Abstract
Purpose :
Dry eye syndrome (DES) has been shown to have gender predilections with females, especially post-menopausal or ovariectomized, being more susceptible than their male counterparts. Sexual dimorphism and neuro-hormonal control of Lacrimal gland (LG) secretion has been studied in rats and mice and these studies have implicated androgen levels to be responsible for this gender susceptibility. However, similar studies from humans are lacking. The present study aimed to investigate the role of androgens on human LG secretions.
Methods :
Human LG cultures (n=3) were established according to the published protocol using tissues from patients undergoing therapeutic exenteration after IRB approval. The cultured cells were stimulated with Testosterone (10μM) and Dihydrotestosterone (10μM) on day 3 and the supernatants collected on day 7 for analysis. Control (unstimulated) and test (stimulated) supernatants were used for total protein quantification by Bradford assay, protein profiling by SDS-PAGE and quantification of scIgA, Lysozyme and Lactoferrin by sandwich ELISA.
Results :
Human LG cells were cultured as adherent monolayer on Matrigel™. Testosterone stimulation of cultures led to an increase in total protein (236.84±6.96mg/ml vs 165.17±30.04mg/ml control; p=0.08) whereas DHT stimulation did not have a significant increase in protein output (227.96±30.61mg/ml vs 165.17±30.04mg/ml control; p=0.21). SDS-PAGE profiling showed a statistically significant increase in the levels of 78kD protein (corresponding to scIgA) and 7kD protein (corresponding to transferrin) on Testosterone and DHT stimulation.The stimulated supernatant also showed a statistically significant increase in scIgA (28.57±5.9ng/ml vs 2.03±0.66 control; p=0.01, 0.02) levels whereas similar increase was not observed with Lysozyme (p=0.43,0.19) and Lactoferrin (p=0.13,0.61) secretion.
Conclusions :
The present study provides preliminary evidence that androgens augment total protein output and scIgA production/secretion by the human LG cells. These results warrant further experimentation to evaluate the mechanism of androgens action towards the long-term goal of using them in pharmacological management of DES.
This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.