Superior cervical ganglionectomy induces changes in growth factor expression in the rat retina.
OBJECTIVE
To determine whether sympathetic nerves regulate expression of known angiogenic growth factors.


METHODS
Surgical sympathectomy (SNX) was used to remove sympathetic innervation to the eye. Real-time PCR was used to measure steady state mRNA expression of VEGF, VEGFR-2, angiopoietin-1, and Tie2. Western blot analysis was performed to assess protein expression. Blood-retinal barrier (BRB) permeability surface area product (PS) was measured using enhanced MRI on a separate group of control and SNX rats.


RESULTS
mRNA of both VEGF and VEGFR-2 decreased significantly at 6 weeks after SNX. VEGF protein expression also decreased significantly. VEGFR-2 protein was unchanged. Both angiopoietin-1 and Tie2 mRNA expression increased significantly after SNX. Immunoblot analysis showed that angiopoietin-1 protein expression coincided with its mRNA expression. Tie2 protein expression was unaffected. Sympathetic denervation did not significantly increase BRB PS.


CONCLUSIONS
Surgical SNX results in a reduction in VEGF gene and protein expression, while increasing protein expression of Ang-1. These findings suggest that sympathetic nerves regulate the expression of angiogenic growth factors in rat retina.
Wiley
Luke A
LA
Department of Physiology, Southern Illinois University School of Medicine, Carbondale, Illinois, USA.
Berkowitz
Bruce A
BA
Steinle
Jena J
JJ
D042683:Angiopoietin-1 / Q000235:genetics* / Q000378:metabolism; D000818:Animals; D001813:Blood-Retinal Barrier; D015153:Blotting, Western; D005260:Female; D015171:Ganglionectomy; D005786:Gene Expression Regulation / Q000502:physiology*; D008279:Magnetic Resonance Imaging; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D042787:Receptor, TIE-2 / Q000235:genetics* / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017783:Superior Cervical Ganglion / Q000502:physiology*; D013997:Time Factors; D042461:Vascular Endothelial Growth Factor A / Q000235:genetics* / Q000378:metabolism; D040301:Vascular Endothelial Growth Factor Receptor-2 / Q000235:genetics* / Q000378:metabolism
D042683:Angiopoietin-1; D012333:RNA, Messenger; D042461:Vascular Endothelial Growth Factor A; C467498:vascular endothelial growth factor A, rat; D042787:Receptor, TIE-2; D040301:Vascular Endothelial Growth Factor Receptor-2