commerciallyA novel cultivated oral mucosal epithelial cell sheet transplantation (COMET) method using a commercially available regenerative product sheet originating from human ectopic autologous tissue

BACKGROUND: We report the first case of cultivated oral mucosal epithelial cell sheet transplantation (COMET) using a commercial product from a different human tissue. CASE PRESENTATION: An 80-year-old man presented with bilateral blurred vision secondary to corneal limbal stem cell deficiency (LSCD) caused by bilateral ocular cicatricial pemphigoid (OCP). The patient first noted the loss of visual acuity in his left eye at 56 years of age. He was referred to a local hospital and was diagnosed with uveitis. He was administered ten bilateral ocular sub-tenon injections of triamcinolone acetonide. The uveitis progressed to cataracts, requiring bilateral phacoemulsification with intraocular lens implantation. Although the uveitis gradually improved, his visual acuity deteriorated due to the LSCD caused by OCP. At 61 years of age, amniotic membrane transplantation was performed in the left eye. However, its effect was limited, and OCP continued progressing in both eyes. On referral to our hospital, he had only light perception on visual acuity testing. The COMET was performed in the right eye using a commercially available product sheet (Oculal®; Japan Tissue Engineering Co., Ltd., Aichi, Japan). Ten days postoperatively, epithelialization was observed in the cornea and conjunctiva. His visual acuity improved to 20/1000. The patient was discharged on the same day. CONCLUSION: This is the first report on the use of a commercially available ectopic product (Japan Tissue Engineering Co., Ltd., Aichi, Japan) originating from different human tissues (oral mucosa) for COMET. COMET may be a radical treatment for corneal LSCD

Functional assessment of retinal pigment epithelium cell transplants with various degrees of pigmentation for age-related macular degeneration

　Age-related macular degeneration (AMD) is the major cause of blindness and reduced vision among adults in Japan, for which only symptomatic therapy using an anti-vascular endothelial growth factor (anti-VEGF) drug is currently available. Recently, transplantation of retinal pigment epithelium (RPE) cells derived from human embryonic or pluripotent stem cells has been extensively applied in clinical practice as a radical therapy for patients with AMD; however, its therapeutic effect remains limited. RPE cells have melanin pigment granules that increase over time; moreover, the degree of pigmentation (dPG) increases with the number of pigment granules. The expression levels of RPE-specific genes and the secretion of cytokines reportedly increase as dPG increases. In this study, we performed functional characterization of human RPE (h-RPE) cells with low and high dPG to determine which might be suitable for transplantation to patients with AMD. Specifically, we isolated h-RPE cells with low and high dPG based on evaluation of lightness parameters, then characterized these cells separately. Our results showed that RPE cells with low dPG exhibited elevated phagocytosis and cell adhesiveness, as well as reduced VEGF secretion, compared with RPE cells with high dPG. Because these traits are considered preferable for transplantation to patients with AMD, RPE cells with low dPG may be more suitable for transplantation. Cellular senescence (indicated by levels of senescence-related proteins) was more advanced in RPE cells with high dPG, suggesting that cellular senescence is an important factor that contributes to the suitability of RPE cells for transplantation to patients with AMD

Generation of retinal pigment epithelium from human induced pluripotent stem cells showed polarized secretion of VEGF and PEDF.

Age-related macular degeneration (AMD) is one of the major diseases that cause severe visual impairment in developed countries and is related to dysfunction of the retinal pigment epithelium (RPE). Human induced pluripotent stem cells (hiPSCs) have been drawing attention as a valuable source of RPE for basic research on or treatment of AMD. Here we investigated whether RPE could be generated from hiPSCs in Kawasaki Medical School. We maintained hiPSCs retaining pluripotent markers after a series of regular culture steps involving passaging, freezing, and thawing. hiPSCs were then cultured in RPE differentiation medium, and pigmented colonies were manually isolated for further differentiation into RPE. Differentiated cells formed pigmented cells with a typical RPE cobblestone appearance, abundant apical microvilli, adherens junctions, and tight junctions. Furthermore, generated pigmented cells expressed typical RPE marker genes, exhibited a barrier function, and secreted growth factors in a polarity-dependent manner similar to native RPE. These results indicate that RPE derived from hiPSCs in our facility can be used for in vitro and in vivo research

Intravitreal injection of corticosteroid attenuates leukostasis and vascular leakage

PURPOSE. Recently, intravitreal injection of corticosteroids has been in wide use as a treatment for diabetic macular edema, and the outcomes have been favorable. However, the exact mechanism remains unclear. The hypothesis for the current study was that intravitreal corticosteroids may improve diabetic retinal edema by amelioration of blood-retinal barrier (BRB) breakdown, by inhibiting leukocyte stasis (leukostasis). METHODS. Diabetes was induced in 6-week-old male Long-Evans rats by intraperitoneal injection of streptozotocin (75 mg/kg). Three weeks after induction of diabetes, intravitreal injection of dexamethasone (40 g/10 L) was performed. At 2 days after intravitreal injection, accumulated leukocytes were counted in vivo by acridine orange leukocyte fluorography, and BRB breakdown was evaluated by measurement of retinal vascular permeability. The mRNA expression and protein levels of intercellular adhesion molecule (ICAM)-1 in the retina were also studied. RESULTS. The number of leukocytes accumulated in the retina, once increased in the diabetic group, was decreased by 31.6% (P ϭ 0.0001) after dexamethasone injection. The level of BRB breakdown, also elevated in the diabetic group, was suppressed by 61.1% (P ϭ 0.0046) after dexamethasone injection. The level of ICAM-1 mRNA expression and its protein, upregulated in the diabetic group, were downregulated by dexamethasone treatment by 70.0% (P Ͻ 0.0001) and 56.4% (P ϭ 0.0003). CONCLUSIONS. Intravitreal injection of corticosteroids improves diabetic retinal edema through inhibiting leukocyte recruitment in the diabetic retina. (Invest Ophthalmol Vis Sci. 2005