ABSTRACT
OBJECTIVES: Members of the glycoprotein 130 (gp130) receptor-gp130 ligand family play a role in angiogenesis in different tissues. We tested the effect of this cytokine family on the angiopoietin (Ang)-Tie system, which is involved in blood vessel maturation, stabilization, and regression. RESULTS: Oncostatin M (OSM) increased Ang2 expression in human umbilical vein endothelial cells via Janus kinase/signal transducer and activator of transcription (JAK/STAT) and mitogen-activated protein (MAP) kinase activation. Furthermore, OSM induced Ang2 expression in macrovascular endothelial cells isolated from the human aorta and in microvascular endothelial cells isolated from human heart. Our in vivo experiments revealed that mRNA expression of Ang2 in hearts of mice injected with OSM increased significantly, and levels of OSM mRNA significantly correlated with mRNA levels of Ang2 in human hearts. In addition, OSM increased the expression of its own receptors, gp130 and OSM receptor, in endothelial cells in vitro and in mice in vivo, and levels of OSM mRNA significantly correlated with mRNA levels of gp130 and OSM receptor in human hearts. CONCLUSION: Our data, showing the effects of OSM on the Ang-Tie system in endothelial cells, in hearts of mice, and in human heart tissue, provide yet another link between inflammation and angiogenesis.
Subject(s)
Angiopoietin-2/metabolism , Endothelial Cells/metabolism , Inflammation Mediators/metabolism , Oncostatin M/metabolism , Angiopoietin-2/genetics , Animals , Cells, Cultured , Coronary Vessels/immunology , Coronary Vessels/metabolism , Cytokine Receptor gp130/metabolism , Endothelial Cells/immunology , Humans , Inflammation Mediators/administration & dosage , Injections, Intraperitoneal , Janus Kinases/metabolism , Ligands , Male , Mice , Mice, Inbred C57BL , Mitogen-Activated Protein Kinases/metabolism , Oncostatin M/administration & dosage , Oncostatin M Receptor beta Subunit/metabolism , RNA, Messenger/metabolism , Recombinant Proteins/metabolism , STAT Transcription Factors/metabolism , Signal Transduction , Time Factors , Tissue Culture Techniques , Umbilical Veins/immunology , Umbilical Veins/metabolism , Up-RegulationABSTRACT
Stromal derived factor 1 (SDF-1) is a CXC chemokine important in the homing process of stem cells to injured tissue. It has been implicated in healing and tissue repair. Growing evidence suggests that the glycoprotein-130 (gp130) ligand family is involved in repair processes in the heart. The aim of our study was to determine whether gp130 ligands could affect SDF-1 expression in cardiac cells. Human adult cardiac myocytes (HACMs) and fibroblasts (HACFs) were treated with gp130 ligands. Protein and mRNA levels of SDF-1 were determined using ELISA and RT-PCR, respectively. mRNA levels of SDF-1 were determined in human and mouse heart samples by RT-PCR. HACMs and HACFs constitutively express SDF-1, which was significantly up-regulated by the gp130 ligand oncostatin M (OSM). This effect was counteracted by a p38 inhibitor and to a lesser extent by a PI3K inhibitor. mRNA expression of SDF-1 in hearts of mice injected with OSM increased significantly. Levels of OSM and SDF-1 mRNA correlated significantly in human failing hearts. Our data, showing that OSM induces SDF-1 protein secretion in human cardiac cells in vitro and murine hearts in vivo, suggest that OSM via the induction of SDF-1 might play a key role in repair and tissue regeneration.
Subject(s)
Chemokine CXCL12/metabolism , Inflammation/metabolism , Myocytes, Cardiac/drug effects , Myocytes, Cardiac/metabolism , Oncostatin M/metabolism , Adult , Animals , Cells, Cultured , Chemokine CCL1/genetics , Chemokine CCL1/metabolism , Chemokine CCL5/genetics , Chemokine CCL5/metabolism , Fibroblasts/drug effects , Fibroblasts/metabolism , Flavonoids/pharmacology , Humans , Ligands , Male , Mice , Mice, Inbred C57BL , Oncostatin M/administration & dosage , Oncostatin M/genetics , Time Factors , Up-RegulationABSTRACT
OBJECTIVES: It is believed that adipose tissue acts as an endocrine organ by producing inflammatory mediators and thereby contributes to the increased cardiovascular risk seen in obesity. A link between adipose tissue mass and angiogenesis has been suggested. Vascular endothelial growth factor (VEGF) seems to be implicated in this process. Members of the glycoprotein (gp)130 ligand family regulate VEGF expression in other cells. METHODS AND RESULTS: We used tissue explants as well as primary cultures of preadipocytes and adipocytes from human subcutaneous and visceral adipose tissue to investigate whether the gp130 ligands oncostatin M (OSM), interleukin-6 (IL-6), leukemia inhibitory factor (LIF), and cardiotrophin-1 (CT-1) regulate VEGF expression in human adipose tissue. Human subcutaneous and visceral adipose tissue responded to treatment with IL-6 and OSM with a significant increase in VEGF production. Human preadipocytes were isolated from subcutaneous and visceral adipose tissue. Adipocyte-differentiation was induced by hormone-supplementation. All cell types responded to IL-6 and OSM with a robust increase in VEGF protein production and a similar increase in VEGF-specific mRNA. Furthermore, IL-1beta synergistically enhanced the effect of OSM on VEGF production. AG-490, a JAK/STAT inhibitor, abolished the OSM-dependent VEGF induction almost completely. In mice, IL-6 and OSM increased serum levels of VEGF and VEGF mRNA and vessel density in adipose tissue. CONCLUSION: We speculate that the inflammatory cytokines IL-6 and OSM might support angiogenesis during adipose tissue growth by upregulating VEGF.
Subject(s)
Adipocytes/metabolism , Cytokine Receptor gp130/metabolism , Interleukin-6/pharmacology , Oncostatin M/pharmacology , Vascular Endothelial Growth Factors/drug effects , Adipocytes/drug effects , Animals , Antigens, CD34/metabolism , Cells, Cultured , Humans , In Vitro Techniques , Inflammation Mediators/metabolism , Mice , Models, Animal , RNA, Messenger/analysis , Sensitivity and Specificity , Up-Regulation , Vascular Endothelial Growth Factors/metabolismABSTRACT
The applicability of Pavlok's method characterising the nuclear status of early preimplantation bovine embryos by nuclear labelling pattern after a short pulse of [5-3H]uridine (revealing in situ detection of RNA transcription at the onset of the major embryonic transcription) was tested on experimentally irradiated 8- to 16-cell bovine embryos. After [5-3H]uridine labelling the semi-thin sections of these embryos were analysed by autoradiography for intranuclear distribution of newly synthesised RNA expected to be influenced by increasing doses of irradiation by gamma rays from a 60Co source. In control embryos, the labelling was homogeneously distributed in nucleoplasm and in nucleoli. The expected effects were clearly detected already in embryos irradiated with a dose of 2 Gy, in which low-level RNA synthesis was localised mostly at the periphery of the nucleus, the nuclear centre being without labelling. A detailed analysis of consecutive sections of embryos from all groups of irradiated and control embryos, using an arbitrary scale considering these effects, confirmed the detectability of the threshold level of genome impairment.
