TY - JOUR
T1 - Role of protein kinase C activity in tumor necrosis factor-α gene expression
T2 - Involvement at the transcriptional level
AU - Il Yup Chung, Yup Chung
AU - Kwon, J.
AU - Benveniste, E. N.
PY - 1992
Y1 - 1992
N2 - Primary rat astrocytes express TNF-α protein in response to various stimuli including a combined treatment with IFN-γ and LPS, or IFN-γ and IL- 1β. This study was undertaken to further elucidate the mechanisms underlying TNF-α gene expression in the astrocyte, and to determine the intracellular signaling pathways involved in IFN-γ/LPS and/or IFN-γ/IL-1β induction of the TNF-α gene. We demonstrate that TNF-α mRNA is rapidly induced, and mRNA levels peak after 2 h of stimulation. De novo protein synthesis is not required for TNF-α expression because the inclusion of cycloheximide does not prevent expression of the gene and acts to superinduce TNF-α mRNA levels. IFN-γ/LPS induces transcriptional activation of the TNF-α gene as assessed by nuclear run-on experiments. Cycloheximide acts to increase both transcription of the TNF-α gene and stability of TNF-α mRNA thereby resulting in increased TNF-α steady state mRNA levels. Two protein kinase C (PKC) inhibitors, H7 and staurosporine, abrogate IFN-γ/LPS- and IFN-γ/IL- 1β-induced TNF-α expression in a dose-dependent manner. PKC activity is required for transcription of the TNF-α gene, and does not appear to be involved in TNF-α mRNA stabilization. Taken together, these data demonstrate that TNF-α gene expression in primary rat astrocytes is induced in a PKC- dependent manner.
AB - Primary rat astrocytes express TNF-α protein in response to various stimuli including a combined treatment with IFN-γ and LPS, or IFN-γ and IL- 1β. This study was undertaken to further elucidate the mechanisms underlying TNF-α gene expression in the astrocyte, and to determine the intracellular signaling pathways involved in IFN-γ/LPS and/or IFN-γ/IL-1β induction of the TNF-α gene. We demonstrate that TNF-α mRNA is rapidly induced, and mRNA levels peak after 2 h of stimulation. De novo protein synthesis is not required for TNF-α expression because the inclusion of cycloheximide does not prevent expression of the gene and acts to superinduce TNF-α mRNA levels. IFN-γ/LPS induces transcriptional activation of the TNF-α gene as assessed by nuclear run-on experiments. Cycloheximide acts to increase both transcription of the TNF-α gene and stability of TNF-α mRNA thereby resulting in increased TNF-α steady state mRNA levels. Two protein kinase C (PKC) inhibitors, H7 and staurosporine, abrogate IFN-γ/LPS- and IFN-γ/IL- 1β-induced TNF-α expression in a dose-dependent manner. PKC activity is required for transcription of the TNF-α gene, and does not appear to be involved in TNF-α mRNA stabilization. Taken together, these data demonstrate that TNF-α gene expression in primary rat astrocytes is induced in a PKC- dependent manner.
UR - http://www.scopus.com/inward/record.url?scp=0027057262&partnerID=8YFLogxK
M3 - Article
C2 - 1460280
AN - SCOPUS:0027057262
SN - 0022-1767
VL - 149
SP - 3894
EP - 3902
JO - Journal of Immunology
JF - Journal of Immunology
IS - 12
ER -