Jiangsu Key Laboratory of Sericultural and Animal Biotechnology, School of Biotechnology, Jiangsu University of Science and Technology, Zhenjiang 212100, China; Key Laboratory of Silkworm and Mulberry Genetic Improvement, Ministry of Agriculture and Rural Affairs, Sericultural Scientific Research Center, Chinese Academy of Agricultural Sciences, Zhenjiang 212100, China.
Shenzhen Branch, Guangdong Laboratory for Lingnan Modern Agriculture, Agricultural Genomics Institute at Shenzhen, Chinese Academy of Agricultural Sciences, Shenzhen 518120, China.
Poult Sci. 2024 Nov;103(11):104175. doi: 10.1016/j.psj.2024.104175. Epub 2024 Aug 14.
The in ovo feeding (IOF) of L-arginine (L-Arg) to chick embryos is a viable method for improving early intestinal development, subsequently leading to an acceleration in growth rate during the posthatch stage. However, the liver, being the pivotal organ for energy metabolism in poultry, the precise effects and mechanisms of L-Arg on the liver development and metabolism remain unclear. To elucidate these, the present study injected 2 doses of L-Arg (10 mg/egg and 15 mg/egg) into the embryos of Hongyao chickens at 17.5 d of incubation, subsequently incubating them until d 19 for further analysis. IOF of 15 mg L-Arg/egg significantly increased the organ indices of liver and small intestine, as well as the duodenal villus height/crypt depth. RNA-Seq analysis of liver tissues showed that the metabolism of xenobiotics, amino acid metabolism, and the fatty acid metabolism were significantly enriched in L-Arg injection group. The core differentially expressed genes (DEGs) were primarily involved in cell proliferation and fatty acid metabolism. The CCK8 assays revealed that supplemental L-Arg significantly enhanced the proliferation of primary embryo hepatocytes and leghorn male hepatoma (LMH) cells. Upregulation of core DEGs, including HBEGF, HES4, NEK3, EGR1, and USP2, significantly promoted the proliferation of liver cells. Additionally, analysis of triglyceride and total cholesterol content, as well as oil red O staining, indicated that supplemental L-Arg effectively reduced lipid accumulation. Overall, L-Arg supplementation in late chick embryos may promote early liver and small intestine development by reducing liver lipid deposition and enhancing energy efficiency, necessitating further experimental validation. This study provides profound insights into the molecular regulatory network of L-Arg in promoting the development of chicken embryos. The identified DEGs that promote cell proliferation and lipid metabolism can serve as novel targets for further developing methods to enhance early development of chicken embryos.
鸡胚灌流 L-精氨酸（L-Arg）是一种可行的方法，可以改善早期肠道发育，随后在孵化后阶段加速生长速度。然而，肝脏作为家禽能量代谢的关键器官，L-Arg 对肝脏发育和代谢的确切影响和机制尚不清楚。为了阐明这些问题，本研究在孵化 17.5 天时向红瑶鸡胚胎注射 2 剂量的 L-Arg（10mg/枚和 15mg/枚），然后孵化至 19 天进行进一步分析。IOF 15mg L-Arg/枚显著增加了肝脏和小肠的器官指数，以及十二指肠绒毛高度/隐窝深度。肝脏组织的 RNA-Seq 分析表明，外源物质代谢、氨基酸代谢和脂肪酸代谢在 L-Arg 注射组中显著富集。核心差异表达基因（DEGs）主要参与细胞增殖和脂肪酸代谢。CCK8 测定表明，补充 L-Arg 显著增强了原代胚胎肝细胞和来亨雄性肝癌（LMH）细胞的增殖。核心 DEGs 的上调，包括 HBEGF、HES4、NEK3、EGR1 和 USP2，显著促进了肝细胞的增殖。此外，甘油三酯和总胆固醇含量的分析以及油红 O 染色表明，补充 L-Arg 有效减少了脂质积累。总体而言，晚期鸡胚补充 L-Arg 可能通过减少肝脏脂质沉积和提高能量效率来促进早期肝脏和小肠发育，需要进一步的实验验证。本研究深入了解了 L-Arg 促进鸡胚胎发育的分子调控网络。鉴定出的促进细胞增殖和脂质代谢的 DEGs 可以作为进一步开发增强鸡胚胎早期发育方法的新靶点。
