Anti-angiogenic effects of a mutant endostatin: a new prospect for treating retinal and choroidal neovascularization

• Published in: PloS one 2014-11, Vol.9 (11), p.e112448-e112448
• Main Authors: Bai, Yujing, Zhao, Min, Zhang, Chunfang, Li, Shanshan, Qi, Yun, Wang, Bin, Huang, Lvzhen, Li, Xiaoxin
• Format: Article
• Language: English
• Subjects: Angiogenesis; Angiogenesis inhibitors; Angiogenesis Inhibitors - chemistry; Angiogenesis Inhibitors - pharmacokinetics; Angiogenesis Inhibitors - pharmacology; Animal models; Animals; Antiangiogenics; Assaying; Base Sequence; Binding; Biology and Life Sciences; Cell Movement - drug effects; Cell Proliferation - drug effects; Cells, Cultured; Choroidal Neovascularization - prevention & control; Collagen; Education; Endostatin; Endostatins - chemistry; Endostatins - genetics; Endostatins - pharmacology; Endothelial cells; Endothelial Cells - drug effects; Endothelial Cells - physiology; Hospitals; Human performance; Human Umbilical Vein Endothelial Cells - drug effects; Human Umbilical Vein Endothelial Cells - physiology; Humans; In vivo methods and tests; Injection; Laboratory animals; Macular degeneration; Medical diagnosis; Medical innovations; Medical research; Medicine and Health Sciences; Mice, Inbred C57BL; Microvasculature; Molecular Sequence Data; Mutation; Neovascularization; Neovascularization, Pathologic - prevention & control; Neovascularization, Physiologic - drug effects; Oxygen; Pharmacology; Polyethylene glycol; Polyethylene Glycols - chemistry; Polyols; Propionaldehyde; Proteins; Rabbits; Researchers; Retina; Retina - metabolism; Retina - pathology; Retinal Diseases - pathology; Retinal Diseases - physiopathology; Retinal Neovascularization - prevention & control; Retinal Vessels - cytology; Retinopathy; Studies; Umbilical vein; Vascular endothelial growth factor; Vascular Endothelial Growth Factor A - pharmacology; Vascularization; Zinc
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0112448

Pathological fundus angiogenesis is a major cause of vision loss in retina diseases. Endostatin, a C-terminal fragment of collagen XVIII, is an endogenous anti-angiogenic protein. The present study aimed to investigate the in vitro and in vivo anti-angiogenic properties of two proteins: an N-terminal H1D/H3D mutant endostatin (M-ES) and a polyethylene glycol propionaldehyde (PEG) covalent M-ES (PEG-M-ES). M-ES and PEG-M-ES properties were characterized in vitro using a zinc ion binding assay and a stability test. Activity assays, including migration, proliferation, and tube formation assays, were performed with human retinal microvascular endothelial cells (HRMECs) and human umbilical vein endothelial cells (HUVECs). Mouse oxygen-induced retinopathy (OIR) and choroidal neovascularization (CNV) models were used to evaluate in vivo anti-angiogenic effects. In addition, a rabbit model was used to study the retinal pharmacokinetic profile following an intravitreal injection. The results indicated that the H1D/H3D mutations of endostatin reduced the zinc binding capacity of M-ES and facilitated PEG covalent binding. PEG-M-ES was more stable and persisted longer in the retina compared with M-ES. The in vitro studies demonstrated that M-ES and PEG-M-ES inhibited HRMEC and HUVEC proliferation, migration, and tube formation more efficiently than ES. In vivo, a single intravitreal injection of M-ES and PEG-M-ES significantly decreased neovascularization in both the OIR and CNV animal models. The present study demonstrated for the first time that PEG-M-ES exhibits a long-term inhibitory effect on neovascularization in vitro and in vivo. These data suggest that PEG-M-ES may represent an innovative therapeutic strategy to prevent fundus neovascularization.