Project description:The airways of the human lung are lined by an epithelium made up of ciliated and secretory luminal cells and undifferentiated p63+ Krt5+ progenitors. The integrity of this epithelium and its ability to act as a selective barrier are critical for normal lung function. In other epithelia there is evidence that transcription factors of the evolutionarily conserved grainyheadlike (GRHL) family play key roles in co-ordinating the expression of numerous proteins required for epithelial morphogenesis, differentiation, remodeling and repair. However, little is known about their function in the adult lung. We used Affymetrix microarray analysis to compare transcripts in lentivirus transfected primary human bronchial epithelial (HBE) cells expressing either EGFP or DN-GRHL2 to help identify GRHL2 target genes and their functions in HBE cells. Primary HBE cells from three donors were infected with modified TripZ lentivirus designed to express EGFP or DN-GRHL2 in response to Dox. Dox was added to cells cultured at the air-liquid interface from day 7 to 14.
Project description:The airways of the human lung are lined by an epithelium made up of ciliated and secretory luminal cells and undifferentiated p63+ Krt5+ basal cells. The integrity of this epithelium and its ability to act as a selective barrier are critical for normal lung function. In other epithelia there is evidence that transcription factors of the evolutionarily conserved grainyheadlike (GRHL) family play key roles in co-ordinating the expression of numerous proteins required for epithelial morphogenesis, differentiation, remodeling and repair. However, little is known about their function in the adult lung. We use Affymetrix microarray analysis to compare transcripts in lentivirus transfected primary human bronchial epithelial (HBE) cells expressing either EGFP or DN-GRHL2 for 48h when the transepithelial electrical resistance (TER) reached a threshold level. The goal is to identify direct target genes of GRHL2 and early events in the uncoupling of junctional interactions, including those regulating transepithelial resistance. Primary HBE cells from three donors were infected with EGFP or DN-GRHL2 expression lentivirus. Dox was added for 48h to induce the expression of either EGFP or DN-GRHL2 when TER reached a threshold level in ALI culture.
Project description:Using a retrovirus-mediated cDNA expression cloning approach we identified the grainyhead-like 2 (GRHL2) transcription factor as novel protooncogene. Overexpression of GRHL2 in NIH3T3 cells induced striking morphological changes, an increase in cell proliferation, anchorage-independent growth, and tumor growth in vivo. By combining a microarray analysis and a phylogenetic footprinting analysis with various biochemical assays we identified the epidermal growth factor receptor family member Erbb3 as a novel GRHL2 target gene. In breast cancer cell lines, shRNA-mediated knockdown of GRHL2 expression or functional inactivation of GRHL2 using dominant-negative GRHL2 proteins induce downregulation of ERBB3 gene expression, a striking reduction in cell proliferation and morphological and phenotypical alterations characteristic of an epithelial-to-mesenchymal transition (EMT), thus implying dual roles of GRHL2 in breast carcinogenesis. Interestingly, we could further demonstrate that expression of GRHL2 is directly suppressed by the transcription factor zinc-finger-enhancer binding protein 1 (ZEB1) which in turn is a direct target for repression by GRHL2, suggesting that the EMT transcription factors GRHL2 and ZEB1 form a double negative regulatory feedback loop in breast cancer cells. Finally, a comprehensive immunohistochemical analysis of GRHL2 expression in primary breast cancers showed loss of GRHL2 expression at the invasive front of primary tumors. A pathophysiological relevance of GRHL2 in breast cancer metastasis is further demonstrated by our finding of a statistically significant association between loss of GRHL2 expression in primary breast cancers and lymph-node metastasis. We thus demonstrate a crucial role of GRHL2 in breast carcinogenesis. To evaluate the role of the GRHL2 transcription factor in carcinogenessis we overexpressed the human GRHL2 protein in NIH3T3 cells. Parental NIH3T3 cells do not express the orthologic protein. Alterations in genome-wide transcriptional profiles were determined by microarray analysis.
Project description:The Grainyhead family of transcription factors controls morphogenesis and differentiation of epithelial cell layers in multicellular organisms by regulating cell junction- and proliferation-related genes. Grainyhead-like 2 (Grhl2) is expressed in developing mouse lung epithelium and is required for normal lung organogenesis. The specific epithelial cells expressing Grhl2 and the genes regulated by Grhl2 in normal lungs are mostly unknown. In these studies, we identified the NK2 homeobox 1 transcription factor (Nkx2-1) as a direct transcriptional target of Grhl2. By binding and transcriptional assays, and by confocal microscopy we showed that these two transcription factors form a positive feed-back loop in vivo and in cell lines, and are co-expressed in lung bronchiolar and alveolar type II cells. The morphological changes observed in flattening lung alveolar type II cells in culture are associated with down-regulation of Grhl2 and Nkx2-1. Reduction of Grhl2 in lung epithelial cell lines results in lower expression levels of Nkx2-1 and of known Grhl2 target genes. By microarray analysis we identified that in addition to Cadherin1 and Claudin4, Grhl2 regulates other cell interaction genes such as semaphorins and their receptors, which also play a functional role in developing lung epithelium. Impaired collective cell migration observed in Grhl2 knockdown cell monolayers is associated with reduced expression of these genes and may contribute to the altered epithelial phenotype reported in Grhl2 mutant mice. Thus, Grhl2 functions at the nexus of a novel regulatory network, connecting lung epithelial cell identity, migration and cell-cell interactions. To identify genes regulated by GRHL2 in lung epithelial cells, we performed cDNA microarray analyses in MLE15 cells transduced with Grhl2-shRNA and compared to a non-silencing control. Independent transductions of MLE15 cells using Grhl2-shRNA (n=3) and a non-silencing control (n=2) were analyzed.
Project description:The airways of the human lung are lined by an epithelium made up of ciliated and secretory luminal cells and undifferentiated p63+ Krt5+ basal cells. The integrity of this epithelium and its ability to act as a selective barrier are critical for normal lung function. In other epithelia there is evidence that transcription factors of the evolutionarily conserved grainyheadlike (GRHL) family play key roles in co-ordinating the expression of numerous proteins required for epithelial morphogenesis, differentiation, remodeling and repair. However, little is known about their function in the adult lung. Here, we focus on the role of GRHL2 in primary human bronchial epithelial (HBE) cells, using either shRNA or a dominant negative protein (DN-GRHL2) to inhibit its function. We follow changes in epithelial phenotype, and in gene transcription using RNA-seq or microarray analysis, both in undifferentiated basal cells and in cells differentiating in air-liquid interface culture into a mucociliary epithelium with transepithelial electrical resistance. We identify several hundreds of genes that are directly or indirectly regulated by GRHL2. Using ChIP-seq to map sites of GRHL2 binding in the basal cells we identify 7,687 potential primary targets, and confirm that GRHL2 binding is strongly enriched near GRHL-regulated genes. Different subsets of the large cohort of potential GRHL2 targets appear to be active in basal and differentiated cells. Taken together, the results strongly support the hypothesis that GRHL2 plays a key role in regulating many physiological functions of human airway epithelium, including those involving cell adhesion, polarity and morphogenesis. Frozen primary human bronchial epithelial (HBE) cells were obtained from three donors. Passage 2 cells at 40% confluence were infected with H2B-GFP or DN-GRHL2 lentivirus and 1 mg/ml puromycin added 48 h later. At confluence, Doxycycline 0.5 mg/ml was added for 24 h. RNA-seq was performed on all six samples, as well as samples from two donors that were not infected.
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:Epithelial ovarian cancer (EOC) is clinically heterogeneous, comprising different histological and biological subtypes. Multiple studies have implicated epithelial-mesenchymal transition (EMT), a biological process by which polarized epithelial cells convert into a mesenchymal phenotype, to contribute significantly to this molecular heterogeneity of EOC. From gene expression analyses of a collection of EMT-characterized EOC cell lines, we found that the expression of the transcription factor Grainyhead-like 2 (GRHL2) correlates with E-cadherin expression and the epithelial phenotype. EOC tumors with lower levels of GRHL2 are associated with the Mes (mesenchymal) molecular subtype and show poorer overall survival in patients. Here, we demonstrate that shRNA-mediated knockdown of GRHL2 in EOC cells with an epithelial phenotype resulted in EMT changes, with increased cell migration, invasion and motility. By ChIP-sequencing and gene expression microarray, we identified a variety of target genes regulated by GRHL2, including protein-coding and non-coding genes. Our data suggest that GRHL2 maintains the epithelial phenotype of EOC cells through the regulatory networks of miR-200b/a, ZEB1 and E-cadherin. These findings support GRHL2 as a crucial player in the molecular heterogeneity of EOC. 7 samples were analyzed (shNon control in duplicates; shGRHL2 #10 in duplicates, shGRHL2 #12 in triplicates)
Project description:Grainyhead genes are involved in wound healing and developmental neural tube closure. In light of the high degree of similarity between the epithelial-mesenchymal transitions (EMTs) occurring in wound healing processes and the cancer stem cell-like compartment of tumors, including TGF-β-dependence, we investigated the role of a Grainyhead gene (GRHL2) in oncogenic EMT. Grainyhead was specifically down-regulated in the claudin-low subclass of mammary tumors and in the basal-B subclass of breast cancer cell lines. Functionally, GRHL2 suppressed TGF-β-induced, Twist-induced or spontaneous EMT, enhanced anoikis-sensitivity, and suppressed mammosphere generation in mammary epithelial cells. These effects were mediated, in part, by its suppression of ZEB1 expression, through direct repression of the ZEB1 promoter. GRHL2 also inhibited Smad-mediated transcription, and up-regulated mir200b/c as well as the TGF-β receptor antagonist, BMP2. The expression of GRHL2 in the breast cancer cell line MDA-MB-231 triggered a mesenchymal-to-epithelial transition and sensitized the cells to anoikis. These results indicate that GRHL2 is a suppressor of the oncogenic EMT. 3 biologic replicates for each cell line. Comparison of HMLE+Twist-ER cells expressing GRHL2/pMIG vs. HMLE+Twist-ER cells expressing empty pMIG.
Project description:Effect of an immunosupressive dose of TCDD, a ligand for the aryl hydrocarbon receptor, on the gene expression profile of fetal DN thymocytes and thymic emigrants C57BL6 mice were mated and the pregnant dams sacrifice at day 15 of gestation. Fetal thymic lobes were prepared and cultured for 6 days on culture inserts (5-6 lobes/culture insert). Medium, containing either 10 nM TCDD or solvent control was exchanged every 48 hours. At day six (gestation day 21, corresponding to birth), single cell suspensions of the thymocytes were prepared and CD4-CD8- cells isolated by MACS sorting. Purity of the population was checked FACS analysis, to be greater 95%. RNA was purified (TRIZOL), amplified (Ambion Kit) and processed (Affymetrix standard protocol) according to manufacturers instructions. Raw cell files were processed with the bioconductor affy package
Project description:Neurons derived from human pluripotent stem cells (hPSCs) are a remarkable tool for modeling human neural development and diseases. However, it remains largely unknown whether the hPSC-derived neurons can be functionally coupled with their target tissues in vitro, which is essential for understanding inter-cellular physiology and further translational studies. Here, we demonstrate that hPSC-derived sympathetic neurons can be obtained from hPSCs and that the resulting neurons form physical and functional connections with cardiac muscle cells. By use of multiple hPSC reporter lines, we recapitulated human autonomic neuron development in vitro, and successfully isolated PHOX2B::eGFP+ neurons exhibiting sympathetic marker expression, electrophysiological properties, and norepinephrine secretion. With pharmacological and optogenetic manipulations, the PHOX2B::eGFP+ neurons controlled the beating rates of cardiomyocytes, and their physical interaction led to neuronal maturation. Our study lays a foundation for the specification of human sympathetic neurons and for the hPSC-based neuronal control of end organs in a dish. Using the four genetic reporter systems (OCT4::eGFP, SOX10::eGFP, ASCL1::eGFP, and PHOX2B::eGFP reporter hESC lines), we were able to purify discrete cell populations at four differentiation stages, recapitulating the sympathoadrenal differentiation process in vitro with purified and defined populations in four specific differentiation stages. We performed transcriptome analysis of OCT4::eGFP+ cells (3 biological replicates, representing undifferentiated hESCs), SOX10::eGFP+ cells (3 biological replicates, multi-potent neural crest), ASCL1::eGFP+ cells (3 biological replicates, putative sympathoadrenal progenitors), and PHOX2B::eGFP+ cells (2 biological replicates, putative sympathetic neuronal precursors).