OBJECTIVETo investigate the expression of adiponectin and its receptors (AdipoRs) in the retina of normal mice and mice with type 1 diabetes mellitus (T1DM).

METHODSC57BL/6 mice were randomly divided into control group and streptozotocin-induced T1DM group. Two months after the modeling, the total protein and adiponectin protein expression in the retina and choroid were measured using BCA method and enzyme-linked immunosorbent assay, respectively. Quantitative RT-PCR was performed to detect the mRNA expressions of AdipoRs in the retina and choroid, and Western blotting was employed to examine the protein expressions of AdipoRs in the retina.

RESULTSAdiponectin and AdipoRs proteins were expressed in the retina and choroid in normal mice. The expressions of adiponectin and AdipoR1 were up-regulated in the retina of mice with T1DM while AdipoR2 expression exhibited no significant changes.

CONCLUSIONAdiponectin and AdipoR1 may play an important role in the evolvement of type 1 diabetic retinopathy.

Adiponectin ; metabolism ; Animals ; Diabetes Mellitus, Experimental ; metabolism ; Diabetes Mellitus, Type 1 ; metabolism ; Diabetic Retinopathy ; metabolism ; pathology ; Male ; Mice ; Mice, Inbred C57BL ; Receptors, Adiponectin ; metabolism ; Retina ; metabolism

OBJECTIVETo investigate the expression of nitric oxide synthase (NOS) in the retina of 8-week-old diabetic rats, and explore the potential molecular mechanisms for the role of NO in diabetic retinopathy (DR).

METHODSRetinal gene expression profile of normal and 8-week-old diabetic rats was constructed with restriction fragment differential display polymerase chain reaction (RFDD-PCR). Bioinformatic analysis of the differentially expressed gene identified the genes coding for 3 subtypes of NOS, namely eNOS, nNOS and iNOS as the candidate genes related to DR, which was verified using semi-quantitative RT-PCR and immunohistochemistry.

RESULTSThe results of RFDD-PCR revealed down-regulated expression of eNOS and nNOS and up-regulated iNOS expression in diabetic rat retina. RT-PCR showed that the expression levels of eNOS and nNOS in diabetic rat retina were obviously lower than that in normal retina (0.23-/+0.03 vs 0.32-/+0.03 for eNOS, P<0.05; 0.25-/+0.02 vs 0.36-/+0.02 for nNOS, P<0.05), but the expression level of iNOS obviously higher (0.27-/+0.02 vs 0.20-/+0.03, P<0.05). Immunohistochemistry of healthy retina visualized eNOS-, nNOS- and iNOS-positive cells, all located in the inner nuclear layer (INL) and ganglion cell layer (GCL), and eNOS-positive cells were also found in vascular endothelium. In diabetic retina, the number of eNOS- and nNOS-positive cells was significantly lowered in comparison with normal rat retina (14.33-/+3.19 vs 22.13-/+3.60 for eNOS, P<0.05; 21.87-/+3.62 vs 34.40-/+7.09 for nNOS, P<0.05), but the number of iNOS-positive cells significantly increased (17.60-/+2.58 vs 11.73-/+2.70, P<0.05).

CONCLUSIONThe alterations in eNOS, nNOS and iNOS expression are associated with the deuelopmant and progression of DR.

Animals ; Diabetes Mellitus, Experimental ; metabolism ; Diabetic Retinopathy ; metabolism ; Gene Expression Profiling ; Gene Expression Regulation ; Nitric Oxide Synthase ; metabolism ; Polymerase Chain Reaction ; Rats ; Rats, Sprague-Dawley ; Retina ; metabolism ; pathology

To understand the pathogenesis of proliferative vitreoretinal membrane formation which occurs in proliferative vitreoretinopathy (PVR) and proliferative diabetic retinopathy (PDR), etc., accurate identification of the cellular components of the membrane is needed. This study was performed to identify cellular components of the membranes by means of immunohistochemical technique. 11 proliferative vitreoretinal membranes which were surgically obtained from 7 eyes with PVR and 4 eyes with PDR were stained with monoclonal antibodies against cytokeratin, glial fibrillary acidic protein (GFAP), or vimentin using immunoperoxidase technique (ABC method). In the PVR membranes, mean cell positivities for cytokeratin, GFAP and vimentin were 48%, 1% and 92%, respectively and in the PDR membranes, 0%, 5% and 93%, respectively. The above results suggest that retinal pigment epithelial cells and fibroblasts are major cellular components of PVR membranes, and that mesenchymal cells are major cellular components and glial cells are minor cellular components of PDR membranes.
Adolescent ; Adult ; Antibodies, Monoclonal ; Cell Membrane/metabolism/pathology ; Diabetic Retinopathy/metabolism/pathology ; Eye Diseases/metabolism/pathology ; Female ; Humans ; Immunoenzyme Techniques ; Intermediate Filament Proteins/*analysis ; Male ; Middle Aged ; Retinal Diseases/metabolism/*pathology ; Vitreous Body/metabolism/*pathology

We performed a retrospective study of serum factors associated with neovascular glaucoma that can occur following vitrectomy for proliferative diabetic retinopathy. The medical records of 183 patients (241 eyes) who received vitrectomy between August 1996 and August 2000 were studied retrospectively and subsequently analyzed by linear logistic regression analysis and multiple logistic regression tests. Neovascular glaucoma developed at an average of 2.7 months in 31 of 241 eyes (14.1%). The overall anatomical success rate of retinal attachment was 82.5% (199 eyes in 241 eyes), although it decreased to 45.1% (14 eyes in 31 eyes) in eyes with neovascular glaucoma. Serum cholesterol (P = 0.041) and fibrinogen levels (P = 0.020) were significantly associated with the development of neovascular glaucoma. However, no significant association could be found concerning hypertension, diabetic retinopathy or hypercholesterolemia (P > 0.05). We suggest that serum creatinine, cholesterol and fibrinogen levels can be used to predict the development of neovascular glaucoma in vitrectomized eyes with diabetic retinopathy and can further provide a more active approach to preventing the development of this condition.
Adult ; Aged ; Aged, 80 and over ; Blood/metabolism ; Cell Division ; Diabetic Retinopathy/*pathology/*surgery ; Glaucoma, Neovascular/*blood/*complications ; Human ; Middle Age ; Postoperative Period ; Retrospective Studies ; *Vitrectomy

Retinopathy is a major cause of morbidity in diabetes and remains the primary cause of new blindness. Therefore, it is necessary to find new drug to treat diabetic retinopathy. Type 2 diabetes mellitus (T2DM) rats were induced by injection (ip) with streptozotocin (STZ) 35 mg x kg(-1) and fed with a high-carbohydrate/high-fat diet 2 weeks later. From week 17 to 32, diabetic rats were given different doses of berberine 75, 150, and 300 mg x kg(-1), fenofibrate 100 mg x kg(-1) and rosiglitazone 4 mg x kg(-1), separately. Retinal structure was observed with hematoxylin-eosin staining and peroxisome proliferator-activated receptors (PPARs) alpha/delta/gamma protein expressions were detected by immunohistochemistry. The retina of control rats was thicker than that of other groups, 16 weeks treatment with berberine (150 and 300 mg x kg(-1)) and rosiglitazone 4 mg x kg(-1) thickened the diabetic retina, but no difference existed in retinal structure among groups. Both berberine (150 and 300 mg x kg(-1)) and rosiglitazone 4 mg x kg(-1) significantly decreased PPARy expression in diabetic retina; while berberine (150 and 300 mg x kg(-1)) and fenofibrate 100 mg x kg(-1) obviously increased both PPARalpha and PPARdelta expressions in diabetic retina. Berberine modulates PPARalpha/delta/gamma protein levels in diabetic retina which may contribute to ameliorate retinopathy complication induced by STZ and a high-carbohydrate/high-fat diet. It is expected that berberine might be a more beneficial drug to treat diabetic retinal complication comparing with fenofibrate and rosiglitazone.
Animals ; Berberine ; pharmacology ; Diabetes Mellitus, Experimental ; metabolism ; Diabetes Mellitus, Type 2 ; metabolism ; Diabetic Retinopathy ; metabolism ; Fenofibrate ; pharmacology ; Hypoglycemic Agents ; pharmacology ; Male ; PPAR alpha ; metabolism ; PPAR delta ; metabolism ; PPAR gamma ; metabolism ; Rats ; Rats, Wistar ; Retina ; metabolism ; pathology ; Thiazolidinediones ; pharmacology

BACKGROUNDNeovascularization can cause vision loss in proliferative diabetic retinopathy (PDR) and may be affected by many factors. Stromal cell-derived factor-1 (SDF-1) is a potent stimulator of angiogenesis. The study was aimed to investigate the expression of SDF-1 and its correlation with vascular endothelial growth factor (VEGF) in the eyes with diabetic retinopathy.

METHODSThe levels of SDF-1 and VEGF were measured by enzyme-linked immunosorbent assay in the vitreous of 41 eyes of 41 patients with PDR and 12 eyes of 12 patients with idiopathic macular hole (IMH). Vitreous fluid samples and fibrovascular preretinal membranes were obtained at vitrectomy. SDF-1 and VEGF were localized using immunohistochemistry.

RESULTSThe vitreous concentration of VEGF was significantly higher in eyes with PDR ((2143.7 +/- 1685.21) pg/ml) than in eyes with IMH ((142.42 +/- 72.83) pg/ml, P < 0.001). The vitreous level of SDF-1 was also significantly higher in eyes with PDR ((306.37 +/- 134.25) pg/ml) than in eyes with IMH ((86.91 +/- 55.05) pg/ml, P < 0.001). The concentrations of both VEGF and SDF-1 were higher in eyes with active PDR than in eyes with inactive PDR. Panretinal photocoagulation (PRP) could decrease the SDF-1 levels in the vitreous of PDR patients. The vitreous concentration of SDF-1 correlated with that of VEGF in eyes with PDR (r = 0.61, P < 0.001). The costaining of SDF-1 and VEGF was confined to the vascular components in preretinal membranes.

CONCLUSIONSSDF-1 protein is highly expressed in both the vitreous and preretinal membranes of PDR patients; SDF-1 may be correlated with VEGF in angiogenesis in PDR.

Chemokine CXCL12 ; metabolism ; Diabetic Retinopathy ; metabolism ; pathology ; Enzyme-Linked Immunosorbent Assay ; Humans ; Immunohistochemistry ; Neovascularization, Pathologic ; metabolism ; physiopathology ; Retinal Perforations ; metabolism ; Vascular Endothelial Growth Factor A ; metabolism ; Vitrectomy ; Vitreous Body ; metabolism

OBJECTIVETo evaluate the potential role of insulin-like growth factor-1 receptor mRNA (IGF-IR mRNA) in the onset and development of retinopathy in diabetic rats.

METHODSA diabetic model was duplicated in Wistar rats. The early changes in the retina were examined using light and transmission electron microscopy. Expression of IGF-IR mRNA was analyzed using in situ hybridization.

RESULTSWeak expression of IGF-IR mRNA (5%) was found in retinas of normal rats, but was significantly increased (15% and 18%) in the retinas of diabetic rats after 3 and 6 months of diabetes (P < 0.01). In situ hybridization and morphological study demonstrated that there was a positive correlation between IGF-IR mRNA expression and retinal changes at various stages.

CONCLUSIONIncreased IGF-IR mRNA might play an important role in the onset and development of diabetic retinopathy.

Animals ; Blood Glucose ; analysis ; Diabetic Retinopathy ; etiology ; Glycated Hemoglobin A ; analysis ; Insulin-Like Growth Factor I ; physiology ; Male ; RNA, Messenger ; analysis ; Rats ; Rats, Wistar ; Receptor, IGF Type 1 ; genetics ; Retina ; metabolism ; pathology

The purpose of this study was to investigate the protective effect of puerarin on retina pigment epithelial (RPE) cells of diabetic rats against apoptosis. One hundred and eight Sprague-Dawley (SD) rats were randomly divided into 3 groups: control group, streptozotocin (STZ) group and puerarin group. STZ and puerarin groups received 3 d of STZ injection (45 mg/kg per day, i.p.). Additionally, puerarin groups were treated with puerarin (140 mg/kg, i.p.) from the 4th day to the end of experiment. The rats from different groups were sacrificed on 20, 40 and 60 d after STZ injection for harvesting RPE cells. Western blot analysis, DNA laddering, RT-PCR and immunohistochemistry were used for determining the expression of nitrotyrosine (NT, the foot print of peroxynitrite), cell apoptosis, iNOS mRNA and Fas/Fas ligand (FasL) signal transduction in RPE cells, respectively. The results showed that control group maintained low apoptosis level and little NT, iNOS mRNA, Fas/FasL protein expressions, as well as normal blood glucose and body weight during 60 d of the experiment. Compared with control group, STZ group showed obvious apoptosis and higher NT, iNOS mRNA, Fas/FasL protein expressions from 20 d after STZ injection. Puerarin relieved apoptosis of RPE cells and decreased NT, iNOS mRNA, Fas/FasL protein expressions in puerarin group 20 or 40 d after STZ injection, compared with STZ group. These results suggest puerarin can decrease RPE cells apoptosis in diabetic rats by reducing peroxynitrite level and iNOS expression, thus being a potential therapeutic agent in controlling of diabetic retinopathy.
Animals ; Apoptosis ; drug effects ; Diabetes Mellitus, Experimental ; metabolism ; pathology ; Diabetic Retinopathy ; prevention & control ; Fas Ligand Protein ; metabolism ; Isoflavones ; pharmacology ; Male ; Nitric Oxide Synthase Type II ; genetics ; metabolism ; Peroxynitrous Acid ; metabolism ; Protective Agents ; pharmacology ; RNA, Messenger ; genetics ; metabolism ; Rats ; Rats, Sprague-Dawley ; Retinal Pigment Epithelium ; pathology ; fas Receptor ; metabolism

To evaluate the effect of chlorogenic acid (CGA), a polyphenol abundant in coffee, on retinal vascular leakage in the rat model of diabetic retinopathy, Sprague-Dawley rats were divided into four groups: controls, streptozotocin-induced diabetic rats, and diabetic rats treated with 10 and 20 mg/kg chlorogenic acid intraperitoneally daily for 14 days, respectively. Blood-retinal barrier (BRB) breakdown was evaluated using FITC-dextran. Vascular endothelial growth factor (VEGF) distribution and expression level was evaluated with immunohistochemistry and Western blot analysis. Expression of tight junction proteins, occludin and claudin-5, and zonula occludens protein, ZO-1 was also evaluated with immunohistochemistry and Western blot analysis. BRB breakdown and increased vascular leakage was found in diabetic rats, with increased VEGF expression and down-regulation of occludin, claudin-5, and ZO-1. CGA treatment effectively preserved the expression of occludin, and decreased VEGF levels, leading to less BRB breakdown and less vascular leakage. CGA may have a preventive role in BRB breakdown in diabetic retinopathy by preserving tight junction protein levels and low VEGF levels.
Animals ; Blood-Retinal Barrier/*drug effects ; Chlorogenic Acid/metabolism/*pharmacology ; Claudin-5/metabolism ; Dextrans/chemistry ; Diabetes Mellitus, Experimental/complications/metabolism/*pathology ; Diabetic Retinopathy/etiology/prevention & control ; Down-Regulation ; Fluorescein-5-isothiocyanate/chemistry ; Male ; Occludin/metabolism ; Rats ; Rats, Sprague-Dawley ; Retina/*metabolism ; Tight Junction Proteins/metabolism ; Vascular Endothelial Growth Factor A/metabolism ; Zonula Occludens-1 Protein/metabolism

BACKGROUNDDiabetic retinopathy (DR) is a leading cause of visual impairment and blindness among the people of occupational age. To prevent the progress of retina injury, effective therapies directed toward the key molecular target are required. Grape seed proanthocyanidin extracts (GSPE) have been reported to be effective in treating diabetic complications, while little is discussed about the functional protein changes.

METHODSWe used streptozotocin (STZ) to induce diabetes in rats. GSPE (250 mg/kg body weight per day) were administrated to diabetic rats for 24 weeks. Serum glucose, glycated hemoglobin and advanced glycation end products (AGEs) were determined. Consequently, 2-D difference gel electrophoresis and mass spectrometry were used to investigate retina protein profiles among control, STZ-induced diabetic rats, and GSPE treated diabetic rats.

RESULTSGSPE significantly reduced the AGEs of diabetic rats (P < 0.05). Moreover, GSPE significantly suppressed the vascular lesions of central regions, decreased capillary enlargements and neovascularization, similar to those of the control rats under light microscope. Eighteen proteins were found either up-regulated or down-regulated in the retina of STZ-induced diabetic rats. And seven proteins in the retina of diabetic rats were found to be back-regulated to normal levels after GSPE therapy. These back-regulated proteins are involved in many important biological processes such as heat shock, ubiquitin-proteasome system, cell proliferation, cell growth and glucose metabolism.

CONCLUSIONSThese findings might promote a better understanding for the mechanism of DR, and provide novel targets for evaluating the effects of GSPE therapy.

Animals ; Blood Glucose ; drug effects ; metabolism ; Body Weight ; drug effects ; Diabetes Mellitus, Experimental ; complications ; metabolism ; pathology ; Diabetic Retinopathy ; drug therapy ; metabolism ; pathology ; Electrophoresis, Gel, Two-Dimensional ; Glycated Hemoglobin A ; metabolism ; Glycation End Products, Advanced ; metabolism ; Grape Seed Extract ; Male ; Plant Extracts ; pharmacology ; Proanthocyanidins ; pharmacology ; Proteomics ; methods ; Rats ; Rats, Wistar