Long-term outcome of cultivated oral mucosal epithelial transplantation for fornix reconstruction in chronic cicatrising diseases.

BACKGROUND/AIMS: To investigate the long-term outcomes of cultivated oral mucosal epithelial transplantation (COMET) for fornix reconstruction in eyes with chronic cicatrising disease. METHODS: This retrospective cohort study involved 16 eyes of 15 patients who underwent COMET for symblepharon release and fornix reconstruction between June 2002 and December 2008. The mean postoperative follow-up period was 102.1±46.0 months (range: 32-183 months). The treated cicatrising disorders included ocular cicatricial pemphigoid (OCP, five eyes), thermal/chemical injury (three eyes) and other chronic diseases (seven eyes; including recurrent pterygium (two eyes), Stevens-Johnson syndrome (one eye) and graft-versus-host disease (one eye)). Ocular-surface appearance was evaluated before surgery, at 1, 4, 12 and 24 weeks postoperative, and then annually based on the previously reported scoring system. Main outcome measures included overall and disease-specific fornix-reconstruction success probabilities analysed by the Kaplan-Meier survival curve. Symblepharon/fornix-shortening recurrence at 24 weeks postoperative, and its relationship to long-term surgical success was also examined. RESULTS: At 5 years postoperative, the mean±SD overall fornix-reconstruction success probability was 79.6%±10.7%, and success probability for thermal/chemical injury and OCP was 100% and 53.3%±24.8%, respectively (p=0.53, log-rank test). The 3-year success probability was significantly higher in the no-disease-recurrence group at 24 weeks postoperative (13 eyes) than in the disease-recurrence group (three eyes) (100% and 33.3%±27.2%, respectively) (p=0.0073, log-rank test). CONCLUSION: COMET was found to be safe and effective for symblepharon release and long-term fornix reconstruction in eyes with chronic cicatrisation. Although the 5-year success probability differed depend on the underlying disease, ocular-surface appearance at 24 weeks postoperative is a factor for predicting long-term outcome.

Oral Mucosal Epithelial Transplantation and Limbal-Rigid Contact Lens: A Therapeutic Modality for the Treatment of Severe Ocular Surface Disorders.

Stevens-Johnson syndrome, ocular cicatricial pemphigoid, and severe thermal or chemical injury are considered severe ocular surface disorders (OSDs) because they affect the entire ocular surface, including corneal and conjunctival epithelial stem cells. In patients with severe OSDs, the long-term prognosis for limbal transplantation is poor, and the related corneal opacity and cicatrization lead to devastating visual impairment. To date, there is no standardized treatment to improve vision in cases with severe OSD. Investigating novel treatment methods for severe OSDs, our group began cultivated oral mucosal epithelial transplantation in 2002 and developed a limbal-supported rigid-type contact lens that can be applied as a nonsurgical treatment. When used in combination, these treatment methods make it possible to successfully restore vision in cases with severe OSDs.

Cell Therapies under Clinical Trials and Polarized Cell Therapies in Pre-Clinical Studies to Treat Ischemic Stroke and Neurological Diseases: A Literature Review.

Stroke remains a major cause of serious disability because the brain has a limited capacity to regenerate. In the last two decades, therapies for stroke have dramatically changed. However, half of the patients cannot achieve functional independence after treatment. Presently, cell-based therapies are being investigated to improve functional outcomes. This review aims to describe conventional cell therapies under clinical trial and outline the novel concept of polarized cell therapies based on protective cell phenotypes, which are currently in pre-clinical studies, to facilitate functional recovery after post-reperfusion treatment in patients with ischemic stroke. In particular, non-neuronal stem cells, such as bone marrow-derived mesenchymal stem/stromal cells and mononuclear cells, confer no risk of tumorigenesis and are safe because they do not induce rejection and allergy; they also pose no ethical issues. Therefore, recent studies have focused on them as a cell source for cell therapies. Some clinical trials have shown beneficial therapeutic effects of bone marrow-derived cells in this regard, whereas others have shown no such effects. Therefore, more clinical trials must be performed to reach a conclusion. Polarized microglia or peripheral blood mononuclear cells might provide promising therapeutic strategies after stroke because they have pleiotropic effects. In traumatic injuries and neurodegenerative diseases, astrocytes, neutrophils, and T cells were polarized to the protective phenotype in pre-clinical studies. As such, they might be useful therapeutic targets. Polarized cell therapies are gaining attention in the treatment of stroke and neurological diseases.

Publisher Correction: A novel therapeutic approach using peripheral blood mononuclear cells preconditioned by oxygen-glucose deprivation.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

A novel therapeutic approach using peripheral blood mononuclear cells preconditioned by oxygen-glucose deprivation.

Cell therapies that invoke pleiotropic mechanisms may facilitate functional recovery in patients with stroke. Based on previous experiments using microglia preconditioned by oxygen-glucose deprivation, we hypothesized that the administration of peripheral blood mononuclear cells (PBMCs) preconditioned by oxygen-glucose deprivation (OGD-PBMCs) to be a therapeutic strategy for ischemic stroke. Here, OGD-PBMCs were identified to secrete remodelling factors, including the vascular endothelial growth factor and transforming growth factor-ß in vitro, while intra-arterial administration of OGD-PBMCs at 7 days after focal cerebral ischemia prompted expression of such factors in the brain parenchyma at 28 days following focal cerebral ischemia in vivo. Furthermore, administration of OGD-PBMCs induced an increasing number of stage-specific embryonic antigen-3-positive cells both in vitro and in vivo. Finally, it was found to prompt angiogenesis and axonal outgrowth, and functional recovery after cerebral ischemia. In conclusion, the administration of OGD-PBMCs might be a novel therapeutic strategy against ischemic stroke.

Improved hypothermic short-term storage of isolated mouse islets by adding serum to preservation solutions.

Preserving isolated islets at low temperature appears attractive because it can keep islet quantity comparable to freshly isolated islets. In this study, we evaluated the effect of serum as an additive to preservation solutions on islet quality after short-term hypothermic storage. Isolated mouse islets were preserved at 4°C in University of Wisconsin solution (UW) alone, UW with serum, M-Kyoto solution (MK) alone or MK with serum. We then assessed islet quantity, morphology, viability and function in vitro as well as in vivo. Islet quantity after storage in all four solutions was well maintained for up to 120 h. However, islets functioned for different duration; glucose-stimulated insulin release assay revealed that the duration was 72 h when islets were stored in UW with serum and MK with serum, but only 24 h in UW alone, and the islet function disappeared immediately in MK alone. Viability assay confirmed that more than 70% islet cells survived for up to 48 h when islets are preserved in UW with serum and MK with serum, but the viability decreased rapidly in UW alone and MK alone. In in vivo bioassays using 48-h preserved isogeneic islets, all recipient mice restored normal blood glucose concentrations by transplants preserved in UW with serum or MK with serum, whereas 33.3% recipients and no recipient restored diabetes by transplants preserved in UW alone and in MK alone respectively. Adding serum to both UW and MK improves their capability to store isolated islets by maintaining islet functional viability.

Characterization of the calcification process modeled in rat embryonic calvarial culture.

An organ culture system to model the physiological calcification process was designed using rat embryonic calvaria as a device for analyzing its mechanism. Standardized calvarial explants were dissected from rat embryos aged 18 and 20 days (E18 and E20) and cultured for 1, 3 and 5 days. The calcium content of the cultured explants was quantified by atomic absorption spectrophotometry. Equivalent explants were fixed, embedded in paraffin, sectioned and stained with von Kossa stain combined with hematoxylin-eosin or processed for energy-dispersive X-ray spectroscopy to determine the concentrations of calcium, phosphorus and carbon in the tissue. The total calcium content increased significantly in E18 and E20 cultured calvaria (E18cc and E20cc) over 5 days of culture. All cultured calvaria were von Kossa-positive, whereas the staining was intensified, and sound osteoblasts and osteocytes were observed in the bone matrix only in E18cc during the 5-day culture period. Concentrations of calcium and carbon increased significantly in E18cc over 5 days, whereas E20 showed little increase. Physiological calcification proceeded in E18cc, but not in E20cc. These results indicate that the organ culture system using E18 calvaria is useful for modeling the physiological calcification process in vitro.

Augmented damage of islets by impaired exocrine acinar cells undergoing apoptosis that is possibly converted to necrosis during isolation.

Islet damage attributed to impaired exocrine cells during pancreas preservation and isolation procedure remains elusive, although released exocrine enzymes could directly damage islets. The aim of this study is to investigate the cellular mechanisms associated with exocrine cells and their possible impact on the islet cell survival and function after isolation. Mouse pancreata were stored in cold University of Wisconsin preservation solution for 0, 24 and 48 h and incubated with or without collagenase at 37°C for 15 min. During preservation, the percentage of exocrine cells with necrosis, which means impaired cellular membrane that allows intracellular enzymes to be released, remains low (< 10%) regardless of preservation time; whereas the percentage of exocrine cells with apoptosis, which means impaired nucleus and possible intact cellular membrane, increases over time of preservation. After collagenase-free incubation, however, the percentage of exocrine cells with necrosis became higher in longer preservation time, and more than 60% of the necrotic exocrine cells contained apoptosis as well. Islet cells located in pancreata with intact structure are almost kept away either from necrotic or apoptotic changes even after 48 h preservation followed by collagenase-free incubation. However, when islets are isolated after collagenase-containing incubation, the percentage of islet cells with necrosis increases over time of preservation up to approximately 40%. This study suggests that exocrine cells with necrosis could cause damage of isolated islets when the pancreas is dissociated and that the necrosis in exocrine cells might be induced mainly as the conversion from apoptosis that has already existed during preservation.

Transgenic mice expressing a fully nontoxic diphtheria toxin mutant, not CRM197 mutant, acquire immune tolerance against diphtheria toxin.

We previously developed a method termed "toxin receptor-mediated cell knockout" (TRECK). By the TRECK method, a single or repeated shot(s) of diphtheria toxin (DT) conditionally ablates a specific cell population from transgenic mice expressing the DT receptor transgene under the control of a cell type-specific promoter. In some cases of TRECK, frequent and high-dose administration of DT is required, raising the concern that these frequent injections of DT could cause production of anti-DT antibody, which would neutralize further DT administration. To solve this problem, we aimed to generate transgenic mice genetically expressing a nontoxic DT mutant, with the expectation that they may naturally acquire immune tolerance to DT. Unexpectedly, the G52E DT mutant, which is well known as the nontoxic DT variant cross reacting material 197 (CRM197), exhibited cytotoxicity in yeast and mammalian cells. Cytotoxicity of CRM197 was abrogated in cells mutated for elongation factor 2 (EF-2), indicating that CRM197 exerts its toxic effects through EF-2, similar to wild-type DT. On the other hand, the K51E/E148K DT mutant exhibited no detectable cytotoxicity. This led us to successfully obtain DT gene transgenic mice, which exhibited no histological abnormalities, and indeed acquired immune tolerance to DT.

Polymorphism of the MPR1 gene required for toxic proline analogue resistance in the Saccharomyces cerevisiae complex species.

We recently discovered, on the chromosome of Saccharomyces cerevisiae sigma 1278b, novel MPR1 and MPR2 genes required for resistance to a toxic analogue of L-proline, L-azetidine-2-carboxylic acid. The MPR genes, which were absent in the S. cerevisiae genome project strain S288C, encoded a novel acetyltransferase of 229 amino acids that detoxifies the analogue by acetylating it. The MPR1 gene homologue found in Schizosaccharomyces pombe was also shown to encode a similar acetyltransferase. To further analyse the origin and the physiological role of the yeast novel gene, we report here the comparative analysis of the MPR1 gene in the S. cerevisiae complex spp. which belong to the Saccharomyces sensu stricto group. Only the type strain of S. paradoxus exhibited resistance and acetyltransferase activity to L-azetidine-2-carboxylic acid. PCR was then used to isolate the new MPR1 homologue (Spa MPR1) from S. paradoxus with the primers based on the sequence of the MPR1 gene. Gene expression and enzymatic analysis showed that the cloned Spa MPR1 gene encodes an L-azetidine-2-carboxylic acid acetyltransferase of 231 amino acids, which has 87% identity to the MPR1 protein. We also found in the protein databases that S. bayanus contains a DNA fragment that is partly homologous to the MPR1 gene. However, the gene product was considered to lose the enzymatic activity, possibly due to the gene truncation or the base substitution(s) at the important region for catalysis. Further, genomic PCR analysis showed that most of the S. cerevisiae complex spp. have the sequence highly homologous to the MPR1 gene.