Abstract
Purpose: :
To investigate whether hyaloids vessel regression is mediated by autophagy in early ocular development
Methods: :
Using developing mouse retina of postnatal 4, 8, 12, 16 and 28, histological examination with H&E staining was performed. In addition, to determine the apoptotic or autophagic processes in hyaloid vessel regression, immunohistochemistry for LC-3 and cleaved caspase-3 and electron microscopy were performed. With treatment of cobalt chloride to mimic hypoxic condition in human umbilical vein endothelial cells (HUVECs), Western blotting for procaspase-3, cleaved caspase-3 and LC-3 I/II was performed. Next, with treatment of an autophagy inducer, rapamycin, LC-3 conversion in HUVEC and hyaloids vessel regression in developing eye was determined to confirm the autophagy processes in hyaloidal vascular endothelial cells.
Results: :
In developing retina, hyaloid vessel regression coincided with retinal vascular development was observed, when interestingly apoptotic and autophagic processes were simultaneously occurred. Moreover, in vascular endothelial cells under hypoxic condition, LC-3 conversion was detected with caspase-3 activation. Actually an autophagy inducer, rapamycin induced autophagy-mediated cell death of vascular endothelial cells in dose-dependent manner. Furthermore, the antopgy inducer, rapamycin significantly remove hyaloids vessels in early developing eye.
Conclusions: :
Our results suggest that hyaloid vessel regression could be mediated by autophagy in early ocular development.
Keywords: apoptosis/cell death • hypoxia • retinal development