Waste product deposition and light stress in the retinal pigment epithelium (RPE) are crucial factors in the pathogenesis of various retinal degenerative diseases, including age-related macular degeneration (AMD), a leading cause of vision loss in elderly individuals worldwide. Given that autophagy in the RPE suppresses waste accumulation, determining the molecular mechanism by which autophagy is compromised in degeneration is necessary. Using polarized human RPE sheets, we found that bis-retinoid N-retinyl-N-retinylidene ethanolamine (A2E), a major toxic fluorophore of lipofuscin, causes significant impairment of autophagy and the simultaneous upregulation of Rubicon, a negative regulator of autophagy. Importantly, this impairment was reversed in Rubicon-specific siRNA-treated RPE sheets. In a retinal functional analysis using electroretinograms (ERGs), mice with the RPE-specific deletion of Rubicon showed no significant differences from control cre-expressing mice but presented partially but significantly enhanced amplitudes compared with Atg7 knockout mice. We also found that an inflammatory reaction in the retina in response to chronic blue light irradiation was alleviated in mice with the RPE-specific deletion of Rubicon. In summary, we propose that upregulating basal autophagy by targeting Rubicon is beneficial for protecting the RPE from functional damage with ageing and the inflammatory reaction caused by light-induced cellular stress.
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http://dx.doi.org/10.1016/j.bbrc.2021.02.148 | DOI Listing |
BMJ Case Rep
January 2025
Endocrinology, Government Medical College Thiruvananthapuram, Thiruvananthapuram, Kerala, India.
We describe the case of a girl in her middle childhood who presented with signs of heterosexual precocious puberty in the form of axillary and pubic hair growth, acne and clitoromegaly. Investigations showed elevated androgens and autonomous cortisol excess, suggesting an adrenal source. CT imaging confirmed a left adrenal mass and multiple colonic polyps.
View Article and Find Full Text PDFEye (Lond)
January 2025
Department of Ophthalmology, Royal Melbourne Hospital, Parkville, VIC, Australia.
J Cell Mol Med
January 2025
Department of Ophthalmology, Muğla Training and Research Hospital, Mugla, Turkey.
Nowadays, the use of monoclonal antibodies to target angiogenic signalling pathways is common, but, unfortunately, the clinical activity of these agents is limited. Thus, the development of approaches targeting multiple pathways for anti-angiogenic effect will lead to increase the clinical benefit. For this purpose, oleuropein, hesperidin, piperine, proanthocyanidins and retinoic acid, which have previously been proven to be bioactive components, anti-angiogenic performances were experimentally tested in retinal pigment epithelial cells.
View Article and Find Full Text PDFStem Cell Reports
December 2024
Department of Cardio Metabolic Diseases Research, Boehringer Ingelheim Pharma GmbH & Co. KG, Biberach, Germany. Electronic address:
Complement factor H (CFH) common genetic variants have been associated with age-related macular degeneration (AMD). While most previous in vitro RPE studies focused on the common p.His402Tyr CFH variant, we characterized rare CFH variants that are highly penetrant for AMD using induced pluripotent stem-cell-derived retinal pigment epithelium (iPSC-RPE).
View Article and Find Full Text PDFNat Commun
January 2025
NIHR Biomedical Research Centre, Moorfields Eye Hospital NHS Foundation Trust & University College London Institute of Ophthalmology, London, UK.
Few metrics exist to describe phenotypic diversity within ophthalmic imaging datasets, with researchers often using ethnicity as a surrogate marker for biological variability. We derived a continuous, measured metric, the retinal pigment score (RPS), that quantifies the degree of pigmentation from a colour fundus photograph of the eye. RPS was validated using two large epidemiological studies with demographic and genetic data (UK Biobank and EPIC-Norfolk Study) and reproduced in a Tanzanian, an Australian, and a Chinese dataset.
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