Effects of acute wound environment on neonatal rat dermal multipotent cells

Dermal multipotent cells (DMCs) with the capacity to differentiate to osteocytes, chondrocytes, adipocytes and neurons were isolated from the dermis of newborn Wistar rats by their adherence to culture plastic dishes. After labeling with a fluorescent nuclear marker, 4',6-diamidino-2-phenylindole, neonatal DMCs were implanted into minced skin. The labeled cells were found in the regenerative skin 2 weeks after implantation. Topical transplantation of DMC suspension on full-thickness excision wounds made on the back of female rats enhanced the initial rate of contraction. Wound fluid collected using polyvinyl alcohol sponges from the incisions on the dorsa of adult rats on day 3 postwounding was used in the experiments. A methylthiazolyldiphenyl tetrazolium bromide assay showed that wound fluid with concentrations from 5 to 30% induced an increase in the number of cultured DMCs. The wound model of a monolayer of cells indicated that 10% wound fluid accelerated the migration rate of DMCs to fill in defects made in the layer of cultured cells. A colorimetric analysis also indicated that 10% wound fluid increased the hydroxyproline content in cultured cells. In conclusion, DMCs have been isolated from newborn rat dermis by their adherence to culture plastic dishes, and acute wound environment in the early stage promotes the viability, migration and collagen synthesis of these cells.