Immune responses of two superoxide dismutases (SODs) after lipopolysaccharide or Aeromonas hydrophila challenge in pufferfish, Takifugu obscurus

As antioxidant metalloenzymes, superoxide dismutases (SODs) represent the first line of defense against oxidative stress caused by excessive reactive oxygen species (ROS) in biological systems. In the present study, the tissue distribution analysis demonstrated that ToMnSOD and ToCu/ZnSOD of pufferfish (Takifugu obscurus) were highly expressed in the liver, followed by heart and brain. The time-course dynamic expressions of ToSODs were observed through the experimental challenges with lipopolysaccharide (LPS) or Aeromonas hydrophila, which were all significantly altered in liver, kidney and gill. Results of the enzymatic activity and western blot analyses also showed that the dynamic changes of ToSODs at the enzymatic activity and protein levels were all regulated by LPS or A. hydrophila challenge. These results suggested that two ToSODs played crucial roles in immune defense system of T. obscurus, and our findings gave useful evidence to further understand the regulatory mechanism of SODs in the innate immune system of pufferfish. Statement of relevance: This study gave useful evidence to further clarify the regulatory mechanism of SODs in the innate immune system of pufferfish and contributed to manage diseases and develop sustainable pufferfish culture. Therefore, this paper may impact to the general field of commercial aquaculture. (C) 2016 Elsevier B.V. All rights reserved.