Identification and Potential Application of Human Corneal Endothelial Progenitor Cells

Abstract

The corneal endothelium is believed to be developmentally originated from the periocular mesenchyme via the neural crest. Human corneal endothelial progenitor cells (HCEPs) have been investigated because of their potential availability for the tissue regenerative medicine. However, the existence and the properties of HCEPs have not been elucidated yet. We first established a novel serum-free culture system for HCEPs. The HCEPs highly expressed p75 neurotrophin receptor, SOX9, and FOXC2, and partially retained the properties of neural crest and periocular mesenchyme. Further, we demonstrated that HCEPs had a high proliferative potency, and the differentiated HCEP sheets had corneal endothelial function by using the Ussing chamber system and transplantation to the rabbit cornea. These findings suggest that the HCEPs can be selectively expanded from the corneal endothelium using a specific culture system and will provide cell sheets for corneal regenerative medicine.

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

“…Similarly, previous studies showed that p75 NTR is highly expressed in corneal endothelial progenitor cells and might be an important cell surface marker for isolation of progenitor cells from tissues. 6,26 However, our study identified that there is a cooperative expression of pluripotency, neural crest, and endothelial lineageerelated genes involved in the phenotypic footprint of the endothelial NCDP cells. In the niche of spheres in vitro, endothelial NCDP cells exhibited a transcriptional profile of pluripotent cells that persisted in high passages (>70 passages), although some markers trended toward lower expression with older donors and higher passages, indicating possible epigenetic modifications of NCDP cells with increased passaging and donor age.…”

“…This underscores the neural crest origin of the human endothelial progenitor cells, a finding that has not been described in the previous studies on endothelial SCs. 6,11,13 Interestingly, the endothelial cell progeny of NCDPs retained the expression of p75 NTR and continued to proliferate without signs of senescence. This indicates that these cells are not yet terminally differentiated in vitro and might provide a source of constructs for regenerative therapies (Figure 7).…”

“…To determine whether continued passaging alters cellular phenotype as previously described in a subpopulation of endothelial progenitors, 6,13 neural crest marker expression was compared between early (10 to 15) and late (70 to 75) passages before induction of SF. For F-HCEnC-69M, passage 10 and passage 45 were compared.…”

“…6e8 The description of purported stem cells (SCs) has been based on ex vivo staining of tissue with progenitor markers 7,9,10 or isolation of progenitor-like cells in vitro based on sphere-forming culture 8,11,12 or surface markers. 6,13 However, there is no direct evidence of the existence of multipotent HCEnC cells in the corneal endothelial layer.…”

Targeted Transplantation of Human Umbilical Cord Blood Endothelial Progenitor Cells with Immunomagnetic Nanoparticles to Repair Corneal Endothelium Defect

“…If this technique could be used in the clinic, the Descemet's membrane should not be stripped away, which might improve the results; (iv) The UCB EPCs might need to be differentiated into corneal endothelial cells first in vitro, which could launch the repair function immediately after transplantation. Recently, Hara et al established a novel serum-free culture system for expanding human corneal endothelial progenitor cells (HCEPs) [35]. The HCEPs highly expressed p75 neurotrophin receptor, SOX9, and had a high proliferative potency.…”