The dark side of BrdU in neural stem cell biology: detrimental effects on cell cycle, differentiation and survival
5-Bromo-2′-deoxyuridin (BrdU) is frequently used in anaylsis of neural stem cell biology, in particular to label and to fate-map dividing cells. However, up to now, only a few studies have addressed the question as to whether BrdU labeling per se affects the cells to be investigated. Here, we focused on the potential impact of BrdU on neurosphere cultures derived from the adult rat brain and on proliferation of progenitors in vivo. In vitro, neurospheres were pulsed for 48 h with BrdU, and cell proliferation, cell cycle, differentiation, survival and adhesion properties were subsequently analyzed. BrdU inhibited the expansion of neural progenitors as assessed by MTS assay and increased the fraction of cells in the G0/G1-phase of the cell cycle. Moreover, BrdU increased cell death and dose-dependently induced adherence of NPCs. Cell adherence was accompanied by a reduced amount of active matrix-metalloproteinase-2 (MMP-2). Furthermore, BrdU repressed neuronal and oligodendroglial differentiation, whereas astroglial fate was not affected. In contrast to the in vitro situation, BrdU apparently did not influence endogenous proliferation of NPCs or neurogenesis in concentrations that are typically used for labeling of neural progenitors in vivo. Our results reveal so far uncharacterized effects of BrdU on adult NPCs. We conclude that, because of its ubiquitous use in stem cell biology, any potential effect of BrdU of NPCs has to be scrutinized prior to interpretation of data.
KeywordsNeural progenitors Neurogenesis Cell culture Cell labeling Rat (Fischer 344)
- Berger S (2001) Untersuchung der Wirkung von Schwerionenstrahlen auf menschliche Hautfibroblasten unter besonderer Berücksichtigung chromosomaler Veränderungen. Dissertation, Universität MainzGoogle Scholar
- Burns TC, Ortiz-Gonzalez XR, Gutierrez-Perez M, Keene CD, Sharda R, Demorest ZL, Jiang Y, Nelson-Holte M, Soriano M, Nakagawa Y, Luquin MR, Garcia-Verdugo JM, Prosper F, Low WC, Verfaillie CM (2006) Thymidine analogs are transferred from prelabeled donor to host cells in the central nervous system after transplantation: a word of caution. Stem Cells 24:1121–1127PubMedCrossRefGoogle Scholar
- Katchanov J, Harms C, Gertz K, Hauck L, Waeber C, Hirt L, Priller J, von Harsdorf R, Bruck W, Hortnagl H, Dirnagl U, Bhide PG, Endres M (2001) Mild cerebral ischemia induces loss of cyclin-dependent kinase inhibitors and activation of cell cycle machinery before delayed neuronal cell death. J Neurosci 21:5045–5053PubMedGoogle Scholar
- Steffenhagen C, Kraus S, Dechant FX, Kandasamy M, Lehner B, Poehler AM, Furtner T, Siebzehnrubl FA, Couillard-Despres S, Strauss O, Aigner L, Rivera FJ (2011) Identity, Fate and Potential of Cells Grown as Neurospheres: Species Matters. Stem Cell Rev: Mar 24. [Epub ahead of print]Google Scholar