The Findings of in vivo and in vitro Studies of the Vocal Fold Stellate Cells with a Focus on Cell Marker Expression and Vitamin A Storage

Abstract

Vitamin A（VA）storing vocal fold stellate cells （VFSCs）, which are found in the anterior and posterior maculae flava（MFs）, are expected to play crucial roles for maintaining the lamina propria（LP）and scar formation in the LP. However, the knowledge on the in vivo and in vitro features of VFSCs is limited. In the present study we compared the features of VFSCs among various species to identify the most appropriate model for a subsequent in vivo study, and cultured primary VFSCs from humans to elucidate the in vitro features. Larynges from humans, dogs, pigs, rabbits and rats were excised and subjected to immunostaining for glial fibrillary acidic protein（GFAP）in VFSCs, and staining for VA and lipid droplets（LD）and VA measurement. VA storing VFSCs located at the MFs were only identified in humans and rats in which the amounts of VA stored in the VF were similar. Primary VFSCs（pVFSCs）and vocal fold fibroblasts（pVFFs）were isolated from human larynges and cultured for immunostaining for VFSC markers（GFAP and vimentin）, and for VA measurement. The expression levels of the VFSC markers and VA storage were identified in the pVFSCs and pVFFs in the same manner as in the in vivo VFSC experiments. The present study revealed that rats and cultured pVFSCs were useful for in vivo and in vitro VFSC studies, respectively.