Platelet-activating factor: improvement in wound healing by a chemotactic factor

Area of Science:

• Wound healing research
• Inflammatory cell biology
• Dermatology

Background:

• Platelet-activating factor (PAF) is known to be chemotactic for inflammatory cells and activates macrophages.
• Unlike growth factors, PAF has not been previously investigated for its effects on wound healing or cell proliferation.
• The role of endogenous PAF in the natural wound repair process remains unexplored.

Purpose of the Study:

• To investigate the effect of topical Platelet-activating factor (PAF) on surgical wound healing in a rat model.
• To determine the optimal concentration of PAF for promoting wound repair.
• To elucidate the cellular mechanisms underlying PAF's influence on healing.

Main Methods:

• A paired rat surgical incision model was utilized to assess topical PAF treatment.
• Wound samples were evaluated on various days post-wounding using tensiometry and histology.
• Cellular infiltration, including fibroblasts, monocytes, and macrophages, was assessed via histochemical studies.

Main Results:

• Topical application of 1 microgram of PAF significantly increased maximal breaking strength of wounds by days 5 and 7 (33.2% and 25.6% increase, respectively).
• The 1 microgram PAF concentration also led to increased cellular infiltration (fibroblasts, monocytes) and macrophage presence on day 7.
• A PAF receptor antagonist blocked the pro-healing effects of exogenous PAF but did not impact normal wound healing.

Conclusions:

• Topical Platelet-activating factor (PAF) demonstrates significant wound-healing properties, enhancing tensile strength and cellular recruitment.
• The optimal concentration for promoting wound repair was found to be 1 microgram.
• While exogenous PAF accelerates healing, its endogenous production does not appear critical for normal wound repair, suggesting a potential therapeutic strategy.