Aya Kodama

Kinki University, Ōsaka, Ōsaka, Japan

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Publications (7)10.71 Total impact

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    ABSTRACT: Purpose: Urokinase-type plasminogen activator (u-PA) plays an important role in corneal wound healing, yet its role in corneal inflammation remains poorly understood. We investigated the role of u-PA in a murine model of lipopolysaccharide (LPS)-induced corneal inflammation. Methods:The corneal epithelium was scraped and LPS was applied to u-PA wild-type (u-PA+/+) and u-PA-deficient mice (u-PA-/-). Corneal reepithelialization and opacity were measured by stereomicroscopy. Fibrin zymography was performed to detect plasminogen activators in corneas from u-PA+/+ and u-PA-/- mice. Neutrophil, macrophage, and u-PA receptor (u-PAR) expressions were determined by immunohistochemistry. Gene expressions of corneal MCP-1 and MIP-2 were assessed with reverse-transcription polymerase chain reaction. The in vitro effects of endogenous u-PA on MCP-1, MIP-2, MMP-2, and MMP-9 expressions, and macrophage migration activity in mouse ocular fibroblasts stimulated by LPS, were examined. Results:The u-PA+/+ mice showed showed enhanced corneal inflammation compared with u-PA-/- mice. The u-PA expression was increased by LPS stimulation. Immunohistochemical analyses indicated that more neutrophils and macrophages were present in corneas from u-PA+/+ mice than u-PA-/- mice. The u-PAR expression was detected in inflammatory cells and in the leading edges of the epithelial migrating cells. Enhanced mRNA expression of MCP-1 and MIP-2 was observed in corneas from u-PA+/+ mice compared to u-PA-/- mice. MCP-1, MIP-2, and MMP-9, but not MMP-2, significantly increased in corneal fibroblasts from u-PA+/+ mice compared with u-PA-/- mice. Conclusions:These data indicate that u-PA promotes LPS-induced leukocyte infiltration in cornea, and that u-PA is an important component in LPS-induced corneal inflammatory responses.
    Investigative ophthalmology & visual science. 07/2014;
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    ABSTRACT: The exact pathogenetic mechanisms of Coats' disease remain unknown. In this report, we show two cases of Coats' disease that achieved a favorable prognosis with the combined treatment of intravitreal bevacizumab (IVB) injection prior to photocoagulation, although both initially resisted photocoagulation therapy.Case presentations: Case 1 was a 15-year-old boy with initial visual acuity of 0.4 OD. At the temporal retina, aneurysms and abnormal telangiectatic vessels were observed. Hard exudates and an exudative retinal detachment extended to the fovea. He was diagnosed as having Coats' disease at stage 3A and we performed laser photocoagulation as an initial approach to treat peripheral aneurysms and telangiectatic vessels. After the treatment, the exudative retinal detachment was eased and visual acuity improved to 1.0; however, recurrence occurred after 5 months. The exudative change was resistant against laser photocoagulation therapy and we therefore added IVB as an adjuvant before photocoagulation. Fourteen days after IVB injection phased laser photocoagulation was given to cover the abnormal capillaries, aneurysms and the leakage area spotted in FA. A good prognosis was obtained with decreased exudation and improved visual acuity.Case 2 was an 11-year-old boy with decreased visual acuity of 0.15 OS at the initial visit. Hard exudates, retinal edema and serous retinal detachment were seen at the macula and peripheral retina. Fluorescein angiography revealed telangiectatic capillaries at the temporal retina. Our diagnosis was Coats' disease at stage 3A. Extensive photocoagulation was performed as an initial treatment to the lesion. However, the exudative change was severe and resistant against the photocoagulation treatment. Therefore, we added IVB as an adjuvant before photocoagulation. Exudative change in the retina seemed to be eased 7 days after IVB injection, therefore, phased laser phototherapy was added to cover the abnormal capillaries. After the combination therapy, exudative change was remarkably ameliorated and better visual acuity was achieved. Bevacizumab is considered an effective adjuvant for Coats' disease with exudative change resistant to retinal photocoagulation therapy.
    BMC Ophthalmology 03/2014; 14(1):36. · 1.44 Impact Factor
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    ABSTRACT: Transforming growth factor-beta (TGF-β) is one of the main epithelial-mesenchymal transition (EMT)-inducing factors. In general, TGF-β-induced EMT promotes cell migration and invasion. TGF-β also acts as a potent regulator of pericellular proteolysis by regulating the expression and secretion of plasminogen activators. Urokinase-type plasminogen activator (uPA) is a serine protease that binds to its cell surface receptor (uPAR) with high affinity. uPA binding to uPAR stimulates uPAR's interaction with transmembrane proteins, such as integrins, to regulate cytoskeletal reorganization and cell migration, differentiation and proliferation. However, the influence of TGF-β and the uPA/uPAR system on EMT in retinal pigment epithelial (RPE) cells is still unclear. The purpose of this study was to determine the effect of TGF-β2, which is the predominant isoform in the retina, and the uPA/uPAR system on RPE cells. In this study, we first examined the effect of TGF-β2 and/or the inhibitor of uPA (u-PA-STOP®) on the proliferation of a human retinal pigment epithelial cell line (ARPE-19 cells). Treatment with TGF-β2 or u-PA-STOP® suppressed cell proliferation. Combination treatment of TGF-β2 and u-PA-STOP® enhanced cell growth suppression. Furthermore, western blot analysis, fibrin zymography and real-time reverse transcription PCR showed that that TGF-β2 induced EMT in ARPE-19 cells and that the expression of uPA and uPAR expression was up-regulated during EMT. The TGF-β inhibitor SB431542 suppressed TGF-β2-stimulated uPA expression and secretion but did not suppress uPAR expression. Furthermore, we seeded ARPE-19 cells onto Transwell chambers and allowed them to invade the collagen matrix in the presence of TGF- β2 alone or with TGF- β2 and u-PA-STOP®. TGF-β2 treatment induced ARPE-19 cell invasion into the collagen gel. Treatment with a combination of TGF-β2 and the uPA inhibitor strongly inhibited ARPE-19 cell invasion compared with treatment with TGF-β2 alone. Furthermore, the interaction between uPA and ARPE-19 cells was analyzed using a surface plasmon biosensor system. The binding of uPA to ARPE-19 cells was observed. In addition, TGF-β2 significantly promoted the binding activity of uPA to ARPE-19 cells in a time-dependent or cell-number-dependent fashion. These results indicate that TGF-β-induced EMT-associated phenotype changes in ARPE-19 cells and the invasiveness of ARPE-19 cells into a collagen gel matrix are mediated, at least in part, by uPA.
    Experimental Eye Research 06/2013; · 3.03 Impact Factor
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    ABSTRACT: BACKGROUND: Corneal ulceration leading to perforation is associated with infectious and non-infectious destructive conditions in the cornea. The fibrinolytic (plasminogen/plasmin) system is considered to contribute to tissue remodeling in the wound healing process and it is believed to play an important role in proteolysis and fibrosis. To determine the localization of urokinase-type plasminogen activator (u-PA), u-PA receptor (u-PAR) and alpha2-antiplasmin (alpha2AP) in the tissue of a corneal perforation, we investigated immunohistochemical expressions of u-PA, u-PAR, alpha2AP, CD68, and alpha-smooth muscle actin (alpha-SMA) in a patient with corneal perforation that developed from an ulcer of no clear cause. CASE PRESENTATION: The patient was a 77-year-old woman who presented with a perforated corneal ulcer in her right eye. The cause of her corneal ulcer was unknown. Double immunohistochemistry was performed for the combinations of u-PA with u-PAR, CD68 or alpha-SMA and alpha2AP with CD68 or alpha-SMA to detect the localization of u-PA and alpha2AP. u-PA and u-PAR co-localization was seen in the corneal ulceration area. u-PA was mainly observed in CD68-positive cells and in some alpha-SMA positive cells. On the other hand, alpha2AP was not expressed in CD68-positive cells, but was expressed in alpha-SMA positive cells. CONCLUSION: We identified expression of the u-PA/u-PAR complex and alpha2AP in a patient with a corneal ulcer. These two molecules are believed to play a crucial role in inflammatory cell recruitment, ECM synthesis and degradation during corneal wound healing.
    BMC Ophthalmology 11/2012; 12(1):60. · 1.44 Impact Factor
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    ABSTRACT: The involvement of the epithelial mesenchymal transition (EMT) in the process of corneal wound healing remains largely unclear. The purpose of the present study was to gain insight into Slug expression and corneal wound healing. Slug expression during wound healing in the murine cornea was evaluated using fluorescence staining in vivo. Slug or Snail was stably introduced into human corneal epithelial cells (HCECs). These stable transfectants were evaluated for the induction of the EMT, cellular growth, migration activity, and expression changes in differentiation-related molecules. Slug, but not Snail, was clearly expressed in the nuclei of corneal epithelial cells in basal lesion of the corneal epithelium during wound healing in vivo. The overexpression of Slug or Snail induced an EMT-like cellular morphology and cadherin switching in HCECs, indicating that these transcription factors were able to mediate the typical EMT in HCECs. The overexpression of Slug or Snail suppressed cellular proliferation but enhanced the migration activity. Furthermore, ABCG2, TP63, and keratin 19, which are known as stemness-related molecules, were downregulated in these transfectants. It was found that Slug is upregulated during corneal wound healing in vivo. The overexpression of Slug mediated a change in the cellular phenotype affecting proliferation, migration, and expression levels of differentiation-related molecules. This is the first evidence that Slug is regulated during the process of corneal wound healing in the corneal epithelium in vivo, providing a novel insight into the EMT and Slug expression in corneal wound healing.
    Investigative ophthalmology & visual science 02/2012; 53(2):751-6. · 3.43 Impact Factor
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    ABSTRACT: Corneal wound healing is a complex process involving the integrated actions of various growth factors, cytokines and extracellular matrix produced by corneal cells and inflammatory cells. Connective tissue growth factor (CTGF) has been linked to wound healing, and fibronectin (FN) is a major component of the extracellular matrix. However, the functions of CTGF and FN in corneal epithelial cells are not well understood. We therefore investigated the coordinated function of CTGF and FN in the attachment and migration of corneal epithelial cells. Treatment of human corneal epithelial cells (HCECs) with transforming growth factor (TGF) beta1 up-regulated the expression of CTGF, but did not noticeably affect FN expression, as judged by immunoblot analysis of cell lysates. In contrast, the amount of FN accumulated in the cultured media was increased in a time-dependent manner, but CTGF was undetectable in the cultured media. The expression level of FN was decreased by the knockdown of CTGF expression with a specific short hairpin RNA, indicating that CTGF acts as an upstream mediator of FN expression. CTGF augmented the FN-mediated increase in the attachment of HCEC by about twofold, although CTGF alone did not influence the attachment. Moreover, the migration assay with rabbit corneal blocks revealed that CTGF (390 nM) alone or in combination of FN (10 microg/mL) promoted corneal epithelial migration; the mean migration distances of control, CTGF, and CTGF + FN were 272, 325, and 626, microm, respectively. In conclusion, CTGF cooperates with FN in enhancing the attachment and migration of corneal epithelial cells.
    The Tohoku Journal of Experimental Medicine 01/2010; 222(1):45-50. · 1.37 Impact Factor
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    ABSTRACT: Neovascular glaucoma (NVG) secondary to internal carotid artery (ICA) occlusion is usually resistant to treatment. We report a case of NVG with ICA occlusion improved by intravitreal bevacizumab (IVB) injection and carotid artery stent replacement (CAS), even though we did not perform panretinal photocoagulation. A 67-year-old male with NVG noted visual loss in his left eye. Magnetic resonance angiography showed left ICA occlusion. He was diagnosed with NVG secondary to ICA occlusion. The next day, we carried out IVB injection in his left eye, following which the iris and angle neovascularization regressed, and the intraocular pressure decreased to normal within a day after the injection. CAS was performed on his left ICA at a month post injection. Two months later, we reinjected bevacizumab in his left eye. His condition remained stable with no recurrence over two years. This case indicates that IVB injection and CAS are useful for early-stage NVG secondary to ICA occlusion.
    Clinical Ophthalmology 01/2010; 4:1177-80.