TY - JOUR
T1 - Regulation of Spi 2.1 and 2.2 gene expression after turpentine inflammation
T2 - Discordant responses to IL-6
AU - Berry, Susan A.
AU - Bergad, Pearl L.
AU - Stolz, Allison M.
AU - Towle, Howard C.
AU - Schwarzenberg, Sarah Jane
PY - 1999
Y1 - 1999
N2 - The rat serine protease inhibitor (Spi) 2 gene family includes both positive (Spi 2.2) and negative (Spi 2.1) acute phase reactants, facilitating modeling of regulation of hepatic acute phase response (APR). To examine the role of signal transducer and activation of transcription (STAT) proteins in the divergent regulation of these model genes after induction of APR, we evaluated the proximal promoters of the genes, focusing on STAT binding sites contained in these promoter elements. Induction of APR by turpentine injection includes activation of a STAT3 complex that can bind to a γ- activated sequence (GAS) in the Spi 2.2 gene promoter, although the Spi 2.2 GAS site can bind STAT1 or STAT5 as well. To create an in vitro model of APR, primary hepatocytes were treated with combinations of cytokines and hormones to mimic the hormonal milieu of the whole animal after APR induction. Incubation of primary rat hepatocytes with interleukin (IL)-6, a critical APR cytokine, leads to activation of STAT3 and a 28-fold induction of a chloramphenicol acetyltransferase reporter construct containing the -319 to +85 region of the Spi 2.2 promoter. This suggests the turpentine-induced increase of Spi 2.2 is mediated primarily by IL-6. In contrast, although turpentine treatment reduces Spi 2.1 mRNA in vivo and IL-6 does hot increase Spi 2.1 mRNA in primary rat hepatocytes, treatment of hepatocytes with IL-6 results in a 5.4-fold induction of Spi 2.1 promoter activity mediated through the paired GAS elements in this promoter. Differential regulation of Spi 2.1 and 2.2 genes is due in part to differences in the promoters of these genes at the GAS sites. IL-6 alone fails to reproduce the pattern of rat Spi 2 gene expression that results from turpentine-induced inflammation.
AB - The rat serine protease inhibitor (Spi) 2 gene family includes both positive (Spi 2.2) and negative (Spi 2.1) acute phase reactants, facilitating modeling of regulation of hepatic acute phase response (APR). To examine the role of signal transducer and activation of transcription (STAT) proteins in the divergent regulation of these model genes after induction of APR, we evaluated the proximal promoters of the genes, focusing on STAT binding sites contained in these promoter elements. Induction of APR by turpentine injection includes activation of a STAT3 complex that can bind to a γ- activated sequence (GAS) in the Spi 2.2 gene promoter, although the Spi 2.2 GAS site can bind STAT1 or STAT5 as well. To create an in vitro model of APR, primary hepatocytes were treated with combinations of cytokines and hormones to mimic the hormonal milieu of the whole animal after APR induction. Incubation of primary rat hepatocytes with interleukin (IL)-6, a critical APR cytokine, leads to activation of STAT3 and a 28-fold induction of a chloramphenicol acetyltransferase reporter construct containing the -319 to +85 region of the Spi 2.2 promoter. This suggests the turpentine-induced increase of Spi 2.2 is mediated primarily by IL-6. In contrast, although turpentine treatment reduces Spi 2.1 mRNA in vivo and IL-6 does hot increase Spi 2.1 mRNA in primary rat hepatocytes, treatment of hepatocytes with IL-6 results in a 5.4-fold induction of Spi 2.1 promoter activity mediated through the paired GAS elements in this promoter. Differential regulation of Spi 2.1 and 2.2 genes is due in part to differences in the promoters of these genes at the GAS sites. IL-6 alone fails to reproduce the pattern of rat Spi 2 gene expression that results from turpentine-induced inflammation.
KW - Acute phase response
KW - Janus kinase-STAT pathway
KW - STAT3
KW - STAT5
KW - Serpin
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UR - http://www.scopus.com/inward/citedby.url?scp=0033067640&partnerID=8YFLogxK
U2 - 10.1152/ajpcell.1999.276.6.c1374
DO - 10.1152/ajpcell.1999.276.6.c1374
M3 - Article
C2 - 10362600
AN - SCOPUS:0033067640
SN - 0363-6143
VL - 276
SP - C1374-C1382
JO - American Journal of Physiology - Cell Physiology
JF - American Journal of Physiology - Cell Physiology
IS - 6 45-6
ER -