花生四烯酸通过钙稳态缓解植核手术诱导马氏珠母贝炎症反应的机制研究

研究如何缓解植核手术诱导的马氏珠母贝炎症，调控其免疫反应，是珍珠养殖业迫切需要解决的问题之一。申请人前期研究发现植核前后钙稳态、内质网应激ERS、凋亡和炎症反应等相关基因显著差异表达；植核后含C20:4链的磷脂均呈下降趋势。鉴于花生四烯酸(ARA; 20:4n-6)可以通过改变生物膜磷脂组成影响细胞免疫信号传导发挥抗炎作用，由此提出科学假说：植核手术后马氏珠母贝ARA水平下降，内质网膜通透性提高，诱发钙紊乱，激发ERS，导致细胞凋亡和炎症。本项目通过脂质组、透射电镜和基因表达等技术明确钙紊乱、内质网磷脂不饱度、ERS、凋亡和炎症在植核后不同时间的发展变化；以饲料为载体探究ARA是否通过提高内质网膜不饱和度抑制钙紊乱和ERS；构建马氏珠母贝原代血细胞钙紊乱模型，验证ARA是否通过调节钙稳态缓解ERS。研究结果可为进一步缓解植核后珍珠贝的炎症反应提供理论和实践上的依据。

Pearl oyster, Pinctada fucata martensii, is economically important because of its ability to produce high-quality pearls. In pearl farming, the process of pearl culture are as follows: 1) preoperative conditioning, 2) transplantation, 3) postoperative care, and 4) culturing and harvest. During pearl culture, a mantle graft, which originates from a donor pearl oyster with a nucleus and is a spherical bead of shell material, is transplanted into a host pearl oyster in a process called transplantation or grafting. An incision (or wound) from the operation might cause cell death, wound healing, reaction to foreign materials, and disturbance of the oxidative–antioxidative equilibrium. The inflammatory response after transplantation is a major factor that affects pearl quality and quantity because it leads to nucleus rejection, pearl sac formation failure, and death of the pearl oyster host. Therefore, it is important to research how to relieve the inflammation in pearl oyster P. f. martensii induced by transplantation and regulate its immune response during postoperative care. In previous study, we have found that the genes about calcium homeostasis, endoplasmic reticulum stress (ERS), apoptosis and inflammation before and after transplantation were significantly different, and phospholipids which contain C20:4 chain showed a downward trend after transplantation. Arachidonic acid (ARA; 20:4n-6) can play an anti-inflammatory effect by changing the phospholipid composition of biological membranes and affecting cellular immune signal transduction. Therefore, a scientific hypothesis is put forward: the ARA content decrease, the unsaturated degree of the endoplasmic reticulum membrane decreased, which induces calcium disturbance and ERS, finally leading to apoptosis and inflammation. This project is firstly conducted to evaluate the changes of calcium disorders, endoplasmic reticulum phospholipid unsaturation, ERS, apoptosis and inflammation at different periods during postoperative care through the lipidomics, transmission electron microscopy, gene expression, and Ca2+ detection. Secondly, we would use feed as a carrier investigate whether ARA have ability to inhibit ERS and Ca2+ disorder through increasing the unsaturated degree of ER membrane. Then a model of Ca2+ disorder in primary hemocyte cells of P. f. martensii was constructed to verify whether ARA can inhibit ERS by regulating calcium homeostasis. The prospective results of this project can provide theoretical and practical basis for further alleviating the inflammatory response of pearl oysters after transplantation.