P4-189: significance of carotenoids in red blood cells of alzheimer's disease patients

Red blood cells (RBC) of Alzheimer's disease (AD) patients are known to be in an excessively oxidized state (i.e., with a high accumulation of peroxidized phospholipids (PLOOH)). Previously we confirmed in vitro, in vivo murine, and in human studies that carotenoids can effectively inhibit accumulation of RBC PLOOH. Thus, the relationship between RBC carotenoids and PLOOH concentrations in AD patients is of interest. In this study, RBC carotenoids and PLOOH were evaluated in 28 normal control subjects (age: 74.1 ± 1.3 years) and 28 patients with AD (age: 72.5 ± 1.4 years). The concentrations of RBC carotenoids, especially lutein, in AD patients were significantly lower than in control subjects. An inverse relationship was seen between RBC carotenoids, especially lutein, and PLOOH concentrations in AD patients. These results suggest that RBC lutein, in particular, may contribute to suppression of PLOOH accumulation in RBC of AD patients1). In addition, results of amyloid beta2) and our new approaches for biomarker research using microRNAs3) will be presented. 1) Kiko T, Nakagawa K, Tsuduki T, Suzuki T, Arai H, Miyazawa T. Significance of lutein in red blood cells of Alzheimer's disease patients. J. Alzheimers Dis., 28, 593-600 (2012). 2) Kiko T, Nakagawa K, Satoh A, Tsuduki T, Furukawa K, Arai H, Miyazawa T. Amyloid β levels in human red blood cells. PLoS One. 7, e49620 (2012). 3) Kiko T, Nakagawa K, Tsuduki T, Furukawa K, Arai H, Miyazawa T. MicroRNAs in plasma and cerebrospinal fluid as potential markers for Alzheimer's disease. J. Alzheimers Dis., 39, 253-259 (2014).