Mus musculus
Ontology highlight
ABSTRACT:
OTHER RELATED OMICS DATASETS IN: E-GEOD-43951
PROVIDER: PRJNA188220 | ENA |
REPOSITORIES: ENA
Similar Datasets
Project description:Conditional knockdown of DNA methyltransferase-1 (Dnmt1) reveals a key role of retinal pigment epithelium integrity in photoreceptor outer segment morphogenesis
2015-07-09 | E-GEOD-43951 | ExpressionAtlas
Project description:Eye photoreceptor membrane discs in outer rod segments are highly enriched in the visual pigment rhodopsin and the omega-3 fatty acid docosahexaenote (DHA). The eye acquires DHA from blood, but transporters for DHA uptake across the blood-retinal barrier (BRB) or retinal pigment epithelium have not been identified. Mfsd2a is a newly described sodium-dependent lysophosphatidylcholine symporter expressed at the BRB. Microarrays were used to determine difference in gene expression between wild-type and Mfsd2a KO eye cups.
2016-03-23 | GSE77403 | GEO
Project description:Balancing the competing demands of phagolysosomal degradation and autophagy is a significant challenge for phagocytic tissues. Yet, how this plasticity is accomplished in health and disease is poorly understood. In the retina, circadian phagocytosis and degradation of photoreceptor outer segments by the postmitotic retinal pigment epithelium (RPE) is essential for healthy vision. Disrupted autophagy due to mTOR overactivation in the RPE is associated with blinding macular degenerations; however, outer segment degradation is unaffected in these diseases, indicating that distinct mechanisms regulate these clearance mechanisms. Here, using advanced imaging and mouse models, we identify optineurin as a key regulator that tunes phagocytosis and lysosomal capacity to meet circadian demands and helps prioritize outer segment clearance by the RPE in macular degenerations. High-resolution live-cell imaging implicates optineurin in scissioning outer segment tips prior to engulfment, analogous to microglial trogocytosis of neuronal processes. Optineurin is essential for recruiting LC3, which anchors outer segment phagosomes to microtubules and facilitates phagosome maturation and fusion with lysosomes. This dynamically activates transcription factor EB (TFEB) to induce lysosome biogenesis in an mTOR-independent, TRPML1 (transient receptor potential-mucolipin 1)-dependent manner. RNAseq analyses show that expression of TFEB target genes temporally tracks with optineurin recruitment, and that lysosomal and autophagy genes are controlled by distinct transcriptional programs in the RPE. The unconventional plasma membrane-to-nucleus signaling mediated by optineurin ensures outer segment degradation under conditions of impaired autophagy in macular degeneration models. Independent regulation of these critical clearance mechanisms would help safeguard metabolic fitness of the RPE through the organismal lifespan.
2023-08-15 | GSE237291 | GEO
Project description:Balancing the competing demands of phagolysosomal degradation and autophagy is a significant challenge for phagocytic tissues. Yet, how this plasticity is accomplished in health and disease is poorly understood. In the retina, circadian phagocytosis and degradation of photoreceptor outer segments by the postmitotic retinal pigment epithelium (RPE) is essential for healthy vision. Disrupted autophagy due to mTOR overactivation in the RPE is associated with blinding macular degenerations; however, outer segment degradation is unaffected in these diseases, indicating that distinct mechanisms regulate these clearance mechanisms. Here, using advanced imaging and mouse models, we identify optineurin as a key regulator that tunes phagocytosis and lysosomal capacity to meet circadian demands and helps prioritize outer segment clearance by the RPE in macular degenerations. High-resolution live-cell imaging implicates optineurin in scissioning outer segment tips prior to engulfment, analogous to microglial trogocytosis of neuronal processes. Optineurin is essential for recruiting LC3, which anchors outer segment phagosomes to microtubules and facilitates phagosome maturation and fusion with lysosomes. This dynamically activates transcription factor EB (TFEB) to induce lysosome biogenesis in an mTOR-independent, TRPML1 (transient receptor potential-mucolipin 1)-dependent manner. RNAseq analyses show that expression of TFEB target genes temporally tracks with optineurin recruitment, and that lysosomal and autophagy genes are controlled by distinct transcriptional programs in the RPE. The unconventional plasma membrane-to-nucleus signaling mediated by optineurin ensures outer segment degradation under conditions of impaired autophagy in macular degeneration models. Independent regulation of these critical clearance mechanisms would help safeguard metabolic fitness of the RPE through the organismal lifespan.
2023-08-15 | GSE237292 | GEO
Project description:The photoreceptor outer segment is the canonical example of a modified and highly specialised cilium, with an expanded membrane surface area in the form of discs or lamellae for efficient light detection. Many ciliary proteins are essential for normal photoreceptor function and cilium dysfunction often results in retinal degeneration leading to impaired vision. Herein, we investigate the function and localisation of the ciliary G-protein RAB28 in zebrafish cone photoreceptors. CRISPR-Cas9 generated rab28 mutant zebrafish display a reduction in shed outer segment material in the RPE at 1 month post fertilisation (mpf), but otherwise normal retinal structure and visual function up to 12 mpf. Cone photoreceptorspecific transgenic reporter lines show Rab28 localises almost exclusively to outer segments, independently of nucleotide binding. Co-immunoprecipitation analysis demonstrates tagged Rab28 interacts with components of the phototransduction cascade, including opsins, Phosphodiesterase 6C and Guanylate Cyclase 2D. Our data shed light on RAB28 function in cones and provide a model for RAB28-associated cone-rod dystrophy
2020-04-09 | PXD017523 | Pride
Project description:Stargardt retinopathy is an inherited form of macular degeneration caused by mutations in gene ABCA4 and characterized by the accumulation of lipid-rich deposits in the retinal pigment epithelium (RPE), RPE atrophy, and photoreceptor cell death. Inadequate mechanistic insights into pathophysiological changes occurring in Stargardt RPE have contributed to its lacking treatments. Here we show that ABCA4 knockout or Stargardt patient’s induced pluripotent stem cells-derived RPE (STGD1-iRPE) differentiate normally but display intracellular lipid and ceramide deposits reminiscent of the disease phenotype. STGD1-iRPE also shows defective photoreceptor outer segment (POS) processing and reduced cathepsin B activity, indicating higher lysosomal pH. Lipid deposits in STGD1-iRPE are reduced by increasing the activity of ABCA1, a lipid transporter, and ABCA4 ortholog. Overall, our work suggests that ABCA4 is involved in POS and lipid handling in RPE cells and provides guidance for ongoing gene therapy approaches to target both RPE and photoreceptor cells for an effective treatment.
2022-11-16 | GSE198362 | GEO
Project description:Mutations in IQCB1/NPHP5 gene encoding the ciliary protein Nephrocystin 5 cause early-onset blinding disease Leber congenital amaurosis (LCA), together with kidney dysfunction in Senior-Løken Syndrome. For in vitro disease modeling, we obtained dermal fibroblasts from NPHP5-LCA patients, which were reprogrammed into induced pluripotent stem cells (iPSCs) and differentiated into retinal pigment epithelium (RPE) and retinal organoids. Patient fibroblasts and RPE demonstrated aberrantly elongated ciliary axonemes. Organoids revealed impaired development of outer segment structures, which are modified primary cilia, and mislocalization of visual pigments to photoreceptor cell soma. All patient-derived cells showed reduced levels of CEP290 protein, a critical cilia transition zone component interacting with NPHP5, providing a plausible mechanism for aberrant ciliary gating and cargo transport. Disease phenotype in NPHP5-LCA retinal organoids could be rescued by AAV-mediated NPHP5 gene augmentation therapy. Our studies thus establish a human disease model and a path for treatment of NPHP5-LCA.
2022-08-26 | GSE200339 | GEO
Project description:Eye photoreceptor membrane discs in outer rod segments are highly enriched in the visual pigment rhodopsin and the omega-3 fatty acid docosahexaenote (DHA). The eye acquires DHA from blood, but transporters for DHA uptake across the blood-retinal barrier (BRB) or retinal pigment epithelium have not been identified. Mfsd2a is a newly described sodium-dependent lysophosphatidylcholine symporter expressed at the BRB. Microarrays were used to determine difference in gene expression between wild-type and Mfsd2a KO eye cups. RNA was extracted from eye cups from postnatal day 13 wild-type and Mfsd2a KO mice. Equal amounts of RNA from 6 wild-type eye cups were pooled for the wild-type sample, or 6 Mfsd2a KO eye cups were pooled for the Mfsd2a KO sample. Microarray profiling was done on pooled samples with a RIN cut-off of 7.0 using Mouse 430 2.0 arrays (Affymetrix).
2016-03-23 | E-GEOD-77403 | biostudies-arrayexpress
Project description:Due to the high energy demands and characteristic morphology, retinal photoreceptor cells require a specialized lipid metabolism for survival and function. This study focused on the roles of saturated fatty acids and their metabolism. A frameshift mutation of lysophosphatidylcholine acyltransferase 1 (Lpcat1), introducing saturated fatty acids into lysophosphatidylcholine to produce disaturated phosphatidylcholine (PC), has been reported to cause spontaneous retinal degeneration in mice (rd11 mice). In this study, we performed a detailed characterization of Lpcat1 in the retina and found that Lpcat1 deficiency induces light-independent and photoreceptor-specific apoptosis in mice. Lipidomic analyses of the retina and isolated photoreceptor outer segment (OS) suggested that loss of Lpcat1 affects disaturated PC production and the proper cellular fatty acid flux, presumably by altering saturated fatty acyl-CoA availabilities. Furthermore, we demonstrated that Lpcat1 deletion increased mitochondrial reactive oxygen species (ROS) levels in photoreceptor cells, but not in other retinal cells without affecting the OS structure and trafficking of OS-localized proteins. These results suggest that the LPCAT1-dependent production of disaturated PC is critical for metabolic adaptation during photoreceptor maturation. Our findings highlight the therapeutic potential of saturated fatty acid metabolism in photoreceptor cell degeneration-related retinal diseases.
2022-01-01 | GSE184817 | GEO
Project description:Mechanical homeostasis in healthy tissues relies on a dynamic balance of mechanical properties essential for maintaining tissue integrity and function. Over time, this integrity decays due to structural reorganization from extracellular remodelling or an imbalance of cell death and proliferation. This is particularly challenging in postmitotic tissues such as the retina, where lack of proliferation requires age-dependent structural adaptation. The retinal pigment epithelium exemplifies this adaptation, compensating for apoptotic events through morphological reconfiguration and cytoskeletal remodelling. To explore the connection between age-related structural changes and mechanical homeostasis, we developed an in vitro model simulating cell density reduction observed in the human retinal pigmented epithelium during ageing. This model is characterized by reduced cell height, shortened apical microvilli, and alterations in the actin cytoskeleton. The resulting age-associated phenotype leads to significant biomechanical changes, including tissue stiffening, enhanced junctional contractility, and apical cell cortex remodelling. Transcriptional profiling revealed notable shifts in actin-associated gene expression, indicating reduced plasticity when remodelling is necessary for phagocytosis of photoreceptor outer segments. Structurally aged monolayers exhibit changes in phagocytic activity that mirror those seen in aged individuals. Additionally, we observed an impaired capacity for apico-lateral remodelling while internalizing photoreceptor outer segments. This altered activity can be partially corrected by regulating actin network remodelling capacity with inhibitors targeting the actin nucleators Arp2/3 and formins. Overall, our findings suggest that age-related structural changes in the postmitotic outer retina shift its mechanical homeostasis, impacting physiological functions that are crucial for healthy vision.
2025-06-20 | GSE297557 | GEO