Purchase this article with an account.
David A Sullivan, Wendy R Kam, Yang Liu, Juan Ding; Comparative gene expression in proliferating versus differentiating human meibomian gland epithelial cells. Invest. Ophthalmol. Vis. Sci. 2019;60(9):4191.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
We recently discovered that Lrig1 and DNase2 serve as biomarkers for progenitor and differentiated cell populations, respectively, in the human meibomian gland (HMG). We also discovered that these biomarkers are plastic, and can be alternately induced or suppressed by changing the proliferation and differentiation status of immortalized (I) HMG epithelial cells (ECs). These changes are mirrored by corresponding shifts in cellular morphology in vitro. We hypothesize that this plasticity in biomarker profile and morphological appearance is paralleled by very significant alterations in cellular gene expression. To begin to test this hypothesis, we compared the gene expression patterns of proliferating versus differentiating IHMGECs.
IHMGECs were cultured for four days in either proliferating (keratinocyte serum free medium supplemented with epidermal growth factor and bovine pituitary extract] or differentiating [DMEM/F12 plus 10% fetal bovine serum] media. After four days of culture, cells were processed for the analysis of gene expression by using Illumina HumanHT-12 v.4 Expression BeadChips. Background-subtracted, cubic spline-normalized and non-log-transformed data were then evaluated with bioinformatic software.
Our study identified significant differences in the expression of more than 9,200 genes in proliferating (4,918 genes upregulated) versus differentiating (4,364 genes upregulated) IHMGECs. Proliferation was associated with extraordinary increases in the expression of specific genes (e.g. cathelicidin antimicrobial peptide; 859,100-fold upregulation) and numerous ontologies (e.g. 152 biological process [bp] ontologies with ≥ 100 genes were upregulated), with the top 10 ontologies related to cell cycle (z scores > 13.9). Differentiation also led to dramatic increases in specific gene expressions (e.g. small proline-rich protein 3; 3,774,864-fold upregulation) and many ontologies (e.g. 134 bp ontologies with ≥ 100 genes were upregulated), with the protein and vesicle transport and lysosome ontologies having high z scores.
Our findings demonstrate that gene expression in proliferating versus differentiating IHMGECs is quite different. Our next objective is to determine whether these genetic differences exhibit plasticity like the biomarker proteins and cellular morphology of IHMGECs.
This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.
This PDF is available to Subscribers Only