Yibo Yu

Proteomic Analysis of Human Lens Epithelial Cells Exposed to Microwaves

PurposeTo study proteomic changes in human lens epithelial cells (HLECs) exposed to 1800-MHz Global System for Mobile Communication (GSM)-like microwaves.MethodsIn three separate experiments, HLECs were exposed and sham-exposed (six dishes each) to 1800-MHz GSM-like radiation for 2 h. The specific absorption rates were 1.0, 2.0, or 3.5 W/kg. Immediately after radiation, the proteome was extracted from the HLECs. Immobilized pH gradient two-dimensional polyacrylamide gel electrophoresis(2-DE; silver staining) and PDQuest 2-DE analysis software were used to separate and analyze the proteome of exposed and sham-exposed HLECs. Four differentially expressed protein spots were selected and identified by using electrospray ionization tandem mass spectrometry (ESI-MS-MS).ResultsWhen the protein profiles of exposed cells were compared with those of sham-exposed cells, four proteins were detected as upregulated. After analysis by ESI-MS-MS and through a database search, heat-shock protein (HSP) 70 and heterogeneous nuclear ribonucleoprotein K (hnRNP K) were determined to be upregulated in the exposed cells.ConclusionsTwo-dimensional polyacrylamide gel electrophoresis combined with mass spectrometry may be a powerful tool for screening potential electromagnetic-reaction protein markers. HSP70 and hnRNP K are involved in the stress reaction of HLECs exposed to microwaves. These cell responses are nonthermal effects of the electromagnetic field. Jpn J Ophthalmol 2007;51:412–416

Study of oxidative stress in human lens epithelial cells exposed to 1.8 GHz radiofrequency fields.

Objectives The aims of the present study were to determine oxidative stress and to explore possible reasons of reactive oxygen species (ROS) increase in human lens epithelial (HLE) B3 cells exposed to low intensity 1.8 GHz radiofrequency fields (RF). Methods The HLE B3 cells were divided into RF exposure and RF sham-exposure groups. The RF exposure intensity was at specific absorption rate (SAR) of 2, 3, or 4 W/kg. The ROS levels were measured by a fluorescent probe 2′7′-dichlorofluorescin diacetate (DCFH-DA) assay in the HLE B3 cells exposed to 1.8 GHz RF for 0.5, 1, and 1.5 h. Lipid peroxidation and cellular viability were detected by an MDA test and Cell Counting Kit-8 (CCK-8) assays, respectively, in the HLE B3 cells exposed to 1.8 GHz RF for 6, 12, and 24 h, respectively. The mRNA expression of SOD1, SOD2, CAT, and GPx1 genes and the expression of SOD1, SOD2, CAT, and GPx1 proteins was measured by qRT-PCR and Western blot assays in the HLE B3 cells exposed to 1.8 GHz RF for 1 h. Results The ROS and MDA levels significantly increased (P<0.05) in the RF exposure group and that the cellular viability, mRNA expression of four genes, and expression of four proteins significantly decreased (P<0.05) compared with the RF sham-exposure group. Conclusions Oxidative stress is present in HLE B3 cells exposed to 1.8 GHz low-intensity RF and that the increased production of ROS may be related to down-regulation of four antioxidant enzyme genes induced by RF exposure.

Evaluation of dry eye after femtosecond laser-assisted cataract surgery.

Purpose To compare dry‐eye signs and symptoms after femtosecond laser–assisted cataract surgery and conventional phacoemulsification. Setting Eye Center of the 2nd Affiliated Hospital, Medical College of Zhejiang University, Hangzhou, China. Design Prospective consecutive nonrandomized comparative cohort study. Methods Consecutive patients who had femtosecond laser–assisted or phacoemulsification cataract surgery were assessed. Dry‐eye markers including the ocular surface disease index (OSDI) and subjective symptom questionnaire, tear‐film assessment using Keratograph 4 corneal topography, Schirmer testing I, and fluorescein staining were sequentially evaluated preoperatively and postoperatively at 1 day, 1 week, and 1 month. Results The study recruited 137 eyes (137 patients) with similar baseline characteristics. Most patients developed dry eye postoperatively. Subjective symptoms and fluorescein staining scores elevated from baseline, tear breakup time and Schirmer testing I values decreased postoperatively, which peaked at 1 week and did not return to baseline within 1 month. There were no significant differences between the 2 groups (all P > .05) except for a higher fluorescein staining score in the femtosecond group at 1 day (P = .001), 1 week (P = .047), and 1 month (P = .025). OSDI score and subjective symptoms were greater in the laser group at 1 week (P = .014 and P = .016, respectively). Subgroup analysis showed obvious worsening by fluorescein staining at 1 day (P = .016) and 1 month (P = .009) in preoperative dry‐eye patients. Conclusions Both methods worsened dry eye postoperatively. Femtosecond‐assisted surgery had a higher risk for staining and dry‐eye symptoms. Patients with preexisting dry eye who had femtosecond‐assisted surgery had more severe ocular surface staining than those having conventional surgery. Financial Disclosure No author has a financial or proprietary interest in any material or method mentioned.

Effects of exposure to 1.8 GHz radiofrequency field on the expression of Hsps and phosphorylation of MAPKs in human lens epithelial cells

Effects of exposure to 1.8 GHz radiofrequency field on the expression of Hsps and phosphorylation of MAPKs in human lens epithelial cells

Association of Glutathione S transferases Polymorphisms with Glaucoma: A Meta-Analysis

Background Glutathione S transferase (GST) polymorphisms have been considered risk factors for the development of glaucoma, including primary open angle glaucoma (POAG) and other types of glaucoma. However, the results remain controversial. In this study, we have conducted a meta-analysis to assess the association between polymorphisms of GSTM1, GSTT1 and GSTP1 and glaucoma risk. Methods Published literature from PubMed and other databases were retrieved. All studies evaluating the association between GSTM1, GSTT1 and GSTP1 polymorphisms and glaucoma risk were included. Pooled odds ratio (OR) and 95% confidence interval (CI) were calculated using random- or fixed-effects model. Results Twelve studies on GSTM1 (1109 cases and 844 controls), ten studies on GSTT1 (709 cases and 664 controls) and four studies on GSTP1 (543 cases and 511 controls) were included. By pooling all the studies, either GSTM1 or GSTT1 null polymorphism was not associated with a POAG risk, and this negative association maintained in Caucasian. The GSTP1 Ile 105 Val polymorphism was significantly correlated with increased POAG risk among Caucasian in a recessive model (Val/Val vs. Ile/Ile+Ile/Val: OR, 1.62, 95%CI: 1.00–2.61). Interestingly, increased glaucoma risk was associated with the combined GSTM1 and GSTT1 null genotypes (OR, 2.20; 95% CI, 1.47–3.31), and with the combined GSTM1 null and GSTP1 Val genotypes (OR, 1.86; 95% CI, 1.15–3.01). Conclusions This meta-analysis suggests that combinations of GST polymorphisms are associated with glaucoma risk. Given the limited sample size, the associations between single GST polymorphism and glaucoma risk await further investigation.

Thioredoxin Binding Protein-2 Regulates Autophagy of Human Lens Epithelial Cells under Oxidative Stress via Inhibition of Akt Phosphorylation

Oxidative stress plays an essential role in the development of age-related cataract. Thioredoxin binding protein-2 (TBP-2) is a negative regulator of thioredoxin (Trx), which deteriorates cellular antioxidant system. Our study focused on the autophagy-regulating effect of TBP-2 under oxidative stress in human lens epithelial cells (LECs). Human lens epithelial cells were used for cell culture and treatment. Lentiviral-based transfection system was used for overexpression of TBP-2. Cytotoxicity assay, western blot analysis, GFP/mCherry-fused LC3 plasmid, immunofluorescence, and transmission electronic microscopy were performed. The results showed that autophagic response of LECs with increased LC3-II, p62, and GFP/mCherry-LC3 puncta (P < 0.01) was induced by oxidative stress. Overexpression of TBP-2 further strengthens this response and worsens the cell viability (P < 0.01). Knockdown of TBP-2 attenuates the autophagic response and cell viability loss induced by oxidative stress. TBP-2 mainly regulates autophagy in the initiation stage, which is mTOR-independent and probably caused by the dephosphorylation of Akt under oxidative stress. These findings suggest a novel role of TBP-2 in human LECs under oxidative stress. Oxidative stress can cause cell injury and autophagy in LECs, and TBP-2 regulates this response. Hence, this study provides evidence regarding the role of TBP-2 in lens and the possible mechanism of cataract development.

Comparison of Drug Concentrations in Human Aqueous Humor after the Administration of 0.3% Gatifloxacin Ophthalmic Gel, 0.3% Gatifloxacin and 0.5% Levofloxacin Ophthalmic Solutions

Purpose: To investigate the penetration of 0.3% gatifloxacin ophthalmic gel, 0.3% gatifloxacin ophthalmic solution and 0.5% levofloxacin ophthalmic solution into aqueous humor after topical application. Materials and Methods: Age-related cataract patients (150 eyes in 150 cases) receiving phacoemulsification were randomly divided into three groups: a 0.3% gatifloxacin gel group (n=50), a 0.3% gatifloxacin solution group (n=50), and a 0.5% levofloxacin solution group (n=50). Each group was administered one drop of gel or solution every 15 minutes for four doses. Aqueous samples were collected at different time points after the last drop. High pressure liquid chromatography (HPLC) was applied to determine the concentrations. The one-way ANOVA analysis was performed. Results: Our data indicated that the concentration of the gatifloxacin gel group was higher than that of the gatifloxacin solution group at all time points (P <0.05); moreover, the gatifloxacin gel group exhibited higher levels than the levofloxacin solution group at 120.0 min and 180.0 min (P<0.05). Furthermore, the gatifloxacin gel produced the highest concentration at 120.0 min, and the gatifloxacin and levofloxacin solutions reached their peak values at 60.0 min. Conclusions: 0.3% gatifloxacin ophthalmic gel application produced highest aqueous humor drug concentration, maintained the longest time, had the best penetration and bioavailability.

Embryonic Surface Ectoderm-specific Mitofusin 2 Conditional Knockout Induces Congenital Cataracts in Mice

Inherited mitochondrial mutations can result in mitochondrial dysfunction or stochastic oxidative damage. Cumulative mitochondrial damage is an important factor in age-related disorders, such as cataracts and macular degeneration. Mfn2 mediates the fusion of mitochondria and contribute to the dynamic balance between fusion and fission that determines mitochondria morphology. We report here that conditional loss of Mfn2 function in the head surface ectoderm leads to a range of congenital eye defects, including small, opacified lens and small eyeball in the most severe phenotypes. The Le-Cre transgenic mouse line and Mfn2 flox mouse line were used in this study to generate Mfn2 conditional knockout mice. Our study revealed Mfn2 gene function in lens development and addressed the relationship between the mitochondria and lens transparency. Conditional loss of Mfn2 affected lens epithelium cell proliferation, apoptosis and ultrastructure of mitochondria. We conclude that proper development of the lens and lens transparency depend on normal Mfn2 gene function.