Distribution of Hypoxia-Inducible Factor-1α and Bcl-2-A Study of Varicose Veins by Confocal Microscopy

Abstract

Objective: The tissue hypoxia caused by chronic venous insufficiency and blood stasis is the etiology of varicose vein formation. Bcl-2 (anti-apoptotic protein) reduces apoptosis may contribute to the dilated and thickened walls of the diseased vessels. We studied the distribution and relationship of hypoxia-inducible factor-1α (HIF-1α) and Bcl-2 in varicose veins by confocal microscopy. Methods: This study consisted of examination of 1cm venous segments (hypertrophic type) from 12 patients obtained during conventional stripping surgery for the varicose saphenous vein in the calf muscle region. All vascular specimens were studied for HIF-1α and Bcl-2αby immunohistochemical stain and confocal laser scanning microscopy. Results: In varicose veins, the immunohistochemical staining of both HIF-1αand Bcl-2 showed strong immunostaining in the hypertrophic smooth muscle layer. In further study, prominent HIF-1αdistribution in the muscle layer and Bcl-2 protein deposition in the endothelial layer were demonstrated under confocal laser scanning microscopy. Conclusions: These results revealed prominent HIF-1αand Bcl-2 distribution in the muscle layer with co-localization, and Bcl-2 overexpression in the endothelial layer of varicose vein vessels under confocal microscopy.