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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 -
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 -
PloS One 2023To explore the changes in vitreous body after vitreous hemorrhage and assess its prognosis from the perspective of vitreoretinal interface.
PURPOSE
To explore the changes in vitreous body after vitreous hemorrhage and assess its prognosis from the perspective of vitreoretinal interface.
METHODS
The experiment was performed on 32 New Zealand rabbits (64 eyes), weighing 2500-3000 g for 4 months and unlimited gender, which was injected with 0.2 mL of autologous blood into the center of vitreous cavity-the study group (right eyes), and the control one was treated in the same manner with equal volumes of saline. The rabbits were randomly and equally divided into the following four batches according to the days of observation: Days 3, 7, 14, and 30 after injection. IOP and severity grading were evaluated before rabbits' execution and eyeballs were enucleated. The anterior segment was separated to flow out the vitreous body naturally to detect the liquefaction degree and viscosity. Then, chemical composition of electrolytes, PCT and bFGF were determined by colorimetry and enzyme-linked immunosorbent assay (ELISA). Finally, the incidence of posterior vitreous detachment (PVD) was observed after vitreous sampled. The studies were double-blind.
RESULTS
After injection, the extent of vitreous opacity and coagulum size decreased over time. Both the degree of liquefaction and the length of tow differed significantly between two groups at different time points (all p < 0.001). The liquefaction degree in the study group rose obviously from the Day 14, which the viscosity declined significantly on the initial time. Biochemical markers fluctuated temporarily, except for basic fibroblast growth factor (bFGF), which continued to rise and was correlated with the liquefaction degree (r = 0.658, p < 0.001). Besides, the incidence of PVD increased from the 14th day (p < 0.05), and it was highly positively correlated with the number of macrophages (r = 0.934; p < 0.001).
CONCLUSION
After vitreous hemorrhage, the changes of the vitreous body are relatively minor earlier (2-4 weeks), but irreversible later. Specifically, the degree of liquefaction increases with a decrease in viscosity, and the chemotaxis of macrophages and bFGF induce incomplete PVD.
Topics: Animals; Rabbits; Injections; Interdisciplinary Studies; Vitreous Body; Vitreous Detachment; Vitreous Hemorrhage
PubMed: 36745670
DOI: 10.1371/journal.pone.0281165 -
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 -
Journal of Alzheimer's Disease : JAD 2019The eye may serve as source for diagnostic testing for early detection of Alzheimer's disease (AD). Examination of amyloid-β (Aβ) and tau protein content in human...
BACKGROUND
The eye may serve as source for diagnostic testing for early detection of Alzheimer's disease (AD). Examination of amyloid-β (Aβ) and tau protein content in human vitreous and its correlation to neuro-cognition may improve ocular-based AD detection methods.
OBJECTIVE
To evaluate levels of Aβ and tau protein in human vitreous humor and investigate the clinical predictive role of these proteins as early diagnostic markers of AD.
METHODS
A prospective, single-center, multi-surgeon cohort study. Vitreous humor samples from 80 eyes were measured quantitatively for Aβ40-42, pTau, and tTau. Linear regression was used to test associations between AD biomarker levels, Mini-Mental State Exam (MMSE), and serum apolipoprotein E (APOE) allele status, with adjustment for age, sex, and education level of patients.
RESULTS
Lower MMSE scores were significantly associated with lower levels of vitreous Aβ40 (p = 0.015), Aβ42 (p = 0.0066), and tTau (p = 0.0085), and these biomarkers were not associated with any pre-existing eye conditions. Presence of the ɛ4 allele and the ɛ2 allele approached significance with reduced Aβ40 level (p = 0.053) and increased p-Tau level (p = 0.056), respectively.
CONCLUSION
Patients with poor cognitive function have significantly lower vitreous humor levels of AD-related biomarkers Aβ40, Aβ42, and tTau. These biomarkers do not correlate with underlying eye conditions, suggesting their specificity in association with cognitive change. This is the first study to our knowledge to correlate cognition with AD-related proteins in the vitreous humor. Results suggest ocular proteins may have a role for early dementia detection in individuals at risk for AD.
Topics: Alzheimer Disease; Amyloid beta-Peptides; Biomarkers; Cognition; Cross-Sectional Studies; Early Diagnosis; Humans; Prospective Studies; Sensitivity and Specificity; Vitreous Body; tau Proteins
PubMed: 30856114
DOI: 10.3233/JAD-181104 -
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