Authors
Gary W. Arendash1, 2, Takashi Mori3, Chuanhai Cao1, 2, 4, Malgorzata Mamcarz1, 2, Melissa Runfeldt1, 2, Alexander Dickson1, 2, Kavon Rezai-Zadeh5, Jun Tan5, Bruce A. Citron6, 7, Xiaoyang Lin1, 4, Valentina Echeverria6, 7, Huntington Potter1, 2, 4, 8
1Florida Alzheimer's Disease Research Center, University of South Florida, Tampa, FL, USA
2Department of Cell Biology, Microbiology, and Molecular Biology, University of South Florida, Tampa, FL, USA
3Departments of Medical Science and Pathology, Saitama Medical Center and Saitama Medical University, Kawagoe, Saitama, Japan
4The Byrd Alzheimer's Center and Research Institute, Tampa, FL, USA
5Department of Psychiatry and Behavioral Medicine, University of South Florida, Tampa, FL, USA
6Department of Molecular Medicine, University of South Florida, Tampa, FL, USA
7Bay Pines VA Healthcare System, Bay Pines, FL, USA
8Suncoast Gerontology and Alzheimer's Center, University of South Florida College of Medicine, Tampa, FL, USA
Abstract
We have recently shown that Alzheimer's disease (AD) transgenic mice given a moderate level of caffeine intake (the human equivalent of 5 cups of coffee per day) are protected from development of otherwise certain cognitive impairment and have decreased hippocampal amyloid-β (Aβ) levels due to suppression of both β-secretase (BACE1) and presenilin 1 (PS1)/γ-secretase expression. To determine if caffeine intake can have beneficial effects in "aged" APPsw mice already demonstrating cognitive impairment, we administered caffeine in the drinking water of 18–19 month old APPsw mice that were impaired in working memory. At 4–5 weeks into caffeine treatment, those impaired transgenic mice given caffeine (Tg/Caff) exhibited vastly superior working memory compared to the continuing impairment of control transgenic mice. In addition, Tg/Caff mice had substantially reduced Aβ deposition in hippocampus (↓ 40% and entorhinal cortex (↓46%), as well as correlated decreases in brain soluble Aβ levels. Mechanistically, evidence is provided that caffeine suppression of BACE1 involves the cRaf-1/NFκB pathway. We also determined that caffeine concentrations within human physiological range effectively reduce active and total glycogen synthase kinase 3 levels in SweAPP N2a cells. Even with pre-existing and substantial Aβ burden, aged APPsw mice exhibited memory restoration and reversal of AD pathology, suggesting a treatment potential of caffeine in cases of established AD.
Keywords
Alzheimer's disease, Alzheimer's transgenic mice, amyloid-β, caffeine, cognitive impairment, memory, treatment
