TITLE:
Isolation, Cultivation, and Morphological Characteristics of Hair Follicle Adult Stem Cells in the Bulge Region in Mouse and Human
AUTHORS:
Bélgica J. Molina, Héctor J. Finol
KEYWORDS:
Stem Cells, Hair Follicle, Bulge, Niche, Alopecia
JOURNAL NAME:
Microscopy Research,
Vol.8 No.2,
April
30,
2020
ABSTRACT: Skin contains various populations of stem cells (SCs). Among these are hair follicle
stem cells (HFSCs) in the bulge region. The behavior of HFSCs deserves to be widely studied due
to the benefits to be derived from their identification, isolation, and
amplification. Skin samples of newborn mice (n = 32) and human adults (n = 10) were used, and the bulge region was isolated
and cultured. The isolation and characterization of cells were conducted
through immunocytochemistry and
immunofluorescence, using mainly CD34 and CD200 monoclonal antibodies.
Initially, cells grew slowly from the explant around the bulge region, accruing
cells with different morphology in both mouse and human, latter being mostly
polygonal; the mouse cells reaching confluence faster (5 to 7 days) than the
human (12 to 15 days). It was possible to isolate into subcultures cells
with small size (10 - 13 μm diameter),
round-shape, scant cytoplasm, central
prominent nucleus and with nucleolus, which formed colonies, maintaining their
phenotype in a high proportion (77% - 83% and
91% in mouse and human, respectively), without showing changes in their
morphology during almost 7 months in the mouse cells, and a month and a half in
the human. These results demonstrate that the selection, the isolation, and the
conditioned mediums allowed population increases of bulge cells and indicate
that cultured cells may retain their sternness in that they maintained their
phenotypic characteristics, expressed specific markers for SCs, and showed a
high proliferative capacity for long periods. Hair follicles, in mice and
humans, are important repositories of multipotent stem cells, due to their
tendency to differentiate into keratinocytes. Human HFSCs, obtained by
depilation, preserve their potential for proliferation and prove to be easily
accessible. This suggests that the bulge cells may present an alternative
source of autologous stem cells for tissue engineering and regenerative
medicine.