Objective To investigate the expression of eotaxin-1, eotaxin-2 and eotaxin-3 in ARPE-19 human RPE cells after exposure to light. Methods Cultured human RPE cells (5th~10th generations) were divided into lightinduced group and control group. Cells light-induced group were exposed to the blue light at the intensity of (600plusmn;100) Lux for 12 h to establish the light damaged model. Eotaxin-1, eotaxin-2 and eotaxin-3 mRNA and protein were determined by real time polymerase chain reaction and Western blot at 0, 3, 6, 12, 24 hours after light-induced. Results In light-induced groups, mRNA levels of eotaxin-1 and eotaxin-2 were increased at 0 h (t1=6.05.t2=12.561) and 3 h （t1=2.95.t2=3.67） significantly(P＜0.05), but the mRNA level of eotaxin-3 had not changed （t3=1.57 and 1.00 respectively，P＞0.05） at that time. At 6 h （t1=4.73，t2=18.64，t3=28.48）, 12 h （t1=3.11，t2=20.62，t3=18.50）, 24 h （t1=8.25，t2=38.27，t3=18.60）, mRNA levels of eotaxin-1, 2, 3 were increased significantly （P＜0.05）. Except for the eotaxin-3 protein had not changed at 3 h （t3=1.28，P＞0.05）, protein expression of eotaxin-1, 2, 3 were increased significantly （P＜0.05） at 0 h （t1=4.85，t2=5.45，t3=6..21）, 3 h （t1=5.64，t2=4.55）, 6 h （t1=31.60，t2=6.63，t3=7.15）, 12 h （t1=14.09，t2=18.22，t3=15.76）, 24 h （t1=6.96，t2=10.47，t3=12.85）. Conclusion Eotaxin-1, eotaxin-2 and eotaxin-3 expression were increased after Light-damage, corresponding to the time after light exposure. Eotaxin-3 was the most prominent isoform.
Objective To investigate the protective effects of riluzole, a sustained activator of K2P subfamily member TRAAK potassium channel, in human retinal pigment epithelium (hRPE) cells with oxidative induce by tert-butyl hydroperoxide (t-BHP) in vitro, and to evaluate the possible involvement of K2P in the cytoprotective function of retina degeneration diseases. Methods The third to fifth passage of the primary cultured hRPE cells were used in the following experiments．hRPE cells were divided into seven groups: normal control group.t-BHP (300 mu;mol/L) group.t-BHP with riluzole (2, 5, 10, 20 mu;mol/L) group and riluzole (10 mu;mol/L) group. The apoptosis was measured by the 3(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) assay, annexinV/PI double staining flow cytometry. Changes of cells and nuclei morphology were observed under a phase contrast microscope and a fluorescence microscope after 4prime;, 6-diamidino-2-phenylindole (DAPI) staining. Immunofluorescence 1abelling was carried out to analysis the expression of TRAAK. Results After 24 hours incubation with 300 mu;mol/L t-BHP, the cells viability decreased to (58.7plusmn;12.2)% as compared to the normal control groups. The cell viability of t-BHP with riluzole group at different concentrations was higher than the t-BHP group, while 10 mu;mol/L riluzole showed maximally protective effect on hRPE death induced by t-BHP（t=4.84.P＜0.05）. Riluzole remarkably decreased pyknotic nucleus and cell swelling when compared with t-BHP group. Morphology of cells was fusiform with the uniform elliptic nuclei in normal and riluzole group. The Results of annexinV/PI double staining flow cytometry showed that ratio of normal cells were （97.6plusmn;1.3）%, （70.3plusmn;7.0）%, （86.9plusmn;5.2）%, （93.9plusmn;1.5）% in normal group.t-BHP group.t-BHP with riluzole group and riluzole group respectively. The ratio significant decreased in t-BHP group when it was compared with the other groups (t=7.53, 4.59, 6.49, respectively.P＜0.05). By contrast with normal group and riluzole group, the ratio of normal cells in t-BHP with riluzole group had no statistical significance（t=2.94, 1.91, respectively.P＞0.05）. Riluzole (10 mu;mol/L) also significantly decreased the ratio of early stage apoptotic cells from (25.50plusmn;8.02)% to (1.20plusmn;0.72)% in t-BHP injured groups （t=7.13，P＜0.05）. The ratio of early stage apoptotic cells significant decreased in t-BHP group when it was compared with the normal group and riluzole group （t=7.07, 5.94, respectively.P＜0.05）. By comparison with normal group and riluzole group, there are no statistical significance in t-BHP with riluzole group（t=0.06, 1.18, respectively.P＞0.05）. The mean gray values of TRAAK expression were 0.040plusmn;0.003, 0.041plusmn;0.001, 0.049plusmn;0.001, 0.055plusmn;0.001 in normal group.t-BHP group.t-BHP with riluzole group and riluzole group respectively. TRAAK density was significantly higher in t-BHP with riluzole group and riluzole group（t=7.40, 12.70, respectively.P＜0.05）. Conclusions Riluzole can protect hRPE cells against oxidative injury-induced cell death at early apoptosis stage. The mechanism may relate to that riluzole can promote the expression of K2P TRAAK potassium channel.
Objective To investigate the effect of blue light on mRNA expression of L-type calcium channel subtypes of human retinal pigment epithelial (RPE) cells in vitro. Methods The fourth-generation of human RPE cells were randomly divided into four groups including control group (no light group), light group, light + nifedipine group, and light + (-) BayK8644 group. The cells were exposed to blue light (2000plusmn;500) lux for 6 hours, and then cultured for another 24 hours. Reverse transcription polymerase chain reaction real time (RT-PCR) and fluorescence quantitative PCR technologies were used to analyze mRNA expression of L-type calcium channel subunit of cardiac subtype ( 1C or CaV1.2), neuroendocrine subtype ( 1D or CaV1.3) and retinal subtypes ( 1F or CaV1.4) in each group. Results The length of PCR product of 1C, 1D, 1F subunit and actin was 68, 157, 125 and 186 base pairs respectively. (1) 1C mRNA expression in light, light + nifedipine and light + (-) BayK8644 group was higher than that in control group, the difference was statistically significant (P＜0.05). 1C mRNA expression in light +nifedipine group and light + (-) BayK8644 group was higher than in light group (P＜0.05). 1C mRNA expression in light + (-) BayK8644 group was higher than that in light + nifedipine group (P＜0.05). (2) Comparing with control group, 1D mRNA expression was higher in light, light +nifedipine and light + (-) BayK8644 group, the difference was statistically significant (P＜0.05). Light + (-) BayK8644 group was higher than light group and light + nifedipine group (P＜0.05), light group and the light + nifedipine group was not statistically significant (P＞0.05). (3) 1F mRNA expression in light, light + nifedipine and light + (-) BayK8644 group was higher than those in control group, there was statistically significant (P＜0.05), light +nifedipine group and light + (-) BayK8644 group was higher than light group (P＜0.05), light + nifedipine group and the light + (-) BayK8644 group was not statistically significant (P＞0.05). Conclusions The human RPE cells mRNA expression of L-type calcium channel 1C, 1D and 1F subunit was increased after exposing to blue light. Application of the 1times;10-5 mmol/L (-) BayK8644 can increase mRNA expression of 1C, 1D and 1F subunit.
Objective To investigate the impact of photodynamic therapy (PDT) with verteporfin on the expression of pigment epithelial derivative factor (PEDF) mRNA and vascular endothelial growth factor (VEGF) mRNA in adult retinal pigment epithelial (RPE) cells in vitro. Methods The changes of cellular viability before and after PDT were assessed by methyl thiazolyl tetrazolum (MTT) colorimetric assay. Semiquantitative reverse transcription-polymerase chain reaction (RT-PCR) was conducted to detect the expression of PEDF and VEGF mRNA in RPE cells before and after PDT. Results PDT caused the death of RPE cells. The cellular mortality was positively correlated with the power of photocoagulation and the concentration of verteporfin. Conclusion PDT could downregulate the expression of PEDF and VEGF mRNA in adult RPE cells in vitro, which may relate to the cure or relapse of subfoveal choroidal neovascular membrane after PDT. (Chin J Ocul Fundus Dis, 2006, 22: 256-260)
Objective To study the inhibitive effect of adenovirus mediated CD gene and 5-FC on proliferative human retinal pigment epithelial (HRPE) cells, and to search for an effective method to take precautions against proliferative vitroretinopathy (PVR).Method Different concentrations of CD and 5-FC were added respectively to the cultured third-growth-generation HRPE cells.Transferance rate was detected by positive HRPE cells marked by X-gal and LacZ. The number of HRPE cells were counted and evaluated by methylthiazol-tetrazollium (MTT) method. Results The adenovirus mediated CD gene could be transfered into HRPE cells with a dose-dependent manner. Positive HRPE cells with CD gene could transform 5-FC to 5-Fu,which could inhibit the increase of HRPE cells effectively. No obvious bystander effect on the growth of HRPE cells was detected.Conclusions The adenovirus may introduce a foreign gene into cultured HRPE cells efficiently. It could be a good method to treat and prevent PVR by medication. (Chin J Ocul Fundus Dis，2003，19：168-171)
The effects of various receptor agonists/antagonists on the accumulation of inositol phosphates(InsPs) in cultured rat retinal pigment epitheium (RPE) cells were analysed. The results showed that serotonin and the 5-HT2 agonists such as alpha;-methyl-serotonin, quipazine, and DOI (1-[2.5-dimethoxy-4-iodopheny1]-2-aminopropane) all stimulated InsPs accumulation in rat RPE cells. The serotonin-induced stimulation of InsPs was effectively blocked by ketanserin, a 5-HT2 antagonist, but also attenuated by the active phorbol ester PMA (4ft-phorbol 12-myristate 13-acetate), a potent protein kinase C activator.The data presented provide clear evidence for the presence of 5-HT2 receptors coupled to phosphoinositide metabolism on cultured rat RPE cells. （Chin J Ocul Fundus Dis,1994,10:80-83）