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Frontiers in Immunology 2020The complement system plays a crucial role in retinal homeostasis. While the proteomic analysis of ocular tissues in diabetic retinopathy (DR) has shown the deposition...
The complement system plays a crucial role in retinal homeostasis. While the proteomic analysis of ocular tissues in diabetic retinopathy (DR) has shown the deposition of complement proteins, their exact role in the pathogenesis of DR is yet unclear. We performed a detailed investigation of the role of the complement system by evaluating the levels of major complement proteins including C3, C1q, C4b, Complement Factor B (CFB), and Complement Factor H (CFH) and their activated fragments from both the classical and alternative pathways in vitreous humor and serum samples from proliferative DR (PDR) patients and controls. Further, the expressions of complements and several other key pro- and anti-angiogenic genes in the serum and vitreous humor were analyzed in the blood samples of PDR and non-PDR (NPDR) patients along with controls without diabetes. We also assessed the pro-inflammatory cytokines and matrix metalloproteinases in the vitreous humor samples. There was a significant increase in C3 and its activated fragment C3bα' (110 kDa) along with a corresponding upregulation of CFH in the vitreous of PDR patients, which confirmed the increased activation of the alternative complement pathway in PDR. Likewise, a significant upregulation of angiogenic genes and downregulation of anti-angiogenic genes was seen in PDR and NPDR cases. Increased MMP9 activity and upregulation of inflammatory markers IL8 and sPECAM with a downregulation of anti-inflammatory marker IL-10 in PDR vitreous indicated the possible involvement of microglia in DR pathogenesis. Further, a significantly high C3 deposition in the capillary wall along with thickening of basement membranes and co-localization of CFH expression with CD11b activated microglial cells in diabetic retina suggested microglia as a source of CFH in diabetic retina. The increased CFH levels could be a feedback mechanism for arresting excessive complement activation in DR eyes. A gradual increase of and expression in retina with early to late changes in epiretinal membranes of DR patients indicated a major role for the alternative complement pathway in disease progression.
Topics: Aged; Biomarkers; Case-Control Studies; Complement C3; Complement Factor H; Complement Pathway, Alternative; Complement Pathway, Classical; Cytokines; Diabetic Retinopathy; Female; Humans; Male; Microglia; Middle Aged; Neovascularization, Pathologic; Retina; Transcriptome; Vitreous Body
PubMed: 32117292
DOI: 10.3389/fimmu.2020.00154 -
Acta Ophthalmologica Feb 2022Diabetic macular oedema (DME) is considered a chronic inflammatory disease associated with aberrations in many intraocular cytokines. Studies assessing the role of these... (Meta-Analysis)
Meta-Analysis
Diabetic macular oedema (DME) is considered a chronic inflammatory disease associated with aberrations in many intraocular cytokines. Studies assessing the role of these cytokines as biomarkers in the diagnosis and management of DME have demonstrated inconsistent findings. We quantitatively summarized data related to 116 candidate aqueous and vitreous inflammatory cytokines as biomarkers in DME. A systematic search without year limitation was performed up to 19 October 2020. Studies were included if they provided data on aqueous or vitreous cytokine concentrations in patients with DME. Effect sizes were generated as standardized mean differences (SMDs) of cytokine concentrations between patients with DME and controls. Data were extracted from 128 studies that included 4163 study eyes with DME and 1281 control eyes. Concentrations (standard mean difference, 95% confidence interval and p-value) of aqueous IL-6 (1.28, 0.57-2.00, p = 0.004), IL-8 (1.06, 0.74-1.39, p < 0.00001), MCP-1 (1.36, 0.57-2.16, p = 0.0008) and VEGF (1.31, 1.01-1.62, p < 0.00001) and vitreous VEGF (2.27, 1.55-2.99, p < 0.00001) were significantly higher in patients with DME (n = 4163) compared to healthy controls (n = 1281). No differences, failed sensitivity analyses or insufficient data were found between patients with DME and healthy controls for the concentrations of the remaining cytokines. This analysis implicates multiple cytokine biomarker candidates other than VEGF in DME and clarifies previously reported inconsistent associations. As the therapeutic options for DME expand to include multiple agents with multiple targets, it will be critical to manage the treatment burden with tailored therapy that optimizes outcomes and minimizes treatment burden. Intraocular cytokines have the promise of providing a robust individualized assessment of disease status and response to therapy. We have identified key candidate cytokines that may serve as biomarkers in individualized treatment algorithms.
Topics: Aqueous Humor; Biomarkers; Cytokines; Diabetic Retinopathy; Humans; Inflammation; Macular Edema; Vitreous Body
PubMed: 33945678
DOI: 10.1111/aos.14891 -
Molecular Pharmaceutics Feb 2021The vitreous humor is the first barrier encountered by intravitreally injected nanoparticles. Lipid-based nanoparticles in the vitreous are studied by evaluating their...
The vitreous humor is the first barrier encountered by intravitreally injected nanoparticles. Lipid-based nanoparticles in the vitreous are studied by evaluating their diffusion with single-particle tracking technology and by characterizing their protein coronae with surface plasmon resonance and high-resolution proteomics. Single-particle tracking results indicate that the vitreal mobility of the formulations is dependent on their charge. Anionic and neutral formulations are mobile, whereas larger (>200 nm) neutral particles have restricted diffusion, and cationic particles are immobilized in the vitreous. PEGylation increases the mobility of cationic and larger neutral formulations but does not affect anionic and smaller neutral particles. Convection has a significant role in the pharmacokinetics of nanoparticles, whereas diffusion drives the transport of antibodies. Surface plasmon resonance studies determine that the vitreal corona of anionic formulations is sparse. Proteomics data reveals 76 differentially abundant proteins, whose enrichment is specific to either the hard or the soft corona. PEGylation does not affect protein enrichment. This suggests that protein-specific rather than formulation-specific factors are drivers of protein adsorption on nanoparticles in the vitreous. In summary, our findings contribute to understanding the pharmacokinetics of nanoparticles in the vitreous and help advance the development of nanoparticle-based treatments for eye diseases.
Topics: Adsorption; Animals; Diffusion; Drug Compounding; Humans; Intravitreal Injections; Liposomes; Nanoparticles; Ophthalmic Solutions; Particle Size; Polyethylene Glycols; Protein Corona; Proteomics; Retinal Diseases; Surface Properties; Sus scrofa; Vitreous Body
PubMed: 32584047
DOI: 10.1021/acs.molpharmaceut.0c00411 -
American Journal of Ophthalmology Jun 2022Although diagnosing vitreoretinal lymphoma (VRL) can be challenging, early detection is critical for visual prognosis. We analyzed the spectrum of optical coherence...
PURPOSE
Although diagnosing vitreoretinal lymphoma (VRL) can be challenging, early detection is critical for visual prognosis. We analyzed the spectrum of optical coherence tomography (OCT) findings in patients with biopsy-proven VRL and correlate these features with clinical parameters.
DESIGN
This retrospective cross-sectional study was a multicenter chart review from 13 retina, uveitis, and ocular oncology clinics worldwide from 2008 to 2019. We included patients with a diagnosis of biopsy-proven VRL imaged with OCT at presentation. Ocular information, systemic information, and multimodal retinal imaging findings were collected and studied. The main outcome measure was the characteristics of VRL on OCT.
RESULTS
A total of 182 eyes of 115 patients (63 women, mean age 65 years) were included in this study. The disease was bilateral in 81 patients (70%), and mean baseline visual acuity was 0.2 ± 0.89 logMAR (Snellen equivalent, 20/32). At baseline, 38 patients (33%) presented with isolated ocular involvement, 54 (45%) with associated central nervous system involvement, and 11 (10%) with other systemic lymphomatous involvement; an additional 12 patients (10%) presented with central nervous system and other systemic involvement. On OCT, tumor infiltration was identified in various retinal layers, including lesions in the subretinal pigment epithelium compartment (91% of eyes), the subretinal compartment (43% of eyes), and the intraretinal compartment (7% of eyes). OCT analysis of eyes with VRL identified 3 main regions of retinal infiltration. Subretinal pigment epithelium location, with or without subretinal infiltration, was the most common pattern of involvement and isolated intraretinal infiltration was the least.
Topics: Aged; Biopsy; Cross-Sectional Studies; Eye Neoplasms; Female; Fluorescein Angiography; Humans; Lymphoma; Retinal Neoplasms; Retrospective Studies; Tomography, Optical Coherence; Vitreous Body
PubMed: 34843686
DOI: 10.1016/j.ajo.2021.11.023 -
Asia-Pacific Journal of Ophthalmology... 2020Vitreous floaters are a common cause for presentation to ophthalmologists, and may significantly affect visual function. In the absence of some more serious underlying... (Review)
Review
Vitreous floaters are a common cause for presentation to ophthalmologists, and may significantly affect visual function. In the absence of some more serious underlying pathology such as uveitis, many patients may not experience significant persistent visual impairment from floaters. For some patients, the symptomatic effects of floaters may persist. For these patients, treatment options are available, of which the most commonly reported is vitrectomy. Other treatment modalities have also become more common, notably YAG vitreolysis. Selection of appropriate patients for surgery is often difficult, in part due to the relative lack of objective outcomes with which to measure both visual impairment and improvement post-procedure. Although well-tolerated, vitrectomy does carry with it risks, including iatrogenic retinal breaks, retinal detachment, and in phakic patients, subsequent cataract formation. Techniques such as small gauge vitrectomy, intraoperative examination and treatment of breaks or other worrying lesions, and careful consideration of the need for posterior vitreous detachment induction may help limit the incidence of these adverse events. For other treatment options such as YAG vitreolysis, research and clinical experience remain more limited, and as such the long-term efficacy and risks of these therapies are still unclear. Here, we review the evidence surrounding the role of vitrectomy and YAG vitreolysis in the treatment of vitreous floaters and potential means to minimize therapeutic complications.
Topics: Eye Diseases; Humans; Laser Therapy; Lasers, Solid-State; Vitrectomy; Vitreous Body
PubMed: 32097127
DOI: 10.1097/APO.0000000000000276 -
PloS One 2022To evaluate the concentrations of brimonidine and timolol in the vitreous and aqueous humors after instillation of a 0.1% brimonidine tartrate and 0.5% timolol... (Clinical Trial)
Clinical Trial
Brimonidine and timolol concentrations in the human vitreous and aqueous humors after topical instillation of a 0.1% brimonidine tartrate and 0.5% timolol fixed-combination ophthalmic solution: An interventional study.
PURPOSE
To evaluate the concentrations of brimonidine and timolol in the vitreous and aqueous humors after instillation of a 0.1% brimonidine tartrate and 0.5% timolol fixed-combination ophthalmic solution.
METHODS
This single-arm open-label interventional study included patients with macular holes or idiopathic epiretinal membranes who were scheduled for vitrectomy. Written informed consent was obtained from all participants. A 0.1% brimonidine tartrate and 0.5% timolol fixed-combination ophthalmic solution was administered topically twice daily for 1 week preoperatively. The vitreous and aqueous humors were sampled before vitrectomy, and brimonidine and timolol concentrations were quantified using liquid chromatography-tandem spectrometry. This study was registered with the Japan Registry of Clinical Trials (jRCT, ID jRCTs051200008; date of access and registration: April 28, 2020). The study protocol was approved by the University of Fukui Certified Review Board (CRB) and complied with the tenets of the Declaration of Helsinki.
RESULTS
Eight eyes of eight patients (7 phakic eyes and 1 pseudophakic eye) were included in this study. The mean brimonidine concentrations in the vitreous and aqueous humors were 5.04 ± 4.08 nM and 324 ± 172 nM, respectively. Five of the eight patients had brimonidine concentrations >2 nM in the vitreous humor, which is necessary to activate α2 receptors. The mean timolol concentrations in the vitreous and aqueous humors were 65.6 ± 56.0 nM and 3,160 ± 1,570 nM, respectively. Brimonidine concentrations showed significant positive correlations with timolol concentrations in the vitreous humor (P < 0.0001, R2 = 0.97) and aqueous humor (P < 0.0001, R2 = 0.96).
CONCLUSIONS
The majority of patients who received a 0.1% brimonidine tartrate and 0.5% timolol topical fixed-combination ophthalmic solution showed a brimonidine concentration >2 nM in the vitreous humor. Brimonidine and timolol may be distributed in the ocular tissues through an identical pathway after topical instillation.
Topics: Humans; Aqueous Humor; Brimonidine Tartrate; Ophthalmic Solutions; Timolol; Vitreous Body
PubMed: 36454807
DOI: 10.1371/journal.pone.0277313 -
Frontiers in Endocrinology 2022We sought to reveal the expression profiles of transfer RNA-derived small RNAs (tsRNAs) and microRNAs (miRNAs) in the vitreous humor of patients with proliferative...
PURPOSE
We sought to reveal the expression profiles of transfer RNA-derived small RNAs (tsRNAs) and microRNAs (miRNAs) in the vitreous humor of patients with proliferative diabetic retinopathy (PDR).
METHODS
Vitreous humor samples were obtained from PDR patients and a control group for this study. Sequencing of small RNAs was conducted to assess the expression profiles of tsRNAs and miRNAs in both groups, which was followed by validation using reverse transcription-quantitative real-time polymerase chain reaction (RT-qPCR). Bioinformatics analyses were conducted to predict the target genes and their potential biological functions and signaling pathways.
RESULTS
A total of 37 tsRNAs and 70 miRNAs with significant differences were screened out from the vitreous humor samples of PDR patients compared to controls. Following validation by RT-qPCR, the target genes of the validated tsRNAs and miRNAs were predicted, and Gene Ontology analysis indicated that the target genes of the tsRNAs were most enriched in the cellular macromolecule metabolic process, cytoplasm, and ion-binding, while those of the miRNAs were most abundant in the regulation of major metabolic process, cytoplasm, and protein-binding. In addition, Kyoto Encyclopedia of Genes and Genomes pathway analysis showed that the target genes of said tsRNAs and miRNAs were most enriched in the adenosine monophosphate-activated protein kinase signaling pathway and Th17 cell differentiation, respectively.
CONCLUSIONS
The present study identified altered tsRNAs and miRNAs in vitreous humor samples of PDR patients, which may play important roles in the pathogenesis of PDR and could be considered potential therapeutic targets in the treatment of PDR.
Topics: Diabetes Mellitus; Diabetic Retinopathy; Gene Ontology; Humans; MicroRNAs; RNA, Transfer; Vitreous Body
PubMed: 35903272
DOI: 10.3389/fendo.2022.913370 -
Acta Ophthalmologica Jun 2023Hydrogel-based vitreous substitutes have the potential to overcome the limitations of current clinically used endotamponades. With the goal of entering clinical trials,...
PURPOSE
Hydrogel-based vitreous substitutes have the potential to overcome the limitations of current clinically used endotamponades. With the goal of entering clinical trials, the present study aimed to (I) transfer the material synthesis of hyaluronic acid-based hydrogels into a routine, pharmaceutical-appropriate production and (II) evaluate the properties of the vitreous substitutes in terms of the current regulations for medical devices (MDR/ISO standards).
METHODS
The multistep manufacturing process of the vitreous substitutes, including the modification of hyaluronic acid with glycidyl methacrylate, photocopolymerization with N-vinylpyrrolidone, and successive hydrogel purification, was developed under laboratory conditions, characterized using H-NMR, FT-IR and UV/Vis spectroscopies and HPLC, and transferred towards a pharmaceutical production environment considering GMP standards. The optical and viscoelastic characteristics of the hyaluronic acid-based hydrogels were compared with those of extracted human vitreous and silicone oil. The effect of the hydrogels on the metabolic activity, proliferation and apoptosis of fibroblast (MRC-5, BJ, L929), retinal pigment epithelial (ARPE-19, hiPSC-derived RPE) and photoreceptor cells (661W) was studied as well as their mucosal tolerance via a HET-CAM assay.
RESULTS
Hyaluronic acid-based hydrogels having a suitable purity, sterility, high transparency (>90%), appropriate refractive index (1.3365) and viscoelasticity (G' > G″) were prepared in a standardized manner under controlled process conditions. The metabolic activity, proliferation and apoptosis of various cell types as well as egg choroid were unaffected by the hyaluronic acid-based vitreous substitutes, demonstrating their biocompatibility.
CONCLUSIONS
The present study demonstrates the successful transferability of the crucial synthesis steps of hyaluronic acid-based hydrogels into a routine, GMP-compliant production process while achieving the optical and viscoelastic properties, biocompatibility and purity required for their clinical use as vitreous substitutes.
Topics: Humans; Vitreous Body; Hyaluronic Acid; Spectroscopy, Fourier Transform Infrared; Hydrogels
PubMed: 36457299
DOI: 10.1111/aos.15301 -
Acta Ophthalmologica Feb 2020Galectin-1 regulates endothelial cell function and promotes angiogenesis. We investigated the hypothesis that galectin-1 may be involved in the pathogenesis of...
PURPOSE
Galectin-1 regulates endothelial cell function and promotes angiogenesis. We investigated the hypothesis that galectin-1 may be involved in the pathogenesis of proliferative diabetic retinopathy (PDR).
METHODS
Vitreous samples from 36 PDR and 20 nondiabetic patients, epiretinal fibrovascular membranes from 13 patients with PDR, rat retinas and human retinal Müller glial cells were studied by enzyme-linked immunosorbent assay (ELISA), immunohistochemistry and Western blot analysis. In vitro angiogenesis assays were performed and the adherence of leukocytes to galectin-1-stimulated human retinal microvascular endothelial cells (HRMECs) was assessed.
RESULTS
The ELISA analysis revealed that galectin-1 and vascular endothelial growth factor (VEGF) levels were significantly higher in vitreous samples from PDR patients than in those from nondiabetics (p < 0.001 for both comparisons). A significant positive correlation was found between the levels of galectin-1 and VEGF (r = 0.354; p = 0.022). In epiretinal membranes, immunohistochemical analysis showed that galectin-1 was expressed in vascular endothelial cells expressing CD31, myofibroblasts expressing α-smooth muscle actin and leukocytes expressing CD45. The galectin-1 receptor neuropilin-1 was expressed on vascular endothelial cells. CD31 staining was used as a marker to assess microvessel density (MVD). Significant positive correlation was detected between MVD in epiretinal membranes and the number of blood vessels expressing galectin-1 (r = 0.848; p < 0.001). Western blot analysis demonstrated significant increase of galectin-1 protein in rat retinas after induction of diabetes. ELISA analysis revealed that hydrogen peroxide and cobalt chloride (CoCl ) induced upregulation of galectin-1 in Müller cells. Treatment with galectin-1 induced upregulation of VEGF in Müller cells and increased leukocyte adhesion to HRMECs. The galectin-1 inhibitor OTX008 attenuated VEGF-induced HRMECs migration and CoCl -induced upregulation of NF-κB, galectin-1 and VEGF in Müller cells.
CONCLUSIONS
These results suggest that galectin-1is involved in the pathogenesis of PDR.
Topics: Adult; Aged; Aged, 80 and over; Animals; Biomarkers; Blotting, Western; Cells, Cultured; Diabetes Mellitus, Experimental; Diabetic Retinopathy; Enzyme-Linked Immunosorbent Assay; Ependymoglial Cells; Female; Galectin 1; Humans; Immunohistochemistry; Male; Middle Aged; Rats; Rats, Sprague-Dawley; Vitrectomy; Vitreous Body; Young Adult
PubMed: 31318490
DOI: 10.1111/aos.14191 -
Cells Dec 2022MicroRNAs (miRNAs) are small noncoding RNAs which mediate some of the pathological mechanisms of diabetic retinopathy. The aim of this study was to identify...
MicroRNAs (miRNAs) are small noncoding RNAs which mediate some of the pathological mechanisms of diabetic retinopathy. The aim of this study was to identify differentially expressed miRNAs in the vitreal exosomes of proliferative diabetic retinopathy (PDR) patients and non-diabetic controls. Exosomes were extracted from the vitreous samples of 10 PDR patients and 10 controls. The expression of 372 miRNAs was determined using a quantitative polymerase chain reaction (qPCR) panel. We have demonstrated a significant dysregulation in 26 miRNAs. The most remarkable findings include a profound attenuation of the miR-125 family, as well as enhanced miR-21-5p expression in the diabetic samples. We also showed the downregulation of miR-204-5p and the upregulation of let-7g in PDR compared to the controls. This study identified miR-125 and miR-21 as potential targets for further functional analysis regarding their putative role in the pathogenesis of PDR.
Topics: Humans; Vitreous Body; Diabetic Retinopathy; MicroRNAs; Body Fluids; Up-Regulation; Diabetes Mellitus
PubMed: 36611916
DOI: 10.3390/cells12010123