水通道蛋白AQP3与仔猪腹泻发生的机制研究

腹泻是导致断奶仔猪生长性能低下及死亡率高的主要原因。腹泻的本质是胃肠道水和电解质的吸收和分泌紊乱。本课题组前期研究结果表明，水通道蛋白AQP3在断奶仔猪胃肠道组织中的表达量显著提高，而在腹泻仔猪中表达显著下降，提示AQP3可能参与腹泻发生且机制尚不清除。本项目拟利用腹泻剂CPT-11及致泄菌ETEC诱导的仔猪腹泻模型，以及氯化汞构建AQP3下调模型，采用免疫荧光、尤斯灌流等技术检测肠道AQP3相关转录因子变化，肠道渗透性和屏障功能变化，探讨AQP3与腹泻发生的关联性。采用基因编辑等手段，研究AQP3对肠上皮细胞增殖迁移以及腹泻相关转录因子及其下游效应蛋白表达的影响；同时利用ETEC与体外猪肠上皮细胞Transwell共培养模型，研究AQP3对肠粘膜上皮屏障及免疫功能的影响。旨在揭示AQP3调控腹泻发生的潜在分子机制，为断奶仔猪腹泻调控提供靶点，同时为开发缓解仔猪腹泻的药物奠定理论基础。

Diarrhea is the most common cause of depressed growth performance and high mortality in the pig industry. It is caused by imbalanced water and electrolyte absorption and secretion. Our primary data show that AQP3 expression is significantly increased in GI track of piglets, while it is significantly decreased in piglets with diarrhea, indicating that AQP3 may be involved in the pathogenesis of diarrhea. Therefore, we propose to use piglet diarrhea models and AQP3 downregulation model to determine the association between AQP3 and diarrhea development. We will examine alterations in AQP3 related transcription factor expression, intestinal permeability and barrier by immunofluorescence and ussing chamber. We will use gene editing techniques in vitro to determine the effects of AQP3 on proliferation, migration, and diarrhea related transcription factor expression of intestinal epithelial cells. In addition, ETEC will be co-cultured with porcine epithelial cells on Transwell to test effects of AQP3 on intestinal mucosal barrier and immune function. Taken together, we aim to elucidate underlying mechanisms of AQP3 regulation on diarrhea. Our findings will lay a theoretical foundation for the exploitation and discovery of drugs to prevent and treat piglet diarrhea.