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.

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.

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.

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.

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<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<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<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<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.

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.

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.

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.

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.

Manejo del desprendimiento de retina regmatógeno / Management of rhegmatogenous retinal detachment

1. INTRODUCCIÓN El desprendimiento de retina es un problema visual grave que puede ocurrir a cualquier edad, aunque suele darse en individuos de edad media o en personas de la tercera edad. La incidencia es relativamente baja considerando que las estima-ciones varían según zonas geográficas; y, se han reportado datos de entre 6,3 y 17,9 por 100 000 habitantes. Otras características im-portantes a considerar son la degeneración en encaje de 45,75% y la miopía de 47,28% que influyen en la presentación del desprendi-miento de retina. Al mismo tiempo que la edad, los cambios vítreos retinianos y la presencia de pseudofaquia1,2. Además, de los factores oculares relacionados también influyen, el seguimiento inadecuado de los factores de riesgo y el difícil acceso a médicos especialistas que se traduce en retraso en el diagnóstico certero y tratamiento tardío que implica deterioro del pronóstico visual cuando el área macular está incluida en el área desprendida con pobres resultados en adultos jóvenes y en edad productiva.El tratamiento evitará el deterioro o pérdida irreversible de la visión. El pronóstico con tratamiento quirúrgico es bueno si el des-prendimiento no incluye a la mácula.

1. INTRODUCTIONRetinal Detachment is a serious visual problem that can occur at any age, although it usually occurs in middle-aged or elderly in-dividuals. The incidence is relatively low considering that estimates vary ac-cording to geographical areas; and, data have been reported be-tween 6,3 and 17,9 per 100 000 inhabitants. Other important cha-racteristics to consider are socket degeneration of 45,75% and myopia of 47,28% that influence the presentation of retinal deta-chment, as well as age, vitreoretinal changes and the presence of pseudophakia1,2.In addition to the related ocular factors, inadequate follow-up of risk factors and difficult access to medical specialists also play a role, resulting in delayed accurate diagnosis and late treatment that implies deterioration of the visual prognosis when the macular area is included in the detached area with poor results in young adults and those of productive age.Treatment will prevent irreversible deterioration or loss of vision. The prognosis with surgical treatment is good if the detachment does not include the macula.

Multimodal imaging in a patient with combined hamartoma of the retina and retina pigment epithelium / Imagem multimodal em paciente com hamartoma combinado da retina e epitélio pigmentar da retina

ABSTRACT Combined hamartoma of the retina and retinal pigment epithelium is a rare, benign intraocular tumor. Hamartoma of the retina and retinal pigment epithelium has been described in the literature as a condition presenting with variable retinal damage, ranging from partial epiretinal involvement to complete distortion of the retinal layers and retinal pigment epithelium. We report the case of an 8-year-old girl presenting with longstanding strabismus who was diagnosed with Hamartoma of the retina and retinal pigment epithelium based on multimodal imaging assessment. We explored the particular imaging findings from studies using spectral-domain optical coherence tomography, fundus autofluorescence, optical coherence tomography angiography, and fluorescein angiography.

RESUMO O hamartoma combinado de retina e epitélio pigmentar da retina consiste em um tumor intraocular raro com comportamento benigno. O hamartoma combinado de retina e epitélio pigmentar da retina foi descrito na literatura apresentando dano retiniano variável, desde o envolvimento epirretiniano parcial até distorção completa das camadas retinianas e do epitélio pigmentar da retina. Relatamos o caso de uma menina de 8 anos com estrabismo de longa data que foi diagnosticada com hamartoma combinado de retina e epitélio pigmentar da retina, com base na avaliação de imagem multimodal. Exploramos os achados de imagem específicos de estudos usando tomografia de coerência óptica de domínio espectral, autofluorescência, angiografia por tomografia de coerência óptica e angiografia fluorescente.

Bone marrow mesenchymal stem cell-derived exosomes miR-183 target regulation of retinal dehydrogenase 11 to inhibit the development of retinitis pigmentosa / 中华眼底病杂志

Objective:To observe the expressions of miR-183 and retinal dehydrogenase 11 (RDH11) in exosomes derived from bone marrow mesenchymal stem cells (BMSC), and to preliminarily explore their targeting relationship and their effects on retinal pigment epithelial (RPE) cells.Methods:BMSC from C57BL/6 (C57) mice were isolated and cultured, and BMSC-derived exosomes were identified. BMSC were divided into blank group, simulation blank control group (mimic-NC group), miR-183 simulation group (miR-183-mimic group). C57 mice and retinal degeneration 10 (rd10) mouse RPE cells were cultured with reference to literature methods. RPE cells from rd10 mice were transfected with BMSC exosomes and co-cultured and divided into control group, exosome group, mimic-NC-exosome group (mimic-NC-exo group), miR-183-mimic-exosome group (miR-183-mimic-exo group). The relative expression levels of miR-183, RDH11 mRNA and protein in C57 mice, rd10 mice and RPE cells in each group were detected by real-time quantitative polymerase chain reaction and western blotting. The targeting relationship between miR-183 and RDH11 was analyzed by bioinformatics website and dual luciferase reporter. Cell counting kit 8 was used to detect the effect of miR-183 on BMSC exosomes on RPE cell proliferation; in situ labeling end labeling method was used to detect RPE cells apoptosis. One-way ANOVA was used to compare multiple groups.Results:Compared with C57 mouse RPE cells, the relative expression of miR-183 in rd10 mouse RPE cells was down-regulated, and the relative expression of RDH11 mRNA was up-regulated, and the differences were statistically significant ( t=5.230, 8.548; P=0.006, 0.001). Compared with the blank group and the mimic-NC group, the relative expression of miR-183 mRNA in the exosomes of the miR-183-mimics group was significantly increased ( F=60.130, P <0.05 ). After 24 h of co-culture, exosomes entered RPE cells. Compared with the mimic-NC-exo group, the relative expression of miR-183 mRNA in RPE cells in the miR-183-mimic-exo group was significantly increased, the proliferation ability was enhanced ( t=7.311, P=0.002), and the number of apoptotic cells was decreased ( F=10.949, P=0.012), and the differences were statistically significant ( t=4.571, P=0.002). Bioinformatics website and dual-luciferase report confirmed that miR-183 has a targeting relationship with RDH11. Compared with the mimic-NC group, the relative expression of RDH11 mRNA and protein in the exosomes of the miR-183-mimic group was decreased, and the difference was statistically significant ( t=5.361, 6.591; P=0.006, 0.003). After co-culture, compared with the control group, there was no significant difference in the relative expression of RDH11 mRNA and protein in RPE cells in the exosome group ( t=0.169, 1.134; P=0.874, 0.320); The relative expressions of RDH11 mRNA and protein in RPE cells in -183-mimic-exo group were decreased, and the difference was statistically significant ( t=5.554, 5.546; P=0.005, 0.005). Conclusion:Up-regulation of BMSC-derived exosomal miR-183 promote the proliferation of RPE cells in vitro by targeting the expression of RDH11 and reduce the number of apoptosis.

Meibomian gland dysfunction and expressions of inflammatory factors and lipid metabolic factors in diabetic mice / 中华实验眼科杂志

Objective:To explore the changes in morphology and function of meibomian gland and the expressions of inflammatory factors and lipid metabolic factors in meibomian gland of diabetic mice.Methods:Fifty 8-week-old male C57BL/6 mice of clean degree were divided into normal control group ( n=20) and diabetes model group ( n=30) according to a random table.Diabetes model was established by the intraperitoneal injection of streptozotocin (60 mg/kg, 10 mg/ml). Mouse tail vein blood glucose ≥16.7 mmol/L was considered as successful modeling.Blood glucose was measured weekly, and body weight was compared between the two groups.Ten mice were randomly selected for fluorescein sodium staining of the cornea to evaluate the integrity of the corneal epithelium from both groups at an interval of 4 weeks.Five mice were randomly selected from the two groups and were sacrificed via anesthesia to collect meibomian gland tissue for hematoxylin and eosin staining in order to observe morphological changes at 8 and 16 weeks after modeling, respectively.At 16 weeks following modeling, mebomian gland of 5 mice randomly selected from both groups was stained with oil red O staining to observe the distribution of lipid.Real-time fluorescence quantitative-PCR was performed to detect the relative expressions of tumor necrosis factor (TNF)-α, pigment epithelium derived factor (PEDF), peroxisome proliferators-activated receptor γ (PPARγ), and adipose differentiation-related protein (ADFP) mRNA in meibomian gland.The use and care of animals complied with the ARVO statement.This study protocol was approved by the Institutional Animal Care and Use Committee of Tianjin Medical University Eye Hospital (No.TJYY20190630009). Results:The successful modeling rate of diabetes in mice was 100%, and the survival rate was 83.3% (25/30). The weight was significantly lower and the blood glucose level was higher in diabetes model group at 8 and 16 weeks after modeling in comparison with normal control group (all at P<0.05). There were significant differences in corneal fluorescein staining score among different time points in diabetes model group ( F=27.155, P<0.05). In diabetes model group, thinner wall of meibomian gland duct, enlarged lumen of the duct, dilated acini and oil red-stained lipid deposition in most acini were observed.At 16 weeks after modeling, the expressions of TNF-α, and PPARγ mRNA in meibomian gland of diabetes model group were 3.33±0.91 and 1.55±0.25, which were significantly higher than 1.00±0.16 and 1.00±0.27 of normal control group (both at P<0.05). The expression of PEDF mRNA in diabetes model group was 0.42±0.08, which was significantly lower than 1.00±0.34 in normal control group ( P<0.05). There was no significant difference in the ADFP mRNA expression between the two groups ( t=0.943, P=0.38). Conclusions:Inflammatory factors and lipid metabolic factors such as TNF-α, PEDF, and PPARγ may be involved in the pathogenesis of meibomian gland dysfunction induced by diabetes.

New insights into the integrity of intercellular junctions between retinal pigment epithelial cells / 中华实验眼科杂志

Retinal pigment epithelium (RPE) is composed of a layer of highly specialized hexagonal pigment epithelial cells.The apical surface of RPE interacts with the photoreceptor, and RPE basal surface interacts with Bruch membrane and choroidal capillaries to maintain the function of retinal photoreceptor.A variety of junction proteins distributed between RPE cells are the basis for RPE to perform normal functions, ensuring the integrity and physiological function of RPE.Under pathological conditions, the abnormal function of RPE is first manifested by the abnormal junctional protein, which leads to the loss of adhesion between cells, cells and basement membrane, and then a series of abnormal biological behaviors, such as dissociation, migration, transdifferentiation and protein expression changes in RPE cells, which have become an important cause of many fundus diseases.The role of RPE junctional complexes during normal and pathological conditions, as well as their role in proliferative vitreoretinopathy, age-related macular degeneration and diabetic vitreoretinopathy was reviewed in this article from the composition and correlation of junctional proteins between RPE cells.

Endoplasmic reticulum stress in the pathogenesis of age-related macular degeneration / 国际眼科杂志(Guoji Yanke Zazhi)

@#Age-related macular degeneration(ARMD)is a main cause of irreversible visual impairment in the elderly. The major pathological features are drusen formation, macular pigment disorder, geographic atrophy and abnormal neovascularization. Retinal pigment epithelium(RPE)function is impaired in ARMD. Endoplasmic reticulum(ER)is an organelle in eukaryotes responsible for protein synthesis, modification, integration and quality control. ER also participates in the maintenance of calcium homeostasis and lipid biosynthesis. Stimuli from the external and internal environment may trigger ER stress and therefore activate the intracellular signal transduction pathway-the unfolded protein response(UPR), to restore cell homeostasis. However, prolonged ER stress may lead to apoptosis. The pathogenesis of ARMD has not been fully elucidated, nevertheless, compelling evidence demonstrates that ER stress is involved. In this article, we summarize recent advances in UPR pathways, as well as the role of ER stress in the physiological function of RPE and in the pathogenesis of ARMD.

Study on the apoptosis of human retinal pigment epithelium cells induced by EGCG / 国际眼科杂志(Guoji Yanke Zazhi)

AIM:To investigate the effect of epigallocatechin gallate(EGCG)on the apoptosis of human retinal pigment epithelium(ARPE-19)cells and its mechanism. METHODS:The ARPE-19 cells were cultured in vitro and treated with 0,40,80 and 160 μg/mL EGCG, respectively. At the proposed time of treatment the morphological changes were detected by hoechst 33258 staining. The apoptosis rate was detected by flow cytometry. The expression of apoptosis-related factors B lymphocytoma-2 gene(bcl-2), BCL2-Associated X protein(Bax),caspase-3 and p53 were detected by quantitative RT-PCR and Western blotting.RESULTS: Hoechst 33258 staining showed that the ARPE-19 cells with the increase of EGCG drug concentration, the number of apoptotic cells gradually increased and the apoptotic bodies were observed. Flow cytometry showed that the apoptosis rate increased gradually with the increase of EGCG drug concentration. The apoptosis rates at 40, 80 and 160 μg/mL were 4.95%±0.071%, 11.75%±0.075% and 21.25%±0.919% respectively, which was significantly different compared with the control group(2.8%±1.556%)(P<0.01), presented with a drug concentration-dependent. The results of quantitative PCR and Western blotting showed that EGCG could significantly up-regulate the expression of apoptosis-promoting factors Bax, caspase-3 and the mRNA and protein expression of p53, and down-regulate the apoptosis-inhibiting factor bcl-2, all of these showed concentration-dependent effects.CONCLUSION:EGCG can obviously induce the apoptosis of ARPE-19 cells. The mechanism is related with the inhibition of bcl-2 and increase the expression of Bax, caspase-3 and p53.

Effects of AG3340 on the migration and invasion of human retinal pigment epithelial cells induced by high glucose / 国际眼科杂志(Guoji Yanke Zazhi)

AIM: To investigate the effect and mechanism of matrix metalloproteinase(MMPs)inhibitor AG3340 on the migration and invasion ability of retinal pigment epithelial cells-19(ARPE-19)cultured in high glucose(CHG). METHODS: ARPE-19 cells cultured in vitro were divided into four groups: Control group, the glucose at the concentration of 5.6mmol/L in DMEM/F12 medium; HG group, the glucose at the concentration of 30mmol/L was cultured with DMEM/F12 medium; HG+AG3340 group, the cells were pretreated with AG3340 for 12h, and then cultured in DMEM/F12 medium containing 30mmol/L glucose; The mannitol(MA)group, cultured with DMEM/F12 medium of 5.6mmol/L glucose and 24.4mmol/L mannitol, which used as hypertonic control group. The migration ability of cells was detected by wound healing assay, the invasion ability of cells was detected by Transwell assay, and the relative expression levels of MMP-9, MMP-2, fibronectin and collagen Ⅳ were detected by Western blot.RESULTS: The results of wound healing assay showed that compared with the Control group, the cell migration rate of scratching after 24h and 48h in the HG group was significantly increased(all P<0.001).After pretreated by AG3340, the cell migration rate was significantly lower than that in the HG group(all P<0.01).Transwell assay showed that compared with the Control group, the number of cell invasion in the HG group was significantly higher than that in the Control group(all P<0.001). After pretreated by AG3340, the number of cell invasion was decreased than the HG group(all P<0.01). Western blot results showed that compared with the Control group, the relative expression levels of MMP-9 and MMP-2 of the cells in the HG group were increased, and the relative expression levels of Fibronectin and Collagen Ⅳ were decreased(all P<0.001). Compared with the HG group, the relative expression levels of MMP-9 and MMP-2 protein in AG3340 pretreatment group were decreased, and the relative expression levels of Fibronectin and Collagen Ⅳ were increased(all P<0.05). CONCLUSION: High glucose induced ARPE-19 cells with enhanced migration and invasion ability, and AG3340 partially reversed this effect, which was related to the inhibition of MMP-9 and MMP-2 expression and the stability of extra-cellular matrix components.

Observation of the effect of autologous retinal pigment epithelium transplantation in the treatment of severe obsolete submacular hemorrhage / 中华眼底病杂志

Objective:To evaluate the functional and anatomical outcomes of autologous single retinal pigment epithelium (RPE) transplantation for severe obsolete submacular hemorrhage (SMH) in late age-related macular degeneration (AMD).Methods:A retrospective clinical study. From January 2012 to December 2015, 11 patients with AMD (11 eyes) with obsolete SMH who were diagnosed and treated by pars plana vitrectomy (PPV) combined with autologous RPE transplantation at the Department of Ophthalmology, Xin Hua Hospital Affiliated to Shanghai Jiao Tong University School of Medicine were included. Among them, there were 9 eyes in 9 males and 2 eyes in 2 females. All the eyes underwent the examinations of best corrected visual acuity (BCVA) and optical coherence tomography; 4 eyes underwent macular fixation function (MAIA) at the same time. The BCVA examination was carried out using the international standard visual acuity chart, which was converted into logarithm of the minimum angle of resolution (logMAR) visual acuity during statistics. All eyes were treated with PPV combined with autologous single-layer RPE transplantation or autologous RPE-choroidal full-thickness transplantation, and were divided into S group and C group, with 5 and 6 eyes respectively. The differences of age ( t=-0.363), gender composition ratio ( χ2=0.549), course and thickness of SMH ( t=0.118, 0.231), average times of anti-vascular endothelial growth factor drug treatments ( t=0.129), times of PPV ( t=-0.452) between the two groups were not statistically significant ( P>0.05). The follow-up period was 6-40 months after the operation, and the BCVA, MAIA, graft status and complications of the eyes after the operation were observed. The comparison of continuous variables between groups was performed by independent-sample t test; the comparison of categorical variables was performed by χ2 test. Results:At the last follow-up, the average logMAR BCVA of the eyes in group S and C were 1.62±0.34 and 1.03±0.20, respectively; group C was better than group S, however, the difference was not statistically significant ( t=1.532, P=0.160). There were 4 eyes (80%, 4/5) and 6 eyes (100%, 6/6) in S group and C group with BCVA better than preoperative, the difference was no statistical significance ( χ2=0.677, P=0.895). There were 2 (40%, 2/5) and 3 (50%, 3/6) eyes with logMAR BCVA better than 1.0 in S group and C group, and the difference was not statistically significant ( χ2=0.572, P=0.423). After the operation, 6 eyes of grafts were in good condition and 5 eyes were in poor condition; the BCVA of grafts in good condition was significantly higher than that of poor condition, the difference was statistically significant ( t=4.894, P=0.001). Among the 4 eyes that underwent MAIA examination, 2 eyes were unstable and diffusely fixed on the graft; the fixation point was located at the normal retina adjacent to the graft area in 2 eyes. Secondary subretinal hemorrhage occurred in 3 eyes after the operation; the intraocular pressure was high in 1 eye after the operation. During the follow-up period, no intraocular infection, secondary retinal detachment, recurrent choroidal neovascularization or low intraocular pressure occurred in all eyes. Conclusions:Both autologous single-layer RPE transplantation and autologous RPE-choroidal full-thickness transplantation can help stabilize or even improve the visual function of eyes with severe SMH secondary to advanced AMD. The visual acuity after surgery is closely related to the state of the graft.