Mesenchymal stem cells (MSCs) are considered as an ideal treatment for multiple diseases including ocular disease. Recent studies have demonstrated that MSCs-derived exosomes have similar functions with MSCs. Exosomes are nanovesicles surrounded by a phospholipid layer that shuttle active cargo between different cells. They are capable of passing the biological barrier and have potentials to be utilized as natural carrier for the ocular drug delivery.
Glucocorticoids (GCS) are the main treatment for non-infectious uveitis (NIU). However, long-term GCS treatment may induce systemic side effects including hypertension, hyperlipidemia and diabetes. Patients may develop cataract, ocular hypertension or glaucoma because of topical application of GCS. Rapamycin (RAPA) exhibits immunosuppressive, antiangiogenic and antiproliferative effects. Animal experiments and clinical trials have shown that RAPA has therapeutic potential for NIU, especially the treatment of intravitreal injection. In particular, intravitreal injection of RAPA can result in minimal systemic exposure and reduce adverse events. Meanwhile, systemic unwanted effects should be concerned about. In recent years, some studies have attempted to employ nanostructured carriers to improve penetrating abilities of RAPA and efficacy of treatment for ocular posterior segment diseases. These carriers include micelles, liposomes, nanocrystals, polymeric nanoparticles, magnetic nanoparticles and so on. Whether they can load RAPA for treating NIU deserves further study and exploration.
Behcet's Disease (BD) is a multisystem vasculitis characterized by disease alternated with recurrent episodes and remissions, involving genital, oral, ocular uvea, cutaneous, and articular manifestations. The nuclear factor (NF)-κB signaling pathway paly an important role in the BD progression. It encompasses diverse gene, protein, and cellular regulatory mechanisms operating across various levels, alongside microbiological and experimental studies involving animals and cells. At the protein research findings, activation of the NF-κB pathway in BD patients is marked by elevated plasma levels of soluble CD40 ligand, which stimulates neutrophils to release reactive oxygen species and extracellular traps, thereby promoting inflammation. At the cellular research findings, macrophages in BD patients polarize towards classically activated macrophages phenotype through the NF-κB pathway, exacerbating the inflammatory response. The activation of NF-κB is associated with increased expression of anti-apoptotic proteins in T cells, leading to prolonged inflammation. Microbiological investigations reveal that the decreased gut microbiota diversity in BD patients compromises intestinal barrier integrity. NF-κB pathway involvement in regulating neutrophil and type 1 helper T cell (Th) 1/Th17 cell function worsens inflammation. Genetically, BD patients exhibit polymorphisms in immune regulatory genes, which contribute to inflammation through the NF-κB pathway. Mutations in NF-κB-associated genes elevate the risk of BD, while mutations in the endogenous inhibitor A20 lead to abnormal NF-κB activity, sustaining inflammation. Animal experiments and in vitro experiments corroborate the efficacy of NF-κB inhibitors in attenuating inflammation. Targeting upstream inflammatory factors within the NF-κB pathway yields positive outcomes in BD patients. In summary, the NF-κB signaling pathway plays a pivotal role in the development of BD. Developing NF-κB inhibitors may open new avenues for treating BD. Further research is necessary to comprehensively elucidate the precise mechanisms by which NF-κB operates in the pathogenesis of BD, as well as its potential clinical applications in therapy.
Acquired syphilis uveitis, due to lack of the characteristic features, presents with various types. The most common type is posterior uveitis and panuveitis, including chorioretinitis, retinal vasculitis, optic nerve retinitis. The diagnosis and assessment of response to treatment depends mainly on the serological diagnostic tests, including nontreponemal and treponemal test. Acquired syphilis uveitis often presents with manifestations similar to various types of uveitis, especially to autoimmune uveitis and other infectious uveitis, so differential diagnosis is important. The gold standard treatment for active syphilitic uveitis is penicillin G, or doxycycline if patient is allergy to penicillin. Clinically misdiagnosis and delayed treatment may result in irreversible visual impairment and severe systemic and eye complications. However such timely treatment always has a good prognosis.
The pathogenesis of diabetic retinopathy (DR) is complicated and has not yet been fully elucidated. To explore the pathogenesis of DR and the mechanism of drug action, proteomics through quantitative analysis techniques is very useful. It can analyzes differentially expressed proteins in the retina, vitreous fluid, aqueous humor, tears, and blood of DR patients and diabetic rats, and analyzes differentially expressed proteins after drug intervention. This paper is a review of the progress in proteomic research of DR in recent years.
Primary vitreoretinal lymphoma (PVRL) is one of the most common type of primary intraocular lymphoma. The current treatment options include local ocular radiotherapy (radiotherapy), systemic chemotherapy (chemotherapy), local ocular chemotherapy, and combination therapy. The treatment options are different at different stages of PVRL, however, there is no uniform treatment guideline. Local ocular chemotherapy can make the drug reach effective therapeutic concentration in the eye, and it can be repeated many times. At the same time, it can avoid the adverse reactions caused by systemic medication or radiotherapy. It is an ideal choice for relieving ocular symptoms. At present, the mainstream ocular local chemotherapeutics are methotrexate (MTX) and rituximab (RTX). The basic consensus about the intravitreal injection of MTX (IVM) is the induction-consolidation-maintenance model, however, the time of each stage and frequency of IVM are diverse. The time interval of intravitreal injection of RTX is also variable, ranging from 1 time/week to 1 time/months and so on. Corneal epithelial lesions caused by frequent MTX injections and the higher recurrence rate after RTX treatment are the main reasons for changing the treatment plan. For patients with primary central nervous system lymphoma and PVRL, combined treatment with neurology department is necessary to save patient's lives, ophthalmology treatment relieves ocular symptoms and improves the patient's quality of life. For patients with PVRL alone without central nervous system involvement, ophthalmology treatment is necessary to control patient's eye symptoms, and close follow-up should be followed to find the involvement of the central nervous system in time, and then combined with neurological treatment to save patient’s lives.
As a new treatment option after conventional corticosteroids and immunomodulatory drugs, biologics have been widely used in the clinical management of non-infectious uveitis in many countries due to their approved efficacy and safety. Anti-tumor necrosis factor-alpha monoclonal antibody is the most commonly used one. However, the guidance on its standardized application is lacking. The Ocular Immunology Group of Immunology and Rheumatology Academy in Cross-Straits Medicine Exchange Association compiled the Chinese expert consensus on treatment of non-infectious uveitis with anti-tumor necrosis factor-alpha monoclonal antibody. This evidence-based consensus is made according to the principle of consensus building and combines the clinical experience of the experts. Twelve recommendations are formatted on the application of Adalimumab and Infliximab. The interpretation of this consensus point will help improve the normative and effective application of anti-tumor necrosis factor-alpha monoclonal antibody in ophthalmologists, rheumatologists and immunologists.
Objective To observe the synergistic effect of metformin and anti-vascular endothelial growth factor (VEGF) in the treatment of diabetic retinopathy. Methods This study was composed of clinical data review and in vitro cell experiment. Ten patients (12 eyes) with diabetic macular edema treated with anti-VEGF drugs were included in the study. Patients were randomly divided into the VEGF group (anti-VEGF drug therapy) and the combined treatment group (anti-VEGF drug combined with metformin). The changes of visual acuity and central retinal thickness (CRT) were compared between the two groups. As far as the in vitro experiment was concerned, vascular endothelial cells were divided into the control group (normal cells), the VEGF group (50 ng/ml VEGF), the anti-VEGF group (50 ng/ml VEGF+2.5 μg/ml of conbercept), and the combined group (50 ng/ml VEGF +2.5 μg/ml of conbercept +2.0 mmol/L of metformin). And then MTT cell viability assay, scratch assay and real-time quantitative polymerase chain reaction assay were performed to analyze the cell viability, cell migration and mRNA level of VEGFR2, protein kinase C (PKC)-α and PKC-β successively. ResultsReview of clinical trial shows that the CRT recovery rates in the combined treatment group were much higher than that in the VEGF group at 3 month after the operation, while the difference was statistically significant (t=−2.462, P＜0.05). In vitro cell experiment results showed that VEGF induction upregulated the viability and mobility of vascular endothelial cells obviously compared with control group, at the same time, the use of anti VEGF drugs can effectively reverse the trend, in contrast, combination of metformin and anti-VEGF showed a more superior effect to some extent (P＜0.05). In the VEGF group, the mRNA expression of VEGFR2, PKC-αand PKC-β were significantly increased compared with the control group (P＜0.01); while the mRNA expression of VEGFR2, PKC-αand PKC-β in the combination group decreased significantly compared with the VEGF group and the control group (P＜0.05). However, in the anti-VEGF group, the mRNA expression of VEGFR2, PKC-αand PKC-β were decreased, but has failed to reach the level of statistical learn the difference. ConclusionsThe combination of metformin and anti-VEGF drugs can reduce the CRT of diabetic retinopathy patients and inhibit the proliferation and migration of retinal vascular endothelial cells which induced by VEGF. The synergistic mechanism may be related to the inhibitory effect of metformin on the expression of VEGFR and PKC.
ObjectiveTo observe the expression of S100A8 in plasma exosomes, microvesicles (MV), plasma and vitreous in patients with diabetic retinopathy (DR), and verify it in a diabetic rat model, and to preliminarily explore its role in the occurrence and development of DR.MethodsA case-control study. From September 2018 to December 2019, a total of 73 patients with type 2 diabetes, hospitalized patients undergoing vitrectomy, and healthy physical examinations in the Tianjin Medical University Eye Hospital were included in the study. Among them, plasma were collected from 32 patients and vitreous fluid were collected from 41 patients, which were divided into plasma sample research cohort and vitreous sample research cohort. The subjects were divided into simple diabetes group (DM group), non-proliferative DR group (NPDR group) and proliferative DR group (PDR group) without fundus changes; healthy subjects were regarded as normal control group (NC group). In the study cohort of vitreous samples, the control group was the vitreous humor of patients with epimacular membrane or macular hole. Plasma exosomes and microvesicles (MVs) were separated using ultracentrifugation. Transmission electron microscopy, nanometer particle size analyzer and Western blot (WB) were used to characterize exosomes and MVs. The mass concentration of S100A8 was determined by enzyme-linked immunosorbent assay. Eighteen healthy male Brown Norway rats were divided into normal control group and diabetic group with 9 rats in each group by random number table method. The rats of diabetes group were induced by streptozotocin to establish diabetic model. Five months after modeling, immunohistochemical staining and WB were used to detect the expression of S100A8 in the retina of rats in the normal control group and the diabetes group. t test was used for the comparison of measurement data between the two groups. Single-factor analysis of variance were used for the comparison of multiple groups of measurement data.parison of measurement data between the two groups. Single-factor analysis of variance were used for the comparison of multiple groups of measurement data.ResultsExosomes and MVs with their own characteristics were successfully separated from plasma. The concentrations of plasma exosomes and vitreous S100A8 in the PDR group were higher than those in the NPDR group, DM group, NC group, and the difference was statistically significant (P=0.039, 0.020, 0.002, 0.002, P＜0.000,＜0.000). In the plasma sample cohort study, It was not statistically significant that the overall comparison of the S100A8 mass concentrations of plasma and plasma MV in the four groups of subjects (F=0.283, 0.015; P=0.836, 0.996). Immunohistochemical staining showed that retinal ganglion cells, bipolar cells, cone rod cells and vascular endothelial cells in the diabetic group all expressed S100A8 protein. Compared with the normal control group, the expression level of S100A8 in the retina of the diabetic group increased, and the difference was statistically significant (t=8.028, P=0.001).ConclusionsThe level of S100A8 protein in circulating exosomes increases significantly with the severity of DR in patients with type 2 diabetes. S100A8 may be an influential factor in the inflammatory environment of DR and a potential anti-inflammatory therapeutic target.
ObjectiveTo observe the efficacy and safety of intravitreal injection of conbercept in the treatment of proliferatived diabetic retinophathy (PDR) complicated with vitreous hemorrhage by minimally invasive vitreoretinal surgery.MethodsProspective clinical study. A total of 50 patients with PDR complicated with vitreous hemorrhage clinically diagnosed in Tianjin Medical University Eye Hospital who needed vitrectomy were recruited in this study. According to the principle of informed consent, the patients were divided into two groups: postoperative injection group and the control group. Twenty-five eyes of 25 patients in each group were examined before operation. No significant proliferative changes in the posterior pole and traction retinal detachment were observed. There was significant difference of age between two groups (t=－24.697, P=0.030), but no significant difference of sex (χ2=0.330, P=0.564), duration of diabetes (t=－1.144, P=0.258), logMAR BCVA (t=－0.148, P=0.883), lens state (χ2=0.397, P=0.529), panretinal laser photocoagulation (χ2=1.333, P=0.248). The postoperative injection group was treated with intravitreous injection of 0.05 ml conbercept (10 mg/ml) immediately after 27G minimally invasive vitrectomy. The other treatment and follow-up were the same as those in the postoperative injection group except for conbercept injection. All patients underwent routine slit-lamp examination, indirect ophthalmoscope and B-ultrasound examination before operation. The main outcome measure included the time of operation, the incidence rate of iatrogenic retinal holes and silicone oil filling. The recurrence of vitreous hemorrhage, BCVA, intraocular pressure, central retinal thickness (CRT), postoperative complications and progression were recorded 1 week, 1 month, 3 months and 6 months after operation.ResultsAt 1 week and 1, 3, 6 months after operation, there was significant difference of logMAR BCVA between the two groups (t=－4.980, －4.840, －4.892, －5.439; P<0.001). At 3 and 6 months after operation, the recurrence of vitreous hemorrhage in the postoperative injection group was lower than that in the control group, but there was no statistical difference between two groups (χ2=3.030, 4.153; P=0.192, 0.103). At 1 week and 1, 3, 6 months after operation, the CRT in the postoperative injection group was lower than that in the control group, the difference was significant (t=－2.622, －2.638, －3.613, －3.037; P=0.012, 0.010, 0.001, 0.004, 0.005). There was no complications such as choroid detachment, proliferative vitreoretinopathy, retinal detachment, iris redness and neovascular glaucoma in all the eyes after operation.ConclusionsIntravitreal injection of conbercept in the treatment of PDR after operation is safe and effective. It can reduce the recurrence of vitreous hemorrhage after vitrectomy, improve the BCVA.