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.
Proliferative vitreoretinopathy (PVR) is a common complication and major cause of blindness of ocular trauma. Many cytokines, including vascular endothelial growth factor (VEGF) and platelet-derived growth factor (PDGF), participate in the process of the pathogenesis of traumatic PVR. VEGF competitively inhibits binding of PDGF to its receptor (PDGFRα), enables indirect activation of PDGFRα by non-PDGF ligands, resulting in reduced p53 expression, cell proliferation and migration, which is a key point in the pathogenesis of traumatic PVR.
Objective To investigate the expression of T cell receptor (TCR) Vβ8.3 gene on CD4+ T lymphocytes in the rats with experimental autoimmune uveoretinitis (EAU). Methods Eighteen Lewis rats were divided into EAU, complete Freund′s adjuvant, and the control group. Inter photoreceptor retinoid-binding protein (IRBP) R16 peptide was synthesized using Fmoc procedure for induction of EAU. Magnetic absorption cell sorting (MACS) me thod was used to isolate the CD4+T lymphocytes from the spleen of the rats. Flow cytometry was used to monitor the efficiency of isolation. The expression of TCR Vβ8.3 gene segment on CD4+T lymphocytes was determined by fluorescent quantitative polymerase chain reaction. Results EAU was successfully induced in the Lewis rats immunized with IRBP R16 peptide. The proportion of CD4+T lymphocytes isolated by means of MACS was statistically higher than that before isolation (P＜0.001). The expression of TCR Vβ8.3 gene segment on CD4+ T lymphocytes in EAU rats was significantly higher than that in the control (P＜0.05). Conclusions There is a predominant usage of antigen-specific TCR Vβ 8.3 gene in EAU rats induced by IR BP R16 peptide, which may serve as a target for immunotherapy of EAU. (Chin J Ocul Fundus Dis，2004，20：165-167)
Retinal neuronal cells are crucial in the formation of vision. Injury or death of these cells may lead to irreversible damage to visual function due to their low regenerative capacity. The P2X7 receptor is a trimeric adenosine triphosphate (ATP)-gated cation channel. Recent studies have shown that P2X7 receptor plays a role in retinal neuronal death. In a series of animal models, when exposed to conditions of hypoxia or ischemia, elevated ocular pressure, trauma and exogenous agonists, P2X7 receptor activated by extracellular ATP can cause death of retinal neuronal cells such as retinal ganglion cells and photoreceptor cells through direct or indirect pathways. Blocking the expression and function of P2X7 receptor by its specific antagonist and gene knocking-out, the loss of retinal neuronal cells is significantly attenuated. P2X7 receptor may become a potential novel neuroprotective target for diseases related to the loss of retinal neurons.
As most patients of central serous retinopathy (CSC), the symptoms of acute onset will alleviate by oneself after 4-6 months. About 30%-50% of patients with CSC experience chronic or recurrent cases. Resulting in persistent neurosensory detachments and subretinal fluid, causing significant vision loss. Mineralocorticoid receptor (MR) is a kind of nuclear hormone receptors, plays a role in theregulation of water and electrolyte balance. Excessive MR signaling is associated with many diseases. Study found that MR antagonists decreased the thickness of the retina and improved in vision, there was no serious adverse reactions during the period of treatment for chronic CSC. Initial dose of MR antagonists was 25 mg per day, 1 week later, dosage was increased to 50 mg per day, and treatment for about 3 months. There is no conclusive effective treatment and the dosage are still unknown. MR antagonists may be a safe and effective way to treat chronic CSC, though evidence is scant. Prospective, multicenter, large-scale trials is required.
Objective To evaluate the inhibiting effect of adenosine on rat retinal ganglion cells (RGC) death induced by P2X7 and N-methyl-D-aspartate (NMDA) receptor. Methods (1) Long-Evan neonatal rats were back labeled with aminostilbamidine to identify RGC. The viability of RGC affected by P2X7 excitomotor BzATP (50 mu;mol/L), glutamate receptor excitomotor NMDA (100 mu;mol/L) and adenosine (300 mu;mol/L) was detected. (2) RGC from the retinae of unlabeled neonatal rats were cultured in vitro. After labeled with Fura-2 methyl acetate, an intracellular calcium indicator, the effect of BzATP, NMDA and adenosine on intracellular Ca2+ level was detected byCa2+ imaging system. Results Both BzATP (50 mu;mol/L) and NMDA(100 mu;mol/L) could kill about 30% of the RGC. Cell death was prevented by adenosine (300 mu;mol/L) with the cell viability increased from (68.9plusmn;2.3)% and (69.9plusmn;3.2)% to (91.2plusmn;3.5)% (P＜0.001) and (102.1plusmn;3.9)% (P＜0.001), respectively. BzATP (50 mu;mol/L) led to a large, sustained increase of intracellular Ca2+ concentration to (1183plusmn;109) nmol/L. After the adenosine intervened, Ca2+ concentration increased slightly to (314plusmn;64) nmol/L (P＜0.001). Conclusion Adenosine may prevent RGC death and increase of intracellular Ca2+ concentration from P2X7and NMDA receptor stimulation. (Chin J Ocul Fundus Dis, 2007, 23: 133-136)
ObjectiveTo investigate the expression and mechanism of miR-1470 in plasma of diabetic retinopathy (DR) patients.MethodsThirty patients with DR (DR group), 30 patients with diabetes (DM group) and 30 normal healthy subjects (normal group) were enrolled in the study. Three groups of subjects were taken 5 ml of venous blood, and total plasma RNA was extracted and purified. The differentially expressed miRNAs in the plasma of DR patients were screened by gene chip, and the results of gene chip detection were verified by reverse transcription polymerase chain reaction (RT-PCR). Bioinformatics was used to predict potential target genes for miRNA regulation, and miR-1470 and its target gene epidermal growth factor receptor (EGFR) were screened. Human retinal microvascular endothelial cells (hREC) were divided into normal group (sugar concentration 5.5 mmol/L) and high glucose group (sugar concentration 25.0 mmol/L). hREC was transfected into miR-1470 mimics to establish a miR-1470 high expression cell model, which was divided into blank control group, high expression group and negative control group. The expression of miR-1470 was detected by RT-PCR. The expression of EGFR protein was detected by Western blot. The measurement data of the two groups were compared using the independent sample t test. The comparison of the measurement data between the two groups was analyzed by ANOVA. The comparison between the measurement data of the groups was compared by multiple comparisons.ResultsThe results of RT-PCR were consistent with those of the gene chip. The expression of miR-1470 in the plasma of the DR group, the DM group and the normal group was statistically significant (F=63.486, P=0.049). Compared with the DM group and the normal group, the expression of miR-1470 in the DR group was significantly decreased, and the difference was statistically significant (q=111.2, 73.9; P＜0.05). The expression of miR-1470 in hREC in the high glucose group was significantly lower than that in the normal group (t=42.082, P=0.015). The expression of EGFR protein in hREC of high glucose group was significantly higher than that of normal group (t=−39.939, P=0.016). The expression of miR-1470 (F=637.069, P=0.000) and EGFR (F=122.908, P=0.000) protein expression in hREC of blank control group, negative control group and high expression group were statistically significant . Compared with the blank control group and the negative control group, the expression of miR-1470 in hREC of high expression group was significantly increased (q=329.7, 328.8; P＜0.05), and the expression of EGFR protein was significantly decreased (q=242.5, 234.6; P＜0.05). There was no significant difference in the expression of miR-1470 and EGFR protein in hREC between the negative control group and the blank control group (q=1.5, 7.9; P＞0.05).ConclusionThe expression of miR-1470 in the plasma of patients with DR is significantly down-regulated, and the increase of EGFR expression may be related to it.
Neovascularization is a characteristic manifestation of a variety of retinal diseases. Vascular endothelial growth factor (VEGF) mainly regulates the proliferation and migration of endothelial cells. VEGF receptor 2 (VEGFR2) is the main receptor to mediate this effect. The activation of downstream signals requires the binding of VEGF and VEGFR2, followed by receptor dimerization and autophosphorylation. Blocking this process and inhibiting neovascularization is very attractive treatment ideas. Monoclonal antibodies and fusion protein drugs currently used in ophthalmology can bind free VEGF. In addition, there are also macromolecular antibodies binding VEGFR2 and small molecule tyrosine kinase inhibitors, which is expected to further expand into the field of ophthalmology. Although anti-VEGFR2 therapy is a revolutionary method to inhibit neovascularization, there are no sufficient clinical evidences at present. In-depth understanding of the application status and progress of anti-VEGFR2 in the treatment of retinal neovascular diseases has important clinical significance.
Objective To investigate the insulin receptor expression and binding characteristics of H22 rat hepatic cancer cell membrane with 125Iinsulin and the possibility of using insulin as a carrier for the receptor mediated targeted therapy. MethodsInsulin was radiolabelled using ChT method, isolated and purified by polyacrylamide gel electrophoresis, the labelled 125Iinsulin was measured by specific activity selfreplacement and over dose receptor combination experiment. The rat H22 hepatocarcinoma cells, normal rat hepatic cells were made, continuing the value Kd and Bmax of 125Iinsulin binding with insulin receptor on rat H22 hepatocarcinoma and normal hepatic cells membrane were evaluated in vitro, the competed binding curve was pictured. The binding Kd and Bmax value of 125Iinsulin receptor were evaluated with t test and receptor binding curve was tested with Scatchard method. ResultsThe Bmax value of rat H22 hepatocarcinoma cell receptor ［(5.6±1.1) pmol/106 cell］ was higher than that of normal hepatic cell ［(3.2±0.8) pmol/106 cell］ significantly (P＜0.05). The Kd value of H22 cell ［high and lowaffinity vs (1.8±0.6) nmol/L and (32.0±10.7) nmol/L］ and normal hepatic cell ［high and low affinity vs (2.1±0.9) nmol/L and (37.0±12.3) nmol/L］ were not significant respectively. In this experiment, it was specific when 125Iinsulin combined with receptor on H22 hepatocarcinoma cell and rat normal hepatic cell membrane. Conclusion This experiment showed that the receptor expresses much more significantly on H22 hepatocarcinoma cell membrane than that on normal rat hepatic cell membrane, 125Iinsulin combining with receptor on H22 hepatocarcinoma cell and rat hepatic cell membrane is highly specific. We may use insulin as an anticancer carrier to mediate insulin combined with receptor on hepatocarcinoma cell membrane in the target treatment of hepatic cancer.
In order to study the expression change of insulin-like growth factor-1 (IGF-1) and its receptor genes in different generations of tendon cell in culture, Dig-labeled synthesized oligonucleotide probes were used to detect the mRNA expression in primary, 6th and 13th generation of tendon cell. The results showed that IGF-1 receptor mRNA was expressed in all of the 3 above generation tendon cells. IGF-1 mRNA was expressed only in primary and 6th generation cells. Tendon cell of 13th generation did not express IGF-1 mRNA. It might suggest that the absence of IGF-1 mRNA expression be one of the causes which led to the decrease of reproductive ability of 13th generation tendon cell.