National Demonstration Center for Experimental Fisheries Science Education, Shanghai Ocean University, Shanghai, 201306, China; Key Laboratory of Exploration and Utilization of Aquatic Genetic Resources, Ministry of Education, Shanghai Ocean University, Shanghai, 201306, China.
National Demonstration Center for Experimental Fisheries Science Education, Shanghai Ocean University, Shanghai, 201306, China; Key Laboratory of Exploration and Utilization of Aquatic Genetic Resources, Ministry of Education, Shanghai Ocean University, Shanghai, 201306, China.
Mol Cell Endocrinol. 2021 May 1;527:111222. doi: 10.1016/j.mce.2021.111222. Epub 2021 Feb 27.
Corticotropin-releasing hormone (CRH) plays a key regulatory role in coordinating the regulation of endocrine, autonomic nervous, immune, and reproductive systems. Two CRH (CRHα and CRHβ) and their receptors (CRHR1 and CRHR2) had been identified in zebrafish. However, their functions remained uncovered in the ovary of zebrafish. Therefore, this study aimed to determine whether CRH acts directly on the ovary to regulate steroidogenesis in cultured zebrafish follicular cells. Firstly, CRH and its receptors are expressed in the zebrafish ovary. The expression profile of CRHβ fluctuated during ovarian development in zebrafish, and the highest CRHα mRNA levels were observed at the mature follicle. The highest CRHR1 and CRHR2 mRNA levels existed in mid-vitellogenic (MV) and early vitellogenic (EV) stages, respectively. In primary cultured zebrafish follicular cells, both of the CRHα and CRHβ inhibited expression of hsd17b3 mRNA levels and decreased content of estradiol (E2) in the medium. Furthermore, CRH activated p38 MAPK and p38 MAPK inhibitor SB203580 attenuated the phosphorylation of p38 MAPK induced by CRHα. Simultaneously, SB203580 changed the effect of CRH on cyp19a1a expression but not hsd17b1 and hsd17b3. SB203580 alone or combined with CRH inhibited the E2 content. Finally, the CRHR inhibitor α-helical 9-41 also blocked the phosphorylation of p38 MAPK induced by CRHα but did not change the inhibitory effect of CRH on the mRNA expression of the steroidogenic gene and the content of E2 in the culture medium. Taken together, our findings suggest that the anti-steroidogenic effects of CRH may be mediated partly through activation of the p38 MAPK signaling pathway.
促肾上腺皮质激素释放激素（CRH）在协调内分泌、自主神经系统、免疫系统和生殖系统的调节中发挥着关键的调节作用。两种 CRH（CRHα 和 CRHβ）及其受体（CRHR1 和 CRHR2）已在斑马鱼中被鉴定出来。然而，它们在斑马鱼卵巢中的功能仍未被揭示。因此，本研究旨在确定 CRH 是否直接作用于卵巢，以调节培养的斑马鱼滤泡细胞中的类固醇生成。首先，CRH 及其受体在斑马鱼卵巢中表达。CRHβ 在斑马鱼卵巢发育过程中的表达谱发生波动，CRHα 的 mRNA 水平在成熟滤泡中最高。CRHR1 和 CRHR2 的 mRNA 水平分别在中卵黄发生（MV）和早期卵黄发生（EV）阶段最高。在原代培养的斑马鱼滤泡细胞中，CRHα 和 CRHβ 均抑制 hsd17b3 mRNA 水平的表达，并降低培养基中雌二醇（E2）的含量。此外，CRH 激活了 p38 MAPK，p38 MAPK 抑制剂 SB203580 减弱了 CRHα 诱导的 p38 MAPK 磷酸化。同时，SB203580 改变了 CRH 对 cyp19a1a 表达的影响，但对 hsd17b1 和 hsd17b3 没有影响。SB203580 单独或与 CRH 联合抑制 E2 含量。最后，CRHR 抑制剂α-螺旋 9-41 也阻断了 CRHα 诱导的 p38 MAPK 的磷酸化，但没有改变 CRH 对类固醇生成基因 mRNA 表达和培养基中 E2 含量的抑制作用。综上所述，我们的研究结果表明，CRH 的抗类固醇生成作用可能部分通过激活 p38 MAPK 信号通路来介导。
