Pentagalloyl Glucose (PGG) Partially Prevents Arterial Mechanical Changes Due to Elastin Degradation

Abstract

Background Elastic fibers are composed primarily of the protein elastin and they provide reversible elasticity to the large arteries. Degradation of elastic fibers is a common histopathology in aortic aneurysms. Pentagalloyl glucose (PGG) has been shown to bind elastin and stabilize elastic fibers in some in vitro studies and in vivo models of abdominal aortic aneurysms, however its effects on native arteries are not well described. Objective Perform detailed studies of the biomechanical effects of PGG on native arteries and the preventative capabilities of PGG for elastin degraded arteries. Methods We treated mouse carotid arteries with PGG, elastase (ELA), and PGG + ELA and compared the wall structure, solid mechanics, and fluid transport properties to untreated (UNT) arteries. Results We found that PGG alone decreased compliance compared to UNT arteries, but did not affect any other structural or biomechanical measures. Mild (30 s) ELA treatment caused collapse and fragmentation of the elastic lamellae, plastic deformation, decreased compliance, increased modulus, and increased hydraulic conductance of the arterial wall compared to UNT. PGG + ELA treatment partially protected from all of these changes, in particular the plastic deformation. PGG mechanical protection varied considerably across PGG + ELA samples and appeared to correlate with the structural changes. Conclusions Our results provide important considerations for the effects of PGG on native arteries and a baseline for further biomechanical studies on preventative elastic fiber stabilization.