5-Aza-2'-Deoxycytidine Ameliorates Choroidal Neovascularization by Inhibiting the Wnt/ß-Catenin Signaling Pathway.

Purpose: Choroidal neovascularization (CNV) can constitute the final pathology of many ocular diseases and result in severe vision loss. Studies have demonstrated that DNA methylation is critical in retinal development, aging, and disorders. The current work investigated the effects and underlying mechanism of 5-Aza-2'-deoxycytidine (5-aza-dC), a suppressor of DNA methylation, in the pathological progression of CNV. Methods: The DNA methylation profiles of retinal pigment epithelial (RPE)/choroidal complexes in normal and laser-induced CNV mice were assessed by Arraystar Mouse RefSeq Promoter Arrays. The CNV area and blood flow density and intensity were observed by optical coherence tomography angiography, and fluorescence leakage was examined by fundus fluorescein angiography in CNV mice with systemic administration of 5-aza-dC. The effects of 5-aza-dC on the biological functions of bEnd.3 cells were estimated by related assays. Notum gene promoter methylation was measured using bisulfite sequencing PCR. Methyltransferases and Wnt signaling-related genes were detected in animal and cell culture experiments by real-time PCR and immunoblot. Results: Methyltransferases were upregulated, but Notum (a secretion inhibitor of Wnt signaling) was downregulated in the RPE/choroidal complexes of mice with experimental CNV. Intraperitoneal injection of 5-aza-dC inactivated the Wnt pathway and ameliorated the lesion area and the intensity and density of blood flow, as well as the degree of leakage in CNV. In vitro, vascular endothelial growth factor A (VEGFA) stimulation promoted methyltransferases expression and suppressed Notum expression, consequently activating Wnt signaling, whereas exogenous 5-aza-dC reversed VEGFA-induced hyperpermeability, proliferation, migration, and tube formation in bEnd.3 cells via demethylation of Notum promoter. Conclusions: We observed that 5-aza-dC attenuates the growth of CNV by inhibiting the Wnt signaling pathway via promoter demethylation of the Wnt antagonist Notum. These findings provide a theoretical basis for methylation-based treatment with the Notum gene as a potential target for CNV treatment.

Assessment of visual function in blind mice and monkeys with subretinally implanted nanowire arrays as artificial photoreceptors.

Retinal prostheses could restore image-forming vision in conditions of photoreceptor degeneration. However, contrast sensitivity and visual acuity are often insufficient. Here we report the performance, in mice and monkeys with induced photoreceptor degeneration, of subretinally implanted gold-nanoparticle-coated titania nanowire arrays providing a spatial resolution of 77.5 µm and a temporal resolution of 3.92 Hz in ex vivo retinas (as determined by patch-clamp recording of retinal ganglion cells). In blind mice, the arrays allowed for the detection of drifting gratings and flashing objects at light-intensity thresholds of 15.70-18.09 µW mm-2, and offered visual acuities of 0.3-0.4 cycles per degree, as determined by recordings of visually evoked potentials and optomotor-response tests. In monkeys, the arrays were stable for 54 weeks, allowed for the detection of a 10-µW mm-2 beam of light (0.5° in beam angle) in visually guided saccade experiments, and induced plastic changes in the primary visual cortex, as indicated by long-term in vivo calcium imaging. Nanomaterials as artificial photoreceptors may ameliorate visual deficits in patients with photoreceptor degeneration.

Neuroprotective effects of idebenone on hydrogen peroxide-induced oxidative damage in retinal ganglion cells-5.

PURPOSE: To investigate the neuroprotective effect of idebenone against hydrogen peroxide (H2O2)-induced oxidative damage in retinal ganglion cells-5 (RGC-5 cells). METHODS: RGC-5 cells were pre-treated with various idebenone concentrations (5, 10, and 20 µM) for 12 h and were then subjected to 300 µM H2O2 for a further 12 h. Apoptosis in RGC-5 was measured by flow cytometry. The changes of mitochondrial membrane potential (MMP) were detected by JC-1 staining. Autophagy in RGC-5 cells was observed by transmission electron microscopy. Western blots were used to measure the expression of autophagy-related protein light chain 3 (LC3), Beclin-1, and the release of Cytochrome c (Cyt-c). RESULTS: Flow cytometry showed that the apoptosis rates in the normal control group, H2O2 group, and idebenone groups were 6.48 ± 0.55%, 27.3 ± 0.51%, 22.8 ± 0.52%, 15.45 ± 0.81%, and 12.59 ± 0.58%, respectively (F = 559.7, P < 0.0001). After incubation with H2O2, the number of autophagosomes increased significantly, whereas it was decreased in the idebenone groups. After incubation of RGC-5 cells with H2O2, MMP levels were significantly decreased, while idebenone could prevent the decrease in MMP levels. Compared with that in the normal control group, LC3 II/I, the expression levels of Beclin-1 and Cyt-c were increased significantly in the H2O2 group (P < 0.05). Compared with that in the H2O2 group, LC3 II/I, the expression of Beclin-1 and Cyt-c was significantly decreased in idebenone groups (P < 0.05). CONCLUSIONS: Idebenone protects RGC-5 cells against H2O2-induced oxidative damage by reducing mitochondrial damage and autophagic activity.

Development of The Chinese Version of Ultra-Low Vision Visual Functioning Questionnaire-150.

Purpose: The purpose of this study was to develop the Chinese version of Ultra-Low Vision Visual Functioning Questionnaire-150 (ULV-VFQ-150) and evaluate its psychometric function. Methods: A standardized procedure for the translation of ULV-VFQ-150 was carried out, including the forward translation, consistency check, back translation, back review, and coordination. Participants with ultra-low vision (ULV) were recruited for the questionnaire survey. Psychometric characteristics were evaluated using Rasch analysis based on Item Response Theory (IRT), and some items were revised and proofread accordingly. Results: In total, 70 out of 74 responders completed the Chinese ULV-VFQ-150, of which 10 were excluded because their vision did not meet the criterion of ULV. Therefore, 60 valid questionnaires were analyzed (valid response rate = 81.1%). The average age of eligible responders was 49.0 years (standard deviation = 16.0), with 35% female subjects (21/60). The person measures (ability) ranged from -1.7 to +4.9 logits, and the item measures (difficulty) ranged from -1.6 to +1.2 logits. The mean value of item difficulty and personnel ability were 0.00 and 0.62 logits, respectively. The reliability index was 0.87 for items and 0.99 for persons, and the overall fit is good. The items conform to unidimensionality as indicated by principal component analysis of the residuals. Conclusions: The Chinese version of ULV-VFQ-150 is a reliable questionnaire for evaluating both visual function and functional vision in people with ULV in China. Translational Relevance: The Chinese version of ULV-VFQ-150 is a new assessment of the visual function of people with ULV in China.

MicroRNA-376b-3p Suppresses Choroidal Neovascularization by Regulating Glutaminolysis in Endothelial Cells.

Purpose: Choroidal neovascularization (CNV) is a common pathological change of various ocular diseases that causes serious damage to central vision. Accumulated evidence shows that microRNAs (miRNAs) are closely related with the regulation of endothelial metabolism, which plays crucial roles in angiogenesis. Here, we investigate the molecular mechanism underlying the regulation of endothelial glutamine metabolism by miR-376b-3p in the progression of CNV. Methods: Human retinal microvascular endothelial cells (HRMECs) were transfected with control or miR-376b-3p mimics, and the expression of glutaminase 1 (GLS1), a rate-limiting enzyme in glutaminolysis, was detected by real-time PCR or Western blotting. The biological function and glutamine metabolism of transfected HRMECs were measured by related kits. Luciferase reporter assays were used to validate the CCAAT/enhancer-binding protein beta (CEBPB) was a target of miR-376b-3p. Chromatin immunoprecipitation and RNA immunoprecipitation assays were performed to verify the binding of CEBPB on the promoter region of GLS1. Fundus fluorescein angiography and immunofluorescence detected the effect of miR-376b-3p agomir on rat laser-induced CNV. Results: The expression of miR-376b-3p was decreased, whereas GLS1 expression was increased in the retinal pigment epithelial-choroidal complexes of rats with CNV. HRMECs transfected with miR-376b-3p mimic showed inhibition of CEBPB, resulting in the inactivation of GLS1 transcription and glutaminolysis. Moreover, the miR-376b-3p mimic inhibited proliferation, migration and tube formation but promoted apoptosis in HRMECs, whereas these effects counteracted by α-ketoglutarate supplementation or transfection with CEBPB overexpression plasmid. Finally, the intravitreal administration of the miR-376b-3p agomir restrained CNV formation. Conclusions: Collectively, miR-376b-3p is a suppressor of glutamine metabolism in endothelial cells that could be expected to become a therapeutic target for the treatment of CNV-related diseases.

Visual cortex encodes timing information in humans and mice.

Despite the importance of timing in our daily lives, our understanding of how the human brain mediates second-scale time perception is limited. Here, we combined intracranial stereoelectroencephalography (SEEG) recordings in epileptic patients and circuit dissection in mice to show that visual cortex (VC) encodes timing information. We first asked human participants to perform an interval-timing task and found VC to be a key timing brain area. We then conducted optogenetic experiments in mice and showed that VC plays an important role in the interval-timing behavior. We further found that VC neurons fired in a time-keeping sequential manner and exhibited increased excitability in a timed manner. Finally, we used a computational model to illustrate a self-correcting learning process that generates interval-timed activities with scalar-timing property. Our work reveals how localized oscillations in VC occurring in the seconds to deca-seconds range relate timing information from the external world to guide behavior.

Changes in retinal vascular bifurcation in eyes with myopia.

OBJECTIVE: To evaluate the effect of myopia on retinal vascular bifurcation. METHODS: A cross-sectional study that retrospectively analyzed the fundus photographs and clinical data of 493 people who participated in routine physical examinations in Huadong Sanatorium. One eye of each subject was included in the analysis. Retinal vascular bifurcation measurements were extracted by using a validated computer program. One-way ANOVA and analysis of covariance were performed to compare the measurements across high myopia, low to moderate myopia, and non-myopia groups. RESULTS: The mean age was 41.83 ± 10.43 years and 63.49% were women. The mean spherical equivalent refraction (SER) was - 4.59 ± 3.07 D. Ninety-nine (20.08%) eyes met the definition of high myopia (SER ≤ -6.0 D), along with 234 (47.46%) low to moderate myopia (-6.0 D < SER <-0.5 D), and 160 (32.45%) non-myopia (SER ≥ -0.5 D). The differences in the arteriolar branching angle, venular branching coefficient, venular asymmetry ratio, venular angular asymmetry, and venular junctional exponent among the three groups remained significant (p < 0.05) after multivariate adjustment. Pairwise comparisons showed arteriolar branching angle and venular angular asymmetry in high myopia were significantly lower than low to moderate myopia (p < 0.001, p = 0.014 respectively) and non-myopia (p = 0.007, p = 0.048 respectively). Venular asymmetry ratio and venular branching coefficient in high myopia were significantly higher than low to moderate myopia (p = 0.029, p = 0.001 respectively) and non-myopia (p = 0.041, p = 0.043 respectively). There was a significant difference in venular junctional exponent between high myopia and low to moderate myopia (p = 0.031). CONCLUSION: The vascular bifurcation differs in dependence on the myopic refractive error and a significant increase in the difference can be observed in high myopic eyes.

A Randomized, Controlled Trial of Treat-and-Extend vs. Pro Re Nata Regimen for Neovascular Age-Related Macular Degeneration.

Purpose: To compare the efficacy and safety of conbercept using a treat-and-extend (T&E) regimen vs. a pro re nata (PRN) regimen in Chinese patients with neovascular age-related macular degeneration (nAMD). Methods: This was a randomized, multicenter, non-inferiority study. After an initial loading phase of three consecutive monthly intravitreal injections of 0.5 mg Conbercept, the patients were treated to PRN or T&E regimen. The prespecified retreatment criteria was defined as a more than 5-letter decrease in BCVA from the previous visit or any evidence of new retinal hemorrhages, or the presence of any IRF and any SRF of more than 200 µm in height at the sub-foveal center. The primary outcome was the mean change in best-corrected visual acuity (BCVA) from baseline to 24 months, with a prespecified non-inferiority limit of -5 letters. Results: From July 2016 through August 2018, 141 participants were allocated and treated (T&E, n = 69; PRN, n = 72). About one fifth of the overall participants were dropped out during the 12-month follow-up (28/141, 19.9%), and about one thirds of the overall participants were lost during the 24-month follow-up (51/141, 36%). At 2 years, mean BCVA letter improvement was + 4.0 in the T&E group vs. + 5.1 in the PRN group, and T&E regimen was not non-inferior to PRN regimen [difference, -1.169 letters; 95% confidence interval (CI): -6.864 ∼ 4.526]. Subgroup analyses also demonstrate the similar results in PCV patients, naive patients and no-naive patients. The mean decrease in central subfield thickness were 180 ± 165 µm in the T&E group and 247 ± 230 µm in the PRN group, respectively. The patients in the PRN group had required significantly fewer injections than those in the T&E group (12.4 vs. 14.6 injections, P = 0.041). The types and rates of adverse events were comparable in the two treatment groups. Conclusion: These findings suggest that the T&E regimen was not non-inferior to the PRN regimen in patients with nAMD in terms of BCVA outcomes through 24 months. Clinical Trial Registration: ClinicalTrials.gov, identifier NCT02802657.

Case Report: A Case of Cystoid Macular Edema in Retinitis Pigmentosa With Central Retinal Vein Occlusion.

Significance: Cystoid macular edema (CME) is a common complication of retinitis pigmentosa (RP). However, CME in RP with central retinal vein occlusion (CRVO) is rare. Prompt administration of anti-vascular endothelial growth factor (anti-VEGF) medication can achieve a satisfactory prognosis. Purpose: This report describes a case of using anti-VEGF medication to treat CME secondary to RP with impending or mild CRVO. Case Report: A 26-year-old female presented for blurred vision in both eyes. Best-corrected visual acuity (BCVA) was 20/50 in the right eye and finger-counting in the left eye. According to ophthalmic examinations, CME secondary to RP in the right eye and CME secondary to RP with impending or mild CRVO in her left eye can be diagnosed. Central macular thickness (CMT) was 554 µ m in the right eye and 831 µm in the left eye. Only the left eye was treated with a single intravitreal injection of anti-VEGF medication. One month later, BCVA increased to 20/200 and CMT decreased to 162 µm in the left eye. Interestingly, BCVA in the right eye also had an improvement (20/40) and intraretinal fluid decreased significantly. However, 3 months after injection, these improvements of both eyes were not maintained. Conclusion: This is the second case of RP with CRVO. Intravitreal injection of anti-VEGF medication for addressing CME secondary to RP with CRVO is an effective treatment, but it needs to be reinjected.

Yes-associated protein promotes endothelial-to-mesenchymal transition of endothelial cells in choroidal neovascularization fibrosis.

AIM: To reveal whether and how Yes-associated protein (YAP) promotes the occurrence of subretinal fibrosis in age-related macular degeneration (AMD). METHODS: Cobalt chloride (CoCl2) was used in primary human umbilical vein endothelial cells (HUVECs) to induce hypoxia in vitro. Eight-week-old male C57BL/6J mice weighing 19-25 g were used for a choroidal neovascularization (CNV) model induced by laser photocoagulation in vivo. Expression levels of YAP, phosphorylated YAP, mesenchymal markers [α smooth muscle actin (α-SMA), vimentin, and Snail], and endothelial cell markers (CD31 and zonula occludens 1) were measured by Western blotting, quantitative real-time PCR, and immunofluorescence microscopy. Small molecules YC-1 (Lificiguat, a specific inhibitor of hypoxia-inducible factor 1α), CA3 (CIL56, an inhibitor of YAP), and XMU-MP-1 (an inhibitor of Hippo kinase MST1/2, which activates YAP) were used to explore the underlying mechanism. RESULTS: CoCl2 increased expression of mesenchymal markers, decreased expression of endothelial cell markers, and enhanced the ability of primary HUVECs to proliferate and migrate. YC-1 suppressed hypoxia-induced endothelial-to-mesenchymal transition (EndMT). Moreover, hypoxia promoted total expression, inhibited phosphorylation, and enhanced the transcriptional activity of YAP. XMU-MP-1 enhanced hypoxia-induced EndMT, whereas CA3 elicited the opposite effect. Expression of YAP, α-SMA, and vimentin were upregulated in the laser-induced CNV model. However, silencing of YAP by vitreous injection of small interfering RNA targeting YAP could reverse these changes. CONCLUSION: The findings reveal a critical role of the hypoxia-inducible factor-1α (HIF-1α)/YAP signaling axis in EndMT and provide a new therapeutic target for treatment of subretinal fibrosis in AMD.

An extension of the RIGHT statement for introductions and interpretations of clinical practice guidelines: RIGHT for INT.

OBJECTIVE: The purpose of the extension of the RIGHT Statement for INTroductions and INTerpretations of Clinical Practice Guidelines (RIGHT for INT) is to promote the development of comprehensive and clear articles that introduce and interpret clinical practice guidelines. METHODS: The RIGHT for INT checklist was developed following methods recommended by the EQUATOR Network. The development process included three stages. In the first stage, a multidisciplinary team of experts was recruited by email and WeChat and further divided into three groups (a steering group, a consensus group, and a secretariat group); in the second stage, the initial items were collected by literature review and brainstorming; and in the third stage, the final items were formed through a Delphi survey and expert consultation. RESULTS: A total of 40 initial items were collected through literature review and brainstorming. A final checklist of 27 items was formed after the Delphi survey and expert consultation. The RIGHT for INT checklist contains items on the following 10 topics: title, abstract, background of guideline interpretation, background of guideline development, guideline development methodology, recommendations, strengths, and limitations, implications for local guidelines and clinical research, dissemination and implementation, and reporting quality. CONCLUSION: The RIGHT for INT checklist provides guidance for guideline interpreters on how to introduce and interpret clinical practice guidelines in a scientific and comprehensive manner.

Silencing of YAP attenuates pericyte-myofibroblast transition and subretinal fibrosis in experimental model of choroidal neovascularization.

Age-related macular degeneration (AMD) is the main reason of irreversible vision loss in the elderly. The subretinal fibrosis subsequent to choroidal neovascularization (CNV) is an important feature in the late stage of wet AMD and is considered to be one reason for incomplete response to anti-VEGF drugs. Recent studies have shown that pericyte-myofibroblast transition (PMT) is an important pathological process involving fibrotic diseases of various organs. However, the specific role and mechanism of PMT in the subretinal fibrosis of CNV have not been clarified. It has been clear that the Hippo pathway along with its downstream effector Yes-associated protein (YAP) plays an important role in both epithelial and endothelial myofibroblast development. Therefore, we speculate whether YAP participates in PMT of pericytes and promotes fibrosis of CNV. In this study, experimental CNV was induced by laser photocoagulation in C57BL/6J (B6) mice, and aberrant YAP overexpression was detected in the retinal pigment epithelial/choroid/sclera tissues of the laser-injured eyes. YAP knockdown reduced the proliferation, migration, and differentiation of human retinal microvascular pericytes in vitro. It also reduced subretinal fibrosis of laser-induced CNV in vivo. Moreover, by proteomics-based analysis of pericyte conditioned medium (PC-CM) and bioinformatic analyses, we identified that the crosstalk between Hippo/YAP and MAPK/Erk was involved in expression of filamin A in hypoxic pericytes. These findings suggest that Hippo/YAP and MAPK/Erk are linked together to mediate pericyte proliferation, migration as well as differentiation, which may embody potential implications for treatment in diseases related to CNV.

MicroRNA Expression Analysis of Mice Retinas with Oxygen-Induced Retinopathy by RNA Sequencing.

Purpose: To characterize the microRNA (miRNA) expression profiles in the retinas of mice with oxygen-induced retinopathy by RNA sequencing and to ascertain miRNAs associated with retinal neovascularization. Methods: Retina samples were obtained from 3 groups (6 retinas/group) of OIR mice and normal mice at P17. RNA was isolated from 24 retina samples and then detected on an Illumina HiSeq. Twelve retina samples were used for quantitative polymerase chain reaction to validate the RNA sequencing. Bioinformatics analyses were performed. Result: The RNA sequence showed that 565 miRNAs were detected in the retina of OIR mice and 583 miRNAs in the retina of normal control mice. A total of 553 miRNAs were expressed in both groups. Thirty-eight miRNAs showed altered expression in both groups (p ≤ 0.05). Compared with the control group, 2 miRNAs were significantly upregulated in the OIR group, while 36 miRNAs were significantly downregulated. Meanwhile, 2 candidate miRNAs (miR-181a-5p and miR-21a-5p) with significant differences in miRNA expression (p < 0.01) were selected for validation. Quantitative real-time polymerase chain reaction (qRT-PCR) was used to confirm the relative expression of the two miRNAs. Bioinformatics analyses showed that pathways involved in ischemic retinopathy (such as TGF-ß, Ras, Hippo, PI3K-Akt, VEGF, and HIF-1 signaling pathways) were enriched. Conclusions: Our study provided an overall view of miRNA profiling in the OIR retina. These miRNA profiles provide a valuable framework for the potential therapy of retinal angiogenesis.

Pharmacological Inhibition of Glutaminase 1 Attenuates Alkali-Induced Corneal Neovascularization by Modulating Macrophages.

Corneal neovascularization (CoNV) in response to chemical burns is a leading cause of vision impairment. Although glutamine metabolism plays a crucial role in macrophage polarization, its regulatory effect on macrophages involved in chemical burn-induced corneal injury is not known. Here, we elucidated the connection between the reprogramming of glutamine metabolism in macrophages and the development of alkali burn-induced CoNV. Glutaminase 1 (GLS1) expression was upregulated in the mouse corneas damaged with alkali burns and was primarily located in F4/80-positive macrophages. Treatment with a selective oral GLS1 inhibitor, CB-839 (telaglenastat), significantly decreased the distribution of polarized M2 macrophages in the alkali-injured corneas and suppressed the development of CoNV. In vitro studies further demonstrated that glutamine deprivation or CB-839 treatment inhibited the proliferation, adhesion, and M2 polarization of bone marrow-derived macrophages (BMDMs) from C57BL/6J mice. CB-839 treatment markedly attenuated the secretion of proangiogenic factors, including vascular endothelial growth factor-A (VEGF-A) and platelet-derived growth factor-BB (PDGF-BB) from interleukin-4- (IL-4-) regulated M2 macrophages. Our findings revealed that GLS1 inhibition or glutamine deprivation prevented alkali-induced CoNV by inhibiting the infiltration and M2 polarization of macrophages. This work suggests that pharmacological GLS1 inhibition is a feasible and effective treatment strategy for chemical burn-related CoNV in humans.

Image enhancement of color fundus photographs for age-related macular degeneration: the Shanghai Changfeng Study.

AIM: To develop and evaluate a new fundus image optimization software based on red, green, blue channels (RGB) for the evaluation of age-related macular degeneration (AMD) in the Chinese population. METHODS: Fundus images that were diagnosed as AMD from the Shanghai Changfeng Study database were analyzed to develop a standardized optimization procedure. Image brightness, contrast, and color balance were measured. Differences between central lesion area and normal retinal area under different image brightness, contrast, and color balance were observed. The optimal optimization parameters were determined based on the visual system to avoid image distortion. A paired-sample diagnostic test was used to evaluate the enhancement software. Fundus optical coherence tomography (OCT) was used as the gold standard. Diagnostic performances were compared between original images and optimized images using McNemar's test. RESULTS: A fundus image optimization procedure was developed using 86 fundus images of 74 subjects diagnosed with AMD. By observing gray-scale images, choroid can be best displayed in red channel and retina in green channel was found. There was limited information in blue channel. Totally 104 participants were included in the paired sample diagnostic test to assess the performance of the optimization software. After the image enhancement, sensitivity increased from 74% to 88% (P=0.008), specificity decreased slightly from 88% to 84% (P=0.500), and Youden index increased by 0.11. CONCLUSION: The standardized image optimization software increases diagnostic sensitivity and may help ophthalmologists in AMD diagnosis and screening.

Measurement of the Lid Margin Thickness in Meibomian Gland Dysfunction with Vernier Micrometer.

INTRODUCTION: To investigate the lid margin thickness (LMT) from the posterior lash line to the mucocutaneous junction at the middle position in adults with and without meibomian gland dysfunction (MGD) by vernier micrometer (VM). METHODS: This is a cross-sectional, observational study. A hundred eyes from 100 volunteers aged 20 to 79, including 56 normal participants and 44 participants with MGD, were recruited. Measurements of the LMT by VM were performed by the same person. RESULTS: The mean age of 56 normal subjects (24 males and 32 females) and 44 MGD subjects (16 males and 28 females) was 40.0 ± 13.2 years and 42.7 ± 17.1 years, respectively. There was a significant difference in the upper LMT between normal and MGD subjects (1.36 ± 0.25 vs. 1.60 ± 0.27 mm, P < 0.001), but not in the lower LMT (1.0 ± 0.23 vs. 1.10 ± 0.28 mm, P = 0.07). In both normal and MGD subjects, the upper or lower LMT was significantly positively correlated with age (P < 0.05), and the upper LMT was greater than the lower LMT (P < 0.001). In addition, the lower LMT in MGD subjects was significantly positively correlated with meibum expressibility (rs = 0.35, P = 0.02). CONCLUSIONS: The LMT was closely related to age and could be an important indicator for detecting MGD. Furthermore, we found that the upper LMT was greater than the lower LMT, and the lower LMT in MGD subjects seemed to be related to meibum expressibility.

Corrigendum: Large-Area Photoreceptor Degeneration Model in Rabbits by Photocoagulation and Oxidative Stress in the Retina.

[This corrects the article DOI: 10.3389/fnins.2021.617175.].

Large-Area Photoreceptor Degeneration Model in Rabbits by Photocoagulation and Oxidative Stress in the Retina.

Photocoagulation is used for the treatment of retinal ischemic disease. However, due to the invasive nature of photocoagulation and variety of melanin concentrations between individuals, it is challenging to avoid damaging the adjacent photoreceptors and inducing several side effects. Previous studies indicate the role of laser power, duration, and spot size on retinal lesions, but the effect of interspot distance of the laser pulses needs to be considered in panretinal photocoagulation. In this study, we examine different parameters of photocoagulation on lesions of the retina in rabbit, finding that the lesion level of the outer nuclear layer of the retina depended on the pulse duration and laser spot size, and decreasing interspot distance could completely abolish the photoreceptor layer. The degeneration of the photoreceptor by photocoagulation occurred in 24 h and was not restored afterward. We then conducted panretinal photocoagulation in rabbit and found that oxidative stress was decreased in the inner nuclear layer of the retina, and pupillary light reflex and ERG signals were impaired. Our study could provide a rabbit model to explore the mechanism of photoreceptor degeneration and therapies for the side effects after photocoagulation.

YAP promotes ocular neovascularization by modifying PFKFB3-driven endothelial glycolysis.

Ocular neovascularization is the leading cause of vision impairment in a variety of ocular diseases, such as age-related macular degeneration and retinopathy of prematurity. Emerging studies have suggested that the yes-associated protein (YAP), a downstream effector of the Hippo pathway, is involved in the pathological angiogenesis, but the mechanism are largely unknown. Here, we demonstrated that hypoxic treatment triggered YAP expression and nuclear translocation in human umbilical vein endothelial cells (HUVECs). YAP acted as a transcriptional co-activator working together with transcriptional enhancer activator domain 1 (TEAD1) to binds the promoter of the key glycolytic regulator 6-phosphofructo-2-kinase/fructose-2,6-biphosphatase3 (PFKFB3), and thereby increases PFKFB3 expression. Moreover, silencing of YAP inhibited glycolysis as well as proliferation, migration, sprouting and tube formation of HUVECs under hypoxia, all of which could be reversed by enforced expression of PFKFB3. Finally, our animal study also showed that intravitreal injection of small interfering RNA of YAP or PFKFB3 dramatically suppressed the neovascular growth in mouse models of choroidal neovascularization and oxygen-induced retinopathy. These findings provide new insights into a previously unrecognized effect of YAP on endothelial glycolysis and highlight the potential of targeting YAP/PFKFB3 axis in the treatment of ocular neovascularization.

CXCR7 Inhibits Fibrosis via Wnt/ß-Catenin Pathways during the Process of Angiogenesis in Human Umbilical Vein Endothelial Cells.

Although SDF-1/CXCR7 plays an important role in angiogenesis, the function and the pathway of the SDF-1/CXCR7 axis might depend on the cell type or tissue origin and not fully understood. In this study, we investigated the effect of CXCR7 in SDF-1-induced proliferation, migration, apoptosis, tube formation, and endothelial-to-mesenchymal transition (EndMT) of human umbilical vein endothelial cells (HUVECs), and the potential pathway of SDF-1/CXCR7. We confirmed that the silencing of CXCR7 inhibited the proliferation of HUVECs and contributed the apoptosis, while overexpressed CXCR7 increased SDF-1-induced HUVECs migration and tube formation. However, upregulated CXCR7 inhibited the expression of α-SMA, suggesting that CXCR7 might attenuate EndMT. In addition, overexpressed CXCR7 activated AKT and ERK signaling pathways but suppressed Wnt/ß-catenin pathways in HUVECs. The inhibition of Wnt/ß-catenin pathways decreased the expression of α-SMA. Altogether, these results suggest that CXCR7 might inhibit fibrosis via Wnt/ß-catenin pathways during the process of angiogenesis.