Publications

2019

Whitman M, Miyake N, Nguyen E, Bell J, Matos Ruiz P, Chan WM, Di Gioia SA, Mukherjee N, Barry B, Bosley, Khan A, Engle E. Decreased ACKR3 (CXCR7) function causes oculomotor synkinesis in mice and humans. Hum Mol Genet. 2019;28(18):3113–3125.
Oculomotor synkinesis is the involuntary movement of the eyes or eyelids with a voluntary attempt at a different movement. The chemokine receptor CXCR4 and its ligand CXCL12 regulate oculomotor nerve development; mice with loss of either molecule have oculomotor synkinesis. In a consanguineous family with congenital ptosis and elevation of the ptotic eyelid with ipsilateral abduction, we identified a co-segregating homozygous missense variant (c.772G>A) in ACKR3, which encodes an atypical chemokine receptor that binds CXCL12 and functions as a scavenger receptor, regulating levels of CXCL12 available for CXCR4 signaling. The mutant protein (p.V258M) is expressed and traffics to the cell surface but has a lower binding affinity for CXCL12. Mice with loss of Ackr3 have variable phenotypes that include misrouting of the oculomotor and abducens nerves. All embryos show oculomotor nerve misrouting, ranging from complete misprojection in the midbrain, to aberrant peripheral branching, to a thin nerve, which aberrantly innervates the lateral rectus (as seen in Duane syndrome). The abducens nerve phenotype ranges from complete absence, to aberrant projections within the orbit, to a normal trajectory. Loss of ACKR3 in the midbrain leads to downregulation of CXCR4 protein, consistent with reports that excess CXCL12 causes ligand-induced degradation of CXCR4. Correspondingly, excess CXCL12 applied to ex vivo oculomotor slices causes axon misrouting, similar to inhibition of CXCR4. Thus, ACKR3, through its regulation of CXCL12 levels, is an important regulator of axon guidance in the oculomotor system; complete loss causes oculomotor synkinesis in mice, while reduced function causes oculomotor synkinesis in humans.
Charles N, Jakobiec F, Ma L, Belinsky I. Angiofibroma of the Eyelid: A Rare Clinical and Histologic Variant. Ophthalmic Plast Reconstr Surg. 2019;35(4):e199-e102.
A flesh-colored, supraciliary lesion of the left upper eyelid in a 47-year-old man was excised for cosmetic reasons. Histopathology and immunohistochemistry demonstrated CD34-positive benign spindle cells, factor XIIIa-positive dendritic cells, and CD163-positive histiocytes, all dispersed within a diffuse collagenous background. Prominent loose perivascular cuffs of fibroblastic cells and collagen surrounded small blood vessels. Interpreted as an angiofibroma, the histopathology bore resemblance to that of a single previously-reported forearm lesion termed a "dermal fibroma with a distinctive perivascular cell arrangement." The lesion represents the first eyelid example of an unusual variant of angiofibroma.
Foulsham W, Mittal S, Nakao T, Coco G, Taketani Y, Chauhan S, Dana R. The purinergic receptor antagonist oxidized adenosine triphosphate suppresses immune-mediated corneal allograft rejection. Sci Rep. 2019;9(1):8617.
Adenosine triphosphate (ATP) is released into the extracellular environment during transplantation, and acts via purinergic receptors to amplify the alloimmune response. Here, using a well-established murine model of allogeneic corneal transplantation, we investigated the immunomodulatory mechanisms of the purinergic receptor antagonist oxidized ATP (oATP). Corneal transplantation was performed using C57BL/6 donors and BALB/c hosts. oATP or sterile saline was administered via intraperitoneal injection for 2 weeks postoperatively. Frequencies of CD45 leukocytes, CD11bMHCII antigen presenting cells (APCs), CD4IFN-γ effector Th1 cells and CD4Foxp3 regulatory T cells (Tregs) were evaluated by flow cytometry. Slit-lamp microscopy was performed weekly for 8 weeks to evaluate graft opacity and determine transplant rejection. Treatment with oATP was shown to significantly reduce graft infiltration of CD45 leukocytes, decrease APC maturation and suppress effector Th1 cell generation relative to saline-treated control. No difference in Treg frequencies or Foxp3 expression was observed between the oATP-treated and control groups. Finally, oATP treatment was shown to reduce graft opacity and increase graft survival. This report demonstrates that oATP limits the alloimmune response by regulating APC maturation and suppressing the generation of alloreactive Th1 immunity.
Perepelkina T, Kegeles E, Baranov P. Optimized conditions and use of synthetic matrix for retinal differentiation from pluripotent cells. Tissue Eng Part C Methods. 2019;
PURPOSE: Since it was first introduced in 2011, three-dimensional "Sasai" method for retinal differentiation became a strategy of choice for retinal tissue and neuron production. It is based on the recapitulation of retinal development and requires several stages: aggregate formation, neuroectoderm induction, and eye field induction, followed by retinal maturation. In order to achieve the consistency of retinal differentiation needed for drug discovery and cell transplantation we have attempted to improve spheroid formation as well as approach xeno-free conditions. METHODS: In this study we compared the effect of cell culture plate shape and material, medium viscosity, lipid and bovine serum albumin concentrations on aggregate formation from mouse embryonic stem cells. We have also assessed the possibility of substituting Matrigel with the synthetic vitronectin-mimicking oligopeptide. RX-GFP mES cell line used for experiments. The dose-response of synthetic ECM has been assessed and quantified by live fluorescence microscopy, immunohistochemistry, flow cytometry and qPCR for early retinal development genes (Rx, Pax6, Lhx2, Sox2, Six6). RESULTS: The comparison of seeding conditions at 24hr. post seeding showed the dose-dependent effects of lipids (lipids concentration of 2% resulted in 100% efficiency of aggregate formation and significant increase in size to 532.8 ± 31.87um, p< 0.05); and viscosity (methylcellulose concentration of 0.06% in OV medium showed 100% efficiency and increase in aggregate size 532±19.23 um, p<0.01). The addition of synthetic matrix resulted in retinal differentiation (34.47% of RX as detected by flow cytometry compared to 33.8%, observed with Matrigel). The early retinal genes expression at day 7 was confirmed by qPCR. CONCLUSIONS: We present the optimized conditions for 3D retinal differentiation including the option of xeno-free extracellular matrix. These defined medium conditions significantly decrease the variability within and between batches and allow substantial scale up of retinal tissue and cell production for drug discovery, disease modeling and transplantation purposes.
Drack A, Utz VM, Wang K, Alcorn D, Brooks B, Costakos D, Couser N, Heon E, Levin A, Lloyd C, Morse C, Schmitt M, Whitman M, Traboulsi E. Survey of practice patterns for the management of ophthalmic genetic disorders among AAPOS members: report by the AAPOS Genetic Eye Disease Task Force. J AAPOS. 2019;
To better understand AAPOS member pediatric ophthalmologists' knowledge and needs regarding genetic eye disorders, the AAPOS Genetic Eye Disease Task Force developed a 16-question survey that was circulated to national and international AAPOS members. Responses to questions on practice patterns, baseline knowledge, and educational interests regarding patients with suspected ophthalmic genetic disorders were collected. A majority of respondents (93%) evaluate patients with suspected genetic disorders. Knowledge gaps were present in heritability of certain conditions, genetic testing strategies, and referral to clinical trials. Most respondents expressed interest in further education in these areas. A model for care is proposed as a first step in the education process.
Mathys H, Davila-Velderrain J, Peng Z, Gao F, Mohammadi S, Young J, Menon M, He L, Abdurrob F, Jiang X, Martorell A, Ransohoff R, Hafler B, Bennett D, Kellis M, Tsai LH. Author Correction: Single-cell transcriptomic analysis of Alzheimer’s disease. Nature. 2019;571(7763):E1.
Change history: In this Article, the Acknowledgements section should have included that the work was supported in part by the Cure Alzheimer's Fund (CAF), and the final NIH grant acknowledged should have been 'U01MH119509' instead of 'RF1AG054012'. In Supplementary Table 2, the column labels 'early.pathology.mean' and 'late.pathology.mean' were reversed in each worksheet (that is, columns Y and Z). These errors have been corrected online.
Frints S, Hennig F, Colombo R, Jacquemont S, Terhal P, Zimmerman H, Hunt D, Mendelsohn B, Kordaß U, Webster R, Sinnema M, Abdul-Rahman O, Suckow V, Fernández-Jaén A, Roozendaal K, Stevens S, Macville M, Al-Nasiry S, Gassen K, Utzig N, Koudijs S, McGregor L, Maas S, Baralle D, Dixit A, Wieacker P, Lee M, Lee A, Engle E, Houge G, Gradek G, Douglas A, Longman C, Joss S, Velasco D, Hennekam R, Hirata H, Kalscheuer V. Deleterious de novo variants of X-linked ZC4H2 in females cause a variable phenotype with neurogenic arthrogryposis multiplex congenita. Hum Mutat. 2019;40(12):2270–2285.
Pathogenic variants in the X-linked gene ZC4H2, which encodes a zinc-finger protein, cause an infrequently described syndromic form of arthrogryposis multiplex congenita (AMC) with central and peripheral nervous system involvement. We present genetic and detailed phenotypic information on 23 newly identified families and simplex cases that include 19 affected females from 18 families and 14 affected males from nine families. Of note, the 15 females with deleterious de novo ZC4H2 variants presented with phenotypes ranging from mild to severe, and their clinical features overlapped with those seen in affected males. By contrast, of the nine carrier females with inherited ZC4H2 missense variants that were deleterious in affected male relatives, four were symptomatic. We also compared clinical phenotypes with previously published cases of both sexes and provide an overview on 48 males and 57 females from 42 families. The spectrum of ZC4H2 defects comprises novel and recurrent mostly inherited missense variants in affected males, and de novo splicing, frameshift, nonsense, and partial ZC4H2 deletions in affected females. Pathogenicity of two newly identified missense variants was further supported by studies in zebrafish. We propose ZC4H2 as a good candidate for early genetic testing of males and females with a clinical suspicion of fetal hypo-/akinesia and/or (neurogenic) AMC.
AbdelAl O, Ashraf M, Sampani K, Sun J. "For Mass Eye and Ear Special Issue" Adaptive Optics in the Evaluation of Diabetic Retinopathy. Semin Ophthalmol. 2019;:1–9.
Retinal imaging is a fundamental tool for clinical and research efforts in the evaluation and management of diabetic retinopathy. Adaptive optics (AO) is an imaging technique that enables correction of over 90% of the optical aberrations of an individual eye induced primarily by the tear film, cornea and lens. The two major tasks of any AO system are to measure the optical imperfections of the eye and to then compensate for these aberrations to generate a corrected wavefront of reflected light from the eye. AO scanning laser ophthalmoscopy (AOSLO) provides a theoretical lateral resolution limit of 1.4 μm, allowing the study of microscopic features of the retinal vascular and neural tissue. AOSLO studies have revealed irregularities of the photoreceptor mosaic, vascular loss, and details of vascular lesions in diabetic eyes that may provide new insight into development, regression, and response to therapy of diabetic eye disease.
Orbital cellulitis is extremely uncommon following strabismus surgery. When it occurs, the infection has been reported to present from day 1 to within 1 week following surgery and has the potential for significant morbidity postoperatively. We report the case of a 6-year-old boy presenting with unilateral orbital cellulitis growing group A Streptococcus pyogenes on postoperative day 1, after uncomplicated bilateral medial rectus recessions. The patient had two contacts with streptococcal pharyngitis at the time of surgery but was completely asymptomatic himself. We hypothesize that these contacts may have led to the rapid onset of his orbital cellulitis.
McHugh K, Li D, Wang J, Kwark L, Loo J, Macha V, Farsiu S, Kim L, Saint-Geniez M. Computational modeling of retinal hypoxia and photoreceptor degeneration in patients with age-related macular degeneration. PLoS One. 2019;14(6):e0216215.
Although drusen have long been acknowledged as a primary hallmark of dry age-related macular degeneration (AMD) their role in the disease remains unclear. We hypothesize that drusen accumulation increases the barrier to metabolite transport ultimately resulting in photoreceptor cell death. To investigate this hypothesis, a computational model was developed to evaluate steady-state oxygen distribution in the retina. Optical coherence tomography images from fifteen AMD patients and six control subjects were segmented and translated into 3D in silico representations of retinal morphology. A finite element model was then used to determine the steady-state oxygen distribution throughout the retina for both generic and patient-specific retinal morphology. Oxygen levels were compared to the change in retinal thickness at a later time point to observe possible correlations. The generic finite element model of oxygen concentration in the retina agreed closely with both experimental measurements from literature and clinical observations, including the minimal pathological drusen size identified by AREDS (64 μm). Modeling oxygen distribution in the outer retina of AMD patients showed a substantially stronger correlation between hypoxia and future retinal thinning (Pearson correlation coefficient, r = 0.2162) than between drusen height and retinal thinning (r = 0.0303) indicating the potential value of this physiology-based approach. This study presents proof-of-concept for the potential utility of finite element modeling in evaluating retinal health and also suggests a potential link between transport and AMD pathogenesis. This strategy may prove useful as a prognostic tool for predicting the clinical risk of AMD progression.