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International Journal of Molecular... Feb 2021Photoreceptors are the light-sensing cells of the retina and the major cell type affected in most inherited retinal degenerations. Different metabolic pathways sustain...
Photoreceptors are the light-sensing cells of the retina and the major cell type affected in most inherited retinal degenerations. Different metabolic pathways sustain their high energetic demand in physiological conditions, particularly aerobic glycolysis. The principal metabolome of the mature retina has been studied, but only limited information is available on metabolic adaptations in response to key developmental events, such as eye opening. Moreover, dynamic metabolic changes due to retinal degeneration are not well understood. Here, we aimed to explore and map the ocular metabolic dynamics induced by eye opening in healthy (wild type) or -mutant (retinal degeneration 1, Rd1) mice, in which photoreceptors degenerate shortly after eye opening. To unravel metabolic differences emerging before and after eye opening under physiological and pathophysiological conditions, we performed nuclear magnetic resonance (NMR) spectroscopy-based metabolome analysis of wild type and Rd1 retina and vitreous/lens. We show that eye opening is accompanied by changes in the concentration of selected metabolites in the retina and by alterations in the vitreous/lens composition only in the retinal degeneration context. As such, we identify NAcetylaspartate as a potential novel vitreous/lens marker reflecting progressive retinal degeneration. Thus, our data can help elucidating mechanisms underlying key events in retinal physiology and reveal changes occurring in pathology, while highlighting the importance of the vitreous/lens in the characterization of retinal diseases.
Topics: Animals; Cyclic Nucleotide Phosphodiesterases, Type 6; Disease Models, Animal; Lens, Crystalline; Metabolome; Mice; Mutation; Retina; Retinal Degeneration; Vitreous Body
PubMed: 33652907
DOI: 10.3390/ijms22052345 -
Retina (Philadelphia, Pa.) Feb 2022The causes of floaters include posterior vitreous detachment and fundus hemorrhage, both of which are risk factors for retinal tears. We observed the vitreous of...
PURPOSE
The causes of floaters include posterior vitreous detachment and fundus hemorrhage, both of which are risk factors for retinal tears. We observed the vitreous of patients with floaters using swept source optical coherence tomography.
METHODS
Fundus examination was performed, and the vitreous was observed using swept source optical coherence tomography in 202 eyes of 202 patients with floaters. Patients with uveitis, diabetic retinopathy, and other fundus diseases were excluded.
RESULTS
Swept source optical coherence tomography revealed posterior vitreous detachment in 145 of 202 eyes (71.8%) and dot reflex like stardust in the vitreous in 42 of 202 eyes (20.8%). Posterior vitreous detachment occurred in 35 of 42 eyes (83.3%) and 110 of 160 eyes (68.8%) in the stardust (+) and stardust (-) groups, respectively; a significant difference was observed (P <0.001). In the stardust (+) group, 11 of 42 eyes (26.2%) had retinal tears with posterior vitreous detachment and 21 of 42 eyes (50.0%) had fundus hemorrhage. Three of 160 eyes (1.9%) and 4 of 160 eyes (2.5%) in the stardust (-) group had retinal tears with posterior vitreous detachment and fundus hemorrhage, respectively. Both tears and fundus hemorrhage were more frequent in the stardust (+) group than in the stardust (-) group (P <0.001).
CONCLUSION
The stardust sign on swept source optical coherence tomography indicates the risk of retinal tear.
Topics: Adult; Aged; Aged, 80 and over; Female; Fundus Oculi; Humans; Male; Middle Aged; Prospective Studies; Retinal Perforations; Tomography, Optical Coherence; Vitreous Body; Vitreous Detachment; Young Adult
PubMed: 35050930
DOI: 10.1097/IAE.0000000000003317 -
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 -
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 -
Journal of Acquired Immune Deficiency... May 2023To determine tenofovir (TFV) penetration into intraocular tissues using ultra high-performance liquid chromatography/tandem mass spectrometry (UHPLC-MS/MS). (Observational Study)
Observational Study
OBJECTIVE
To determine tenofovir (TFV) penetration into intraocular tissues using ultra high-performance liquid chromatography/tandem mass spectrometry (UHPLC-MS/MS).
METHODS
Nineteen participants taking tenofovir in combination antiretroviral therapy (cART) regimen who underwent pars plana vitrectomy (PPV) surgery were enrolled in the observational retrospective study between January 2019 and August 2021. The participants were divided into mild, moderate, and severe groups according to retinal manifestations. Basic information was recorded during PPV surgery. Paired blood plasma and vitreous humor samples (n = 19) were collected for UHPLC-MS/MS.
RESULTS
The median plasma and vitreous tenofovir concentrations were 106.00 ng/mL (interquartile range[IQR], 54.6-142.5) and 41.40 ng/mL (IQR 9.4-91.6), respectively. The median vitreous/plasma concentration ratio from the paired samples was 0.42 (IQR 0.16-0.84). The plasma and vitreous tenofovir concentrations were significantly correlated (r = 0.483, P = 0.036). The median vitreous tenofovir concentration was the lowest in the mild group (4.58 ng/mL). Six vitreous samples were below 50% inhibitory concentration (IC50) (11.5 ng/mL), and 2 of them were undetectable. Significant differences were noted in vitreous/plasma and vitreous tenofovir concentrations ( P = 0.035 and P = 0.045, respectively) among the 3 groups but not in plasma tenofovir concentration ( P = 0.577). No correlation was noted between vitreous HIV-1 RNA and vitreous tenofovir concentrations (r = 0.049, P = 0.845).
CONCLUSION
Vitreous tenofovir did not reliably or consistently achieve concentrations sufficient to inhibit viral replication in intraocular tissues due to poor penetration of the blood-retinal barrier (BRB). The higher vitreous tenofovir concentrations were associated with moderate or severe disease compared with mild disease, indicating an association with the severity of BRB disruption.
Topics: Humans; Anti-HIV Agents; HIV Infections; Retrospective Studies; Tandem Mass Spectrometry; Tenofovir; Vitrectomy; Vitreous Body
PubMed: 36881850
DOI: 10.1097/QAI.0000000000003171 -
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 -
Investigative Ophthalmology & Visual... Mar 2023Age-related macular degeneration (AMD) is the leading cause of visual impairment worldwide. In this study, we aimed to investigate the vitreous humor metabolite profiles...
PURPOSE
Age-related macular degeneration (AMD) is the leading cause of visual impairment worldwide. In this study, we aimed to investigate the vitreous humor metabolite profiles of patients with intermediate AMD using untargeted metabolomics.
METHODS
We performed metabolomics using high-resolution liquid chromatography mass spectrometry on the vitreous humor of 31 patients with intermediate AMD and 30 controls who underwent vitrectomy for epiretinal membrane with or without cataract surgery. Univariate analyses after false discovery rate correction were performed to discriminate the metabolites and identify the significant metabolites of intermediate AMD. For biologic interpretation, enrichment and pathway analysis were conducted using MetaboAnalyst 5.0.
RESULTS
Of the 858 metabolites analyzed in the vitreous humor, 258 metabolites that distinguished patients with AMD from controls were identified (P values < 0.05). Ascorbic acid and uric acid levels increased in the AMD group (all P values < 0.05). The acyl carnitines, such as acetyl L-carnitine (1.37-fold), and fatty amides, such as anandamide (0.9-fold) and docosanamide (0.67-fold), were higher in patients with intermediate AMD. In contrast, nicotinamide (-0.55-fold), and succinic acid (-1.69-fold) were lower in patients with intermediate AMD. The metabolic pathway related oxidation of branched chain fatty acids and carnitine synthesis showed enrichment.
CONCLUSIONS
Multiple metabolites related to fatty amides and acyl carnitine were found to be increased in the vitreous humor of patients with intermediate AMD, whereas succinic acid and nicotinamide were reduced, suggesting that altered metabolites related to fatty amides and acyl carnitines and energy metabolism may be implicated in the etiology of AMD.
Topics: Humans; Amides; Carnitine; Macular Degeneration; Niacinamide; Succinates; Vitreous Body
PubMed: 36939720
DOI: 10.1167/iovs.64.3.28 -
Molecular Vision 2023Increased inflammatory factor levels have been reported in the vitreous humor (VH) of diabetic retinopathy and neovascular age-related macular degeneration, ocular...
PURPOSE
Increased inflammatory factor levels have been reported in the vitreous humor (VH) of diabetic retinopathy and neovascular age-related macular degeneration, ocular diseases generally associated with the formation of new retinal blood vessels and leakage. However, the levels of inflammatory mediators are less known in retinal degeneration without neovascularization. Human retinitis pigmentosa (RP) and animal models of light-induced retinal degeneration (LIRD) share several features, such as photoreceptor death and retinal inflammation. Here, we aimed to determine the levels of inflammatory factors in the VH of the LIRD mouse model.
METHODS
LIRD was induced by exposing BALB/c mice to white light (15,000 lx, 2 h), and the mice were recovered for 2 days before analysis (n = 50 mice). We assessed retinal morphology using optical coherence tomography and hematoxylin and eosin staining; retinal cell viability was determined using terminal deoxynucleotidyl transferase dUTP nick-end labeling, and retinal responses were measured based on electroretinogram signals. Total retinal RNAs were extracted and subjected to RNA sequencing analysis. VH samples from control (n = 4) and LIRD mice (n = 9) were assayed in triplicate for a panel of four inflammatory mediators using the Simple Plex Cartridge on an Ella System.
RESULTS
Retinal degeneration, photoreceptor death, infiltration of microglia/macrophages into the photoreceptor layer, and loss of a- and b-waves were obviously detected after LIRD. RNA sequencing revealed that light damage (LD) led to the significant upregulation of inflammatory factors in mouse retinas. In the VH, LD increased the total protein concentration. Dramatic induction of CCL2 (~3000 fold) and IL6 (~10 fold) was detected in VH in response to LD. Increased but not significant levels of TNFα and IL1β were also detected in light-exposed VH.
CONCLUSIONS
Given that the LIRD model mimics RP pathogenesis in some aspects, these results suggest a causative link between retinal degeneration and VH inflammation in RP progression, and the increased CCL2 level in VH may reflect similar elevated CCL2 expression in the degenerative retina.
Topics: Mice; Humans; Animals; Retinal Degeneration; Vitreous Body; Retina; Retinitis Pigmentosa; Inflammation; Disease Models, Animal; Inflammation Mediators
PubMed: 38222454
DOI: No ID Found -
PloS One 2016We investigated the spatial variation of vitreous oxygen consumption in enucleated porcine eyes. A custom made oxygen source was fabricated that could be localized to...
We investigated the spatial variation of vitreous oxygen consumption in enucleated porcine eyes. A custom made oxygen source was fabricated that could be localized to either the mid or posterior vitreous cavity and steady state vitreous oxygen tension was measured as a function of distance from the source using a commercially available probe. The reaction rate constant of ascorbate oxidation was estimated ex vivo by measuring the change in oxygen tension over time using vitreous harvested from porcine eyes. Vitreous ascorbate from mid and posterior vitreous was measured spectrophotometrically. When the oxygen source was placed in either the mid-vitreous (N = 6) or the posterior vitreous (N = 6), we measured a statistically significant decrease in vitreous oxygen tension as a function of distance from the oxygen source when compared to control experiments without an oxygen source; (p<0.005 for mid-vitreous and p<0.018 for posterior vitreous at all distances). The mid-vitreous oxygen tension change was significantly different from the posterior vitreous oxygen tension change at 2 and 3mm distances from the respective oxygen source (p<0.001). We also found a statistically significant lower concentration of ascorbate in the mid-vitreous as compared to posterior vitreous (p = 0.02). We determined the reaction rate constant, k = 1.61 M(-1) s(-1) ± 0.708 M(-1) s(-1) (SE), of the oxidation of ascorbate which was modeled following a second order rate equation. Our data demonstrates that vitreous oxygen consumption is higher in the posterior vitreous compared to the mid-vitreous. We also show spatial variations in vitreous ascorbate concentration.
Topics: Animals; Ascorbic Acid; Kinetics; Oxygen; Oxygen Consumption; Swine; Vitreous Body
PubMed: 26930281
DOI: 10.1371/journal.pone.0149961 -
Biomolecules Dec 2021Vitreous fluid is commonly collected for toxicological analysis during forensic postmortem investigations. Vitreous fluid is also often analyzed for potassium, sodium,...
Vitreous fluid is commonly collected for toxicological analysis during forensic postmortem investigations. Vitreous fluid is also often analyzed for potassium, sodium, chloride and glucose for estimation of time since death, and for the evaluation of electrolyte imbalances and hyperglycemia, respectively. Obtaining such results in the early phase of a death investigation is desirable both in regard to assisting the police and in the decision-making prior to the autopsy. We analyzed vitreous fluid with blood gas instruments to evaluate/examine the possible impact of different sampling and pre-analytical treatment. We found that samples from the right and left eye, the center of the eye as well as whole vitreous samples gave similar results. We also found imprecision to be very low and that centrifugation and dilution were not necessary when analyzing vitreous samples with blood gas instruments. Similar results were obtained when analyzing the same samples with a regular multi-analysis instrument, but we found that such instruments could require dilution of samples with high viscosity, and that such dilution might impact measurement accuracy. In conclusion, using a blood gas instrument, the analysis of postmortem vitreous fluid for electrolytes and glucose without sample pretreatment produces rapid and reliable results.
Topics: Autopsy; Humans; Postmortem Changes; Potassium; Sodium; Vitreous Body
PubMed: 35053180
DOI: 10.3390/biom12010032