Objective To observe the oxidative damage of mtDNA, apoptosis and expression of adhesion molecules in retinal capillary cells of diabetic rat with different disease courses. Methods One hundred Sprague-Dawley rats were randomly divided into the control group and the experimental group. The rats of experimental group were induced with streptozotocin (STZ) injection creating a diabetic model. Then they were divided into DR1m, DR2m DR3m group according to disease courses. The rats of control group were divided into NR1m, NR2m, NR3m group. Rat retinal capillaries were prepared, and then the contents of undamaged mtDNA were examined by Southern blot combined with Fpg. The expression of cyclooxygenase (COX)-1 encoded by mtDNA and transcription factors A (mtTFA) mRNA were detected by real-time quantitative polymerase chain reaction (RT-PCR). Apoptosis and expression of intercellular adhesion molecule-1 (ICAM-1) were detected by terminal dUT nick endlabeling (TUNEL) immuno-fluorescence and immunohistochemistry respectively. Results The contents of undamaged mtDNA in rats of DR1m, DR2m, DR3m were less than those of NR1m、NR2m、NR3m. The contents of undamaged mtDNA in diabetic rats decreased with the increase of disease courses. In addition, the mRNA levels of COX-1 and mtTFA were downregulated in diabetic rats. The positive cells of TUNEL and ICAM-1TUNEL and ICAM-1 in diabetic rats increased with the increase of disease courses. Conclusion With the increase of disease courses, mtDNA damage and apoptotic cells are increased, while the expression of mRNA encoded by mtDNA and ICAM-1 decreased in retinal capillary cells in diabetic rats.
Objective To observe the influence of prolyl hydroxylase 2 (PHD2) expression on endothelial barrier dysfunction induced by high glucose in human retinal vascular endothelial cells (HRECs). Methods The HRECs were treated by different culture medium with various glucose concentrations (5 mmol/L glucose, 5 mmol/L glucose +25 mmol/L mannitol, 30 mmol/L glucose) as normal control group, mannitol control group and high glucose group, respectively. After the cells cultured for 24 and 48 hours, the protein levels of PHD2, hypoxia-inducible factor-1alpha; (HIF-1alpha;) and occludin was detected by Western blot; the expression of vascular endothelial growth factor (VEGF) in the supernatant was determined by enzymelinked immuno sorbent assay (ELISA); the transcription levels of PHD2, HIF-1alpha;, VEGF and occludin were determined by the reversetranscription polymerase chain reaction (RT-PCR); the paracellular permeability between endotheliums was detected by 7times;104 molecular weight FITCdextran. Results Compared with normal control group, the protein level of PHD2 in mannitol control group and high glucose group firstly decreased and then increased, the protein level of HIF-1alpha; increased while that of occludin decreased; the secretion of VEGF increased in high glucose group but not in mannitol control group (PHD2：F=7.618, 8.627;P＜0.05. HIF-1alpha;：chi;2=7.692, 7.652;P＜0.05. occludin：F=23.23, 7.317;P＜0.05. VEGF：F=10.768, 4.562; P＜0.05). Compared with normal control group, the mRNA levels of PHD2, HIF-1alpha;, VEGF and occludin in mannitol control group and high glucose group increased (PHD2：F=5.69, 14.27;P＜0.05. HIF-1alpha;：F=6.07, 10.47;P＜0.05. VEGF：F=12.31, 9.14;P＜0.05. occludin：F=8.77, 8.00;P＜0.05). Compared with normal control group, the paracellular permeability of mannitol control group and high glucose group increased (chi;2=20.57,F=56.09;P＜0.05). Conclusions High glucose induced altered expression of PHD2 which might play an important role in endothelial barrier dysfunction. The mechanism might be associated with HIF-1alpha; and VEGF.
Objective To observe the effect of resveratrol on retinal vasculopathy in diabetic rats. Methods Forty-five Sprague-Dawley male rats were randomly divided into the resveratrol group, treatment control group and the normal control group, 15 rats in each group. Diabetic rat models were induced with streptozotocin injection in resveratrol group and treatment control group. The same volume of sterile saline solution was injected into the rats of the normal control group. The rats of resveratrol group and treatment control group were feed with highfat diet. The rats of resveratrol group received oral gavage of resveratrol (75 mg/kg) twice a day for four months. The same volume of sterile saline solution was given by gavage in rats of treatment control group twice a day for four months. 2 ml femoral vein blood and 50 mu;l aqueous fluid of anterior chamber of the eye from rats of three groups were collected to detect fasting blood glucose, aqueous fluid glucose, cholesterol and triglyceride. The retinal vascular permeability was test by labeling with evans blue. Whole retina was isolated to detect the pericyte number. Total protein was extracted from retina to test the level of vascular endothelial growth factor (VEGF). Results The fasting blood glucose, aqueous fluid glucose, cholesterol and triglyceride in treatment control group were higher than those in normal control group, also higher than those in resveratrol group except cholesterol. The differences among the three groups were statistically significant (F=152.809, 65.230, 3.861, 15.059; P＜0.05). The retinal vascular permeability in treatment control group was higher than that in normal control group, while it in resveratrol group was lower than that in treatment control group. The differences among the three groups was statistically significant (F=11.626,P＜0.05). The pericyte number in treatment control group decreased as compared to normal control group, while it in resveratrol group increased as compared to treatment control group. The differences among the three groups was statistically significant (F=43.284, P＜0.05). The VEGF expression in treatment control group increased as compared to normal control group, while it in resveratrol group decreased as compared to treatment control group. The differences among the three groups was statistically significant (F=14.017, P＜0.05). Conclusion Resveratrol can improve abnormal retinal vasculopathy structure and function, down-regulated level of fasting blood glucose, aqueous fluid glucose, triglyceride and VEGF may be the mechanism.
Objective To observe the effects of dual targets intervention on the expression of vascular endothelial growth factor (VEGF) and connective tissue growth factor (CTGF) in diabetic rat retina. Methods Forty-eight Sprague -Dawley rats were randomly divided into control group (CON1 group) and diabetes mellitus group (DM group). The rats of DM group were induced with streptozotocin injection creating a diabetic model. Retinas were obtained at eight, 10, 12 weeks after DM induction from both groups. CTGF and VEGF mRNA levels were examined by realtime reverse transcriptionpolymerase chain reaction (RT-PCR). Based on the results of above experiments, 60 rats with same conditions were selected. Fifty rats were induced with streptozotocin injection creating a diabetic model, and 10 rats comprised the control group (CON2 group). Then the 50 diabetic rats were randomly divided into ranibizumab and CTGF shRNA dual targets intervention group, ranibizumab singletarget intervention group, CTGF shRNA singletarget intervention group and nonintervention group. Retinas were obtained at one week after intervention from all the groups. CTGF and VEGF mRNA levels were examined by RT-PCR. Results The levels of CTGF mRNA were significantly higher in DM group than that in CON1 group at the 8th weeks after DM induction, and this upregulation was maintained through the 12th week (t=-2.49, -2.67, -2.42;P＜0.05). There was no difference on VEGF mRNA levels between DM group and CON1 group at the 8th weeks after DM induction(t=-0.443,P=0.669). VEGF mRNA levels of DM group started to be significantly elevated over those in the CON1 group at the 10th week, and remained to be higher at the 12th week (t=-2.35, -2.57;P＜0.05). The VEGF mRNA of ranibizumab single-target intervention group was significantly lower than that in non-intervention group (t=-3.44,P=0.014), which was similar to CON2 group (t=-1.37,P＞0.05); however, the CTGF mRNA level was significantly increased as compared to the nonintervention group (t=2.48,P＜0.05). In the CTGF shRNA single-target intervention group, the levels of CTGF and VEGF mRNA were decreased as compared to the non-intervention group (t=0.23, -2.92;P＜0.05). In the ranibizumab and CTGF shRNA dual targets intervention group, the levels of CTGF and VEGF mRNA were decreased as compared to the non-intervention group (t=-6.09, -5.11;P＜0.001), which was similar to CON2 group (t=-1.16, 1.139; P＞0.05). Conclusions Both CTGF and VEGF gene expression are up-regulated in early diabetic rat retina, and the level of CTGF increased earlier than VEGF. Ranibizumab combined with CTGF shRNA could simultaneously reduce the level of CTGF and VEGF mRNA in diabetic rat retina.
Objective To observe the therapeutic effect of mensenchymal stem cells (MSCs) for experimental autoimmune uveitis (EAU). Methods MSCs were obtained from Wistar rats and selected by plastic adherence. Lewis rats were divided into treatment group and control group, six rats in each group. EAU models were induced by immunization with an emulsion (0.2 ml) containing 30 mu;g interphotoreceptor retinoid-binding protein derived peptide R16 and complete Freundprime;s adjuvant. The clinical manifestations of two groups were observed. Nine to 11 day after modeling, 1 ml MSCs suspension, which contained 5times;106 MSCs, were injected into the rats in treatment group via tail vein, and the rats in control group were given equal volume of phosphate buffer solution. Fifteen day after modeling, the eyes were collected to test the proportion of interferon gamma;, interleukin-17 and Foxp3 positive cells by flow cytometry. The clinical scores were analyzed by mixed linear model and statistical analysis of variance of repeated measurement data. The results of flow cytometry were analyzed using independent-sample t test. Results Six days after immunization, mild dilatation and congestion of iris vascular was observed. Nine days after immunization, mild muddy anterior chamber, myosis and absent pupillary reaction to light were observed. Twelve days after immunization, muddy anterior chamber, occlusion of pupil and dimmed or disappeared red reflex were observed, and then inflammation was slowly reduced. From 11 to 15 days after immunization, the clinical score of treatment group was lower than that in control group, the difference was statistically significant (t=2.42, 2.21, 4.16, 5.24, 4.03; P＜0.05). The results of flow cytometry showed that MSCs treatment could decrease the proportion of CD4＋T cells, Th1 cells and Th17 cells, increase the proportion of Treg cells. Conclusion MSCs treatment can ameliorate EAU, up-regulate the expression of Treg cells and down-regulate the expression of CD4＋T cells, Th1 cells and Th17 cells.
Objective To observe the expression of cyclin dependent kinase 5 (Cdk5) and p25 in the pathogenesis of retinitis pigmentosa (RP) in Royal College of Surgeon (RCS) rats and its relationships with apoptosis. To explore the mechanism of Cdk5 and p25 induced photoreceptor apoptosis in the pathogenesis of RP. Methods Retinas of RCS and RCS-rdy+ rats were obtained at the ages of postnatal day 17, 25, 35, 60. The retinal structure and thickness of outer nuclear layer were measured by optical microscopy. The expression of Cdk5, p25, cleave-caspase 3 in the retina was evaluated by immunohistochemistry. The protein expression of cleave-caspase 3 in the retina was determined by Western blot. The apoptosis of retinal cells was examined by terminal-deoxynucleotidyl transferase mediated nick end labeling (TUNEL). The mean absorbance value of apoptotic cells was analyzed by SPSS 17.0 software. Results The retinal thickness of the RCS rats was significantly reduced in comparison to the RCS-rdy+ rats as the postnatal days progressed, particularly in the layer of rods and cones and the outer nuclear layer. The expression level of Cdk5, p25, cleave-caspase 3 of RCS rats increased from postnatal 17 days to postnatal 35 days, while decreased on postnatal 60 days; but there was no obvious change of above indexes in RCS-rdy+ rats. The protein expression of cleave-caspase 3 in the RCS rats was significantly increased with progression of postnatal days to postnatal 35; but there was no obvious similar change in RCS-rdy+ rats. The results of TUNEL showed that the apoptotic cells significantly increased in the outer nuclear layer of RCS rats from postnatal 17 days to postnatal 35 days, while decreased on postnatal 60 days; but there was no obvious change of above index in RCS-rdy+ rats. This study showed that there were significant correlations between the following variables: Cdk5 expression and p25 expression, Cdk5 expression and cleave-caspase 3 expression, Cdk5 expression and apoptotic cells, p25 expression and cleave-caspase 3 expression, p25 expression and apoptotic cells, cleave-caspase 3 expression and apoptotic cells. The partial correlation coefficients were 0.949, 0.808, 0.959, 0.887, 0.979, 0.852, respectively and the P value was 0.000. Conclusions The apoptotic cells significantly increases and the expression level of Cdk5, p25, cleave-caspase 3 of RCS rats increases from postnatal 17 days to postnatal 35 days. The tendency of apoptotic cells to increase is consistent with the change of Cdk5, p25, cleave-caspase 3 expression. The apoptosis of photoreceptor cells is related to increasing expression of Cdk5 and p25 in RCS rats. Cdk5 may be involved in the development of RP in RCS rats.
Objective To observe the effect of Chinese Herbal Preparation -Mingjing Granule on the recruitment and adhesion of bonemarrow derived cells (BMCs) to choroidal neovascu1arization (CNV) in mice induced by laser photocoagulation. Methods A total of 75 C57BL/6 mice were divided into treatment group (30 mice), control group (30 mice) and normal control group (15 mice). CNV was induced by krypton laser in the mice of treatment group and control group. BMCs from GFPtransgenic mice were injected through tail vein to those mice 0.5 -1.0 hours after laser surgery. On day one after laser surgery, the mice of treatment group were gavaged with 0.3 ml Mingjing Granule solution every day［30 g/(kg?d)］, while the control group mice were gavaged with distilled water. The mice of normal group fed with normal cereals. 7, 14, 28 days after treatment, choroidal flatmount were prepared to measure the CNV severity and BMCs recruitment. The choroidal histopathological change was observed by optical microscope. CXCR4 level in peripheral blood was measured by enzymelinked immuno sorbent assay (ELISA). Stromal cell derived factor1alpha; (SDF-1alpha;), vascular cell adhesion molecule-1 (VCAM-1), inter-cellular adhesion molecule 1 (ICAM-1) were detected by immunofluorescent staining. Results Choroidal flatmount showed that CNV developed in treatment group and control group, but not in normal group. On day seven and 14, CNV lesions in the treatment group showed less incorporation of BMCs and smaller CNV in size compared with the control group (t=10, 9; P=0.007, 0.024), histologic sections also showed less severe lesions in the treatment group. CXCR4 level in peripheral blood in the treatment group was less than that in the control group and normal control group on day seven and day 14（t=8.107, 2.747;P＜0.05). The expression of SDF-1alpha;, ICAM-1 and VCAM-1 in the treatment group was lower compared with the control group. Conclusions Mingjing Granule could inhibit the recruitment and adhesion of BMCs in peripheral blood to CNV at the early stage. The mechanism may be related with the action of Mingjing Granule in lowing chemokines levels in peripheral blood and expression of adhesion molecules around CNV.
ObjectiveTo observe the effect of Crocin on structure and the expression of tumor necrosis factor-alpha; (TNF-alpha;) and interleukin-1beta; (IL-1beta;) in rat retina after injury by ischemia-reperfusion. Methods A total of 80 Sprague-Dawley male rats at the age of 8 -10 weeks were divided into control group, model group, low-dose Crocin group and high-dose Crocin group, with 20 rats in each group. The rats of control group were not treated. The rats in model, low-dose Crocin and high-dose Crocin group were induced with normal saline by anterior chamber perfusion creating a retinal ischemia-reperfusion (RIR) model. The rats of the low-dose Crocin and highdose Crocin group received intraperitoneal injection with different doses of Crocin solution (5 mg/kg, or 50 mg/kg) 30 minutes prior to ischemic injury and one time per day after successful RIR. Optical microscopy was used to observe the retinal structure. Enzymelinked immunosorbent assay (ELISA) was used to measure the expression of TNF-alpha; and IL-1beta; 6, 12, 24 and 48 hours after RIR. ResultsThe retinal structure of control group was normal. Pathological changes were found in the RIR model and low-dose Crocin group, such as retinal edema, disorganized structure and loosely packed cells. The degree of pathological changes in lowdose Crocin group was less than the RIR model group. The retinal structure of high-dose Crocin group was similar to the control group. The expression of TNF-alpha; was the highest at 24 hours after modeling, while the expression of IL-1beta; was the highest at 12 and 48 hours after RIR modeling. Six, 12, 24 and 48 hours after RIR modeling, compared with the control group, the TNF-alpha; expression of model (t=5.42, 7.94, 9.32, 9.18;P＜0.05 ), low-dose Crocin (t=3.94, 4.12, 4.98, 3.84;P＜0.05) and high-dose Crocin group (t=2.13, 2.34, 2.96, 2.78;P＞0.05) were increased. Compared with the RIR model group, the TNF-alpha; expression of low-dose Crocin (t=3.95, 4.56, 4.01, 5.12) and high-dose Crocin group (t=5.23, 7.65, 7.74, 7.63) was decreased. Compared with the control group, the IL-1beta; expression of model (t=7.23, 7.87, 7.15, 15.60), low-dose Crocin (t=5.65, 5.10, 5.54, 6.87;P＜0.05) and high-dose Crocin group (t=4.38, 5.21, 4.56, 4.75) was increased (P＜0.05). Compared with the model group, the IL-1beta; expression of low.dose Crocin group was decreased significantly 48 hours after RIR modeling (t=7.56,P＜0.05); but it decreased significantly at each time point in high-dose Crocin group (t=6.94, 5.36, 6.05, 10.50;P＜0.05). Conclusion Crocin can improve the retinal pathologic changes, while down-regulating TNF-alpha; and IL-1beta; expression in RIR rats.
Objective To observe the inhibition of LipofectamineTM2000 (LF2000)mediated pSUPER recombinant plasmid expressing small interference RNA targeting hypoxia-induced factor (HIF)-1alpha;(pSUPERsiHIF-1alpha;) on retinal neovascularization in mice. Methods pSUPERsiHIF-1alpha; recombinant plasmid was created. Forty-eight (seven-day-old) C57BL/6J mice were randomly divided into a normal group, the control group, empty vector group and gene therapy group with 12 mice in each group. Mice in the normal group were kept in normal room air, while the other three groups retinal neovascularization was induced by hypoxia. The mice in control group were not treated. The mice in the vector group received intravitreous injection of pSUPER and LF2000 (1 mu;l), and the gene therapy group received pSUPERsiHIF-1alpha; and LF2000 (1 mu;l)one day before being returned to normal room air．Fluorescent angiography was used to assess the vascular pattern. The proliferative neovascular response was quantified by counting the nuclei of new vessels extending from the retina into the vitreous in cross-sections．HIF-lalpha;and vascular endothelial growth factor (VEGF) levels in retinas were measured by immune histochemical staining method and reverse transeriptase-polymerase chain reaction (RT-PCR). Results Fluorescent angiography showed radial branching pattern vessels in the normal group and distorted large vessels, obstructed capillaries, many neovascular tuffs, fluorescence leakage in the peripheral retina in the control group and vector group. The gene therapy group demonstrated a significant reduction in neovascular tufts and fluorescence leakage compared with the control group and the vector group. The number of vascular cell nuclei extending breaking through the internal limiting membrane(ILM) of control group and vector group increased significantly compared with normal group (F=5850.016,P＜0.05), while obviously decreasing in the gene therapy group compared with control group (F=3012.469,P＜0.05). Immunohistochemical staining showed the expression of HIF-1alpha; protein in nucleus and VEGF protein in cytoplasm. The expression of HIF-1alpha; protein in retina was negative, while VEGF protein was weakly positive in normal group. The expression of HIF-1alpha; and VEGF protein were both positive in control group and vector group, while weakly positive in gene therapy group. The Results of RT-PCR showed that the expression of HIF-1alpha; mRNA in retina was increased significantly in control group and vector group as compared with normal group (F=3102.326,P＜0.05), while decreasing significantly in gene therapy group as compared with control group (F=3336.425,P＜0.05). Conclusion Retinal neovascularization in the mice is significantly inhibited by intravitreal injection of LF2000-mediated recombinant plasmid pSUPERsiHIF-1alpha;.
Objective To investigate the inhibitory effects of 15-lipoxygenase-1 (15-LOX-1) gene transfer on oxygen-induced retinal neovascularization in mice. Methods Ninety-six 7-day-old C57BL/6J mice were randomly divided into normal control group, oxygeninduced retinopathy (OIR) model group, gene treated group and empty vector group. The mice with their mothers were kept in (75plusmn;2) % 02 environment for 5 days and then returned to normoxia for 5 days to establish the OIR model. At postnatal day 12, the gene treated group received intravitreous injection of recombinant adenovirus (Ad) vector containing both enhanced green fluorescent protein (EGFP) and mouse 15-LOX-1 genes (Ad-15-LOX-1-EGFP) at 1 l, while the empty vector group received the same volume of recombinant Ad vector containing EGFP (Ad-EGFP). The expression of EGFP was observed on flat-mounted retina by fluorescence microscopy 2 days after intravitreous injection of Ad-15-LOX-1-EGFP. At postnatal day 17, the efficacy of 15-LOX-1 gene transfer on retinal tissue was detected by immunofluorescence staining, real-time polymerase chain reaction and Western blot. The changes of retinal vessels, relative retinal non-perfusion and neovascularization areas were evaluated by fluorescein isothiocyanate-dextran fluorescein angiography on flatmounted retina. The number of endothelium cell nuclei breaking through the inner limiting membrane (ILM) was counted on hematoxylin and eosin-stained retinal section. Results Two days after intravitreous injection of Ad-15-LOX-1-EGFP, the expression of EGFP had been seen by fluorescence microscopy on Flat-mounted retina. Immunofluorescence staining of retinal section revealed that 15-LOX-1 expression was primarily in the outer plexiform layer, inner nuclear layer and ganglion cell layer of retina. The 15-LOX-1 protein and mRNA expression levels were higher in gene treated group than those in OIR model group and empty vector group (tprotein=22.74 and 24.13 respectively.tmRNA=12.51 and 13.40 respectively; P＜0.01). The relative retinal non-perfusion and neovascularization areas were significantly smaller in gene treated group than those in OIR model group and empty vector group (tnon-perfusion=16.22 and 14.31 respectively.tneovascularization=9.97 and 9.07 respectively; P＜0.01), and the number of endothelium cell nuclei breaking through the ILM in gene treated group was obviously lower than the other two groups (t=14.25 and 11.62 respectively，P＜0.01). Conclusion 15-LOX-1 gene transfer can decrease the oxygen-induced retinal non-perfusion areas and inhibit the retinal neovascularization in mice.