Mammalian numb-interacting protein 1/dual oxidase maturation factor 1 directs neuronal fate in stem cells.
In this study, we describe a role for the mammalian Numb-interacting protein 1 (Nip1) in regulation of neuronal differentiation in stem cells. The expression of Nip1 was detected in the developing mouse brain, embryonic stem cells, primary neuronal stem cells, and retinoic acid-treated P19 embryonal carcinoma cells. The highest expression of Nip1 was observed in undifferentiated neuronal stem cells and was associated with Duox1-mediated reactive oxygen species ROS production. Ectopic nip1 expression in P19 embryonal carcinoma cells induced neuronal differentiation, and this phenotype was also linked to elevated ROS production. The neuronal differentiation in nip1-overexpressing P19 cells was achieved in a retinoic acid-independent manner and was corroborated by an increase in the expression of the neuronal basic helix-loop-helix transcription factors and neural-lineage cell markers. Furthermore, depletion of nip1 by short hairpin RNA led to a decrease in the expression of neuronal basic helix-loop-helix transcription factors and ROS. However, inhibition of ROS production in nip1-overexpressing P19 cells restricted but did not extinguish neuronal differentiation. Microarray and mass spectrometry analysis identified intermediate filaments as the principal cytoskeletal elements affected by up-regulation of nip1. We show here the first evidence for a functional interaction between Nip1 and a component of the nuclear lamina, lamin A/C. associated with a neuronal-specific phenotype. Taken together, our data reveal an important role for Nip1 in the guidance of neuronal differentiation through ROS generation and modulation of intermediate filaments and implicate Nip1 as a novel intrinsic regulator of neuronal cell fate.
Department of Biochemistry, Siebens-Drake Medical Research Institute, Schulich School of Medicine and Dentistry, University of Western Ontario, London, Ontario N6A 5C1, Canada.
Karen A M
KA
Kennedy
Elena A
EA
Ostrakhovitch
Shelley D E
SD
Sandiford
Thamara
T
Dayarathna
Xiaojun
X
Xie
Elaine Y L
EY
Waese
Wing Y
WY
Chang
Qingping
Q
Feng
Ilona S
IS
Skerjanc
William L
WL
Stanford
Shawn S C
SS
Li
D000818:Animals; D001921:Brain / Q000378:metabolism; D045744:Cell Line, Tumor; D019070:Cell Lineage; D003599:Cytoskeleton / Q000378:metabolism; D000074623:Dual Oxidases; D034904:Lamin Type A / Q000737:chemistry; D051379:Mice; D019255:NADPH Oxidases / Q000378:metabolism*; D009474:Neurons / Q000378:metabolism*; D039502:Nuclear Cap-Binding Protein Complex / Q000378:metabolism; D010641:Phenotype; D034741:RNA, Small Interfering / Q000378:metabolism; D017382:Reactive Oxygen Species; D013234:Stem Cells / Q000166:cytology* / Q000378:metabolism
D034904:Lamin Type A; D039502:Nuclear Cap-Binding Protein Complex; D034741:RNA, Small Interfering; D017382:Reactive Oxygen Species; C440308:lamin C; D000074623:Dual Oxidases; D019255:NADPH Oxidases; C519130:Duox1 protein, mouse