Project description:Induced pluripotent stem cells (iPSCs) directed to endothelial identity (iPSC-ECs) lose expression of key identity markers under standard in vitro conditions, limiting their clinical applications. We examined iPSC-ECs at late passage (>2 weeks) under hyperoxic (21%)conditions with single cell RNA sequencing
Project description:PURPOSE: Hyperoxia is toxic to photoreceptors, and this toxicity may be important in the progress of retinal dystrophies. This microarray study examines gene expression induced in the C57BL/6J mouse retina by hyperoxia over the 14-day period during which photoreceptors first resist, then succumb to, hyperoxia. METHODS: Young adult C57BL/6J mice were exposed to hyperoxia (75% oxygen) for up to 14 days. On day 0 (control), day 3, day 7, and day 14, retinal RNA was extracted and processed on Affymetrix GeneChip Mouse Genome 430 2.0 arrays. Microarray data were analyzed using GCOS Version 1.4 and GeneSpring Version 7.3.1. RESULTS: The overall numbers of hyperoxia-regulated genes increased monotonically with exposure. Within that increase, however, a distinctive temporal pattern was apparent. At 3 days exposure, there was prominent upregulation of genes associated with neuroprotection. By day 14, these early-responsive genes were downregulated, and genes related to cell death were strongly expressed. At day 7, the regulation of these genes was mixed, indicating a possible transition period from stability at day 3 to degeneration at day 14. CONCLUSIONS: Microarray analysis of the response of the retina to prolonged hyperoxia demonstrated a temporal pattern involving early neuroprotection and later cell death, and provided insight into the mechanisms involved in the two phases of response. As hyperoxia is a consistent feature of the late stages of photoreceptor degenerations, understanding the mechanisms of oxygen toxicity may be important therapeutically. 4 timepoints in total, 0d (control), 3d, 7d and 14d and a replicate per timepoint. Total of 8 chips.
Project description:Endothelial cell (EC) dysfunction is crucial in chronic vascular inflammation and diseases like atherosclerosis. An unknown endothelial pathological phenotype potentially driving atherosclerosis was hinted in our previous study. However, the detailed characterizations and underlying molecular mechanisms remain unclear. In the present study, using single-cell RNA sequencing, the new endothelial pathological phenotype was defined by high expression of fibroblast markers, extracellular matrix, and inflammatory genes, concurrently with a rapid decline in endothelial markers. By performing RNA-seq, we found that increased CEBPB contributes to the fibroblast and inflammatory feature of these atherogenic ECs. Further analysis revealed that IL-1β-induced high expression of CEBPB triggers TGF-β signaling and subsequent regulation of downstream genes. This occurs through direct interaction of CEBPB with the promotor region of TGF-β receptor type I (TGFBR1), resulting in its upregulation. Furthermore, exacerbating atherosclerotic plaque area, enhanced vascular inflammation and increased endothelial TGFBR1 expression were confirmed by endothelial overexpression of CEBPB in vivo. These findings suggest endothelial CEBPB functions as a novel regulator of TGFBR1, driving endothelial pathological phenotype, promoting vascular inflammation and atherosclerosis.
Project description:Endothelial cell (EC) dysfunction is crucial in chronic vascular inflammation and diseases like atherosclerosis. An unknown endothelial pathological phenotype potentially driving atherosclerosis was hinted in our previous study. However, the detailed characterizations and underlying molecular mechanisms remain unclear. In the present study, using single-cell RNA sequencing, the new endothelial pathological phenotype was defined by high expression of fibroblast markers, extracellular matrix, and inflammatory genes, concurrently with a rapid decline in endothelial markers. Further analysis revealed that increased CEBPB contributes to the fibroblast and inflammatory feature of these atherogenic ECs, which was further confirmed in cultured human aortic ECs. Mechanistically, IL-1β-induced high expression of CEBPB triggers TGF-β signaling and subsequent regulation of downstream genes. By performing CUT&Tag analysis, we further investigated that CEBPB directly regulates TGFBR1 expression in endothelial cells through direct interaction of CEBPB with the promotor region of TGF-β receptor type I (TGFBR1). These findings suggest endothelial CEBPB functions as a novel regulator of TGFBR1, driving endothelial pathological phenotype, promoting vascular inflammation and atherosclerosis.
Project description:Endothelial cell (EC) dysfunction is crucial in chronic vascular inflammation and diseases like atherosclerosis. An unknown endothelial pathological phenotype potentially driving atherosclerosis was hinted in our previous study. However, the detailed characterizations and underlying molecular mechanisms remain unclear. Here, we have defined a new endothelial pathological phenotype, characterized by high expression of fibroblast and pro-inflammatory genes with a rapid reduction in EC fate genes by performing single-cell RNA sequencing. Further analysis revealed that increased CEBPB contributes to the fibroblast and inflammatory feature of these atherogenic ECs, which was further confirmed in cultured human aortic ECs. Mechanistically, IL-1β-induced high expression of CEBPB triggers TGF-β signaling and subsequent regulation of downstream genes. This occurs through direct interaction of CEBPB with the promotor region of TGF-β receptor type I (TGFBR1), resulting in its upregulation. Furthermore, exacerbating atherosclerotic plaque area, enhanced vascular inflammation and increased endothelial TGFBR1 expression were confirmed by endothelial overexpression of CEBPB in vivo. These findings suggest endothelial CEBPB functions as a novel regulator of TGFBR1, driving endothelial pathological phenotype, promoting vascular inflammation and atherosclerosis. Targeting endothelial CEBPB may offer new therapeutic avenues for atherosclerotic diseases.
Project description:PURPOSE: Hyperoxia is toxic to photoreceptors, and this toxicity may be important in the progress of retinal dystrophies. This microarray study examines gene expression induced in the C57BL/6J mouse retina by hyperoxia over the 14-day period during which photoreceptors first resist, then succumb to, hyperoxia. METHODS: Young adult C57BL/6J mice were exposed to hyperoxia (75% oxygen) for up to 14 days. On day 0 (control), day 3, day 7, and day 14, retinal RNA was extracted and processed on Affymetrix GeneChip Mouse Genome 430 2.0 arrays. Microarray data were analyzed using GCOS Version 1.4 and GeneSpring Version 7.3.1. RESULTS: The overall numbers of hyperoxia-regulated genes increased monotonically with exposure. Within that increase, however, a distinctive temporal pattern was apparent. At 3 days exposure, there was prominent upregulation of genes associated with neuroprotection. By day 14, these early-responsive genes were downregulated, and genes related to cell death were strongly expressed. At day 7, the regulation of these genes was mixed, indicating a possible transition period from stability at day 3 to degeneration at day 14. CONCLUSIONS: Microarray analysis of the response of the retina to prolonged hyperoxia demonstrated a temporal pattern involving early neuroprotection and later cell death, and provided insight into the mechanisms involved in the two phases of response. As hyperoxia is a consistent feature of the late stages of photoreceptor degenerations, understanding the mechanisms of oxygen toxicity may be important therapeutically.
Project description:Extracellular vesicles derived from induced pluripotent stem cells (iPSC EVs) have immunoregulatory potential with the ability to alter monocyte-derived macrophages. Macrophages function in the propagation and resolution of inflammation which is mediated by their phenotype. Macrophages are an ideal therapeutic target as modulating their phenotype towards an anti-inflammatory pro-resolving state may be beneficial in chronic inflammatory diseases such as atherosclerosis. Macrophages are naturally phagocytotic cells and readily take up iPSC EVs however the contents of iPSC EVs and their effects on macrophages are poorly understood. Here iPSC EVs were characterized and analysed by mass-spectrometry based proteomics and a targeted microRNA (miR) panel. Their immunomodulatory effects on macrophages were assessed and a monocyte transmigration assay was used to assess the chemotactic potency of the secretome from iPSC EV treated macrophages. Proteomic analysis on iPSC EVs identified Podocalyxin-like protein 1 (PODXL1), Insulin (INS) and Solute Carrier Family 2 (Facilitated Glucose Transporter), Member 3 (SLC2A3) as the most abundant proteins unique to the iPSC EVs when compared to control NT-2 EVs. Notably, thioredoxin and peroxiredoxin related proteins were detected. miR-302d-3p was the most abundant miR in these iPSC EVs. miR-25-3p, previously reported to alter the macrophage phenotype, was significantly increased in comparison to the control NT-2 EVs. iPSC EVs increased expression of the anti-inflammatory associated MRC1 and miR-21 in human primary macrophages and decreased monocyte chemoattractant protein1 (MCP-1). Mass spectrometry based proteomics revealed that treated macrophages had decreased levels of secretory proteins, some of which have chemotactic properties, these included Azurocidin 1 (AZU1), Growth Differentiation Factor 15 (GDF15), and Ribosomal Protein S19 (RPS19). There was a decrease in monocyte transmigration towards conditioned media from macrophages treated with iPSC EVs. Collectively this study provides insights into the protein content and miR cargo of iPSC EVs and highlights their capacity to inhibit chemotactic proteins in macrophages and upregulate MRC1.
Project description:Akap1 KO and Wt mice were exposed to normoxia or hyperoxia for 48h. Total RNA was extracted from lungs of Wt Normoxia (n=3), Wt hyperoxia (n=3), Akap1 KO (n=3) and Akap1 hyperoxia (n=3) mice. RNA-sequencing was carried out followed by differential expression of genes in the following groups. Wt Normoxia vs Wt Hyperoxia, Akap1 KO Normoxia versus Akap1 KO Hyperoxia, Wt Normoxia versus Akap1 KO Normoxia and Wt Hperoxia versus Akap1 Hyperoxia.