Miller JW, Le Couter J, Strauss EC, Ferrara N. Vascular endothelial growth factor a in intraocular vascular disease. Ophthalmology 2013;120(1):106-14.Abstract
UNLABELLED: The vascular beds supplying the retina may sustain injury as a result of underlying disease such as diabetes, and/or the interaction of genetic predisposition, environmental insults, and age. The vascular pathologic features observed in different intraocular vascular diseases can be categorized broadly as proliferation, exemplified by proliferative diabetic retinopathy, leakage such as macular edema secondary to retinal vein occlusion, or a combination of proliferation and leakage, as seen in neovascular age-related macular degeneration (AMD). The World Health Organization has identified diabetic retinopathy and AMD as priority eye diseases for the prevention of vision loss in developed countries. The pathologic transformations of the retinal vasculature seen in intraocular vascular disease are associated with increased expression of vascular endothelial growth factor A (VEGF), a potent endothelial-specific mitogen. Furthermore, in model systems, VEGF alone is sufficient to trigger intraocular neovascularization, and its inhibition is associated with functional and anatomic improvements in the affected eye. Therapeutic interventions with effect on VEGF include intraocular capture and neutralization by engineered antibodies or chimeric receptors, downregulation of its expression with steroids, or alleviation of retinal ischemia, a major stimulus for VEGF expression, with retinal ablation by laser treatment. Data from prospective randomized clinical trials indicate that VEGF inhibition is a potent therapeutic strategy for intraocular vascular disease. These findings are changing clinical practice and are stimuli for further study of the basic mechanisms controlling intraocular angiogenesis. FINANCIAL DISCLOSURE(S): Proprietary or commercial disclosure may be found after the references.
Qu J, Jakobs TC. The Time Course of Gene Expression during Reactive Gliosis in the Optic Nerve. PLoS One 2013;8(6):e67094.Abstract
Reactive gliosis is a complex process that involves changes in gene expression and morphological remodeling. The mouse optic nerve, where astrocytes, microglia and oligodendrocytes interact with retinal ganglion cell axons and each other, is a particularly suitable model for studying the molecular mechanisms of reactive gliosis. We triggered gliosis at the mouse optic nerve head by retro orbital nerve crush. We followed the expression profiles of 14,000 genes from 1 day to 3 months, as the optic nerve formed a glial scar. The transcriptome showed profound changes. These were greatest shortly after injury; the numbers of differentially regulated genes then dropped, returning nearly to resting levels by 3 months. Different genes were modulated with very different time courses, and functionally distinct groups of genes responded in partially overlapping waves. These correspond roughly to two quick waves of inflammation and cell proliferation, a slow wave of tissue remodeling and debris removal, and a final stationary phase that primarily reflects permanent structural changes in the axons. Responses from astrocytes, microglia and oligodendrocytes were distinctively different, both molecularly and morphologically. Comparisons to other models of brain injury and to glaucoma indicated that the glial responses depended on both the tissue and the injury. Attempts to modulate glial function after axonal injuries should consider different mechanistic targets at different times following the insult.
Melo MB, Nguyen QP, Cordeiro C, Hassan MA, Yang N, McKell R, Rosowski EE, Julien L, Butty V, Dardé M-L, Ajzenberg D, Fitzgerald K, Young LH, Saeij JPJ. Transcriptional analysis of murine macrophages infected with different Toxoplasma strains identifies novel regulation of host signaling pathways. PLoS Pathog 2013;9(12):e1003779.Abstract
Most isolates of Toxoplasma from Europe and North America fall into one of three genetically distinct clonal lineages, the type I, II and III lineages. However, in South America these strains are rarely isolated and instead a great variety of other strains are found. T. gondii strains differ widely in a number of phenotypes in mice, such as virulence, persistence, oral infectivity, migratory capacity, induction of cytokine expression and modulation of host gene expression. The outcome of toxoplasmosis in patients is also variable and we hypothesize that, besides host and environmental factors, the genotype of the parasite strain plays a major role. The molecular basis for these differences in pathogenesis, especially in strains other than the clonal lineages, remains largely unexplored. Macrophages play an essential role in the early immune response against T. gondii and are also the cell type preferentially infected in vivo. To determine if non-canonical Toxoplasma strains have unique interactions with the host cell, we infected murine macrophages with 29 different Toxoplasma strains, representing global diversity, and used RNA-sequencing to determine host and parasite transcriptomes. We identified large differences between strains in the expression level of known parasite effectors and large chromosomal structural variation in some strains. We also identified novel strain-specifically regulated host pathways, including the regulation of the type I interferon response by some atypical strains. IFNβ production by infected cells was associated with parasite killing, independent of interferon gamma activation, and dependent on endosomal Toll-like receptors in macrophages and the cytoplasmic receptor retinoic acid-inducible gene 1 (RIG-I) in fibroblasts.
Patel MM, Stacy RC. Paraneoplastic dermatomyositis related to a chondrosarcoma involving the cavernous sinus. J Neuroophthalmol 2013;33(4):363-6.Abstract
Approximately one third of all cases of dermatomyositis may be associated with malignancy. We describe a patient with unexplained rash, joint pain, and muscle weakness, who subsequently developed a cavernous sinus syndrome due to a central nervous system chondrosarcoma. Discovery of this tumor and further dermatologic evaluation, including skin biopsy, resulted in diagnosis of paraneoplastic dermatomyositis due to cavernous sinus chondrosarcoma.
Greiner JV. Long-term (12-month) improvement in meibomian gland function and reduced dry eye symptoms with a single thermal pulsation treatment. Clin Exp Ophthalmol 2013;41(6):524-30.Abstract
PURPOSE: To determine the 1-year post-treatment dry eye status of subjects with meibomian gland dysfunction and dry eye symptoms after receiving a single LipiFlow Thermal Pulsation System treatment. DESIGN: Single-centre, prospective, observational, open-label, 1-month-registered clinical trial with a 1-year follow-up examination. PARTICIPANTS: Patients with evaporative dry eye disease with meibomian gland dysfunction and dry eye symptoms who had participated in the registered 1-month clinical trial. METHODS: Eighteen of 30 subjects initially enrolled were able to return for a 1-year follow-up. Both eyes of all patients were treated with a single 12-min treatment using the LipiFlow Thermal Pulsation System. Meibomian gland function, tear break-up time and dry eye symptoms were measured. Data are presented for pretreatment (baseline), and 1-month and 1-year post-treatment. MAIN OUTCOME MEASURES: Meibomian gland secretion scores, and tear break-up time and dry eye symptoms. RESULTS: Significant improvement in meibomian gland secretion scores from baseline measurements (4.0 ± 3.4) to 1-month post-treatment (11.3 ± 4.7; P < 0.0005) was maintained at 1-year (7.3 ± 4.6; P < 0.05). Baseline tear break-up time (4.9 ± 3.0) was significantly increased at 1-month (9.5 ± 6.9; P < 0.05); however, this improvement was no longer evident at 1-year post-treatment (6.0 ± 4.4). The significant improvement in symptom scores on Ocular Surface Disease Index and Standard Patient Evaluation of Eye Dryness questionnaires observed at 1-month (P < 0.0005) was maintained at 1-year (Ocular Surface Disease Index [P < 0.05]; Standard Patient Evaluation of Eye Dryness [P < 0.0005]). CONCLUSION: A single 12-min treatment with the Lipi Flow Thermal Pulsation System offers an effective treatment for evaporative dry eye and meibomian gland dysfunction resulting in significant and sustained improvement in signs and symptoms for up to 1 year.
Liu Y, Yang X, Utheim TP, Guo C, Xiao M, Liu Y, Yin Z, Ma J. Correlation of cytokine levels and microglial cell infiltration during retinal degeneration in RCS rats. PLoS One 2013;8(12):e82061.Abstract
Microglial cells, which are immunocompetent cells, are involved in all diseases of the central nervous system. During their activation in various diseases, a variety of soluble factors are released. In the present study, the correlation between cytokine levels and microglial cell migration in the course of retinal degeneration of Royal College of Surgeons (RCS) rats was evaluated. MFG-E8 and CD11b were used to confirm the microglial cells. In the retina of RCS rats, the mRNA expression of seven genes (MFG-E8 and its integrins αυ and ß5, CD11b and the cytokines TNF-α, IL-1ß, and MCP-1) formed almost similar bimodal peak distributions, which were centred at P7 and P45 to P60. In contrast, in rdy rats, which comprised the control group, a unimodal peak distribution centred at P14 was observed. The gene expression accompanied the activation and migration of microglial cells from the inner to the outer layer of the retina during the process of degeneration. Principal component analysis and discriminant function analysis revealed that the expression of these seven genes, especially TNF-α and CD11b, positively correlated with retinal degeneration and microglial activity during retinal degeneration in RCS rats, but not in the control rats. Furthermore, linear regression analysis demonstrated a significant correlation between the expression of these genes and the activation of microglial cells in the dystrophic retina. Our findings suggest that the suppression of microglial cells and the blockade of their cytotoxic effects may constitute a novel therapeutic strategy for treating photoreceptor death in various retinal disorders.
Lei H, Kazlauskas A. Detection of H2O2-mediated phosphorylation of kinase-inactive PDGFRα. Methods Enzymol 2013;528:189-94.Abstract
Platelet-derived growth factor (PDGF) receptor α (PDGFRα) belongs to the 58-member family of receptor tyrosine kinases and contributes to a variety of physiological and pathological settings. Activation of PDGFRα proceeds by at least two mechanisms. The traditional route involves PDGF-dependent dimerization and activation of the receptor's intrinsic kinase activity. The second mechanism proceeds intracellularly and involves reactive oxygen species and Src family kinases, which activate monomeric PDGFRα. Herein we describe an assay to investigate reactive oxygen species-mediated phosphorylation of PDGFRα that is independent of the receptor's intrinsic kinase activity.
Lebreton F, Valentino MD, Duncan LB, Zeng Q, McGuire AM, Earl AM, Gilmore MS. High-Quality Draft Genome Sequence of Vagococcus lutrae Strain LBD1, Isolated from the Largemouth Bass Micropterus salmoides. Genome Announc 2013;1(6)Abstract
Vagococci are usually isolated from marine hosts and occasionally from endodontic infections. Using 16S rRNA gene comparison, the closest relatives are members of the genera Enterococcus and Carnobacterium. A draft sequence of Vagococcus lutrae was generated to clarify the relationship of Vagococcus to these and other related low-G+C Gram-positive bacteria.
Khandelwal P, Blanco-Mezquita T, Emami P, Lee HS, Reyes NJ, Mathew R, Huang R, Saban DR. Ocular mucosal CD11b+ and CD103+ mouse dendritic cells under normal conditions and in allergic immune responses. PLoS One 2013;8(5):e64193.Abstract
Steady state dendritic cells (DC) found in non-lymphoid tissue sites under normal physiologic conditions play a pivotal role in triggering T cell responses upon immune provocation. CD11b+ and CD103+ DC have received considerable attention in this regard. However, still unknown is whether such CD11b+ and CD103+ DC even exist in the ocular mucosa, and if so, what functions they have in shaping immune responses. We herein identified in the ocular mucosa of normal wild-type (WT) and Flt3-/- mice the presence of a CD11b+ DC (i.e., CD11c+ MHCII+ CD11b+ CD103- F4/80+ Sirp-a+). CD103+ DC (i.e. CD11c+ MHCII+ CD11b low CD103+ CD8a+ DEC205+ Langerin+) were also present in WT, but not in Flt3-/- mice. These CD103+ DC expressed high levels of Id2 and Flt3 mRNA; whereas CD11b+ DC expressed high Irf4, Csfr, and Cx3cr1 mRNA. Additionally, the functions of these DC differed in response to allergic immune provocation. This was assessed utilizing a previously validated model, which includes transferring specific populations of exogenous DC into the ocular mucosa of ovalbumin (OVA)/alum-primed mice. Interestingly, in such mice, topical OVA instillation following engraftment of exogenous CD11b+ DC led to dominant allergic T cell responses and clinical signs of ocular allergy relative to those engrafted with CD103+ DC. Thus, although CD11b+ and CD103+ DC are both present in the normal ocular mucosa, the CD11b+ DC subset plays a dominant role in a mouse model of ocular allergy.
Jakobiec FA, Zakka FR, Perry LP. The cytologic composition of dacryops: an immunohistochemical investigation of 15 lesions compared to the normal lacrimal gland. Am J Ophthalmol 2013;155(2):380-396.e1.Abstract
PURPOSE: To define the cytologic composition of the double-layered epithelial lining of dacryops (lacrimal duct cyst), improve histopathologic diagnosis, and better understand pathogenesis. DESIGN: Clinicopathologic retrospective study with immunohistochemical studies of 15 lesions compared with normal lacrimal gland. METHODS: Clinical data from 14 patients were reviewed and microscopy was performed with routine stains and immunohistochemical probes for epithelial membrane antigen (EMA), gross cystic disease fluid protein-15 (GCDFP-15), cytokeratin 7 (CK7), and smooth muscle actin (SMA). RESULTS: The major lacrimal gland was involved in 13 lesions; 2 lesions arose in an accessory gland of Krause. One case was bilateral; the average age of the patients was 50.7 years. Neither visual acuity nor motility was disturbed. No lesion was discovered to have recurred after excision. Microscopically, in all dacryops specimens goblet cells and luminal pseudoapocrine apical cytoplasmic projections were identified. Lacrimal acinar cells immunoreacted with GCDFP-15 and CK7, whereas the normal ducts and the epithelium of the dacryops lesions reacted diffusely only with CK7. SMA-positive myoepithelial cells were found in the acini but not in the normal ducts or dacryops epithelium. CONCLUSIONS: Negative GCDFP-15 staining ruled out apocrine metaplasia in dacryops. Normal ducts and dacryops showed no immunohistochemical evidence for the presence of myoepithelial cells. Pathogenetic theories of dacryops that implicate a failure of ductular "neuromuscular" contractility must therefore be revised. A dysfunction of the rich neural plexus around the ductules may play a role in the development of dacryops in conjunction with periductular inflammation and induced scarring.
Mauris J, Mantelli F, Woodward AM, Cao Z, Bertozzi CR, Panjwani N, Godula K, Argüeso P. Modulation of ocular surface glycocalyx barrier function by a galectin-3 N-terminal deletion mutant and membrane-anchored synthetic glycopolymers. PLoS One 2013;8(8):e72304.Abstract
BACKGROUND: Interaction of transmembrane mucins with the multivalent carbohydrate-binding protein galectin-3 is critical to maintaining the integrity of the ocular surface epithelial glycocalyx. This study aimed to determine whether disruption of galectin-3 multimerization and insertion of synthetic glycopolymers in the plasma membrane could be used to modulate glycocalyx barrier function in corneal epithelial cells. METHODOLOGY/PRINCIPAL FINDINGS: Abrogation of galectin-3 biosynthesis in multilayered cultures of human corneal epithelial cells using siRNA, and in galectin-3 null mice, resulted in significant loss of corneal barrier function, as indicated by increased permeability to the rose bengal diagnostic dye. Addition of β-lactose, a competitive carbohydrate inhibitor of galectin-3 binding activity, to the cell culture system, transiently disrupted barrier function. In these experiments, treatment with a dominant negative inhibitor of galectin-3 polymerization lacking the N-terminal domain, but not full-length galectin-3, prevented the recovery of barrier function to basal levels. As determined by fluorescence microscopy, both cellobiose- and lactose-containing glycopolymers incorporated into apical membranes of corneal epithelial cells, independently of the chain length distribution of the densely glycosylated, polymeric backbones. Membrane incorporation of cellobiose glycopolymers impaired barrier function in corneal epithelial cells, contrary to their lactose-containing counterparts, which bound to galectin-3 in pull-down assays. CONCLUSIONS/SIGNIFICANCE: These results indicate that galectin-3 multimerization and surface recognition of lactosyl residues is required to maintain glycocalyx barrier function at the ocular surface. Transient modification of galectin-3 binding could be therapeutically used to enhance the efficiency of topical drug delivery.
Haddock LJ, Kim DY, Mukai S. Simple, inexpensive technique for high-quality smartphone fundus photography in human and animal eyes. J Ophthalmol 2013;2013:518479.Abstract
Purpose. We describe in detail a relatively simple technique of fundus photography in human and rabbit eyes using a smartphone, an inexpensive app for the smartphone, and instruments that are readily available in an ophthalmic practice. Methods. Fundus images were captured with a smartphone and a 20D lens with or without a Koeppe lens. By using the coaxial light source of the phone, this system works as an indirect ophthalmoscope that creates a digital image of the fundus. The application whose software allows for independent control of focus, exposure, and light intensity during video filming was used. With this app, we recorded high-definition videos of the fundus and subsequently extracted high-quality, still images from the video clip. Results. The described technique of smartphone fundus photography was able to capture excellent high-quality fundus images in both children under anesthesia and in awake adults. Excellent images were acquired with the 20D lens alone in the clinic, and the addition of the Koeppe lens in the operating room resulted in the best quality images. Successful photodocumentation of rabbit fundus was achieved in control and experimental eyes. Conclusion. The currently described system was able to take consistently high-quality fundus photographs in patients and in animals using readily available instruments that are portable with simple power sources. It is relatively simple to master, is relatively inexpensive, and can take advantage of the expanding mobile-telephone networks for telemedicine.
MacKinnon S, Proctor MR, Rogers GF, Meara JG, Whitecross S, Dagi LR. Improving ophthalmic outcomes in children with unilateral coronal synostosis by treatment with endoscopic strip craniectomy and helmet therapy rather than fronto-orbital advancement. J AAPOS 2013;17(3):259-65.Abstract
PURPOSE: To compare long-term ophthalmic outcomes in infants treated for unilateral coronal synostosis (UCS) by endoscopic strip craniectomy (ESC) and helmet therapy with those treated by fronto-orbital advancement (FOA). METHODS: Consecutive patients with UCS, uncomplicated by other suture synostosis, were identified by a retrospective review of medical records. Assessment of presence of amblyopia, cycloplegic refraction, strabismus, and strabismus surgical intervention at all visits was recorded. RESULTS: Between 2004 and 2010, 22 patients were treated by FOA (mean follow-up, 21.5 months) and 21 patients with ESC and helmet therapy (mean follow-up, 23.5 months). The mean aniso-astigmatism was equal; however, the SD was greater for those treated by FOA (P < 0.05). A more severe pattern of strabismus developed in those treated by FOA (P < 0.0001). Those treated by FOA were more likely to have amblyopia (P = 0.0015) and to undergo surgical correction of their strabismus (odds ratio, 6.3:1). CONCLUSIONS: Children with UCS treated with ESC and helmeting had less severe overelevation in adduction, amblyopia, extremes of astigmatism, and less need for strabismus surgery than those treated by FOA. Although the reason for these more favorable outcomes remains uncertain, we speculate that the earlier timing of ESC or differences in the anatomical changes resulting from the two procedures may play a role.
Li D, Shatos MA, Hodges RR, Dartt DA. Role of PKCα activation of Src, PI-3K/AKT, and ERK in EGF-stimulated proliferation of rat and human conjunctival goblet cells. Invest Ophthalmol Vis Sci 2013;54(8):5661-74.Abstract
PURPOSE: To determine the order and components of the signaling pathway utilized by epidermal growth factor (EGF) to stimulate conjunctival goblet cell proliferation. METHODS: Goblet cells from rat bulbar and forniceal conjunctiva and human bulbar conjunctiva were grown in organ culture. Goblet cells (GCs) were serum starved for 24 hours and preincubated with inhibitors for 30 minutes or small interfering RNA (siRNA) for 48 hours prior to addition of EGF. Proliferation was then measured or Western blot analysis was performed using antibodies against phosphorylated protein kinase B (AKT), extracellular signal-regulated kinase 1/2 (ERK1/2), or the non-receptor tyrosine kinase Src. Rat GCs were also incubated with adenoviruses expressing dominant negative protein kinase Cα (DNPKCα) or constitutively activated protein kinase Cα (myrPKCα), and activation of AKT and ERK1/2 was determined by Western blot analysis. RESULTS: Inhibitors of phosphoinositol-3 kinase (PI-3K)/AKT pathway blocked EGF-stimulated ERK1/2 activation and GC proliferation. Inhibitors of EGF-stimulated ERK1/2 activity did not inhibit AKT activation but blocked proliferation. DNPKCα blocked EGF-stimulated activation of AKT and ERK1/2 while myrPKCα increased activation of these kinases. Inhibitors of PI-3K, ERK1/2, and protein kinase C (PKC) blocked myrPKCα-stimulated GC proliferation. EGF and myrPKCα increased phosphorylation of Src, and inhibition of Src with the chemical inhibitor PP1 or siRNA inhibited EGF-stimulated GC proliferation. CONCLUSIONS: We found that EGF activates a major pathway to stimulate goblet cell proliferation. This pathway consists of induction of phospholipase C (PLC)γ to activate PKCα. Active PKCα phosphorylates Src to induce PI-3K to phosphorylate AKT that subsequently activates the ERK1/2 cascade to stimulate goblet cell proliferation.