Inhibition of RACK1 ameliorates choroidal neovascularization formation in vitro and in vivo.
Choroidal neovascularization (CNV) occurs as a result of age-related macular degeneration (AMD) and causes severe vision loss among elderly patients. The receptor for activated C-kinase 1 (RACK1) serves as a scaffold protein which is recently found to promote angiogenesis. However, the impact of RACK1 on the vascular endothelial growth factor (VEGF) expression in endothelial cells and subsequent choroidal angiogenesis formation remains to be elucidated. In this study, we found that RACK1 and VEGF expression increased, and reached the peak at 7d in mouse CNV model by laser application. Furthermore, on RPE/choroid cryosections, RACK1 co-localized with CD31, suggesting that RACK1 was expressed in endothelial cells. In vitro, RF/6A cell hypoxia model showed that RACK1 expression was up-regulated in parallel with hypoxia-induced factor 1 (HIF-1α) and VEGF expression, reaching the peak at 6h. Silencing of RACK1 suppressed the invasion and tube formation activity of RF/6A cells in ARPE-19 and RF/6A co-culture system, possibly through VEGF signal pathway. Overexpression of RACK1 showed the opposite effect. Intravitreal injection of anti-RACK1 monoclonal antibody predominantly decreased RACK1 and VEGF expression in mouse laser-induced CNV model. Meanwhile, anti-RACK1 monoclonal antibody intravitreal injection also decreased incidence of CNV and leakage area. These data indicated that RACK1 promoted CNV formation via VEGF pathway. Additionally, anti-RACK1 monoclonal antibody significantly decreased CNV in mouse model and may have therapeutic potential in human CNV.
Department of Pathogen Biology, Medical College, Nantong University, Nantong, Jiangsu 226001, China; Jiangsu Province Key Laboratory for Inflammation and Molecular Drug Target, Medical College, Nantong University, Nantong, Jiangsu 226001, China.
Xiaojuan
X
Liu
Department of Ophthalmology, Affiliated Hospital of Nantong University, Nantong, Jiangsu 226001, China; Jiangsu Province Key Laboratory for Inflammation and Molecular Drug Target, Medical College, Nantong University, Nantong, Jiangsu 226001, China.
Manhui
M
Zhu
Department of Ophthalmology, Affiliated Hospital of Nantong University, Nantong, Jiangsu 226001, China; Jiangsu Province Key Laboratory for Inflammation and Molecular Drug Target, Medical College, Nantong University, Nantong, Jiangsu 226001, China.
Xiaowei
X
Yang
Department of Ophthalmology, Affiliated Hospital of Nantong University, Nantong, Jiangsu 226001, China; Jiangsu Province Key Laboratory for Inflammation and Molecular Drug Target, Medical College, Nantong University, Nantong, Jiangsu 226001, China.
Ying
Y
Wang
Department of Ophthalmology, Affiliated Hospital of Nantong University, Nantong, Jiangsu 226001, China; Jiangsu Province Key Laboratory for Inflammation and Molecular Drug Target, Medical College, Nantong University, Nantong, Jiangsu 226001, China.
Bai
B
Qin
Department of Ophthalmology, Affiliated Hospital of Nantong University, Nantong, Jiangsu 226001, China; Jiangsu Province Key Laboratory for Inflammation and Molecular Drug Target, Medical College, Nantong University, Nantong, Jiangsu 226001, China.
Chen
C
Cui
Department of Ophthalmology, Affiliated Hospital of Nantong University, Nantong, Jiangsu 226001, China; Jiangsu Province Key Laboratory for Inflammation and Molecular Drug Target, Medical College, Nantong University, Nantong, Jiangsu 226001, China. Electronic address: chenhuieye@126.com.
Hui
H
Chen
Department of Ophthalmology, Affiliated Hospital of Nantong University, Nantong, Jiangsu 226001, China; Jiangsu Province Key Laboratory for Inflammation and Molecular Drug Target, Medical College, Nantong University, Nantong, Jiangsu 226001, China. Electronic address: sangam@ntu.edu.cn.
Aimin
A
Sang
D000818:Animals; D015153:Blotting, Western; D015687:Cell Hypoxia; D002460:Cell Line; D020256:Choroidal Neovascularization / Q000209:etiology / Q000235:genetics / Q000378:metabolism*; D018920:Coculture Techniques; D042783:Endothelial Cells / Q000378:metabolism; D004730:Endothelium, Vascular / Q000378:metabolism*; D004847:Epithelial Cells / Q000378:metabolism; D006801:Humans; D051795:Hypoxia-Inducible Factor 1, alpha Subunit / Q000378:metabolism; D007834:Lasers / Q000009:adverse effects; D008810:Mice, Inbred C57BL; D018613:Microscopy, Confocal; D019408:Platelet Endothelial Cell Adhesion Molecule-1 / Q000378:metabolism; D034622:RNA Interference; D000075370:Receptors for Activated C Kinase; D011956:Receptors, Cell Surface / Q000235:genetics / Q000378:metabolism*; D055213:Retinal Pigment Epithelium / Q000166:cytology; D013997:Time Factors; D042461:Vascular Endothelial Growth Factor A / Q000378:metabolism*
D051795:Hypoxia-Inducible Factor 1, alpha Subunit; D019408:Platelet Endothelial Cell Adhesion Molecule-1; D000075370:Receptors for Activated C Kinase; D011956:Receptors, Cell Surface; D042461:Vascular Endothelial Growth Factor A
Age-related macular degeneration (AMD); Choroidal neovascularization (CNV); Receptor for activated C-kinase 1 (RACK1); Vascular endothelial growth factor (VEGF)