Comparative analysis of Retinal Angiogenesis during Inflammatory stage
Ontology highlight
ABSTRACT: Choroidal neovascularization (CNV) and the resulting retinal angiogenesis are pathological hallmarks of wet Age-related macular degeneration (AMD). The pathogenesis of CNV is not fully understood, but accumulated evidence has suggested the role of inflammation in the early stage of CNV. To better understand the molecular landscape during the early stage, we performed RNA-Seq and mass spectrometry-based proteomic analysis in the retina of the laser-induced CNV mouse model. Both transcriptomic and proteomic data showed dramatic activation of inflammatory response 3 days post photocoagulation. Integrative analysis suggested a moderate correlation between RNA-Seq and mass spec. Up-regulation of angiogenic factor, basic fibroblast growth factor-2 (Fgf-2), but not vascular endothelial growth factor (Vegf) was observed at both RNA and protein levels, highlighting Fgf-2 as a biomarker and potential therapeutic target during the early stage of CNV. In addition, enrichment analysis indicated a large overlap of inflammation-related genes and pathways at both levels. We also compared our findings with human retinal RNA-Seq data from AMD patients and controls. By using a multi-omics and comparative approach, our findings demonstrate the molecular landscape during the inflammatory stage of mouse CNV and provided new insight into the translation from the mouse model to understanding human AMD and its potential intervention and therapies.
Project description:Age-related macular degeneration (AMD) is a leading cause of blindness among the elderly. Using clinical samples and knockout mice, we reported that the m1A eraser ALKBH3 reshaped retinal metabolism to promote AMD. In retinal pigment epithelium (RPE), the dm1ACRISPR system demonstrated that ALKBH3 demethylated the glycolytic enzyme HK2 to activate anaerobic glycolysis, producing excessive lactate. The lactate promoted histone lactylation at H3K18, which in turn bound to ALKBH3 to amplify its transcription, establishing a positive feedback loop. The ALKBH3 inhibitor HUHS015 disrupted this loop, effectively mitigating RPE degeneration. Furthermore, ALKBH3 directly targeted the pro-angiogenic factor VEGFA to modulate the metabolic cross-talk between RPE and choroidal capillaries, thus promoting choroidal neovascularization (CNV). HUHS015 inhibited CNV synergistically with the anti-VEGF drug Aflibercept. Our study provides critical insights into the molecular mechanisms and metabolic events facilitating the progression from RPE degeneration to CNV in AMD, laying the groundwork for new treatments of AMD.
Project description:This project identifies and quantitates Hydroxyapatite binding proteins (HAP) in plasma genotyped for complement factor H (CFH) polymorphism in late stage age-related macular degeneration (AMD) patients by sequential window acquisition of all theoretical mass spectra (SWATH). This study provides insights into factors contributing to the formation of sub-retinal pigment epithelial (RPE) deposits and explores the effect of AMD-associated CFH polymorphism on deposit composition.
Project description:Age-related macular degeneration (AMD) is a leading cause of blindness. Vision loss is caused by the loss of the retinal pigment epithelium (RPE) and photoreceptors and/or retinal and choroidal angiogenesis. Here we use AMD patient specific RPE cells with the Y402H high-risk polymorphism in the complement factor H to perform a comprehensive analysis of EVs, their cargo and role in disease pathology. We show that AMD RPE is characterised by enhanced and polarised EV secretion. Transcriptomic, proteomic and lipidomic analyses demonstrate that AMD RPE EVs carry RNA, proteins and lipids that reflect changes in the parental RPE and mediate key AMD pathological processes including oxidative stress, cytoskeletal dysfunction, angiogenesis and drusen accumulation. We demonstrate that exposure of control RPE to AMD RPE apical EVs leads to the formation of stress vacuoles, cytoskeletal destabilization, and abnormalities in the morphology of the nucleus in the recipient cells. Treatment of retinal organoids with apical AMD RPE EVs leads to disrupted neuroepithelium and appearance of cytoprotective alpha B crystallin immunopositive cells, with some co-expressing retinal progenitor cell markers Pax6 or Vsx2, suggesting activation of regenerative pathways upon injury. These findings indicate that AMD RPE EVs mediated signalling have an important role in disease progression.
Project description:Purpose: Age-related degeneration (AMD) is a major cause of blindness in developed countries. The molecular pathogenesis of early events in AMD is poorly understood. We investigated differential gene expression in samples of human retinal pigment epithelium (RPE)/choroid from early AMD and control maculas using exon-based arrays. Methods: Gene expression levels in nine early AMD and nine control human donor eyes were assessed using Affymetrix Human Exon ST 1.0 arrays. Two controls did not pass quality control and were removed. Differentially expressed genes were annotated using DAVID, and gene set enrichment analysis (GSEA) was performed on RPE-specific and endothelium-associated gene sets. CFH genotype was also assessed and differential expression was analyzed with respect to high AMD risk (YH/HH) and low AMD risk (YY) genotypes. Results: Seventy-five genes were identified as differentially expressed (raw p-value < 0.01; >50% fold change, mean log2 expression level in AMD or control M-bM-^IM-% median of all average gene expression values); however, no genes were significant (adj. p-value < 0.01) after correction for multiple hypothesis testing. Of 52 genes with decreased expression in AMD (fold change < 0.5; raw p-value < 0.01), 18 genes were identified by DAVID analysis as associated with vision or neurological processes. GSEA of RPE-associated and endothelium-associated genes revealed a significant decrease in genes typically expressed by endothelial cells in the early AMD group compared to controls, consistent with previous histologic and proteomic studies. Analysis with respect to CFH genotype indicated decreased expression of ADAMTS9 in eyes with high-risk genotypes (fold change = -2.61; raw p-value = 0.0008). Conclusions: GSEA results suggest that RPE transcripts are preserved or elevated in early AMD, concomitant with loss of endothelial cell marker expression. These results are consistent with the notion that choroidal endothelial cell dropout occurs early in the pathogenesis of AMD. Using AltAnalyze (ver. 2.0.7 beta), we analyzed nine early AMD and nine control eyes using Affymetrix Human Exon ST 1.0 arrays. Following initial processing in AltAnalyze, two control arrays were identified as potential outliers by tests implement in arrayQualityMetrics, a package for R.
Project description:Purpose: Anti-angiogenic treatment is well established in the management of exudative AMD, but not sufficient in all patients. Characterization of factors driving this chronic disease could serve to identify additional treatment options. The purpose of this study was to assess gene expression patterns and distinct changes in cells derived from surgically extracted CNV (chorioidal neovascularization) membranes. Materials and Methods: Expression of >11.000 genes was analyzed by means of a microarray in cells cultured from two late-stage CNV membranes, compared to primary human RPE and ARPE-19 cells. A pathway analysis was performed to identify gene expression patterns associated with exudative AMD. Results: The analysis revealed significant alterations in gene sets associated with inflammatory processes in CNV-derived cells, involving up-regulation of pro-inflammatory factors IL6, C3, and C5 and downregulation of anti-inflammatory CFB and CFI. Factors associated with angiogenesis, such as VEGFA or ANGPT2, were not significantly regulated in the two RPE-derived cell lines. Conclusion: In late-stage CNV membrane-derived RPE, gene expression was shifted towards a pro-inflammatory state. Angiogenesis-associated factors were regulated differently in the two CNV-derived RPE membranes. While inflammation seems to be continuously stimulated by RPE associated with late exudative AMD, this seems not the case with regard to angioregulatory mechanisms.
Project description:Purpose: Age-related degeneration (AMD) is a major cause of blindness in developed countries. The molecular pathogenesis of early events in AMD is poorly understood. We investigated differential gene expression in samples of human retinal pigment epithelium (RPE)/choroid from early AMD and control maculas using exon-based arrays. Methods: Gene expression levels in nine early AMD and nine control human donor eyes were assessed using Affymetrix Human Exon ST 1.0 arrays. Two controls did not pass quality control and were removed. Differentially expressed genes were annotated using DAVID, and gene set enrichment analysis (GSEA) was performed on RPE-specific and endothelium-associated gene sets. CFH genotype was also assessed and differential expression was analyzed with respect to high AMD risk (YH/HH) and low AMD risk (YY) genotypes. Results: Seventy-five genes were identified as differentially expressed (raw p-value < 0.01; >50% fold change, mean log2 expression level in AMD or control ≥ median of all average gene expression values); however, no genes were significant (adj. p-value < 0.01) after correction for multiple hypothesis testing. Of 52 genes with decreased expression in AMD (fold change < 0.5; raw p-value < 0.01), 18 genes were identified by DAVID analysis as associated with vision or neurological processes. GSEA of RPE-associated and endothelium-associated genes revealed a significant decrease in genes typically expressed by endothelial cells in the early AMD group compared to controls, consistent with previous histologic and proteomic studies. Analysis with respect to CFH genotype indicated decreased expression of ADAMTS9 in eyes with high-risk genotypes (fold change = -2.61; raw p-value = 0.0008). Conclusions: GSEA results suggest that RPE transcripts are preserved or elevated in early AMD, concomitant with loss of endothelial cell marker expression. These results are consistent with the notion that choroidal endothelial cell dropout occurs early in the pathogenesis of AMD.
Project description:How retinal pigmented epithelial (RPE) cells degenerate from oxidative stress in age-related macular degeneration (AMD) is incompletely understood. The study's intent was to identify key cytoprotective pathways activated by oxidative stress, and to determine the extent of their protection. Immunohistochemistry was used to identify the unfolded protein response (UPR) and mitochondria in the RPE of AMD samples. Maculas with early AMD had prominent IRE1α, but minimal mitochondrial TOM20 immunolabeling in mildly degenerated RPE. RPE cells treated with cigarette smoke extract (CSE), by microarray analysis, had over-represented genes involved in the antioxidant and unfolded protein response, and mitochondrial location. CSE induced the UPR sensors IRE1α, p-PERK, and ATP6, which activated CHOP. CHOP knockdown compromised cell viability after CSE exposure. At the same CSE doses, mitochondria generated superoxide anion and produced less ATP. In mice given intravitreal CSE, the RPE had increased IRE1α and decreased ATP, which elicited RPE epithelial-mesenchymal transition, as suggested by altered ZO1 immunolabeling of RPE flatmounts. Our experiments indicate that RPE cells exposed to oxidative stress respond with a cytoprotective antioxidant and unfolded protein response, but develop mitochondrial impairment that contributed to epithelial mesenchymal transition. With similar responses in the RPE of early AMD samples, these results suggest that mitochondria are vulnerable to oxidative stress while the ER elicits a protective response during early AMD. A total of 9 samples were analyzed: 3 control samples, 3 samples treated with 100ug/ml of Cigarette Smoke Condensate, and 3 samples treated with 250ug/ml of Cigarettes Smoke Condensate.
Project description:Age-related macular degeneration (AMD) is a leading cause of blindness. Vision loss is caused by the loss of the retinal pigment epithelium (RPE) and photoreceptors and/or retinal and choroidal angiogenesis. Here we use AMD patient specific RPE cells with the Y402H high-risk polymorphism in the complement factor H to perform a comprehensive analysis of EVs, their cargo and role in disease pathology. We show that AMD RPE is characterised by enhanced and polarised EV secretion. Transcriptomic, proteomic and lipidomic analyses demonstrate that AMD RPE EVs carry RNA, proteins and lipids that reflect changes in the parental RPE and mediate key AMD pathological processes including oxidative stress, cytoskeletal dysfunction, angiogenesis and drusen accumulation. We demonstrate that exposure of control RPE to AMD RPE apical EVs leads to the formation of stress vacuoles, cytoskeletal destabilization, and abnormalities in the morphology of the nucleus in the recipient cells. Treatment of retinal organoids with apical AMD RPE EVs leads to disrupted neuroepithelium and appearance of cytoprotective alpha B crystallin immunopositive cells, with some co-expressing retinal progenitor cell markers Pax6 or Vsx2, suggesting activation of regenerative pathways upon injury. These findings indicate that AMD RPE EVs mediated signalling have an important role in disease progression.
Project description:The exact pathogenesis of age-related macular degeneration (AMD) leading to visual impairment and severe vision loss is still unclear, and the currently available treatments are often unsatisfactory. Previous studies have demonstrated both oxidative stress-induced damage to the retinal pigment epithelium (RPE) and inflammation are involved in AMD. Although anti-vascular endothelial growth factor (VEGF) therapy can impair the growth of new blood vessels, serious side effects were found with repeated monthly intravitreal injections. Here, an injectable hydrogel based on an anti-inflammatory betamethasone phosphate (BetP) drug (BetP-Gel) was designed to enable long-term efficient release of ranibizumab (RZB) to attenuate choroidal neovascularization (CNV), reduce vascular leakage and inhibit vascular proliferation in the retina, which significantly increased the effective treatment time of ranibizumab compared with that in clinical practice. In particular, experimental data with in vitro and in vivo models revealed that BetP-Gel itself had a strong ability to scavenge intracellular reactive oxygen species (ROS) and reduce tumour necrosis factor-α (TNF-α) as well as interleukin (IL-1β, IL-6, IL-8, and IL-18) inflammatory cytokines, inhibiting ROS- and inflammation-induced retinal damage. Altogether, the carrier-free system (RZB@BetP-Gel) could serve as a novel antioxidant, anti-inflammatory and anti-neovascularization agent for the treatment of AMD.
Project description:Age-related macular degeneration (AMD) is a leading cause of blindness in the elderly. The extent to which epigenetic changes regulate the progression of AMD is unclear. Here we profiled chromatin accessibility in the retina and retinal pigmented epithelium (RPE) from AMD patients and controls. Global decreases in chromatin accessibility occur in the RPE in early AMD and in the retina with advanced disease. Footprints of photoreceptor and RPE-specific transcription factors are enriched in differentially accessible regions (DARs) and reduced AMD. Genes associated with DARs show altered expression in AMD. Cigarette smoke, an established risk factor for AMD, applied to human iPSC-derived RPE cells recapitulates epigenomic changes seen in AMD. In addition to providing a comprehensive profile of chromatin accessibility in human RPE and retina, this study shows that global decreases in chromatin accessibility may play a critical role in AMD progression.