Aging process alters hippocampal and cortical secretase activities of Wistar rats

作者:Bertoldi Karine; Cechinel Laura Reck; Schallenberger Bruna; Meireles Louisiana; Basso Carla; Lovatel Gisele Agustini; Bernardi Lisiane; Lamers Marcelo Lazzaron; Siqueira Ionara Rodrigues
来源:Behavioural Brain Research, 2017, 317: 374-381.
DOI:10.1016/j.bbr.2016.09.066

摘要

A growing body of evidence has demonstrated amyloid plaques in aged brain; however, little attention has been given to amyloid precursor protein (APP) processing machinery during the healthy aging process. The amyloidogenic and non-amyloidogenic pathways, represented respectively by beta- and alpha-secretases (BACE and TACE), are responsible for APP cleavage. Our working hypothesis is that the normal aging process could imbalance amyloidogenic and non-amyloidogenic pathways specifically BACE and TACE activities. Besides, although it has been showed that exercise can modulate secretase activities in Alzheimer Disease models the relationship between exercise effects and APP processing during healthy aging process is rarely studied. Our aim was to investigate the aging process and the exercise effects on cortical and hippocampal BACE and TACE activities and aversive memory performance. Young adult and aged Wistar rats were subjected to an exercise protocol (20 min/day for 2 weeks) and to inhibitory avoidance task. Biochemical parameters were evaluated 1 h and 18 h after the last exercise session in order to verify transitory and delayed exercise effects. Aged rats exhibited impaired aversive memory and diminished cortical TACE activity. Moreover, an imbalance between TACE and BACE activities in favor of BACE activity was observed in aged brain. Moderate treadmill exercise was unable to alter secretase activities in any brain areas or time points evaluated. Our results suggest that aging-related aversive memory decline is partly linked to decreased cortical TACE activity. Additionally, an imbalance between secretase activities can be related to the higher vulnerability to neurodegenerative diseases induced by aging.

  • 出版日期2017-1-15