Retinal Outer Nuclear Layer Research Articles

Glucose tolerance and insulin resistance/sensitivity associate with retinal layer characteristics: the LIFE-Adult-Study

Aims/hypothesisAs the prevalence of insulin resistance and glucose intolerance is increasing throughout the world, diabetes-induced eye diseases are a global health burden. We aim to identify distinct optical bands which are closely related to insulin and glucose metabolism, using non-invasive, high-resolution spectral domain optical coherence tomography (SD-OCT) in a large, population-based dataset.MethodsThe LIFE-Adult-Study randomly selected 10,000 participants from the population registry of Leipzig, Germany. Cross-sectional, standardised phenotyping included the assessment of various metabolic risk markers and ocular imaging, such as SD-OCT-derived thicknesses of ten optical bands of the retina. Global and Early Treatment Diabetic Retinopathy Study (ETDRS) subfield-specific optical retinal layer thicknesses were investigated in 7384 healthy eyes of 7384 participants from the LIFE-Adult-Study stratified by normal glucose tolerance, prediabetes (impaired fasting glucose and/or impaired glucose tolerance and/or HbA1c 5.7–6.4% [39–47 mmol/mol]) and diabetes. The association of optical retinal band characteristics with different indices of glucose tolerance (e.g. fasting glucose, area under the glucose curve), insulin resistance (e.g. HOMA2-IR, triglyceride glucose index), or insulin sensitivity (e.g. estimated glucose disposal rate [eGDR], Stumvoll metabolic clearance rate) was determined using multivariable linear regression analyses for the individual markers adjusted for age, sex and refraction. Various sensitivity analyses were performed to validate the observed findings.ResultsIn the study cohort, nine out of ten optical bands of the retina showed significant sex- and glucose tolerance-dependent differences in band thicknesses. Multivariable linear regression analyses revealed a significant, independent, and inverse association between markers of glucose intolerance and insulin resistance (e.g. HOMA2-IR) with the thickness of the optical bands representing the anatomical retinal outer nuclear layer (ONL, standardised β=−0.096; p<0.001 for HOMA2-IR) and myoid zone (MZ; β=−0.096; p<0.001 for HOMA2-IR) of the photoreceptors. Conversely, markers of insulin sensitivity (e.g. eGDR) positively and independently associated with ONL (β=0.090; p<0.001 for eGDR) and MZ (β=0.133; p<0.001 for eGDR) band thicknesses. These global associations were confirmed in ETDRS subfield-specific analyses. Sensitivity analyses further validated our findings when physical activity, neuroanatomical cell/tissue types and ETDRS subfield categories were investigated after stratifying the cohort by glucose homeostasis.Conclusions/interpretationAn impaired glucose homeostasis associates with a thinning of the optical bands of retinal ONL and photoreceptor MZ. Changes in ONL and MZ thicknesses might predict early metabolic retinal alterations in diabetes.Graphical

Müller cells are activated in response to retinal outer nuclear layer degeneration in rats subjected to simulated weightlessness conditions.

JOURNAL/nrgr/04.03/01300535-202507000-00032/figure1/v/2024-09-09T124005Z/r/image-tiff A microgravity environment has been shown to cause ocular damage and affect visual acuity, but the underlying mechanisms remain unclear. Therefore, we established an animal model of weightlessness via tail suspension to examine the pathological changes and molecular mechanisms of retinal damage under microgravity. After 4 weeks of tail suspension, there were no notable alterations in retinal function and morphology, while after 8 weeks of tail suspension, significant reductions in retinal function were observed, and the outer nuclear layer was thinner, with abundant apoptotic cells. To investigate the mechanism underlying the degenerative changes that occurred in the outer nuclear layer of the retina, proteomics was used to analyze differentially expressed proteins in rat retinas after 8 weeks of tail suspension. The results showed that the expression levels of fibroblast growth factor 2 (also known as basic fibroblast growth factor) and glial fibrillary acidic protein, which are closely related to Müller cell activation, were significantly upregulated. In addition, Müller cell regeneration and Müller cell gliosis were observed after 4 and 8 weeks, respectively, of simulated weightlessness. These findings indicate that Müller cells play an important regulatory role in retinal outer nuclear layer degeneration during weightlessness.

Requirement of a novel gene, drish, in the zebrafish retinal ganglion cell and primary motor axon development.

During neurogenesis, growing axons must navigate through the complex extracellular environment and make correct synaptic connections for the proper functioning of neural circuits. The mechanisms underlying the formation of functional neural networks are still only partially understood. Here we analyzed the role of a novel gene si:ch73-364h19.1/drish in the neural and vascular development of zebrafish embryos. We show that drish mRNA is expressed broadly and dynamically in multiple cell types including neural, glial, retinal progenitor and vascular endothelial cells throughout the early stages of embryonic development. To study Drish function during embryogenesis, we generated drish genetic mutant using CRISPR/Cas9 genome editing. drish loss-of-function mutant larvae displayed defects in early retinal ganglion cell, optic nerve and the retinal inner nuclear layer formation, as well as ectopic motor axon branching. In addition, drish mutant adults exhibited deficient retinal outer nuclear layer and showed defective light response and locomotory behavior. However, vascular patterning and blood circulation were not significantly affected. Together, these data demonstrate important roles of zebrafish drish in the retinal ganglion cell, optic nerve and interneuron development and in spinal motor axon branching.

Piceid Octanoate Protects Retinal Cells against Oxidative Damage by Regulating the Sirtuin 1/Poly-ADP-Ribose Polymerase 1 Axis In Vitro and in rd10 Mice.

Retinitis pigmentosa is a common cause of inherited blindness in adults, which in many cases is associated with an increase in the formation of reactive oxygen species (ROS) that induces DNA damage, triggering Poly-ADP-Ribose Polymerase 1 (PARP1) activation and leading to parthanatos-mediated cell death. Previous studies have shown that resveratrol (RSV) is a promising molecule that can mitigate PARP1 overactivity, but its low bioavailability is a limitation for medical use. This study examined the impact of a synthesized new acylated RSV prodrug, piceid octanoate (PIC-OCT), in the 661W cell line against H2O2 oxidative stress and in rd10 mice. PIC-OCT possesses a better ADME profile than RSV. In response to H2O2, 661W cells pretreated with PIC-OCT preserved cell viability in more than 38% of cells by significantly promoting SIRT1 nuclear translocation, preserving NAD+/NADH ratio, and suppressing intracellular ROS formation. These effects result from expressing antioxidant genes, maintaining mitochondrial function, reducing PARP1 nuclear expression, and preventing AIF nuclear translocation. In rd10 mice, PIC-OCT inhibited PAR-polymer formation, increased SIRT1 expression, significantly reduced TUNEL-positive cells in the retinal outer nuclear layer, preserved ERGs, and enhanced light chamber activity (all p values < 0.05). Our findings corroborate that PIC-OCT protects photoreceptors by modulating the SIRT1/PARP1 axis in models of retinal degeneration.

PolySialic acid-nanoparticles inhibit macrophage mediated inflammation through Siglec agonism: a potential treatment for age related macular degeneration.

Age-related macular degeneration (AMD) is a chronic, progressive retinal disease characterized by an inflammatory response mediated by activated macrophages and microglia infiltrating the inner layer of the retina. In this study, we demonstrate that inhibition of macrophages through Siglec binding in the AMD eye can generate therapeutically useful effects. We show that Siglecs-7, -9 and -11 are upregulated in AMD associated M0 and M1 macrophages, and that these can be selectively targeted using polysialic acid (PolySia)-nanoparticles (NPs) to control dampen AMD-associated inflammation. In vitro studies showed that PolySia-NPs bind to macrophages through human Siglecs-7, -9, -11 as well as murine ortholog Siglec-E. Following treatment with PolySia-NPs, we observed that the PolySia-NPs bound and agonized the macrophage Siglecs resulting in a significant decrease in the secretion of IL-6, IL-1β, TNF-α and VEGF, and an increased secretion of IL-10. In vivo intravitreal (IVT) injection of PolySia-NPs was found to be well-tolerated and safe making it effective in preventing thinning of the retinal outer nuclear layer (ONL), inhibiting macrophage infiltration, and restoring electrophysiological retinal function in a model of bright light-induced retinal degeneration. In a clinically validated, laser-induced choroidal neovascularization (CNV) model of exudative AMD, PolySia-NPs reduced the size of neovascular lesions with associated reduction in macrophages. The PolySia-NPs described herein are therefore a promising therapeutic strategy for repolarizing pro-inflammatory macrophages to a more anti-inflammatory, non-angiogenic phenotype, which play a key role in the pathophysiology of non-exudative AMD.

Mechanistic insight into the adverse outcome of tire wear and road particle leachate exposure in zebrafish (Danio rerio) larvae

Tire wear particles (TWP) have become the major microplastic pollution in China. Road runoff containing TWP leachate can decrease the eye size and even induced mortality in the aquatic organisms. However, the toxic mechanism of TWP and road particles (RP) leachate on aquatic organisms is still unclear. In this study, the zebrafish embryos were exposed to TWP or RP leachate for 5 days at both environmental relevant and high concentrations. The adverse outcome pathways (AOPs) were screened from individual to molecular levels. The morphological and behavioral analysis demonstrated that the leachate exposure mainly impaired the eye development of zebrafish larvae and inhibited the larval swim behavior and phototactic response, which are the adverse outcomes. The phototransduction modulated by zebrafish retina was significantly down-regulated through transcriptomics and metabolomics analysis. The eye histopathological analysis showed that the decreased thickness of the retinal outer nuclear layer (ONL) and retinal pigmented epithelium (RPE) after leachate exposure were caused by the decreased photoreceptor cells. Moreover, the expression of NR2E3 and TPO genes showed concentration-dependent down-regulation after leachate exposure. The inhibition of photoreceptor cell proliferation was identified as the main reason for photoreceptor cell decrease in zebrafish larval eye. This study, for the first time, uncovered the underlying toxic mechanism of TWP and RP on zebrafish larval eyes.

Wolfberry water extract attenuates blue light‐emitting diode damage to ARPE‐19 cells and mouse retina by activating the NRF2 signaling pathway

The wolfberry is believed to improve eyesight in traditional Chinese medicine. Soaking wolfberry in thermos cups has become a common health-preserving practice. The object of this paper was to research the protective effects of wolfberry water extract (WWE) on oxidative injury induced by blue light-emitting diodes (LEDs) in ARPE-19 cells and C57BL/6J mice. Wolfberry water extract significantly increased cell viability, reduced ROS production, stabilized mitochondrial membrane potential, and inhibited apoptosis in blue LED-induced cells (P<0.05). The protective effects of WWE against blue LED-induced cytotoxicity and ROS accumulation in cells were abolished by transfection with Nrf2 siRNA. In blue LED-exposed C57BL/6J mice, WWE treatment markedly increased the amplitudes of electroretinogram (ERG) waves a and b, increased the thickness of retinal outer nuclear layer (ONL), activated endogenous antioxidant enzymes, and decreased MDA levels in the retina and lens. WWE also promoted NRF2 translocation and the expression of the downstream genes Ho-1, Nqo1, Gclc, and Gclm in the retina. The protection of WWE in ERG a and b wave amplitudes and ROS levels were abrogated in Nrf2 knockout mice. These results suggested that WWE has beneficial effects on retinal injury induced by blue LED, and mechanisms of action at least partly via the NRF2 signaling pathway.

Macular outer nuclear layer, ellipsoid zone and outer photoreceptor segment band thickness, axial length and other determinants

The study aims to assess the thickness of the retinal outer nuclear layer (ONL), ellipsoid zone (EZ) and photoreceptor outer segment (POS) band in various macular regions and its associations with axial length and other parameters. Participants of the Beijing Eye Study 2011 underwent a series of examinations including spectral-domain optical coherence tomography of the macula. The current study included 2213 participants without retinal or optic nerve diseases (age: 61.7 ± 8.4 years; range 50–93 years); axial length: 23.15 ± 0.95 mm; range 18.96–29.15 mm). The ONL (fovea: 98.9 ± 8.8 µm), EZ (fovea: 24.1 ± 0.5 µm) and POS band (fovea: 24.3 ± 3.5 µm) were the thickest (P < 0.001) in the fovea (defined as the thinnest central point), followed by the temporal inner, nasal inner, inferior inner, superior inner, inferior outer, temporal outer, nasal outer, and superior outer region. In multivariable analysis, a thicker retinal ONL was associated (correlation coefficient r: 0.40) with shorter axial length (beta: − 0.14; P < 0.001) and shorter disc–fovea distance (beta: − 0.10; P = 0.001), after adjusting for younger age (beta: − 0.26; P < 0.001), male sex (beta: 0.24; P < 0.001), lower serum cholesterol concentration (beta: − 0.05; P = 0.04), and thicker subfoveal choroidal thickness (beta: 0.08; P < 0.001). The POS thickness increased with shorter axial length (beta: − 0.06; P < 0.001) and shorter optic disc–fovea distance (beta: − 0.05; P = 0.03), after adjusting for younger age (beta: − 0.34; P < 0.001), male sex (beta: 0.15; P < 0.001), and thicker subfoveal choroidal thickness (beta: 0.24; P < 0.001). As a conclusion, the photoreceptor ONL, EZ and POS band vary in thickness between different macular regions and differ in their correlations with axial length, disc–fovea distance, age, sex, and subfoveal choroidal thickness. The ONL thickness decrease with longer axial length and longer disc–fovea distance may point to an axial elongation-associated retinal stretching in the macula.

The downregulation of HSP90-controlled CRALBP expression is associated with age-related vision attenuation.

The dysfunction of CRALBP, a key regulator of the visual cycle, is associated with retinitis punctata albescens characterized by night vision loss and retinal degeneration. In this paper, we find that the expression of CRALBP is regulated by heat shock protein 90 (HSP90). Inhibition of HSP90α or HSP90β expression by using the CRISPR-Cas9 technology downregulates CRALBP's mRNA and protein expression in ARPE-19 cells by triggering the degradation of transcription factor SP1 in the ubiquitin-proteasome pathway. SP1 can bind to CRALBP's promoter, and inhibition of SP1 by its inhibitor plicamycin or siRNA downregulates CRALBP's mRNA expression. In the zebrafish, inhibition of HSP90 by the intraperitoneal injection of IPI504 reduces the thickness of the retinal outer nuclear layer and Rlbp1b mRNA expression. Interestingly, the expression of HSP90, SP1, and CRALBP is correlatedly downregulated in the senescent ARPE-19 and Pig primary RPE cells in vitro and in the aged zebrafish and mouse retinal tissues in vivo. The aged mice exhibit the low night adaption activity. Taken together, these data indicate that the HSP90-SP1 is a novel regulatory axis of CRALBP transcriptional expression in RPE cells. The age-mediated downregulation of the HSP90-SP1-CRALBP axis is a potential etiology for the night vision reduction in senior people.

Ageing changes in retinal outer nuclear layer thickness and cone photoreceptor density using adaptive optics-free imaging.

To investigate age-related changes of the outer nuclear layer (ONL) thickness and cone density, and their associations in healthy participants using a modified, narrow scan-angle Heidelberg Retina Angiograph (HRA2). Retinal cones were imaged outside the fovea at 8.8° eccentricity and cone density was compared to ONL thickness measurements obtained by Spectral-Domain Optical Coherence Tomography (SD-OCT) at the same locations. Fifty-six eyes of 56 healthy participants with a median age (interquartile range, IQR) of 37 years (29-55) were included. Median (IQR) cone count was 7,472 (7,188, 7,746) cones/mm2 and median (IQR) ONL thickness was 56 (52, 60) µm for healthy participants. Both cone density and ONL thickness were negatively associated with age: cone density, R2 = 0.16 (F(1,54) = 10.41, P = 0.002); ONL thickness, R2 = 0.12 (F(1,54) = 7.41, P = 0.009). No significant association was seen between cone density and ONL thickness (R2 = 0.03; F(1,54) = 1.66, P = 0.20). Cone density was lower, and ONL thinner, in older compared to younger participants, therefore, image-based structural measures should be compared to age-related data. However, cone density and ONL thickness were not strongly associated, indicating that determinants of ONL thickness measurements other than cone density measurements, and including measurement error, have a major influence.

Repopulated retinal microglia promote Müller glia reprogramming and preserve visual function in retinal degenerative mice.

Rationale: Müller glia (MG) play a key role in maintaining homeostasis of the retinal microenvironment. In zebrafish, MG reprogram into retinal progenitors and repair the injured retina, while this MG regenerative capability is suppressed in mammals. It has been revealed that microglia in zebrafish contribute to MG reprogramming, whereas those in mammals are over-activated during retinal injury or degeneration, causing chronic inflammation, acceleration of photoreceptor apoptosis, and gliosis of MG. Therefore, how to modulate the phenotype of microglia to enhance MG reprogramming rather than gliosis is critical. Methods: PLX3397, a colony-stimulating factor 1 receptor inhibitor, was applied to deplete microglia in the retinas of retinal degeneration 10 (rd10) mice, and withdrawal of PLX3397 was used to induce the repopulated microglia (Rep-MiG). The protective roles of the Rep-MiG on the degenerative retina were assessed using a light/dark transition test, and scotopic electroretinogram recordings. Immunofluorescence, western blot, transcriptomic sequencing, and bioinformatics analysis were performed to investigate the effects and mechanisms of microglia on MG reprogramming. Results: Following PLX3397 withdrawal, Rep-MiG replenished the entire retina with a ramified morphology and significantly improved the retinal outer nuclear layer structure, the electroretinography response, and the visual behavior of rd10 mice. Coincidentally, MG were activated, de-differentiated, and showed properties of retina progenitors in a spatial correlation with Rep-MiG. Morphological and transcriptomic analyses revealed Rep-MiG significantly enhanced protease inhibitor activity and suppressed extracellular matrix (ECM) levels during retinal degeneration. Conclusions: It suggested that Rep-MiG with the homeostasis characteristic stimulated the progenitor cell-like properties of MG, probably through regulating ECM remodeling, which protected photoreceptors and improved visual function of rd10 mice. It might be a potential protocol to reprogram MG and delay mammal retinal degeneration.

Myopic macular Bruch's membrane defects

AbstractPurpose: To examine peculiarities of macular Bruch's membrane defects (BMD) in axially elongated eyes.Methods: Using light microscopy, enucleated human globes were histomorphometrically.Results: The study included 247 eyes (axial length: 20.0–37.0 mm). BMDs were detected in 15 (6.1%) eyes (axial length: 30.6 ± 2.4 mm) (1.9 ± 0.9 BMD/eye with BMDs), located in the macular region in 10 eyes. Mean BMD size was 1.93 ± 1.62 mm (range: 0.22 mm–6.24 mm). Prevalence and size of BMDs were associated with longer axial length (OR: 1.52; p = 0.001) and higher prevalence of scleral staphyloma (OR: 16.3; p &lt; 0.001). BMD width was smaller than the defect width in the overlying retinal pigment epithelium (RPE) layer (p = 0.003) and larger than the length of a defect in the overlying inner nuclear layer (0.43 ± 0.76 mm; p = 0.008) and the width of an inner limiting membrane bridge (0.13 ± 0.33 mm; p = 0.001). Choriocapillaris thickness (8.8 ± 5.0 μm vs. 7.9 ± 3.2 μm; p = 0.94), BM thickness (3.1 ± 0.6 μm versus 3.0 ± 0.5 μm; p = 0.43) and RPE cell density (31.6 ± 8.4 cells/480 μm vs. 27.4 ± 8.8 cells/480 μm; p = 0.051) did not differ significantly between the region at the BDM margin and neighbouring regions. The sclera was thinner in the BDM region than in the neighbouring regions (0.28 ± 0.19 mm vs. 0.36 ± 0.13 mm; p = 0.006).Conclusions: BMDs as hallmark of myopic macular degeneration are characterized by a larger defect in the overlying RPE layer, smaller defects in the overlying retinal outer nuclear layer and inner nuclear layer, localized scleral thinning and an association with scleral staphylomas. Thickness of the choriocapillaris and density of the RPE cell layer, both absent within the BDMs, do not differ between the BMD margin and neighbouring regions. The results suggest an association between BDMs and absolute scotomas, stretching of the overlying retinal nerve fiver layer, an axial elongation‐associated stretching effect as aetiology of the BDMs, and a biomechanical role BM may play.

TCF7L2 promotes ER stress signaling in diabetic retinopathy

Diabetic retinopathy (DR) is one of the most common blindness in working-age adults. Transcription factor 7 like 2 (TCF7L2) is a susceptibility gene of DR, however, its roles in the pathogenesis of DR are still largely unknown. In this study, we found that TCF7L2 was mainly located in the cell nucleus of retinal ganglion cell layer (GCL) and inner nuclear layer (INL), while it was not expressed in the cell nucleus of retinal outer nuclear layer (ONL). Expression of TCF7L2 was significantly elevated in the retinas of db/db diabetic mice and oxygen-induced retinopathy (OIR) mice. Also, in Ad-hTCF7L2 treated hiPSCs-derived retinal progenitor cells (RPCs), activating transcription factor 6 (ATF6)-related endoplasmic reticulum (ER) stress signaling was remarkably activated. Moreover, knockdown of TCF7L2 significantly inhibited ATF6-related ER stress signaling. Furthermore, the data of endothelial permeability assay showed that RPCs pretreated with Ad-hTCF7L2 lead to enhanced monolayer permeability of human umbilical vein endothelial cells (HUVECs), and knockdown of TCF7L2 or ATF6 in RPCs could alleviate the monolayer permeability of HUVECs. Thus, our results showed that TCF7L2 could trigger ATF6-related ER stress signaling and promote vein endothelial cell permeability, which will provide important insight into the role of TCF7L2 in the pathogenesis of DR and contribute to designing potential therapies.

Evaluation of eye protection efficacy of sweet potato leaf ethanolic extracts In Vivo

Many studies have been verified that human retina contains a large amount of carotenoids such as lutein and zeaxanthin, especially the concentrations of lutein and zeaxanthin in the retina and macula are 1,000 times higher than other tissues in human. Therefore, lutein and zeaxanthin play an important role in the health of human vision. The research and development (R&amp;D) of agricultural functional materials or products for eye protection is urgently needed. In this experiment, except for the normal control group, the other groups were irradiated with light-emitting diode (LED) light at the range of 600-1,000 lux for 12 hours / day for 6 weeks. All BALB/c mice were fed with the normal composition for 6 weeks during the experiment. BALB/c mice in the negative control group and three sweet potato leaf ethanolic extracts (SPLEE) groups were fed SPLEE [0.31, 0.62, and 1.23 mg/kg body weight (BW), respectively] for 6 weeks by gavage during the experiment. During the experiment, the eye status of BALB/c mice in each group were observed every week. At the end of the experiment, the BALB/c mice were sacrificed and their eyes in each group were collected for hematoxylin &amp; eosin (H&amp;E) staining, immunohistochemical (IHC) staining, free radical detection, and the detection of cytokine gene expressions (IL-6; interleukin-6 and TNF-α; tumor necrosis factor-α) and caspase-3 gene expression. Based on the results of this experiment, no obvious lesions by ophthalmoscopy were observed in the eyes of BALB/c mice in three SPLEE groups. H&amp;E and IHC staining results showed that the consumption of high dose (1.23 mg/kg BW) of SPLEE significantly improved retinal outer nuclear layer (ONL) thickness, which was compared to the negative control group. Other evaluation indicators included retinal out segments-inner segments (OS/IS) thickness, glial fibrillary acidic protein (GFAP) staining, and middle-wavelength opsin (M-opsin) staining, showed no significant difference among three SPLEE groups and the negative control group. The free radical detection results showed that no statistical difference between all groups (p &gt; 0.05), however, the trend showed that the free radicals in the high and middle doses (1.23 and 0.62 mg/kg BW) of SPLEE groups were lower than those in the negative control group and the low dose (0.31 mg/kg BW) of SPLEE group. The results of IL-6 and TNF-α gene expression showed that the normal control group and three SPLEE groups were significantly lower than the negative control group (p &lt; 0.05), while the gene expression of caspase-3 was not significantly differences between all groups (p &gt; 0.05). Taken these results together, the high dose SPLEE (1.23 mg/kg BW) has the better potential for improving the retinal ONL thickness and anti-inflammatory effects under LED irradiation.

Intravenous infusion of small umbilical cord mesenchymal stem cells could enhance safety and delay retinal degeneration in RCS rats

BackgroundHuman umbilical cord mesenchymal stem cells (UCMSCs) transplantation is a promising therapy for the treatment of retinitis pigmentosa (RP). However, intravenously infused cells may be blocked in the lung, increasing the risk of vascular obstruction, which needs to be optimized to further improve safety and efficacy.MethodsWe derived small UCMSCs (S-UCMSCs) from filtering UCMSCs with a 10-μm filter, and compared with UCMSCs by flow cytometry, directional differentiation culture and transcriptome sequencing. Then the S-UCMSCs and UCMSCs were intravenously infused in the Royal College Surgeons (RCS) rats to evaluate the safety and the efficacy.ResultsThe diameter of S-UCMSCs ranged from 5.568 to 17.231 μm, with an average diameter of 8.636 ± 2.256 μm, which was significantly smaller than that of UCMSCs. Flow cytometry, immunofluorescence and transcriptome sequencing demonstrated that the S-UCMSCs and UCMSCs were the same kind of MSCs, and the S-UCMSCs were more proliferative. After the S-UCMSCs and UCMSCs were intravenously infused into the Royal College of Surgeons (RCS) rats at a dose of 1 × 106 cells/rat, the S-UCMSCs blocked in the lungs were significantly fewer and disappeared more quickly than UCMSCs. The b wave of the flash electroretinogram was improved at 7 d, and the retinal outer nuclear layer thickness was thicker at 7 d and 14 d. The expression level of inflammation was inhibited, and the expression level of neurotrophic factors was upregulated in the retina and serum after transplantation.ConclusionsS-UCMSCs intravenous infusion was safer than UCMSCs and could delay retinal degeneration and protect visual function in RCS rats, which may be a preferable therapeutic approach for RP.

Anti-CXCL10 monoclonal antibody therapy protects against the diabetic retinopathy in the mouse model induced by streptozotocin

ObjectiveTo explore the effect of CXC chemokine CXCL10 in the mice with diabetic retinopathy (DR). MethodsDR models were constructed on mice via injection of streptozotocin (STZ). At 3 weeks of STZ, mice were treated with anti-CXCL10 monoclonal antibodies (mAb)/control mAb, and a series of experiments were then conducted at 6 weeks of STZ, including HE staining, western blotting, retinal trypsin digestion, real-time qPCR and enzyme-linked immuno sorbent assay (ELISA). The corresponding kits were used to detect the activity of oxidative stress markers. ResultsCompared with nondiabetic eyes, DR mice both at 3 and 6 weeks presented the decreases in the total retinal thickness, the retinal outer nuclear layer (ONL) thickness, and the cells of ganglion cell layer (GCL), with the upregulated CXCL10, pro-inflammatory cytokines and malondialdehyde (MDA), as well as the downregulated levels of superoxide dismutase (SOD), glutathione peroxidase (GPx) and CAT, especially in those at 6 weeks, which were attenuated by the anti-CXCL10 mAb treatment. Moreover, in comparison with the DR mice, mice in the DR + anti-CXCL10 mAb group gained the significant decrease in the number of acellular capillaries of retina, with up-regulations of Claudin-5 and ZO-1 and down-regulations of VEGF and FGF-2. The DR mice injected with anti-CXCL10 mAb demonstrated alleviated retinal pathology as compared to mice at 3 weeks of STZ. ConclusionAnti-CXCL10 mAb could mitigate the retinal pathology of DR mice, with the decreased inflammation and oxidative stress, thus mediating a delay in the development or disease improvement in patients of DR.

Zebrafish as a Model to Evaluate a CRISPR/Cas9-Based Exon Excision Approach as a Future Treatment Option for EYS-Associated Retinitis Pigmentosa.

Retinitis pigmentosa (RP) is an inherited retinal disease (IRD) with an overall prevalence of 1 in 4000 individuals. Mutations in EYS (Eyes shut homolog) are among the most frequent causes of non-syndromic autosomal recessively inherited RP and act via a loss-of-function mechanism. In light of the recent successes for other IRDs, we investigated the therapeutic potential of exon skipping for EYS-associated RP. CRISPR/Cas9 was employed to generate zebrafish from which the region encompassing the orthologous exons 37-41 of human EYS (eys exons 40-44) was excised from the genome. The excision of these exons was predicted to maintain the open reading frame and to result in the removal of exactly one Laminin G and two EGF domains. Although the eysΔexon40-44 transcript was found at levels comparable to wild-type eys, and no unwanted off-target modifications were identified within the eys coding sequence after single-molecule sequencing, EysΔexon40-44 protein expression could not be detected. Visual motor response experiments revealed that eysΔexon40-44 larvae were visually impaired and histological analysis revealed a progressive degeneration of the retinal outer nuclear layer in these zebrafish. Altogether, the data obtained in our zebrafish model currently provide no indications for the skipping of EYS exons 37-41 as an effective future treatment strategy for EYS-associated RP.

Photoelectric Dye, NK-5962, as a Potential Drug for Preventing Retinal Neurons from Apoptosis: Pharmacokinetic Studies Based on Review of the Evidence.

NK-5962 is a key component of photoelectric dye-based retinal prosthesis (OUReP). In testing the safety and efficacy, NK-5962 was safe in all tests for the biological evaluation of medical devices (ISO 10993) and effective in preventing retinal cells from death even under dark conditions. The long-term implantation of the photoelectric dye-coupled polyethylene film in the subretinal space of hereditary retinal dystrophic (RCS) rats prevented neurons from apoptosis in the adjacent retinal tissue. The intravitreous injection of NK-5962 in the eyes of RCS rats, indeed, reduced the number of apoptotic cells in the retinal outer nuclear layer irrespective of light or dark conditions. In this study, we reviewed the in vitro and in vivo evidence of neuroprotective effect of NK-5962 and designed pharmacokinetic experiments. The in vitro IC50 of 1.7 μM, based on the protective effect on retinal cells in culture, could explain the in vivo EC50 of 3 μM that is calculated from concentrations of intravitreous injection to prevent retinal neurons from apoptosis. Pharmacokinetics of NK-5962 showed that intravenous administration, but not oral administration, led to the effective concentration in the eye of rats. NK-5962 would be a candidate drug for delaying the deterioration of retinal dystrophy, such as retinitis pigmentosa.

Antisense oligonucleotide-based treatment of retinitis pigmentosa caused by USH2A exon 13 mutations

Mutations in USH2A are among the most common causes of syndromic and non-syndromic retinitis pigmentosa (RP). The two most recurrent mutations in USH2A, c.2299delG and c.2276G > T, both reside in exon 13. Skipping exon 13 from the USH2A transcript presents a potential treatment modality in which the resulting transcript is predicted to encode a slightly shortened usherin protein. Morpholino-induced skipping of ush2a exon 13 in zebrafish ush2armc1 mutants resulted in the production of usherinΔexon 13 protein and a completely restored retinal function. Antisense oligonucleotides were investigated for their potential to selectively induce human USH2A exon 13 skipping. Lead candidate QR-421a induced a concentration-dependent exon 13 skipping in induced pluripotent stem cell (iPSC)-derived photoreceptor precursors from an Usher syndrome patient homozygous for the c.2299delG mutation. Mouse surrogate mQR-421a reached the retinal outer nuclear layer after a single intravitreal injection and induced a detectable level of exon skipping until at least 6 months post-injection. In conclusion, QR-421a-induced exon skipping proves to be a highly promising treatment option for RP caused by mutations in USH2A exon 13.

Classification Criteria For Multiple Evanescent White Dot Syndrome

The purpose of this study was to determine classification criteria for multiple evanescent white dot syndrome (MEWDS). Machine learning of cases with MEWDS and 8 other posterior uveitides. Cases of posterior uveitides were collected in an informatics-designed preliminary database, and a final database was constructed of cases achieving supermajority agreement on diagnosis using formal consensus techniques. Cases were split into a training set and a validation set. Machine learning using multinomial logistic regression was used in the training set to determine a parsimonious set of criteria that minimized the misclassification rate among the infectious posterior, or panuveitides. The resulting criteria were evaluated in the validation set. A total of 1,068 cases of posterior uveitides, including 51 cases of MEWDS, were evaluated by machine learning. Key criteria for MEWDS included: 1) multifocal gray-white chorioretinal spots with foveal granularity; 2) characteristic imaging on fluorescein angiography ("wreath-like" hyperfluorescent lesions) and/or optical coherence tomography (hyper-reflective lesions extending from retinal pigment epithelium through ellipsoid zone into the retinal outer nuclear layer); and 3) absent to mild anterior chamber and vitreous inflammation. Overall accuracy for posterior uveitides was 93.9% in the training set and 98.0% (95% confidence interval: 94.3-99.3) in the validation set. Misclassification rates for MEWDS were 7% in the training set and 0% in the validation set. The criteria for MEWDS had a low misclassification rate and appeared to perform sufficiently well for use in clinical and translational research.