Mesenchymal stromal cells promote the proliferation of basal stem cells and efficient epithelization in organotypic models of wound healing.

Adipose derived mesenchymal stromal cells (ADSCs) represent a fascinating tool in the scenario of wound healing and regenerative medicine. Recent data already demonstrated that ADSCs could exert a stimulatory action on epithelial cells through secretion of soluble factors. The aim of the present study was to assess how ADSCs guide wound re-epithelization in vitro in the presence of keratinocytes. We used an organotypic model of wound healing and we seeded keratinocytes on a ADSC-induced dermal matrix. Conventional hematoxylin-eosin stain and immunohistochemistry staining for Ki67, p63 and pan-keratins were performed at different timepoints. Histological sections of organotypic cultures showed complete coverage of the ADSC-induced matrix by keratinocytes. Proliferation of basal stem cells was found to be the main mechanism responsible for epithelization of the dermis. In conclusion, ADSC do not only stimulate dermal regeneration through collagen deposition but also promote epithelization. HIGHLIGHTS: Mesenchymal stromal cells (MSCs) are widely used in regenerative medicine and wound healing. MSCs do not only stimulate dermal regeneration through collagen deposition but also promote epithelization. MSCs directly target the basal stem cell niche and promote its proliferation, migration and subsequent differentiation.