ObjectiveTo observe the inhibitory effect of intraocular injection of recombinant adeno-associated virus-polypyrimidine tract-binding protein-associated splicing factor (rAAV-PSF) in oxygen induced retinopathy mice model. MethodsEighteen C57BL/6J mice were divided into 3 groups randomly, including normal group, rAAV-PSF injection group, rAAV injection group. Western blot analysis was applied to detect the transfection expression level of PSF. The other 48 C57BL/6J mice were randomly divided into 4 groups: normal group, ischemia-induced retinopathy (OIR) group, rAAV-PSF treated OIR group, rAAV treated OIR group, 12 mice in each group. Placed all mice (excepted the mice in control group) in cages of (75±2)% oxygen concentration environment for 5 days then moved to a normal environment for 5 days to induced the OIR model. At the 12th day the OIR rAAV-PSF treated OIR group was intravitreal injected with 2 μl 5×1013 pfu/ml rAAV-PSF and the rAAV treated OIR group was treated with intravitreal injection of 2 μl 5×1013 pfu/ml rAAV. The mice in OIR group were left intact after moved out of oxygen cages. Five days after injection, the eyeballs were harvested and retinal sections were stained to count the nuclear of retinal endothelium cells. Western blot analysis was applied to detect the protein level of vascular endothelial growth factor (VEGF) in retina. ResultsThere was a significant difference of the expression PSF between normal group and rAAV-PSF treated group (F=16.05,P=0.001). There was no significant difference of the PSF expression between normal group and rAAV treated group(F=16.05,P=0.890). There was a significant difference of the number of retinal endothelium cells nuclear between normal group and OIR group (F=101.00,P=0.007). There is a significant difference of the number of retinal endothelium cells nuclear between rAAV-PSF treated group and OIR group (F=101.00,P=0v002). There was no significant difference of the number of retinal endothelium cells nuclear between OIR rAAV treated group and OIR group (F=101.00,P=0.550). There was a significant difference of VEGF protein expression between normal group and OIR group (F=13.20,P=0.005), OIR group and rAAV treated OIR group (F=13.20,P=0.001). There was no difference of VEGF protein expression between OIR rAAV treated group and OIR group (F=13.20,P=0.071). ConclusionThe rAAV-PSF vitreous injection can inhibit the expression of VEGF in OIR mice, hence to restrain the proliferation of neovascularization.
ObjectiveTo study morphological characteristics and microRNA (miR) expression profiling in a mouse model of oxygen-induced retinopathy (OIR). MethodsHealthy C57BL/6J female mice and pups were randomly divided into normal and OIR group at postnatal day 7 (P7). The normal group was raised in a conventional cage and exposed to room air for 10 days. The OIR group was raised in a sealed chamber and exposed to (75±2)% oxygen. The moms were alternated between the two groups every day to promote their survival under hyperoxia. The OIR group was returned to the room air at P12. At P17, mice from either group were retro-orbitally injected with high molecular weight fluorescein isothiocyanate-dextran (FITC-dextran), the eye balls were fixed in 4% paraformaldehyde, and the retinal whole mounts were prepared. The retinal vessels labeled with FITC-dextran were observed under a fluorescence microscope; the eye balls were also processed for paraffin sections and Hematoxylin and Eosin (H&E) staining. The cell nucleus in the newly-formed vessels beyond the inner limiting membrane was quantified. The miR was extracted from the eyes, reverse transcribed, and subjected to a customized miR array analysis. The real-time PCR was preformed to verify the results of the miR array. ResultsRetinal whole mounts labeled with FITC-dextran showed that the peripheral retinal microvessels in the OIR group were tortuous, disorganized with neovascular buds, and the avascular area was prominent in central retina. In contrast, the vessels were smooth, organized, and evenly distributed in the retinas of normal group. The percentage of avascular area in total retina area in OIR group (25.81±2.12)% was 4-fold that in normal group (6.57±3.6)% (P < 0.01, normal group vs OIR group). H & E staining showed that the number of the cell nuclei beyond inner limiting membrane was (28.41±4.01) in OIR retina, which was substantially higher than that (0.16±0.31) in normal retina (P < 0.01, normal group vs OIR group). More interestingly, the results of miR array showed that 21 out of the 80 miRs examined exhibited more than 1.5-fold changes at expression level. Among these 21 miRs, 9 were up-regulated, 12 were down-regulated; 4 miRs showed more than 3-fold expression changes, 3 were down-regulated and 1 was up-regulated. The expression of the 4 miRs was verified by real-time PCR. The expression trends of miR-3078, miR-140, miR-29b and miR-29c were consistent with those revealed by the miR array. MiR-3078 was significantly up-regulated (t=-2.380, P < 0.05. normal group vs OIR group), and the other 3 miRs were significantly down-regulated (t=2.638, 2.323, 2.415, P < 0.05. normal group vs OIR group). ConclusionsThe OIR mouse model has been established in our study. Differential expression of the microRNAs, including miR-3078, 140, 29b and 29c, was detected in normal and OIR mouse retinas. These miR expression changes may be associated with retinal neovascularization. These results would provide the new leads for further studying pathogenic mechanisms and therapeutic targets for neovascular retinopathy.
ObjectiveTo observe the regulation of PTB-associated splicing factor (PSF) exerts on phosphatidylinositol 3 kinase (PI3K)/Akt signaling pathway in cultured retinal pigment epithelial (RPE) cells. MethodsARPE-19 RPE cells were divided into five groups including PSF overexpression (0.25, 0.50, 1.00 μg of pEGFP-C2-PSF plasmid DNA), PSF overexpression control (pEGFP-C2 empty vector DNA), PSF inhibition (0.25, 0.50, 1.00 μg of pGenesil-PSF-RNAi plasmid DNA), PSF inhibition control (pGenesil-scramble-siRNA empty vector) and sham transfected group (treated with lipofactamine 2000 reagent, but without adding plasmid DNA) groups. After transfecting with plasmid DNA, the cells were stimulated with insulin-like growth factor-1 (IGF-1). IGF-1-stimulated ARPE-19 cells were also treated with Wortmannin and /or PSF over-expression. WST-1 assay was used to detect the proliferation rates, the VEGF mRNA levels were analyzed using real time polymerase chain reaction (PCR), the levels of phosphorylation Akt and total Akt expression were measured by western blotting. ResultsAfter IGF-1 stimulation, the difference of the cell proliferation rates between PSF overexpression group, PSF overexpression control group and sham transfected group was statistically significant (F=29.728, P<0.05). The difference of the cell proliferation rates between PSF inhibition group, PSF inhibition control group and sham transfected was also statistically significant (F=14.121, P<0.05). Compared with control group, the VEGF mRNA levels was decreased in PSF overexpression group (P=0.000 3), but increased in PSF low expression group (P=0.030 9). Furthermore, overexpression of PSF could down-regulate the activation of pAkt after IGF-1 stimulation. When combined with Wortmannin treatment, the VEGF mRNA levels in PSF overexpression group was significantly lower than the control group (P<0.05). ConclusionsAfter IGF-1 treatment, PSF plays a role in suppressing the proliferation and VEGF expression in RPE cells by inactivating PI3K/Akt signaling pathway.