Three-Dimensional Extracellular Matrix Protein Hydrogels for Human Trabecular Meshwork Cell Studies.

The extracellular microenvironment plays a crucial role in regulating a wide range of cell behaviors. Biopolymer hydrogels are ideally suited to present a realistic three-dimensional extracellular milieu to cells in vitro. Here, we describe the fabrication and use of soft tissue-mimetic extracellular matrix protein hydrogels for investigations of human trabecular meshwork cell biology.

Targeting YAP/TAZ mechanosignaling to ameliorate stiffness-induced Schlemm's canal cell pathobiology.

Pathological alterations in the biomechanical properties of the Schlemm's canal (SC) inner wall endothelium and its immediate vicinity are strongly associated with ocular hypertension in glaucoma due to decreased outflow facility. Specifically, the underlying trabecular meshwork is substantially stiffer in glaucomatous eyes compared with that from normal eyes. This raises the possibility of a critical involvement of mechanotransduction processes in driving SC cell dysfunction.

Targeting YAP mechanosignaling to ameliorate stiffness-induced Schlemm's canal cell pathobiology.

Pathologic alterations in the biomechanical properties of the Schlemm's canal (SC) inner wall endothelium and its immediate vicinity are strongly associated with ocular hypertension in glaucoma due to decreased outflow facility. Specifically, the underlying trabecular meshwork is substantially stiffer in glaucomatous eyes compared to that from normal eyes. This raises the possibility of a critical involvement of mechanotransduction processes in driving SC cell dysfunction.

Association between Autism Spectrum Disorder (ASD) and vision problems. A systematic review and meta-analysis.

Aim: To conduct a systematic review and meta-analysis assessing whether vision and/or eye disorders are associated with Autism Spectrum Disorder (ASD).

Method: Based on a pre-registered protocol (PROSPERO: CRD42022328485), we searched PubMed, Web of Knowledge/Science, Ovid Medline, Embase and APA PsycINFO up to 5 February 2022, with no language/type of document restrictions. We included observational studies 1) reporting at least one measure of vision in people of any age with a diagnosis of ASD based on DSM or ICD criteria, or ADOS; or 2) reporting the prevalence of ASD in people with and without vision disorders.

Simvastatin Attenuates Glucocorticoid-Induced Human Trabecular Meshwork Cell Dysfunction via YAP/TAZ Inactivation.

Purpose: Impairment of the trabecular meshwork (TM) is the principal cause of increased outflow resistance in the glaucomatous eye. Yes-associated protein (YAP) and transcriptional coactivator with PDZ binding motif (TAZ) are emerging as potential mediators of TM cell/tissue dysfunction. Furthermore, YAP/TAZ activity was recently found to be controlled by the mevalonate pathway in non-ocular cells.

YAP/TAZ Mediate TGFβ2-Induced Schlemm's Canal Cell Dysfunction.

Purpose: Elevated transforming growth factor beta2 (TGFβ2) levels in the aqueous humor have been linked to glaucomatous outflow tissue dysfunction. Potential mediators of dysfunction are the transcriptional coactivators, Yes-associated protein (YAP) and transcriptional coactivator with PDZ binding motif (TAZ). However, the molecular underpinnings of YAP/TAZ modulation in Schlemm's canal (SC) cells under glaucomatous conditions are not well understood.

Association between ADHD and vision problems. A systematic review and meta-analysis.

Aim: To conduct the first systematic review and meta-analysis assessing whether attention-deficit/hyperactivity disorder (ADHD) is associated with disorders of the eye, and/or altered measures of visual function.

Method: Based on a pre-registered protocol (PROSPERO: CRD42021256352), we searched PubMed, Web of Knowledge/Science, Ovid Medline, Embase and APA PsycINFO up to 16th November 2021, with no language/type of document restrictions. We included observational studies reporting at least one measure of vision in people of any age meeting DSM/ICD criteria for ADHD and in people without ADHD; or the prevalence of ADHD in people with and without vision disorders.

Engineering a 3D hydrogel system to study optic nerve head astrocyte morphology and behavior.

In glaucoma, astrocytes within the optic nerve head (ONH) rearrange their actin cytoskeleton, while becoming reactive and upregulating intermediate filament glial fibrillary acidic protein (GFAP). Increased transforming growth factor beta 2 (TGF β2) levels have been implicated in glaucomatous ONH dysfunction. A key limitation of using conventional 2D culture to study ONH astrocyte behavior is the inability to faithfully replicate the in vivo ONH microenvironment.

TGFβ2 Regulates Human Trabecular Meshwork Cell Contractility ERK and ROCK Pathways with Distinct Signaling Crosstalk Dependent on the Culture Substrate.

Purpose: Transforming growth factor-beta 2 (TGFβ2) is a major contributor to the pathologic changes occurring in human trabecular meshwork (HTM) cells in primary open-angle glaucoma (POAG). TGFβ2 activates extracellular-signal-regulated kinase (ERK) and Rho-associated kinase (ROCK) signaling pathways, both affecting HTM cell behavior. However, exactly how these signaling pathways converge to regulate HTM cell contractility is unclear.

Extracellular Matrix Stiffness and TGFβ2 Regulate YAP/TAZ Activity in Human Trabecular Meshwork Cells.

Primary open-angle glaucoma progression is associated with increased human trabecular meshwork (HTM) stiffness and elevated transforming growth factor beta 2 (TGFβ2) levels in the aqueous humor. Increased transcriptional activity of Yes-associated protein (YAP) and transcriptional coactivator with PDZ-binding motif (TAZ), central players in mechanotransduction, are implicated in glaucomatous HTM cell dysfunction. Yet, the detailed mechanisms underlying YAP/TAZ modulation in HTM cells in response to alterations in extracellular matrix (ECM) stiffness and TGFβ2 levels are not well understood.

Consensus Recommendation for Mouse Models of Ocular Hypertension to Study Aqueous Humor Outflow and Its Mechanisms.

Due to their similarities in anatomy, physiology, and pharmacology to humans, mice are a valuable model system to study the generation and mechanisms modulating conventional outflow resistance and thus intraocular pressure. In addition, mouse models are critical for understanding the complex nature of conventional outflow homeostasis and dysfunction that results in ocular hypertension. In this review, we describe a set of minimum acceptable standards for developing, characterizing, and utilizing mouse models of open-angle ocular hypertension.

Mechanosensitive channel inhibition attenuates TGFβ2-induced actin cytoskeletal remodeling and reactivity in mouse optic nerve head astrocytes.

Astrocytes within the optic nerve head undergo actin cytoskeletal rearrangement early in glaucoma, which coincides with astrocyte reactivity and extracellular matrix (ECM) deposition. Elevated transforming growth factor beta 2 (TGFβ2) levels within astrocytes have been described in glaucoma, and TGFβ signaling induces actin cytoskeletal remodeling and ECM deposition in many tissues. A key mechanism by which astrocytes sense and respond to external stimuli is via mechanosensitive ion channels.

A tissue-engineered human trabecular meshwork hydrogel for advanced glaucoma disease modeling.

Abnormal human trabecular meshwork (HTM) cell function and extracellular matrix (ECM) remodeling contribute to HTM stiffening in primary open-angle glaucoma (POAG). Most current cellular HTM model systems do not sufficiently replicate the complex native three dimensional (3D) cell-ECM interface, limiting their use for investigating POAG pathology. Tissue-engineered hydrogels are ideally positioned to overcome shortcomings of current models.

Treatment Duration and Side Effect Profile of Long-Term Use of Intravitreal Preservative-Free Triamcinolone Acetonide in Uveitis.

Purpose: Noninfectious uveitis has been treated historically with corticosteroid therapy in varying doses and routes. Triesence, a preservative-free sterile formulation of triamcinolone acetonide, has been used in a wide spectrum of ocular pathologies, but there have been few large studies validating its dosing or detailing long-term side effects in uveitic disease. The primary aim of this study was to describe the relative duration of action and side effects of 2 doses of preservative-free intravitreal triamcinolone acetonide (PF-IVTA) in uveitis.

Conjunctival squamous papilloma refractory to interferon α-2b in a patient on systemic immunosuppression (tacrolimus).

Purpose: To describe a case of diffuse conjunctival papilloma in an immunocompromised individual on tacrolimus that was refractory to treatment with interferon α-2b, but responded to topical mitomycin-c.

Observations: A 79-year-old Caucasian female with a history of a liver transplant twenty years ago, who was immunosuppressed with tacrolimus (2 mg daily) presented with a diffuse conjunctival and corneal squamous papilloma. Following treatment with four weekly subconjunctival interferon-α2b injections (3 million units/0.

Aggressive Initial Presentation of HLA-B27 Uveitis in Older Individuals: A Case Series.

Purpose: HLA-B27-associated uveitis is classically thought to be a disease of the young, with a median age of onset in the 30s. There is a paucity of literature reporting on older individuals with HLA-B27 uveitis. Here, we describe cases of HLA-B27 uveitis presenting initially at age ≥70.

Safety and Effectiveness of a Small Incision Lateral Eyebrow Ptosis Repair Technique Using a Frontalis Muscle Transposition Flap.

Purpose: To evaluate the safety and effectiveness of a frontalis muscle transposition flap for treatment of lateral eyebrow ptosis.

Methods: The charts of all patients undergoing frontalis muscle transposition flap eyebrow ptosis repair from December 2013 to September 2014 were reviewed. Charts with inadequate photographs were excluded.

Alterations of retinal vasculature in cystathionine-Beta-synthase mutant mice, a model of hyperhomocysteinemia.

Purpose: Mice with moderate/severe hyperhomocysteinemia due to deficiency or absence of the cbs gene encoding cystathionine-beta-synthase (CBS) have marked retinal disruption, ganglion cell loss, optic nerve mitochondrial dysfunction, and ERG defects; those with mild hyperhomocysteinemia have delayed retinal morphological/functional phenotype. Excess homocysteine is a risk factor for cardiovascular diseases; however, it is not known whether excess homocysteine alters retinal vasculature.

Methods: Cbs(+/+), cbs(+/-), and cbs(-/-) mice (age ∼3 weeks) were subjected to angiography; retinas were harvested for cryosections, flat-mount preparations, or trypsin digestion and subjected to immunofluorescence microscopy to visualize vessels using isolectin-B4, to detect angiogenesis using anti-VEGF and anti-endoglin (anti-CD105) and activated glial cells (anti-glial fibrillary acidic protein [anti-GFAP]) and to investigate the blood-retinal barrier using the tight junction markers zonula occludens-1 (ZO-1) and occludin.

Transport of the synthetic opioid peptide DADLE ([D-Ala2,D-Leu5]-enkephalin) in neuronal cells.

The sodium-coupled oligopeptide transporters 1 and 2 (SOPT1 and SOPT2) transport peptides consisting of at least five amino acids and show potential for the delivery of therapeutically relevant peptides/peptidomimetics. Here, we examined the expression of these two transporters in the retinal neuronal cell line RGC-5. These cells showed robust uptake activity for the synthetic pentapeptide DADLE ([D-Ala(2),D-Leu(5)]-Enkephalin).

Homocysteine-mediated modulation of mitochondrial dynamics in retinal ganglion cells.

Purpose: To evaluate the effect of excess homocysteine on the regulation of retinal ganglion cell mitochondrial dynamics.

Methods: Mice deficient in cystathionine-β-synthase (cbs) were used as a model of hyperhomocysteinemia. Gene and protein expression analyses of Opa1 and Fis1 were performed on cbs⁺/⁻ neural retinas.

The role of N-methyl-D-aspartate receptor activation in homocysteine-induced death of retinal ganglion cells.

Purpose: Elevated plasma homocysteine has been implicated in glaucoma, a vision disorder characterized by retinal ganglion cell death. The toxic potential of homocysteine to ganglion cells is known, but the mechanisms are not clear. A mechanism of homocysteine-induced death of cerebral neurons is via N-methyl-D-aspartate (NMDA) receptor overstimulation, leading to excess calcium influx and oxidative stress.

Molecular and biochemical characterization of folate transport proteins in retinal Müller cells.

Purpose: To analyze the mechanisms of folate uptake in retinal Müller cells.

Methods: RT-PCR and Western blot analysis were performed in freshly isolated neural retina and RPE/eyecup, primary mouse Müller cells, and rMC-1 cells for the three known folate transport proteins folate receptor alpha (FRalpha), proton-coupled folate transporter (PCFT), and reduced folate carrier (RFC). Laser scanning confocal microscopy (LSCM) and immunoelectron microscopy were used to determine the subcellular location of FRalpha and PCFT in primary Müller cells.

Sensitivity of staurosporine-induced differentiated RGC-5 cells to homocysteine.

Purpose: Homocysteine is implicated in ganglion cell death associated with glaucoma. To understand mechanisms of homocysteine-induced cell death, we analyzed the sensitivity of the RGC-5 cell line, differentiated using staurosporine, to physiologically-relevant levels of the excitotoxic amino acid homocysteine.

Methods: RGC-5 cells were differentiated 24 hr using 316 nM staurosporine and tested for expression of Thy 1.