Prostaglandin A2 influences gene expression in an established insect cell line (BCIRL-HzAM1) cells

Prostaglandins (PGs) and other eicosanoids are oxygenated metabolites of arachidonic acid and two other C20 polyunsaturated fatty acids. While most well studied in mammals, PGs exert important actions in insects and virtually all other invertebrates. We have been researching the mechanisms of PG actions in established insect cell lines and reported earlier that two PGs, PGA1 and PGE1, influence gene and protein expression in HzAM1 cells. Here we report on further experiments with three 2-series PGs, PGA2, PGE2 and PGF2α. In separate experiments we treated cells with each of the three PGs for 12 and 24 h and then analyzed cell lysates by 2-D electrophoresis. Analysis of the gels by Delta2D software showed that PGA2 influenced expression of 60 proteins while PGE2 and PGF2α treatments led to expression changes for only a few proteins. All spots representing changes in protein expression were processed for analysis by MALDI TOF/TOF mass spectrometry. Bioinformatic analysis of the resulting sequences yielded in silico identifications of all proteins. The apparent changes in some proteins were confirmed by quantitative PCR, which demonstrated that changes in protein expression were parallel to changes in mRNA expression. We assorted the proteins into functional categories, including 1/cell structure and function; 2/cell protection and immunity; 3/energetics and metabolism; 4/nucleotide processing; 5/protein action and processing and 6/signal transduction. These findings substantially extend our idea that one mechanism of PG actions in insect cells is the modulation of gene and protein expression.