Effect of FTY720 in rat small bowel transplantation: expression of mucosal addressin cell adhesion molecule-1

The intestinal barrier in multiple sclerosis: implications for pathophysiology and therapeutics

Biological barriers are essential for the maintenance of homeostasis in health and disease. Breakdown of the intestinal barrier is an essential aspect of the pathophysiology of gastrointestinal inflammatory diseases, such as inflammatory bowel disease. A wealth of recent studies has shown that the intestinal microbiome, part of the brain-gut axis, could play a role in the pathophysiology of multiple sclerosis. However, an essential component of this axis, the intestinal barrier, has received much less attention. In this review, we describe the intestinal barrier as the physical and functional zone of interaction between the luminal microbiome and the host. Besides its essential role in the regulation of homeostatic processes, the intestinal barrier contains the gut mucosal immune system, a guardian of the integrity of the intestinal tract and the whole organism. Gastrointestinal disorders with intestinal barrier breakdown show evidence of CNS demyelination, and content of the intestinal microbiome entering into the circulation can impact the functions of CNS microglia. We highlight currently available studies suggesting that there is intestinal barrier dysfunction in multiple sclerosis. Finally, we address the mechanisms by which commonly used disease-modifying drugs in multiple sclerosis could alter the intestinal barrier and the microbiome, and we discuss the potential of barrier-stabilizing strategies, including probiotics and stabilization of tight junctions, as novel therapeutic avenues in multiple sclerosis.

Effect of combined treatment with FK506, FTY720, and ex vivo graft irradiation in rat small bowel transplantation: expression of mucosal addressin cell adhesion molecule-1

We studied the effect of the combined treatment with FK506, FTY720, and ex vivo graft irradiation. Five groups of SBT animals were studied on days 3, 5, and 7 after operation (untreated, FK506, FTY720, FK506 + FTY720, FK506 + FTY720 + irradiation). Indirect immunoperoxidase staining was performed against CD4 and MAdCAM-1. The numbers of CD4 positive cells in allografts were also analyzed by flow cytometry. The graft survival was prolonged in all of the FK506- and FTY720-treated groups. SBT allografts treated by FK506 and FTY720 demonstrated less infiltration of CD4 positive cells, but the irradiation group did not show any effects on its expression. In FK506- and FTY720-treated groups, MAdCAM-1 expression on the HEVs in PPs was up-regulated, and its expression on the ECVs in the LP was down-regulated compared with other allograft groups. Irradiation did not show any effects on MAdCAM-1 expression on both HEVs in PPs and ECVs in LP. FK506 and FTY720 prevented the infiltration of CD4 positive cells, the down-regulation of MAdCAM-1 expression on HEVs in PPs, and the up-regulation of MAdCAM-1 expression on ECVs in LP during the early phase of SBT.