DAILY PATTERNS OF APO E ARE MODIFIED BY AN I.C.V. INJECTION OF AMYLOID BETA PEPTIDE IN THE RAT TEMPORAL CORTEX

CORIA LUCERO, C; DELGADO SM; ANZULOVICH AC; NAVIGATORE FONZO LS

Merlo, San Luis

Congreso; XXXV Reunión Anual de la Sociedad de Biología de Cuyo; 2017

Alzheimer?s disease (AD) is a devastating disease characterized by loss of synaptic and neural cells in the elderly. Accumulation of theβ-amyloid peptide (Aβ) in the brain is thought to be central to the pathogenesis of AD. ApoE plays a key role in normal andphysiological clearance of Aß, since it facilitates the peptide intra- and extracellular proteolytic degradation. Besides the cognitivedeficit, AD patients also show alterations in their circadian rhythms. The objective of this study was to investigate the effects of an i.c.v.injection of Aβ (1-42) peptide on the 24h rhythms of Apo E, BMAL1, RORa and Aβ in the rat temporal cortex. Four-month-old males Holtzman rats were used in this study. Groups were defined as: control (CO) and Aβ-injected (Aβ). Rats were maintained under 12hlight:12h-dark conditions before the sacrifice. Apo E, BMAL, RORa, and Aβ protein were analyzed by immunoblotting, in temporal cortex samples isolated every 6 h throughout a 24h period. We found that i.c.v. injection of Aβ (1-42) phase shifted ApoE, BMAL 1, RORa and Aβ daily rhythms in the rat cortex. These findings might constitute, at least in part, molecular and biochemical basis of altered daily beta clearance in AD.