Heparanase and vascular endothelial growth factor expression is increased in hypoxia-induced retinal neovascularization.

Abstract

PURPOSE:

Heparanase and VEGF are related closely to angiogenesis in cancer. The purpose of our study was to evaluate the expression and correlation of heparanase and VEGF in hypoxia-induced retinal neovascularization.

METHODS:

C57BL/6 oxygen-induced retinopathy (OIR) mice and human retinal microvascular endothelial cells (HRECs) were treated with the hypoxia mimetic agent cobalt chloride (CoCl₂), and in the presence of the heparanase inhibitor phosphomannopentaose sulfate (Muparfostat, PI-88). Heparanase activity was assayed in HRECs, and the expression of heparanase, VEGF protein and mRNA were evaluated by immunofluorescence, ELISA, Western blot, and real-time PCR while retinal flat mounts were used to evaluate the area of neovascularization of mice retina.

RESULTS:

HREC heparanase activity was increased by treatment with CoCl₂, but was decreased by PI-88. Immunofluorescence showed that heparanase and VEGF staining was intense in hypoxia-treated HRECs and OIR mice retina, while VEGF staining was faint in the normoxia and PI-88-treated ones. Western blot and real-time PCR results indicated that the expression of heparanase and VEGF was increased under hypoxic conditions, and the increase of VEGF was inhibited by PI-88. Retinal flat mounts showed that the area of new vessels in retina of OIR mice was increased compared to the normoxic mice, and this effect was inhibited by PI-88.

CONCLUSIONS:

Heparanase is upregulated and associated with the VEGF expression in hypoxia-induced retinal diseases. Heparanase is involved in hypoxia-induced neovascularization through promoting VEGF expression and may be a new therapeutic target for hypoxia-induced neovascularization retinal diseases.

• Authors: Jie Hu, Xin Song, Yi Qing He, Craig Freeman, Christopher R Parish, Ling Yuan, Honghua Yu, Shibo Tang
• Journal: Investigative ophthalmology & visual science (Invest Ophthalmol Vis Sci) Vol. 53 Issue 11 Pg. 6810-7 (Oct 03 2012) ISSN: 1552-5783 [Electronic] United States
• PMID: 22956610 (Publication Type: Comparative Study, Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Vascular Endothelial Growth Factor A
• RNA
• heparanase
• Glucuronidase

Topics

• Animals
• Animals, Newborn
• Blotting, Western
• Disease Models, Animal
• Enzyme-Linked Immunosorbent Assay
• Female
• Gene Expression Regulation
• Glucuronidase (biosynthesis, genetics)
• Humans
• Hypoxia (complications)
• Male
• Mice
• Mice, Inbred C57BL
• RNA (biosynthesis, genetics)
• Real-Time Polymerase Chain Reaction
• Retina (metabolism, pathology)
• Retinal Neovascularization (etiology, genetics, metabolism)
• Vascular Endothelial Growth Factor A (biosynthesis, genetics)