Fig. 1

MerTK expression in human THP-1 macrophages is decreased by treatment with Aβ1-42. To measure MerTK expression in response to Aβ1-42 stimulation, THP-1 cells were incubated with either the vehicle only (−) or increasing amounts of Aβ1-42 for 8 h in serum-free RPMI 1640 medium supplemented with glucose (0.5%). a Total cell lysates were examined for MerTK protein via immunoblot. Aβ1-42 decreased MerTK in a dose-dependent manner. b THP-1 cells were also incubated with cycloheximide (CHX, 2 μM), actinomycin D (ActD, 100 nM), or Aβ1-42 (10 μM) for 8 h. Western blot analyses were conducted to determine the effect of actinomycin D or cycloheximide on MerTK expression. Levels of β-actin were examined to ensure equal amounts of total protein as a loading control. Results are representative of three independent experiments. c, d Quantitative analyses of a and b showing levels of MerTK protein. All data are presented as means ± SEM (n = 3). *P < 0.05, **P < 0.01, versus vehicle-treated samples. ActD, actinomycin; Aβ, amyloid-β; CHX, cyclohexamide, MerTK, Mer tyrosine kinase