Prostaglandin E2 inhibits migration of colonic lamina propria fibroblasts.
BACKGROUND
Migration of colonic lamina propria fibroblasts (CLPF) is an important mechanism during wound healing in inflammatory bowel disease (IBD). The concentration of prostaglandin E2 (PGE2) is increased in the intestinal mucosa of IBD patients. We therefore investigated the role of PGE2 in CLPF migration.


METHODS
Primary cultures of CLPF were isolated from healthy controls and Crohn's disease patients. Migration assays were performed in the Boyden chamber and scratch assays. EP receptors, PGE2, intracellular cyclic adenosine monophosphate (cAMP), expression and distribution of F-actin, alpha-smooth muscle actin (SMA), and myosin light chain (MLC) were determined by immunoblotting, immunocytochemistry, and enzyme-linked immunosorbent assay (ELISA).


RESULTS
All four EP receptor subtypes were present on CLPF. PGE2 and agonists to the EP2 and EP4 receptor reduced the migration of CLPF. Blockade of the EP2 and the EP4 receptor inhibited the effect of PGE2 on CLPF migration. An increase in intracellular cAMP reduced CLPF migration. PGE2 increased the concentrations of cAMP in CLPF, with abrogation after addition of EP2 and EP4 receptor antagonists. PGE2 and forskolin decreased the expression of alpha-SMA and F-actin and reduced cell polarization and lamellipodium formation in a scratch assay. In addition, forskolin reduced the phosphorylation of MLC (pMLC) and led to lack of accumulation of pMLC in the leading edge of CLPF.


CONCLUSIONS
PGE2 reduced the migration of CLPF via elevation of intracellular cAMP. Potential mechanisms are changes in expression of cytoskeletal proteins, failure of CLPF to polarize, and a decreased amount of pMLC. This might be a possible reason for the impairment of intestinal wound healing in IBD.
Rieder
Florian
F
Department of Internal Medicine I, University of Regensburg, Regensburg, Germany. florian.rieder@t-online.de
Georgieva
Martina
M
Schirbel
Anja
A
Artinger
Monika
M
Zügner
Anita
A
Blank
Martin
M
Brenmoehl
Julia
J
Schölmerich
Jürgen
J
Rogler
Gerhard
G
D015153:Blotting, Western; D002465:Cell Movement / Q000187:drug effects*; D002478:Cells, Cultured; D003106:Colon / Q000166:cytology* / Q000187:drug effects* / Q000378:metabolism; D000242:Cyclic AMP / Q000378:metabolism; D015232:Dinoprostone / Q000494:pharmacology*; D005347:Fibroblasts / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism; D005455:Fluorescent Antibody Technique; D006801:Humans; D009092:Mucous Membrane / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism; D010120:Oxytocics / Q000494:pharmacology*; D058306:Receptors, Prostaglandin E, EP1 Subtype / Q000378:metabolism; D058307:Receptors, Prostaglandin E, EP2 Subtype / Q000378:metabolism; D058308:Receptors, Prostaglandin E, EP3 Subtype / Q000378:metabolism; D058309:Receptors, Prostaglandin E, EP4 Subtype / Q000378:metabolism; D014945:Wound Healing / Q000187:drug effects
D010120:Oxytocics; C545635:PTGER1 protein, human; C545644:PTGER2 protein, human; C545647:PTGER3 protein, human; D058306:Receptors, Prostaglandin E, EP1 Subtype; D058307:Receptors, Prostaglandin E, EP2 Subtype; D058308:Receptors, Prostaglandin E, EP3 Subtype; D058309:Receptors, Prostaglandin E, EP4 Subtype; D000242:Cyclic AMP; D015232:Dinoprostone