Molecular Vision最新文献

Purpose: Diabetic macular edema (DME) is a sight-threatening complication of diabetes. Consequently, studying the proteome of DME may provide novel insights into underlying molecular mechanisms.

Methods: In this study, aqueous humor samples from eyes with treatment-naïve clinically significant DME (n = 13) and age-matched controls (n = 11) were compared with label-free liquid chromatography-tandem mass spectrometry. Additional aqueous humor samples from eyes with treatment-naïve DME (n = 15) and controls (n = 8) were obtained for validation by enzyme-linked immunosorbent assay (ELISA). Best-corrected visual acuity (BCVA) was evaluated, and the severity of DME was measured as central subfield thickness (CST) employing optical coherence tomography. Control samples were obtained before cataract surgery. Significantly changed proteins were identified using a permutation-based calculation, with a false discovery rate of 0.05. A human donor eye with DME and a control eye were used for immunofluorescence.

Results: A total of 101 proteins were differentially expressed in the DME. Regulated proteins were involved in complement activation, glycolysis, extracellular matrix interaction, and cholesterol metabolism. The highest-fold change was observed for the fibrinogen alpha chain (fold change = 17.8). Complement components C2, C5, and C8, fibronectin, and hepatocyte growth factor-like protein were increased in DME and correlated with best-corrected visual acuity (BCVA). Ceruloplasmin and complement component C8 correlated with central subfield thickness (CST). Hemopexin, plasma kallikrein, monocyte differentiation antigen CD14 (CD14), and lipopolysaccharide-binding protein (LBP) were upregulated in the DME. LBP was correlated with vascular endothelial growth factor. The increased level of LBP in DME was confirmed using ELISA. The proteins involved in desmosomal integrity, including desmocollin-1 and desmoglein-1, were downregulated in DME and correlated negatively with CST. Immunofluorescence confirmed the extravasation of fibrinogen at the retinal level in the DME.

Conclusion: Elevated levels of pro-inflammatory proteins, including the complement components LBP and CD14, were observed in DME. DME was associated with the loss of basal membrane proteins, compromised desmosomal integrity, and perturbation of glycolysis.

Purpose: To determine whether salidroside (SAL) modulates inflammatory cytokines in rat retinal Müller cells (rMC-1) in a hyperglycemic environment by investigating the anti-inflammatory mechanisms of SAL in vitro and in vivo.

Methods: A streptozotocin (STZ)-induced diabetic rat model was established to examine the effects of SAL using hematoxylin and eosin (H&E) staining and immunohistochemistry. rMC-1 cells were grown in 50 mM of high-glucose medium. These simulated diabetic conditions were used to evaluate the anti-inflammatory effects of SAL using a Cell Counting Kit-8 (CCK-8) assay, immunofluorescence staining, western blotting, and real-time polymerase chain reaction (qRT‒PCR). H&E staining was used to analyze the number of ganglion cells in the retina. rMC-1 lysates were processed for qRT‒PCR to measure the steady-state mRNA expression levels of inflammatory markers, such as interleukin 6 (IL-6), interleukin 10 (IL-10), and interleukin 1β (IL-1β). Western blot analysis and immunofluorescence staining were performed to determine the levels of these inflammatory markers.

Results: Our study showed that SAL reversed retinal ganglion cell loss and attenuated nuclear factor kappa B (NF-𝜅B) p65 translocation to the nucleus in STZ-induced diabetic rats. Incubating rMC-1 in different concentrations of SAL for 24 to 48 h affected cell viability. Furthermore, SAL treatment significantly decreased the protein levels of IL-6, TNF-α, and IL-1β compared with those in cells cultured in high glucose (HG). The mRNA expression levels of IL-6 and IL-1β were considerably reduced after SAL treatment, whereas the mRNA expression levels of IL-10 were significantly increased. Interestingly, the beneficial effects of SAL on HG-treated rMC-1 cells were abolished by the PI3K inhibitor LY294002.

Conclusions: These results indicate that SAL treatment reduces cytokine activation in cultured rMC-1. Furthermore, SAL prevents diabetic retinopathy (DR), in part, by modulating the PI3K/Akt/GSK-3β/NF-kB pathway to inhibit Müller cell activation. Thus, SAL is expected to be a potential agent for ameliorating the progression of DR.

Purpose: Acute anterior uveitis (AAU) is the most common extra-articular symptom of ankylosing spondylitis (AS). This study aims to reveal the cytokines and chemokines involved in the immunopathogenesis of human leucocyte antigen (HLA)-B27⁺ AS-associated AAU.

Methods: Twenty-one HLA-B27⁺ AS-associated AAU patients and 21 healthy controls (HCs) were recruited for this study. Serum cytokine concentrations in all 42 subjects were determined by the Meso Scale Discovery (MSD) electrochemiluminescence method. In each sample, 34 cytokines, 10 chemokines, eight angiogenesis mediators, and four vascular injury mediators were measured. The differences in cytokine and chemokine concentrations were compared between the two groups.

Results: Concentrations of serum IL-3, TNF-α, IL-6, IL-17D, IL-22, IP10/CXCL10, MIP-3α/CCL20, sFlt-1/VEGFR-1, CRP, and MCP-4/CCL13 were significantly higher in patients with HL-B27⁺ AS-associated AAU than in HCs (p < 0.05). In contrast, concentrations of serum IL-4, IL-8, MIP-1α/CCL3, Eotaxin-3/CCL26, PlGF, VEGF-C, and VEGF-D were significantly lower in patients with HL-B27⁺ AS-associated AAU than in HCs (p < 0.05).

Conclusions: Significant differences were detected in the levels of several cytokines and chemokines in the serum of HLA-B27⁺ AS-associated AAU compared with HCs. Some novel differential cytokines and chemokines that have not been reported in other kinds of uveitis were also identified. These results reveal the underlying pathogenesis of HLA-B27⁺ AS-associated AAU and could potentially aid in clinical diagnosis.

Purpose: To investigate systemic and ocular toll-like receptor (TLR)-4 expression and its association with oxidative stress markers in ocular rosacea (OR).

Methods: This prospective study included 40 patients with rosacea with ocular involvement and 20 healthy volunteers. Tear break-up time (TBUT), Schirmer test, meibomoscore, and ocular surface disease index (OSDI) scores were estimated for all participants. TLR-4 expression in conjunctival epithelium and peripheral blood mononuclear cells was quantified using real-time polymerase chain reaction (RT-PCR). In the tears and serum samples of all participants, antioxidant status (TAS), total oxidant status (TOS), and arylesterase (ARE) activation levels were measured using a fully automated spectrophotometric method, and the oxidative stress index (OSI) was calculated.

Results: TLR-4 expression levels and oxidative stress status (TOS and OSI values) were significantly higher (p < 0.01), and antioxidant status (TAS and ARE values) were significantly lower (p < 0.01) in both ocular and blood samples of patients with OR compared with those in controls. A significant positive correlation was found between the ocular and blood values in all parameters (p < 0.05). According to the clinical associations of these results, we found negative correlations between TLR-4, OSI, and TBUT and between TLR-4 and Schirmer, whereas a positive correlation was observed between TLR-4, OSI, and meiboscore and between TLR-4, OSI, and OSDI (p < 0.05). No correlation was found between the OSI and Schirmer results (p = 0.92).

Conclusions: TLR-4 and oxidative stress both play important roles in OR pathophysiology and are closely related to clinical findings.

Purpose: To describe a novel association of TGFBI variants with congenital glaucoma in a family with GAPO (growth retardation, alopecia, pseudoanodontia, and progressive optic atrophy) syndrome, as well as among other unrelated cases of juvenile onset open-angle glaucoma (JOAG) and primary congenital glaucoma (PCG).

Methods: This study of one family of GAPO with congenital glaucoma and three unrelated patients with JOAG analyzed a common link to glaucoma pathogenesis. Three girls with GAPO syndrome born to consanguineous parents in a multi-generation consanguineous family were identified. Two of the girls had congenital glaucoma in both eyes, while the elder sibling (a 10-year-old female) had features of GAPO syndrome without glaucoma.

Results: A genetic evaluation using whole exome sequencing revealed a novel homozygous ANTXR1 mutation in all three affected siblings with GAPO. No other mutations were detected in the genes associated with glaucoma. A rare missense variant in the TGFBI gene was shared in the two siblings with congenital glaucoma and GAPO syndrome. We found three other unrelated patients with JOAG and one patient with primary congenital glaucoma with no known glaucoma causing gene mutations, but having four different missense variants in the TGFBI gene. One of these patients with JOAG had familial granular corneal dystrophy. Molecular dynamic simulations of TGFBI and 3-D structural models of three of its variants showed significant alterations that could influence TGFBI protein function.

Conclusions: The possibility that variations in the TGFBI gene could have a possible role in the pathogenesis of congenital and juvenile onset open-angle glaucomas needs further evaluation.

Purpose: Inflammation and oxidative stress contribute to age-related macular degeneration (AMD) and other retinal diseases. We tested a cell-penetrating peptide from the kinase inhibitory region of an intracellular checkpoint inhibitor suppressor of cytokine signaling 3 (R9-SOCS3-KIR) peptide for its ability to blunt the inflammatory or oxidative pathways leading to AMD.

Methods: We used anaphylatoxin C5a to mimic the effect of activated complement, lipopolysaccharide (LPS), and tumor necrosis factor alpha (TNFα) to stimulate inflammation and paraquat to induce mitochondrial oxidative stress. We used a human retinal pigment epithelium (RPE) cell line (ARPE-19) as proliferating cells and a mouse macrophage cell line (J774A.1) to follow cell propagation using microscopy or cell titer assays. We evaluated inflammatory pathways by monitoring the nuclear translocation of NF-κB p65 and mitogen-activated protein kinase p38. Quantitative reverse transcription polymerase chain reaction (qRT-PCR) and Western blot were used to evaluate the induction of inflammatory markers. In differentiated ARPE-19 monolayers, we evaluated the integrity of tight junction proteins through microscopy and the measurement of transepithelial electrical resistance (TEER). We used intraperitoneal injection of sodium iodate in mice to test the ability of R9-SOC3-KIR to prevent RPE and retinal injury, as assessed by fundoscopy, optical coherence tomography, and histology.

Results: R9-SOCS3-KIR treatment suppressed C5a-induced nuclear translocation of the NF-kB activation domain p65 in undifferentiated ARPE-19 cells. TNF-mediated damage to tight junction proteins in RPE, and the loss of TEER was prevented in the presence of R9-SOCS3-KIR. Treatment with the R9-SOCS3-KIR peptide blocked the C5a-induced expression of inflammatory genes. The R9-SOCS3-KIR treatment also blocked the LPS-induced expression of interleukin-6, MCP1, cyclooxygenase 2, and interleukin-1 beta. R9-SOCS3-KIR prevented paraquat-mediated cell death and enhanced the levels of antioxidant effectors. Daily eye drop treatment with R9-SOCS3-KIR protected against retinal injury caused by i.p. administration of sodium iodate.

Conclusions: R9-SOCS3-KIR blocks the induction of inflammatory signaling in cell culture and reduces retinal damage in a widely used RPE/retinal oxidative injury model. As this peptide can be administered through corneal instillation, this treatment may offer a convenient way to slow down the progression of ocular diseases arising from inflammation and chronic oxidative stress.

Purpose: Corneal alkali burns can progress to corneal epithelial defects, inflammation, scarring, and angiogenesis, potentially leading to blindness. Therefore, we examined the therapeutic effects of a novel ophthalmic solution (ZK002) on wound healing in alkali-burned rat corneas.

Methods: In this study, we attempted to treat alkali-exposed rat corneas using topical application of either an ophthalmic solution with ZK002 or an anti-vascular endothelial growth factor agent for 14 days. We evaluated corneal edema, corneal neovascularization area, and histological changes. We also assessed the inflammatory (MMP-9, MMP-2, and interleukin-1β) and angiogenic (vascular endothelial growth factor receptor 2, VEGFR2) markers. Levels of inflammatory (matrix metalloproteinase (MMP)-9, MMP-2, and interleukin-1β), profibrotic (α-smooth muscle actin, α-SMA; transforming growth factor-β2,TGF-β2), and angiogenic (vascular endothelial growth factor-receptor 2, VEGFR2) factors, as well as peroxisome proliferator-activated receptor γ (PPARγ) mRNA expression, were measured.

Results: The analyses showed that alkali exposure caused an increase in corneal edema and fibrosis with corneal neovascularization. The accumulation of α-smooth muscle actin-positive myofibroblasts and the deposition of transforming growth factor-β2 on the alkali-exposed corneas were noted on day 14. The mRNA expression levels of interleukin-1β, MMP-9, MMP-2, VEGFR2, and profibrotic factors were decreased in the ZK002 group compared with the control group during the early period of corneal alkali burns on day 14. However, the expression level of PPARγ mRNA was increased in the ZK002 group.

Conclusions: ZK002 decreased the fibrotic reaction and prevented neovascularization in the cornea after an alkali burn. Therefore, the novel ophthalmic solution ZK002 could be a potentially promising therapeutic clinical treatment for corneal wound healing.

Purpose: Autosomal recessive cone and cone-rod dystrophies (CD/CRD) are inherited forms of vison loss. Here, we report on and correlate the clinical phenotypes with the underlying genetic mutations.

Methods: Clinical information was collected from subjects, including a family history with a chart review. They underwent a full ophthalmic examination, including best-corrected visual acuity, direct and indirect ophthalmoscopy, color vision testing, color fundus photography, contrast sensitivity, autofluorescence, and spectral domain-optical coherence tomography (SD-OCT), and full-field electroretinography. Next-generation panel-based genetic testing was used to identify DNA variants in subject buccal swab samples.

Results: Genetic testing in two patients revealed three novel variants in the TTLL5 gene associated with CD/CRD: two missense variants (c.1433G>A;p.(Arg478Gln), c.241C>G;p.(Leu81Val), and one loss-of-function variant (c.2384_2387del;p.(Ala795Valfs*9). Based on in-silico analysis, structural modeling, and comparison to previously reported mutations, these novel variants are very likely to be disease-causing mutations. Combining retinal imaging with SD-OCT analysis, we observed an unusual sheen in the CD/CRD phenotypes.

Conclusion: Based on the protein domain location of novel TTLL5 variants and the localization of TTLL5 to the connecting cilium, we conclude that the CD/CRD disease phenotype is characterized as a ciliopathy caused by protein tracking dysfunction. This initially affects cone photoreceptors, where photoreceptor cilia express a high level of TTLL5, but extends to rod photoreceptors over time. Fundus photography correlated with SD-OCT imaging suggests that the macular sheen characteristically seen with TTLL5 mutations derives from the photoreceptor's outer segments at the posterior pole.

Purpose: Subconjunctival fibrosis is the main cause of failure after glaucoma filtration surgery. We explored the effects of sulforaphane (SFN) on the conversion of human Tenon's fibroblasts (HTFs) into myofibroblasts, transforming growth factor (TGF)-β-induced contraction of collagen gel, and inflammation.

Methods: After treatment with the combination of TGF-β and SFN or TGF-β alone, primary HTFs were subjected to a three-dimensional collagen contraction experiment to examine their contractility. Levels of α smooth muscle actin (α-SMA), synthesis of extracellular matrix (ECM), and phosphorylation of various signaling molecules were determined by western blot or quantitative reverse transcription-polymerase chain reaction (RT-qPCR). Fluorescence microscopy was employed to examine stress fiber formation in HTFs. The expressions of interleukin (IL)-6, IL-8, and connective tissue growth factor (CTGF) were determined using RT-qPCR.

Results: The contraction of myofibroblasts caused by TGF-β was significantly suppressed by SFN. This suppressive effect was exerted via the differentiation of HTFs into myofibroblasts by inhibiting the production of fibronectin and the expression of α-SMA. Moreover, SFN treatment reduced the expression of TGF-β-promoted integrins β1 and α5, myosin light chain (MLC) phosphorylation, and stress fiber formation, as well as the expression of IL-6, IL-8, and CTGF. Finally, TGF-β-induced Smad2/3 and extracellular signal-regulated kinase (ERK) phosphorylations were attenuated by SFN.

Conclusions: SFN inhibits HTF contractility, differentiation into myofibroblasts, and inflammation caused by TGF-β. These effects are mediated by both classic and non-classic signaling pathways. Our results indicate that SFN has potent anti-fibrotic and anti-inflammatory effects in HTFs and is a potential candidate for subconjunctival fibrosis therapy.

Purpose: The cystine/glutamate antiporter is involved in the export of intracellular glutamate in exchange for extracellular cystine. Glutamate is the main neurotransmitter in the retina and plays a key metabolic role as a major anaplerotic substrate in the tricarboxylic acid cycle to generate adenosine triphosphate (ATP). In addition, glutamate is also involved in the outer plexiform glutamate-glutamine cycle, which links photoreceptors and supporting Müller cells and assists in maintaining photoreceptor neurotransmitter supply. In this study, we investigated the role of xCT, the light chain subunit responsible for antiporter function, in glutamate pathways in the mouse retina using an xCT knockout mouse. As xCT is a glutamate exporter, we hypothesized that loss of xCT function may influence the presynaptic metabolism of photoreceptors and postsynaptic levels of glutamate.

Methods: Retinas of C57BL/6J wild-type (WT) and xCT knockout (KO) mice of either sex were analyzed from 6 weeks to 12 months of age. Biochemical assays were used to determine the effect of loss of xCT on glycolysis and energy metabolism by measuring lactate dehydrogenase activity and ATP levels. Next, biochemical assays were used to measure whole-tissue glutamate and glutamine levels, while silver-intensified immunogold labeling was performed on 6-week and 9-month-old retinas to visualize and quantify the distribution of glutamate, glutamine, and related neurochemical substrates gamma-aminobutyric acid (GABA) and glycine in the different layers of the retina.

Results: Biochemical analysis revealed that loss of xCT function did not alter the lactate dehydrogenase activity, ATP levels, or glutamate and glutamine contents in whole retinas in any age group. However, at 6 weeks of age, the xCT KO retinas revealed altered glutamate distribution compared with the age-matched WT retinas, with accumulation of glutamate in the photoreceptors and outer plexiform layer. In addition, at 6 weeks and 9 months of age, the xCT KO retinas also showed altered glutamine distribution compared with the WT retinas, with glutamine labeling significantly decreased in Müller cell bodies. No significant difference in GABA or glycine distribution were found between the WT and xCT KO retinas at 6 weeks or 9 months of age.

Conclusion: Loss of xCT function results in glutamate metabolic disruption through the accumulation of glutamate in photoreceptors and a reduced uptake of glutamate by Müller cells, which in turn decreases glutamine production. These findings support the idea that xCT plays a role in the presynaptic metabolism of photoreceptors and postsynaptic levels of glutamate and derived neurotransmitters in the retina.