Homozygous deletion of early growth response 1 gene and critical limb ischemia after vascular ligation in mice: Evidence for a central role in vascular homeostasis

Northern blot analysis of EGR-1 after iliac artery ligation in rats. Left femoral artery was ligated, and proximal iliac and femoral arteries were harvested as indicated. Right iliac and femoral arteries were taken as control. Peak Egr1 expression is noted 60 minutes after ligation. Lanes: 1, nonligated control; 2, 30 minutes after ligation (1.6 × control); 3, 60 minutes after ligation (2.1 × control); 4, 120 minutes after ligation (0.6 × control). EtBr, Ethidium bromide.

Distal hind limb perfusion after ipsilateral vascular excision in wild-type and Egr1 knockout C57 BL/6 mice. Perfusion index is calculated as described in Methods section from laser Doppler perfusion imaging of ligated and nonligated hind limbs.

Laser Doppler perfusion images and macroscopic appearances of ligated and nonligated hind limbs of wild-type and Egr1 knockout mice. Perfusion is illustrated by means of color scale, with red-yellow being highest and blue-black being lowest. Perfusion images correlate with development of severe necrosis at indicated intervals after ligation.

Distal hind limb perfusion after ipsilateral vascular excision in Egr1 knockout mice treated with AdVEGF. For comparison purposes, shaded curve shows pattern of recovery in wild-type mice, as shown in Figure 2.

Distal hind limb perfusion after ipsilateral vascular excision in Egr1 knockout mice treated with AdEgr. For comparison purposes, filled circles show pattern of recovery in AdVEGF-treated knockouts, as shown in Figure 4. Difference in perfusion from AdVEGF-treated Egr1 knockout animals on postligation day 35 was not significant.