Objective To clarify the relationship between inhibition of proliferation and cxpression of Ki-67 in cultured human retinal pigment epithelial(RPE) cells. Methods The cultured human RPE cells were treated with daunoblastina at a dose of 180 mu;g/L for 12h.Twenty-four hours later,DNA inhibiting rate was studied by using tritium-labelled thymidine deoxyribose(3H-TdR)incorporation assay.The expression of Ki-67 was evaluated by immunocytochemical staining technique and image analysis system.Flow cytometry was used to analyse cell cycle. Results DNA inhibiting rate was directly proportional to the dosage of daunoblastina.The proportion of the cells positive staining to Ki-67 in the control and the daunoblastina-treated group were 89.3% and 45.6%(Plt;0. 01),and the integral optical density values for expression of Ki-67 in the two groups were 68.1plusmn;6.2 and 27.3plusmn;5.5(Plt;0.01),respectively.The percen tage of cells in G2 phase of cell cycle increased from 8.9% to 29.5%. Conclusion G2 block was induced and poliferation was inhibited by daunoblastina in cultured human RPE cells.There is a relatively good correlation between Ki-67 immunostaining and inhibition of RPE cell proliferation. (Chin J Ocul Fundus Dis，2000，16：1-70)
Objective To study the influence of transforming growth factor-β1(TGF-β1), dentin non-collagen proteins(dNCPs) and their complexon tissue engineering pulp system. Methods Collagen I and dentin powder were used to construct the system of pulp cells in 3dimensional culture, dentin powder was added in the gel. The tissue engineering pulp were divided TGF-β1 group, dNCPs group, TGF-β1/dNCPsgroup and control group.After3, 6 and 14 days, the appearance and the differentiation of pulp cells were observed by HE staining and immunohistochemical staining -respectively. Results Collagen I could form netted collagen gel construction. Growing condition of pulp cells in gel was similar to that of pulp cells in vivo. After the TGF-β1 and dNCPswere added, the pulp cells had some characteristics of odontoblasts and had unilateral cell process after culture 6 days. Pulp cells arranged with parallel columnar and form dentin-pulp-like complex after 14 days. Immunohistochemical staining showed dentin salivary protein(DSP) began to express in some cells.The number of positive cell was most in the TGF-β1 group. No positive cells were detected in the control group. Conclusion The transforming growth factor-β1 and noncollagen proteins can stimulate the pulp cells to transform into odontoblasts to some extent, which promote the formation of tissue engineering pulp.
Objective To investigate the relationship of the expression between heat shock protein (HSP) 70 and 90, and Survivin and its effects on the proliferative activity in retinoblastoma (RB) cells. Methods Expression of Survivin, HSP70 and 90, and Ki-67 in conventional paraffin samples from 43 patients with RB and 6 healthy people was detected by streptavidin-biotin peroxidase (SP) immunohistochemical method. Ki67 labeling index was used to evaluate the proliferative activity in RB. Results In 43 cases of RB, positive expression of HSP70 and 90 and Survivin was found in 28 (65.12%), 37 (86.05%) and 27 (62.79%) cases, respectively. None of the 6 normal retinal tissue expressed HSP70, HSP90 or Survivin. Positive expression of Survivin was more frequent in positive expressions of HSP90 than that in negative expressions of HSP90 (P＜0.05). Ki67 labeling index was higher in positive expressions of HSP90 and positive expressions of Survivin than that in their negative expressions respectively (P＜0.05). Meanwhile, higher Ki67 labeling index was found in positive HSP90Survivin expressions than that in negative HSP90Survivin expressions and those cases where only HSP90 or Survivin was found (P＜0.05). Expression of HSP70 did not correlate with that of Survivin, nor had any significant effect on Ki67 labeling index (P＞0.05). Expression of HSPs and Survivin and Ki67 labeling index did not correlate with histological types (P＞0.05). Conclusion Expression of HSP90 correlates with that of Survivin in RB. Co-existence of Survivin and HSP90 probably plays an important role in the genesis of RB.
Objective To investigate the enhancing effect of ultrasound microbubbles on transfection of recombinant adenoassociated virus (rAAV) mediated green fluorecent protein (EGFP) gene into retinal ganglion cells (RGC) in vivo.Methods A total of 40 adult Sprague-Dawley (SD) rats were divided into four groups randomly (group A,B,C,D) with 10 rats in each. Group A was the normal control, in which the rats underwent intravitreal injection with 5 mu;l phosphate buffered solution. The rats in group B underwent intravitreal injection with 5 mu;l recombinant adenoassociated virus encoding EGFP gene (rAAV2-EGFP). The rats in group C underwent ultrasound irradiation on eyes right after intravitreal injection with 5 mu;l rAAV2-EGFP; The ultrasound irradiation was performed on the rats in group D right after intravitreal injection with the mixture solution of microbubbles and rAAV2-EGFP ultrasound. After 21 days, RGC were labeled retogradely with fluogold. Seven days after labeling, the retinal flatmounts and frozen sections were made from five rats in each group. Expression of EGFP reporter gene was observed by laser scanning confocal microscope and evaluated via average optical intensity (AOD) and RGC transfection rate. Labeled RGC were counted to evaluate the adverse effects.Results Green fluorescence can be observed exactly in labeled RGC in B，C，and D groups. The AOD and transfection rate in group D was （95.02plusmn;7.25）% and（20.10plusmn;0.74）% , respectively; which were higher than those in group B and C (F=25.970，25.799；P＜0.01). The difference of the number of RGC among the four groups was not significant(F=0.877,P＞0.05). Conclusion Under the condition of low frequency and with certain energy, ultrasoundmediated microbubble destruction can effectively and safely enhance rAAV delivery to RGC in rats.
ObjectiveTo investigate the expression of miR-195 and the underlying molecular mechanisms of miR-195 regulating HMGB1 in diabetic retinopathy (DR). MethodsExtract 5 ml venous blood from DR patients, diabetes mellitus (DM) patients and normal subjects, then extract and perificate plasma total RNA. MicroRNA array and real time polymerase chain reaction (RT-PCR) was used to screen out miRNAs which were expressed with significant differences in the serum of patients with DR. Bioinformatics was employed to predict the miR-195 related to high mobility group box 1 (HMGB1) regulation. Next, miR-195 was down-regulated or up-regulated in umbilical vein endothelial cells through transfection of miR-195 inhibitor and miR-29b mimics respectively.Then we analyzed expression of HMGB1 mRNA and protein by RT-PCR and Western blot. ResultsMicroRNA array results showed the expression of miR-195 in DR group is decreased by 8.34 times and 11.47 times compared with DM group and the normal group. RT-PCR verification results conforms to the microRNA array results. Compared with the DM group (F=0.034, t=8.057) and the normal group (F=0.370, t=9.522), the expression of miR-195 in DR group were significantly reduced, the differences were statistically significant (P < 0.05). RT-PCR showed that the expression of HMGB1 mRNA was significantly decreased in up-regulation group, compared with blank (F=0.023, t=11.287) and negative control group (F=0.365, t=7.471), the difference was statistically significant (P < 0.05). The expression of HMGB1 mRNA was significantly increased in down-regulation group, compared with blank (F=0.053, t=10.871) and negative control group (F=0.492, t=6.883), the difference was statistically significant (P < 0.05). Western blot showed that the expression of HMGB1 protein was significantly decreased in up-regulation group, compared with blank (F=0.021, t=8.820) and negative control group (F=0.039, t=7.401), the difference was statistically significant (P < 0.05); and significantly increased in down-regulation group, compared with blank (F=0.186, t=10.092) and negative control group (F=0.017, t=12.923), the difference was statistically significant (P < 0.05). ConclusionMiR-195 can inhibit the expression of HMGB1, reduce the inflammation and angiogenesis, thereby delaying or inhibiting the occurrence and development of DR.
Objective To investigate the effects of knocking down Rac1 gene (ras-related C3 botulinum toxin substrate 1) by small hairpin RNA (shRNA) on retinal neovascularization in a mouse model of oxygen-induced retinopathy (OIR). Methods One hundred and eight 7-day-old C57BL/6J mice were divided into three groups randomly.The OIR was induced by Smith protocol in 2 groups. OIR mice received an intravitreal injection of Rac1-shRNA plasmid or the nonsense plasmid in the geneintervention group and control group respectively at the age of postnatal day 11 (P11). Non-OIR mice also received an intravitreal injection of Rac1-shRNA plasmid at P11 as the blankintervention group which lived in the normoxic environment.Retinal neovascularization was investigated on flat-mounts after fluorescence angiography at P15 and P17. Endothelial cell nuclei breaking through the internal limiting membrane were counted on pathological section at P17.The expression of Rac1 and NF-kappa;B p65 subunit was measured by immuohistochemistry, Western blot, real-time polymerase chain reaction (RT-PCR) and in situ hybridization. Results Compared with the blank-control group,the level of Rac1 mRNA in the gene-intervention group decreased obviously（t=4.500，P=0.001）;the retinal non-perfusion areas,fluorescence leakage, neovascularization and the number of endothelial cell nuclei breaking through the internal limiting membrane were reduced significantly（t=6.521,P＜0.001）; the level of NF-kappa;B p65 nuclear translocation decreased（t=16.008,P＜0.001）while the expression of NF-kappa;B p65 mRNA was reduced obviously（t=3.354,P=0.006）, which was positively correlated with the expression of Rac1-mRNA (P=0.012).Conclusion Intravitreal injection of Rac1-shRNA with liposome in mice can effectively inhibit the expression of Rac1,and inhibit the retinal neovascularization under relative hypoxia via blocking the ROS-NF-kappa;B pathway.
Objective To study the relationship between the expression of sonic hedgehog (Shh) and vascular endothelial growth factor (VEGF) in hypoxic human retinal pigment epithelial (hRPE) cells. Methods Cultured hRPE-19 cells (3rd - 6th generations) were used in this experiment. hRPE-19 cells were divided into three groups including the control group, the hypoxia experimental group (100 μmol/L CoCl2) and the inhibition group (pretreatment with 20 μmol/L cyclopamine 1 hour before hypoxia). After culturing for 4, 8, 12 and 24 hours, the mRNA level of Shh and VEGF genes in these cells were measured by fluorescence quantitative polymerase chain reaction, and the protein level of Shh and VEGF in the supernatants were measure by enzyme-linked immunosorbent assay. The relationship between the expression of Shh and VEGF was analyzed by Pearson correlation analysis. Results The control group expressed low levels of Shh and VEGF mRNA/protein. The expression of Shh and VEGF mRNA/protein in the hypoxia experimental group was significantly higher than that in the control group (F=178.364, 183.732, 77.456, 91.572; P＜0.01). The expression of Shh and VEGF mRNA in the inhibition group was significantly lower than that in the hypoxia experimental group (F=68.745, 121.834; P＜0.01). In the hypoxia experimental group, the expression of VEGF protein was positively correlated with the expression of Shh protein (r=0.942, P＜0.05); and the expression of VEGF and Shh mRNA was positively correlated (r=0.970, P＜0.01). However, there was no significant correlation in the expression of VEGF and Shh mRNA in the inhibition group (r=0.915, P＞0.05). Conclusion There is a positive correlation between the expression of Shh and VEGF in hypoxic hRPE cells.
Objective To explore the relationship between the diabetic retinopathy (DR) and the changes of erythrocyte deformability(ED),erythrocyte membrane phospholipid and spectrin. Methods One hundred and eight patients with non-insulin dependent diabetes mellitus were divided into DR group(55 cases)and nonDR(NDR)group(53 cases).The changes of erythrocyte filtration index(EFI),erythrocyte membrane phospholipid and spectrin dimers(SP-D)and spectrin tetramers (SP-T)were measured in patients of DR and NDR groups and compared with the results of 53 cases of normal control group. Results The EFI,SP-D, SP-D/SP-T,sphingomyelin (SM) /phophatidylcholine(PC)were higher,and SPT,SM,PC,phophatidylserine(PS)and phatidylethanolamine(PE)were lower in patients with DR than those in control and NDR patients (F=8.467～18.925,q=6.845～12.627,Plt;0.001).The changes of all indicators in proliferative DR(PDR) patients were more obvious than those in background DR(BDR) patients(t=5,825-15.443,Plt;0.001).The EFI in DR patients was positively correlated to SM/PC,SP-D and SP-D/SP-T(Plt;0.01)，negatively correlated to SM,PC,PE,PS and SP-T(Plt;0.01). Conclusions The decrease of ED caused by the abnormalities of erythrocyte membrane phospholipid and spectrin might participate in the occurance and development of DR,and correlated to the degree of pathologic changes. (Chin J Ocul Fundus Dis, 1999, 15: 160-162)
OBJECTIVE: To clarify the mechanisms of the signal transduction of bone morphogenetic proteins (BMPs) inducing bone formation and to provide theoretical basis for basic and applying research of BMPs. METHOD: We looked up the literature of the role of Smads and related transcription factors in the signal transduction of BMPs inducing bone formation. RESULTS: The signal transduction processes of BMPs included: 1. BMPs combined with type II and type I receptors; 2. the type I receptor phosphorylated Smads; and 3. Smads entered the cell nucleus, interacted with transcription factors and influenced the transcription of related proteins. Smads could be divided into receptor-regulated Smads (R-Smads: Smad1, Smad2, Smad3, Smad5, Smad8 and Smad9), common-mediator Smad (co-Smad: Smad4), and inhibitory Smads (I-Smads: Smad6 and Smad7). Smad1, Smad5, Smad8, and probable Smad9 were involved in the signal transduction of BMPs. Multiple kinases, such as focal adhesion kinase (FAK), Ras-extracellular signal-regulated kinase (ERK), phosphatidylinositol 3-kinase (PI3K), and Akt serine/threonine kinase were related to Smads signal transduction. Smad1 and Smad5 related with transcription factors included core binding factor A1 (CBFA1), smad-interacting protein 1 (SIP1), ornithine decarboxylase antizyme (OAZ), activating protein-1 (AP-1), xenopus ventralizing homeobox protein-2 (Xvent-2), sandostatin (Ski), antiproliferative proteins (Tob), and homeodomain-containing transcriptian factor-8 (Hoxc-8), et al. CBFA1 could interact with Smad1, Smad2, Smad3, and Smad5, so it was involved in TGF-beta and BMP-2 signal transduction, and played an important role in the bone formation. Cleidocranial dysplasia (CCD) was thought to be caused by heterozygous mutations in CBFA1. The CBFA1 knockout mice showed no osteogenesis and had maturational disturbance of chondrocytes. CONCLUSION: Smads and related transcription factors, especially Smad1, Smad5, Smad8 and CBFA1, play an important role in the signal transduction of BMPs inducing bone formation.
Objective To investigate the expression and significance of T-bet in experimental autoimmune uveoretinitis (EAU). Methods EAU was induced in 24 Lewis rats by immunization with retinal S-antigen (50 μg) and complete Freund′s adjuvant, and another 4 rats were the healthy control. The rats with EAU were executed 7, 12, 15, 21 days after immunization, respectively. Immunohistochemical single and double staining were performed using monoclonal antibodies of T-bet or CD4 on the ocular wholemounts and the consecutive sections of the eye and spleen from both 24 immunized Lewis rats and 4 normal controls. The positive cells were counted under the optic microscope and the data were analyzed by SPSS 11.0 statistic software. Results A few T-bet positive cells were observed in the normal ocular tissues and spleen. The expressions of T-bet in the iris, retina, and spleen increased 7 days after immunization, reached the peak at the 15th day, and decreased at the 21st day, which were higher than those in the control. Double staining on the consecutive sections revealed that most of the T-bet positive cells were positive for CD4 monoclona l antibody. Conclusion T-bet may affect the occurrence of EAU by activating Th1 cells. (Chin J Ocul Fundus Dis，2004，20：172-174)