Yasuhiro Miyagawa

Expression profiles of cytokines and chemokines in vitreous fluid in diabetic retinopathy and central retinal vein occlusion

PurposeThe involvement of cytokines and chemokines in vitreous fluid is important in the development and progression of diabetic retinopathy (DR) and central retinal vein occlusion (CRVO). In this study, the concentrations of cytokines and chemokines in the vitreous fluid of eyes with DR and CRVO were measured and compared.MethodsWe studied 76 eyes with proliferative DR and diabetic macular edema (DR group), 10 eyes with CRVO (CRVO group), and 23 eyes with an epiretinal membrane and macular hole (control group), among a series of 160 eyes from which vitreous fluid samples were collected during vitrectomy. The vitreous fluid samples were collected by suction with a vitreous cutter at the initial stage of vitrectomy. Twenty-seven different cytokines and chemokines were measured simultaneously using an array system (Bio-Plex®) with beads combined with antibodies (Bio-Rad), as follows: interleukin (IL)-1β, IL-1 receptor agonist, IL-2, IL-4, IL-5, IL-6, IL-7, IL-8, IL-9, IL-10, IL-12, IL-13, IL-15, IL-17, eotaxin, basic fibroblast growth factor, granulocyte colony-stimulating factor (G-CSF), granulocyte/macrophage colony-stimulating factor (GM-CSF), interferon (IFN)-γ, interferon-inducible 10-kDa protein (IP-10), monocytochemotactic protein-1 (MCP-1), macrophage inflammatory protein-1 alpha (MIP-1α), MIP-1β, platelet-derived growth factor (PDGF)-BB, regulated upon activation, normal T cell expressed and secreted, tumor necrosis factor alpha (TNF-α), and vascular endothelial growth factor (VEGF).ResultsCompared to the control group, the levels of IL-6, IL-8, IL-10, IL-13, IP-10, MCP-1, MIP-1β, PDGF and VEGF in the vitreous fluid were significantly higher in the DR group, while the levels of IL-1β, IL-2, IL-5, IL-8, IL-9, IL-10, IL-12, IL-13, eotaxin, G-CSF, IFN-γ, IP-10, MCP-1, MIP-1β, TNF-α and VEGF were significantly higher in the CRVO group. Compared to the DR group, IL-2, IL-9, IL-12, MCP-1 and IFN-γ were significantly elevated in the CRVO group. Multivariate regression analysis revealed that among 6 factors correlated to VEGF in the DR group, IL-10 and IL-13 were more positively correlated and PDGF was most inversely correlated to VEGF.ConclusionIn addition to inflammatory cytokines and neurotrophic factors such as VEGF, anti-inflammatory cytokines such as IL-10 and IL-13 may be involved more in the pathogenesis of DR and CRVO than in other diseases; cytokines and chemokines may also be correlated to VEGF in the vitreous fluid. It is also suggested that the inflammatory reaction may be more activate in CRVO than in DR.

Effect of nilvadipine on central visual field in retinitis pigmentosa: a 30-month clinical trial.

Purpose: To assess the effects of nilvadipine on the progression of central visual field defect in retinitis pigmentosa (RP). Design: Prospective, randomized, nonmasked, single-center trial. Methods: Patients with RP were randomly divided into a treated group receiving oral nilvadipine at 4 mg/day for ≧30 months and a control group receiving tocopherol nicotinate at 300 mg/day, helenien at 15 mg/day or no medication for the same periods. Progression of RP was evaluated using the 10-2 SITA Fast Program of the Humphrey Visual Field Analyzer, and regression coefficients calculated from the time courses of mean deviation (MD slope) were compared between groups. Results: Nineteen patients in the treated group and 14 patients in the control group completed the follow-up for ≧30 months. The mean (±standard deviation) duration of observation was 48.8 ± 11.8 months (median 48 months, range 30–66 months) for the treated group and 49.2 ± 18.1 months (median 48 months, range 30–90 months) for the control group (p = 0.94). Mean (±standard error of the mean, SEM) regression coefficients of the averaged MD values for the initial 30 months were –0.35 ± 0.17 dB/year in the treated group and –0.75 ± 0.06 dB/year in the control group (p < 0.01). Mean (±SEM) MD slopes for total observational periods were –0.49 ± 0.17 dB/year in the treated group and –0.89 ± 0.16 dB/year in the control group (mean ± SEM, p = 0.042). Conclusion: Nilvadipine at 4 mg/day significantly retarded progression of central visual field defects in RP in this small patient series.

Study of pharmacological effects of nilvadipine on RCS rat retinal degeneration by microarray analysis.

In our recent study, we found that the Ca(2+) antagonist, nilvadipine caused significant preservation of photoreceptor cells in The Royal College of Surgeons (RCS) rats [Invest. Ophthalmol. Vis. Sci. 43 (2002) 919]. Here, to elucidate the mechanisms of nilvadipine-induced effects we analyzed altered gene expression of 1101 genes commonly expressed in rodent by DNA microarray analysis in the retinas of nilvadipine-treated and untreated RCS rats and SD rat. In the total number of genes, the expression of 30 genes was altered upon administration of nilvadipine to RCS rats, including several genes related to the apoptotic pathway and other mechanisms. Remarkably, neurotrophic factors, FGF-2 and Arc, known to suppress the apoptosis in the central nervous system, were up-regulated. These changes were also confirmed by real-time quantitative (Taqman) RT-PCR and Western blot analysis. Therefore, our present data suggested that administration of nilvadipine to RCS rats increases the expression of endogenous FGF-2 and Arc in retina, and potentially has a protective effect against retinal degeneration.

Aberrantly expressed recoverin is functionally associated with G-protein-coupled receptor kinases in cancer cell lines

Cancer-associated retinopathy (CAR) is an ocular manifestation of a paraneoplastic syndrome whereby immunological reactions toward recoverin (Rec), a retina-specific Ca(2+) binding protein, and its aberrant expression in tumor cells lead to the retinal degeneration. To elucidate functional roles of the aberrantly expression in cancer cells, we performed immunoprecipitation using anti-human Rec mAb. We observed co-precipitation of G-protein-coupled receptor kinases (GRKs) and caveolin-1 with Rec from cell lysates of 293 or SSTW cells. Immunocytochemistry revealed that immunoreactivities toward Rec within the cancer cells were almost identical to those toward GRKs and caveolin-1. The present data strongly suggest that aberrantly expressed Rec should be involved in the GRK-dependent cellular regulation in cancer cells.

Inhibitory effects of trehalose on fibroblast proliferation and implications for ocular surgery

Trehalose is a disaccharide which plays an important role in preserving cells from completely dehydrated circumstances. In this study, we investigated effects of trehalose on proliferative activity of fibroblasts and epithelial cells both in vitro and in vivo. As in vitro assessment, normal human dermal fibroblasts and normal human epidermal keratinocytes were cultured in media containing various concentrations of trehalose. Growth activities of cells were evaluated with MTT assay and diff-quick™ staining. Expressions of vimentin and α smooth muscle actin (α-SMA) changed by trehalose were semiquantitatively measured by Western blot. As an in vivo study, 5% or 10% trehalose was topically instilled onto rabbit eyes after simple conjunctival incision or trabeculectomy. Condition of the surgical wound was evaluated by morphologically and immunohistochemically using isolectin B4 and antibodies specific for vimentin and α-SMA. Intraocular pressures (IOPs) after trabeculectomy were compared between eyes treated with trehalose and 0.04% mitomycin C (MMC). Results obtained by in vitro experiments showed that growth activities of cultured fibroblasts and keratinocytes were inhibited by trehalose in a dose-dependent manner. Fibroblasts were strongly inhibited by trehalose concentrations ≧ 5% of trehalose, whereas keratinocytes were less inhibited compared to fibroblasts. Expressions of vimentin and α-SMA were reduced by trehalose. With in vivo experiments, postoperative application of trehalose resulted in less firm adhesion between conjunctiva and sclera compared to controls. Immunohistochemical studies showed reduced staining of isolectin B4, vimentin and α-SMA in conjunctival wounds treated by topical trehalose. Also, after trabeculectomy, IOP remained in a low range during instillation of topical trehalose solution. We concluded that trehalose has inhibitory effects on proliferation of fibroblasts and vascular tissues, partially due to inhibition of transformation of fibroblasts into myofibroblasts in wound tissues. The present results imply that trehalose can be a potential agent for preventing postoperative fibrous scar formation after ocular surgery such as glaucoma filtration surgery.

Solid Hyaluronic Acid Film and the Prevention of Postoperative Fibrous Scar Formation in Experimental Animal Eyes

OBJECTIVE To investigate the inhibitory effect of solid hyaluronic acid-carboxymethyl cellulose film (hyaluronic acid film) on the formation of postoperative wound adhesion on rabbit eyes. METHODS We first created a conjunctival flap under which hyaluronic acid film was inserted. Then, we performed trabeculectomy on other rabbit eyes with hyaluronic acid film applied under and above the scleral flaps. Expression of proliferative cell nuclear antigen and alpha-smooth muscle actin (alpha-SMA) were histologically and immunohistochemically examined. RESULTS Hyaluronic acid film significantly prevented adhesions after both kinds of surgery. Particularly, subconjunctival scar formation was significantly inhibited when the film was simply inserted under the wound. Furthermore, the adhesion around the scleral flap of trabeculectomy was less formed in eyes treated with hyaluronic acid film than in control eyes. Immunoreactivity to proliferative cell nuclear antigen almost disappeared after 28 days postoperatively in both treated and control groups. The alpha-SMA-positive cells appeared much less around the film-treated wound than the control eye. CONCLUSION The present results indicate that hyaluronic acid film can inhibit the formation of postoperative adhesion around the conjunctiva and sclera. CLINICAL RELEVANCE The results of this study indicate that this substance has potential benefits for improving ophthalmic surgery, such as filtering surgery for glaucoma.

Effects of intravitreal injection of bevacizumab on inflammatory cytokines in the vitreous with proliferative diabetic retinopathy.

Background: To investigate the effects of preoperative intravitreal injection of bevacizumab (IVB) on the levels of 27 inflammatory cytokines, including interleukins (ILs) and vascular endothelial growth factor. Methods: From among 200 patients who had proliferative diabetic retinopathy and underwent vitrectomy in our department from September 2009 to October 2010, 8 study subjects met the enrollment criteria in which both eyes at nearly equivalent stages underwent vitrectomy. The first vitrectomy for each patient was performed without IVB (control group), whereas the second vitrectomy on the contralateral eye was performed with IVB treatment (1.25 mg/0.05 mL) 3 days before surgery (IVB group). Undiluted vitreous fluid was collected at the start of each vitrectomy. A multiplex assay was used to simultaneously determine the levels of 27 inflammatory cytokines and growth factors. Results: Mean vascular endothelial growth factor levels were significantly lower in the IVB group (519.69 pg/mL) than in the control group (11,807.44 pg/mL) (P = 0.012, Wilcoxon signed rank test). Moreover, the mean levels (IVB/control, pg/mL) of IL-1RA (38.50/62.31, P = 0.036), IL-5 (27.75/34.00, P = 0.018), IL-10 (433.63/1,995.94, P = 0.012), IL-12 (246.69/1,033.69, P = 0.012), IL-13 (707.50/1,450.38, P = 0.012), and interferon &ggr; (71.13/84.69, P = 0.036) were significantly lower in the IVB group. No other significant differences were observed in the levels of the other 20 cytokines and growth factors between the 2 groups. Conclusion: Preoperative IVB reduced not only the intravitreal vascular endothelial growth factor level but also the intravitreal levels of other inflammatory cytokines, including IL-1RA, IL-5, IL-10, IL-12, IL-13, and interferon &ggr;. These results indicate the interaction of some cytokines in the vitreous fluid of proliferative diabetic retinopathy patients and suggest the possibility that preoperative IVB may not only reduce vascular proliferation by its direct antivascular endothelial growth factor effect but also modulate the inflammatory response through putative cytokine networks. None of the other cytokines examined were elevated after IVB.

Epidermal nevus syndrome associated with anterior scleral staphyloma and ectopic bone and cartilaginous intraocular tissue.

BackgroundEpidermal nevus syndrome encompasses a group of congenital neurocutaneous anomalies characterized by epidermal nevi in association with cerebral, ocular, and skeletal abnormalities. We report herein the case of a Japanese girl with epidermal nevus syndrome associated with complex ocular choristoma and discuss the histopathological findings.CaseA mass lesion was noted on the left eyeball of a newborn Japanese girl. The lesion appeared to be a scleral staphyloma. Linear and diffuse acanthoses were also apparent on the face. Skin biopsy revealed an epidermal nevus. Histopathological examination of the enucleated left eyeball demonstrated that extremely thin sclera adjacent to the corneal limbus resulted in anterior staphyloma, and ectopic osteocartilaginous tissues were present in the posterior sclera.ConclusionEpidermal nevus syndrome associated with complex ocular choristoma was diagnosed. The anterior staphylomatous lesion observed in this case has not been reported previously.

Ocular fundus images by scanning laser ophthalmoscopy in a patient with enhanced S-cone syndrome.

Purpose: To present ocular fundus images in a patient with enhanced S-cone syndrome by scanning laser ophthalmoscopy. A 34-year-old Japanese woman whose parents were consanguineous showed mismatched electroretinographic responses to photopically balanced single-flash stimuli, with a larger signal to blue light than to red light. The central macula lacked a foveal reflex, and the surface was dull. Yellowish flecks and retinal pigment epithelium atrophy were evident in a ring at and around the vascular arcades. Faint black pigmentation was deposited in the mid peripheral retina. Methods: The ocular fundus of the patient was observed by scanning laser ophthalmoscopy with the use of an argon blue laser (wavelength, 488 nm), a helium-neon laser (633 nm), and an infrared laser (780 nm). Results: The argon blue laser showed numerous black spots of pigment, which were observed as faint pigmentation by conventional ophthalmoscopy. The spots were more enhanced with the argon blue laser than with the helium-neon laser. The white spots, which corresponded to the yellowish flecks in a ring at and around the vascular arcades, were more enhanced with the helium-neon laser than with the argon blue or infrared laser. Hypopigmentation of the retinal pigment epithelium was best shown with the infrared laser. Conclusion: An abnormality of the retinal structure in enhanced S-cone syndrome may exist in the inner and outer retinal levels, in at least some patients.

von Hippel–Lindau disease type 2A in a family with a duplicated 21-base-pair in-frame insertion mutation in the VHL gene

Backgroundvon Hippel–Lindau disease (VHL), also called angiomatosis retinae, is inherited as an autosomal dominant trait. It is frequently associated with other tumors in the central nervous system, kidneys, or adrenal glands. In order to investigate the relationship between genotype and corresponding phenotypes, we performed molecular genetic analysis in a Japanese patient with VHL type 2A.MethodsAfter informed consent had been obtained, the three exons of the VHL gene were PCR-amplified and sequenced either directly or after subcloning. Clinical features were also examined.ResultsA novel in-frame duplication of the 21 base pairs at nucleotide 806 (the position of codon 198) of the VHL gene was found in our patient. The clinical phenotype of the patient included retinal hemangiomas associated with vitreous hemorrhage and traction retinal detachment, pheochromocytoma, and hemangioma-like lesions in the cerebellum which corresponded to those of VHL type 2A. Abnormal diffuse vascular leakage was observed in the apparently intact retina by fluorescein angiography.ConclusionAn insertion mutation of the VHL gene is a rare association with VHL type 2. This insertion mutation may interfere the binding between the VHL gene and elongins. Abnormal retinal vascular leakage suggests the possible effects of overexpressed vascular permeability factors such as vascular endothelial growth factor from hemangiomas associated with defective VHL gene.