Abstract
Purpose :
Human meibomian glands and immortalised human meibomian gland epithelial cells (iHMGEC) contain sex hormone receptors and the molecular machinery required for their biosynthesis, suggesting a role of sex hormones in MG biological function. This study aimed to determine the effects of dihydrotestosterone (DHT) and estradiol (E2) on lipid production in iHMGEC cultured in serum-free medium with rosiglitazone (Rosi, a PPARγ-agonist), a known inducer of iHMGEC differentiation. We also examined the effect of Rosi on iHMGEC viability.
Methods :
iHMGEC were cultured to 80% confluence in keratinocyte serum-free medium, then switched for 2-4 days to serum-free media containing various concentrations of DHT, E2, and Rosi, alone and in combination (n=4 wells/each treatment, n=3 experiments/treatment). Cell viability was assessed using the MTT assay. Accumulation of intracellular lipid droplets was quantified using a Nile Red-cell nucleus (DAPI) spectroscopic assay. Differences between treatments were compared using one-way ANOVA with post-hoc comparisons using Tukey’s test (α=0.05).
Results :
DHT (1-100 nM) or E2 (0.1-10 nM) alone did not significantly affect cell viability. However, treatment with Rosi (alone and in combination with DHT and/or E2) significantly decreased iHMGEC viability by up to 50% when used at 50 μM (p<0.001). Lipid accumulation in iHMGEC treated with Rosi (30 μM) was significantly higher relative to the medium-only control (p<0.001), but the addition of DHT (10 nM) and/or E2 (1 nM) had no further significant effect. DHT (10 nM), E2 (1 nM) and DHT+E2 without Rosi did not affect lipid accumulation in iHMGEC cultured in serum-free medium.
Conclusions :
The sex hormones DHT and E2 did not induce lipid accumulation in iHMGEC cultured in serum-free medium, nor affect cell viability. In contrast, treatment with Rosi significantly increased lipid accumulation but adversely affected iHMGEC viability when used at the higher concentration (50 µM). Further investigations are required to better understand the mechanisms of iHMGEC differentiation, cell survival and lipid secretion.
This is a 2021 ARVO Annual Meeting abstract.