Drosophila melanogaster phototransduction proceeds via a phospholipase C (PLC)-triggered cascade of phosphatidylinositol (PI) lipid modifications, many steps of which remain undefined. We describe the involvement of the lipid phosphatidic acid and the enzyme that generates it, phospholipase D (Pld), in this process. Pld(null) flies exhibit decreased light sensitivity as well as a heightened susceptibility to retinal degeneration. Pld overexpression rescues flies lacking PLC from light-induced, metarhodopsin-mediated degeneration and restores visual signaling in flies lacking the PI transfer protein, which is a key player in the replenishment of the PI 4,5-bisphosphate (PIP2) substrate used by PLC to transduce light stimuli into neurological signals. Altogether, these findings suggest that Pld facilitates phototransduction by maintaining adequate levels of PIP2 and by protecting the visual system from metarhodopsin-induced, low light degeneration.
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http://dx.doi.org/10.1083/jcb.200502122 | DOI Listing |
Surv Ophthalmol
January 2025
Department of Biomedical Sciences, Humanitas University, Via Rita Levi Montalcini 4, 20072 Pieve Emanuele-Milan, Italy; Department of Ophthalmology, Eye Unit Humanitas Gavazzeni-Castelli, via Mazzini 11, Bergamo, Italy.
Bacillary layer detachment (BALAD) refers to the distinctive splitting at the level of the photoreceptor inner segment myoid and accumulation of intraretinal fluid, as seen on optical coherence tomography (OCT).BALAD is an increasingly recognized OCT biomarker of numerous heterogeneous chorioretinal diseases, including posterior uveitis, age-related macular degeneration and macular neovascularization, neoplastic and paraneoplastic retinal disorders, rhegmatogenous retinal detachment, blunt ocular trauma, and miscellaneous conditions. The recognition of BALAD is clinically relevant because, based on the specific etiology, BALAD may require simple observation, ocular or systemic medical treatment, or even surgical intervention, with subsequent different prognosis.
View Article and Find Full Text PDFThe retinal pigment epithelium (RPE) performs a number of functions essential for retinal health. RPE dysregulation and degeneration can occur in diseases. Methods to image the human RPE directly are limited, as it is only about 10 µm thick and situated between the photoreceptor outer segments and Bruch's membrane (BM).
View Article and Find Full Text PDFNat Commun
January 2025
State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangdong Provincial Clinical Study Center for Ocular Diseases, Guangzhou, China.
Photoreceptors are specialized neurons at the core of the retina's functionality, with optical accessibility and exceptional sensitivity to systemic metabolic stresses. Here we show the ability of risk-free, in vivo photoreceptor assessment as a window into systemic health and identify shared metabolic underpinnings of photoreceptor degeneration and multisystem health outcomes. A thinner photoreceptor layer thickness is significantly associated with an increased risk of future mortality and 13 multisystem diseases, while systematic analyses of circulating metabolomics enable the identification of 109 photoreceptor-related metabolites, which in turn elevate or reduce the risk of these health outcomes.
View Article and Find Full Text PDFInvest Ophthalmol Vis Sci
January 2025
Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Departamento de Química Biológica Ranwel Caputto. Córdoba, Argentina.
Purpose: Stress granules (SGs) are cytoplasmic biocondensates formed in response to various cellular stressors, contributing to cell survival. Although implicated in diverse pathologies, their role in retinal degeneration (RD) remains unclear. We aimed to investigate SG formation in the retina and its induction by excessive LED light in an RD model.
View Article and Find Full Text PDFGraefes Arch Clin Exp Ophthalmol
January 2025
Department of Ophthalmology, University Hospital Munster, Munster, Germany.
Purpose: The retinal pigment epithelium (RPE) plays an important role in the pathogenesis of age-related macular degeneration (AMD) and other retinal degenerative diseases. The introduction of healthy RPE cell cultures into the subretinal space offers a potential treatment strategy. The aim of this study was the long-term culture and characterisation of RPE cells on nanofiber scaffolds.
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