Publications

2018

Chen X, Liu Y, Zhang Y, Kam W, Pasquale L, Sullivan D. Impact of aromatase absence on murine intraocular pressure and retinal ganglion cells. Sci Rep. 2018;8(1):3280.
We hypothesize that aromatase, an enzyme that regulates estrogen production, plays a significant role in the control of intraocular pressure (IOP) and retinal ganglion cells (RGCs). To begin to test our hypothesis, we examined the impact of aromatase absence, which completely eliminates estrogen synthesis, in male and female mice. Studies were performed with adult, age-matched wild type (WT) and aromatase knockout (ArKO) mice. IOP was measured in a masked fashion in both eyes of conscious mice at 12 and 24 weeks of age. Retinas were obtained and processed for RGC counting with a confocal microscope. IOP levels in both 12- and 24-week old female ArKO mice were significantly higher than those of age- and sex-matched WT controls. The mean increase in IOP was 7.9% in the 12-week-, and 19.7% in the 24-week-old mice, respectively. These changes were accompanied by significant 9% and 7% decreases in RGC numbers in the ArKO female mice, relative to controls, at 12- and 24-weeks, respectively. In contrast, aromatase deficiency did not lead to an increased IOP in male mice. There was a significant reduction in RGC counts in the 12-, but not 24-, week-old male ArKO mice, as compared to their age- and sex-matched WT controls. Overall, our findings show that aromatase inhibition in females is associated with elevated IOP and reduced RGC counts.
Shiga Y, Akiyama M, Nishiguchi K, Sato K, Shimozawa N, Takahashi A, Momozawa Y, Hirata M, Matsuda K, Yamaji T, Iwasaki M, Tsugane S, Oze I, Mikami H, Naito M, Wakai K, Yoshikawa M, Miyake M, Yamashiro K, Japan Glaucoma Society Omics Group (JGS-OG), Kashiwagi K, Iwata T, Mabuchi F, Takamoto M, Ozaki M, Kawase K, Aihara M, Araie M, Yamamoto T, Kiuchi Y, Nakamura M, Ikeda Y, Sonoda KH, Ishibashi T, Nitta K, Iwase A, Shirato S, Oka Y, Satoh M, Sasaki M, Fuse N, Suzuki Y, Cheng CY, Khor CC, Baskaran M, Perera S, Aung T, Vithana E, Cooke Bailey J, Kang J, Pasquale L, Haines J, NEIGHBORHOOD Consortium, Wiggs J, Burdon K, Gharahkhani P, Hewitt A, Mackey D, Macgregor S, Craig J, Allingham R, Hauser M, Ashaye A, Budenz D, Akafo S, Williams S, Kamatani Y, Nakazawa T, Kubo M. Genome-wide association study identifies seven novel susceptibility loci for primary open-angle glaucoma. Hum Mol Genet. 2018;27(8):1486–1496.
Primary open-angle glaucoma (POAG) is the leading cause of irreversible blindness worldwide for which 15 disease-associated loci had been discovered. Among them, only 5 loci have been associated with POAG in Asians. We carried out a genome-wide association study and a replication study that included a total of 7378 POAG cases and 36 385 controls from a Japanese population. After combining the genome-wide association study and the two replication sets, we identified 11 POAG-associated loci, including 4 known (CDKN2B-AS1, ABCA1, SIX6 and AFAP1) and 7 novel loci (FNDC3B, ANKRD55-MAP3K1, LMX1B, LHPP, HMGA2, MEIS2 and LOXL1) at a genome-wide significance level (P  5.0×10-8), bringing the total number of POAG-susceptibility loci to 22. The 7 novel variants were subsequently evaluated in a multiethnic population comprising non-Japanese East Asians (1008 cases, 591 controls), Europeans (5008 cases, 35 472 controls) and Africans (2341 cases, 2037 controls). The candidate genes located within the new loci were related to ocular development (LMX1B, HMGA2 and MAP3K1) and glaucoma-related phenotypes (FNDC3B, LMX1B and LOXL1). Pathway analysis suggested epidermal growth factor receptor signaling might be involved in POAG pathogenesis. Genetic correlation analysis revealed the relationships between POAG and systemic diseases, including type 2 diabetes and cardiovascular diseases. These results improve our understanding of the genetic factors that affect the risk of developing POAG and provide new insight into the genetic architecture of POAG in Asians.
Han X, Liu Y, Kam W, Sullivan D. Effect of brimonidine, an α2 adrenergic agonist, on human meibomian gland epithelial cells. Exp Eye Res. 2018;170:20–28.
We recently discovered that the anti-glaucoma pharmaceuticals timolol, a β adrenergic antagonist, and pilocarpine, a cholinergic compound, negatively influence the morphology, proliferative capacity and survival of human meibomian gland epithelial cells (HMGECs). We hypothesize that another class of anti-glaucoma drugs, the α2 adrenergic agonists, also acts directly on HMGECs to affect their structure and function. We tested this hypothesis. Immortalized (i) HMGECs were cultured with brimonidine, as well as clonidine (α2 agonist), phenylephrine (α1 agonist), RX821002 (inverse α2 agonist) and MK912 (neutral α2 agonist) for up to 7 days. Cells were counted with a hemocytometer, and evaluated for morphology, signaling pathway activity, protein biomarker expression, and the accumulation of neutral lipids, phospholipids and lysosomes. Our findings demonstrate that brimondine treatment induces a dose-dependent decrease in Akt signaling and proliferation of iHMGECs. In contrast, brimonidine also promotes a dose-dependent differentiation of iHMGECs, including an increase in neutral lipid, phospholipid and lysosome levels. These effects were paralleled by an inhibition of p38 signaling, and duplicated by cellular exposure to clonidine, but not phenylephrine. Brimonidine also enhanced the cellular content of sterol regulatory binding protein-1, a master regulator of lipid synthesis. Of particular interest, the putative α2 antagonists, RX821002 and MK912, did not interfere with brimonidine action, but rather stimulated IHMGEC differentiation. Our results support our hypothesis and demonstrate that α2 adrenergic agonists act directly on iHMGECs. However, these compounds do not elicit an overall negative effect. Rather, the α2 agonists promote the differentiation of iHMGECs.
Cao J, Brouwer N, Jordanova E, Marinkovic M, Duinen S, Waard N, Ksander B, Mulder A, Claas F, Heemskerk M, Jager M. HLA Class I Antigen Expression in Conjunctival Melanoma Is Not Associated With PD-L1/PD-1 Status. Invest Ophthalmol Vis Sci. 2018;59(2):1005–1015.
Purpose: Antitumor T cells need expression of HLA class I molecules but can be inhibited by ligands such as programmed death ligand 1 (PD-L1). We determined expression and regulation of these molecules in human conjunctival melanoma (CM) samples, cell lines, and murine xenografts. Methods: Immunofluorescence staining was performed to examine the expression of HLA-A, HLA-B/C, and β-2-microglobulin (B2M) in 23 primary CM samples. HLA class I expression was compared with clinicopathologic characteristics, the presence of tumor-infiltrating leukocytes, and PD-L1/PD-1 status. The effect of interferon γ (IFN-γ) on HLA class I expression was tested on three CM cell lines using quantitative PCR and flow cytometry. Furthermore, HLA class I expression was determined in CM cell line-derived murine xenografts. Results: One third of tumors had positive HLA-A, HLA-B/C, and B2M expression. A positive expression was especially seen in thin and epibulbar tumors but was not associated with recurrences. HLA class I expression was correlated with M2 macrophage density and tended to associate with CD8+ T-cell density but was independent of PD-L1 or PD-1 expression. IFN-γ upregulated HLA class I expression and genes involved in HLA transcription and transportation on CM cell lines. Murine xenografts showed a comparable HLA class I expression as their respective cell lines. Conclusions: Our data indicate that subsets of CM have positive HLA class I expression, and HLA class I and PD-L1/PD-1 are expressed independently. When one considers immunotherapy, one should also analyze HLA class I expression, whose downregulation can limit the efficacy of T cell-mediated therapies.
Deiner M, McLeod S, Chodosh J, Oldenburg C, Fathy C, Lietman T, Porco T. Clinical Age-Specific Seasonal Conjunctivitis Patterns and Their Online Detection in Twitter, Blog, Forum, and Comment Social Media Posts. Invest Ophthalmol Vis Sci. 2018;59(2):910–920.
Purpose: We sought to determine whether big data from social media might reveal seasonal trends of conjunctivitis, most forms of which are nonreportable. Methods: Social media posts (from Twitter, and from online forums and blogs) were classified by age and by conjunctivitis type (allergic or infectious) using Boolean and machine learning methods. Based on spline smoothing, we estimated the circular mean occurrence time (a measure of central tendency for occurrence) and the circular variance (a measure of uniformity of occurrence throughout the year, providing an index of seasonality). Clinical records from a large tertiary care provider were analyzed in a similar way for comparison. Results: Social media posts machine-coded as being related to infectious conjunctivitis showed similar times of occurrence and degree of seasonality to clinical infectious cases, and likewise for machine-coded allergic conjunctivitis posts compared to clinical allergic cases. Allergic conjunctivitis showed a distinctively different seasonal pattern than infectious conjunctivitis, with a mean occurrence time later in the spring. Infectious conjunctivitis for children showed markedly greater seasonality than for adults, though the occurrence times were similar; no such difference for allergic conjunctivitis was seen. Conclusions: Social media posts broadly track the seasonal occurrence of allergic and infectious conjunctivitis, and may be a useful supplement for epidemiologic monitoring.
Strainiene E, Binkis M, Urnikyte S, Stankevicius V, Sasnauskiene A, Kundrotas G, Kazlauskas A, Suziedelis K. Microenvironment dependent gene expression signatures in reprogrammed human colon normal and cancer cell lines. BMC Cancer. 2018;18(1):222.
BACKGROUND: Since the first evidence suggesting existence of stem-like cancer cells, the process of cells reprogramming to the stem cell state remains as an attractive tool for cancer stemness research. Current knowledge in the field of cancer stemness, indicates that the microenvironment is a fundamental regulator of cell behavior. With regard to this, we investigated the changes of genome wide gene expression in reprogrammed human colon normal epithelial CRL-1831 and colon carcinoma DLD1 cell lines grown under more physiologically relevant three-dimensional (3D) cell culture microenvironment compared to 2D monolayer. METHODS: Whole genome gene expression changes were evaluated in both cell lines cultured under 3D conditions over a 2D monolayer by gene expression microarray analysis. To evaluate the biological significance of gene expression changes, we performed pathway enrichment analysis using the Kyoto Encyclopedia of Genes and Genomes (KEGG) database. Gene network analysis was used to study relationships between differentially expressed genes (DEGs) in functional categories by the GeneMANIA Cytoscape toolkit. RESULTS: In total, we identified 3228 and 2654 differentially expressed genes (DEGs) for colon normal and cancer reprogrammed cell lines, respectively. Furthermore, the expression of 1097 genes was commonly regulated in both cell lines. KEGG enrichment analysis revealed that in total 129 and 101 pathways for iPSC-CRL-1831 and for CSC-DLD1, respectively, were enriched. Next, we grouped these pathways into three functional categories: cancer transformation/metastasis, cell interaction, and stemness. β-catenin (CTNNB1) was confirmed as a hub gene of all three functional categories. CONCLUSIONS: Our present findings suggest common pathways between reprogrammed human colon normal epithelium (iPSC-CRL-1831) and adenocarcinoma (CSC-DLD1) cells grown under 3D microenvironment. In addition, we demonstrated that pathways important for cancer transformation and tumor metastatic activity are altered both in normal and cancer stem-like cells during the transfer from 2D to 3D culture conditions. Thus, we indicate the potential of cell culture models enriched in normal and cancer stem-like cells for the identification of new therapeutic targets in cancer treatment.
We report an unusual case of acute large-angle left exotropia associated with blunt orbital trauma in a healthy 8-year-old boy. Examination revealed a large-angle left exotropia with limitation in adduction of the left eye. Microhyphema and commotio retinae of the left eye were also present. High-resolution orbital magnetic resonance imaging (MRI) demonstrated perimuscular and intramuscular edema mostly involving the left medial rectus muscle but also involving the left lateral rectus muscle. The extraocular muscle insertions were intact. Complete resolution of the strabismus and adduction limitation occurred within 24 hours of starting systemic steroid therapy. This case highlights the utility of high-resolution imaging to assess for injury to the extraocular muscles. If disinsertion, transection, or rupture of the muscle is not present on imaging, resolution may occur with systemic steroid therapy and surgical intervention is not needed.
Gharahkhani P, Burdon K, Cooke Bailey J, Hewitt A, Law M, Pasquale L, Kang J, Haines J, Souzeau E, Zhou T, Siggs O, Landers J, Awadalla M, Sharma S, Mills R, Ridge B, Lynn D, Casson R, Graham S, Goldberg I, White A, Healey P, Grigg J, Lawlor M, Mitchell P, Ruddle J, Coote M, Walland M, Best S, Vincent A, Gale J, RadfordSmith G, Whiteman D, Montgomery G, Martin N, Mackey D, Wiggs J, Macgregor S, Craig J, NEIGHBORHOOD Consortium. Analysis combining correlated glaucoma traits identifies five new risk loci for open-angle glaucoma. Sci Rep. 2018;8(1):3124.
Open-angle glaucoma (OAG) is a major cause of blindness worldwide. To identify new risk loci for OAG, we performed a genome-wide association study in 3,071 OAG cases and 6,750 unscreened controls, and meta-analysed the results with GWAS data for intraocular pressure (IOP) and optic disc parameters (the overall meta-analysis sample size varying between 32,000 to 48,000 participants), which are glaucoma-related traits. We identified and independently validated four novel genome-wide significant associations within or near MYOF and CYP26A1, LINC02052 and CRYGS, LMX1B, and LMO7 using single variant tests, one additional locus (C9) using gene-based tests, and two genetic pathways - "response to fluid shear stress" and "abnormal retina morphology" - in pathway-based tests. Interestingly, some of the new risk loci contribute to risk of other genetically-correlated eye diseases including myopia and age-related macular degeneration. To our knowledge, this study is the first integrative study to combine genetic data from OAG and its correlated traits to identify new risk variants and genetic pathways, highlighting the future potential of combining genetic data from genetically-correlated eye traits for the purpose of gene discovery and mapping.