Vasoactive Intestinal Peptide Promotes Corneal Allograft Survival.

Corneal transplantation is the most prevalent form of tissue transplantation. The success of corneal transplantation mainly relies on the integrity of corneal endothelial cells (CEnCs), which maintain graft transparency. CEnC density decreases significantly after corneal transplantation even in the absence of graft rejection.

Association of the Gutta-Induced Microenvironment With Corneal Endothelial Cell Behavior and Demise in Fuchs Endothelial Corneal Dystrophy.

Importance: The number and size of guttae increase over time in Fuchs endothelial corneal dystrophy (FECD); however, the association between these physical parameters and disease pathogenesis is unclear.

Objective: To determine the role of guttae in corneal endothelial cell function.

Design, Settings, And Participants: In an in vitro model, cells from a human corneal endothelial cell line, HCENC-21T, were seeded on decellularized normal (n = 30) and FECD (n = 70) endothelial basement (Descemet) membranes (DMs).

NQO1 downregulation potentiates menadione-induced endothelial-mesenchymal transition during rosette formation in Fuchs endothelial corneal dystrophy.

Fuchs endothelial corneal dystrophy (FECD) is a genetic and oxidative stress disorder of post-mitotic human corneal endothelial cells (HCEnCs), which normally exhibit hexagonal shape and form a compact monolayer compatible with normal corneal functioning and clear vision. FECD is associated with increased DNA damage, which in turn leads to HCEnC loss, resulting in the formation rosettes and aberrant extracellular matrix (ECM) deposition in the form of pro-fibrotic guttae. Since the mechanism of ECM deposition in FECD is currently unknown, we aimed to investigate the role of endothelial-mesenchymal transition (EMT) in FECD using a previously established cellular in vitro model that recapitulates the characteristic rosette formation, by employing menadione (MN)-induced oxidative stress.

Limbal Cysts: A Subset Exhibiting Cornea-Specific Cytokeratins.

Two cases of limbal cysts lined by nonkeratinizing epithelium were studied with a panel of cytokeratins. One was a long-standing lesion in a 30-year-old man, whereas the other was excised from a 40-year-old man following pterygium surgery. Each cyst was immunostained with a panel of cytokeratins that were specific exclusively and separately for corneal and conjunctival epithelia.

Activation of mitophagy leads to decline in Mfn2 and loss of mitochondrial mass in Fuchs endothelial corneal dystrophy.

Human corneal endothelial cells (HCEnCs) are terminally differentiated cells that have limited regenerative potential. The large numbers of mitochondria in HCEnCs are critical for pump and barrier function required for corneal hydration and transparency. Fuchs Endothelial Corneal Dystrophy (FECD) is a highly prevalent late-onset oxidative stress disorder characterized by progressive loss of HCEnCs.

Hepatocyte Growth Factor Suppresses Inflammation and Promotes Epithelium Repair in Corneal Injury.

Corneal injuries are among the major causes of ocular morbidity and vision impairment. Optimal epithelial wound healing is critical for the integrity and transparency of the cornea after injury. Hepatocyte growth factor (HGF) is a mitogen and motility factor that primarily regulates epithelial cell function.

Restoration of Corneal Transparency by Mesenchymal Stem Cells.

Transparency of the cornea is indispensable for optimal vision. Ocular trauma is a leading cause of corneal opacity, leading to 25 million cases of blindness annually. Recently, mesenchymal stem cells (MSCs) have gained prominence due to their inflammation-suppressing and tissue repair functions.

Existence of Neural Crest-Derived Progenitor Cells in Normal and Fuchs Endothelial Dystrophy Corneal Endothelium.

Human corneal endothelial cells are derived from neural crest and because of postmitotic arrest lack competence to repair cell loss from trauma, aging, and degenerative disorders such as Fuchs endothelial corneal dystrophy (FECD). Herein, we identified a rapidly proliferating subpopulation of cells from the corneal endothelium of adult normal and FECD donors that exhibited features of neural crest-derived progenitor (NCDP) cells by showing absence of senescence with passaging, propensity to form spheres, and increased colony forming efficacy compared with the primary cells. The collective expression of stem cell-related genes SOX2, OCT4, LGR5, TP63 (p63), as well as neural crest marker genes PSIP1 (p75(NTR)), PAX3, SOX9, AP2B1 (AP-2β), and NES, generated a phenotypic footprint of endothelial NCDPs.

Science and Art of Cell-Based Ocular Surface Regeneration.

The potential cause of blindness worldwide includes diseases of the cornea, ocular surface (limbal stem cell deficiency, allergic conjunctivitis, dry eye diseases), and retinal diseases. The presence of stem cells (limbal stem cells) in the basal region of the limbus makes it an important tool for the ocular regeneration and also in maintaining the transparency of eye by replacing the corneal epithelium continuously. Various surgical modalities have been developed like cultured limbal epithelial transplantation, cultured oral mucosal epithelial transplantation, simple limbal epithelial transplantation, etc.

Limbal Stromal Tissue Specific Stem Cells and Their Differentiation Potential to Corneal Epithelial Cells.

From the derivation of the first human embryonic stem (hES) cell line to the development of induced pluripotent stem (iPS) cells; it has become evident that tissue specific stem cells are able to differentiate into a specific somatic cell types. The understanding of key processes such as the signaling pathways and the role of the microenvironment in epidermal/epithelial development has provided important clues for the derivation of specific epithelial cell types.Various differentiation protocols/methods were used to attain specific epithelial cell types.

Mesenchymal stem cells home to inflamed ocular surface and suppress allosensitization in corneal transplantation.

Purpose: To investigate whether systemically injected syngeneic mesenchymal stem cells (MSCs) can home to the transplanted cornea, suppress induction of alloimmunity, and promote allograft survival.

Methods: Mesenchymal stem cells were generated from bone marrow of wild-type BALB/c or GFP (green fluorescent protein)+ C57BL/6 mice, and 1×10(6) cells were intravenously injected to allografted recipients 3 hours after surgery. Mesenchymal stem cells homing to the cornea were examined at day 3 post transplantation by immunohistochemistry.

Comparative transcriptomic analysis of cultivated limbal epithelium and donor corneal tissue reveals altered wound healing gene expression.

Purpose: The improved surgical outcomes associated with transplantation of cultivated amniotic membrane expanded limbal epithelium (AMLE) compared to traditional donor methods has led to substantial adoption of this technique for treatment of limbal stem cell deficiency.

Methods: The mRNA expression profiles of AMLE and CE were assayed using microarrays. Transcripts with a 1.

Regenerative medicine for diabetes: differentiation of human pluripotent stem cells into functional β-cells in vitro and their proposed journey to clinical translation.

Diabetes is a group of metabolic diseases, rising globally at an alarming rate. Type 1 (juvenile diabetes) is the autoimmune version of diabetes where the pancreas is unable to produce insulin, whereas type 2 (adult onset diabetes) is caused due to insulin resistance of the cells. In either of the cases, elevated blood glucose levels are observed which leads to progressive comorbidity like renal failure, cardiovascular disease, retinopathy, etc.

Differentiation potential of limbal fibroblasts and bone marrow mesenchymal stem cells to corneal epithelial cells.

The cornea is covered by a stratified epithelium that is renewed by stem cells located in the peripheral region of the cornea known as the limbus. This stroma of the limbus contains stromal keratocytes that, when expanded in culture, are termed limbal fibroblasts (LFs). It is thought that LFs exhibit similar characteristics to bone marrow mesenchymal stem cells (BM MSCs) and help maintain the epithelial stem cell phenotype in the limbal region.

Dependence of corneal stem/progenitor cells on ocular surface innervation.

Purpose: Neurotrophic keratopathy (NK) is a corneal degeneration associated with corneal nerve dysfunction. It can cause corneal epithelial defects, stromal thinning, and perforation. However, it is not clear if and to which extent epithelial stem cells are affected in NK.

Comparative analysis of human-derived feeder layers with 3T3 fibroblasts for the ex vivo expansion of human limbal and oral epithelium.

Corneal transplantation with cultivated limbal or oral epithelium is a feasible treatment option for limbal stem cell deficiency (LSCD). Currently utilized co-culture of stem cells with murine 3T3 feeder layer renders the epithelial constructs as xenografts. To overcome the potential risks involved with xenotransplantation, we investigated the use of human-derived feeder layers for the ex vivo expansion of epithelial (stem) cells.

Immunohistochemical and immunofluorescence procedures for protein analysis.

Immunohistochemistry (IHC) and immunofluorescence (IF) involve the binding of an antibody to a cellular or tissue antigen of interest and then visualisation of the bound product by fluorescence/with the 3,3'-diaminobenzidine (DAB) chromogen detection system. With increasing numbers of available antibodies against cellular epitopes, IHC and IF are very useful diagnostic tools as well as a means to guide specific therapies that target a particular antigen on cell/tissue samples.There are several IHC and IF staining methods that can be employed depending on the type of specimen under study, the degree of sensitivity required, and the cost considerations.