Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
1995289 | Microvascular Research | 2009 | 9 Pages |
Abstract
Our previous studies have shown that very low-density lipoprotein receptor (VLDLR) is a negative regulator of the Wnt pathway. The present study showed that VLDLR gene knockout (Vldlrâ/â) mice displayed impaired cone ERG responses at early ages. Immunostaining of mid-wavelength cones showed significantly decreased cone densities in the retina and shortened cone outer segments in Vldlrâ/â mice. At older ages, Vldlrâ/â mice displayed declined rod ERG responses, decreased layers of photoreceptor nuclei, reduced rhodopsin levels and decreased levels of 11-cis retinal, the chromophore of visual pigments. As shown by fluorescein angiography and permeability assay, Vldlrâ/â mice had severe retinal vascular leakage. ZO-1, a tight junction protein, was down-regulated in Vldlrâ/â mouse retinae, further supporting the impaired blood-retinal barrier. Double staining of pericytes and endothelial cells in retinal sections revealed that neovasculature in Vldlrâ/â mice lacks pericyte coverage, suggesting impaired maturation of retinal vasculature in Vldlrâ/â mice. Staining of adherent leukocytes in the retinal vasculature revealed significant leukostasis in Vldlrâ/â mice. Moreover, Vldlrâ/â mice displayed up-regulated expression of multiple pro-inflammatory factors and activated NF-κB and HIF-1α, key regulators of inflammation. These findings suggest that deficiency of VLDLR leads to retinal degeneration and inflammation.
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Authors
Ying Chen, Yang Hu, Gennadiy Moiseyev, Kevin K. Zhou, Danyang Chen, Jian-xing Ma,