Vascular smooth muscle cell remodelling in elastase-induced aortic aneurysm.

Abstract

UNLABELLED: OBJECTIVE; ; The objective of this study was to identify developmental changes in vascular smooth muscle cells (VSMC) during aneurysm formation using an elastase-induced rabbit carotid artery aneurysm model. METHODS: - Aneurysms were induced in carotid arteries of rabbits by exposure to elastase. Tissues from developing aneurysms were isolated at various time points for histological, immunohistochemical and RT-PCR analysis. RESULTS: During aneurysm growth, the vascular media became thinner and elastic fibres became fragmented.The expression of smooth muscle marker SM22alpha and cytoskeleton proteins (SM alpha-actin, beta-tubulin and desmin) expression was decreased while platelet-derived growth factor (PDGF) was increased, which correlated with a remodelling ofVSMC from contractile to synthetic functions. CONCLUSION: During the development of aneurysm, despite the induction of apoptosis, VSMC undergoes a remodelling from a contractile phenotype to a synthetic phenotype as a potential repair mechanism. Further studies may reveal the causative effects between these events.