Effect of memantine on Klk7‐dependent Aβ degradation activity Effect of memantine on Klk7‐dependent Aβ degradation activity A, BEffect of memantine in human Aβ spike experiment. Primary neuron culture or neuron and glia coculture were treated with or without 30 μM of memantine (Mem) at DIV8. 30 nM of synthetic human Aβ42 peptide was spiked to these cultures. Levels of remaining human Aβ42 at days in vitro measured by human Aβ‐specific sandwich enzyme immunosorbent assay are shown in (B) (n = 6, mean ± s.e.m., ***P < 0.001 by Student's t‐test).CRelative levels of Klk5, Klk6, Klk7, and Spink5 mRNA in the brains of memantine (Mem)‐treated female Tg2576 mice (n = 5 or 4, mean ± s.e.m., *P < 0.05 by Student's t‐test). Veh, vehicle.DEffect of 30 μM memantine or 10 μM MK‐801 on Klk7 mRNA expression in primary astrocytes obtained from wild‐type mice (n = 5 or 6, mean ± s.e.m., **P < 0.01 by Tukey's test).EEffect of 20 μM l‐glutamate or 50 μM N‐methyl‐d‐aspartate on Klk7 mRNA expression in primary astrocytes obtained from wild‐type mice (n = 5 or 6, mean ± s.e.m., **P < 0.01 and ***P < 0.001 by Tukey's test).FEffect of 30 μM memantine on Aβ degradation activity in the conditioned medium of primary astrocytes obtained from wild‐type or Klk7−/− mice. Remaining Aβ40 and Aβ42 are quantified (n = 4, mean ± s.e.m., *P < 0.05, **P < 0.01 by Student's t‐test). Kiwami Kidana et al. EMBO Mol Med. 2018;emmm.201708184 © as stated in the article, figure or figure legend