Macrophage activation contributes to diabetic retinopathy.

Diabetic retinopathy (DR) is recognized as a neurovascular complication of diabetes, and emerging evidence underscores the pivotal role of inflammation in its pathophysiology. Macrophage activation is increasingly acknowledged as a key contributor to the onset and progression of DR. Different populations of macrophages originating from distinct sources contribute to DR-associated inflammation. Retinal macrophages can be broadly categorized into two main groups based on their origin: intrinsic macrophages situated within the retina and vitreoretinal interface and macrophages derived from infiltrating monocytes. The former comprises microglia (MG), perivascular macrophages, and macrophage-like hyalocytes. Retinal MG, as the principal population of tissue-resident population of mononuclear phagocytes, exhibits high heterogeneity and plasticity while serving as a crucial connector between retinal capillaries and synapses. This makes MG actively involved in the pathological processes across various stages of DR. Activated hyalocytes also contribute to the pathological progression of advanced DR. Additionally, recruited monocytes, displaying rapid turnover in circulation, augment the population of retinal macrophages during DR pathogenesis, exerting pathogenic or protective effect based on different subtypes. In this review, we examine novel perspectives on macrophage biology based on recent studies elucidating the diversity of macrophage identity and function, as well as the mechanisms influencing macrophage behavior. These insights may pave the way for innovative therapeutic strategies in the management of DR.

Fetuin-B Overexpression Promotes Inflammation in Diabetic Retinopathy Through Activating Microglia and the NF-κB Signaling Pathway.

PURPOSE: To investigate the expression, source, role, and mechanism of Fetuin-B (FETUB) in diabetic retinopathy (DR). METHODS: ELISA and immunofluorescence were used to analyze the concentration of FETUB in plasma, aqueous fluid, and tissue specimens of patients with DR and healthy controls. Immunofluorescence, q-PCR, and western blotting were used to examine the expression of FETUB in DR mice and cells cultured with different concentrations of glucose. BV2 microglia cell line and DR mice were treated using FETUB recombination protein and FETUB shRNA to explore the function of FETUB in DR by q-PCR, western blotting, and immunofluorescence. RESULTS: FETUB concentrations in plasma, aqueous fluid, and tissue specimens were significantly increased in DR patients. The mice in DR group had a higher concentration of FETUB in the retina and liver tissues than those in the control group, and the expression of FETUB was increased in both ARPE19 and BV2 cells under a high-glucose environment. The ratio of p-P65 (Phospho-P65)/P65 and the expression levels of TNF-α, VEGF, and ionized calcium binding adaptor molecule (IBA)-1 were increased in BV2 cells cultured with FETUB recombinant protein, while they were decreased in BV2 cells transfected with FETUB shRNA. Immunofluorescence staining showed that there were more IBA-1+ activated microglia in the retinas of the FETUB recombination protein group than in the retinas of the DR group, and there were fewer IBA-1+ activated microglia in the retinas of the FETUB shRNA group than in the retinas of the DR group. CONCLUSIONS: FETUB sourced from endocrine, autocrine, and paracrine pathways could promote inflammation in DR by activating the NF-κB pathway and microglia.

Panretinal photocoagulation plus intravitreal conbercept for diabetic retinopathy in real world: a retrospective study.

BACKGROUND: To evaluate outcomes of panretinal photocoagulation (PRP) plus intravitreal conbercept (IVC) for diabetic retinopathy (DR) in real world and explore risk factors for patients with poor reactivity and presence of vision-threatening complications after combination treatment. METHODS: Retrospective review of DR patients received PRP plus IVC over 6 months. The main outcome was improvement ≥ 2 steps in ETDRS diabetic retinopathy severity scale (DRSS) levels. Different strategies for eyes receiving IVC within or over 1 month after PRP were analyzed. For patients with DRSS improvement < 2 steps and presence of vision-threatening adverse events, a binary logistic regression method was used to select risk factors. RESULTS: Sixty one eyes were involved in this study. After treated with combination therapy with a median number of 3 injections, 44% of eyes improved ≥ 2 steps in DRSS levels. A total of 14 eyes (23%) occurred vision-threatening adverse events. No significant difference was found in eyes receiving conbercept within or over 1 month after PRP. Duration of diabetes (OR 0.849, 95%CI 0.734-0.982, P = 0.027), GFR (OR 0.961, 95%CI 0.933-0.990, P = 0.010) and baseline DRSS levels (OR 3.290, 95%CI 1.483-7.295, P = 0.003) were independent risk factors for DRSS improvement < 2 steps after treatment. Occurrence of vision-threatening complications was only related to high DRSS levels (OR 3.668, 95%CI 1.710-7.868, P = 0.001). CONCLUSIONS: The combination therapy was effective for most patients with DR in real world. Eyes received PRP combined with earlier or later conbercept was demonstrated no significant difference for outcomes. For patients with poor renal function, high DRSS levels or occurred DR at the early stage of diabetes, follow-up should be strengthened.

Aerobic capacity and [Formula: see text] kinetics adaptive responses to short-term high-intensity interval training and detraining in untrained females.

PURPOSE: This study investigated the physical fitness and oxygen uptake kinetics (τ[Formula: see text]) along with the O2 delivery and utilization (heart rate kinetics, τHR; deoxyhemoglobin/[Formula: see text] ratio, ∆[HHb]/[Formula: see text]) adaptations of untrained female participants responding to 4 weeks of high-intensity interval training (HIIT) and 2 weeks of detraining. METHODS: Participants were randomly assigned to HIIT (n = 11, 4 × 4 protocol) or nonexercising control (n = 9) groups. Exercising group engaged 4 weeks of treadmill HIIT followed by 2 weeks of detraining while maintaining daily activity level. Ramp-incremental (RI) tests and step-transitions to moderate-intensity exercise were performed. Aerobic capacity and performance (maximal oxygen uptake, [Formula: see text]; gas-exchange threshold, GET; power output, PO), body composition (skeletal muscle mass, SMM; body fat percentage, BF%), muscle oxygenation status (∆[HHb]), [Formula: see text], and HR kinetics were assessed. RESULTS: HIIT elicited improvements in aerobic capacity ([Formula: see text], + 0.17 ± 0.04 L/min; GET, + 0.18 ± 0.05 L/min, P < 0.01; PO-[Formula: see text], ± 23.36 ± 8.37 W; PO-GET, + 17.18 ± 3.07 W, P < 0.05), body composition (SMM, + 0.92 ± 0.17 kg; BF%, - 3.08% ± 0.58%, P < 0.001), and speed up the τ[Formula: see text] (- 8.04 ± 1.57 s, P < 0.001) significantly, extending to better ∆[HHb]/[Formula: see text] ratio (1.18 ± 0.08 to 1.05 ± 0.14). After a period of detraining, the adaptation in body composition and aerobic capacity, as well as the accelerated τ[Formula: see text] were maintained in the HIIT group, but the PO-[Formula: see text] and PO-GET declined below the post-training level (P < 0.05), whereas no changes were reported in controls (P > 0.05). Four weeks of HIIT induced widespread physiological adaptations in females, and the majority of improvements were preserved after 2 weeks of detraining except for power output corresponding to [Formula: see text] and GET.

Adaptations to 4 weeks of high-intensity interval training in healthy adults with different training backgrounds.

PURPOSE: This study investigated the physical fitness and oxygen uptake kinetics ([Formula: see text]) along with the exercise-onset O2 delivery (heart rate kinetics, τHR; changes in normalized deoxyhemoglobin/[Formula: see text] ratio, Δ[HHb]/[Formula: see text]) adaptations of individuals with different physical activity (PA) backgrounds responding to 4 weeks of high-intensity interval training (HIIT), and the possible effects of skeletal muscle mass (SMM) on training-induced adaptations. METHODS: Twenty subjects (10 high-PA level, HIIT-H; 10 moderate-PA level, HIIT-M) engaged in 4 weeks of treadmill HIIT. Ramp-incremental (RI) test and step-transitions to moderate-intensity exercise were performed. Cardiorespiratory fitness, body composition, muscle oxygenation status, VO2 and HR kinetics were assessed at baseline and post-training. RESULTS: HIIT improved fitness status for HIIT-H ([Formula: see text], + 0.26 ± 0.07 L/min; SMM, + 0.66 ± 0.70 kg; body fat, - 1.52 ± 1.93 kg; [Formula: see text], - 7.11 ± 1.05 s, p < 0.05) and HIIT-M ([Formula: see text], 0.24 ± 0.07 L/min, SMM, + 0.58 ± 0.61 kg; body fat, - 1.64 ± 1.37 kg; [Formula: see text], - 5.48 ± 1.05 s, p < 0.05) except for visceral fat area (p = 0.293) without between-group differences (p > 0.05). Oxygenated and deoxygenated hemoglobin amplitude during the RI test increased for both groups (p < 0.05) except for total hemoglobin (p = 0.179). The Δ[HHb]/[Formula: see text] overshoot was attenuated for both groups (p < 0.05) but only eliminated in HIIT-H (1.05 ± 0.14 to 0.92 ± 0.11), and no change was observed in τHR (p = 0.144). Linear mixed-effect models presented positive effects of SMM on absolute [Formula: see text] (p < 0.001) and ΔHHb (p = 0.034). CONCLUSION: Four weeks of HIIT promoted positive adaptations in physical fitness and [Formula: see text] kinetics, with the peripheral adaptations attributing to the observed improvements. The training effects are similar between groups suggesting that HIIT is effective for reaching higher physical fitness levels.

Inhibitory effect on subretinal fibrosis by anti-placental growth factor treatment in a laser-induced choroidal neovascularization model in mice.

AIM: To investigate whether anti-placental growth factor (PGF) can inhibit subretinal fibrosis and whether this effect is mediated by the inhibitory effect of PGF on epithelial-mesenchymal transition (EMT) of retinal pigment epithelial (RPE) cells. METHODS: Subretinal fibrosis model was established in laser induced choroidal neovascularization (CNV) mice on day 21 after laser photocoagulation. Immunofluorescence staining (IFS) of cryosections and enzyme-linked immunosorbent assay (ELISA) were used to detect the expression of PGF. IFS of whole choroidal flat-mounts was used to detect the degree of subretinal fibrosis. IFS of cryosections and ELISA were used to detect the expression of EMT related indicators in subretinal fibrosis lesions. RESULTS: The expression of PGF protein in subretinal fibrosis lesions was significantly up-regulated (P<0.05), and mainly co-stained with pan-cytokeratin labeled RPE cells. Intravitreal injection of anti-PGF neutralizing antibody reduced the area of subretinal fibrosis and the ratio of fibrotic/angiogenic area significantly at the concentrations of 0.25, 0.5, 1.0, and 2.0 µg/µL (all P<0.05). The expression of E-cadherin in the local RPE cells decreased, while α-SMA increased significantly in subretinal fibrosis lesions, and the application of anti-PGF neutralizing antibody could reverse these changes (P<0.05). CONCLUSION: The expression of PGF is up-regulated in the lesion site of subretinal fibrosis and mainly expressed in RPE cells. Intravitreal injection of anti-PGF neutralizing antibody can significantly inhibit the degree of subretinal fibrosis in CNV mice, and this effect may be mediated by the inhibition of PGF on EMT of RPE cells.

[Autofluorescence combined with spectral domain optical coherence tomography for diagnosis and follow-up of acute Vogt-Koyanagi-Harada disease].

OBJECTIVE: To evaluate the value of fundus autofluorescence (FAF) imaging combined with spectral domain optical coherence tomography (SD-OCT) in diagnosis, prognostic assessment and follow-up observation of acute Vogt-KoyanagiHarada (VKH) disease. METHODS: Clinical data were collected from 12 patients (23 eyes) with acute VKH disease treated in our hospital from May, 2018 to November, 2019, including detailed medical history, best corrected visual acuity (BCVA), and results of slit lamp biomicroscopy, fundus photography, SD-OCT, fundus fluorescein angiography (FFA) and FAF imaging.SDOCT and FAF imaging were repeated after a course of treatment and in follow-up examination, and the results were compared with those at the time of admission. RESULTS: VKH disease involved both eyes in 11 patients (91.7%).Fundus photography showed optic disc edema in 16 eyes (69.6%), and multiple retinal neuroepithelial detachment was detected by SD-OCT in all the involved eyes (100%).IN all the eyes, FFA revealed small and dense fluorescein leakage in the early stage and fluorescein accumulation in advanced stages of VHK disease to form multiple dye pooling in the areas of serous detachment.Hyperauto fluorescence was a common finding in FAF imaging (100%), and the area involved was consistent with that of fluorescein accumulation shown by FAF imaging.Ten eyes (43.5%) showed patches of relative hypoautofluorescence in the hyperauto fl uorescence areas, and granular hyperauto fl uorescence was found in the lesions in 4 eyes (17.4%).During the remission period of VKH disease, FAF imaging showed normal finding in 8 eyes (34.8%) and reduced areas (by 55.2%) and intensity (by 46.5%) of hyperautofluorescence in 9 eyes (39.1%).In 6 eyes (26.1%), only a few hyperautofluorescent spots scattered in the macula were observed.SD-OCT demonstrated significantly reduced (by 69.5% on average) or even disappearance of subretinal fluid in the eyes.The fluorescence intensity in FAF imaging showed a significant positive correlation with the volume of subretinal fluid detected by SD-OCT (r=0.626, P < 0.05). CONCLUSIONS: The combination of fluorescein angiography, FAF imaging and SD-OCT can significantly improve the diagnostic accuracy of VKH disease.FAF imaging combined with SD-OCT provides an effective and noninvasive modality for evaluation of remission and monitoring the changes in VKH disease.

Placental growth factor promotes epithelial-mesenchymal transition-like changes in ARPE-19 cells under hypoxia.

Purpose: To investigate the role of placental growth factor (PGF) in the epithelial-mesenchymal transition (EMT) of ARPE-19 cells under hypoxia, and whether the NF-κB signaling pathway is involved in this process. Methods: ARPE-19 cells were treated in five groups: a control group, hypoxia group, PGF group, hypoxia+PGF group, and NF-κB-blocked group. A chemical hypoxia model was established in the ARPE-19 cells by adding CoCl2 to the culture medium. The morphological changes after treatment were observed. The proliferation rates were measured with 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay. The migration abilities were measured with scratch assay. The EMT biomarkers were measured with quantitative real-time PCR (qRT-PCR), western blotting, and immunofluorescence. The relative protein expression of components of the NF-κB signaling pathway was measured with western blotting and immunofluorescence. Results: Cells treated with PGF under hypoxia exhibited morphological changes consistent with the transition from an epithelial to a mesenchymal phenotype. In the ARPE-19 cells, exogenous PGF under hypoxia increased the proliferation rate compared to the rate under hypoxia alone (p<0.05) and increased the migration rate (p<0.05). Treatment of hypoxia-exposed cells with PGF caused decreased expression of the epithelial biomarkers E-cadherin and ZO-1 (both p<0.05) and increased expression of the mesenchymal marker α-SMA (p<0.05) by enhancing the phosphorylation of NF-κB p65 of the total protein, promoting the translocation of p65 to the nucleus, and inducing the degradation of IκB-α (a negative regulator of the NF-κB pathway) in the ARPE-19 cells. Additionally, the effect of PGF-induced EMT in the ARPE-19 cells under hypoxia was counteracted with BAY 11-7082 (a selective NF-κB inhibitor). Conclusions: Exogenous PGF promotes EMT-like changes in ARPE-19 cells under hypoxia by activating the NF-κB signaling pathway. The study results suggest that PGF may play a role in scar formation in neovascular age-related macular degeneration (AMD) and that the inhibition of PGF may be a promising target for the prevention and treatment of AMD.

Comparison of efficacy between coaxial microincision and standard-incision phacoemulsification in patients with age-related cataracts: a meta-analysis.

BACKGROUND: Incision size plays a critical role in the efficacy of cataract surgery, but the available evidence on ideal incision size is inconsistent. In this study, we conducted a meta-analysis to evaluate the efficacy of coaxial microincisional phacoemulsification surgery (MICS) compared with that of standard-incision phacoemulsification surgery (SICS) in patients with age-related cataracts. METHODS: The Cochrane Library (Wiley Online Library), PubMed, Medline, National Knowledge Infrastructure (CNKI), and VIP databases were searched to identify reports of clinical randomized controlled trials (RCTs) comparing MICS to SICS for the treatment of age-related cataracts. The outcomes of interest included surgically induced astigmatism (SIA), effective phacoemulsification time (EPT), central corneal thickness (CCT), endothelial cell count (ECC), endothelial cell count loss (ECC Loss %), and average ultrasonic energy (AVE). RESULTS: Eleven RCT studies were included in this meta-analysis. No statistically significant differences were observed in EPT (Z = 1.29, P > 0.05), CCT (1 day: Z = 1.37, P > 0.05; 7 days: Z = 0.75, P > 0.05; 30 days: Z = 0.38, P > 0.05; 90 days: Z = 0.29, P > 0.05), ECC (7 days: Z = 1.13, P > 0.05; 30 days: Z = 1.42, P > 0.05) or ECC Loss % (7 days: Z = 0.24, P > 0.05; 30 days: Z = 0.06, P > 0.05; 90 days: Z = 0.10, P > 0.05) between MICS and SICS. However, statistically significant differences were found in AVE (Z = 4.19, P < 0.0001) and SIA (1 day: Z = 10.33, P < 0.00001; 7 days: Z = 10.71, P < 0.00001; 30 days: Z = 10.95, P < 0.00001; 90 days: Z = 2.21,- P < 0.01) between MICS and SICS. CONCLUSION: Compared with SICS, MICS can reduce short-term and long-term SIA, but it does not differ in safety outcomes or in the time required for surgery.

Panretinal photocoagulation versus panretinal photocoagulation plus intravitreal bevacizumab for high-risk proliferative diabetic retinopathy.

AIM: To evaluate the effects of panretinal photocoagulation (PRP) compared with PRP plus intravitreal bevacizumab (IVB) in patients with high-risk proliferative diabetic retinopathy (PDR) according to the Early Treatment Diabetic Retinopathy Study criteria. METHODS: The data were collected retrospectively from the eyes of high-risk PDR patients, which were divided into two groups. After treated with standard PRP, the eyes were randomly assigned to receive only PRP (PRP group) or PRP plus intravitreal injection of 1.25 mg of bevacizumab (PRP-Plus group). Patients underwent complete ophthalmic evaluation, including best corrected visual acuity (BCVA), intraocular pressure (IOP), and new vessel size in fluorescein angiography (FA) and optical coherence tomography for the assessment of central subfield macular thickness (CSMT) at baseline and at weeks 12 (±2), 16 (±2), 24 (±2) and 48 (±2). Main outcome measures also included vitreous clear-up time and neovascularization on the disc (NVD) regression time. Adverse events associated with intravitreal injection were investigated. RESULTS: Thirty consecutive patients (n=36 eyes) completed the 48-week follow-up. There was no significant difference between the PRP and PRP-Plus groups with respect to age, gender, type or duration of diabetes, area of fluorescein leakage from active neovascularizations (NVs), BCVA or CSMT at baseline. The mean vitreous clear-up time was 12.1±3.4wk after PRP and 8.4±3.5wk after PRP combined with IVB. The mean time interval from treatment to complete NVD regression on FA examination was 15.2±3.5wk in PRP group and 12.5±3.1wk in PRP-Plus group. No significant difference in CSMT was observed between the groups throughout the study period. However, the total area of actively leaking NVs was significantly reduced in the PRP-Plus group compared with the PRP group (P<0.05). Patients received an average of 1.3 injections (range: 1-2). Ten eyes (27.8%) underwent 2 injections. Two eyes had ocular complication of PDR progression to dense vitreous hemorrhage (VH). No major adverse events were identified. CONCLUSION: The adjunctive use of IVB with PRP is associated with a greater reduction in the area of active leaking NVs than PRP alone in patients with high-risk PDR. Short-term results suggest combined IVB and PRP achieved rapid clearance of VH and regression of retinal NV in the treatment of high-risk PDR. Further studies are needed to determine the effect of repeated intravitreal bevacizumab injections and the proper number of bevacizumab injections as an adjuvant.

[Sensitivity and specificity of optical coherence tomography in diagnosing polypoidal choroidal vasculopathy].

OBJECTIVE: To establish the diagnostic criteria for polypoidal choroidal vasculopathy (PCV) based on spectral-domain optical coherence tomography (SD OCT) by evaluating the sensitivity and specificity of SD OCT in differentiating PCV from wet age-related macular degeneration (wAMD). METHODS: The clinical data were reviewed for 62 patients (63 eyes) with the initial diagnosis of PCV or wAMD between August, 2012 and June, 2016. Twenty-four patients (25 eyes) were diagnosed to have PCV and 38 (38 eyes) had wAMD based on findings by fundus photography, fluorescein angiography (FFA) and indocyanine green angiography (ICGA). Among the 6 features of SD OCT, namely a sharp RPED peak, double-layer sign, multiple RPED, an RPED notch, a hyporeflective lumen representing polyps, and hyperreflective intraretinal hard exudates, findings of the first two features and at least one of the other features sufficed the diagnosis of PCV; in the absence of the first two features, the diagnosis of PCV was also made when at least 3 of the other features were present simultaneously. The sensitivity and specificity of SD OCT-based diagnosis were estimated by comparison with the gold standard ICGA-based diagnosis. RESULTS: In the 25 eyes with an established diagnosis of PCV, 23 eyes (92.0%) met the diagnostic criteria based on SD OCT findings; in the 38 eyes with the diagnosis of wAMD, only 4 eyes (10.5%) met the criteria. The sensitivity and specificity of SD OCT-based diagnosis of PCV was 92.0% and 89.5%, respectively. CONCLUSION: s We established the diagnostic criteria for PCV based on SD OCT findings with a high sensitivity and specificity. SD OCT shows a strong capacity for differentiating PCV from wAMD.

Vitamin C inhibit the proliferation, migration and epithelial-mesenchymal-transition of lens epithelial cells by destabilizing HIF-1α.

Posterior capsular opacification (PCO), the main complication of cataract surgery, is mainly caused by the proliferation, migration, and epithelial-mesenchymal transition (EMT) of the residual lens epithelial cells (LECs).Vitamin C was reported to reduce the risk of forming a cataract. However, there has been no study showing the association between vitamin C and PCO. In this study, we found that vitamin C could inhibit the migration and proliferation of human lens epithelial cells. We also found that vitamin C could increase the proline hydroxylation of HIF-1α and reduce the activity of HIF-1α. Moreover, vitamin C could not inhibit the activity of proline-mutant HIF-1α (402/564). Overexpression of wild-type HIF-1α or proline-mutant HIF-1α was found to increase the proliferation and migration of human lens epithelial cells. Differently, vitamin C could inhibit the proliferation and migration in wild-type HIF-1α-overexpressing lens epithelial cells but not the proline-mutant HIF-1α-overexpressing cells. Additionally, vitamin C was also found to inhibit the expression of EMT transcription factors TWIST. We then found that vitamin C could repress the EMT phenotypes induced by the overexpression of wild-type HIF-1α but not the proline-mutant HIF-1α. These results provide evidence that vitamin C plays a role in the repression of proliferation, migration, and EMT of human lens epithelial cells by destabilizing HIF-1α.

Placental growth factor expression is reversed by antivascular endothelial growth factor therapy under hypoxic conditions.

BACKGROUND: Clinical trials have revealed that the antivascular endothelial growth factor (VEGF) therapies are effective in retinopathy of prematurity (ROP). But the low level of VEGF was necessary as a survival signal in healthy conditions, and endogenous placental growth factor (PIGF) is redundant for development. The purpose of this study was to elucidate the PIGF expression under hypoxia as well as the influence of anti-VEGF therapy on PIGF. METHODS: CoCl2-induced hypoxic human umbilical vein endothelial cells (HUVECs) were used for an in vitro study, and oxygen-induced retinopathy (OIR) mice models were used for an in vivo study. The expression patterns of PIGF under hypoxic conditions and the influence of anti-VEGF therapy on PIGF were evaluated by quantitative reverse transcription-polymerase chain reaction (RTPCR). The retinal avascular areas and neovascularization (NV) areas of anti-VEGF, anti-PIGF and combination treatments were calculated. Retina PIGF concentration was evaluated by ELISA after treatment. The vasoactive effects of exogenous PIGF on HUVECs were investigated by proliferation and migration studies. RESULTS: PIGF mRNA expression was reduced by hypoxia in OIR mice, in HUVECs under hypoxia and anti-VEGF treatment. However, PIGF expression was reversed by anti-VEGF therapy in the OIR model and in HUVECs under hypoxia. Exogenous PIGF significantly inhibited HUVECs proliferation and migration under normal conditions, but it stimulated cell proliferation and migration under hypoxia. Anti-PIGF treatment was effective for neovascular tufts in OIR mice (P<0.05). CONCLUSION: The finding that PIGF expression is iatrogenically up-regulated by anti-VEGF therapy provides a consideration to combine it with anti-PIGF therapy.

[Poisoning effect of Ca depositing over Mn-Ce/TiO2 catalyst for low-temperature selective catalytic reduction of NO by NH3].

Calcium carbonate (CaCO3), calcium sulfate (CaSO4), and calcium chloride (CaCl2) were chosen as the precursors to prepare the Ca salts deposited Mn-Ce/TiO2 catalysts through an impregnation method. The influence of Ca on the performance of the Mn-Ce/TiO2 catalyst for low-temperature selective catalytic reduction of NO by NH3 was investigated. Experimental results showed that Ca salts had negative effects on the activity of Mn-Ce/TiO2 and the precursors of Ca salts also affected the catalytic activity. The precursor CaCl2 had a greater impact on the catalytic activity, while CaCO3 had minimal effect. The samples were characterized by Brunner-Emmet-Teller measurements (BET), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), and NH3temperature programmed desorption (NH3 -TPD). The characterization results indicated that the significant changes in physical and chemical properties of Mn-Ce/TiO2 were observed after Ca was deposited on the catalysts. The significant decreases in surface areas and NH,3adsorption amounts were observed after Ca was deposited on the catalysts, which could be considered as the main reasons for the deactivation of Ca deposited Mn-Ce/TiO,2

Effects of semaphorin 3A on retinal pigment epithelial cell activity.

PURPOSE: Semaphorin 3A (Sema3A), a chemorepellant guidance protein, has been shown to be crucial for neural and vascular remodeling. This study is designed to examine the effects of Sema3A on RPE cell activity both in vitro and in vivo. METHODS: Retinal pigment epithelial were incubated with Sema3A, or VEGF- and Sema3A-containing medium. Cell proliferation, migration, cell cycle, apoptosis, cocultured human umbilical vein endothelial cells tube formation, VEGF receptor 2 (VEGFR2) and neuropilin 1 (Nrp1) receptor expression, VEGF- and pigment epithelium-derived factor (PEDF) concentration, and c-Jun N-terminal kinase (JNK) and p38 mitogen-activated protein kinases (p38MAPK) signaling pathway studies were measured. A rabbit proliferative vitreoretinopathy (PVR) model was used for in vivo study. Subconfluent ARPE19 cells were injected intravitreously with or without Sema3A. Data were analyzed with Graphpad Prism 5.0 software. RESULTS: In vitro, Sema3A not only induced RPE cell cycle arrest and inhibited RPE migration under normal culture conditions, but also inhibited exogenous and endogenous VEGF165-induced cell activities. These activities included proliferation, migration, cell cycle arrest, JNK and p38MAPK signaling pathway phosphorylation, and cocultured endothelial cell tube formation. It is shown that both VEGF165 and Sema3A induced the upregulation of VEGFR2 and Nrp1 receptors. Activity inhibition was mediated by impeding VEGF165 utilization and possibly mediated by competitive inhibition of VEGF165 binding to its receptor VEGFR2, but not by the suppression of VEGF165 secretion. In vivo, Sema3A inhibited PVR, which is induced by RPE proliferation. CONCLUSIONS: These results suggested that Sema3A could be a useful therapeutic strategy for preventing RPE malfunction.

KH902, a recombinant human VEGF receptor fusion protein, reduced the level of placental growth factor in alkali burn induced-corneal neovascularization.

AIMS: To investigate the expression of placental growth factor (PIGF) in alkali burn-induced murine corneal neovascularization (NV); to evaluate the effects of KH902, a vascular endothelial growth factor receptor decoy, on prevention and regression of new vessels growths in the cornea; and to determine the influence of KH902 on the levels of vascular endothelial growth factor (VEGF) and PIGF in alkali burn-induced corneal NV. METHODS: Mouse corneal NV was induced by alkali burn. The expression of PIGF was detected by immunohistochemistry and reverse-transcription polymerase chain reaction (RT-PCR). To evaluate the effects of KH902, corneal NV was observed and photographed every 3 days for a total of 28 days after the alkali burn. The percentage of NV area was measured and compared with that of the control group. The VEGF and PIGF levels in the cornea were evaluated by enzyme linked immunosorbent assay (ELISA). RESULTS: PIGF was expressed during the alkali burn-induced corneal neovascularization. On day 3 (D3), day 6 (D6) and day 9 (D9) after chemical cauterization, the length of the longest new vessel and the neovascularization areas in the KH902-treated groups were significantly smaller than those of the PBS-treated group (p < 0.05). The areas of established corneal NV of the KH902-treated groups regressed with time, but the control groups showed no natural regression. The VEGF and PIGF levels of the cornea in the treated groups were significantly decreased compared to those of the control group (p < 0.05). CONCLUSIONS: PIGF may be involved in alkali burn-induced corneal NV. KH902 significantly inhibited new vessel growth and promoted the regression of established vessels in a mouse model of corneal NV, and it also reduced the levels of VEGF and PIGF in the cornea.

Anti-angiogenic effect of KH902 on retinal neovascularization.

PURPOSE: KH902 is a fusion protein derived from the extracellular domains of vascular endothelial growth factor (VEGF) receptors 1 and 2 and the Fc portion of immunoglobulin G1 (IgG1). Retinopathy of prematurity (ROP) is an eye disease that affects premature babies who have received intensive neonatal care, and the disorganization of retinal blood vessels may result in scarring and retinal detachment. This study was designed to examine the inhibitory effects of KH902 on mice with oxygen-induced retinopathy (OIR), one of the animal models of ROP. METHODS: Human umbilical vein endothelial cells (HUVECs) were used for an in vitro study, and the C57BL/6 J OIR mouse model was used for an in vivo study. HUVECs were incubated with KH902 or a VEGF- and KH902-containing medium. Cell proliferation, migration, apoptosis, and tube formation were measured with BrdU incorporation, Transwell, flow cytometry, and Matrigel assays. C57BL/6 J mice were exposed to 75 % oxygen from postnatal day 7 (P7) to P12, after which the mice were brought to room air and intravitreously injected with KH902. At P18, the mice were perfused with fluorescein isothiocyanate (FITC)-dextran and Evans Blue, and flat-mounted retinas were used to measure the non-perfused and leakage areas. The data were analyzed with GraphPad Prism 5.0 software. RESULTS: In vitro, KH902 dose-dependently inhibited HUVEC proliferation in general culture medium and in VEGF165-containing medium at different time points. Moreover, KH902 inhibited HUVEC migration and tube formation and induced HUVEC apoptosis. In vivo, an intravitreous injection of KH902 reduced the retinal non-perfused area from 34 % in the control group to 19 % in the treatment group and significantly reduced the retinal leakage area from 18 % to 9 %. CONCLUSION: KH902 had marked inhibitory effects on angiogenesis both in vitro and in vivo. These data suggest that KH902 could serve as an innovative pharmaceutical agent to prevent retinal neovascularization (NV) and as a strategy for the treatment of ROP.

Antiangiogenesis effects of endostatin in retinal neovascularization.

PURPOSE: Pathological retinal angiogenesis is a major cause of vision loss. Endostatin is a natural antiangiogenesis antitumor protein that is widely used in cancer studies. In this study, we investigated the efficacy and potential mechanisms of endostatin for the prevention of retinal neovascularization both in vitro and in vivo. METHODS: Human umbilical vein endothelial cells (HUVECs) were used for the in vitro studies. HUVECs were incubated with endostatin or the vascular endothelial growth factor (VEGF) and endostatin for different time points. Cell proliferation, migration, cell cycling, and tube formation studies were carried out using a Cell Counting Kit-8 assay, a Transwell assay, flow cytometry, and a Matrigel assay, respectively. Enzyme-Linked Immunosorbent Assay (ELISA) was used to study VEGF and pigment epithelial-derived factor (PEDF) protein secretion from the HUVECs at different time points. A murine oxygen-induced retinopathy (OIR) model was used for the in vivo studies. Seven-day-old C57BL/6J pups (p7) were exposed to 75% oxygen for 5 days. On p12, the animals were returned to a normal atmosphere and were immediately injected intravitreously with 1.5 µL of a 5 mg/mL endostatin solution. At p18, the mice were perfused with fluorescein-dextran-FITC, and their retinas were flat mounted to measure the nonperfused area. Retinal VEGF and PEDF levels were also measured by ELISA Kits in the OIR mice at p18. RESULTS: In vitro, endostatin inhibited HUVEC proliferation in a dose-dependent manner and also inhibited HUVEC proliferation in a VEGF-containing medium. Additionally, endostatin can inhibit migration, tube formation, and VEGF secretion in HUVECs, while also inducing apoptosis in HUVECs at several time points. These effects were statistically significant when compared to the control group (P<0.05). In vivo, a single intravitreous injection of endostatin reduced the retinal nonperfused area from 30% in the control group to 23% in the treatment group (P<0.0001). Intravitrous injection of endostatin reduced VEGF levels in retinas, while it increased PEDF levels. CONCLUSIONS: Endostatin showed convincing inhibitory effects on angiogenesis both in vitro and in vivo. The inhibitory effects may be, at least partly, resulted from the restoration of the PEDF/VEGF ratio. These data suggest that endostatin could offer an innovative pharmaceutical strategy for the prevention of retinal neovascularization.

Association between complementary factor H Y402H polymorphisms and age-related macular degeneration in Chinese: Systematic review and meta-analysis.

AIM: Age-related macular degeneration (AMD) is the leading cause of blindness in the developed world and complement factor H (CFH) polymorphism has been found to associate with the AMD. To investigate whether the Y402H variant in CFH is associated with AMD in Chinese populations, a systematic review and meta-analysis were performed to estimate the magnitude of the gene effect and the possible mode of action. METHODS: A meta-analysis was performed using data available from ten case-control studies assessing association between the CFH Y402H polymorphism and AMD in Chinese populations involving 1538 AMD. Data extraction and study quality assessment were performed in duplicate. Summary odds ratios (ORs) and 95% confidence intervals (CIs) an allele contrast and genotype contrast were estimated using fixed- effects models. The Q-statistic test was used to assess heterogeneity, and Funnel plot was used to evaluate publication bias. RESULTS: Seven of ten case-control studies were neovascular AMD, and few studies came from west and north of China. There was strong evidence for association between CFH and AMD in Chinese population, with those having risk allele C 2.35 times more likely to have AMD than subjects with T allele. Evidence of publication bias was not observed in our meta-analysis. CONCLUSION: [corrected] This meta-analysis summarizes the strong evidence for an association between CFH and AMD in Chinese and indicates each C allele increasing the odds of AMD by 2.33-fold.But more evidences about the relation between CFH polymorphism and different type of Chinese AMD from various district were needed.

Polyethylene glycol-modified pigment epithelial-derived factor: new prospects for treatment of retinal neovascularization.

Pathological retinal neovascularization and choroidal neovascularization are major causes of vision loss in a variety of clinical conditions, such as retinopathy of prematurity, age-related macular degeneration, and diabetic retinopathy. Pigment epithelial-derived factor (PEDF) has been found to be the most potent natural, endogenous inhibitor of neovascularization, but its application is restricted because of its instability and short half-life. Polyethylene glycol (PEG) has been used as a drug carrier to slow clearance rate for decades. The present study investigated PEGylated-PEDF for the first time and evaluated its long-term effects on preventing angiogenesis in vitro and in vivo. PEG showed lower cytotoxicity to human umbilical vein endothelial cells (HUVECs). In vitro, PEGylated-PEDF inhibited HUVEC proliferation, migration, tube formation, and vascular endothelium growth factor secretion and induced HUVEC apoptosis in a dose-dependent manner, and it showed a statistically significant difference compared with the PEDF treatment group. In vivo, PEGylated-PEDF had a long-lasting effect in both plasma and retinal concentrations. In an oxygen-induced retinopathy model, one intravitreous injection of PEGylated-PEDF after mouse pups were moved into room air resulted in a significant difference in the inhibition of retinal neovascularization, which decreased the nonperfusion area, compared with the PEDF-treated group. Our present study demonstrated for the first time the long-term inhibitory effects of PEGylated-PEDF on the prevention of neovascularization in vitro and in vivo. These data suggest that PEGylated-PEDF could offer an innovative therapeutic strategy for preventing retinal neovascularization.