[Role and possible mechanism of regulators of G-protein signaling 5 in development of experimental choroidal neovascularization].
OBJECTIVE
To observe the role and possible mechanism of regulators of G-protein signaling 5 (RGS5) in the development of experimental choroidal neovascularization (CNV).


METHODS
It was an experimental study. A total of 88 male Brown Norway (BN) rats underwent the 532 nm photocoagulation to set up the CNV model. Forty of them were sort by time after the photocoagulation as follows: 1 d (n = 6), 3 d (n = 6), 7 d (n = 7) and 14 d (n = 21), then 48 of them were divided by treatment factor: intravitreal injection of physiological saline or Avastin. Nineteen of them served as the controls. The expression of RGS5 and VEGF were examined by immunofluorescence, western blot and reverse transcription polymerase chain reaction (RT-PCR). The thickness and area of CNV were qualified by histopathological sections and choroidal flatmounts. All of the results were analyzed by Student's t-test.


RESULTS
(1) The expression of RGS5 and VEGF proteins: there was no statistical significance in gray-scale value of RGS5 between 14 d group (0.899 ± 0.057) and control group (0.820 ± 0.032), although RGS5 expression reached a peak at 14 days (t = 2.079, P > 0.05). There was statistical significance in gray-scale value of VEGF between 7 d group (0.600 ± 0.031) and control group (0.382 ± 0.036), and VEGF expression reached a peak at 7 days (t = 7.959, P < 0.01). (2) The expression of RGS5 and VEGF mRNAs: the RGS5 mRNA expression decreased at 1 day (0.763 ± 0.035) and 3 days (0.725 ± 0.054) in comparison with the control (0.886 ± 0.047, t = 3.646, 3.888; P < 0.05, 0.05), and reached a peak at 14 days after photocoagulation (t = 2.194, P > 0.05). There was statistical significance in gray-scale value of VEGF between 7 d group (0.855 ± 0.029) and control group (0.274 ± 0.039), and VEGF expression reached a peak at 7 days after photocoagulation (t = 20.709, P < 0.01). (3) The changes of thickness and area of CNV: the thickness and area of CNV were significantly decreased (t = 2.616, 15.179; P < 0.05, 0.01) after intravitreal injection with Avastin.


CONCLUSIONS
RGS5 and VEGF coexpressed in the area of CNV, and RGS5 expressed later than VEGF. The expression of RGS5 was decreased when CNV was inhibited by anti-VEGF treatment. Therefore, it is possible that RGS5 may be involved in VEGF-regulated CNV formation.
Institute of Ophthalmology of Chinese PLA, Department of Ophthalmology, Xijing Hospital, Fourth Military Medical University, Xi'an 710032, China.
Zi
Z
Ye
Yu-sheng
YS
Wang
Yan
Y
Cai
Ke
K
Ma
D000818:Animals; D020256:Choroidal Neovascularization / Q000378:metabolism* / Q000473:pathology; D008297:Male; D020710:RGS Proteins / Q000378:metabolism*; D051381:Rats; D011914:Rats, Inbred BN; D015398:Signal Transduction; D042461:Vascular Endothelial Growth Factor A / Q000378:metabolism*
D020710:RGS Proteins; C491348:Rgs5 protein, rat; D042461:Vascular Endothelial Growth Factor A; C467498:vascular endothelial growth factor A, rat