琥珀酰化修饰对马氏珠母贝植核免疫的影响

Effect of Succinylation Modification on Nucleus-implantation Immune Response of Pinctada fucata martensii

【目的】研究蛋白质琥珀酰化修饰在马氏珠母贝(Pinctada fucata martensii)植核后免疫应答中的作用,为阐明珍珠贝植核反应的分子调控机制提供理论依据。【方法】通过对马氏珠母贝注射琥珀酸钠模拟提高琥珀酰化修饰水平,检测马氏珠母贝植核后鳃组织总蛋白琥珀酰化程度、免疫相关基因表达、抗氧化相关酶酶活以及珍珠贝的存活率和留核率。【结果与结论】注射琥珀酸钠后,鳃组织琥珀酰化修饰水平在12 h和72 h显著上升;使用实时荧光定量PCR检测胁迫应激相关基因的时序表达,胁迫应激相关因子SOD和Caspase2在6 h表达量显著上调,NF-κB和IRAK1在48 h表达量显著上调,TRAF3和IκK的表达量在96 h显著上调(P <0.05),表明琥珀酰化修饰水平提高后受体贝机体细胞免疫增强;抗氧化相关酶、过氧化物酶和谷胱甘肽活性都在96 h出现显著上调(P <0.05),表明受体贝体液免疫增强。与对照组[磷酸盐缓冲溶液(PBS)+植核]和植核组相比,实验组(琥珀酸钠+植核)中珍珠贝的存活率在7 d和45 d存在显著差异,在60 d留核率显著上升(P <0.05)。结果说明,琥珀酰化修饰参与了马氏珠母贝的植核免疫反应,注射琥珀酸钠可以提高受体贝的免疫活力,并提高其在植核后的存活率和留核率。

【Objective】To study the effect of protein succinylation modification on nucleus-implantation immune response of Pinctada fucata martensii and provide a theoretical basis for elucidation of the molecular regulatory mechanism of nucleus-inserting reaction of pearl oyster.【Method】We simulated increasing the level of succinylation modification by injecting sodium succinate into P.f.martensii,and examined the degree of succinylation of total protein in gill tissues,the expression of immune-related genes,the enzyme activities of antioxidant-related enzymes,as well as the survival and retention rate of pearly shells after nucleus implantation in P.f.martensii.【Result and Conclusion】After injection of sodium succinate,it was found that the level of succinylation in gill tissue increased significantly at 12 h and 72 h.The temporal expression of immune-associated factors was detected using qRT-PCR,and the results showed that the expression of immune-related factors SOD and Caspase2 were significantly up-regulated at 6 h,NFκB and IRAK1 were significantly up-regulated at 48 h,and TRAF3 and IκK mRNA were significantly up-regulated at 96 h(P<0.05),suggesting that cellular immunity of the recipient oysters was enhanced by the increased level of succinylation modification.The enzymatic activity of antioxidant-related enzyme activities SOD,POD and GSH were significantly up-regulated at 96 h(P<0.05),indicating enhanced humoral immunity in the recipient oysters.Compared to the control group(PBS+implantation)and implantation group,the experimental group(sodium succinate+implantation)’s survival rate was significantly increased at 7 d and 45 d,and the experimental group’s retention rate significantly improveed at 60 d(P<0.05).Succinylation modification is involved in the immune response to implantation in P.f.martensii,and injection of sodium succinate improves immune viability of recipient oysters and helps them to survive the difficult post-implantation period.