）和胆固醇摄取受体（SCARB1 和 LDLR）以及 LXR 途径（NR1H3、NR1H2、ABCA1 和 ABCG1）的 mRNA 表达水平，并使用 Western blot 检测 LXR 途径的蛋白。采用原位杂交检测 mRNA 定位。与 C12 相比，C16 中的类固醇生成和胆固醇摄取 mRNA 减少，而 NR1H2 和 ABCG1 增加。与 C16 相比，P16 中的类固醇生成和胆固醇摄取 mRNA 更高。与 C16 相比，P16 中的 NR1H2 和 ABCA1 蛋白表达更高。与 P12 相比，P22 中的 LDLR mRNA 更高，而 P16 中的 SCARB1 mRNA 更高。与 P12 相比，P22 中的 NR1H2 mRNA 更高。与 C12 相比，PGF2α 诱导的黄体溶解组中的类固醇生成和胆固醇摄取 mRNA 减少。与 PG4 和 PG1 相比，PG16 中的 ABCG1 mRNA 更高。脂蛋白受体的减少而不是 LXR 介导的反向转运可能导致自然和功能性黄体溶解中孕酮（P4）的下降。
