Abstract
Purpose: :
Mice lacking Very low–density lipoprotein receptor (Vldlr) as well as apoER2 show inversion of cortical layers and deficiency of cerebellar foliation. In the retina, retinal angiogenesis and subretinal neovascularization are found as early as postnatal day 15. The purpose of this study was to examine retinal gene expression in Vldlr deficient mice from the onset of the phenotype through its progression using cDNA–microarrays.
Methods: :
All mouse protocols were in accordance with ARVO guidelines. Three Vldlr deficient mice were used for each time point (Postnatal day 10, 15, or 1 and 2 months). Whole eyes were fixed in 4% paraformaldehyde for morphological and immunohistological studies. Retinas were isolated and total RNA extracted by Trizol (Invitrogen) and purified by RNeasy Mini Kit (Qiagen). RNA samples with 280/260 ratios more than 1.8 were used for microarray hybridization on custom slides on which 12k mouse non–redundant retina ESTs were printed. after hybridiztion with cy3 and cy5 labeled vldlr and control retinal cDNAs, Slides were scanned on a GenePix 4000B scanner, the data manipulated with GenePix software Version 4.0 (Axon Instruments). and uploaded to a Mouse Retina Microarrray Analysis System we have generated to annotate and manage the data. Cluster v2.20 and TreeView v1.60 were used for gene cluster analysis.
Results: :
The results confirmed our previous findings by PCR of increases in several genes associated with angiogenesis. For example, we found hypoxia inducible factor 1 alpha subunit (HIF1a) and angiopoietin 1 increased at PN 10 and 15. A group of genes associated with functions of sensory perception including rod and cone specific genes such as rhodopsin, retinal S–antigen, opsin 1 (cone pigments) were upregulated at postnatal day 10 and 15.
Conclusions: :
Our results confirmed the molecular correlates of the neovascularization phenotype of this model and suggest that disruption of the Vldlr gene may also be involved in neuronal maturation during postnatal retina development.
Keywords: gene/expression • retinal development • photoreceptors