Descemet's Membrane Biomimetic Microtopography Differentiates Human Mesenchymal Stem Cells Into Corneal Endothelial-Like Cells.

PURPOSE: Loss of corneal endothelial cells (CECs) bears disastrous consequences for the patient, including corneal clouding and blindness. Corneal transplantation is currently the only therapy for severe corneal disorders. However, the worldwide shortages of corneal donor material generate a strong demand for personalized stem cell-based alternative therapies. Because human mesenchymal stem cells are known to be sensitive to their mechanical environments, we investigated the mechanotransductive potential of Descemet membrane-like microtopography (DLT) to differentiate human mesenchymal stem cells into CEC-like cells. METHODS: Master molds with inverted DLT were produced by 2-photon lithography (2-PL). To measure the mechanotransductive potential of DLT, mesenchymal stem cells were cultivated on silicone or collagen imprints with DLT. Changes in morphology were imaged, and changes in gene expression of CEC typical genes such as zonula occludens (ZO-1), sodium/potassium (Na/K)-ATPase, paired-like homeodomain 2 (PITX2), and collagen 8 (COL-8) were measured with real-time polymerase chain reaction. At least immunofluorescence analysis has been conducted to confirm gene data on the protein level. RESULTS: Adhesion of MSCs to DLT molded in silicone and particularly in collagen initiates polygonal morphology and monolayer formation and enhances not only transcription of CEC typical genes such as ZO-1, Na/K-ATPase, PITX2, and COL-8 but also expression of the corresponding proteins. CONCLUSIONS: Artificial reproduction of Descemet membrane with respect to topography and similar stiffness offers a potential innovative way to bioengineer a functional CEC monolayer from autologous stem cells.

Effects of non-ablative fractional erbium glass laser treatment on gene regulation in human three-dimensional skin models.

Clinical experiences with non-ablative fractional erbium glass laser therapy have demonstrated promising results for dermal remodelling and for the indications of striae, surgical scars and acne scars. So far, molecular effects on human skin following treatment with these laser systems have not been elucidated. Our aim was to investigate laser-induced effects on skin morphology and to analyse molecular effects on gene regulation. Therefore, human three-dimensional (3D) organotypic skin models were irradiated with non-ablative fractional erbium glass laser systems enabling qRT-PCR, microarray and histological studies at same and different time points. A decreased mRNA expression of matrix metalloproteinases (MMPs) 3 and 9 was observed 3 days after treatment. MMP3 also remained downregulated on protein level, whereas the expression of other MMPs like MMP9 was recovered or even upregulated 5 days after irradiation. Inflammatory gene regulatory responses measured by the expression of chemokine (C-X-C motif) ligands (CXCL1, 2, 5, 6) and interleukin expression (IL8) were predominantly reduced. Epidermal differentiation markers such as loricrin, filaggrin-1 and filaggrin-2 were upregulated by both tested laser optics, indicating a potential epidermal involvement. These effects were also shown on protein level in the immunofluorescence analysis. This novel standardised laser-treated human 3D skin model proves useful for monitoring time-dependent ex vivo effects of various laser systems on gene expression and human skin morphology. Our study reveals erbium glass laser-induced regulations of MMP and interleukin expression. We speculate that these alterations on gene expression level could play a role for dermal remodelling, anti-inflammatory effects and increased epidermal differentiation. Our finding may have implications for further understanding of the molecular mechanism of erbium glass laser-induced effects on human skin.