Differential regulation of c-Jun expression in liver and lung of mice after thermal injury

In addition to skin injury, burns may also damage distant organs. Understan ding the mechanisms of distant organ injury will substantially improve the survival of burn patients, Transcription factors are the major regulators o f gene expression in response to most types of injury, C-Jun, which is a pa rt of the activator protein-1 transcription factor complex, is one of the m ajor immediate-early response genes, which is rapidly induced after injury. The expression of c-Jun in mouse liver and lung at different time points ( 3 h to 29 days) after thermal injury was examined by using Reverse Transcri ption-Polymerase Chain Reaction (RT-PCR), Western blot, and immunohistochem istry. Rapid induction of c-Jun mRNA and protein was observed in the liver 3 h after an 18% TBSA burn. C-Jun expression returned to basal levels withi n 3 days after injury. In contrast to the up-regulation observed in liver, lungs from the same mice expressed c-Jun constitutively throughout the same time points. The finding that thermal injury leads to up-regulation of c-J un in liver but not lungs suggests that either the liver has a lower thresh old for early response to injury or that different cellular events exist wh en each organ is stressed.