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Cell Proliferation Apr 2022'Human retinal pigment epithelial cells' is the first set of guidelines on human retinal pigment epithelial cells in China, jointly drafted and agreed upon by experts...
'Human retinal pigment epithelial cells' is the first set of guidelines on human retinal pigment epithelial cells in China, jointly drafted and agreed upon by experts from the Chinese Society for Stem Cell Research. This standard specifies technical requirements, test methods, inspection rules, instructions for usage, labelling requirements, packaging requirements, storage requirements and transportation requirements and waste disposal requirements for human retinal pigment epithelial cells, which is applicable to quality control during the process of manufacturing and testing of human retinal pigment epithelial cells. It was originally released by the Chinese Society for Cell Biology on 9 January 2021. We hope that publication of these guidelines will promote institutional establishment, acceptance and execution of proper protocols and accelerate the international standardization of human retinal pigment epithelial cells for applications.
Topics: China; Epithelial Cells; Humans; Neurons; Retinal Pigments
PubMed: 34773310
DOI: 10.1111/cpr.13153 -
Journal of Leukocyte Biology Mar 2023The ocular tissue microenvironment is immune-privileged and uses multiple immunosuppressive mechanisms to prevent the induction of inflammation. The retinal pigment... (Review)
Review
The ocular tissue microenvironment is immune-privileged and uses multiple immunosuppressive mechanisms to prevent the induction of inflammation. The retinal pigment epithelium plays an essential role in ocular immune privilege. In addition to serving as a blood barrier separating the fenestrated choriocapillaris from the retina, the retinal pigment epithelium is a source of immunosuppressive cytokines and membrane-bound negative regulators that modulate the activity of immune cells within the retina. This article reviews the current understanding of how retinal pigment epithelium cells mediate immune regulation, focusing on the changes under pathologic conditions.
Topics: Humans; Immune Privilege; Retina; Inflammation; Epithelial Cells; Retinal Pigments
PubMed: 36805720
DOI: 10.1093/jleuko/qiac016 -
Trends in Neurosciences Jan 2022MicroRNAs are short, evolutionarily conserved noncoding RNAs that are critical for the control of normal cellular physiology. In the retina, photoreceptors are highly... (Review)
Review
MicroRNAs are short, evolutionarily conserved noncoding RNAs that are critical for the control of normal cellular physiology. In the retina, photoreceptors are highly specialized neurons that transduce light into electrical signals. Photoreceptors, however, are unable to process visual stimuli without the support of the retinal pigment epithelium (RPE). The RPE performs numerous functions to aid the retina, including the generation of visual chromophore and metabolic support. Recent work has underscored how microRNAs enable vision through their contributions to RPE functions. This review focuses on the biogenesis and control of microRNAs in rodents and humans, the roles microRNAs play in RPE function and degeneration, and how microRNAs could serve as potential therapeutics and biomarkers for visual diseases.
Topics: Humans; MicroRNAs; Retina; Retinal Pigment Epithelium; Retinal Pigments; Vision, Ocular
PubMed: 34753606
DOI: 10.1016/j.tins.2021.10.008 -
Biomolecules May 2023Age-related macular degeneration (AMD) causes vision loss in the elderly population. Dry AMD leads to the formation of Drusen, while wet AMD is characterized by cell... (Review)
Review
Age-related macular degeneration (AMD) causes vision loss in the elderly population. Dry AMD leads to the formation of Drusen, while wet AMD is characterized by cell proliferation and choroidal angiogenesis. The retinal pigment epithelium (RPE) plays a key role in AMD pathogenesis. In particular, helioreceptor renewal depends on outer segment phagocytosis of RPE cells, while RPE autophagy can protect cells from oxidative stress damage. However, when the oxidative stress burden is too high and homeostasis is disturbed, the phagocytosis and autophagy functions of RPE become damaged, leading to AMD development and progression. Hence, characterizing the roles of RPE cell phagocytosis and autophagy in the pathogenesis of AMD can inform the development of potential therapeutic targets to prevent irreversible RPE and photoreceptor cell death, thus protecting against AMD.
Topics: Aged; Humans; Phagocytosis; Autophagy; Macular Degeneration; Oxidative Stress; Epithelial Cells; Retinal Pigments
PubMed: 37371481
DOI: 10.3390/biom13060901 -
Vestnik Oftalmologii 2021Retinal pigment epithelial tear (RPET) occurs in a number of diseases, most often in age-related macular degeneration (AMD). RPET develops in the setting of retinal... (Review)
Review
Retinal pigment epithelial tear (RPET) occurs in a number of diseases, most often in age-related macular degeneration (AMD). RPET develops in the setting of retinal pigment epithelium (RPE) detachment and represents a violation of the integrity of its monolayer accompanied by the formation of a demarcation line between the RPE atrophy area and RPE folds. Its incidence varies widely. In the earlier studies, diagnosis of RPET was performed using fluorescent angiography or angiography with indocyanine green (ICG-FA). The advent of optical coherence tomography made the detection of RPET easier and more accessible. The mechanism of RPET formation is quite polymorphic and ambiguous. Scientific literature contains descriptions of the occurrence of RPET when using both ranibizumab and aflibercept, and bevacizumab in equal proportions, implying that the drug choice does not affect the occurrence of complications. Continuous monitoring and adherence to anti-VEGF therapy leads to better anatomical and functional results in the long term, which is crucial for improving the quality of life of patients with age-related macular degeneration. This article reviews the literature and presents current data on RPET, identifies risk factors and mechanisms of its development, provides classification, and describes modern options for its diagnosis and treatment.
Topics: Angiogenesis Inhibitors; Fluorescein Angiography; Humans; Intravitreal Injections; Macular Degeneration; Quality of Life; Ranibizumab; Retinal Perforations; Retinal Pigment Epithelium; Retinal Pigments; Tomography, Optical Coherence; Vascular Endothelial Growth Factor A; Visual Acuity
PubMed: 34156786
DOI: 10.17116/oftalma2021137031115 -
Bioengineered Apr 2022Astragaloside-IV (AS-IV) (CHO) is a high-purity natural product extracted from , which has demonstrated biological activities. However, the effect of AS-IV on retinal...
Astragaloside-IV (AS-IV) (CHO) is a high-purity natural product extracted from , which has demonstrated biological activities. However, the effect of AS-IV on retinal pigment epithelial (RPE) cells in diabetic retinopathy (DR) remains unclear. In this study, high glucose (HG) was shown to promote ARPE-19 RPE cell death, increase the contents of reactive oxygen species (ROS) and oxidized glutathione (GSSG), and enhance lipid peroxidation density of mitochondrial membrane. In contrast, AS-IV decreased glutathione (GSH) content, mitochondria size and ridge. Addition of iron death inhibitor Ferrostatin-1 (Fer-1) to RPE cells decreased cell dead rate, thus indicating that HG-induced mitochondrial damage occurred due to ferroptosis. AS-IV alleviated HG-induced RPE cell damage. Furthermore, HG decreased levels of silent information regulator 1 (Sirt1) and nuclear factor (erythroid-derived 2)-like 2 (Nrf2) in the nucleus of RPE cells; AS-IV could alleviate these effects and increased expression of glutathione peroxidase 4 (GPX4), glutamate cysteine ligase (GCLM) and glutamate cysteine ligase catalytic subunit (GCLC), which are Nrf2 downstream genes. Mechanistically, AS-IV was shown to alleviate the effects of HG by increasing mir-138-5p expression in RPE cells and promoting expression of Sirt1 and Nrf2 in the nucleus. Transfection of mir-138-5p agonist inhibited the regulatory effects of AS-IV on Sirt1 and Nrf2, accompanied by decreased GPX4, GCLM and GCLC levels, and restoration of ferroptosis-related changes. Collectively, HG increased ferroptosis rate in RPE cells. In addition, AS-IV inhibited miR-138-5p expression, subsequently increasing Sirt1/Nrf2 activity and cellular antioxidant capacity to alleviate ferroptosis, resulting decreased cell death, which potentially inhibits the DR pathological process.
Topics: Epithelial Cells; Ferroptosis; Glucose; Glutamate-Cysteine Ligase; MicroRNAs; NF-E2-Related Factor 2; Oxidative Stress; Reactive Oxygen Species; Retinal Pigment Epithelium; Retinal Pigments; Sirtuin 1
PubMed: 35302431
DOI: 10.1080/21655979.2022.2049471 -
Arquivos Brasileiros de Oftalmologia 2021Acute retinal pigment epitheliitis (ARPE) is an idiopathic, self-limiting inflammatory retinal disorder that particularly affects healthy young individuals. The... (Review)
Review
Acute retinal pigment epitheliitis (ARPE) is an idiopathic, self-limiting inflammatory retinal disorder that particularly affects healthy young individuals. The characteristic fundoscopic appearance of the acute retinal pigment epitheliitis includes a fine pigment stippling surrounded by a yellow-white hypopigmented halos in the macula. Although the exact pathogenesis of the disease remains unknown, some reports have suggested a relationship between a viral infection and acute retinal pigment epitheliitis. Acute retinal pigment epitheliitis is a rare disorder, and only single case reports or case series are found in the literature. The clinical and demographic characteristics of patients with this disease are not fully understood because of its rarity. In this study, we searched the literature to collect clinical and demographic features of the reported cases. We detail the characteristics of acute retinal pigment epitheliitis were pointed and discuss the pathogenesis of the disease.
Topics: Acute Disease; Fluorescein Angiography; Humans; Retinal Diseases; Retinal Pigments; Retinitis; Visual Acuity
PubMed: 33567017
DOI: 10.5935/0004-2749.20210028 -
International Journal of Toxicology 2002Ocular morphology is specifically directed at facilitating the transmittance of visible light to the retina for the purposes of photoreceptor absorption and... (Review)
Review
Ocular morphology is specifically directed at facilitating the transmittance of visible light to the retina for the purposes of photoreceptor absorption and phototransduction, thereby initiating the process of vision. By absorbing excess radiation, melanin significantly enhances this process. It can also act as a photoprotector by quenching reactive oxygen species and other radicals produced as a result of the high oxygen dependency of the retina for its metabolism. However, melanin also binds numerous pharmaceuticals, a process that can result in ocular toxicity. Although our understanding of this binding remains somewhat limited, melanin chemistry, its distribution, and other factors influencing binding appear to play a significant role in predisposing ocular tissues, such as the choroid and retinal pigment epithelium, to toxicological insult. Many of the drugs that have been identified as causing these effects are known photosensitizers in which radiation plays a significant role in eliciting the pathologies. The phototoxic effects range from minor histological/chemical changes, which do not impact the quality of vision, to pigmentary retinopathies, which could potentially involve the loss of sight. Such effects, resulting from photosensitizer-drug binding to melanin, are to be separated from toxic effects, such as some ganglion cell abnormalities, that result from pharmaceuticals affecting ocular tissues directly.
Topics: Eye Diseases; Humans; Melanins; Ocular Physiological Phenomena; Pharmaceutical Preparations; Pigment Epithelium of Eye; Protein Binding; Retina; Retinal Pigments
PubMed: 12537641
DOI: 10.1080/10915810290169873 -
Journal of Histotechnology Dec 2022The health and activity of photoreceptors and Bruch's membrane are promoted by the retinal pigment epithelium (RPE), which is essential for normal vision. Age-related... (Review)
Review
The health and activity of photoreceptors and Bruch's membrane are promoted by the retinal pigment epithelium (RPE), which is essential for normal vision. Age-related macular degeneration (AMD), diabetic retinopathy (DR), and proliferative vitreoretinopathy (PVR) are examples of retinopathies that result in vision loss. Epithelial-mesenchymal transition (EMT) is a process in which epithelial cells transform into mesenchymal cells as a result of a faulty microenvironment, and it is associated with the oculopathies stated above. Cell differentiation, autophagy, growth factors (GFs), the blood-retinal barrier (BRB), and other complicated signaling pathways all contribute to proper morphology, and their disruption by harmful compounds has an impact on RPE function. The inducer and suppressor of EMT in RPE, on the other hand, are unknown. The current article reviews the experimental research investigations, suggested that certain modulators like glucosamine (Glc-N) and bradykinin (BK) suppress the TGFβ signaling pathway and that other variables like oxidative stress triggered EMT, which is not found in normal RPE homeostasis. Finding molecular targets and treatments to prevent and restore RPE function, as well as understanding how EMT regulators affect RPE degeneration, are therefore crucial.
Topics: Humans; Epithelial-Mesenchymal Transition; Retinal Pigment Epithelium; Vitreoretinopathy, Proliferative; Epithelial Cells; Homeostasis; Retinal Pigments
PubMed: 36377481
DOI: 10.1080/01478885.2022.2137665 -
Discovery Medicine 2022Transepithelial/transendothelial electrical resistance (TEER) is a widely accepted quantitative technique to measure the integrity of tight junction dynamics in cell... (Review)
Review
Transepithelial/transendothelial electrical resistance (TEER) is a widely accepted quantitative technique to measure the integrity of tight junction dynamics in cell culture models of endothelial and epithelial monolayers. The value of TEER reflects the physical structure and characteristics of epithelial/endothelial cells. TEER value is a preferred physiological indicator reflecting transport rate of ions and macromolecules through the paracellular pathway, which is used to evaluate permeability of paracellular pathway. TEER value has a high specificity for the permeability of reactive tightly connected complex. TEER value is an effective indicator to evaluate the integrity of cell barrier. The cell barrier not only controls the diffusion penetration of various substances in adjacent intercellular spaces, but also regulates the transport of ions and macromolecules across. On one hand, the cell barrier protects the body from harmful substances; on the other hand, it restricts the entry of therapeutic drugs. Therefore, with the increase of permeability in paraepithelial pathway, the TEER value decreased, otherwise, it increased. In this review article, we compared the advantages and disadvantages of the existing methods for measuring TEER and summarized the factors affecting TEER accuracy, as well as the roles of TEER in mechanisms of retinal pigment epithelial barrier and retinal disorders such as proliferative vitreoretinopathy (PVR), age-related macular degeneration (AMD), diabetic retinopathy, and retinitis pigmentosa.
Topics: Humans; Electric Impedance; Retinal Pigments; Endothelial Cells; Tight Junctions; Permeability; Epithelial Cells; Retinal Diseases
PubMed: 36274257
DOI: No ID Found