Modelling mitochondrial dysfunction induced - aging phenotypes in human neural stem cells

QUEVEDO PROL, SOL; NIEVAS, MICAELA; MUCCI, SOFÍA; RODRÍGUEZ VARELA, MARÍA SOLEDAD; ROMORINI, LEONARDO; SCASSA, MARÍA ELIDA; SEVLEVER, GUSTAVO EMILIO; MARAZITA, MARIELA

Hinxton

Conferencia; Mitochondrial Medicine - Therapeutic Development 2022; 2022

wellcome genome campus

Cellular senescence has emerged as a driver of multiple age-related pathologies through the senescence-associated secretory phenotype. This state may be triggered by a myriad of stressors including mitochondrial dysfunction. The decline in mitochondrial function and the consequent increase in reactive oxidative species (ROS) are key features of neurodegenerative pathologies. In particular, age-associated alterations in mitochondrial function are thought to have a profound effect on neural stem cells (NSC) properties. The aim of this work was to test the effect of mitochondrial impairment on the induction of cellular senescence in a model of human NSCs. Mitochondrial dysfunction may be experimentally achieved by rotenone (ROT) which impairs mitochondrial respiration by inhibiting electron transport chain complex I, leading to ATP depletion, ROS production and loss of mitochondrial membrane potential. First, Human embryonic stem cell-derived NSCs were exposed to a ROT dose-response curve. Cell viability was assessed by flow cytometry with propidium iodide staining. Twelve days after the initial damage morphological analysis showed an increase in a flat enlarged morphology typical of senescent cells. ROT treatment led to a decrease in the proliferation rate and showed an enhanced senescence-associated β-galactosidase activity. Immunofluorescence microscopy assays revealed a change in the expression of NSCs and neurons lineage defining markers. We conclude that mitochondrial dysfunction disturbs proliferation, stemness and leads to a senescent phenotype in human NSCs. Elucidating mitochondrial-induced damage is key for understanding mechanisms underlying neurodegeneration, and will help identify novel therapeutic targets to restore neurological function.