Modulation of type I interleukin-1 receptor messenger RNA followed by one and repeated endotoxin treatment in the mouse

• Published in: Journal of neuroimmunology 2000-06, Vol.105 (2), p.154-160
• Main Authors: Nagano, Isao, Takao, Toshihiro, Nanamiya, Wakako, Hashimoto, Kozo
• Format: Article
• Language: English
• Subjects: Adrenal gland; Adrenal Glands - metabolism; Animals; Gene Expression Regulation - drug effects; Hippocampus; Hippocampus - metabolism; Hypothalamus - metabolism; interleukin 1 receptors; Interleukin-1 receptor; Lipopolysaccharide; Lipopolysaccharides - pharmacology; Male; Mice; Mice, Inbred C57BL; Pituitary Gland - metabolism; Receptors, Interleukin-1 - genetics; RNA, Messenger - analysis; RT-PCR; Testis; Testis - metabolism
• ISSN: 0165-5728; 1872-8421
• DOI: 10.1016/S0165-5728(00)00206-X

The expression of transcripts for type 1 interleukin-1 receptors (IL-1R1) were investigated utilizing reverse transcription-polymerase chain reaction (RT-PCR) techniques in male C57BL/6 mice. First, we measured IL-1R1 mRNA 1, 2, 6, and 12 h after a single injection of endotoxin lipopolysaccharide (LPS; 30 μg/mouse). IL-1R1 mRNA was measured in relevant tissues utilizing semiquantitative RT-PCR. IL-1R1 mRNA levels were significantly increased 2 and 6 h after one LPS injection group in comparison with the saline injection group in the hippocampus and testis. Next, we investigated the effect of repeated injections of LPS on IL-1R1 expression. LPS or saline were injected at 24-h intervals for 4 consecutive days. The mice were divided into four groups: (1) LPS injections for 4 days and LPS injection on day 5 (LPS–LPS); (2) LPS injections for 4 days and saline injection on day 5 (LPS–saline); (3) saline injections for 4 days and LPS injection on day 5 (saline–LPS); (4) saline injections for 4 days and saline injection on day 5 (saline–saline). The mice were sacrificed by decapitation 2 h after the last injection. In the hippocampus and pituitary gland, significant increases of IL-1R1 mRNA levels were observed in the saline–LPS group, however, the increases were attenuated in LPS–LPS group. IL-1R1 mRNA levels in the hypothalamus were unchanged in all four groups. In the adrenal gland and testis, IL-1R1 mRNA levels were significantly increased in the LPS–LPS group as well as saline–LPS group. These data demonstrate differential regulation of IL-1R1 mRNA by one and repeated endotoxin treatment and suggest the importance of the cytokines in mediating the effects of infectious challenge on brain, endocrine and immune function during endotoxemia.