Retinal microglia exacerbate uveitis by functioning as local antigen-presenting cells.

Autoimmune uveitis is a major cause of blindness in the working-age population of developed countries. Experimental autoimmune uveitis (EAU) depends on activation of interphotoreceptor retinoid-binding protein (IRBP) specific CD4 + effector T cells that migrate systemically and infiltrate into the retina. Following systemic induction of retinal antigen-specific T cells, the development of EAU can be broken down into three phases: early phase when inflammatory cells begin to infiltrate the retina, amplification phase, and peak phase. Although studied extensively, the function of local antigen-presenting cells (APCs) within the retina remains unclear. Two potential types of APCs are present during uveitis, resident microglia and infiltrating CD11c + dendritic cells (DCs). MHC class II (MHC II) is expressed within the retina on both CD11c + DCs and microglia during the amplification phase of EAU. Therefore, we used microglia specific (P2RY12 and TMEM119) and CD11c + DC specific MHC II knockout mice to study the function of APCs within the retina using the conventional and adoptive transfer methods of inducing EAU. Microglia were essential during all phases of EAU development: the early phase when microglia were MHC Il negative, and amplification and peak phases when microglia were MHC II positive. Unexpectedly, retinal infiltrating MHC Il + CD11c + DCs were present within the retina but their antigen-presenting function was not required for all phases of uveitis. Our data indicate microglia are the critical APCs within the retina and an important therapeutic target that can prevent and/or diminish uveitis even in the presence of circulating IRBP-specific CD4 + effector T cells.

CD47 Deficiency Ameliorates Ocular Autoimmune Inflammation.

Autoimmune uveitis is a sight-threatening ocular inflammatory condition in which the retina and uveal tissues become a target of autoreactive immune cells. The CD47 is a ubiquitously expressed transmembrane protein which plays multiple roles in fundamental cellular functions including phagocytosis, proliferation, and adhesion. Signal regulatory protein alpha (SIRPα), one of the CD47 ligands, is predominantly expressed in myeloid lineage cells such as dendritic cells (DCs) or macrophages, and CD47-SIRPα signaling pathway is implicated in the development of autoimmune diseases. Our current study demonstrates how CD47 depletion is effective in the prevention of experimental autoimmune uveitis (EAU), an animal model of human autoimmune uveitis, in animals deficient of CD47 (CD47-/- ). Systemic suppression of SIRPα+ DCs in animals deficient in CD47 resulted in the inability of autoreactive CD4+ T cells to develop, which is crucial to induction of EAU. Of interest, retinal microglia, the resident immune cell of the retina, express SIRPα, however these cells were not operative in EAU suppression in response to CD47 depletion. These results identify CD47 as a significant regulator in the development of SIRPα+ DCs that is vital to disease induction in EAU.

Retinal microglia initiate neuroinflammation in ocular autoimmunity.

Autoimmune uveitis is a sight-threatening ocular inflammatory condition in which the retina and uveal tissues become a target of autoreactive immune cells. While microglia have been studied extensively in autoimmune uveitis, their exact function remains uncertain. The objective of the current study was to determine whether resident microglia are necessary and sufficient to initiate and amplify retinal inflammation in autoimmune uveitis. In this study, we clearly demonstrate that microglia are essential for initiating infiltration of immune cells utilizing a murine model of experimental autoimmune uveoretinitis (EAU) and the recently identified microglia-specific marker P2ry12. Initiating disease is the primary function of microglia in EAU, since eliminating microglia during the later stages of EAU had little effect, indicating that the function of circulating leukocytes is to amplify and sustain destructive inflammation once microglia have triggered disease. In the absence of microglia, uveitis does not develop, since leukocytes cannot gain entry through the blood-retinal barrier, illustrating that microglia play a critical role in regulating infiltration of inflammatory cells into the retina.

Mouse model of ocular hypertension with retinal ganglion cell degeneration.

OBJECTIVES: Ocular hypertension is a primary risk factor for glaucoma and results in retinal ganglion cell (RGC) degeneration. Current animal models of glaucoma lack severe RGC cell death as seen in glaucoma, making assessment of physiological mediators of cell death difficult. We developed a modified mouse model of ocular hypertension whereby long-lasting elevation of intraocular pressure (IOP) is achieved, resulting in significant reproducible damage to RGCs. RESULTS: In this model, microbeads are mixed with hyaluronic acid and injected into the anterior chamber of C57BL/6J mice. The hyaluronic acid allows for a gradual release of microbeads, resulting in sustained blockage of Schlemm's canal. IOP elevation was bimodal during the course of the model's progression. The first peak occurred 1 hours after beads injection, with an IOP value of 44.69 ± 6.00 mmHg, and the second peak occurred 6-12 days post-induction, with an IOP value of 34.91 ± 5.21 mmHg. RGC damage was most severe in the peripheral retina, with a loss of 64.1% compared to that of untreated eyes, while the midperiphery exhibited a 32.4% loss, 4 weeks following disease induction. CONCLUSIONS: These results suggest that sustained IOP elevation causes more RGC damage in the periphery than in the midperiphery of the retina. This model yields significant and reproducible RGC degeneration.

Microglia inhibit photoreceptor cell death and regulate immune cell infiltration in response to retinal detachment.

Retinal detachment (RD) is a sight-threatening complication common in many highly prevalent retinal disorders. RD rapidly leads to photoreceptor cell death beginning within 12 h following detachment. In patients with sustained RD, progressive visual decline due to photoreceptor cell death is common, leading to significant and permanent loss of vision. Microglia are the resident immune cells of the central nervous system, including the retina, and function in the homeostatic maintenance of the neuro-retinal microenvironment. It is known that microglia become activated and change their morphology in retinal diseases. However, the function of activated microglia in RD is incompletely understood, in part because of the lack of microglia-specific markers. Here, using the newly identified microglia marker P2ry12 and microglial depletion strategies, we demonstrate that retinal microglia are rapidly activated in response to RD and migrate into the injured area within 24 h post-RD, where they closely associate with infiltrating macrophages, a population distinct from microglia. Once in the injured photoreceptor layer, activated microglia can be observed to contain autofluorescence within their cell bodies, suggesting they function to phagocytose injured or dying photoreceptors. Depletion of retinal microglia results in increased disease severity and inhibition of macrophage infiltration, suggesting that microglia are involved in regulating neuroinflammation in the retina. Our work identifies that microglia mediate photoreceptor survival in RD and suggests that this effect may be due to microglial regulation of immune cells and photoreceptor phagocytosis.

The Complement System Is Critical in Maintaining Retinal Integrity during Aging.

The complement system is a key component of innate immunity comprised of soluble components that form a proteolytic cascade leading to the generation of effector molecules involved in cellular clearance. This system is highly activated not only under general inflammatory conditions such as infections, collagen diseases, nephritis, and liver diseases, but also in focal ocular diseases. However, little is known about the role of the complement system in retinal homeostasis during aging. Using young (6-week-old) and adult (6-month-old) mice in wild type (C57BL/6) and complement knockout strains (C1q-/-, Mbl a/c-/-, Fb-/-, C3-/-, and C5-/-), we compared amplitudes of electroretinograms (ERG) and thicknesses of retinal layers in spectral domain optical coherence tomography between young and adult mice. The ERG amplitudes in adult mice were significantly decreased (p < 0.001, p < 0.0001) compared to that of young mice in all complement knockout strains, and there were significant decreases in the inner nuclear layer (INL) thickness in adult mice compared to young mice in all complement knockout strains (p < 0.0001). There were no significant differences in ERG amplitude or thickness of the INL between young and adult control mice. These data suggest that the complement system plays an important role in maintaining normal retinal integrity over time.

Cytochrome P450 monooxygenase lipid metabolites are significant second messengers in the resolution of choroidal neovascularization.

Age-related macular degeneration (AMD) is the most common cause of blindness for individuals age 50 and above in the developed world. Abnormal growth of choroidal blood vessels, or choroidal neovascularization (CNV), is a hallmark of the neovascular (wet) form of advanced AMD and leads to significant vision loss. A growing body of evidence supports a strong link between neovascular disease and inflammation. Metabolites of long-chain polyunsaturated fatty acids derived from the cytochrome P450 (CYP) monooxygenase pathway serve as vital second messengers that regulate a number of hormones and growth factors involved in inflammation and vascular function. Using transgenic mice with altered CYP lipid biosynthetic pathways in a mouse model of laser-induced CNV, we characterized the role of these lipid metabolites in regulating neovascular disease. We discovered that the CYP-derived lipid metabolites epoxydocosapentaenoic acids (EDPs) and epoxyeicosatetraenoic acids (EEQs) are vital in dampening CNV severity. Specifically, overexpression of the monooxygenase CYP2C8 or genetic ablation or inhibition of the soluble epoxide hydrolase (sEH) enzyme led to increased levels of EDP and EEQ with attenuated CNV development. In contrast, when we promoted the degradation of these CYP-derived metabolites by transgenic overexpression of sEH, the protective effect against CNV was lost. We found that these molecules work in part through their ability to regulate the expression of key leukocyte adhesion molecules, on both leukocytes and endothelial cells, thereby mediating leukocyte recruitment. These results suggest that CYP lipid signaling molecules and their regulators are potential therapeutic targets in neovascular diseases.

Aqueous immune mediators in malignant uveal melanomas in comparison to benign pigmented intraocular tumors.

BACKGROUND: To examine the usefulness of measuring immune mediators in aqueous humor samples for differentiating malignant uveal melanoma from benign pigmented intraocular tumors. METHODS: Thirteen eyes of 13 patients with uveal melanoma were studied, and 13 eyes of 13 patients with benign pigmented intraocular tumors served as controls. Undiluted samples of aqueous humor were collected, and a cytometric bead array was used to determine the aqueous humor concentrations of 35 immune mediators comprising 14 interleukins (IL), interferon-γ, interferon-γ-inducible protein-10, monocyte chemoattractant protein (MCP)-1, macrophage inflammatory protein (MIP)-1α, MIP-1ß, regulated on activation normal T cell expressed and secreted, monokine induced by interferon-γ, basic fibroblast growth factor, Fas ligand, granzyme A, granzyme B, eotaxin, interferon-inducible T-cell alpha chemoattractant, fractalkine, granulocyte macrophage colony-stimulating factor, granulocyte colony-stimulating factor, vascular endothelial growth factor, angiogenin, tumor necrosis factor-α, lymphotoxin-α, and CD40L. RESULTS: Aqueous humor levels of angiogenin, IL-8, and MCP-1 were significantly higher in eyes with malignant melanoma than in those with benign tumors (p < 0.05). CONCLUSIONS: Angiogenin, IL-8, and MCP-1 levels in aqueous humor may be potential markers for distinguishing malignant uveal melanoma from benign pigmented intraocular tumors, and may be a useful adjunct to histomorphology, diagnostic imaging, and other biomarkers for the diagnosis and appropriate clinical management of malignant uveal melanoma.

Clinical Profile of Anti-Myelin Oligodendrocyte Glycoprotein Antibody Seropositive Cases of Optic Neuritis.

We have studied the clinical picture of anti-aquaporin antibody (AQP4-Ab)- and anti-myelin oligodendrocyte glycoprotein antibody (MOG-Ab)-positive optic neuritis. However, optic neuritis associated with MOG-Abs has not been elucidated using new methods such as cell-based assay. Hence, we conducted a comprehensive investigation on its clinical profile. Serum samples from 70 patients (17 males and 53 females, mean age 43.1 years) with optic neuritis were tested for MOG-Abs by cell-based assay. In MOG-Ab seropositive patients, the disease type, recurrence status, and visual function outcome were analysed. Among 70 patients, 18 were MOG-Ab seropositive. The 18 patients comprised 2 with chronic relapsing inflammatory optic neuropathy, 2 with AQP4-Ab seropositive optic neuritis (neuromyelitis optica), 12 with idiopathic optic neuritis, and 2 with optic neuritis associated with multiple sclerosis. Excluding two cases that were also AQP4-Ab seropositive, MOG-Ab seropositive cases had relatively favourable visual acuity outcome (although not significantly different from seronegative cases) but had significant residual visual field deficit (p = 0.0015). Furthermore, the number of relapses of optic neuritis per year was significantly greater in MOG-Ab seropositive cases than in seronegative cases (0.82 vs. 0.40; p = 0.0005). MOG-Abs may contribute to the heterogeneous clinical picture of optic neuritis, and although visual acuity outcome is favourable, there is a tendency of residual visual field deficit and a possibility of repeated relapses.

Differences in the clinical features of two types of Vogt-Koyanagi-Harada disease: serous retinal detachment and optic disc swelling.

PURPOSE: To elucidate the clinical differences between serous retinal detachment (RD)-type and optic disc (OD) swelling-type Vogt-Koyanagi-Harada (VKH) disease. METHODS: We performed a retrospective review of 96 patients with new-onset, active VKH disease. Patients were classified into serous RD-type or OD swelling-type VKH disease groups by means of optical coherence tomography and fluorescein angiography, and the differences between the 2 groups were analyzed. RESULTS: Eighty-two patients were classified as having RD-type VKH disease (34 men and 48 women, aged 40.5 ± 12.6 years) and 14 patients as having OD swelling-type VKH disease (1 man and 13 women, aged 54.6 ± 11.6 years). Patients with the OD swelling type had older onset (P < 0.001) and were more proportionately female (P = 0.02) than those with the RD type. OD swelling-type VKH disease had a longer interval between disease onset and treatment initiation (22.4 ± 14.0 days vs 12.6 ± 14.7 days; P = 0.02) and a higher frequency of chronic disease (64.3 vs 30.5 %; P = 0.03) than did serous RD-type VKH disease. In the OD swelling type, patients with pretreatment visual acuity (VA) lower than 20/20 developed chronic disease more frequently than did those with VA of 20/20 or better (P = 0.02). CONCLUSIONS: Patients with OD swelling-type VKH disease are more likely to be female, have older onset, and develop chronic disease than patients with RD-type VKH disease. In OD swelling-type VKH disease, worse VA before treatment is associated with the development of chronic disease.

A case of herpes zoster uveitis with severe hyphema.

BACKGROUND: Uveitis sometimes causes hyphema, but severe hyphema as a complication following herpes zoster uveitis has rarely been reported. We report a rare case of zoster sine herpete with unusually severe hyphema. CASE PRESENTATION: A 41-year-old Japanese female developed hyphema filling almost one-half of the depth of the anterior chamber after a two-week history of unilateral anterior uveitis. Hyphema persisted for four weeks while sectorial iris atrophy became gradually apparent. Systemic prednisolone and valaciclovir resulted in prompt resolution of uveitis and hyphema. Serum anti-varicella zoster virus (VZV) IgG measured by enzyme immunoassay was 116 at presentation and decreased to 20.3 four month later. In addition, the antibody level in aqueous humor was almost 10-fold higher than that in serum examined 9 months after presentation. Because there was no skin lesion, this case was diagnosed as zoster sine herpete. The patient underwent cataract operation due to secondary cataract. The final visual acuity in decimal notation was 1.0, but complications such as severe iris atrophy, wide anterior synechiae, corneal opacity, and decrease in corneal endothelial cell count remained. CONCLUSION: Zoster sine herpete is an important differential diagnosis in a case of acute anterior uveitis with severe hyphema, although such cases are quite rare. Measurement of anti-VZV IgG levels by enzyme immunoassay in aqueous humor and serum would be useful in the diagnosis of VZV reactivation. Prompt diagnosis and administration of corticosteroids and anti-herpes virus medication may improve the outcome.

Profile of intraocular immune mediators in patients with age-related macular degeneration and the effect of intravitreal bevacizumab injection.

PURPOSE: To measure intraocular cytokine levels in patients with exudative age-related macular degeneration and analyze changes in the cytokine profile 2 days after intravitreal bevacizumab injection. METHODS: This prospective case-control study enrolled 37 patients (37 eyes) with age-related macular degeneration including polypoidal choroidal vasculopathy. Twenty-eight age-matched patients (28 eyes) who underwent cataract surgery were used as controls. Undiluted aqueous humor samples were collected after intravitreal bevacizumab injection. Two days after intravitreal bevacizumab injection, cataract surgery was performed and undiluted aqueous humor samples were collected at the beginning of surgery (10 eyes). Twenty-three cytokines were measured using flow cytometry. P values were corrected in multiple comparisons using the conservative Bonferroni-Holm method. The level of significance was set at 0.0022 (0.05/23). RESULTS: At baseline, aqueous humor levels of vascular endothelial growth factor, angiogenin, interferon gamma-inducible protein (IP)-10, macrophage inflammatory protein (MIP)-1ß, monokine induced by interferon γ (Mig), and monocyte chemotactic protein (MCP)-1 were significantly higher in the age-related macular degeneration group than in the control group (P < 0.0022). The result of exploratory multivariate analysis showed that elevated angiogenin level was an important factor that discriminates the two groups (P = 0.0004). Two days after intravitreal bevacizumab injection, vascular endothelial growth factor levels tended to be reduced (P = 0.049), whereas interleukin (IL)-6 and IL-8 levels increased significantly (P < 0.0022). CONCLUSION: Vascular endothelial growth factor and also angiogenin, IP-10, MCP-1, MIP-1ß, and Mig may be related to the pathogenesis of age-related macular degeneration. Intravitreal bevacizumab injection increases inflammatory cytokine levels, suggesting the induction of an inflammatory process.

Prediction of severe cardiac involvement by fundus lesion in sarcoidosis.

PURPOSE: We examined the relation between ocular sarcoidosis and severe cardiac sarcoidosis necessitating pacemaker implantation. METHODS: In this retrospective, observational, cross-sectional study, we reviewed the clinical records of 108 patients diagnosed with ocular sarcoidosis based on new diagnostic criteria established in Japan. We examined and compared the relationship between fundus findings of ocular sarcoidosis and severe cardiac sarcoidosis necessitating pacemaker implantation. RESULTS: Of 108 patients with ocular sarcoidosis, seven patients (6.5 %) with median age of 61 years (interquartile range 59-63 years) also had severe heart disease leading to implantation of a pacemaker. Median duration of ocular symptoms was 4.5 years (interquartile range 3.6-7.8 years). Of seven patients with severe cardiac involvement, six had multiple peripheral chorioretinal atrophic lesions (MPCAL), two had nodules in the angle and tent-like peripheral anterior synechia, and two had snowball vitreous opacity. The prevalence of atrophic MPCAL lesions was significantly higher than that of other ocular findings (P < 0.05). CONCLUSIONS: In patients with concurrent ocular sarcoidosis and severe cardiac sarcoidosis, MPCAL atrophic lesions were observed significantly more frequently, suggesting that severe cardiac involvement may be predicted by specific fundus lesions.

Peroxisome proliferator-activated receptor-γ agonist pioglitazone suppresses experimental autoimmune uveitis.

Peroxisome proliferator-activated receptor (PPAR)-γ agonists are clinically used as anti-diabetes agents. Recent research has discovered that an anti-inflammatory effect of PPAR agonist may have the potential to treat autoimmune disease. In the present study, we investigated the anti-inflammatory effects of PPAR-γ agonist, pioglitazone, on murine model of endogenous uveitis. Experimental autoimmune uveoretinitis (EAU) was induced by immunizing C57BL/6 mice with human interphotoreceptor retinoid binding protein-derived peptide (1-20). Pioglitazone or vehicle was injected intravenously from day -1 (whole phase treatment) or day 8 (effector phase study) until day 20. Severity of EAU was assessed clinically and pathologically on day 21. Immunological status was assessed by measuring intraocular inflammatory factors, and activation and regulatory markers of CD4(+) T cells in draining lymph nodes (LNs). Treatment with pioglitazone suppressed both whole-phase and effector-phase of EAU. In effector-phase treatment, intraocular concentrations of TNF-α and IL-6 were significantly suppressed, and CD4(+)Foxp3(+) regulatory T cells and CD4(+)CD62L(high) naïve T cells increased in draining LNs, although there were no differences in CD4(+)CD44(high) effector T cells and IL-17 producing CD4(+) T cells between pioglitazone- and vehicle-treated mice. Administration of pioglitazone before and after the onset of EAU significantly reduced disease severity. The present results suggest that pioglitazone may be a novel therapeutic agent for endogenous uveitis.

Correlation of complement fragment C5a with inflammatory cytokines in the vitreous of patients with proliferative diabetic retinopathy.

PURPOSE: To determine the vitreous concentration of complement fragment C5a in patients with proliferative diabetic retinopathy (PDR) and the relation between C5a and inflammatory cytokines including vascular endothelial growth factor (VEGF) and monocyte chemotactic protein-1 (MCP-1). METHODS: Vitreous samples were obtained at the time of vitrectomy from 12 eyes of 11 PDR patients and from 11 eyes of 11 patients without diabetes with macular disease (controls). Vitreous and serum concentrations of human C5a, VEGF, and MCP-1 were quantified using FACS Caliber flow cytometer. RESULTS: Vitreous concentration of C5a increased significantly in patients with PDR [median (range): 928.7 (46.6 to 3,319.4) pg/ml] compared with controls [58.7 (22.2 to 1,432.4) pg/ml; p < 0.01]. In PDR patients, vitreous concentration of C5a correlated significantly with those of VEGF (p < 0.05) and MCP-1 (p < 0.05). CONCLUSIONS: Our results suggest that C5a may play an important role in the pathogenesis of PDR and work in concert with inflammatory cytokines such as VEGF and MCP-1 in pathological angiogenesis.

Effects of soluble CD14 and cytokine levels on diabetic macular edema and visual acuity.

PURPOSE: The pathogenesis of diabetic retinopathy has been suggested to be associated with ocular inflammation. Macrophages and monocytes that infiltrate the eye are known to express CD14. After shedding from the membrane-bound CD14, soluble CD14 (sCD14) is released, which could potentially activate inflammatory signaling. In this study, the authors investigated ocular fluid and serum levels of vascular endothelial growth factor (VEGF), sCD14, and other inflammatory cytokines in patients with diabetic macular edema (DME). Furthermore, the authors determined any potential correlation between these factors and visual acuity. METHODS: Vitreous fluid, aqueous humor, and serum samples from 14 eyes with DME and 24 control eyes were investigated. Soluble CD14, interleukin 8, interferon-inducible protein 10, monocyte chemotactic protein 1, monokine induced by interferon γ, and VEGF were measured simultaneously by FACSCalibur flow cytometer. Visual acuity was measured in all patients with DME before surgery, with the assessors being blinded to the patients' diagnoses. RESULTS: All factors were significantly elevated in vitreous fluid of DME eyes. Soluble CD14 and VEGF levels in vitreous fluid and aqueous humor were significantly higher in patients with DME than in nondiabetic controls (P < 0.05). In patients with DME, vitreous and aqueous humor concentrations of sCD14 correlated significantly. In these patients, vitreous fluid concentration of sCD14 correlated significantly with that of VEGF or interleukin 8 or monocyte chemotactic protein 1. In addition, there was a significant positive correlation between preoperative visual acuity and intraocular sCD14 concentrations. CONCLUSION: Soluble CD14 may act as key regulator of VEGF production and contribute to the pathogenesis of diabetic retinopathy.

Interleukin-10 gene-transfected mature dendritic cells suppress murine experimental autoimmune optic neuritis.

PURPOSE: We have reported that calcitonin gene-related peptide gene-transfected mature dendritic cells (mDC) suppress murine experimental autoimmune optic neuritis (EAON) and experimental autoimmune encephalitis (EAE) via interleukin-10 (IL-10) production. In our study, we examined whether IL-10-transfected mDC prevent development of EAON and EAE. METHODS: A plasmid expressing mouse IL-10 was constructed and used to transfect C57BL/6 mouse bone marrow-derived mDC by electroporation methods. C57BL/6 mice (with or without GFP expression) were immunized with myelo-oligodendrocyte glycoprotein35₋55 (MOG35₋55), and injected intravenously with IL-10-transfected mDC either in the induction or effector phase. RESULTS: When IL-10-transfected mDC were injected in the induction phase, EAE developed clinically in 60% of mice in the IL-10-transfected group compared to 100% in the mock-transfected group (P < 0.05), and mean pathologic score for EAON was 1.1 in the IL-10-transfected group compared to 2.1 in the mock-transfected group (P < 0.05). When IL-10-transfected mDC were injected in the effector phase, mean EAE clinical scores were not significantly different between the two groups (2.0 vs. 3.0), while the mean EAON pathologic score was lower in the IL-10-transfected group compared to the mock-transfected group (1.0 vs. 2.7, P < 0.05). Delayed hypersensitivity was suppressed significantly in the IL-10-transfected group. Interestingly, the proportions of CD80/86⁺ and MHC class II⁺ cells decreased significantly (P < 0.05), whereas Foxp3⁺ cells increased significantly in the spleen and lymph node in the IL-10-transfected group by flow cytometry analysis. Immunohistochemical analysis demonstrated the localization of IL-10-transfected GFP-expressing mDC not only in the spleen and lymph nodes but also in the inflamed optic nerve. CONCLUSIONS: Treatment with IL-10-expressing mDC was effective in suppressing the development of EAON and EAE.

Intraocular VEGF level as a risk factor for postoperative complications after vitrectomy for proliferative diabetic retinopathy.

PURPOSE: To investigate whether vitreous and aqueous humor concentrations of vascular endothelial growth factor (VEGF) predict postoperative complications after vitrectomy for proliferative diabetic retinopathy (PDR). METHODS: Sixty eyes of 52 patients with PDR who underwent vitrectomy were enrolled. Vitreous and aqueous humor were obtained from eyes with PDR during primary vitrectomy and the levels of VEGF were measured using a commercial flow cytometer. Patients were followed for more than 6 months after surgery. Demographic data and both intraoperative and postoperative findings were recorded. The relationship between VEGF levels in ocular fluids and the main postoperative complications of early vitreous hemorrhage (VH) and neovascular glaucoma (NVG) occurring during follow-up was analyzed. Logistic regression analyses were performed to examine risk factors related to postoperative complications. RESULTS: Early VH occurred in 25%, and NVG occurred in 8% of 60 eyes. The vitreous levels of VEGF were significantly higher (P = 0.015) in eyes with early VH than in those without. The aqueous humor and vitreous levels of VEGF were significantly higher (P = 0.005 and P = 0.001, respectively) in eyes with NVG than in those without. Axial length was significantly shorter in eyes with early VH than in those without (P = 0.028). Multivariate logistic regression analysis showed that the higher vitreous VEGF level was associated with a risk of early VH after vitrectomy for PDR (odds ratio, 5.1; P = 0.020). CONCLUSIONS: High intraocular VEGF level at the time of primary vitrectomy in patients with PDR was identified as a significant risk factor for postoperative early VH.

Suppression of murine experimental autoimmune optic neuritis by mature dendritic cells transfected with calcitonin gene-related Peptide gene.

PURPOSE: Calcitonin gene-related peptide (CGRP) exhibits prominent anti-inflammatory actions. We examined whether CGRP-transfected dendritic cells (DC) prevent the development of experimental autoimmune optic neuritis (EAON) and experimental autoimmune encephalomyelitis (EAE). METHODS: A human CGRP-expressing plasmid was constructed, and used to transfect C57BL/6 mouse bone marrow-derived matured DC (mDC) by electroporation METHODS: Transfection efficiency was 50% with 80% cell viability. C57BL/6 mice were immunized with myelo-oligodendrocyte glycoprotein 35-55, and injected intravenously with CGRP-expressing mDC (CGRP gene-transfected group) or mock-transfected mDC (mock-transfected group) at the induction or effector phase. EAE was diagnosed clinically and EAON was assessed histopathologically. Delayed hypersensitivity was measured. Supernatants of spleen cell cultures were assayed for cytokines using ELISA. The CD4(+)CD25(+)Foxp3(+) fraction in spleen cells was analyzed using flow cytometry. RESULTS: For gene therapy in the induction phase, EAE developed in 50% of mice in the CGRP-transfected group compared with 80% in the mock-transfected group, and the mean pathological score for EAON was 1 in the CGRP-transfected group compared with 2 in the mock-transfected group (P < 0.05). For gene therapy in the effector phase, the mean EAE clinical score (1.5 vs. 3.0) and mean EAON pathological score (1.0 vs. 2.0) were both lower in the CGRP-transfected group compared with the mock-transfected group (P < 0.05). Delayed hypersensitivity was suppressed significantly in the CGRP-transfected group. IL-10 production by spleen cells in the CGRP-transfected group increased independent of MOG concentration, compared with the mock-transfected group. Interestingly, the proportion of CD4(+)CD25(+)Foxp3(+) cells increased significantly (P < 0.05) in the CGRP-transfected group compared with the mock-transfected group. CONCLUSIONS: Gene therapy with CGRP-expressing mDC was effective in suppressing the development of EAON and EAE.