title: Serum-induced differentiation of human meibomian gland epithelial cells.
abstract: OBJECTIVE
  We hypothesize that culturing immortalized human meibomian gland epithelial cells in serum-containing medium will induce their differentiation. The purpose of this investigation was to begin to test our hypothesis, and explore the impact of serum on gene expression and lipid accumulation in human meibomian gland epithelial cells.
  
  
  METHODS
  Immortalized and primary human meibomian gland epithelial cells were cultured in the presence or absence of serum. Cells were evaluated for lysosome and lipid accumulation, polar and neutral lipid profiles, and gene expression.
  
  
  RESULTS
  Our results support our hypothesis that serum stimulates the differentiation of human meibomian gland epithelial cells. This serum-induced effect is associated with a significant increase in the expression of genes linked to cell differentiation, epithelium development, the endoplasmic reticulum, Golgi apparatus, vesicles, and lysosomes, and a significant decrease in gene activity related to the cell cycle, mitochondria, ribosomes, and translation. These cellular responses are accompanied by an accumulation of lipids within lysosomes, as well as alterations in the fatty acid content of polar and nonpolar lipids. Of particular importance, our results show that the molecular and biochemical changes of immortalized human meibomian gland epithelial cells during differentiation are analogous to those of primary cells.
  
  
  CONCLUSIONS
  Overall, our findings indicate that immortalized human meibomian gland epithelial cells may serve as an ideal preclinical model to identify factors that control cellular differentiation in the meibomian gland.
authors.affiliation: Schepens Eye Research Institute, Boston, Massachusetts, United States.
authors.forename: David A
authors.initials: DA
authors.lastname: Sullivan
authors.affiliation: Schepens Eye Research Institute, Boston, Massachusetts, United States.
authors.forename: Yang
authors.initials: Y
authors.lastname: Liu
authors.affiliation: Schepens Eye Research Institute, Boston, Massachusetts, United States.
authors.forename: Wendy R
authors.initials: WR
authors.lastname: Kam
authors.affiliation: Schepens Eye Research Institute, Boston, Massachusetts, United States.
authors.forename: Juan
authors.initials: J
authors.lastname: Ding
authors.affiliation: Proteomics and Mass Spectrometry Facility, University of Massachusetts Medical School, Shrewsbury, Massachusetts, United States.
authors.forename: Karin M
authors.initials: KM
authors.lastname: Green
authors.affiliation: Proteomics and Mass Spectrometry Facility, University of Massachusetts Medical School, Shrewsbury, Massachusetts, United States.
authors.forename: Scott A
authors.initials: SA
authors.lastname: Shaffer
authors.affiliation: Ophthalmic Consultants of Boston, Boston, Massachusetts, United States.
authors.forename: Mark P
authors.initials: MP
authors.lastname: Hatton
authors.affiliation: Schepens Eye Research Institute, Boston, Massachusetts, United States Department of Ophthalmology, Harvard Medical School, Boston, Massachusetts, United States.
authors.forename: Shaohui
authors.initials: S
authors.lastname: Liu
mesh_terms: D002454:Cell Differentiation / Q000502:physiology*; D002478:Cells, Cultured; D004847:Epithelial Cells / Q000166:cytology*; D005136:Eye Proteins / Q000235:genetics; D005786:Gene Expression Regulation / Q000502:physiology; D006801:Humans; D050356:Lipid Metabolism / Q000502:physiology; D008247:Lysosomes / Q000378:metabolism; D008537:Meibomian Glands / Q000166:cytology* / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D060888:Real-Time Polymerase Chain Reaction; D044967:Serum / Q000502:physiology*
chemical_list: D005136:Eye Proteins; D012333:RNA, Messenger
keywords: differentiation; epithelial cells; gene expression; lipids; meibomian gland