Label Retaining Cells (LRCs) with Myoepithelial Characteristic from the Proximal Acinar Region Define Stem Cells in the Sweat Gland
Figure 8
Dissociated sweat gland cells can regenerate sweat glands, hair follicles, and the epidermis.
(A) Chamber graft of K5TetOff/TreH2BGFP dissociated 4 weeks chased sweat gland cells mixed with unmarked newborn dermal fibroblasts yield GFP positive hair-like fibers at 29 days. (B) Section through graft confirms the presence of H2BGFP positive hair follicles. (C) K5 staining marks the outer root sheath of this H2BGFP+ hair follicle. (C’) AE15 stains the inner root sheath and medulla, arrows. (C”) AE13 stains the hair shaft. (D) 70 days after transplantation, H2BGFP positive sweat gland structures were found, as confirmed by Na+/K+ ATPase expression (inset), in addition to H2BGFP positive hair follicle. (E) Magnification of the hair follicle in “D” with (E’) GFP single channel. (F) The sweat gland structures found also expressed K5 basal and K8 lumenal layer markers. (G) H2BGFP positive cells were also found in the K5 basal layer, (H) K1 suprabasal layer, and (I) loricrin marked granular layer of the newly regenerated epidermis. (J,K) In an independent experiment, 39 days after subcutaneous injections of 4 weeks chased unsorted dissociated cells from H2BGFP labeled SGs with unmarked newborn dermal fibroblasts, a cluster of GFP positive cells containing hair follicles were observed. (L) Magnification of a GFP+ hair follicle from panel “K”. (M) Sections show the presence of H2BGFP labeled SG structures expressing K8 lumenal layer marker. (N) H2BGFP positive cells are again also found in the basal, suprabasal, and (O) granular layers of the epidermis. White dotted lines mark dermal-epidermal interfaces.