Figure 3.

Injury-Induced Activation of the PERK Pathway and Exacerbated IH in Balloon-Injured Rat Carotid Arteries Overexpressing PERK

(A) Activation of the PERK pathway in injured arteries. Following angioplasty, rat common carotid arteries were harvested at days 3, 7, and 14 (3 to 14 days) and homogenized for immunoblotting analysis. (B) Quantitation of PERK phosphorylation level following rat balloon angioplasty. Mean ± SEM, n = 3 rats; *p < 0.05, 1-way analysis of variance with Bonferroni post hoc test. (C) Increase of P-PERK on cross sections of injured arteries. Immunofluorescent staining of P-PERK and α-SMA was performed as described in Methods. Shown are representative images, and quantified data are presented in Supplemental Figure S2. Neointima lesion is indicated between arrowheads. (D) In vivo PERK gain-of-function. Adenovirus (Ad) GFP (Ad-GFP) or Ad-PERK was intraluminally infused with the injured artery for 25 min immediately after balloon angioplasty. Shown are representative VVG-stained sections. Scale bar: 100 μm for 10×, 50 μm for 40×. (E and F) Quantification of I/M area ratio and lumen area. Mean ± SEM, n = 6 rats; *p < 0.05, unpaired Student’s t-test. ATF = activating transcription factor; CHOP = CCAAT-enhancer-binding protein homologous protein; GFP = green fluorescent protein; SMA = smooth muscle actin; other abbreviations as in Figure 1.