Corneal Endothelial-like Cells Derived from Induced Pluripotent Stem Cells for Cell Therapy.

Corneal endothelial dysfunction is one of the leading causes of corneal blindness, and the current conventional treatment option is corneal transplantation using a cadaveric donor cornea. However, there is a global shortage of suitable donor graft material, necessitating the exploration of novel therapeutic approaches. A stem cell-based regenerative medicine approach using induced pluripotent stem cells (iPSCs) offers a promising solution, as they possess self-renewal capabilities, can be derived from adult somatic cells, and can be differentiated into all cell types including corneal endothelial cells (CECs).

Culture of Primary Neurons from Dissociated and Cryopreserved Mouse Trigeminal Ganglion.

Corneal nerves originate from the ophthalmic branch of the trigeminal nerve, which enters the cornea at the limbus radially from all directions toward the central cornea. The cell bodies of the sensory neurons of trigeminal nerve are located in the trigeminal ganglion (TG), while the axons are extended into the three divisions, including ophthalmic branch that supplies corneal nerves. Study of primary neuronal cultures established from the TG fibers can therefore provide a knowledge basis for corneal nerve biology and potentially be developed as an platform for drug testing.

Early Visibility of Cellular Aggregates and Changes in Central Corneal Thickness as Predictors of Successful Corneal Endothelial Cell Injection Therapy.

(1) Background: Cell injection therapy is an emerging treatment for bullous keratopathy (BK). Anterior segment optical coherence tomography (AS-OCT) imaging allows the high-resolution assessment of the anterior chamber. Our study aimed to investigate the predictive value of the visibility of cellular aggregates for corneal deturgescence in an animal model of bullous keratopathy.

Effects of Rho-Associated Kinase (Rock) Inhibitors (Alternative to Y-27632) on Primary Human Corneal Endothelial Cells.

(1) Rho-associated coiled-coil protein kinase (ROCK) signaling cascade impacts a wide array of cellular events. For cellular therapeutics, scalable expansion of primary human corneal endothelial cells (CECs) is crucial, and the inhibition of ROCK signaling using a well characterized ROCK inhibitor (ROCKi) Y-27632 had been shown to enhance overall endothelial cell yield. (2) In this study, we compared several classes of ROCK inhibitors to both ROCK-I and ROCK-II, using in silico binding simulation.

Release of frustration drives corneal amyloid disaggregation by brain chaperone.

TGFBI-related corneal dystrophy (CD) is characterized by the accumulation of insoluble protein deposits in the corneal tissues, eventually leading to progressive corneal opacity. Here we show that ATP-independent amyloid-β chaperone L-PGDS can effectively disaggregate corneal amyloids in surgically excised human cornea of TGFBI-CD patients and release trapped amyloid hallmark proteins. Since the mechanism of amyloid disassembly by ATP-independent chaperones is unknown, we reconstructed atomic models of the amyloids self-assembled from TGFBIp-derived peptides and their complex with L-PGDS using cryo-EM and NMR.

New Therapies for Corneal Endothelial Diseases: 2020 and Beyond.

Penetrating keratoplasty used to be the only surgical technique for the treatment of end-stage corneal endothelial diseases. Improvements in surgical techniques over the past decade have now firmly established endothelial keratoplasty as a safe and effective modality for the treatment of corneal endothelial diseases. However, there is a worldwide shortage of corneal tissue, with more than 50% of the world having no access to cadaveric tissue.

Translational and Regulatory Challenges of Corneal Endothelial Cell Therapy: A Global Perspective.

Cell therapies are emerging as a unique class of clinical therapeutics in medicine. In 2015, Holoclar ( expanded autologous human corneal epithelial cells containing stem cells) gained the regulatory approval for treating limbal stem cell deficiency after chemical eye burn. This has set a precedent in ophthalmology and in medicine, reinforcing the therapeutic promise of cell therapy.

Automated Clinical Assessment of Corneal Guttae in Fuchs Endothelial Corneal Dystrophy.

Purpose: To describe the validation and implementation of an automated system for the detection and quantification of guttae in Fuchs endothelial corneal dystrophy (FECD).

Design: Observational reliability study.

Methods: Patients with FECD underwent retroillumination corneal photography, followed by determination of the distributions and sizes of corneal guttae by an automated image analysis algorithm.

Phenotypic and functional characterization of corneal endothelial cells during in vitro expansion.

The advent of cell culture-based methods for the establishment and expansion of human corneal endothelial cells (CEnC) has provided a source of transplantable corneal endothelium, with a significant potential to challenge the one donor-one recipient paradigm. However, concerns over cell identity remain, and a comprehensive characterization of the cultured CEnC across serial passages has not been performed. To this end, we compared two established CEnC culture methods by assessing the transcriptomic changes that occur during in vitro expansion.

Effect of osmolytes on in-vitro aggregation properties of peptides derived from TGFBIp.

Protein aggregation has been one of the leading triggers of various disease conditions, such as Alzheimer's, Parkinson's and other amyloidosis. TGFBI-associated corneal dystrophies are protein aggregation disorders in which the mutant TGFBIp aggregates and accumulates in the cornea, leading to a reduction in visual acuity and blindness in severe cases. Currently, the only therapy available is invasive and there is a known recurrence after surgery.

Optimisation of Storage and Transportation Conditions of Cultured Corneal Endothelial Cells for Cell Replacement Therapy.

As the cornea is one of the most transplanted tissues in the body it has placed a burden on the provision of corneas from cadaveric donors. Corneal endothelial dysfunction is the leading indication for cornea transplant. Therefore, tissue engineering is emerging as an alternative approach to overcome the global shortage of transplant-grade corneas.

Descemet Membrane Endothelial Keratoplasty With a Pull-Through Insertion Device: Surgical Technique, Endothelial Cell Loss, and Early Clinical Results.

Purpose: To describe a surgical technique for Descemet membrane endothelial keratoplasty (DMEK) using a pull-through, endothelium-in insertion device, the DMEK EndoGlide. We evaluated the endothelial cell loss (ECL) associated with the EndoGlide-DMEK (E-DMEK) technique in both ex vivo and prospective clinical studies.

Methods: The ex vivo study involved calcein acetoxymethyl staining and preparation of DMEK grafts, which were trifolded endothelium-in, loaded into the EndoGlide, pulled through, and unfolded in imaging dishes.

Peroxiredoxin-1 regulates lipid peroxidation in corneal endothelial cells.

Corneal transparency is maintained by a monolayer of corneal endothelial cells. Defects in corneal endothelial cells (CEnCs) can be rectified surgically through transplantation. Fuchs' endothelial corneal dystrophy (FECD) is the foremost cause of endothelial dysfunction and the leading indication for transplantation.

Defective cell adhesion function of solute transporter, SLC4A11, in endothelial corneal dystrophies.

Corneal endothelial cell (CEnC) loss is often associated with blinding endothelial corneal dystrophies: dominantly inherited, common (5%) Fuchs endothelial corneal dystrophy (FECD) and recessive, rare congenital hereditary endothelial dystrophy (CHED). Mutations of SLC4A11, an abundant corneal solute transporter, cause CHED and some cases of FECD. The link between defective SLC4A11 solute transport function and CEnC loss is, however, unclear.

Characterization of Human Transition Zone Reveals a Putative Progenitor-Enriched Niche of Corneal Endothelium.

The corneal endothelium regulates corneal hydration to maintain the transparency of cornea. Lacking regenerative capacity, corneal endothelial cell loss due to aging and diseases can lead to corneal edema and vision loss. There is limited information on the existence of corneal endothelial progenitors.

Ultrathin, Strong, and Cell-Adhesive Agarose-Based Membranes Engineered as Substrates for Corneal Endothelial Cells.

We aimed to bioengineer a scaffold that can facilitate the transplantation of corneal endothelial cells (CEC), given the global shortage of cadaveric donor tissues. Although agarose (A) has outstanding biocompatibility and mechanical properties, it natively does not permit cell adhesion. In this study, agarose was modified with different attachment signals: GRGD (giving AR as product), lysine (AK), poly lysine (AP), and fish-derived gelatin (AG).

Lamellar Dissection Technique for Descemet Membrane Endothelial Keratoplasty Graft Preparation.

Purpose: To describe a novel lamellar dissection technique for Descemet membrane endothelial keratoplasty (DMEK) graft preparation, and to evaluate the rate of endothelial cell loss (ECL) and graft preparation failure associated with this technique.

Methods: We conducted an ex vivo laboratory-based study comparing ECL between the lamellar dissection and peeling techniques. Eight pairs of human donor corneas underwent calcein acetoxymethyl staining-all right eyes underwent the peeling technique and all left eyes underwent the lamellar dissection technique.

Functional Evaluation of Two Corneal Endothelial Cell-Based Therapies: Tissue-Engineered Construct and Cell Injection.

Restoration of vision due to corneal blindness from corneal endothelial dysfunction can be achieved via a corneal transplantation. However, global shortage of donor tissues has driven the development cell-based therapeutics. With the capacity to propagate regulatory compliant human corneal endothelial cells (CEnCs), this study evaluated the functionality of propagated CEnCs delivered via tissue-engineered endothelial keratoplasty (TE-EK) or corneal endothelial cell injection (CE-CI) within a rabbit model of bullous keratopathy.

Regulation of Oxidative Stress in Corneal Endothelial Cells by Prdx6.

The inner layer of the cornea, the corneal endothelium, is post-mitotic and unable to regenerate if damaged. The corneal endothelium is one of the most transplanted tissues in the body. Fuchs' endothelial corneal dystrophy (FECD) is the leading indication for corneal endothelial transplantation.

Corneal lenticule storage before reimplantation.

Purpose: To explore the optimal lenticule storage conditions that maintain lenticule integrity and clarity.

Methods: A total of 99 lenticules obtained from myopic patients undergoing small incision lenticule extraction (SMILE) were divided into four combinations for short-term storage conditions: PBS, Dulbecco's Modified Eagle's Medium (DMEM), Optisol GS, or anhydrous glycerol. Two thirds of the lenticules were further stored for 4 weeks under eight different conditions.

Regulatory Compliant Tissue-Engineered Human Corneal Endothelial Grafts Restore Corneal Function of Rabbits with Bullous Keratopathy.

Corneal transplantation is the only treatment available to restore vision for individuals with blindness due to corneal endothelial dysfunction. However, severe shortage of available donor corneas remains a global challenge. Functional regulatory compliant tissue-engineered corneal endothelial graft substitute can alleviate this reliance on cadaveric corneal graft material.

Effect of position-specific single-point mutations and biophysical characterization of amyloidogenic peptide fragments identified from lattice corneal dystrophy patients.

Corneal stromal dystrophies are a group of genetic disorders that may be caused by mutations in the transforming growth factor β-induced () gene which results in the aggregation and deposition of mutant proteins in various layers of the cornea. The type of amino acid substitution dictates the age of onset, anatomical location of the deposits, morphological features of deposits (amyloid, amorphous powder or a mixture of both forms) and the severity of disease presentation. It has been suggested that abnormal turnover and aberrant proteolytic processing of the mutant proteins result in the accumulation of insoluble protein deposits.

Sequentially-crosslinked bioactive hydrogels as nano-patterned substrates with customizable stiffness and degradation for corneal tissue engineering applications.

Naturally-bioactive hydrogels like gelatin provide favorable properties for tissue-engineering but lack sufficient mechanical strength for use as implantable tissue engineering substrates. Complex fabrication or multi-component additives can improve material strength, but often compromises other properties. Studies have shown gelatin methacrylate (GelMA) as a bioactive hydrogel with diverse tissue growth applications.

Translational issues for human corneal endothelial tissue engineering.

Corneal endothelial disorders collectively represent a significant healthcare burden in most developed nations, and corneal transplantation is currently the only treatment available for patients with poor visual acuity and corneal blindness secondary to endothelial failure. Although vision in these patients can be restored by transplantation, the global demand for donor human corneas is far in excess of what can be provided for by eye banks around the world, and this deficit is set to increase with an ageing global population. As such, there has been a pressing need to explore novel and more sustainable options for the treatment of corneal endothelial diseases.