Aquaporins 8 and 9 as Possible Markers for Adult Murine Lacrimal Gland Cells

Aquaporins (AQPs) are proteins that selectively transport water across the cell membrane. Although AQPs play important roles in secretion in the lacrimal gland, the expression and localization of AQPs have not been clarified yet. In the current study, we investigated the expression pattern of AQP family members in the murine lacrimal gland during development. Lacrimal gland tissues were harvested from E13.5 and E17.5 murine embryos and from mice 8 weeks of age (adults). Corneal and conjunctival tissues from the latter served as controls. Total RNA was isolated and analyzed for the expression of AQP family members using qPCR. The localization of AQPs in the adult lacrimal gland in adult murine lacrimal glands was also analyzed. Expression of Aqp8 and Aqp9 mRNAs was detected in the adult lacrimal gland but not in the cornea, conjunctiva, or fetal lacrimal gland. AQP8 and AQP9 and α-SMA partially colocalized around the basal regions of the acinar unit. The levels of Aqp3 mRNAs and protein were much lower in the adult lacrimal gland but were readily detected in the adult cornea and conjunctiva. Our study suggests that AQP8 and AQP9 may serve as markers for adult murine lacrimal gland, ductal, and myoepithelial cells.

Dry anophthalmic socket syndrome – morphological alterations in meibomian glands

Purpose To evaluate morphological alterations of meibomian glands (MGs) in the dry anophthalmic socket syndrome (DASS). Methods Fifteen unilateral anophthalmic patients wearing cryolite glass prosthetic eyes were enrolled. All patients with clinical blepharitis or other significant eyelid abnormalities were excluded. In vivo laser scanning confocal microscopy (LSCM) of the MGs in the lower eyelids both on the anophthalmic side and the healthy fellow eye was performed to quantify acinar unit density, acinar unit diameter, acinar unit area, meibum secretion reflectivity, the inhomogeneous appearance of the glandular interstice, and inhomogeneous appearance of the acinar walls. Results The lower eyelids of the anophthalmic sockets revealed a significant reduction of the acinar unit density (p = 0.003) as well as a significantly more inhomogeneous appearance of the periglandular interstices (p = 0.018) and the acinar unit walls (p = 0.015) than the healthy fellow eyelid. However, there were no significant differences regarding the acinar unit diameter, acinar unit area, and meibum secretion reflectivity of the MGs on the anophthalmic side compared to the healthy fellow eyelid (p ≥ 0.05, respectively). Conclusions The eyelids of anophthalmic sockets without clinical blepharitis demonstrate a reduced density of MG acinar units and a more inhomogeneous appearance of the periglandular interstices and the acinar unit walls. This can cause meibomian gland dysfunction contributing to DASS and suggests early treatment of these symptomatic patients, even in the clinical absence of any blepharitis signs.