Project description:Complete identification of the bone marrow niche remains one of the most progressing fields. Attempts to identify soluble factors involved in stem cell renewal have been less successful. We have previously shown that endothelial cells (EC) can induce the long-term proliferation of hematopoietic progenitor cells (HPC), especially when they had been subjected to an inflammatory stimulus like interleukins (IL) 1. To identify yet unknown growth factors, we compared the expression profile of IL-1 stimulated and non-stimulated endothelial cells.
Project description:Complete identification of the bone marrow niche remains one of the most progressing fields. Attempts to identify soluble factors involved in stem cell renewal have been less successful. We have previously shown that endothelial cells (EC) can induce the long-term proliferation of hematopoietic progenitor cells (HPC), especially when they had been subjected to an inflammatory stimulus like interleukins (IL) 1. To identify yet unknown growth factors, we compared the expression profile of IL-1 stimulated and non-stimulated endothelial cells. Human endothelial cells were subjected to IL-1 for 4, 8, and 16 hours. Isolated mRNA was analyzed by oligonucleotide microarray chips covering over 46,000 human genes.
Project description:Gene expression in brain lines was compared to non-brain cell lines to identify growth factors uniquely expressed in brain lines In this study, human endothelial cells isolated from brain and non-brain sources were cultured for 1 week & total RNA was isolated from the cells. RNA was amplified, labeled and hybridized to a spotted array containing oligos from the Operon human H034K chip set.
Project description:Active immunotherapy is a promising strategy for anti-angiogenic cancer therapy. Recently, we have reported that a vaccine using human umbilical vein endothelial cells (HUVECs) induced specific anti-endothelial immune responses in the most of immunized patients, and resulted in tumor regression in some patients with recurrent malignant brain tumors, whereas not in colorectal cancer patients. In this study, we hypothesized that non-hypoxic perivascular tumor associated macrophages (TAMs) in colorectal cancer, but not in glioblastoma, might negatively alter the therapeutic efficacy of anti-angiogenic active immunotherapy. To test this hypothesis, we examined global gene expression profiles of non-hypoxic macrophages stimulated in vitro by soluble factors released from tumor cells of human glioblastoma U-87MG (‘brain TAMs’) or colorectal adenocarcinoma HT-29 (‘colon TAMs’). Murine non-hypoxic TAMs were induced in vitro by incubation with soluble factors released from human cancer cell lines U-87MG ('brain TAMs') or HT-29 ('colon TAMs'), for RNA extraction and subsequent hybridization on Affymetrix microarrays. To evaluate homogeneous macrophage populations at different tumour developmental stages, RNA aliquots of control macrophages and TAMs obtained at five different time-points, i.e. 8h, 16h, 24h, 32h and 40h, were pooled and used for screening of differentially expressed genes. The experiments for TAMs as well as for control unstimulated macrophages were performed in triplicates.
Project description:Coronary artery disease (CAD) is a major cause of death worldwide, and more prevalent in men than in women. This study examines explored the differences in endothelium-dependent relaxation and associated transcriptomic signature in plaque-free internal thoracic arterial segments of age-matched men and women undergoing CABG procedure. Endothelium-dependent relaxations were better in female arteries compared to male. Using single nuclei mRNA sequencing, our analysis revealed the prevalence of senescence-associated inflammation in male but not female endothelial cells (EC), that also had longer telomeres than male EC. Furthermore, we found a large common transcriptomic signature in EC of men with severe endothelial dysfunction and in EC expressing CDKN1A (p21), a canonical marker of cellular senescence, validating the link between senescence, inflammation and endothelial dysfunction in men. In contrast, compared to male, female EC overexpressed pathways suggestive of a better stress resistance in association with the better endothelial function.
Project description:Endothelial cells (ECs) are constantly submitted in vivo to hemodynamical forces derived from the blood circulation, including shear stress (SS). EC are able to detect SS and consequently adapt their phenotype, thus affecting many endothelial functions. If a plethora of shear stress-regulated molecular networks have been described in peripheral EC, less is known about the molecular responses of microvascular brain ECs which constitute the blood-brain barrier (BBB). In this work, we investigated the response of human cerebral microvascular ECs to laminar physiological shear stress using the well characterized hCMEC/D3 cell line. Interestingly, we showed that hCMEC/D3 cells responded to shear stress by aligning perpendicularly to the flow direction, contrary to peripheral endothelial cells which aligned in the flow direction. Whole proteomic profiles were compared between hCMEC/D3 cells cultured either in static condition or under 5 or 10 dyn.cm-2 SS for three days. 3592 proteins were identified and expression levels were significantly affected for 3% of them upon both SS conditions. Pathway analyses were performed which revealed that most proteins overexpressed by SS refer to the antioxidant defense, probably mediated by activation of the NRF2 transcriptional factor. Regarding down-regulated proteins, most of them participate to the pro-inflammatory response, cell motility and proliferation. These findings confirm the induction of EC quiescence by laminar physiological SS and reveal a strong neuroprotective effect of SS on hCMEC/D3 cells, suggesting a similar effect on the BBB. Our results also showed that SS did not significantly increase expression levels nor did it affect the localization of junctional proteins or the functional activity of several ABC transporters (P-glycoprotein and MRPs). This work provides new insights on the response of microvascular brain EC to SS and on the importance of SS for optimizing in vitro BBB models.
Project description:MicroRNA microarrays and RNA expression arrays were used to identify functional signaling between neural stem cell progenitor cells (NSPC) and brain endothelial cells (EC) that are critical during embryonic development and tissue repair following brain injury. Mouse neural stem /progenitor cells (NSPC) and brain endothelial cells (EC) were co-cultured to identify changes in gene and miRNA profiles induced in ECs under the influence of NSPCs
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:Angiogenesis, a process mediating the expansion of vascular beds in many physiological and pathological settings, requires dynamic changes in endothelial cell (EC) behavior. The molecular mechanisms governing EC activity during different phases of vascular growth, remodeling, maturation, and quiescence remain elusive. Here, we have employed actively translating transcriptome analysis of mouse retinal ECs for the characterization of dynamic gene expression changes during postnatal development and the identification of critical angiogenic factors.