TYRP1 Protects Against the Apoptosis and Oxidative Stress of Retinal Ganglion Cells by Binding to PMEL.

OBJECTIVES: This research aimed to dissect the function of TYRP1 and PMEL in glaucomatous animal and cell models. METHODS: A chronic ocular hypertension (COH) rat model was induced in the right eyes of rats through the electrocoagulation of superficial iris veins. In addition, an oxygen-glucose deprivation (OGD)-retinal ganglion cell (RGC) model was constructed through OGD. TYRP1 and PMEL expression was altered in the animal and cell models to explore their effects. RESULTS: TYRP1 and PMEL expression was poor in glaucoma patients, COH rats, and OGD-RGCs. Mechanistically, TYRP1 interacted with PMEL to upregulate PMEL in OGD-RGCs. TYRP1 overexpression enhanced viability and diminished apoptosis and oxidative stress of OGD-RGCs, which was abolished by PMEL knockdown. TYRP1 upregulation reduced intraocular pressure, RGC apoptosis, and oxidative stress in COH rats, which was reversed by PMEL knockdown. CONCLUSIONS: TYRP1 elevates PMEL expression to reduce RGC apoptosis and oxidative stress in vivo and in vitro.

Biocompatibility and Efficacy of a Linearly Cross-Linked Sodium Hyaluronic Acid Hydrogel as a Retinal Patch in Rhegmatogenous Retinal Detachment Repairment.

To prevent the migration of retinal pigment epithelium (RPE) cells into the vitreous cavity through retinal breaks after the pars plana vitrectomy for the repair of rhegmatogenous retinal detachment (RRD), sealing retinal breaks with an appropriate material appears to be a logical approach. According to a review of ocular experiments or clinical trials, the procedure for covering retinal breaks with adhesives is complex. A commercially available cross-linked sodium hyaluronic acid (HA) hydrogel (Healaflow®) with the injectable property was demonstrated to be a perfect retinal patch in RRD clinical trials by our team. Based on the properties of Healaflow®, a linearly cross-linked sodium HA hydrogel (HA-engineered hydrogel) (Qisheng Biological Preparation Co. Ltd. Shanghai, China) with the injectable property was designed, whose cross-linker and cross-linking method was improved. The purpose of this study is to report the characteristics of an HA-engineered hydrogel using Healaflow® as a reference, and the biocompatibility and efficacy of the HA-engineered hydrogel as a retinal patch in the rabbit RRD model. The HA-engineered hydrogel exhibited similar dynamic viscosity and cohesiveness and G' compared with Healaflow®. The G' of the HA-engineered hydrogel varied from 80 to 160 Pa at 2% strain under 25°C, and remained constantly higher than G″ over the range of frequency from 0.1 to 10 Hz. In the animal experiment, clinical examinations, electroretinograms, and histology suggested no adverse effects of the HA-engineered hydrogel on retinal function and morphology, confirming its favorable biocompatibility. Simultaneously, our results demonstrated the efficacy of the HA-engineered hydrogel as a retinal patch in the RRD model of rabbit eyes, which can aid in the complete reattachment of the retina without the need for expansile gas or silicone oil endotamponade. The HA-engineered hydrogel could play the role of an ophthalmologic sealant due to its high viscosity and cohesiveness. This pilot study of a small series of RRD models with a short-term follow-up provides preliminary evidence to support the favorable biocompatibility and efficacy of the HA-engineered hydrogel as a promising retinal patch for sealing retinal breaks in retinal detachment repair. More cases and longer follow-up studies are needed to assess its safety and long-term effects.

Influences of Rapamycin on Retinal Ganglion Cells in Rats with Acute High Intraocular Pressure Through Regulating COX-2.

The study aimed to explore the influences of rapamycin on the retinal ganglion cells in rats with acute high intraocular pressure through regulating cyclooxygenase-2 (COX-2). 36 Sprague-Dawley rats were randomly assigned to the normal group (n=12), model group (n=12) and rapamycin group (n=12). The rats in the normal group were normally fed, those in the model group were prepared the model of acute high intraocular pressure and injected with normal saline, and those in the rapamycin group were given rapamycin. At 7 d after the operation, sampling was performed. The expressions of COX-2 and Caspase-3 were detected via immunohistochemistry, and their protein expressions were determined using Western blotting (WB). Quantitative polymerase chain reaction (qPCR) was conducted to measure the messenger ribonucleic acid (mRNA) expression levels, and cell apoptosis was evaluated using terminal deoxynucleotidyltransferase-mediated dUTP nick end labeling (TUNEL) assay. The content of interleukin (IL)-6 and tumor necrosis factor-alpha (TNF-α) was determined via enzyme-linked immunosorbent assay (ELISA). Compared with those in the normal group, the positive expression levels rose substantially in the other two groups, and those in the rapamycin group were notably lower (p<0.05). The relative protein expression levels in the model group and rapamycin group were higher, and the rapamycin group exhibited remarkable decreases (p<0.05). In comparison with the normal group, the other two groups had considerably raised relative mRNA expression levels and those in the rapamycin group were lower (p<0.05). The cells in the model and rapamycin groups had a higher apoptosis rate, and the apoptosis rate of cells in the rapamycin group was lower (p<0.05). Compared with that in the normal group, the content of IL-6 and TNF-α was elevated in the other two groups and their content in the rapamycin group was lower. Rapamycin inhibits COX-2 to repress inflammation and apoptosis, thereby exerting a protective effect on the retinal ganglion cells in rats with acute high intraocular pressure.

Embryonic stem cells-derived exosomes enhance retrodifferentiation of retinal Müller cells by delivering BDNF protein to activate Wnt pathway.

OBJECTIVE: The present study was intended to investigate the role of embryonic stem cell-derived exosomes (ESC-Exos) in Müller cell retrodifferentiation and their specific mechanism. METHODS: Following co-incubation of the extracted ESC-Exos and Müller cells, their effects on the retrodifferentiation and proliferation of Müller cells were measured by EdU staining, immunofluorescence, and western blot. ESCs transfected with small interfering RNA of BDNF were co-incubated with Müller cells to determine Müller cell proliferation and retrodifferentiation. ß-catenin expression in the nucleus and GSK-3ß phosphorylation were measured to determine the role of the Wnt pathway in Müller cells. The function of the retina in RCS rats was observed using flash electroretinogram. RESULTS: Co-incubation of ESCs with Müller cells or overexpression of BDNF contributed to Müller cell retrodifferentiation and proliferation, as evidenced by increased cell proliferation, fluorescence intensities of proliferation markers and retinal stem cell markers, and expression of BDNF and ß-catenin, and suppressed GSK-3ß phosphorylation. However, co-incubation with ESCs silencing BDNF or treatment with GW4869 inhibited the proliferation and retrodifferentiation of retinal Müller cells. In addition, exosome injection increased BDNF, BrdU, PH3, SOX2, and Pax6 expression, enhanced ß-catenin expression in the nucleus, diminished GSK-3ß, and improved retinal degeneration in RCS rats. CONCLUSION: ESC-Exos accelerated Müller cell retrodifferentiation and proliferation through Wnt pathway activation by delivering BDNF protein to Müller cells.

A Pilot Application of an iTRAQ-Based Proteomics Screen Estimates the Effects of Cigarette Smokers' Serum on RPE Cells With AMD High-Risk Alleles.

PURPOSE: The aim of this study was to explore whether there are interactions between genetic (ARMS2/HTRA1) and environmental factors (cigarette smoking) in the pathogenesis of age-related macular degeneration (AMD). METHODS: Primary human retinal pigment epithelial (hRPE) cells were obtained from four donors' eyes with AMD high-risk ARMS2/HTRA1 alleles, and two donors' eyes with wild-type alleles were used as controls. The pooled serum from 32 smokers and 35 nonsmokers were collected and used separately to treat hRPE cells. The isobaric tag for relative and absolute quantitation (iTRAQ)-based proteomics was used to identify associated proteins and comparing the differences between AMD high-risk and low-risk HTRA1/ARMS2 alleles after exposure to smokers' serum. RESULTS: After stimulation with the smokers' serum, 400 differentially expressed proteins (DEPs) were detected in the high-risk allele cells. Several DEPs are involved in neuronal protein degeneration and oxidative stress pathways. The smokers' serum stimulation or HTRA1 overexpression can both upregulate caveolin-1, which was one of the DEPs. Besides, the smokers' serum enhanced the phagocytosis of cultured human RPE cells. CONCLUSIONS: The study confirmed the AMD high-risk alleles, HTRA1, and cigarette smoking can promote AMD development by regulating caveolin-1 expression. TRANSLATIONAL RELEVANCE: AMD high-risk alleles and environmental risk factors can promote the occurrence and development of AMD by regulating caveolin-1 expression, upregulation of which will induce apoptotic cell death in response to cellular stress in early AMD conditions.

Application of iris fluorescein angiography in diabetic iridopathy and retinopathy in brown iris.

PURPOSE: This study aimed to evaluate the relationship between diabetic iridopathy (DI) and diabetic retinopathy (DR) and distinguish iris neovascular and physiological leakage using iris fluorescein angiography (IFA). METHODS: A total of 210 subjects were prospectively recruited in this study. Sixty normal subjects were divided equally into three groups (<40 years old, 40-59 years old, and 60-79 years old). One hundred fifty patients with diabetic mellitus (DM) were divided equally into five groups (no retinopathy, mild non proliferative DR (mildnPDR), moderate nPDR, severe nPDR, and PDR group). Normal subjects underwent IFA. Patients with DR underwent both IFA and ultrawide field fundus fluorescein angiography (uwFFA) at the same time. The leakage time and area were recorded and compared with each group. RESULTS: Fluorescein leakage occurred at the pupillary edge of patients that were 40-59 and 60-79 years old but not in those <40 years old. In the PDR group, the leakage time was earlier and the leakage area was larger than nPDR and patients with no retinopathy (p = 0.039 and p = 0.005, respectively). However, the leakage time and area were not significantly different between patients with no retinopathy and nPDR (p > 0.05). CONCLUSION: IFA examination can only assist in estimating the fundus severity of PDR patients, whereas the fundus changes of patients with no retinopathy and nPDR were not related to DI changes.Trial registration No.: ChiCTR1800018003.The date of registration: Aug 26th, 2018.

Antioxidative effects of polypyrimidine tract-binding protein-associated splicing factor against pathological retinal angiogenesis through promotion of mitochondrial function.

Reactive oxygen species (ROS), a by-product of oxygen metabolism mainly originating from mitochondria, participate in many pathological processes related to ophthalmopathy. Excessive production of ROS leads to oxidative stress, which influences the permeability, proliferation, migration, and tube formation of human retinal microcapillary endothelial cells (HRMECs). The molecular mechanisms underlying the effects of ROS are not clear. In Vldlr-/- mice, we used fundus fluorescein angiography and retinal flat mount staining to observe the effect of polypyrimidine tract-binding protein-associated splicing factor (PSF) on pathological retinal neovascularization in vivo. Additionally, in human retinal microvascular endothelial cells treated with 4-HNE, cell viability, tube formation, wound healing, and Transwell assays were performed to study the effect of PSF on the proliferation, migration, and tube formation of retinal vascular endothelial cells in vitro. Moreover, reactive oxygen species assay, real-time PCR, and Western blot were included to analyze the potential mechanism of PSF in the above series of effects. PSF ameliorated intraretinal neovascularization (IRNV) in vivo in Vldlr-/- mice. Under 4-hydroxynonenal (4-HNE) conditions in vitro, PSF reprogrammed mitochondrial bioenergetic and glycolytic profiles. It also reduced ROS levels and inhibited 4-HNE-induced angiogenesis, which involves the proliferation, migration, and tube formation of HRMECs. These results suggest that PSF participates in the regulation of HRMECs proliferation and migration during the development of pathological angiogenesis. We demonstrated that PSF enhanced Nrf2 activation and heme oxygenase-1 (HO-1) expression via extracellular signal-regulated kinase (ERK) and Akt signaling in HRMECs, which subsequently resulted in intracellular ROS scavenging. PSF restored endoplasmic reticulum (ER) redox homeostasis, which was indicated by an increase in protein disulfide isomerase (PDI) and Ero-1α and a reduction in GRP78 and C/EBP homologous protein (CHOP). PSF also attenuated ER stress via regulation of the protein kinase R (PKR)-like endoplasmic reticulum kinase PERK/eukaryotic translation factor 2 alpha (eIF2α)/activating transcription factor 4 (ATF4) pathway in 4-HNE-treated HRMECs. Our research shows that PSF may be a potential antioxidant that regulates pathological angiogenesis through ERK-AKT/Nrf2/HO-1 and PERK/eIF2α/ATF4 signal regulation. KEY MESSAGES: Reactive oxygen species (ROS) mainly originating from mitochondria is a by-product of oxygen metabolism in the body and participates in the pathological process related to multiple blindness-related ophthalmopathy. Moreover , excessive production of ROS will lead to oxidative stress. Consequently, oxidative stress influences the permeability, proliferation, migration, and tube formation of human retinal microcapillary endothelial cells (HRMECs). The molecular mechanisms underlying the effects of ROS remain unclear. Here, we reveal that Polypyrimidine tract-binding protein-associated splicing factor (PSF) ameliorates intraretinal neovascularization (IRNV) in vivo in Vldlr-/- mice. Furthermore, under 4-HNE conditions in vitro, PSF reprograms mitochondrial bioenergetic and glycolytic profiles, reduces ROS levels, and inhibits 4-HNE-induced angiogenesis, which involves the proliferation, migration, and tube formation of HRMECs, suggesting that it participates in regulating the proliferation and migration of HRMECs during the development of pathological angiogenesis. Furthermore, PSF enhances Nrf2 activation and HO-1 expression through ERK and AKT signaling in HRMECs, resulting in intracellular ROS scavenging. PSF restores endoplasmic reticulum (ER) redox homeostasis, as indicated by an increase in PDI and Ero-1α and a reduction in GRP78 and CHOP. PSF also attenuates ER stress by regulating the PERK/eIF2α/ATF4 pathway in 4-HNE-treated HRMECs.

Human embryonic stem cell-derived extracellular vesicles alleviate retinal degeneration by upregulating Oct4 to promote retinal Müller cell retrodifferentiation via HSP90.

OBJECTIVE: Retinal degenerative diseases remain the dominant causes of blindness worldwide, and cell replacement is viewed as a promising therapeutic direction. However, the resources of seed cells are hard to obtain. To further explore this therapeutic approach, human embryonic stem extracellular vesicles (hESEVs) were extracted from human embryonic stem cells (hESCs) to inspect its effect and the possible mechanism on retinal Müller cells and retinal function. METHODS: hESEVs were extracted by multi-step differential centrifugation, whose morphologies and specific biomarkers (TSG101, CD9, CD63, and CD81) were observed and measured. After hESEVs were injected into the vitreous cavity of RCS rats, the retinal tissues and retinal functions of rats were assessed. The alteration of Müller cells and retinal progenitor cells was also recorded. Microvesicles (MVs) or exosomes (EXOs) were extracted from hESCs transfected with sh-HSP90 or pcDNA3.1-HSP9, and then incubated with Müller cells to measure the uptake of EVs, MVs, or EXOs in Müller cells by immunofluorescence. The retrodifferentiation of Müller cells was determined by measuring Vimentin and CHX10. qRT-PCR and western blot were used to detect HSP90 expression in MVs and evaluate Oct4 level in Müller cells, and Co-IP to inspect the interaction of HSP90 and Oct4. RESULTS: RCS rats at the postnatal 30 days had increased retinal progenitor cells which were dedifferentiated from Müller cells. hESEVs were successfully extracted from hESCs, evidenced by morphology observation and positive expressions of specific biomarkers (TSG101, CD9, CD63, and CD81). hESEVs promoted Müller cells dedifferentiated and retrodifferentiated into retinal progenitor cells evidenced by the existence of a large amount of CHX10-positive cells in the retinal inner layer of RCS rats in response to hESEV injection. The promotive role of hESEVs was exerted by MVs demonstrated by elevated fluorescence intensity of CHX10 and suppressed Vimentin fluorescence intensity in MVs rather than in EXOs. HSP90 in MVs inhibited the retrodifferentiation of Müller cells and suppressed the expression level of Oct4 in Müller cells. Co-IP revealed that HSP90 can target Oct4 in Müller cells. CONCLUSION: hESEVs could promote the retrodifferentiation of Müller cells into retinal progenitor cells by regulating the expression of Oct4 in Müller cells by HSP90 mediation in MVs.

Proteomic analysis of aqueous humor in patients with pathologic myopia.

Complications from pathologic myopia (PM) are a major cause of visual impairment and blindness. However, an efficient clinical therapeutic strategy for PM is still lacking. The aim of this study was to quantitatively compare the proteomic profiles of aqueous humor between PM and non-PM cataract patients. Twenty aqueous humor samples from each group were analyzed with label-free quantitative proteomic analysis to identify the differentially expressed proteins for function enrichment analyses and protein-protein interaction network construction. Hub protein was validated with ELISA using an independent cohort consisting of 20 samples from each group and its receiver operating characteristic (ROC) curve analysis was conducted. A total of 583 proteins were identified and 101 proteins were found to be differentially expressed, including 63 up-regulated proteins and 38 down-regulated proteins. The bioinformatics analysis suggested that PM is closely associated with immunity and inflammation interactions, and remodeling of extracellular matrix. Apolipoprotein A-I (ApoA1) was enriched as the hub protein of the network with the highest score, degree and centrality. ROC analysis showed that ApoA1 could distinguish PM from controls with an area under the curve of 0.963 (p < 0.001). The findings could provide potential clues for further study on the molecular mechanisms and developing new treatments for PM, especially related to immunity and inflammation interactions. ApoA1 may be a potential key protein and therapeutic target in human PM. SIGNIFICANCE: It is important and urgent to discover the mechanisms of pathologic myopia (PM) to inhibit its progression. This study applied the quantitative proteomic analysis to study aqueous humor from patients with or without PM, aiming to discover dysregulated proteins related to PM. Our results suggested that those dysregulated proteins are closely associated with immunity and inflammation interactions, and remodeling of extracellular matrix. The findings from this study could provide potential clues for further research on the molecular mechanisms and developing new treatments for PM, especially related to immunity and inflammation. ApoA1 may be a potential key protein and therapeutic target in human PM.

Exosomes derived from RPE cells under oxidative stress mediate inflammation and apoptosis of normal RPE cells through Apaf1/caspase-9 axis.

This study aims to explore the effects of exosomes, secreted by retinal pigment epithelial (RPE) cells under oxidative stress (OS), on apoptosis and inflammation of normal RPE cells. Exosomes secreted by normal RPE cells (named as exo) and rotenone (2.5 µmol/L) stimulated RPE cells (named as rot-exo) were isolated and extracted by multi-step differential centrifugation for morphology observation under a transmission electron microscopy. pcDNA3.1a, pcDNA3.1a-Apaf1, and p3xFlag-CMV-caspase-9 plasmids were constructed and transfected into ARPE-19 cells. Exosomes secreted by ARPE-19 cells were injected into the vitreous body of rats to verify the effect of Apaf1 and caspase-9 on cell apoptosis and inflammation. Co-immunoprecipitation was applied to clarify the interaction of Apaf1 with caspase-9. Exosomes secreted by rotenone stimulated ARPE-19 cells could induce cell apoptosis, oxidative injury, and inflammation in ARPE-19 cells. Exosomes secreted under OS can damage retinal functions of rats and have upregulated expression of Apaf1. Overexpression of Apaf1 in exosomes secreted under OS can cause the inhibition of cell proliferation, the increase of cell apoptosis and elicitation of inflammatory response in ARPE-19 cells. Exosomes derived from ARPE-19 cells under OS regulate Apaf1 expression to increase cell apoptosis and to induce oxidative injury and inflammatory response through a caspase-9 apoptotic pathway.

The effect of hemodialysis on ocular changes in patients with the end-stage renal disease.

Background: Numerous metabolic parameters can be changed during hemodialysis in the end-stage renal disease (ESRD) caused by systemic diseases, such as diabetes mellitus, hypertension. Some ocular parameters also can be variable due to the changes after hemodialysis. This study evaluates the effects of ocular parameters, including best-corrected visual acuity (BCVA), intraocular pressure (IOP), central macular thickness (CMT), subfoveal choroidal thickness (SFCT), retinal arteriolar caliber (RAC), retinal venular calibre (RVC), in ESRD patients following hemodialysis. Materials and methods: Two-hundred and two ESRD patients were recruited resulting in 404 eyes evaluations. All patients underwent hemodialysis in the Dialysis Unit of the Second Hospital of Tianjin Medical University. BCVA, CMT, IOP, SFCT, RAC and RVC were evaluated before and after hemodialysis. Systemic parameters were collected such as age, body weight, systolic blood pressure (SBP), diastolic blood pressure (DBP), duration of hemodialysis, body weight changes, high density lipoprotein cholesterol (HDLC), low density lipoprotein cholesterol (LDLC), very low density lipoprotein cholesterol (VLDLC), glycosylated hemoglobin (HbA1c). Results: The causes of ESRD patients included chronic glomerulonephritis (n = 65), diabetes mellitus (n = 60), hypertensive nephrosclerosis (n = 37), and other causes (n = 40). In our study, BCVA (p = .817), CMT (p = .252) and IOP (p = .978) did not significantly change after hemodialysis. SFCT significantly decreased from 254.29 ± 69.36 µm to 235.54 ± 659.90 µm (p = .002) following hemodialysis. SFCT changes were significantly correlated with SBP (p = .042) and body weight changes (p = .044). The RAC and RVC were dilated significantly (p = .033, p = .007). RVC changes were correlated with baseline DBP (p = .003), HDLC (p = .009), LDLC (p = .004) and changes in DBP (p = .037) and body weight (p = .001). Conclusion: Hemodialysis can affect various ocular parameters including SFCT, RAC and RVC, which changed significantly following hemodialysis. Whereas BCVA, IOP and CMT did not change after hemodialysis in ESRD patients. The systemic compensatory mechanisms of the changes in SBP, DBP, body weight following hemodialysis need further study.

The prevalence of vision impairment and refractive error in 3654 first year students at Tianjin Medical University.

AIM: To determine the prevalence of vision impairment (VI) and refractive error in first year university students at the Tianjin Medical University. METHODS: This is a cross-sectional observational cohort study of VI and refractive error among first year university students at the Tianjin Medical University. The first year university students were involved in this study and were given a detailed questionnaire including age, birth date, and spectacle wearing history. A standardized ophthalmologic examination including visual acuity (VA), slit-lamp examination, non-cycloplegic auto-refraction, objective refraction, fundus photography, and examination of their spectacles were recorded. RESULTS: A total of 3654 participants were included in this study. Totally 3436 (94.03%) individuals had VI in this population. Totally 150 (4.10%) individuals had VI due to ocular disease, including amblyopia, congenital cataract, retinal atrophy or degeneration, strabismus, congenital nystagmus, refractive surgery orthokeratology. Totally 3286 (89.93%) subjects had VI due to refractive error. Only 218 (5.97%) students were emmetropia. Moreover, refractive error was the main cause for the VI (95.63%). Totally 3242 (92.52%) students were myopia and the prevalence of mild, moderate, and high myopia subgroup was 27.05%, 44.35%, and 21.26% respectively. Totally 44 (1.29%) subjects were hyperopic. The rates of uncorrected visual acuity (UCVA), presenting visual acuity (PVA) and best corrected visual acuity (BCVA) which better than 20/20 in both eyes were 5.65%, 22.32% and 82.13% respectively. The rates of correction, under correction and well correction in myopia subjects were 82.73%, 84.39% and 15.61%, respectively. CONCLUSION: We present a high prevalence of refractive errors and high rates of under correction refractive error among first year university students. These results may help to promote vision protection work in young adults.

Application of CRISPR/Cas9 technologies combined with iPSCs in the study and treatment of retinal degenerative diseases.

Retinal degeneration diseases, such as age-related macular degeneration and retinitis pigmentosa, affect millions of people worldwide and are major causes of irreversible blindness. Effective treatments for retinal degeneration, including drug therapy, gene augmentation or transplantation approaches, have been widely investigated. Nevertheless, more research should be dedicated to therapeutic methods to improve future clinical treatments. Recently, with the rapid development of genome-editing technology, gene therapy has become a potentially effective treatment for retinal degeneration diseases. A clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein 9 (Cas9) system has been developed as a powerful genome-editing tool in ophthalmic studies. The CRISPR/Cas9 system has been widely applied in basic research to develop animal models and gene therapies in vivo. With the ability to self-renew and the potential to differentiate into different types of cells, induced pluripotent stem cells (iPSCs) have already been used as a promising tool for understanding disease pathophysiology and evaluating the effect of drug and gene therapeutics. iPSCs are also a cell source for autologous transplantation. In this review, we compared genome-editing strategies and highlighted the advantages and concerns of the CRISPR/Cas9 system. Moreover, the latest progress and applications of the CRISPR/Cas9 system and its combination with iPSCs for the treatment of retinal degenerative diseases are summarized.

Human embryonic stem cells extracellular vesicles and their effects on immortalized human retinal Müller cells.

Extracellular vesicles (EVs) released by virtually every cell of all organisms are involved in processes of intercellular communication through the delivery of their functional mRNAs, proteins and bioactive lipids. We previously demonstrated that mouse embryonic stem cell-released EVs (mESEVs) are able to transfer their content to different target retinal cells, inducing morphological and biochemical changes in them. The main objective of this paper is to characterize EVs derived from human embryonic stem cells (hESEVs) and investigate the effects that they have on cultured retinal glial, progenitor Müller cells, which are known to give rise to retinal neurons under specific conditions. This would allow us to establish if hESEVs have a pro-regenerative potential not yet described that could be used in the future for treatment of human retinal degenerative diseases. Initially, we showed that hESEVs are heterogeneous in size, contain mRNAs and proteins involved in the induction and maintenance of stem cell pluripotency and can be internalized by cultured Müller cells. After a single exposure to hESEVs these cells display changes in their gene expression profile, and with multiple exposures they de-differentiate and trans-differentiate into retinal neuronal precursors. hESEVs were then fractionated into microvesicles (MVs) and exosomes (EXOs), which were characterized by size, specific surface proteins and biochemical/molecular components. We demonstrate that despite the similar internalization of non-fractionated hESEVs, MVs and EXOs by Müller progenitor cells, in vitro, only the release of MVs' cargo into the cells' cytoplasm induces specific changes in their levels of pluripotency mRNAs and early retinal proteins. EXOs do not produce any detectable effect. Thus, we conclude that MVs and MVs-containing hESEVs are promising agents that possibly could promote the regeneration of diseased or damaged retinas in vivo through inducing glial Müller cells to become replacement neurons.

The efficacy of conbercept or ranibizumab intravitreal injection combined with laser therapy for Coats' disease.

PURPOSE: The current treatment approaches for Coats' disease by intravitreal injection of anti-vascular endothelial growth factor (VEGF) agents (ranibizumab or conbercept) combined with laser therapy were evaluated for the efficacy during the treatment. METHODS: The medical records of 28 patients diagnosed with Coats' disease followed by the treatment with intravitreal injection of anti-VEGF agents and laser therapies at Tianjin Medical University Eye Hospital and Hebei Eye Hospital during July 2012 and October 2017 were reviewed retrospectively. Clinical outcomes were recorded with a minimum follow-up of 6 months. The patients were divided into ranibizumab- and conbercept-treated groups, as well as based on age: pediatric and adult groups. RESULT: Twenty-eight patients were involved in this study. The average number of the injections was 2.82 ± 0.98. Laser photocoagulation was conducted in all patients, and the average number of lasers was 2.63 ± 0.74. The average follow-up period was 24.29 ± 9.85 months. Fourteen patients (50%) were stable, 12 (43%) patients were improved, and 2 patients (7%) showed recurred subretinal fluid and exudation. The final best corrected visual acuity (BCVA) increased markedly after intravitreal injection of ranibizumab or conbercept combined with laser therapy (p = 0.029, p = 0.009, respectively). The number of injections and lasers between conbercept and ranibizumab groups did not vary significantly (p = 0.160, p = 0.573, respectively). Nine patients (60%) in the ranibizumab-treated group and five (38%) in the conbercept-treated group reached a stable phase, and five (33%) and seven (54%) patients got the vision improved after treated with ranibizumab or conbercept, respectively. In pediatric and adult groups, the initial and final BCVA differed significantly (p = 0.03, p = 0.008, respectively). However, the injection number was remarkably different (p = 0.02), while the laser numbers did not have any markedly difference (p = 0.38). CONCLUSION: Intravitreal injection of ranibizumab or conbercept combined with laser therapy is an effective therapeutic option in Coats' disease. Moreover, the intravitreal injection of ranibizumab or conbercept had no significant adverse effects and appeared to offer visual improvement in Coats' disease.

The evaluation of ICHD-3 beta diagnostic criteria for Tolosa-Hunt syndrome: a study of 22 cases of Tolosa-Hunt syndrome.

The objective of the study was to evaluate the amended International Classification of Headache Disorders (third edition, beta version, ICHD-3 beta) with a retrospective analysis. A total of 22 patients diagnosed with painful ophthalmoplegia and Tolosa-Hunt syndrome (THS) in our hospital were retrospectively studied. The following clinical data were collected: symptoms, signs, location of inflammatory tissue, time interval of paresis following the onset of pain, pain and signs of resolution, follow-up and relapse. Pain and diplopia were found in 22 (100 %) and 20 cases (91 %). The sympathetic nerve was involved in 6 cases (27 %). Paresis followed the pain for an average of 8 ± 5.87 days. Serial magnetic resonance imaging (MRI) revealed granulomatous lesion that was visible in 20 patients (91 %). 19 patients (86 %) demonstrated the lesions located in the cavernous sinus, orbital apex or superior orbital fissure. One lesion extended to the intracranial structure. Pain was relieved in 20 cases (91 %) within 72 h and no patient had complete relief from paresis. According to our study, we think the time course of relief should be undefined. Headache location is hard to describe accurately. Normal MRI should be involved in THS diagnoses. The lesion of THS can extend beyond the cavernous sinus and the orbit. The time interval between headache and paresis can exceed 2 weeks.

Polysaccharide hydrogel combined with mesenchymal stem cells promotes the healing of corneal alkali burn in rats.

Corneal chemical burns are common ophthalmic injuries that may result in permanent visual impairment. Although significant advances have been achieved on the treatment of such cases, the structural and functional restoration of a chemical burn-injured cornea remains challenging. The applications of polysaccharide hydrogel and subconjunctival injection of mesenchymal stem cells (MSCs) have been reported to promote the healing of corneal wounds. In this study, polysaccharide was extracted from Hardy Orchid and mesenchymal stem cells (MSCs) were derived from Sprague-Dawley rats. Supplementation of the polysaccharide significantly enhanced the migration rate of primarily cultured rat corneal epithelial cells. We examined the therapeutic effects of polysaccharide in conjunction with MSCs application on the healing of corneal alkali burns in rats. Compared with either treatment alone, the combination strategy resulted in significantly better recovery of corneal epithelium and reduction in inflammation, neovascularization and opacity of healed cornea. Polysaccharide and MSCs acted additively to increase the expression of anti-inflammatory cytokine (TGF-ß), antiangiogenic cytokine (TSP-1) and decrease those promoting inflammation (TNF-α), chemotaxis (MIP-1α and MCP-1) and angiogenesis (VEGF and MMP-2). This study provided evidence that Hardy Orchid derived polysaccharide and MSCs are safe and effective treatments for corneal alkali burns and that their benefits are additive when used in combination. We concluded that combination therapy with polysaccharide and MSCs is a promising clinical treatment for corneal alkali burns and may be applicable for other types of corneal disorder.