Guan Kaiyu, Ye Minjie, Guo Anqi, Chen Xiaoyu, Shan Yunfeng, Li Xi
Zhejiang Clinical Research Center for Mental Disorders, The Affiliated Kangning Hospital of Wenzhou Medical University, Wenzhou, Zhejiang, 325000, China.
Peking University Sixth Hospital, Peking University Institute of Mental Health, Beijing, China.
Heliyon. 2024 Aug 15;10(18):e36397. doi: 10.1016/j.heliyon.2024.e36397. eCollection 2024 Sep 30.
Liver-expressed antimicrobial peptide-2 (LEAP2) is identified as an endogenous antagonist and inverse agonist of the growth hormone secretagogue receptor type 1a (GHSR1a), its effect on the GHSR1a is contrary to the role of GHRELIN. Growth hormone (GH) is a crucial hormone for early development. Previous studies report that LEAP2 dose-dependently attenuates ghrelin-induced GH secretion, and Leap2-knockout mice exhibit increased plasma GH levels after GHRELIN administration. Clinical data revealed a possible correlation between LEAP2 and height development. However, the role of LEAP2 in early development remains unclear. This study aimed to investigate the role of LEAP2 in early development using mutant zebrafish larvae as a model.
We analyzed the conservation of LEAP2 peptide across multiple species and generated 2 mutants in zebrafish by CRISPR-Cas9, dynamically observed and measured the growth and development of zebrafish larvae from fertilization to 5 day post fertilization (dpf). In situ hybridization, transcriptome sequencing, quantitative real-time PCR and Western blot were used to detect the expression levels of GH and its signaling in early stage of embryonic development.
Our data demonstrate that zebrafish with a knockout of the gene display a significant increase in hatching rate, body length, and the distance between their eyes, all without visible developmental defects in the early stages of development. In addition, both RNA and protein analyses revealed a significant increase in GH expression in mutant.
In general, this study demonstrates that LEAP2 regulates the expression of GH during early development, particularly influencing body length.
肝脏表达抗菌肽-2（LEAP2）被鉴定为生长激素促分泌素受体1a型（GHSR1a）的内源性拮抗剂和反向激动剂，其对GHSR1a的作用与胃饥饿素的作用相反。生长激素（GH）是早期发育的关键激素。先前的研究报道，LEAP2剂量依赖性地减弱胃饥饿素诱导的GH分泌，并且Leap2基因敲除小鼠在给予胃饥饿素后血浆GH水平升高。临床数据揭示了LEAP2与身高发育之间可能存在的相关性。然而，LEAP2在早期发育中的作用仍不清楚。本研究旨在以突变斑马鱼幼虫为模型，研究LEAP2在早期发育中的作用。
我们分析了LEAP2肽在多个物种中的保守性，并通过CRISPR-Cas9在斑马鱼中产生了2种突变体，动态观察并测量了斑马鱼幼虫从受精到受精后5天（dpf）的生长和发育情况。采用原位杂交、转录组测序、定量实时PCR和蛋白质免疫印迹法检测胚胎发育早期GH及其信号通路的表达水平。
我们的数据表明，基因敲除的斑马鱼在发育早期的孵化率、体长和眼间距均显著增加，且无明显发育缺陷。此外，RNA和蛋白质分析均显示突变体中GH表达显著增加。
总体而言，本研究表明LEAP2在早期发育过程中调节GH的表达，尤其影响体长。
