Abstract
Purpose :
Surfactant proteins (SP) are well known from human lung and have also been described in tears and tissues of the ocular surface.The objective of this study was to determine the possible expression of SP-G (SFTA2) at the ocular surface and in tears and to analyze possible functional aspects.
Methods :
Ocular tissues, human corneal (HCE) and conjunctival (HCjE) epithelial cell linesas as well as tear fluid from volunteers were analyzed by means of RT-PCR, western blot and immunohistochemistry. A possible role of recombinant SP-G in corneal wound healing was investigated by in vitro assays using a human corneal cell line. Possible tear film regulatory properties were analyzed by means of tensiometry measurements.
Results :
Lacrimal gland cells, corneal epithelium and endothelium, conjunctival epithelium, meibocytes as well as accessory lacrimal glands express SP-G which also could be detected in tears of volunteers. In vitro wounding of cultured HCE cells that were treated with recombinant SP-G revealed an increased wound closure rate compared to control. Moreover, recombinant SP-G altered the surface tension of tear fluid from healthy volunteers compared to water or BSA.
Conclusions :
The results indicate that SP-G is an important part of the tear film and ocular surface tissues. There, it is involved in wound healing processes and in regulation of tear film surface tension.
This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.