Biochemical bases in differentiation of a mouse cell line GSM06 to gastric surface cells

Abstract

A mouse gastric surface cell line GSM06 established from a transgenic mouse harboring temperature-sensitive simian virus 40 large T-antigen gene was subjected to the lipid and glycoprotein analysis. When GSM06 cells were cultured for a long time after formation of a confluent monolayer, they differentiated to resemble foveolar epithelial cells morphologically. Biochemical changes during culture were studied in cells harvested just when a monolayer had formed (day 0), on day 7, and on day 21. Content of total phospholipids, cholesterol cholesterol sulfate, total sugar and sialic acid increased about 1.5-fold from day 0 to day 7 and remained elevated till day 21. The fatty acid composition of phospholipids revealed increased relative levels of oleic acid in phosphatidylcholine and phosphatidylethanolamine and an increased level of plasmenylethanolamine from day 0 to 7. The level of dolichylphosphate continued to increase in a time-dependent manner. Glycosylation of various proteins, detected with lectins, was enhanced from day 7. In addition, greater resistance to taurodeoxycholate and acetylsalicylic acid was observed on days 7 and 21 than on day 0. Thus, enhanced glycosylation of proteins and an overall increase in the area of cellular membranes were the major changes in GSM06 cells during culture, and they were accompanied by an enhancement of cytoprotective potential.