Abstract
Purpose :
To validate the ATP-binding cassette transporter A1 (ABCA1) expression and distribution in human eyelid tissues and meibomian gland epithelial cells.
Methods :
Meibomian gland tissues from human eyelids were isolated by collagenase A digestion, and cultured in Defined keratinocyte serum-free medium (DKSFM). Infrared imaging was used to analyze the general morphology of meibomian glands. Hematoxylin and eosin (H&E) and Oil Red O staining were used to observe the morphological structure and lipid secretion in the human meibomian gland tissues. qRT-PCR, western blotting, and immunostaining were used to detect the mRNA and protein expression and cyto-localization of ABCA1 in the meibomian gland tissues and cultured cells.
Results :
The degree of loss of human meibomian gland tissue was related to age. Meibomian gland lipid metabolism was associated with age. Additionally, human meibomian gland tissues express ABCA1 mRNA and protein while glandular epithelial cells express more ABCA1 mRNA and protein than acinar cells, and their expression in acinar cells decreases with differentiation. Furthermore, the expression of ABCA1 was downregulated in abnormal meibomian gland tissues. ABCA1 was mainly localized on the cell membrane in primary human meibomian gland epithelial cells (pHMGEC), while it was localized in the cytoplasm of immortalized human meibomian gland epithelial cells (iHMGEC). The mRNA and protein levels of ABCA1 in pHMGEC were higher than those in iHMGEC.
Conclusions :
Meibomian gland tissues of the human eyelid degenerate with age. ABCA1 expression in acinar cells decreases after differentiation. In all, this molecule plays an important role in meibomian gland metabolism.
This abstract was presented at the 2024 ARVO Annual Meeting, held in Seattle, WA, May 5-9, 2024.