Noriyasu Hashida

Nuclear cataract caused by a lack of DNA degradation in the mouse eye lens

The eye lens is composed of fibre cells, which develop from the epithelial cells on the anterior surface of the lens. Differentiation into a lens fibre cell is accompanied by changes in cell shape, the expression of crystallins and the degradation of cellular organelles. The loss of organelles is believed to ensure the transparency of the lens, but the molecular mechanism behind this process is not known. Here we show that DLAD (‘DNase II-like acid DNase’, also called DNase IIβ) is expressed in human and murine lens cells, and that mice deficient in the DLAD gene are incapable of degrading DNA during lens cell differentiation—the undigested DNA accumulates in the fibre cells. The DLAD-/- mice develop cataracts of the nucleus lentis, and their response to light on electroretinograms is severely reduced. These results indicate that DLAD is responsible for the degradation of nuclear DNA during lens cell differentiation, and that if DNA is left undigested in the lens, it causes cataracts of the nucleus lentis, blocking the light path.

Comparison of three techniques of foveal translocation in patients with subfoveal choroidal neovascularization resulting from age-related macular degeneration

PURPOSE To report the results of three methods of foveal translocation in the presence of subfoveal choroidal neovascular membrane resulting from age-related macular degeneration. METHODS We treated 51 eyes of 51 consecutive patients with subfoveal choroidal neovascular membranes resulting from age-related macular degeneration with one of three techniques of foveal translocation surgery: foveal translocation with partial retinotomy (n = 6), limited translocation (n = 9), and translocation with 360-degree retinotomy (n = 36). All patients were followed for at least 6 months postoperatively. The size of the choroidal neovascular membrane and the amount of foveal displacement, the best-corrected visual acuity, and complications were recorded preoperatively and postoperatively. RESULTS The mean distance of the foveal translocation was greater in the 360-degree retinotomy group (3340 microm) than in the partial retinotomy (1060 microm, P <.001) and the limited translocation groups (1120 microm, P <.001). A final visual acuity of 20/200 or better was achieved in two eyes (33%) in the partial retinotomy group, seven eyes (78%) in the limited translocation group, and 23 eyes (64%) in the 360-degree retinotomy group. The final visual acuity improved by 0.2 logarithm of minimal angle of resolution (logMAR) unit or more in one eye (17%), one eye (11%), and seven eyes (19%), respectively. The final visual acuity was maintained within 1 line in zero eyes, five eyes (56%), and 19 eyes (53%), respectively. A retinal detachment developed postoperatively in five eyes (83%), zero eyes (0%), and 15 eyes (42%), respectively. CONCLUSIONS A significant number of patients improved or maintained best-corrected visual acuity after translocation with 360-degree retinotomy, and limited translocation, whereas translocation with 360-degree retinotomy is suitable for larger choroidal neovascular membranes because it resulted in the greatest foveal displacement among the three translocation procedures.

Effect of Intravitreous Rituximab Injections in Patients With Recurrent Ocular Lesions Associated With Central Nervous System Lymphoma

Most central nervous system (CNS) lymphomas, including primary intraocular lymphoma, are large Bcell neoplasms that express CD20. Although intravenously administered rituximab, which is a chimeric anti-CD20 human monoclonal antibody, contributes to prolonged survival in patients with systemic large B-cell lymphoma, the drug may not affect the prognosis of CNS lymphoma, possibly because the monoclonal antibody does not effectively penetrate the intact bloodbrain barrier. Therefore, intravenous rituximab treatment of ocular lesions associated with CNS lymphoma also could not be expected to be beneficial because of the bloodocular barrier. Recent studies have shown that 1 intravitreous injection of rituximab is safe in rabbit eyes. Kitzmann et al also reported that 3 to 4 injections of rituximab did not cause significant ocular toxic effects in patients with primary CNS lymphoma. However, because their patients were all treated with either additional systemic treatment or ocular treatment, they could not draw conclusions about the effectiveness of intravitreous rituximab therapy. We report the effect of intravitreous injections of rituximab on ocular lesions in 2 patients with recurrent CNS lymphoma.

Comprehensive gene-expression profile in murine oxygen-induced retinopathy

Background/aims: To investigate the correlation between the clinical course and gene-expression pattern in murine oxygen-induced retinopathy (OIR), a commonly used model of retinopathy of prematurity (ROP). Methods: OIR was induced in C57BL/6N mice by placing postnatal day 7 (P7) pups in 75% oxygen for 5 days. The clinical course of the OIR was evaluated on retinal flat-mounts after fluorescein isothiocyanate-conjugated dextran perfusion from P12 to P21. The expression values of 94 genes, selected by microarray analyses, were determined daily from P12 through P21 by RT-PCR with TaqMan low-density array (TLDA) and analysed by hierarchical clustering. Results: TLDA cluster analyses showed a homology of gene-expression pattern between P12 and P13 and between P16 and P17. Many genes associated with inflammation were upregulated on P12 and P13 when the degree of both central avascular area and central vasoconstriction were maximal, and the upregulation of the genes continued to P21. At P16 and P17 when extraretinal neovascularisation became most noticeable, several genes associated with angiogenesis, for example, vascular endothelial growth factor-A and angiopoietin-2, were most upregulated. Conclusion: The gene-expression pattern was well correlated with the clinical appearance in murine OIR. These findings should contribute to the understanding of the pathological conditions in ROP.

Sustained delivery of a HIF-1 antagonist for ocular neovascularization.

Doxorubicin (DXR) and daunorubicin (DNR) inhibit hypoxia-inducible factor-1 (HIF-1) transcriptional activity by blocking its binding to DNA. Intraocular injections of DXR or DNR suppressed choroidal and retinal neovascularization (NV), but also perturbed retinal function as demonstrated by electroretinograms (ERGs). DXR was conjugated to novel copolymers of branched polyethylene glycol and poly(sebacic acid) (DXR-PSA-PEG3) and formulated into nanoparticles that when placed in aqueous buffer, slowly released small DXR-conjugates. Intraocular injection of DXR-PSA-PEG3 nanoparticles (1 or 10 μg DXR content) reduced HIF-1-responsive gene products, strongly suppressed choroidal and retinal NV, and did not cause retinal toxicity. In transgenic mice that express VEGF in photoreceptors, intraocular injection of DXR-PSA-PEG3 nanoparticles (10 μg DXR content) suppressed NV for at least 35 days. Intraocular injection of DXR-PSA-PEG3 nanoparticles (2.7 mg DXR content) in rabbits resulted in sustained DXR-conjugate release with detectable levels in aqueous humor and vitreous for at least 105 days. This study demonstrates a novel HIF-1-inhibitor-polymer conjugate formulated into controlled-release particles that maximizes efficacy and duration of activity, minimizes toxicity, and provides a promising new chemical entity for treatment of ocular NV.

Neutrophil Chemotaxis and Local Expression of Interleukin-10 in the Tolerance of Endotoxin-Induced Uveitis

PURPOSE To study the mechanism of lipopolysaccharide (LPS) tolerance in a rat model of footpad injection endotoxin-induced uveitis (EIU). METHODS EIU was produced by footpad injection of 1 mg/kg LPS in male Sprague-Dawley rats. Four experiments were undertaken in this study. First, on days 3, 7, 14, 28, 56, and 84 after LPS injection, the iris-ciliary body (ICB) was isolated. LPS tolerance-associated gene expression in the ICB was determined by quantitative polymerase chain reaction. Second, the distribution of IL-10-producing cells in frozen sections of ocular tissues was analyzed by fluorescence and confocal microscopy. Third, peripheral blood neutrophil chemotaxis was determined using a fluorescent in vitro migration assay. Fourth, for in vivo neutrophil chemotaxis assay, neutrophils isolated from EIU-tolerant or control rats were transfused into green fluorescence protein (GFP) rats injected with LPS 18 hours earlier. Six hours after transfusion, the percentage of GFP-negative neutrophils in the aqueous humor was determined by flow cytometry. RESULTS IL-10 gene expression in ICB was significantly upregulated for at least 1 month. Immunohistochemical examination indicated that dendritic cells in the ICB produced IL-10. Peripheral blood neutrophil chemotaxis in EIU-tolerant rats was inhibited significantly in vitro and in vivo. IL-10 enhanced the reduction of neutrophil chemotaxis in EIU-tolerant rats in vitro. CONCLUSIONS The results suggest that continuous high expression of IL-10 in the eye and the reduction of peripheral blood neutrophil chemotaxis play significant roles in the mechanism of LPS tolerance in a rat model of footpad injection EIU.

Ethnic specific association of the CAV1/CAV2 locus with primary open-angle glaucoma.

A single-nucleotide polymorphism (SNP) rs4236601 at the CAV1/CAV2 locus is associated with primary open-angle glaucoma (POAG). Rs4236601 is common in Caucasians but rare in East Asians. Here we conducted a haplotype-tagging SNP analysis followed by replication in a total of 848 POAG cases and 1574 controls drawn from 3 cities in China and 1 city in Japan. Two SNPs, rs4236601 (odds ratio [OR] = 6.25; P = 0.0086) and a tagging-SNP rs3801994 (OR = 1.32; P = 0.042), were associated with POAG in the Hong Kong Chinese cohort after age and gender adjustments. Rs4236601 was associated with POAG also in Shantou (OR = 6.09; P = 0.0037) and Beijing (OR = 3.92; P = 0.030) cohorts after age and gender adjustment, with a pooled-OR of 5.26 (P = 9.0 × 10−6) in Chinese; but it is non-polymorphic in the Osaka cohort. SNP rs3801994 showed a similar trend of effect in the Shantou and Beijing cohorts, with a pooled-OR of 1.23 (P = 0.022) and 1.20 (P = 0.063) in Chinese, prior to and after age and gender adjustment, respectively; but it showed a reverse effect in the Osaka cohort (OR = 0.58; P = 0.033) after the adjustments. We have thus confirmed the association of rs4236601 with POAG in different Chinese cohorts. Also, we found a common SNP rs3801994 of diverse associations with POAG between Chinese and Japanese.

Topical Pazopanib Blocks VEGF-Induced Vascular Leakage and Neovascularization in the Mouse Retina but Is Ineffective in the Rabbit

PURPOSE To test the effect of pazopanib, a tyrosine kinase inhibitor that blocks VEGF and platelet-derived growth factor (PDGF) receptors and c-Kit, on vascular leakage and neovascularization (NV) in the retina. METHODS Pazopanib was tested to determine its effect on VEGF-induced vascular permeability via measurement of [(3)H]mannitol retina to lung (RLLR) and retina to renal leakage ratios (RRLR) and in rho/VEGF mice with subretinal NV. In rabbits, the effect of intravitreal, topical, and systemic pazopanib on VEGF-induced leakage was tested by vitreous fluorophotometry. RESULTS In mice, oral pazopanib (40 mg/kg twice a day [bid]) reduced RLLR (0.84 to 0.58, P = 0.0014) and RRLR (0.55 to 0.30, P = 0.0018) in VEGF-injected eyes. After intraocular injection of VEGF into both eyes, topical pazopanib (10 mg/mL three times a day [tid] for 14 days) reduced RLLR (0.85 vs. 0.56, P = 0.001), RRLR (0.44 vs. 0.28, P = 0.0075), and immunoreactive albumin in the retina compared to values in fellow eye controls. Treatment of one eye of rho/VEGF mice with 10 mg/mL, but not 5 mg/mL, pazopanib tid reduced the mean area of subretinal NV compared to that in fellow eyes (0.0055 vs. 0.0025 mm(2), P = 0.020). In rabbits, intravitreal pazopanib suppressed VEGF-induced fluorescein leakage, but topical (10 mg/mL four times a day [qid] or 12 mg/mL bid) had no significant effect. Systemic administration of pazopanib by osmotic pump with or without 10 mg/mL drops tid also failed to suppress VEGF-induced leakage. CONCLUSIONS Administration of pazopanib topically or systemically suppressed retinal vascular leakage in mice, but not rabbits. These data suggest differences in the blood-retinal barrier (BRB) of mice and rabbits and indicate that penetration through the outer BRB may be needed for topically administered drugs to exert effects in the retina.

Pharmacokinetic Behavior of Intravitreal Triamcinolone Acetonide Prepared by a Hospital Pharmacy

PurposeWe developed a new hospital pharmaceutical preparation of triamcinolone acetonide (TA) for intravitreal injections using sodium hyaluronate as the vehicle. The purpose of this study was to compare the pharmacokinetic behavior of this hospital pharmacy preparation of TA (HPP-TA) to that of a commercial preparation of TA (CP-TA) in rats.MethodsWe injected the two preparations of TA into the vitreous humor of male Wistar rats. The rats were killed between days 1 and 21, and the concentration of TA in the vitreous was measured by high-performance liquid chromatography to determine the pharmacokinetic parameters. We also examined the microscopic appearance of the TA particles in these preparations.ResultsThe elimination half-life was 6.08 days for the CP-TA and 5.78 days for the HPP-TA. A two-compartment model was suitable to approximate the pharmacokinetic behavior of HPP-TA in the vitreous body, but this model was not suitable for CP-TA, because its pharmacokinetic behavior was not sufficiently stable. The particle size of CP-TA was largest, followed by TA powder and HPP-TA. Many particles were agglutinated in the CP-TA preparation, whereas the TA particles were fine and dispersed in the HPP-TA medium.ConclusionsThe TA particle size and the suspension medium are likely important factors in the preparation of a safe and stable suspension of TA. HPP-TA satisfied these requirements and should be suitable for clinical use.

Unusual neutrophil infiltration under the soft contact lens in a patient with Behçet's disease

BACKGROUND Behçets disease (BD) characterized by multisystemic disorders has many kinds of ocular involvement. We report one case of BD with unusual neutrophil infiltration under a soft contact lens (SCL). CASE A 31-year-old woman diagnosed as having BD exhibited bilateral recurrent phlyctenular keratitis and finally developed corneal perforation in the cornea of her right eye. OBSERVATIONS A therapeutic SCL was immediately fitted on the right cornea as a bandage and another SCL on the left, as prophylaxis. White gelatinous membrane suddenly appeared between the bandage SCL and the cornea in the left eye. After peeling off this gelatinous membrane from the cornea, we examined it after hematoxylin-eosin staining. We also measured the levels of interleukin-8 (IL-8) both in the tears of the patient and on the surface of the SCL. A great amount of neutrophils had infiltrated into this gelatinous membrane. Laboratory data showed a marked increase of IL-8 levels both on the SCL and in the reflex tears (right SCL, 4980 pg/mL; left SCL, 6810 pg/mL. Reflex tears: right, 2080 pg/mL; left, 2170 pg/mL). CONCLUSION This case emphasizes the association between the IL-8 level and the disease activity in BD, and provides additional evidence that a BD attack can be induced on the ocular surface under certain conditions.