Conjunctival Lymphatic Response to Corneal Inflammation in Mice

Due to its unique characteristics, the cornea has been widely used for vascular research. However, it has never been studied whether lymphatic vessels in the conjunctiva, its neighboring tissue, are affected by corneal lymphangiogenesis (LG). The purpose of this study was to investigate whether the distribution pattern of conjunctival lymphatic vessels changes during LG using a standardized two-suture placement model. Our data from immunofluorescent microscopic studies demonstrate, for the first time, that conjunctival lymphatic vessels were more distributed in the nasal side under both normal and inflamed conditions. Additionally, under the inflamed condition, conjunctival lymphatic vessels showed a higher density and more branching points, indicating that LG occurs in the conjunctiva in response to corneal inflammation. This study not only provides novel insights into lymphatic events in the ocular surface but also offers new guidelines for developing therapeutic strategies to treat lymphatic diseases at related sites

Characterization of Effector T Cells in Dry Eye Disease

purpose. Dry eye disease (DED) is associated with ocular surface inflammation that is thought to be mediated primarily by CD4 T cells. The purpose of this study was to investigate whether this T cell–mediated immune response is generated in the lymphoid compartment and to characterize the functional phenotype of the T cells activated in DED. methods. DED was induced in female C57BL/6 mice by exposure to a desiccating environment in the controlled environment chamber and to systemic scopolamine. T cells from regional draining lymph nodes (LNs) of DED mice and normally sighted mice were analyzed for surface activation markers (CD69 and CD154), chemokine and cytokine receptors, and proliferation potential. results. Draining LNs of DED mice showed increased frequencies of CD69- and CD154-expressing T cells with higher proliferative capacity. In addition, these LN T cells primarily showed a helper T-cell (Th)1 phenotype, expressing significantly higher levels of IFN-γ and IL-12Rβ2 but not IL-4R. Similarly, the LNs of DED mice showed significantly increased frequencies of T cells expressing CXCR3 and CCR5, but not CCR4, suggesting a bias toward a Th1 phenotype. conclusions. These data demonstrate that a Th1-type immune response is induced in the regional LNs of DED mice. The identification of specific cytokine/chemokine receptors overexpressed by these T cells may signify potential novel targets/strategies for the treatment of DED

Novel Characterization of Lymphatic Valve Formation during Corneal Inflammation

Lymphatic research has progressed rapidly in recent years. Though lymphatic dysfunction has been found in a wide array of disorders from transplant rejection to cancer metastasis, to date, there is still little effective treatment for lymphatic diseases. The cornea offers an optimal site for lymphatic research due to its accessible location, transparent nature, and lymphatic-free but inducible features. However, it still remains unknown whether lymphatic valves exist in newly formed lymphatic vessels in the cornea, and how this relates to an inflammatory response. In this study, we provide the first evidence showing that lymphatic valves were formed in mouse cornea during suture-induced inflammation with the up-regulation of integrin alpha 9. The number of corneal valves increased with the progression of inflammatory lymphangiogenesis. Moreover, we have detected lymphatic valves at various developmental stages, from incomplete to more developed ones. In addition to defining the average diameter of lymphatic vessels equipped with lymphatic valves, we also report that lymphatic valves were more often located near the branching points. Taken together, these novel findings not only provide new insights into corneal lymphatic formation and maturation, but also identify a new model for future investigation on lymphatic valve formation and possibly therapeutic intervention

Differential distribution of blood and lymphatic vessels in the murine cornea. Invest Ophthalmol Vis Sci. 2010;51(5):2436-40. Rev Bras Oftalmol. 2015; 74 (1): 24-9 The main findings in histopathological examination of human corneal buttons with lymphangio

PURPOSE. Because of its unique characteristics, the cornea has been widely used for blood and lymphatic vessel research. However, whether limbal or corneal vessels are evenly distributed under normal or inflamed conditions has never been studied. The purpose of this study was to investigate this question and to examine whether and how the distribution patterns change during corneal inflammatory lymphangiogenesis (LG) and hemangiogenesis (HG). METHODS. Corneal inflammatory LG and HG were induced in two most commonly used mouse strains, BALB/c and C57BL/6 (6 -8 weeks of age), by a standardized two-suture placement model. Oriented flat-mount corneas together with the limbal tissues were used for immunofluorescence microscope studies. Blood and lymphatic vessels under normal and inflamed conditions were analyzed and quantified to compare their distributions. RESULTS. The data demonstrate, for the first time, greater distribution of both blood and lymphatic vessels in the nasal side in normal murine limbal areas. This nasal-dominant pattern was maintained during corneal inflammatory LG, whereas it was lost for HG. CONCLUSIONS. Blood and lymphatic vessels are not evenly distributed in normal limbal areas. Furthermore, corneal LG and HG respond differently to inflammatory stimuli. These new findings will shed some light on corneal physiology and pathogenesis and on the development of experimental models and therapeutic strategies for corneal diseases. (Invest Ophthalmol Vis Sci

Differential Distribution of Blood and Lymphatic Vessels in the Murine Cornea

This report provides the first evidence of a nasal-dominant distribution of blood and lymphatic vessels in the cornea, which not only will shed light on corneal physiology and pathogenesis but also will provide a new concept in designing experimental models using the cornea and developing therapeutic protocols for corneal diseases

Very Late Antigen-1 Mediates Corneal Lymphangiogenesis

This article reports the novel finding that VLA-1 directly mediates lymphangiogenesis. Anti–VLA-1 treatment is effective in suppressing corneal inflammatory lymphangiogenesis in vivo and several lymphatic endothelial cell functions in vitro

Modulation of Integrin α4β1 (VLA-4) in Dry Eye Disease

Objective To study the effect of topical application of very late antigen 4 (VLA-4) small-molecule antagonist (anti–VLA-4 sm) in a mouse model of dry eye disease. Methods Anti–VLA-4 sm (or control vehicle) was applied topically to mice placed in a controlled-environment chamber. Corneal fluorescein staining and conjunctival T-cell enumeration were performed in the different treatment groups. Real-time polymerase chain reaction was used to quantify expression of inflammatory cytokines in the cornea and conjunctiva. Results Dry eye syndrome induced increased corneal fluorescein staining, corneal and conjunctival tumor necrosis factor α messenger RNA expression, and T-cell infiltration into the conjunctiva. Very late antigen 4 blockade significantly decreased corneal fluorescein staining compared with the untreated dry eye disease and control vehicle–treated groups (P < .001 and P = .02, respectively). In addition, VLA-4 blockade was associated with a significant decrease in conjunctival T-cell numbers (P < .001 vs control vehicle–treated group) and tumor necrosis factor-α transcript levels in the cornea (P = .04 vs control vehicle–treated group) and conjunctiva (P = .048 vs control vehicle–treated group). Conclusion Application of topical anti–VLA-4 sm led to a significant decrease in dry eye signs and suppression of inflammatory changes at the cellular and molecular levels. Clinical Relevance Topical blockade of VLA-4 may be a novel therapeutic approach to treat the clinical signs and inflammatory changes accompanying dry eye disease

Topical Omega-3 and Omega-6 Fatty Acids for Treatment of Dry Eye

Objective To study the efficacy of topical application of alpha-linolenic acid (ALA) and linoleic acid (LA) for dry eye treatment. Methods Formulations containing ALA, LA, combined ALA and LA, or vehicle alone, were applied to dry eyes induced in mice. Corneal fluorescein staining and the number and maturation of corneal CD11b+ cells were determined by a masked observer in the different treatment groups. Real-time polymerase chain reaction was used to quantify expression of inflammatory cytokines in the cornea and conjunctiva. Results Dry eye induction significantly increased corneal fluorescein staining; CD11b+ cell number and major histocompatibility complex Class II expression; corneal IL-1α and tumor necrosis factor α (TNF-α) expression; and conjunctival IL-1α, TNF-α, interferon γ, IL-2, IL-6, and IL-10 expression. Treatment with ALA significantly decreased corneal fluorescein staining compared with both vehicle and untreated controls. Additionally, ALA treatment was associated with a significant decrease in CD11b+ cell number, expression of corneal IL-1α and TNF-α, and conjunctival TNF-α. Conclusions Topical ALA treatment led to a significant decrease in dry eye signs and inflammatory changes at both cellular and molecular levels. Clinical Relevance Topical application of ALA omega-3 fatty acid may be a novel therapy to treat the clinical signs and inflammatory changes accompanying dry eye syndrome