Critical role of TNF-α-induced macrophage VEGF and iNOS production in the experimental corneal neovascularization.
ABSTRACT We evaluated the roles of tumor necrosis factor (TNF)-α in alkali-induced corneal neovascularization (CNV).
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.
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.
TNF-Rp55-KO mice exhibited impaired alkali-induced CNV through reduced intracorneal infiltrating macrophage VEGF and iNOS expression.
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ABSTRACT: Diabetic retinopathy (DR) is recognized as a chronic low-grade inflammatory disease. Retinal microvascular cell dysfunction and loss play an important role in the pathogenesis of DR. However, the basic mechanisms underlying the development and progression of DR are poorly understood. Many recent studies indicate that increased production of inflammatory factors either systemically and/or locally, is strongly associated with vascular dysfunction during diabetes. Here we sought to determine the specific impact of different inflammatory mediators on retinal endothelial cell (EC) function. Inflammatory mediators TNF-α and IL-1β attenuated the migration and capillary morphogenesis of retinal EC. These dysfunctions were associated with increased production of reactive oxygen species, expression of inducible nitric oxide synthase, and production of total nitrate/nitrite. Incubation of retinal EC with TNF-α and IL-1β altered VE-cadherin localization, as well as the expression of other junctional proteins. In addition, TNF-α and IL-1β also altered the production of various ECM proteins including osteopontin, collagen IV, and tenascin-C. Mechanistically, these changes were concomitant with the activation of the mitogen-activated protein kinase (MAPK) and nuclear factor-κB (NF-κB) signaling pathways. In contrast, incubation of retinal EC with MCP-1 minimally affected their migratory, junctional, and ECM properties. Together our results indicate that the presence of inflammatory mediators in diabetes may have specific and significant impact on vascular cell function, and contribute to the pathogenesis of DR.Microvascular Research 06/2013; · 2.93 Impact Factor
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ABSTRACT: PURPOSE:: To evaluate the effect of thalidomide analogue CC-3052 on corneal neovascularization in the rabbit model. METHODS:: Corneal neovascularization was induced in 15 rabbits by a silk suture in the corneal stroma. At 1 week after suturing, 30 eyes were divided into 5 groups of 6 eyes each. Three groups were treated with topical CC-3052 at 3 different concentrations: 0.25% (group 1), 0.5% (group 2), and 1.0% (group 3). All treatments were performed twice a day for a week. A 0.5% concentration of CC-3052 was injected subconjunctivally once in group 4. In group 5, a topical balanced salt solution was added twice a day for a week as the experimental control group. Rabbit corneas were photographed by a digital camera and examined by the operating microscope. Half of the corneal specimens were analyzed histopathologically, and the other half were used to measure the concentration of tumor necrosis factor α and vascular endothelial growth factor (VEGF) messenger RNA by reverse transcriptase-polymerase chain reaction. RESULTS:: The neovascularized area was decreased in all treatment groups compared with the control group. There was a significant difference in the percentage and score of corneal neovascularization between the control and all treatment groups. Inflammation, fibroblast, neovascularization, and anti-VEGF antibody intensities were significantly lower in the control group. The concentration of VEGF and tumor necrosis factor α was significantly lower in the control group. There was no difference between the treatment groups. CONCLUSIONS:: Topical and subconjunctival administration of thalidomide analogue CC-3052 was found to be effective for the inhibition of corneal neovascularization.Cornea 06/2013; · 1.75 Impact Factor
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ABSTRACT: There is evidence that plasminogen K1-5 (PlgK1-5) directly affects tumour cells and inflammation. Therefore, we analysed if PlgK1-5 has immediate effects on hepatoma cells and inflammatory factors in vitro and in vivo. In vitro, effects of plasmid encoding PlgK1-5 (pK1-5) on Hepa129, Hepa1-6, and HuH7 cell viability, apoptosis, and proliferation as well as VEGF and TNF-alpha expression and STAT3-phosphorylation were investigated. In vivo, tumour growth, proliferation, vessel density, and effects on vascular endothelial growth factor (VEGF) and tumour necrosis factor alpha (TNF-alpha) expression were examined following treatment with pK1-5. In vivo, pK1-5 halved cell viability; cell death was increased by up to 15% compared to the corresponding controls. Proliferation was not affected. VEGF, TNF-alpha, and STAT3-phosphorylation were affected following treatment with pK1-5. In vivo, ten days after treatment initiation, pK1-5 reduced subcutaneous tumour growth by 32% and mitosis by up to 77% compared to the controls. Vessel density was reduced by 50%. TNF-alpha levels in tumour and liver tissue were increased, whereas VEGF levels in tumours and livers were reduced after pK1-5 treatment. Taken together, plasmid gene transfer of PlgK1-5 inhibits hepatoma (cell) growth not only by reducing vessel density but also by inducing apoptosis, inhibiting proliferation, and triggering inflammation.BioMed Research International 01/2014; 2014:656527. · 2.71 Impact Factor