Research progress on the mechanism of subthreshold micropulse laser photocoagulation in central serous chorioretinopathy / 国际眼科杂志(Guoji Yanke Zazhi)

Central serous chorioretinopathy(CSC)is a common macular degeneration that primarily affects young patients. While the disease may resolve on its own to some extent, delayed or inadequate treatment can result in recurrence and progression to chronic CSC. This can lead to complications such as retinal pigment epithelium(RPE)atrophy and choroidal neovascularization, ultimately causing irreversible damage to central vision. Subthreshold micropulse laser photocoagulation(SMLP)is a type of laser therapy that differs from traditional lasers in that it does not cause damage or thermal injury to RPE cells and photoreceptors. SMLP has become widely used in clinical treatment of CSC due to its effectiveness, safety, and reproducibility, particularly in cases where verteporfin is not available in photodynamic therapy(PDT). The purpose of this review is to explain the mechanism of SMLP in CSC and summarize the effector cells, cytokines, and mechanisms of action involved in its treatment. This will provide a theoretical basis for promoting and rationalizing the use of SMLP in clinical practice.

Research progress of microRNA in oxidative stress and lipid metabolism of non-exudative age-related macular degeneration / 国际眼科杂志(Guoji Yanke Zazhi)

Age-related macular degeneration(ARMD)is a neurodegenerative disease associated with oxidative stress. It is characterized by progressive death of photoreceptors and retinal pigment epithelium(RPE), and is one of the leading causes of irreversible loss of central vision in patients over the age of 65 years old. MicroRNA(miRNA)is a class of regulatory short-chain non-coding RNA that can bind and inhibit multiple gene targets in the same biological pathway. This unique property makes microRNA an ideal target for exploring the pathogenesis, diagnosis and treatment of non-exudative ARMD. Previous studies have found that the pathogenesis of non-exudative ARMD involves age, genetics, environment, oxidative stress, lipid metabolism, autophagy and immunity. However, the exact mechanisms have not been fully clarified. As biomarkers of non-exudative ARMD, miRNA play a role in oxidative stress and lipid metabolism. This article summarizes the role of various miRNA in targeting Nrf2 and HIF-1α to inhibit hypoxia-related angiogenesis signaling, thereby affecting oxidative stress. Additionally, miRNA regulate lipid uptake and the expression of ABCA1 in RPE and macrophages, thereby influencing lipid metabolism. This deepens the understanding of the role of miRNA in oxidative stress and lipid metabolism in non-exudative ARMD, and provides directions for further improving the understanding of the pathogenesis and prevention of non-exudative ARMD.

Effects of inhibiting CAMKⅡ expression in ARPE-19 cells on the migration, invasion, and tube formation of HUVECs in a non-contact co-culture system / 国际眼科杂志(Guoji Yanke Zazhi)

AIM: To investigate the effect of inhibiting Ca2+/calmodulin-dependent protein kinase Ⅱ(CAMKⅡ)expression in adult retinal pigment epithelial cell line-19(ARPE-19)cells on the migration, invasion, and tube formation of human umbilical vein endothelial cells(HUVECs)in a non-contact co-culture system.METHODS: RNA sequencing was performed on ARPE-19 cells overexpressing CAMKⅡ-δ, and bioinformatics was used to analyze the biological functions of the differentially expressed genes. Transwell inserts was used to construct a non-contact co-culture system of ARPE-19 and HUVECs. The experimental groups included: blank group: only HUVECs were inoculated without ARPE-19 cells; control group: ARPE-19 and HUVECs cells were co-cultured with complete medium; AIP group(CAMKⅡ inhibition group): ARPE-19 cells in AIP(160 nmol/L)were co-cultured with HUVECs in complete medium. The migration, invasion and tube formation abilities of HUVECs were detected. The protein expression levels of CAMKⅡ/AMPK/mTOR/VEGFA were detected by Western blotting.RESULTS:Bioinformatics analysis found that the differentially expressed genes could affect biological processes such as cell growth and death and cell movement. The scratch test and transwell migration test showed that the relative mobility of HUVECs in the AIP group was significantly lower than that in the control group(all P<0.05). However, the invasion and tube formation assay showed that the relative invasion rate and tube formation rate of the AIP group were not significantly different from those of the control group(both P>0.05). Western blotting results showed that the expression levels of CAMKⅡ, P-mTOR, and VEGFA proteins in the AIP group were significantly lower than those in the control group, while the expression level of the P-AMPK protein was significantly higher than that in the control group(all P<0.05).CONCLUSION:In the non-contact co-culture system, inhibition of CAMKⅡ expression in ARPE-19 cells significantly reduced the migration ability of HUVECs, but it cannot change the invasion and tube formation ability, which may be achieved by AMPK/mTOR/VEGFA.

Pigment deposits in the retrolental space of Berger: a rare feature of pigment dispersion syndrome? / Depósitos de pigmento no espaço de Berger: uma característica rara de síndrome de dispersão pigmentar?

ABSTRACT Pigment dispersion syndrome is associated with clinical features such as Krukenberg's spindles, trabecular pigmentation, Scheie's stripe and Zentmayer's ring. Another less common feature of this syndrome is retrolental pigment deposits due to anterior hyaloid detachment or a defect in the Wieger's ligament. We present two cases of pigment deposits on the posterior lens capsule. In both cases, there is bilateral dispersion of pigment throughout the anterior segment. The retrolental deposits are unilateral in the first case and bilateral in the second. Both patients report a history of ocular trauma. This is a possible important clinical sign of pigment dispersion syndrome, rarely described.

RESUMO A síndrome de dispersão pigmentar associa-se a sinais clínicos característicos como fuso de Krukenberg, hiperpigmentação da malha trabecular, linha de Scheie e anel de Zentmeyer. Um sinal menos comum dessa síndrome é o depósito de pigmento posterior ao cristalino, que ocorre por um descolamento da hialoide anterior ou um defeito no ligamento de Wieger. Apresentamos dois casos de depósitos de pigmento posterior à cápsula posterior do cristalino. Em ambos os casos, existia dispersão bilateral de pigmento por todo o segmento anterior. No primeiro caso, os depósitos eram unilaterais e, no segundo, estavam presentes em ambos os olhos. Este pode corresponder a um sinal potencialmente importante da síndrome de dispersão pigmentar, raramente descrito.

Presumed acute posterior multifocal placoid pigmentary epitheliopathy associated with Bartonella infection / Epiteliopatia pigmentar placoide multifocal posterior aguda presumível associada com infecção por Bartonella

ABSTRACT To report a unique case of acute posterior multifocal placoid pigment epitheliopathy (APMPPE) in a patient with positive serology for Bartonella, presenting with ocular signs and symptoms not attributable to other diseases. A 27-year-old woman presented with decreased visual acuity in both eyes. Multimodal fundus image analysis was performed. A color fundus photograph of both eyes revealed peripapillary and macular yellow-white placoid lesions. The fundus autofluorescence of both eyes demonstrated hypo- and hyperautofluorescence of the macular lesions. Fluorescein angiography showed early-stage hypofluorescence and late staining of placoid lesions in both eyes. Spectral domain optical coherence tomography (SD-OCT) of both eyes revealed irregular elevations in the retinal pigment epithelium with the disruption of the ellipsoid zone on the topography of macular lesions. At 3 months after the treatment initiation for Bartonella infection, the placoid lesions became atrophic and hyperpigmented, and SD-OCT revealed loss of both the outer retinal layers and retinal pigment epithelium on the topography of macular lesions in both eyes.

RESUMO Caso de epiteliopatia pigmentada placoide multifocal posterior aguda presumida em paciente com sorologia positiva para Bartonella. Paciente feminina de 27 anos apresentou diminuição da acuidade visual em ambos os olhos. Análise multimodal de imagem foi realizada. A retinografia mostrou revelou lesões placoides amarelo-esbranquiçadas nas áreas peripapilar e macular de ambos os olhos. A autofluorescência demonstrou hipo e hiperautofluorescência em ambos os olhos, na mesma topografia das lesões detectadas na retinografia. A angiofluoresceínografia mostrou hipofluorescência na fase inicial do exame e hiperfluorescência tardia das lesões placoides em ambos os olhos. A tomografia de coerência óptica de domínio espectral de ambos os olhos revelou elevações irregulares do epitélio pigmentado da retina com descontinuação da zona elipsoide na área macular. Três meses após o início do tratamento para infecção por Bartonella, as lesões placoides tornaram-se atróficas e hiperpigmentadas, e a tomografia de coerência óptica revelou perda das camadas externas da retina e do epitélio pigmentado da retina na topografia das lesões maculares em ambos os olhos.

A bullous variant of central serous chorioretinopathy treated with oral spironolactone / Uma variante bolhosa da coriorretinopatia serosa central tratada com espironolactona oral

ABSTRACT We report the case of a 39-year-old male patient who presented with visual loss in the right eye for 6 weeks. The best-corrected visual acuity was counting fingers in the right eye and 20/30 in the left eye. The fundus examination demonstrated a right retinal detachment inferiorly extending to the fovea and a left macular serous detachment. After multimodal imaging study, the patient was diagnosed as having a bullous variant of central serous chorioretinopathy and treated with oral spironolactone associated with adjuvant laser photocoagulation. The retinal changes resolved after 6 months. The final visual acuity was 20/20 in both eyes.

RESUMO Relatamos o caso de um homem de 39 anos apresentando perda visual no olho direito há seis semanas. A melhor acuidade visual corrigida foi conta-dedos no olho direito e 20/30 no esquerdo. A fundoscopia demonstrou descolamento de retina direito inferiormente com extensão à fóvea e descolamento macular seroso à esquerda. Após estudos de imagem multimodal, o paciente foi diagnosticado com uma variante bolhosa de coriorretinopatia serosa central e tratado com espironolactona oral associada à fotocoagulação a laser adjuvante. As alterações retinianas resolveram após seis meses. A acuidade visual final foi 20/20 em ambos os olhos.

Pyridine pigments from functional Monascus rice / 药学学报

The trace chemical components in functional Monascus rice were studied to explore the potential bioactive substances. MCI column, Sephadex LH-20 gel, and preparative liquid chromatography were used to purified the ethyl acetate extract from functional Monascus rice. Two novel pyridine Monascus pigments were isolated and identified, named monascopyridine G (1) and monascopyridine H (2), respectively based on extensive mass spectrometry (MS), infrared radiation (IR), and nuclear magnetic resonance (NMR) analysis. The molecular docking experiments between compounds 1 and 2 and peroxisome proliferators-activated receptor-gamma (PPARγ) showed that they exhibited obvious binding force with the receptor protein. Besides, the biosynthetic pathways of the two compounds were proposed, which provide a valuable reference for the selective production of these potential bioactive substances.

Mechanism of blue light-induced ferroptosis in retinal pigment epithelium cells / 国际眼科杂志(Guoji Yanke Zazhi)

AIM: To investigate the occurrence and possible mechanism of blue light-induced ferroptosis in retinal pigment epithelial cells.METHODS: ARPE-19 cells cultured in vitro were irradiated by 405 nm blue light at 50 mW/cm2 irradiance with different duration and were divided into control, 16.3J/cm2, 32.6J/cm2, and 65.2J/cm2 groups; the 65.2J/cm2 group was defined as the high-level blue light irradiation group and cells were further divided into control, high-level blue light irradiation group and high-level blue light irradiation + ferroptosis inhibitor group. CCK-8 assay was used to detect cell viability, commercial kits were used to detect intracellular glutathione(GSH), ferrous iron and malondialdehyde(MDA)concentration, and Western blot was used to detect the relative expression of glutathione peroxidase 4(GPX4)and xCT proteins in cells.RESULTS: The decrease of ARPE-19 cell viability caused by blue light irradiation was dose-dependent, and the reduction of intracellular GSH concentration, the increase of ferrous iron concentration and MDA concentration were all caused by high-level blue light irradiation(all P<0.05); the ferroptosis inhibitor partially restored cell viability and recovered intracellular GSH, reduced concentrations of MDA and ferrous iron in the blue light irradiation group(all P<0.05). The relative expressions of GPX4 and xCT proteins were significantly decreased in the blue light irradiation group, and such change was alleviated by the ferroptosis inhibitor(P<0.05).CONCLUSION: Blue light irradiation may induce ferroptosis in RPE cells by targeting the xCT and GPX4-associated antioxidant pathways.

Research progress of tight junction between retinal pigment epithelium cells and its disruption in the pathogenesis of age-related macular degeneration / 国际眼科杂志(Guoji Yanke Zazhi)

Age-related macular degeneration(AMD)is a common eye disease causing irreversible visual impairment in the elderly. The tight junction(TJ)between retinal pigment epithelium cells(RPECs)is an important structural unit of the outer blood retinal barrier(oBRB). The TJ is defective in the pathogenesis of AMD, which in turn promotes the destruction of oBRB and accelerates the occurrence and progression of AMD. In this paper, the roles of TJ and TJ protein in maintaining oBRB function, TJ protein abnormality and oBRB destruction in the pathogenesis of AMD were reviewed, aiming to provide new ideas for the treatment of AMD.

Medium-long-term efficacy of trabeculectomy in the treatment of pigmentary glaucoma / 国际眼科杂志(Guoji Yanke Zazhi)

AIM: To observe the medium-long-term efficacy of trabeculectomy in the treatment of pigmentary glaucoma(PG).METHODS: The clinical data of 38 patients(51 eyes)who were diagnosed with PG and received trabeculectomy at the Affiliated Hospital of Yunnan University from January 2010 to September 2022 were retrospectively analyzed. The postoperative follow-up ranged from 3 to 144mo. The intraocular pressure(IOP), visual acuity and refractive status were analyzed, complications were recorded and surgical efficacy was evaluated.RESULTS: The average preoperative use of IOP lowering drugs was 2.90±0.12, with a mean IOP of 18.89±7.40mmHg. The IOP at 3d, 1, 3, 6mo, 1a after surgery and the last follow-up visit were 14.68±5.08, 13.99±2.95, 14.25±2.50, 14.36±2.83, 14.33±2.66, 14.94±1.95mmHg, respectively, and postoperative IOP was significantly lower at all time points than that before surgery(P<0.05), while there was no significant difference at all time points after surgery(P>0.05). During the follow-up period, the visual acuity of all patients was stable, and no endophthalmitis or malignant glaucoma occurred. At the last follow-up, the complete success rate was 90%, the qualified success was 8%, and the failure rate was 2%.CONCLUSION: Trabeculectomy is a safe and effective treatment method for PG, which can effectively control the IOP, and stabilize the visual acuity and relieve the reverse pupil block.

Mogroside regulates the oxidative stress response of retinal pigment epithelial cells induced by H 2O 2 through silent information regulator of transcription 1/nuclear factor erythroid-2-related actor 2 signaling pathway / 中华眼底病杂志

Objective:To observe and preliminarily explore the effect of mogroside on oxidative stress of retinal pigment epitheliaum (RPE) cells induced by hydrogen peroxide (H 2O 2) and its possible mechanism. Methods:A experimental study. The RPE cells were divided into control group, H 2O 2 group, silent information regulator of transcription 1 (SIRT1) inhibitor EX527 group (EX527 group), mogroside group, mogroside+EX527 group. Methyl thiazolete trazolium method was used to detect cell survival rate. Flow cytometry was used to detect cell apoptosis rate. 2' ,7'-dichlorodihydrofluorescein diacetate fluorescent probe method, xanthine method and enzyme-linked immunosorbent assay method were used to detect the level of reactive oxygen species (ROS), superoxide dismutase (SOD) activity and malondialdehyde (MDA) content in cells respectively. Real-time quantitative polymerase chain reaction and Western blot were used to detect relative expressions of SIRT1, nuclear factor erythroid-2-related actor 2 (Nrf2), heme oxygenase-1 (HO-1) mRNA and protein in cells. One-way ANOVA was used for comparison among groups. The pairwise comparison between groups was tested by the least significant difference t test. Results:Compared with the control group, the H 2O 2 group cell survival rate decreased, the apoptosis rate increased, the ROS level in the cells increased, the SOD activity decreased, the MDA content increased, and the relative expression of SIRT1, Nrf2, HO-1 mRNA and protein decreased ( P<0.05). Compared with H 2O 2 group, the cell survival rate decreased, apoptosis rate increased, the cell ROS level increased, SOD activity decreased, MDA content increased, SIRT1, Nrf2, HO-1 mRNA and protein expression decreased in EX527 group ( P<0.05); the cell survival rate increased, apoptosis rate decreased, ROS level decreased, SOD activity increased, MDA content decreased, and the relative expression of SIRT1, Nrf2, HO-1 mRNA and protein increased in mogroside group ( P<0.05). Compared with the mogrosides group, the cell survival rate decreased, the apoptosis rate increased, the level of ROS increased, SOD activity decreased, MDA content increased, SIRT1, Nrf2, HO-1 mRNA and protein decreased in mogrosides+EX527 group ( P<0.05). Conclusions:Mogrosides can alleviate the oxidative stress response of visual RPE cells induced by H 2O 2, promote cell proliferation, and reduce cell apoptosis. Mogrosides may exert antioxidant effects by activating the SIRT1/Nrf2 signaling pathway.

Progress on the function and mechanism of pigment epithelium derived factor receptors in the occurrence and development of diabetic retinopathy / 中华眼底病杂志

Endogenous pigment epithelium derived factor (PEDF) shows great potential as a drug target for the treatment of diabetes retinopathy (DR) due to its anti-angiogenesis, anti-inflammatory, neuroprotective and neurotrophic effects. PEDF plays a biological role by combining with receptor proteins on cell membrane surface and regulating a variety of signaling pathways. Low density lipoprotein receptor related protein 6 plays a role in inhibiting oxidative stress reaction, inflammatory reaction, and neovascularization of DR. Adipose triglyceride lipase, laminin receptor, plexin domain containing 1 (PLXDC) 1, PLXDC2 and F 1-adenosine triphosphate synthase have the effect of promoting endothelial cell apoptosis, among which PLXDC1 also has neuroprotective effect. By clarifying the receptor that PEDF acts on, exploring the affinity between the receptor and PEDF, the difference in the expression level of each receptor in the process of disease, and the specific function that PEDF plays after binding with specific receptors, we can develop fusion protein drugs for the active domain of high affinity of receptors, have a clearer understanding of the pathogenesis of DR, and take PEDF or PEDF receptor as the target to consolidate the theoretical basis for the development of new therapeutic drugs and strategies for DR.

Overexpression of SARS-CoV-2 spike protein mediates growth inhibition in human retinal pigment epithelial cells / 中华眼底病杂志

Objective:To observe the inhibition of SARS-CoV-2 spike protein (S-protein) on the proliferation of human retinal pigment epithelium (RPE) cells.Methods:SARS-CoV-2 S-protein gene fragment expression plasmid (p3xflag-S) was constructed and transfected into human RPE, HEK293 cells. DNA sequencing was used for identification, and the expression of Flag-S was detected by Western blot. HEK293 cells were divided into the cells 1, 2, 3 and 4 and transfected with GFP11 plasmid and vector, GFP1-10 plasmid and vector, transfected with GFP11 and pCMV-HA-ACE2 plasmid, GFP1-10 and p3xflag-S plasmid. Cell 1 was co-cultured with cell 2 (control group 1), cell 2 with cell 3 (control group 2), cell 3 with cell 4 (observation group), and cell 1 mixed with cells 2, 3 and 4 (control group 3). Bright-field microscopy and fluorescence microscopy were used to observe cell fusion. RPE cells were divided into control group and overexpression S-protein group. The cell cycle was detected by flow cytometry; the cell proliferation level was detected by Counting Kit 8 (CCK-8); and the S-protein expression level in RPE cells was detected by Western blot. The Student’s t-test was performed for comparison between groups. Results:DNA sequence assay showed that S-protein cDNA was fused with flag-tagged protein. Western blot assay showed that S-protein-related expression was elevated in transfected HEK293 cells compared with untransfected p3xflag-S cells. Large, multinucleated fused cell clusters were visible under bright-field microscopy; multiple nuclear with distinct green fluorescence were visible in the fused cells under fluorescence microscopy. Western blot assay showed elevated S-protein-related expression in transfected p3xflag-S plasmid RPE cells compared to untransfected p3xflag-S plasmid RPE cells. CCK-8 results showed that the proliferative capacity of RPE cells in the S-protein overexpression group was significantly reduced compared with the control group, with statistically significant differences ( t=22.70, 16.75, 23.38; P<0.000 1). The results of flow cytometry showed that the G1 phase cells in the control and overexpression S-protein groups were 41.1 % and 67.0%, respectively; compared with the control group, the G1 phase cells in the overexpression S-protein group were significantly higher, and the difference was statistically significant ( t=4.76, P=0.018). The apoptosis rate was significantly increased in the S-protein overexpression group compared with the control group, and the difference was statistically significant ( t=4.91, P=0.008). Conclusion:Overexpression of the SARS-CoV-2 spike protein reduced the proliferation of human RPE cells.

Antagonistic effect of SC79 on high glucose-induced apoptosis of RPE cells and its regulatory mechanism on AKT-XIAP signaling pathway / 中华实验眼科杂志

Objective:To investigate the antagonistic effect and potential mechanism of specific AKT activator SC79 on the apoptosis of human retinal pigment epithelial (ARPE)-19 cells induced by high glucose in vitro. Methods:The ARPE-19 cells were cultured in high glucose medium (containing 30 mmol/L glucose) plus 5, 10 or 20 μg/ml SC79, respectively.After 6-, 12- and 24-hour culture, the optimal experimental concentration and timing were determined according to cell proliferation rate.Then ARPE-19 cells were divided into four groups, normal control group cultured in normal medium containing 5.6 mmol/L glucose for 48 hours, mannitol group cultured in medium containing 5.6 mmol/L glucose and 24.4 mmol/L mannitol for 48 hours, high glucose group cultured in high glucose medium for 48 hours, and high glucose+ SC79 group cultured in normal medium containing 10 μg/ml SC79 for 12 hours plus in high glucose medium for 36 hours.The proliferation rate of APRE-19 cells was detected by MTS assay.The apoptosis rate was measured by flow cytometry.The relative expression levels of phosphorylated protein kinase B (p-Akt), X-linked inhibitor of apoptosis protein (XIAP), caspase-9, caspase-3 and its active fragments (active-caspase-3) were assayed by Western blot.The ARPE-19 cells were divided into Neg-shRNA group, AKT shRNA group and blank control group and were treated with the corresponding transfection complex and serum-free medium.The AKT mRNA expression was detected by real-time PCR.The transfected ARPE-19 cells were divided into Neg-shRNA+ SC79 group and AKT shRNA+ SC79 group and were cultured according to the culturing method of high-glucose+ SC79 group.The apoptosis rate of the two groups was tested by flow cytometry.Results:Among different concentrations of SC79 and treatment times, the proliferation rate of cells treated with 10 μg/ml SC79 for 12 hours was the highest.The proliferation rate of ARPE-19 cells in high-glucose group was significantly lower than that in normal control group, mannitol group and high-glucose+ SC79 group, and the differences were statistically significant (all at P<0.01). The apoptosis rate of cells in the high-glucose group was (52.27±3.21)%, which was significantly higher than (3.90±0.71)% in normal control group and (20.70±3.62)% in high-glucose+ SC79 group (both at P<0.01). The relative expression levels of p-Akt, XIAP, caspase-9 and caspase-3 were significantly lower and the relative expression level of active-caspase-3 was significantly higher in high glucose group than those in normal control group and high-glucose+ SC79 group (all at P<0.05). The relative expression level of AKT mRNA in normal control group, Neg-shRNA group and AKT shRNA group was 0.60±0.07, 0.59±0.03 and 0.11±0.10, respectively, showing a statistically significant difference among the groups ( F=30.44, P<0.01). The apoptosis rate of cells in the AKT shRNA+ SC79 group was significantly higher than that in high-glucose+ SC79 group and Neg-shRNA+ SC79 group (both at P<0.001). Conclusions:SC79 can partially antagonize the apoptosis of ARPE-19 cells induced by high glucose, which is related to the activation of AKT/XIAP pathway and the inhibition of the caspase family.

Inhibitory effects of N-acetylcysteine and salubrinal on apoptosis of retinal pigment epithelial cells induced by all-trans-retinoic acid / 中华实验眼科杂志

Objective:To observe the effect of the antioxidant N-acetylcysteine (NAC) and selective endoplasmic reticulum stress response inhibitor salubrinal on the apoptosis of retinal pigment epithelial cells induced by all-trans-retinoic acid (ATRA).Methods:Human ARPE-19 cell line was used as the experimental cell line, and was divided into normal control group cultured with complete medium, model control group cultured with complete medium containing 10 μmol/L ATRA, NAC treatment group cultured with complete medium containing 10 μmol/L ATRA+ 5 mmol/L NAC, salubrinal group cultured with complete medium containing 10 μmol/L ATRA+ 40 μmol/L salubrinal, NAC+ salubrinal group cultured with complete medium containing 10 μmol/L ATRA+ 5 mmol/L NAC+ 40 μmol/L salubrinal.After 24-hour culture, apoptosis rate, multicaspase level and reactive oxygen species (ROS) level of ARPE-19 cells were detected by flow cytometry.The expressions of vascular endothelial growth factor A (VEGF-A), C/EBP-homologous protein (CHOP), cleaved-caspase 3 in cells were detected by Western blot.Results:There were significant differences in the apoptosis rate, multicaspase and ROS levels among the five groups ( F=113.23, 602.41, 160.39; all at P<0.001). The apoptosis rate, multicaspase and ROS levels of normal control group, NAC treatment group, salubrinal group and NAC+ salubrinal group were significantly lower than those of model control group (all at P<0.05). There were significant differences in the expression levels of VEGF-A, CHOP and cleaved-caspase 3 among the five groups ( F=24.62, 36.35, 60.25; all at P<0.001). The protein expression levels of VEGF-A, CHOP and cleaved-caspase 3 of normal control group, NAC treatment group, salubrinal group and NAC+ salubrinal group were significantly lower than those of model control group (all at P<0.05). Conclusions:ATRA can induce RPE cells to produce oxidative stress and endoplasmic reticulum stress injury, which leads to apoptosis.NAC and salubrinal can effectively reduce the RPE cell apoptosis by inhibiting stress response.

Effects and mechanisms of ferroptosis on high glucose-induced retinal pigment epithelial cells injury / 国际眼科杂志(Guoji Yanke Zazhi)

AIM: To observe the effects and mechanisms of ferroptosis on high glucose(HG)-induced retinal pigment epithelium(RPE)cells injury, and to provide new ideas for the treatment of diabetic retinopathy(DR).METHODS: The ARPE-19 cell lines cultured in vitro were divided into normal control group(NC group), high glucose group(HG group), and high glucose+Ferrostatin-1 group(Fer-1 group). The cell viability of each group was detected by CCK-8 assay. The expressions of interleukin 6(IL-6), IL-1β and monocyte chemotactic protein-1(MCP-1)were detected using ELISA kits. The levels of malondialdehyde(MDA), glutathione(GSH), glutathione peroxidase 4(GPX4)and iron content were detected using the corresponding assay kits. The mitochondrial changes in ARPE-19 cells were observed by transmission electron microscopy. The expressions of ferroptosis-related proteins including long-chain lipoyl CoA synthase 4(ACSL4)and GPX4, as well as vascular endothelial growth factor(VEGF)were detected by Western blotting and immunofluorescence staining.RESULTS: Compared with NC group, the cell viability of HG group decreased significantly, the expression levels of inflammatory factors in cell supernatant increased, the contents of MDA and iron significantly increased, GSH and GPX4 significantly decreased(all P&#x003C;0.01), the mitochondria of ARPE-19 cells shrunk, the expression of proteins ACSL4 and VEGF increased, while the expression of GPX4 decreased(all P&#x003C;0.01). Compared with HG group, the cell viability of Fer-1 group significantly increased, the expression levels of inflammatory factors in cell supernatant decreased, MDA and iron contents significantly decreased, GSH contents and GPX4 viability significantly increased(all P&#x003C;0.05), the morphology of mitochondria in ARPE-19 cells improved, the expression of ACSL4 and VEGF decreased, while the expression of GPX4 increased(all P&#x003C;0.05).CONCLUSION: Ferroptosis is involved in the injury of RPE induced by HG. Inhibiting ferroptosis can improve cell viability, reduce inflammation and oxidative stress, and alleviate HG-induced RPE cells injury.

Research progress of pigment epithelial-derived factor in ocular diseases / 国际眼科杂志(Guoji Yanke Zazhi)

As a secreted glycoprotein with a molecular weight of 50kDa, pigment epithelial-derived factor(PEDF)was originally found to be secreted by pigment epithelial cells; afterwards, it was found to be widely distributed in various organs and tissues throughout the body and played multiple biological roles. In recent years, a large number of studies have confirmed that PEDF can initiate a wide range of cellular responses in eye tissues by binding with a variety of receptors, which has the functions of regulating angiogenesis, anti-inflammatory, antioxidant stress and neurotrophic. Recent studies have found that the application of exogenous PEDF has a preferable therapeutic effect on the repair of dry eye and corneal injury. In addition, the PEDF gene encoding therapy has shown promising in the treatment of age-related macular degeneration and diabetic retinopathy. This review mainly summarizes the potential therapeutic effects and limitations of pigment epithelium-derived factors in dry eye, corneal injury, age-related macular degeneration, diabetic retinopathy and other diseases in recent years, which provides help for further research on the diagnosis and treatment of ocular diseases with PEDF.

Krill's disease: a newer management option

Purpose: To report a case of a young female who presented with scotoma in the right eye for few days. Case Report: Krill's disease or acute retinal pigment epithelitis (ARPE) is a self-limiting retinal disease with no specific treatment. Typical clinical and imaging features helped us to diagnose her with ARPE. Intravenous methylprednisolone (IVMP), which gives a rapid anti-inflammatory response, was advised. An SD-OCT scan post-injection showed a reduction in hyperreflectivity and height of lesion at day 3 and near total resolution by day 5. Conclusion: This case suggests rapid resolution of ARPE with the use of IVMP.

Neovascular Glaucoma Secondary to Bloch-Sulzberger Syndrome Documented by Retinography and Wide Field Angiography

Aims: To describe a Neovascular Glaucoma Secondary to Bloch-Sulzberger Syndrome.Presentation of Case: A.B.F. female, 23 years old, claimed significant pain sensation and hyperemia in the left eye (LE) for 45 days, without triggering factors. She came to the consultation with a previous diagnosis of Bloch-Sulzberger Syndrome with pigmented lesions in the lower limbs since childhood, being followed up by dermatology since then.Discussion: The diagnosis of IP (Incontinentia Pigmenti) is complex because it mimics other dermatoses. The impairment in other systems, such as the ophthalmic system, with the possibility of loss of vision and functional disability is a reality. The natural history of retinal lesions is not fully understood. Vascular changes seem to start in the first weeks of life and progress after birth for weeks or months, and may stabilize at any stage, leaving numerous sequelae.Conclusions: Incontinentia pigmenti is difficult to diagnose and, at each evolutionary stage, presents many differential diagnoses. Eye injuries can lead to blindness as a consequence of ischemic events that can start soon after birth.

External Limiting Membrane, Photoreceptor Ellipsoid Zone Disruption, and Retinal Pigment Epithelium Alterations in Diabetic Retinopathy

Objective?Diabetic retinopathy (DR), a microvascular complication of diabetes, is a leading cause of preventable blindness. Spectral domain optical coherence tomography (SD-OCT) provides cross-sectional and topographical imaging of the retina. SD-OCT resolves outer retinal layers into three hyperreflective bands—external limiting membrane (ELM), ellipsoid zone (EZ), and retinal pigment epithelium (RPE). In this article, we have studied the role of these outer retinal layers in structural and molecular changes taking place in DR. Materials and Methods?Articles with clinical features, pathogenesis, diagnosis, and treatment of DR were thoroughly studied. Articles were searched on PubMed, MEDLINE, and Cochrane Library from 2000 to 2020. Studies focusing on the role of ELM, EZ, and RPE in pathogenesis of DR based on SD-OCT were included. Results?The long-standing hyperglycemia leads to protein glycosylation resulting in formation of advanced glycation end products (AGEs). AGEs have an impact through their effect on retinal microvasculature, vascular endothelial growth factor (VEGF), intercellular adhesion molecule-1, nitrosative and oxidative stress, and vitamin D and calcium metabolism. All these factors have been linked with disruption of outer retinal layers. AGEs lead to vascular endothelial dysfunction and release of proangiogenic factors by increasing the expression of VEGF in retinal pericytes and RPE cells. This leads to leakage and fluid accumulation resulting in diabetic macular edema (DME). In DME, there is sequential disruption of ELM and EZ and decrease in visual acuity (VA). The RPE alterations have been reported to be associated with the severity of DR and decrease in VA. Anti-VEGF therapy, most common treatment of DME, leads to restoration of barrier effect of ELM, it was found to be restored first followed by EZ restoration. Newer anti-AGEs agents and their receptor blockers are being developed which have a positive effect on maintaining the health of RPE. Conclusion?A complex molecular association exists between the structural changes in ELM, EZ, and RPE in DR. SD-OCT is an indispensable tool to study these changes as integrity of these outer layers of retina is essential for maintaining visual function of retina in DR.