ABSTRACT
AIMS/HYPOTHESIS: Proliferative diabetic retinopathy (PDR) with retinal neovascularisation (NV) is a leading cause of vision loss. This study identified a set of metabolites that were altered in the vitreous humour of PDR patients compared with non-diabetic control participants. We corroborated changes in vitreous metabolites identified in prior studies and identified novel dysregulated metabolites that may lead to treatment strategies for PDR. METHODS: We analysed metabolites in vitreous samples from 43 PDR patients and 21 non-diabetic epiretinal membrane control patients from Japan (age 27-80 years) via ultra-high-performance liquid chromatography-mass spectrometry. We then investigated the association of a novel metabolite (creatine) with retinal NV in mouse oxygen-induced retinopathy (OIR). Creatine or vehicle was administered from postnatal day (P)12 to P16 (during induced NV) via oral gavage. P17 retinas were quantified for NV and vaso-obliteration. RESULTS: We identified 158 metabolites in vitreous samples that were altered in PDR patients vs control participants. We corroborated increases in pyruvate, lactate, proline and allantoin in PDR, which were identified in prior studies. We also found changes in metabolites not previously identified, including creatine. In human vitreous humour, creatine levels were decreased in PDR patients compared with epiretinal membrane control participants (false-discovery rate <0.001). We validated that lower creatine levels were associated with vascular proliferation in mouse retina in the OIR model (p = 0.027) using retinal metabolomics. Oral creatine supplementation reduced NV compared with vehicle (P12 to P16) in OIR (p = 0.0024). CONCLUSIONS/INTERPRETATION: These results suggest that metabolites from vitreous humour may reflect changes in metabolism that can be used to find pathways influencing retinopathy. Creatine supplementation could be useful to suppress NV in PDR. Graphical abstract.
Subject(s)
Diabetic Retinopathy/metabolism , Metabolomics , Vitreous Body/metabolism , Adult , Aged , Aged, 80 and over , Amino Acids/analysis , Animals , Chromatography, High Pressure Liquid , Creatine/administration & dosage , Creatine/analysis , Diabetic Retinopathy/physiopathology , Female , Humans , Male , Mass Spectrometry , Mice , Mice, Inbred C57BL , Middle Aged , Retinal Neovascularization/metabolism , Vitreous Body/chemistryABSTRACT
To examine whether free fatty acid receptor 4 (FFAR4) activation can protect against choroidal neovascularization (CNV), which is a common cause of blindness, and to elucidate the mechanism underlying the inhibition, we used the mouse model of laser-induced CNV to mimic angiogenic aspects of age-related macular degeneration (AMD). Laser-induced CNV was compared between groups treated with an FFAR4 agonist or vehicle, and between FFAR4 wild-type (Ffar4+/+) and knock out (Ffar4-/-) mice on a C57BL/6J/6N background. The ex vivo choroid-sprouting assay, including primary retinal pigment epithelium (RPE) and choroid, without retina was used to investigate whether FFAR4 affects choroidal angiogenesis. Western blotting for pNF-ĸB/NF-ĸB and qRT-PCR for Il-6, Il-1ß, Tnf-α, Vegf, and Nf-ĸb were used to examine the influence of FFAR4 on inflammation, known to influence CNV. RPE isolated from Ffar4+/+ and Ffar4-/- mice were used to assess RPE contribution to inflammation. The FFAR4 agonist suppressed laser-induced CNV in C57BL/6J mice, and CNV increased in Ffar4-/- compared to Ffar4+/+ mice. We showed that the FFAR4 agonist acted through the FFAR4 receptor. The FFAR4 agonist suppressed mRNA expression of inflammation markers (Il-6, Il-1ß) via the NF-ĸB pathway in the retina, choroid, RPE complex. The FFAR4 agonist suppressed neovascularization in the choroid-sprouting ex vivo assay and FFAR4 deficiency exacerbated sprouting. Inflammation markers were increased in primary RPE cells of Ffar4-/- mice compared with Ffar4+/+ RPE. In this mouse model, the FFAR4 agonist suppressed CNV, suggesting FFAR4 to be a new molecular target to reduce pathological angiogenesis in CNV.
Subject(s)
Choroidal Neovascularization/metabolism , Choroidal Neovascularization/prevention & control , Receptors, G-Protein-Coupled/metabolism , Animals , Choroidal Neovascularization/genetics , Cytokines/genetics , Cytokines/metabolism , Male , Mice , Mice, Knockout , NF-kappa B/genetics , NF-kappa B/metabolism , Receptors, G-Protein-Coupled/geneticsABSTRACT
The aim of the current study was to investigate the impact of long-acting fibroblast growth factor 21 (FGF21) on retinal vascular leakage utilizing machine learning and to clarify the mechanism underlying the protection. To assess the effect on retinal vascular leakage, C57BL/6J mice were pre-treated with long-acting FGF21 analog or vehicle (Phosphate Buffered Saline; PBS) intraperitoneally (i.p.) before induction of retinal vascular leakage with intravitreal injection of mouse (m) vascular endothelial growth factor 164 (VEGF164) or PBS control. Five hours after mVEGF164 injection, we retro-orbitally injected Fluorescein isothiocyanate (FITC) -dextran and quantified fluorescence intensity as a readout of vascular leakage, using the Image Analysis Module with a machine learning algorithm. In FGF21- or vehicle-treated primary human retinal microvascular endothelial cells (HRMECs), cell permeability was induced with human (h) VEGF165 and evaluated using FITC-dextran and trans-endothelial electrical resistance (TEER). Western blots for tight junction markers were performed. Retinal vascular leakage in vivo was reduced in the FGF21 versus vehicle- treated mice. In HRMECs in vitro, FGF21 versus vehicle prevented hVEGF-induced increase in cell permeability, identified with FITC-dextran. FGF21 significantly preserved TEER compared to hVEGF. Taken together, FGF21 regulates permeability through tight junctions; in particular, FGF21 increases Claudin-1 protein levels in hVEGF-induced HRMECs. Long-acting FGF21 may help reduce retinal vascular leakage in retinal disorders and machine learning assessment can help to standardize vascular leakage quantification.
Subject(s)
Capillary Permeability/drug effects , Fibroblast Growth Factors/pharmacology , Retina/drug effects , Retinal Vessels/drug effects , Animals , Blood-Retinal Barrier/drug effects , Blood-Retinal Barrier/metabolism , Blood-Retinal Barrier/pathology , Cells, Cultured , Female , Fibroblast Growth Factors/administration & dosage , Humans , Machine Learning , Male , Mice, Inbred C57BL , Retina/metabolism , Retina/pathology , Retinal Vessels/metabolism , Retinal Vessels/pathologyABSTRACT
The tightly structured neural retina has a unique vascular network comprised of three interconnected plexuses in the inner retina (and choroid for outer retina), which provide oxygen and nutrients to neurons to maintain normal function. Clinical and experimental evidence suggests that neuronal metabolic needs control both normal retinal vascular development and pathological aberrant vascular growth. Particularly, photoreceptors, with the highest density of mitochondria in the body, regulate retinal vascular development by modulating angiogenic and inflammatory factors. Photoreceptor metabolic dysfunction, oxidative stress, and inflammation may cause adaptive but ultimately pathological retinal vascular responses, leading to blindness. Here we focus on the factors involved in neurovascular interactions, which are potential therapeutic targets to decrease energy demand and/or to increase energy production for neovascular retinal disorders.
Subject(s)
Photoreceptor Cells, Vertebrate/metabolism , Retina/metabolism , Retinal Diseases/metabolism , Retinal Neovascularization/metabolism , Retinal Vessels/metabolism , Animals , Blood Flow Velocity , Humans , Mitochondria/metabolism , Reactive Oxygen Species/metabolism , Retinal Diseases/physiopathology , Retinal Neovascularization/physiopathology , Retinal Vessels/physiologyABSTRACT
PURPOSE: To characterize the choriocapillaris (CC) structure in relation to subretinal fluid (SRF) as a possible systematic error source using spectral domain (SD-OCTA) compared to swept-source optical coherence tomography angiography (SS-OCTA). METHODS: This is a prospective case-control study of 23 eyes. Ten patients with acute central serous chorioretinopathy (CSC), three patients with partial macular-off retinal detachment (RD) and ten healthy, age-matched controls were included. Abnormal CC decorrelation signals were quantitatively compared in CSC and controls by means of custom image processing. To investigate the influence of SRF on CC OCTA signal, the extent of SRF was quantified with a macular heatmap and compared with the corresponding OCTA signal of the CC. RESULTS: SS-OCTA yielded a more homogeneous OCTA signal from the CC than SD-OCTA, offering less signal dispersion and variability in healthy and diseased eyes. Both devices demonstrated CC signal voids in CSC and RD, respectively. In CCS, the voids were predominantly located in the area with SRF. Compared to SD-OCTA, SS-OCTA delivered a more homogenous OCTA signal and reduced signal voids in the CC underneath SRF in both RD and CSC (CSC, 7.6% ± 6.3% vs, 19.7% ± 9.6%, p < 0.01). Despite this significant attenuation of signal voids, SS-OCTA continued to reveal signal voids below SRF and more pixels with reduced OCTA signals in CSC patients compared to controls (7.6% ± 6.3%, 0.1% ± 0.1%, p < 0.0001). CONCLUSION: Understanding OCTA artifacts is critical to ensure accurate clinical evaluations. In this study, we describe the presence of SRF as an important shadow-causing artifact source for CC OCTA analysis which can be mitigated but not completely eliminated by employing SS-OCTA.
Subject(s)
Artifacts , Tomography, Optical Coherence , Case-Control Studies , Choroid , Fluorescein Angiography , Humans , Prospective Studies , Subretinal Fluid/diagnostic imagingABSTRACT
BACKGROUND: Human retinal microvascular endothelial cells (HRMVECs) are involved in the pathogenesis of retinopathy of prematurity. In this study, the microRNA (miRNA) expression profiles of HRMVECs were investigated under resting conditions, angiogenic stimulation (VEGF treatment) and anti-VEGF treatment. MATERIALS AND METHODS: The miRNA profiles of HRMVECs under resting and angiogenic conditions (VEGF treatment), as well as after addition of aflibercept, bevacizumab or ranibizumab were evaluated by analyzing the transcriptome of small non-coding RNAs. Differentially expressed miRNAs were validated using qPCR and classified using Gene Ontology enrichment analysis. RESULTS: Ten miRNAs were found to be significantly changed more than 2-fold. Seven of these miRNAs were changed between resting conditions and angiogenic stimulation. Four of these miRNAs (miR-139-5p/-3p and miR-335-5p/-3p) were validated by qPCR in independent experiments and were found to be associated with angiogenesis and cell migration in Gene Ontology analysis. In addition, analysis of the most abundant miRNAs in the HRMVEC miRNome (representing at least 1% of the miRNome) was conducted and identified miR-21-5p, miR-29a-3p, miR-100-5p and miR-126-5p/-3p to be differently expressed by at least 15% between resting conditions and angiogenic conditions. These miRNAs were found to be associated with apoptotic signaling, regulation of kinase activity, intracellular signal transduction, cell surface receptor signaling and positive regulation of cell differentiation in Gene Ontology analysis. No differentially regulated miRNAs between angiogenic stimulation and angiogenic stimulation plus anti-VEGF treatment were identified. CONCLUSION: In this study we characterized the miRNA profile of HRMVECs under resting, angiogenic and anti-angiogenic conditions and identified several miRNAs of potential pathophysiologic importance for angioproliferative retinal diseases. Our results have implications for possible miRNA-targeted angiomodulatory approaches in diseases like diabetic retinopathy or retinopathy of prematurity.
Subject(s)
Angiogenesis Inhibitors/pharmacology , Endothelial Cells/drug effects , MicroRNAs/drug effects , Retina/cytology , Vascular Endothelial Growth Factor A/pharmacology , Bevacizumab/pharmacology , Cell Differentiation/drug effects , Endothelial Cells/metabolism , Humans , MicroRNAs/metabolism , Ranibizumab/pharmacology , Receptors, Vascular Endothelial Growth Factor , Recombinant Fusion Proteins/pharmacology , Retinopathy of Prematurity , Vascular Endothelial Growth Factor A/antagonists & inhibitorsABSTRACT
BACKGROUND: To report the case of a 31-year-old patient with Hand, Foot and Mouth Disease (HFMD) and concurrent acute monocular maculopathy, and to describe multimodal imaging findings never before described including optical coherence tomography angiography (OCT-A). CASE PRESENTATION: Nine days after the onset of clinically highly probable but not laboratory-verified HFMD, a 31-year old male noticed a central scotoma, distorted lines and loss of visual acuity (Snellen visual acuity 20/400) in his right eye. Funduscopy revealed focal alterations in the retinal pigmented epithelium (RPE) and yellow retinal dots corresponding to focal dots of decreased fundus autofluorescence (FAF) surrounded by increased FAF. Spectral domain optical coherence tomography (SD-OCT) demonstrated irregularities in the ellipsoide zone, hyperreflective dots above the RPE and RPE thickening. Fundus fluorescein angiography (FAG) revealed central hypofluorescence in the macular area in the early phase, as well as increasing focal hyperfluorescence in the late phase corresponding with RPE defects observed in FAF. Indocyanine green angiography (ICGA) showed central hypofluorescence in the early and late phase, corresponding with areas of reduced flow in the choroidea and choriocapillaris as apparent in OCT-A. Visual acuity improved within 3 months without any systemic or local therapy. At his three-month follow-up, SD-OCT revealed subtle subretinal fluid that resolved spontaneously over time. No signs of choroidal neovascularization were observed. Twelve months following the onset of symptoms Snellen visual acuity was 400/400. Multimodal imaging revealed subtly changed, decreased FAF while the choroidal architecture recovered completely as demonstrated by OCT-A. CONCLUSIONS: HFMD-associated maculopahty is an uncommon but important differential diagnosis of chorioretinitis with macular involvement. The prognosis can be good and the initially observed morphological pathologies such as impaired perfusion of the choroidal vessels can recover spontaneously over a period lasting 12 months. OCT-A can be employed as a non-invasive tool to detect the reduced perfusion of the choroidal vessels and for monitoring the disease course.
Subject(s)
Choroid Diseases/virology , Hand, Foot and Mouth Disease/complications , Retinal Diseases/virology , Adult , Choroid/blood supply , Humans , Male , Scotoma/virologyABSTRACT
The formation of new blood vessels, or angiogenesis, is a complex process that plays important roles in growth and development, tissue and organ regeneration, as well as numerous pathological conditions. Angiogenesis undergoes multiple discrete steps that can be individually evaluated and quantified by a large number of bioassays. These independent assessments hold advantages but also have limitations. This article describes in vivo, ex vivo, and in vitro bioassays that are available for the evaluation of angiogenesis and highlights critical aspects that are relevant for their execution and proper interpretation. As such, this collaborative work is the first edition of consensus guidelines on angiogenesis bioassays to serve for current and future reference.
Subject(s)
Biological Assay/methods , Neoplasms , Neovascularization, Pathologic , Animals , Biological Assay/instrumentation , Guidelines as Topic , Humans , Mice , Neoplasms/blood supply , Neoplasms/metabolism , Neoplasms/pathology , Neovascularization, Pathologic/metabolism , Neovascularization, Pathologic/pathologyABSTRACT
PURPOSE: Chronic central serous chorioretinopathy (CSC) is a vision-threatening eye disease for which there is still no approved treatment. Recent studies suggest that the corticosteroid pathway in the choroid is implicated in CSC pathogenesis, and that therapy with the aldosterone antagonist eplerenone improves clinical outcomes. However, there is still little clinical data to support this hypothesis. We performed a retrospective chart review to further investigate the clinical value of eplerenone treatment in patients with chronic CSC and to identify possible response predictors. METHODS: Twenty-four patients with chronic CSC resistant to conventional therapy over at least 4 months were included in this retrospective study. Patients were initially treated with 25 mg/day of eplerenone administered orally for 1 week, followed by a sustained daily dose of 50 mg. The primary outcome measure was percentage of eyes achieving complete resolution of subretinal fluid (SRF), recorded by spectral domain optical coherence tomography (SD-OCT). Secondary outcomes included changes in central macular thickness (CMT) and best-corrected visual acuity (BCVA). Baseline SD-OCT images were also evaluated as possible predictors of treatment response. RESULTS: Twenty-nine percent of patients experienced complete resolution of SRF after a median of 106 days of treatment, while 33 % of patients showed a transient initial decrease in SRF, and 25 % failed to respond to treatment. Treatment had to be stopped in 13 % of patients because of adverse effects of the eplerenone treatment. In the study population, CMT decreased from 342 to 275 µm after treatment, which was associated with a modest improvement in mean BCVA from 0.35 to 0.3 logMar. The integrity of the ellipsoid zone and the retinal pigment epithelium (RPE) at baseline were associated with a tendency towards a favourable visual outcome. CONCLUSION: This study confirms the proposed clinical value of eplerenone for treating patients with therapy-resistant CSC. However, patients presenting widespread RPE changes are less likely to benefit from eplerenone treatment, which may argue for an earlier intervention. Larger studies are needed to characterise patient subgroups that may benefit the most from eplerenone treatment.
Subject(s)
Central Serous Chorioretinopathy/drug therapy , Retinal Pigment Epithelium/pathology , Spironolactone/analogs & derivatives , Tomography, Optical Coherence/methods , Visual Acuity , Administration, Oral , Adult , Aged , Aged, 80 and over , Central Serous Chorioretinopathy/diagnosis , Chronic Disease , Dose-Response Relationship, Drug , Eplerenone , Female , Fluorescein Angiography , Follow-Up Studies , Fundus Oculi , Humans , Male , Middle Aged , Mineralocorticoid Receptor Antagonists/administration & dosage , Retrospective Studies , Spironolactone/administration & dosage , Treatment OutcomeABSTRACT
BACKGROUND AND OBJECTIVE: Epiretinal membrane (ERM) formation, a common complication following pars plana vitrectomy (PPV) for primary rhegmatogenous retinal detachment (RRD) repair, is associated with vision loss and metamorphopsias. Although laser retinopexy is generally associated with ERM formation, the correlation between the extent of laser treatment and ERM formation during PPV is not well established. The aim of this study was to identify risk factors associated with ERM formation including extend of endolaser retinopexy after PPV for primary RRD. PATIENTS AND METHODS: A retrospective, observational case series of 181 consecutive patients (185 eyes) who underwent PPV for primary RRD repair by a single surgeon was performed. Charts were reviewed by two independent reviewers, and de-identified data including patient characteristics and intraoperative findings such as number of laser spots placed were recorded. RESULTS: Postoperative ERM formation occurred in 75 eyes (40.5%) of which 68 (90.6%) were Stage 1, two (2.6%) were Stage 2, three (4%) were Stage 3, and two (2.6%) were Stage 4. Only one patient required secondary PPV for visually significant ERM. Patients with ERM had significantly more laser spots compared with patients with no ERM, with a mean of 807 and 519 laser spots respectively (95% CI: 387.6 to -187.3; P < 0.0001). Univariable analysis identified ≥750 endolaser spots (odds ratio [OR] = 4.0, 95% CI: 2.0 to 8.4; P < 0.0001), ≥4 retinal tears (OR = 2.8, 95%: CI 1.4 to 6.4; P = 0.005), and female sex (OR = 2.0, 95% CI: 1.1 to 3.7; P = 0.02) as significantly associated factors. After adjusting for potential confounding factors (ie, age, sex, macula status, lattice degeneration, length of symptoms, vitreous hemorrhage, number of endolaser spots, number of retinal tears) in multivariable logistic regression, ≥ 750 endolaser spots (OR = 2.4; P = 0.04) and female sex (OR = 2.4; P = 0.03) persisted as significant independent factors. CONCLUSIONS: Our study identified ≥ 750 laser spots and female sex as independent risk factors for ERM formation following PPV for RRD with an OR of 2.4 each. Although the incidence of ERM formation was generally high (40.5%), only one case required secondary PPV with ERM peeling, and visual outcomes were comparable between patients with and without ERM at final follow up. While endolaser photocoagulation is critical for successful RRD repair, consideration of the risk of ERM formation with extensive laser exposure is warranted. [Ophthalmic Surg Lasers Imaging Retina 2024;55:326-333.].
Subject(s)
Epiretinal Membrane , Retinal Detachment , Visual Acuity , Vitrectomy , Humans , Retinal Detachment/surgery , Retinal Detachment/etiology , Retinal Detachment/diagnosis , Vitrectomy/adverse effects , Vitrectomy/methods , Retrospective Studies , Female , Epiretinal Membrane/surgery , Male , Middle Aged , Aged , Risk Factors , Postoperative Complications/etiology , Adult , Laser Therapy/methods , Laser Therapy/adverse effects , Aged, 80 and over , Tomography, Optical Coherence/methodsABSTRACT
The use of checkpoint inhibitors has been associated with multiple ocular and orbital complications including Vogt-Koyanagi-Harada disease. In the current case, a 55-year-old man presented with visual changes 3 months following discontinuation of nivolumab for metastatic renal cell carcinoma. This is the second report of delayed presentation following discontinuation of a checkpoint inhibitor and the only case not associated with an alternative targeted therapy at the time of presentation. This article highlights a unique presentation of delayed checkpoint inhibitor-associated Vogt-Koyanagi-Harada and summarizes the reported cases. [Ophthalmic Surg Lasers Imaging Retina 2023;54(3):183-187.].
Subject(s)
Immune Checkpoint Inhibitors , Nivolumab , Uveomeningoencephalitic Syndrome , Humans , Male , Middle Aged , Carcinoma, Renal Cell/drug therapy , Carcinoma, Renal Cell/complications , Eye , Kidney Neoplasms/drug therapy , Kidney Neoplasms/complications , Nivolumab/adverse effects , Uveomeningoencephalitic Syndrome/chemically induced , Uveomeningoencephalitic Syndrome/diagnosis , Uveomeningoencephalitic Syndrome/drug therapy , Immune Checkpoint Inhibitors/adverse effectsABSTRACT
Three-Dimensional (3D) heads-up visualization systems have significantly advanced vitreoretinal surgery, providing enhanced detail and improved ergonomics. This review discusses the application of 3D systems in vitreoretinal surgery, their use in various procedures, their combination with other imaging modalities, and the role of this technology in medical education and telementoring. Furthermore, the review highlights the benefits of 3D systems, such as improved ergonomics, reduced phototoxicity, enhanced depth of field, and the use of color filters. Potential challenges, including the learning curve and additional costs, are also addressed. The review concludes by exploring promising future applications, including teleophthalmology for remote assistance and specialist availability expansion, virtual reality integration for global clinical education, and the combination of remotely robotic-guided surgery with artificial intelligence for precise, efficient surgical procedures. This comprehensive review offers insights into the current state and future potential of 3D heads-up visualization systems in vitreoretinal surgery, underscoring the transformative impact of this technology on ophthalmology.
ABSTRACT
Eye diseases are diagnosed by visualizing often irreversible structural changes occurring late in disease progression, such as retinal ganglion cell loss in glaucoma. The retina and optic nerve head have high mitochondrial energy need. Early mitochondrial/energetics dysfunction may predict vulnerability to permanent structural changes. In the in vivo murine eye, we used light-based resonance Raman spectroscopy (RRS) to assess noninvasively the redox states of mitochondria and hemoglobin which reflect availability of electron donors (fuel) and acceptors (oxygen). As proof of principle, we demonstrated that the mitochondrial redox state at the optic nerve head correlates with later retinal ganglion loss after acute intraocular pressure (IOP) elevation. This technology can potentially map the metabolic health of eye tissue in vivo complementary to optical coherence tomography, defining structural changes. Early detection (and normalization) of mitochondrial dysfunction before irreversible damage could lead to prevention of permanent neural loss.
ABSTRACT
Dyslipidemia and autophagy have been implicated in the pathogenesis of blinding neovascular age-related macular degeneration (NV-AMD). VLDL receptor (VLDLR), expressed in photoreceptors with a high metabolic rate, facilitates the uptake of triglyceride-derived fatty acids. Since fatty acid uptake is reduced in Vldlr-/- tissues, more remain in circulation, and the retina is fuel deficient, driving the formation in mice of neovascular lesions reminiscent of retinal angiomatous proliferation (RAP), a subtype of NV-AMD. Nutrient scarcity and energy failure are classically mitigated by increasing autophagy. We found that excess circulating lipids restrained retinal autophagy, which contributed to pathological angiogenesis in the Vldlr-/- RAP model. Triglyceride-derived fatty acid sensed by free fatty acid receptor 1 (FFAR1) restricted autophagy and oxidative metabolism in photoreceptors. FFAR1 suppressed transcription factor EB (TFEB), a master regulator of autophagy and lipid metabolism. Reduced TFEB, in turn, decreased sirtuin-3 expression and mitochondrial respiration. Metabolomic signatures of mouse RAP-like retinas were consistent with a role in promoting angiogenesis. This signature was also found in human NV-AMD vitreous. Restoring photoreceptor autophagy in Vldlr-/- retinas, either pharmacologically or by deleting Ffar1, enhanced metabolic efficiency and suppressed pathological angiogenesis. Dysregulated autophagy by circulating lipids might therefore contribute to the energy failure of photoreceptors driving neovascular eye diseases, and FFAR1 may be a target for intervention.
Subject(s)
Macular Degeneration , Retinal Neovascularization , Animals , Autophagy , Cell Proliferation , Fatty Acids , Macular Degeneration/pathology , Mice , Neovascularization, Pathologic , Receptors, G-Protein-Coupled , Retinal Neovascularization/pathology , TriglyceridesABSTRACT
The group of retinal degenerations, retinitis pigmentosa (RP), comprises more than 150 genetic abnormalities affecting photoreceptors. Finding degenerative pathways common to all genetic abnormalities may allow general treatment such as neuroprotection. Neuroprotection may include enhancing the function of cells that directly support photoreceptors, retinal pigment epithelial cells, and Müller glia. Treatment with fibroblast growth factor 21 (FGF21), a neuroprotectant, from postnatal week 4-10, during rod and cone loss in P23H mice (an RP model) with retinal degeneration, preserved photoreceptor function and normalized Müller glial cell morphology. Single-cell transcriptomics of retinal cells showed that FGF21 receptor Fgfr1 was specifically expressed in Müller glia/astrocytes. Of all retinal cells, FGF21 predominantly affected genes in Müller glia/astrocytes with increased expression of axon development and synapse formation pathway genes. Therefore, enhancing retinal glial axon and synapse formation with neurons may preserve retinal function in RP and may suggest a general therapeutic approach for retinal degenerative diseases.
ABSTRACT
Pathological choroidal angiogenesis, a salient feature of age-related macular degeneration, leads to vision impairment and blindness. Endothelial cell (EC) proliferation assays using human retinal microvascular endothelial cells (HRMECs) or isolated primary retinal ECs are widely used in vitro models to study retinal angiogenesis. However, isolating pure murine retinal endothelial cells is technically challenging and retinal ECs may have different proliferation responses than choroidal endothelial cells and different cell/cell interactions. A highly reproducible ex vivo choroidal sprouting assay as a model of choroidal microvascular proliferation was developed. This model includes the interaction between choroid vasculature (EC, macrophages, pericytes) and retinal pigment epithelium (RPE). Mouse RPE/choroid/scleral explants are isolated and incubated in growth-factor-reduced basal membrane extract (BME) (day 0). Medium is changed every other day and choroid sprouting is quantified at day 6. The images of individual choroid explant are taken with an inverted phase microscope and the sprouting area is quantified using a semi-automated macro plug-in to the ImageJ software developed in this lab. This reproducible ex vivo choroidal sprouting assay can be used to assess compounds for potential treatment and for microvascular disease research to assess pathways involved in choroidal micro vessel proliferation using wild type and genetically modified mouse tissue.
Subject(s)
Biological Assay/methods , Choroid/blood supply , Microvessels/growth & development , Neovascularization, Physiologic , Animals , Choroidal Neovascularization/metabolism , Choroidal Neovascularization/pathology , Endothelial Cells/metabolism , Humans , Mice, Inbred C57BL , Receptors, G-Protein-Coupled/metabolismABSTRACT
BACKGROUNDHyperglycemia, insulin insensitivity, and low IGF1 levels in extremely preterm infants are associated with an increased risk of retinopathy of prematurity (ROP), but the interactions are incompletely understood.METHODSIn 117 extremely preterm infants, serum glucose levels and parenteral glucose intake were recoded daily in the first postnatal week. Serum IGF1 levels were measured weekly. Mice with oxygen-induced retinopathy alone versus oxygen-induced retinopathy plus streptozotocin-induced hyperglycemia/hypoinsulinemia were assessed for glucose, insulin, IGF1, IGFBP1, and IGFBP3 in blood and liver. Recombinant human IGF1 was injected to assess the effect on glucose and retinopathy.RESULTSThe highest mean plasma glucose tertile of infants positively correlated with parenteral glucose intake [r(39) = 0.67, P < 0.0001]. IGF1 plasma levels were lower in the high tertile compared with those in low and intermediate tertiles at day 28 (P = 0.038 and P = 0.03). In high versus lower glucose tertiles, ROP was more prevalent (34 of 39 versus 19 of 39) and more severe (ROP stage 3 or higher; 71% versus 32%). In oxygen-induced retinopathy, hyperglycemia/hypoinsulinemia decreased liver IGF1 expression (P < 0.0001); rh-IGF1 treatment improved normal vascular regrowth (P = 0.027) and reduced neovascularization (P < 0.0001).CONCLUSIONIn extremely preterm infants, high early postnatal plasma glucose levels and signs of insulin insensitivity were associated with lower IGF1 levels and increased ROP severity. In a hyperglycemia retinopathy mouse model, decreased insulin signaling suppressed liver IGF1 production, lowered serum IGF1 levels, and increased neovascularization. IGF1 supplementation improved retinal revascularization and decreased pathological neovascularization. The data support IGF1 as a potential treatment for prevention of ROP.TRIAL REGISTRATIONClinicalTrials.gov NCT02760472 (Donna Mega).FUNDINGThis study has been supported by the Swedish Medical Research Council (14940, 4732, 20144-01-3, and 21144-01-3), a Swedish government grant (ALFGB2770), Lund medical faculty grants (ALFL, 11615 and 11601), the Skåne Council Foundation for Research and Development, the Linnéa and Josef Carlsson Foundation, the Knut and Alice Wallenberg Foundation, the NIH/National Eye Institute (EY022275, EY017017, EY017017-13S1, and P01 HD18655), European Commission FP7 project 305485 PREVENT-ROP, Deutsche Forschungsgemeinschaft (CA-1940/1-1), and Stiftelsen De Blindas Vänner.
Subject(s)
Blood Glucose/analysis , Hyperglycemia/complications , Infant, Extremely Premature , Infant, Premature, Diseases/pathology , Insulin-Like Growth Factor I/metabolism , Retinopathy of Prematurity/pathology , Animals , Animals, Newborn , Diabetes Mellitus, Experimental/physiopathology , Female , Gestational Age , Humans , Infant, Newborn , Infant, Premature, Diseases/etiology , Infant, Premature, Diseases/metabolism , Longitudinal Studies , Male , Mice , Mice, Inbred C57BL , Oxygen/metabolism , Prospective Studies , Retinopathy of Prematurity/etiology , Retinopathy of Prematurity/metabolismABSTRACT
INTRODUCTION: To describe the influence of subretinal fluid (SRF) in analysis of the flow signal from the choriocapillaris (CC) via optical coherence tomography angiography (OCTA) in patients with acute central serous chorioretinopathy (CSC). METHODS: Observational, longitudinal, cross-sectional case-control study. Twenty-three eyes of 22 patients with acute CSC were compared with 20 eyes of 20 healthy controls. OCTA images (AngioPlex®, Zeiss) were recorded at baseline and follow-up examination and automatically quantified using an image-processing algorithm. Abnormal CC decorrelation signals (increased and decreased flow, IF and DF) were quantified using a custom image-processing algorithm. To analyze the spatial correlation between SRF and OCTA, CC signal heat-map images containing macular thickness information were used. RESULTS: Choriocapillaris flow alterations were significantly more pronounced at baseline than at follow-up examination in patients with acute CSC and resolving SRF (IF: p < 0.002; DF: p < 0.003). The extent of SRF correlated significantly with the abnormal CC decorrelation signals when comparing baseline with follow-up examinations (IF: rho = 0.56, p < 0.005; DF: rho = 0.64, p < 0.001). In particular, the reduced OCTA flow signal in the area occupied by SRF at baseline disappeared at follow-up examination (p < 0.02). In comparison with controls, CSC patients with complete resorption of SRF continued to show a reduced OCTA flow signal in the CC (p < 0.008). CONCLUSIONS: The temporospatial association between SRF and reduced OCTA signal from the CC demonstrates that fluid might be a significant confounder for OCTA analysis in patients with CSC. CSC patients with complete absorption of the SRF at follow-up, however, show persistently reduced CC flow signals.
ABSTRACT
OBJECTIVE: To describe vascular changes in different stages of Stargardt disease (STGD) via double swept-source optical coherence tomography angiography. METHODS AND ANALYSIS: Prospective, cross-sectional case-control study. Twenty-three patients (45 eyes) with ABCA4 mutations graded according to the Fishman STGD classification and 23 controls (23 eyes) were included. Two independent investigators quantified the foveal avascular zone (FAZ) in the superficial and deep capillary plexus (SCP/DCP) and the areas presenting rarefied flow and complete vascular atrophy in the outer retina to choriocapillaris (ORCC) and choriocapillaris (CC) slab. RESULTS: The mean age at first diagnosis of STGD was 24.0 years (range 9-50) and 37.9 years (range 18-74) at the time of examination. Eleven patients were assigned to the Fishman STGD classification stage (S) 1, three to S2, eight to S3 and one to S4. The FAZ in SCP and DCP was increased in all stages compared with controls (p<0.01). Areas with rarefied flow signal and vascular atrophy were detected in the ORCC and the CC layer and grew with increasing stage of disease (p<0.01). The duration of disease correlated with the extent of the enlarged FAZ in the SCP/DCP and with the area of reduced flow in the ORCC and CC layer (p<0.01). Best corrected visual acuity correlated negatively with the extent of the enlarged FAZ in the SCP/DCP (p<0.0001), as well as with enlarged atrophic area in the ORCC and CC layer (p=0.026 and p=0.074). CONCLUSIONS: Patients with STGD reveal vascular changes in the retina and CC in all disease stages. The avascular zone in the SCP/DCP and areas with rarefied flow signal in the ORCC/CC increase with the duration and stage of disease, indicating progressive vascular decay most likely secondary to retinal pigment epithelium and neuronal loss. Furthermore, increased vascular damage is associated with decreased vision.