Citation: Stanley, D.W., Goodman, C.L., An, S., Song, Q. 2012. Prostaglandin A2 influences gene expression in an established insect cell line (BCIRL-HzAm1) cells. Journal of Insect Physiology. 58:837-849.
Interpretive Summary: Long-term agricultural sustainability is severely threatened by widespread use of classical insecticides. Threats include increasing resistance to insecticides and sharply decreasing environmental quality. The concept of biological control of insects is a potentially powerful alternative to classical insecticides. Biological control is based on the idea that direct application of certain insect-specific predators, pathogens and parasites can reduce pest insect populations to a point that the pests exert only negligible economic damage. A major problem, however, is that pest insects have very potent immune reactions to invaders. This limits the usefulness of many potential biological control agents. In this paper, we report on details of immune signaling that may be exploited in future research to inhibit pest insect immunity. Scientists who study insect immunology will use this information in future research designed to understand how insect immunity can be manipulated to improve the efficiency of biological control programs. Ultimately, this research will benefit growers who produce vegetable crops and the people who consume vegetables.
Technical Abstract: 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 PGF2a. 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 PGF2a 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.