101. Role of metallothioneins 1 and 2 in ocular neovascularization
- Author
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Kazuhiro Tsuruma, Tsunehiko Ikeda, Yasushi Ito, Shinsuke Takata, Shinsuke Nakamura, Akiko Honda, Masamitsu Shimazawa, Masahiko Satoh, Hideaki Hara, and Yuki Inoue
- Subjects
Male ,genetic structures ,Eye Diseases ,Angiogenesis ,Fundus Oculi ,Blotting, Western ,Immunoblotting ,Enzyme-Linked Immunosorbent Assay ,Neovascularization ,Cellular and Molecular Neuroscience ,chemistry.chemical_compound ,Mice ,medicine ,Animals ,Humans ,Fluorescein Angiography ,Aged ,Mice, Knockout ,Retina ,Neovascularization, Pathologic ,business.industry ,Retinal ,Diabetic retinopathy ,Middle Aged ,medicine.disease ,Immunohistochemistry ,eye diseases ,Sensory Systems ,Mice, Inbred C57BL ,Vitreous Body ,Ophthalmology ,Vascular endothelial growth factor A ,Disease Models, Animal ,Choroidal neovascularization ,medicine.anatomical_structure ,chemistry ,Cancer research ,Matrix Metalloproteinase 2 ,Female ,sense organs ,medicine.symptom ,Matrix Metalloproteinase 1 ,business ,Retinopathy - Abstract
PURPOSE The incidence of blindness is increasing, in part, because of abnormal ocular neovascularization. Anti-VEGF therapies have yielded impressive results; however, they are not a cure for blindness. Recently, metallothioneins (MTs) 1 and 2 have been implicated in the process of angiogenesis. Therefore, we investigated whether MT-1 and MT-2 were also involved in ocular neovascularization. METHODS The concentrations of MT-1 and MT-2 (hereafter MT-1/2) were observed by ELISA. We examined the role of MT-1/2 in ocular neovascularization by using both an oxygen-induced retinopathy (OIR) model and a laser-induced choroidal neovascularization (CNV) model. We investigated the localization of MT-1/2 in retina. Furthermore, we investigated the expression of hypoxia-inducible factor (HIF)-1α and VEGF in OIR. In vitro, we investigated the degradation of HIF-1α. RESULTS The MT-1/2 were significantly elevated in proliferative diabetic retinopathy patients. Ocular neovascularization, which was induced in both the OIR model and the CNV model, was decreased in MT-1/2 knockout (KO) mice. We confirmed that although MT-1/2 was expressed throughout the murine retina, its expression levels were highest in the endothelial cells. Further, OIR enhanced MT-1/2 expression in the retina. Interestingly, in the OIR model, both HIF-1α and VEGF levels were significantly decreased in the retina of MT-1/2 KO mice. In addition, we found that knockdown of MT-1/2 accelerated ubiquitination of HIF-1α. CONCLUSIONS These results indicate that MT-1/2 are involved in retinal and choroidal neovascularization, and that MT-1/2 might be a new therapeutic target in diseases in which ocular angiogenesis is implicated.
- Published
- 2014