Submitted on August 5, 2008
Revised on December 22, 2008
Accepted on January 11, 2009
Lactobacillus reuteri prevents colitis by reducing P-selectin-associated leukocyte- and platelet-endothelial cell interactions
Olof Schreiber1*, Joel Petersson1, Mia Phillipson1, Michael A. Perry2, Stefan Roos3, and Lena Holm1
1 Uppsala University
2 University of New South Wales
3 Swedish University of Agricultural Sciences
* To whom correspondence should be addressed. E-mail: Olof.Schreiber{at}mcb.uu.se.
Recent findings indicate that DSS induced colitis is associated with a prothrombogenic phenotype, with P-selectin playing a major role in platelet recruitment. Probiotics have been suggested to ameliorate colonic inflammation. We therefore investigated how treatment with L. reuteri influenced P-selectin expression, leukocyte and platelet endothelial cell interactions, and colitis severity in DSS treated rats. Rats were divided into four groups; non-treated, DSS treated (5% in drinking water for 9 days), L. reuteri and L. reuteri and DSS treated. The rats were anesthetized with Inactin (120 mg/kg i.p.) and the dual radiolabeled monoclonal antibody technique was used to quantify P-selectin expression. Leukocyte-endothelial and platelet-endothelial cell interactions were studied in colonic venules with intravital microscopy. Colitis severity was assessed using a Disease Activity Index. Disease activity index increased, as did the expression of P-selectin in the entire colon after DSS treatment, but both were reduced to control levels with L. reuteri pretreatment. The increased platelet- and leukocyte endothelial cell interactions after DSS-treatment were abolished by pretreatment with L. reuteri. Lactobacillus reuteri protects against DSS induced colitis in rats. The protection is associated with reduced P-selectin expression and a decrease in leukocyte- and platelet- endothelial cell interactions.
