NOVEL MECHANISMS IN INFLAMMATORY BOWEL DISEASE

Inflammatory Bowel Diseases, Crohn\u27s Disease and Ulcerative colitis, are idiopathic chronic conditions with multifactorial determinants. In general, terms, intestinal inflammation results from abnormal host-microbe interactions. Alterations in homeostasis involve host genetic factors, environmental cues and unique luminal microbial niches. We have examined the coordinated expressions of several molecular targets relevant to the mucosal immune system and identified signature biomarkers of IBD. Qualitative and quantitative changes in the composition of microbiota can be related to unique immuno-phenotypes. This in turn can have more systemic effects that involve energy metabolism. Adiponectin, an adipose tissue derived adipokine, can restore cellular ATP levels and fulfills innate immune functions. We have concluded that IBD might represent a state of adiponectin resistance relating to chronic inflammation and obesity status. Lastly we hypothesized that activation of xenobiotic pathway (AHR-aryl hydrocarbon receptor) can further modulate host immune and metabolic responses, and thus contribute to IBD phenotypes. We found that IBD is associated with robust mucosal, aryl hydrocarbon receptor pathway and related to proinflammatory cytokine secretion. We conclude that IBD heterogeneity is reflected through distinct immunophenotypes. Furthermore, environmental cues that involve the AhR receptor and adipose tissue derived adiponectin are important regulators of the inflammatory process in IBD

Inflammatory Bowel Disease: How Effective Is TNF-α Suppression?

Crohn's Disease (CD) results from inappropriate response toward commensal flora. Earlier studies described CD as a Th1 mediated disease. Current models view both phenotypes as a continuum of various permutations between Th1, Th2 and Th17 pathways compounded by a range of Treg disfunctions. In the present paper, we develop a mathematical model, by a system of differential equations, which describe the dynamic relations among these T cells and their cytokines. The model identities four groups of CD patients according to up/down regulation of Th1 and Th2. The model simulations show that immunosuppression by TNF-α blockage benefits the group with Th1High/Th2Low while, by contrast, the group with Th1Low/Th2High will benefit from immune activation

Fold changes of the cytokine and T cell concentrations obtained from the clinical data and the simulations in different types of diseases.

<p>Fold changes of the cytokine and T cell concentrations obtained from the clinical data and the simulations in different types of diseases.</p

List of the variables included in the model.

<p>List of the variables included in the model.</p

Parameters used in the equations of T cells and a list of half-saturation constants.

<p>Parameters used in the equations of T cells and a list of half-saturation constants.</p

Simulation results: Parameter variations in different types of diseases.

<p>Simulation results: Parameter variations in different types of diseases.</p