Intranasal Resveratrol Nanoparticles Enhance Neuroprotection in a Model of Multiple Sclerosis.

PURPOSE: Resveratrol is a natural polyphenol which has a very low bioavailability but whose antioxidant, anti-inflammatory and anti-apoptotic properties may have therapeutic potential for the treatment of neurodegenerative diseases such as multiple sclerosis (MS). Previously, we reported the oral administration of resveratrol nanoparticles (RNs) elicited a neuroprotective effect in an experimental autoimmune encephalomyelitis (EAE) mouse model of MS, at significantly lower doses than unconjugated resveratrol (RSV) due to enhanced bioavailability. Furthermore, we demonstrated that the intranasal administration of a cell-derived secretome-based therapy at low concentrations leads to the selective neuroprotection of the optic nerve in EAE mice. The current study sought to assess the potential selective efficacy of lower concentrations of intranasal RNs for attenuating optic nerve damage in EAE mice. METHODS: EAE mice received either a daily intranasal vehicle, RNs or unconjugated resveratrol (RSV) for a period of thirty days beginning on the day of EAE induction. Mice were assessed daily for limb paralysis and weekly for visual function using the optokinetic response (OKR) by observers masked to treatment regimes. After sacrifice at day 30, spinal cords and optic nerves were stained to assess inflammation and demyelination, and retinas were immunostained to quantify retinal ganglion cell (RGC) survival. RESULTS: Intranasal RNs significantly increased RGC survival at half the dose previously shown to be required when given orally, reducing the risk of systemic side effects associated with prolonged use. Both intranasal RSV and RN therapies enhanced RGC survival trends, however, only the effects of intranasal RNs were significant. RGC loss was prevented even in the presence of inflammatory and demyelinating changes induced by EAE in optic nerves. CONCLUSIONS: The intranasal administration of RNs is able to reduce RGC loss independent of the inflammatory and demyelinating effects on the optic nerve and the spinal cord. The concentration of RNs needed to achieve neuroprotection is lower than previously demonstrated with oral administration, suggesting intranasal drug delivery combined with nanoparticle conjugation warrants further exploration as a potential neuroprotective strategy for the treatment of optic neuritis, alone as well as in combination with glucocorticoids.

Comparison of Brn3a and RBPMS Labeling to Assess Retinal Ganglion Cell Loss During Aging and in a Model of Optic Neuropathy.

Purpose: Retinal ganglion cell (RGC) loss provides the basis for diagnosis and stage determination of many optic neuropathies, and quantification of RGC survival is a critical outcome measure in models of optic neuropathy. This study examines the accuracy of manual RGC counting using two selective markers, Brn3a and RBPMS. Methods: Retinal flat mounts from 1- to 18-month-old C57BL/6 mice, and from mice after microbead (MB)-induced intraocular pressure (IOP) elevation, are immunostained with Brn3a and/or RBPMS antibodies. Four individuals masked to the experimental conditions manually counted labeled RGCs in three copies of five images, and inter- and intra-person reliability was evaluated by the intraclass correlation coefficient (ICC). Results: A larger population (approximately 10% higher) of RGCs are labeled with RBPMS than Brn3a antibody up to 6 months of age, but differences decrease to approximately 1% at older ages. Both RGC-labeled populations significantly decrease with age. MB-induced IOP elevation is associated with a significant decrease of both Brn3a- and RBPMS-positive RGCs. Notably, RGC labeling with Brn3a provides more consistent cell counts than RBPMS in interpersonal (ICC = 0.87 to 0.11, respectively) and intra-personal reliability (ICC = 0.97 to 0.66, respectively). Conclusions: Brn3a and RBPMS markers are independently capable of detecting significant decreases of RGC number with age and in response to IOP elevation despite RPBMS detecting a larger number of RGCs up to 6 months of age. Brn3a labeling is less prone to manual cell counting variability than RBPMS labeling. Overall, either marker can be used as a single marker to detect significant changes in RGC survival, each offering distinct advantages.

AAV2 vector optimization for retinal ganglion cell-targeted delivery of therapeutic genes.

Recombinant adeno-associated virus (AAV)-2 has significant potential as a delivery vehicle of therapeutic genes to retinal ganglion cells (RGCs), which are key interventional targets in optic neuropathies. Here we show that when injected intravitreally, AAV2 engineered with a reporter gene driven by cytomegalovirus (CMV) enhancer and chicken ß-actin (CBA) promoters, displays ubiquitous and high RGC expression, similar to its synthetic derivative AAV8BP2. A novel AAV2 vector combining the promoter of the human RGC-selective γ-synuclein (hSNCG) gene and woodchuck hepatitis post-transcriptional regulatory element (WPRE) inserted upstream and downstream of a reporter gene, respectively, induces widespread transduction and strong transgene expression in RGCs. High transduction efficiency and selectivity to RGCs is further achieved by incorporating in the vector backbone a leading CMV enhancer and an SV40 intron at the 5' and 3' ends, respectively, of the reporter gene. As a delivery vehicle of hSIRT1, a 2.2-kb therapeutic gene with anti-apoptotic, anti-inflammatory and anti-oxidative stress properties, this recombinant vector displayed improved transduction efficiency, a strong, widespread and selective RGC expression of hSIRT1, and increased RGC survival following optic nerve crush. Thus, AAV2 vector carrying hSNCG promoter with additional regulatory sequences may offer strong potential for enhanced effects of candidate gene therapies targeting RGCs.

Emerging Gene Therapy Technologies for Retinal Ganglion Cell Neuroprotection.

ABSTRACT: Optic neuropathies encompass a breadth of diseases that ultimately result in dysfunction and/or loss of retinal ganglion cells (RGCs). Although visual impairment from optic neuropathies is common, there is a lack of effective clinical treatments. Addressing a critical need for novel interventions, preclinical studies have been generating a growing body of evidence that identify promising new drug-based and cell-based therapies. Gene therapy is another emerging therapeutic field that offers the potential of specifically and robustly increasing long-term RGC survival in optic neuropathies. Gene therapy offers additional benefits of driving improvements following a single treatment administration, and it can be designed to target a variety of pathways that may be involved in individual optic neuropathies or across multiple etiologies. This review explores the history of gene therapy, the fundamentals of its application, and the emerging development of gene therapy technology as it relates to treatment of optic neuropathies.

A Randomized Prospective Trial Comparing Repository Corticotropin Injection and Intravenous Methylprednisolone for Neuroprotection in Acute Optic Neuritis.

BACKGROUND: Repository corticotrophin injection (RCI, Acthar Gel) and intravenous methylprednisolone (IVMP) improve the rate but not the extent of visual recovery following acute optic neuritis. RCI has adrenal-stimulating and melanocortin receptor-stimulating properties that may endow it with unique anti-inflammatory properties relative to IVMP. METHODS: Individuals with acute optic neuritis of less than 2 weeks duration were prospectively enrolled and randomized 1:1 to receive either RCI or IVMP. Peripapillary retinal nerve fiber layer (pRNFL) and ganglion cell plus inner plexiform layer thickness (GC + IPL) were serially evaluated by OCT. In addition, patient-reported outcomes (PROs) for changes in fatigue, mood, visual function, depression, and quality of life (QOL) were measured, and high and low contrast visual acuity were recorded. RESULTS: Thirty-seven subjects were enrolled (19 RCI; 18 IVMP); the average time from symptom to treatment was 8.8 days. At 6 months, there was no difference in the primary outcome: loss of average pRNFL thickness in the affected eye (RCI vs IVMP: -13.1 vs -11.7 µm, P = 0.88) 6 months after randomization. Additional outcomes also showed no difference between treatment groups: 6-month attenuation of GC + IPL thickness (RCI vs IVMP: -13.8 vs -12.0 µm, P = 0.58) and frequency of pRNFL swelling at 1 month (RCI vs IVMP: 63% vs 72%, P = 0.73) and 3 months (RCI vs IVMP: 26% vs 31%, P = 0.99). Both treatments resulted in improvement in visual function and PROs. CONCLUSIONS: Treatment of acute optic neuritis with RCI or IVMP produced no clinically meaningful differences in optic nerve structure or visual function.

Nanoparticles Enhance Solubility and Neuroprotective Effects of Resveratrol in Demyelinating Disease.

Resveratrol is a natural polyphenol which may be useful for treating neurodegenerative diseases such as multiple sclerosis (MS). To date, current immunomodulatory treatments for MS aim to reduce inflammation with limited effects on the neurodegenerative component of this disease. The purpose of the current study is to develop a novel nanoparticle formulation of resveratrol to increase its solubility, and to assess its ability to prevent optic nerve and spinal cord degeneration in an experimental autoimmune encephalomyelitis (EAE) mouse model of MS. Resveratrol nanoparticles (RNs) were made using a thin rehydration technique. EAE mice received a daily oral administration of vehicle, RNs or unconjugated resveratrol for one month. They were assessed daily for clinical signs of paralysis and weekly for their visual acuity with optokinetic responses (OKR). After one month, their spinal cords and optic nerves were stained for inflammation and demyelination and retinal ganglion cells immunostained for Brn3a. RNs were stable for three months. The administration of RNs did not have any effect on clinical manifestation of EAE and did not preserve OKR scores but reduced the intensity of the disease. It did not reduce inflammation and demyelination in the spinal cord and the optic nerve. However, RNs were able to decrease RGC loss compared to the vehicle. Results demonstrate that resveratrol is neuroprotective by reducing RGC loss. Interestingly, neuroprotective effects and decreased disease severity occurred without reduction of inflammation or demyelination, suggesting this therapy may fill an unmet need to limit the neurodegenerative component of MS.

Cell-Specific Expression of Human SIRT1 by Gene Therapy Reduces Retinal Ganglion Cell Loss Induced by Elevated Intraocular Pressure.

SIRT1 prevents retinal ganglion cell (RGC) loss in several acute and subacute optic neuropathy models following pharmacologic activation or genetic overexpression. We hypothesized that adeno-associated virus (AAV)-mediated overexpression of SIRT1 in RGCs in a chronic ocular hypertension model can reduce RGC loss, thereby preserving visual function by sustained therapeutic effect. A control vector AAV-eGFP and therapeutic vector AAV-SIRT1 were constructed and optimized for transduction efficiency. A magnetic microbead mouse model of ocular hypertension was optimized to induce a time-dependent and chronic loss of visual function and RGC degeneration. Mice received intravitreal injection of control or therapeutic AAV in which a codon-optimized human SIRT1 expression is driven by a RGC selective promoter. Intraocular pressure (IOP) was measured, and visual function was examined by optokinetic response (OKR) weekly for 49 days following microbead injection. Visual function, RGC survival, and axon numbers were compared among control and therapeutic AAV-treated animals. AAV-eGFP and AAV-SIRT1 showed transduction efficiency of ~ 40%. AAV-SIRT1 maintains the transduction of SIRT1 over time and is selectively expressed in RGCs. Intravitreal injections of AAV-SIRT1 in a glaucoma model preserved visual function, increased RGC survival, and reduced axonal degeneration compared with the control construct. Over-expression of SIRT1 through AAV-mediated gene transduction indicates a RGC-selective component of neuroprotection in multiple models of acute optic nerve degeneration. Results here show a neuroprotective effect of RGC-selective gene therapy in a chronic glaucoma model characterized by sustained elevation of IOP and subsequent RGC loss. Results suggest that this strategy may be an effective therapeutic approach for treating glaucoma, and warrants evaluation for the treatment of other chronic neurodegenerative diseases.

Frequency and Etiologies of Visual Disturbance After Cataract Surgery Identified in Neuro-Ophthalmology Clinics.

BACKGROUND: To identify the frequency and etiologies of visual disturbances after cataract surgery in patients referred to Neuro-ophthalmology. METHODS: This study is a retrospective chart review. Records of patients 18 years and older referred to neuro-ophthalmology clinics for new-onset visual disturbances within 6 months of cataract surgery were reviewed. Those with pre-existing neuro-ophthalmic disorders, combined intraocular procedures with cataract surgery, or inadequate follow-up were excluded. The main outcome measures were frequency and etiologies of visual disturbances after cataract surgery. Secondary analyses of a cohort of patients who had cataract surgery at our institution were performed to determine the frequency and etiology of visual disturbances after uneventful cataract surgery. RESULTS: One hundred seventy-three patients met the inclusion criteria (internal referral: 36/173, from outside surgeons: 137/173). Sixty-one percent (106/173) were newly diagnosed with neuro-ophthalmic etiologies, including 21% (36/173) with afferent and 40% (70/173) with efferent disorders. Thirty-six percent (62/173) of patients had non neuro-ophthalmic causes and 3% (5/173) had systemic conditions responsible for visual disturbances postoperatively. Decompensated strabismus causing diplopia was the most common neuro-ophthalmic diagnosis after cataract surgery (50%, 53/106). Of the 13,715 patients who had cataract surgery performed at our institution over a 9-year period, 20 of 36 patients referred for visual disturbances were identified with neuro-ophthalmic etiologies of which 85% (17/20) had postoperative diplopia. CONCLUSIONS: In our study, decompensated strabismus causing diplopia was the most common neuro-ophthalmic visual disturbance after cataract surgery. Detailed history and ocular alignment should be assessed before cataract surgery to identify patients with the risk.

Repeat Brn3a immunolabeling rescues faded staining and improves detection of retinal ganglion cells.

Immunofluorescence is used in numerous research areas including eye research to detect specific antigens in cells and tissues. One limitation is that fluorescent signal can fade, causing detection problems if data recording was not completed in a timely manner or if additional data acquisition is required. The ability to repeat immunostaining for the same antigen after initial fluorescence has faded may require time-consuming and potentially damaging steps to remove primary antibodies. Our studies assessed whether immunofluorescence could be reapplied to previously labeled retinal ganglion cells (RGCs). To examine whether immunostaining of Brn3a, a commonly used RGC marker, could be repeated in retinas with previously faded immunostaining, retinal whole mounts were labeled with anti-Brn3a primary antibodies and green fluorescent secondary antibodies, then allowed to fade over time. Faded retinas were restained with anti-Brn3a antibody followed by secondary antibody, or with secondary antibody alone. Results show restaining with anti-Brn3a primary antibody followed by Alexa-fluor green secondary antibody is effective for RGC detection. Repeat RGC labeling improved the clarity of staining compared with original staining prior to fading, with significant reduction in the percentage of blurry/out of focus fluorescent cells (6 vs 26%); whereas, repeat application of secondary antibody alone was not effective. Preflattening retinas under a coverslip prior to initial Brn3a staining also increased the clarity of staining, and facilitated significantly more accurate automated counting of RGCs. Findings suggest Brn3a antigen remains accessible for repeat immunofluorescence labeling after original staining fades. Staining retinas after flattening tissue may enhance the clarity of staining and accuracy of automated RGC counting. Repeat immunofluorescence staining, without the need to strip off prior bound antibodies, may be useful in other tissues as well and warrants future examination.

Resolution of COVID-19 induced anosmia following treatment with ST266.

Background: Persistent anosmia following COVID-19 disease affects a significant subset of patients. Symptoms of this olfactory dysfunction negatively impact patient quality of life, and effective treatments are lacking; therefore, novel therapies that restore the ability to smell have tremendous clinical potential. Case report: A 46-year-old female enrolled in a phase I clinical trial to assess the safety of targeted intranasal administration of a novel acellular secretome therapy (ST266) in patients diagnosed as glaucoma suspects. The patient reported greater than one year history of loss of smell that started following a presumed positive case of COVID-19. Following a 28-day treatment course of bilateral intranasal administration of ST266, the patient had resolution of her long-standing anosmia. Conclusion: This case demonstrates resolution of COVID-19-induced persistent anosmia after intranasal treatment with a novel acellular secretome therapy. Further studies are warranted to determine the potential of ST266 and its components to treat anosmia.

Selective Upregulation of SIRT1 Expression in Retinal Ganglion Cells by AAV-Mediated Gene Delivery Increases Neuronal Cell Survival and Alleviates Axon Demyelination Associated with Optic Neuritis.

Optic neuritis (ON), the most common ocular manifestation of multiple sclerosis, is an autoimmune inflammatory demyelinating disease also characterized by degeneration of retinal ganglion cells (RGCs) and their axons, which commonly leads to visual impairment despite attempted treatments. Although ON disease etiology is not known, changes in the redox system and exacerbated optic nerve inflammation play a major role in the pathogenesis of the disease. Silent information regulator 1 (sirtuin-1/SIRT1) is a ubiquitously expressed NAD+-dependent deacetylase, which functions to reduce/prevent both oxidative stress and inflammation in various tissues. Non-specific upregulation of SIRT1 by pharmacologic and genetic approaches attenuates RGC loss in experimental ON. Herein, we hypothesized that targeted expression of SIRT1 selectively in RGCs using an adeno-associated virus (AAV) vector as a delivery vehicle is an effective approach to reducing neurodegeneration and preserving vision in ON. We tested this hypothesis through intravitreal injection of AAV7m8.SNCG.SIRT1, an AAV2-derived vector optimized for highly efficient SIRT1 transgene transfer and protein expression into RGCs in mice with experimental autoimmune encephalomyelitis (EAE), a model of multiple sclerosis that recapitulates optic neuritis RGC loss and axon demyelination. Our data show that EAE mice injected with a control vehicle exhibit progressive alteration of visual function reflected by decreasing optokinetic response (OKR) scores, whereas comparatively, AAV7m8.SNCG.SIRT1-injected EAE mice maintain higher OKR scores, suggesting that SIRT1 reduces the visual deficit imparted by EAE. Consistent with this, RGC survival determined by immunolabeling is increased and axon demyelination is decreased in the AAV7m8.SNCG.SIRT1 RGC-injected group of EAE mice compared to the mouse EAE counterpart injected with a vehicle or with control vector AAV7m8.SNCG.eGFP. However, immune cell infiltration of the optic nerve is not significantly different among all EAE groups of mice injected with either vehicle or AAV7m8.SNCG.SIRT1. We conclude that despite minimally affecting the inflammatory response in the optic nerve, AAV7m8-mediated SIRT1 transfer into RGCs has a neuroprotective potential against RGC loss, axon demyelination and vison deficits associated with EAE. Together, these data suggest that SIRT1 exerts direct effects on RGC survival and function.

Azadirachta indica A. Juss bark extract and its Nimbin isomers restrict ß-coronaviral infection and replication.

Emerging mutations in the SARS-CoV-2 genome pose a challenge for vaccine development and antiviral therapy. The antiviral efficacy of Azadirachta indica bark extract (NBE) was assessed against SARS-CoV-2 and m-CoV-RSA59 infection. Effects of in vivo intranasal or oral NBE administration on viral load, inflammatory response, and histopathological changes were assessed in m-CoV-RSA59-infection. NBE administered inhibits SARS-CoV-2 and m-CoV-RSA59 infection and replication in vitro, reducing Envelope and Nucleocapsid gene expression. NBE ameliorates neuroinflammation and hepatitis in vivo by restricting viral replication and spread. Isolated fractions of NBE enriched in Nimbin isomers shows potent inhibition of m-CoV-RSA59 infection in vitro. In silico studies revealed that NBE could target Spike and RdRp of m-CoV and SARS-CoV-2 with high affinity. NBE has a triterpenoids origin that may allow them to competitively target panoply of viral proteins to inhibit mouse and different strains of human coronavirus infections, suggesting its potential as an antiviral against pan-ß-Coronaviruses.

CD40L protects against mouse hepatitis virus-induced neuroinflammatory demyelination.

Neurotropic mouse hepatitis virus (MHV-A59/RSA59) infection in mice induces acute neuroinflammation due to direct neural cell dystrophy, which proceeds with demyelination with or without axonal loss, the pathological hallmarks of human neurological disease, Multiple sclerosis (MS). Recent studies in the RSA59-induced neuroinflammation model of MS showed a protective role of CNS-infiltrating CD4+ T cells compared to their pathogenic role in the autoimmune model. The current study further investigated the molecular nexus between CD4+ T cell-expressed CD40Ligand and microglia/macrophage-expressed CD40 using CD40L-/- mice. Results demonstrate CD40L expression in the CNS is modulated upon RSA59 infection. We show evidence that CD40L-/- mice are more susceptible to RSA59 induced disease due to reduced microglia/macrophage activation and significantly dampened effector CD4+ T recruitment to the CNS on day 10 p.i. Additionally, CD40L-/- mice exhibited severe demyelination mediated by phagocytic microglia/macrophages, axonal loss, and persistent poliomyelitis during chronic infection, indicating CD40-CD40L as host-protective against RSA59-induced demyelination. This suggests a novel target in designing prophylaxis for virus-induced demyelination and axonal degeneration, in contrast to immunosuppression which holds only for autoimmune mechanisms of inflammatory demyelination.

Socioeconomic and Geographic Disparities in Idiopathic Intracranial Hypertension.

OBJECTIVE: To identify relationships between idiopathic intracranial hypertension (IIH) and socioeconomic determinants of health, such as low-income status and proximity to healthy food. METHODS: This retrospective case-control study of adult female neuro-ophthalmology patients from one institution identified 223 women with and 4,783 women without IIH. Street addresses were geocoded and merged with US census data to obtain census tract-level information on income and food access. Choropleth maps visualized IIH clusters within certain neighborhoods. Logistic regression compared the proportion of patients with IIH from racial and ethnic minority backgrounds, low-income census tracts, and food deserts and swamps to controls without IIH. RESULTS: In our cohort, when adjusted for age, women with IIH were more likely to be Black (odds ratio [OR] 3.96, 95% confidence interval [CI] 2.98-5.25), Hispanic (OR 2.23, 95% CI 1.14-4.36), and live in low-income tracts (OR 2.24, 95% CI 1.71-2.95) or food swamps (OR 1.54, 95% CI 1.15-2.07). Patients with IIH were less likely to live in food deserts than controls (OR 0.61, 95% CI 0.45-0.83). The association between Black race and IIH remained significant even after adjusting for other variables. CONCLUSION: IIH is more common among Black and Hispanic women than expected even when accounting for the demographics of a metropolitan city. Some of this relationship is driven by the association of obesity and IIH incidence with low income and proximity to unhealthy foods.

Rescue of retinal ganglion cells in optic nerve injury using cell-selective AAV mediated delivery of SIRT1.

SIRT1 prevents retinal ganglion cell (RGC) loss in models of optic neuropathy following pharmacologic activation or genetic overexpression. The exact mechanism of loss is not known, prior evidence suggests this is through oxidative stress to either neighboring cells or RGC specifically. We investigated the neuroprotective potential of RGC-selective SIRT1 gene therapy in the optic nerve crush (ONC) model. We hypothesized that AAV-mediated overexpression of SIRT1 in RGCs reduces RGC loss, thereby preserving visual function. Cohorts of C57Bl/6J mice received intravitreal injection of experimental or control AAVs using either a ganglion cell promoter or a constitutive promoter and ONC was performed. Visual function was examined by optokinetic response (OKR) for 7 days following ONC. Retina and optic nerves were harvested to investigate RGC survival by immunolabeling. The AAV7m8-SNCG.SIRT1 vector showed 44% transduction efficiency for RGCs compared with 25% (P > 0.05) by AAV2-CAG.SIRT1, and AAV7m8-SNCG.SIRT1 drives expression selectively in RGCs in vivo. Animals modeling ONC demonstrated reduced visual acuity compared to controls. Intravitreal delivery of AAV7m8-SNCG.SIRT1 mediated significant preservation of the OKR and RGC survival compared to AAV7m8-SNCG.eGFP controls, an effect not seen with the AAV2 vector. RGC-selective expression of SIRT1 offers a targeted therapy for an animal model with significant ganglion cell loss. Over-expression of SIRT1 through AAV-mediated gene transduction suggests a RGC selective component of neuro-protection using the ONC model. This study expands our understanding of SIRT1 mediated neuroprotection in the context of compressive or traumatic optic neuropathy, making it a strong therapeutic candidate for testing in all optic neuropathies.

RGC and Vision Loss From Traumatic Optic Neuropathy Induced by Repetitive Closed Head Trauma Is Dependent on Timing and Force of Impact.

Purpose: Traumatic optic neuropathy (TON) is often caused by blunt head trauma and has no currently effective treatment. Common animal models of TON induced by surgical crush injury are plagued by variability and do not mimic typical mechanisms of TON injury. Traumatic head impact models have recently shown evidence of TON, but the degree of head impact necessary to consistently induce TON is not well characterized, and it is examined here. Methods: Traumatic skull impacts to C57BL/6J mice were induced using an electromagnetic controlled impact device. One impact performed at two depths (mild and severe), as well as three and five repetitive impacts with an interconcussion interval of 48 hours, were tested. Optokinetic responses (OKRs) and retinal ganglion cell (RGC) loss were measured. Results: Five repetitive mild impacts significantly decreased OKR scores and RGC numbers compared with control mice 10 weeks after initial impact, with maximal pathology observed by 6 weeks and partial but significant loss present by 3 weeks. One severe impact induced similar TON. Three mild impacts also induced early OKR and RGC loss, but one mild impact did not. Equivalent degrees of TON were induced bilaterally, and a significant correlation was observed between OKR scores and RGC numbers. Conclusions: Repetitive, mild closed head trauma in mice induces progressive RGC and vision loss that worsens with increasing impacts. Translational Relevance: Results detail a reproducible model of TON that provides a reliable platform for studying potential treatments over a 3- to 6-week time course.

The sensitivity and specificity of retinal and choroidal folds to distinguish between mild papilloedema and pseudopapilledema.

PURPOSE: To determine if the presence or absence of retinal and choroidal folds on SD-OCT imaging can distinguish between mild papilloedema and pseudopapilledema. DESIGN: Cross-sectional cohort study METHODS: Subjects with optic disc elevation (Frisen grades 1 and 2 only) were eligible to be enrolled prospectively. Pseudopapilledema was defined as a lack of change in optic disc appearance between two visits <6 months apart, and papilloedema was defined as change in optic disc appearance between two visits <6 months apart determined by review of fundus photographs by a masked neuro-ophthalmologist. Three masked neuro-ophthalmologists independently reviewed en face and axial optical coherence tomography (OCT) images of the optic nerve of the study subjects for the presence or absence of retinal and choroidal folds. Concordance was determined when there was agreement between at least 2 of the 3 observers. RESULTS: Forty-five subjects (78 eyes) met inclusion criteria. There were 32 eyes with papilloedema and 46 eyes with pseudopapilledema. Choroidal and/or retinal folds were detected in 38% of eyes (12/32) with papilloedema and 19.6% of eyes (9/46) with pseudopapilledema. Post-hoc analyses eliminated six questionable cases of pseudopapilledema that had ancillary testing suggestive of elevated intracranial pressure and resulted in one remaining eye (2%) with more certain pseudopapilledema that was found to have folds. En face OCT imaging was more sensitive (71%) in detection of folds than axial OCT imaging (57%). CONCLUSIONS: Choroidal and/or retinal folds on OCT are commonly observed in patients with mild papilloedema and are uncommon in those with pseudopapilledema. The presence of folds on OCT in patients presenting with disc elevation suggests papilloedema.

Neuroprotection mediated by ST266 requires full complement of proteins secreted by amnion-derived multipotent progenitor cells.

ST266 is the biological secretome of cultured Amnion-derived Multipotent Progenitor cells containing multiple growth factors and cytokines. While intranasally-administered ST266 improves the phenotype in experimental optic neuritis, specific ST266 components mediating these effects are not known. We compared the effects of ST266 with and without removal of large molecular weight proteins both in vitro and in the multiple sclerosis model experimental autoimmune encephalomyelitis (EAE) in C57BL/6J mice. Mice were treated daily with intranasal vehicle, ST266 or lower molecular weight fraction of ST266. Retinal ganglion cells were counted in isolated retinas, and optic nerves were assessed for inflammation and demyelination. ST266 treatment significantly improved retinal ganglion cell survival and reduced optic nerve demyelination in EAE mice. The lower molecular weight ST266 fraction significantly improved optic nerve demyelination, but only showed a trend towards improved retinal ganglion cell survival. ST266 fractions below 50kDa increased Schwann cell proliferation in vitro, but were less effective than non-fractionated ST266. Demyelination attenuation was partially associated with the lower molecular weight ST266 fraction, but removal of higher molecular weight biomolecules from ST266 diminishes its neuroprotective effects, suggesting at least some high molecular weight proteins play a role in ST266-mediated neuroprotection.

Amnion-Derived Multipotent Progenitor Cells Suppress Experimental Optic Neuritis and Myelitis.

The human amnion has been used for decades in wound healing, particularly burns. Amnion epithelial cells (AECs) have been the focus of extensive research based on their possible pluripotent differentiation ability. A novel, cultured cell population derived from AECs, termed human amnion-derived multipotent progenitor (AMP) cells, secrete numerous cytokines and growth factors that enhance tissue regeneration and reduce inflammation. This AMP cell secretome, termed ST266, is a unique biological solution that accumulates in eyes and optic nerves following intranasal delivery, resulting in selective suppression of optic neuritis in the experimental autoimmune encephalomyelitis (EAE) model of multiple sclerosis, but not myelitis at the administered dose. We tested the hypothesis that systemic AMP cell administration could suppress both optic neuritis and myelitis in EAE. Intravenous and intraperitoneal administration of AMP cells significantly reduced ascending paralysis and attenuated visual dysfunction in EAE mice. AMP cell treatment increased retinal ganglion cell (RGC) survival and decreased optic nerve inflammation, with variable improvement in optic nerve demyelination and spinal cord inflammation and demyelination. Results show systemic AMP cell administration inhibits RGC loss and visual dysfunction similar to previously demonstrated effects of intranasally delivered ST266. Importantly, AMP cells also promote neuroprotective effects in EAE spinal cords, marked by reduced paralysis. Protective effects of systemically administered AMP cells suggest they may serve as a potential novel treatment for multiple sclerosis.