TY - JOUR
T1 - Induction of colitis causes inflammatory responses in fat depots
T2 - Evidence for substance P pathways in human mesenteric preadipocytes
AU - Karagiannides, Iordanes
AU - Kokkotou, Efi
AU - Tansky, Morris
AU - Tchkonia, Tamara
AU - Giorgadza, Nino
AU - O'Brien, Michael
AU - Leeman, Susan E.
AU - Kirkland, James L.
AU - Pothoulakis, Charalabos
PY - 2006/3/28
Y1 - 2006/3/28
N2 - Intracolonic administration of trinitrobenzene sulfonic acid in mice causes inflammation in the colon that is accompanied by increased expression of proinflammatory cytokines and of the substance P (SP), neurokinin 1 receptor (NK-1R) in the proximal mesenteric fat depot. We also investigated whether human mesenteric preadipocytes contain NK-1R and examined the functional consequences of exposure of these cells to SP as it relates to proinflammatory signaling. We found that human mesenteric preadipocytes express NK-1R both at the mRNA and protein levels. Exposure of human mesenteric preadipocytes to SP increased NK-1R mRNA and protein expression by 3-fold, and stimulated IL-8 mRNA expression and protein secretion. This effect was abolished when these cells were pretreated with the specific NK-1R antagonist CJ 012,255. Moreover, human mesenteric preadipocytes transfected with a luciferase promoter/reporter system containing the IL-8 promoter with a mutated NF-κB site lost their ability to respond to SP, indicating that SP-induced IL-8 expression is NF-κB-dependent. This report indicates that human mesenteric preadipocytes contain functional SP receptors that are linked to proinflammatory pathways, and that SP can directly increase NK-1R expression. We speculate that mesenteric fat depots may participate in intestinal inflammatory responses via SP-NK-1R-related pathways, as well as other systemic responses to the presence of an ongoing inflammation of the colon.
AB - Intracolonic administration of trinitrobenzene sulfonic acid in mice causes inflammation in the colon that is accompanied by increased expression of proinflammatory cytokines and of the substance P (SP), neurokinin 1 receptor (NK-1R) in the proximal mesenteric fat depot. We also investigated whether human mesenteric preadipocytes contain NK-1R and examined the functional consequences of exposure of these cells to SP as it relates to proinflammatory signaling. We found that human mesenteric preadipocytes express NK-1R both at the mRNA and protein levels. Exposure of human mesenteric preadipocytes to SP increased NK-1R mRNA and protein expression by 3-fold, and stimulated IL-8 mRNA expression and protein secretion. This effect was abolished when these cells were pretreated with the specific NK-1R antagonist CJ 012,255. Moreover, human mesenteric preadipocytes transfected with a luciferase promoter/reporter system containing the IL-8 promoter with a mutated NF-κB site lost their ability to respond to SP, indicating that SP-induced IL-8 expression is NF-κB-dependent. This report indicates that human mesenteric preadipocytes contain functional SP receptors that are linked to proinflammatory pathways, and that SP can directly increase NK-1R expression. We speculate that mesenteric fat depots may participate in intestinal inflammatory responses via SP-NK-1R-related pathways, as well as other systemic responses to the presence of an ongoing inflammation of the colon.
KW - Inflammatory bowel disease
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U2 - 10.1073/pnas.0600821103
DO - 10.1073/pnas.0600821103
M3 - Article
C2 - 16549770
AN - SCOPUS:33645521371
SN - 0027-8424
VL - 103
SP - 5207
EP - 5212
JO - Proceedings of the National Academy of Sciences of the United States of America
JF - Proceedings of the National Academy of Sciences of the United States of America
IS - 13
ER -