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:We generated the transcriptional regulatory footprint of phthalimide neovascular factor 1 (PNF1)—a novel synthetic small molecule that exhibits significant in vitro endothelial potency and significant in vivo microvascular network expansion—by performing comparative microarray analysis on PNF1-stimulated (versus control) human microvascular endothelial cells (HMVEC) spanning 1-48 h post-supplementation. We subsequently applied network analysis tools (including substantial libraries of information regarding known associations among network components) to elucidate key signaling components and pathways involved in the PNF1 mechanism-of-action. We identified that PNF1 first induces function of the tumor necrosis factor-alpha (TNF-α) signaling pathway, which in turn affects transforming growth factor-beta (TGF-β) signaling.
Project description:The increased secretion of pro-inflammatory cytokines, such as tumor necrosis factor-alpha, is often associated with adipose tissue dysregulation, which often accompanies obesity. High levels of TNF-alpha have been linked to development of insulin resistance in several tissues and organs, including skeletal muscle and the liver. In this study, we examined the complex regulatory roles of TNF-alpha in murine hepatocytes utilizing a combination of global proteomics and phosphoproteomics analyses. Our results show that TNF-alpha promotes extensive, dynamic changes not only of protein levels, but also the dynamics of their downstream phosphorylation signaling states. We provide evidence that TNF-alpha likely induces DNA replication, and promotes G1/S transition through the activation of the MAPK pathway. Our data also highlights several other novel proteins, many of which are regulated by phosphorylation and that play a role in the progression and development of insulin resistance in hepatocytes.
Project description:Cerebral malaria is a severe complication of Plasmodium falciparum infection characterized by the loss of blood-brain barrier (BBB) integrity, which is associated with brain swelling and mortality in patients. P. falciparum-infected red blood cells and in!ammatory cytokines, like tumor necrosis factor alpha (TNF-a), have been implicated in the development of cerebral malaria, but it is still unclear how they contribute to the loss of BBB integrity. Here, a combination of transcriptomic analysis and cellular assays detecting changes in barrier integrity and endothelial activation were used to distinguish between the effects of P. falciparum and TNF-a on a human brain microvascular endothelial cell (HBMEC) line and in primary human brain microvascular endothelial cells. We observed that while TNF-a induced high levels of endothelial activation, it only caused a small increase in HBMEC permeability. Conversely, P. falciparum-infected red blood cells (iRBCLs) led to a strong increase in HBMEC permeability that was not mediated by cell death. Distinct transcriptomic pro"les of TNF-a and P. falciparum in HBMECs con"rm the differential effects of these stimuli, with the parasite preferentially inducing an endoplasmic reticulum stress response. Our results establish that there are fundamental differences in the responses induced by TNF-a and P. falciparum on brain endothelial cells and suggest that parasite-induced signaling is a major component driving the disruption of the BBB during cerebral malaria, proposing a potential target for much needed therapeutics.
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: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-M-NM-1, 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-M-NM-1 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-M-NM-1 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. To investigate the genes associated with TNF-M-NM-1 signaling in tumor endothelium, we performed expression profiling of tumor-associated endothelial cells isolated from B16F1 tumors grown in syngeneic TNFR 1, 2 -/- (KO) and C57BL/6 (WT) mice. Tumor endothelial cells were isolated from WT and KO tumors when tumor volumes were ~180 mm^3. This was based on a stepwise immunopurification of combined tumor tissue (Seaman, S. et al. Genes that distinguish physiological and pathological angiogenesis. Cancer Cell 11, 539-54 (2007)). Tumor endothelial cells were lysed to collect total RNA and analyzed in duplicates with Affymetrix GeneChipM-BM-. Mouse Genome 430 2.0 Arrays.
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:Notch signaling activation drives endothelial-to-mesenchymal transition (EndMT), which is key to heart development. Accumulating evidence indicates that endothelial cell metabolism reprogramming regulates endothelial function independent of canonical cell signaling. Herein, we investigated whether and how Notch signaling and metabolism reprogramming crosstalk in the EndMT process. We found Notch1 intracellular domain (NICD1) was localized within the mitochondria of endothelial cells and interacted with the PDH E1 subunit beta, influencing the phosphorylation of the PDH E1 subunit alpha, thereby activating PDH and enhancing mitochondrial metabolism.
Project description:Purpose: Analyze the potential signaling pathways regulated by MLKL under TNF-induced endothelial cell inflammatory response Methods: HUVECs were allowed to grow to confluency and were starved with basal medium containing 0.5% FBS for 6h. Then treat HUVECs with vehicle, NSA, TNF-alpha, TNF-alpha+NSA for 6h and extract RNA. Results: NSA reduces the mRNA level of TNF-induced inflammation-related genes and most of these genes are downstream of NF-kappa B signaling pathway.