ABSTRACT
[This corrects the article DOI: 10.1371/journal.pone.0147279.].
ABSTRACT
C-C chemokine receptor 2 (Ccr2) is a key pro-inflammatory marker of classic (M1) macrophage activation. Although Ccr2 is known to be expressed both constitutively and inductively, the full regulatory mechanism of its expression remains unclear. AMP-activated protein kinase (AMPK) is not only a master regulator of energy homeostasis but also a central regulator of inflammation. In this study, we sought to assess AMPK's role in regulating RAW264.7 macrophage Ccr2 protein levels in resting (M0) or LPS-induced M1 states. In both M0 and M1 RAW264.7 macrophages, knockdown of the AMPKα1 subunit by siRNA led to increased Ccr2 levels whereas pharmacologic (A769662) activation of AMPK, attenuated LPS-induced increases in Ccr2 expression in an AMPK dependent fashion. The increases in Ccr2 levels by AMPK downregulation were partially reversed by NF-κB inhibition whereas TNF-a inhibition had minimal effects. Our results indicate that AMPK is a negative regulator of Ccr2 expression in RAW264.7 macrophages, and that the mechanism of action of AMPK inhibition of Ccr2 is mediated, in part, through the NF-κB pathway.
Subject(s)
AMP-Activated Protein Kinases/metabolism , Macrophage Activation/immunology , Macrophages/immunology , NF-kappa B/metabolism , Receptors, CCR2/biosynthesis , AMP-Activated Protein Kinases/genetics , Animals , Cell Line , Enzyme Activation/drug effects , Gene Expression Regulation/genetics , Inflammation/immunology , Lipopolysaccharides , Macrophages/metabolism , Mice , NF-kappa B/antagonists & inhibitors , RNA Interference , RNA, Small Interfering/genetics , Signal Transduction/immunology , Tumor Necrosis Factor-alpha/antagonists & inhibitorsABSTRACT
Recent studies suggest that the anti-diabetic drug metformin may reduce the risk of cancer and have anti-proliferative effects for some but not all cancers. In this study, we examined the effects of metformin on human retinoblastoma cell proliferation in vitro and in vivo. Two different human retinoblastoma cell lines (Y79, WERI) were treated with metformin in vitro and xenografts of Y79 cells were established in nu/nu immune-deficient mice and used to assess the effects of pharmacological levels of metformin in vivo. Metformin inhibited proliferation of the retinoblastoma cells in vitro. Similar to other studies, high concentrations of metformin (mM) blocked the cell cycle in G0G1, indicated by a strong decrease of G1 cyclins, especially cyclin D, cyclin-dependent kinases (4 and 6), and flow cytometry assessment of the cell cycle. This was associated with activation of AMPK, inhibition of the mTOR pathways and autophagy marker LC3B. However, metformin failed to suppress growth of xenografted tumors of Y79 human retinoblastoma cells in nu/nu mice, even when treated with a maximally tolerated dose level achieved in human patients. In conclusion, suprapharmacological levels (mM) of metformin, well above those tolerated in vivo, inhibited the proliferation of retinoblastoma cells in vitro. However, physiological levels of metformin, such as seen in the clinical setting, did not affect the growth of retinoblastoma cells in vitro or in vivo. This suggests that the potential beneficial effects of metformin seen in epidemiological studies may be limited to specific tumor types or be related to indirect effects/mechanisms not observed under acute laboratory conditions.
Subject(s)
Cell Proliferation/drug effects , Metformin/administration & dosage , Retinoblastoma/drug therapy , AMP-Activated Protein Kinases/biosynthesis , Animals , Apoptosis/drug effects , Autophagy/drug effects , Gene Expression Regulation, Neoplastic/drug effects , Humans , Mice , Retinoblastoma/genetics , Retinoblastoma/pathology , TOR Serine-Threonine Kinases/biosynthesis , Xenograft Model Antitumor AssaysABSTRACT
Ocular neovascularization, including age-related macular degeneration (AMD), is a primary cause of blindness in individuals of industrialized countries. With a projected increase in the prevalence of these blinding neovascular diseases, there is an urgent need for new pharmacological interventions for their treatment or prevention. Increasing evidence has implicated eicosanoid-like metabolites of long-chain polyunsaturated fatty acids (LCPUFAs) in the regulation of neovascular disease. In particular, metabolites generated by the cytochrome P450 (CYP)-epoxygenase pathway have been shown to be potent modulators of angiogenesis, making this pathway a reasonable previously unidentified target for intervention in neovascular ocular disease. Here we show that dietary supplementation with ω-3 LCPUFAs promotes regression of choroidal neovessels in a well-characterized mouse model of neovascular AMD. Leukocyte recruitment and adhesion molecule expression in choroidal neovascular lesions were down-regulated in mice fed ω-3 LCPUFAs. The serum of these mice showed increased levels of anti-inflammatory eicosanoids derived from eicosapentaenoic acid and docosahexaenoic acid. 17,18-epoxyeicosatetraenoic acid and 19,20-epoxydocosapentaenoic acid, the major CYP-generated metabolites of these primary ω-3 LCPUFAs, were identified as key lipid mediators of disease resolution. We conclude that CYP-derived bioactive lipid metabolites from ω-3 LCPUFAs are potent inhibitors of intraocular neovascular disease and show promising therapeutic potential for resolution of neovascular AMD.
Subject(s)
Choroidal Neovascularization/drug therapy , Cytochrome P-450 Enzyme System/metabolism , Fatty Acids, Omega-3/pharmacology , Food, Fortified , Macular Degeneration/physiopathology , Animals , Arachidonic Acids , Chromatography, Liquid , DNA, Complementary/genetics , Enzyme-Linked Immunosorbent Assay , Fatty Acids, Omega-3/therapeutic use , Flow Cytometry , Immunoblotting , Laser Capture Microdissection , Macular Degeneration/drug therapy , Mice , PPAR gamma/metabolism , Real-Time Polymerase Chain Reaction , Tandem Mass SpectrometryABSTRACT
EGFL7 is a secreted angiogenic factor, which in contrast to the well-known secreted angiogenic molecules VEGF and FGF-2, is almost exclusively expressed by endothelial cells and may act in an autocrine fashion. Prior studies have shown EGFL7 to mediate its angiogenic effects by interfering with the Notch pathway and/or via the intronic miR126. Less is known about its effects on VEGF signaling. We wanted to investigate the role of epidermal growth factor-like domain 7 (EGFL7) in VEGF-driven angiogenesis using an ex vivo Matrigel-embedded mouse eye cup assay and siRNA mediated knockdown of EGFL7 by siRNA. Our results suggested that VEGF-induced vascular tube formation was significantly impaired after siRNA downregulation of EGFL7. In addition, knockdown of EGFL7 suppressed VEGF upregulation of phospho-Akt and phospho-Erk(1/2) in endothelial cells, but did not alter VEGFR phosphorylation and neuropilin-1 protein expression or miR126 expression. Thus, in conclusion, EGFL7 is required for VEGF upregulation of the Akt/Erk (1/2) pathway during angiogenesis, and may represent a new therapeutic target in diseases of pathological neovascularization.
Subject(s)
Biological Assay , Extracellular Signal-Regulated MAP Kinases/metabolism , In Vitro Techniques , Neovascularization, Physiologic/drug effects , Proteins/metabolism , Proto-Oncogene Proteins c-akt/metabolism , Vascular Endothelial Growth Factor A/pharmacology , Animals , Calcium-Binding Proteins , EGF Family of Proteins , Endothelial Cells/drug effects , Endothelial Cells/enzymology , Enzyme Activation/drug effects , Gene Knockdown Techniques , Mice, Inbred C57BL , Neuropilin-1/metabolism , Phosphorylation/drug effects , Vascular Endothelial Growth Factor Receptor-2/metabolismABSTRACT
Caveolin-1 is the primary structural component of endothelial caveolae that is essential for transcellular trafficking of albumin and is also a critical scaffolding protein that regulates the activity of signaling molecules in caveolae. Phosphorylation of caveolin-1 plays a fundamental role in the mechanism of oxidant-induced vascular hyper permeability. However, the regulatory mechanism of caveolin-1 phosphorylation remains unclear. Here we identify a previously unexpected role for AMPK in inhibition of caveolin-1 phosphorylation under oxidative stress. A pharmacological activator of AMPK, 5-amino-4-imidazole carboxamide riboside (AICAR), inhibited oxidative stress-induced phosphorylation of both caveolin-1 and c-Abl, which is the major kinase of caveolin-1, and endocytosis of albumin in human umbilical vein endothelial cell. These effects were abolished by treatment with two specific inhibitors of AICAR, dipyridamole, and 5-iodotubericidin. Consistently, knockdown of the catalytic AMPKα subunit by siRNA abolished the inhibitory effect of AICAR on oxidant-induced phosphorylation of both caveolin-1 and c-Abl. Pretreatment with specific c-Abl inhibitor, imatinib mesylate, and knock down of c-Abl significantly decreased the caveolin-1 phosphorylation after H2O2 exposure and abolished the inhibitory effect of AICAR on the caveolin-1 phosphorylation. Interestingly, knockdown of Prdx-1, an antioxidant enzyme associated with c-Abl, increased phosphorylation of both caveolin-1 and c-Abl and abolished the inhibitory effect of AICAR on the caveolin-1 phosphorylation. Furthermore, co-immunoprecipitation experiment showed that AICAR suppressed the oxidant-induced dissociation between c-Abl and Prdx1. Overall, our results suggest that activation of AMPK inhibits oxidative stress-induced caveolin-1 phosphorylation and endocytosis, and this effect is mediated in part by stabilizing the interaction between c-Abl and Prdx-1.
Subject(s)
AMP-Activated Protein Kinases/metabolism , Caveolin 1/metabolism , Endocytosis , Human Umbilical Vein Endothelial Cells/metabolism , Peroxiredoxins/metabolism , Proto-Oncogene Proteins c-abl/metabolism , AMP-Activated Protein Kinases/genetics , Albumins/metabolism , Albumins/pharmacokinetics , Aminoimidazole Carboxamide/analogs & derivatives , Aminoimidazole Carboxamide/pharmacology , Blotting, Western , Caveolin 1/genetics , Cells, Cultured , Dipyridamole/pharmacology , Enzyme Activation/drug effects , Humans , Hydrogen Peroxide/pharmacology , Isoenzymes/genetics , Isoenzymes/metabolism , Microscopy, Confocal , Oxidants/pharmacology , Oxidative Stress , Peroxiredoxins/genetics , Phosphorylation/drug effects , Protein Binding , Proto-Oncogene Proteins c-abl/genetics , RNA Interference , Ribonucleotides/pharmacology , Tubercidin/analogs & derivatives , Tubercidin/pharmacologyABSTRACT
PURPOSE: To investigate the anti-inflammatory effect of an adenosine monophosphate (AMP) analog, aminoimidazole carboxamide ribonucleotide (AICAR), in experimental autoimmune uveoretinitis (EAU). METHODS: C57BL/6 mice were injected daily with AICAR (200 mg/kg, intraperitoneally [IP]) from day 0, the day of interphotoreceptor retinoid-binding protein (IRBP) immunization, until day 21. The severity of uveitis was assessed clinically and histopathologically. T-cell proliferation and cytokine production of IFN-γ, IL-17, and IL-10 in response to IRBP stimulation were determined. In addition, regulatory T-cell (Treg) populations were measured. Co-stimulatory molecule expression (CD40, 80, 86, and I-Ab) on dendritic cells (DCs) in EAU and on bone marrow-derived dendritic cells (BMDCs) treated with AICAR was measured. RESULTS: AICAR treatment significantly reduced clinical and histologic severity of EAU as well as ocular cytokine production. An anti-inflammatory effect associated with the inhibition of T-cell proliferation and Th1 and Th17 cytokine production was observed. Increases in the Th2 response and Treg population were not observed with AICAR treatment. AICAR did significantly inhibit BMDC maturation by reducing co-stimulatory molecule expression. CONCLUSIONS: AICAR attenuates EAU by preventing generation of Ag-specific Th1 and Th17 cells. Impaired DC maturation may be an underlying mechanism for this anti-inflammatory effect observed with AICAR.
Subject(s)
Aminoimidazole Carboxamide/analogs & derivatives , Autoimmune Diseases/drug therapy , Immunity, Cellular , Ribonucleotides/administration & dosage , T-Lymphocytes/immunology , Uveitis/drug therapy , Aminoimidazole Carboxamide/administration & dosage , Aminoimidazole Carboxamide/therapeutic use , Animals , Autoimmune Diseases/immunology , Autoimmune Diseases/metabolism , Blotting, Western , Cell Proliferation , Cytokines/metabolism , Disease Models, Animal , Female , Flow Cytometry , Hypoglycemic Agents/administration & dosage , Hypoglycemic Agents/therapeutic use , Injections, Intraperitoneal , Mice , Mice, Inbred C57BL , Ribonucleotides/therapeutic use , Treatment Outcome , Uvea/immunology , Uvea/metabolism , Uvea/pathology , Uveitis/immunology , Uveitis/metabolismABSTRACT
Purpose. To investigate the inhibitory effects of trehalose on malignant melanoma cell growth. Methods. We cultured human malignant melanoma cells in a medium containing trehalose (control/2.5%/5.0%/7.5%/10.0%) and used the MTT assay to evaluate the growth activities. Subsequently, trehalose was topically instilled on subconjunctivally inoculated melanoma cells in F334/NJcl-rmu/rmu rats, followed by a histopathological evaluation of tumor growth. Using flow cytometry, we compared the distribution of the cell cycle, rate of apoptotic cells, and intracellular factors related to the cell cycle in cultured melanoma cells after trehalose treatment. Results. The MTT study showed that proliferation of melanoma cells was significantly inhibited by ⧠5% of trehalose concentrations in the culture media. Subconjunctivally inoculated melanoma cell masses were significantly smaller in eyes administered trehalose as compared to controls. Flow cytometry analyses demonstrated that the trehalose groups had increased rates of G2/M phase cells and apoptotic cells in the cell culture. These cells also exhibited increased expressions of cell-cycle inhibitory factors. Conclusions. The current results show trehalose inhibits malignant melanoma cell growth by inducing G2/M cell cycle arrest and apoptosis, suggesting trehalose as a potential candidate for a topical agent to inhibit proliferation of malignant tumor cells of the ocular surface.
ABSTRACT
PURPOSE. To investigate the anti-inflammatory effect of aminoimidazole carboxamide ribonucleotide (AICAR), an analog of adenosine monophosphate (AMP), in endotoxin-induced uveitis (EIU). METHODS. EIU was induced by subcutaneous injection of lipopolysaccharide (LPS) (200 µg) in Lewis rats. AICAR (50 mg/kg, intraperitoneally) was given 6 hours prior and at the same time as LPS injection. Clinical uveitis scores, number of anterior chamber (AC) infiltrating cells, anterior chamber protein concentration, retinal vessel leukocyte adhesion, and protein leakage were measured 24 hours later. Protein levels of C-C chemokine ligand-2 (CCL-2)/monocyte chemotactic protein-1 (MCP-1), tumor necrosis factor-α (TNF-α) and intercellular adhesion molecule-1 (ICAM-1) in aqueous humor and retina and nuclear translocation of nuclear factor-κB (NF-κB) in the retina were determined by enzyme-linked immunosorbent assay (ELISA). Both mRNA and protein levels of CD14 in peripheral blood mononuclear cells were also measured. RESULTS. AICAR treatment significantly reduced EIU clinical severity as well as inflammatory cell infiltration and protein concentration in aqueous humor. Similarly, the number of retinal vessel-adherent leukocytes and protein leakage were decreased by AICAR treatment. Protein levels of TNF-α, CCL-2/MCP-1, and ICAM-1 in aqueous humor and CCL-2/MCP-1 and ICAM-1 levels in retina were suppressed with AICAR treatment. AICAR also reduced NF-κB translocation and CD14 expression. CONCLUSIONS. AICAR reduces systemic LPS susceptibility and attenuates intraocular inflammation in a rat EIU model by limiting infiltration of leukocytes, suppressing inflammatory mediators, and inhibiting the NF-κB pathway.
Subject(s)
Aminoimidazole Carboxamide/analogs & derivatives , Anti-Inflammatory Agents/therapeutic use , Disease Models, Animal , Lipopolysaccharides , Ribonucleotides/therapeutic use , Salmonella typhimurium , Uveitis, Anterior/drug therapy , Aminoimidazole Carboxamide/therapeutic use , Animals , Anterior Chamber/pathology , Aqueous Humor/metabolism , Blotting, Western , Chemokine CCL2/metabolism , Enzyme-Linked Immunosorbent Assay , Injections, Intraperitoneal , Intercellular Adhesion Molecule-1/metabolism , Lipopolysaccharide Receptors/genetics , Lipopolysaccharide Receptors/metabolism , Male , NF-kappa B/metabolism , RNA, Messenger/metabolism , Rats , Rats, Inbred Lew , Retina/metabolism , Reverse Transcriptase Polymerase Chain Reaction , Tumor Necrosis Factor-alpha/metabolism , Uveitis, Anterior/chemically induced , Uveitis, Anterior/metabolism , Uveitis, Anterior/pathologyABSTRACT
PURPOSE: To investigate whether trehalose inhibits VEGF-stimulated or inflammatory angiogenesis and the proliferation of myofibroblasts. METHODS: Normal human dermal fibroblasts and human umbilical vein endothelial cells (HUVECs)were cocultured in trehalose-containing medium (2.5/5.0/7.5/10.0%) with or without VEGF (10 ng/mL). After 11 days, the area, length, joint, and path of neovascularization were evaluated. The effect of topical trehalose on corneal neovascularization was examined in vivo by treating Balb/c mice with alkali burn-induced corneal neovascularization. After 14 days of trehalose treatment, corneal vessels were visualized in flatmounts. The expressions of VEGFR2, phospho-VEGFR2, and vimentin were observed. Then a separate coculture model of the myofibroblasts and HUVECs was used to observe the morphologic changes of the myofibroblasts by trehalose. Furthermore, myofibroblasts were cultured with trehalose to examine the cytokeratin and E-cadherin expressions. RESULTS: In the in vitro models, there was a significant trehalose dose-dependent inhibition of neovascularization. In the in vivo alkali burn models, corneal neovascularization was significantly inhibited by treatments using ≥ 2.5% trehalose eyedrops. The expressions of VEGFR2, phospho-VEGFR2, and vimentin were downregulated by trehalose. When trehalose was added to the medium, the myofibroblasts were transformed into epithelial cell-like cells. The transformed myofibroblasts expressed cytokeratin but not E-cadherin. CONCLUSIONS: Trehalose prevents angiogenesis by partially downregulating VEGFR2 expression. In addition, trehalose inhibits the proliferation of myofibroblasts partially by inducing mesenchymal-epithelial transition. These findings suggest that trehalose has potential for use as a new agent that can control angiogenesis and fibrosis and potential for use in glaucoma surgery.
Subject(s)
Cell Proliferation/drug effects , Filtering Surgery , Glaucoma/surgery , Myofibroblasts/drug effects , Neovascularization, Pathologic/prevention & control , Trehalose/pharmacology , Vascular Endothelial Growth Factor A/pharmacology , Animals , Cell Transdifferentiation/drug effects , Coculture Techniques , Corneal Neovascularization/drug therapy , Corneal Neovascularization/metabolism , Dose-Response Relationship, Drug , Endothelium, Vascular/drug effects , Humans , Keratitis/prevention & control , Mice , Mice, Inbred BALB C , Neovascularization, Pathologic/metabolism , Skin/cytology , Umbilical Veins/cytology , Vascular Endothelial Growth Factor Receptor-2/metabolism , Vimentin/metabolismABSTRACT
Matrix metalloproteinase-9 (MMP-9) plays a critical role in tissue remodeling under both physiological and pathological conditions. Although MMP-9 expression is low in most cells and is tightly controlled, the mechanism of its regulation is poorly understood. We utilized mouse embryonic fibroblasts (MEFs) that were nullizygous for the catalytic α subunit of AMP-activated protein kinase (AMPK), which is a key regulator of energy homeostasis, to identify AMPK as a suppressor of MMP-9 expression. Total AMPKα deletion significantly elevated MMP-9 expression compared with wild-type (WT) MEFs, whereas single knock-out of the isoforms AMPKα1 and AMPKα2 caused minimal change in the level of MMP-9 expression. The suppressive role of AMPK on MMP-9 expression was mediated through both its activity and presence. The AMPK activators 5-amino-4-imidazole carboxamide riboside and A769662 suppressed MMP-9 expression in WT MEFs, and AMPK inhibition by the overexpression of dominant negative (DN) AMPKα elevated MMP-9 expression. However, in AMPKα(-/-) MEFs transduced with DN AMPKα, MMP-9 expression was suppressed. AMPKα(-/-) MEFs showed increased phosphorylation of IκBα, expression of IκBα mRNA, nuclear localization of nuclear factor-κB (NF-κB), and DNA-binding activity of NF-κB compared with WT. Consistently, selective NF-κB inhibitors BMS345541 and SM7368 decreased MMP-9 expression in AMPKα(-/-) MEFs. Overall, our results suggest that both AMPKα isoforms suppress MMP-9 expression and that both the activity and presence of AMPKα contribute to its function as a regulator of MMP-9 expression by inhibiting the NF-κB pathway.
Subject(s)
AMP-Activated Protein Kinases/metabolism , Embryo, Mammalian/enzymology , Fibroblasts/enzymology , Gene Expression Regulation, Enzymologic/physiology , Matrix Metalloproteinase 9/biosynthesis , AMP-Activated Protein Kinases/antagonists & inhibitors , AMP-Activated Protein Kinases/genetics , Animals , Benzamides/pharmacology , Cell Line , Embryo, Mammalian/cytology , Enzyme Activators/pharmacology , Fibroblasts/cytology , Gene Expression Regulation, Enzymologic/drug effects , I-kappa B Proteins/genetics , I-kappa B Proteins/metabolism , Imidazoles/pharmacology , Matrix Metalloproteinase 9/genetics , Mice , Mice, Knockout , NF-KappaB Inhibitor alpha , NF-kappa B/antagonists & inhibitors , NF-kappa B/genetics , NF-kappa B/metabolism , Phosphorylation/drug effects , Phosphorylation/physiology , Quinoxalines/pharmacology , RNA, Messenger/biosynthesis , RNA, Messenger/genetics , Ribonucleotides/pharmacology , Thiazoles/pharmacologyABSTRACT
PURPOSE: To assess the effects of nilvadipine on the progression of central visual field defect in retinitis pigmentosa (RP). DESIGN: Prospective, randomized, nonmasked, single-center trial. METHODS: Patients with RP were randomly divided into a treated group receiving oral nilvadipine at 4 mg/day for ≥30 months and a control group receiving tocopherol nicotinate at 300 mg/day, helenien at 15 mg/day or no medication for the same periods. Progression of RP was evaluated using the 10-2 SITA Fast Program of the Humphrey Visual Field Analyzer, and regression coefficients calculated from the time courses of mean deviation (MD slope) were compared between groups. RESULTS: Nineteen patients in the treated group and 14 patients in the control group completed the follow-up for ≥30 months. The mean (±standard deviation) duration of observation was 48.8 ± 11.8 months (median 48 months, range 30-66 months) for the treated group and 49.2 ± 18.1 months (median 48 months, range 30-90 months) for the control group (p = 0.94). Mean (±standard error of the mean, SEM) regression coefficients of the averaged MD values for the initial 30 months were -0.35 ± 0.17 dB/year in the treated group and -0.75 ± 0.06 dB/year in the control group (p < 0.01). Mean (±SEM) MD slopes for total observational periods were -0.49 ± 0.17 dB/year in the treated group and -0.89 ± 0.16 dB/year in the control group (mean ± SEM, p = 0.042). CONCLUSION: Nilvadipine at 4 mg/day significantly retarded progression of central visual field defects in RP in this small patient series.
Subject(s)
Calcium Channel Blockers/therapeutic use , Nifedipine/analogs & derivatives , Retinitis Pigmentosa/drug therapy , Vision Disorders/prevention & control , Visual Fields/drug effects , Administration, Oral , Adult , Aged , Disease Progression , Female , Follow-Up Studies , Humans , Lutein/analogs & derivatives , Lutein/therapeutic use , Male , Middle Aged , Nifedipine/therapeutic use , Pilot Projects , Prospective Studies , Retinitis Pigmentosa/physiopathology , Tocopherols/therapeutic use , Vision Disorders/physiopathology , Visual Field Tests , Visual Fields/physiology , Young AdultABSTRACT
PURPOSE: The purpose of this study was to investigate the inhibitory effect of solid hyaluronic acid-carboxymethylcellulose film on the formation of wound adhesion after strabismus surgery on rabbit eyes. METHODS: The authors performed strabismus surgery on rabbit eyes with hyaluronic acid film applied under and above the muscles. Histological examination was performed 90 days postoperatively using Masson trichrome staining. The length of adhesion tissues in the operated area was quantitatively compared between film-treated and control eyes. RESULTS: Hyaluronic acid film significantly prevented the formation of adhesions between muscle, conjunctiva, and sclera after strabismus surgery (t test, P < .05). CONCLUSION: The current results indicate that hyaluronic acid film can inhibit the formation of postoperative adhesion around conjunctiva, muscle, and sclera to some extent. The authors conclude that this substance offers potential benefits for ophthalmic surgery, not only with strabismus surgery but also procedures such as scleral buckle.
Subject(s)
Cicatrix/prevention & control , Hyaluronic Acid , Membranes, Artificial , Oculomotor Muscles/surgery , Ophthalmologic Surgical Procedures , Postoperative Complications/prevention & control , Strabismus/surgery , Animals , Carboxymethylcellulose Sodium , Conjunctival Diseases/prevention & control , Rabbits , Scleral Diseases/prevention & control , Tissue Adhesions/prevention & controlABSTRACT
Trehalose is a disaccharide which plays an important role in preserving cells from completely dehydrated circumstances. In this study, we investigated effects of trehalose on proliferative activity of fibroblasts and epithelial cells both in vitro and in vivo. As in vitro assessment, normal human dermal fibroblasts and normal human epidermal keratinocytes were cultured in media containing various concentrations of trehalose. Growth activities of cells were evaluated with MTT assay and diff-quick™ staining. Expressions of vimentin and α smooth muscle actin (α-SMA) changed by trehalose were semiquantitatively measured by Western blot. As an in vivo study, 5% or 10% trehalose was topically instilled onto rabbit eyes after simple conjunctival incision or trabeculectomy. Condition of the surgical wound was evaluated by morphologically and immunohistochemically using isolectin B4 and antibodies specific for vimentin and α-SMA. Intraocular pressures (IOPs) after trabeculectomy were compared between eyes treated with trehalose and 0.04% mitomycin C (MMC). Results obtained by in vitro experiments showed that growth activities of cultured fibroblasts and keratinocytes were inhibited by trehalose in a dose-dependent manner. Fibroblasts were strongly inhibited by trehalose concentrations ⧠5% of trehalose, whereas keratinocytes were less inhibited compared to fibroblasts. Expressions of vimentin and α-SMA were reduced by trehalose. With in vivo experiments, postoperative application of trehalose resulted in less firm adhesion between conjunctiva and sclera compared to controls. Immunohistochemical studies showed reduced staining of isolectin B4, vimentin and α-SMA in conjunctival wounds treated by topical trehalose. Also, after trabeculectomy, IOP remained in a low range during instillation of topical trehalose solution. We concluded that trehalose has inhibitory effects on proliferation of fibroblasts and vascular tissues, partially due to inhibition of transformation of fibroblasts into myofibroblasts in wound tissues. The present results imply that trehalose can be a potential agent for preventing postoperative fibrous scar formation after ocular surgery such as glaucoma filtration surgery.
Subject(s)
Cell Proliferation/drug effects , Fibroblasts/cytology , Keratinocytes/cytology , Trehalose/pharmacology , Actins/metabolism , Animals , Apoptosis/drug effects , Blotting, Western , Cells, Cultured , Cicatrix/prevention & control , Dermis/cytology , Dose-Response Relationship, Drug , Electrophoresis, Polyacrylamide Gel , Epidermal Cells , Fibroblasts/metabolism , Fibrosis/prevention & control , Flow Cytometry , Humans , In Situ Nick-End Labeling , Keratinocytes/metabolism , Postoperative Complications/prevention & control , Rabbits , Trabeculectomy , Trehalose/administration & dosage , Vimentin/metabolismABSTRACT
Retinal pigment epithelium-specific protein 65 kDa (RPE65) is a key enzyme for the visual cycle in the eye. Rpe65(-/-) mice lack 11-cis-retinal, and show early cone degeneration and mislocalization of cone opsins. The present study investigated whether abnormal modification of cone opsins at the protein level is present in Rpe65(-/-) mice. Retina-RPE-choroids of Rpe65(-/-) mice at 3, 5 and 7 weeks old were used. Immunohistochemistry of opsins was performed using cryosections and retinal flatmounts. We evaluated levels of mRNA for cone and rod opsin genes by RT-PCR and levels of proteins by western blotting. To examine modification patterns of N-glycan in Rpe65(-/-) mice, cone opsins were digested with peptide-N-glycosidase (PNGase) F. S-opsin protein was detected at approximately 40-kDa as a major band in wild-type mice, whereas approximately 42-kDa S-opsin protein was detected in Rpe65(-/-) mice. After PNGase F treatment, mobility of S-opsin protein in wild-type and Rpe65(-/-) mice on SDS-PAGE was similar. In addition, approximately 25-kDa S-opsin polypeptide was notably detected in Rpe65(-/-) mice. Conversely, M-opsin proteins were not observed by immunohistochemistry or western blotting in Rpe65(-/-) mice, but expression of M-opsin mRNA in Rpe65(-/-) mice did not differ significantly from that in wild-type mice at 3 and 5 weeks. Mobility of M-opsin protein in Rpe65(-/-) mice was unchanged. Our data suggest that S-opsin protein is incompletely modified during N-glycan processing in Rpe65(-/-) mice, whereas M-opsin protein is severely reduced by posttranslational degradation in the absence of incomplete N-glycan processing in Rpe65(-/-) mice.
Subject(s)
Carrier Proteins/physiology , Eye Proteins/physiology , Protein Processing, Post-Translational , Retinal Degeneration/metabolism , Rod Opsins/metabolism , Animals , Blotting, Western , Choroid/metabolism , Electrophoresis, Polyacrylamide Gel , Glycosylation , Immunohistochemistry , Mice , Mice, Inbred C57BL , Mice, Knockout , Microscopy, Confocal , RNA, Messenger/metabolism , Retina/metabolism , Retinal Pigment Epithelium/metabolism , Reverse Transcriptase Polymerase Chain Reaction , Rhodopsin/genetics , Rhodopsin/metabolism , Rod Opsins/genetics , cis-trans-IsomerasesABSTRACT
PURPOSE: We report a patient (Case 1) with Bietti crystalline corneoretinal dystrophy (BCD) associated with previously unknown findings of crystal-like deposits on the anterior and posterior lens capsules. This patient is one of four (Cases 1-4) in whom we have found BCD associated with the same mutation in the CYP4V2 gene. METHODS: We present a case report with molecular diagnosis. A 45-year-old man (Case 1) was referred to our clinic with complaints of gradual progression of visual disturbances and night blindness. His visual acuity was limited to hand movement bilaterally. Slit-lamp biomicroscopy disclosed glistening, crystal-like deposits on the anterior and posterior lens capsules, as well as on the corneal stroma near the corneoscleral limbus. No such deposit was found in the lens stroma. Fundus examination disclosed profound chorioretinal atrophy with scarce crystal deposits. Full-field electroretinography showed extinguished responses of isolated rods, isolated cones, and mixed rods and cones. RESULTS: Molecular genetic analysis revealed that the subject had a homozygous mutation in the CYP4V2 gene (IVS6-8delTCATACAGGTCATCGCG/insGC), which is most commonly found in Japanese patients with BCD. Three other cases (Cases 2-4) of BCD associated with the same mutation did not show such crystal-like deposits on the lens surface. CONCLUSIONS: Although their exact origin remains unknown, crystal-like deposits may appear on the lens capsule of patients with BCD associated with a mutation in the CYP4V2 gene.
Subject(s)
Corneal Dystrophies, Hereditary/genetics , Cytochrome P-450 Enzyme System/genetics , Lens Capsule, Crystalline/pathology , Lens Diseases/genetics , Mutation , Retinal Degeneration/genetics , Corneal Stroma/pathology , Crystallization , Cytochrome P450 Family 4 , DNA Mutational Analysis , Electroretinography , Female , Humans , Male , Middle Aged , Polymerase Chain Reaction , Visual AcuityABSTRACT
OBJECTIVE: To investigate the inhibitory effect of solid hyaluronic acid-carboxymethyl cellulose film (hyaluronic acid film) on the formation of postoperative wound adhesion on rabbit eyes. METHODS: We first created a conjunctival flap under which hyaluronic acid film was inserted. Then, we performed trabeculectomy on other rabbit eyes with hyaluronic acid film applied under and above the scleral flaps. Expression of proliferative cell nuclear antigen and alpha-smooth muscle actin (alpha-SMA) were histologically and immunohistochemically examined. RESULTS: Hyaluronic acid film significantly prevented adhesions after both kinds of surgery. Particularly, subconjunctival scar formation was significantly inhibited when the film was simply inserted under the wound. Furthermore, the adhesion around the scleral flap of trabeculectomy was less formed in eyes treated with hyaluronic acid film than in control eyes. Immunoreactivity to proliferative cell nuclear antigen almost disappeared after 28 days postoperatively in both treated and control groups. The alpha-SMA-positive cells appeared much less around the film-treated wound than the control eye. CONCLUSION: The present results indicate that hyaluronic acid film can inhibit the formation of postoperative adhesion around the conjunctiva and sclera. CLINICAL RELEVANCE: The results of this study indicate that this substance has potential benefits for improving ophthalmic surgery, such as filtering surgery for glaucoma.
Subject(s)
Cicatrix/prevention & control , Conjunctiva/surgery , Hyaluronic Acid , Membranes, Artificial , Postoperative Complications/prevention & control , Sclera/surgery , Trabeculectomy , Actins/metabolism , Animals , Carboxymethylcellulose Sodium , Cell Count , Conjunctiva/metabolism , Conjunctiva/pathology , Fibrosis/prevention & control , Immunoenzyme Techniques , Proliferating Cell Nuclear Antigen/metabolism , Rabbits , Sclera/metabolism , Sclera/pathology , Surgical FlapsABSTRACT
To investigate the effect of nilvadipine, a calcium channel blocker, upon the retina of retinal degeneration slow (rds) mouse, nilvadipine was intraperitoneally injected into heterozygous rds mice for up to 200 days. The effect of nilvadipine was evaluated by electroretinography (ERG), light and electron microscopies, DNA microarray, quantitative reverse transcriptase polymerase chain reaction (RT-PCR), and western-blot analysis. After nilvadipine treatment, both a- and b-waves of ERG were significantly higher than in the control group (p<0.01). Although there was no difference in histological findings by light microscopy between the nilvadipine treated group and control group, apparent preservation of photoreceptor disc was demonstrated by electron microscopy in the treated group. Rhodopsin level was also increased in the treated group comparing to the control group. The DNA microarray analysis detected increased expression of genes encoding proteins which function in protein synthesis, growth factors and neurotrophic factor like ciliary neurotrophic factor (CNTF) and fibroblast growth factors (FGFs22 and 13). Decreased expression of genes coding for proteins related to proteolysis, apoptosis and growth factor (FGF18) was also demonstrated. Increased expression of CNTF, FGF22 and FGF13 and decreased expression of FGF18 were confirmed by both quantitative RT-PCR and western-blot analysis. In addition, FGF2 was constitutively expressed in both treated and control groups. Since CNTF has been known to retard retinal degeneration by rds mouse or other models of inherited retinal degeneration, it is possible that nilvadipine has a photoreceptor survival effect on rds retinal degeneration partly by enhancing expression of endogenous CNTF in the retina.