嗜水气单胞菌感染对团头鲂肝脏铁代谢的影响
Effect of Aeromonas hydiophila infection on iron metabolism in Megalobrama amblycephala liver

为研究细菌感染对鱼类肝脏铁代谢的影响，以团头鲂为研究对象，通过腹腔注射嗜水气单胞菌，在感染后不同时间点取团头鲂的血液和肝脏组织，分别采用分光光度法和ICP法检测血清和肝脏中的铁含量，采用实时荧光定量PCR法对铁代谢调节相关基因——铁调素（hepc）、白细胞介素6（il-6）、JAK/STAT信号通路的蛋白质酪氨酸激酶3（jak3）、信号转导子和转录激活因子3（stat3）等表达量进行检测。结果显示：感染嗜水气单胞菌后，团头鲂血清中铁浓度明显降低，在12、24 h时显著低于对照组，总铁结合力有所上升，但没有达到显著水平；肝脏中铁含量相对于对照组虽没有达到显著性差异水平，但仍有明显升高。肝脏中hepc基因的表达量显著上升；il-6、jak3和stat3基因表达量开始均有所上调，随后有所下降，但各时间点的表达量均高于对照。试验结果说明，机体通过调节hepc等铁代谢相关基因的表达，进而降低自身游离铁和增加储存铁来应对病原菌的感染。
To study the effects of Aeromonas hydiophila infection on iron metabolism of Megalobrama amblycephala,the iron content of serum and liver was determined by spectrophotometer and Inductive Coupled Plasma Emission Spectrometer,respectively,and expression of the iron metabolism related genes were detected by quantitative real-time PCR at 0,4 h,12 h,24 h,72 h and 120 h after A.hydiophila infection. The results showed that the content of serum iron in the experimental group was significantly descended at 12 h and 24 h after infection (P＜0.05),while the iron content in the liver was increased though not significantly (P＞0.05). After infection,the expression level of hepc,il-6,jak3,stat3 genes increased firstly,and then descended in the liver,but still significantly higher than that in the control. The results indicated that fish reduced the iron serum content in response to bacterial infections. The hepc,il-6,jak3 and stat3 genes may play important roles in both innate immunity and iron metabolism regulation upon bacterial infection.