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International Journal of Molecular... Nov 2023Ischemia is the main cause of cell death in retinal diseases such as vascular occlusions, diabetic retinopathy, glaucoma, or retinopathy of prematurity. Although...
Ischemia is the main cause of cell death in retinal diseases such as vascular occlusions, diabetic retinopathy, glaucoma, or retinopathy of prematurity. Although excitotoxicity is considered the primary mechanism of cell death during an ischemic event, antagonists of glutamatergic receptors have been unsuccessful in clinical trials with patients suffering ischemia or stroke. Our main purpose was to analyze if the transient receptor potential channel 7 (TRPM7) could contribute to retinal dysfunction in retinal pathologies associated with ischemia. By using an experimental model of acute retinal ischemia, we analyzed the changes in retinal function by electroretinography and the changes in retinal morphology by optical coherence tomography (OCT) and OCT-angiography (OCTA). Immunohistochemistry was performed to assess the pattern of TRPM7 and its expression level in the retina. Our results show that ischemia elicited a decrease in retinal responsiveness to light stimuli along with reactive gliosis and a significant increase in the expression of TRPM7 in Müller cells. TRPM7 could emerge as a new drug target to be explored in retinal pathologies associated with ischemia.
Topics: Animals; Humans; Infant, Newborn; Mice; Ischemia; Protein Serine-Threonine Kinases; Reperfusion; Retina; Retinal Diseases; Retinal Vessels; TRPM Cation Channels
PubMed: 38003256
DOI: 10.3390/ijms242216068 -
Investigative Ophthalmology & Visual... Dec 2023The purpose of this study is to investigate the anti-pyroptotic effect of resveratrol in the context of ischemia-reperfusion (I/R)-induced retinal injury, with a...
PURPOSE
The purpose of this study is to investigate the anti-pyroptotic effect of resveratrol in the context of ischemia-reperfusion (I/R)-induced retinal injury, with a particular focus on Müller glial cells (MGCs) and to elucidate the underlying molecular mechanisms.
METHODS
The retinal I/R model was constructed in mice and pyroptotic markers were measured at six, 12, 24, 48, and 72 hours after I/R injury to determine the peak of pyroptotic activity. The effects of resveratrol on pyroptosis, inflammasomes, and the activation of MGCs after I/R injury were observed on the retina of mice. Moreover, induction of pyroptosis in rat Müller glial cells (r-MC) via lipopolysaccharide was used to explore the effects of resveratrol on pyroptosis of r-MC in vitro.
RESULTS
After the induction of retinal I/R injury in mice, the intricate involvement of pyroptosis in the progressive degeneration of the retina was observed, reaching its zenith at the onset of 24 hours after I/R injury. Resveratrol treatment alleviated I/R injury on the retina, relieved retinal ganglion cells death. In addition, resveratrol inhibited Caspase-1 activation, gasdermin D (GSDMD-N) cleavage, the inflammasome assembly, and the release of inflammatory cytokines, simultaneously relieving the MGCs activation. Furthermore, resveratrol inhibited the pyroptosis-related NLRP3/GSDMD-N/TMS1/ASC/Caspase-1/IL-1β pathway in r-MC cells, and mitigated cells death in vitro.
CONCLUSIONS
Pyroptosis plays an important role in the pathogenesis of retinal I/R injury. Resveratrol can attenuate pyroptotic-driven damage in the retina and MGC by inhibiting the NLRP3/GSDMD-N/TMS1/ASC/Caspase-1/IL-1β pyroptosis pathway.
Topics: Animals; Mice; Rats; Caspase 1; Gasdermins; Inflammasomes; Interleukin-1beta; NLR Family, Pyrin Domain-Containing 3 Protein; Pyroptosis; Reperfusion Injury; Resveratrol; Retina
PubMed: 38133508
DOI: 10.1167/iovs.64.15.28 -
Molecular Therapy. Methods & Clinical... Dec 2023The majority of patients with mutations in develop either early-onset retinitis pigmentosa as young children or Leber congenital amaurosis as newborns. The cause for...
The majority of patients with mutations in develop either early-onset retinitis pigmentosa as young children or Leber congenital amaurosis as newborns. The cause for the phenotypic variability in -associated retinopathies is unknown, but might be linked to differences in CRB1 and CRB2 protein levels in Müller glial cells and photoreceptor cells. Here, and differentiation day 210 retinal organoids showed a significant decrease in the number of photoreceptor nuclei in a row and a significant increase in the number of photoreceptor cell nuclei above the outer limiting membrane. This phenotype with outer retinal abnormalities is similar to patient-derived retinal organoids and or mutant mouse retinal disease models. The and retinal organoids develop an additional inner retinal phenotype due to the complete loss of CRB1 from Müller glial cells, suggesting an essential role for CRB1 in proper localization of neuronal cell types. Adeno-associated viral (AAV) transduction was explored at early and late stages of organoid development. Moreover, AAV-mediated gene augmentation therapy with AAV.h improved the outer retinal phenotype in retinal organoids. Altogether, these data provide essential information for future gene therapy approaches for patients with -associated retinal dystrophies.
PubMed: 37886604
DOI: 10.1016/j.omtm.2023.101128 -
Nature Communications Aug 2023Replicative stress promotes genomic instability and tumorigenesis but also presents an effective therapeutic endpoint, rationalizing detailed analysis of pathways that...
Replicative stress promotes genomic instability and tumorigenesis but also presents an effective therapeutic endpoint, rationalizing detailed analysis of pathways that control DNA replication. We show here that the transcription factor E2f4 recruits the DNA helicase Recql to facilitate progression of DNA replication forks upon drug- or oncogene-induced replicative stress. In unperturbed cells, the Trim33 ubiquitin ligase targets E2f4 for degradation, limiting its genomic binding and interactions with Recql. Replicative stress blunts Trim33-dependent ubiquitination of E2f4, which stimulates transient Recql recruitment to chromatin and facilitates recovery of DNA synthesis. In contrast, deletion of Trim33 induces chronic genome-wide recruitment of Recql and strongly accelerates DNA replication under stress, compromising checkpoint signaling and DNA repair. Depletion of Trim33 in Myc-overexpressing cells leads to accumulation of replication-associated DNA damage and delays Myc-driven tumorigenesis. We propose that the Trim33-E2f4-Recql axis controls progression of DNA replication forks along transcriptionally active chromatin to maintain genome integrity.
Topics: Humans; Genetic Predisposition to Disease; RecQ Helicases; Chromatin; Personal Protective Equipment; Carcinogenesis; Cell Transformation, Neoplastic
PubMed: 37612308
DOI: 10.1038/s41467-023-40847-0 -
Protein & Cell Aug 2023Light adaptation enables the vertebrate visual system to operate over a wide range of ambient illumination. Regulation of phototransduction in photoreceptors is...
Light adaptation enables the vertebrate visual system to operate over a wide range of ambient illumination. Regulation of phototransduction in photoreceptors is considered a major mechanism underlying light adaptation. However, various types of neurons and glial cells exist in the retina, and whether and how all retinal cells interact to adapt to light/dark conditions at the cellular and molecular levels requires systematic investigation. Therefore, we utilized single-cell RNA sequencing to dissect retinal cell-type-specific transcriptomes during light/dark adaptation in mice. The results demonstrated that, in addition to photoreceptors, other retinal cell types also showed dynamic molecular changes and specifically enriched signaling pathways under light/dark adaptation. Importantly, Müller glial cells (MGs) were identified as hub cells for intercellular interactions, displaying complex cell‒cell communication with other retinal cells. Furthermore, light increased the transcription of the deiodinase Dio2 in MGs, which converted thyroxine (T4) to active triiodothyronine (T3). Subsequently, light increased T3 levels and regulated mitochondrial respiration in retinal cells in response to light conditions. As cones specifically express the thyroid hormone receptor Thrb, they responded to the increase in T3 by adjusting light responsiveness. Loss of the expression of Dio2 specifically in MGs decreased the light responsive ability of cones. These results suggest that retinal cells display global transcriptional changes under light/dark adaptation and that MGs coordinate intercellular communication during light/dark adaptation via thyroid hormone signaling.
Topics: Animals; Mice; Dark Adaptation; Light; Retina; Retinal Cone Photoreceptor Cells; Adaptation, Ocular; Neuroglia; Cell Communication; Thyroid Hormones
PubMed: 36930538
DOI: 10.1093/procel/pwad007 -
Glia Mar 2024Retinal degeneration, characterized by Müller cell gliosis and photoreceptor apoptosis, is considered an early event in diabetic retinopathy (DR). Our previous study...
Retinal degeneration, characterized by Müller cell gliosis and photoreceptor apoptosis, is considered an early event in diabetic retinopathy (DR). Our previous study proposed that GMFB may mediate diabetic retinal degeneration. This study identified GMFB as a sensitive and functional gliosis marker for DR. Compared to the wild type (WT) group, Gmfb knockout (KO) significantly improved visual function, attenuated gliosis, reduced the apoptosis of neurons, and decreased the mRNA levels of tumor necrosis factor α (Tnf-α) and interleukin-1β (Il-1β) in diabetic retinas. Tgf-β3 was enriched by hub genes using RNA sequencing in primary WT and KO Müller cells. Gmfb KO significantly upregulated the transforming growth factor (TGF)-β3 protein level via the AKT pathway. The protective effect of TGF-β3 in the vitreous resulted in significantly improved visual function and decreased the number of apoptotic cells in the diabetic retina. The protection of Gmfb KO in primary Müller cells against high glucose (HG)-induced photoreceptor apoptosis was partially counteracted by TGF-β3 antibody and administration of TGFBR1/2 inhibitors. Nuclear receptor subfamily 3 group C member 1 (NR3C1) binds to the promoter region of Gmfb and regulates Gmfb mRNA at the transcriptional level. NR3C1 was increased in the retinas of early diabetic rats but decreased in the retinas of late diabetic rats. N'-[(1E)-(3-Methoxyphenyl)Methylene]-3-Methyl-1H-Pyrazole-5-Carbohydrazide (DS-5) was identified as an inhibitor of GMFB, having a protective role in DR. We demonstrated that GMFB/AKT/TGF-β3 mediated early diabetic retinal degeneration in diabetic rats. This study provides a novel therapeutic strategy for treating retinal degeneration in patients with DR.
Topics: Humans; Rats; Animals; Retinal Degeneration; Ependymoglial Cells; Streptozocin; Proto-Oncogene Proteins c-akt; Transforming Growth Factor beta3; Diabetes Mellitus, Experimental; Gliosis; Retina; Diabetic Retinopathy; RNA, Messenger
PubMed: 37904673
DOI: 10.1002/glia.24486 -
Clinical & Translational Immunology 2023Characterised by intraocular inflammation, non-infectious uveitis includes a large group of autoimmune and autoinflammatory diseases that either involve the eye alone or... (Review)
Review
Characterised by intraocular inflammation, non-infectious uveitis includes a large group of autoimmune and autoinflammatory diseases that either involve the eye alone or have both ocular and systemic manifestations. When non-infectious uveitis involves the posterior segment of the eye, specifically the retina, there is substantial risk of vision loss, often linked to breakdown of the inner blood-retinal barrier. This barrier is formed by non-fenestrated retinal vascular endothelial cells, reinforced by supporting cells that include pericytes, Müller cells and astrocytes. Across the published literature, a group of inflammatory cytokines stand out as prominent mediators of intraocular inflammation, with effects on the retinal endothelium that may contribute to breakdown of the inner blood-retinal barrier, namely tumour necrosis factor (TNF)-α, interleukin (IL)-1β, IL-6, IL-8, IL-17 and chemokine C-C motif ligand (CCL)2. This article reviews the function of each cytokine and discusses the evidence for their involvement in retinal endothelial barrier dysfunction in non-infectious uveitis, including basic laboratory investigations, studies of ocular fluids collected from patients with non-infectious uveitis, and results of clinical treatment trials. The review also outlines gaps in knowledge in this area. Understanding the disease processes at a molecular level can suggest treatment alternatives that are directed against appropriate biological targets to protect the posterior segment of eye and preserve vision in non-infectious uveitis.
PubMed: 38090668
DOI: 10.1002/cti2.1479 -
Glia Nov 2023The expressions of ion channels by Müller glial cells (MGCs) may change in response to various retinal pathophysiological conditions. There remains a gap in our...
The expressions of ion channels by Müller glial cells (MGCs) may change in response to various retinal pathophysiological conditions. There remains a gap in our understanding of MGCs' responses to photoreceptor degeneration towards finding therapies. The study explores how an inhibition of store-operated Ca entry (SOCE) and its major component, Orai1 channel, in MGCs protects photoreceptors from degeneration. The study revealed increased Orai1 expression in the MGCs of retinal degeneration 10 (rd10) mice. Enhanced expression of oxidative stress markers was confirmed as a crucial pathological mechanism in rd10 retina. Inducing oxidative stress in rat MGCs resulted in increasing SOCE and Ca release-activated Ca (CRAC) currents. SOCE inhibition by 2-Aminoethoxydiphenyl borate (2-APB) protected photoreceptors in degenerated retinas. Finally, molecular simulations proved the structural and dynamical features of 2-APB to the target structure Orai1. Our results provide new insights into the physiology of MGCs regarding retinal degeneration and shed a light on SOCE and Orai1 as new therapeutic targets.
Topics: Rats; Mice; Animals; Calcium Channels; Ependymoglial Cells; Retinal Degeneration; Calcium; ORAI1 Protein; Stromal Interaction Molecule 1; Calcium Signaling
PubMed: 37533369
DOI: 10.1002/glia.24429 -
Frontiers in Cell and Developmental... 2023Sirtuin 6 (SIRT6) is a member of the mammalian sirtuin family of NAD-dependent protein deacylases, homologues of the yeast silent information regulator 2 (Sir2). SIRT6... (Review)
Review
Sirtuin 6 (SIRT6) is a member of the mammalian sirtuin family of NAD-dependent protein deacylases, homologues of the yeast silent information regulator 2 (Sir2). SIRT6 has remarkably diverse functions and plays a key role in a variety of biological processes for maintaining cellular and organismal homeostasis. In this review, our primary aim is to summarize recent progress in understanding SIRT6's functions in the retina and retinal pigment epithelium (RPE), with the hope of further drawing interests in SIRT6 to increase efforts in exploring the therapeutic potential of this unique protein in the vision field. Before describing SIRT6's role in the eye, we first discuss SIRT6's general functions in a wide range of biological contexts. SIRT6 plays an important role in gene silencing, metabolism, DNA repair, antioxidant defense, inflammation, aging and longevity, early development, and stress response. In addition, recent studies have revealed SIRT6's role in macrophage polarization and mitochondrial homeostasis. Despite being initially understudied in the context of the eye, recent efforts have begun to elucidate the critical functions of SIRT6 in the retina and RPE. In the retina, SIRT6 is essential for adult retinal function, regulates energy metabolism by suppressing glycolysis that affects photoreceptor cell survival, protects retinal ganglion cells from oxidative stress, and plays a role in Müller cells during early neurodegenerative events in diabetic retinopathy. In the RPE, SIRT6 activates autophagy in culture and protects against oxidative stress in mice. Taken together, this review demonstrates that better understanding of SIRT6's functions and their mechanisms, both in and out of the context of the eye, holds great promise for the development of SIRT6-targeted strategies for prevention and treatment of blinding eye diseases.
PubMed: 38016059
DOI: 10.3389/fcell.2023.1244765 -
Prostaglandins & Other Lipid Mediators Apr 2024Diabetic retinopathy (DR) is a neurovascular complication of diabetes, driven by an intricate network of cellular and molecular mechanisms. This study sought to explore...
Diabetic retinopathy (DR) is a neurovascular complication of diabetes, driven by an intricate network of cellular and molecular mechanisms. This study sought to explore the mechanisms by investigating the role of 12-hydroxyeicosatetraenoic acid (12-HETE), its receptor GPR31, and microRNA (miR-29) in the context of DR, specifically focusing on their impact on Müller glial cells. We found that 12-HETE activates Müller cells (MCs), elevates glutamate production, and induces inflammatory and oxidative responses, all of which are instrumental in DR progression. The expression of GPR31, the receptor for 12-HETE, was prominently found in the retina, especially in MCs and retinal ganglion cells, and was upregulated in diabetes. Interestingly, miR29 showed potential as a protective agent, mitigating the harmful effects of 12-HETE by attenuating inflammation and oxidative stress, and restoring the expression of pigment epithelium-derived factor (PEDF). Our results underline the central role of 12-HETE in DR progression through activation of a neurovascular toxic pathway in MCs and illuminate the protective capabilities of miR-29, highlighting both as promising therapeutic targets for the management of DR.
Topics: 12-Hydroxy-5,8,10,14-eicosatetraenoic Acid; Diabetic Retinopathy; Ependymoglial Cells; MicroRNAs; Receptors, G-Protein-Coupled; Retina
PubMed: 38141777
DOI: 10.1016/j.prostaglandins.2023.106805