Yao K

Parthenolide protects human lens epithelial cells from oxidative stress-induced apoptosis via inhibition of activation of caspase-3 and caspase-9.

The apoptosis of lens epithelial cells has been proposed as the common basis of cataract formation, with oxidative stress as the major cause. This study was performed to investigate the protective effect of the herbal constituent parthenolide against oxidative stress-induced apoptosis of human lens epithelial (HLE) cells and the possible molecular mechanisms involved. HLE cells (SRA01-04) were incubated with 50 μM H2O2 in the absence or presence of different doses of parthenolide (10, 20 and 50 μM). To study apoptosis, the cells were assessed by morphologic examination and Annexin V-propidium iodide double staining flow cytometry; to investigate the underlying molecular mechanisms, the expression of caspase-3 and caspase-9 were assayed by Western blot and quantitative RT-PCR, and the activities of caspase-3 and caspase-9 were measured by a Chemicon caspase colorimetric activity assay kit. Stimulated with H2O2 for 18 h, a high fraction of HLE cells underwent apoptosis, while in the presence of parthenolide of different concentrations, dose-dependent blocking of HLE cell apoptosis was observed. The expression of caspase-3 and caspase-9 induced by H2O2 in HLE cells was significantly reduced by parthenolide both at the protein and mRNA levels, and the activation of caspase-3 and caspase-9 was also suppressed by parthenolide in a dose-dependent manner. In conclusion, parthenolide prevents HLE cells from oxidative stress-induced apoptosis through inhibition of the activation of caspase-3 and caspase-9, suggesting a potential protective effect against cataract formation.

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 2u2009h. The specific absorption rates were 1.0, 2.0, or 3.5u2009W/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.u2003Jpn J Ophthalmol 2007;51:412–416

Honokiol inhibits H2O2-induced apoptosis in human lens epithelial cells via inhibition of the mitogen-activated protein kinase and Akt pathways

Oxidative stress-induced apoptosis in lens epithelial cells plays an important role in cataract formation, and its prevention may be of therapeutic interest. This study was performed to investigate the protective effect and mechanisms of honokiol on H(2)O(2)-induced apoptosis in human lens epithelial (HLE) cells. HLE cells (SRA01-04) were pretreated with honokiol at concentrations of 5μM, 10μM and 20μM before 50μM H(2)O(2) treatment. The results demonstrated that pretreatment of honokiol inhibited the activation of caspase-3 and caspase-9 and downregulated the expression of Bcl-2. Mechanistically, honokiol suppressed H(2)O(2)-induced phosphorylation of ERK1/2, p38 mitogen-activated protein kinase (MAPK), JNK and Akt. Honokiol also inhibited H(2)O(2)-induced nuclear factor-κB (NF-κB)/p65 phosphorylation and translocation in HLE cells. These results demonstrate that honokiol suppresses H(2)O(2)-induced HLE cell apoptosis via interference with the MAPKs, Akt and NF-κB signaling, suggesting that honokiol might have a potential effect against cataract formation.

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

Endostar, a recently introduced recombinant human endostatin, inhibits proliferation and migration through regulating growth factors, adhesion factors and inflammatory mediators in choroid-retinal endothelial cells.

Retinal neovascularization is one of the leading causes for complete blindness in a number of diseases around the world. Endostar, a recently introduced recombinant human endostatin, has been considered as one of the most valuable anti-angiogenic agents. In this study, we demonstrate that Endostar inhibits both the proliferation of the choroid-retinal endothelial cells through limiting the progression of the cell cycle and their migration. Furthermore, Endostar induces the expression of the pigment epithelial-derived factor (PEDF) and suppresses the expression of the vascular endothelial growth factor (VEGF) and the fibroblast growth factor (FGF). Endostar also reduces the expression of the inflammatory mediator tumor necrosis factor-α (TNF-α), matrix metalloproteinases (MMPs) and vascular cell adhesion molecule-1 (VCAM-1). These findings reveal an integrated role of Endostar in the program of retinal vascular control and highlight its significant potential for broad clinical application.

Change in outflow pathway of porcine eyes in vitro by nonpenetrating filtering surgery

OBJECTIVEnTo study the change in different outflow pathways of porcine eyes in vitro by nonpenetrating filtering surgery.nnnDESIGNnExperimental study.nnnPARTICIPANTSnSixty-four enucleated porcine eyes were studied.nnnMETHODSnDeep sclerectomy was performed on isolated porcine eyes (Group 1A), then the superficial scleral flap was watertight sealed (Group 1B), and finally the oracles and the exterior wall of the Schlemm canal were watertight sealed (Group 1C). In another series of experiments, deep sclerectomy was performed with the scleral lake volume of 4 mm × 4 mm × 0.5 mm (Group 2A), 4 mm × 2 mm × 0.5 mm (Group 2B), and 4 mm × 1 mm × 0.5 mm (Group 2C), respectively; then the superficial scleral flap was watertight sealed. The control eye (Groups 1D and 2D) underwent creation and watertight sealing of a superficial scleral flap. Intraocular pressure (IOP) and outflow facility were determined preoperatively and postoperatively.nnnRESULTSnCompared with the preoperative value, IOP was decreased and outflow facility was increased in Groups 1A, 1B, and 1C (p < 0.05). In deep sclerectomy, the outflow facility was decreased by more than 0.18 µL/min/mm Hg after the conjunctival pathway was blocked. After the oracles and external wall of the Schlemm canal were blocked, the outflow facility decreased further by more than 0.09 µL/min/mm Hg but was still 0.06 µL/min/mm Hg higher than before surgery. There was a positive linear correlation between the deep sclerectomy volume and the ratio of IOP decrease or outflow facility increase postoperatively.nnnCONCLUSIONSnDeep sclerectomy can increase the outflow of porcine eyes in vitro. The major factors maintaining the postoperative outflow increase include the subconjunctival pathway, the functional deep scleral lake, and the opening of the Schlemm canal.

Effects of 1.8 GHz radiofrequency radiation on protein expression in human lens epithelial cells

Objective: The aim of the present study was to observe the effects of 1.8 GHz radiofrequency (RF) radiation on the protein expression of human lens epithelial cells (hLECs) in vitro. Methods: The hLECs were exposed and sham-exposed to 1.8 GHz RF radiation (specific absorption rate (SAR) of 4 W/kg) for 2 h. After exposure, the proteins extracted from LECs were loaded on the Ettan MDLC system connected to the LTQ-Orbitrap MS for screening the candidate protein biomarkers induced by RF. The quantitative real-time polymerase chain reaction (qRT-PCR) was used to detect the levels of messenger RNA of candidate biomarkers. After the hLECs were exposed to 1.8 GHz RF (SAR of 2, 3 and 4 W/kg) for 2 h, the Western blot assay was utilized to measure the expression levels of the above-screened candidate protein biomarkers. Results: The results of shotgun proteomic analysis indicated that there were eight proteins with differential expression between exposure and sham exposure groups. The results of qRT-PCR showed that there were three genes with expressional differences (valosin containing protein (VCP), ubiquitin specific peptidase 35 (USP35) and signal recognition particle 68 kDa (SRP68)) between exposure and sham exposure groups. The results of Western blot assay exhibited that the expressional levels of VCP and USP35 proteins significantly increased and the expressional level of protein SRP68 significantly decreased in hLECs exposed to 1.8 GHz RF radiation (SAR of 3 and 4 W/kg) for 2 h when compared with the corresponding sham groups (p < 0.05). Conclusion: The shotgun proteomics technique can be applied to screen the proteins with differential expression between hLECs exposed to 1.8 GHz RF and hLECs sham-exposed to 1.8 GHz RF, and three protein biomarkers associated with RF radiation were validated by Western blot assay.

Inhibition of calpain expression by E-64d in the rat retina subjected to ischemia/reperfusion injury

To investigate the effect of E-64d, a selective inhibitor of calpain, on the expression of calpain and calpastatin in rat retina was subjected to ischemia/reperfusion injury (IRI). An animal model of retinal IRI was set up by increasing the intraocular pressure (110 mm Hg) of a rat eye for 1 h. The retinal thickness and morphologic changes were detected by histology. The protein expression of m-calpain (a calpain isoform) in the retina was assessed by immunohistochemistry and Western blot assay. The mRNA of m-calpain, as well as calpastatin (an endogenous protein inhibitor of calpain), in the retina was assessed by RT-PCR, and the ratio of m-calpain/calpastatin was then calculated. To evaluate the effect of E-64d on the expression of calpain, the drug (5 μl of 100 μM) was injected intravitreously immediately after IRI. There were retinal edematous changes, particularly in the inner plexiform layer after IRI. The protein expression of m-calpain in the retina was increased 24 h after IRI, an effect that was inhibited by E-64d (P < 0.05). The mRNA expression of m-calpain and calpastatin was also increased 24 h and 3 h after IRI, respectively. Neither m-calpain nor calpastatin mRNA expression was influenced by E-64d (P > 0.05). The mRNA ratio of m-calpain to calpastatin was increased at the 6 h, 24 h and 72 h after IRI, and only at 24 h the increase of the ratio of m-calpain to calpastatin was inhibited by E-64d (P < 0.05). In the rat retina of IRI, E-64d inhibits the increase of m-calpain protein expression, as well as the mRNA ratio increase of m-calpain to calpastatin. E-64d also inhibited the retinal damage induced by IRI, suggesting a role for E-64d in the protection of the retinal apoptosis induced by IRI.

Successful Diagnosis and Treatment of a Single Case of Bilateral Necrotizing Keratitis following Femtosecond-LASIK

Corneal infiltrates are a relatively uncommon complication after refractive surgery. Infectious corneal infiltrates may result in a significant loss of vision. Diffuse lamellar keratitis (DLK) is one of the most common sterile inflammations after LASIK. Recent studies have documented the clinical course of peripheral necrotizing keratitis following femtosecond-LASIK. We report the first case of bilateral peripheral necrotizing keratitis following femtosecond-LASIK using a high-frequency, low-energy VisuMax femtosecond laser system.

Correlation of the Recurrent FBN1 Mutation (c.364C>T) with a Unique Phenotype in a Chinese Patient with Marfan Syndrome

PurposeTo describe a Chinese patient with Marfan syndrome who had a unique phenotype and a recurrent mutation in the fibrillin-1 (FBN1) gene.Case and MethodsA 31-year-old man who had a spontaneous bilateral lens dislocation into the vitreous cavity in childhood was found to have retinal and choroidal detachments in both eyes. A congenital atrial septal defect was detected. Pars plana vitrectomy, lensectomy, and silicone oil tamponade were performed on his right eye. Genomic DNA was extracted from leukocytes of peripheral blood, and the 65 exons and flanking intronic sequences of the FBN1 gene were amplified by polymerase chain reaction for mutational screening.ResultsA recurrent mutation, c.364C>T was detected in exon 4 that resulted in p.Arg122Cys. The visual acuity of the right eye improved to 6/60 one year after the surgeries.ConclusionDNA screening helps in the diagnosis of Marfan syndrome with unique phenotypes. The mutation c.364C>T can be considered to be a hotspot for Marfan patients with predominant ectopia lentis.