Regulator of G-protein signaling 1 promotes choroidal neovascularization in age-related macular degeneration

Abstract

Background: Age-related macular degeneration (AMD) is the leading cause of blindness, and is associated with oxidative stress and the development of new blood vessels. At present, the main clinical treatment for AMD includes intraocular injection of vascular endothelial growth factor (VEGF). However, treatment includes repeated injections with significant side-effects. Therefore, new treatment options are required. The aim of the present study was to discover the new treatment target of AMD from the gene level. Methods: The Gene Expression Omnibus (GEO) database was used to analyze the differential gene expression in AMD, and the regulator of G-protein signaling 1 (RGS1) was obtained by bioassay. Western blotting and quantitative reverse transcription polymerase chain reaction (qRT-PCR) were used to detect the expression levels of RGS1, VEGF, and other related molecules in human microvascular endothelial cells (HMECs) under different conditions. Cell viability, apoptosis, and proliferation of HMECs were measured by Cell Counting Kit-8 proliferation assay. Immunofluorescence and immunohistochemistry detected the interaction between RGS1, platelet endothelial cell adhesion molecule-1, and VEGF. Results: RGS1 was found to closely associated with the proliferation of vascular endothelial cells, and therefore, with angiogenesis. The expression of RGS1, VEGF, and platelet endothelial cell adhesion molecule-1 was upregulated in laser model mice and hypoxia model HMECs. Knockout of RGS1 inhibits the expression of VEGF and HMEC proliferation, thereby inhibiting AMD angiogenesis. Conclusions: Our results support the use of RGS1 as a new potential target for the future treatment of AMD.

Large differences in collateral blood vessel abundance among individuals arise from multiple genetic variants

“…57, see also Bioinformatics analysis in Supplement Knockout/down of Rgs1 reduced expression of VEGF, proliferation of ECs, and suppressed angiogenesis and neovascularization. 58,59 These reports are consistent with our finding that wildtype (B6 allele) AAV9-Rgs1 induced collateral formation in collateral-deficient CC016 mice and conclusion that deficient Rgs1 activity contributes to their reduced collaterogenesis/sparse collaterals. However, findings from other studies could be interpreted to suggest that increased signaling by certain GPCRs that may contribute to collaterogenesis, resulting from interacting with a deficient Rgs1, would be expected to lead to more abundant collaterals in CC016, and therefore that wildtype AAV9-Rgs1 should have had no effect.…”

“…56–69 : see Bioinformatics analysis in Supplement for details Future in vivo studies will be required to resolve this discrepancy, for example using conditional cell-specific gene editing in CC049 and CC016 mice to determine if and how, based on our findings, Rgs1 acts to augment collateral formation during development, while potentially restraining new collateral formation induced by arterial occlusion or exposure to prolonged hypoxemia reported in previous studies. 56–60…”

“…However, findings from other studies could be interpreted to suggest that increased signaling by certain GPCRs that may contribute to collaterogenesis, resulting from interacting with a deficient Rgs1, would be expected to lead to more abundant collaterals in CC016, and therefore that wildtype AAV9- Rgs1 should have had no effect. 56–69 : see Bioinformatics analysis in Supplement for details Future in vivo studies will be required to resolve this discrepancy, for example using conditional cell-specific gene editing in CC049 and CC016 mice to determine if and how, based on our findings, Rgs1 acts to augment collateral formation during development, while potentially restraining new collateral formation induced by arterial occlusion or exposure to prolonged hypoxemia reported in previous studies. 56–60…”

“…56-69: see Bioinformatics analysis in Supplement for details Future in vivo studies will be required to resolve this discrepancy, for example using conditional cell-specific gene editing in CC049 and CC016 mice to determine if and how, based on our findings, Rgs1 acts to augment collateral formation during development, while potentially restraining new collateral formation induced by arterial occlusion or exposure to prolonged hypoxemia reported in previous studies. [56][57][58][59][60] This study has several limitations. Sexual dimorphism has been reported for various cerebrovascular properties 70,71 As stated in Methods, although $equal numbers of both sexes were studied, the sample sizes used in this study were not powered to study sex differences in collateral blood vessel abundance.…”