Vocal Fold Stellate Cells in the Human Macula Flava and the Diffuse Stellate Cell System

Abstract

Objectives: Hepatic stellate cells (HSCs) are desmin-positive cells with perinuclear vitamin A droplets that play important roles in liver fibrogenesis. Morphologically similar cells have been found at many extrahepatic sites. Consequently, the concept of a diffuse stellate cell system has been proposed. Vocal fold stellate cells (VFSCs) in the human maculae flavae (MFs) are starlike in shape and possess lipid droplets and store vitamin A. In this study, the relationship between the VFSCs in the human MFs and the diffuse stellate cell system was investigated. Methods: Light and electron microscopic investigations and immunohistochemical studies were performed in 5 samples of human adult vocal fold mucosa. Results: The VFSCs showed the morphological features of the HSCs (ie, they were desmin-positive cells with perinuclear vitamin A droplets). Glial fibrillary acidic protein and vimentin were identified in the VFSCs in the MFs. Conclusions: The VFSCs in the human adult MFs express the neural and muscle-associated proteins seen in HSCs. Our present and previous investigations suggest that the VFSCs in the human MFs are a member of the diffuse stellate cell system. The VFSCs are considered a new category of cells in the human vocal fold. The MFs are proposed to be special microenvironments, known as niches, that nurture a pool of VFSCs.