Expression of Egr-1 in late stage emphysema

The transcription factor early growth response (Egr)-1 is an immediate-earl y gene product rapidly and transiently expressed after acute tissue injury. In contrast, in this report we demonstrate that lung tissue from patients undergoing lung reduction surgery for advanced emphysema, without clinical or anatomical evidence of acute infection, displays a selective and apparen tly sustained increase in Egr-1 transcripts and antigen, compared with a br oad survey of other genes, including the transcription factor Spl, whose le vels were not significantly altered. Enhanced Egr-1 expression was especial ly evident in smooth muscle cells of bronchial and vascular walls, in alveo lar macrophages, and some vascular endothelium, Gel shift analysis with P-3 2-labeled Egr probe showed a band with nuclear extracts from emphysematous lung which was supershifted with antibody to Egr-1. Egr-1 has the capacity to regulate genes relevant to the pathophysiology of emphysema, namely thos e related to extracellular matrix formation and remodeling, thrombogenesis, and those encoding cytokines/chemokines and growth factors. Thus, we propo se that further analysis of Egr-1, which appears to be up-regulated in a su stained fashion in patients with late stage emphysema, may provide insights into the pathogenesis of this destructive pulmonary disease, as well as a new facet In the biology of Egr-1.