Epigenetic adaptation drives monocyte differentiation into microglia-like cells upon engraftment into the retina.

The identification of specific markers for microglia has been a long-standing challenge. Recently, markers such as P2ry12, TMEM119, and Fcrls have been proposed as microglia-specific and widely used to explore microglial functions within various central nervous system (CNS) contexts. The specificity of these markers was based on the assumption that circulating monocytes retain their distinct signatures even after infiltrating the CNS.

Frequency of Agreement Between Structural and Functional Glaucoma Testing: A Longitudinal Study of 3D OCT and Current Clinical Tests.

Purpose: To evaluate how often tests of structure and function detect glaucoma progression at the same study visit. Tests include current glaucoma clinical tests and a new 3-dimensional (3D) optical coherence tomography (OCT) rim measurement.

Design: Prospective cohort study.

Steroid Response Following Dropless Cataract Surgery Using Subconjunctival Triamcinolone.

Purpose: To assess the rates of postoperative steroid response following dropless cataract surgery using a subconjunctival depot of triamcinolone versus conventional cataract surgery using topical prednisolone.

Patients And Methods: We reviewed consecutive cataract surgery cases performed by a single surgeon to determine the likelihood of steroid response, defined as intraocular pressure (IOP) 50% above baseline or IOP > 24 mmHg postoperatively, excluding the first 72 hours. Logistic regression models were performed including baseline characteristics as exposures in the model and steroid response as the outcome.

APOE4 impairs the microglial response in Alzheimer's disease by inducing TGFβ-mediated checkpoints.

The APOE4 allele is the strongest genetic risk factor for late-onset Alzheimer's disease (AD). The contribution of microglial APOE4 to AD pathogenesis is unknown, although APOE has the most enriched gene expression in neurodegenerative microglia (MGnD). Here, we show in mice and humans a negative role of microglial APOE4 in the induction of the MGnD response to neurodegeneration.

Neurofilament Light Chain in Aqueous Humor as a Marker of Neurodegeneration in Glaucoma.

Purpose: Neurofilament light chain (NfL) is a neuronal cytoskeletal protein that has been identified as a marker of neurodegeneration in diseases of the central nervous system. In this study, we investigated whether NfL in the aqueous humor (AH) can serve as a marker of neurodegeneration in glaucoma in a racially diverse North American population.

Design: Single-center, case-control study.

Identification of a protective microglial state mediated by miR-155 and interferon-γ signaling in a mouse model of Alzheimer's disease.

Microglia play a critical role in brain homeostasis and disease progression. In neurodegenerative conditions, microglia acquire the neurodegenerative phenotype (MGnD), whose function is poorly understood. MicroRNA-155 (miR-155), enriched in immune cells, critically regulates MGnD.

Myeloid masquerade: Microglial transcriptional signatures in retinal development and disease.

Microglia are dynamic guardians of neural tissue and the resident immune cells of the central nervous system (CNS). The disease-associated microglial signature (DAM), also known as the microglial neurodegenerative phenotype (MGnD), has gained significant attention in recent years as a fundamental microglial response common to various neurodegenerative disease pathologies. Interestingly, this signature shares many features in common with developmental microglia, suggesting the existence of recycled gene programs which play a role both in early neural circuit formation as well as in response to aging and disease.

Neurodegeneration Markers Galectin-3 and Apolipoprotein E Are Elevated in the Aqueous Humor of Eyes With Glaucoma.

Purpose: Galectin-3 (Gal-3) and apolipoprotein E (APOE) are markers of activated microglia in neurodegenerative diseases of the central nervous system, whose targeting is protective in mouse models of glaucoma. In this study, we examined levels of Gal-3 and APOE in human aqueous humor (AH) and defined their clinical associations with glaucoma.

Methods: We collected AH from 59 glaucoma patients and 15 controls at the start of planned ophthalmic surgery.

Regulating microglial miR-155 transcriptional phenotype alleviates Alzheimer's-induced retinal vasculopathy by limiting Clec7a/Galectin-3 neurodegenerative microglia.

Single cell RNA sequencing studies identified novel neurodegeneration-associated microglial (MGnD/DAM) subtypes activated around cerebral amyloid plaques. Micro-RNA (miR)-155 of the TREM2-APOE pathway was shown to be a key transcriptional regulator of MGnD microglial phenotype. Despite growing interest in studying manifestations of Alzheimer's disease (AD) in the retina, a CNS organ accessible to noninvasive high-resolution imaging, to date MGnD microglia have not been studied in the AD retina.

Apolipoprotein E4 impairs the response of neurodegenerative retinal microglia and prevents neuronal loss in glaucoma.

The apolipoprotein E4 (APOE4) allele is associated with an increased risk of Alzheimer disease and a decreased risk of glaucoma, but the underlying mechanisms remain poorly understood. Here, we found that in two mouse glaucoma models, microglia transitioned to a neurodegenerative phenotype characterized by upregulation of Apoe and Lgals3 (Galectin-3), which were also upregulated in human glaucomatous retinas. Mice with targeted deletion of Apoe in microglia or carrying the human APOE4 allele were protected from retinal ganglion cell (RGC) loss, despite elevated intraocular pressure (IOP).

The Prevalence of Autoimmune Diseases in Patients with Primary Open-Angle Glaucoma Undergoing Ophthalmic Surgeries.

Purpose: To assess the prevalence of autoimmune disease (AiD) in patients with primary open-angle glaucoma (POAG) undergoing ophthalmic surgery.

Design: Retrospective, cross-sectional study.

Participants: Patients with POAG undergoing any ophthalmic surgery and control subjects undergoing cataract surgery at the Massachusetts Eye and Ear from March 2019 to April 2020.

Disc Hemorrhages Are Associated With Localized Three-Dimensional Neuroretinal Rim Thickness Progression in Open-Angle Glaucoma.

Purpose: To evaluate the relationship between the occurrence of optic disc hemorrhages (DH) and glaucoma progression as determined by multiple glaucoma testing modalities.

Design: Prospective cohort study.

Methods: A longitudinal study was undertaken of 124 open-angle glaucoma patients who had yearly disc photography, visual fields (VFs), spectral-domain optical coherence tomography (SD-OCT), retinal nerve fiber layer (RNFL) thickness scans, and optic nerve volume scans (Spectralis), all performed on the same day over a 5-year period.

Earlier Detection of Glaucoma Progression Using High-Density 3-Dimensional Spectral-Domain OCT Optic Nerve Volume Scans.

Purpose: To compare onset times of glaucoma progression among different glaucoma tests: disc photography (DP), visual field (VF) testing, 2-dimensional (2D) retinal nerve fiber layer (RNFL) thickness, and 3-dimensional (3D) spectral-domain (SD) OCT neuroretinal rim measurements.

Design: Prospective, longitudinal cohort study.

Participants: One hundred twenty-four eyes of 124 patients with open-angle glaucoma.

CD163+ macrophages infiltrate axon bundles of postmortem optic nerves with glaucoma.

Purpose: Prior research in animal models has shown that macrophages and microglia play an important role in pathogenesis of glaucoma, but the phenotype and distribution of macrophages in human glaucomatous tissue have not been sufficiently characterized.

Methods: We analyzed H&E, CD68-, and CD163-immunostained slides from 25 formaldehyde-fixed, paraffin-embedded autopsy eyes: 12 control eyes and 13 eyes with glaucoma. The diagnosis of glaucoma was made based on a history of glaucoma as reported in the medical record and histological changes characteristic of glaucoma.

Staying away from the optic nerve: a formula for modifying glaucoma drainage device surgery in pediatric and other small eyes.

Purpose: To provide guidelines for safe implantation of glaucoma drainage devices (GDDs) in small and pediatric eyes to avoid contact between the optic nerve (ON) and the posterior edge of the GDD plate.

Methods: We developed a formula for calculating limbus-to-ON distance to estimate the available "real estate" for GDD placement in small eyes. The formula was validated using eyes of pediatric decedents undergoing clinical autopsy, with axial lengths (AL) of 15-24 mm.

Molecular mechanisms of synaptic specificity.

Synapses are specialized junctions that mediate information flow between neurons and their targets. A striking feature of the nervous system is the specificity of its synaptic connections: an individual neuron will form synapses only with a small subset of available presynaptic and postsynaptic partners. Synaptic specificity has been classically thought to arise from homophilic or heterophilic interactions between adhesive molecules acting across the synaptic cleft.

Clathrin adaptor AP-1 complex excludes multiple postsynaptic receptors from axons in C. elegans.

Neurons are highly polarized cells with morphologically and molecularly distinct axonal and dendritic compartments. It is not well understood how postsynaptic receptors are selectively enriched in dendrites in vivo. We investigated the molecular mechanisms of dendritically polarized localization of a glutamate receptor, an acetylcholine receptor, and a ROR-type receptor tyrosine kinase in the interneuron RIA in C.

Building a synapse: lessons on synaptic specificity and presynaptic assembly from the nematode C. elegans.

Synapses are specialized sites of cell contact that mediate information flow between neurons and their targets. Genetic screens in the nematode C. elegans have led to the discovery of a number of molecules required for synapse patterning and assembly.