Project description:Our earlier study showed that hearing loss in Nhe6 KO animals was due to cochlear damage and that NHE6 is important for normal hearing function. These results were based on the data extracted from experiments involving hearing/sensory structures in organ of Corti. Considering the importance of blood-labyrinth barrier (BLB) in transport of substances between the blood and intrastrial space, and the fact that the physiology and overall properties of the BLB are not completely elucidated so far, we have isolated and subcultured endothelial cells from mouse BLB and by RNAseq we want to compare overall gene expression between Nhe6 KO and WT mice in order to discover further differences between the two phenotypes.
Project description:Adrenomedullin (AM) is a vasodilating peptide involved in the regulation of circulatory homeostasis and in the pathophysiology of certain cardiovascular diseases. AM plays critical roles in blood vessels, including regulation of vascular stability and permeability. To elucidate the autocrine / paracrine function of AM in endothelial cells in vivo. A conditional knockout of AM in endothelial cells (AM EC-KO) was used. The amount of vascularization the matrigel implants was lower in AM EC-KO mice indicating a defective angiogenesis. Moreover, ablation of AM in endothelial cells revealed increased vascular permeability in comparison with wildtype littermates. In addition, AM EC-KO lungs exhibited significantly less tumor growth than littermate WT mice using a syngeneic model of metastasis. Furthermore, following middle cerebral artery permanent occlusion, there was a significant infarct size decrease in animals lacking endothelial AM when compared to their wild type counterparts. AM is an important regulator of EC function, angiogenesis, tumorigenesis and brain response to ischemia. Studies of AM should bring novel approaches to the treatment of vascular diseases. Lung endothelial mRNA profiles of wild type (WT) and adrenomedullin endothelial cell conditional knockout (AM EC-KO) mice were generated by deep sequencing using Illumina GAIIx.
Project description:Vascular permeability is frequently associated with inflammation and it is triggered by chemokines and by a cohort of secreted permeability factors, such as VEGF. In contrast, here we showed that the physiological vascular permeability that precedes implantation is directly controlled by progesterone receptor (PR) and it is independent of VEGF. Both global and endothelial-specific deletion of PR block physiological vascular permeability in the uterus while misexpression of PR in the endothelium of other organs results in ectopic vascular leakage. Integration of genome-wide transcriptional profile of endothelium and ChIP-sequencing revealed that PR induces a NR4A1 (Nur77/TR3) specific transcriptional program that broadly regulates vascular permeability in response to progesterone. This program triggers concurrent suppression of several junctional proteins and leads to an effective, timely and venule-specific regulation of vascular barrier function. Silencing NR4A1 blocks PR-mediated permeability responses indicating a direct link between PR and NR4A1. These results reveal a previously unknown function for progesterone receptor on endothelial cell biology with consequences to physiological vascular permeability and implications to the clinical use of progestins and anti-progestins on blood vessel integrity. Examination of PR target genes in human umbilical vein endothelial cells (HUVECs) using RNA-seq (PR infected only -PR only and PR infected followed by ligand treatment-PR+P)
Project description:Adrenomedullin (AM) is a vasodilating peptide involved in the regulation of circulatory homeostasis and in the pathophysiology of certain cardiovascular diseases. AM plays critical roles in blood vessels, including regulation of vascular stability and permeability. To elucidate the autocrine / paracrine function of AM in endothelial cells in vivo. A conditional knockout of AM in endothelial cells (AM EC-KO) was used. The amount of vascularization the matrigel implants was lower in AM EC-KO mice indicating a defective angiogenesis. Moreover, ablation of AM in endothelial cells revealed increased vascular permeability in comparison with wildtype littermates. In addition, AM EC-KO lungs exhibited significantly less tumor growth than littermate WT mice using a syngeneic model of metastasis. Furthermore, following middle cerebral artery permanent occlusion, there was a significant infarct size decrease in animals lacking endothelial AM when compared to their wild type counterparts. AM is an important regulator of EC function, angiogenesis, tumorigenesis and brain response to ischemia. Studies of AM should bring novel approaches to the treatment of vascular diseases.
Project description:Vascular permeability is frequently associated with inflammation and it is triggered by chemokines and by a cohort of secreted permeability factors, such as VEGF. In contrast, here we showed that the physiological vascular permeability that precedes implantation is directly controlled by progesterone receptor (PR) and it is independent of VEGF. Both global and endothelial-specific deletion of PR block physiological vascular permeability in the uterus while misexpression of PR in the endothelium of other organs results in ectopic vascular leakage. Integration of genome-wide transcriptional profile of endothelium and ChIP-sequencing revealed that PR induces a NR4A1 (Nur77/TR3) specific transcriptional program that broadly regulates vascular permeability in response to progesterone. This program triggers concurrent suppression of several junctional proteins and leads to an effective, timely and venule-specific regulation of vascular barrier function. Silencing NR4A1 blocks PR-mediated permeability responses indicating a direct link between PR and NR4A1. These results reveal a previously unknown function for progesterone receptor on endothelial cell biology with consequences to physiological vascular permeability and implications to the clinical use of progestins and anti-progestins on blood vessel integrity. Examination of PR binding sites in HUVEC cells using ChIP-seq (non-infected-negative control, PR infected followed by ligand treatment-PR+P or vehicle PR)
Project description:Vascular permeability is frequently associated with inflammation and it is triggered by chemokines and by a cohort of secreted permeability factors, such as VEGF. In contrast, here we showed that the physiological vascular permeability that precedes implantation is directly controlled by progesterone receptor (PR) and it is independent of VEGF. Both global and endothelial-specific deletion of PR block physiological vascular permeability in the uterus while misexpression of PR in the endothelium of other organs results in ectopic vascular leakage. Integration of genome-wide transcriptional profile of endothelium and ChIP-sequencing revealed that PR induces a NR4A1 (Nur77/TR3) specific transcriptional program that broadly regulates vascular permeability in response to progesterone. This program triggers concurrent suppression of several junctional proteins and leads to an effective, timely and venule-specific regulation of vascular barrier function. Silencing NR4A1 blocks PR-mediated permeability responses indicating a direct link between PR and NR4A1. These results reveal a previously unknown function for progesterone receptor on endothelial cell biology with consequences to physiological vascular permeability and implications to the clinical use of progestins and anti-progestins on blood vessel integrity.
Project description:Vascular permeability is frequently associated with inflammation and it is triggered by chemokines and by a cohort of secreted permeability factors, such as VEGF. In contrast, here we showed that the physiological vascular permeability that precedes implantation is directly controlled by progesterone receptor (PR) and it is independent of VEGF. Both global and endothelial-specific deletion of PR block physiological vascular permeability in the uterus while misexpression of PR in the endothelium of other organs results in ectopic vascular leakage. Integration of genome-wide transcriptional profile of endothelium and ChIP-sequencing revealed that PR induces a NR4A1 (Nur77/TR3) specific transcriptional program that broadly regulates vascular permeability in response to progesterone. This program triggers concurrent suppression of several junctional proteins and leads to an effective, timely and venule-specific regulation of vascular barrier function. Silencing NR4A1 blocks PR-mediated permeability responses indicating a direct link between PR and NR4A1. These results reveal a previously unknown function for progesterone receptor on endothelial cell biology with consequences to physiological vascular permeability and implications to the clinical use of progestins and anti-progestins on blood vessel integrity.
Project description:Tumor necrosis factor alpha induces vascular permeability, playing an important role in inflammation. Also, TNF-induced vascular leakage is involved in the increased extravasation of nanoparticle formulated chemotherapeutics improving drug delivery and subsequently tumor response, and we found a positive correlation between the presence of pericytes in the tumor-associated vasculature and TNF-induced leakage. RNA sequencing and pathway analysis of TNF-stimulated versus non-stimulated pericytes and endothelial cells show significant upregulation of several pathways involving interferon regulating pathways with a high expression of CXCL10, also known as Interferon gamma-inducible protein 10 (IP-10) in TNF-stimulated pericytes. In addition, CXCL10 protein production was significantly increased in conditioned medium from TNF-exposed pericytes compared to the other conditions. In our animal studies, we observed that tumor types with high pericyte covered vessels show enhanced permeability when exposed to TNF, which can be blocked with a neutralizing CXCL10 antibody. Vice versa, tumors with vessels low in pericyte number do not respond to TNF, i.e., do not express elevated permeability. Importantly, this lack of pericyte coverage can be compensated by co-administration of CXCL10. Our finding reveals a mechanism where TNF induces CXCL10 release from pericytes, being at the basis of increased permeability and thus vascular leakage.
Project description:Blood-brain barrier (BBB) dysfunction is emerging as a key pathogenic factor in the progression of Alzheimer’s disease (AD), where increased microvascular endothelial permeability has been proposed to play an important role. However, the molecular mechanisms leading to increased brain microvascular permeability in AD are not fully understood. We observed that brain endothelial permeability in the APPswe/PS1DE9 (APP/PS1) transgenic mouse model of amyloid-beta (Ab) amyloidosis increases with aging in the areas with the greatest amyloid plaque deposition. We performed an unbiased bulk RNA-sequencing analysis of brain endothelial cells (BECs) in APP/PS1 transgenic mice. We observed that upregulation of interferon signaling gene expression pathways in BECs were among the most prominent transcriptomic signatures in the brain endothelium of APP/PS1 mice. Immunofluorescence analysis of isolated BECs from APP/PS1 mice demonstrated higher levels of the Type I interferon-stimulated gene IFIT2. Immunoblotting of APP/PS1 BECs showed downregulation of the adherens junction protein VE-cadherin. Stimulation of human brain endothelial cells with interferon-β decreased the levels of the adherens junction protein VE-cadherin as well as tight junction proteins Occludin and Claudin-5 and increased barrier leakiness. Depletion of the Type I interferon receptor in human brain endothelial cells prevented interferon-β-induced VE- cadherin downregulation and restored endothelial barrier integrity. Our study suggests that Type I interferon signaling contributes to brain endothelial dysfunction in AD.
Project description:Human induced pluripotent stem cells (hiPSCs) are used to study organogenesis and model disease as well as being developed for regenerative medicine. Endothelial cells are among the many cell types differentiated from hiPSC, but their maturation and stabilization fall short of that in adult endothelium. We examined whether shear stress alone or in combination with pericyte co-culture would induce flow alignment and maturation of hiPSC-derived endothelial cells (hiPSC-ECs) but found no effects comparable to those in primary microvascular EC. In addition, hiPSC-ECs lacked a luminal glycocalyx, critical for vasculature homeostasis, shear stress sensing and signalling. We noted however, that hiPSC-EC have dysfunctional mitochondrial permeability transition pores, resulting in reduced mitochondrial function and increased reactive oxygen species (ROS). Closure of these pores by cyclosporine-A improved EC mitochondrial function but also restored the glycocalyx such that alignment to flow took place. These indicated that mitochondrial maturation is required for proper hiPSC-EC functionality.