EXPERIMENTAL EYE RESEARCH

Monochromatic light effects on refractive error, cone cell density and retinoic acid signaling in dorsal and ventral retina in guinea pigs
Zou L, Fang C, Liu H, Liu R and Dai J
Cone cells have been found to influence refractive states. This study investigated whether cone cells and retinal acid (RA) plays a role in refractive states under monochromatic lights. Guinea pigs were exposed to blue (BL), green (GL), or white light (WL), respectively, for 8 weeks. Refractive error (RE), cone cell density, RA, retinoic acid receptor-β (RAR-β), collagen-I expression, and scleral thickness in dorsal and ventral eyes were assessed. Eyes exposed to BL showed a slower shift from hyperopia to emmetropia, particularly in the ventral retina, where higher S-cone density was linked to greater remaining hyperopia. In contrast, GL exposure led to myopic shifts, notably in the dorsal retina, where increased M-cone density was associated with greater reductions in refractive error. BL exposure resulted in similar decreases in RA and retinoic acid receptor-β (RAR-β) expression in both dorsal and ventral regions, along with elevated scleral collagen-I and thicker sclera. In contrast, GL exposure increased RA and RAR-β levels, while reducing scleral collagen-I and thickness. GL-associated changes in RAR-β expression and scleral thinning were more pronounced in the dorsal retina compared to the ventral retina, despite similar RA levels in both regions. These findings suggested that RA may not contribute to the hyperopic shifts with increased S-cone cell density in BL. However, increased RA and RAR-β may be correlated with ocular growth in guinea pigs exposed to GL, it may underlie myopic shifts with increased M-cone cell density.
Association of a COL1A1 Gene Haplotype with Pathologic Myopia in a Northern Chinese Han Population
An G, Zhang M, Gao W, Yang F, Li L, Xu Y, Jin X and Du L
To investigate the relationship between COL1A1 variations and the susceptibility to pathologic myopia (PM) among the general population in Northern China, we included 525 PM patients and 1105 non-myopic controls. All PM patients underwent comprehensive ophthalmologic examinations. DNA was extracted from peripheral venous blood samples and genotyped using the MassArray System. Statistical analyses, including Hardy-Weinberg equilibrium, χ test, and linkage disequilibrium analysis, were conducted to compare the genotypic and allelic distributions of SNPs between PM patients and controls. The results showed no significant differences in the genotypic and allelic distributions of rs2075555, rs2269336, and rs1107946 between the PM and control groups. However, haplotype analysis revealed that the G-G-C and T-C-A haplotypes are risk factors for PM (G-G-C: OR = 1.399, 95% CI = 1.206-1.623, P < 0.001, Pc < 0.001; T-C-A: OR = 1.248, 95% CI = 1.064-1.456, P = 0.007, Pc = 0.021). Although individual SNPs in COL1A1 were not significantly associated with PM, specific haplotypes (G-G-C and T-C-A) were identified as risk factors. This suggests a potential role of COL1A1 in the development of PM.
Deferiprone protects photoreceptors by inhibiting ferroptosis after experimental retinal detachment
Ye Z, Yan Y, Jin F, Jiang J, Deng C, Wang L and Dong K
The detachment of the retinal neuroepithelium from the retinal pigment epithelium (RPE), often due to a retinal tear and subsequent subretinal fluid (SRF) accumulation, is a critical factor leading to photoreceptor cells (PR) death and permanent vision impairment in retinal detachment (RD) scenarios. Predicting postoperative visual recovery is challenging, even with surgical reattachment. Research has indicated that increased iron and transferrin (TF) saturation in the vitreous fluid (VF) correlates with poorer visual outcomes, suggesting a potential role for ferroptosis, a form of regulated cell death, in PR following RD. To explore this hypothesis, we analyzed the VF of RD patients for ferroptosis markers, revealing reduced levels of glutathione peroxidase 4 (GPX4), glutathione (GSH), and reduced nicotinamide adenine dinucleotide phosphate (NADPH), alongside elevated levels of Long-chain acyl-CoA synthetase 4(ACSL4), malondialdehyde (MDA), and ferrous iron. We then developed a mouse model to simulate RD and administered the iron chelator deferiprone (DFP) as a treatment. Our findings indicated that DFP mitigated ferroptosis in the retina, thereby preserving retinal architecture and function. Collectively, our study establishes the occurrence of ferroptosis in RD and demonstrates the therapeutic potential of DFP in protecting PR and treating RD.
Blood integrin and cytokine producing T cells are associated with stage and genetic risk score in age-related macular degeneration
Rijken R, Pameijer EM, Gerritsen B, Hiddingh S, Stehouwer M, de Boer JH, Imhof SM, van Leeuwen R and Kuiper JJ
Age-related macular degeneration (AMD) remains a leading cause of vision loss in the geriatric population. There are age-related changes in peripheral blood leukocyte composition, but their significance for AMD remains unclear. We aimed to determine changes in immune cell populations in blood of AMD patients. A standardized 31 parameter flow cytometry analysis was conducted on peripheral blood mononuclear cells from 59 patients with early and advanced AMD and 39 controls without AMD older than 65 years. Fundus photography and optical coherence tomography were used to classify disease stages and a custom genotype array was used to compute an AMD genetic risk score based on 52 AMD disease risk variants (GRS-52). A generalized linear regression model corrected for age, sex, and smoking status revealed that AMD patients showed decreased frequencies of CD4-positive T helper cell population expressing Integrin Alpha E (CD103) (Padj = 0.019). We further noted that early AMD was characterized by increased interleukin-4 (IL-4)-producing CD4+ T helper cells (Padj = 0.013; <0.001), as well as IL-4-producing cytotoxic CD8+ T cells (Padj = 0.016; <0.001). Reclassification of samples based on the GRS-52 revealed that IL-17-producing T cells decreased incrementally across GRS-52 categories. In AMD, alterations in peripheral blood leukocyte populations are associated with genetic risk score and disease stage and include specifically IL-4 and IL-17A cytokine-producing and CD103 integrin expressing T cell populations.
Assessment of Protein Profile ın Vitreous Samples of Patients with Epiretinal Membrane by Proteomic Approaches
Sumer F, Ozkan B, Karabas VL, Akpinar G and Kasap M
This study aims to characterize idiopathic epiretinal membrane (iERM) using proteomic analysis to enhance diagnosis and treatment strategies. In a prospective case-control clinical trial, vitreous fluids (VF) from twelve iERM patients were collected during surgery and analyzed by 2DE-based MALDI TOF-TOF MS/MS. PANTHER and STRING analyses were performed to investigate the biological relationships between the identified proteins and to determine relevant cellular pathways. A total of 148 proteins were identified, including 24 that were unique to iERM. Grouping the proteins by biological processes revealed that most were involved in cell adhesion (n = 6), proteolysis (n = 10), and complement activation (n = 8). Compared to control VF, 12 proteins were upregulated and 12 downregulated in iERM VF, with the differentially expressed proteins strongly associated with inflammation. Proteomic analysis highlighted complement and inflammatory proteins as potential biomarkers or therapeutic targets for iERM. Given that inflammation and fibrosis play critical roles in iERM, further investigation into these differential proteins holds significant clinical relevance. Despite the challenge of recruiting suitable patients, we believe the results of this study provide a valuable foundation for future research.
A Novel Three-dimensional Method for Detailed Analysis of RGC Central Projections under Acute Ocular Hypertension
Lu W, Wang Y, Hu W, Lin X, Tong X, Tian Y, Chen Y, Wang Y, Xiao Y, Yang H, Feng Y and Sun X
Normal perception of visual information relies not only on the quantity and quality of retinal ganglion cells (RGCs), but also on the integrity of the visual pathway, within which RGC central projection predominates. However, the exact changes of RGC central projection under particular pathological conditions remain to be elucidated. Here, we report a whole-brain clearing method modified from iDISCO for 3D visualization of RGC central projection. The CTB-labeled RGC central projection was visualized three-dimensionally with minimized both fluorescence quenching and the time taken. For observation of RGC axonal degeneration pattern under pathological conditions, we took acute ocular hypertension (AOH) as an example. Mice were intracamerally irrigated, and fluorescent signal in brain subregions where RGC axons projected to were quantified. The novel methodology is well-applied for rapid clearing and observation of RGC central projection in C57BL/6J, showing damaged RGC central projection on the AOH side and the most statistically significant degeneration in the superior colliculi (SC). Detailed analysis also revealed a distinct injury pattern among lateral geniculate nuclei (LGN) subregions, with the parvocellular part of the pregeniculate nuclei (PrGPC) being more vulnerable compared with the magnocellular part (PrGMC). The intracranial retrograde labeling of RGC subgroups based on brain damage variation showed PrGPC-projecting RGCs (Plgn RGC) being smaller than PrGMC-projecting RGCs (Mlgn RGC) in size and less in number, yet more vulnerable in terms of degeneration under AOH. Our data revealed the methodology for visualizing selective neuronal vulnerability under AOH, and in the meantime provided novel approach for future mechanisms exploration regarding RGC degeneration.
Role of semaphorin7A in epithelial-mesenchymal transition and proliferative vitreoretinopathy
Song S, Yang R, Su Y and Wang F
Proliferative vitreoretinopathy (PVR) is a multifactorial ocular condition characterized by the development of fibrotic membranes inside the vitreous cavity and on the detached retina, which can result in severe blindness. Semaphorin7A (Sema7a) is involved in axon growth, inflammatory responses, and immune regulation; however, its role in PVR and regulatory mechanisms in retinal pigment epithelium (RPE) cells remains unclear. This study aimed to examine Sema7a in PVR and the underlying mechanisms. Transcriptome sequencing was used to investigate the changes in mRNA expression profiles. Western blotting, immunofluorescence, and real-time polymerase chain reaction (RT-PCR) were utilized to investigate the potential mechanism of Sema7a on epithelial-mesenchymal transition (EMT) in RPE cells. Stimulating RPE cells with transforming growth factor beta-1 (TGF-β1) decreased the levels of epithelial markers but increased those of mesenchymal markers. Based on transcriptome sequencing, many molecules associated with PVR progression were regulated. PVR vitreous fluid proteomics data analysis showed that Sema7a significantly changed at different levels. Silencing Sema7a in RPE cells attenuated TGF-β1-induced EMT and their ability to induce experimental PVR; in contrast, recombinant Sema7a (rSema7a) directly triggered EMT in RPE cells. TGF-β1 induction mechanically activated the PI3k-AKT and MAPK pathways, while Sema7a knockdown by short interfering RNA lowered the phosphorylation of the PI3k-AKT/MAPK signaling pathway. Therefore, Sema7a may be a viable therapeutic target for PVR due to its crucial role in the TGF-β1-induced EMT of RPE cells.
Pigment epithelium-derived factor exerts neuroprotection in oxygen-induced retinopathy by targeting endoplasmic reticulum stress and oxidative stress
Wang Y, Gao S, Gao S, Li N, Huang H, Liu X, Yao H and Shen X
Endoplasmic reticulum (ER) stress and oxidative stress have been involved in the occurrence of neuronal apoptosis in ischemic retinopathy. Pigment epitheliu-derived factor (PEDF) is well known for its multifunctional properties, including neuroprotection, anti-inflammation and antioxidant. However, the association between PEDF and ER stress or oxidative stress in ischemic retinopathy remain incompletely understood. In this study, the concentration of the key factor of ER stress C/EBP homologous protein (CHOP) in aqueous humor (AqH) and vitreous samples of proliferative diabetic retinopathy (PDR) patients were measured by ELISA assays. Oxygen-induced retinopathy (OIR) mice model was established and PEDF intravitreal injections were conducted. Primary bone marrow derived macrophages (BMDMs) were isolated and cultured under hypoxic conditions in vitro. Western blotting, real-time RT-PCR, immunofluorescence, transmission electron microscopy (TEM), TUNEL assays were performed to explore roles of PEDF on ER stress and oxidative stress, as well as subsequently neuronal apoptosis under hypoxic conditions in vivo and in vitro. The results revealed that ER stress and oxidative stress were notably activated under hypoxic conditions. We also observed that hypoxia evoked ultrastructural damage of ER and mitochondrion in the retina. However, PEDF significantly prevented ER stress and oxidative stress, as well as the damage of ultrastructure, resulting in diminution of photoreceptor apoptosis in OIR retinas. These results indicate that PEDF may play its neuroprotection role through inhibiting ER stress and oxidative stress in ischemic retinopathy, which is a novel molecular mechanism of PEDF protecting photoreceptors from ischemic damage, thereby suggesting that PEDF is an effective therapeutic agent for the treatment of neuron damage in ischemic retinal diseases.
Conditioned media from Dental Pulp Stem Cells to counteract Age-Related Macular Degeneration
G C, D Z, F P, L L, S DM, V M and R M
Age-related macular degeneration (AMD) is the leading cause of blindness in the elderly. To date, there are no effective therapies to counteract AMD towards the most severe stages characterised by a progressive loss of photoreceptors triggered by retinal pigmented epithelium dysfunction. Given their easy source and their high proliferative potential, Dental Pulp Stem Cells (DPSCs) are considered promising for regenerative medicine. The main advantage of DPSCs is related to their paracrine immunosuppressive and immunoregulatory abilities, including the capability to promote regeneration of damaged tissues. Recent studies demonstrated the therapeutic potential of DPSCs-conditioned media (CM) in neurodegenerative diseases. In addition, we have already shown a differential expression of some growth factors and cytokines in CM derived from DPSCs cultured in hypoxia and normoxia conditions.
A modified calculation formula for meibomian gland grading
Liu Y, Ren Y, Li W, Liu W and Ke M
This study aimed to establish a modified calculation formula for the grading of meibomian glands. Meibography images from 102 participants by different examiners on separate machines on two consecutive days were analyzed, quantified and compared side-by-side. Measure and calculate the ratio of the MGs area to the whole eyelid area and the ratio of the MGs to the corneal base area. Our findings demonstrate that there were significant differences in the ratio of the meibomian gland area to the whole eyelid area between two measurements, but not in the ratio of the meibomian gland area to the corneal base area. The measurement of the eyelid area showed bigger variations and poorer repeatability than the meibomian gland area and the corneal base area. As such, the ratio of the meibomian gland area to the corneal base area is a more stable indicator for the grading of meibomian glands over multiple measurement.
Macromolecular crowding agent dependent extracellular matrix deposition and growth factor retention in human corneal fibroblast cultures
Gurdal M and Zeugolis DI
The major obstacle in the commercialisation and clinical translation of tissue engineered medicines is the required for the development of implantable tissue surrogates prolonged in vitro culture. Macromolecular crowding (MMC) enhances and accelerates extracellular matrix (ECM) deposition, thus offering an opportunity to bridge the gap between research and development in tissue engineered substitutes. However, the optimal MMC agent is still elusive. Herein, we first assessed the biophysical properties of the most widely used MMC agents [κλ carrageenan (κλ CR), λ carrageenan (λ CR) and Ficoll™ cocktail (FC)] and then assessed their effect in basic cell function, ECM deposition and growth factor retention in human corneal fibroblast (hCF) cultures. Dynamic light scattering analysis revealed that both CR macromolecules had significantly lower and higher zeta potential and hydrodynamic radius, respectively, than the FC. None of the MMC agents affected hCF morphology and all induced similar hCF viability, proliferation and metabolic activity. Electrophoresis and immunofluorescence analyses made apparent that at day 10 (longest time point assessed), the FC brought about the highest fibronectin and collagen types I, III, IV, V and VI deposition. Deposited ECM pattern analysis showed that at day 10, the FC induced the lowest lacunarity and normalised end points and the highest fractal dimension and % high density matrix. Further immunofluorescence analysis revealed no significant differences between the groups in vimentin, aldehyde dehydrogenase 3 family member A1, keratocan, paired box protein 6 and α-smooth muscle actin. Importantly, at day 10, the FC resulted in the highest growth factor retention (20 molecules). Our data clearly illustrate a MMC agent dependent cell response, with the FC having the highest positive effect in hCF cultures.
The Effect of Immobilisation Strategies on the Ability of Peptoids to Reduce the Adhesion of P. aeruginosa strains to Contact Lenses
Sara M, Chakraborty S, Chen R, Palms D, Katsifis G, Li Z, Farajikhah S, Massedupally V, Hui A, Wong EHH, Kumar N, Vasilev K, Mackenzie D, Losurdo L, Dehghani F, Jenssen H, Sorensen K, Lin JS, Barron AE and Willcox M
Previous studies have demonstrated that contact lenses coated with the antimicrobial cationic peptide Mel4, a derivative of melimine, can reduce the occurrence of keratitis. However, the antimicrobial activity of Mel4 weakened over time due to its susceptibility to proteolytic degradation. Oligo-N-substituted glycine peptoids such as TM5 and TM18 possess antimicrobial properties and are resistant to proteolytic breakdown. This study focused on exploring methods for covalently attaching these peptoids to contact lenses to enhance their durability and performance in vitro.
Topical application of 666-15, a potent inhibitor of CREB, alleviates alkali-induced corneal neovascularization
Li Z, Chen J, Huang Z, Huang W, Wang K, Liang X and Su W
Corneal neovascularization (CNV) is a dynamically regulated process that arises due to a disruption in the equilibrium between pro-angiogenic and anti-angiogenic factors. Various cytokines are released by vascular endothelial cells and macrophages in damaged cornea, ultimately inducing CNV. The cAMP-response element-binding protein (CREB), a nuclear transcription factor, potentially impacts tumor angiogenesis by modulating the secretion of angiogenic proteins. This study aimed to assess the impact of 666-15, a potent inhibitor of CREB, on angiogenesis using human microvascular retinal endothelial cells (HMRECs), RAW 264.7 macrophage cell line and alkali-induce CNV mouse model. In vivo, the topical application of 666-15 (0.05 mg/mL) to the alkali-burn corneas led to 45% reduction in CNV. Additionally, in vitro treatment with 666-15 is effective in suppressing the migration, proliferation, and tube formation by HMRECs. Furthermore, treatment with 666-15 resulted in a down-regulation of pro-angiogenic cytokines expression, including VEGF-A, TGF-β1, b-FGF, and MMP-2 but simultaneously increasing anti-angiogenic cytokines expression, such as ADAMTS-1, Thrombospondin-1 (Tsp-1) and Tsp-2, both in alkali-burn corneas and HMRECs. And 666-15 inhibited the recruitment and the cytokines expression (VEGF-A, MMP-2, IL-1β, TNF-α, MCP-1 and MIP-1) of macrophage. Our findings revealed that 666-15 may suppress the function of endothelial cells and angiogenesis by restoring the homeostasis of pro-angiogenic stimuli, suggesting its potential as a therapeutic agent in the treatment of CNV and other angiogenesis-driven diseases.
Endomucin regulates the endothelial cytoskeleton independently of VEGF
Moon J, Chaudhary S, Rodriguez-Martinez L, Hu Z and D'Amore PA
The endothelial glycocalyx, lining the apical surface of the endothelium, is involved in a host of vascular processes. The glycocalyx is comprised of a network of membrane-bound proteoglycans and glycoproteins along with associated plasma proteins. One such glycoprotein is endomucin (EMCN), which our lab has revealed is a modulator of VEGFR2 function. Intravitreal injection of siEMCN into the eyes of P5 mice impairs vascular development. In vitro silencing of EMCN suppresses VEGF-induced proliferation and migration. Signaling pathways that drive cell migration converge on cytoskeletal remodeling. By coupling co-immunoprecipitation with liquid chromatography/mass spectrometry, we identified interactions between EMCN and proteins associated with actin cytoskeleton organization. The aim of the study was to investigate the influence of EMCN on cytoskeleton dynamics in angiogenesis. EMCN depletion resulted in reduction of F-actin levels, whereas overexpression of EMCN induced increased membrane protrusions in cells that were rich in stress fibers. The reorganization of the actin filaments did not depend on VEGFR2 signaling, suggesting that EMCN connects the cytoskeleton and the glycocalyx.
Complement C3 knockout protects photoreceptors in the sodium iodate model
Wang T, Song Y, Bell BA, Anderson BD, Lee TT, Yu W and Dunaief JL
Complement factor 3 (C3) has emerged as a primary therapeutic target in age-related macular degeneration (AMD) supported by genetic, histologic, and clinical trial evidence. Yet, the site(s) of action are unclear. The purpose of this study was to test the effect of C3 knockout on photoreceptors and retinal pigment epithelial cells (RPE) in the sodium iodate (NaIO) model, which mirrors some features of AMD. C3 and WT mice, both on a C57Bl/6J background, were injected intraperitoneally with 25 mg/kg NaIO. Electroretinography and optical coherence tomography were performed 7 days later to assess retinal function and structure, respectively. Then, mice were euthanized for retinal immunohistochemistry, quantitative real-time PCR and enzyme-linked immunosorbent assays. NaIO increased C3 protein levels in the neural retina but not RPE. WT but not C3 mice showed NaIO-induced iC3b deposition on photoreceptor outer segments. C3 mice were partially protected against photoreceptor layer thinning. There was partial preservation of rod and cone function in the C3 group. Neither RPE structure nor function was protected. These results suggest outer segment opsonization contributes to photoreceptor death in this model, and that targeting C3 can protect photoreceptor structure and function when RPE cells are stressed.
Comparative study of physicochemical properties on corneal stromal lenticules following four decellularization methods
Sun B, Zhang Z, Yu Y, Xia F, Ma Y, Ding X, Han X, Wang T, Zhou X and Zhao J
This study compares the physicochemical properties of corneal stromal lenticules following decellularization via four methods. Human corneal stromal lenticules, derived from small incision lenticule extraction surgery, underwent decellularization with sodium dodecyl sulfate (SDS), Triton X-100 (Tx) combined with SDS, trypsin-ethylenediaminetetraacetic acid (TE), or NaCl combined with deoxyribonuclease (DNase), respectively. Lenticule DNA and glycosaminoglycan (GAG) content, immunofluorescence staining of cell nuclei and collagen, transparency, biomechanics, histological structure, and immunogenicity were examined in each group and compared with fresh lenticules. All decellularized groups exhibited effective cell removal, with no significant decrease in GAG content (all P > 0.05). DNA content decreased in all decellularization groups (all P < 0.01), most notably in the SDS and Tx + SDS groups. Additionally, collagen I and IV fluorescence intensity was reduced in the TE group only (P < 0.0001). Histological staining revealed close similarity in collagen arrangement between the Tx + SDS group and fresh lenticules. Collagen fiber density increased while spacing and diameter decreased in all decellularized groups (all P < 0.05), with partial collagen degradation detected in the TE group. Light transmittance remained above 60% in the visible light spectrum in all groups. The Young's modulus or elastic modulus did not decrease significantly among decellularized lenticules (all P > 0.05). Human leukocyte antigen (HLA)-DR, HLA-ABC, and CD45 expression decreased in the Tx + SDS and NaCl + DNase groups (all P < 0.001). Although all four decellularization methods showed varying decellularization efficacy, Tx + SDS effectively removed cells without damaging corneal morphology, extracellular matrix, or biomechanics, indicating its potential for lenticule storage, transplantation, and bio-scaffold fabrication.
SN promote retinal pathological neovascularization through activation of EGFR, IR and IGF-1R
Deng W, Huang K, Cui L, Niu Z, Ke D, Jiang L, Tang N, Zhong H, Lan Q, Xu F and Tang F
Secretoneurin (SN) is a neuropeptide derived from secretogranin II (SgII), mainly are involved in neuroendocrine system. The present study is aimed to investigate the role of SN in retinal pathological neovascularization and physiological vasculature. In the study, we found the overexpression of SgII in retina of Oxygen-Induced Retinopathy (OIR) mouse model, and SgII knockdown could alleviate pathological retinal neovascularization in OIR. Conversely, SgII knockdown have no detectable effect in embryonic physiological vasculature. Experiments in vitro and in vivo further verified SN's angiogenic effect on the eye. In further, we identified that SN promoted angiogenesis via activation of Epidermal Growth Factor Receptor (EGFR), Insulin Receptor (IR), and Insulin-like Growth Factor 1 Receptor (IGF-1R), and followed by the phosphorylation of PI3K-AKT-mTOR signaling. In summarize, our study suggests that SN might be a postnatal angiogenic factor, which was critically involved in retinal pathological neovascularization, but not in embryonic retinal physiological vasculature. Moreover, we identified the receptors and the downstream signaling involved in SN induced retinal angiogenesis.
Role of angiopoietin-like 4 in neovascularization associated with retinopathy of prematurity
Lu X, Fan Z, Yang S, Zheng L, Yu Z, Yang Y, Zheng M, Zeng J and Zhang G
To elucidate the mechanisms of angiopoietin-like 4 (ANGTPL4) in neovascularization (NV) in retinopathy of prematurity (ROP). We compared ANGPTL4 expression levels of aqueous humour and vitreous fluid samples in infants with acute-phase ROP and control group. ANGPTL4 mice and WT mice were used to constructed oxygen-induced retinopathy (OIR) mouse models, with retinal tissues collected on postnatal days 12 (P12), 15 (P15) and 17 (P17). Analysis of retinal vessels and transcriptomics were performed to explore the role of ANGTPL4 in NV. The results showed ANGPTL4 level was significantly higher in the aqueous humour and vitreous fluid of children with ROP than that of control group. At P15 and P17, the vascular indices in the ANGPTL4-CON group were lower than those in the WT-CON group. The central non-perfused area of the retina and number of neovascular nuclei were also smaller in the ANGPTL4-OIR group than in the WT-OIR group. Immunofluorescence results showed the overexpression of ANGPTL4 protein in the WT-OIR group than in the WT-CON group, especially at P17. Furthermore, extracellular matrix (ECM) organisation was one of the key involved pathways based on gene ontology (GO) enrichment analyses. ANGPTL4 was one of the core genes involved in ECM organization, and neuralized E3 ubiquitin protein ligase 1B (NEURL1B), cd36 Molecule (CD36), matrix metallopeptidase 3 (MMP3) and collagen type III alpha 1 chain (COL3A1) were the first nodes interacting with ANGPTL4.In conclusion, ANGPTL4 is involved in the pathological NV by regulating NEURL1B, CD36, MMP3, and COL3A1. Thus, ANGPTL4 is a potential therapeutic target for ROP.
Human embryonic stem cell-derived immunity-and-matrix-regulatory cells on collagen scaffold effectively treat rat corneal alkali burn
Lin H, Guo B, Li Z, Wang C, Wu W, Lu Z, Wang L, Wu J, Li J, Hao J and Feng Y
Corneal alkali burns (CAB) are a severe form of ocular injury that often leads to significant vision loss, with limited effective treatment options available beyond corneal transplantation. Immunity and matrix-regulatory cells (IMRCs) have emerged as a promising alternative due to their ability to modulate immune responses and support tissue repair. This study investigates the efficacy of IMRCs on collagen scaffolds (IMRCs-col) for treating CAB in a rat model. We developed a novel treatment combining IMRCs with a collagen scaffold to align with the ocular surface structure. In vitro analyses showed that IMRCs-col significantly upregulated the expression of immune regulatory molecules, including IL-1RA and SCF. Additionally, IMRCs-col effectively inhibited the production of pro-inflammatory cytokines (IL-8 and Gro-a/CXCL1) while promoting pro-regenerative cytokines (bFGF, HGF, and PDGF). In an animal model of CAB, IMRCs-col transplantation demonstrated substantial efficacy in restoring corneal opacity and reducing neovascularization. Histological examination revealed reduced inflammation and improved corneal tissue regeneration compared to untreated CAB. Enhanced activation of pathways associated with anti-inflammatory responses and tissue repair was observed at days 3, 7, and 21 post-treatment.
Comprehensive landscape of RNA N6-methyladenosine modification in lens epithelial cells from normal and diabetic cataract
Zhang X, Dou S and Huang Y
To gain more insight into the mechanism of cataract formation from the perspective of epigenetics in the diabetic population, lens epithelium from diabetic cataract patients and health individuals were collected separately and analyzed for N6-methyladenosine (mA)-modified RNA using methylated RNA immunoprecipitation sequencing (MeRIP-Seq). Subsequently, differential expression analysis was performed on mA-regulated messenger RNA (mRNA), circular RNA (circRNA), and long non-coding RNA (lncRNA), followed by functional annotation using the Gene Ontology (GO) database. Furthermore, analysis of single-cell data of lens complemented the intrinsic association and cellular heterogeneity of cataract and mA regulators. In this study, both the global expression levels and peak intensity of mA-tagged RNAs were increased in patients with diabetic cataract. And we noted multiple core enzymes were upregulated in the diabetic cataract (DC) samples. Besides, single-cell RNA sequencing analysis of the lens revealed the heterogeneous expression of RNA mA regulators across different cell types, and we noted that the early fiber cell cluster was also closely associated with the onset of cataract and mA modification. The results comprehensively revealed the dynamic modification landscape of mA on mRNA, circRNA, and lncRNA, which might provide valuable resources for future studies of the pathogenesis of DCs.
Tetramethylpyrazine inhibits keratitis and neovascularization induced by corneal alkali burn by suppressing the TLR4/NF-κB pathway activation and NLRP1/NLRP3 inflammasomes in rats
Jiang T, Wang CY and Chen Y
The role and related mechanisms of tetramethylpyrazine (TMP) in corneal alkali burn in rats were expected to be explored in this article. After construction of corneal alkali burn rat models, TMP eye drops were given four times daily for consecutive 7 days. H&E staining was utilized for observing the histopathological changes of corneas on the 3rd and 7th days of treatment; immunohistochemistry for detecting the Nestin protein expression changes; qRT-PCR for determining the expression changes of genes correlated with neovascularization [C-X-C Motif Chemokine Ligand 1 (CXCL-1), vascular endothelial growth factor A (VEGFA) and CD31] and inflammation-related factors [monocyte chemoattractant protein-1 (MCP-1), interleukin-1β (IL-1β), tumour necrosis factor α (TNF-α), and IL-6]; Western blot for testing NLR Family Pyrin Domain Containing 1 (NLRP1)/NLRP3 inflammasomes and toll-like receptor 4 (TLR4)/nuclear factor kappa-B (NF-κB) pathway-related protein expression changes. All above trials were completed based on rat corneal tissue. TMP ameliorated the pathological damage in alkali-burned rat corneal tissue. Specifically, TMP treatment decreased Nestin-positive cell expression and the CXCL-1, VEGFA and CD31 mRNA expression in alkali-burned rat corneal tissue dose-dependently. TMP also down-regulated the IL-1β, TNF-α, MCP-1 and IL-6 mRNA expression and inhibited the NLRP1, caspase-1, NLRP3, pro-IL-1β and mature IL-1β protein expression in the alkali-burned rat corneal tissue. In addition, TMP treatment down-regulated the myeloid differentiation factor 88 (MyD88) and TLR4 protein expression and decreased the p-NF-κB p65/NF-κB p65 ratio in the alkali-burned rat corneal tissue. The mechanism of TMP relieving the inflammatory response and inhibiting neovascularization caused by corneal alkali burn in rats might have a correlation with the suppression of acitivation of TLR4/NF-κB pathway and NLRP1/NLRP3 inflammasomes in rats.