Cytokine-mediated PGE₂expression in human colonic fibroblasts

Abstract

We investigated prostanoid biogenesis in human colonic fibroblasts (CCD-18Co and 5 primary fibroblast cultures) and epithelial cell lines (NCM460, T84, HT-29, and LS 174T) and the effect of PGE2 on fibroblast morphology. Cytokine-stimulated PGE2production was measured. PGH synthase-1 and -2 (PGHS-1 and -2) protein and mRNA expression were evaluated. Basal PGE2 levels were low in all cell types (0.15–6.47 ng/mg protein). Treatment for 24 h with interleukin-1β (IL-1β; 10 ng/ml) or tumor necrosis factor-α (50 ng/ml), respectively, elicited maximal 25- and 6-fold inductions of PGE2 synthesis in CCD-18Co cultures and similar results in primary fibroblast cultures; maximal inductions with IL-1β in colonic epithelial cell lines were from zero to fivefold. Treatment of CCD-18Co fibroblasts with IL-1β caused maximal 21- and 53-fold increases, respectively, in PGHS-2 protein and mRNA levels without altering PGHS-1 expression. PGE2 (0.1 μmol/l) elicited a dramatic shape change in selected fibroblasts. Colonic fibroblasts are potentially important as cytokine targets and a source of and target for colonic prostanoids in vivo.

Epigallocatechin-3-gallate Impairs Chemokine Production in Human Colon Epithelial Cell Lines

“…PGE 2 production was increased in colonic fibroblasts and in IBD patients. Intestinal fibroblasts, in addition to epithelial cells, could be targets for PGE 2 and sites of colonic prostanoid biosynthesis in vivo (Kim et al, 1998). The expression of COX-2 has also been observed after Salmonella infection in intestinal epithelial cells (Singer et al, 1998), and COX-2 protein was reported to be expressed in three of eight colon cancer cell lines, including HT29 (Parker et al, 1997).…”

“…PGE 2 and other prostanoids are generated through two bifunctional enzymes, cyclooxygenases (COXs)-1 and -2 (Kim et al, 1998). In general, COX-1 is constitutively expressed in a wide range of tissues, including the gastrointestinal tract and plays a role in the tissue homeostasis, e.g., maintenance of gastrointestinal integrity (Singer et al, 1998).…”

“…In general, COX-1 is constitutively expressed in a wide range of tissues, including the gastrointestinal tract and plays a role in the tissue homeostasis, e.g., maintenance of gastrointestinal integrity (Singer et al, 1998). The inducible form, COX-2, which regulates prostaglandin synthesis, is overexpressed in several epithelial cancers and at sites of inflammation (Parker et al, 1997;Kim et al, 1998;Singer et al, 1998;Poligone and Baldwin, 2001;Martel-Pelletier et al, 2003). The expression of this enzyme is induced by various stimuli, e.g., TNF-␣ and IL-1␤, in a variety of cell lines.…”

HGF-activated colonic fibroblasts mediates carcinogenesis of colonic epithelial cancer cells via PKC-cMET-ERK1/2-COX-2 signaling

“…49 Traditionally, the causation of colonic cancers was attributed largely 50 to genetic alterations within the epithelial compartment [10]. However, 51 recent evidence suggests that the stromal compartment also plays a 52 major role in COX-2-mediated carcinogenesis [11,[11][12][13][14][15][16][17][18][19][20][21]. 53 The stroma of an organ is underlying the epithelium, serving as 54 the connective tissue framework.…”

“…Other 58 types of cells such as macrophages might also promote the tumorigenic 59 progression of intestinal epithelial cells by the activation of COX-2 sig-60 naling [23]. We have shown that colonic fibroblasts are a potent source 61 of inducible COX-2 and PGE 2 and that inflammatory factors such as 62 IL1-β, TNF-α and deoxycholic acid promote a sustained COX-2 expres-63 sion and PGE 2 production in colonic fibroblasts [12][13][14][15][16][17][18]. Maximal levels 64 of COX-2 expression and PGE 2 production were far greater in CAFs initi-65 ated from biopsies of colonic cancers than those in normal fibroblasts 66 (NFs) initiated from normal colorectums [13].…”