H-RN, a novel antiangiogenic peptide derived from the kringle 1 domain of hepatocyte growth factor (HGF), consists of the sequence RNPRGEEGGPW (molecular weight: 1254.34Da). Emerging evidence indicates that HGF and the kringle domain exhibit anti-inflammatory effects in inflammatory diseases. In the present study, we assessed the anti-inflammatory effect of H-RN in models of experimental ocular inflammation, including endotoxin-induced uveitis (EIU) and experimental autoimmune uveitis (EAU). The results demonstrated that intravitreal treatment of H-RN concentration-dependently suppressed clinical manifestation, inhibited ocular inflammatory cytokine production and improved histopathologic scores. Moreover, H-RN attenuated the LPS-induced mRNA and protein expression of tumor necrosis factor (TNF)-α and interleukin (IL)-6 in RAW 264.7 cells and inhibited cell chemotactic migration toward LPS. We also demonstrated that H-RN suppressed TNF-α-induced adhesion molecule expression in HUVECs, including ICAM-1, VCAM-1 and E-selectin, which contributed to its suppressive effect on adherence of U937 cells to endothelial cells. We also demonstrated the possible anti-inflammation mechanism of H-RN. Western blot and immunofluorescence staining analyses revealed that H-RN significantly suppressed LPS-induced phosphorylation of nuclear factor (NF)-κB-p65 at Ser276. Based on examination of upstream pathways, we found that H-RN inhibited PI3K-p85 and AKT(Ser473) phosphorylation, which may result in the attenuation of LPS-induced IKK complex activation and IκB degradation. Thus, our studies suggest that the 11-amino-acid peptide H-RN exhibits anti-inflammatory effects in vitro and in vivo and may represent a promising candidate for ocular inflammatory diseases.
Lili Wang, Yan Xu, Qi Yu et al., Biochem Pharmacol 2014 May 11;89(2):255-65. Epub 2014 Mar 11.
BACKGROUND:
The goal of this study was to investigate the anti-angiogenic activity of a novel peptide H-RN, derived from the hepatocyte growth factor kringle 1 domain (HGF K1), in a mouse model of corneal neovascularization. The anti-angiogenic effect of H-RN on vascular endothelial growth factor (VEGF)-stimulated cell proliferation, cell migration and endothelial cell tube formation was assessed in vitro using Human Umbilical Vein Endothelial Cells (HUVECs) and in vivo using a mouse cornea micropocket assay. Apoptosis and cell cycle arrest were assessed by flow cytometry. A scrambled peptide was used as a negative control.
RESULTS:
H-RN effectively inhibited VEGF-stimulated HUVEC proliferation, migration and tube formation on Matrigel, while a scrambled peptide exerted no effect. In the mouse model of corneal angiogenesis, VEGF-stimulated angiogenesis was significantly inhibited by H-RN compared to a scrambled peptide that had no such activity. VEGF protected HUVECs from apoptosis, while H-RN inhibited this protective effect of VEGF. VEGF significantly increased the proportion of cells in the S phase compared to control treated cells (p<0.05). Treatment with H-RN (1.5 mM) induced the accumulation of cells in G0/G1 phase, while the proportion of cells in the S phase and G2/M phase decreased significantly compared to control group (p<0.05).
CONCLUSIONS:
H-RN has anti-angiogenic activity in HUVECs and in a mouse model of VEGF-induced corneal neovascularization. The anti-angiogenic activity of H-RN was related to apoptosis and cell cycle arrest, indicating a potential strategy for anti-angiogenic treatment in the cornea.
Sun Y, Su L, Wang Z et al., BMC Cell Biol. 2013 Feb 24;14:8. doi: 10.1186/1471-2121-14-8.
PURPOSE:
To study the antiangiogenic activity of two small peptides (H-RN and H-FT) derived from the hepatocyte growth factor kringle 1 domain (HGF K1) using in vitro and in vivo assays.
METHODS:
RF/6A rhesus macaque choroid-retina endothelial cells were used for in vitro studies. The inhibiting effect of two peptides on a vascular endothelial growth factor (VEGF)-stimulated cell proliferation, cell migration, and endothelial cell tube formation were investigated. For in vivo assays, the antiangiogenic activity of H-RN and H-FT in the chick chorioallantoic membrane model (CAM) and a mice oxygen-induced retinopathy model (OIR) were studied. A recombinant mouse VEGF-neutralizing antibody, bevacizumab, and a scrambled peptide were used as two control groups in separate studies.
RESULTS:
H-RN effectively inhibited VEGF-stimulated RF/6A cell proliferation, migration, and tube formation on Matrigel™, while H-FT did not. H-RN was also able to inhibit angiogenesis when applied to the CAM, and had antineovascularization activity in the retinal neovascularization of a mouse OIR model when administrated as an intravitreous injection. The antiangiogenic activity of H-RN was not as strong as that of VEGF antibodies. The H-FT and scrambled peptide had no such activity.
CONCLUSIONS:
H-RN, a new peptide derived from the HGF K1 domain, was shown to have antiangiogenic activity in vitro and in vivo. It may lead to new potential drug discoveries and the development of new treatments for pathological retinal angiogenesis.
Xu Y, Zhao H, Zheng Y et al., Mol Vis. 2010 Oct 7;16:1982-95.
