The retinal pigment epithelial (RPE) cells contain intrinsic fluorophores that can be visualized using infrared autofluorescence (IRAF). Although IRAF is routinely utilized in the clinic for visualizing retinal health and disease, currently, it is not possible to discern cellular details using IRAF due to limits in resolution. We demonstrate that the combination of adaptive optics (AO) with IRAF (AO-IRAF) enables higher-resolution imaging of the IRAF signal, revealing the RPE mosaic in the living human eye. Quantitative analysis of visualized RPE cells in 10 healthy subjects across various eccentricities demonstrates the possibility for density measurements of RPE cells, which range from 6505 to 5388 cells/mm for the areas measured (peaking at the fovea). We also identified cone photoreceptors in relation to underlying RPE cells, and found that RPE cells support on average up to 18.74 cone photoreceptors in the fovea down to an average of 1.03 cone photoreceptors per RPE cell at an eccentricity of 6 mm. Clinical application of AO-IRAF to a patient with retinitis pigmentosa illustrates the potential for AO-IRAF imaging to become a valuable complementary approach to the current landscape of high resolution imaging modalities.
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http://dx.doi.org/10.1364/BOE.8.004348 | DOI Listing |
Biomolecules
January 2025
Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, MN 55455, USA.
RAD18 is a conserved eukaryotic E3 ubiquitin ligase that promotes genome stability through multiple pathways. One of these is gap-filling DNA synthesis at active replication forks and in post-replicative DNA. RAD18 also regulates homologous recombination (HR) repair of DNA breaks; however, the current literature describing the contribution of RAD18 to HR in mammalian systems has not reached a consensus.
View Article and Find Full Text PDFExp Eye Res
January 2025
Institutes of Biology and Medical Sciences, Soochow University, Suzhou, 215000, China; Key Laboratory of Geriatric Diseases and Immunology, Ministry of Education, Institutes of Biology and Medical Sciences, Suzhou Medical College of Soochow University, Suzhou, 215123, China. Electronic address:
Due to its unique physiological structure and functions, the eye has received considerable attention in the field of adeno-associated virus (AAV) gene therapy. Inherited retinal degenerative diseases, which arise from pathogenic mutations in mRNA transcripts expressed in the eye's photoreceptor cells or retinal pigment epithelium (RPE), are the most common cause of vision loss. However, current retinal gene therapy mostly involves subretinal injection of therapeutic genes, which treats a limited area, entails retinal detachment, and requires sophisticated techniques.
View Article and Find Full Text PDFPhytomedicine
January 2025
School of Pharmaceutical Sciences, Zhejiang Chinese Medical University, Hangzhou 310053, China; Department of Ophthalmology, The Quzhou Affiliated Hospital of Wenzhou Medical University, Quzhou People's Hospital, Quzhou 324000, China. Electronic address:
Background: Resistance to senescence in retinal pigment epithelial (RPE) cells can delay the progression of age-related macular degeneration (AMD). However, the mechanisms underlying RPE cell senescence remain inadequately understood, and effective therapeutic strategies are lacking. While astragaloside IV (Ast) has demonstrated anti-aging properties, its specific effects on RPE cell senescence and potential mechanisms are not yet fully clarified.
View Article and Find Full Text PDFAmyloid β (Aβ) has emerged as a pathophysiological driver in age-related macular degeneration (AMD), emphasizing its significance in the aetiology of this prevalent sight-threatening condition. The multifaceted nature of AMD pathophysiology, presumably involving diverse retinal cascades, corresponds with the complexity of Aβ-induced retinopathy. Therefore, targeting a broad array of pathogenic processes holds promise for therapeutic intervention in AMD-associated retinal pathology.
View Article and Find Full Text PDFSci Adv
January 2025
Lee Kong Chian School of Medicine, Nanyang Technological University, 11 Mandalay Road, Singapore 308232, Singapore.
Reward prediction errors (RPEs) quantify the difference between expected and actual rewards, serving to refine future actions. Although reinforcement learning (RL) provides ample theoretical evidence suggesting that the long-term accumulation of these error signals improves learning efficiency, it remains unclear whether the brain uses similar mechanisms. To explore this, we constructed RL-based theoretical models and used multiregional two-photon calcium imaging in the mouse dorsal cortex.
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