Glucocorticoid hormones (GHs) regulate cell proliferation of neural progenitor cells (NPCs) contributing to reduction of neurogenesis after stress. We show here that dexamethasone (Dex) decreases BRUCE/Apollon (BRUCE) in cultured NPCs in a GH-receptor-dependent manner. Downregulation of BRUCE by Dex or using silencing RNA reduced the number of proliferating NPCs, whilst overexpression of BRUCE counteracted the effect of Dex. Dex also elevated the deubiquitinating enzyme, Usp8/Ubpy, which via Nrdp1 decreases BRUCE. The results show that BRUCE is a target for GHs in the NPCs, and that BRUCE controls cell division of NPCs and possibly of other stem cells. Structured summary: MINT-7148564: Nrdp1 (uniprotkb: Q8BH75) physically interacts (MI: 0914) with BRUCE (uniprotkb: O88738) by anti bait co-immunoprecipitation (MI: 0006) MINT-7148555: Nrdp1 (uniprotkb: Q8BH75) physically interacts (MI: 0914) with Usp8 (uniprotkb: Q80U87) by anti bait co-immunoprecipitation (MI: 0006) (C) 2009 Federation of European Biochemical Societies. Published by Elsevier B. V. All rights reserved.