Identification of glutamate-related disease-dependent alterations in subventricular NSCs of the 3xTg Alzheimer's disease model, could they be involved in attempting damage repair?

Alzheimer's disease (AD) is an age-related neurodegenerative disorder characterised by several factors, such as impaired glutamate neurotransmission affecting crucial functions. Neural stem cells (NSCs) are present in the adult brains of all mammalian species and contribute to the continuous generation of neural cells throughout life. The disruption of glutamate levels during the development of AD could impact NSCs' functionality, influencing their response to the microenvironment. In this work, we isolated adult neural stem cells from both triple transgenic (3xTg)-AD mice and age-matched wild type (WT) mice in order to gather information on any differences between them, particularly concerning the potential mechanisms involved in the internalisation of glutamate and its utilisation for energy production. The 3xTg model offers the ability to recapitulate human pathology with both plaque and tangle hallmarks that are involved in the process of glutamate release. In vitro culture 3xTg NSCs showed a slight morphological difference compared to WT cells and a massive reduction of proliferation and viability. Furthermore, 3xTg NSCs displayed an increase in the expression of glutamate transporters and glutamine synthetase, while glutamate dehydrogenase did not show any reduction, which is typical in AD brains. Data obtained from this basic research study suggest a possible involvement of glutamate in the cellular energy balance, indicating an attempted response of NSCs to the cytotoxic microenvironment in the early stage of AD pathology. This finding is of great interest, as it corroborates the hypothesis that targeting the glutamatergic system could be an extremely promising strategy for new therapeutics in AD.