Methyl deficient diet aggravates experimental colitis in rats.
Fiche publication
Date publication
novembre 2011
Auteurs
Membres identifiés du Cancéropôle Est :
Pr GUEANT Jean-Louis, Dr NAMOUR Bernard, Pr PEYRIN-BIROULET Laurent
Tous les auteurs :
Chen M, Peyrin-Biroulet L, George A, Coste F, Bressenot A, Bossenmeyer-Pourie C, Alberto JM, Xia B, Namour B, Gueant JL
Lien Pubmed
Résumé
Inflammatory bowel diseases (IBD) result from complex interactions between environmental and genetic factors. Low blood levels of vitamin B12 and folate and genetic variants of related target enzymes are associated with IBD risk, in population studies. To investigate the underlying mechanisms, we evaluated the effects of a methyl-deficient diet (MDD, folate, vitamin B12 and choline) in an experimental model of colitis induced by dextran sodium sulphate (DSS), in rat pups from dams subjected to the MDD during gestation and lactation. Four groups were considered (n= 1216 per group): C DSS- (control/DSS-), D DSS- (deficient/DSS-), C DSS+ (control/DSS+) and D DSS+ (deficient/DSS+). Changes in apoptosis, oxidant stress and pro-inflammatory pathways were studied within colonic mucosa. In rat pups, the MDD produced a decreased plasma concentration of vitamin B12 and folate and an increased homocysteine (7.8 +/- 0.9 versus 22.6 +/- 1.2 mu mol/l, P < 0.001). The DSS-induced colitis was dramatically more severe in the D DSS+ group compared with each other group, with no change in superoxide dismutase and glutathione peroxidase activity, but decreased expression of caspase-3 and Bax, and increased Bcl-2 levels. The mRNA levels of tumour necrosis factor (TNF)-a and protein levels of p38, cytosolic phospolipase A2 and cyclooxygenase 2 were significantly increased in the D DSS+ pups and were accompanied by a decrease in the protein level of tissue inhibitor of metalloproteinases (TIMP)3, a negative regulator of TNF-a. MDD may cause an overexpression of pro-inflammatory pathways, indicating an aggravating effect of folate and/or vitamin B12 deficiency in experimental IBD. These findings suggest paying attention to vitamin B12 and folate deficits, frequently reported in IBD patients.
Référence
J Cell Mol Med. 2011 Nov;15(11):2486-97