Syndecan-3调节猪采食的作用机制及其营养调控

采食量不足是限制猪生产性能的重要障碍，影响采食量的核心因素是食欲。近年来有研究表明，细胞外基质的一种重要成分Syndecan-3能够影响动物的食欲，但其作用机制尚不清楚。本项目拟在前期基础上，采用Transwell共培养模型，研究猪Syndecan-3参与血脑屏障对脂肪酸转运的机制；同时，以猪下丘脑原代细胞和脑片为模型，研究Syndecan-3调控AgRP、NPY和α-MSH的表达和分泌的信号通路及其转录调控机制。在此基础上，采用Cre-LoxP转基因小鼠模型，研究AgRP和POMC神经元特异性敲除Syndecan-3对小鼠采食的影响机制，最后通过猪的饲养试验和营养调控手段，在日粮中添加Syndecan-3合成底物和肝素酶营养性调控物，验证其对猪采食量的影响，并揭示其调控机制。研究结果不仅可从理论上阐明Syndecan-3调控猪采食的作用机制，还可为研发安全、高效的新型诱食剂提供试验依据。

Limited feed intake is a crucial obstacle for pig growth and development.The key determinant of voluntary feed take of pig is the appetite. Recent evidences demonstrated that syndecan-3,an important extra-cellular matrix, plays important role in modulating the appetite of animals. However, the exact mechanism of syndecan-3 to effect animal's appetite remains unclear. Based on our previous research, the transwell co-culture system will adopted to reveal the potential role of syndecan-3 in facilitating the fatty acids across the blood-brain barrier in this project. Meanwhile, we also investigate the function of syndecan-3 to modulate the expression and secretion of several nueropeptides, such as AgRP, NPY and α-MSH, as well as the signaling pathway and the transcript control using porcine primary hypothalamic neurons and brain slices. Moreover, the Cre-LoxP strategy will also applied to generate the syndecan-3 knockout mouse specifically in AgRP or POMC neurons to find out how the syndecan-3 in different hypothalamic neurons modulate animal appetite. Finally, the effect of substrates to synthesis syndecan-3 and the nutritional regulators for heparinase on pig feed intake and growth performance were also investigated by the in vivo experiments of pig. The main purpose of this project is to reveal the potential mechanisms underlines the effect of syndecan-3 on pig appetite, and the results will also provide the fundamental data for the development of novel nutritional and efficient feed additives to promote pig appetite.