Galectin-1-dependent ceRNA network in HRMECs revealed its association with retinal neovascularization
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ABSTRACT: Background: Retinal neovascularization (RNV) is a leading cause of blindness worldwide. Long non-coding RNA (lncRNA) and competing endogenous RNA (ceRNA) regulatory networks play vital roles in angiogenesis. The RNA-binding protein galectin-1 (Gal-1) participates in pathological RNV in oxygen-induced retinopathy mouse models. However, the molecular associations between Gal-1 and lncRNAs remain unclear. Herein, we aimed to explore the potential mechanism of action of Gal-1 as an RNA-binding protein. Results: A comprehensive network of Gal-1, ceRNAs, and neovascularization-related genes was constructed based on transcriptome chip data and bioinformatics analysis of human retinal microvascular endothelial cells. We also conducted functional enrichment and pathway enrichment analyses. Fourteen lncRNAs, twenty-nine miRNAs, and eleven differentially expressed angiogenic genes were included in the Gal-1/ceRNA network. WT1-AS, LINC01140, and LUCAT1 were situated at the center of the network. Additionally, several key angiogenic genes, such as apelin, angiomotin, and C-X-C motif chemokine ligand 10, were found to potentionally interact with Gal-1 via the ceRNA axis. Furthermore, Gal-1 may be involved in regulating biological processes related to chemotaxis, chemokine-mediated signaling, the immune response, and the inflammatory response. Conclusions: The Gal-1/ceRNA axis identified in this study may play a vital role in RNV. This study provides a foundation for the continued exploration of therapeutic targets and biomarkers associated with RNV.
Project description:In order to find out the vital genes during retinal neovascularization (RNV), we set up OIR (oxygen-induced retinopathy; induced with 75%±2% oxygen) and wild-type C57BL/6J murine models. We observed the retinal vascular growth process daily both in OIR and wild-type mice through retinal flat-mount, and isolated total retinal RNA at different time points (P8, P9, P12, P13, P30) both in OIR and wild-type mice for gene expression analysis.
Project description:In order to find out the vital genes during retinal neovascularization (RNV), we set up OIR (oxygen-induced retinopathy; induced with 75%±2% oxygen) and wild-type C57BL/6J murine models. We observed the retinal vascular growth process daily both in OIR and wild-type mice through retinal flat-mount, and isolated total retinal RNA at different time points (P8, P9, P12, P13, P30) both in OIR and wild-type mice for gene expression analysis. At least three different retinae were accessed at each time point for observing the retinal vascular growth process. Ten neural retinae from five mice were harvested and pooled into one sample for gene expression analysis. Three biological replicates were used for each time point. Dye-swaps were performed.
Project description:Myeloid cells such as resident retinal microglia or infiltrating blood-derived macrophages accumulate in areas of retinal ischemia and neovascularization (RNV) and modulate neovascular eye disease. Their temporo-spatial distribution and biological function in this process, however, remain unclarified. We determined the extent of microglia proliferation and macrophage infiltration in areas of ischemia and RNV using Cx3cr1CreERT2:Rosa26-tdTomato mice and assessed the transcriptional profile of microglia in the oxygen-induced retinopathy (OIR) mouse model. We show that microglia are the predominant myeloid cell population in areas of RNV. Thirty percent of retinal microglia were EdU-positive indicating considerable expansion of local microglia. RNA-Seq revealed an enrichment of processes related to cell division and chemokine receptor binding. We propose that activated retinal MG alter their transcriptional profile, exhibit proliferative ability and are by far the most frequent myeloid cell population in areas of RNV in the OIR model thus presenting a potential target for future therapeutic approaches.
Project description:Background: Retinal neovascularization (RNV) as a result of retinal ischemia, such as in proliferative diabetic retinopathy (PDR) and retinopathy of prematurity (ROP), can lead to vitreous hemorrhage, tractional retinal detachment, and irreversible loss of vision if left untreated. Although panretinal laser photocoagulation and anti-vascular endothelial growth factor (VEGF) injections are efficient treatment modalities, a significant number of patients do not respond to either treatment. This clinical finding suggests that other, previously unrecognized mediators and signaling pathways may contribute to RNV development and could represent valuable targets for future treatments. Methods: In search of phylogenetically conserved angiogenic mediators, we examined the transcriptional profile of murine RNV from C57BL/6J mice (n=14) in the oxygen-induced retinopathy (OIR) model as well as human RNV membranes from PDR patients (n=7), who had undergone vitrectomy and compared them with corresponding control tissues (n=13, 10 respectively). Genes that were differentially expressed (DEGs) between RNV and control samples were identified for human and murine samples and their associated gene ontology (GO) clusters analyzed. Lastly, human and murine DEGs were compared to identify phylogenetically conserved factors. Findings: Transcriptional profiles of murine RNV showed that DEGs linked to the activation of the innate immune system (Msn, Cd34), extracellular matrix organisation (Col4a1, Gfap), and regulation of angiogenesis (Col4a2, Fgf2) were significantly upregulated both at the ischemic, preproliferative stage of the disease (OIR p14) as well as at the proliferative stage (OIR p17). While similar GO terms were upregulated in human RNV, only a small overlap in DEGs between both species was detected. Phylogenetically conserved mediators upregulated in both murine and human RNV included ANGPT2, S100A8, MCAM, EDNRA, MRC1, and CCR7. Interpretation: This study identifies phylogenetically conserved inflammatory and pro-angiogenic mediators that are significantly upregulated in both murine and human RNV. Among them, MCAM, ENDRA and MRC1 emerged as the most upregulated, phylogenetically conserved DEGs not yet implicated in human RNV, thus representing potential new treatment targets for ischemic retinal diseases.
Project description:Background: Proliferative diabetic retinopathy (PDR) is hallmarked by the formation of retinal neovascularization (RNV) membranes, which can lead to a tractional retinal detachment, the primary reason for severe vision loss in end-stage disease. The aim of this study was to characterize the molecular and cellular features of RNV in order to unravel potential novel drug treatments for PDR. Methods: A total of 42 patients undergoing vitrectomy for PDR, macular pucker or macular hole (control patients) were included in this study. The surgically removed RNV and epiretinal membranes were analyzed by RNA sequencing, single-cell based Imaging Mass Cytometry and conventional immunohistochemistry. Since macrophages were found to be abundant in RNV tissue, vitreal macrophages, also known as hyalocytes, were isolated from the vitreous of patients with PDR by flow cytometry, cultivated and characterized by immunhistochemistry. A bioinformatical drug repurposing approach was applied, in order to identify novel drug options for end-stage diabetic retinopathy disease. Results: The in-depth transcriptional and single-cell protein analysis of diabetic RNV tissue samples revealed an accumulation of endothelial cells, macrophages and myofibroblasts as well as an abundance of secreted ECM proteins such as SPARC, FN1 and several types of collagen in RNV tissue. The immunohistochemical staining of cultivated vitreal hyalocytes from patients with PDR showed that hyalocytes express α-SMA (alpha-smooth muscle actin), a classic myofibroblast marker. According to our drug repurposing analysis, imatinib emerged as a potential drug option for future treatment of PDR. Conclusion: This study delivers the first in-depth transcriptional and single-cell proteomic characterization of RNV tissue samples. Our data suggest an important role of hyalocyte-to-myofibroblast transdifferentiation in the pathogenesis of diabetic vitreoretinal disease and suggests their modulation as a novel possible clinical approach.
Project description:Exosomes serve as signaling messengers that facilitate intercellular communication through delivering molecular cargo. Here, we observed elevated levels of exosomal periostin (POSTN) in blood plasma of patients with proliferative diabetic retinopathy (PDR). Monocytes-derived exosomal POSTN was increased under high glucose condition, and deletion of Postn in myeloid cells reduced retinal neovascularization. Monocytes isolated from the blood of PDR patients exhibited heightened glycolytic activity and elevated histone lactylation levels, particularly H4K8 lactylation (H4K8la). Knockout of Hexokinase 2 (Hk2) in myeloid cells led to reduced H4K8la and POSTN levels and inhibited retinal neovascularization. Exogenous exosomal POSTN partially reversed the angiogenic defects caused by Postn or Hk2 deletion in myeloid cells. Mechanistically, exosomal POSTN stabilized hypoxia-inducible factor 1-alpha (HIF1-α) and upregulated the expression of angiogenic genes. Notably, treatment with metformin reduced retinal neovascularization by decreasing monocytes glycolysis and lowering exosomal POSTN levels. In summary, these findings underscore the critical role of circulating exosomal POSTN in retinal neovascularization and highlight its potential as a therapeutic target for angiogenic retinopathies.
Project description:Emerging evidence suggests a link between the circadian clock and retinopathies though the causality has not been established. Circadian clocks in the mammalian retina regulate a diverse range of retinal functions that allow the retina to adapt to the light-dark cycle. We report that clock genes are expressed in the embryonic retina, and the embryonic retina requires light cues to maintain robust circadian expression of the core clock gene, Bmal1. Deletion of Bmal1 and Per2 from the retinal neurons results in retinal angiogenic defects similar to when animals are maintained under constant light conditions. Using two different models to assess pathological neovascularization, we show that neuronal Bmal1 deletion reduces neovascularization with reduced vascular leakage, suggesting that a dysregulated circadian clock primarily drives neovascularization. Chromatin immunoprecipitation sequencing analysis suggests that semaphorin signaling is the dominant pathway regulated by Bmal1. Our data indicate that therapeutic silencing of the retinal clock could be a common approach for the treatment of certain retinopathies like diabetic retinopathy and retinopathy of prematurity.
Project description:Retinal neovascularization poses heightened risks of vision loss and blindness. Despite its clinical significance, the molecular mechanisms underlying the pathogenesis of retinal neovascularization remain elusive. This study utilized single-cell multiomics profiling in an oxygen-induced retinopathy (OIR) model to comprehensively investigate the intricate molecular landscape of retinal neovascularization.
Project description:Retinal neovascularization is a severe complication of proliferative diabetic retinopathy. We have previously identified that miRNAs is directly involved in the development of retinal neovascularization. Here, we explored the role of miRNAs and its underlying mechanism in modulating angiogenesis.