Wound Healing and Expression of Antimicrobial Peptides/Polypeptides in Human Keratinocytes, a Consequence of Common Growth Factors

TLDR

The skin’s physical barrier is complemented by antimicrobial peptides, whose expression is stimulated by growth factors released during wound healing and subsides once tissue regeneration restores the barrier. Insulin‑like growth factor I and TGF‑α stimulate human keratinocytes to produce hCAP‑18/LL‑37, β‑defensin 3, NGAL, and SLPI, both individually and synergistically, revealing a host‑defence function for growth factors in wound healing and psoriasis.

Abstract

Abstract In addition to acting as a physical barrier against microorganisms, the skin produces antimicrobial peptides and proteins. After wounding, growth factors are produced to stimulate the regeneration of tissue. The growth factor response ceases after regeneration of the tissue, when the physical barrier protecting against microbial infections is re-established. We found that the growth factors important in wound healing, insulin-like growth factor I and TGF-α, induce the expression of the antimicrobial peptides/polypeptides human cationic antimicrobial protein hCAP-18/LL-37, human β-defensin 3, neutrophil gelatinase-associated lipocalin, and secretory leukocyte protease inhibitor in human keratinocytes. Both an individual and a synergistic effect of these growth factors were observed. These findings offer an explanation for the expression of these peptides/polypeptides in the skin disease psoriasis and in wound healing and define a host defense role for growth factors in wound healing.