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Methods in Molecular Biology (Clifton,... 2019Metabolomics refers to the systematic identification and quantification of the small molecule metabolites (the metabolome) of a biological system in a given space (cell,...
Metabolomics refers to the systematic identification and quantification of the small molecule metabolites (the metabolome) of a biological system in a given space (cell, tissue, organ, biological fluid, or organism) and time. Global metabolic profiling provides broad range of coverage for most of the analytes present in any tissue. Human retina is metabolically highly active, and retinal vascular diseases such as age-related macular degeneration (AMD), diabetic retinopathy (DR), retinal vein occlusion (RVO), central retinal artery occlusion, and retinopathy of prematurity (ROP) are often associated with the disruptions in metabolic activities. A systematic study of total retinal metabolites from human diseased retina is a major challenge owing to the nonavailability of tissue specimens. Therefore, vitreous humor being very proximal to retina could be used as surrogate for retinal metabolomic analysis. As the extraction method adopted for such analysis determines the type of metabolites, two different types of solvent (methanol and chloroform)-based extraction methods could be used for retinal vascular patient samples (vitreous humor). Metabolites obtained from both the extraction methods are then subjected to LC-MS/MS for detection and identification.
Topics: Chemical Fractionation; Chloroform; Chromatography, High Pressure Liquid; Humans; Metabolomics; Methanol; Retina; Retinal Diseases; Solvents; Tandem Mass Spectrometry; Vitreous Body
PubMed: 31127565
DOI: 10.1007/978-1-4939-9488-5_24 -
Pharmaceutical Research Jan 2019Biomarkers provide a powerful and dynamic approach to improve our understanding of the mechanisms underlying ocular diseases with applications in diagnosis, disease... (Review)
Review
Biomarkers provide a powerful and dynamic approach to improve our understanding of the mechanisms underlying ocular diseases with applications in diagnosis, disease modulation or for predicting and monitoring of clinical response to treatment. Defined as measurable indicator of normal or pathological processes, biomarker evaluation has been used extensively in drug development within clinical settings to better comprehend effectiveness of treatment in ocular diseases. Biomarkers in the eye have the advantage of access to multiple ocular matrices via minimally invasive methods. Repeat sampling for biomarker assessment has enabled reproducible objective measures of disease process or biological responses to a drug treatment. This review describes the usage of biomarkers with respect to four commonly sampled ocular matrices in clinic: tears, conjunctiva, aqueous humor and vitreous. Issues that affect the evaluation of biomarkers are discussed along with opportunities to leverage biomarkers such that ultimately, they can be used for customized targeted therapy.
Topics: Animals; Aqueous Humor; Biomarkers; Conjunctiva; Eye Diseases; Humans; Tears; Vitreous Body
PubMed: 30673862
DOI: 10.1007/s11095-019-2569-8 -
Acta Diabetologica Jul 2019To compare the vitreous levels of chemokines in diabetic patients with and without retinopathy. To find the relationship between stages of diabetic retinopathy (DR) and...
AIMS
To compare the vitreous levels of chemokines in diabetic patients with and without retinopathy. To find the relationship between stages of diabetic retinopathy (DR) and levels of vitreous chemokines.
METHODS
The study involved 20 non-diabetic and 20 diabetic patients without clinical signs of DR (NDR) and 40 diabetic patients with proliferative diabetic retinopathy (PDR). The vitreous humor was collected and the levels of 40 chemokines were measured using magnetic color-bead-based multiplex assay.
RESULTS
The control group, NDR group, PDR with vitreous hemorrhage (VH) group, and PDR with tractional retinal detachment group comprised 20, 20, 21, and 19 eyes, respectively. Only the concentration of CCL3 was significantly higher in the NDR group compared with the controls (p = 0.038). Twenty-five types of chemokines were statistically higher in the PDR with VH group in comparison to NDR group (all p < 0.05). All chemokines were statistically higher in the PDR with TRD group in comparison to NDR group (all p < 0.05) apart from 3 chemokines: GM-CSF, MIF, and CCL3(p = 0.086, p = 0.109, p = 0.094, respectively). The concentration of CCL21, CCL15 in PDR with TRD group was significantly higher compared with PDR with VH group, while other 36 chemokines were not significantly different between PDR with VH group and PDR with TRD group.
CONCLUSIONS
The inflammation gradually worsen with the progression of DR. CCL3 may be associated with the onset of early diabetic retinal damage, and CCL15 and CCL21 may be closely related to the formation of fibrovascular membrane and the progression of the end stage of DR.
Topics: Adult; Aged; Case-Control Studies; Chemokines; Chemokines, CC; Diabetes Mellitus, Type 2; Diabetic Retinopathy; Disease Progression; Enzyme-Linked Immunosorbent Assay; Female; Humans; Macrophage Inflammatory Proteins; Male; Middle Aged; Vitreous Body
PubMed: 30911832
DOI: 10.1007/s00592-019-01317-6 -
Alzheimer's Research & Therapy Sep 2020Neurofilament light chain (NfL) is a promising biomarker of neurodegeneration in the cerebrospinal fluid and blood. This study investigated the presence of NfL in the...
BACKGROUND
Neurofilament light chain (NfL) is a promising biomarker of neurodegeneration in the cerebrospinal fluid and blood. This study investigated the presence of NfL in the vitreous humor and its associations with amyloid beta, tau, inflammatory cytokines and vascular proteins, apolipoprotein E (APOE) genotypes, Mini-Mental State Examination (MMSE) scores, systemic disease, and ophthalmic diseases.
METHODS
This is a single-site, prospective, cross-sectional cohort study. Undiluted vitreous fluid (0.5-1.0 mL) was aspirated during vitrectomy, and whole blood was drawn for APOE genotyping. NfL, amyloid beta (Aβ), total Tau (t-Tau), phosphorylated Tau (p-Tau181), inflammatory cytokines, chemokines, and vascular proteins in the vitreous were quantitatively measured by immunoassay. The main outcome measures were the detection of NfL levels in the vitreous humor and its associations with the aforementioned proteins. Linear regression was used to test the associations of NfL with other proteins, APOE genotypes, MMSE scores, and ophthalmic and systemic diseases after adjustment for age, sex, education level, and other eye diseases.
RESULTS
NfL was detected in all 77 vitreous samples. NfL was not found to be associated with ophthalmic conditions, APOE genotypes, MMSE scores, or systemic disease (p > 0.05). NfL levels were positively associated with increased vitreous levels of Aβ (p = 7.7 × 10), Aβ (p = 2.8 × 10), and t-tau (p = 5.5 × 10), but not with p-tau181 (p = 0.53). NfL also had significant associations with inflammatory cytokines such as interleukin-15 (IL-15, p = 5.3 × 10), IL-16 (p = 2.2 × 10), monocyte chemoattractant protein-1 (MCP1, p = 4.1 × 10), and vascular proteins such as vascular endothelial growth factor receptor-1 (VEGFR1, p = 2.9 × 10), Vegf-C (p = 8.6 × 10), vascular cell adhesion molecule-1 (VCAM-1, p = 5.0 × 10), Tie-2 (p = 6.3 × 10), and intracellular adhesion molecular-1 (ICAM-1, p = 1.6 × 10).
CONCLUSION
NfL is detectable in the vitreous humor of the eye and significantly associated with amyloid beta, t-tau, and select inflammatory and vascular proteins in the vitreous. Additionally, NfL was not associated with patients' clinical eye condition. Our results serve as a foundation for further investigation of NfL in the ocular fluids to inform us about the potential utility of its presence in the eye.
Topics: Alzheimer Disease; Amyloid beta-Peptides; Biomarkers; Cross-Sectional Studies; Humans; Intermediate Filaments; Neurofilament Proteins; Prospective Studies; Vascular Endothelial Growth Factor A; Vitreous Body; tau Proteins
PubMed: 32943089
DOI: 10.1186/s13195-020-00677-4 -
Forensic Science, Medicine, and... Sep 2016After death, a series of changes occur naturally in the human body in a fairly regular pattern. These postmortem changes are detectable on postmortem CT scans (PMCT) and...
PURPOSE
After death, a series of changes occur naturally in the human body in a fairly regular pattern. These postmortem changes are detectable on postmortem CT scans (PMCT) and may be useful in estimating the postmortem interval (PMI). The purpose of our study is to correlate the PMCT radiodensities of the cerebrospinal fluid (CSF) and vitreous humor (VH) to the PMI.
METHODS
Three patient groups were included: group A consisted of 5 donated cadavers, group B, 100 in-hospital deceased patients, and group C, 12 out-of-hospital forensic cadavers. Group A were scanned every hour for a maximum of 36 h postmortem, and the tympanic temperature was measured prior to each scan. Groups B and C were scanned once after death (PMI range 0.2-63.8 h). Radiodensities of the VH and CSF were measured in Hounsfield units. Correlation between density and PMI was determined using linear regression and the influence of temperature was assessed by a multivariate regression model. Results from group A were validated in groups B and C.
RESULTS
Group A showed increasing radiodensity of the CSF and VH over time (r (2) CSF, 0.65). PMI overruled the influence of temperature (r = 0.99 and p = 0.000). Groups B and C showed more diversity, with CSF and VH radiodensities below the mean regression line of Group A. The formula of this upper limit indicated the maximum PMI and was correct for >95 % of the cadavers.
CONCLUSION
The results of group A showed a significant correlation between CSF radiodensity and PMI. The radiodensities in groups B and C were higher than in group A, therefore the maximum PMI can be estimated with the upper 95 % confidence interval of the correlation line of group A.
Topics: Adolescent; Adult; Aged; Aged, 80 and over; Body Temperature; Cerebrospinal Fluid; Child; Child, Preschool; Female; Humans; Infant; Linear Models; Male; Middle Aged; Postmortem Changes; Tomography, X-Ray Computed; Vitreous Body; Young Adult
PubMed: 27117292
DOI: 10.1007/s12024-016-9778-9 -
Vestnik Oftalmologii 2021This literature review provides modern information on the unique structure of the vitreous body, its functions, and its role in the pathogenesis of glaucoma, describes... (Review)
Review
This literature review provides modern information on the unique structure of the vitreous body, its functions, and its role in the pathogenesis of glaucoma, describes the features of the vitreous morphology and metabolism, notes its biomechanical and trophic functions, outlines its role in healthy hydrodynamics and hemodynamics of the eye, as well as in aqueous humor outflow. The review presents clinical observations on the association of pathological changes in the vitreous body with glaucoma development and examines the role of involutional changes in the vitreous in the pathogenesis of glaucoma. The article also discusses possible pathogenetic mechanisms of glaucoma development in terms of pathological changes in the vitreous.
Topics: Aqueous Humor; Glaucoma; Humans; Vitreous Body
PubMed: 34669344
DOI: 10.17116/oftalma2021137052323 -
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 -
System-wide vitreous proteome dissection reveals impaired sheddase activity in diabetic retinopathy.Theranostics 2022Diabetic retinopathy (DR) is a major complication of diabetes mellitus causing significant vision loss. DR is a multifactorial disease involving changes in retinal...
Diabetic retinopathy (DR) is a major complication of diabetes mellitus causing significant vision loss. DR is a multifactorial disease involving changes in retinal microvasculature and neuronal layers, and aberrations in vascular endothelial growth factors (VEGF) and inflammatory pathways. Despite the success of anti-VEGF therapy, many DR patients do not respond well to the treatment, emphasizing the involvement of other molecular players in neuronal and vascular aberrations in DR. We employed advanced mass spectrometry-based proteome profiling to obtain a global snapshot of altered protein abundances in vitreous humor from patients with proliferative DR (PDR) in comparison to individuals with epiretinal membrane without active DR or other retinal vascular complications. Global proteome correlation map and protein-protein interaction networks were used to probe into the functional inclination of proteins and aberrated molecular networks in PDR vitreous. In addition, peptide-centric analysis of the proteome data was carried out to identify proteolytic processing, primarily ectodomain shedding events in PDR vitreous. Functional validation experiments were performed using preclinical models of ocular angiogenesis. The vitreous proteome landscape revealed distinct dysregulations in several metabolic, signaling, and immune networks in PDR. Systematic analysis of altered proteins uncovered specific impairment in ectodomain shedding of several transmembrane proteins playing critical roles in neurodegeneration and angiogenesis, pointing to defects in their regulating sheddases, particularly ADAM10, which emerged as the predominant sheddase. We confirmed that ADAM10 protease activity was reduced in animal models of ocular angiogenesis and established that activation of ADAM10 can suppress endothelial cell activation and angiogenesis. Furthermore, we identified the impaired ADAM10-AXL axis as a driver of retinal angiogenesis. We demonstrate restoration of aberrant ectodomain shedding as an effective strategy for treating PDR and propose ADAM10 as an attractive therapeutic target. In all, our study uncovered impaired ectodomain shedding as a prominent feature of PDR, opening new possibilities for advancement in the DR therapeutic space.
Topics: Animals; Diabetes Mellitus; Diabetic Retinopathy; Peptide Hydrolases; Proteome; Vascular Endothelial Growth Factors; Vitreous Body
PubMed: 36185601
DOI: 10.7150/thno.72947 -
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 -
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