Coordinated microRNA/mRNA expression profiles reveal a putative mechanism of corneal epithelial cell transdifferentiation from skin epidermal stem cells

Abstract

Skin epidermal stem cells (SESCs), which share a single origin with corneal epithelial cells (CECs), are considered to be one of the most ideal seed cells for the construction of tissue engineered corneas. However, the mechanism underlying the transdifferentiation of SESCs to CECs has not been fully elucidated. In the present study, to identify critical microRNAs (miRNAs/miRs) and genes that regulate the transdifferentiation of SESCs to CECs, SESCs and CECs were collected from sheep and used for small RNA sequencing and mRNA microarray analyses. Among the differentially expressed miRNAs and genes, 36 miRNAs were downregulated and 123 genes were upregulated in the CECs compared with those in the SESCs. miR-10b exhibited the largest change in expression between the cell types. Target genes of the 36 downregulated miRNAs were predicted and a computational approach demonstrated that these target genes may be involved in several signaling pathways, including the 'PI3K signaling pathway', the 'Wnt signaling pathway' and the 'MAPK signaling pathway', as well as in 'focal adhesion'. Comparison of these target genes to the 123 upregulated genes identified 43 intersection genes. A regulatory network of these 43 intersection genes and its correlative miRNAs were constructed, and three genes (dedicator of cytokinesis 9, neuronal differentiation 1 and activated leukocyte cell adhesion molecule) were found to have high interaction frequencies. The expression levels of 7 randomly selected miRNAs and the 3 intersection genes were further validated by reverse transcription-quantitative polymerase chain reaction. It was found that miR-10b, the Wnt signaling pathway and the 3 intersection genes may act together and serve a critical role in the transdifferentiation process. This study identified miRNAs and genes that were expressed in SESCs and CECs that may assist in uncovering its underlying molecular mechanism, as well as promote corneal tissue engineering using epidermal stem cells for clinical applications.

Cellular plasticity, caspases and autophagy; that which does not kill us, well, makes us different

“…miRNAs are induced or repressed during transdifferentiation in various models (e.g. [35,36]), and their overexpression can induce transdifferentiation, suggesting the potential of using miRNAs to reprogramme cells for therapeutic purposes [26][27][28]. But are miRNAs required for transdifferentiation?…”

Adult stem cells in the eye: Identification, characterisation, and therapeutic application in ocular regeneration – A review

“…132 Studies show that epidermal stem cells can be induced to transdifferentiate into corneal epithelial-like cells. 133 Moreover, epidermal stem cell-derived sheets have successfully reconstructed the conjunctiva in conjunctival damaged monkeys, 134 suggesting that epidermal stem cells could be a new substitute for ocular surface reconstruction. The hair follicles undergo a dynamic cycle of growth (anagen), transition (catagen), and resting (telogen) phases.…”

“…The continuous regeneration of the stratified epidermis is maintained through the division of epidermal stem cells in the basal layer, which terminally differentiate and migrate to the superficial layer 132 . Studies show that epidermal stem cells can be induced to transdifferentiate into corneal epithelial‐like cells 133 . Moreover, epidermal stem cell‐derived sheets have successfully reconstructed the conjunctiva in conjunctival damaged monkeys, 134 suggesting that epidermal stem cells could be a new substitute for ocular surface reconstruction.…”

Focus on seed cells: stem cells in 3D bioprinting of corneal grafts

“…Guo and Cieślar-Pobuda successfully transdifferentiated skin epidermal stem cells and fibroblasts into corneal epithelioid cells ( Cieślar-Pobuda et al, 2016 ; Guo et al, 2018 ). Several breakthroughs have been made in corneal cell transdifferentiation strategies, but their application in corneal tissue engineering remains to be explored.…”