Project description:Purpose: To investigate the role of endothelial-mesenchymal transition (EndoMT) in pathological retinal angiogenesis and identify key molecular mediators in retina angiogenesis. Methods: RNA sequencing was performed on retinal tissue from oxygen-induced retinopathy (OIR) mouse model to analyze gene expression patterns. Gene Set Enrichment Analysis was used to examine the correlation between EMT and angiogenesis gene sets. Fibronectin (FN1) expression was evaluated in endothelial cells, and its function was assessed through siRNA mediated knockdown in both in vitro angiogenesis assays and the OIR model. Results: EndoMT occurred early in retinal angiogenesis development, with significant correlation between EMT and angiogenesis gene sets. FN1 was identified as the most significantly upregulated EMT-related gene in endothelial cells. siRNA-mediated inhibition of FN1 effectively prevented VEGF-induced angiogenesis in vitro and reduced pathological angiogenesis in the OIR model. Conclusions: EndoMT is a crucial early event in pathological retinal angiogenesis, with FN1 serving as a key mediator. Targeting FN1 may provide a novel therapeutic strategy that could synergize with anti-VEGF treatments to more effectively treat pathological angiogenesis in DR and ROP, particularly in cases of poor response to anti-VEGF therapy alone.
Project description:We determined which metabolic pathways are activated by hypoxia-inducible factor 1-mediated (HIF-1-mediated) protection against oxygen-induced retinopathy (OIR) in newborn mice, the experimental correlate to retinopathy of prematurity, a leading cause of infant blindness. HIF-1 coordinates the change from oxidative to glycolytic metabolism and mediates flux through serine and 1-carbon metabolism (1CM) in hypoxic and cancer cells. We used untargeted metabolite profiling in vivo to demonstrate that hypoxia mimesis activates serine/1CM. Both [13C6] glucose labeling of metabolites in ex vivo retinal explants as well as in vivo [13C3] serine labeling of metabolites followed in liver lysates strongly suggest that retinal serine is primarily derived from hepatic glycolytic carbon and not from retinal glycolytic carbon in newborn pups. In HIF-1α2lox/2lox albumin-Cre-knockout mice, reduced or near-0 levels of serine/glycine further demonstrate the hepatic origin of retinal serine. Furthermore, inhibition of 1CM by methotrexate blocked HIF-mediated protection against OIR. This demonstrated that 1CM participates in protection induced by HIF-1 stabilization. The urea cycle also dominated pathway enrichment analyses of plasma samples. The dependence of retinal serine on hepatic HIF-1 and the upregulation of the urea cycle emphasize the importance of the liver to remote protection of the retina.
Project description:Diabetic retinopathy (DR) causes vision loss due to sustained inflammation and vascular dam-age. The vascular damage is characterized fibrinogen leakage, angiogenesis, and hypoxia exac-erbating retinal damage. Neuronal regulation of microglia via the CX3CL1 (FKN)-CX3CR1 pathway also play a significant role in retinal pathology; here defects in the FKN-CX3CR1 pathway exacerbate inflammation, vascular damage and vision impairment. However, the con-tribution of hypoxic astrocytes to the pathological process of DR is unclear.
Project description:We determined which metabolic pathways are activated by hypoxia-inducible factor 1-mediated (HIF-1-mediated) protection against oxygen-induced retinopathy (OIR) in newborn mice, the experimental correlate to retinopathy of prematurity, a leading cause of infant blindness. HIF-1 coordinates the change from oxidative to glycolytic metabolism and mediates flux through serine and 1-carbon metabolism (1CM) in hypoxic and cancer cells. We used untargeted metabolite profiling in vivo to demonstrate that hypoxia mimesis activates serine/1CM. Both [13C6] glucose labeling of metabolites in ex vivo retinal explants as well as in vivo [13C3] serine labeling of metabolites followed in liver lysates strongly suggest that retinal serine is primarily derived from hepatic glycolytic carbon and not from retinal glycolytic carbon in newborn pups. In HIF-1?2lox/2lox albumin-Cre-knockout mice, reduced or near-0 levels of serine/glycine further demonstrate the hepatic origin of retinal serine. Furthermore, inhibition of 1CM by methotrexate blocked HIF-mediated protection against OIR. This demonstrated that 1CM participates in protection induced by HIF-1 stabilization. The urea cycle also dominated pathway enrichment analyses of plasma samples. The dependence of retinal serine on hepatic HIF-1 and the upregulation of the urea cycle emphasize the importance of the liver to remote protection of the retina.
Project description:Phlebotomy-induced-anemia (PIA), which induces tissue hypoxia and angiogenesis, occurs universally among infants at risk for severe retinopathy of prematurity (ROP). We hypothesized that PIA exacerbates pathologic retinal neovascularization in ROP. Methods: We induced PIA to a hematocrit of 18% among rats undergoing the established 50/10 oxygen-induced retinopathy (OIR) model. Rats were euthanized at P15 and P20, during the avascular and neovascular phases of OIR, respectively. Whole retinal transcriptomes were compared to non-PIA controls. Results: RNA sequencing showed dampened pathways of angiogenesis, inflammation, and neural development in anemic OIR females at P20. Conclusion: PIA dampened transcriptomic pathways central to retinal vascular and neural development in neonatal rats. These data suggest PIA provides a protective effect from ROP.
Project description:Here we show that suppressing the serine biosynthesis pathway, either by inhibiting the activity of the key enzyme phosphoglycerate dehydrogenase or by exogenous serine and glycine restriction, robustly enhances polarization of interferon-g-activated macrophages (M(IFN-g)) but suppresses that of interleukin-4-activated macrophages (M(IL-4)) both in vitro and in vivo.To further explore its mechanism, we used high-throughput sequencing technology (RNA-seq) to assess gene expression in serine-deficiency or not BMDMs
Project description:In this study, we demonstrate that SH-42 and SH-80, novel heat shock protein 90 inhibitors, suppress retinal neovascularization via inhibition of hypoxia-mediated angiogenesis. To figure out any genotoxic effect of these compounds related with heat shock protein 90 inhibition, we performed microarray analyses with retinal tissues treated with SH-42 and SH-80 for 7 days. We intravitreally injected PBS, SH42, or SH80 into the right eyes of C57BL/6 male mice (n = 12 per group). PBS-treated mice were regarded as negative control. Four retinal tissues were pooled into 1 test tube and prepared for further analyses.