Calpain-specific breakdown fragment in human drusen.

Purpose: With aging and age-related macular dystrophy (AMD), proteolytic fragments are deposited in extracellular drusen located between the RPE and Bruch's membrane. Localized hypoxia may be a risk factor for AMD. Our hypothesis is that following hypoxia, activation of proteolytic enzymes called calpains may cause proteolysis/degeneration of retinal cells and RPE.

GCL loss in BRAO.

Purpose: Our recent publication used optical coherence tomography (OCT) to follow thinning of the retinal ganglion cell layer (GCL) in central retinal artery occlusion (CRAO). Thinning of the inner layers also occurs in patients with branch retinal artery occlusion (BRAO). The mechanism for such thinning may be partially due to proteolysis by a calcium-activated protease called calpain.

A descriptive analysis of predoctoral surgical requirements in US dental schools in 2020.

Objectives: This study aims to describe surgical graduation requirements in US dental schools in 2020, including changes made due to the COVID-19 pandemic.

Methods: Representatives of Commission on Dental Accreditation-approved predoctoral dental programs in the US (n = 66) received a 13-item questionnaire about operative and observational surgical requirements. Responses were assigned values to tabulate a surgical score (zero- to eight-point scale) as a proxy for required surgical experience, and statistical analyses were performed to explore for predictors.

Segmenting OCT for detecting drug efficacy in CRAO.

Purpose: Thinning of the inner layers of the retina occurs in patients with central retinal artery occlusion (CRAO). The mechanism for such thinning may be partially due to proteolysis by a calcium-activated protease called calpain. Calpain inhibitor SNJ-1945 ameliorated the proteolysis in a past series of model experiments.

Activation of Cytosolic Calpain, Not Caspase, Is Underlying Mechanism for Hypoxic RGC Damage in Human Retinal Explants.

Purpose: Activation of proteolytic enzymes, calpains and caspases, have been observed in many models of retinal disease. We previously demonstrated calpain activation in monkey retinal explants cultured under hypoxia. However, cellular responses are often species-specific.

Contribution of Calpain and Caspases to Cell Death in Cultured Monkey RPE Cells.

Purpose: AMD is the leading cause of human vision loss after 65 years of age. Several mechanisms have been proposed: (1) age-related failure of the choroidal vasculature leads to loss of RPE; (2) RPE dysfunctions due to accumulation of phagocytized, but unreleased A2E (N-retinylidene-N-retinylethanolamine); (3) zinc deficiency activation of calpain and caspase proteases, leading to cell death. The purpose of the present study is to compare activation of calpain and caspase in monkey RPE cells cultured under hypoxia or with A2E.

Selecting Fuchs patients for drug trials involving endothelial cell proliferation.

Purpose: Fuchs endothelial corneal dystrophy (FECD) might be managed by drug treatment before becoming severe enough to require surgery. For a clinical trial of such a drug, we hypothesize that selecting an adequate number of patients with FECD with only moderately compromised cell densities will be challenging. Thus, the purpose of the present study was to measure the prevalence of patients with FECD exhibiting moderately decreased corneal cell densities.

FK962 induces neurite outgrowth in cultured monkey trigeminal ganglion cells.

Purpose: Corneal sensation, cell proliferation, and wound healing all depend on adequate corneal innervation. Disruption of corneal innervation can lead to dry eye and delayed wound healing. Our studies in rats and rabbits show that the substituted fluorobenzamide drug FK962 accelerates the extension of neuronal processes and recovery of corneal sensitivity.

Hypoxia Activates Calpains in the Nerve Fiber Layer of Monkey Retinal Explants.

Purpose: The vascular ischemic hypothesis attributes nerve damage in the retina to decreased blood flow in the ophthalmic artery, reduced oxygenation, and impaired axonal transport. Activation of calpain enzymes contributes to retinal cell death during hypoxia. However, we still do not know in which specific retinal layers calpains are activated.

Galectin-3 enhances extracellular matrix associations and wound healing in monkey corneal epithelium.

Poor healing of epithelial wounds in cornea is a major clinical problem, leading to persistent epithelial defects and ulceration. The primary cause is poor cell migration over the wound. Carbohydrate-binding protein galectin-3 binds to extracellular matrixes (ECMs) and promotes lamellipodia formation by cross-linking to α3 integrin.

Loss of calpastatin leads to activation of calpain in human lens epithelial cells.

Purpose: Activation of calpains (calpain 2 and Lp82) in rodent lenses readily causes proteolysis and cataract formation. In contrast, primate lenses are quite resistant to activation of calpains. The hypothesis is that high levels of human endogenous calpain inhibitor, calpastatin (CS), prevent calpain activation in human lenses.

Dry eye in LASIK patients.

Background: Increasing age is a known risk factor for developing dry eye. The specific aims of the present study were to determine the prevalence of dry eye syndrome (DES) and use of post-operative dry eye medications in a relatively young population presenting for LASIK surgery at an academic ophthalmology clinic.

Findings: A retrospective, analysis of 948 de-identified patient charts (median age 39 years, not age stratified) was performed to extract pre-LASIK diagnoses and post-LASIK medication lists.

Mechanism for laser-induced neovascularization in rat choroid: accumulation of integrin α chain-positive cells and their ligands.

Purpose: Inhibitors binding to integrins α5 and αv are antiangiogenic in models of choroidal neovascularization (CNV). However, a comprehensive understanding of the accumulation of integrin α isoform-positive cells, their ligands, and associations is limited. The purpose of the present study was to examine the localization of integrin α chain-positive cells and their extracellular matrix (ECM) ligands in the RPE/choroid after laser injury.

Degeneration and dysfunction of retinal neurons in acute ocular hypertensive rats: involvement of calpains.

Purpose: Retinal ischemic diseases primarily lead to damage of the inner retinal neurons. Electrophysiological studies also suggest impairment of the inner retinal neurons. Our recent studies with acute ocular hypertensive rats confirmed damage predominantly in the inner retinal layer along with the ganglion cell layer, changes that are ameliorated by the calpain inhibitor SNJ-1945.

Calpain protease causes hypoxia-induced proteolysis in cultured human retina.

Purpose/aim: Calpain proteases are known to be involved in retinal cell death in animal models. The purpose of the present study was to test for calpain activation in human retinas cultured under hypoxic conditions.

Materials And Methods: Calpain activation was detected by immunoblotting for calpain substrates in human and monkey retinas cultured in gas generating pouches to reduce oxygen.

Serum antibodies against βH-crystallins in the American Cocker Spaniel.

Objective: To detect antibodies for lens βH-crystallins in the serum from the American Cocker Spaniel (ACS) presenting with and without cataracts and with and without uveitis.

Animal Studied: Seventy-three American Cocker Spaniels and six normal Beagles.

Procedures: Sera were collected from 73 ACSs, including those with normal lenses and those with cataracts, or uveitis.

Concerted inhibition of HIF-1α and -2α expression markedly suppresses angiogenesis in cultured RPE cells.

HIF-1α is known to play an important role in the induction of VEGF by hypoxia in retinal pigment epithelial (RPE) cells. However, the involvement of the other isoform, HIF-2α, in RPE cells remains unclear. Thus, the purpose of present study was to clarify the role of HIF-2α during induction of angiogenic genes in hypoxic RPE cells.

Involvement of NFκB in the production of chemokines by rat and human conjunctival cells cultured under allergenic conditions.

Purpose: The purpose of present studies was to determine the involvement of NFκB and STAT6 transcription factors in the production of cytokines by the fibroblasts and epithelial cells in conjunctiva.

Methods: An in vitro model of allergic conjunctivitis was developed by sensitizing and challenging rat mast cells with anti-dinitrophenyl (DNP) IgE and DNP-BSA, and then using the conditioned medium to stimulate rat conjunctival fibroblasts. Chemokines (eotaxin-1, IL-8, and RANTES -- Regulated and Normal T cell Expressed and Secreted) released from cells into the medium was determined by ELISA.

Lacritin-induced secretion of tear proteins from cultured monkey lacrimal acinar cells.

Purpose: During inflammation of the ocular surface, increased proinflammatory cytokines depress tear protein secretion, suggesting that a decline in lacrimal cell function contributes to dry eye. Lacritin, a glycoprotein secreted from lacrimal acinar cells, may function as an autocrine factor to stimulate tear protein secretion. The purpose of the present experiment was to investigate lacritin-induced protein secretion in normal and cytokine-pretreated (inflammation model) monkey acinar cells.

Pituitary adenylate cyclase-activating peptide induces neurite outgrowth in cultured monkey trigeminal ganglion cells: involvement of receptor PAC1.

Purpose: Our previous studies in the rabbit trigeminal nerve (TgN) showed that pituitary adenylate cyclase-activating peptide (PACAP) accelerated the extension of neuronal processes and recovery of corneal sensitivity. The purposes of the present study were 1) develop a procedure to culture trigeminal nerve (TgN) cells from monkeys, 2) test whether PACAP induces sprouting and elongation of axons in our culture system, 3) investigate the signaling mechanisms producing axon elongation induced by PACAP, and 4) test the action of PACAP on tear protein secretion by monkey lacrimal acinar cells.

Methods: Primary cultures of TgN cells were established from rhesus monkeys.

Involvement of calpain 2 in ionomycin-induced cell death in cultured mouse lens epithelial cells.

Purpose: Calpains are calcium-activated, intracellular, non-lysosomal, cysteine proteases that hydrolyze lens crystallins and cytoskeletal proteins. Elevated calcium is a frequent finding in both rodent and human cataracts, and calpain 2 is present in lenses of both species. Lens epithelium forms a critical barrier to influx of calcium, but the role of calpain 2 in lens epithelium is poorly characterized.

Calpain, not caspase, is the causative protease for hypoxic damage in cultured monkey retinal cells.

Purpose: Cell death occurring in human retina during AMD, high IOP, and diabetic retinopathy could be caused by activation of calpain or caspase proteolytic enzymes. The purpose of the present study was to determine whether calpains and/or caspase-3 were involved in cell death during retinal hypoxia in a monkey model.

Methods: Dissociated monkey retinal cells were cultured for two weeks and subjected to 24-hour hypoxia/24-hour reoxygenation.

Patient selection criteria for pilot studies on amelioration of non-neovascular age-related macular degeneration.

Purposes: Non-neovascular age-related macular degeneration (AMD) is characterized by accumulation of macular drusen, changes in pigmentation of the retinal pigment epithelium, and geographic atrophy. The purposes of this study were to (1) measure the rate of progression of non-neovascular AMD and (2) from the rate data, to propose patient selection criteria for testing drugs to prevent progression of non-neovascular AMD.

Methods: Medical charts were searched for all AMD billing codes, consecutively reviewed, and 51 patients with a median age of 76 years were mined for severity of AMD using a standardized worsening scale from 0 to 6, visual acuity (VA, Snellen), medications or procedures to treat eye diseases, date of eye examinations, age, and sex.