Prominin-1 Knockdown Causes RPE Degeneration in a Mouse Model.

There are currently no effective treatments for retinal pigment epithelial (RPE) cell loss in atrophic AMD (aAMD). However, our research on (), a known structural protein in photoreceptors (PRs), has revealed its distinct role in RPE and offers promising insights. While pathogenic mutations have been linked to macular diseases with RPE atrophy, the broader physiological impact of dysfunctional in RPE loss is unclear.

Pilot Safety Study of a Microfabricated Device for Anterior Stromal Puncture to Treat Corneal Epithelial Disease in the Optical Axis.

Purpose: Anterior stromal puncture is an inexpensive and widely used technique at the slit lamp to treat recurrent corneal erosions (RCE), common sequelae of corneal abrasions, trauma, and epithelial basement membrane dystrophies (EBMDs). The purpose of this study was to determine safety of a novel anterior stromal micropuncture device (termed a "plexitome") for use in the optical axis of the cornea.

Methods: We performed an IRB-approved clinical pilot study on 45 patients with diverse corneal pathologies to determine the safety of the plexitome device and examined corneal healing responses clinically for a minimum of 30 days after treatment.

A Microfluidic Platform for the Time-Resolved Interrogation of Polarized Retinal Pigment Epithelial Cells.

Purpose: Cells grown in milliliter volume devices have difficulty measuring low-abundance secreted factors due to low resulting concentrations. Using microfluidic devices increases concentration; however, the constrained geometry makes phenotypic characterization with transepithelial electrical resistance more difficult and less reliable. Our device resolves this problem.

Loss of Prom1 impairs autophagy and promotes epithelial-mesenchymal transition in mouse retinal pigment epithelial cells.

Mutations in the Prominin-1 (Prom1) gene disrupt photoreceptor disk morphogenesis, leading to macular dystrophies. We have shown that human retinal pigment epithelial (RPE) homeostasis is under the control of Prom1-dependent autophagy, demonstrating that Prom1 plays different roles in the photoreceptors and RPE. It is unclear if retinal and macular degeneration caused by the loss of Prom1 function is a cell-autonomous feature of the RPE or a generalized disease of photoreceptor degeneration.

Modeling of mitochondrial bioenergetics and autophagy impairment in MELAS-mutant iPSC-derived retinal pigment epithelial cells.

Background: Mitochondrial dysfunction and mitochondrial DNA (mtDNA) damage in the retinal pigment epithelium (RPE) have been implicated in the pathogenesis of age-related macular degeneration (AMD). However, a deeper understanding is required to determine the contribution of mitochondrial dysfunction and impaired mitochondrial autophagy (mitophagy) to RPE damage and AMD pathobiology. In this study, we model the impact of a prototypical systemic mitochondrial defect, mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes (MELAS), in RPE health and homeostasis as an in vitro model for impaired mitochondrial bioenergetics.

STAT3 suppresses the AMPKα/ULK1-dependent induction of autophagy in glioblastoma cells.

Despite advances in molecular characterization, glioblastoma (GBM) remains the most common and lethal brain tumour with high mortality rates in both paediatric and adult patients. The signal transducer and activator of transcription 3 (STAT3) is an important oncogenic driver of GBM. Although STAT3 reportedly plays a role in autophagy of some cells, its role in cancer cell autophagy remains unclear.

Electrochemical sensor for tricyclic antidepressants with low nanomolar detection limit: Quantitative Determination of Amitriptyline and Nortriptyline in blood.

Amitriptyline and its metabolite, Nortriptyline are commonly used tricyclic antidepressant (TCA) drugs that are electrochemically active. In this work, the performance characteristics of a plasticized PVC membrane-coated glassy carbon (GC) electrode are described for the voltammetric quantification of Amitriptyline and Nortriptyline in whole blood. The highly lipophilic Amitriptyline and Nortriptyline preferentially partition into the plasticized PVC membrane where the free drug is oxidized on the GC electrode.

Polymeric membrane-modified voltammetric sensors for lipophilic analytes with nanomolar detection limit: Key parameters influencing the response characteristics.

Thin plasticized PVC membrane-coated glassy carbon working electrodes have been used for the voltammetric measurement of highly lipophilic, electroactive drugs. Compared to conventional working electrodes, these membrane-coated electrodes exhibit remarkable detection limit and selectivity and are less prone to electrode fouling. The unique performance characteristics of these sensors are related to the large partition coefficient of the analyte in the membrane coating where it is oxidized in a non-aqueous membrane phase.

A "Smart" Biosensor-Enabled Intravascular Catheter and Platform for Dynamic Delivery of Propofol to "Close the Loop" for Total Intravenous Anesthesia.

Background: Target-controlled infusion anesthesia is used worldwide to provide user-defined, stable, blood concentrations of propofol for sedation and anesthesia. The drug infusion is controlled by a microprocessor that uses population-based pharmacokinetic data and patient biometrics to estimate the required infusion rate to replace losses from the blood compartment due to drug distribution and metabolism. The objective of the research was to develop and validate a method to detect and quantify propofol levels in the blood, to improve the safety of propofol use, and to demonstrate a pathway for regulatory approval for its use in the USA.

Plasticized PVC Membrane Modified Electrodes: Voltammetry of Highly Hydrophobic Compounds.

In the last 50 years, plasticized polyvinyl chloride (PVC) membranes have gained unique importance in chemical sensor development. Originally, these membranes separated two solutions in conventional ion-selective electrodes. Later, the same membranes were applied over a variety of supporting electrodes and used in both potentiometric and voltammetric measurements of ions and electrically charged molecules.

Preclinical Studies of a Novel Microfabricated Device to Treat Corneal Epithelial Disease.

Purpose: Anterior stromal puncture is an inexpensive technique for treating recurrent corneal erosions but is often ineffective and cannot be used in the optical axis because of scarring. These studies tested a novel microfabricated imprinting instrument to assess its potential efficacy for the treatment of corneal epithelial disease in the optical axis.

Methods: The device is made using glass rods, bundled and drawn through multiple iterative cycles, and then fused under high heat to generate a solid rod comprised of many parallel, aligned, cladded fibers.

Knockdown of survivin results in inhibition of epithelial to mesenchymal transition in retinal pigment epithelial cells by attenuating the TGFβ pathway.

Proliferative vitreoretinopathy (PVR) is a common complication of open globe injury and the most common cause of failed retinal detachment surgery. The response by retinal pigment epithelial (RPE) cells liberated into the vitreous includes proliferation and migration; most importantly, epithelial to mesenchymal transition (EMT) of RPE plays a central role in the development and progress of PVR. For the first time, we show that knockdown of BIRC5, a member of the inhibitor of apoptosis protein family, using either lentiviral vector based CRISPR/Cas9 nickase gene editing or inhibition of survivin using the small-molecule inhibitor YM155, results in the suppression of EMT in RPE cells.

Recent Advances in Retinal Stem Cell Therapy.

Purpose Of Review: Progress in stem cell research for blinding diseases over the past decade is now being applied to patients with retinal degenerative diseases and soon perhaps, glaucoma. However, the field still has much to learn about the conversion of stem cells into various retinal cell types, and the potential delivery methods that will be required to optimize the clinical efficacy of stem cells delivered into the eye.

Recent Findings: Recent groundbreaking human clinical trials have demonstrated both the opportunities and current limitations of stem cell transplantation for retinal diseases.

Prominin-1 Is a Novel Regulator of Autophagy in the Human Retinal Pigment Epithelium.

Purpose: Prominin-1 (Prom1) is a transmembrane glycoprotein, which is expressed in stem cell lineages, and has recently been implicated in cancer stem cell survival. Mutations in the Prom1 gene have been shown to disrupt photoreceptor disk morphogenesis and cause an autosomal dominant form of Stargardt-like macular dystrophy (STGD4). Despite the apparent structural role of Prom1 in photoreceptors, its role in other cells of the retina is unknown.

Lentiviral CRISPR/Cas9 vector mediated miR-21 gene editing inhibits the epithelial to mesenchymal transition in ovarian cancer cells.

CRISPR/Cas9 (clustered regularly interspaced short palindromic repeats) mediated genome editing is a powerful approach for loss of function studies. Here we report that lentiviral CRISPR/Cas9 vectors are highly efficient in introducing mutations in the precursor miRNA sequence, thus leading to the loss of miRNA expression and function. We constructed four different lentiviral CRISPR/Cas9 vectors that target different regions of the precursor miR-21 sequence and found that these lentiviral CRISPR/Cas9 miR-21 gRNA vectors induced mutations in the precursor sequences as shown by DNA surveyor mutation assay and Sanger sequencing.

Novel Small Molecule JP-153 Targets the Src-FAK-Paxillin Signaling Complex to Inhibit VEGF-Induced Retinal Angiogenesis.

Targeting vascular endothelial growth factor (VEGF) is a common treatment strategy for neovascular eye disease, a major cause of vision loss in diabetic retinopathy and age-related macular degeneration. However, the decline in clinical efficacy over time in many patients suggests that monotherapy of anti-VEGF protein therapeutics may benefit from adjunctive treatments. Our previous work has shown that through decreased activation of the cytoskeletal protein paxillin, growth factor-induced ischemic retinopathy in the murine oxygen-induced retinopathy model could be inhibited.

A Feedback Control Approach to Organic Drug Infusions Using Electrochemical Measurement.

Goal: Target-controlled infusion of anesthesia is a closed-loop automated drug delivery method with a computer-aided control. Our goal is to design and test an automated drug infusion platform for propofol delivery in total intravenous anesthesia (TIVA) administration.

Methods: In the proposed method, a dilution chamber with first-order exponential decay characteristics was used to model the pharmacodynamics decay of a drug.

Propofol detection and quantification in human blood: the promise of feedback controlled, closed-loop anesthesia.

The performance of a membrane-coated voltammetric sensor for propofol (2,6-diisopropylphenol) has been characterized in long term monitoring experiments using an automated flow analytical system (AFAS) and by analyzing human serum and whole blood samples by standard addition. It is shown that the signal of the membrane-coated electrochemical sensor for propofol is not influenced by the components of the pharmaceutical formulation of propofol (propofol injectable emulsion). The current values recorded with the electrochemical propofol sensor in buffer solutions and human serum samples spiked with propofol injectable emulsion showed excellent correlation with the peak heights recorded with an UV-Vis detector during the HPLC analysis of these samples (R(2) = 0.

Automated detection of microaneurysms using scale-adapted blob analysis and semi-supervised learning.

Despite several attempts, automated detection of microaneurysm (MA) from digital fundus images still remains to be an open issue. This is due to the subtle nature of MAs against the surrounding tissues. In this paper, the microaneurysm detection problem is modeled as finding interest regions or blobs from an image and an automatic local-scale selection technique is presented.