Objective To investigate the effects of transformin growth factor-beta (TGF-beta;) and interferon-gamma(IFN-gamma;)on collagen synthesis in human retinal pigment epithelial cells(RPE)． Methods TGF-beta;(0.01～10 ng/ml),recombinant IFN-gamma;(100～10000 Ｕ/ml)or a combination of two were added to cultures of RPE and collagen synthesis of the cells were measured by3 H-proline incorporation assay,indirect immunofluorescence staining and dot-blot hybridization. Results TGF-beta; at 10 ng/ml increased cell uptake of 3 H-proline to 130．87% of controls．It intensified Type IV,I and Ⅲ collagen fluorescent staining as well as mRNA expression．IFN-gamma; at 10000 Ｕ/ml caused 54．72% inhibition of 3 H-proline uptake by RPE,and decreased TypeⅣ collagen fluorescent staining as well as mRNA expression of Type Ⅳ,I and Ⅲ collagens. Conclusion TGF-beta; and IFN-gamma; stimulated and inhibited collagen synthesis of human RPE,respectively．The combination of two had antagonistic effects．IFN-gamma; can be used for inhibition of collagen synthesis of RPE. (Chin J Ocul Fundus Dis, 1999, 15: 245-248)
ObjectiveTo observe the expression of connective tissue growth factor (CTGF) in injured model of retinal pigment epithelial (RPE) cells and the promoting effect of CTGF on migration of RPE cells.MethodsCultured monolayer-confluent human RPE cells were scraped with a trephine and a cotton stick, and set up the injured model of RPE cells with round scraped area. Immunohistochemistry and in situ hybridization(ISH) were used to detect the expression of CTGF protein and mRNA in injured RPE cells at distinct time points after injury. The number of RPE cells migrated to injured area was measured and the effect of CTGF on migration of RPE cells and the effect of dexamethasone (DEX) on the promoting process of CTGF were observed.ResultsThe results of immunohstochemistry and ISH indicated the weak positive expression of CTGF in RPE cells at the edge of scrape 6 hours after injury, and the positive expression increased gradually as time goes by after the injury. Strong positive expression of CTGF in RPE cells at the edge of scrape was found 24 and 48 hours after injury. Rebuilt human CTGF stimulated migration of RPE cells in a dose-depended manner, and DEX significantly inhabited the migration.ConclusionCTGF involves in the procedure of repair of injury of RPE cells, which may play an important role in the pathogenesis of intraocular proliferative diseases such as proliferative vitreoretinaopathy.(Chin J Ocul Fundus Dis, 2005,21:306-309)
Objective To examine the expression of proliferating cell nuclear antigen (PCNA) of retinal pigment epithelial (RPE) cells, thus assessing the role of mechanism of contact inhibition playing in the process of experimental retinal detachment and reattachemnt.Methods Retinal detachment was produced in 72 cats by subretinal injection of 0.25% solution of healon through a micropipette three weeks after extracapsular lens extraction and vitrectomy. Some of the detached retinae were reattached 24 hours later. At different time, the cats were killed and eye globes were fixed and embeded in paraffin. Histologic sections were processed for immunohistochemistry examination using an antibody to detect PCNA protein. Labeled RPE cells were identified, and the proliferation was quantified in detached and un-detached retinae of detachment group, and also in reattached retinae of reattachment group. The comparsion of PCNA-labeled RPE cells in different groups were analyzed by ANOVA. Results In detached regions of detachment group, PCNA-expression of RPE cells occured within 24 hours, and reached a maximum after 5-6 days, then gradually declined to barely detectable levels after 20 days. Similar tendency was found in reattached retinae, but the number of PCNA-labeled RPE cells was obviously small. Fewer PCNA-labeled RPE cells were found in regions of un-detached retinae in detachment group. The difference of these three groups was significant.Conclusion Proliferation of RPE cells is induced when they lose contact with neural retina, but inhibited after neural retina reattached to RPE cells. It suggests that the mechanism of contact inhibition plays a role in the proliferative process after retinal detachment and reattachment. (Chin J Ocul Fundus Dis，2003，19：20-23)
Endogenous pigment epithelium derived factor (PEDF) shows great potential as a drug target for the treatment of diabetes retinopathy (DR) due to its anti-angiogenesis, anti-inflammatory, neuroprotective and neurotrophic effects. PEDF plays a biological role by combining with receptor proteins on cell membrane surface and regulating a variety of signaling pathways. Low density lipoprotein receptor related protein 6 plays a role in inhibiting oxidative stress reaction, inflammatory reaction, and neovascularization of DR. Adipose triglyceride lipase, laminin receptor, plexin domain containing 1 (PLXDC) 1, PLXDC2 and F1-adenosine triphosphate synthase have the effect of promoting endothelial cell apoptosis, among which PLXDC1 also has neuroprotective effect. By clarifying the receptor that PEDF acts on, exploring the affinity between the receptor and PEDF, the difference in the expression level of each receptor in the process of disease, and the specific function that PEDF plays after binding with specific receptors, we can develop fusion protein drugs for the active domain of high affinity of receptors, have a clearer understanding of the pathogenesis of DR, and take PEDF or PEDF receptor as the target to consolidate the theoretical basis for the development of new therapeutic drugs and strategies for DR.
ObjectiveTo detect the induction of inducible nitric oxide synthase (iNOS) and nitric oxide (NO) production in immunostimulated retinal pigment epithelial (RPE) cells to seek for the supplying of the arginine, a substrate for NOS; as well as the effects of produced NO on the tight junction of RPE-J cells. MethodsRat′s RPE-J cells were treated with interferon-γ(INF-γ), tumor necrosis factor-α(TNF-α) and lipopolysaccharide (LPS), and Northern and Western blotting were applied to analyze the expression of the citrulline-NO cycle enzymes and related enzymes and the effect of dexamethasone and cyclic adenosine monophosphate (camp) on the expression of iNOS. Immunocytochemistry reaction and Western blotting were used to evaluate the effect of produced NO on the tight junctions of RPE-J cells.ResultsiNOS and argininosuccinate synthetase (AS) were highly induced at both mRNA and protection levels in immunostimulated RPE cells while arginiosuccinate lyase (AL) was not induced. NO was produced by cells after stimulation with TNFα, IFNγ and LPS. The induction of iNOS mRNA and the production of NO by these immunostimulated cells was further enhanced by cAMP. NO was produced from citrulline as well as from arginine. And the produced NO impaired the tight junction of RPE-J cells, decreased the production of tight junction related protein ZO-1.ConclusionIn activated RPE-J cells, citrullinearginine recycling is important for NO production, and the produced NO weakened the function of tight junction of RPE-J cells.(Chin J Ocul Fundus Dis, 2005,21:32-36)
ObjectiveTo investigate the correlation between infection and capsular contracture by observing the effect of infection on the formation of the surrounding capsule after breast implants. MethodsThree healthy adult female Diannan small-ear pigs underwent augmentation mammaplasty using miniature implants, which were randomly divided into group A (12 nipples), group B (10 nipples), and group C (12 nipples). Staphylococcus epidermidis (SE ATCC12228 and SE RP62A, 1.2×105 CFU/mL) was inoculated into the periprosthetics of groups B and C, and sterile PBS in group A before breast implants. Then the silica gel prosthesis was put, total 34 implants in 3 groups. After 13 weeks, the capsule was harvested to measure the capsular tension and weight. HE staining was used to observe the structure characteristics of the capsule and to measure the capsule thickness, Van-Gieson (VG) staining to observe the capsule collagen characteristics, and α-smooth muscle actin (α-SMA) immunocytochemistry staining to observe myofibroblasts in capsule. ResultsPrimary healing of incision was obtained, and 3 small-ear pigs showed stable life indication. The complete fibrous capsule was observed after 13 weeks in 3 groups. Capsule tension showed no significant difference among 3 groups (P>0.05). Capsule weight was significantly greater in group C than in groups A and B (P<0.05). HE staining showed that capsule structure of the 3 groups was similar with obvious dense layer and loose layer, and the capsule thickness was also significantly greater in group C than in groups A and B (P<0.05), but no significant difference was found between groups A and B (P>0.05). VG staining showed that collagenous fiber in the capsule were more compact in group C than in groups A and B. The α-SMA immunocytochemistry staining indicated the myofibroblasts in capsule were the most in group C. ConclusionInfection after breast implants has obvious impacts on the formation of the capsule, and there was a causal link between infection and capsular contracture.
Objective To study degradation of the antigen-extracted meniscus in PBS solution with no enzyme or with different enzymes. Methods Four types of enzymes (collagenase, hyaluronidase, trypsin, papain) were used to enzymolyze the antigen-extracted meniscus and the fresh meniscus for 3, 7, 15 and 30 days (37℃). The antigenextracted meniscus and the fresh meniscus were immersed in PBS solution (37℃) for 30 days. Weight loss measurement, UV spectrophotometry, and scanning electron microscopy (SEM) were used to characterize the degraded materials. Results The two types of the materials were remarkably digested under the enzymes, especially under trypsin. The degradation curves showed that the antigen-extracted meniscus was enzymolyzed less than the fresh meniscus. The degradation products were grouped as amino, peptide, and polyose by the analysis. Both of the materials could hardly behydrolyzed in PBS solution without the enzymes. The four different enzymes had different surface morphologies under the examination of SEM. Conclusion The antigen-extracted meniscus is enzymolyzed more slowly than the fresh meniscus in vitro, and the result can be used as a guideline to the further research.
Objective To observe the morphological changes and gene expression during the transdifferentiation of adult retinal pigment epith elial(RPE) cells into neuronal phenotype in vitro induced by retrovirus and ciliary neurotrophic factor (CNTF). Meothds The adult RPE cells derived from CRL 2302 were infected by retrovirus with green fluoresence protein(GFP)and then were transfected further by liposome mediated CNTF expressing plasmid.The cellular ability of producing CNTG,and the expression of CNTF, CNTF receptor (CNTFR), and signal transduction molecule janus tyrosine kinases (JAK) were detected by enzyme linked immunosorbent assay, immunohistochemical stainin gand Western blotting method. Results After infected by retrovirus, the configuration of adult RPE cells didnrsquo;t change much, but expressions of neurons and some glial cells markers likeneurofilament (NF) protein and glial fibraillary acidic protein (GFAP) were detected. After further transfected by CNTF expressing plasmid, RPE cells which expressed CNTF highly and continuously had differential neurocytes; the expression of CNTFR didnrsquo;t change, but the distribution position changed to the cell membrane; expression of signal transduction molecule JAK increased obviously. Conclusion The adult RPE cells may transdifferentiate into neurons induced by retrvirus and CNTF. The transdifferentiation may relate to CNTF-CNTFR-JAK signal transduction pathway. (Chin J Ocul Fundus Dis, 2006, 22: 400-403)
Purpose To study inhibition effects of retinal pigment epithelial (RPE) cells by hyaluronic acid-stimulating activity(HASA)． Methods The cultured human RPE cells added with a series of HASA was measured with cell counting,tetrazolium(MTT)colorimetric assay and tritium labelled thymidine deoxyribosｅ(3H-TdR)incorporation assay.Flow cytometry(FCM)analysis was used to examine RPE cells cycles. Results HASA at concentrations of 12.5～200 mu;g/ml and within 48 hours inhibited RPE cells proliferation with a dose-dependant and time dependant manners.The maximal inhibition rate of RPE cells by HASF was about 48.0%.FCM revealed that the cells in G1 phase increased 7.2% and cells in S phase decreased 9.7%,compared to controls. Conclusion HASA at a certain dose range and period can inhibit RPE cells proliferation. (Chin J Ocul Fundus Dis,1999,15:72-74)