BACKGROUND
Ethanol exposure prior to traumatic injury, such as a burn, elevates systemic and local inflammatory responses and increases morbidity and mortality. Adipose is a large tissue mass that is often inflamed during obesity or other stresses which disturbs metabolic homeostasis. To date, there has been little investigation into the inflammatory response of adipose tissue after combined ethanol exposure and burn injury.
METHODS
Two ethanol exposure regimens were utilized to examine the role of inflammation in adipose tissue after ethanol and burn injury. Mice were either given a single or episodic binge exposure to ethanol or saline followed by scald (burn) or sham injury 30 minutes later. Twenty-four hours post injury, serum and adipose tissue were collected for assessment of inflammatory mediators.
RESULTS
Single binge ethanol alone induced no inflammation in adipose when compared with sham vehicle treated mice. However, single binge ethanol followed by burn injury induced significant elevations in mRNA and protein concentrations of pro-inflammatory mediators interleukin-6 (IL-6), KC, and monocyte chemoattractant protein 1 (MCP-1) compared to either insult alone or sham vehicle group. Additionally, ethanol exposure and burn injury significantly blunted inducible nitric oxide synthase (iNOS), indicating a complex inflammatory response. Episodic binge ethanol exposure followed by burn injury exacerbated the post-burn adipose inflammatory response. The magnitude of the episodic binge-induced inflammatory parameters post-burn were 2- to 5- fold greater than the response detected after a single exposure of ethanol, indicating ethanol-induced potentiation of burn-induced inflammatory response. Finally, inflammatory loci and crown-like structures in adipose were significantly increased by episodic binge ethanol and burn injury.
CONCLUSIONS
This is the first report of binge and burn-induced crown-like structure formation. Evidence presented herein suggests an important role for alcohol and burn as an additional mediator of adipose inflammation in post-burn injury, a common complication in burn patients.