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Foster JW, Shinde V, Soiberman US, Sathe G, Liu S, Wan J, Qian J, Dauoud Y, Pandey A, Jun AS, Chakravarti S. Integrated Stress Response and Decreased ECM in Cultured Stromal Cells From Keratoconus Corneas. Invest Ophthalmol Vis Sci 2019; 59:2977-2986. [PMID: 30029277 PMCID: PMC5995483 DOI: 10.1167/iovs.18-24367] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Purpose Keratoconus (KC) is a multifactorial disease where progressive thinning and weakening of the cornea leads to loss of visual acuity. Although the underlying etiology is poorly understood, a major endpoint is a dysfunctional stromal connective tissue matrix. Using multiple individual KC corneas, we determined that matrix production by keratocytes is severely impeded due to an altered stress response program. Methods KC and donor (DN) stromal keratocytes were cultured in low glucose serum-free medium containing insulin, selenium and transferrin. Fibronectin, collagens and proteins related to their chaperone, processing and export, matrix metalloproteinase, and stress response related proteins were investigated by immunoblotting, immunocytochemistry, hydroxyproline quantification, and gelatin zymography. Multiplexed mass spectrometry was used for global proteomic profiling of 5 individual DN and KC cell culture. Transcription of selected proteins was assayed by qPCR. Results DN and KC cells showed comparable survival and growth. However, immunoblotting of selected ECM proteins and global proteomics showed decreased fibronectin, collagens, PCOLCE, ADAMTS2, BMP1, HSP47, other structural and cytoskeletal proteins in KC. Phosphorylated (p) eIF2α, a translation regulator and its target, ATF4 were increased in KC cultured cells and corneal sections. Conclusions The profound decrease in structural proteins in cultured KC cells and increase in the p-eIF2α, and ATF4, suggest a stress related blockade in structural proteins not immediately needed for cell survival. Therefore, this cell culture system reveals an intrinsic aggravated stress response with consequent decrease in ECM proteins as potential pathogenic underpinnings in KC.
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Mannschreck DB, Rubinfeld RS, Soiberman US, Jun AS. Diffuse lamellar keratitis after epi-off corneal crosslinking: An under-recognized complication? Am J Ophthalmol Case Rep 2019; 13:140-142. [PMID: 30705998 PMCID: PMC6348932 DOI: 10.1016/j.ajoc.2019.01.004] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2018] [Revised: 12/09/2018] [Accepted: 01/08/2019] [Indexed: 11/03/2022] Open
Abstract
Purpose To report diffuse lamellar keratitis (DLK) occurring in an eye that underwent epithelium-off (epi-off) corneal cross-linking (CXL) as a treatment for post-surgical ectasia and the successful treatment of progressive ectasia with a novel epi-on CXL and conductive keratoplasty (CK) treatment. Observations A 42-year-old man presented with corneal ectasia in his right eye 3 years after laser in situ keratomileusis (LASIK) surgery. He underwent epi-off corneal CXL using the Dresden protocol. Grade II DLK was diagnosed within days of CXL. Despite successful treatment of DLK, best-corrected visual acuity in the right eye deteriorated over the next 4 months due to progression of ectasia and remained worse than the patient's pre-operative baseline 1 year after epi-off CXL. Because of apparent disease progression, despite his CXL treatment, the patient underwent a novel, transepithelial CXL (TE-CXL) treatment combined with conductive keratoplasty (CK). This treatment improved his vision and stabilized his ectasia without subsequent DLK. Approximately 3 years after CK and TE-CXL, his eye remains stable with 4 Snellen lines of improved vision and no progression of ectasia. Conclusion and importance Epithelium-off CXL is used increasingly to treat post-LASIK ectasia. First, in this case, DLK occurred after epi-off CXL. We suggest careful scrutiny of such cases as DLK is difficult to identify after epi-off CXL. Second, the epi-off CXL was unsuccessful in stopping the post-LASIK ectasia. Transepithelial CXL successfully treated the ongoing ectasia after resolution of the DLK with no subsequent re-occurrence of DLK. We suggest that TE-CXL may provide a successful initial treatment for post-LASIK ectasia that also minimizes the epithelial disruption that can lead to DLK.
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Leonard BC, Jalilian I, Raghunathan VK, Wang W, Jun AS, Murphy CJ, Thomasy SM. Biomechanical changes to Descemet's membrane precede endothelial cell loss in an early-onset murine model of Fuchs endothelial corneal dystrophy. Exp Eye Res 2018; 180:18-22. [PMID: 30471280 DOI: 10.1016/j.exer.2018.11.021] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2018] [Revised: 11/08/2018] [Accepted: 11/20/2018] [Indexed: 01/20/2023]
Abstract
Early-onset Fuchs endothelial corneal dystrophy (FECD) has been associated with nonsynonymous mutations in collagen VIII α2 (COL8A2), a key extracellular matrix (ECM) protein in Descemet's membrane (DM). Two knock-in strains of mice have been generated to each express a mutant COL8A2 protein (Col8a2L450W/L450W and Col8a2Q455K/Q455K) that recapitulate the clinical phenotype of early-onset FECD including endothelial cell loss, cellular polymegathism and pleomorphism, and guttae. Due to abnormalities in ECM protein composition and structure in FECD, the stiffness of DM in Col8a2 knock-in mice and wildtype (WT) controls was measured using atomic force microscopy at 5 and 10 months of age, coinciding with the onset of FECD phenotypic abnormalities. At 5 months, only sporadic guttae were identified via in vivo confocal microscopy (IVCM) in Col8a2Q455K/Q455K mice, otherwise both strains of Col8a2 transgenic mice were indistinguishable from WT controls in terms of endothelial cell density and size. By 10 months of age, Col8a2L450W/L450W and Col8a2Q455K/Q455K mice developed reduced corneal endothelial density, increased endothelial cell area and guttae, with the Col8a2Q455K/Q455K strain exhibiting a more severe phenotype. However, at 5 months of age, prior to the development endothelial cell abnormalities, Col8a2L450W/L450W and Col8a2Q455K/Q455K mice knock-in mice had reduced tissue stiffness of DM that was statistically significant in the Col8a2Q455K/Q455K mice when compared with wildtype controls. These data indicate that alterations in the tissue compliance of DM precede phenotypic changes in endothelial cell count and morphology, and may play a role in onset and progression of FECD.
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Zhu AY, Jaskula-Ranga V, Jun AS. Gene Editing as a Potential Therapeutic Solution for Fuchs Endothelial Corneal Dystrophy. JAMA Ophthalmol 2018; 136:969-970. [DOI: 10.1001/jamaophthalmol.2018.2324] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
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Linz MO, Jun AS, Clever SL, Lawson SM, Sanyal A, Scott AW. Evaluation of Medical Students' Perception of an Ophthalmology Career. Ophthalmology 2018; 125:461-462. [DOI: 10.1016/j.ophtha.2017.10.032] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2017] [Revised: 10/13/2017] [Accepted: 10/24/2017] [Indexed: 10/18/2022] Open
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Li Z, Breitwieser FP, Lu J, Jun AS, Asnaghi L, Salzberg SL, Eberhart CG. Identifying Corneal Infections in Formalin-Fixed Specimens Using Next Generation Sequencing. Invest Ophthalmol Vis Sci 2018; 59:280-288. [PMID: 29340642 PMCID: PMC5770184 DOI: 10.1167/iovs.17-21617] [Citation(s) in RCA: 44] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2017] [Accepted: 12/06/2017] [Indexed: 12/14/2022] Open
Abstract
Purpose We test the ability of next-generation sequencing, combined with computational analysis, to identify a range of organisms causing infectious keratitis. Methods This retrospective study evaluated 16 cases of infectious keratitis and four control corneas in formalin-fixed tissues from the pathology laboratory. Infectious cases also were analyzed in the microbiology laboratory using culture, polymerase chain reaction, and direct staining. Classified sequence reads were analyzed with two different metagenomics classification engines, Kraken and Centrifuge, and visualized using the Pavian software tool. Results Sequencing generated 20 to 46 million reads per sample. On average, 96% of the reads were classified as human, 0.3% corresponded to known vectors or contaminant sequences, 1.7% represented microbial sequences, and 2.4% could not be classified. The two computational strategies successfully identified the fungal, bacterial, and amoebal pathogens in most patients, including all four bacterial and mycobacterial cases, five of six fungal cases, three of three Acanthamoeba cases, and one of three herpetic keratitis cases. In several cases, additional potential pathogens also were identified. In one case with cytomegalovirus identified by Kraken and Centrifuge, the virus was confirmed by direct testing, while two where Staphylococcus aureus or cytomegalovirus were identified by Centrifuge but not Kraken could not be confirmed. Confirmation was not attempted for an additional three potential pathogens identified by Kraken and 11 identified by Centrifuge. Conclusions Next generation sequencing combined with computational analysis can identify a wide range of pathogens in formalin-fixed corneal specimens, with potential applications in clinical diagnostics and research.
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Soiberman U, Foster JW, Jun AS, Chakravarti S. Pathophysiology of Keratoconus: What Do We Know Today. Open Ophthalmol J 2017; 11:252-261. [PMID: 28932341 PMCID: PMC5585454 DOI: 10.2174/1874364101711010252] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2017] [Revised: 04/01/2017] [Accepted: 06/14/2017] [Indexed: 12/19/2022] Open
Abstract
Keratoconus is a common corneal ectasia that leads to progressive visual impairment. Numerous studies have shown abnormal protein expression patterns in keratoconic corneas. However, the specific mechanisms causing this disease remain ambiguous. This review aims to provide an update on morphological studies of the keratoconic cornea, relate these early studies with current findings from proteomic, biochemical and cell culture studies and to postulate possible pathogenic pathways.
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Vedana G, Cardoso FG, Marcon AS, Araújo LEK, Zanon M, Birriel DC, Watte G, Jun AS. Cumulative sum analysis score and phacoemulsification competency learning curve. Int J Ophthalmol 2017; 10:1088-1093. [PMID: 28730111 DOI: 10.18240/ijo.2017.07.11] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2016] [Accepted: 05/11/2017] [Indexed: 11/23/2022] Open
Abstract
AIM To use the cumulative sum analysis score (CUSUM) to construct objectively the learning curve of phacoemulsification competency. METHODS Three second-year residents and an experienced consultant were monitored for a series of 70 phacoemulsification cases each and had their series analysed by CUSUM regarding posterior capsule rupture (PCR) and best-corrected visual acuity. The acceptable rate for PCR was <5% (lower limit h) and the unacceptable rate was >10% (upper limit h). The acceptable rate for best-corrected visual acuity worse than 20/40 was <10% (lower limit h) and the unacceptable rate was >20% (upper limit h). The area between lower limit h and upper limit h is called the decision interval. RESULTS There was no statistically significant difference in the mean age, sex or cataract grades between groups. The first trainee achieved PCR CUSUM competency at his 22nd case. His best-corrected visual acuity CUSUM was in the decision interval from his third case and stayed there until the end, never reaching competency. The second trainee achieved PCR CUSUM competency at his 39th case. He could reach best-corrected visual acuity CUSUM competency at his 22nd case. The third trainee achieved PCR CUSUM competency at his 41st case. He reached best-corrected visual acuity CUSUM competency at his 14th case. CONCLUSION The learning curve of competency in phacoemulsification is constructed by CUSUM and in average took 38 cases for each trainee to achieve it.
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Kim EC, Toyono T, Berlinicke CA, Zack DJ, Jurkunas U, Usui T, Jun AS. Screening and Characterization of Drugs That Protect Corneal Endothelial Cells Against Unfolded Protein Response and Oxidative Stress. Invest Ophthalmol Vis Sci 2017; 58:892-900. [PMID: 28159976 PMCID: PMC5295784 DOI: 10.1167/iovs.16-20147] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Purpose To screen for and characterize compounds that protect corneal endothelial cells against unfolded protein response (UPR) and oxidative stress. Methods Bovine corneal endothelial cells (BCECs) were treated for 48 hours with 640 compounds from a Food and Drug Administration (FDA)-approved drug library and then challenged with thapsigargin or H2O2 to induce UPR or oxidative stress, respectively. Cell viability was measured using the CellTiter-Glo survival assay. Selected “hits” were subjected to further dose-response testing, and their ability to modulate expression of UPR and oxidative stress markers was assessed by RT-PCR, Western blot, and measurement of protein carbonyl and 8-hydroxydeoxyguanosine (8-OHdG) adducts in immortalized human corneal endothelial cells (iHCECs). Results Forty-one drugs at 20 μM and 55 drugs at 100 μM increased survival of H2O2-challenged cells, and 8 drugs at 20 μM and 2 drugs at 100 μM increased survival of thapsigargin-challenged cells, compared with untreated control cells. Nicergoline, ergothioneine, nimesulide, oxotremorine, and mefenamic acid increased survival of both H2O2- and thapsigargin-challenged cells. Oxotremorine altered DNA damage inducible 3 (CHOP) gene expression, glucose-regulated protein 78 kDa (GRP78) and activating transcription factor 4 (ATF4) protein expression, and protein carbonyl and 8-OHdG levels. Mefenamic acid altered GRP78 protein expression and protein carbonyl and 8-OHdG levels. Conclusions Oxotremorine and mefenamic acid are potential survival factors for corneal endothelial cells under UPR and oxidative stress. The described assay can be further expanded to screen additional drugs for potential therapeutic effect in corneal endothelial diseases such as Fuchs' endothelial corneal dystrophy.
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Ladas JG, Jun AS, Devgan U. Origin of Multiple Formula Use to Calculate Intraocular Lens Power-Reply. JAMA Ophthalmol 2016; 134:848-9. [PMID: 27259075 DOI: 10.1001/jamaophthalmol.2016.1049] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
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Losick VP, Jun AS, Spradling AC. Wound-Induced Polyploidization: Regulation by Hippo and JNK Signaling and Conservation in Mammals. PLoS One 2016; 11:e0151251. [PMID: 26958853 PMCID: PMC4784922 DOI: 10.1371/journal.pone.0151251] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2016] [Accepted: 02/25/2016] [Indexed: 12/13/2022] Open
Abstract
Tissue integrity and homeostasis often rely on the proliferation of stem cells or differentiated cells to replace lost, aged, or damaged cells. Recently, we described an alternative source of cell replacement- the expansion of resident, non-dividing diploid cells by wound-induced polyploidization (WIP). Here we show that the magnitude of WIP is proportional to the extent of cell loss using a new semi-automated assay with single cell resolution. Hippo and JNK signaling regulate WIP; unexpectedly however, JNK signaling through AP-1 limits rather than stimulates the level of Yki activation and polyploidization in the Drosophila epidermis. We found that polyploidization also quantitatively compensates for cell loss in a mammalian tissue, mouse corneal endothelium, where increased cell death occurs with age in a mouse model of Fuchs Endothelial Corneal Dystrophy (FECD). Our results suggest that WIP is an evolutionarily conserved homeostatic mechanism that maintains the size and synthetic capacity of adult tissues.
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Abstract
Fuchs endothelial corneal dystrophy (FECD) is the most common corneal dystrophy and frequently results in vision loss. Hallmarks of the disease include loss of corneal endothelial cells and formation of excrescences of Descemet's membrane. Later stages involve all layers of the cornea. Impairment of endothelial barrier and pump function and cell death from oxidative and unfolded protein stress contribute to disease progression. The genetic basis of FECD includes numerous genes and chromosomal loci, although alterations in the transcription factor 4 gene are associated with the majority of cases. Definitive treatment of FECD is corneal transplantation. In this paper, we highlight advances that have been made in understanding FECD's clinical features, pathophysiology, and genetics. We also discuss recent advances in endothelial keratoplasty and potential future treatments.
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Botsford B, Vedana G, Cope L, Yiu SC, Jun AS. Comparison of 20% sulfur hexafluoride with air for intraocular tamponade in Descemet membrane endothelial keratoplasty (DMEK). Arq Bras Oftalmol 2016; 79:299-302. [DOI: 10.5935/0004-2749.20160086] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2016] [Accepted: 04/14/2016] [Indexed: 11/20/2022] Open
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Vianna LMM, Li HD, Holiman JD, Stoeger C, Belfort Jr. R, Jun AS. Characterization of cryopreserved primary human corneal endothelial cells cultured in human serum-supplemented media. Arq Bras Oftalmol 2016; 79:37-41. [DOI: 10.5935/0004-2749.20160011] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2015] [Accepted: 11/13/2015] [Indexed: 11/20/2022] Open
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Ladas JG, Siddiqui AA, Devgan U, Jun AS. A 3-D “Super Surface” Combining Modern Intraocular Lens Formulas to Generate a “Super Formula” and Maximize Accuracy. JAMA Ophthalmol 2015; 133:1431-6. [DOI: 10.1001/jamaophthalmol.2015.3832] [Citation(s) in RCA: 48] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
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Vianna LM, Stoeger CG, Galloway JD, Terry M, Cope L, Belfort R, Jun AS. Risk factors for eye bank preparation failure of Descemet membrane endothelial keratoplasty tissue. Am J Ophthalmol 2015; 159:829-34.e2. [PMID: 25640409 DOI: 10.1016/j.ajo.2015.01.030] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2014] [Revised: 01/25/2015] [Accepted: 01/26/2015] [Indexed: 10/24/2022]
Abstract
PURPOSE To assess the results of a single eye bank preparing a high volume of Descemet membrane endothelial keratoplasty (DMEK) tissues using multiple technicians to provide an overview of the experience and to identify possible risk factors for DMEK preparation failure. DESIGN Cross-sectional study. METHODS setting: Lions VisionGift and Wilmer Eye Institute at Johns Hopkins Hospital. STUDY POPULATION All 563 corneal tissues processed by technicians at Lions VisionGift for DMEK between October 2011 and May 2014 inclusive. OBSERVATION PROCEDURES Tissues were divided into 2 groups: DMEK preparation success and DMEK preparation failure. MAIN OUTCOME MEASURES We compared donor characteristics, including past medical history. RESULTS The overall tissue preparation failure rate was 5.2%. Univariate analysis showed diabetes mellitus (P = .000028) and its duration (P = .023), hypertension (P = .021), and hyperlipidemia or obesity (P = .0004) were more common in the failure group. Multivariate analysis showed diabetes mellitus (P = .0001) and hyperlipidemia or obesity (P = .0142) were more common in the failure group. Elimination of tissues from donors either with diabetes or with hyperlipidemia or obesity reduced the failure rate from 5.2% to 2.2%. Trends toward lower failure rates occurring with increased technician experience also were found. CONCLUSIONS Our work showed that tissues from donors with diabetes mellitus (especially with longer disease duration) and hyperlipidemia or obesity were associated with higher failure rates in DMEK preparation. Elimination of tissues from donors either with diabetes mellitus or with hyperlipidemia or obesity reduced the failure rate. In addition, our data may provide useful initial guidelines and benchmark values for eye banks seeking to establish and maintain DMEK programs.
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Vianna LMM, Leatherman J, Jun AS. Vision with Fuchs endothelial dystrophy. JAMA Ophthalmol 2015; 133:e145353. [PMID: 25856653 DOI: 10.1001/jamaophthalmol.2014.5353] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
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Muthappan V, Paskowitz D, Kazimierczak A, Jun AS, Ladas J, Kuo IC. Measurement and use of postoperative anterior chamber depth of fellow eye in refractive outcomes. J Cataract Refract Surg 2015; 41:778-84. [DOI: 10.1016/j.jcrs.2014.08.034] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2014] [Revised: 07/15/2014] [Accepted: 08/12/2014] [Indexed: 11/30/2022]
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Bonfadini G, Arora K, Vianna LM, Campos M, Friedman D, Muñoz B, Jun AS. Quantitative analysis of iris parameters in keratoconus patients using optical coherence tomography. Arq Bras Oftalmol 2015; 78:305-9. [DOI: 10.5935/0004-2749.20150080] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2015] [Accepted: 07/06/2015] [Indexed: 11/20/2022] Open
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Vianna LMM, Kallay L, Toyono T, Belfort R, Holiman JD, Jun AS. Use of human serum for human corneal endothelial cell culture. Br J Ophthalmol 2014; 99:267-71. [DOI: 10.1136/bjophthalmol-2014-306034] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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Matthaei M, Zhu AY, Kallay L, Eberhart CG, Cursiefen C, Jun AS. Transcript profile of cellular senescence-related genes in Fuchs endothelial corneal dystrophy. Exp Eye Res 2014; 129:13-7. [PMID: 25311168 DOI: 10.1016/j.exer.2014.10.011] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2014] [Revised: 09/03/2014] [Accepted: 10/09/2014] [Indexed: 12/13/2022]
Abstract
Fuchs endothelial corneal dystrophy (FECD) is a genetically heterogeneous disease. Hypothesizing that cellular senescence may be relevant in FECD pathogenesis, genetically undifferentiated late-onset FECD endothelial samples were analyzed to identify common changes of specific senescence-related transcripts. Total RNA was extracted from 21 FECD endothelial samples retrieved from patients undergoing lamellar keratoplasty due to clinically diagnosed end-stage FECD and from 12 endothelial samples retrieved from normal autopsy eyes. Taqman low density array (TLDA) cards were used to analyze differential expression of 89 cellular senescence-related transcripts. Result validation was performed using individual real-time PCR assays. TLDA-analysis demonstrated differential expression of 31 transcripts (fold-change >1.5; p < 0.05). Thereof, 27 showed significant up-regulation and 4 significant down-regulation. Markedly elevated mRNA-levels of the constitutively active and reactive oxygen species-generating enzyme NOX4 were found in all evaluable FECD samples. In addition, increased expression of CDKN2A and its transcriptional activators ETS1 and ARHGAP18 (SENEX) along with decreased expression of CDKN2A inhibitor ID1 were detected in FECD samples. Consistent over-expression of NOX4 in FECD endothelial samples suggests a role as pathogenic factor and as a potential new treatment target in FECD. Transcriptional up-regulation of the CDKN2A-pathway provides further evidence for increased cellular senescence in FECD endothelium.
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Giovannini J, Lee R, Zhang SX, Jun AS, Bower KS. Rhodotorula keratitis: a rarely encountered ocular pathogen. Case Rep Ophthalmol 2014; 5:302-10. [PMID: 25408670 PMCID: PMC4224248 DOI: 10.1159/000365986] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Purpose To describe a case of fungal keratitis involving an atypical organism with confirmatory in vivo confocal microscopy and to review the literature on Rhodotorula keratitis. Methods Case report and review of the medical literature. Results A 22-year-old college student was struck in the left eye with a tree branch and subsequently developed pain, redness and photophobia. Upon presentation, visual acuity was 20/200 and there was a large epithelial defect with diffuse stromal inflammation involving the anterior one-third of the cornea. Cultures of the infiltrate were performed for bacterial, viral and fungal organisms that resulted in a positive culture for Rhodotorula mucilaginosa. Fungal elements were confirmed in vivo by confocal microscopy. The patient was treated with voriconazole initially and had amphotericin added once Rhodotorula infection was confirmed. The patient responded well clinically, and one month after therapy was initiated, the corneal infiltrate had resolved leaving mild anterior stromal haze. Upon completion of therapy at three months, the patient was asymptomatic, had a clear cornea and had a best corrected visual acuity of 20/20 in the involved eye. There was no measurable change in his manifest refraction. Conclusions Prior cases of Rhodotorula keratitis most often required surgical intervention and were associated with poor outcomes. This case shows that Rhodotorula keratitis can be successfully treated with topical antifungal agents if diagnosed early and appropriate treatment is initiated promptly. We report the first case of Rhodotorula keratitis confirmed by in vivo confocal microscopy. This is also the first description of pseudomycelium formation that has not been previously described in vivo, a morphological structure that this organism rarely demonstrates. Finally, this case shows that confocal microscopy may aid in the early diagnosis and management of fungal keratitis involving this rare but potentially damaging organism.
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Foster J, Wu WH, Scott SG, Bassi M, Mohan D, Daoud Y, Stark WJ, Jun AS, Chakravarti S. Transforming growth factor β and insulin signal changes in stromal fibroblasts of individual keratoconus patients. PLoS One 2014; 9:e106556. [PMID: 25247416 PMCID: PMC4172437 DOI: 10.1371/journal.pone.0106556] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2014] [Accepted: 08/07/2014] [Indexed: 11/19/2022] Open
Abstract
Keratoconus (KC) is a complex thinning disease of the cornea that often requires transplantation. The underlying pathogenic molecular changes in this disease are poorly understood. Earlier studies reported oxidative stress, metabolic dysfunctions and accelerated death of stromal keratocytes in keratoconus (KC) patients. Utilizing mass spectrometry we found reduced stromal extracellular matrix (ECM) proteins in KC, suggesting ECM-regulatory changes that may be due to altered TGFβ signals. Here we investigated properties of stromal cells from donor (DN) and KC corneas grown as fibroblasts in serum containing DMEM: F12 or in serum-free medium containing insulin, transferrin, selenium (ITS). Phosphorylation of SMAD2/3 of the canonical TGFβ pathway, was high in serum-starved DN and KC fibroblast protein extracts, but pSMAD1/5/8 low at base line, was induced within 30 minutes of TGFβ1 stimulation, more so in KC than DN, suggesting a novel TGFβ1-SMAD1/5/8 axis in the cornea, that may be altered in KC. The serine/threonine kinases AKT, known to regulate proliferation, survival and biosynthetic activities of cells, were poorly activated in KC fibroblasts in high glucose media. Concordantly, alcohol dehydrogenase 1 (ADH1), an indicator of increased glucose uptake and metabolism, was reduced in KC compared to DN fibroblasts. By contrast, in low glucose (5.5 mM, normoglycemic) serum-free DMEM and ITS, cell survival and pAKT levels were comparable in KC and DN cells. Therefore, high glucose combined with serum-deprivation presents some cellular stress difficult to overcome by the KC stromal cells. Our study provides molecular insights into AKT and TGFβ signal changes in KC, and a mechanism for functional studies of stromal cells from KC corneas.
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Mitry D, Bhogal M, Patel AK, Lee BS, Chai SM, Price MO, Price FW, Jun AS, Aldave AJ, Mehta JS, Busin M, Allan BD. Descemet stripping automated endothelial keratoplasty after failed penetrating keratoplasty: survival, rejection risk, and visual outcome. JAMA Ophthalmol 2014; 132:742-9. [PMID: 24763830 DOI: 10.1001/jamaophthalmol.2014.352] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
IMPORTANCE Descemet stripping automated endothelial keratoplasty (DSAEK) for isolated endothelial dysfunction has become the preferred surgical option for many corneal surgeons. However, there are limited large-scale reports on DSAEK survival and clinical variables affecting the risk of rejection and failure after failed penetrating keratoplasty (PK). OBJECTIVE To report the survival, risk factors for graft rejection and failure, and visual outcome of DSAEK after failed PK. DESIGN, SETTING, AND PARTICIPANTS A multicenter retrospective interventional case series included patients recruited from 6 tertiary referral surgical centers: 3 in the United States, 2 in Europe, and 1 in Asia. A total of 246 consecutive eyes (246 patients) that underwent DSAEK after failed PK, with a minimum follow-up period of 1 month, was included. Data comprising demographic details, preoperative and postoperative risk factors, time to rejection, time to failure, and corrected distance visual acuity were collected. MAIN OUTCOMES AND MEASURES Cumulative probability of graft survival, hazard ratio estimates for survival, and corrected distance visual acuity were determined. RESULTS The mean (SD) recipient age was 63.2 (16.6) years and the median follow-up period was 17 months (interquartile range, 6-30 months). One-third of the grafts (n = 82) had follow-up data for more than 2 years; 18.3% had more than 1 failed PK before DSAEK. In total, 19.1% (47 of 246) of DSAEK grafts failed. The cumulative probability of DSAEK survival after a failed PK was 0.89 (95% CI, 0.84-0.92), 0.74 (95% CI, 0.64-0.81), and 0.47 (95% CI, 0.29-0.61) at 1 year, 3 years, and 5 years, respectively. Based on multivariate analysis, significant preoperative risk factors for failure were young recipient age (hazard ratio [HR], 5.18 [95% CI, 1.57-17.18]), previous tube filtration surgery (HR, 5.23 [95% CI, 1.47-7.33]), and rejection episodes before PK failure (HR, 3.28 [95% CI, 1.47-7.33]); single-surgeon centers had a protective effect. Any rejection episode prior to PK failure was a significant predictor of post-DSAEK rejection, which in turn was a significant predictor of DSAEK failure. After a median follow-up of 17 months, 33.3% of the grafts achieved 0.3 or greater logMAR (20/40) corrected distance visual acuity. CONCLUSIONS AND RELEVANCE Descemet stripping automated endothelial keratoplasty after failed PK combines greater wound stability and reduced suture-related complications, with visual outcomes and graft survival rates comparable to those of a second PK.
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