Idiopathic macular hole (IMH) refers to full thickness defects of retina in macular area with no clear reasons. The management of IMH includes vitrectomy combined with internal limiting membrane (ILM) peeling and pharmacological vitreolysis. But ILM peeling may damage the inner retina; novel techniques, such as inverted ILM flap technique and foveola non-peeling ILM surgery, autologous ILM transplantation had made the method of ILM peeling more diversified with less damage. Pharmacological vitreolysis targeting fibronectin and laminin is considered to work in a two-step mechanism, involving both vitreoretinal separation and vitreous liquefaction. Furthermore, IMH judgment and prognosis indicators like ellipsoid zone, macular hole index, hole formation factor, diameter hole index and tractional hole index based on spectral domain optical coherence tomography enriched the assessment of macular hole diameter, depth and shape. How to make full use of new interventions to reduce the incidence of macular hole and obtain a better visual acuity with closed holes is an important direction for future research.
ObjectiveTo observe the inhibitory effect of lentivirus mediated small interference RNA (siRNA) targeting cyclic adenosine monophosphate responsive element binding protein 1 (CREB1) on retinal neovascularization (RNV) in mice. MethodsCREB1 siRNA construct was created, screened and packaged to produce CREB1 RNAi-lentivirus. One hundred and forty (5-day-old) C57BL/6J mice were randomly divided into 4 groups including normal group, oxygen induced retinopathy (OIR) group, empty vector group and CREB1 therapy group with 35 mice in each group. Mice in the normal group were kept in normal room air, while in the other three groups retinal neovascularization was induced by hypoxia on postnatal day 7 (P7). The mice in the OIR group were not treated. The mice in the vector group received intravitreal injection of lentivirus-green fluorescent protein (lenti-GFP, 1 μl), and the CREB1 therapy group received CREB1 RNAi-lentivirus (1 μl) on P5.The proliferative neovascular response was quantified by counting the vascular cell nuclei extending breaking through the internal limiting membrane (ILM) and fluorescent angiography. The areas of RNV and non-perfusion region were calculated. The expression of CREB1, phosphorylated-CREB1 (P-CREB1) and vascular endothelial growth factor (VEGF)-A levels, Akt and phosphoinositide 3-kinases (PI3K) in retinas were measured by reverse transcriptase-polymerase chain reaction (RT-PCR) and Western blot. ResultsThe number of vascular cell nuclei breaking through the ILM of the OIR group and the empty vector group increased significantly compared with the normal group (P<0.05), while obviously decreased in the CREB1 therapy group compared with the OIR group and the empty vector group(P<0.05). The area of RNV and non-perfusion region of the OIR group and the empty vector group increased significantly compared with the normal group, while obviously decreased in the CREB1 therapy group compared with the OIR group and the empty vector group. The difference of area of RNV and non-perfusion region among 4 groups were significant (F=67.220, 110.090; P<0.05). The mRNA expression of CREB1 and protein expression of P-CREB1, the mRNA and protein expression of VEGF-A, Akt, PI3K in the retina were increased significantly in the OIR group and the empty vector group as compared with the normal group, while decreased significantly in the CREB1 therapy group as compared with the OIR group and the empty vector group. The difference of mRNA expression of CREB1, VEGF-A, Akt, PI3K in the retina among 4 groups were significant (F=6.087, 5.464, 6.191, 8.627; P<0.05). The protein expression of P-CREB1, VEGF-A, Akt, PI3K in the retina among 4 groups were significant (F=162.944, 13.861, 19.710, 22.827; P<0.05). ConclusionRNV in the mice is significantly inhibited by intravitreal injection of lentivirus-mediated CREB1 down-regulation.
ObjectiveTo observe the changes of eotaxin-1(CCL11), eotaxin-2(CCL24)and eotaxin-3(CCL26)in ranibizumab treated light-injured human retinal pigment epithelium (RPE) cells ARPE-19 and investigate the effects of vascular endothelial growth factor (VEGF) antagonist to the expressions of eotaxins. MethodsCultured human RPE cells(8th-12th generations)were divided into light-injured group, ranibizumab treated group and normal control group. Cells of the three groups were exposed to the blue light at the intensity of(600±100) Lux for 12 h to establish the light injured model, while cell culture dishes of the normal control group were wrapped with double-layer foil. The cells of ranibizumab treated group were treated with VEGF-A antagonist(ranibizumab)at the final concentration of 0.125 mg/ml for 24 hours directly after the illumination. The mRNA and protein of VEGF-A, eotaxin-1, eotaxin-2, eotaxin-3, NF-κB were determined by Real time-PCR, enzyme-linked immunosorbent assay, Western blot, immunohistochemical staining at 0, 3, 6, 12, 24 hours after light damage. ResultsThe mRNA and protein level of VEGF-A, eotaxin-1, eotaxin-2, eotaxin-3, NF-κB in the light-injuried group increased significantly compared to that in normal control group (P < 0.05). After treating with ranibizumab, the expression of eotaxin-1, eotaxin-2, eotaxin-3, NF-κB were significantly suppressed (P < 0.05). ConclusionThe suppression of over-expression of VEGF in human RPE may down-regulate the expression of eotaxins, via the suppression of NF-κB.
ObjectiveTo investigate the inhibitory effects and related mechanism of S100A4 gene silencing on oxygen-induced retinal neovascularization. Methods7-day-old C57BL/6J mice were randomly divided into 5 groups including normal group, normal-S100A4 group, oxygen induced retinopathy (OIR) group, OIR-S100A4 group, OIR-green fluorescent protein (GFP) group. To establish the OIR model, mice from all groups except normal one were exposed to (75±2)% oxygen for 5 days and then to room air. In the OIR-S100A4 group and OIR-GFP group, the OIR mice were given an intravitreal injection of 1μl of 1.0×109 PFU/ml adenovirus of Ad-S100A4-RNAi or Ad-GFP at P12, and then returned to normoxia for the next 5 days. In the OIR group, OIR was induced in C57bl/6J mice from P7 to P17. In the normal-S100A4 group, the normal P12 mice were give an intravitreal injection of 1 μl of Ad-S100A4-RNAi adenovirus, and maintained in room air from P12 to P17. In normal group, newborn mouse litters were maintained in room air from P0 to P17 without any treatment. Mice in all five groups were euthanized at P17, and retinas were collected for biochemical assays and morphological study. Retinal neovascularization (RNV) was evaluated by counting the number of pre-retinal neovascular cells and the whole mount immunofluorescent staining of the mouse retina. Protein and mRNA expression levels of S100A4, cAMP responsive element binding protein (CREB), B cell lymphoma-2 (bcl-2), Caspase-3 were determined with western blot and real-time PCR. ResultsThe number of pre-retinal neovascular cell nuclei in retinas from OIR-S100A4 group were obviously lower than those in the retinas from OIR group and OIR-GFP group (t=13.61, 14.64; P < 0.05). In OIR-S100A4 group, the retinal neovascular tufts area and the vaso-oblitertion area were both significantly smaller than those in OIR group and OIR-GFP group (P < 0.05). Protein level of CREB and bcl-2 were significantly down-regulated in OIR-S100A4 group than those in OIR and OIR-GFP group (P < 0.05).On the contrary, protein levels of Caspase-3 were up-regulated in OIR-S100A4 group than those in OIR and OIR-GFP group (P < 0.05). ConclusionAd-S100A4-RNAi transfer ameliorates RNV in mouse model of OIR maybe through down-regulating the expression of bcl-2 and CREB, and up-regulating the Caspase-3.
Optogenetics is a novel technique which combines optics with genetics. Using genetic means, a selected opsin protein is ectopically expressed in target neurons, which are then stimulated by light to moderate the neuronal circuit, as a consequence to regulate the animal's behaviors. Retinal degeneration like retinitis pigmentosa and aged macular degeneration causes visual impairment and eventual blindness. Optogenetics techniques have opened the door to creating artificial photoreceptors in the remaining retinal circuits of retinal degeneration retinas via gene therapy. However, there are still limitations in optogenetics technique, for example, potential risk in virus infection, the choice of target cells and the low visual resolution of the experiment animal. It has been reported that vision was successfully restored to a certain extent in animal model using optogenetics technique. With higher photosensitivity of opsin protein, longer activation kinetics and higher transfection efficiency of virus vector, optogenetics techniques' application in ophthalmology will be improved.
ObjectiveTo observe the influence of down-regulation of HtrA1 expression by small interfering RNA on light-injured human retinal pigment epithelium (RPE) cells. MethodsCultured human RPE cells(8th-12th generations)were exposed to the blue light at the intensity of (2000±500) Lux for 6 hours to establish the light injured model. Light injured cells were divided into HtrA1 siRNA group, negative control group and blank control group. HtrA1 siRNA group and negative control group were transfected with HtrA1 siRNA and control siRNA respectively. The proliferation of cells was assayed by CCK-8 method. Transwell test was used to detect the invasion ability of these three groups. Flow cytometry was used to detect the cell cycle and apoptosis. The expression of HtrA1 and vascular endothelial growth factor (VEGF)-A was detected by real time-polymerase chain reaction and Western blot respectively. ResultsThe mRNA and protein level of HtrA1 in the light injured cells increased significantly compared to that in normal RPE cells (t=17.62, 15.09; P<0.05). Compared with negative control group and blank control group, the knockdown of HtrA1 in HtrA1 siRNA group was associated with reduced cellular proliferation (t=6.37, 4.52), migration (t=9.56, 12.13), apoptosis (t=23.37, 29.08) and decreased mRNA (t=17.36, 11.32, 7.29, 4.05) and protein levels (t=12.02, 15.28, 4.98, 6.24) of HtrA1 and VEGF-A. Cells of HtrA1 siRNA group mainly remained in G0/G1 phase, the difference was statistically significant (t=6.24, 4.93; P<0.05). ConclusionKnockdown of HtrA1 gene may reduce the proliferation, migration capability and apoptosis of light-injured RPE cells, and decrease the expression of VEGF-A.
Objective To evaluate the correlation of oxygen saturation of retinal vessels and diabetic retinopathy (DR) stages or HbA1c level in patients with DR. Methods Cross sectional study. A total of 102 patients (102 eyes) with DR and 20 age-matched healthy controls (20 eyes) (normal control group) were enrolled in this study. DR patients were divided into mild and moderate non-proliferative DR (NPDR) group (55 patients), severe NPDR group (26 patients) and proliferative DR (PDR) group (21 patients). DR patients were also divided into 3 groups according to the HbA1c level including HbA1c＞9% (8 patients), HbA1c 7% – 9% (33 patients) and HbA1c＜7% group (61 patients). The oxygen saturation of retinal vessel was measured by spectrophotometric oximetry unit in the retinal vessels with a diameter greater than 60 μm in the area around the optic disc. Results The retinal artery oxygen saturation of patients in severe NPDR group was significantly higher than that in mild to moderate NPDR group and normal control group (F=13.670,P＜0.05). The retinal vein oxygen saturation of patients in PDR group was significantly higher than that in mild to moderate NPDR group and normal control group (F=6.379,P＜0.05). The difference between retinal artery and vein oxygen saturation of patients in severe NPDR group was significantly bigger than that in mild to moderate NPDR group and PDR group (F=5.536,P＜0.05). The retinal artery and vein oxygen saturation in patients of HbA1c＞9% group were significantly higher than that in HbA1c 7% – 9% group and HbA1c＜7% group (F=9.989, 10.208;P＜0.05). The differences between retinal artery and vein oxygen saturation were same between patients in HbA1c＞9%, HbA1c 7%＜9% and HbA1c＜7% group (F=1.836,P＞0.05). Conclusions The retinal artery and vein oxygen saturation in DR patients are related to the DR stages. Severe NPDR patients show the highest retinal artery oxygen saturation as well as biggest difference between retinal artery and vein oxygen saturation. There is also a trend that retinal vein oxygen saturation increases with higher DR stages. In addition, there is a positive correlation between the levels of HbA1c and retinal vessel oxygen saturation.