Project description:Formation and maturation of a functional blood vascular system is required for the development and maintenance of all tissues in the body. During the process of blood vessel development, primordial endothelial cells are formed and become specified toward arterial or venous fates to generate a circulatory network that provides nutrients and oxygen to, and removes metabolic waste from, all tissues. Specification of arterial and venous endothelial cells occurs in conjunction with suppression of endothelial cell cycle progression, and endothelial cell hyperproliferation is associated with potentially lethal arterial-venous malformations. However, the mechanistic role that cell cycle state plays in arterial-venous specification is unknown. Herein, studying vascular development in Cdh5-CreERT2;R26FUCCI2aR reporter mice, we find that venous and arterial endothelial cells exhibit a propensity for different cell cycle states during development and in adulthood. That is, venous endothelial cells are predominantly FUCCI-Negative, while arterial endothelial cells are enriched for the FUCCI-Red reporter. Single cell RNA sequencing analysis of developing retinal endothelial cells reveals that venous endothelial cells are enriched for the FUCCI-Negative state and BMP signaling, while arterial endothelial cells are enriched for the FUCCI-Red state and TGF-b signaling. Further transcriptional analyses and live imaging of cultured endothelial cells expressing the FUCCI reporter show that reporter-negative corresponds to an early G1 state and reporter-red corresponds to late G1 state. We find the early G1 state is essential for BMP4-induced venous gene expression, whereas late G1 state is essential for TGF-b1-induced arterial gene expression. In a mouse model of endothelial cell hyperproliferation and disrupted arterial-venous specification, pharmacological inhibition of endothelial cell cycle prevents the vascular defects. Collectively, our results show that endothelial cell cycle control plays a key role in arterial-venous network formation, and distinct cell cycle states provide distinct windows of opportunity for the molecular induction of arterial vs. venous specification.
Project description:Formation and maturation of a functional blood vascular system is required for the development and maintenance of all tissues in the body. During the process of blood vessel development, primordial endothelial cells are formed and become specified toward arterial or venous fates to generate a circulatory network that provides nutrients and oxygen to, and removes metabolic waste from, all tissues. Specification of arterial and venous endothelial cells occurs in conjunction with suppression of endothelial cell cycle progression, and endothelial cell hyperproliferation is associated with potentially lethal arterial-venous malformations. However, the mechanistic role that cell cycle state plays in arterial-venous specification is unknown. Herein, studying vascular development in Cdh5-CreERT2;R26FUCCI2aR reporter mice, we find that venous and arterial endothelial cells exhibit a propensity for different cell cycle states during development and in adulthood. That is, venous endothelial cells are predominantly FUCCI-Negative, while arterial endothelial cells are enriched for the FUCCI-Red reporter. Single cell RNA sequencing analysis of developing retinal endothelial cells reveals that venous endothelial cells are enriched for the FUCCI-Negative state and BMP signaling, while arterial endothelial cells are enriched for the FUCCI-Red state and TGF-b signaling. Further transcriptional analyses and live imaging of cultured endothelial cells expressing the FUCCI reporter show that reporter-negative corresponds to an early G1 state and reporter-red corresponds to late G1 state. We find the early G1 state is essential for BMP4-induced venous gene expression, whereas late G1 state is essential for TGF-b1-induced arterial gene expression. In a mouse model of endothelial cell hyperproliferation and disrupted arterial-venous specification, pharmacological inhibition of endothelial cell cycle prevents the vascular defects. Collectively, our results show that endothelial cell cycle control plays a key role in arterial-venous network formation, and distinct cell cycle states provide distinct windows of opportunity for the molecular induction of arterial vs. venous specification.
Project description:Circulating microRNAs (miRNAs) presented in venous plasma have recently been demonstrated as powerful biomarkers for the diagnosis and prognostic prediction of complex diseases like cancer. Nevertheless, those presented in arterial plasma have been ignored based on the assumption that the miRNA profiles in arterial and venous plasma would be identical. Here, we disputed this intuitive assumption by comparing arterial and venous plasma miRNA expression profiles from male rats using microarray technique. Though the microRNA profiles were largely similar, a considerable number of miRNAs showed significant differential expression, including 10 arterial highly expressed miRNAs and 14 venous highly expressed miRNAs. The differentially expressed miRNAs were validated by qRT-PCR. We performed computational analysis of the function enrichment and disease association of these miRNAs and their targets. Our analysis also suggested significant correlations between plasma miRNA expression and tissue miRNA expression. Four arterial highly expressed miRNAs showed enriched expression in specific tissues and thus could serve as novel biomarker candidates.
Project description:The vascular tree has considerable diversity, with discrete regions having different physiologic characteristics and permeability. Of note are venules that are significantly more sensitive to pro-inflammatory cytokines than arterioles. We used microarrays to identify molecular signatures that distinguish primary human venous endothelial cells from arterial endothelial cells. We used microarrays to identify genes differentially expressed by venous vs arterial human endothelial cells.
Project description:The cellular evolutions and molecular programs underlying the arteriovenous fate settling of embryonic vascular endothelial cells (ECs) are critical for understanding arteriogenesis and inspiring new approaches for regenerative biology. Using different strategies of single-cell RNA sequencing, we constructed the transcriptional landscape of early arteriovenous EC development in both mouse and human embryos, demonstrating the evolutionary conservation of principal vascular EC types and providing a series of conserved arteriovenous genes. We showed an unexpected diversity of arteriovenous characteristics in morphologically alike vascular plexus and further uncovered two transcriptomically distinct arterial EC types, whereas most of heterologous ligand-receptor pairs were shared by different arterial vasculatures. By computational predicting and further genetic lineage tracing, we revealed the widespread venous arterialization in the mid-gestational mouse embryo proper. Interestingly, we demonstrated at transcriptomic level that Notch1 was dispensable for venous arterialization but required subsequently for the arterial feature strengthening in the arterial plexus ECs. Altogether, our findings unprecedentedly detail the comprehensive single-cell mapping of early embryonic vascular ECs in vivo, decipher an asymmetric arteriovenous characteristics different than that in adults, and reveal an extensive venous-to-arterial fate conversion in the vascular plexus.
Project description:Distinct endothelial cell cycle states (early G1 vs. late G1) provide different “windows of opportunity” to enable the differential expression of genes that regulate venous and arterial specification, respectively. Endothelial cell cycle control and arterial-venous identities are disrupted in vascular malformations including arteriovenous (AV) shunts which is a hallmark of hereditary hemorrhagic telangiectasia (HHT). We show how endothelial cell late G1 arrest induced by Palbociclib modulates the expression of genes regulating arterio-venous identity and prevents AVM development induced by BMP9/10 inhibition.
Project description:HUVEC-FUCCI cells were used to demonstrate that different endothelial cell cycle states provide distict windows of opportunity for gene expression in response to extrinsic signals. HUVEC-FUCCI were FACS-isolated into three different cell cycle states. Peptide digests from the resulting lysates showed differentially expressed proteins among the three cell cycles. These studies show that endothelial cell cycle state determines the propensity for arterial vs. venous fate specification.
Project description:During embryonic vascular development, endothelial cells that line all blood vessels undergo specification into arterial, capillary, and venous subtypes to form a circulatory network. Regulation of endothelial cell cycle state has been shown to play a critical role in enabling arterial-venous specification and remodeling in a postnatal, blood flow-mediated, and tissue specific manner; however, if a similar cell cycle-mediated mechanism is a common mechanism that regulates embryonic vascular development, even prior to blood flow, is unknown. To investigate this, we first defined the emergence of distinct subtypes by isolating endothelial cells from wild type embryos at embryonic day (E)8.0, prior to blood flow; E8.5, just after flow begins; and E9.5. We performed single cell RNA sequencing and analyses, and found increased specification of arterial, venous and hemogenic subtypes over time, concomitant with decreased primordial and capillary endothelial cells. Gene Ontology analysis revealed that cell cycle control was significantly enriched over time, and we found arterial identity highly correlated with growth arrest. To gain more insight into the potential role of cell cycle control in specification, we isolated similar endothelial cells from Fucci-expressing embryos, sorted them into distinct cell cycle states (early G1, late G1 and S/G2/M), performed bulk RNA sequencing, and bioinformatically correlated endothelial cell cycle states with subtype identities. We found venous endothelial cells are highly enriched in early G1 and arterial endothelial cells highly enriched in late G1, which was corroborated with fluorescent imaging of Fucci embryos. Furthermore, we showed that endothelial cell hyperproliferation, induced by deletion of cell cycle inhibitor Cdkn1b (p27), impaired arterial-venous specification and vascular development. These results support that at the earliest stage of vascular development, endothelial cells in arterial and venous vessels reside in different cell cycle states and endothelial cell cycle control is required for their specification.
Project description:Background: miRNAs derived from peripheral venous blood gained extensive attention as clinical biomarkers, while arterial miRNAs exhibited slightly different expression profiles. We compared the expression profiles of venous- and arterial-derived plasma miRNA between young and aged male SD rats by next-generation sequencing, in order to explore whether peripheral venous miRNAs can represent entire circulating vessels in abnormal conditions like aging. Results: MSigDB Hallmark Gene Set reference and TAM 2.0 server were used to investigate the enriched functions and associated diseases. The aging-related de-regulated miRNAs in artery and vein shown similar enriched functional terms. Of note, refer to the arterial-versus-venous differential-expressed miRNA profiles, only a few miRNAs shared between young and aged rats. Among them, miR-450a/b and miR-223 shown the similar tendency between young and aged rat, while miR-136 and miR-503 etc displayed the opposite direction under the same scenario. Since miRNAs are under the control of their specific transcriptional factors, we further analyzed upstream regulators which influence miRNAs level for vascular vessel location. TransmiR v2.0 tool was used and found enriched upstream transcription factors like NFκB and SIRT1. These transcriptional factors could be organ-specific expression and/or regulated in physiological and aging states as parts of plausible causal factors. Conclusion: This study screened and analyzed the differential differential-expressed miRNA profiles in arterial and venous plasma under aging conditions, suggesting the importance of origin of candidate circulating miRNA biomarkers upon the certain scenario and its potential regulatory rule.
Project description:During embryonic vascular development, endothelial cells that line all blood vessels undergo specification into arterial, capillary, and venous subtypes to form a circulatory network. Regulation of endothelial cell cycle state has been shown to play a critical role in enabling arterial-venous specification and remodeling in a postnatal, blood flow-mediated, and tissue specific manner; however, if a similar cell cycle-mediated mechanism is a common mechanism that regulates embryonic vascular development, even prior to blood flow, is unknown. To investigate this, we first defined the emergence of distinct subtypes by isolating endothelial cells from wild type embryos at embryonic day (E)8.0, prior to blood flow; E8.5, just after flow begins; and E9.5. We performed single cell RNA sequencing and analyses, and found increased specification of arterial, venous and hemogenic subtypes over time, concomitant with decreased primordial and capillary endothelial cells. Gene Ontology analysis revealed that cell cycle control was significantly enriched over time, and we found arterial identity highly correlated with growth arrest. To gain more insight into the potential role of cell cycle control in specification, we isolated similar endothelial cells from Fucci-expressing embryos, sorted them into distinct cell cycle states (early G1, late G1 and S/G2/M), performed bulk RNA sequencing, and bioinformatically correlated endothelial cell cycle states with subtype identities. We found venous endothelial cells are highly enriched in early G1 and arterial endothelial cells highly enriched in late G1, which was corroborated with fluorescent imaging of Fucci embryos. Furthermore, we showed that endothelial cell hyperproliferation, induced by deletion of cell cycle inhibitor Cdkn1b (p27), impaired arterial-venous specification and vascular development. These results support that at the earliest stage of vascular development, endothelial cells in arterial and venous vessels reside in different cell cycle states and endothelial cell cycle control is required for their specification.