Sulphation patterns of keratan sulphate proteoglycan in sclerocornea resemble cornea rather than sclera.
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Cornea↗
Biomedical subjects
C Sotozono
Publications and source records attributed to C Sotozono.
A novel mutation in the alternative splice region of the PAX6 gene in a patient with Peters' anomaly.
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Adult↗
Transplantation of cultivated autologous oral mucosal epithelial cells in patients with severe ocular surface disorders.
BACKGROUND/AIMS: To determine outcomes of transplants of cultivated autologous oral epithelial cells in patients with severe ocular surface disorders. METHODS: The eyes (n = 6) of four patients with Stevens-Johnson syndrome (three eyes) or chemical burns (three eyes) were studied. Autologous oral epithelial cells, grown for 2-3 weeks on a denuded amniotic membrane carrier in the presence of 3T3 fibroblasts, were air lifted. The resultant sheet was transplanted onto the damaged eye, and acceptance of the sheet by the corneal surface was confirmed 48 hours after surgery. The success of ocular surface reconstruction, graft survival, changes in visual acuity, and postoperative complications were assessed and the quality of the cultivated oral epithelial sheet was evaluated histologically. RESULTS: At 48 hours after transplant, the entire corneal surface of all six eyes was free of epithelial defects indicating complete survival of the transplanted oral epithelium. Visual acuity was improved in all eyes. During follow up (mean 13.8 (SD 2.9) months), the corneal surface remained stable, although all eyes manifested mild peripheral neovascularisation. CONCLUSIONS: Autologous oral epithelial cells grown on denuded amniotic membrane can be transplanted to treat severe ocular surface disorders.
Adolescent↗
Immunosuppressive properties of human amniotic membrane for mixed lymphocyte reaction.
The combination of allograft limbal transplantation (ALT) and amniotic membrane transplantation (AMT) has been applied in the treatment of severe ocular surface diseases. The beneficial effect of this combination has been thought to result from possible immunosuppressive ability of amniotic membrane (AM). However, the mechanisms of any such ability remain unknown. In this study, we investigated whether human AM has the ability to suppress allo-reactive T cell responses in vitro. For mixed lymphocyte reaction (MLR), lymphocytes isolated from lymph nodes of C57BL/6 mice (Mls1b, Vbeta6+) were cultured with irradiated splenocytes from DBA/2 mice (Mls1a, Vbeta6-) with or without human AM. For carboxyfluorescein diacetate succinimidyl ester (CFSE) experiments, responder lymph node cells were labelled with a stable intracellular fluorescent dye and cultured with irradiated stimulator cells. The ratio of responder Vbeta6+ T cells was then determined by FACS analysis, and the division profiles of responder Vbeta6+ T cells were analysed by CFSE content. Furthermore, Th1 and Th2 cytokine synthesis by allo-reactive T cells in MLR culture supernatants was determined by enzyme-linked immunosorbent assay (ELISA). Addition of AM to the MLR culture resulted in the significant inhibition of thymidine incorporation compared with control culture lacking AM. The population of responder CD4+Vbeta6+ T cells was significantly reduced in the AM-treated culture in comparison to control. CFSE analysis revealed less division and lower proliferation of responder CD4+Vbeta6+ T cells in cultures with AM than without. In addition, allo-rective T cell synthesis of both Th1 (IL-2 and IFNgamma) and Th2 (IL-6 and IL-10) type cytokine was significantly decreased in the presence of AM. These results indicate that human AM has the ability to suppress allo-reactive T cells in vitro. This inhibitory effect likely contributes to the success of the ALT-AMT combination.
Amnion↗
The epidermal growth factor receptor (EGFR): role in corneal wound healing and homeostasis.
To evaluate the role of the epidermal growth factor receptor (EGFR) in corneal epithelial wound healing, the effect of an EGFR inhibitor on epithelial cell proliferation and cell stratification during wound healing was investigated. From 3 days prior to wounding until wound healing was complete, rats were systemically treated with either an EGFR tyrosine kinase inhibitor (ZD1839) at 40 mg kg(-1) day(-1)or 80 mg kg(-1) day(-1), or with vehicle only (control). A single corneal wound was made in the center of 66 rat corneas, using a 6.0 mm glass tube wrapped in tissue paper soaked in n-heptanol. Subsequently, each wound was photographed and measured by a computer-assisted digitizer every 12 hr. To determine the number of cells in S phase, entire corneas were labelled with (3)H-thymidine and subjected to autoradiography at 0, 12, 24 and 48 hr after wounding. Epithelial thickness was also measured at these time points by microscopy. Epithelial wound healing was significantly and dose-dependently delayed following administration of ZD1839. At 24 hr after wounding, the number of S-phase cells in the limbal corneal epithelium was significantly lower in both the treated groups compared with the control group (P < 0.05). In the cornea before wounding (0 hr) and at 48 hr post-wounding, epithelial thickness was also significantly less in treated rats compared with controls (P < 0.05). These results indicate that EGFR inhibition affects epithelial cell proliferation and stratification during corneal epithelial wound healing and may play a role in maintaining normal corneal epithelial thickness.
Animals↗
Cultivated corneal epithelial stem cell transplantation in ocular surface disorders.
PURPOSE: To investigate the outcome of cultivated corneal epithelial transplantation for severe stem cell deficiencies using denuded amniotic membrane (AM) as a carrier. DESIGN: Retrospective, noncomparative case series. PARTICIPANTS: Thirteen eyes of 11 patients were studied. These consisted of five eyes with acute Stevens-Johnson syndrome (SJS), two with chronic SJS, one with an acute chemical injury, two with chronic chemical injuries, two with ocular cicatricial pemphigoid, and one with drug-induced pseudopemphigoid. All of these eyes had total stem cell deficiencies. MAIN OUTCOME MEASURES: Adaptation of the cultivated corneal epithelium onto the host corneal surface was confirmed 48 hours after surgery. The reconstruction of the ocular surface and visual acuity were measured. METHODS: Corneal limbal epithelium from donor corneas was cultivated for 4 weeks on a denuded AM carrier, with 3T3 fibroblast coculture and air lifting. The cultivated corneal epithelium showed four to five layers of stratification and was well differentiated. After conjunctival tissue removal from the cornea up to 3 mm outside the limbus and subconjunctival tissue treatment with 0.04% mitomycin C, cultivated allocorneal epithelium, including the AM carrier, was transplanted onto the corneal surface up to the limbus. Lamellar keratoplasty, using preserved donor graft without epithelium, was performed simultaneously for five chronic-phase patients showing corneal stromal scarring. Systemic immunosuppression was used to prevent allograft rejection. RESULTS: In all 13 eyes, the entire corneal surface, on which cultivated allocorneal epithelium had been placed, was free from epithelial defects 48 hours after surgery, indicating complete survival of the transplanted corneal epithelium. Visual acuity improved in all eyes after surgery, and 10 of the 13 eyes were restored to good vision (postoperative visual acuity improved two or more lines) 6 months after the operation. During the follow-up period (mean +/- standard deviation, 11.2 +/- 1.3 months), the corneal surfaces were clear, although three eyes experienced epithelial rejection. CONCLUSIONS: Cultivated corneal epithelial transplantation using denuded AM as a carrier can be used for severe stem cell deficiencies.
Adult↗
Characteristics of the human ocular surface epithelium.
An appreciation of the biological characteristics of the human ocular surface epithelium affords us a great insight into the physiology of the human ocular surface in health and disease. Here, we review five important aspects of the human ocular surface epithelium. First, we recognize the discovery of corneal epithelial stem cells, and note how the palisades of Vogt have been suggested as a clinical marker of their presence. Second, we introduce the concept of the gene expression profile of the ocular surface epithelium as arrived at using a new strategy for the systematic analysis of active genes. We also provide a summary of several genes abundantly or uniquely expressed in the human corneal epithelium, namely clusterin, keratin 3, keratin 12, aldehyde dehydrogenase 3 (ALDH3), troponin-I fast-twitch isoform, ssig-h3, cathepsin L2 (cathepsin V), uroplakin Ib, and Ca(2+)-activated chloride channel. Genes related to limbal and conjunctival epithelia are also described. Third, we touch upon the genetic abnormalities thought to be involved with epithelial dysfunction in Meesmann's dystrophy, gelatinous drop-like corneal dystrophy, and the ssig-h3-mutated corneal dystrophies. Fourth, we provide an update regarding the current state of knowledge of the role of cytokines, growth factors and apoptosis in relation to ocular surface homeostasis and tissue reconstruction; the main factors being epidermal growth factor (EGF), keratinocyte growth factor (KGF), hepatocyte growth factor (HGF), transforming growth factor-ss (TGF-ss), and some inflammatory cytokines. Fifth, corneal epithelial barrier function and dysfunction as measured by fluorophotometry is remarked upon, with an explanation of the FL-500 fluorophotometer and its ability to detect corneal epithelial dysfunction at a subclinical level. The research described in this review has undoubtedly generated a complete understanding of corneal epithelial pathophysiology-an understanding that, directly or indirectly, has helped advance the development of new therapeutic modalities for ocular surface reconstruction.
Apoptosis↗
Expression of sex steroid hormone receptors in human cornea.
PURPOSE: Previously we reported the occurrence of estrogen receptor alpha (ER beta), estrogen receptor beta (ER beta) and androgen receptor (AR) in mouse corneas. The present study was designed to investigate the occurrence of various sex steroid hormone receptors, including ER alpha, progesterone receptor (PR) and AR, in human corneas. METHODS: We used reverse transcription-polymerase chain reaction (RT-PCR) to look for sex hormone receptor mRNAs (ER alpha, PR and AR) in human corneal epithelial cells obtained at autopsy. Next, using an immunocytochemical technique, we localized these receptors in donor human corneas. RESULTS: mRNAs encoding all receptors tested for were found in corneal epithelial cells obtained from male and female donor eyes. Immunocytochemical examination revealed that the receptors were located in the nuclei of corneal epithelial, stromal, and endothelial cells. CONCLUSIONS: Since receptors for both male and female sex hormones are present in human corneas of both genders, we postulate that the receptors may influence the biological functions of corneal cells through direct interaction with specific hormones.
Aged↗
Interleukin-6 (IL-6) production by cytokine-stimulated human Müller cells.
PURPOSE: To investigate whether or not human Müller cells synthesize interleukin (IL)-6. METHODS: Using RT-PCR, we first confirmed whether cultured human Müller cells express IL-6 mRNA. Then, to determine Müller cell IL-6 production after stimulation, cultured Müller cells were exposed to various concentrations of IL-1beta (0.2 ng/ml, 2 ng/ml, 20 ng/ml) or lipopolysaccharide (LPS) (0.001 microg/ml, 0.1 microg/ml, 10 microg/ml) in 24 hr assays. In addition, to determine Müller cell time-dependent induction of IL-6 production, cultured Müller cells were exposed to IL-1beta (0.02 ng/ml, 2 ng/ml) or LPS (10 microg/ml) for 6, 12, 24, 36 hr. IL-6 production in supernatants was quantified by ELISA: RESULTS: IL-6 mRNA was expressed in cultured human Müller cells, which produced IL-6 after stimulation with either IL-1beta or LPS for 24 hours. IL-1beta was a significantly more potent stimulator of IL-6 production than was LPS. Exposure of cultured human Müller cells to either IL-1beta or LPS stimulated IL-6 production in a time-dependent fashion. CONCLUSIONS: Our findings indicate that human Müller cells can produce IL-6 when stimulated by IL-1beta or LPS. Müller cell IL-6 production may have an important role in various conditions involving ocular inflammation
Cell Division↗
Vitreous levels of insulin-like growth factor-I in patients with proliferative diabetic retinopathy.
The levels of IGF-I in the vitreous body and the intraocular fluid of patients with proliferative diabetic retinopathy (PDR) were determined using radioimmunoassay (RIA). Eleven vitreous specimens were obtained from the intraocular fluid of eyes of patients with PDR who underwent surgery during the operation. Eleven intraocular fluids from the same patients during reoperations were compared with controls. The expression of IGF-I mRNA in cultured human Muller glial cells was evaluated using reverse transcription-polymerase chain reaction (RT-PCR). The mean IGF-I level in the vitreous samples during initial PDR surgery and reoperation was significantly higher than that found in the vitreous of the control (p < 0.05). The level of IGF-I increased in 6 of the 11 cases. Cultured human Muller cells expressed IGF-I mRNA. The results indicate increased levels of IGF-I both in the initial vitreous and ocular fluid at post-operative re-proliferation. Muller cell is suggested as an origin of local IGF-I production.
Adult↗
Cultivated corneal epithelial transplantation for ocular surface reconstruction in acute phase of Stevens-Johnson syndrome.
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Acute Disease↗
Growth factors: importance in wound healing and maintenance of transparency of the cornea.
The mechanism of corneal wound healing has not been clarified yet. However, evidence has accumulated that various kinds of growth factor such as epidermal growth factor (EGF), fibroblast growth factor (FGF), transforming growth factor (TGF), keratinocyte growth factor (KGF), hepatocyte growth factor (HGF), platelet-derived growth factor (PDGF) and insulin-like growth factor (IGF) play a key role in corneal wound healing. For example, these growth factors are expressed in the corneal epithelial cells, keratocytes and endothelial cells, and their receptors are expressed in the corneal cells. Furthermore, these growth factors promote the proliferation of corneal cells and induce the migration of corneal cells. In addition to the growth factors, inflammatory cytokines such as interleukin (IL)-1, IL-6 and TNF-alpha are involved in corneal wound healing. These cytokines are expressed in the normal and inflammatory cornea after infections, alkaliburn, etc. where they control the growth of corneal cells and induce the migration of corneal cells. Thus, a number of growth factors and cytokines function in the regulation of corneal cell proliferation and in the maintenance of corneal transparency.
Animals↗
Conjunctival inflammation in the chronic phase of Stevens-Johnson syndrome.
AIMS: To understand the immunopathogenesis of the corneal conjunctivalisation in Stevens-Johnson syndrome. METHODS: Conjunctivalised corneas from five patients with Stevens-Johnson syndrome were studied immunohistochemically for several cell surface antigens and two cytokines. Chemical injury specimens were also studied. RESULTS: In all cases, immunohistochemistry revealed LFA-1, CD4, CD8, and CD68 on subepithelial infiltrating cells. Also, HLA-DR and ICAM-1 were found on the surfaces of epithelial cells, subepithelial infiltrating cells, subepithelial fibroblasts, and endothelial cells in blood vessels. IFN-gamma was found in basal epithelial cells; subepithelial cells and subepithelial extracellular matrix CD19 and IL4 were not detected. CONCLUSIONS: The infiltrating cell population in the Stevens-Johnson syndrome samples includes macrophages, CD4 positive T cells, and CD8 positive T cells. The cytokine expression pattern suggests CD4 positive T cells are Th1 cells. The infiltrating cell population is similar in Stevens-Johnson syndrome and chemical injury conjunctivalised corneas.
Adult↗
Soluble Fas ligand expression in the ocular fluids of uveitis patients.
PURPOSE: The expression of Fas ligand (FasL) in ocular tissues is thought to play a critical role in maintaining immune privilege in the eye. In this study, to clarify the involvement of the Fas-FasL system in inflammatory processes of the eye,we examined soluble FasL (sFasL) in ocular inflammation. METHODS: Using ELISA systems recently developed, sFasL concentrations in aqueous humor (AH) and/or vitreous fluid (VF) were measured. AH was obtained from 17 eyes of 17 uveitis patients and from 12 eyes of 12 non-uveitis (cataract) patients. VF was obtained from 22 eyes of 22 uveitis patients and 7 eyes of 7 non-uveitis (macular hole) patients. Serum levels of sFasL were also determined. RESULTS: sFasL in AH and VF was below the detection limit of the ELISA systems in all non-uveitis eyes. On the other hand, sFasL was detected in AH from uveitis patients where it measured 367.0 +/- 154.7 pg/ml (mean +/- SEM). sFasL was also detected in VF from uveitis patients where it measured 1132.2 +/- 281.7 pg/ml. None of the sera from patients with or without uveitis contained a detectable level of sFas L. CONCLUSIONS: sFasL levels in AH and VF are elevated in the eye during ocular inflammation. Fas-FasL mediated apoptosis may play an important role in the regulation of inflammation during uveitis.
Aged↗
Regulatory effects of 1alpha,25-dihydroxyvitamin D(3) on cytokine production by human corneal epithelial cells.
PURPOSE: The topical administration of 1alpha,25-dihydroxy-vitamin D(3) [1alpha,25(OH)(2)D(3) ] inhibits Langerhans cell (LC) migration and corneal neovascularization in mice. Since the cytokines that induce LC migration [e.g. interleukin-1 (IL-1)] and corneal neovascularization [e.g. interleukin-8 (IL-8)] are produced by human corneal epithelial cells, we investigated the inhibitory effects of 1alpha,25(OH)(2)D( 3) on cytokine production by these cells in vitro. METHODS: In this experiment, human corneal epithelial cells, cultured in DMEM-FBS until confluence, were then switched to serum-free DMEM containing insulin, transferrin, and sodium selenite (DMEM-ITS) for 48 hours. Next, they were cultured with DMEM-ITS containing 1alpha,25(OH)(2)D(3 ) at concentrations of 10(-7) M, 10(-11) M, or 10( -15) M, and vehicle only (0.1% ethanol). After 6 or 12 hours in this culture, the supernatants were collected and concentrations of IL-1alpha, IL-1b, and IL-8 were quantified by ELISA. RESULTS: Significantly lower levels of IL-1alpha and IL-1b were detected in supernatants from cells cultured with 1alpha, 25(OH)(2)D( 3) (10(-7) M, 10(-11) M, and 10(-15) M), compared to cells cultured with vehicle only. This was true at 6 and 12 hours after the addition of 1alpha,25(OH)(2)D(3) (p < 0.05). IL-8 production inhibition by 1alpha,25(OH)(2)D(3), on the other hand, was detected at 6 hours (p < 0.0005) but not at 12 hours (p> 0.1). CONCLUSIONS: 1alpha,25(OH)(2)D(3) inhibits cytokine (IL-1alpha, IL-1b, and IL-8) production by human corneal epithelial cells in vitro. We suspect that 1alpha,25(OH)(2)D(3) can inhibit LC migration and corneal neovascularization, as is seen in ocular surface inflammation.
Calcitriol↗
Kinetics of cytokine production in the cornea and trigeminal ganglion of C57BL/6 mice after corneal HSV-1 infection.
To investigate the role of cytokines in the pathogenesis of acute herpetic keratitis (HK), we examined the kinetics of cytokine expression in the corneas and the trigeminal ganglia (TG) of C57BL/6Cr (B6) mice after herpes simplex virus type 1 (HSV-1) infection and observed the influence of the targeted disruption of interferon-gamma (IFN-gamma) gene on the clinical course of HK and/or viral clearance. Following corneal infection with HSV-1 Amakata strain, all corneas developed a typical dendritic keratitis. Quantitative analysis using enzyme-linked immunosorbent assay (ELISA) revealed that the expression of interleukin-1alpha (IL-1alpha), IL-5, IL-6, and IFN-gamma in corneas and TGs significantly elevated immediately after infection, peaked between days 2 and 7 postinfection (p.i.), and then diminished. One exception was IFN-gamma, whose expression significantly persisted in the TGs until day 30 p.i. An additional experiment using IFN-gamma-/- (gko) mice revealed that there was no significant difference in the peak level of viral replication in corneas and TGs between gko and B6 mice, although gko mice showed a significant delay of virus clearance in both corneas and TGs (p < 0.005) and higher mortality rate than B6 mice after HSV-1 infection (p < 0.01). These data suggest that the production of proinflammatory cytokines closely correlates with the pathogenesis of HK, and that IFN-gamma plays an important role in enhancing viral clearance from the cornea and TG.
Animals↗
Peripheral lamellar keratoplasty for corneoscleral cyst: three case reports.
PURPOSE: To examine whether peripheral lamellar keratoplasty (LKP) using preserved cornea was effective for the treatment of corneoscleral cysts. METHODS: Three patients with corneoscleral cysts underwent peripheral lamellar keratoplasty. Two patients had no history of trauma or ocular surgery and were considered to have congenital cysts. The other patient had a history of strabismus surgery that had been performed 7 years previously. The anterior wall of the cysts was removed by trephination, and the epithelial membrane lining the posterior wall was peeled off. Lamellar corneal buttons obtained from preserved corneas then were put in place and secured with 8-10 interrupted sutures. In one case, because the cyst was large and extended to the pupillary axis, peripheral LKP was performed for removal of the scleral and peripheral corneal cyst, and the inner wall of the central corneal cyst was removed with vigorous irrigation and a spatula. RESULTS: Histologic examination showed that all of the cysts were lined with nonkeratinizing epithelial cells. In all three cases, cysts have not reformed after a 1-5-year follow-up. CONCLUSIONS: The cysts were lined in epithelial cells, and removal of these epithelial cells was considered to be important for the prevention of recurrence. Peripheral LKP is effective for the treatment of corneoscleral cysts, since this procedure removes displaced epithelial cells and reconstructs the thin part of the cornea and sclera.
Adolescent↗
Detection of herpes simplex virus DNA in atypical epithelial keratitis using polymerase chain reaction.
AIM: To study herpes simplex virus (HSV) DNA in tears from patients with atypical epithelial keratitis of unknown aetiology. METHODS: Tear samples were collected from 17 affected eyes of 17 consecutive patients suffering from epithelial keratitis in whom HSV keratitis was suspected but whose diagnosis was difficult on the basis of clinical manifestations alone. Using reduced sensitivity polymerase chain reaction (PCR), tear samples were tested for HSV DNA. Tears from the unaffected eyes of the 17 patients were also examined, along with 38 tear samples from 19 normal volunteers. Southern blot analysis was performed to confirm that amplified DNA bands were specific for HSV. Clinical correlation with photographs of corneal lesions was also investigated. RESULTS: HSV DNA was detected in tears from the affected eyes of eight of the 17 patients with suspected HSV keratitis. Tears from the affected eyes of the other patients were PCR negative, as were tears from the unaffected eyes of all 17 patients, and from the 38 normal eyes. There was no correlation between PCR results and clinical manifestation of keratitis. CONCLUSIONS: Based on the sensitivity of the PCR system, eight of 17 suspected HSV keratitis patients were confirmed as suffering from HSV keratitis. HSV keratitis should therefore be considered as a possible diagnosis in atypical epithelial keratitis.
Adult↗