Project description:Mesenchymal stem cells (MSCs) can differentiate into endothelial cells; however, the mechanisms underlying this process in the tumor microenvironment (TME) remain elusive. This study shows that tumor necrosis factor alpha (TNF-α), a key cytokine present in the TME, promotes the endothelial differentiation of MSCs by inducing vascular endothelial growth factor receptor 2 (VEGFR2) gene expression. EGR1 is a member of the zinc-finger transcription factor family induced by TNF-α. Our findings indicate that EGR1 directly binds to the VEGFR2 promoter and transactivates VEGFR2 expression. We also demonstrate that EGR1 forms a complex with c-JUN activated by c-JUN N-terminal kinase (JNK) to promote VEGFR2 transcription and endothelial differentiation in MSCs in response to TNF-α stimulation. The shRNA-mediated silencing of EGR1 or c-JUN abrogates TNF-α-induced VEGFR2 transcription and the endothelial differentiation of MSCs. Collectively, these findings demonstrate that the JNK-EGR1 signaling axis plays a crucial role in the TNF-α-induced endothelial differentiation of MSCs in the TME, which could be a potential therapeutic target for solid tumors vasculatures.
Project description:Endothelial-mesenchymal-transition (EndMT) is an important source of cancer-associated fibroblasts (CAFs), which are known to facilitate tumor progression. We have previously shown that EndMT is present in pancreatic tumors and that deficiency of the Tie1 receptor induces EndMT in human endothelial cells. Pancreatic tumors are characterized by the presence of tumor necrosis factor-α (TNF-α). We now show that TNF-α strongly induces human endothelial cells to undergo EndMT. In order to know the secretory feature of cells which undergo EndMT by TNF-α, we conducted a comparative analysis of HMVEC secretome treated or not for 24h and 48h with TNF-α. Secretome study shows that cells treated with TNF-α have an important fibroblast-like secretory capacity, and a proinflamatory signature. Moreover, Ingenuity Pathway Analysis (IPA) shows that pathways implicated in migration, inflammation and fibrosis are predicted to be activated and that necrosis and apoptosis pathways are inhibited. Accordingly cell survival, viability and cycle progression are activated. We show that TNF-α- treated cells secrete proteins related to 16 protumoral pathways, confirming their fibroblastic characteristic. Finally, among the predicted upstream regulators activated, IPA analysis shows that, TNFSF12 and its receptor are present at hight levels in PDAC patients. Altogether these results show the fibroblastic characteristic of treated cells and demonstrate that TNF-α induces CAFs.
Project description:The pathobiology of pulmonary hypertension (PH) is complex and multiple cell types (endothelial, smooth muscle, fibroblast, pericyte) contribute to disease pathogenesis. However, the specific molecular crosstalk between endothelial and mesenchymal cells to promote PH is poorly characterized. We previously demonstrated that tumor necrosis factor alpha transgenic (TNF-Tg) mice have a severe PH phenotype.
Project description:TNF-alpha has a number of pro-atherogenic effects in macrovascular endothelial cells, including induction of leukocyte adhesion molecules and chemokines. We investigated the role of acyl-CoA synthetase 3 (ACSL3) in the response of cultured human macrovascular endothelial cells to TNF-alpha. TNF-alpha induced ACSL3 both in human umbilical vein endothelial cells (HUVECs) and in human coronary artery endothelial cells (HCAECs). RNA sequencing demonstrated that knockdown of ACSL3 had no marked effects on the TNF-alpha transcriptome in HCAECs. Instead, ACSL3 was required for TNF-alpha-induced lipid droplet formation from fatty acids.
Project description:Effect of TNF-alpha on microRNAs levels in Human Umbilical Endothelial Cells (HUVECs). HUVEC that were treated or not for 2 or 24 hours with TNF (10 ng/ml). Duplicate samples (1 or 2) of two different isolations of HUVEC (A or B)
Project description:Endothelial inflammation contributes to the pathogenesis of numerous human diseases; however, the role of tumor endothelial inflammation in the growth of experimental tumors and its influence on the prognosis of human cancers is less understood. TNF-α, an important mediator of tumor stromal inflammation, is known to target the tumor vasculature. In this study, we demonstrate that B16-F1 melanomas grew more rapidly in C57BL/6 wild-type (WT) mice than in syngeneic mice with germline deletions of both TNF-α receptors (KO). This enhanced tumor growth was associated with increased COX2 inflammatory expression in WT tumor endothelium compared to endothelium in KO mice. We purified endothelial cells from WT and KO tumors and characterized dysregulated gene expression, which ultimately formed the basis of a 6-gene Inflammation-Related Endothelial-derived Gene (IREG) signature. This inflammatory signature expressed in WT tumor endothelial cells was trained in human cancer datasets and predicted a poor clinical outcome in breast cancer, colon cancer, lung cancer and glioma. Consistent with this observation, conditioned media from human endothelial cells treated with pro-inflammatory cytokines (TNF-α and interferons) accelerated the growth of human colon and breast tumors in immune-deprived mice as compared with conditioned media from untreated endothelial cells. These findings demonstrate that activation of endothelial inflammatory pathways contributes to tumor growth and progression in diverse human cancers.
Project description:Skeletal myocyte differentiation involves fusion of myoblasts to multinucleated myotubes. In vitro differentiation can be induced by serum withdrawal. The differentiation process is negatively regulated by pathological concentrations of TNF-alpha but can be positively regulated by IGF1. This study focuses on elucidating the expression kinetics of mRNAs right after induction of differentiation (4 hours), during very early differentiation (12 h), early differentiation (24 h) as well as later differentiation (72 h) and how gene expression is modulated by TNF-alpha or IGF1, respectively.
Project description:Obesity is a clinical condition characterised by a chronic, low-grade inflammatory state. Adipose-derived mesenchymal stem cells (ADSCs) have a multidirectional differentiation potential to adipocytes. However, the relationship between adipogenesis and inflammation is not yet fully understood.TAZ (WW domain containing transcription regulator 1) can act as a molecular rheostat to fine-tune the osteoblast and adipocyte differentiation balance. In this study, we investigated the role of TAZ in the adipogenesis of Arbas cashmere goat ADSCs (gADSCs). We observed elevated TAZ expression levels during the adipogenesis of gADSCs. Overexpression and knockdown of TAZ were performed in stably transfected gADSCs cell lines, and RNA-seq analysis revealed that TAZ was associated with adipogenesis. TAZ overexpression promoted adipose differentiation of gADSCs, while TAZ knockdown had the opposite effect. In addition, TAZ overexpression and knockdown altered the expression of YAP1 (Yes1 associated transcriptional regulator) and TAZ in the nucleus. TAZ regulated the mRNA expression level and secretion level of tumor necrosis factor (TNF)-α, promoting adipose differentiation of gADSCs. Notably, TNF-α counteracted the inhibitory effect of sh-TAZ on the adipose differentiation of gADSCs. Collectively, these findings suggest that TAZ regulates adipogenesis in gADSCs by modulating TNF-α, which is of particular significance in several metabolic disorders where the amount or function of adipose tissue is altered.