| Autor: |
Gumeni S; Department of Cell Biology and Biophysics, Faculty of Biology, National and Kapodistrian University of Athens, Panepistimiopolis, 15784 Athens, Greece., Lamprou M; Department of Cell Biology and Biophysics, Faculty of Biology, National and Kapodistrian University of Athens, Panepistimiopolis, 15784 Athens, Greece., Evangelakou Z; Department of Cell Biology and Biophysics, Faculty of Biology, National and Kapodistrian University of Athens, Panepistimiopolis, 15784 Athens, Greece., Manola MS; Department of Cell Biology and Biophysics, Faculty of Biology, National and Kapodistrian University of Athens, Panepistimiopolis, 15784 Athens, Greece., Trougakos IP; Department of Cell Biology and Biophysics, Faculty of Biology, National and Kapodistrian University of Athens, Panepistimiopolis, 15784 Athens, Greece. |
| Abstrakt: |
The modulation of insulin/insulin-like growth factor signaling (IIS) is associated with altered nutritional and metabolic states. The Drosophila genome encodes eight insulin-like peptides, whose activity is regulated by a group of secreted factors, including Ecdysone-inducible gene L2 ( ImpL2 ), which acts as a potent IIS inhibitor. We recently reported that cncC (cncC/Nrf2), the fly ortholog of Nrf2, is a positive transcriptional regulator of ImpL2, as part of a negative feedback loop aiming to suppress cncC/Nrf2 activity. This finding correlated with our observation that sustained cncC/Nrf2 overexpression/activation ( cncC OE ; a condition that signals organismal stress) deregulates IIS, causing hyperglycemia, the exhaustion of energy stores in flies' tissues, and accelerated aging. Here, we extend these studies in Drosophila by assaying the functional implication of ImpL2 in cncC OE -mediated metabolic deregulation. We found that ImpL2 knockdown (KD) in cncC OE flies partially reactivated IIS, attenuated hyperglycemia and restored tissue energetics. Moreover, ImpL2 KD largely suppressed cncC OE -mediated premature aging. In support, pharmacological treatment of cncC OE flies with Metformin, a first-line medication for type 2 diabetes, restored (dose-dependently) IIS functionality and extended cncC OE flies' longevity. These findings exemplify the effect of chronic stress in predisposition to diabetic phenotypes, indicating the potential prophylactic role of maintaining normal IIS functionality. |
