Project description:We analyzed gene expression in human fibroblasts stimulated by platelet-derived growth factor-BB (PDGF-BB) or basic fibroblast growth factor (bFGF) for 1h and 24h. The results of two independent experiments were merged. SAM analysis identified 116 relevant probe sets. Hierarchical clustering of these probe sets showed divergent early gene regulation by PDGF and FGF but overlapping late response. We first analyzed genes commonly regulated by PDGF-BB and b-FGF more than 2 fold after 24h of stimulation and we found that these two growth factors activated SREBP and E2F and repressed FOXO. We then focused on the early gene expression response induced by both growth factors. We performed a fold change analysis and found 114 probe sets regulated by PDGF-BB and 42 probe sets regulated by b-FGF, 37 of which were shared between the two gene lists . We found by data mining that both PDGF-BB and b-FGF activated AP-1 and NF-kB. Next we analyzed genes specifically regulated by PDGF-BB and found that STATs are specifically activated by PDGF and not by FGF. Experiment Overall Design: Human foreskin fibroblasts (AG01518) were cultured (1.5E6 cells/10 cm dish) in MEM medium with 10% fetal calf serum and glutamine for 24h, then washed and incubated for 47h in serum-free medium. Cells were stimulated for 1h by PDGF-BB (25ng/ml) or b-FGF (10ng/ml, + heparine 50 microg/ml). Alternatively, cells were incubated for 24h in starvation medium and treated for 24h with growth factors, or left untreated for 48h in serum-free medium (control treatment). Experiment Overall Design: Two biological replicates were performed
Project description:We analyzed gene expression in human fibroblasts stimulated by platelet-derived growth factor-BB (PDGF-BB) or basic fibroblast growth factor (bFGF) for 1h and 24h. The results of two independent experiments were merged. SAM analysis identified 116 relevant probe sets. Hierarchical clustering of these probe sets showed divergent early gene regulation by PDGF and FGF but overlapping late response. We first analyzed genes commonly regulated by PDGF-BB and b-FGF more than 2 fold after 24h of stimulation and we found that these two growth factors repressed FOXO. We then focused on the early gene expression response induced by both growth factors. We performed a fold change analysis and found 114 probe sets regulated by PDGF-BB and 42 probe sets regulated by b-FGF, 37 of which were shared between the two gene lists . Keywords: Time course, cell Treatment comparison
Project description:The platelet-derived growth factor (PDGF) signaling system contributes to tumor angiogenesis and vascular remodeling. Here, we show PDGF-BB markedly induces erythropoietin (EPO) mRNA and protein expression by targeting the PDGFR-beta+ stromal and perivascular compartments. In mouse tumor models, PDGF-BB-induced EPO promotes tumor growth via two mechanisms: 1) paracrine stimulation of tumor angiogenesis by directly inducing endothelial cell proliferation, migration, sprouting and tube formation; and 2) endocrine stimulation of extramedullary hematopoiesis leading to increased oxygen perfusion and protection against tumor-associated anemia. Similarly, delivery of an adenovirus-PDGF-BB to tumor-free mice markedly increases EPO production and hematopoietic parameters. An EPO blockade specifically attenuates PDGF-BB-induced tumor growth, angiogenesis and hematopoiesis. At the molecular level, we show that the PDGF-BB-PDGFR-beta signaling system activates EPO promoter via in part transcriptional regulation of ATF3 by possible association with c-Jun and SP1. These findings uncover a novel mechanism of PDGF-BB-induced tumor growth, angiogenesis and hematopoiesis. Comparison of S17 stromal cells treated with PDGF-BB for 72h to control
Project description:The platelet-derived growth factor (PDGF) signaling system contributes to tumor angiogenesis and vascular remodeling. Here, we show PDGF-BB markedly induces erythropoietin (EPO) mRNA and protein expression by targeting the PDGFR-beta+ stromal and perivascular compartments. In mouse tumor models, PDGF-BB-induced EPO promotes tumor growth via two mechanisms: 1) paracrine stimulation of tumor angiogenesis by directly inducing endothelial cell proliferation, migration, sprouting and tube formation; and 2) endocrine stimulation of extramedullary hematopoiesis leading to increased oxygen perfusion and protection against tumor-associated anemia. Similarly, delivery of an adenovirus-PDGF-BB to tumor-free mice markedly increases EPO production and hematopoietic parameters. An EPO blockade specifically attenuates PDGF-BB-induced tumor growth, angiogenesis and hematopoiesis. At the molecular level, we show that the PDGF-BB-PDGFR-beta signaling system activates EPO promoter via in part transcriptional regulation of ATF3 by possible association with c-Jun and SP1. These findings uncover a novel mechanism of PDGF-BB-induced tumor growth, angiogenesis and hematopoiesis.
Project description:Vascular pericytes, an important cellular component, in the tumor microenvironment, are often associated with tumor vasculatures and their functions in cancer invasion and metastasis are poorly understood. Here we show that PDGF-BB induces pericyte fibroblast transition (designated as PFT), which significantly contributes to tumor invasion and metastasis. Gain- and loss-of-function experiments demonstrate that the PDGF-BB-PDGFRβ signaling promotes PFT in vitro and in in vivo tumors. Genome-wide expression analysis indicates that PDGF-BB-activated pericytes acquire mesenchymal progenitor features. Pharmacological inhibition and genetic deletion of PDGFRβ ablate the PDGF-BB-induced PFT. Genetic tracing of pericytes with two independent mouse strains, i.e., TN-AP-CreERT2:R26R-tdTomato and NG2:R26R-tdTomato, shows that PFT cells gains stromal fibroblast and myofibroblast markers in tumors. Importantly, co-implantation of PFT cells with less-invasive tumor cells in mice markedly promotes tumor dissemination and invasion, leading to an increased number of circulating tumor cells (CTCs) and metastasis. Our findings reveal a novel mechanism of vascular pericytes in PDGF-BB-promoted cancer invasion and metastasis by inducing PFT and thus targeting PFT may offer a new treatment option of cancer metastasis. Pericytes were isolated and treated with PDGF-BB or control for 1 or 5 days
Project description:Vascular pericytes, an important cellular component, in the tumor microenvironment, are often associated with tumor vasculatures and their functions in cancer invasion and metastasis are poorly understood. Here we show that PDGF-BB induces pericyte fibroblast transition (designated as PFT), which significantly contributes to tumor invasion and metastasis. Gain- and loss-of-function experiments demonstrate that the PDGF-BB-PDGFRβ signaling promotes PFT in vitro and in in vivo tumors. Genome-wide expression analysis indicates that PDGF-BB-activated pericytes acquire mesenchymal progenitor features. Pharmacological inhibition and genetic deletion of PDGFRβ ablate the PDGF-BB-induced PFT. Genetic tracing of pericytes with two independent mouse strains, i.e., TN-AP-CreERT2:R26R-tdTomato and NG2:R26R-tdTomato, shows that PFT cells gains stromal fibroblast and myofibroblast markers in tumors. Importantly, co-implantation of PFT cells with less-invasive tumor cells in mice markedly promotes tumor dissemination and invasion, leading to an increased number of circulating tumor cells (CTCs) and metastasis. Our findings reveal a novel mechanism of vascular pericytes in PDGF-BB-promoted cancer invasion and metastasis by inducing PFT and thus targeting PFT may offer a new treatment option of cancer metastasis.
Project description:PDGF-BB:PDGFRβ signalling in brain pericytes is critical to the development, maintenance and function of a healthy blood-brain barrier (BBB). Furthermore, BBB impairment and pericyte loss in Alzheimer’s disease (AD) is well documented. We used tissue microarrays from control and AD brains to determine if PDGF-BB:PDGFRβ signalling components were altered in AD, and found that there was a reduction in vascular expression of PDGFB. We hypothesised that reduced PDGF-BB:PDGFRβ signalling in pericytes may have an impact on functions related to the BBB. We therefore tested the effects of PDGF-BB on primary human brain pericytes in vitro to define important signalling pathways and outcomes related to BBB function. Pericytes demonstrate a biphasic response to PDGF-BB, predominantly dependent on Akt and ERK. We determined that the actions of PDGF-BB are on-target at PDGFRβ, leading to internalisation and degradation of PDGFRβ. Using pharmacological inhibitors, we dissected distinct aspects of the PDGF-BB response that are controlled by ERK and Akt pathways. PDGF-BB promotes the proliferation of pericytes and protection from toxic stimuli through ERK signalling. In contrast, PDGF-BB:PDGFRβ signalling through Akt and NF-κB augments pericyte-derived inflammatory secretions. It may therefore be possible to supplement PDGF-BB or small molecule agonists to stabilise the cerebrovasculature in AD.
Project description:To explore global molecular changes in smooth muscle in response to PDGFR activation, primary human bladder smooth muscle cells were treated with 1 nM PDGF-BB (hereafter PDGF) for 0, 4 or 24 h. Total RNA were prepared, and analyzed using expression profiling, and subjected to bioinformatic and functional interrogation. To identify molecular signatures of bladder smooth muscle peturbed by PDGF, primary human bladder smooth muscle cells were treated with 1 nM PDGF-BB (hereafter PDGF) for 0, 4 or 24 h.
Project description:To further understand the mechanism approach to occlusive vein grafts, we have employed RNA-seq to identify key genes in occlusive venin grafts following CABG in human. The occluded vein graft and intraoperative spare great saphenous vein of patients undergoing clinical re-coronary artery bypass grafting were obtained for RNA-seq. The sequencing results were cleaned and bioinformatics annlysis was conducted by using WGCNA and a variety of online databases and software. The key genes or proteins affecting the occurrence of vein graft restenosis were screened out(ITGB2), and the expression level of the target genes or proteins was verified by real-time PCR and Western blot. And to further learn the effect of ITGB2 in human primary venous smooth muscle cells, ITGB2 gene was silenced by SiRNA. The effect of ITGB2 silencing on proliferation, migration and invasion of venous smooth muscle cells after PDGF-BB-stimulation were detected by Edu assay, scrathch experiment and transwell experiment. And Edu assay showed that ITGB2 silencing could inhibit the proliferation of PDGF-BB sitmulated smooth muscle cells. Scratch assay showed that ITGB2 silencing inhibited the migration of PDGF-BB stimulated smooth muscle cells. Transwell assay showed that ITGB2 silencing significantly inhibited the invasion of PDGF-BB stimulated smooth muscle cells. It is indicated that ITGB2 was the key gene in vein graft restenosis,and may be the potential treatment target in restenosis patients.