ABSTRACT
Objective:To investigate the changes of glutathione peroxidase 4 (GPX4) in retinal photoreceptor cells, and the related mechanism correlated with retinal photoreceptor cell damage.Methods:The posterior segment tissues of 8 age-matched male donors were collected from the Body (Organ) Donation Register and Corneal Receiving Station of Tongji Hospital of Wuhan Red Cross from 2018 to 2021, including 4 non-diabetic donors and 4 diabetic donors.The tissues were divided into diabetes group and control group according to their donors.A total of 14 healthy SPF 8-week-old male C57BL/6 mice were selected and randomly divided into diabetes group and control group by the random number method, with 7 mice in each group.The mice in diabetes group were intraperitoneally injected with streptozotocin at a dose of 50 mg/kg for 5 days, and no intervention was given to mice in control group.Mouse photoreceptor cells 661W were divided into advanced glycation end products (AGEs) group and control group.AGEs group was treated with 100 μg/ml AGEs for 24 hours to simulate diabetic injury, and no intervention was given to control group.The outer segment morphology of retinal photoreceptors in human and mouse retinas was observed by hematoxylin-eosin staining.The expressions of glial fibrillary acidic protein (GFAP), rhodopsin and GPX4 in human and mouse retinas were detected by immunofluorescence staining.The expressions of GFAP, rhodopsin and GPX4 in mouse retina and the expression of GPX4 in 661W cells were determined by Western blot.The activity of 661W cells was detected by cell counting kit-8 (CCK8) method.The concentration of malondialdehyde (MDA) in mouse retina and cells was detected by TBA method.The activity of superoxide dismutase (SOD) in mouse retina and cells was detected by hydroxylamine assay.The use of human tissues was approved by the Ethics Committee of Tongji Hospital, Tongji Medical College of Huazhong University of Science and Technology (No.TJ-C20230301). The animal experiments were conducted with reference to the Standards Guide for the Care and Use of Laboratory Animals of the National Institutes of Health, and the study protocol was approved by the Experimental Animal Ethics Committee of Tongji Hospital, Tongji Medical College of Huazhong University of Science and Technology (No.TJH-2016001).Results:Hematoxylin-eosin staining showed that retinal photoreceptor outer segments were deformed or broken in diabetic donors and diabetic mice compared with control groups.GFAP fluorescent signal mainly appeared in the inner retina of human and mice, and the stained cells were spindle or polygonal, which was consistent with the shape of glial cells.The retinal GFAP fluorescent signal of diabetic tissue and mouse groups was stronger than that of respective control groups.Rhodopsin was only expressed in the outer segment layer of photoreceptors with clear boundaries, and GPX4 was expressed in the whole retina with strong signal in the outer segment layer of photoreceptors.The fluorescent signals of rhodopsin and GPX4 in diabetic tissue and mouse groups were weaker than those in respective control groups.The relative expressions of GFAP were significantly higher and the relative expressions of rhodopsin and GPX4 were significantly lower in diabetic tissue and mouse groups than in respective control groups (all at P<0.05). The cell viability of AGEs group was significantly lower than that of control group ( t=13.490, P<0.001). The relative expression of GPX4 protein in AGEs group was 0.42±0.12, which was significantly lower than 1.00±0.04 in control group ( t=9.041, P<0.001). MDA concentration was higher and SOD activity was lower in retinal tissue of diabetic mice and AGEs group than those in respective control groups, and the differences were statistically significant (all at P<0.05). Conclusions:Diabetes can reduce the GPX4 level in retinal photoreceptor cells and cause the imbalance of oxidation-antioxidant system, which may be the mechanism of the damage to retinal photoreceptor cells caused by diabetes.
ABSTRACT
Diabetic macular edema is a common complication of diabetic retinopathy, and is the main cause of vision decline.Antivascular endothelial growth factor (VEGF) agents are the first-line therapy for DME, but some patients still have refractory or recurrent macular edema after anti-VEGF treatment.This suggests that the pathogenesis of DME may involve inflammation-related cytokines other than VEGF.With the development of high-throughput detection technology, the analysis of inflammatory cytokines in the intraocular fluid of patients such as aqueous humor and vitreous humor has attracted more and more attention.At the same time, recognizing the impact of current treatments on inflammatory cytokines will help to formulate more efficient treatment plans.This article reviewed the changes of inflammatory cytokines, such as interleukin-1β (IL-1β), IL-6, IL-8, monocyte chemoattractant protein-1 and intercellular adhesion factor-1 in the course of DME, analyzed the possible mechanisms involved, and discussed the effects of anti-VEGF agents and glucocorticoids on these inflammatory cytokines.
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In the past, panretinal photocoagulation (PRP) and vitrectomy (PPV) were the main treatments for proliferative diabetic retinopathy (PDR). In recent years, anti-vascular endothelial growth factor (VEGF) drugs have been used more and more widely in PDR due to their advantages in rapidly subtracting new blood vessels, reducing leakage, and promoting the absorption of blood. The combination of anti-VEGF drugs and PRP in the treatment of PDR, especially high-risk PDR, can increase the rate of neovascularization and prevent some patients with mild to moderate vitreous hemorrhage from PPV. The application of anti-VEGF drugs during the perioperative period of PPV can also reduce bleeding during the operation, shorten the operation time, and reduce surgical complications. Although clinical studies have confirmed that anti-VEGF drugs can be used as an alternative treatment for PRP, most patients require multiple and long-term treatments, which increase the psychological and economic burden of patients. It is expected that the cost of anti-VEGF drugs and the development of long-acting dosage forms can be reduced and bring better efficacy and benefits to PDR patients in the future.
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Mobile learning has the characteristics of mobility,timeliness,network and virtu-ality. We developed virtual hospital suitable for mobile devices and organized students in to a network. Through early training,clinical case screen,learning objective fix,learning process and results evaluation,mobile devices were employed to do problem-based learning,which is conducive to the integration of theory with practice,the shifting from discipline-centered to system-based courses and the improving of utilization rate of learning resource.
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In order to study the in vitro culture and expansion of bone marrow mesenchymal stem cells in rats (rMSCs) and the possibility of rMSCs differentiation into retinal neural cells, the bone marrow-derived cells in SD rats were isolated and cultured in vitro. The retinal neural cells in SD rats were cultured and the supernatants were collected to prepare conditioned medium. The cultured rMSCs were induced to differentiate by two steps. Immunofluorescence method and anti-nestin, anti-NeuN, anti-GFAP and anti-Thy1.1 antibodies were used to identify the cells derived from the rMSCs. The results showed that the in vitro cultured rMSCs grew well and expanded quickly. After induction with two conditioned media, rMSCs was induced to differentiate into neural progenitor cells, then into retinal neural-like cells which were positive for nestin, NeuN, GFAP and Thy1.1 detected by fluorescence method. The findings suggested that rMSCs could be culture and expanded in vitro, and induced to differentiate into retinal neural-like cells.
Subject(s)
Animals, Newborn , Bone Marrow Cells/cytology , Cell Differentiation/physiology , Cells, Cultured , Mesenchymal Stem Cells/cytology , Neurons/cytology , Rats, Sprague-Dawley , Retina/cytologyABSTRACT
In order to study the in vitro culture and expansion of bone marrow mesenchymal stem cells in rats (rMSCs) and the possibility of rMSCs differentiation into retinal neural cells, the bone marrow-derived cells in SD rats were isolated and cultured in vitro. The retinal neural cells in SD rats were cultured and the supernatants were collected to prepare conditioned medium. The cultured rMSCs were induced to differentiate by two steps. Imrnunofluorescence method and anti-nestin, anti-NeuN, anti-GFAP and anti-Thy1.1 antibodies were used to identify the cells derived from the rMSCs. The results showed that the in vitro cultured rMSCs grew well and expanded quickly. After induction with two conditioned media, rMSCs was induced to differentiate into neural progenitor cells, then into retinal neural-like cells which were positive for nestin, NeuN, GFAP and Thy1.1 de-tected by fluorescence method. The findings suggested that rMSCs could be culture and expanded in vitro, and induced to differentiate into retinal neural-like cells.
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Objective To observe the effects of angiostatin on the activity of extra-cellular signal-regulated protein kinase (ERK) of retinal microvascular endothelial cells of mice. Methods Angiostatin was separated and purified by l-lysine sepharose 4B from human plasma. The primary retinal microvascular endothelial cells were divided into 4 groups: the control group, vascular endothelial growth factor (VEGF) 10 ng/ml group, angiostatin 130 ?g/ml group, and VEGF (10 ng/ml) + angiostatin (130 ?g/ml) group. The expression of ERK-1 was assayed by Western-blotting method 1, 2, 5, 10, 15, and 30 minutes after the treatment of angiostatin. Results Compared with the control group, the expression of ERK-1 reduced 1 minute after treatment, reduced markedly after 10 minutes. After 30 minutes, no differences of the expression of ERK were seen between the control group and angiostatin group. The activation of ERK-1 of retinal microvascular endothelial cells occurred after stimulated by VEGF, and at the pitch at the peak after 5 minutes. The level of ERK in VEGF group increased 210% than that in the control ( P