Phenotypic changes of vascular smooth muscle cells in human abdominal aortic aneurysms / 中国病理生理杂志

ABSTRACT

AIM:To study phenotypic changes of vascular smooth muscle cells (VSMC) in abdominal aortic aneurysmal (AAA) pathogenesis. METHODS: Tissue samples of human infrarenal aneurysmal and normal aorta(NA), and arterial occlusive diseases(AOD) were evaluated. Monoclonic antibodies of ?-smooth muscle actin(?-SMA), desmin and smooth muscle myosin heavy chain isoforms (SM1, SM2 and SMemb) were used in immunohistochemistry to determine VSMC isoforms. Immunohistochemical results were analyzed with the use of computer-generated image technique. Ultrstructures of VSMC in three tissues above were observed by electron microscope. RESULTS: In control AOD and NA, VSMC in the media were strongly immunostained for ?-SMA, desmin, SM1 and SM2. Immunoreactivity for SMemb was faint or weakly positive in AOD, but negative in NA. In AAA,the balance shifts to SMemb predominance with suppressed ?-SMA, SM1 and SM2 and negative desmin, while in ruptured aneurysmal walls, the expression of SM2 and SMemb were decreased compared with the non-ruptured aneurysmal walls. CONCLUSION:Phenotypic changes of VSMC are concerned with abdominal aortic structure lesion and remodeling, which contributes to AAA formation and development.