Vocal fold stem cells and their niche in the human vocal fold.
OBJECTIVE
Vocal fold stellate cells (VFSCs) in the maculae flavae have many morphological differences from conventional fibroblasts in the human vocal fold mucosa. It is uncertain whether the VFSCs are derived from the same embryonic source as conventional fibroblasts. The purpose of this study was to investigate the stemness of the VFSCs and whether the pericellular matrices in the maculae flavae are a hyaluronan-rich matrix, which is required for a stem cell niche.


METHODS
Paraffin-embedded specimens were stained with Alcian blue (pH 2.5) for a hyaluronidase digestion study. Immunoreactivity to antibodies directed to CD44, CD133, Oct-4, Ki67, and telomerase was investigated in 5 human adult vocal fold mucosae.


RESULTS
The VFSCs were resting cells (G0-phase) and expressed a mesenchymal stem cell marker. The VFSCs did not express hematopoietic or embryonic stem cell markers. Telomerase resided in the VFSCs. The hyaluronan concentration in the maculae flavae was high and the VFSCs expressed hyaluronan receptors, indicating that maculae flavae are characterized by a certain criterion of hyaluronan-rich matrix.


CONCLUSIONS
There is growing evidence that the VFSCs in the human maculae flavae are somatic (mesenchymal) stem cells of the vocal fold, and that the maculae flavae may be a candidate for a stem cell niche that is a microenvironment nurturing a pool of VFSCs.
Department of Otolaryngology-Head and Neck Surgery, Kurume University School of Medicine, Kurume, Japan.
Kiminori
K
Sato
Hirohito
H
Umeno
Tadashi
T
Nakashima
D000328:Adult; D005347:Fibroblasts / Q000378:metabolism; D006801:Humans; D018960:Hyaluronan Receptors / Q000378:metabolism; D006820:Hyaluronic Acid / Q000378:metabolism; D007150:Immunohistochemistry; D016192:Resting Phase, Cell Cycle / Q000502:physiology; D055153:Stem Cell Niche / Q000502:physiology*; D014827:Vocal Cords / Q000166:cytology* / Q000502:physiology*
D018960:Hyaluronan Receptors; D006820:Hyaluronic Acid