Abstract
Type 1 diabetes (T1D) is a chronic metabolic disease characterized by impaired glucose homeostasis and persistent hyperglycemia. Drosophila has emerged as a valuable model to study conserved insulin signaling mechanisms; proteomic insights into T1D-like conditions remain limited. Existing T1D models based on complete ablation of insulin-producing cells (IPCs) often exhibit severe developmental defects limiting their utility for dissecting disease-associated molecular and circadian mechanisms. Here, we report the establishment of an alternative Drosophila T1D model by targeting IPC-specific knockdown of dilp2, a homolog of human insulin, without IPC ablation. This novel model recapitulates key T1D-like features without affecting body size or weight, unlike other conventional models. Molecular analysis revealed elevation in phosphorylated Akt, reduced dfoxo and mTOR expression, and lifespan extension, suggesting a compensatory upregulation of dilp3 and dilp5. Our HRAMS-based proteomics study, for the first time, identifies five differentially expressed proteins (DEPs): Disc overgrown kinase (dco), Glutathione S-transferase 1 (GstS1), Turandot A (TotA), Turandot C (TotC), and Proteasome subunit beta type 6 (Prosβ6), validated by qRT-PCR. Downregulation of dco and GstS1 is associated with circadian arrhythmicity and elevated oxidative stress, respectively, whereas upregulation of TotA, TotC, and Prosβ6 reflects activation of stress responses and disruption of proteostasis under T1D-like conditions. Notably, circadian rhythm analysis exhibited hyperactivity and arrhythmic locomotor behavior in T1D flies. Collectively, these findings demonstrate dilp2 knockdown alone can induce T1D-like symptoms including multiple metabolic, circadian, and proteomic insights. The newly identified DEPs may serve as potential candidates for biomarker/therapeutic targets in T1D pathophysiology.
