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2014
Purpose: To investigate whether systemically-injected syngeneic mesenchymal stem cells (MSCs) can home to the inflamed transplanted cornea, suppress induction of alloimmunity, and promote allograft survival. Methods: MSCs were generated from bone marrow of wild-type BALB/c or GFP+ C57BL/6 mice, and 1x106 cells were intravenously injected to allografted recipients 3 hours after surgery. MSCs homing to the cornea were examined at day 3 post-transplantation by immunohistochemistry. CD11c+MHC II+ cells were detected in the cornea and lymph nodes (LNs) 14 days post-transplantation using flow cytometry. Cytokine expression of bone marrow-derived dendritic cells (BMDCs) was determined using real-time PCR. ELISPOT assay was used to assess indirect and direct host T cell allosensitization, and graft survival was evaluated by slit-lamp biomicroscopy weekly up to 8 weeks. Results: Intravenously injected GFP+ MSCs were found in abundance in the transplanted cornea, conjunctiva, and lymph nodes, but not in the ungrafted (contralateral) tissue. The frequencies of mature CD11c+MHC II+ APCs were substantially decreased in the corneas and draining LNs of MSC-injected allograft recipients compared to control recipients. Maturation and function of in vitro cultured BMDCs was decreased when cocultured with MSCs. Draining LNs of MSC-injected allograft recipients showed significantly lower frequencies of IFNγ-secreting Th1 cells compared to the control group. Allograft survival rate was significantly higher in MSC-injected recipients compared to non-MSC injected recipients. Conclusions: Our data demonstrate that systemically-administered MSCs specifically home to transplanted corneas and promote allograft survival by inhibiting APC maturation and induction of alloreactive T cells.
Proliferative vitreoretinopathy (PVR) is a nonneovascular blinding disease and the leading cause for failure in surgical repair of rhegmatogenous retinal detachments. Once formed, PVR is difficult to treat. Hence, there is an acute interest in developing approaches to prevent PVR. Of the many growth factors and cytokines that accumulate in vitreous as PVR develops, neutralizing vascular endothelial growth factor (VEGF) A has recently been found to prevent PVR in at least one animal model. The goal of this study was to test if Food and Drug Administration-approved agents could protect the eye from PVR in multiple animal models and to further investigate the underlying mechanisms. Neutralizing VEGF with aflibercept (VEGF Trap-Eye) safely and effectively protected rabbits from PVR in multiple models of disease. Furthermore, aflibercept reduced the bioactivity of both experimental and clinical PVR vitreous. Finally, although VEGF could promote some PVR-associated cellular responses via VEGF receptors expressed on the retinal pigment epithelial cells that drive this disease, VEGF's major contribution to vitreal bioactivity occurred via platelet-derived growth factor receptor α. Thus, VEGF promotes PVR by a noncanonical ability to engage platelet-derived growth factor receptor α. These findings indicate that VEGF contributes to nonangiogenic diseases and that anti-VEGF-based therapies may be effective on a wider spectrum of diseases than previously appreciated.
Hypotropia following orbital fracture repair is traditionally attributed to residual tissue entrapment, scarring, direct muscle injury, or damage to the branches of the oculomotor nerve serving the inferior oblique or inferior rectus muscles. We present a case of acquired hypotropia and incyclotropia that occurred following repair of an orbital fracture involving the floor and medial wall. In order to enable adequate visualization and treatment of the combined fractures, access via a transcaruncular approach and disinsertion of the inferior oblique muscle at its origin was necessary. Whereas the possibility of inferior oblique paresis due to repair of an orbital fracture via the transcaruncular approach has received some acknowledgment, there are no prior reports in the ophthalmic literature. Strabismus surgeons should be aware of this possibility when planning surgical correction of hypotropia and incyclotropia in similar cases.
PURPOSE. Uveal melanoma (UM) is fatal in up to 50% of patients because of liver metastases, that are refractory to therapies currently available. While murine xenograft models for human uveal melanoma are available, they have limited utility for screening large compound libraries in drug discovery studies. Therefore, new robust preclinical models are needed that can efficiently evaluate drug efficacy for treatment of this malignancy. METHODS. UM cell lines generated from primary tumors (92.1, Mel270) and metastases (OMM2.3, OMM2.5, OMM1) were injected into the yolk of two-day-old zebrafish embryos. After six days, proliferation and active migration was quantified via automated confocal image analysis. To determine the suitability of this xenotransplantation model for drug testing, drugs with three different activities (Dasatinib, Quisinostat and MLN-4924) were added to the water of uveal melanoma-engrafted embryos. RESULTS. All tested UM cell lines proliferated and migrated in the embryos; significant differences could be discerned between cell lines: cells derived from metastases showed more migration and proliferation than cells derived from the primary tumors, and provided preclinical models for drug testing. Addition of the Src-inhibitor Dasatinib in the water of engrafted embryos reduced proliferation and migration of high Src-expressing 92.1 cells, but did not affect low Src-expressing metastatic OMM2.3 cells. Two experimental anticancer drugs, Quisinostat (a histone deacetylase inhibitor) and MLN-4924 (neddylation pathway inhibitor), blocked migration and proliferation of 92.1 and OMM2.3. CONCLUSIONS. We established a zebrafish xenograft model of human uveal melanoma with demonstrated applicability for screening large libraries of compounds in drug discovery studies.
Glaucoma is characterized by irreversible optic nerve degeneration and is the most frequent cause of irreversible blindness worldwide. Here, the International Glaucoma Genetics Consortium conducts a meta-analysis of genome-wide association studies of vertical cup-disc ratio (VCDR), an important disease-related optic nerve parameter. In 21,094 individuals of European ancestry and 6,784 individuals of Asian ancestry, we identify 10 new loci associated with variation in VCDR. In a separate risk-score analysis of five case-control studies, Caucasians in the highest quintile have a 2.5-fold increased risk of primary open-angle glaucoma as compared with those in the lowest quintile. This study has more than doubled the known loci associated with optic disc cupping and will allow greater understanding of mechanisms involved in this common blinding condition.
PURPOSE: To design, fabricate, and evaluate novel materials to remove silicone oil (SiO) droplets from intraocular lenses (IOL) during vitreoretinal surgery. METHODS: Three different designs were fabricated using soft lithography of polydimethylsiloxane (PDMS), three-dimensional (3D) inverse PDMS fabrication using water dissolvable particles, and atomic layer deposition (ALD) of alumina (Al2O3) on surgical cellulose fibers. Laboratory tests included static and dynamic contact angle (CA) measurements with water and SiO, nondestructive x-ray microcomputer tomography (micro-CT), and microscopy. SiO removal was performed in vitro and ex vivo using implantable IOLs and explanted porcine eyes. RESULTS: All designs exhibited enhanced hydrophobicity and oleophilicity. Static CA measurements with water ranged from 131° to 160° and with SiO CA approximately 0° in 120 seconds following exposure. Nondestructive x-ray analysis of the 3D PDMS showed presence of interconnected polydispersed porosity of 100 to 300 μm in diameter. SiO removal from IOLs was achieved in vitro and ex vivo using standard 20-G vitrectomy instrumentation. CONCLUSION: Removal of SiO from IOLs can be achieved using materials with lower surface energy than that of the IOLs. This can be achieved using appropriate surface chemistry and surface topography. Three designs, with enhanced hydrophobic properties, were fabricated and tested in vitro and ex vivo. All materials remove SiO within an aqueous environment. Preliminary ex vivo results were very promising, opening new possibilities for SiO removal in vitreoretinal surgeries. TRANSLATIONAL RELEVANCE: This is the first report of an instrument that can lead to successful removal of SiO from the surface of IOL. In addition to the use of this instrument/material in medicine it can also be used in the industry, for example, retrieval of oil spills from bodies of water.
The characterization of genes responsible for glaucoma is the critical first step toward the development of gene-based diagnostic and screening tests, which could identify individuals at risk for disease before irreversible optic nerve damage occurs. Early-onset forms of glaucoma affecting children and young adults are typically inherited as Mendelian autosomal dominant or recessive traits whereas glaucoma affecting older adults has complex inheritance. In this report, we present a comprehensive overview of the genes and genomic regions contributing to inherited glaucoma.
PURPOSE. To determine the risk factors for and relationship between diabetic retinopathy (DR) and diabetic nephropathy (DN), including microalbuminuria and overt nephropathy, in a population-based study of diabetes mellitus (DM) patients in Korea. METHODS. This was a population-based, cross-sectional study. From the fifth (2011, 2012) Korea National Health and Nutrition Examination Survey (KNHANES), 971 participants with type 2 DM were included. The prevalence of DR and DN was determined. Multivariate logistic regression was performed to determine risk factors, including DR, associated with DN in the Korean population. RESULTS. In DM patients, we observed a prevalence of 20.0% for any DR and 3.8% for proliferative diabetic retinopathy (PDR). Microalbuminuria prevalence was 19.3% and overt nephropathy prevalence was 5.5%. The risk factors of microalbuminuria were presence of hypertension, higher systolic blood pressure, serum hemoglobin A1c (HbA1c) and serum blood urea nitrogen level as well as the presence of PDR. The risk factors of overt nephropathy were long duration of DM, high levels of HbA1c, systolic blood pressure, total cholesterol and serum creatinine as well as the presence of DR. CONCLUSIONS. PDR is associated with microalbuminuria and DR is associated with overt nephropathy in Korean DM patients. Our findings suggest that when an ophthalmologist finds the presence of DR or PDR, timely evaluation of the patient's renal status should be recommended.
Experience-dependent gene transcription is required for nervous system development and function. However, the DNA regulatory elements that control this program of gene expression are not well defined. Here we characterize the enhancers that function across the genome to mediate activity-dependent transcription in mouse cortical neurons. We find that the subset of enhancers enriched for monomethylation of histone H3 Lys4 (H3K4me1) and binding of the transcriptional coactivator CREBBP (also called CBP) that shows increased acetylation of histone H3 Lys27 (H3K27ac) after membrane depolarization of cortical neurons functions to regulate activity-dependent transcription. A subset of these enhancers appears to require binding of FOS, which was previously thought to bind primarily to promoters. These findings suggest that FOS functions at enhancers to control activity-dependent gene programs that are critical for nervous system function and provide a resource of functional cis-regulatory elements that may give insight into the genetic variants that contribute to brain development and disease.
BACKGROUND: Vision loss due to vascular disease of the retina is a leading cause of blindness in the world. Retinal angiomatous proliferation (RAP) is a subgroup of neovascular age-related macular degeneration (AMD), whereby abnormal blood vessels develop in the retina leading to debilitating vision loss and eventual blindness. The novel mouse strain, neoretinal vascularization 2 (NRV2), shows spontaneous fundus changes associated with abnormal neovascularization. The purpose of this study is to characterize the induction of pathologic angiogenesis in this mouse model. METHODS: The NRV2 mice were examined from postnatal day 12 (p12) to 3 months. The phenotypic changes within the retina were evaluated by fundus photography, fluorescein angiography, optical coherence tomography, and immunohistochemical and electron microscopic analysis. The pathological neovascularization was imaged by confocal microscopy and reconstructed using three-dimensional image analysis software. RESULTS: We found that NRV2 mice develop multifocal retinal depigmentation in the posterior fundus. Depigmented lesions developed vascular leakage observed by fluorescein angiography. The spontaneous angiogenesis arose from the retinal vascular plexus at postnatal day (p)15 and extended toward retinal pigment epithelium (RPE). By three months of age, histological analysis revealed encapsulation of the neovascular lesion by the RPE in the photoreceptor cell layer and subretinal space. CONCLUSIONS: The NRV2 mouse strain develops early neovascular lesions within the retina, which grow downward towards the RPE beginning at p15. This retinal neovascularization model mimics early stages of human retinal angiomatous proliferation (RAP) and will likely be a useful in elucidating targeted therapeutics for patients with ocular neovascular disease.
: A critical review of the literature indicates that idiopathic opticochiasmatic arachnoiditis, once considered an important consideration in patients with otherwise unexplained optic atrophy, is not a valid disease entity.
