Purpose: The purpose of the study was to test the hypothesis that estrogen and progesterone regulate gene expression in the meibomian gland.
Methods: Meibomian glands were obtained from young adult, ovariectomized mice that were administered 17beta-estradiol, progesterone, 17beta-estradiol plus progesterone, or vehicle for 14 days. Glands were pooled according to treatment, processed for the extraction of RNA, and analyzed for differentially expressed mRNAs by using mouse gene microarrays. Bioarray data were evaluated with sophisticated bioinformatics software and statistical programs. The expression of selected genes was confirmed with gene chips and quantitative real-time PCR techniques.
Results: The findings show that 17beta-estradiol, progesterone, or both hormones administered together significantly influenced the expression of numerous genes in the mouse meibomian gland. Notable were the effects of 17beta-estradiol on genes related to lipid metabolism, tyrosine kinases, immune factors, extracellular matrix components, steroidogenesis, and prolactin dynamics. Also very significant were the actions of progesterone or 17beta-estradiol plus progesterone on ribosome or localization gene ontologies, respectively. The various hormone treatments led to many analogous, opposite, or unique effects on gene expression.
Conclusions: These findings support the study hypothesis that estrogen and progesterone modulate gene expression in the meibomian gland.