HEME OXYGENASE-1 AND BRAIN OXYSTEROLS METABOLISM ARE LINKED TO EGR-1 EXPRESSION IN AGED MICE CORTEX, BUT NOT IN HIPPOCAMPUS

Abstract

Age is the main risk factor for many pathologies, neurodegenerative disorders included. With theworld population getting older, aging will represent the disease of the future leaving an increasing need tounderstand the molecular basis of this process in normal and pathological conditions. Egr-1 (early growthresponse 1) is a transcriptional factor rapidly induced by many stress stimuli and it is involved in cellsurvival, proliferation and differentiation, as well as in memory, cognition and synaptic plasticity. Anothermolecule with neuroprotective properties is HO-1 (heme oxygenase-1), which converts heme to iron,carbon monoxide and biliverdin and it was shown to regulate the metabolism of oxysterols (derivatives ofcholesterol oxidation) which represent new markers of oxidative stress. The only evidence of a link betweenEgr-1 and HO-1 was described in mouse lung cells exposed to cigarettes smoke. The aim of this study wasto investigate whether Egr-1 can be implicated in oxysterol metabolism during brain aging.