Project description:Evaluation of microRNAs that are downstream of apelin/APJ signaling in the pulmonary artery endothelial cells. Triplicates per group, subjected to: 1) control siRNA, 2) apelin siRNA, 3) APJ siRNA, 4) apelin + APJ siRNA
Project description:We have identified the apelin-APJ axis as a mechanism of protection mediated by AHR signalling in lund=g endothelial cells. This RNAseq experiment will compare the effects of apelin receptor blockade on endothelial and epithelial responses in the lung during influenza infection.
Project description:Evaluation of gene transcripts that are downstream of apelin/APJ signaling in HUVECs Duplicates per group, subjected to: 1) control siRNA, 2) MEF2A and MEF2C siRNA, 3) G alpha 13 siRNA, and 4) apelin and APJ siRNA
Project description:Molecular pathways regulating the development of arterial and venous endothelial cells (ECs) are now well-established, but control of parallel arterial-venous (A-V) alignment is unclear. We report that arterial-venous alignment in the skin is determined by apelin receptor (APJ) expression in venous ECs. We used microarrays to detail the global programme of gene expression in endothelial cells that has relationship with the deficient of APJ. Endothelial cells were marked and isolated by Fluorescence-activated cell sorting in Trizol.
Project description:Brain arteriovenous malformations (bAVM) are characterized by enlarged blood vessels, which direct blood through arteriovenous AV shunts, bypassing the artery-capillary-vein network and disrupting blood flow. Clinically, bAVM treatments are invasive and not routinely applicable. There is critical need to understand mechanisms of bAVM pathologies and develop pharmacological therapies. We used an in vivo mouse model of Rbpj-mediated bAVM, which develops pathologies in the early postnatal period and an siRNA in vitro system to knockdown RBPJ in human brain microvascular endothelial cells (ECs). To understand molecular events regulated by endothelial Rbpj, we conducted RNA-Seq and ChIP-Seq analyses from isolated brain ECs. Rbpj-deficient (mutant) brain ECs acquired abnormally rounded shape (with no change to cell area), altered basement membrane dynamics, and increased EC density along AV shunts, compared to controls, suggesting impaired remodeling of neonatal brain vasculature. Consistent with impaired EC dynamics, we found increased Cdc42 activity in isolated mutant ECs, suggesting that Rbpj regulates small GTPase-mediated cellular functions in brain ECs. siRNA treated, RBPJ-deficient human brain ECs displayed increased Cdc42 activity, disrupted cell polarity and focal adhesion properties, and impaired migration in vitro. RNA-Seq analysis from isolated brain ECs identified differentially expressed genes in mutants, including Apelin, which encodes a ligand for G protein-coupled receptor signaling known to influence small GTPase activity. ChIP-Seq analysis revealed chromatin loci occupied by Rbpj in brain ECs that corresponded to G-protein and Apelin signaling molecules. In vivo administration of a competitive peptide antagonist against the Apelin receptor (Aplnr/Apj) attenuated Cdc42 activity and restored EC morphology and AV connection diameter in Rbpj-mutant brain vessels. Conclusions: Our data suggest that endothelial Rbpj promotes rearrangement of brain ECs during cerebrovascular remodeling, through Apelin/Apj-mediated small GTPase activity, and prevents bAVM. By inhibiting Apelin/Apj signaling in vivo, we demonstrated pharmacological prevention of Rbpj mediated bAVM.
