Sun T, Shu H-Y, Wu J-L, Su T, Liu Y-J, Zhang L-J, Li Q-Y, Pan Y-C, Ge Q-M, Shao Y. Investigation of changes in the activity and function of dry eye-associated brain regions using the amplitude of low-frequency fluctuations method. Biosci Rep 2022;42(1)Abstract
OBJECTIVE: The local characteristics of spontaneous brain activity in patients with dry eye (DE) and its relationship with clinical characteristics were evaluated using the amplitude of low-frequency fluctuations (ALFF) method. METHODS: A total of 27 patients with DE (10 males and 17 females) and 28 healthy controls (HCs) (10 males and 18 females) were recruited, matched according to sex, age, weight and height, classified into the DE and HC groups, and examined using functional magnetic resonance imaging (fMRI) scans. Spontaneous brain activity changes were recorded using ALFF technology. Data were recorded and plotted on the receiver operating characteristic (ROC) curve, reflecting changes in activity in different brain areas. Finally, Pearson correlation analysis was used to calculate the potential relationship between spontaneous brain activity abnormalities in multiple brain regions and clinical features in patients with DE. GraphPad Prism 8 (GraphPad Software, Inc.) was used to analyze the linear correlation between the Hospital Anxiety and Depression Scale and ALFF value. RESULTS: Compared with HCs, the ALFF values of patients with DE were decreased in the right middle frontal gyrus (MFG)/right inferior orbitofrontal cortex (OFC), left triangle inferior frontal gyrus, left MFG, and right superior frontal gyrus. In contrast, the ALFF value of patients with DE was increased in the left calcarine. CONCLUSION: There are significant fluctuations in the ALFF value of specific brain regions in patients with DE versus HCs. This corroborates previous evidence showing that the symptoms of ocular surface damage in patients with DE are related to dysfunction in specific brain areas.
Fote GM, Geller NR, Efstathiou NE, Hendricks N, Vavvas DG, Reidling JC, Thompson LM, Steffan JS. Isoform-dependent lysosomal degradation and internalization of apolipoprotein E requires autophagy proteins. J Cell Sci 2022;135(2)Abstract
The human apolipoprotein E4 isoform (APOE4) is the strongest genetic risk factor for late-onset Alzheimer's disease (AD), and lysosomal dysfunction has been implicated in AD pathogenesis. We found, by examining cells stably expressing each APOE isoform, that APOE4 increases lysosomal trafficking, accumulates in enlarged lysosomes and late endosomes, alters autophagic flux and the abundance of autophagy proteins and lipid droplets, and alters the proteomic contents of lysosomes following internalization. We investigated APOE-related lysosomal trafficking further in cell culture, and found that APOE from the post-Golgi compartment is degraded through autophagy. We found that this autophagic process requires the lysosomal membrane protein LAMP2 in immortalized neuron-like and hepatic cells, and in mouse brain tissue. Several macroautophagy-associated proteins were also required for autophagic degradation and internalization of APOE in hepatic cells. The dysregulated autophagic flux and lysosomal trafficking of APOE4 that we observed suggest a possible novel mechanism that might contribute to AD pathogenesis. This article has an associated First Person interview with the first author of the paper.
Silpa-Archa S, Sriyuttagrai W, Foster SC. Treatment for Epstein-Barr Virus-associated uveitis confirmed by polymerase chain reaction: Efficacy of Anti-Viral Agents and a literature review. J Clin Virol 2022;147:105079.Abstract
BACKGROUND: There are still many research challenges and unanswered questions in relation to Epstein-Barr virus-associated uveitis. These include the presence of Epstein-Barr virus (EBV) DNA in asymptomatic patients, its pathogenicity in the uveitis eye, and the role of antiviral therapy for EBV-associated intraocular inflammation. METHODS: This was a retrospective review of prospectively collected data from the Ophthalmology Department, Rajavithi Hospital between 2015 and 2020. A qualitative assay using multiplex real-time PCR was performed to detect pathogen genes from specimens obtained from a total of 344 patients. The main outcome measure was treatment success defined by clinical improvement and absence of viral DNA confirmed by PCR. RESULTS: Of the 35 cases, 24 with complete data were enrolled in the study, including 22 with post-treatment PCR results. Sixty-seven percent were HIV-infected, and other plausible causes or coinfection with other pathogens were found in 75% of patients. Cytomegalovirus (38%) was the most common co-infecting pathogen. The most commonly employed regimen was a combination of systemic acyclovir and intravitreal ganciclovir injection (58%). Of the 22 cases who had post-treatment PCR results, absence of detection of the virus by PCR in the intraocular fluid after treatment was demonstrated in 73% of patients. CONCLUSION: Patients with EBV infection can be simultaneously co-infected with other pathogens. Systemic acyclovir and ganciclovir achieved clinical improvement in most cases, and EBV infection was cured in the majority of patients.
Silpa-Archa S, Hoopholerb T, Foster CS. Appraisal of vitreous syphilis antibody as a novel biomarker for the diagnosis of syphilitic uveitis: a prospective case-control study. Eye (Lond) 2022;Abstract
PURPOSE: To determine the sensitivity and specificity of syphilis antibody tests in vitreous samples and to propose an algorithm using vitreous syphilis antibody as a supplementary test to confirm syphilitic uveitis (SU). METHODS: A prospective case-control study was conducted at the Retina and Uveitis Clinic from May 2017 to January 2020. Initially, patients were classified based on syphilis serology into group 1 (positive testing) and group 2 (negative testing). Group 1 was further divided into 2 subgroups (group 1A and 1B) depending on their relevant clinical manifestations and clinical improvement. Group 2 served as a control group. RESULTS: Thirty-eight patients were enrolled in the study: 14 in group 1A, 5 in group 1B, and 19 in group 2B. No patient was assigned to group 2A. All patients in group 1A, representing definite SU, completed syphilis test (rapid plasma reagin [RPR], enzyme immunoassay [EIA], and fluorescent treponemal antibody-absorption [FTA-ABS]) for vitreous, and all vitreous samples yielded positive results. Of the 5 subjects in group 1B, 3 cases were considered to be not SU with different conditions, and 2 were indeterminate for SU. They presented with different features not typical of SU, and they had variable and fewer positive syphilis antibody responses. The most sensitive test for detecting syphilis antibodies in vitreous was EIA (90.9%), followed by RPR (80.0%) and FTA-ABS IgG (78.9%). EIA and FTA-ABS had the highest specificity, detecting 100% of the syphilis antibody. CONCLUSIONS: Vitreous analysis of syphilis antibody can serve as a supplementary test to confirm SU in selected cases as the proposed algorithm.
Solli E, Doshi H, Elze T, Pasquale L, Wall M, Kupersmith M. Archetypal Analysis Reveals Quantifiable Patterns of Visual Field Loss in Optic Neuritis. Transl Vis Sci Technol 2022;11(1):27.Abstract
Purpose: Identifying and monitoring visual field (VF) defects due to optic neuritis (ON) relies on qualitative clinician interpretation. Archetypal analysis (AA), a form of unsupervised machine learning, is used to quantify VF defects in glaucoma. We hypothesized that AA can identify quantifiable, ON-specific patterns (as archetypes [ATs]) of VF loss that resemble known ON VF defects. Methods: We applied AA to a dataset of 3892 VFs prospectively collected from 456 eyes in the Optic Neuritis Treatment Trial (ONTT), and decomposed each VF into component ATs (total weight = 100%). AA of 568 VFs from 61 control eyes was used to define a minimum meaningful (≤7%) AT weight and weight change. We correlated baseline ON AT weights with global VF indices, visual acuity, and contrast sensitivity. For eyes with a dominant AT (weight ≥50%), we compared the ONTT VF classification with the AT pattern. Results: AA generated a set of 16 ATs containing patterns seen in the ONTT. These were distinct from control ATs. Baseline study eye VFs were decomposed into 2.9 ± 1.5 ATs. AT2, a global dysfunction pattern, had the highest mean weight at baseline (36%; 95% confidence interval, 33%-40%), and showed the strongest correlation with MD (r = -0.91; P < 0.001), visual acuity (r = 0.70; P < 0.001), and contrast sensitivity (r = -0.77; P < 0.001). Of 191 baseline VFs with a dominant AT, 81% matched the descriptive classifications. Conclusions: AA identifies and quantifies archetypal, ON-specific patterns of VF loss. Translational Relevance: AA is a quantitative, objective method for demonstrating and monitoring change in regional VF deficits in ON.
Zolotukhin S, Vandenberghe LH. AAV capsid design: A Goldilocks challenge. Trends Mol Med 2022;28(3):183-193.Abstract
In vivo therapeutic gene transfer has emerged as a novel class of medicines. Its feasibility relies on the safe and efficacious delivery of genetic cargo to the appropriate targets. The adeno-associated virus (AAV) vector manifested itself as a preferred gene delivery vehicle enabling therapeutic gene expression for several clinical indications. Here, we cover the recent trends in AAV capsid engineering to enhance its targeting specificity, safety, and endurance. While each and every desirable trait can be individually remodeled, combining several attributes in one capsid amounts to a significant engineering challenge. Taking advantage of virion structure and phylogenetics, harnessing directed evolution, sequence analyses, and machine learning, researchers develop novel capsid variants to realize the goals of safe and enduring gene therapy.
Pham AT, Whitescarver TD, Beatson B, Purt B, Yonekawa Y, Shah AS, Colyer MH, Woreta FA, Justin GA. Ophthalmic trauma: the top 100 cited articles in Ophthalmology journals. Eye (Lond) 2022;Abstract
OBJECTIVES: To analyze the top 100 cited papers on ophthalmic trauma. METHODS: A literature search of Ophthalmology journals within the ISI Web of Science database for the most cited papers related to ophthalmic trauma. RESULTS: The most cited articles were published between 1943 and 2013, the greatest number being published in 2000. Ophthalmology (45), Archives of Ophthalmology (17), and the American Journal of Ophthalmology (15) published most of the articles. The institutions with the highest number of publications were Wilmer Eye Institute (10) and Massachusetts Eye and Ear Infirmary (7). Sixty-seven percent of the articles originated from the USA. The most common type of trauma studied was non-open-globe injuries and the most frequent topic studied were pathological conditions secondary to trauma (34), particularly endophthalmitis (8), and optic neuropathy (6). Articles presenting a standardized classification system for eye injury received the highest average of citations per publication. Types of research most frequently cited were observational clinical studies (62) and epidemiological studies (30); the least frequent were clinical trials (2). CONCLUSION: This bibliographic study provides a historical perspective of the literature and identifies trends within the most highly influential papers on ophthalmic trauma. Many of these articles emerged within the past three decades and came from Ophthalmology journals that remain high impact to this day. Clinical trials have been difficult to conduct and are lacking, reflecting a critical need in ophthalmic trauma research, as most of our understanding of ophthalmic trauma comes from observational and epidemiological studies.
Natera-de Benito D, Jurgens JA, Yeung A, Zaharieva IT, Manzur A, DiTroia SP, Di Gioia SA, Pais L, Pini V, Barry BJ, Chan W-M, Elder JE, Christodoulou J, Hay E, England EM, Munot P, Hunter DG, Feng L, Ledoux D, O'Donnell-Luria A, Phadke R, Engle EC, Sarkozy A, Muntoni F. Recessive variants in COL25A1 gene as novel cause of arthrogryposis multiplex congenita with ocular congenital cranial dysinnervation disorder. Hum Mutat 2022;43(4):487-498.Abstract
A proper interaction between muscle-derived collagen XXV and its motor neuron-derived receptors protein tyrosine phosphatases σ and δ (PTP σ/δ) is indispensable for intramuscular motor innervation. Despite this, thus far, pathogenic recessive variants in the COL25A1 gene had only been detected in a few patients with isolated ocular congenital cranial dysinnervation disorders. Here we describe five patients from three unrelated families with recessive missense and splice site COL25A1 variants presenting with a recognizable phenotype characterized by arthrogryposis multiplex congenita with or without an ocular congenital cranial dysinnervation disorder phenotype. The clinical features of the older patients remained stable over time, without central nervous system involvement. This study extends the phenotypic and genotypic spectrum of COL25A1 related conditions, and further adds to our knowledge of the complex process of intramuscular motor innervation. Our observations indicate a role for collagen XXV in regulating the appropriate innervation not only of extraocular muscles, but also of bulbar, axial, and limb muscles in the human.
Göz Aytürk D, You W, Cepko CL. Mouse Lines with Cre-Mediated Recombination in Retinal Amacrine Cells. eNeuro 2022;9(1)Abstract
Amacrine cells (ACs) are the most diverse neuronal cell type in the vertebrate retina. Yet little is known about the contribution of ACs to visual processing and retinal disease. A major challenge in evaluating AC function is genetic accessibility. A classic tool of mouse genetics, Cre-mediated recombination, can provide such access. We have screened existing genetically-modified mouse strains and identified multiple candidates that express Cre-recombinase in subsets of retinal ACs. The Cre-expressing mice were crossed to fluorescent-reporter mice to assay Cre expression. In addition, a Cre-dependent fluorescent reporter plasmid was electroporated into the subretinal space of Cre strains. Herein, we report three mouse lines (Tac1::IRES-cre, Camk2a-cre, and Scx-cre) that express Cre recombinase in sub-populations of ACs. In two of these lines, recombination occurred in multiple AC types and a small number of other retinal cell types, while recombination in the Camk2a-cre line appears specific to a morphologically distinct AC. We anticipate that these characterized mouse lines will be valuable tools to the community of researchers who study retinal biology and disease.
Catomeris AJ, Ballios BG, Sangermano R, Wagner NE, Comander JI, Pierce EA, Place EM, Bujakowska KM, Huckfeldt RM. Novel RCBTB1 variants causing later-onset non-syndromic retinal dystrophy with macular chorioretinal atrophy. Ophthalmic Genet 2022;43(3):332-339.Abstract
BACKGROUND: Variants in RCBTB1 were recently described to cause a retinal dystrophy with only eight families described to date and a predominant phenotype of macular atrophy and peripheral reticular degeneration. Here, we further evaluate the genotypic and phenotypic characteristics of biallelic RCBTB1-associated retinal dystrophy in a North American clinic population. METHODS: A retrospective analysis of genetic and clinical features was performed in individuals with biallelic variants in RCBTB1. RESULTS: Three unrelated individuals of French-Canadian descent with rare biallelic RCBTB1 variants were identified. All individuals shared a novel p.(Ser342Leu) missense variant; one patient was homozygous whereas the other two each possessed a second unique novel variant p.(Gln120*) and p.(Pro224Leu). All three had macula-predominant disease with symptom onset in the fifth decade of life. CONCLUSION: This report adds to the genetic diversity of RCBTB1-associated disease. These cases confirm the later-onset, relative to many other retinal dystrophies, and macular focus of disease described in most cases to-date. They are thus a reminder of considering hereditary disease in the differential for later-onset macular atrophy.
Lains I, Mendez K, Nigalye A, Katz R, Douglas VP, Kelly RS, Kim IK, Miller JB, Vavvas DG, Liang L, Lasky-Su J, Miller JW, Husain D. Plasma Metabolomic Profiles Associated with Three-Year Progression of Age-Related Macular Degeneration. Metabolites 2022;12(1)Abstract
Plasma metabolomic profiles have been shown to be associated with age-related macular degeneration (AMD) and its severity stages. However, all studies performed to date have been cross-sectional and have not assessed progression of AMD. This prospective, longitudinal, pilot study analyzes, for the first time, the association between plasma metabolomic profiles and progression of AMD over a 3-year period. At baseline and 3 years later, subjects with AMD (n = 108 eyes) and controls (n = 45 eyes) were imaged with color fundus photos for AMD staging and tested for retinal function with dark adaptation (DA). Fasting plasma samples were also collected for metabolomic profiling. AMD progression was considered present if AMD stage at 3 years was more advanced than at baseline (n = 26 eyes, 17%). Results showed that, of the metabolites measured at baseline, eight were associated with 3-year AMD progression (p < 0.01) and 19 (p < 0.01) with changes in DA. Additionally, changes in the levels (i.e., between 3 years and baseline) of 6 and 17 metabolites demonstrated significant associations (p < 0.01) with AMD progression and DA, respectively. In conclusion, plasma metabolomic profiles are associated with clinical and functional progression of AMD at 3 years. These findings contribute to our understanding of mechanisms of AMD progression and the identification of potential therapeutics for this blinding disease.
Banskota S, Raguram A, Suh S, Du SW, Davis JR, Choi EH, Wang X, Nielsen SC, Newby GA, Randolph PB, Osborn MJ, Musunuru K, Palczewski K, Liu DR. Engineered virus-like particles for efficient in vivo delivery of therapeutic proteins. Cell 2022;185(2):250-265.e16.Abstract
Methods to deliver gene editing agents in vivo as ribonucleoproteins could offer safety advantages over nucleic acid delivery approaches. We report the development and application of engineered DNA-free virus-like particles (eVLPs) that efficiently package and deliver base editor or Cas9 ribonucleoproteins. By engineering VLPs to overcome cargo packaging, release, and localization bottlenecks, we developed fourth-generation eVLPs that mediate efficient base editing in several primary mouse and human cell types. Using different glycoproteins in eVLPs alters their cellular tropism. Single injections of eVLPs into mice support therapeutic levels of base editing in multiple tissues, reducing serum Pcsk9 levels 78% following 63% liver editing, and partially restoring visual function in a mouse model of genetic blindness. In vitro and in vivo off-target editing from eVLPs was virtually undetected, an improvement over AAV or plasmid delivery. These results establish eVLPs as promising vehicles for therapeutic macromolecule delivery that combine key advantages of both viral and nonviral delivery.
Li H, Deng Y, Sampani K, Cai S, Li Z, Sun JK, Karniadakis GE. Computational investigation of blood cell transport in retinal microaneurysms. PLoS Comput Biol 2022;18(1):e1009728.Abstract
Microaneurysms (MAs) are one of the earliest clinically visible signs of diabetic retinopathy (DR). MA leakage or rupture may precipitate local pathology in the surrounding neural retina that impacts visual function. Thrombosis in MAs may affect their turnover time, an indicator associated with visual and anatomic outcomes in the diabetic eyes. In this work, we perform computational modeling of blood flow in microchannels containing various MAs to investigate the pathologies of MAs in DR. The particle-based model employed in this study can explicitly represent red blood cells (RBCs) and platelets as well as their interaction in the blood flow, a process that is very difficult to observe in vivo. Our simulations illustrate that while the main blood flow from the parent vessels can perfuse the entire lumen of MAs with small body-to-neck ratio (BNR), it can only perfuse part of the lumen in MAs with large BNR, particularly at a low hematocrit level, leading to possible hypoxic conditions inside MAs. We also quantify the impacts of the size of MAs, blood flow velocity, hematocrit and RBC stiffness and adhesion on the likelihood of platelets entering MAs as well as their residence time inside, two factors that are thought to be associated with thrombus formation in MAs. Our results show that enlarged MA size, increased blood velocity and hematocrit in the parent vessel of MAs as well as the RBC-RBC adhesion promote the migration of platelets into MAs and also prolong their residence time, thereby increasing the propensity of thrombosis within MAs. Overall, our work suggests that computational simulations using particle-based models can help to understand the microvascular pathology pertaining to MAs in DR and provide insights to stimulate and steer new experimental and computational studies in this area.