Daily patterns of Apo E are modified by an I.C.V injection of amyloid beta peptide in the rat temporal cortex

DELGADO, MARCELA; ANZULOVICH, ANA CECILIA; CORIA LUCERO,CINTHIA; NAVIGATORE FONZO, LORENA

Villa de Merlo

Congreso; XXXV Reunión Científica Anual de la Sociedad de Biología de Cuyo, San Luis, 2017; 2017

Alzheimer?s disease (AD) is a devastating disease characterized by synaptic and neuronal loss in the elderly. The accumulation of the β-amyloid peptide (Aβ) in the brain is thought to be central to the pathogenesis of AD. ApoE plays a key role in normal and physiological clearance of Aß, since it facilitates the peptide intra- and extracellular proteolytic degradation Besides the cognitive deficit, 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(40-42) 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 12h-light: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 injection of Aβ(40-42) 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 circadian rhythms alterations observed in AD patients.