Adipose-derived aldehyde dehydrogenase-expressing cells promote dermal regenerative potential with collagen-glycosaminoglycan scaffold

摘要

Aldehyde dehydrogenase (ALDH) is an enzyme that plays an important role in retinoid metabolism and highly expressed in stem cells. This study isolated ALDH-expressing cells from subcutaneous adipose tissue and investigated their potential to enhance healing in a full-thickness skin wound in rats by coimplanting them with collagen-glycosaminoglycan (c-GAG) scaffolds. ALDHpositive cells were isolated by a fluorescence-activated cell sorting technique from Lewis rat's stromal-vascular-fraction (SVF) and transplanted with c-GAG scaffolds in a rat full-thickness skin wound model. At 7 days after surgery, the microscopic appearance of c-GAG scaffolds seeded with ALDH-positive was compared with those of uncultured-SVF, and cultured-SVF adipose-derived stromal cells (ASCs). The thickness of cellular ingrowth in the ASC group (630 +/- 180 mu m) was significantly thicker than that in the control (390 +/- 120 mu m) or SVF (380 +/- 140 mu m) groups, but non-significantly thicker than that in the ALDH-positive group (570 +/- 220 lm). The thickness of regenerated collagen layer was significantly thicker in the ALDH-positive group (160 +/- 110 mu m) than in the ASCs (816 +/- 41 mu m), the control (65 +/- 24 mu m), or SVF (646 +/- 34 mu m) groups. Immunofluorescent staining with CD31 proved that transplanted ALDHpositive cells differentiated into vascular endothelial cells in c-GAG scaffolds. Combined transplantation with c-GAG scaffolds and adipose-derived ALDHpositive cells promoted dermal regeneration, giving a possibility that ALDHpositive cells would greatly shorten the waiting period before secondary autologous skin grafting was possible.