Project description:Cystathionine Beta Synthase (CBS), an enzyme that utilizes a methionine precursor to generate glutathione (GSSH), has been implicated in the mitigation of ROS production in COPD lung. Additionally, post-translational modification analysis on mouse and human cells treated with cigarette smoke showed the unique presence of mono- and di-methylated histone H3 lysine 27 that was not seen in controls, suggesting that cigarette smoke could lead to loss of Polycomb Repressive Complex 2 (PRC2) activity. To elucidate CBS as a potential upstream target for PRC2 inhibition, we overexpressed CBS in Human Bronchial Epithelial Cells (HBECs), grew them as 2D cultures, then conducted bulk RNA seq analysis.
Project description:We constructed a primary lung cell model to permit regulated expression of KRASG12D. To do this, we leveraged a non-transformed, immortalized, human primary bronchial epithelial cell line (HBEC; hTert, CDK4, TP53 knockdown) that remains anchorage dependent and do not develop tumors when implanted into mice. We next modified these cells by stably integrating a regulatable KRASG12D allele, iKRASG12D, such that physiological expression of mutant KRAS is activated upon addition of doxycycline. The HBEC-iKRAS (WT) cell line and HBEC-iKRASG12D (MUT) cell line were propagated with or without Doxycycline (500ng/ml) respectively. RNA profiling of HBEC-iKRASG12D and HBEC-iKRASWT cells revealed widespread changes for HBECs harboring the activated KRAS allele in the presence of Dox. Within the KRASG12D-induced genes, the Molecular Signatures Database identified the oncogenic RAS signature as a top-enriched gene set. Upregulation of Ras signaling in Dox-treated HBEC-iKRASG12D cells was also supported by a significant overlap with a KRAS signature previously characterized by Singh et al.
Project description:In this study, we assess potential differences in mechanism of action for two PAHs, benzo[a]pyrene (BAP) and dibenzo-[def,p]chrysene (DBC), in a primary human 3D bronchial epithelial culture (HBEC) model based on short-term biosignatures identified from global transcriptional profiling.
Project description:In this study, we assess potential differences in mechanism of action for two PAHs, benzo[a]pyrene (BAP) and dibenzo-[def,p]chrysene (DBC), in a primary human 3D bronchial epithelial culture (HBEC) model based on short-term biosignatures identified from global transcriptional profiling.
Project description:Purpose: Core 3 derived glycans, a major type of O-glycan expressed by normal epithelial cells of the gastrointestinal tract, are downregulated during malignancy, because of loss of expression of functional β3-N-acetylglucosaminyltransferase-6 (core 3 synthase). We investigated the expression of core 3 synthase in normal pancreas and pancreatic cancer and evaluated the biological effects of re-expressing core 3 synthase in pancreatic cancer cells that had lost expression. Experimental Design: We determined that pancreatic tumors and tumor cell lines have lost expression of core 3 synthase. We therefore re-expressed in human pancreatic cancer cells (Capan-2 and FG) to investigate the contribution of core 3 glycans to malignant progression. Results: Pancreatic cancer cells expressing core 3 synthase showed reduced in vitro cell proliferation, migration and invasion compared with vector control cells. Expression of core 3 O-glycans induced altered expression of β1 integrin, decreased activation of focal adhesion kinase, led to the down regulation of expression of several genes including REG1α and FGFR3, and altered lamellipodia formation. The addition of a GlcNAc residue by core 3 synthase leads to the extension of the tumor associated Tn structure on MUC1. Orthotopic injection of FG cells expressing core 3 synthase into the pancreas of nude mice produced significantly smaller tumors and decreased metastasis to the surrounding tissues compared to vector control FG cells. Conclusions: These findings indicate that expression of core 3 derived O-glycans in pancreatic cancer cells suppresses tumor growth and metastasis through modulation of glycosylation of mucins and other cell surface and extracellular matrix proteins.
Project description:Idiopathic pulmonary fibrosis (IPF) is characterized by devastating and progressive lung parenchymal fibrosis with poor prognosis. An aberrant recapitulation of lung developmental genes including transforming growth factor (TGF)-β and WNT has been widely implicated in the abnormal wound healing process following repetitive alveolar epithelial injury during IPF pathogenesis. Extracellular vesicles (EVs) including exosomes and microvesicles have been shown to carry various bioactive molecules and are involved in a variety of physiological and pathological processes. Here, we demonstrate that human bronchial epithelial cell-derived EVs (HBEC EVs) inhibited TGF-β-induced both myofibroblast differentiation and lung epithelial cellular senescence through attenuating WNT signaling. To ask how HBEC-EVs inhibited TGF-β-induced both myofibroblast differentiation and lung epithelial cellular senescence through attenuating WNT signaling, miRNA RNA-seq of HBEC-EVs was performed.
Project description:Idiopathic pulmonary fibrosis (IPF) is characterized by devastating and progressive lung parenchymal fibrosis with poor prognosis. An aberrant recapitulation of lung developmental genes including transforming growth factor (TGF)-β and WNT has been widely implicated in the abnormal wound healing process following repetitive alveolar epithelial injury during IPF pathogenesis. Extracellular vesicles (EVs) including exosomes and microvesicles have been shown to carry various bioactive molecules and are involved in a variety of physiological and pathological processes. Here, we demonstrate that human bronchial epithelial cell-derived EVs (HBEC EVs) inhibited TGF-β-induced both myofibroblast differentiation and lung epithelial cellular senescence through attenuating WNT signaling. To ask how HBEC-EVs inhibited TGF-β-induced both myofibroblast differentiation and lung epithelial cellular senescence through attenuating WNT signaling, miRNA RNA-seq of HBEC-EVs was performed.
Project description:Purpose: Core 3 derived glycans, a major type of O-glycan expressed by normal epithelial cells of the gastrointestinal tract, are downregulated during malignancy, because of loss of expression of functional β3-N-acetylglucosaminyltransferase-6 (core 3 synthase). We investigated the expression of core 3 synthase in normal pancreas and pancreatic cancer and evaluated the biological effects of re-expressing core 3 synthase in pancreatic cancer cells that had lost expression. Experimental Design: We determined that pancreatic tumors and tumor cell lines have lost expression of core 3 synthase. We therefore re-expressed in human pancreatic cancer cells (Capan-2 and FG) to investigate the contribution of core 3 glycans to malignant progression. Results: Pancreatic cancer cells expressing core 3 synthase showed reduced in vitro cell proliferation, migration and invasion compared with vector control cells. Expression of core 3 O-glycans induced altered expression of β1 integrin, decreased activation of focal adhesion kinase, led to the down regulation of expression of several genes including REG1α and FGFR3, and altered lamellipodia formation. The addition of a GlcNAc residue by core 3 synthase leads to the extension of the tumor associated Tn structure on MUC1. Orthotopic injection of FG cells expressing core 3 synthase into the pancreas of nude mice produced significantly smaller tumors and decreased metastasis to the surrounding tissues compared to vector control FG cells. Conclusions: These findings indicate that expression of core 3 derived O-glycans in pancreatic cancer cells suppresses tumor growth and metastasis through modulation of glycosylation of mucins and other cell surface and extracellular matrix proteins. Two-condition experiment, Core 3 synthase stable expression (C3) vs. vector control (PLVX) cells. Biological replicates: 3 Core 3 synthase stable expression, 3 vector control, independently grown and harvested. One replicate per array.
Project description:Abstract Purpose: Cystathionine ?-synthase (CBS), a key enzyme in the transsulfuration metabolic pathway, converts homocysteine to cystathionine, which is converted to cysteine required for the synthesis of major retinal antioxidant glutathione (GSH). Enzyme activity assays suggest that CBS is present in human and pig retina, however recent studies reported that CBS is not expressed in mouse retina. We found this species difference puzzling. Given the plethora of studies using mouse retina as a model system, coupled with the importance of GSH in retina, we investigated CBS expression in mouse retina at the molecular and cell biological level.Wildtype (WT) mice or mice lacking the gene encoding CBS (cbs(-)(/)(-)) were used in these studies. RNA and protein were isolated from retinas and liver (positive control) for the analysis of cbs gene expression by RT-PCR and CBS protein expression by Western blotting, respectively. CBS was analyzed by immunofluorescence in retinal cryosections and primary retinal cells (ganglion, Müller, retinal pigment epithelial). CBS enzyme activity was measured in primary Müller cells.RT-PCR revealed robust cbs expression in WT liver, brain and retina. Western blotting detected CBS in retina, brain and liver of WT mice, but not in cbs(-)(/)(-) mice liver. In immunohistochemical studies, CBS was present abundantly in the ganglion cell layer of retina; it was detected also in primary isolations of Müller, RPE and ganglion cells. CBS activity was detected in Müller cells by fluorescent detection of H2S.We have compelling molecular evidence that CBS is expressed in mouse retina at the gene and protein level. Our immunofluorescence data suggest that it is present in several retinal cell types and the data from the enzyme activity assay suggest activity in Müller cells. These findings set the stage to investigate the role of CBS and the transsulfuration pathway in the generation of GSH in mouse retina.
Project description:Ectopic expression of a deletion variant of cystathionine gamma-synthase 2 (GmCGS2) in soybean increases expression of genes encoding sulfur amino acid-rich proteins