title: Effects of p75 neurotrophin receptor on regulating hypoxia-induced angiogenic factors in retinal pigment epithelial cells.
abstract: Retinal pigment epithelium (RPE) exerts critical roles in the maintenance of the normal functions of the retina, whereas RPE dysfunction can induce retina neovascularization. p75 neurotrophin receptor (p75(NTR)) has been shown to play essential roles in angiogenesis. However, the function of p75(NTR) in the RPE remains unclear. In the present study, we demonstrated that p75(NTR) was highly expressed in the human choroidal neovascularization membranes. For in vitro study, RPE was exposed to hypoxia, and a knockdown of p75(NTR) was achieved via lentivirus-mediated RNA interference. The results showed that hypoxia induced the expression of p75(NTR) in the RPE, and the knockdown of p75(NTR) rescued RPE proliferation activity and inhibited apoptosis which induced by hypoxia. After the deletion of p75(NTR), RPE-secreted pro-angiogenic factors (vascular endothelial growth factor and platelet-derived growth factor), inflammatory factors [interleukin 1 beta (IL1β), IL18, and stromal cell-derived factor 1], and matrix metalloproteinases (MMPs) (MMP3 and MMP9) were down-regulated under hypoxic conditions. While the RPE secreted anti-angiogenic factors (pigment epithelium-derived factor) and angiostatin, the tissue inhibitors of metalloproteinases (TIMPs) (TIMP-1 and TIMP-3) were up-regulated after the knockdown of p75(NTR). The human umbilical vein endothelial tube formation ability can be inhibited when it is co-cultured with the supernatant extract from p75(NTR)-knockdown RPE under hypoxic induction. These results suggest that the knockdown of p75(NTR) suppressed pro-angiogenic factors which induced by hypoxia while promoting the anti-angiogenesis-related factors in the RPE. It is indicated that p75(NTR) could be a potential therapeutic target for RPE hypoxia or oxidative stress diseases.
authors.affiliation: Key Laboratory of Vision Loss and Restoration, Ministry of Education, Beijing Key Laboratory for the Diagnosis and Treatment of Retinal and Choroid Diseases, Department of Ophthalmology, Peking University People's Hospital, Xizhimen South Street 11, Xi Cheng District, Beijing, 100044, China.
authors.forename: Jingjing
authors.initials: J
authors.lastname: Zhang
authors.forename: Jun
authors.initials: J
authors.lastname: Zhao
authors.forename: Yujing
authors.initials: Y
authors.lastname: Bai
authors.forename: Lvzhen
authors.initials: L
authors.lastname: Huang
authors.forename: Wenzhen
authors.initials: W
authors.lastname: Yu
authors.forename: Xiaoxin
authors.initials: X
authors.lastname: Li
mesh_terms: D042501:Angiogenic Proteins / Q000378:metabolism*; D043168:Angiostatins / Q000378:metabolism; D017209:Apoptosis / Q000235:genetics; D015153:Blotting, Western; D015687:Cell Hypoxia; D002460:Cell Line; D049109:Cell Proliferation / Q000235:genetics; D002478:Cells, Cultured; D020256:Choroidal Neovascularization / Q000378:metabolism / Q000473:pathology; D018920:Coculture Techniques; D016207:Cytokines / Q000378:metabolism; D015870:Gene Expression; D061307:Human Umbilical Vein Endothelial Cells / Q000378:metabolism / Q000502:physiology; D006801:Humans; D007150:Immunohistochemistry; D018836:Inflammation Mediators / Q000378:metabolism; D018919:Neovascularization, Physiologic; D010982:Platelet-Derived Growth Factor / Q000378:metabolism; D034622:RNA Interference; D020800:Receptor, Nerve Growth Factor / Q000235:genetics / Q000378:metabolism*; D012160:Retina / Q000378:metabolism; D055213:Retinal Pigment Epithelium / Q000166:cytology / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D042461:Vascular Endothelial Growth Factor A / Q000378:metabolism
chemical_list: D042501:Angiogenic Proteins; D016207:Cytokines; D018836:Inflammation Mediators; D010982:Platelet-Derived Growth Factor; D020800:Receptor, Nerve Growth Factor; D042461:Vascular Endothelial Growth Factor A; D043168:Angiostatins