Human-Induced Pluripotent Stem Cells-Derived Corneal Endothelial-Like Cells Promote Corneal Transparency in a Rabbit Model of Bullous Keratopathy.

The corneal endothelium (CE) is vital for the cornea to maintain its transparency. However, CE dysfunction occurs due to aging, intraocular surgery, trauma, dystrophy, etc. Corneal transplantation is the only method to clinically treat CE dysfunction; however, this treatment strategy faces the disadvantages of a global cornea shortage, graft failure, and severe side effects. There is a recognized need for a substitute for the CE. Stem cells are becoming increasingly common for the treatment of human diseases. In fact, several studies have documented the induction of corneal endothelial-like cells (CECs) from stem cells, but an ideal procedure has not yet been established. Thus, this study aimed at exploring a more efficient and robust differentiation method. We used a modified approach to differentiate induced pluripotent stem cells (iPSCs) into CECs. After the identification of differentiated CECs, the CECs were injected into the anterior chambers of the eyes of a rabbit model of bullous keratopathy. The rabbits were maintained in the eye-down position to ensure that the cells attached to the cornea. The results showed that corneal edema was alleviated in the rabbits injected with CECs compared with that in the rabbits belonging to the control group. This study extends the ability to differentiate iPSCs into CECs and provides a potential strategy for the treatment of reduced visual acuity caused by CE deficiency in the future.

Human induced pluripotent stem cell line HMUi001-A derived from corneal stromal cells.

A human corneal stroma induced pluripotent stem cell (HMUi001-A) line was created from primary cultured human corneal fibroblasts. Reprogramming was performed using episomal vector delivery of OCT4, SOX2, KLF4, L-MYC and LIN28. Further characterization of the HMUi001-A confirmed that the cell line was pluripotent, free from Epstein Barr viral genome, and retained normal karyotype.

Comprehensive evaluation of decellularized porcine corneal after clinical transplantation.

Corneal disease is the second most common blinding disease in the world. The shortage of cornea donors has become the greatest challenge in curing corneal disease. Decellularized porcine corneas have the potential to be clinically applied as a substitute for human cornea in lamellar keratoplasty. Porcine corneas will help relieve the cornea donor shortage. To comprehensively evaluate the characteristics of the grafts and the effect of the decellularized porcine cornea on the host cornea after clinical transplantation, we assessed the microstructure of the transplanted decellularized porcine corneal tissues. Through the analysis of the microstructure of the tissues by H&E staining, TEM and immunofluorescence of anti-human vimentin, anti-pig vimentin,IL-1, IL-2, IL-3, IL-6, IL-8, INF-γ, and TNF-α immunofluorescence staining, we found that despite the slight rejection that occurred, the porcine cornea has good biocompatibility and can provide a scaffold for cell growth. Genetic analysis using Solexa sequencing of the samples showed that decellularized porcine corneas cannot affect genes in patients' corneas. Decellularized porcine corneas are effective biological materials for use in corneal transplantation.

Melatonin protects bone marrow mesenchymal stem cells against iron overload-induced aberrant differentiation and senescence.

Bone marrow mesenchymal stem cells (BMSCs) are an expandable population of stem cells which can differentiate into osteoblasts, chondrocytes and adipocytes. Dysfunction of BMSCs in response to pathological stimuli contributes to bone diseases. Melatonin, a hormone secreted from pineal gland, has been proved to be an important mediator in bone formation and mineralization. The aim of this study was to investigate whether melatonin protected against iron overload-induced dysfunction of BMSCs and its underlying mechanisms. Here, we found that iron overload induced by ferric ammonium citrate (FAC) caused irregularly morphological changes and markedly reduced the viability in BMSCs. Consistently, osteogenic differentiation of BMSCs was significantly inhibited by iron overload, but melatonin treatment rescued osteogenic differentiation of BMSCs. Furthermore, exposure to FAC led to the senescence in BMSCs, which was attenuated by melatonin as well. Meanwhile, melatonin was able to counter the reduction in cell proliferation by iron overload in BMSCs. In addition, protective effects of melatonin on iron overload-induced dysfunction of BMSCs were abolished by its inhibitor luzindole. Also, melatonin protected BMSCs against iron overload-induced ROS accumulation and membrane potential depolarization. Further study uncovered that melatonin inhibited the upregulation of p53, ERK and p38 protein expressions in BMSCs with iron overload. Collectively, melatonin plays a protective role in iron overload-induced osteogenic differentiation dysfunction and senescence through blocking ROS accumulation and p53/ERK/p38 activation.