Tieg1/Klf10 is upregulated by NGF and attenuates cell cycle progression in the pheochromocytoma cell line PC12.
The transcription factor Tieg1/Klf10 belongs to a family of Sp1/Klf proteins that have been shown to play important roles during development and maintenance of various tissues and cell types. Upregulation of Tieg1/Klf10 has been reported for TGF-beta, BMP2, BMP4, ActivinA and GDNF as members of the TGF-beta superfamily. Moreover, estrogen, the cytostatic drugs homoharringtonine and velcade as well as nitric oxide are also able to trigger Tieg1/Klf10 transcription. Recent studies suggest a role for members of the neurotrophin family in regulating Tieg1/Klf10 transcriptional upregulation. Using semi-quantitative RT-PCR and immunoblotting, we present data describing that nerve growth factor (NGF) regulates the expression of Tieg1/Klf10 in the pheochromocytoma cell line PC12 in a TrkA-dependent manner. Moreover, we provide evidence for the existence of NGF-responsive elements in the 5'-regulatory region of Tieg1/Klf10 that contain binding sites for the transcription factors Sp1 and CREB. After treatment with NGF PC12 cells exit the cell cycle and start to differentiate towards a neuron-like phenotype indicated by neurite outgrowth. Using flow cytometry and differentiation assays we demonstrate that Tieg1/Klf10 reduces cell cycle progression in PC12 cells but fails to promote their terminal differentiation. Together, our results identify Tieg1/Klf10 as a new NGF target gene and substantiate its anti-proliferative function in the NGF signaling pathway in PC12 cells.
Spittau
Gabriele
G
Department of Molecular Embryology, Institute of Anatomy & Cell Biology, University of Freiburg, 17, 79104 Freiburg, Germany.
Happel
Nicole
N
Behrendt
Maik
M
Chao
T Ivo
TI
Krieglstein
Kerstin
K
Spittau
Björn
B
D000818:Animals; D001483:Base Sequence; D002453:Cell Cycle / Q000502:physiology*; D002454:Cell Differentiation / Q000502:physiology; D049108:Cell Enlargement; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D005434:Flow Cytometry; D015151:Immunoblotting; D020932:Nerve Growth Factor / Q000378:metabolism*; D016501:Neurites / Q000502:physiology; D055495:Neurogenesis / Q000502:physiology; D009474:Neurons / Q000502:physiology; D016716:PC12 Cells; D051381:Rats; D020917:Receptor, trkA / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*; D014158:Transcription, Genetic; D015854:Up-Regulation
D004268:DNA-Binding Proteins; C491385:Klf10 protein, rat; D014157:Transcription Factors; D020932:Nerve Growth Factor; D020917:Receptor, trkA