Mechanisms and Efficacy of Immunobiologic Therapies for Inflammatory Bowel Diseases

Inhibition of selective adhesion molecules in treatment of inflammatory bowel disease

Lymphocyte infiltration into the intestinal tract in inflammatory bowel disease (IBD) is mediated by interaction between α4 integrin and its specific ligands. Development of monoclonal antibodies against α4 integrin allowed targeting of lymphocyte trafficking into the intestine as a novel therapeutic intervention. Natalizumab, vedolizumab, alicaforsen AJM300, rhuMAb β7, CCX282-B, and PF-00547,659 are few of monoclonal antibodies that have shown high promise in trials with the potential for more attractive benefit:risk ratio than currently available therapies. In this review, an attempt is made to underline the therapeutic potential and the safety of anti-adhesion molecule treatment in IBD.

Kruppel-like factor 2 is a transcriptional regulator of chronic and acute inflammation

Although myeloid cell activation is requisite for an optimal innate immune response, this process must be tightly controlled to prevent collateral host tissue damage. Kruppel-like factor 2 (KLF2) is a potent regulator of myeloid cell proinflammatory activation. As an approximately 30% to 50% reduction in KLF2 levels has been observed in human subjects with acute or chronic inflammatory disorders, we studied the biological response to inflammation in KLF2(+/-) mice. Herein, we show that partial deficiency of KLF2 modulates the in vivo response to acute (sepsis) and subacute (skin) inflammatory challenge. Mechanistically, we link the anti-inflammatory effects of KLF2 to the inhibition of NF-κB transcriptional activity. Collectively, the observations provide biologically relevant insights into KLF2-mediated modulation of these inflammatory processes that could potentially be manipulated for therapeutic gain.

Increasing endogenous 2-arachidonoylglycerol levels counteracts colitis and related systemic inflammation

Inflammatory bowel diseases (IBDs) are chronic inflammatory conditions for which new therapeutic approaches are needed. Genetic and pharmacological data point to a protective role of CB(1) and CB(2) cannabinoid receptor activation in IBD experimental models. Therefore, increasing the endogenous levels of 2-arachidonoylglycerol, the main full agonist of these receptors, should have beneficial effects on colitis. 2-Arachidonoylglycerol levels were raised in the trinitrobenzene sulfonic acid (TNBS)-induced colitis mouse model by inhibiting monoacylglycerol lipase (MAGL), the primary enzyme responsible for hydrolysis of 2-arachidonoylglycerol, using the selective inhibitor JZL184. MAGL inhibition in diseased mice increased 2-arachidonoylglycerol levels, leading to a reduction of macroscopic and histological colon alterations, as well as of colonic expression of proinflammatory cytokines. The restored integrity of the intestinal barrier function after MAGL inhibition resulted in reduced endotoxemia as well as reduced peripheral and brain inflammation. Coadministration of either CB(1) (SR141716A) or CB(2) (AM630) selective antagonists with JZL184 completely abolished the protective effect of MAGL inhibition on TNBS-induced colon alterations, thus demonstrating the involvement of both cannabinoid receptors. In conclusion, increasing 2-arachidonoylglycerol levels resulted in a dramatic reduction of colitis and of the related systemic and central inflammation. This could offer a novel pharmacological approach for the treatment of IBD based on the new protective role of 2-arachidonoylglycerol described here.

Protective effects of Kurozu and Kurozu Moromimatsu on dextran sulfate sodium-induced experimental colitis

BACKGROUND

Kurozu, a traditional Japanese black vinegar made from unpolished rice, and Kurozu Moromimatsu (Kurozu-M), its sediment, are both consumed in Japan as health foods or supplements. However, it is not known whether they have anti-colitis activity.

AIMS

We examined the protective effects of Kurozu and Kurozu-M in an animal model of dextran sulfate sodium (DSS)-induced colitis.

METHODS

DSS-induced colitis was induced in C57 black 6 mice by orally administering 3.5% DSS solution for 12 days. The control group received basal CE-2 diet (n = 10), the Kurozu group received CE-2 containing Kurozu (n = 10), the Kurozu-M group received CE-2 containing Kurozu-M (n = 10), and the acetic acid group received CE-2 containing acetic acid (n = 10), starting a week before DSS administration. Changes of body weight and bloody stool frequency were monitored. At 12 days after DSS administration, mice were killed for pathological examination and measurement of nitrotyrosine levels in rectal tissues.

RESULTS

Kurozu significantly inhibited body weight loss during 6-12 days after DSS administration and reduced bloody stool frequency during 2-12 days, and also significantly decreased nitrotyrosine levels at 12 days, compared to the control group. Kurozu-M significantly inhibited body weight loss during 6-8 days after DSS administration and reduced bloody stool frequency during 2-12 days, but tissue nitrotyrosine level was not significantly different from the control. Acetic acid had no ameliorating effect on DSS-induced colitis compared to the control group.

CONCLUSIONS

Kurozu and Kurozu-M have protective effects against DSS-induced colitis. Kurozu has anti-oxidative and anti-nitration activity.