Publications

2020

Efstathiou N, Moustafa G, Maidana D, Konstantinou E, Notomi S, Barbisan P, Georgakopoulos C, Miller J, Vavvas D. Acadesine suppresses TNF-α induced complement component 3 (C3), in retinal pigment epithelial (RPE) cells. PLoS One. 2020;15(12):e0244307.
RATIONALE: Age-related macular degeneration (AMD) is the most prevalent form of irreversible blindness in the developed world. Aging, inflammation and complement dysregulation affecting the retinal pigment epithelium (RPE), are considered significant contributors in its pathogenesis and several evidences have linked tumor necrosis factor alpha (TNF-α) and complement component 3 (C3) with AMD. Acadesine, an analog of AMP and an AMP-activated protein kinase (AMPK) activator, has been shown to have cytoprotective effects in human clinical trials as well as having anti-inflammatory and anti-vascular exudative effects in animals. The purpose of this study was to evaluate if acadesine is able to suppress TNF-α induced C3 in RPE cells. METHODS: ARPE-19 and human primary RPE cells were cultured and allowed to grow to confluence. TNF-α was used for C3 induction in the presence or absence of acadesine. Small molecule inhibitors and siRNA were used to determine if acadesine exerts its effect via the extracellular or intracellular pathway and to evaluate the importance of AMPK for these effects. The expression level of C3 was determined by immunoblot analysis. RESULTS: Acadesine suppresses TNF-α induced C3 in a dose dependent manner. When we utilized the adenosine receptor inhibitor dipyridamole (DPY) along with acadesine, acadesine's effects were abolished, indicating the necessity of acadesine to enter the cell in order to exert it's action. However, pretreatment with 5-iodotubericidin (5-Iodo), an adenosine kinase (AK) inhibitor, didn't prevent acadesine from decreasing TNF-α induced C3 expression suggesting that acadesine does not exert its effect through AMP conversion and subsequent activation of AMPK. Consistent with this, knockdown of AMPK α catalytic subunit did not affect the inhibitory effect of acadesine on TNF-α upregulation of C3. CONCLUSIONS: Our results suggest that acadesine suppresses TNF-α induced C3, likely through an AMPK-independent pathway, and could have potential use in complement over activation diseases.
Antoszyk A, Glassman A, Beaulieu W, Jampol L, Jhaveri C, Punjabi O, Salehi-Had H, Wells J, Maguire M, Stockdale C, Martin D, Sun J, DRCR Retina Network. Effect of Intravitreous Aflibercept vs Vitrectomy With Panretinal Photocoagulation on Visual Acuity in Patients With Vitreous Hemorrhage From Proliferative Diabetic Retinopathy: A Randomized Clinical Trial. JAMA. 2020;324(23):2383–2395.
Importance: Vitreous hemorrhage from proliferative diabetic retinopathy can cause loss of vision. The best management approach is unknown. Objective: To compare initial treatment with intravitreous aflibercept vs vitrectomy with panretinal photocoagulation for vitreous hemorrhage from proliferative diabetic retinopathy. Design, Setting, and Participants: Randomized clinical trial at 39 DRCR Retina Network sites in the US and Canada including 205 adults with vison loss due to vitreous hemorrhage from proliferative diabetic retinopathy who were enrolled from November 2016 to December 2017. The final follow-up visit was completed in January 2020. Interventions: Random assignment of eyes (1 per participant) to aflibercept (100 participants) or vitrectomy with panretinal photocoagulation (105 participants). Participants whose eyes were assigned to aflibercept initially received 4 monthly injections. Both groups could receive aflibercept or vitrectomy during follow-up based on protocol criteria. Main Outcomes and Measures: The primary outcome was mean visual acuity letter score (range, 0-100; higher scores indicate better vision) over 24 weeks (area under the curve); the study was powered to detect a difference of 8 letters. Secondary outcomes included mean visual acuity at 4 weeks and 2 years. Results: Among 205 participants (205 eyes) who were randomized (mean [SD] age, 57 [11] years; 115 [56%] men; mean visual acuity letter score, 34.5 [Snellen equivalent, 20/200]), 95% (195 of 205) completed the 24-week visit and 90% (177 of 196, excluding 9 deaths) completed the 2-year visit. The mean visual acuity letter score over 24 weeks was 59.3 (Snellen equivalent, 20/63) (95% CI, 54.9 to 63.7) in the aflibercept group vs 63.0 (Snellen equivalent, 20/63) (95% CI, 58.6 to 67.3) in the vitrectomy group (adjusted difference, -5.0 [95% CI, -10.2 to 0.3], P = .06). Among 23 secondary outcomes, 15 showed no significant difference. The mean visual acuity letter score was 52.6 (Snellen equivalent, 20/100) in the aflibercept group vs 62.3 (Snellen equivalent, 20/63) in the vitrectomy group at 4 weeks (adjusted difference, -11.2 [95% CI, -18.5 to -3.9], P = .003) and 73.7 (Snellen equivalent, 20/40) vs 71.0 (Snellen equivalent, 20/40) at 2 years (adjusted difference, 2.7 [95% CI, -3.1 to 8.4], P = .36). Over 2 years, 33 eyes (33%) assigned to aflibercept received vitrectomy and 34 eyes (32%) assigned to vitrectomy received subsequent aflibercept. Conclusions and Relevance: Among participants whose eyes had vitreous hemorrhage from proliferative diabetic retinopathy, there was no statistically significant difference in the primary outcome of mean visual acuity letter score over 24 weeks following initial treatment with intravitreous aflibercept vs vitrectomy with panretinal photocoagulation. However, the study may have been underpowered, considering the range of the 95% CI, to detect a clinically important benefit in favor of initial vitrectomy with panretinal photocoagulation. Trial Registration: ClinicalTrials.gov Identifier: NCT02858076.
McKay T, Guo X, Hutcheon A, Karamichos D, Ciolino J. Methods for Investigating Corneal Cell Interactions and Extracellular Vesicles In Vitro. Curr Protoc Cell Biol. 2020;89(1):e114.
Science and medicine have become increasingly "human-centric" over the years. A growing shift away from the use of animals in basic research has led to the development of sophisticated in vitro models of various tissues utilizing human-derived cells to study physiology and disease. The human cornea has likewise been modeled in vitro using primary cells derived from corneas obtained from cadavers or post-transplantation. By utilizing a cell's intrinsic ability to maintain its tissue phenotype in a pre-designed microenvironment containing the required growth factors, physiological temperature, and humidity, tissue-engineered corneas can be grown and maintained in culture for relatively long periods of time on the scale of weeks to months. Due to its transparency and avascularity, the cornea is an optimal tissue for studies of extracellular matrix and cell-cell interactions, toxicology and permeability of drugs, and underlying mechanisms of scarring and tissue regeneration. This paper describes methods for the cultivation of corneal keratocytes, fibroblasts, epithelial, and endothelial cells for in vitro applications. We also provide detailed, step-by-step protocols for assembling and culturing 3D constructs of the corneal stroma, epithelial- and endothelial-stromal co-cultures and isolation of extracellular vesicles. © 2020 Wiley Periodicals LLC. Basic Protocol 1: Isolating and culturing human corneal keratocytes and fibroblasts Basic Protocol 2: Isolating and culturing human corneal epithelial cells Basic Protocol 3: Isolating and culturing human corneal endothelial cells Basic Protocol 4: 3D corneal stromal construct assembly Basic Protocol 5: 3D corneal epithelial-stromal construct assembly Basic Protocol 6: 3D corneal endothelial-stromal construct assembly Basic Protocol 7: Isolating extracellular vesicles from corneal cell conditioned medium Support Protocol: Cryopreserving human corneal fibroblasts, corneal epithelial cells, and corneal endothelial cells.
The vasa hyaloidea propria, a component of the fetal hyaloidal vasculature, is characterized by multiple persistent fetal vasculatures branching into the vitreous. We present a 4-month-old girl with stage 4 familial exudative vitreoretinopathy, with multiple ectopic retinal vessels extending into the vitreous, confirmed with fluorescein angiography, which was consistent with persistent vasa hyaloidea propia/retinae making contact with the retina. The patient underwent vitreoretinal surgery to address the retinal detachment, during which the patent stalks of the persistent vasa hyaloidea propia/retinae were transected.
Silpa-Archa S, Dejkong A, Kumsiang K, Chotcomwongse P, Preble J, Foster S. Poor prognostic factors in post-traumatic endophthalmitis following open globe injury. Int J Ophthalmol. 2020;13(12):1968–1975.
AIM: To demonstrate prognostic factors for poor visual outcome in patients with post-traumatic endophthalmitis (PTE) following open globe injury. METHODS: A retrospective study was conducted on 66 patients (66 eyes) with PTE following open globe injury from 2005 to 2015. Potential factors accounting for good and poor visual outcome were statistically analyzed by Chi-square test and Logistic regression model. RESULTS: In 66 cases, 39 cases (59%) had a poor visual outcome. Univariate and multivariate Logistic regression analysis identified retained intraocular foreign body (IOFB) as the only factor significantly associated with poor visual outcome [adjusted odds ratio, 4.62; 95% confidence interval (1.04-20.53); =0.04]. The most common causative agents were gram-positive organisms (83%), of which (33%), was the most common pathogen. All cases received intravitreal antibiotic injections. Oral ciprofloxacin was the most used systemic antibiotic (33%). Pars plana vitrectomy was performed in 83% (55/66) of cases. At 6mo follow-up, mean BCVA was 1.74±0.72 logMAR units. CONCLUSION: In patients with PTE following open globe injury, the only predictor of poor visual outcome is the presence of IOFB. is the most isolated microorganism.
Chen X, Amorim J, Moustafa G, Lee JJ, Yu Z, Ishihara K, Iesato Y, Barbisan P, Ueta T, Togka K, Lu L, Sinclair D, Vavvas D. Neuroprotective effects and mechanisms of action of nicotinamide mononucleotide (NMN) in a photoreceptor degenerative model of retinal detachment. Aging (Albany NY). 2020;12.
Currently, no pharmacotherapy has been proven effective in treating photoreceptor degeneration in patients. Discovering readily available and safe neuroprotectants is therefore highly sought after. Here, we investigated nicotinamide mononucleotide (NMN), a precursor of nicotinamide adenine dinucleotide (NAD), in a retinal detachment (RD) induced photoreceptor degeneration. NMN administration after RD resulted in a significant reduction of TUNEL photoreceptors, CD11b macrophages, and GFAP labeled glial activation; a normalization of protein carbonyl content (PCC), and a preservation of the outer nuclear layer (ONL) thickness. NMN administration significantly increased NAD levels, SIRT1 protein expression, and heme oxygenase-1 (HO-1) expression. Delayed NMN administration still exerted protective effects after RD. Mechanistic studies using 661W cells revealed a SIRT1/HO-1 signaling as a downstream effector of NMN-mediated protection under oxidative stress and LPS stimulation. In conclusion, NMN administration exerts neuroprotective effects on photoreceptors after RD and oxidative injury, suggesting a therapeutic avenue to treating photoreceptor degeneration.
Singh T, Ichhpujani P, Singh RB. First Line of Defense in COVID-19: Masks in Clinical Practice. Asia Pac J Public Health. 2020;:1010539520979928.
The current evidence suggests that masks are efficacious in limiting the transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV2). Although cloth masks are effective in outdoor environments, there is a consensus about the requirement of N95 masks or respirators when working in close proximity to patients who may be asymptomatic carriers, specifically in ophthalmology clinics, where slit-lamp examinations, noncontact tonometry, and other procedures place the physicians and patients in close proximity with each other. In this report, we review the available evidence regarding the efficacy of different types of masks in clinical practice in ophthalmology.
Dee EC, Mitchell WG, D’Amico A. Enabling hope. Lancet Oncol. 2020;21(12):e549.
Tripathy K, Ying H, Maldonado Cerda A, Filipowicz A, Kaya M, Seymen Z, Anesi S, Chang P, Foster CS. Widefield Fundus Fluorescein Angiography Features of Uveitis Associated with Juvenile Idiopathic Arthritis. Ocul Immunol Inflamm. 2020;:1–10.
PURPOSE: To evaluate the wide-field fundus fluorescein angiography (WFA) characteristics of uveitis associated with juvenile idiopathic arthritis (JIA-uveitis). METHODS: Retrospective review of records. WFA with Spectralis (Heidelberg) of JIA-uveitis patients were analyzed using the scoring system by Angiography Scoring for Uveitis Nomenclature. RESULTS: Thirty-seven eyes of 20 patients were studied. A total score of at least 1 was noted in 27 eyes (72.97%). WFA features included optic disc hyperfluorescence (51.35%), macular leakage (27.03%), retinal vascular staining/leakage at posterior pole (27.03%) and peripheral retina (64.86%), capillary leakage at the posterior pole (37.84%), and peripheral retina (59.46%). A decision to change the management plan was made in 8 of 9 patients with bilateral quiet anterior chambers after WFA results. CONCLUSION: More than 70% of JIA-uveitis eyes showed some WFA-evidence of posterior segment inflammation, which changed the course of therapy for a major proportion of patients with no clinically active anterior chamber inflammation.