title: Cholesterol Efflux Capacity of Apolipoprotein A-I Varies with the Extent of Differentiation and Foam Cell Formation of THP-1 Cells.
abstract: Apolipoprotein A-I (apoA-I), the main protein component of high-density lipoprotein (HDL), has many protective functions against atherosclerosis, one of them being cholesterol efflux capacity. Although cholesterol efflux capacity measurement is suggested to be a key biomarker for evaluating the risk of development of atherosclerosis, the assay has not been optimized till date. This study aims at investigating the effect of different states of cells on the cholesterol efflux capacity. We also studied the effect of apoA-I modification by homocysteine, a risk factor for atherosclerosis, on cholesterol efflux capacity in different states of cells. The cholesterol efflux capacity of apoA-I was greatly influenced by the extent of differentiation of THP-1 cells and attenuated by excessive foam cell formation.N-Homocysteinylated apoA-I indicated a lower cholesterol efflux capacity than normal apoA-I in the optimized condition, whereas no significant difference was observed in the cholesterol efflux capacity between apoA-I in the excessive cell differentiation or foam cell formation states. These results suggest that cholesterol efflux capacity of apoA-I varies depending on the state of cells. Therefore, the cholesterol efflux assay should be performed using protocols optimized according to the objective of the experiment.
authors.affiliation: Analytical Laboratory Chemistry, Field of Applied Laboratory Science, Graduate School of Health Care Sciences, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo 113-8519, Japan.
authors.forename: Kouji
authors.initials: K
authors.lastname: Yano
authors.affiliation: Analytical Laboratory Chemistry, Field of Applied Laboratory Science, Graduate School of Health Care Sciences, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo 113-8519, Japan.
authors.forename: Ryunosuke
authors.identifier: 0000-0002-8584-133X
authors.initials: R
authors.lastname: Ohkawa
authors.affiliation: Analytical Laboratory Chemistry, Field of Applied Laboratory Science, Graduate School of Health Care Sciences, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo 113-8519, Japan.
authors.forename: Megumi
authors.initials: M
authors.lastname: Sato
authors.affiliation: Analytical Laboratory Chemistry, Field of Applied Laboratory Science, Graduate School of Health Care Sciences, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo 113-8519, Japan.
authors.forename: Akira
authors.initials: A
authors.lastname: Yoshimoto
authors.affiliation: Analytical Laboratory Chemistry, Field of Applied Laboratory Science, Graduate School of Health Care Sciences, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo 113-8519, Japan.
authors.forename: Naoya
authors.initials: N
authors.lastname: Ichimura
authors.affiliation: Department of Medical Technology, School of Health Sciences, Tokyo University of Technology, 5-23-22 Nishi-Kamata, Ohta-ku, Tokyo 144-8535, Japan.
authors.forename: Takahiro
authors.initials: T
authors.lastname: Kameda
authors.affiliation: Microbiology and Immunology, Field of Applied Laboratory Science, Graduate School of Health Care Sciences, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo 113-8519, Japan.
authors.forename: Tetsuo
authors.initials: T
authors.lastname: Kubota
authors.affiliation: Analytical Laboratory Chemistry, Field of Applied Laboratory Science, Graduate School of Health Care Sciences, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo 113-8519, Japan.
authors.forename: Minoru
authors.identifier: 0000-0001-7366-1262
authors.initials: M
authors.lastname: Tozuka