Anti-inflammatory effects of a synthetic peptide derived from pigment epithelium-derived factor on H₂O₂-induced corneal injury in vitro.
BACKGROUND
The common pathological characteristics of corneal injury include inflammatory factors activation, vascular endothelial cells or inflammatory cells infiltration into lesions, corneal edema, corneal neovascularization (CNV), and scar formation. PEDF-34 is the functional fragment of pigment epithelium-derived factor (PEDF) that has anti-angiogenic and anti-inflammatory properties and contains an N-terminal 34-amino acid peptide. This study was to investigate the anti-inflammatory effects of PEDF-34 on H2O2-induced corneal injury in vitro.


METHODS
After cultured in H2O2 (0.1 mmol/L) for 2 hours, human corneal fibroblasts (HCFs) and human umbilical vein endothelial cells (HUVECs) were treated with PEDF-34-nanoparticles (NPs) at different concentrations (0.1, 0.5, 1.0, 2.0 µg/ml) or 2.0 µg/ml control-NPs for 24 hours. The viable cells were quantified using the MTT assay. Western blotting or ELISA analysis was performed for measuring the human vascular endothelial growth factor (VEGF) and intercellular adhesion molecule-1 (ICAM-1) expression of both HCFs and HUVECs. VEGF and nuclear factor κB (NF-κB) mRNA levels of HCFs were semi-quantified by RT-PCR.


RESULTS
The survival rates of HCFs or HUVECs stimulated by H2O2 did not decrease significantly (P > 0.05) compared to those in the normal conditions. As compared to control-NP group, PEDF-34-NPs had dose-dependent inhibitive effect on HUVECs with the MTT assay, but not HCFs. Western blotting analysis showed that the VEGF and ICAM-1 levels in the HCFs and HUVECs stimulated by H2O2 were significantly higher than those in the normal conditions, which were decreased dramatically in those treated with PEDF-34-NPs. RT-PCR analysis revealed that the VEGF mRNA and NF-κB mRNA levels increased in H2O2-stimulated HCFs, while both of them decreased in PEDF-34-NP groups dose dependently.


CONCLUSIONS
PEDF-34-NPs may play an important role in regulating the NF-κB pathway, inhibiting inflammatory activity. PEDF-34-NPs may be a potential new drug for treating corneal injury in the future.
Department of Ophthalmology, First People's Hospital of Shanghai, Shanghai Jiao Tong University, Shanghai 200080, China.
Yi
Y
Lu
Department of Ophthalmology, Children's Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310003, China.
Jia
J
Feng
Department of Ophthalmology, Children's Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310003, China.
Lili
L
Yang
Department of Ophthalmology, Children's Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310003, China.
Hongfeng
H
Tang
Department of Ophthalmology, Children's Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310003, China. Email: jinji2@sina.com.cn.
Ji
J
Jin
Department of Ophthalmology, First People's Hospital of Shanghai, Shanghai Jiao Tong University, Shanghai 200080, China. Email: drxuxun@sjtu.edu.cn.
Xun
X
Xu
D000893:Anti-Inflammatory Agents / Q000737:chemistry* / Q000494:pharmacology*; D002478:Cells, Cultured; D065306:Corneal Injuries / Q000139:chemically induced* / Q000378:metabolism; D005136:Eye Proteins / Q000737:chemistry*; D061307:Human Umbilical Vein Endothelial Cells / Q000187:drug effects / Q000378:metabolism; D006801:Humans; D006861:Hydrogen Peroxide / Q000494:pharmacology*; D009414:Nerve Growth Factors / Q000737:chemistry*; D010455:Peptides / Q000737:chemistry* / Q000494:pharmacology*; D015843:Serpins / Q000737:chemistry*; D000099174:Pigment Epithelium-Derived Factor
D000893:Anti-Inflammatory Agents; D005136:Eye Proteins; D006861:Hydrogen Peroxide; D009414:Nerve Growth Factors; D010455:Peptides; D015843:Serpins; D000099174:Pigment Epithelium-Derived Factor