Effect of vascular endothelial growth factor upregulation on retinal gene expression in the Kimba mouse.
BACKGROUND
The Kimba mouse carries a human vascular endothelial growth factor transgene causing retinal neovascularisation similar to that seen in diabetic retinopathy. Here, we examine the relationship between differential gene expression induced by vascular endothelial growth factor overexpression and the architectural changes that occur in the retinae of these mice.


METHODS
Retinal gene expression changes in juvenile and adult Kimba mice were assayed by microarray and compared with age-matched wild-type littermates. Transcription of selected genes was validated by quantitative real-time polymerase chain reaction. Protein translation was determined using immunohistochemistry and enzyme-linked immunosorbent assay.


RESULTS
Semaphorin 3C was upregulated, and nuclear receptor subfamily 2, group 3, member 3 (Nr2e3) was downregulated in juvenile Kimba mice. Betacellulin and endothelin 2 were upregulated in adults. Semaphorin 3C colocalized with glial fibrillary acidic protein in Müller cells of Kimba retinae at greater signal intensities than in wild type. Endothelin 2 colocalised to Müller cell end feet and extended into the outer limiting membrane. Endothelin receptor type B staining was most pronounced in the inner nuclear layer, the region containing Müller cell somata.


CONCLUSIONS
An early spike in vascular endothelial growth factor induced significant long-term retinal neovascularisation associated with changes to the retinal ganglion, photoreceptor and Müller cells. Overexpression of vascular endothelial growth factor led to dysregulation of photoreceptor metabolism through differential expression of Nr2e3, endothelin 2, betacellulin and semaphorin 3C. Alterations in the expression of these genes may therefore play key roles in the pathological mechanisms that result from retinal neovascularisation.
Department of Molecular Ophthalmology, Lions Eye Institute, Nedlands Centre for Ophthalmology and Visual Science, The University of Western Australia, Crawley, Western Australia.
Nicolette
N
Binz
Ireni S
IS
Ali Rahman
Holly R
HR
Chinnery
Richard
R
McKeone
Ken M
KM
Simpson
Terence P
TP
Speed
Chooi-May
CM
Lai
P Elizabeth
PE
Rakoczy
D000818:Animals; D066259:Betacellulin; D003930:Diabetic Retinopathy / Q000235:genetics* / Q000378:metabolism; D019333:Endothelin-2 / Q000378:metabolism; D004797:Enzyme-Linked Immunosorbent Assay; D020869:Gene Expression Profiling; D005786:Gene Expression Regulation / Q000502:physiology*; D007150:Immunohistochemistry; D036341:Intercellular Signaling Peptides and Proteins / Q000378:metabolism; D051379:Mice; D008822:Mice, Transgenic; D057093:Orphan Nuclear Receptors / Q000378:metabolism; D060888:Real-Time Polymerase Chain Reaction; D015861:Retinal Neovascularization / Q000235:genetics* / Q000378:metabolism; D039961:Semaphorins / Q000378:metabolism; D042461:Vascular Endothelial Growth Factor A / Q000235:genetics*
C587851:BTC protein, human; D066259:Betacellulin; C587852:Btc protein, mouse; D019333:Endothelin-2; D036341:Intercellular Signaling Peptides and Proteins; C485736:Nr2e3 protein, mouse; D057093:Orphan Nuclear Receptors; D039961:Semaphorins; C467484:VEGFA protein, human; D042461:Vascular Endothelial Growth Factor A; C510203:semaphorin 3C protein, mouse