ObjectiveTo observe the influence of human umbilical cord mesenchymal stem cells (hUCMSC) transplantation into vitreous cavity of diabetic rats on the retinal morphology, and the expression of glial fibrillary acidic protein (GFAP) and rhodopsin (RHO). Methods78 male Sprague-Dawley rats were used. 70 rats were injected with streptozotocin by tail vein injection at a dose of 40 mg/kg to establish the diabetes mellitus model, and another 8 rats were injected with 0.1 mol/L pH 4.0 citric acid buffer at the same dose as the normal control group. After 6 weeks of modeling, 10 rats were taken as the control group of diabetic model. hUCMSC suspension was injected into the right eye vitreous cavity of the remaining 60 rats, and the same volume of Dulbecco's modified Eagle/F12 medium was injected into the left vitreous cavity as control eyes. 1, 2 and 4 weeks after transplantation, follow-up experiments were performed. The experimental eyes were labeled as U1, U2, and U4 groups, while the control eyes were recorded as D1, D2, D4, and each group consisted of 20 eyes. After paraffin section and hematoxylin-eosin staining, the structure of the retina was observed by optical microscopy and the thickness of the outer nuclear layer and the inner nuclear layer (INL) were measured. The distribution and migration of hUCMSC in rat retina were observed by frozen section-tissue immunofluorescence assay. The mRNA and protein expression of GFAP and RHO in the retina were detected by real-time quantitative polymerase chain reaction (PCR) and Western blot assays. ResultsThe results of optical microscope observation showed the normal structure of retina in normal control group. The retinal nerve fiber layer (NFL) was thinned and the number of retinal ganglion cells (RGC) in the control group of diabetic rats was decreased. The decreased number and disorder arrangement of RGC were observed as well in U1, D1 rats. The RGC number of U2, U4, D2, D4 rats was gradually decreased. Compared with D4 group, the thickness of INL in U4 group was significantly increased (P < 0.05). Tissue immunofluorescence assay showed that hUCMSC were distributed along the inner limiting membrane in the retina of the U1 group, while the number of hUCMSC in the U2 group was gradually decreased, mainly in the NFL and ganglion cell layers. Real-time PCR and Western blot data indicated that the relative expression of GFAP mRNA and protein in the diabetic retina was significantly increased, and the relative expression of RHO mRNA and protein decreased gradually in the diabetic model group and the D1, D2, D4 groups. Compared with D2 and D4 groups, the mRNA and protein expression of GFAP in U2 and U4 groups were decreased, and the relative expression of RHO mRNA and protein were all increased (P < 0.01). ConclusionhUCMSC could migrate and integrate into the retina, after the transplantation into the vitreous cavity of diabetic rats, which reduced the expression of GFAP, but enhanced the expression of RHO.
Mesenchymal stem cells (MSC) are considered to have important value in the treatment of various diseases because of their low immunogenicity, transferability, and strong tissue repair capacity. Stromal cell derived factor-1 (SDF-1) and its receptor CXC chemokine receptor 4 (CXCR4) pathway plays an important role in migration of MSC. The induction of homing of MSC to retina by regulating SDF-1/CXCR4 may exert the curative effect on diabetic retinopathy to greatest exent.
Objective To observe the expression of the pigment epithelium derived growth factor (PEDF) in retina and the effects of PEDF for vascular endothelial growth factor (VEGF) and retinal microvascular after recombinant adeno-associated virus mediated pigment epithelium derived factor（rAAV-mediated-PEDF）transferred retina of diabetic rats. Methods Male Wister rats were induced diabetes with intraperitoneal injection of streptozocin, then divided into 1 month group (DM1), 3month group(DM3) and 6 month group randomly. In diabetic rats, right eyes were injected rAAV2CMVhPEDF into vitreum as treat group,left eyes were injected into rAAV2-CMV-GFP (1times;1011 v.g/ml) as self-control group. In normal rats, right eyes were punctured but not injected (CONf), left eyes let it be without any disposal. The levels of VEGFmRNA and hPEDFmRNA in retina were evaluated using RT-PCR in different period. The protein levels of VEGF, PEDF within the retina were determined using western blot. The change of retinal capillary were observed through retinal vascular flattening. Result The expression of hPEDFmRNA in retina was enhanced persistence after rAAV2-CMV-hPEDF injected, achieved climax until 6 months. The levels of PEDF were also incerased consecutive, the differences were statistically significant in treatment group compared with own control group （Plt;0.01）. Levels of mRNA and protein of VEGF at different time-points among therapy group were not statistically significant, all obviously higher than normal （Plt;0.05），but all lower obviously than respectively own control group at the same timepoint （Plt;0.01）. The morphology of retinal capillary was not different significant with normal rats in 1 month diabetic rats. Morphology changes of therapy groups were less than those of respective own control group in DM3 and DM6. Conclusion Intravitreous injection rAAV2-CMV-hPEDF can increase expression of mRNA and protein of PEDF，alleviate lesion of retinal microvascular in early period of diabetic rats and supress expression of VEGF in retina of diabetic rats.The regulation occur on mRNA level. （Chin J Ocul Fundus Dis，2008，24：259-264）
Objective To investigate the early influences of laser photocoagulation on macular retinal thickness in diabetic retinopathy(DR). Methods Optic coherence tomography examination was performed in 30 eyes with DR(phase Ⅲ~Ⅳ) before, and on the 3rd day and the 7th day after photocoagulation respectively. The thickness of neuroretina and pigment epithelium were measured in the areas of fovea macula and 750 μm from fovea macula. Results Three days after photocoagulation, significant thickening of neuroretina was observed in the fovea macula, which is positively related with age, fasting blood sugar and duration of DR. There was no significant changes in the thickness of pigment epithelium in macula and in the thickness of neuroretina 750 μm from fovea macula. Conclusion Significant thickening of neuroretina in fovea macula in DR early after photocoagulation reveals progressed macular edema induced by photocoagulation which is positively related with age, fasting blood sugar and duration of DR. (Chin J Ocul Fundus Dis, 2002, 18: 31-33)
bjective To observe the therapeutic effect of laser photocoagulation on diabetic retinopathy (DR)at different stages.Methods A total of 534 eyes of 304 patients with DR diagnosed by fundus fluorescein angiography (FFA) were enrolled in this study. In the 534 eyes, 92 with nonproliferative DR (NPDR) had the bestcorrected visual acuity(BCVA) of 0.52plusmn;0.32,108 with preproliferative DR (PPDR) had the BCVA of 0.49plusmn;0.23,196 with early PDR had the BCVA of 0.20plusmn;0.31,and 138 with highrisk PDR had the BCVA of 0.17plusmn;0.22． According to the rules of ETDRS, retinal photocoagu1ation,pan retinal photocoagu1ation or extrapanretinal photocoagu1ation were performed on the paitents with NPDR,PPDR,and highrisk PDR,respectivelyThe patients were followed up for 10-18 months after the operations and the results of the examinations at the last time were regarded as the criteria for judgement. The examination of BCVA and ocular fundus and FFA were performed with the time interval of 3 months．The judgement for BCVA was(1)improved:improved ge;2 lines;(2) kept still: changed within 2 lines;(3)decreased:decreased ge;2 lines.And the effect on BCVA was positve when it was improved or kept still.The judgement for the therapeutic effect on DR was:retinal edeama was alleviated,leakage of hemorrhage was obsorbed,microaneurysm disappeared or decreased, neovascularization (NV) was relieved completely or partly,nonperfusion area disappeared or narrowed, and no new NV or nonperfusion area came into being. Results After the operations, BCVA in NPDR,PPDR and early PDR groups was improved or kept still in 73(79.3%),83(76.9%)，and 146 eyes (74.5%), respectively,without any statistical difference among these three groups（P＞0.05）.BCVA in highrisk PDR group was significant lower than that in the NPDR,PPDR,and early PDR groups (P＜0.05). The positive rate of therapeutic effect on DR was 89.1%,85.2%,82.7% in NPDR,PPDR,and early PDR groups, respectively without any statistical difference among the groups(P＞0.05). The positive rate of therapeutic effect on DR in highrisk PDR group was significant lower than that in the NPDR,PPDR,and early PDR groups(P＜0.05). Conclusion The prognosis of DR at different stages after laser photocoagulation is different;timely and effective laser photocoagulation is important to prevent the development of the disease and decrease the blindness rate.
ObjectiveTo observe the changes of macular choroidal thickness before and after laser treatment for diabetic retinopathy patients. Methods For patients with diabetes by fundus fluorescein angiography (FFA) examination, diagnosed as severe non-proliferative and proliferative diabetic retinopathy and in accordance with the laser photocoagulation treatment indications of 23 patients (45 eyes) included in the study. There were 10 cases of male, 13 cases of female; the average age was (55.48±5.43) years old. All patients underwent macular grid laser photocoagulation and pan-retinal photocoagulation. The macular choroidal thickness before and after laser treatment was measured by enhanced depth imaging technique of optical coherence tomography during follow-up at 1, 2, 3 weeks and one month at specific sites of choroidal. The specific sites included subfoveal choroidal thickness (SFCT), from the foveal 1mm, 3mm, 6mm distance of nasal choroidal thickness (NCT) and temporal choroidal thickness (TCT). ResultsOne week after the treatment, SFCT, NCT1 mm, NCT3 mm, TCT1 mm, TCT3 mm, TCT6 mm were obviously thickening(t=4.728, 4.422, 3.759, 3.743, 5.713, 2.502; P < 0.05). Two weeks after the treatment the SFCT, NCT1 mm, NCT3 mm, TCT1 mm, TCT3 mm were decreased gradually(t=3.189, 2.122, 2.742, 2.196, 2.076; P < 0.05).The choroidal thickness returned to pretreatment level from 2 weeks to 4 weeks after treatment, the NCT6 mm had no obvious change in the whole treatment period(P > 0.05). ConclusionThe choroidal thickness was significantly thicker after laser photocoagulation treatment within 1 week, with the time prolonging the choroidal thickness gradually decreases.