Figure 3. The inclusion of HD-1^bri pericytes in the dermal equivalent of OCs reconstituted with P7 HFFs stimulates epidermal regeneration capacity of α₆^dim differentiating keratinocytes.

Sections of OCs stained with H&E showing reconstituted skin tissue from α₆^bri (stem and TA) keratinocytes (A–C) or α₆^dim early differentiating keratinocytes (D–F) grown on dermal equivalents containing either P7 HFFs alone (A and D), P7 HFFs plus 10% HD-1^bri cells (B and E), or fresh HFFs depleted of HD-1^bri cells (C and F). The intrinsically low epidermal tissue-regenerative capacity of α₆^dim keratinocytes is substantially enhanced by coculture with dermal equivalents containing HD-1^bri cells (E; n = 3), while depletion of HD-1^bri cells diminishes their tissue-regenerative capacity (F; n = 2). Notably, the α₆^bri stem and TA–containing fraction exhibits excellent tissue regeneration irrespective of the presence of pericytes (A–C; n = 3). (G–I) Ki67 staining of OCs of α₆^bri (stem and TA) keratinocytes (G) or α₆^dim early differentiating keratinocytes (H and I) grown on dermal equivalents containing either P7 HFFs alone (G and H) or P7 HFFs plus 10% HD-1^bri cells (I). Note the increase in cellularity and number of Ki67-positive cells in the α₆^dim epithelium upon coculture with the HD-1^bri cells compared with P7 HFFs alone (I versus H), restoring epithelial regeneration to levels comparable to those obtained with the α₆^bri stem and TA compartment (G). Scale bars: 100 μm.