The regulation of triglyceride storage by ornithine decarboxylase (Odc1) in Drosophila

• Published in: Biochemical and biophysical research communications Vol. 523; no. 2; pp. 429 - 433
• Main Authors: Leon, Kelly E., Fruin, Austin M., Nowotarski, Shannon L., DiAngelo, Justin R.
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 05-03-2020
• Subjects: ACC; Acetyl-CoA Carboxylase - genetics; Acetyl-CoA Carboxylase - metabolism; Animals; Drosophila; Drosophila melanogaster - genetics; Drosophila melanogaster - metabolism; Drosophila Proteins - genetics; Drosophila Proteins - metabolism; FASN; Fatty Acid Synthase, Type I - genetics; Fatty Acid Synthase, Type I - metabolism; Fatty Acids - genetics; Fatty Acids - metabolism; Female; Gene Expression Regulation; Heterozygote; Mutation; Odc1; Ornithine Decarboxylase - genetics; Ornithine Decarboxylase - metabolism; Triglyceride; Triglycerides - genetics; Triglycerides - metabolism; ACC; Triglyceride; Odc1; FASN; Drosophila
• ISSN: 0006-291X; 1090-2104
• DOI: 10.1016/j.bbrc.2019.12.078

Polyamines are low molecular weight, organic cations that play a critical role in many major cellular processes including cell cycle regulation and apoptosis, cellular division, tissue proliferation, and cellular differentiation; however, the functions of polyamines in regulating the storage of metabolic fuels such as triglycerides and glycogen is poorly understood. To address this question, we focused on the Drosophila homolog of ornithine decarboxylase (Odc1), the first rate-limiting enzyme in the synthesis of polyamines. Mutants in Odc1 are lethal, but heterozygotes were viable to adulthood. Odc1 heterozygotes appeared larger than their genetic background control flies and consistent with this observation, weighed more than the controls. However, the increased weight was not due to increased food consumption as heterozygotes ate less than the controls. Interestingly, Odc1 heterozygous flies had augmented triglyceride storage, and this lipid phenotype was due to increased triglyceride storage per cell and an increase in the number of fat cells produced. Odc1 heterozygous flies also displayed increased expression of the lipid synthesis genes fatty acid synthase (FASN) and acetyl-CoA carboxylase (ACC), suggesting increased lipid synthesis was the cause of the augmented triglyceride phenotype. These results provide a link between the expression of Odc1 and triglyceride storage suggesting that the polyamine pathway plays a role in regulating lipid metabolism.
•Odc heterozygous flies weigh more than control flies.•Odc heterozygous flies store more triglyceride than control flies.•Odc heterozygous flies have an increased expression of fatty acid synthesis genes.