Functional Inactivation of Drosophila GCK Orthologs Causes Genomic Instability and Oxidative Stress in a Fly Model of MODY-2.
Elisa MascoloFrancesco LiguoriLorenzo Stufera MecarelliNoemi AmorosoChiara MeriglianoSusanna AmadioCinzia VolontéRoberto ContestabileAngela TramontiFiammetta VernìPublished in: International journal of molecular sciences (2021)
Maturity-onset diabetes of the young (MODY) type 2 is caused by heterozygous inactivating mutations in the gene encoding glucokinase (GCK), a pivotal enzyme for glucose homeostasis. In the pancreas GCK regulates insulin secretion, while in the liver it promotes glucose utilization and storage. We showed that silencing the Drosophila GCK orthologs Hex-A and Hex-C results in a MODY-2-like hyperglycemia. Targeted knock-down revealed that Hex-A is expressed in insulin producing cells (IPCs) whereas Hex-C is specifically expressed in the fat body. We showed that Hex-A is essential for insulin secretion and it is required for Hex-C expression. Reduced levels of either Hex-A or Hex-C resulted in chromosome aberrations (CABs), together with an increased production of advanced glycation end-products (AGEs) and reactive oxygen species (ROS). This result suggests that CABs, in GCK depleted cells, are likely due to hyperglycemia, which produces oxidative stress through AGE metabolism. In agreement with this hypothesis, treating GCK-depleted larvae with the antioxidant vitamin B6 rescued CABs, whereas the treatment with a B6 inhibitor enhanced genomic instability. Although MODY-2 rarely produces complications, our data revealed the possibility that MODY-2 impacts genome integrity.
Keyphrases
- oxidative stress
- induced apoptosis
- copy number
- reactive oxygen species
- type diabetes
- dna damage
- diabetic rats
- cell cycle arrest
- endoplasmic reticulum stress
- poor prognosis
- blood glucose
- cardiovascular disease
- adipose tissue
- cell death
- signaling pathway
- dna methylation
- glycemic control
- drug delivery
- risk factors
- blood pressure
- cell proliferation
- insulin resistance
- binding protein
- weight loss
- cancer therapy
- aedes aegypti