Monocytic Tissue Transglutaminase in a XXXX Model for Reversible Acute Rejection and Chronic Renal Allograft Injury.

@entity70708 @entity35 @entity4124 @entity8638 @entity16249
Acute rejection is a major risk factor for @entity8638 ( @entity8638 ). Blood leukocytes interacting with allograft endothelial cells during acute rejection were suggested to contribute to the still enigmatic pathogenesis of @entity8638 . We hypothesize that tissue transglutaminase ( @entity70708 ), a multifunctional protein and established marker of M2 macrophages, is involved in acute and chronic graft rejection. We focus on leukocytes accumulating in blood vessels of @entity35 renal allografts (Fischer-344 to Lewis), an established model for reversible acute rejection and @entity8638 . Monocytes in graft blood vessels overexpress @entity70708 when acute rejection peaks on day 9 after transplantation. Concomitantly, @entity4124 is activated, suggesting that @entity70708 expression is linked to apoptosis. After resolution of acute rejection on day 42, leukocytic @entity70708 levels are lower and activated @entity4124 does not differ among isografts and allografts. @entity16249 was applied for 4 weeks after transplantation to inhibit extracellular transglutaminase activity, which did, however, not reduce @entity8638 in the long run. In conclusion, this is the first report on @entity70708 expression by monocytes in vivo. @entity70708 may be involved in leukocytic apoptosis and thus in reversion of acute rejection. However, our data do not support a role of extracellular transglutaminase activity as a factor triggering @entity8638 during self-limiting acute rejection.
