Effect of Conversion Cocktail on Astrocyte and Neuronal Status in the Primary Hippocampal Culture of 5xFAD Mice with Angiotensin-Converting Enzyme 2 Inhibition

Neurodegenerative diseases are intricate pathological conditions characterized by the progressive degeneration and death of neurons in the nervous system. As a result, researchers are increasingly focusing on strategies that use combinations of bioactive chemical compounds to convert other, more stable cell types into functional neurons. Chemical conversion has shown particular promise in astrocyte-only models; however, more realistic experimental systems include different cell types whose interactions may influence the response to chemical conversion. In this study, we investigated the effect of a multicomponent chemical cocktail on cells in mixed astro-neuronal cultures derived from the hippocampus of transgenic mice of the 5xFAD strain, a genetic model of Alzheimer’s disease (AD). In addition, we recreated a model that simulates the reduction in ACE2 receptor activity observed in COVID-19 patients due to internalization of the receptor after it binds to the coronavirus, in order to study the consequences of chemical conversion upon disruption of this enzyme activity in the brain. Our results indicate that the increase in neuronal density and the emergence of new neurons following exposure to the conversion cocktail in complex multi-component cell systems is apparent at later time points in cultures derived from non-transgenic animals as well as in cultures derived from the 5xFAD mice. This may be due to the natural increase in astroglial levels during culture degradation. Notably, ACE2 inhibition significantly affects the morphology of individual astrocytes and neurons. When we evaluated the effects of the chemical cocktail, we observed that its efficacy was influenced by both the transgenic status of the culture and the timing of the conversion cocktail administration in relation to ACE2 inhibition. Cultures derived from transgenic animals were more sensitive to both the ACE2 inhibitor and the chemical conversion agents.