PURPOSE: Cancer-associated retinopathy is a paraneoplastic retinal degeneration which may primarily result from auto-immune mediated apoptosis. It has been hypothesized that high titer of auto-antibodies are able to cross the blood-retinal barrier (BRB) and to enter retinal cells to activate apoptotic pathway which has been already well-established. However, it still remains to be elucidated whether auto-antibodies could cross BRB in the retina. Herein, we demonstrated that intravenously administrated anti-recoverin antibodies could not pass through BRB and not lead to retinal cell death. METHODS: Anti-recoverin antibody was intravenously injected to C57BL/6 mice, which were sacrificed 1 and 7 days to obtain eye. Vascular endothelial growth factor was intravitreally injected to induce BRB breakdown, which was confirmed by fluorescein angiography and western blotting for zonula occludens (ZO)-1, ZO-2 and occludin. To investigate the location of anti-recoverin antibody in the retina, immunofluorescein was performed. The retinal toxicity of intravenous anti-recoverin antibody was evaluated by histological examination and transferase-mediated dUTP nick-end labeling. Immunofluorescein staining for glial fibrillary acidic protein was done to address glial activation as well. RESULTS: Intravenously administrated anti-recoverin antibodies were exclusively distributed on retinal vessels which were co-localized with CD31, and led to neither increase of glial fibrillary acidic protein expression, as an indicator of retinal stress, nor apoptotic retinal cell death. Moreover, even in the condition of vascular endothelial growth factor-induced BRB breakdown, anti-recoverin antibodies could not migrate across BRB and still remained on retinal vessels without retinal cytotoxicity. CONCLUSIONS: Our results suggest that high titer of intravascular anti-recoverin antibodies could not penetrate into the retina by themselves, and BRB breakdown mediated by dysregulation of tight junction might not be sufficient to allow anti-recoverin antibodies to pass through BRB.
Animals ; Antibodies/*administration & dosage/*metabolism ; Blood-Retinal Barrier/*metabolism ; Cell Death/drug effects ; Cells, Cultured ; Female ; Injections, Intravenous ; Mice ; Mice, Inbred C57BL ; Recoverin/*immunology ; Retina/cytology/drug effects ; Retinal Vessels/metabolism

OBJECTIVETo explore VEGF siRNA's effect on the immature fetal retinal microvascular endothelial cells in vitro.

METHODThe fresh retinal micrangium was primarily cultured to obtain microvascular endothelial cells. CoCl2 was used to simulate oxygen-deficient conditions. siRNA directed against human VEGF was designed and chemically synthesized. There were 3 groups in our experiment: VEGF siRNA group, hypoxia control group, and negative siRNA control group. The fetal retinal micrangium vascular endothelial cells were transfected by using liposome. The expression levels of VEGF mRNA and protein were evaluated by RT-PCR and Western blotting 24, 48, 72 h after transfection, cell proliferation was evaluated by MTT method.

RESULTThe expression levels of VEGF mRNA decreased by 21.05%, 79.67%, and 90.48% 24 h, 48 h, and 72 h after transfection as compared to those in hypoxia control group, the expression level of VEGF protein had decreased by 14.58%, 66.97%, and 81.61% as compared to those in hypoxia control group. The siRNA could decrease cell proliferation under hypoxia too, the multiplication rate after 12, 24, 48, and 72 h decreased by 15.0%, 42.9%, 78.3% and 65.9%.

CONCLUSIONVEGF siRNA could down-regulate the expression of VEGF in immature fetal retinal microvascular endothelial cells and suppressed cell proliferation. Application of siRNA to inhibit expression of VEGF may be a hopeful way to prevent and cure ROP.

Cell Hypoxia ; Cell Line ; Endothelial Cells ; metabolism ; Humans ; Infant, Newborn ; RNA, Messenger ; genetics ; RNA, Small Interfering ; Retina ; metabolism ; pathology ; Retinal Vessels ; cytology ; metabolism ; Retinopathy of Prematurity ; metabolism ; Transfection ; Vascular Endothelial Growth Factor A ; genetics ; metabolism

OBJECTIVETo observe the effect of recombinant human erythropoietin (rhEPO) on the expression of hypoxia inducible factor-1alpha (HIF-1alpha) in the retina of rabbits with acute high intraocular pressure and investigate the mechanism of rhEPO in protecting the retina from ischemia-reperfusion injury.

METHODSAcute high intraocular pressure was induced in the rabbits by perfusion of normal saline into the anterior chamber, and rhEPO was injected subcutaneously. The changes in HIF-1alpha protein expression in the retina was observed by immunohistochemistry on days 1, 3, 7, and 14 after retinal ischemia- reperfusion.

RESULTSHIF-1alpha expression was not observed in the retina of the normal control rats, but intense HIF-1alpha expression was found in the model group (P<0.01). In rabbits with rhEPO injection and those in the model group, the patterns of HIF-1alpha expression alterations were similar, but the HIF-1alpha-positive cells in the retina were significantly fewer in rhEPO group (P<0.05).

CONCLUSIONrhEPO can down-regulate HIF-1alpha expression in the retina of rabbits with acute high intraocular pressure, which may be one of the mechanisms that rhEPO protects the retina from ischemia-reperfusion injury.

Animals ; Down-Regulation ; Erythropoietin ; pharmacology ; Humans ; Hypoxia-Inducible Factor 1, alpha Subunit ; metabolism ; Neuroprotective Agents ; pharmacology ; Ocular Hypertension ; metabolism ; Rabbits ; Recombinant Proteins ; Reperfusion Injury ; prevention & control ; Retina ; metabolism ; Retinal Vessels ; metabolism

OBJECTIVETo investigate the protective effect of progesterone against high intraocular pressure-induced ischemia-reperfusion (IR) injury.

METHODSTwenty-four SD rats were randomly divided into normal control, IR model, dimethyl sulfoxide (DMSO) solvent treatment group, and progesterone treatment group. In the latter 3 groups, retinal IR injury was induced by intraocular injection of saline. In the progesterone group, intraperitoneal injections of 4 mg/kg progesterone were administered 30 min before and 2 h after ischemia, and an equivalent volume of DMSO was used in the DMSO group. The content of malondialdehyde (MDA) and superoxide dismutase (SOD) activity were measured by spectrophotometer after the treatment, and the pathological changes of the retina were observed by transmission electron microscope and light microscope.

RESULTSSix hours after reperfusion, the content of MDA in the model group was significantly higher than that in the normal control group (P<0.01), but lower than that in progesterone treatment group (P<0.01); reverse changes in SOD activity was observed. In the model group, the inner nuclear layer and nerve fiber layer became thinner with obvious cellular pathologies including nuclear condensation, mitochondria vacuolization and endocytoplasmic reticulum swelling. Progesterone treatment markedly alleviated these pathologies in the inner nuclear layer and nerve fiber layer of the retina.

CONCLUSIONProgesterone offers protection of the retina against IR injury in SD rats by increasing SOD activity and decreasing MDA content in the retina.

Animals ; Dimethyl Sulfoxide ; Female ; Ischemia ; etiology ; pathology ; Male ; Malondialdehyde ; metabolism ; Ocular Hypertension ; complications ; Progesterone ; pharmacology ; Random Allocation ; Rats ; Rats, Sprague-Dawley ; Reperfusion Injury ; etiology ; prevention & control ; Retina ; metabolism ; Retinal Vessels ; physiopathology ; Superoxide Dismutase ; metabolism

BACKGROUNDCerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is a hereditary small artery disease caused by NOTCH3 gene mutation. We performed enhanced depth imaging optical coherence tomography (EDI-OCT) to evaluate the retinal vessel changes in CADASIL patients and assessed their consonance with brain magnetic resonance imaging (MRI) findings.

METHODSOf 27 genetically confirmed patients and an equal number of controls were recruited at the Peking University First Hospital from January 2015 to August 2016. All patients underwent 7T-MRI of the brain. Fazekas score, number of small infarcts and microbleeds were evaluated. All patients and controls underwent EDI-OCT to measure subfoveal choroidal thickness (SFCT), inner and outer diameters as well as arterial and venous wall thickness, and arterial venous ratio of the inner (AVRin) and outer diameters (AVRout). The relation between retinal vessel changes and Fazekas scores, numbers of small infarcts, or microbleeds was analyzed. Paired t-test was used to compare the SFCT and retinal vessel measurement data between patients and controls. Spearman's correlation was used to investigate the correlation between retinal vessel changes and MRI lesions.

RESULTSIn CADASIL patients, mean SFCT (268.37 ± 46.50 μm) and mean arterial inner diameter (93.46 ± 9.70 μm) were significantly lower than that in controls (P < 0.001,P = 0.048, respectively). Mean arterial outer diameter (131.74 ± 10.87 μm), venous inner (128.99 ± 13.62 μm) and outer diameter (164.82 ± 14.77 μm), and mean arterial (19.13 ± 1.85 μm) and venous (17.91 ± 2.76 μm) wall thickness were significantly higher than that in controls (P = 0.023,P = 0.004,P < 0.001,P < 0.001, respectively). Arterial inner diameter (rs= -0.39, P= 0.044), AVRin (rs= -0.65,P < 0.001), and AVRout (rs= -0.56, P= 0.002) showed a negative correlation with the number of small infarcts. Venous inner diameter (rs = 0.46, P= 0.016) showed a positive correlation with the number of small infarcts. Venous inner diameter (rs = 0.59, P= 0.002), outer diameter (rs = 0.47, P= 0.017), showed a positive correlation with the number of cerebral microbleeds (CMBs). AVRin (rs= -0.52, P= 0.007) and AVRout (rs= -0.40, P= 0.048) showed a negative correlation with the number of CMBs.

CONCLUSIONSMeasurement of retinal vessels using EDI-OCT correlates moderately well with MRI parameters. EDI-OCT might be a useful evaluation tool for CADASIL patients.

Adult ; Brain ; metabolism ; CADASIL ; Cerebral Infarction ; pathology ; Female ; Humans ; Leukoencephalopathies ; pathology ; Magnetic Resonance Imaging ; methods ; Male ; Middle Aged ; Mutation ; Receptor, Notch3 ; genetics ; Retinal Vessels ; metabolism ; Tomography, Optical Coherence ; methods

Hyperhomocysteinemia (Hhcy) is an independent risk factor for Alzheimer's disease (AD). Visual dysfunction is commonly found and is positively correlated with the severity of cognitive defects in AD patients. Our previous study demonstrated that Hhcy induces memory deficits with AD-like tau and amyloid-β (Aβ) pathologies in the hippocampus, and supplementation with folate and vitamin B12 (FB) prevents the Hhcy-induced AD-like pathologies in the hippocampus. Here, we investigated whether Hhcy also induces AD-like pathologies in the retina and the effects of FB. An Hhcy rat model was produced by vena caudalis injection of homocysteine for 14 days, and the effects of FB were assessed by simultaneous supplementation with FB in drinking water. We found that Hhcy induced vessel damage with Aβ and tau pathologies in the retina, while simultaneous supplementation with FB remarkably attenuated the Hhcy-induced tau hyperphosphorylation at multiple AD-related sites and Aβ accumulation in the retina. The mechanisms involved downregulation of amyloid precursor protein (APP), presenilin-1, beta-site APP-cleaving enzyme 1, and protein phosphatase-2A. Our data suggest that the retina may serve as a window for evaluating the effects of FB on hyperhomocysteinemia-induced Alzheimer-like pathologies.
Alzheimer Disease ; etiology ; metabolism ; pathology ; therapy ; Amyloid beta-Peptides ; metabolism ; Animals ; Dietary Supplements ; Disease Models, Animal ; Folic Acid ; therapeutic use ; Homocysteine ; Hyperhomocysteinemia ; complications ; metabolism ; pathology ; therapy ; Male ; Rats, Sprague-Dawley ; Retina ; metabolism ; pathology ; Retinal Vessels ; metabolism ; pathology ; Vitamin B 12 ; therapeutic use ; tau Proteins ; metabolism