氧化油脂致母猪乳腺损伤及子代氧化应激的分子机制和生物抗氧化剂保护作用的研究

Oil is a high-energy feed which is widely used in animal production, however, in the process of storage, processing and feeding, it is prone to oxidative to cause animal oxidative stress and endanger animal health and performance. At present, there is still a lack of research on the effects, molecular mechanism and effective intervention methods of sows mammary gland damage and progeny oxidative stress caused by oxidized oil. Firstly, this project intends to study the effect of different-content oxidized soybean oil and its peroxidation products on the apoptosis of porcine mammary epithelial cells in vitro and gene expression of related metabolic pathway, clarify the harm of main metabolites and its concentrations. Secondly, this study intend to investigate the effect of bioantioxidants which ease the damage of mammary gland cells caused by oxidized oil according to the established damage cell model. Finally, we plan to illustrate the effect of oxidative stress on sow mammary gland and their offspring, meanwhile, verify the availability of bioantioxidants by detecting the residues of peroxidation products in sows placenta and milk and the change of offspring oxidative stress-related signaling pathways through conducting animal experiment during the late of gestation to lactation of sows. We predict that the results of this project will provide a new idea and experimental basis for understanding the harm and molecular mechanism of the sow and offspring caused by oxidized oil, and establishing the effective intervention measures to strengthen the nutrition of sows.

油脂是广泛应用于动物生产中的一种高能饲料原料，但其在储存、加工和饲喂过程中易发生氧化酸败，从而使动物发生氧化应激，进而危害动物健康和生产性能。目前尚缺乏关于氧化油脂对母猪乳腺损伤及子代氧化应激的影响和分子机制以及有效干预手段研究。本项目拟首先研究不同程度氧化豆油和各级氧化产物对体外培养乳腺上皮细胞凋亡及相关代谢通路基因表达的影响，阐明危害的主要代谢产物及浓度；其次利用建立的乳腺上皮细胞损伤模型筛选生物抗氧化剂，研究其对氧化油脂致母猪乳腺细胞损伤的缓解作用；最后选取妊娠后期母猪开展动物试验，通过检测母猪胎盘、乳中油脂氧化产物的残留量和仔猪组织氧化应激相关分子信号通路的变化，阐明氧化油脂对母猪乳腺及子代氧化应激的影响和作用分子途径，同时验证生物抗氧化剂是否具有缓解功效。试验结果对深入了解氧化油脂对母猪和子代的危害、分子机制，建立有效的干预措施提供了新思路和实验依据。

油脂是动物生产中一种常见的高能饲料原料，但其在储存、加工过程中易发生氧化酸败，从而使动物发生氧化应激，甚至对后代产生不利影响。本研究围绕着氧化大豆油对母体和子代的损伤及白藜芦醇的缓解作用所开展。本项目选择大鼠和母猪为研究对象，首先通过细胞试验建立氧化大豆油对猪乳腺上皮细胞损伤模型，其次以哺乳期大鼠为模型研究氧化大豆油对母代及子代发育造成的损伤；再通过母猪试验探究氧化大豆油对哺乳母猪和子代健康的影响及白藜芦醇对其缓解作用的研究。研究哺乳母猪体况变化（体重损失、背标损失、采食量）、繁殖性能（初生窝重、初生活仔数）、乳质变化（乳糖、乳脂、乳蛋白、乳总固形物、免疫球蛋白水平和炎症因子水平）、乳抗氧化能力、血液生化指标变化及子代在哺乳阶段生长发育（断奶重、日增重）、肠道屏障和肝脏抗氧化等的影响。结果表明：母猪饲粮中添加3%的氧化豆油显著提高母猪乳中MDA、TNF-α和IL-6的含量，降低T-AOC的活性；显著降低子代空肠GSH-Px的活性和IL-10、occludin和claudin4的mRNA水平；还会降低子代肝脏的抗氧化能力，影响肝脏脂质合成相关基因的mRNA水平。在含有氧化大豆油的饲粮中添加300mg/kg的白藜芦醇后，可显著降低子代空肠的MDA水平，显著提高子代空肠紧密连接蛋白Occludin和Claudin4的mRNA表达水平；改善子代肝脏抗氧化能力等。本研究证明，母猪饲粮中添加氧化大豆油会升高乳中促炎因子水平，损伤子代空肠和肝脏。同时发现在含有氧化大豆油的饲粮中添加白藜芦醇能够改善母猪乳品质，缓解母体摄入氧化大豆油对子代肠道屏障功能和肝脏的损伤。