Project description:We hypothesized that the trophoblast secretes anti-angiogenic factors, which increase in late pregnancy to limit angiogenesis. Therefore, we determined the paracrine effect of primary human trophoblasts from early versus late pregnancy on the angiogenic potential of isolated feto-placental endothelial cells. We found that the expression and secretion of anti-angiogenic factors differs in early vs late pregnancy, and differentially affects feto-placental angiogenesis.
Project description:We show that Retinal pigment epithelium (RPE) secreted-factor, pigment epithelium derived factor (PEDF) secreted/derived from primary or iPSC-derived retinal pigment epithelium (RPE)RPE, dramatically inhibitsed the cell growth of iPSCs. PEDF was detected abundantly in culture supernatant media of primary and iPSC-derived RPE. We examined the gene expression in primary RPE and iPS-derived RPE.
Project description:We show that Retinal pigment epithelium (RPE) secreted-factor, pigment epithelium derived factor (PEDF) secreted/derived from primary or iPSC-derived retinal pigment epithelium (RPE)RPE, dramatically inhibitsed the cell growth of iPSCs. PEDF was detected abundantly in culture supernatant media of primary and iPSC-derived RPE. We examined the gene expression in primary RPE and iPS-derived RPE. Two samples: RPE derived from 253G1 iPSC, Primary RPE.
Project description:MicroRNA expression profiling of human microvascular endothelial cells (HMVECs) treated with either vascular endothelial growth factor (VEGF) only or in combination with the natural angiogenesis inhibitor pigment epithelial-derived factor (PEDF). Originally we were interested in the microRNA-mediated regulation of angiogenesis by the endogenous anti-angiogenic PEDF. To identify the microRNAs involved in PEDF signaling in activated endothelial cells, we compared the levels of microRNAs in non-treated microvascular endothelial cells, cells treated with VEGF, and cells treated with a combination of VEGF and PEDF. After treatment, total RNA content was isolated and sent for analysis to LC Sciences, LLC. They performed expression profiling and completed statistical analysis, based on which we confirmed the regulation of one of the microRNAs, mir-27b. In the following experiments, we identified the targets of mir-27b relevant for angiogenesis and confirmed our findings in zebrafish and mouse models. The manuscript describes the key role of mir-27b in determination of the endothelial tip cell fate and venous differentiation by regulating Notch ligand Delta-like ligand 4 (Dll4) and Sprouty homologue 2 (Spry2). Three-condition experiment: untreated (control) HMVECs vs. VEGF-treated HMVECs vs. PEDF/VEGF-treated HMVECs.
Project description:Healthy placental development is essential for reproductive success; failure of the feto-maternal interface results in preeclampsia and intrauterine growth retardation. We found that grainyhead-like 2 (GRHL2), a CP2-type transcription factor, is highly expressed in chorionic trophoblast cells, including basal chorionic trophoblast (BCT) cells located at the chorioallantoic interface in murine placentas. Placentas from Grhl2-deficient mouse embryos displayed defects in BCT cell polarity and basement membrane integrity at the chorioallantoic interface, as well as a severe disruption of labyrinth branchingmorphogenesis.Selective Grhl2 inactivation only in epiblastderived cells rescued all placental defects but phenocopied intraembryonic defects observed in global Grhl2 deficiency, implying the importance of Grhl2 activity in trophectoderm-derived cells. ChIPseq identified 5282 GRHL2 binding sites in placental tissue. By integrating these data with placental gene expression profiles, we identified direct and indirect Grhl2 targets and found a marked enrichment of GRHL2 binding adjacent to genes downregulated in Grhl2−/− placentas, which encoded known regulators of placental development and epithelial morphogenesis. These genes included that encoding the serine protease inhibitor Kunitz type 1 (Spint1), which regulates BCT cell integrity and labyrinth formation. In human placenta, we found that human orthologs of murine GRHL2 and its targets displayed co-regulation and were expressed in trophoblast cells in a similar domain as in mouse placenta. Our data indicate that a conserved Grhl2-coordinated gene network controls trophoblast branching morphogenesis, thereby facilitating development of the site of feto-maternal exchange. This might have implications for syndromes related to placental dysfunction. In vivo genome-wide examination of binding sites of the transcription factor GRHL2 by ChIP-seq using wild-type murine E17.5 placenta tissue. Two samples in total: one GRHL2 ChIP sample and one IgG ChIP sample using wild-type placentas tissue as antibody control.
Project description:MicroRNA expression profiling of human microvascular endothelial cells (HMVECs) treated with either vascular endothelial growth factor (VEGF) only or in combination with the natural angiogenesis inhibitor pigment epithelial-derived factor (PEDF). Originally we were interested in the microRNA-mediated regulation of angiogenesis by the endogenous anti-angiogenic PEDF. To identify the microRNAs involved in PEDF signaling in activated endothelial cells, we compared the levels of microRNAs in non-treated microvascular endothelial cells, cells treated with VEGF, and cells treated with a combination of VEGF and PEDF. After treatment, total RNA content was isolated and sent for analysis to LC Sciences, LLC. They performed expression profiling and completed statistical analysis, based on which we confirmed the regulation of one of the microRNAs, mir-27b. In the following experiments, we identified the targets of mir-27b relevant for angiogenesis and confirmed our findings in zebrafish and mouse models. The manuscript describes the key role of mir-27b in determination of the endothelial tip cell fate and venous differentiation by regulating Notch ligand Delta-like ligand 4 (Dll4) and Sprouty homologue 2 (Spry2).
Project description:A balance between angiogenesis inducers and inhibitors in the microenvironment controls the rate of new blood vessel formation. We hypothesized that fibroblasts, an important cellular constituent of the tissue stroma, secrete molecules that contribute to this balance. We further hypothesized that fibroblasts secrete molecules that promote angiogenesis when they are in a proliferative state and molecules that inhibit angiogenesis when they are not actively cycling (quiescent). Microarray analysis revealed that angiogenesis inducers and inhibitors are regulated as fibroblasts transition into a quiescent state and reenter the cell cycle in response to changes in serum. To assess whether changes in transcript levels result in changes in the levels of secreted proteins, we collected conditioned medium from proliferating and quiescent fibroblasts and performed immunoblotting for selected proteins. Secreted protein levels of the angiogenesis inhibitor pigment epithelium derived factor (PEDF) were higher in quiescent than proliferating fibroblasts. Conversely, proliferating fibroblasts secreted increased levels of the angiogenesis inducer vascular endothelial growth factor-C (VEGF-C). For the angiogenesis inhibitor thrombospondin-2, quiescent cells secreted a prominent 160 kDa form in addition to the 200 kDa form secreted by proliferating and restimulated fibroblasts. Using immunohistochemistry we discovered that fibroblasts surround blood vessels and that the angiogenesis inhibitor PEDF is expressed by quiescent fibroblasts in uterine tissue, supporting a role for PEDF in maintaining quiescence of the vasculature. This work takes a new approach to the study of angiogenesis by examining the expression of multiple angiogenesis regulators secreted from a key stromal cell, the fibroblast. mRNAs were analyzed by two color microarray from a human neonatal dermal fibroblasts cell line over a timecourse of serum starvation and serum restimulation.
Project description:Pigment Epithelium-Derived Factor (PEDF) has recently been identified as a factor that is significantly upregulated in late-stage osteoarthritic cartilage in which chondrocytes are confronted with terminal differentiation and cell death. Since PEDF is known to induce cell death of endothelial cells, it may also be responsible for terminal differentiation and cell death in cartilage. Using cDNA microarray analysis, we found PEDF among the factors with the strongest differential expression and significant higher levels (118.5-fold) in osteophytic cartilage compared with articular cartilage. This study explored if PEDF interferes with the stable chondrocyte phenotype by promoting terminal differentiation or cell death.
Project description:Pigment Epithelium-Derived Factor (PEDF) has recently been identified as a factor that is significantly upregulated in late-stage osteoarthritic cartilage in which chondrocytes are confronted with terminal differentiation and cell death. Since PEDF is known to induce cell death of endothelial cells, it may also be responsible for terminal differentiation and cell death in cartilage.
Project description:Healthy placental development is essential for reproductive success; failure of the feto-maternal interface results in preeclampsia and intrauterine growth retardation. We found that grainyhead-like 2 (GRHL2), a CP2-type transcription factor, is highly expressed in chorionic trophoblast cells, including basal chorionic trophoblast (BCT) cells located at the chorioallantoic interface in murine placentas. Placentas from Grhl2-deficient mouse embryos displayed defects in BCT cell polarity and basement membrane integrity at the chorioallantoic interface, as well as a severe disruption of labyrinth branchingmorphogenesis.Selective Grhl2 inactivation only in epiblastderived cells rescued all placental defects but phenocopied intraembryonic defects observed in global Grhl2 deficiency, implying the importance of Grhl2 activity in trophectoderm-derived cells. ChIPseq identified 5282 GRHL2 binding sites in placental tissue. By integrating these data with placental gene expression profiles, we identified direct and indirect Grhl2 targets and found a marked enrichment of GRHL2 binding adjacent to genes downregulated in Grhl2−/− placentas, which encoded known regulators of placental development and epithelial morphogenesis. These genes included that encoding the serine protease inhibitor Kunitz type 1 (Spint1), which regulates BCT cell integrity and labyrinth formation. In human placenta, we found that human orthologs of murine GRHL2 and its targets displayed co-regulation and were expressed in trophoblast cells in a similar domain as in mouse placenta. Our data indicate that a conserved Grhl2-coordinated gene network controls trophoblast branching morphogenesis, thereby facilitating development of the site of feto-maternal exchange. This might have implications for syndromes related to placental dysfunction.