Table 10.

Phospholipid Expression in Human Primary and Immortalized Meibomian Gland Epithelial Cells In Vitro

Phospholipid	Serum-Free Media		Serum-Containing Media
	Primary Cells	Immortalized Cells	Primary Cells	Immortalized Cells
Phosphati-dylcholine	57.00, 52.35	49.43, 43.93	55.97, 50.63	47.04, 44.97
Sphingomyelin	19.93, 16.91	20.55, 20.47	13.49, 15.45	18.47, 17.95
Lysophosphati-dylethanolamine	11.24, 13.16	11.98, 15.48	14.13, 15.30	14.77, 16.89
Lysophospha-tidylserine	3.70, 5.01	5.61, 7.03	6.45, 6.76	7.24, 7.97
Phosphatidyl-serine	2.39, 4.69	4.17, 4.53	4.05, 5.27	5.47, 4.91
Phosphatidyl-ethanolamine	2.47, 3.63	3.29, 3.05	2.59, 3.60	3.02, 2.68
Lysophosphati-dylglycerol	1.55, 2.26	2.46, 2.55	1.94, 1.29	1.51, 2.67
Lysophosphatidic acid	1.27, 1.17	1.41, 1.46	0.91, 1.12	1.57, 1.22
Phosphatidic acid	0.41, 0.70	0.97, 1.31	0.41, 0.51	0.84, 0.63
Phosphati-dylglycerol	0.05, 0.13	0.13, 0.19	0.08, 0.07	0.07, 0.10

Primary and immortalized human meibomian gland epithelial cells (n = 2 samples/condition) were cultured serum-free or containing media and then processed for the analysis of phospholipids. The numbers represent the percentage expression of a given phospholipid in the total phospholipid amount of each sample/condition. The total amount was determined by calculating and adding the picogram quantities of phospholipids shown in this table. Lysophosphatidylcholine, lysophosphatidylinositol, and phosphatidylinositol also were identified in the cellular samples. However, without internal standards for these species, their picogram amounts could not be calculated.