Lactobacillus casei prevents the upregulation of ICAM-1 expression and leukocyte recruitment in experimental colitis.
Lactobacillus casei has been shown to attenuate the severity of experimental colitis. The objective of the present study was to determine whether the effects of L. casei on colitis are related to modulation of leukocyte recruitment into the inflamed intestine. Rats with a colonic segment excluded from fecal transit were surgically prepared. The segment was decontaminated with antibiotics and recolonized with normal flora isolated from the inflamed rat colon, associated or not to L. casei. Control and colitic [2,4,6-trinitrobenzenesulfonic acid (TNBS)-induced] animals were studied. Leukocyte-endothelial cell interactions were characterized in the colonic microcirculation by intravital microscopy, and ICAM-1 and VCAM-1 expression was measured by the radiolabeled antibody technique. Compared with the noninflamed colonic segment, induction of colitis by TNBS provoked a marked increase in the number of leukocytes firmly adherent to the venular wall (0.5 +/- 0.1 vs. 2.1 +/- 0.6 leukocytes/100 mum, P < 0.01). Colonization with L. casei significantly reduced the number of adherent leukocytes (1.3 +/- 0.4 leukocytes/100 mum; P < 0.05) but did not affect the increased rolling interactions associated with the induction of colitis. Compared with the noncolitic group, induction of colitis was associated with a marked increase in ICAM-1 expression (117 +/- 4 vs. 180 +/- 3 ng antibody/g tissue) that was abrogated when the colitic segment was colonized by L. casei (117 +/- 3 ng antibody/g tissue, P < 0.05). However, L. casei administration did not modify VCAM-1 upregulation in colitic animals. L. casei attenuates leukocyte recruitment observed in experimental colitis induced by TNBS. This effect is possibly related to abrogation of ICAM-1 upregulation.
Angulo
Sandra
S
Department of Gastroenterology, Hospital Clínic of Barcelona, University of Barcelona, Barcelona, Spain.
Llopis
Marta
M
Antolín
María
M
Gironella
Meritxell
M
Sans
Miquel
M
Malagelada
Juan Ramon
JR
Piqué
Josep Maria
JM
Guarner
Francisco
F
Panés
Julián
J
D000818:Animals; D003092:Colitis / Q000276:immunology* / Q000382:microbiology*; D004195:Disease Models, Animal; D018799:Intercellular Adhesion Molecule-1 / Q000276:immunology*; D007780:Lacticaseibacillus casei / Q000276:immunology*; D007962:Leukocytes / Q000276:immunology* / Q000382:microbiology*; D008297:Male; D019936:Probiotics; D051381:Rats; D017207:Rats, Sprague-Dawley; D015854:Up-Regulation
D018799:Intercellular Adhesion Molecule-1