Endocannabinoid (eCB) signaling modulates the brain wiring by regulating axonal growth, guidance and synaptogenesis. The diacylglycerol lipases (DAGL-α and DAGL-β) synthesize 2-arachidonoyl-glycerol (2-AG), an endogenous ligand for the cannabinoid recepto

ALLOATTI MATIAS; FALZONE, TOMAS; FERNANDEZ BESSONE, IVAN; HOLUBIEC, MARIANA; SARGIOTTO DE RAEDEMAEKER, MARIA SOL

Workshop; Baltic Redox Workshop Greifswald; 2020

Alzheimer disease (AD) is a multifactorial neurodegenerative disease distinguished by thepresence of neuritic plaques (extracellular amyloid-β (Aβ) deposits) as well as neurofibrillarytangles (intracellular deposits of hyperphosphorylated Tau). Other changes include synaptic loss,neuronal death and astrogliosis.While neurons deal with physiological levels of reactive oxygen species (ROS), it is known thatin early stages of AD imbalances in the management of ROS occur, promoting the abnormaloxidation of macromolecules. To test the importance of increased ROS levels in the progression ofAD we developed human brain organoids from iPSC control and APP Swedish mutation (APPSwe).Regarding the cellular composition of this 3D neural tissue we found neural progenitors,different types of mature neurons, astrocytes and low amounts of olygodendrocites. We thencharacterized different AD pathological hallmarks, such as amyloid-like deposits stained withantibodies and classical Congo-red. Furthermore, we observed, in APPSwe organoids, an increase in Aβ reactive area as well as a decrease in full length APP levels by western blots andimmunostaining. In addition, we developed a technique for microinjecting organoids with viralvectors or probes in order to measure mitochondrial dynamics and morphology, superoxide anionlevels and reactive oxygen species. We found a significant increase of superoxide anion levels,measured by reactive area, in live imaging of APPSwe organoids. By immunofluorescence wedescribed an increase in Glutaredoxin 2 reactive area and integrated intensity, suggesting changes in thiol-based regulation. Our results highlight the relevance of modeling neurological diseases using complex tissue arrangements, and points to an impairment in redox pathways that, if modulated, could be used as a therapeutic strategy for treatment of abnormal oxidation in AD.