Expression of Angiogenic Molecules in Cochlear Vasculature

An altered vascular function may be related with several inner ear diseases such as Meniere’s disease, sudden deafness, and noise-induced hearing loss. The present study was aimed to visualize the cochlear blood-labyrinth barrier and to analyze angiogenic molecules in the cochlear vasculature. Murine cochlea was obtained and its bony shell was removed. Whole mount immunostaining of endothelial cell markers, PECAM-1 and VE-cadherin, was done. There were pericytes and vascular smooth muscle cells shown. Angiogenic molecules including VEGFR2, VEGFR3, Sox17 and Dll4 were expressed. Precapillary arterioles, stria vascularis, and postcapillary venules were shown in the cochlear vasculature. The components of blood-labyrinth barrier were observed from basal turn to apical turn of the cochlea. The endothelial expression of VEGFR3, VEGFR2, and Sox17 denotes that the cochlea is not in a static, but in an active state. The robust expression of claudin-5 suggests its important role in blood-labyrinth barrier. The expression of α-SMA represents its need for vascular contraction. Visualizing cochlear vessels and determining angiogenic molecules could help to understand the pathophysiology of hearing loss ailments.