Lipopolysaccharide-induced elevation and secretion of interleukin-1beta in the submandibular gland of male mice.
The intraperitoneal injection of lipopolysaccharide (LPS) (400 microg/kg body weight) induced the expression of mRNAs of inflammatory cytokines such as interleukin (IL)-1beta, IL-6 and tumour necrosis factor (TNF)-alpha in the submandibular gland (SMG) of C3H/HeN mice but not that of C3H/HeJ mice, a mutant strain for Toll-like receptor-4 (TLR-4(-) mutant). The mRNA levels of these cytokines in the SMG of the wild-type mice increased as early as 3 hr after injection, peaked at 3-6 hr, and had decreased again by 24 hr. In this study, we particularly focused on IL-1beta, and induction by this endotoxin was investigated in detail. Denervation of the superior cervical trunk and chorda tympani nerve did not diminish the LPS-induced elevation of IL-1beta mRNA in the SMG, indicating the irrelevance of the central nervous system in this induction. TLR-4 mRNA and protein were shown to be strongly expressed in the SMG, suggesting the direct action of LPS on this gland. IL-1beta proteins were localized in the secretory granules of granular convoluted tubular (GCT) cells, and their molecular weights in the gland were 17.5 and 20 kDa. IL-1beta of the same size appeared in the saliva 6 hr after LPS injection in C3H/HeN but not in C3H/HeJ mice. The present study thus suggests that IL-1beta, an inflammation cytokine, is induced and secreted into the saliva in response to endotoxin injected intraperitoneally.
Yao
Chenjuan
C
Department of Molecular Oral Physiology, Institute of Health Biosciences, The University of Tokushima Graduate School, Tokushima-shi, Tokushima, Japan.
Li
Xuefei
X
Murdiastuti
Kwartarini
K
Kosugi-Tanaka
Chisato
C
Akamatsu
Tetsuya
T
Kanamori
Norio
N
Hosoi
Kazuo
K
D000818:Animals; D015153:Blotting, Western / Q000379:methods; D016207:Cytokines / Q000096:biosynthesis / Q000235:genetics; D005786:Gene Expression Regulation / Q000276:immunology; D007274:Injections, Intraperitoneal; D007375:Interleukin-1 / Q000096:biosynthesis* / Q000235:genetics; D008070:Lipopolysaccharides / Q000276:immunology*; D008297:Male; D051379:Mice; D008809:Mice, Inbred C3H; D012333:RNA, Messenger / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000379:methods; D012463:Saliva / Q000276:immunology; D013363:Submandibular Gland / Q000276:immunology*
D016207:Cytokines; D007375:Interleukin-1; D008070:Lipopolysaccharides; D012333:RNA, Messenger