AUTHOR=Lomniczi Alejandro , Luna Selva L. , Cervera-Juanes Rita , Appleman Maria-Luisa , Kohama Steven G. , Urbanski Henryk F. TITLE=Age-related increase in the expression of 11β-hydroxysteroid dehydrogenase type 1 in the hippocampus of male rhesus macaques JOURNAL=Frontiers in Aging Neuroscience VOLUME=Volume 16 - 2024 YEAR=2024 URL=https://www.frontiersin.org/journals/aging-neuroscience/articles/10.3389/fnagi.2024.1328543 DOI=10.3389/fnagi.2024.1328543 ISSN=1663-4365 ABSTRACT=The hippocampus is especially susceptible to age-associated neuronal pathologies, and there is concern that the age-associated rise in cortisol secretion from the adrenal gland may contribute to their etiology. Furthermore, because 11β-hydroxysteroid dehydrogenase type 1 (HSD11B1) catalyzes the reduction of cortisone to the active hormone cortisol, it is plausible that an increase in the expression of this enzyme enhances the deleterious impact of cortisol in the hippocampus and contributes to the neuronal pathologies that underlie cognitive decline in the elderly.Methods: Rhesus macaques were used as a translational animal model of human aging, to examine age-related changes in gene and protein expressions of (HSD11B1/HSD11B1) in the hippocampus, a region of the brain that plays a crucial role in learning and memory.Results: Older animals showed significantly (p<0.01) higher base-line cortisol levels in the circulation. In addition, they showed significantly (p<0.05) higher hippocampal expression of HSD11B1 but not NR3C1 and NR3C2 (i.e., two receptor-encoding genes through which cortisol exerts its physiological actions). A similar age-related significant (p<0.05) increase in the expression of the HSD11B1 was revealed at the protein level by Western blot analysis.