Autophagy regulates Müller glial cell inflammatory activation
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PROVIDER: PRJNA1242865 | ENA |
REPOSITORIES: ENA
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Project description:Purpose. Immune privilege in the eye is a compilation of anti-inflammatory mechanisms that protect vision from the damaging sequelae of intense immune responses. Although the breakdown of privilege can lead to ocular disease, little is known about how these mechanisms are regulated. Since retinal Müller glial cells and autophagy also have anti-inflammatory properties, we tested the idea that Müller cells utilize autophagy to support immune privilege. Methods. The essential autophagy regulator Atg5 was deleted in retinal Muller cells using a tamoxifen inducible GlastCre ERT X Atg5f/f strain. Intraocular inflammation was induced by intravitreal injection of LPS and monitored by H&E staining, immunofluorescent confocal microscopy, and flow cytometry. scRNA-seq was performed on retinal Müller cells isolated from control and Atg5-deficient mice. Additionally, markers of Müller cell gliosis and function were assessed by western blotting and cytokines were detected by Luminex cytokine/chemokine arrays. In cultured Müller cells siRNA knockdown techniques were used to examine the role of autophagy in regulation of LPS-induced inflammatory pathways. Results. We observed increased and prolonged intraocular inflammation when Müller cells were autophagy (Atg5) deficient. Müller cell gliosis (as measured by Gfap expression) was significantly increased and inflammation was sustained over 5 days post-LPS injection compared to control. The retinae with Atg5-deficient Müller cells also contained increased inflammatory mediators and neuroprotective molecules. Gene expression analysis revealed a heterogeneous response to LPS in Müller glial cell population that revealed 2 states of activation. The normal retinae contain Müller cells in both a basal and an activated state, while autophagy deficient retinae (Atg5iΔMüller) contained only activated Müller cells. Analysis of gliosis markers Gfap and Lcn2 confirmed this heterogeneity showing that in control eyes basal and activated (gliotic) Müller glia were observed; however, with autophagy deficiency nearly all Müller cells were gliotic. Interestingly, activated cells were largely indistinguishable between autophagy sufficient and deficient Müller cells. In cultured Müller cells, siRNA knockdown of autophagy genes resulted in heightened mTOR activation, increased Gfap expression, and upregulated cytokine/chemokine production. Conclusions. Autophagy deficiency in Müller cells leads to enhanced intraocular inflammation though activation of the mTOR pathway. Our data suggests that autophagy defines a novel perspective on Müller glial heterogeneity based on their activation state. Thus, autophagy restrains cellular activation and inflammation, supporting immune privilege by preventing excessive and potentially destructive immune responses.
2025-09-10 | GSE293132 | GEO
Project description:To address the function of Rax in differentiated Müller glial cells, we generated Rax tamoxifen-induced conditional knock-out (Rax iCKO) mice, where Rax can be depleted in mTFP-labeled Müller glial cells upon tamoxifen treatment, by crossing Raxflox/flox mice with Rlbp1-CreERT2 mice and found histological characteristic of reactive gliosis and an enhanced gliosis of Müller glial cells in the Rax iCKO retina under normal and stress conditions, respectively. RNA sequencing using isolated Müller glial cells from the Rax iCKO retina by fluorescence-activated cell sorting demonstrated that reduced expression of suppressor of cytokine signaling-3 (Socs3), whose depletion leads to reactive gliosis in Müller glial cells. Reporter gene assays showed that Rax directly transactivates Socs3 and we observed decreased expression of Socs3 in Müller glial cells of the Rax iCKO retina by immunostaining. Taken together, these results suggest that the Rax homeoprotein suppresses reactive gliosis in Müller glial cells by transactivating Socs3 in vivo. Our results may shed light on the transcriptional regulatory mechanisms underlying Müller glial cell homeostasis.
2023-12-20 | GSE237650 | GEO
Project description:Purpose: Zebrafish neurons regenerate from Müller glia following retinal lesions. Genes and signaling pathways important for retinal regeneration in zebrafish have been described, but our understanding of how Müller glial stem cell properties are regulated is incomplete. Mammalian Müller glia possess a latent neurogenic capacity that might be enhanced in regenerative therapies to treat degenerative retinal diseases. Methods: To identify transcriptional changes associated with stem cell properties in zebrafish Müller glia, we performed a comparative transcriptome analysis from isolated cells at 8 and 16 hours following an acute, photic lesion, prior to the asymmetric division that produces retinal progenitors. Results: We report a rapid, dynamic response of zebrafish Müller glia, characterized by activation of pathways related to stress, NF-kappa B signaling, cytokine signaling, immunity, prostaglandin metabolism, circadian rhythm, and pluripotency, and an initial repression of Wnt signaling. When we compared publicly available transcriptomes of isolated mouse Müller glia from two retinal degeneration models, we found that mouse Müller glia showed evidence of oxidative stress, variable responses associated with immune regulation, and repression of pathways associated with pluripotency, development, and proliferation. Conclusions: Categories of biological processes/pathways activated following photoreceptor loss in regeneration-competent zebrafish Müller glia, which distinguished them from mouse Müller glia in retinal degeneration models, included: cytokine signaling (notably NF-kappa B), prostaglandin E2 synthesis, expression of core clock genes, and pathways/metabolic states associated with pluripotency. These regulatory mechanisms are relatively unexplored as potential mediators of stem cell properties likely to be important in Müller glial cells for successful retinal regeneration.
2016-09-14 | GSE86872 | GEO
Project description:Small extracellular vesicles (sEVs) are critical for cell-to-cell communication in retinal health and disease. This study aims to characterize the proteome of sEVs derived from human retinal Müller glial cells under normal glucose and high glucose conditions to understand their role in diabetic retinopathy. We performed high-resolution proteomic analyses on sEVs and their parent retinal Müller glial cells under both normal glucose and high glucose conditions. Comprehensive bioinformatics analyses, including gene ontology and protein-protein interaction network analyses, were conducted to assess the biological processes, molecular functions, cellular components, and signaling pathways associated with differentially expressed proteins. Additionally, physical attributes of sEVs, such as particle size, concentration, and morphology, were evaluated. Our analysis revealed no significant differences in the physical attributes of sEVs between normal glucose and high glucose conditions. However, proteomic analysis identified substantial alterations in the protein composition of sEVs under high glucose conditions. Differentially expressed proteins included common sEV proteins as well as cell-specific proteins. Gene ontology analysis highlighted enriched biological processes, molecular functions, cellular components, and signaling pathways associated with these differentially expressed proteins. Protein-protein interaction network analysis illustrated the interaction networks of differentially expressed proteins and identified specific functional modules within these networks. The main conclusions are that sEVs derived from retinal Müller glial cells transmit altered protein constituents under diabetic conditions, contributing to the pathogenesis of diabetic retinopathy.
2025-09-11 | PXD057318 | Pride
Project description:As any other radial glia in the central nervous system, Müller glia derive from the same neuroepithelial precursors, perform similar functions and exhibit neurogenic properties as radial glia in the brain. Müller glial cells retain progenitor-like characteristics in the adult human eye, and can partially restore visual function upon intravitreal transplantation into animal models of glaucoma. Recently, it has been demonstrated that intracellular communication is possible via the secretion of nano-sized membrane-bound extracellular vesicles (EV), which contain bioactive molecules like microRNA (miRNA) and proteins that induce phenotypic changes when internalised by recipient cells. We conducted high-throughput sequencing to profile the microRNA signature of EV populations secreted by Müller glia in culture, and used bioinformatic tools to evaluate their potential role in the neuroprotective signalling attributed to these cells. Sequencing of miRNA within Müller EV suggested enrichment with species associated with stem cells such as miR-21 and miR-16, as well as with miRNA previously found to play a role in diverse Müller cell functions in the retina: miR-9, miR-125b and the let-7 family. A total of 51 miRNA were found to be differentially enriched in EV compared to whole cells from which EV originated. Bioinformatic analyses also indicated preferential enrichment of species demonstrated to regulate genes involved in cell proliferation and survival, including PTEN the master inhibitor of the PI3K/AKT pathway. The results suggest that the release by Müller cells of miRNA-enriched EV abundant in species that regulate anti-apoptotic signalling networks, is likely to represent a significant proportion of the neuroprotective effect observed after transplantation of these cells into animal models of retinal ganglion cell (RGC)-depletion. Future work will seek to evaluate the modulation of putative genes, as well as the activation of these pathways in in vitro and in vivo models following the internalisation of Müller-EV by target retinal neurons.
2024-01-03 | GSE245286 | GEO
Project description:MicroRNA profile of extracellular vesicles released by Müller glial cells
| PRJNA1027764 | ENA
Project description:The Hippo Pathway Blocks Mammalian Retinal Müller Glial Cell Reprogramming
| PRJNA498120 | ENA
Project description:Non-mammalian vertebrates have a robust ability to regenerate injured retinal neurons from Müller glia cells (MG) that activate the proneural factor Achaete-scute homolog 1 (Ascl1/Mash1) and de-differentiate into progenitors cells. In contrast, mammalian MG have a limited regenerative response and fail to upregulate Ascl1 after injury. To test whether Ascl1 could restore a neurogenic potential to mammalian MG, we over-expressed Ascl1 in dissociated mouse MG cultures and intact retinal explants. Ascl1-infected MG upregulate retinal progenitor-specific genes, while downregulating glial genes. Furthermore, Ascl1 remodeled the chromatin at its targets from a repressive to active configuration. MG-derived progenitors differentiated into cells that exhibited neuronal morphologies, expressed retinal subtype-specific neuronal markers, and displayed neuron-like physiological responses. These results indicate that a single transcription factor, Ascl1, can produce a neurogenic state in mature Muller glia. Expresssion profiling was used to determine the genes that were changed after Ascl1 infection of P12 cultured Müller glia compared with those present in P0 progenitors and P7-P21 Müller glia Retinas were dissociated and FAC-sorted from Hes5-GFP mice at P0, P7, P10, P14 or P21 and submitted for profiling. WT Retinas were dissociated at P12, grown for 1 week in culture, and infected with lentiviruses expressing Ascl1 or GFP for four days. Total RNA was extracted and submitted for profiling.
2013-04-06 | E-GEOD-45835 | biostudies-arrayexpress
Project description:In order to identify the miRNAs in adult Dicer1-CKO Müller glia of the neural retina, we isolated the Müller glia from Rlbp-CreER: Stopf/f-tdTomato/Dicerf/f mice by means of fluorescent activated cell sorting and analyzed their miRNAs using NanoStrings Technologies®. miRNA expression of Dicer1-CKO Müller glia was compared to wild type Müller glia (a re-analyzed sample from GSE94759). We found that all highly expressed miRNAs declined in the Dicer-CKO leading to a disruption in retinal architecture over time.
2017-10-31 | GSE103098 | GEO
Project description:Müller cells are the main macroglial cells of the retina exerting a wealth of functions to maintain retinal homoeostasis. Upon pathological changes in the retina, they become gliotic with both protective and detrimental consequences. Accumulating data also provide evidence for a pivotal role of Müller cells in the pathogenesis of diabetic retinopathy (DR). While microglial cells, the resident immune cells of the retina are considered as main players in inflammatory processes associated with DR, the implication of activated Müller cells in chronic retinal inflammation remains to be elucidated. In order to assess the signaling capacity of Müller cells and their role in retinal inflammation, we performed in-depth proteomic analysis of Müller cell proteomes and secretomes after stimulation with INFγ, TNFα, IL-4, IL-6, IL-10, TGFβ1, TGFβ2 and TGFβ3. We used both, primary porcine Müller cells and the human Müller cell line MIO-M1 for our hypothesis generating approach. Our results point towards an intense signaling capacity of Müller cells, which reacted in a highly discriminating manner upon treatment with different cytokines. Stimulation of Müller cells results in a primarily pro-inflammatory phenotype with secretion of cytokines and components of the complement system. Furthermore, we observed evidence for mitochondrial dysfunction, implying oxidative stress after treatment with the various cytokines. Finally, both MIO-M1 cells and primary porcine Müller cells showed several characteristics of atypical antigen-presenting cells, as they are capable of inducing MHC class I and MHC class II with co-stimulatory molecules. In line with this, they express proteins associated with formation and maturation of phagosomes. Thus, our findings underline the importance of Müller cell signaling in the inflamed retina, indicating an active role in chronic retinal inflammation underlying the pathogenesis of diabetic retinopathy.
2022-02-16 | PXD028390 | Pride