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Updated: Jul 13, 2026
Rat Burn Model to Study Full-Thickness Cutaneous Thermal Burn and Infection
Published on: August 23, 2022
Topical p38 MAPK inhibition reduces bacterial growth in an in vivo burn wound model
Kyros Ipaktchi1, Aladdein Mattar, Andreas D Niederbichler
1Department of Surgery, University of Michigan, Ann Arbor, MI, USA.
Background:
Although the inflammatory response is a prerequisite for wound healing, excessive activation of the innate immune system can induce epithelial cell damage and apoptosis, which may further compromise dermal integrity. In a noninfectious burn wound model, we previously demonstrated that topical inhibition of p38 MAPK, an important inflammatory signaling pathway, attenuated epithelial cell damage and apoptosis. We now question whether attenuating local inflammation would weaken bacterial wound resistance and compromise host defense.
Methods:
Rats received 30% total body surface area burn, and the wound was treated with topical application of a p38 MAPK inhibitor or vehicle. At 24 hours after injury, burn wounds were inoculated with Pseudomonas aeruginosa. At 48 hours postinjury, animals were sacrificed, and the burn wound was analyzed.
Results:
Inoculating burn wounds induced significant bacterial growth. Dermal inflammatory changes were markedly accentuated in the inoculated animals. Topical p38 MAPK inhibition reduced the proinflammatory cytokine expression in the burn wounds and neutrophil sequestration with or without bacterial inoculation. Interestingly, the bacterial wound growth was significantly attenuated in animals treated with topical p38 MAPK inhibitor.
Conclusions:
Topical p38 MAPK inhibition attenuated wound inflammation without interfering with bacterial host defense. Attenuation of excessive burn wound inflammatory signaling may prevent secondary damage of the dermal barrier and reduce the growth of opportunistic pathogens.
Insights
Topical p38 MAPK inhibition reduced burn wound inflammation and bacterial growth. This suggests that targeting inflammatory pathways may improve healing without compromising the immune response to infection.
Area of Science:
- Immunology
- Wound Healing
- Dermatology
Background:
- Excessive inflammation can damage skin and impair wound healing.
- Previous studies showed p38 MAPK inhibition reduced burn-induced cell damage.
- This study investigates if inhibiting inflammation affects bacterial resistance.
Purpose of the Study:
- To determine if topical p38 MAPK inhibition in burn wounds affects bacterial resistance.
- To assess the impact of inflammation attenuation on host defense against Pseudomonas aeruginosa.
Main Methods:
- Rats with burn wounds received topical p38 MAPK inhibitor or vehicle.
- Burn wounds were inoculated with Pseudomonas aeruginosa 24 hours post-injury.
- Wound analysis occurred 48 hours post-injury.
Main Results:
- Burn wounds showed significant bacterial growth and inflammation.
- p38 MAPK inhibition decreased pro-inflammatory cytokines and neutrophil infiltration.
- Surprisingly, bacterial growth was reduced in inhibitor-treated wounds.
Conclusions:
- Topical p38 MAPK inhibition reduces burn wound inflammation without hindering bacterial defense.
- Targeting excessive inflammation may protect the dermal barrier and limit pathogen growth.
