Akiko Ishimori

Anti-inflammatory effect of IL-6 receptor blockade in corneal alkali burn

We investigated the effect of soluble IL-6R (sIL-6R) blockade on corneal inflammation. Topical instillation of either anti-IL-6R antibody (MR16-1) or phosphate buffered saline (PBS) was applied after wounding BALB/c mice corneas with alkali burn. The vascularized area was significantly reduced in the MR16-1 group. The immunoreactivity of phosphorylated STAT3, Gr-1, and F4/80 diminished significantly in the MR16-1 group. Laser capture microdissection resulted in a significant down-regulation of the mRNA expressions of ICAM-1, MCP-1, and VEGF-A in the corneal stroma of the MR16-1 group. Adding a combination of recombinant IL-6 and sIL-6R resulted in a significant increase in the release of VEGF from human corneal fibroblasts. As the infiltration of inflammatory cells, the expression of phosphorylated STAT3, and the expressions of inflammatory-related molecules in the experimental model of corneal inflammation were significantly inhibited by topical instillation of MR16-1, we deduce that IL-6 trans-signaling plays a significant role in ocular surface inflammation and that the blockade of IL-6R contributes to the reduction in corneal inflammation.

Minimum endotoxin concentration causing inflammation in the anterior segment of rabbit eyes

PurposeThis was a quantitative study to investigate the minimum endotoxin concentration causing inflammation in the anterior segment of the eye.MethodsEndotoxin was injected intracamerally in pigmented rabbits. A quantitative determination of flare and cells in the aqueous was performed using a laser flare-cell photometer, before and until 72 h after the treatment. An area under the curve (AUC) analysis was employed to evaluate the whole inflammatory reaction regarding flare values.ResultsThe time course of flare values in each endotoxin group showed a similar pattern with a peak value at 3 h. An AUC corresponding to values for “average +2σ”, 19301.8 in control eyes, was considered the cutoff value. Using this cutoff value and the regression curve in endotoxin-treated groups, the minimum endotoxin concentration causing inflammation regarding flare values was determined to be 0.60 endotoxin units (EU). Cell counts (cells/0.5 mm3·0.5 s) corresponding to the value “average +2σ”, 6.07 at 24 h, in control eyes was considered to be the cutoff value. The minimum endotoxin concentration regarding cell counts was determined to be 0.23 EU.ConclusionThere was a dissociation in response between flare and cells in the aqueous to intracameral endotoxin. The minimum endotoxin concentration causing inflammation ranged between 0.23 and 0.60 EU.

Simultaneous study of matrix metalloproteinases, proinflammatory cytokines, and soluble cytokine receptors in the tears of noninfectious corneal ulcer patients

BackgroundWe investigated the presence of matrix metalloproteinases (MMPs), tissue inhibitors of metalloproteinases (TIMPs), proinflammatory cytokines, and soluble cytokine receptors in the tear fluid of patients with noninfectious corneal ulcers in the peripheral cornea.MethodsThe subjects were 20 eyes of 17 patients with peripheral noninfectious corneal ulcers and 20 eyes of 20 volunteers. Tear samples were taken by the Schirmer test I method and the presence of MMPs (MMP-1, MMP-2, MMP-3, MMP-8, MMP-9, MMP-10, and MMP-13) and TIMPs (TIMP-1, TIMP-2, and TIMP-4) were investigated using an MMP antibody array system. The concentrations of proinflammatory cytokines {IL-1β, IL-6, and TNF-α (tumor necrosis factor-alpha)} and soluble cytokine receptors {soluble (s) IL-1R1, sIL-1R2, sIL-2Rα, sIL-4R, sIL-6R, sTNFR1, sTNFR2, s-vascular endothelial growth factor receptor (VEGFR) 1, sVEGFR2, sVEGFR3, and sgp130} were determined using the multiplex bead immunoassay system.ResultsThe concentrations of MMP-8 and MMP-9 were significantly up-regulated in the tear fluid of the ulcer patients, whereas TIMPs concentrations did not change. The concentrations of IL-1β, IL-6, sIL-1R2, sIL-6R, sTNFR1, and sTNFR2 were up-regulated in the ulcer patients, whereas sgp130 and sVEGFR1 concentrations significantly decreased.ConclusionsThe presence of some MMPs increased significantly in the patients with peripheral noninfectious corneal ulcers, whereas the presence of TIMPs remained unchanged. Although some proinflammatory cytokines were up-regulated, their antagonists, soluble cytokine receptors, were also up-regulated. It is thus possible that the up-regulation of MMPs disrupts the balance between the MMPs and TIMPs and that this balance may play a pivotal role in the pathophysiology of corneal ulceration.

Evaluation of Eosinophilic Inflammation in a Novel Murine Atopic Keratoconjunctivitis Model Induced by Crude Dermatophagoides farinae Antigen

BACKGROUND The purpose of this study is to conduct a histopathological research of the conjunctival findings and eosinophilic inflammation of novel atopic keratoconjunctivitis in a NC/Nga mouse model using crude Dermatophagoides farina. METHODS NC/Nga mice were sensitized by repeated topical applications of an ointment containing Dermatophagoides farinae body (Dfb). They were then divided into 4 groups depending on the following topical ophthalmic treatment: DFb group undergoing topical ophthalmic ointment containing Dfb; DFco group undergoing topical instillation of allergen extracts of Dermatophagoides farinae; Ba group undergoing topical ointment with substrate alone and NT group without after-topical ophthalmic treatment. At 24 hours after the last ophthalmic treatment, histopathological examination was performed. The density of the subepithelial infiltration of the eosinophils was determined. Serum total IgE and house-dust-mite (HDM)-specific IgE antibody concentrations were determined by enzyme-linked immunosorbent assay (ELISA). RESULTS In the DFb group, the conjunctiva showed similar findings to those of atopic keratoconjunctivitis, i.e. intraepithelial pseudotubular formation, Torus-form infiltration due to massive lymphocytes in the palpebral conjunctiva and gelatinous hyperplasia in the limbus with subepithelial granuloma composed of lymphocytes and eosinophils. Subepithelial infiltration of eosinophil density in the DFb group [878.4 ± 399.7cells/mm2 (mean ± SD)] was significantly higher than in the other 2 groups (DFco 85.6 ± 40.1 Ba 49.2 ± 32.3) (P < 0.001). Total serum IgE concentration and HDM-specific serum IgE antibody concentration in the DFb group and the DFco group were significantly higher compared with those in the NT group. CONCLUSIONS Topical application of an ointment containing DFb to both the skin and eyes of NC/Nga mice can induce an atopic keratoconjunctivitis (AKC) model in these mice.

CCL20/MIP-3 alpha mRNA expression in the conjunctival epithelium of normal individuals and patients with vernal keratoconjunctivitis

BackgroundCCL20, the single chemokine ligand for CCR6, contributes to recruiting CCR6-expressing memory B cells, memory T cells, Th17 cells and dendritic cells, and is involved in regulating immune responses, homeostasis, and inflammation in mucosal tissues.MethodsCCL20 messenger RNA (mRNA) expression was analyzed in the conjunctival epithelium in an in vivo study of patients with vernal keratoconjunctivitis (VKC group) and healthy volunteers (control group) using impression cytology. In vitro analysis of CCL20 mRNA was performed using cultured conjunctival epithelial cells (CECs). Real-time polymerase chain reaction was used to assess IL-8 and eotaxin-2 mRNA expression for comparison with CCL20 mRNA expression.ResultsIn the control group, CCL20 mRNA expression was present in all conjunctival locations. However, CCL20 mRNA expression was significantly higher in the upper palpebral conjunctiva in the severe VKC group than in the mild VKC and control groups (p < 0.05, Steel test). In vitro stimulation of CECs with lipopolysaccharide (LPS) significantly increased CCL20 expression in a concentration-dependent manner that was significantly correlated with expression of IL-8 (p < 0.001, Spearman’s rank correlation coefficient), but not eotaxin-2.ConclusionWe conclude that CCL 20 mRNA expression in the conjunctival epithelium plays a crucial role in regulating homeostasis at the ocular surface and in exacerbation of VKC.

Involvement of Chemokines and a CD4-Positive T Cell Subset in the Development of Conjunctival Secondary Lymphoid Follicles in an Atopic Keratoconjunctivitis Mouse Model

Background: Massive B cell lymphoid hyperplasia and its associated factors may play a role in exacerbating inflammation in allergic disorders. We here investigated the chemokines and CD4-positive T cell subset involved in the development of secondary lymphoid follicles (iCALT) in conjunctival tissues in an atopic keratoconjunctivitis mouse model (AKC mouse). Methods: NC/Nga mice were divided into three groups: AKC (percutaneous sensitization and instillation of crude house dust mite antigen), AD (percutaneous sensitization only) and C (untreated control). Pathological changes in the conjunctival tissues of each group were investigated using histological and immunohistochemical detection of CD4 and CD20. Furthermore, tissue sections of iCALT (AKC-iCALT subgroup) and conjunctiva without iCALT (AKC-conjunctiva subgroup) were obtained from AKC mice using laser-assisted microdissection. mRNA expression of chemokine and T cell subset-related transcription factors were compared between the AKC-iCALT and AKC-conjunctiva subgroups using polymerase chain reaction (PCR) array and real-time reverse transcription-PCR (RT-PCR) methods. Results: iCALT with central aggregation of CD20-positive B cells and CD4-positive T cell infiltration surrounding B cells was observed in the palpebral conjunctival tissue of the AKC group, but not in that of the AD and C groups. Chemokine and T cell subset-related transcription factor expression was confirmed using real-time RT-PCR, with significant increases in Ccl5, Ccl17, Cxl20, Cxcl3, Ccr7, Foxp3 and T-bet mRNA expression in the AKC-iCALT subgroup compared with those in the AKC-conjunctiva subgroup. Conclusions: We concluded that CCL5, CCL17 and CCL20, as well as T-bet- and Foxp3-positive lymphocytes may be iCALT-related factors and that iCALT-related chemokines are worth evaluating as biomarkers.