OBJECTIVETo investigate the DNA damage of human lens epithelial cells (LECs) caused by acute exposure to low-power 217 Hz modulated 1.8 GHz microwave radiation and DNA repair.

METHODSCultured LECs were exposed to 217 Hz modulated 1.8 GHz microwave radiation at SAR (specific absorption rate) of 0, 1, 2, 3 and 4 W/kg for 2 hours in an sXc-1800 incubator and irradiate system. The DNA single strand breaks were detected with comet assay in sham-irradiated cells and irradiated cells incubated for varying periods: 0, 30, 60, 120 and 240 min after irradiation. Images of comets were digitized and analyzed using an Imagine-pro plus software, and the indexes used in this study were tail length (TL) and tail moment (TM).

RESULTSThe difference in DNA-breaks between the exposure and sham exposure groups induced by 1 and 2 W/kg irradiation was not significant at every detect time (P > 0.05). As for the dosage of 3 and 4 W/kg there was difference in both group immediately after irradiation (P < 0.01). At the time of 30 min after irradiation the difference went on at both group (P < 0.01). However, the difference disappeared after one hour's incubation in 3 W/kg group (P > 0.05), and existed in 4 W/kg group.

CONCLUSIONNo or repairable DNA damage was observed after 2 hour irradiation of 1.8 GHz microwave on LECs when SAR < or = 3 W/kg. The DNA damages caused by 4 W/kg irradiation were irreversible.

Cell Phone ; Cells, Cultured ; Comet Assay ; DNA Damage ; radiation effects ; DNA Repair ; Dose-Response Relationship, Radiation ; Epithelial Cells ; radiation effects ; Humans ; Lens, Crystalline ; cytology ; radiation effects ; Microwaves

OBJECTIVETo compare the effects of different doses of microwave on the proliferative activity and cell cycle of cultured epithelial cells of rabbit lens, and to investigate the limit tolerant of microwave exposure.

METHODSCultured epithelial cells of rabbit lens were exposed to microwave radiation with frequency of 2,450 MHz and power density of 0.10, 0.25, 0.50, 1.00, 2.00 mW/cm(2) for 8 h in vitro. HE staining was used to observe the morphological changes of lens epithelial cells, the proliferative activity and cell cycle were measured by MTT assay and PI fluorescent staining.

RESULTS8 h after radiation, 0.50, 1.00 and 2.00 mW/cm(2) microwave could decrease the proliferation of lens epithelial cells, make the cells disordered arrangement, shrinkage, detachment, and inhibit the synthesis of cell DNA. The percentage of G(0)/G(1) phase cells were 71.95% +/- 2.12%, 75.68% +/- 3.35% and 82.40% +/- 8.68% respectively, which were higher than that in control group (61.68% +/- 5.76%, P < 0.05 or P < 0.01). The percentage of S phase cells were 19.32% +/- 3.07%, 16.08% +/- 4.91% and 12.98% +/- 8.08% respectively, which were lower than that in control group (28.05% +/- 5.12%, P < 0.05 or P < 0.01). No obvious changes could be detected in 0.10, 0.25 mW/cm(2) microwave groups (P > 0.05).

CONCLUSIONMicrowave exceeding 0.50 mW/cm(2) may make injury to lens epithelial cells after 8 hour radiation, which may be related to the effect of microwave radiation on cell cycle.

Animals ; Cell Cycle ; radiation effects ; Cells, Cultured ; DNA ; metabolism ; Epithelial Cells ; cytology ; metabolism ; radiation effects ; Lens, Crystalline ; cytology ; metabolism ; radiation effects ; Microwaves ; Rabbits

OBJECTIVETo investigate the effects of 50 Hz magnetic fields (MF) on DNA double-strand breaks in human lens epithelial cells (hLECs).

METHODSThe cultured human lens epithelial cells were exposed to 0.4 mT 50 Hz MF for 2 h, 6 h, 12 h, 24 h and 48 h. Cells exposed to 4-nitroquinoline-1-oxide, a DNA damage agent, at a final concentration of 0.1 micromol/L for 1 h were used as positive controls.After exposure, cells were fixed with 4 % paraformaldehyde and for H2AX (gamma H2AX) immunofluorescence measurement. gamma H2AX foci were detected at least 200 cells for each sample. Cells were classified as positive when more than three foci per cell were observed. Mean values of foci per cell and percentage of foci positive cells were adopted as indexes of DNA double-strand breaks.

RESULTThe mean value of foci per cell and the percentage of gamma H2AX foci positive cells in 50 Hz MF exposure group for 24 h were (2.93 +/-0.43) and (27.88 +/-2.59)%, respectively, which were significantly higher than those of sham-exposure group [(1.77 +/-0.37) and (19.38+/-2.70)%, P <0.05], and the mean value of foci per cell and the percentage of gamma H2AX foci positive cells in 50 Hz MF exposure group for 48 h were (3.14 +/-0.35) and (31.00 +/-3.44)%, which were significantly higher than those of sham-exposure group (P <0.01). However there was no significant difference between 50 Hz MF exposure groups for 2 h, 6 h, 12 h and sham-exposure group for above two indexes (P >0.05).

CONCLUSION0.4 mT 50 Hz MF exposure for longer duration might induce DNA double-strand breaks in human lens epithelial cells in vitro.

Cells, Cultured ; DNA ; radiation effects ; DNA Breaks, Double-Stranded ; radiation effects ; DNA Damage ; radiation effects ; DNA Repair ; radiation effects ; Electromagnetic Fields ; Epithelial Cells ; metabolism ; radiation effects ; Humans ; Lens, Crystalline ; cytology

OBJECTIVETo investigate whether the exposure to the electromagnetic noise can block reactive oxygen species (ROS) production and DNA damage of lens epithelial cells induced by 1800 MHz mobile phone radiation.

METHODSThe DCFH-DA method and comet assay were used respectively to detect the intracellular ROS and DNA damage of cultured human lens epithelial cells induced by 4 W/kg 1800 MHz mobile phone radiation or/and 2 muT electromagnetic noise for 24 h intermittently.

RESULT1800 MHz mobile phone radiation at 4 W/kg for 24 h increased intracellular ROS and DNA damage significantly (P<0.05). However, the ROS level and DNA damage of mobile phone radiation plus noise group were not significant enhanced (P>0.05) as compared to sham exposure group.

CONCLUSIONElectromagnetic noise can block intracellular ROS production and DNA damage of human lens epithelial cells induced by 1800 MHz mobile phone radiation.

Cell Phone ; Cells, Cultured ; DNA ; radiation effects ; DNA Damage ; radiation effects ; Electromagnetic Fields ; Epithelial Cells ; metabolism ; radiation effects ; Humans ; Lens, Crystalline ; cytology ; Microwaves ; adverse effects ; Radiation ; Reactive Oxygen Species ; metabolism

PURPOSE: The purpose of this study is to understand the mechanism of apoptosis occurring on a cultured human lens epithelial cell line after exposure to ultraviolet (UV) light. We intended to confirm the presence of cellular toxicity and apoptosis and to reveal the roles of p53, caspase 3 and NOXA in these processes. METHODS: Cells were irradiated with an ultraviolet lamp. Cellular toxicity was measured by a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. Hoechst staining and fluorescent anti-caspase 3 antibodies were used for apoptosis investigation. The quantities of p53, caspase 3, and NOXA were measured by Western blotting for to investigate the apoptosis pathway. RESULTS: Cellular toxicity on the human lens epithelium markedly increased with time after UV exposure. On Hoechst staining, we found that apoptosis also remarkably increased after exposure to ultraviolet light, compared with a control group. In the immunochemical study using anti-caspase 3 antibodies, active caspase 3 significantly increased after exposure to ultraviolet light. On Western blotting, p53 decreased, while caspase 3 and NOXA increased. CONCLUSIONS: Exposure of cultured human lens epithelial cell lines to ultraviolet light induces apoptosis, which promotes the expression of NOXA and caspase 3 increases without increasing p53. This may suggest that UV induced apoptosis is caused by a p53-independent pathway in human lens epithelial cells.
Apoptosis/*physiology ; Caspase 3/metabolism ; Cell Line ; Cell Survival/radiation effects ; Epithelial Cells/radiation effects ; Humans ; Lens, Crystalline/cytology/*physiology/*radiation effects ; Proto-Oncogene Proteins c-bcl-2/metabolism ; Tumor Suppressor Protein p53/metabolism ; *Ultraviolet Rays

OBJECTIVE: To determine the apoptosis-inducing effect of ultraviolet light (UV) on human lens epithelial cell (HLEC) and to explore the involvement of changes in ALDH1 folowing UV radiation. METHODS: HLEC was exposed to the same UV light source and was subsequently divided into 6 groups according to UV radiation time of 0 (control group), 5, 10, 15, and 30 min. Apoptosis was detected by AO/EB staining. Changes of ALDH1 in HLEC were detected by immunohistochemical staining and Western blot. RESULTS: The intensity of immunohistochemical staining and the rate of positive cells decreased with increase of UV time (P<0.05). The rate of positive ALDH1 cells was negatively correlated with the rate of apoptosis (r= -0.92, P<0.05). Western blot showed the integrated absorbance values significantly decreased with the increase of UV time (P<0.05). CONCLUSION ALDH1 in HLEC decreases with an increase of UV exposure, which may be related to UV induced apoptosis of HLEC.
Aldehyde Dehydrogenase 1 ; Apoptosis ; radiation effects ; Cells, Cultured ; Epithelial Cells ; cytology ; metabolism ; radiation effects ; Humans ; Isoenzymes ; genetics ; metabolism ; Lens, Crystalline ; cytology ; Retinal Dehydrogenase ; genetics ; metabolism ; Ultraviolet Rays ; adverse effects

OBJECTIVE: To explore the apoptosis-inducing effect of ultraviolet(UV) radiation on human lens epithelial cells (HLEC), with particular focus on changes in Bcl-2 or Bax expression as possible mechanisms. METHODS: All experimental groups were exposed to the same UV light source. HLEC were divided into 6 groups according to duration of UV radiation : 0 min group (control group), 5 min group, 10 min group,15 min group, and 30 min group. Analysis on apoptosis of HLEC was performed by flow cytometry analysis (FCA, Annexin V + PI staining). Changes of Bax and Bcl-2 expression in HLEC were detected by hybridization in situ. RESULTS: Apoptosis in HLEC increased with UV exposure time. The expression level of Bax mRNA was increased with the increase of UV exposure time, whereas the expression level of Bcl-2 mRNA decreased with the increase of UV exposure time. The proportion of apoptotic cells was negatively correlated with ratio of Bcl-2/Bax (r=-0.874, P<0.05). CONCLUSION UA radiation can induce apoptosis of HLEC in vitro. Bcl-2 and Bax genes may play an important role in regulating this apoptotic process.
Apoptosis ; radiation effects ; Cells, Cultured ; Epithelial Cells ; cytology ; metabolism ; radiation effects ; Humans ; Lens, Crystalline ; cytology ; radiation effects ; Proto-Oncogene Proteins c-bcl-2 ; genetics ; metabolism ; RNA, Messenger ; genetics ; metabolism ; Time Factors ; Ultraviolet Rays ; adverse effects ; bcl-2-Associated X Protein ; genetics ; metabolism

PURPOSE: To evaluate the protective effects of epigallocatechin gallate (EGCG) against UV irradiation of cultured human lens epithelial cells. METHODS: We irradiated cultured human lens epithelial cells with a 30-second pulse from a UV lamp with an irradiance of 0.6 mW/cm2. Five minutes and 1 hour after UV irradiation, we administered 0, 5, 10, 15, 25, 50, or 100 uM EGCG. The cell number was measured with a microscopic counting chamber and cell viability was evaluated using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay. RESULTS: Compared to untreated cells, the total number of cultured human lens epithelial cells was markedly higher after UV irradiation. In a dose-dependent manner, viability was also higher in EGCG-treated cells. CONCLUSIONS: EGCG increased the cell count and cell viability after UV irradiation of cultured human lens epithelial cells, indicating that EGCG can protect lens epithelium against UV damage.
Antioxidants/*pharmacology ; Catechin/*analogs & derivatives/pharmacology ; Cell Count ; Cell Survival/drug effects ; Cells, Cultured ; Coloring Agents/diagnostic use ; Dose-Response Relationship, Drug ; Epithelial Cells/radiation effects ; Humans ; Lens, Crystalline/cytology/*radiation effects ; Radiation Injuries/*prevention & control ; Radiation-Protective Agents/*pharmacology ; Tetrazolium Salts/diagnostic use ; Thiazoles/diagnostic use ; *Ultraviolet Rays