The aim of this study was to examine whether mesenchymal stem cells (MSCs) and/or corneal limbal epithelial stem cells (LSCs) influence restoration of an antioxidant protective mechanism in the corneal epithelium and renewal of corneal optical properties changed after alkali burns. The injured rabbit corneas (with 0.25 N NaOH) were untreated or treated with nanofiber scaffolds free of stem cells, with nanofiber scaffolds seeded with bone marrow MSCs (BM-MSCs), with adipose tissue MSCs (Ad-MSCs), or with LSCs. On day 15 following the injury, after BM-MSCs or LSCs nanofiber treatment (less after Ad-MSCs treatment) the expression of antioxidant enzymes was restored in the regenerated corneal epithelium and the expressions of matrix metalloproteinase 9 (MMP9), inducible nitric oxide synthase (iNOS), α-smooth muscle actin (α-SMA), transforming growth factor-β1 (TGF-β1), and vascular endothelial factor (VEGF) were low. The central corneal thickness (taken as an index of corneal hydration) increased after the injury and returned to levels before the injury. In injured untreated corneas the epithelium was absent and numerous cells revealed the expressions of iNOS, MMP9, α-SMA, TGF-β1, and VEGF. In conclusion, stem cell treatment accelerated regeneration of the corneal epithelium, restored the antioxidant protective mechanism, and renewed corneal optical properties.

• MeSH
• Alkalies MeSH
• Antioxidants therapeutic use   MeSH
• Cell Differentiation drug effects   MeSH
• Burns, Chemical enzymology   genetics   pathology   therapy   MeSH
• Immunohistochemistry MeSH
• Rabbits MeSH
• Limbus Corneae cytology   MeSH
• Matrix Metalloproteinase 9 metabolism   MeSH
• Mesenchymal Stem Cells cytology   drug effects   MeSH
• Protective Agents pharmacology   therapeutic use   MeSH
• Corneal Pachymetry MeSH
• Gene Expression Regulation drug effects   MeSH
• Epithelium, Corneal pathology   MeSH
• Superoxide Dismutase metabolism   MeSH
• Nitric Oxide Synthase Type II metabolism   MeSH
• Transforming Growth Factor beta genetics   metabolism   MeSH
• Mesenchymal Stem Cell Transplantation * MeSH
• Adipocytes cytology   drug effects   MeSH
• Vascular Endothelial Growth Factor A metabolism   MeSH
• Corneal Opacity complications   therapy   MeSH
• Animals MeSH
• Check Tag
• Rabbits MeSH
• Female MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Retracted Publication MeSH
• Research Support, Non-U.S. Gov't MeSH
• Names of Substances
• Alkalies MeSH
• Antioxidants MeSH
• Matrix Metalloproteinase 9 MeSH
• Protective Agents MeSH
• Superoxide Dismutase MeSH
• Nitric Oxide Synthase Type II MeSH
• Transforming Growth Factor beta MeSH
• Vascular Endothelial Growth Factor A MeSH

UNLABELLED: Stem cell-based therapy has become an attractive and promising approach for the treatment of severe injuries or thus-far incurable diseases. However, the use of stem cells is often limited by a shortage of available tissue-specific stem cells; therefore, other sources of stem cells are being investigated and tested. In this respect, mesenchymal stromal/stem cells (MSCs) have proven to be a promising stem cell type. In the present study, we prepared MSCs from bone marrow (BM-MSCs) or adipose tissue (Ad-MSCs) as well as limbal epithelial stem cells (LSCs), and their growth, differentiation, and secretory properties were compared. The cells were grown on nanofiber scaffolds and transferred onto the alkali-injured eye in a rabbit model, and their therapeutic potential was characterized. We found that BM-MSCs and tissue-specific LSCs had similar therapeutic effects. Clinical characterization of the healing process, as well as the evaluation of corneal thickness, re-epithelialization, neovascularization, and the suppression of a local inflammatory reaction, were comparable in the BM-MSC- and LSC-treated eyes, but results were significantly better than in injured, untreated eyes or in eyes treated with a nanofiber scaffold alone or with a nanofiber scaffold seeded with Ad-MSCs. Taken together, the results show that BM-MSCs' therapeutic effect on healing of injured corneal surface is comparable to that of tissue-specific LSCs. We suggest that BM-MSCs can be used for ocular surface regeneration in cases when autologous LSCs are absent or difficult to obtain. SIGNIFICANCE: Damage of ocular surface represents one of the most common causes of impaired vision or even blindness. Cell therapy, based on transplantation of stem cells, is an optimal treatment. However, if limbal stem cells (LSCs) are not available, other sources of stem cells are tested. Mesenchymal stem cells (MSCs) are a convenient type of cell for stem cell therapy. The therapeutic potential of LSCs and MSCs was compared in an experimental model of corneal injury, and healing was observed following chemical injury. MSCs and tissue-specific LSCs had similar therapeutic effects. The results suggest that bone marrow-derived MSCs can be used for ocular surface regeneration in cases when autologous LSCs are absent or difficult to obtain.

• Keywords
• Alkali-injured ocular surface, Corneal regeneration, Limbal stem cells, Mesenchymal stem cells, Stem cell-based therapy,
• MeSH
• Biomarkers metabolism   MeSH
• Cell- and Tissue-Based Therapy methods   MeSH
• Cell Differentiation MeSH
• Bone Marrow Cells cytology   physiology   MeSH
• Burns, Chemical pathology   therapy   MeSH
• Epithelial Cells cytology   physiology   transplantation   MeSH
• Gene Expression MeSH
• Neovascularization, Physiologic MeSH
• Rabbits MeSH
• Limbus Corneae blood supply   injuries   MeSH
• Mesenchymal Stem Cells cytology   physiology   MeSH
• Primary Cell Culture MeSH
• Cell Proliferation MeSH
• Re-Epithelialization physiology   MeSH
• Epithelium, Corneal blood supply   injuries   MeSH
• Tissue Scaffolds MeSH
• Mesenchymal Stem Cell Transplantation * MeSH
• Adipose Tissue cytology   physiology   MeSH
• Adipocytes cytology   physiology   MeSH
• Animals MeSH
• Check Tag
• Rabbits MeSH
• Female MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Comparative Study MeSH
• Names of Substances
• Biomarkers MeSH

Regulatory T cells have been well described and the factors regulating their development and function have been identified. Recently, a growing body of evidence has documented the existence of interleukin-10 (IL-10) -producing B cells, which are called regulatory B10 cells. These cells attenuate autoimmune, inflammatory and transplantation reactions, and the main mechanism of their inhibitory action is the production of IL-10. We show that the production of IL-10 by lipopolysaccharide-stimulated B cells is significantly enhanced by IL-12 and interferon-γ and negatively regulated by IL-21 and transforming growth factor-β. In addition, exogenous IL-10 also inhibits B-cell proliferation and the expression of the IL-10 gene in lipopolysaccharide-stimulated B cells. The negative autoregulation of IL-10 production is supported by the observation that the inclusion of anti-IL-10 receptor monoclonal antibody enhances IL-10 production and the proliferation of activated B cells. The effects of cytokines on IL-10 production by B10 cells did not correlate with their effects on B-cell proliferation or on IL-10 production by T cells or macrophages. The cytokine-induced changes in IL-10 production occurred on the level of IL-10 gene expression, as confirmed by increased or decreased IL-10 mRNA expression in the presence of a particular cytokine. The regulatory cytokines modulate the number of IL-10-producing cells rather than augmenting or decreasing the secretion of IL-10 on a single-cell level. Altogether these data show that the production of IL-10 by B cells is under the strict regulatory control of cytokines and that individual cytokines differentially regulate the development and activity of regulatory T cells and IL-10-producing regulatory B cells.

• Keywords
• B cells, autoregulation, cytokines, immunosuppression, interleukin-10 production,
• MeSH
• Lymphocyte Activation MeSH
• Cell Differentiation * drug effects   MeSH
• Cytokines genetics   metabolism   MeSH
• Homeostasis MeSH
• Interferon-gamma metabolism   MeSH
• Interleukin-10 genetics   metabolism   MeSH
• Cells, Cultured MeSH
• Humans MeSH
• Lipopolysaccharides pharmacology   MeSH
• RNA, Messenger metabolism   MeSH
• Mice, Inbred C57BL MeSH
• Mice MeSH
• Cell Proliferation MeSH
• Gene Expression Regulation MeSH
• B-Lymphocytes, Regulatory drug effects   immunology   metabolism   MeSH
• T-Lymphocytes, Regulatory immunology   metabolism   MeSH
• Recombinant Proteins metabolism   MeSH
• Signal Transduction MeSH
• Tumor Necrosis Factor-alpha metabolism   MeSH
• Transforming Growth Factor beta1 metabolism   MeSH
• Animals MeSH
• Check Tag
• Humans MeSH
• Male MeSH
• Mice MeSH
• Female MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Names of Substances
• Cytokines MeSH
• IFNG protein, human MeSH Browser
• IL10 protein, mouse MeSH Browser
• Interferon-gamma MeSH
• Interleukin-10 MeSH
• Lipopolysaccharides MeSH
• RNA, Messenger MeSH
• Recombinant Proteins MeSH
• TGFB1 protein, human MeSH Browser
• Tumor Necrosis Factor-alpha MeSH
• Transforming Growth Factor beta1 MeSH

Limbal stem cells (LSC), which reside in the basal layer of the limbus, are thought to be responsible for corneal epithelial healing after injury. When the cornea is damaged, LSC start to proliferate, differentiate, and migrate to the site of injury. To characterize the signaling molecules ensuring communication between the cornea and LSC, we established a mouse model of mechanical corneal damage. The central cornea or limbal tissue was excised at different time intervals after injury, and the expression of genes in the explants was determined. It was observed that a number of genes for growth and differentiation factors were significantly upregulated in the cornea rapidly after injury. The ability of these factors to regulate the differentiation and proliferation of limbal cells was tested. It was found that the insulin-like growth factor-I (IGF-I), which is rapidly overexpressed after injury, enhances the expression of IGF receptor in limbal cells and induces the differentiation of LSC into cells expressing the corneal cell marker, cytokeratin K12, without any effect on limbal cell proliferation. In contrast, the epidermal growth factor (EGF) and fibroblast growth factor-β (FGF-β), which are also produced by the damaged corneal epithelium, supported limbal cell proliferation without any effect on their differentiation. Other factors did not affect limbal cell differentiation or proliferation. Thus, IGF-I was identified as the main factor stimulating the expression of IGF receptors in limbal cells and inducing the differentiation of LSC into cells expressing corneal epithelial cell markers. The proliferation of these cells was supported by EGF and FGF.

• MeSH
• Cell Differentiation genetics   MeSH
• Epidermal Growth Factor biosynthesis   metabolism   MeSH
• Fibroblast Growth Factors biosynthesis   metabolism   MeSH
• Wound Healing physiology   MeSH
• Insulin-Like Growth Factor I biosynthesis   metabolism   MeSH
• Keratin-12 biosynthesis   MeSH
• Stem Cells metabolism   MeSH
• Limbus Corneae cytology   metabolism   MeSH
• Mice, Inbred BALB C MeSH
• Mice MeSH
• Cell Proliferation MeSH
• Receptor, IGF Type 1 biosynthesis   metabolism   MeSH
• Epithelium, Corneal * cytology   injuries   metabolism   MeSH
• Signal Transduction MeSH
• Gene Expression Profiling MeSH
• Up-Regulation MeSH
• Animals MeSH
• Check Tag
• Male MeSH
• Mice MeSH
• Female MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Names of Substances
• Epidermal Growth Factor MeSH
• Fibroblast Growth Factors MeSH
• Insulin-Like Growth Factor I MeSH
• Keratin-12 MeSH
• Receptor, IGF Type 1 MeSH