Jumu Protein Regulates Insulin Metabolism In Drosophila

Physiological dysfunction such as nutritional signal transduction and energy homeostasis has a great impact on human growth and development.Under normal circumstances,insulin metabolism maintains the balance of energy storage and consumption by regulating the conversion of glucose in the body,and then regulating the growth and development of organisms.When insulin metabolism is disordered,maintaining homeostasis of energy will be broken and resulting in diabetes.Drosophila melanogaster,as a model organism,has successfully established diabetes model by the perfect organ system,stable biochemical mechanism,homologous endocrine hormone and insulin signaling pathway similar to human.Jumeau(Jumu)protein is a new member of winged-helix/forkhead(WH/FKH)family transcription factors,its human homolog FOXN1 regulates the development of thymic epithelial cells.Previous studies have found that Jumu is involved in the development of Drosophila wings and heart as well as the production of plasmatocytes and melanotic nodules,but its function in fat body is not clear.In this experiment,low or over expression of jumu in the fat body of Drosophila by using the UAS/Gal4 system.The growth rate,pupal volume,body size,body weight,crawling ability,wing area,food intake,sugar and lipid metabolism indexes were tested,and the size of fat body cells,lipid droplets,nuclei and the transcription level of each node of insulin signal pathway were detected by immunofluorescence staining and RT-PCR.The results are as follows:1.Jumu protein regulates the growth and development of flies.Low expression of jumu increased adult body size,body weight,wing area,crawling ability and pupal volume;over expression of jumu reduced the adult’s crawling ability,food intake and pupal volume,and failed to emerge,delayed larval growth and long-term feeding.2.Jumu protein regulates lipid droplets and adipocytes in larval adipocytes.Low expression of jumu increased the size of lipid droplets,cells and nuclei of larval fat body;over expression of jumu reduced the size of fat body oil droplets,but abnormally increased the size of fat body cells and nuclei and leads to fat body broke.3.Jumu protein regulates larval glucose and lipid metabolism.Low expression of jumu increased the levels of triglyceride,trehalose and glycogen in larvae;over expression of jumu increased circulating glucose level and decreased trehalose level.4.Jumu protein regulates insulin metabolism in larvae.Low expression of jumu insulin signal pathway activated;over expression of jumu increased brain secretion of Dilp1,2 and 5,but the inhibition of insulin signal pathway was caused by the increase of d FOXO nuclear signal in fat body.To sum up,Jumu protein in fat body regulates the insulin signaling pathway d FOXO nuclear signaling level,affecting lipid and glycogen accumulation,thereby regulating the growth and development of Drosophila.Therefore,this study explored and analyzed the function of Jumu protein in Drosophila fat body,providing an important theoretical basis and reference value for FOXN1 and other FOX families to regulate insulin metabolism mechanism,and has important significance for the prevention and treatment of human diabetes.