Human galectin­3: Molecular switch of gene expression in dermal fibroblasts in vitro and of skin collagen organization in open wounds and tensile strength in incisions in vivo.

Understanding the molecular and cellular processes in skin wound healing can pave the way for devising innovative concepts by turning the identified natural effectors into therapeutic tools. Based on the concept of broad­scale engagement of members of the family of galactoside­binding lectins (galectins) in pathophysiological processes, such as cancer or tissue repair/regeneration, the present study investigated the potential of galectins­1 (Gal­1) and ­3 (Gal­3) in wound healing. Human dermal fibroblasts, which are key cells involved in skin wound healing, responded to galectin exposure (Gal­1 at 300 or Gal­3 at 600 ng/ml) with selective changes in gene expression among a panel of 84 wound­healing­related genes, as well as remodeling of the extracellular matrix. In the case of Gal­3, positive expression of Ki67 and cell number increased when using a decellularized matrix produced by Gal­3­treated fibroblasts as substrate for culture of interfollicular keratinocytes. In vivo wounds were topically treated with 20 ng/ml Gal­1 or ­3, and collagen score was found to be elevated in excisional wound repair in rats treated with Gal­3. The tensile strength measured in incisions was significantly increased from 79.5±17.5 g/mm2 in controls to 103.1±21.4 g/mm2 after 21 days of healing. These data warrant further testing mixtures of galectins and other types of compounds, for example a combination of galectins and TGF­ß1.