Early growth-response factor 1 and basic transcriptional element-binding protein 2 expression in cardiac allografts.

Early growth-response factor 1 (Egr-1) and basic transcriptional element-binding protein 2 (BTEB2) are transcriptional factors that regulate multiple genes involved in phenotypic changes of smooth muscle cells (SMCs), one of the outstanding pathologic features of chronic cardiac allograft rejection. In this study, we used a heterotopic abdominal heart transplant model in monkeys to evaluate the roles of these molecules in graft coronary vasculopathy. We demonstrated that Egr-1 and BTEB2 are induced in vascular SMCs of rejected cardiac allografts well before morphologic changes, such as intimal thickening. These findings suggest that expression of Egr-1 and BTEB2 is one of the initial events in allograft angiopathy.