Critical role of TNF-α-induced macrophage VEGF and iNOS production in the experimental corneal neovascularization.

Abstract

PURPOSE:

We evaluated the roles of tumor necrosis factor (TNF)-α in alkali-induced corneal neovascularization (CNV).

METHODS:

CNV was induced by alkali injury and compared in wild-type (WT) BALB/c mice, and TNF receptor 1-deficient (TNF-Rp55 KO) counterparts, or in mice treated with TNF-α antagonist and recombinant TNF-α. Angiogenic factor expression and leukocyte accumulation in the early phase after injury were quantified by real-time PCR and immunohistochemical analysis, respectively.

RESULTS:

Alkali injury augmented the intraocular mRNA expression of TNF-α and its receptor, together with a transient macrophage and neutrophil infiltration. Compared to WT mice, TNF-Rp55 KO mice exhibited reduced CNV. Intraocular F4/80-positive macrophages and Ly-6G-positive neutrophils infiltration did not change in KO mice compared to WT mice after the injury. Alkali injury induced a massively increased intraocular mRNA expression of angiogenic factors, including vascular endothelial growth factor (VEGF), inducible nitric oxide synthase (iNOS), interleukin (IL)-6, E-selectin, and intercellular adhesion molecule (ICAM)-1 in WT mice, whereas these increments were retarded severely in KO mice. Immunofluorescence analysis demonstrated that F4/80-positive cells expressed VEGF and iNOS. Moreover, TNF-α enhanced VEGF and iNOS expression by peritoneal macrophage from WT, but not KO mice. Topical application of TNF-α antagonist reduced CNV, while topical application of recombinant TNF-α enhanced it.

CONCLUSIONS:

TNF-Rp55-KO mice exhibited impaired alkali-induced CNV through reduced intracorneal infiltrating macrophage VEGF and iNOS expression.

• Authors: Peirong Lu, Longbiao Li, Gaoqin Liu, Tomohisa Baba, Yuko Ishida, Mizuho Nosaka, Toshikazu Kondo, Xueguang Zhang, Naofumi Mukaida
• Journal: Investigative ophthalmology & visual science (Invest Ophthalmol Vis Sci) Vol. 53 Issue 7 Pg. 3516-26 (Jun 14 2012) ISSN: 1552-5783 [Electronic] United States
• PMID: 22570350 (Publication Type: Comparative Study, Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Alkalies
• RNA, Messenger
• Tumor Necrosis Factor-alpha
• Vascular Endothelial Growth Factor A
• Nitric Oxide Synthase Type II

Topics

• Alkalies (toxicity)
• Animals
• Cells, Cultured
• Cornea (drug effects, metabolism, pathology, physiopathology)
• Corneal Neovascularization (chemically induced, genetics, metabolism)
• Disease Models, Animal
• Gene Expression Regulation
• Immunohistochemistry
• Macrophages (metabolism, pathology)
• Male
• Mice
• Mice, Inbred BALB C
• Nitric Oxide Synthase Type II (biosynthesis, genetics)
• RNA, Messenger (biosynthesis, genetics)
• Reverse Transcriptase Polymerase Chain Reaction
• Tumor Necrosis Factor-alpha (physiology)
• Vascular Endothelial Growth Factor A (biosynthesis, genetics)