Publications

2017

Taniguchi E, Paschalis E, Crnej A, Ren A, Colby K, Chodosh J, Pasquale L, Shen L, Dohlman C, Cruzat A. The Role of the Back Plate in Angle Anatomy with the Boston Type I Keratoprosthesis. Cornea. 2017;36(9):1096–1101.
PURPOSE: To quantitatively evaluate the angle anatomy in eyes with the Boston type I keratoprosthesis (B-KPro) differing in the back plate (BP) material and size using anterior segment optical coherence tomography. METHODS: B-KPro eyes with poly(methyl methacrylate) (PMMA) (7.0 and 8.5 mm) and titanium (7.0, 8.5, and 9.5 mm) BPs were imaged with anterior segment optical coherence tomography. The angle opening distance at 500 μm from the scleral spur (AOD500), trabecular iris surface area at 500 μm from the scleral spur (TISA500), and trabecular iris angle at 500 μm from the scleral spur (TIA500) were measured. Among the visible quadrants, the average, the temporal, the widest, and the narrowest angle of each eye were included in the analysis. Average time between B-KPro implantation and imaging was 7.5 ± 1.4 years for a PMMA BP and 2.4 ± 2.3 years for a titanium BP (P < 0.0001). RESULTS: We analyzed 17 B-KPro eyes with PMMA BPs and 24 B-KPro eyes with titanium BPs. The average AOD500 (394.1 ± 226.9 vs. 454.5 ± 255.6 μm, P = 0.44), average TIA500 (26.2 ± 14.2 vs. 29.8 ± 13.9 degrees, P = 0.43), and average TISA500 (0.15 ± 0.08 vs. 0.17 ± 0.10 μm, P = 0.52) were not statistically different between eyes with PMMA and titanium BPs, nor were the temporal, the narrowest, and the widest angle measurements of each eye (all P > 0.05). Similarly, no significant differences were found between the angle measurements of B-KPro eyes with a titanium BP diameter of 8.5 or 9.5 mm (all P > 0.05). CONCLUSIONS: We successfully visualized the angle anatomy in 66.1% of the imaged eyes, including all BPs studied. Neither the material nor the size of the B-KPro BP had a significant impact on the angle anatomy.
Taniguchi T, Woodward A, Magnelli P, McColgan N, Lehoux S, Jacobo SM, Mauris J, Argüeso P. N-Glycosylation affects the stability and barrier function of the MUC16 mucin. J Biol Chem. 2017;292(26):11079–11090.
Transmembrane mucins are highly O-glycosylated glycoproteins that coat the apical glycocalyx on mucosal surfaces and represent the first line of cellular defense against infection and injury. Relatively low levels of N-glycans are found on transmembrane mucins, and their structure and function remain poorly characterized. We previously reported that carbohydrate-dependent interactions of transmembrane mucins with galectin-3 contribute to maintenance of the epithelial barrier at the ocular surface. Now, using MALDI-TOF mass spectrometry, we report that transmembrane mucin N-glycans in differentiated human corneal epithelial cells contain primarily complex-type structures with N-acetyllactosamine, a preferred galectin ligand. In N-glycosylation inhibition experiments, we find that treatment with tunicamycin and siRNA-mediated knockdown of the Golgi N-acetylglucosaminyltransferase I gene (MGAT1) induce partial loss of both total and cell-surface levels of the largest mucin, MUC16, and a concomitant reduction in glycocalyx barrier function. Moreover, we identified a distinct role for N-glycans in promoting MUC16's binding affinity toward galectin-3 and in causing retention of the lectin on the epithelial cell surface. Taken together, these studies define a role for N-linked oligosaccharides in supporting the stability and function of transmembrane mucins on mucosal surfaces.
Khajavi M, Zhou Y, Birsner A, Bazinet L, Rosa Di Sant A, Schiffer A, Rogers M, Krishnaji ST, Hu B, Nguyen V, Zon L, D’Amato R. Identification of Padi2 as a novel angiogenesis-regulating gene by genome association studies in mice. PLoS Genet. 2017;13(6):e1006848.
Recent findings indicate that growth factor-driven angiogenesis is markedly influenced by genetic variation. This variation in angiogenic responsiveness may alter the susceptibility to a number of angiogenesis-dependent diseases. Here, we utilized the genetic diversity available in common inbred mouse strains to identify the loci and candidate genes responsible for differences in angiogenic response. The corneal micropocket neovascularization assay was performed on 42 different inbred mouse strains using basic fibroblast growth factor (bFGF) pellets. We performed a genome-wide association study utilizing efficient mixed-model association (EMMA) mapping using the induced vessel area from all strains. Our analysis yielded five loci with genome-wide significance on chromosomes 4, 8, 11, 15 and 16. We further refined the mapping on chromosome 4 within a haplotype block containing multiple candidate genes. These genes were evaluated by expression analysis in corneas of various inbred strains and in vitro functional assays in human microvascular endothelial cells (HMVECs). Of these, we found the expression of peptidyl arginine deiminase type II (Padi2), known to be involved in metabolic pathways, to have a strong correlation with a haplotype shared by multiple high angiogenic strains. In addition, inhibition of Padi2 demonstrated a dosage-dependent effect in HMVECs. To investigate its role in vivo, we knocked down Padi2 in transgenic kdrl:zsGreen zebrafish embryos using morpholinos. These embryos had disrupted vessel formation compared to control siblings. The impaired vascular pattern was partially rescued by human PADI2 mRNA, providing evidence for the specificity of the morphant phenotype. Taken together, our study is the first to indicate the potential role of Padi2 as an angiogenesis-regulating gene. The characterization of Padi2 and other genes in associated pathways may provide new understanding of angiogenesis regulation and novel targets for diagnosis and treatment of a wide variety of angiogenesis-dependent diseases.
Laíns I, Wang J, Providência J, Mach S, Gil P, Gil J, Marques M, Armstrong G, Garas S, Barreto P, Kim I, Vavvas D, Miller J, Husain D, Silva R, Miller J. Choroidal Changes Associated With Subretinal Drusenoid Deposits in Age-related Macular Degeneration Using Swept-source Optical Coherence Tomography. Am J Ophthalmol. 2017;180:55–63.
PURPOSE: To compare choroidal vascular features of eyes with and without subretinal drusenoid deposits (SDD), using swept-source optical coherence tomography (SS OCT). DESIGN: Multicenter, cross-sectional study. METHODS: We prospectively recruited patients with intermediate age-related macular degeneration (AMD), without other vitreoretinal pathology. All participants underwent complete ophthalmic examination, color fundus photography (used for AMD staging), and spectral-domain OCT (to evaluate the presence of SDD). SS OCT was used to obtain automatic macular choroidal thickness (CT) maps, according to the Early Treatment Diabetic Retinopathy Study (ETDRS) sectors. For data analysis, we considered mean choroidal thickness as the arithmetic mean value of the 9 ETDRS sectors. SS OCT en face images of choroidal vasculature were also captured and converted to binary images. Choroidal vascular density (CVD) was calculated as a percent area occupied by choroidal vessels in a 6-mm-diameter submacular circular. Choroidal vessel volume was calculated by multiplying the average CVD by macular area and CT. Multilevel mixed linear models (to account for the inclusion of 2 eyes of same subject) were performed for analysis. RESULTS: We included 186 eyes (n = 118 subjects), 94 (50.5%) presenting SDD. Multiple regression analysis revealed that, controlling for age, eyes with SDD presented a statistically thinner mean CT (ß = -21.9, P = .006) and CT in all the individual ETDRS fields (ß ≤ -18.79, P ≤ .026). Mean choroidal vessel volume was also significantly reduced in eyes with SDD (ß = -0.003, P = .007). No significant associations were observed with mean CVD. CONCLUSION: In subjects with intermediate AMD, choroidal thickness and vessel volume are reduced in the presence of subretinal drusenoid deposits.
Lee J, Shin S, Desalvo A, Lee G, Lee JY, Polini A, Chae S, Jeong H, Kim J, Choi H, Lee H. Nonmediated, Label-Free Based Detection of Cardiovascular Biomarker in a Biological Sample. Adv Healthc Mater. 2017;6(17).
Direct electrochemical (EC) monitoring in a cell culture medium without electron transporter as called mediator is attractive topic in vitro organoid based on chip with frequently and long-time monitoring since it can avoid to its disadvantage as stability, toxicity. Here, direct monitoring with nonmediator is demonstrated based on impedance spectroscopy under the culture medium in order to overcome the limitation of mediator. The applicability of EC monitoring is shown by detecting alpha-1-anti trypsin (A1AT) which is known as biomarkers for cardiac damage and is widely chosen in organoid cardiac cell-based chip. The validity of presented EC monitoring is proved by observing signal processing and transduction in medium, mediator, medium-mediator complex. After the observation of electron behavior, A1AT as target analyte is immobilized on the electrode and detected using antibody-antigen interaction. As a result, the result indicates limit of detection is 10 ng mL(-1) and linearity for the 10-1000 ng mL(-1) range, with a sensitivity of 3980 nF (log [g mL])(-1) retaining specificity. This EC monitoring is based on label-free and reagentless detection, will pave the way to use for continuous and simple monitoring of in vitro organoid platform.
Li H, Reksten TR, Ice J, Kelly J, Adrianto I, Rasmussen A, Wang S, He B, Grundahl K, Glenn S, Miceli-Richard C, Bowman S, Lester S, Eriksson P, Eloranta ML, Brun J, Gøransson L, Harboe E, Guthridge J, Kaufman K, Kvarnström M, Cunninghame Graham D, Patel K, Adler A, Farris D, Brennan M, Chodosh J, Gopalakrishnan R, Weisman M, Venuturupalli S, Wallace D, Hefner K, Houston G, Huang A, Hughes P, Lewis D, Radfar L, Vista E, Edgar C, Rohrer M, Stone D, Vyse T, Harley J, Gaffney P, James J, Turner S, Alevizos I, Anaya JM, Rhodus N, Segal B, Montgomery C, Scofield H, Kovats S, Mariette X, Rönnblom L, Witte T, Rischmueller M, Wahren-Herlenius M, Omdal R, Jonsson R, Ng WF, Registry UPSS, Nordmark G, Lessard C, Sivils K. Identification of a Sjögren’s syndrome susceptibility locus at OAS1 that influences isoform switching, protein expression, and responsiveness to type I interferons. PLoS Genet. 2017;13(6):e1006820.
Sjögren's syndrome (SS) is a common, autoimmune exocrinopathy distinguished by keratoconjunctivitis sicca and xerostomia. Patients frequently develop serious complications including lymphoma, pulmonary dysfunction, neuropathy, vasculitis, and debilitating fatigue. Dysregulation of type I interferon (IFN) pathway is a prominent feature of SS and is correlated with increased autoantibody titers and disease severity. To identify genetic determinants of IFN pathway dysregulation in SS, we performed cis-expression quantitative trait locus (eQTL) analyses focusing on differentially expressed type I IFN-inducible transcripts identified through a transcriptome profiling study. Multiple cis-eQTLs were associated with transcript levels of 2'-5'-oligoadenylate synthetase 1 (OAS1) peaking at rs10774671 (PeQTL = 6.05 × 10-14). Association of rs10774671 with SS susceptibility was identified and confirmed through meta-analysis of two independent cohorts (Pmeta = 2.59 × 10-9; odds ratio = 0.75; 95% confidence interval = 0.66-0.86). The risk allele of rs10774671 shifts splicing of OAS1 from production of the p46 isoform to multiple alternative transcripts, including p42, p48, and p44. We found that the isoforms were differentially expressed within each genotype in controls and patients with and without autoantibodies. Furthermore, our results showed that the three alternatively spliced isoforms lacked translational response to type I IFN stimulation. The p48 and p44 isoforms also had impaired protein expression governed by the 3' end of the transcripts. The SS risk allele of rs10774671 has been shown by others to be associated with reduced OAS1 enzymatic activity and ability to clear viral infections, as well as reduced responsiveness to IFN treatment. Our results establish OAS1 as a risk locus for SS and support a potential role for defective viral clearance due to altered IFN response as a genetic pathophysiological basis of this complex autoimmune disease.
Mahmoud M, Serbanovic-Canic J, Feng S, Souilhol C, Xing R, Hsiao S, Mammoto A, Chen J, Ariaans M, Francis S, Van der Heiden K, Ridger V, Evans P. Shear stress induces endothelial-to-mesenchymal transition via the transcription factor Snail. Sci Rep. 2017;7(1):3375.
Blood flow influences atherosclerosis by generating wall shear stress, which alters endothelial cell (EC) physiology. Low shear stress induces dedifferentiation of EC through a process termed endothelial-to-mesenchymal transition (EndMT). The mechanisms underlying shear stress-regulation of EndMT are uncertain. Here we investigated the role of the transcription factor Snail in low shear stress-induced EndMT. Studies of cultured EC exposed to flow revealed that low shear stress induced Snail expression. Using gene silencing it was demonstrated that Snail positively regulated the expression of EndMT markers (Slug, N-cadherin, α-SMA) in EC exposed to low shear stress. Gene silencing also revealed that Snail enhanced the permeability of endothelial monolayers to macromolecules by promoting EC proliferation and migration. En face staining of the murine aorta or carotid arteries modified with flow-altering cuffs demonstrated that Snail was expressed preferentially at low shear stress sites that are predisposed to atherosclerosis. Snail was also expressed in EC overlying atherosclerotic plaques in coronary arteries from patients with ischemic heart disease implying a role in human arterial disease. We conclude that Snail is an essential driver of EndMT under low shear stress conditions and may promote early atherogenesis by enhancing vascular permeability.
Mombaerts I, Bilyk J, Rose G, McNab A, Fay A, Dolman P, Allen R, Devoto M, Harris G, Society EPO. Consensus on Diagnostic Criteria of Idiopathic Orbital Inflammation Using a Modified Delphi Approach. JAMA Ophthalmol. 2017;
Importance: Current practice to diagnose idiopathic orbital inflammation (IOI) is inconsistent, leading to frequent misdiagnosis of other orbital entities, including cancer. By specifying criteria, diagnosis of orbital inflammation will be improved. Objective: To define a set of criteria specific for the diagnosis of IOI. Design, Setting, and Participants: A 3-round modified Delphi process with an expert panel was conducted from June 8, 2015, to January 25, 2016. Fifty-three orbital scientist experts, identified through membership in the Orbital Society, were invited to participate in on online survey and they scored, using 5-point Likert scales, items that are eligible as diagnostic criteria from the literature and from personal experience. The items were clustered around the anatomic subtypes of IOI: idiopathic dacryoadenitis and idiopathic orbital fat inflammation (2 nonmyositic IOIs), and idiopathic orbital myositis (myositic IOI). Items with dissensus were rescored in the second round, and all items with consensus (median, ≥4; interquartile range, ≤1) were ranked by importance in the third round. Main Outcomes and Measures: Consensus on items to be included in the criteria. Results: Of the 53 experts invited to participate, a multinational panel of 35 (66%) individuals with a mean (SD) years of experience of 31 (11) years were included. Consensus was achieved on 7 of 14 clinical and radiologic items and 5 of 7 pathologic items related to diagnosis of nonmyositic IOI, and 11 of 14 clinical and radiologic items and 1 of 5 pathologic items for myositic IOI. There was agreement among panelists to focus on surgical tissue biopsy results in the diagnosis of nonmyositic IOI and on a trial with systemic corticosteroids in myositic IOI. Panelists agreed that a maximum number of 30 IgG4-positive plasma cells per high-power field in the orbital tissue is compatible with the diagnosis of IOI. Conclusions and Relevance: An international panel of experts endorsed consensus diagnostic criteria of IOI. These criteria define a level of exclusion suggested for diagnosis and include tissue biopsy for lesions not confined to the extraocular muscles. This consensus is a step toward developing guidelines for the management of IOI, which needs to be followed by validation studies of the criteria.
Species that are highly reliant on their visual system have a specialized retinal area subserving high-acuity vision, e.g., the fovea in humans. Although of critical importance for our daily activities, little is known about the mechanisms driving the development of retinal high-acuity areas (HAAs). Using the chick as a model, we found a precise and dynamic expression pattern of fibroblast growth factor 8 (Fgf8) in the HAA anlage, which was regulated by enzymes that degrade retinoic acid (RA). Transient manipulation of RA signaling, or reduction of Fgf8 expression, disrupted several features of HAA patterning, including photoreceptor distribution, ganglion cell density, and organization of interneurons. Notably, patterned expression of RA signaling components was also found in humans, suggesting that RA also plays a role in setting up the human fovea.