September 2015

B
Bauskar A, Mack WJ, Mauris J, Argüeso P, Heur M, Nagel BA, Kolar GR, Gleave ME, Nakamura T, Kinoshita S, Moradian-Oldak J, Panjwani N, Pflugfelder SC, Wilson MR, Fini EM, Jeong S. Clusterin Seals the Ocular Surface Barrier in Mouse Dry Eye. PLoS One 2015;10(9):e0138958.Abstract

Dry eye is a common disorder caused by inadequate hydration of the ocular surface that results in disruption of barrier function. The homeostatic protein clusterin (CLU) is prominent at fluid-tissue interfaces throughout the body. CLU levels are reduced at the ocular surface in human inflammatory disorders that manifest as severe dry eye, as well as in a preclinical mouse model for desiccating stress that mimics dry eye. Using this mouse model, we show here that CLU prevents and ameliorates ocular surface barrier disruption by a remarkable sealing mechanism dependent on attainment of a critical all-or-none concentration. When the CLU level drops below the critical all-or-none threshold, the barrier becomes vulnerable to desiccating stress. CLU binds selectively to the ocular surface subjected to desiccating stress in vivo, and in vitro to the galectin LGALS3, a key barrier component. Positioned in this way, CLU not only physically seals the ocular surface barrier, but it also protects the barrier cells and prevents further damage to barrier structure. These findings define a fundamentally new mechanism for ocular surface protection and suggest CLU as a biotherapeutic for dry eye.

Bronstad MP, Albu A, Bowers AR, Goldstein R, Peli E. Driving with Central Visual Field Loss II: How Scotomas above or below the Preferred Retinal Locus (PRL) Affect Hazard Detection in a Driving Simulator. PLoS One 2015;10(9):e0136517.Abstract

We determined whether binocular central scotomas above or below the preferred retinal locus affect detection of hazards (pedestrians) approaching from the side. Seven participants with central field loss (CFL), and seven age-and sex-matched controls with normal vision (NV), each completed two sessions of 5 test drives (each approximately 10 minutes long) in a driving simulator. Participants pressed the horn when detecting pedestrians that appeared at one of four eccentricities (-14°, -4°, left, 4°, or 14°, right, relative to car heading). Pedestrians walked or ran towards the travel lane on a collision course with the participant's vehicle, thus remaining in the same area of the visual field, assuming participant's steady forward gaze down the travel lane. Detection rates were nearly 100% for all participants. CFL participant reaction times were longer (median 2.27s, 95% CI 2.13 to 2.47) than NVs (median 1.17s, 95%CI 1.10 to 2.13; difference p<0.01), and CFL participants would have been unable to stop for 21% of pedestrians, compared with 3% for NV, p<0.001. Although the scotomas were not expected to obscure pedestrian hazards, gaze tracking revealed that scotomas did sometimes interfere with detection; late reactions usually occurred when pedestrians were entirely or partially obscured by the scotoma (time obscured correlated with reaction times, r = 0.57, p<0.001). We previously showed that scotomas lateral to the preferred retinal locus delay reaction times to a greater extent; however, taken together, the results of our studies suggest that any binocular CFL might negatively impact timely hazard detection while driving and should be a consideration when evaluating vision for driving.

C
Campbell AA, Cunnane ME, Dunn GP, Gray ST, Lefebvre DR. Spontaneous Resorption of a Penetrating Orbital Bone Fracture Fragment. Ophthal Plast Reconstr Surg 2015;31(5):e123-5.Abstract

The authors describe a 20-year-old man who sustained multiple facial fractures in a high-speed motor vehicle crash, including a bone fragment from a skull base fracture that penetrated the orbital soft tissues superomedially. Serial CT scans documented spontaneous resorption over a 6-month period. While it is known that autologous bone grafts used in craniofacial reconstruction exhibit variable amounts of bone resorption, the complete resorption of an intraorbital fracture fragment has not been documented in the literature. His clinical care and the report of his case were undertaken in a fashion in accordance with the principles of the Health Insurance Portability and Accountability Act regulations.

Cestari DM, Lessell S, Mantopoulos D. Early Diagnosis of Subclinical Interferon Alpha-Associated Optic Neuropathy Using Fluorescein Angiography. J Neuroophthalmol 2015;35(3):280-3.Abstract

We report a case of a 57-year-old man who presented with decreased visual acuity in the left eye secondary to nonarteritic anterior ischemic optic neuropathy (NAION) while on therapy with interferon-α for hepatitis C. Fundus fluorescein angiography revealed late leakage of both optic discs, consistent with bilateral disease. One week later, the patient developed clinical signs and symptoms consistent with NAION in the fellow eye. Fluorescein angiography may play an important role in identifying subclinical NAION in patients taking interferon-α.

Chee YE, Newman LR, Loewenstein JI, Kloek CE. Improving the Teaching Skills of Residents in a Surgical Training Program: Results of the Pilot Year of a Curricular Initiative in an Ophthalmology Residency Program. J Surg Educ 2015;72(5):890-7.Abstract

OBJECTIVE: To design and implement a teaching skills curriculum that addressed the needs of an ophthalmology residency training program, to assess the effect of the curriculum, and to present important lessons learned. DESIGN: A teaching skills curriculum was designed for the Harvard Medical School (HMS) Residency Training Program in Ophthalmology. Results of a needs assessment survey were used to guide curriculum objectives. Overall, 3 teaching workshops were conducted between October 2012 and March 2013 that addressed areas of need, including procedural teaching. A postcurriculum survey was used to assess the effect of the curriculum. SETTING: Massachusetts Eye and Ear Infirmary, a tertiary care institution in Boston, MA. PARTICIPANTS: Overall, 24 residents in the HMS Residency Training Program in Ophthalmology were included. RESULTS: The needs assessment survey demonstrated that although most residents anticipated that teaching would be important in their future career, only one-third had prior formal training in teaching. All residents reported they found the teaching workshops to be either very or extremely useful. All residents reported they would like further training in teaching, with most residents requesting additional training in best procedural teaching practices for future sessions. CONCLUSIONS: The pilot year of the resident-as-teacher curriculum for the HMS Residency Training Program in Ophthalmology demonstrated a need for this curriculum and was perceived as beneficial by the residents, who reported increased comfort in their teaching skills after attending the workshops.

Chi M, Kim JH, Basham R, Yoon MK, Vagefi R, Kersten RC. Temporal Artery Calciphylaxis Presenting as Temporal Arteritis in a Case of Rhinoorbitocerebral Mucormycosis. Ophthal Plast Reconstr Surg 2015;31(5):e132-5.Abstract

Mucormycosis is a rare often fatal opportunistic fungal infection. It is typically described in patients with diabetes in ketoacidotic status and is rare in renal transplant recipients. Calciphylaxis is a rare and highly morbid disease of vascular calcification affecting patients with end-stage renal disease (ESRD). The first case of a renal transplant recipient who was inflicted with both rhinoorbitocerebral mucormycosis and calciphylaxis is reported. A 45-year-old man presented with 2-day history of left upper blepharoptosis, periorbital pain, left-sided headache, binocular diplopia, and left V2 numbness. He had undergone renal transplant for ESRD 7 months earlier with resultant immunosuppressive therapy. MRI and nasal biopsy confirmed rhinoorbitocerebral mucormycosis. Immunosuppressive therapy was stopped and antifungal therapy begun. He had orbital exenteration for progressive rhinoorbitocerebral mucormycosis. Two months later, the patient reported new-onset intermittent bitemporal headache and bilateral swollen, tender temporal arteries. Temporal artery biopsy revealed features consistent with calciphylaxis. Clinical presentation, treatment course, and follow up are discussed.

D
Doherty AL, Peli E, Luo G. Hazard detection with a monocular bioptic telescope. Ophthalmic Physiol Opt 2015;35(5):530-9.Abstract

PURPOSE: The safety of bioptic telescopes for driving remains controversial. The ring scotoma, an area to the telescope eye due to the telescope magnification, has been the main cause of concern. This study evaluates whether bioptic users can use the fellow eye to detect in hazards driving videos that fall in the ring scotoma area. METHODS: Twelve visually impaired bioptic users watched a series of driving hazard perception training videos and responded as soon as they detected a hazard while reading aloud letters presented on the screen. The letters were placed such that when reading them through the telescope the hazard fell in the ring scotoma area. Four conditions were tested: no bioptic and no reading, reading without bioptic, reading with a bioptic that did not occlude the fellow eye (non-occluding bioptic), and reading with a bioptic that partially-occluded the fellow eye. Eight normally sighted subjects performed the same task with the partially occluding bioptic detecting lateral hazards (blocked by the device scotoma) and vertical hazards (outside the scotoma) to further determine the cause-and-effect relationship between hazard detection and the fellow eye. RESULTS: There were significant differences in performance between conditions: 83% of hazards were detected with no reading task, dropping to 67% in the reading task with no bioptic, to 50% while reading with the non-occluding bioptic, and 34% while reading with the partially occluding bioptic. For normally sighted, detection of vertical hazards (53%) was significantly higher than lateral hazards (38%) with the partially occluding bioptic. CONCLUSIONS: Detection of driving hazards is impaired by the addition of a secondary reading like task. Detection is further impaired when reading through a monocular telescope. The effect of the partially-occluding bioptic supports the role of the non-occluded fellow eye in compensating for the ring scotoma.

Duminuco R, Noble JW, Goody J, Sharma M, Ksander BR, Roskelley CD, Cox ME, Mills J. Integrin-linked kinase regulates senescence in an Rb-dependent manner in cancer cell lines. Cell Cycle 2015;14(18):2924-37.Abstract

Anti-integrin-linked kinase (ILK) therapies result in aberrant mitosis including altered mitotic spindle organization, centrosome declustering and mitotic arrest. In contrast to cells that expressed the retinoblastoma tumor suppressor protein Rb, we have shown that in retinoblastoma cell lines that do not express Rb, anti-ILK therapies induced aberrant mitosis that led to the accumulation of temporarily viable multinucleated cells. The present work was undertaken to: 1) determine the ultimate fate of cells that had survived anti-ILK therapies and 2) determine whether or not Rb expression altered the outcome of these cells. Our data indicate that ILK, a chemotherapy drug target is expressed in both well-differentiated, Rb-negative and relatively undifferentiated, Rb-positive retinoblastoma tissue. We show that small molecule targeting of ILK in Rb-positive and Rb-deficient cancer cells results in increased centrosomal declustering, aberrant mitotic spindle formation and multinucleation. However, anti-ILK therapies in vitro have different outcomes in retinoblastoma and glioblastoma cell lines that depend on Rb expression. TUNEL labeling and propidium iodide FACS analysis indicate that Rb-positive cells exposed to anti-ILK therapies are more susceptible to apoptosis and senescence than their Rb-deficient counterparts wherein aberrant mitosis induced by anti-ILK therapies exhibit mitotic arrest instead. These studies are the first to show a role for ILK in chemotherapy-induced senescence in Rb-positive cancer lines. Taken together these results indicate that the oncosuppressive outcomes for anti-ILK therapies in vitro, depend on the expression of the tumor suppressor Rb, a known G1 checkpoint and senescence regulator.

H
Harwell CC, Fuentealba LC, Gonzalez-Cerrillo A, Parker PRL, Gertz CC, Mazzola E, Garcia MT, Alvarez-Buylla A, Cepko CL, Kriegstein AR. Wide Dispersion and Diversity of Clonally Related Inhibitory Interneurons. Neuron 2015;87(5):999-1007.Abstract

The mammalian neocortex is composed of two major neuronal cell types with distinct origins: excitatory pyramidal neurons and inhibitory interneurons, generated in dorsal and ventral progenitor zones of the embryonic telencephalon, respectively. Thus, inhibitory neurons migrate relatively long distances to reach their destination in the developing forebrain. The role of lineage in the organization and circuitry of interneurons is still not well understood. Utilizing a combination of genetics, retroviral fate mapping, and lineage-specific retroviral barcode labeling, we find that clonally related interneurons can be widely dispersed while unrelated interneurons can be closely clustered. These data suggest that migratory mechanisms related to the clustering of interneurons occur largely independent of their clonal origin.

Hu K, Harris DL, Yamaguchi T, von Andrian UH, Hamrah P. A Dual Role for Corneal Dendritic Cells in Herpes Simplex Keratitis: Local Suppression of Corneal Damage and Promotion of Systemic Viral Dissemination. PLoS One 2015;10(9):e0137123.Abstract

The cornea is the shield to the foreign world and thus, a primary site for peripheral infections. However, transparency and vision are incompatible with inflammation and scarring that may result from infections. Thus, the cornea is required to perform a delicate balance between fighting infections and preserving vision. To date, little is known about the specific role of antigen-presenting cells in viral keratitis. In this study, utilizing an established murine model of primary acute herpes simplex virus (HSV)-1 keratitis, we demonstrate that primary HSV keratitis results in increased conventional dendritic cells (cDCs) and macrophages within 24 hours after infection. Local depletion of cDCs in CD11c-DTR mice by subconjuntival diphtheria toxin injections, led to increased viral proliferation, and influx of inflammatory cells, resulting in increased scarring and clinical keratitis. In addition, while HSV infection resulted in significant corneal nerve destruction, local depletion of cDCs resulted in a much more severe loss of corneal nerves. Further, local cDC depletion resulted in decreased corneal nerve infection, and subsequently decreased and delayed systemic viral transmission in the trigeminal ganglion and draining lymph node, resulting in decreased mortality of mice. In contrast, sham depletion or depletion of macrophages through local injection of clodronate liposomes had neither a significant impact on the cornea, nor an effect on systemic viral transmission. In conclusion, we demonstrate that corneal cDCs may play a primary role in local corneal defense during viral keratitis and preserve vision, at the cost of inducing systemic viral dissemination, leading to increased mortality.

Huang T, Zheng Y, Qi Q, Xu M, Ley SH, Li Y, Kang JH, Wiggs J, Pasquale LR, Chan AT, Rimm EB, Hunter DJ, Manson JAE, Willett WC, Hu FB, Qi L. DNA Methylation Variants at HIF3A Locus, B-Vitamin Intake, and Long-term Weight Change: Gene-Diet Interactions in Two U.S. Cohorts. Diabetes 2015;64(9):3146-54.Abstract

The first epigenome-wide association study of BMI identified DNA methylation at an HIF3A locus associated with BMI. We tested the hypothesis that DNA methylation variants are associated with BMI according to intake of B vitamins. In two large cohorts, we found significant interactions between the DNA methylation-associated HIF3A single nucleotide polymorphism (SNP) rs3826795 and intake of B vitamins on 10-year changes in BMI. The association between rs3826795 and BMI changes consistently increased across the tertiles of total vitamin B2 and B12 intake (all P for interaction <0.01). The differences in the BMI changes per increment of minor allele were -0.10 (SE 0.06), -0.01 (SE 0.06), and 0.12 (SE 0.07) within subgroups defined by increasing tertiles of total vitamin B2 intake and -0.10 (SE 0.06), -0.01 (SE 0.06), and 0.10 (SE 0.07) within subgroups defined by increasing tertiles of total vitamin B12 intake. In two independent cohorts, a DNA methylation variant in HIF3A was associated with BMI changes through interactions with total or supplemental vitamin B2, vitamin B12, and folate. These findings suggest a potential causal relation between DNA methylation and adiposity.

J
Jakobiec FA, Rai R, Rashid A, Sutula FC. Bilateral Eyelid Pseudoptosis From Lipogranulomas of the Preaponeurotic Fat Pads. Ophthal Plast Reconstr Surg 2015;31(5):e125-31.Abstract

Lipogranulomas of the periocular tissues with fulminant fibrotic and lymphohistiocytic responses were initially described in cases of exogenous paraffin or petrolatum jelly injections ("paraffinomas"). A 49-year-old Cambodian woman slowly developed bilateral pseudoptosis with intact levator function and redundant, taut upper eyelid skin. At surgery, vesiculations or "bubbles" in the preaponeurotic fat were encountered and were demonstrated histopathologically to be empty locules surrounded by a thin collagenous lamina. Outside these extracellular spaces were CD68/CD163-positive mononucleated and univacuolated histiocytes simulating damaged fat cells or neoplastic lipoblasts in hematoxylin and eosin sections. Giant cells and chronic sclerosing inflammation were absent. The patient denied any previous injections. The bland character of the lipogranulomas in comparison with that of other injectable agents, the absence of any residual particles associated with other cosmetic fillers, and the distinctive histiocytic response of lipoblast-like cells that were sufficiently characteristic to compel the diagnosis of surreptitious silicone injections. Other conditions were excluded based on comparative clinicopathologic criteria.

Jakobiec FA, Stagner AM, Sutula FC, Freitag SK, Yoon MK. Pigmentation of the Lacrimal Sac Epithelium. Ophthal Plast Reconstr Surg 2015;Abstract

PURPOSE: To describe the patterns of the melanocytic populations of 3 cases of lacrimal sac benign melanosis and 1 of atypical primary-acquired sac melanosis with a melanomatous nodule secondary to spread of atypical conjunctival primary-acquired melanosis to the sac. METHODS: Clinical records, photographs, and paraffin sections stained with hematoxylin and eosin and the Fontana reaction were critically reviewed. Additional sections were immunoreacted for melanoma antigen recognized by T cells and microphthalmia-associated transcription factor. Five nonpigmented pterygia and 4 nonpigmented lacrimal sacs served as controls. RESULTS: Three patients with obstructive dacryocystitis and benign melanosis were African-Americans whose sacs disclosed the presence of nonclustering, melanoma antigen recognized by T cells, and microphthalmia-associated transcription factor-positive intraepithelial dendritic melanocytes at all levels of the epithelium. The transferred melanin granules were concentrated in the adlumenal apical region of the epithelial cells. No fusiform melanocytes were found in the lamina propria. The fourth patient, a Caucasian, had atypical conjunctival and sac primary-acquired melanosis and conjunctival and sac melanomas. The intraepithelial sac melanocytes in this case were strikingly atypical and profusely distributed in a back to back fashion at all levels of a thickened epithelial layer focally approximating the appearance of a melanoma in situ. Five nonpigmented pterygia and 4 nonpigmented lacrimal sacs served as controls. Each displayed nonnesting dendritic melanocytes of various densities without back to back contact. CONCLUSION: Low densities of intraepithelial melanocytes were discovered in all controls and therefore represent a normal subpopulation within the conjunctival and lacrimal sacs. Due to the pseudostratification of the sac epithelium, melanocytes can move to higher levels without implying atypia. Benign melanosis is produced by small diffusely distributed individual intraepithelial melanocytes, whereas primary-acquired melanosis with atypia exhibits back to back, dense proliferations of large atypical melanocytes.

K
Karki P, Kim C, Smith K, Son D-S, Aschner M, Lee E. Transcriptional Regulation of the Astrocytic Excitatory Amino Acid Transporter 1 (EAAT1) via NF-κB and Yin Yang 1 (YY1). J Biol Chem 2015;290(39):23725-37.Abstract

Astrocytic glutamate transporter excitatory amino acid transporter (EAAT) 1, also known as glutamate aspartate transporter (GLAST) in rodents, is one of two glial glutamate transporters that are responsible for removing excess glutamate from synaptic clefts to prevent excitotoxic neuronal death. Despite its important role in neurophysiological functions, the molecular mechanisms of EAAT1 regulation at the transcriptional level remain to be established. Here, we report that NF-κB is a main positive transcription factor for EAAT1, supported by the following: 1) EAAT1 contains two consensus sites for NF-κB, 2) mutation of NF-κB binding sites decreased EAAT1 promoter activity, and 3) activation of NF-κB increased, whereas inhibition of NF-κB decreased EAAT1 promoter activity and mRNA/protein levels. EGF increased EAAT1 mRNA/protein levels and glutamate uptake via NF-κB. The transcription factor yin yang 1 (YY1) plays a role as a critical negative regulator of EAAT1, supported by the following: 1) the EAAT1 promoter contains multiple consensus sites for YY1, 2) overexpression of YY1 decreased EAAT1 promoter activity and mRNA/protein levels, and 3) knockdown of YY1 increased EAAT1 promoter activity and mRNA/protein levels. Manganese decreased EAAT1 expression via YY1. Epigenetic modifiers histone deacetylases (HDACs) served as co-repressors of YY1 to further decrease EAAT1 promoter activity, whereas inhibition of HDACs reversed manganese-induced decrease of EAAT1 expression. Taken together, our findings suggest that NF-κB is a critical positive regulator of EAAT1, mediating the stimulatory effects of EGF, whereas YY1 is a negative regulator of EAAT1 with HDACs as co-repressors, mediating the inhibitory effects of manganese on EAAT1 regulation.

Kheirkhah A, Muller R, Mikolajczak J, Ren A, Kadas EM, Zimmermann H, Pruess H, Paul F, Brandt AU, Hamrah P. Comparison of Standard Versus Wide-Field Composite Images of the Corneal Subbasal Layer by In Vivo Confocal Microscopy. Invest Ophthalmol Vis Sci 2015;56(10):5801-7.Abstract

PURPOSE: To evaluate whether the densities of corneal subbasal nerves and epithelial immune dendritiform cells (DCs) are comparable between a set of three representative standard images of in vivo confocal microscopy (IVCM) and the wide-field mapped composite IVCM images. METHODS: This prospective, cross-sectional, and masked study included 110 eyes of 58 patients seen in a neurology clinic who underwent laser-scanning IVCM (Heidelberg Retina Tomograph 3) of the central cornea. Densities of subbasal corneal nerves and DCs were compared between the average of three representative standard images and the wide-field mapped composite images, which were reconstructed by automated mapping. RESULTS: There were no statistically significant differences between the average of three representative standard images (0.16 mm2 each) and the wide-field composite images (1.29 ± 0.64 mm2) in terms of mean subbasal nerve density (17.10 ± 6.10 vs. 17.17 ± 5.60 mm/mm2, respectively, P = 0.87) and mean subbasal DC density (53.2 ± 67.8 vs. 49.0 ± 54.3 cells/mm2, respectively, P = 0.43). However, there were notable differences in subbasal nerve and DC densities between these two methods in eyes with very low nerve density or very high DC density. CONCLUSIONS: There are no significant differences in the mean subbasal nerve and DC densities between the average values of three representative standard IVCM images and wide-field mapped composite images. Therefore, these standard images can be used in clinical studies to accurately measure cellular structures in the subbasal layer.

L
Liu Y, Magro C, Loewenstein JI, Makar RS, Stowell CP, Dzik WH, Hochberg EP, Oaklander AL, Sobrin L. A Man with Paraneoplastic Retinopathy plus Small Fiber Polyneuropathy Associated with Waldenström Macroglobulinemia (Lymphoplasmacytic Lymphoma): Insights into Mechanisms. Ocul Immunol Inflamm 2015;23(5):405-9.Abstract
PURPOSE: To report a well-characterized Waldenström's macroglobulinemia (WM) case that provides insight into the mechanisms of two paraneoplastic complications -- cancer-associated retinopathy (CAR) and small fiber polyneuropathy (SFPN). METHODS: Retrospective medical chart review. RESULTS: A 58-year old man with WM developed vision loss and bilateral lower extremity pain. CAR was diagnosed by history, a depressed electroretinogram (ERG) and positive anti-retinal antibodies. SFPN diagnosis was based on abnormal autonomic nerve function testing and a distal-leg skin biopsy that demonstrated absent epidermal small-fiber innervation, IgM and complement deposition and microvasculopathy. Plasma exchange (PLEX) led to dramatic pain relief and subjective improvement in eye symptoms along with improvement of some ERG parameters. Repeat skin biopsy after treatment showed less microvascular abnormalities and decreased complement deposition. CONCLUSIONS: The concurrence of CAR and SFPN in this patient suggest that both were complications of WM and their common response to PLEX suggests co-mediation by humoral factors that accessed target antigens through IgM-triggered, complement-mediated vascular damage.
Liu C-H, Sun Y, Li J, Gong Y, Tian KT, Evans LP, Morss PC, Fredrick TW, Saba NJ, Chen J. Endothelial microRNA-150 is an intrinsic suppressor of pathologic ocular neovascularization. Proc Natl Acad Sci U S A 2015;112(39):12163-8.Abstract

Pathologic ocular neovascularization commonly causes blindness. It is critical to identify the factors altered in pathologically proliferating versus normally quiescent vessels to develop effective targeted therapeutics. MicroRNAs regulate both physiological and pathological angiogenesis through modulating expression of gene targets at the posttranscriptional level. However, it is not completely understood if specific microRNAs are altered in pathologic ocular blood vessels, influencing vascular eye diseases. Here we investigated the potential role of a specific microRNA, miR-150, in regulating ocular neovascularization. We found that miR-150 was highly expressed in normal quiescent retinal blood vessels and significantly suppressed in pathologic neovessels in a mouse model of oxygen-induced proliferative retinopathy. MiR-150 substantially decreased endothelial cell function including cell proliferation, migration, and tubular formation and specifically suppressed the expression of multiple angiogenic regulators, CXCR4, DLL4, and FZD4, in endothelial cells. Intravitreal injection of miR-150 mimic significantly decreased pathologic retinal neovascularization in vivo in both wild-type and miR-150 knockout mice. Loss of miR-150 significantly promoted angiogenesis in aortic rings and choroidal explants ex vivo and laser-induced choroidal neovascularization in vivo. In conclusion, miR-150 is specifically enriched in quiescent normal vessels and functions as an endothelium-specific endogenous inhibitor of pathologic ocular neovascularization.

M
MacIntosh PW, Jakobiec FA, Stagner AM, Gilani S, Fay A. High grade neuroendocrine neoplasm of the antrum and orbit. Surv Ophthalmol 2015;60(5):486-94.Abstract

Neuroendocrine malignancies-tumors characterized by the production of dense-core secretory granules-are most often encountered in the lungs and can also be found in extrapulmonary sites. Our patient had a primary neuroendocrine tumor of the antrum with an elusive cell of origin that secondarily invaded the inferior orbit. In the sinuses, neuroendocrine tumors may be confused with infectious sinusitis or squamous cell carcinoma. There are no known pathognomonic clinical or radiographic signs to distinguish these tumors from other conditions. Diagnosis depends on a biopsy with histopathologic and immunohistochemical analysis to identify biomarkers such as synaptophysin, chromogranin, CD56 and neuron specific enolase. Our patient's tumor defied precise immunohistochemical characterization because of its primitive character and erratic biomarker expression. The diagnosis oscillated between a neuroendocrine carcinoma and an ectopic esthesioneuroblastoma grade IV-hence the use of the more generic nosologic category of neuroendocrine neoplasm without specifying a neuronal or epithelial origin. Data to guide management are limited, particularly in the ophthalmic literature, and derive from experience with tumors of the sinonasal compartments. In the present case of a sino-orbital high grade neuroendocrine neoplasm, regional lymph node metastases developed shortly after presentation. The tumor has responded well to chemotherapy and radiation, but recurrence is often encountered within 2 years in this class of neoplasms.

Mayer C, Jaglin XH, Cobbs LV, Bandler RC, Streicher C, Cepko CL, Hippenmeyer S, Fishell G. Clonally Related Forebrain Interneurons Disperse Broadly across Both Functional Areas and Structural Boundaries. Neuron 2015;87(5):989-98.Abstract

The medial ganglionic eminence (MGE) gives rise to the majority of mouse forebrain interneurons. Here, we examine the lineage relationship among MGE-derived interneurons using a replication-defective retroviral library containing a highly diverse set of DNA barcodes. Recovering the barcodes from the mature progeny of infected progenitor cells enabled us to unambiguously determine their respective lineal relationship. We found that clonal dispersion occurs across large areas of the brain and is not restricted by anatomical divisions. As such, sibling interneurons can populate the cortex, hippocampus striatum, and globus pallidus. The majority of interneurons appeared to be generated from asymmetric divisions of MGE progenitor cells, followed by symmetric divisions within the subventricular zone. Altogether, our findings uncover that lineage relationships do not appear to determine interneuron allocation to particular regions. As such, it is likely that clonally related interneurons have considerable flexibility as to the particular forebrain circuits to which they can contribute.

Menon BB, Kaiser-Marko C, Spurr-Michaud S, Tisdale AS, Gipson IK. Suppression of Toll-like receptor-mediated innate immune responses at the ocular surface by the membrane-associated mucins MUC1 and MUC16. Mucosal Immunol 2015;8(5):1000-8.Abstract

Membrane-associated mucins (MAMs) expressed on the ocular surface epithelium form a dense glycocalyx that is hypothesized to protect the cornea and conjunctiva from external insult. In this study, the hypothesis that the MAMs MUC1 and MUC16, expressed on the apical surface of the corneal epithelium, suppress Toll-like receptor (TLR)-mediated innate immune responses was tested. Using an in vitro model of corneal epithelial cells that are cultured to express MAMs, we show that reduced expression of either MUC1 or MUC16 correlates with increased message and secreted protein levels of the proinflammatory cytokines interleukin (IL)-6, IL-8, and tumor necrosis factor-α (TNF-α) following exposure of cells to the TLR2 and TLR5 agonists, heat-killed Listeria monocytogenes and flagellin, respectively. As mice express Muc1 (but not Muc16) in the corneal epithelium, a Muc1(-/-) mouse model was used to extend in vitro findings. Indeed, IL-6 and TNF-α message levels were increased in the corneal epithelium of Muc1(-/-) mice, in comparison with wild-type mice, following exposure of enucleated eyes to the TLR2 and TLR5 agonists. Our results suggest that the MAMs MUC1 and MUC16 contribute to the maintenance of immune homeostasis at the ocular surface by limiting TLR-mediated innate immune responses.

Pages