Related Experiment Videos
Burn injury with infection alters prostaglandin E2 synthesis and metabolism
1The Burn and Shock Trauma Institute, Loyola University Medical Center, Maywood, Illinois 60153, USA.
Objective:
The aim of this study was to examine the relationship between prostaglandin synthesis and prostaglandin degradation in a model of burn injury with infection.
Methods:
Male B2D6F1 mice were assigned to control, burn (16% dorsal scald burn), or burn with infection (burn with topical application of 1,000 colony forming units of Pseudomonas aeruginosa) groups. Lung tissue was harvested at 1, 2, and 3 days after burn injury and subsequently processed for total RNA and protein. Northern and Western blot analyses were used to examine differences in cyclooxygenase 2 (COX-2) and prostaglandin 15-OH dehydrogenase (PGDH) protein and mRNA expression. Total RNA was probed with the riboprobe for murine PGDH and COX-2 and the 100,000g protein fraction was immunoblotted by using an rabbit anti-murine PGDH and anti-murine COX-2 antibody.
Results:
COX-2 expression was elevated in the burn with infection animals on day 1 and day 2 after burn injury. At these time points in the burn + infection group, PGDH was significantly depressed. Burn injury increased COX-2 expression on day 1, but by day 2, COX-2 expression had decreased to control values. A corresponding increase in PGDH expression was observed on day 2 in the burned mice. The mRNA expression of COX-2 was followed by a similar increase in COX-2 protein expression at all time points in the injured animals. This was not the case with PGDH expression. On day 1, PGDH mRNA expression was depressed in the burn with infection mice with no change in PGDH protein expression. This finding indicates that PGDH is subject to regulation at both the transcriptional and posttranscriptional levels.
Conclusion:
Burn wound infection depressed both PGDH mRNA and protein expression and increased COX-2 mRNA and protein expression. Therefore, increases in circulating prostaglandin E2 levels during septic injury are derived from alterations in synthesis and degradation of prostaglandin E2.
Insights
Burn wound infection in mice decreased prostaglandin degradation (PGDH) and increased prostaglandin synthesis (COX-2). These changes explain elevated prostaglandin E2 levels during septic injury.
Area of Science:
- Biomedical research
- Inflammation and immunology
- Wound healing and infection
Background:
- Prostaglandins play a crucial role in inflammatory processes.
- Understanding prostaglandin metabolism is vital for managing burn injuries and infections.
Purpose of the Study:
- To investigate the relationship between prostaglandin synthesis and degradation in a murine model of burn injury with infection.
- To analyze the expression of cyclooxygenase-2 (COX-2) and prostaglandin 15-OH dehydrogenase (PGDH) in response to burn and infection.
Main Methods:
- Male B2D6F1 mice were subjected to burn injury or burn with Pseudomonas aeruginosa infection.
- Lung tissue was collected at 1, 2, and 3 days post-injury.
- Northern and Western blot analyses assessed COX-2 and PGDH mRNA and protein expression.
Main Results:
- Burn with infection significantly increased COX-2 expression and decreased PGDH expression on days 1 and 2.
- Burn injury alone elevated COX-2 on day 1 and PGDH on day 2.
- PGDH showed both transcriptional and post-transcriptional regulation.
Conclusions:
- Burn wound infection markedly reduced PGDH expression and elevated COX-2 expression.
- Alterations in prostaglandin E2 synthesis and degradation contribute to increased levels during septic injury.