Experimental eye research最新文献

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 (NaIO₃) model, which mirrors some features of AMD. C3^-/- and WT mice, both on a C57Bl/6J background, were injected intraperitoneally with 25 mg/kg NaIO₃. 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. NaIO₃ increased C3 protein levels in the neural retina but not RPE. WT but not C3^-/- mice showed NaIO₃-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.

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.

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.

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.

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.

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, χ² 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.

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.

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 with deoxyribonuclease (DNase), respectively. Lenticule DNA and glycosaminoglycan (GAG) contents, immunofluorescence staining intensity 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 contents (all P > 0.05). DNA contents 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 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.