Linked Life Data

15613498

Source:http://linkedlifedata.com/resource/pubmed/id/15613498

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
4
pubmed:dateCreated
2005-3-11
pubmed:abstractText
Neovascularization of the retina and choroids is the pathological hallmark of many retinopathies, but its molecular mechanisms remain unclear. Vascular endothelial growth factor (VEGF), which is induced by hypoxia or cytokines, plays a critical role in the abnormal growth of blood vessels. In this study, we report that visible light exposure induces VEGF gene expression in retinoblastoma Y79 cells. Fluorescent light exposure (700 lux, wavelength 400 approximately 740 nm) caused a significant increase in VEGF transcripts and protein levels. Such an induction seemed to be specific to certain cells, including photoreceptor cells, because light-induced VEGF expression was not observed in either nontransformed cells, such as retinal pigment epithelium cells, and bovine aortic endothelial cells or transformed cells, such as CV-1 and HepG2 cells. Pertussis toxin and guanosine 5'-[beta-thio]diphosphate, specific inhibitors for rhodopsin-associated G protein, blunted this induction. Progressive deletion and site-specific mutation analyses indicate that light stimulation increases VEGF promoter activity through G+C-rich sequence, which is proven by Sp1 binding sites by supershift assays. Electrophoretic mobility shift assays show that light stimulation increases Sp1 binding. Synthetic retinoic acid receptor-alpha (RARalpha) antagonist completely abrogated light-mediated increase in VEGF expression. Transfection of Y79 cells with dominant negative mutant of RARalpha significantly attenuated the light-mediated induction of VEGF promoter activity. In conclusion, our data indicate that light exposure increases VEGF expression through the mechanisms involving activation of Sp1 and RARalpha signaling in Y79 cells. This study provides new insight into the role of visible light in the transcription and induction of VEGF gene expression.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Apr
pubmed:issn
0363-6143
pubmed:author
pubmed:issnType
Print
pubmed:volume
288
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
C913-20
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
2005
pubmed:articleTitle
Visible light exposure induces VEGF gene expression through activation of retinoic acid receptor-alpha in retinoblastoma Y79 cells.
pubmed:affiliation
Department of Ophthalmology, Gunma University School of Medicine, Gunma, Japan.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't