Accelerated wound closure in neutrophil-depleted mice

TLDR

Neutrophil infiltration protects wounds from infection but may also impede repair. The study aimed to determine how neutrophil depletion affects wound healing. Neutrophils were depleted by injecting rabbit anti‑mouse neutrophil serum, and wound healing was assessed in both normal and diabetic mice. Neutrophil depletion accelerated epidermal wound closure in both normal and diabetic mice without affecting dermal healing, indicating that neutrophils may retard wound closure.

Abstract

The infiltration of neutrophils into injured tissue is known to protect wounds from invading pathogens. However, more recent studies suggest that neutrophils might inhibit the wound repair process. To investigate the role of neutrophils in wounds, mice were neutrophil-depleted by injection with rabbit anti-mouse neutrophil serum. Remarkably, epidermal healing, measured by wound closure, proceeded significantly faster in neutropenic than control mice (77.7+14.2% vs. 41.2+0.9%, P<0.02 at day 2). Dermal healing was not affected by neutrophil depletion, as neither collagen deposition nor wound-breaking strength was significantly different between neutropenic and control mice. As the delayed repair of diabetic individuals exhibits robust inflammation, the effect of neutrophil depletion on diabetic wound healing was investigated. Similar to the observations in wild-type mice, wound closure was accelerated by nearly 50% in neutropenic, diabetic mice. The results suggest that although neutrophils may provide protection against infection, they may retard wound closure.