Activation of the prostaglandin D2 metabolic pathway in Crohn's disease: involvement of the enteric nervous system.
BACKGROUND
Recent works provide evidence of the importance of the prostaglandin D2 (PGD2) metabolic pathway in inflammatory bowel diseases. We investigated the expression of PGD2 metabolic pathway actors in Crohn's disease (CD) and the ability of the enteric nervous system (ENS) to produce PGD2 in inflammatory conditions.


METHODS
Expression of key actors involved in the PGD2 metabolic pathway and its receptors was analyzed using quantitative reverse transcriptase polymerase chain reaction (qRT-PCR) in colonic mucosal biopsies of patients from three groups: controls, quiescent and active CD patients. To determine the ability of the ENS to secrete PGD2 in proinflammatory conditions, Lipocalin-type prostaglandin D synthase (L-PGDS) expression by neurons and glial cells was analyzed by immunostaining. PGD2 levels were determined in a medium of primary culture of ENS and neuro-glial coculture model treated by lipopolysaccharide (LPS).


RESULTS
In patients with active CD, inflamed colonic mucosa showed significantly higher COX2 and L-PGDS mRNA expression, and significantly higher PGD2 levels than healthy colonic mucosa. On the contrary, peroxysome proliferator-activated receptor Gamma (PPARG) expression was reduced in inflamed colonic mucosa of CD patients with active disease. Immunostaining showed that L-PGDS was expressed in the neurons of human myenteric and submucosal plexi. A rat ENS primary culture model confirmed this expression. PGD2 levels were significantly increased on primary culture of ENS treated with LPS. This production was abolished by AT-56, a specific competitive L-PGDS inhibitor. The neuro-glial coculture model revealed that each component of the ENS, ECG and neurons, could contribute to PGD2 production.


CONCLUSIONS
Our results highlight the activation of the PGD2 metabolic pathway in Crohn's disease. This study supports the hypothesis that in Crohn's disease, enteric neurons and glial cells form a functional unit reacting to inflammation by producing PGD2.
INSERM Unité 913, 1 rue Gaston Veil, Nantes, F-44035, France. ag.leloupp@yahoo.fr.|Université Nantes, 1 quai de Tourville, BP 13522, Nantes, F-44035, France. ag.leloupp@yahoo.fr.|Institut des Maladies de l'Appareil Digestif, 1 place Alexis Ricordeau, Nantes, F-44093, France. ag.leloupp@yahoo.fr.|Laboratoire de Biochimie, Institut de Biologie, CHU de Nantes, 1 place Alexis Ricordeau, Nantes, F-44093, France. ag.leloupp@yahoo.fr.
Anne-Gaelle
AG
Le Loupp
INSERM Unité 913, 1 rue Gaston Veil, Nantes, F-44035, France. kalyane.bach@chu-nantes.fr.|Université Nantes, 1 quai de Tourville, BP 13522, Nantes, F-44035, France. kalyane.bach@chu-nantes.fr.|Institut des Maladies de l'Appareil Digestif, 1 place Alexis Ricordeau, Nantes, F-44093, France. kalyane.bach@chu-nantes.fr.|Laboratoire de Biochimie, Institut de Biologie, CHU de Nantes, 1 place Alexis Ricordeau, Nantes, F-44093, France. kalyane.bach@chu-nantes.fr.
Kalyane
K
Bach-Ngohou
INSERM Unité 913, 1 rue Gaston Veil, Nantes, F-44035, France. arnaud.boureille@chu-nantes.fr.|Université Nantes, 1 quai de Tourville, BP 13522, Nantes, F-44035, France. arnaud.boureille@chu-nantes.fr.|Institut des Maladies de l'Appareil Digestif, 1 place Alexis Ricordeau, Nantes, F-44093, France. arnaud.boureille@chu-nantes.fr.|Laboratoire de Biochimie, Institut de Biologie, CHU de Nantes, 1 place Alexis Ricordeau, Nantes, F-44093, France. arnaud.boureille@chu-nantes.fr.
Arnaud
A
Bourreille
INSERM Unité 913, 1 rue Gaston Veil, Nantes, F-44035, France. helene.boudin@univ-nantes.fr.|Université Nantes, 1 quai de Tourville, BP 13522, Nantes, F-44035, France. helene.boudin@univ-nantes.fr.|Institut des Maladies de l'Appareil Digestif, 1 place Alexis Ricordeau, Nantes, F-44093, France. helene.boudin@univ-nantes.fr.
Hélène
H
Boudin
INSERM Unité 913, 1 rue Gaston Veil, Nantes, F-44035, France. malvyne.derkinderen@univ-nantes.fr.|Université Nantes, 1 quai de Tourville, BP 13522, Nantes, F-44035, France. malvyne.derkinderen@univ-nantes.fr.|Institut des Maladies de l'Appareil Digestif, 1 place Alexis Ricordeau, Nantes, F-44093, France. malvyne.derkinderen@univ-nantes.fr.
Malvyne
M
Rolli-Derkinderen
INSERM Unité 913, 1 rue Gaston Veil, Nantes, F-44035, France. marc.denis@chu-nantes.fr.|Université Nantes, 1 quai de Tourville, BP 13522, Nantes, F-44035, France. marc.denis@chu-nantes.fr.|Institut des Maladies de l'Appareil Digestif, 1 place Alexis Ricordeau, Nantes, F-44093, France. marc.denis@chu-nantes.fr.|Laboratoire de Biochimie, Institut de Biologie, CHU de Nantes, 1 place Alexis Ricordeau, Nantes, F-44093, France. marc.denis@chu-nantes.fr.
Marc G
MG
Denis
INSERM Unité 913, 1 rue Gaston Veil, Nantes, F-44035, France. michel.neunlist@univ-nantes.fr.|Université Nantes, 1 quai de Tourville, BP 13522, Nantes, F-44035, France. michel.neunlist@univ-nantes.fr.|Institut des Maladies de l'Appareil Digestif, 1 place Alexis Ricordeau, Nantes, F-44093, France. michel.neunlist@univ-nantes.fr.
Michel
M
Neunlist
INSERM Unité 913, 1 rue Gaston Veil, Nantes, F-44035, France. damien.masson@chu-nantes.fr.|Université Nantes, 1 quai de Tourville, BP 13522, Nantes, F-44035, France. damien.masson@chu-nantes.fr.|Institut des Maladies de l'Appareil Digestif, 1 place Alexis Ricordeau, Nantes, F-44093, France. damien.masson@chu-nantes.fr.|Laboratoire de Biochimie, Institut de Biologie, CHU de Nantes, 1 place Alexis Ricordeau, Nantes, F-44093, France. damien.masson@chu-nantes.fr.
Damien
D
Masson
D000293:Adolescent; D000328:Adult; D000368:Aged; D000818:Animals; D002478:Cells, Cultured; D018920:Coculture Techniques; D003424:Crohn Disease / Q000378:metabolism* / Q000473:pathology; D051546:Cyclooxygenase 2 / Q000235:genetics; D016207:Cytokines / Q000235:genetics; D017615:Enteric Nervous System / Q000166:cytology / Q000378:metabolism; D005260:Female; D006801:Humans; D007413:Intestinal Mucosa / Q000378:metabolism; D019746:Intramolecular Oxidoreductases / Q000235:genetics / Q000378:metabolism*; D054834:Lipocalins / Q000235:genetics / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D009197:Myenteric Plexus / Q000378:metabolism*; D009457:Neuroglia / Q000378:metabolism*; D009474:Neurons / Q000378:metabolism*; D047495:PPAR gamma / Q000378:metabolism; D015230:Prostaglandin D2 / Q000235:genetics / Q000378:metabolism*; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D012720:Severity of Illness Index; D013368:Submucous Plexus / Q000378:metabolism*; D055815:Young Adult
D016207:Cytokines; D054834:Lipocalins; D047495:PPAR gamma; D012333:RNA, Messenger; D051546:Cyclooxygenase 2; D019746:Intramolecular Oxidoreductases; C022466:prostaglandin R2 D-isomerase; D015230:Prostaglandin D2