State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Innovation Academy for Seed Design, Chinese Academy of Sciences, Wuhan, 430072, China.
State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Innovation Academy for Seed Design, Chinese Academy of Sciences, Wuhan, 430072, China; Qingdao National Laboratory for Marine Science and Technology, Qingdao, 266237, China.
Mol Cell Endocrinol. 2020 Aug 1;513:110858. doi: 10.1016/j.mce.2020.110858. Epub 2020 May 13.
Kisspeptin2 is a neuropeptide widely found in the brain and multiple peripheral tissues in the zebrafish. The pituitary is the center of synthesis and secretes various endocrine hormones. However, Kiss2 innervation in the zebrafish pituitary is unknown. In this study, the organization of Kiss2 cells and structures in the zebrafish pituitary by promoter-driving mCherry-labeling Kiss2 neurons were investigated. Kiss2 neurons in the hypothalamus do not project into the pituitary. Kiss2 cells are found in the female pituitary. Unidentified Kiss2 cells and extensions are located in the proximal pars distalis (PPD), similar to the distribution of Gnrh3 fibers. Kiss2 structures reside alongside Gnrh3 fibers. No Kiss2 structures are found in the male pituitary. The transcriptional expression of the kisspeptin receptor kiss1rb is detected in both female and male pituitaries. In situ hybridization shows that kiss1rb-positive cells are located in the PPD and pars intermedia (PI). In vitro Kiss2-10 treatment stimulates Akt and Erk phosphorylation and significantly induces lhβ, fshβ, and prl1 mRNA expression in the female pituitary. The results in this study suggest that Kiss2 and Kiss1rb may form an independent paracrine or autocrine system in the female zebrafish pituitary. Kiss2 and Kiss1rb signaling regulates the expression of pituitary hormones.
Kisspeptin2 是一种广泛存在于斑马鱼大脑和多种外周组织中的神经肽。垂体是合成和分泌各种内分泌激素的中心。然而，Kiss2 在斑马鱼垂体中的神经支配尚不清楚。在这项研究中，通过启动子驱动 mCherry 标记 Kiss2 神经元来研究斑马鱼垂体中 Kiss2 细胞和结构的组织。下丘脑的 Kiss2 神经元不会投射到垂体。在雌性垂体中发现了 Kiss2 细胞。在近端部（PPD）中发现了未识别的 Kiss2 细胞和延伸物，类似于 Gnrh3 纤维的分布。Kiss2 结构与 Gnrh3 纤维并存。在雄性垂体中未发现 Kiss2 结构。在雌性和雄性垂体中检测到 kisspeptin 受体 kiss1rb 的转录表达。原位杂交显示 kiss1rb 阳性细胞位于 PPD 和中间部（PI）。体外 Kiss2-10 处理刺激 Akt 和 Erk 磷酸化，并显著诱导雌性垂体中 lhβ、fshβ 和 prl1 mRNA 的表达。本研究结果表明，Kiss2 和 Kiss1rb 可能在雌性斑马鱼垂体中形成独立的旁分泌或自分泌系统。Kiss2 和 Kiss1rb 信号调节垂体激素的表达。
