TY - JOUR
T1 - Involvement of PU.1 in the transcriptional regulation of TNF-α
AU - Fukai, Tatsuo
AU - Nishiyama, Chiharu
AU - Kanada, Shunsuke
AU - Nakano, Nobuhiro
AU - Hara, Mutsuko
AU - Tokura, Tomoko
AU - Ikeda, Shigaku
AU - Ogawa, Hideoki
AU - Okumura, Ko
N1 - Funding Information:
We are grateful to members of Atopy Research Center, Department of Immunology, and Department of Dermatology for helpful discussions. We thank Drs. Atsushi Takagi, Yusuke Niwa, Naomi Shimokawa, Qing-hui Wang, Nao Kitamura, and Mr. Hokuto Yokoyama for critical advice and support in experiments, and Ms. Michiyo Matsumoto for secretarial assistance. This study was supported in part by a Grant-in-aid for Scientific Research (C) (C.N.) from the Ministry of Education, Culture, Sports, Science, and Technology of Japan.
PY - 2009/10/9
Y1 - 2009/10/9
N2 - PU.1 is a myeloid- and lymphoid-specific transcription factor that serves many important roles in the development and specific gene regulation of hematopoietic lineages. Mast cells (MC) and dendritic cells (DC) express PU.1 at low and high levels, respectively. Previously, we found that enforced expression of PU.1 in MC resulted in acquisition of DC-like characteristics, including repression of several IgE-mediated responses due to reduced expression of IgE-signaling related molecules. In contrast, PU.1 overexpression in MC up-regulated TNF-α production in response to IgE- and LPS-stimulation suggesting that PU.1 positively regulates TNF-α expression. However, the role of PU.1 in the expression of TNF-α is largely unknown. In the present study, the effects of PU.1 on the TNF-α promoter in mouse bone marrow-derived (BM) MC and DC were studied. Real-time PCR, ELISA, and chromatin immunoprecipitation assays indicated that the kinetics and magnitude of TNF-α expression levels following LPS- or IgE-stimulation are related to the amount of PU.1 binding to the promoter. In brief, higher and delayed up-regulation of TNF-α promoter function was observed in DC, whereas there were lower and rapid responses in MC. When PU.1-overexpressing retrovirus vector was introduced into MC, the amount of PU.1 recruited to the TNF-α promoter markedly increased. The knockdown of PU.1 in BMDC by siRNA resulted in a reduction of TNF-α protein produced from LPS-stimulated BMDC. These observations indicate that PU.1 transactivates the TNF-α promoter and that the amount of PU.1 binding on the promoter is associated with promoter activity.
AB - PU.1 is a myeloid- and lymphoid-specific transcription factor that serves many important roles in the development and specific gene regulation of hematopoietic lineages. Mast cells (MC) and dendritic cells (DC) express PU.1 at low and high levels, respectively. Previously, we found that enforced expression of PU.1 in MC resulted in acquisition of DC-like characteristics, including repression of several IgE-mediated responses due to reduced expression of IgE-signaling related molecules. In contrast, PU.1 overexpression in MC up-regulated TNF-α production in response to IgE- and LPS-stimulation suggesting that PU.1 positively regulates TNF-α expression. However, the role of PU.1 in the expression of TNF-α is largely unknown. In the present study, the effects of PU.1 on the TNF-α promoter in mouse bone marrow-derived (BM) MC and DC were studied. Real-time PCR, ELISA, and chromatin immunoprecipitation assays indicated that the kinetics and magnitude of TNF-α expression levels following LPS- or IgE-stimulation are related to the amount of PU.1 binding to the promoter. In brief, higher and delayed up-regulation of TNF-α promoter function was observed in DC, whereas there were lower and rapid responses in MC. When PU.1-overexpressing retrovirus vector was introduced into MC, the amount of PU.1 recruited to the TNF-α promoter markedly increased. The knockdown of PU.1 in BMDC by siRNA resulted in a reduction of TNF-α protein produced from LPS-stimulated BMDC. These observations indicate that PU.1 transactivates the TNF-α promoter and that the amount of PU.1 binding on the promoter is associated with promoter activity.
KW - Dendritic cells
KW - Mast cells
KW - PU.1
KW - TNF-α
KW - Transcription factor
UR - http://www.scopus.com/inward/record.url?scp=68949131064&partnerID=8YFLogxK
U2 - 10.1016/j.bbrc.2009.07.126
DO - 10.1016/j.bbrc.2009.07.126
M3 - Article
C2 - 19646961
AN - SCOPUS:68949131064
SN - 0006-291X
VL - 388
SP - 102
EP - 106
JO - Biochemical and Biophysical Research Communications
JF - Biochemical and Biophysical Research Communications
IS - 1
ER -