Resveratrol inhibits TGF-ß1-induced fibrotic effects in human pterygium fibroblasts.

BACKGROUND: Resveratrol is a polyphenolic phytoalexin which has the properties of anti-oxidant, anti-inflammatory and anti-fibrotic effects. The aim of this study was to investigate the anti-fibrotic effects of resveratrol in primary human pterygium fibroblasts (HPFs) and elucidate the underlying mechanisms. METHOD: Profibrotic activation was induced by transforming growth factor-beta1 (TGF-ß1). The expression of profibrotic markers, including type 1 collagen (COL1), α-smooth muscle actin (α-SMA), and fibronectin, were detected by western blot and quantitative real-time-PCR after treatment with various concentrations of resveratrol in HPFs to investigate the anti-fibrotic effects. Relative signaling pathways downstream of TGF-ß1 were detected by Western blot to assess the underlying mechanism. Cell viability and apoptosis were assessed using CCK-8 assay and flow cytometry to evaluate proliferation and drug-induced cytotoxicity. Cell migration and contractile phenotype were detected through wound healing assay and collagen gel contraction assay. RESULTS: The expression of α-SMA, FN and COL1 induced by TGF-ß1 were suppressed by treatment with resveratrol in dose-dependent manner. The Smad3, mitogen-activated protein kinase (p38 MAPK) and phosphatidylinositol-3-kinase (PI3K) / protein kinase B (AKT) pathways were activated by TGF-ß1, while resveratrol attenuated those pathways. Resveratrol also inhibited cellular proliferation, migration and contractile phenotype, and induced apoptosis in HPFs. CONCLUSIONS: Resveratrol inhibit TGF-ß1-induced myofibroblast activation and extra cellular matrix synthesis in HPFs, at least partly, by regulating the TGF-ß/Smad3, p38 MAPK and PI3K/AKT pathways.

A Random Walk-Based Method to Identify Candidate Genes Associated With Lymphoma.

Lymphoma is a serious type of cancer, especially for adolescents and elder adults, although this malignancy is quite rare compared with other types of cancer. The cause of this malignancy remains ambiguous. Genetic factor is deemed to be highly associated with the initiation and progression of lymphoma, and several genes have been related to this disease. Determining the pathogeny of lymphoma by identifying the related genes is important. In this study, we presented a random walk-based method to infer the novel lymphoma-associated genes. From the reported 1,458 lymphoma-associated genes and protein-protein interaction network, raw candidate genes were mined by using the random walk with restart algorithm. The determined raw genes were further filtered by using three screening tests (i.e., permutation, linkage, and enrichment tests). These tests could control false-positive genes and screen out essential candidate genes with strong linkages to validate the lymphoma-associated genes. A total of 108 inferred genes were obtained. Analytical results indicated that some inferred genes, such as RAC3, TEC, IRAK2/3/4, PRKCE, SMAD3, BLK, TXK, PRKCQ, were associated with the initiation and progression of lymphoma.

SPARC knockdown attenuated TGF-ß1-induced fibrotic effects through Smad2/3 pathways in human pterygium fibroblasts.

PURPOSE: Secreted protein acidic and rich in cysteine (SPARC), a matricellular glycoprotein, has been found to regulate processes involved in fibrotic diseases. The aim of this study was to investigate the anti-fibrotic effects of SPARC in primary human pterygium fibroblasts (HPFs) and elucidate the underlying mechanisms. METHODS: The expression of SPARC in HPFs was knocked down by RNA interference-based approach. Subsequently, we examined the expression of profibrotic markers induced by transforming growth factor-ß1 (TGF-ß1), including type 1 collagen (COL1), α-smooth muscle actin (α-SMA), and fibronectin (FN). The changes in signaling pathways and matrix metalloproteinases (MMPs) were also detected by western blotting. The cellular migration ability, proliferation ability, apoptosis, and contractile phenotype were detected using the wound healing assay, Cell Counting Kit-8 assay, flow cytometry, and collagen gel contraction assay, respectively. The interaction between SPARC and TGF-ß RII was detected by Co-IP RESULTS: Silencing of SPARC inhibited the basal and TGF-ß1-induced expression of COL1, α-SMA, and FN in HPFs, and suppressed the expression of p-Smad2, p-Smad3, Smad4 and MMP2, MMP9. The downregulation of SPARC also attenuated the cell migration and contractile phenotype of HPFs. SPARC could bind to TGF-ßRII under TGF-ß1 treatment. However, knockdown of SPARC did not affect the proliferation and apoptosis of HPFs. CONCLUSION: SPARC knockdown attenuated the fibrotic effect induced by TGF-ß1 at least in part by inactivating the Smad2/3 pathways in HPFs. Therefore, SPARC may be a promising therapeutic target for the treatment of pterygium.

Association between Inflammatory Factors in the Aqueous Humor and Hyperreflective Foci in Patients with Intractable Macular Edema Treated with Antivascular Endothelial Growth Factor.

BACKGROUND: To evaluate the correlations between the inflammatory factors in the aqueous humor and hyperreflective foci (HRF) in patients with intractable macular edema treated with antivascular endothelial growth factor (anti-VEGF). METHODS: This study included 17 patients with intractable macular edema (ME) treated with anti-VEGF agents. Inflammatory factors in the aqueous humor were measured by the Cytometric Beads Array before injection, and the numbers of HRF pre- and post-anti-VEGF treatment were counted from four different directions (90 degrees, 45 degrees, 180 degrees, and 135 degrees) in the SD-OCT images, respectively, before treatment and one month after treatment. The correlations between inflammatory factors and the numbers of HRF were assessed. RESULTS: The numbers of HRF were reduced significantly after anti-VEGF treatment. The change in the HRFs at the 90-degree location was significantly positively correlated with IL-8 and VCAM-1. The change of all HRFs was significantly positively correlated with IL-8. The HRFs before the treatment also had a positive correlation with IL-8 and VCAM-1. CONCLUSION: After anti-VEGF treatment, the numbers of HRF in intractable ME declined greatly. The higher the levels of IL-8 and VCAM-1 before treatment, the more significant the reduction of HRF after anti-VEGF treatment, which indicated that HRF could be an effective noninvasive imaging indicator for evaluating the effect of anti-VEGF on intractable macular edema. The OCT images at the 90-degree location could better show the inflammatory reaction of patients and also had better clinical significance for the prognosis evaluation of ME associated with inflammation.

Sirt1 attenuates diabetic keratopathy by regulating the endoplasmic reticulum stress pathway.

AIMS: The objectives of this study were to explore physiological and pathological changes in the corneas of diabetic rats by intervening in the expression of silent information regulator 1 (Sirt1) and to investigate whether Sirt1 can regulate the activation of endoplasmic reticulum stress (ERS) while influencing corneal epithelial cell apoptosis under high glucose conditions. MATERIALS AND METHODS: Using 8-week old Sprague-Dawley rats, we established a model of type 1 diabetes, with or without Sirt1 intervention. Clinical evaluation was performed once per week. Primary rat corneal epithelial cells (RCECs) were cultured by combining Sirt1 intervention under high glucose conditions. Generation of reactive oxygen species (ROS), apoptosis, and the expression of Sirt1 and ERS-related proteins were evaluated in rat corneal tissues and RCECs. KEY FINDINGS: During the intervention, clinical evaluation of the ocular surface, ROS generation, apoptosis, and protein expression of ERS-related proteins in corneal tissue and cultured RCECs were altered with Sirt1expression levels. SIGNIFICANCE: Sirt1 expression influences the pathological progression of diabetic keratopathy, plays an important role in regulating the ERS pathway, and decreases corneal epithelial cell apoptosis.

High glucose causes apoptosis of rabbit corneal epithelial cells involving activation of PERK-eIF2α-CHOP-caspase-12 signaling pathway.

AIM: To investigate the effect of high concentration of glucose (HCG) on double stranded RNA-activated protein kinase-like ER kinase (PERK)-eukaryotic initiation factor-2α (eIF2α)-transcription factor C/EBP homologous protein (CHOP)-cysteine aspartate specific proteinase (caspase-12) signaling pathway activation and apoptosis in rabbit corneal epithelial cells (RCECs). METHODS: RCECs were treated by different concentrations of glucose for 0-48h. The expressions of PERK, p-PERK, eIF2α, p-eIF2α, 78 kDa glucose-regulated protein 78 (GRP78), CHOP, B-cell lymphoma 2 (Bcl-2), B-cell lymphoma-2-associated X protein (Bax) and caspase-12 were determined by Western blot. Apoptosis was detected by TUNEL assay. Meanwhile, the function of PERK-eIF2α-CHOP-caspase-12 signaling pathway activation in high glucose-induced apoptosis was evaluated using PERK inhibitor, GSK2606414. RESULTS: HCG significantly promoted the expression of p-PERK, p-eIF2α, GRP78, CHOP, Bax and cleaved caspase-12 in RCECs (P<0.05), while remarkably decreased the expression of Bcl-2 and caspase-12 (P<0.05), and the alterations caused by glucose were in concentration- and time-dependent manners. Meanwhile, PERK and eIF2α expressions were not affected in all groups (P>0.05). TUNEL assay showed that the apoptosis rate of RCECs in the HCG group increased significantly in contrast with that in the normal concentration of glucose or osmotic pressure control group (P<0.05), and the apoptosis rate increased with the increase of glucose concentration within limits (P<0.05). GSK2606414 down-regulated the expression of p-PERK and p-eIF2α in the HCG group (P<0.05), while still did not affect the expression of PERK and eIF2α among groups (P>0.05). Correspondingly, GSK2606414 also significantly reduced the apoptosis rate induced by high glucose (P<0.05). CONCLUSION: HCG activates PERK-eIF2α-CHOP-caspase-12 signaling pathway and promotes apoptosis of RCECs.

High Concentration of Glucose Increases Reactive Oxygen Species Generation and Apoptosis Induced by Endoplasmic Reticulum Stress Pathway in Rabbit Corneal Epithelial Cells.

OBJECTIVE: To investigate the effect of high concentration of glucose on reactive oxygen species (ROS) production in rabbit corneal epithelial cells (RECEs) and explore whether the increased ROS initiates the apoptosis process of RECEs through oxidative stress and endoplasmic reticulum (ER) stress pathway. METHODS: RECEs were treated by different concentrations of glucose for a while, and then the production of ROS was detected by flow cytometry. The expressions of PERK, p-PERK, Akt, p-Akt, and CHOP were determined by western blot, and the cell viability was measured by Cell Counting Kit-8 (CCK-8). Flow cytometry was used to detect the early apoptosis rate. Meanwhile, the effects of N-acetyl-L-cysteine (NAC), an active oxygen inhibitor, on the experimental results were observed. RESULTS: Compared with the normal glucose concentration group, the fluorescence intensity of ROS in the high concentration (1 mM glucose) of glucose group was significantly increased (P < 0.05). NAC-inhibited ROS production was induced by high concentration of glucose (P < 0.05).Western blot demonstrated that the expressions of the p-PERK and CHOP increased significantly (P < 0.05), the p-Akt expression decreased (P < 0.05), and the PERK and Akt expressions did not change significantly in the high concentration of glucose group compared to the normal concentration group. CCK-8 results revealed that compared with the normal concentration of glucose group, the cell activity of the high concentration of glucose group decreased. For the cells in the high concentration of glucose group, the cell survival rate of NAC-treated cells was higher than that of untreated (P < 0.05). The flow cytometry results indicated that the early apoptosis rate of the cells in the high concentration of glucose group increased in contrast with that in the normal concentration of glucose group (P < 0.05). Treating the cells in the high concentration of glucose group with NAC could reduce the cell apoptosis resulted from high glucose (P < 0.05). CONCLUSIONS: High concentration of glucose may induce the formation of ROS which leads to oxidative stress and ER stress in RECEs and even leads to cell apoptosis. The reactive oxygen inhibitor, NAC, can play a protective character in the high concentration of glucose environment. These results might provide theoretical basis for the study of the diabetes-related dry eye.

The injection of DisCoVisc into the anterior chamber improved corneal preservation and transplantation for cornea blind patients.

PURPOSE: In this study, we aimed to provide a new method of corneal preservation by injecting DisCoVisc into the anterior chamber of eyeballs and evaluate its efficiency for corneal transplantation. METHODS: Three pairs of eyeballs (n=6) were preserved by DisCoVisc viscoelastic agent, and the corneas were stored for 1 to 6 days. Then, the structure and morphology of cornea were analyzed by hematoxylin-eosin (H&E) staining, terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) staining, and transmission electron microscopy (TEM). The corneas preserved by this method were transplanted into 15 patients with corneal disease and the efficacy was assessed. RESULTS: Epithelial cells and endothelial cells were intact and a normal morphology was preserved in both fresh corneas and corneas stored for 1-6 days by DisCoVisc viscoelastic agent. Corneal endothelial cells did not appear apoptosis in fresh corneas and corneas stored for 1-3 days, whereas a few apoptosis positive cells were shown on the 4th day. The results of TEM showed that all corneas had active corneal endothelial cells with normal nuclei and homogenous nucleoplasm. Desmosomes and hemidesmosomes were closely connected. Mild nuclear pyknosis and autophagic cell death were only found from the 6th day, and mitochondria appeared a little bubble from the 5th day. Visual acuity in 11 of the 15 patients receiving transplantation of the preserved corneas was improved by more than 0.5. Average corneal endothelial cell counts, areas of corneal endothelial cells, and CV% of average area were not affected during the 6-month follow-up. Compared to the values obtained one-month postoperatively, the values of corneal thickness were significantly reduced in the three-month and six-month periods. CONCLUSIONS: Corneal preservation technology with the injection of DisCoVisc viscoelastic agent may effectively extend the preservation time of corneas for five days, which could be used for patients as penetrating keratoplasty surgery.

Expression of SIRT1 and oxidative stress in diabetic dry eye.

OBJECTIVE: To explore the expression of SIRT1 with oxidative stress and observe physiological and pathological changes in the corneas as well as the association between SIRT1 and oxidative stress of diabetic dry eyes in mice. METHOD: Forty-eight C57BL/6Jdb/db mice at eight weeks of age were divided randomly into two groups: the diabetic dry eye group and the diabetic group. An additional forty-eight C57BL/6J mice at eight weeks of age were divided randomly into two groups: the dry eye group and the control group. Every mouse in the dry eye groups (diabetic and normal) was injected with scopolamine hydrobromide three times daily, combined with low humidity to establish a dry eye model. After the intervention, phenol red cotton string tests and corneal fluorescein staining were performed. In addition, HE staining and immunofluorescence were done. Expression of SIRT1 in the cornea was examined by real-time PCR and Western Blot and expression of FOXO3 and MnSOD proteins was detected by Western Blot. RESULTS: At one, four, and eight weeks post intervention, all of the groups except the controls showed significant decreases in tear production and increases in the corneal fluorescein stain (P<0.05 vs control). Between the experimental groups, the diabetic dry eye group had the least tear production and the highest corneal fluorescein stain score (P<0.05). As the disease progressed, all of the experimental groups showed obviously pathological changes in HE staining, particularly the diabetic dry eye group. In the 1(st) and 4(th) week, the expression of SIRT1, FOXO3, and MnSOD were significantly higher in the diabetic DE and DM groups but lower in the DE group compared to the controls (P<0.05). In the 8(th) week, the expression of SIRT1, FOXO3, and MnSOD was significantly down-regulated in the diabetic DE group and the DM group (P<0.05). Immunofluorescence showed similar results. CONCLUSION: In the condition of diabetic dry eye, tear production declined markedly coupled with seriously wounded corneal epithelium. Oxidative stress in the cornea was enhanced significantly and the expression of SIRT1 was decreased.

Comparison of 1-day versus 1-hour application of topical neomycin/polymyxin-B before cataract surgery.

PURPOSE: To compare the efficacy of 2 prophylaxis regimens before cataract surgery using topical antibiotics (1 hour before surgery versus the day before), both with povidone-iodine, with regard to reducing the preoperative conjunctival bacterial load. SETTING: Tertiary ophthalmic referral center, Munich, Germany. DESIGN: Prospective comparative case series. METHODS: Eyes were treated with topical antibiotics and their conjunctival sac flush irrigated using 10 mL of povidone-iodine 1.0%. All eyes were randomized to receive either 4 applications of topical 3500 IU/mL neomycin sulfate/6000 IU/mL polymyxin-B sulfate within 1 hour preoperatively (Group 1) or on the day before surgery (Group 2). Conjunctival specimens were obtained at 4 timepoints: T0C untreated fellow eye (control), T0 surgery eye (after antibiotic prophylaxis but before povidone-iodine irrigation), T1 after povidone-iodine, and T2 at the conclusion of surgery. All specimens were inoculated onto blood and chocolate-blood agar and into thioglycollate broth. RESULTS: One hundred thirty-three eyes of 133 consecutive patients were included (Group 1, 64 eyes; Group 2, 69 eyes). The antibiotic regimens were equally effective in reducing the aerobic and microaerophilic conjunctival flora (Group 1, P=.028; Group 2, P=.000), but had no significant effect on anaerobic bacteria (Group 1, P=.201; Group 2, P=.117). Flush irrigation of the conjunctival sac using 10.0 mL povidone-iodine 1.0% significantly decreased the conjunctival bacterial load in both groups. CONCLUSION: Topical neomycin/polymyxin-B was equally effective in reducing the conjunctival bacterial load whether given 1 day or 1 hour before surgery. The greatest effect was achieved by irrigating the conjunctival sac using povidone-iodine. FINANCIAL DISCLOSURE: No author has a financial or proprietary interest in any material or method mentioned.

Decreased PPAR-γ expression in the conjunctiva and increased expression of TNF-α and IL-1ß in the conjunctiva and tear fluid of dry eye mice.

The aim of this study was to investigate the expression of peroxisome proliferator-activated receptor Î³ (PPAR-γ), tumor necrosis factor (TNF)-α and interleukin (IL)-1ß in the conjunctiva and the association between inflammatory cytokines and PPAR-γ in dry eye mice. Dry eye was induced in 6-week-old female C57 mice. mRNA expression of PPAR-γ, TNF-α and IL-1ß were measured. PPAR-γ protein expression in the conjunctiva, and the contents of TNF-α and IL-1ß in the conjunctiva and tear-wash fluid were determined. A PPAR-γ agonist, pioglitazone (PIO), was used to treat dry eye mice. Dry eye mice presented with similar manifestations as in humans. The PPAR-γ expression in the conjunctiva of dry eye mice was downregulated, accompanied by increased contents of TNF-α and IL-1ß. PIO treatment markedly reduced the contents of TNF-α and IL-1ß in tear fluid of dry eye mice. Following PIO treatment, the PPAR-γ expression increased markedly. PIO may activate PPAR-γ to inhibit the expression of the inflammatory cytokines TNF-α and IL-1ß in dry eye mice. This suppresses the inflammatory progression, increases the tear fluid production, elevates the tear film stability and reduces the damage to the ocular surface, exerting a therapeutic effect on dry eye.

Effect of reactive oxygen species generation in rabbit corneal epithelial cells on inflammatory and apoptotic signaling pathways in the presence of high osmotic pressure.

It is generally accepted that high osmotic pressure (HOP) of lacrimal fluid is the core mechanism causing ocular inflammation and injury. However, the association between HOP and the regulation of cell inflammatory response and apoptotic pathways remains unclear. In the present study, we used HOP to interfere with in vitro cultured rabbit corneal epithelial cells, and found that HOP increased the generation of reactive oxygen species (ROS) in rabbit corneal epithelial cells, and increased ROS in turn induced the activation of JNK inflammatory signaling pathway, which further promoted the expression of pro-inflammatory factor NF-κß and induced the generation of inflammatory factor IL-1ß and TNF-α. In addition, HOP-induced ROS in rabbit corneal epithelial cells regulated the CD95/CD95L-mediated cell apoptotic signaling pathway by activating JNK inflammatory signaling pathway. These findings may serve as new theoretical basis and a new way of thinking about the treatment of ocular diseases, especially dry eye.

Comparison of the efficacy of povidone-iodine 1.0%, 5.0%, and 10.0% irrigation combined with topical levofloxacin 0.3% as preoperative prophylaxis in cataract surgery.

PURPOSE: To compare the efficacy of povidone-iodine 1.0%, 5.0%, and 10.0% in combination with topical levofloxacin 0.3% in reducing the preoperative conjunctival bacterial load before cataract surgery. SETTING: Department of Ophthalmology, Ludwig-Maximilians-University, Munich, Germany. DESIGN: Randomized clinical trial. METHODS: This study enrolled patients scheduled for cataract surgery between July 2010 and January 2011. All patients received topical levofloxacin 0.3% 4 times on the preoperative day and were randomly assigned to these study groups: Group 1 (povidone-iodine 1.0%), Group 2 (povidone-iodine 5.0%), and Group 3 (povidone-iodine 10.0%). In all groups, the conjunctiva was flush irrigated with 10 mL of povidone-iodine of the respective concentration. Conjunctival specimens were obtained at 4 timepoints: baseline (no-surgery eye), before povidone-iodine irrigation, after povidone-iodine irrigation, and at the end of surgery. All specimens were inoculated onto blood and chocolate agars and into thioglycolate broth. RESULTS: The study was completed by 271 patients. In the control smear (no-surgery eye), no significant difference in positive cultures was found. After 10 mL povidone-iodine irrigation, a considerable reduction in the conjunctival bacterial load occurred in all groups. The difference in positive cultures was statistically significant between Group 1 and Group 3 (P=.024) and between Group 2 and Group 3 (P=.029). Coagulase-negative Staphylococcus was the most commonly isolated bacteria in all groups. CONCLUSION: Povidone-iodine 10.0% was more effective than povidone-iodine 1.0% and 5.0% in decreasing the conjunctival bacterial load before surgery. FINANCIAL DISCLOSURE: No author has a financial or proprietary interest in any material or method mentioned.

Acid-sensing ion channel 1a is involved in retinal ganglion cell death induced by hypoxia.

PURPOSE: Loss of retinal ganglion cells (RGCs) during retinal ischemia is the potentially blinding mechanism that underlies several sight-threatening disorders. Fluctuations in extracellular pH are associated with such pathological conditions. It has been demonstrated that the retina is a functionally distinct region of central neurons that are known to contain acid-sensing ion channels (ASICs), which are depolarizing conductance channels directly activated by protons. This study was conducted to determine whether ASIC1a channels in RGCs are essential for ischemia-induced cell death. METHODS: Expression of ASIC1a channels was detected in primary cultures of rat RGCs and in retinal sections. The patch-clamp technique in the conventional whole-cell configuration was used to examine the currents evoked by acid in the cultured RGCs. Intracellular Ca(2+) ([Ca(2+)]i) elevation was detected by Ca(2+) imaging. Furthermore, hypoxia-induced cell death in RGC cultures was measured by methyl thiazolyl tetrazolium assay. RESULTS: RGCs expressed a high density of ASIC1a channels. The expression and function of ASIC1a channels were upregulated after hypoxia in cultured RGCs. Ratiometric Ca(2+) imaging showed that RGCs responding to a drop in pH presented an increase in the concentration of (Ca(2+))i. Acute blockade of ASIC1a channels with the specific inhibitor amiloride or psalmotoxin 1 reduced RGC death in vitro. CONCLUSIONS: Based on these novel findings, we conclude that ASIC1a plays a role in RGC death induced by hypoxia. Therefore, neuroprotective strategies in glaucoma could include tools to improve the ability of these neurons to survive the cytotoxic consequences of ASIC1a activation.

Effects of asymmetric dimethylarginine on bovine retinal capillary endothelial cell proliferation, reactive oxygen species production, permeability, intercellular adhesion molecule-1, and occludin expression.

PURPOSE: Asymmetric dimethylarginine (ADMA), an endogenous competitive inhibitor of nitric oxide synthase, is associated with impaired endothelial dysfunction, such as chronic heart failure, hypertension, diabetes, and pulmonary hypertension. The effects of ADMA on cell proliferation, reactive oxygen species (ROS) production, cell permeability, intercellular adhesion molecule-1 (ICAM-1), and tight-junction protein occludin levels in bovine retinal capillary endothelial cells (BRCECs) were investigated. METHODS: A cell proliferation assay was performed using the novel tetrazolium compound 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium and an electron coupling reagent. Intracellular ROS levels were determined using the fluorescent probe CM-H(2)DCFDA. Horseradish peroxidase was used for a permeability assay. ICAM-1 and tight-junction protein occludin were assessed by western blotting and quantitative real-time PCR. RESULTS: Cell proliferation was significantly inhibited by ADMA. ADMA increased intracellular ROS generation in BRCECs. The increased ROS production induced by ADMA was markedly inhibited by the angiotensin II receptor-blocker telmisartan, the angiotensin-converting enzyme inhibitor benazepril, the reduced form of nicotinamide-adenine dinucleotide phosphate (NADPH) oxidase inhibitor diphenyliodonium (DPI), or the antioxidant and free-radical scavenger N-acetyl-L-cysteine (NAC). ADMA significantly increased horseradish peroxidase (HRP) permeability in BRCECs. Benazepril, telmisartan, DPI, and NAC downregulated cell permeability. ADMA markedly upregulated ICAM-1 expression in BRCECs, which were downregulated by telmisartan, DPI, and NAC. ADMA significantly downregulated occludin expression in BRCECs. Benazepril and telmisartan upregulated occludin expression in BRCECs exposed to ADMA. CONCLUSIONS: Our results provide the first reported evidence that ADMA has potent adverse effects on cell proliferation, intracellular ROS generation, cell permeability, levels of ICAM-1, and the tight-junction protein occludin. Angiotensin-converting enzyme inhibitors, angiotensin II receptor blockers, and antioxidants are effective inhibitors of the adverse effects of ADMA.

PRMT-1 and DDAHs-induced ADMA upregulation is involved in ROS- and RAS-mediated diabetic retinopathy.

Asymmetric dimethylarginine (ADMA), an endogenous competitive inhibitor of nitric oxide synthase, is generated in presence of type 1 protein arginine N-methyltransferase (PRMT-1) and is metabolized by dimethylarginine dimethylaminohydrolases (DDAHs). Reportedly ADMA is associated with endothelial dysfunction. The aim of this study is to investigate whether PRMT-1- and DDAHs-induced ADMA increase in diabetic rat retina and high glucose-treated bovine retinal capillary endothelial cells (BRCECs) is involved in reactive oxygen species (ROS)- and renin-angiotensin system (RAS)-mediated diabetic retinopathy. Rats were divided into four groups: sham-injected group, streptozotocin (STZ)-induced diabetic model group, STZ-induced diabetic model plus 12-week ACEI benazepril treatment group, and STZ-induced diabetic model plus 12-week ARB telmisartan treatment group. BRCECs were exposed to 5mM glucose, 30mM glucose, and 30mM glucose plus benazepril, telmisartan, diphenyliodonium (NADPH oxidase inhibitor, DPI), or N-Acetyl-l-cysteine (antioxidant and free radical scavenger, NAC) until passage four. We found that the concentrations of ADMA were significantly elevated in the plasma of diabetic rat models, and were significantly reduced by benazepril or telmisartan. DDAHs expression was decreased and PRMT-1 expression was increased in diabetic rat retina, which was reversed by benazepril. Telmisartan decreased PRMT-1 expression and increased DDAH II expression, but had no effect on DDAH I expression. In vitro, BRCECs exposed to high glucose had elevated ROS production, decreased cGMP, increased PRMT-1 expression, and decreased DDAH activity and DDAH II expression. Coincubating BRCECs with benazepril, telmisartan, DPI or NAC reversed the effects of high glucose. It can be concluded that PRMT-I and DDAHs-induced upregulation of ADMA levels might be involved in ROS- and RAS-mediated diabetic retinopathy.

Pediatric penetrating keratoplasty in Shanghai: a retrospective multiple centre study from 2003 to 2007.

BACKGROUND: With advances in pediatric keratoplasty over the last two decades, the success rate of surgery has increased remarkably. However, few epidemiological studies in this field have been performed in China. The present study investigated the indications and characteristics of pediatric penetrating keratoplasty in Shanghai. METHODS: All records of pediatric keratoplasty performed on 156 eyes in 149 children (< 14 years) at four ophthalmic units in Shanghai during a 5-year period (2003 - 2007) were used for this retrospective study. Patients were from the Eye, Ear, Nose & Throat Hospital of Fudan University, Shanghai No.10 People's Hospital, Shanghai No.1 People's Hospital, and Shanghai Peace Ophthalmology Hospital; and included mostly school-age children (97 boys and 59 girls). RESULTS: The median age at surgery was 9 years with an interval quartile range of 6-12 years. Scarring after keratitis (29.5%, 46/156) and traumatic corneal scar (19.2%, 30/156) were the most common indications. Best Corrected Snellen visual acuity (BCSVA) was reported only in 72% (112/156) of cases. Visual acuity outcomes were significantly better for keratoplasty 1 year postoperatively compared to preoperative visual acuity (P = 0.001). Of all patients, 13% (14/112) achieved a BCSVA of 6/18 or better. None of the indications was associated with a higher rate of failure compared to after 1 year follow-up. CONCLUSION: We obtained valuable information on pediatric keratoplasty in Shanghai. There was no significant difference in graft survival rate among the two indications. Vision outcomes after corneal transplantation in Chinese children were significantly better compared with pre-operation status. In conclusion, corneal graft survival can be achieved in childhood.