Inflammation induces serine protease inhibitor 3 expression in the rat pineal gland.
In the rat pineal gland, prominent expression of serine protease inhibitor 3 (SPI-3) mRNA is seen after systemic injection of lipopolysaccharide. The up-regulation of SPI-3 mRNA expression is also confirmed by northern blotting. Most SPI-3 mRNA-positive cells simultaneously express synaptophysin, a marker for pinealocytes, but not glial fibrillary acidic protein, a marker for astrocytes. This indicates that SPI-3 mRNA-positive cells are pinealocytes. Almost all SPI-3 mRNA-positive cells also showed translocation of the signal transducers and activators of transcription 3 (STAT3) into nuclei after lipopolysaccharide injection. These data support previous in vitro results that SPI-3 expression is induced in a STAT3-mediated manner. In addition, the expression of ciliary neurotrophic factor receptor (CNTFR) and leukemia inhibitory factor receptor (LIFR) mRNAs, but not of interleukin 6 receptor mRNA, was up-regulated after systemic lipopolysaccharide treatment. Because these receptors are upstream of STAT3, the present results suggest that cytokines such as LIF and/or CNTF induce SPI-3 expression via STAT3 in the pineal gland in response to inflammatory stimulus. We conclude that although the functional consequences of SPI-3 in the pineal gland during systemic inflammation are unknown, SPI-3 may have a crucial role in preventing some degenerative proteolysis induced by inflammatory stimuli.
Department of Anatomy, Asahikawa Medical College, 2-1 Midorigaoka Higashi Asahikawa, Hokkaido 078-8510, Japan.
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Takamiya
M
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Takeda
A
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Yoshida
H
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Kiyama
D000209:Acute-Phase Proteins / Q000235:genetics / Q000378:metabolism*; D000818:Animals; D004268:DNA-Binding Proteins / Q000378:metabolism; D007150:Immunohistochemistry; D007249:Inflammation / Q000378:metabolism*; D053680:Leukemia Inhibitory Factor Receptor alpha Subunit; D008070:Lipopolysaccharides / Q000494:pharmacology; D008297:Male; D010870:Pineal Gland / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D020801:Receptor, Ciliary Neurotrophic Factor / Q000235:genetics; D018121:Receptors, Cytokine / Q000235:genetics; D053606:Receptors, OSM-LIF; D050796:STAT3 Transcription Factor; D015843:Serpins; D015534:Trans-Activators / Q000378:metabolism
D000209:Acute-Phase Proteins; D004268:DNA-Binding Proteins; D053680:Leukemia Inhibitory Factor Receptor alpha Subunit; C507842:Lifr protein, rat; D008070:Lipopolysaccharides; D012333:RNA, Messenger; D020801:Receptor, Ciliary Neurotrophic Factor; D018121:Receptors, Cytokine; D053606:Receptors, OSM-LIF; D050796:STAT3 Transcription Factor; C403317:Serpina3n protein, rat; D015843:Serpins; C494088:Stat3 protein, rat; D015534:Trans-Activators