Isolation, culture and phenotypic characterization of human sweat gland epithelial cells

Sweat gland epithelial cells (SGECs) have been identified as essential for the regeneration of sweat glands and for the construction of skin substitutes containing skin appendages. Consequently, the isolation, culture and phenotypic characterization of SGECs are of paramount importance. In the present study study, human sweat glands were isolated by pipetting under a phase contrast microscope following digestion with collagenase type I. Subsequently, a microscopic organ culture technique was used for the primary culture of human SGECs, and the culture conditions were modified in order to achieve optimal cell growth status. Primary SGECs were identified based on their expression of markers specific for sweat glands, including carcinoembryonic antigen (CEA), CK7, CK8, CK14, CK15, CK18 and CK19. We explored the possible presence of stem cells in human sweat glands by detecting their expression of leucine-rich repeat-containing G protein-coupled receptor 5 (LGR5). Primary SGECs achieved a good growth state when cultured under serum-free conditions. After one passage, the cells cultured in keratinocyte serum-free medium with 1% fetal bovine serum (FBS) still showed a prominent proliferative activity. Phenotypic analysis by immunofluorescence microscopy, reverse transcription-polymerase chain reaction (RT-PCR), and western blot analysis demonstrated the expression of sweat gland-specific markers, including CEA, CK7, CK8, CK14, CK15, CK18 and CK19. In addition, RT-PCR and immunochemistry detected the expression of LGR5. In comparison with traditional serum-containing conditions, serum-free culture provides the preferred culture conditions for human SGECs. LGR5 is a novel marker that identifies human sweat gland-derived stem cells.