1759.3 Intermediate Filaments of the Cells in the Human Adult
Maculae Flavae
The expression of proteins in the intermediate filaments of the cytoplasm is specific
to cell type and differentiation (Becker et al. 2006a).
Proteins in the intermediate filaments containing cytokeratin, vimentin, glial
fibrillary acidic protein (GFAP) and desmin are distributed in the cytoplasm of the
cells in the adult maculae flavae (Sato et al. 2012a). Additionally, cells in the human
maculae flavae express SOX 17, which is an endodermal cell marker. Consequently,
the cells in the human adult maculae flavae express proteins of all three germ layers.
This suggests that the cells in the maculae flavae are undifferentiated cells and have
the ability of multipotency.
9.4 Radiosensitivity of the Cells in the Human Adult
Maculae Flavae
The radiosensitivity of the cells in the maculae flavae is morphologically higher
than that of fibroblasts in Reinke’s space of the human vocal fold mucosa, indicating
that the cells in the maculae flavae are not yet as fully differentiated as fibroblasts
(Sato et al. 2008b).
9.5 Telomerase of the Cells in the Human Adult Maculae
Flavae
In multicellular organisms, telomerase resides mainly in the germ cells that give rise
to sperm and eggs, and in a few other kinds of proliferating normal cells such as
stem cells (Becker et al. 2006b).
The cells in the maculae flavae express telomerase reverse transcriptase, indicating
the special DNA polymerase called telomerase resides in the cells in the maculae
flavae (Sato et al. 2012b). This suggests that the cells in the human maculae flavae
are a tissue stem cell of the human vocal fold mucosa.
9.6 Cell Cycle of the Cells in the Human Adult Maculae Flavae
Cells express Ki-67 during proliferation (G1-, S-, G2- M-phase) in the cell cycle, but
cells that are in an arrested state (G0-phase) do not express Ki-67 (Schlüter et al. 1993 ).
The cells in the human maculae flavae do not express Ki-67, indicating that they
are resting cells (G0-phase), as are other stem cells (Sato et al. 2012b).
9 The Macula Flava of the Human Vocal Fold as a Stem Cell Microenvironment