Project description:Tumor microenvironment contains various components including cancer cells, tumor vessels, and cancer associated fibroblasts (CAFs), comprising of tumor-promoting myofibroblasts and tumor-suppressing fibroblasts. Multiple lines of evidence indicated that transforming growth factor-β (TGF-β) induces the formation of myofibroblasts and other types of mesenchymal (non-myofibroblastic) cells from endothelial cells. Recent reports showed that fibroblast growth factor 2 (FGF2) modulates TGF-β-induced mesenchymal transition of endothelial cells, but the molecular mechanisms regarding the signals that control the transcriptional networks during the formation of different groups of fibroblasts remain largely unclear. Here, we studied the roles of FGF2 during the regulation of TGF-β-induced mesenchymal transition of tumor endothelial cells (TECs). We demonstrated that auto/paracrine FGF signals in TECs inhibit TGF-β-induced endothelial-to-myofibroblast transition (End-MyoT), leading to suppressed formation of contractile myofibroblast cells, but on the other hand can also collaborate with TGF-β in promoting the formation of active fibroblastic cells which have migratory and proliferative properties. FGF2 modulated TGF-β-induced formation of myofibroblastic and non-myofibroblastic cells from TECs via transcriptional regulation of the array of various mesenchymal markers and growth factors. Furthermore, we observed that TECs treated with TGF-β were more competent in promoting in vivo tumor growth than TECs treated with TGF-β and FGF2. Mechanistically, we showed that Elk1 mediated this FGF2-induced inhibition of End-MyoT via inhibition of TGF-β-induced transcriptional activation of α-SMA promoter by myocardin-related transcription factor (MRTF)-A. Our data suggest that TGF-β and FGF2 oppose and cooperate with each other during the formation of myofibroblastic and non-myofibroblastic cells from TECs to determine the characteristics of the mesenchymal cells in tumor microenvironment. Identification of marker genes for TGF-β-induced endothelial-to-myofibroblast transition
Project description:Endothelial-mesenchymal transition (EndMT) is a complex process, in which differentiated endothelial cells undergo phenotypic transition to mesenchymal cells. Given the diversity of the vascular system in architecture, structure, and embryonic origins, it is not clear if endothelial cells lining different vessels are able to undergo EndMT. Therefore, the aim of this study was to evaluate the molecular and functional changes that occur in different types of endothelial cells after induction of EndMT through overexpression of Snail and TGF-β2. Different types of endothelial cells (human umbilical vein, heart, and lung) have distinct response when induced to undergo EndMT. Coronary artery endothelial cells (HCAEC) induced with combined Snail overexpression plus TGF-β2 treatment promotes a decrease of endothelial markers, an increase of mesenchymal markers and migration. The mechanism that HCAEC undergoing EndMT may be mediated through Notch and non-canonical Wnt signaling pathways. These results provide the foundation for understanding the roles of specific signaling pathways in mediating EndMT in endothelial cells from different anatomical origin.
Project description:Endothelial to mesenchymal transition (EndoMT) plays a key role in heart development, but is also implicated in cardiovascular diseases in postnatal life. While the roles of TGF-β as inducer of EndoMT on the transcriptional level are well characterised, its post-transcriptional regulatory mechanisms remain largely unknown. Here, we identified global changes in the endothelial mRNA bound proteome upon TGF-β stimulation using RNA interactome capture. Characterisation of TGF-β regulated RNA binding proteins (RBPs) revealed heterogeneous nuclear ribonucleoprotein H1 (hnRNP H1) and Cold Shock Domain Containing E1 (Csde1) as key regulators of endothelial function and EndoMT. We profiled TGF-β driven changes in the RNA binding patterns of hnRNP H1 and Csde1 and found that they dynamically bind and regulate specific subsets of functionally connected RNAs related to mesenchymal activation upon TGF-β stimulation. Together, we show that RBPs play a key role in EndoMT and that the RBPs hnRNP H1 and Csde1 maintain endothelial cell function and counteract mesenchymal activation.
Project description:Endothelial to mesenchymal transition (EndoMT) plays a key role in heart development, but is also implicated in cardiovascular diseases in postnatal life. While the roles of TGF-β as inducer of EndoMT on the transcriptional level are well characterised, its post-transcriptional regulatory mechanisms remain largely unknown. Here, we identified global changes in the endothelial mRNA bound proteome upon TGF-β stimulation using RNA interactome capture. Characterisation of TGF-β regulated RNA binding proteins (RBPs) revealed heterogeneous nuclear ribonucleoprotein H1 (hnRNP H1) and Cold Shock Domain Containing E1 (Csde1) as key regulators of endothelial function and EndoMT. We profiled TGF-β driven changes in the RNA binding patterns of hnRNP H1 and Csde1 and found that they dynamically bind and regulate specific subsets of functionally connected RNAs related to mesenchymal activation upon TGF-β stimulation. Together, we show that RBPs play a key role in EndoMT and that the RBPs hnRNP H1 and Csde1 maintain endothelial cell function and counteract mesenchymal activation.
Project description:Analysis of primary bovine aortic endothelial cells treated for 24 hours with TGF-beta 1 5 ng/ml. TGF-beta 1 has been shown to induce endothelial-to-mesenchymal transition (EndoMT) and to be implicated in differentiation of endothelial cells into smooth muscle-like cells as occurred in vascular neointimal formation. Primary aortic endothelial cells seeded on 10 mm diameter plates were incubated with TGF-beta 1 (5 ng/ml) for 24 hours or left under basal conditions. Triplicates from three different cultures.
Project description:Glioma-associated oncogene homolog-1 (Gli1)-positive resident mesenchymal stem cell-like cells are the predominant source of kidney myofibroblasts in fibrosis, but investigating Gli1-positive myofibroblast progenitor activation is hampered by the difficulty of isolating and propagating primary cultures of these cells. Using a genetic strategy with positive and negative selection, we isolated Kidney-Gli1 (KGli1) cells that maintain expression of appropriate mesenchymal stem cell-like cell markers, respond to hedgehog pathway activation, and display robust myofibroblast differentiation upon treatment with transforming growth factor-β (TGF-β). Coculture of KGli1 cells with endothelium stabilizes capillary formation. Single-cell RNA sequencing (scRNA-seq) analysis during differentiation identified autocrine ligand-receptor pair upregulation and a strong focal adhesion pathway signal. This led us to test the serum response factor inhibitor CCG-203971 that potently inhibited TGF-β-induced pericyte-to-myofibroblast transition. scRNA-seq also identified the unexpected upregulation of nerve growth factor (NGF), which we confirmed in two mouse kidney fibrosis models. The Ngf receptor Ntrk1 is expressed in tubular epithelium in vivo, suggesting a novel interstitial-to-tubule paracrine signaling axis. Thus, KGli1 cells accurately model myofibroblast activation in vitro, and the development of this cell line provides a new tool to study resident mesenchymal stem cell-like progenitors in health and disease.
Project description:Analysis of primary bovine aortic endothelial cells treated for 24 hours with TGF-beta 1 5 ng/ml. TGF-beta 1 has been shown to induce endothelial-to-mesenchymal transition (EndoMT) and to be implicated in differentiation of endothelial cells into smooth muscle-like cells as occurred in vascular neointimal formation.