Project description:Transcriptome analysis of: 1- WM1716 melanoma cell line transfected with scrambled control or with miR-211. 2- WM3682 cell line mono-cultured or co-cultured with adipocytes.
Project description:We recently isolated and identified (7E)-9-oxohexadec-7-enoic acid (1) and (10E)-9-oxohexadec-10-enoic acid (2) from the marine algae Chaetoceros karianus. Synthesis and biological characterization show that these are PPARα/γ dual agonists. Herein we report the gene expression data from human SGBS pre-adipocytes, stimulated to differentiate with 1, 2 or the classical PPARγ agonist rosiglitazone. The transcriptome analysis shows that both compounds induce anti-diabetic gene programs in adipocytes by upregulating insulin-sensitizing adipokines and repressing pro-inflammatory cytokines.
Project description:We have identified a population of adipocytes in fat tissue that arise from bone marrow-derived progenitor cells. We used microarrays to compare the global gene expression patterns of the bone marrow progenitor-derived adipocytes as well as conventional white and brown adipocytes to evaluate the relationship between these adipocyte subpopulations. Gonadal fat tissue (for white adipocytes) and intrascapular fat tissue (for brown adipocytes) was digested with collagenase and adipocytes were recovered by centrifugation/flotation. Bone marrow derived adipocytes were isolated from the adipocyte fraction of gonadal fat tissue from mice receiving bone marrow tranplants from donors expressing either green fluorescent protein (GFP) or beta-galactosidase (LacZ) by flow cytometry.
Project description:Oncogenic PIK3CA mutations activate phosphoinositide 3-kinase (PI3K) and are among the commonest somatic mutations in cancer and mosaic, developmental overgrowth disorders. We recently demonstrated that the ‘hotspot’ variant PIK3CAH1047R exerts striking allele dose-dependent effects on stemness in human induced pluripotent stem cells (iPSCs), and moreover demonstrated multiple oncogenic PIK3CA copies in a substantial subset of human cancers. To identify the molecular mechanism underpinning PIK3CAH1047R allele dose-dependent stemness, we profiled isogenic wild-type, PIK3CAWT/H1047R and PIK3CAH1047R/H1047R iPSCs by high-depth transcriptomics, proteomics and reverse-phase protein arrays (RPPA). PIK3CAH1047R/H1047R iPSCs exhibited altered expression of 5644 genes and 248 proteins, whereas heterozygous hPSCs showed 492 and 54 differentially-expressed genes and proteins, respectively, confirming a nearly deterministic phenotypic effect of homozygosity for PIK3CAH1047R. Pathway and network-based analyses predicted a strong association between self-sustained TGFb/NODAL signaling and the ‘locked’ stemness phenotype induced by homozygosity for PIK3CAH1047R. This stemness gene signature was maintained without exogenous NODAL in PIK3CAH1047R/H1047R iPSCs and was reversed by pharmacological inhibition of TGFb/NODAL signaling but not by PIK3CA-specific inhibition. Analysis of PIK3CA-associated human breast cancers revealed increased expression of the stemness markers NODAL and POU5F1 as a function of disease stage and PIK3CAH1047R allele dosage. Together with emerging realization of the link between NODAL re-expression and aggressive cancer behavior, our data suggest that TGFb/NODAL inhibitors warrant testing in advanced breast tumors with multiple oncogenic PIK3CA copies.
Project description:White adipose tissue (WAT) is a key regulator of systemic energy metabolism, and impaired WAT plasticity characterized by enlargement of preexisting adipocytes associates with WAT dysfunction, obesity and metabolic complications. However, the mechanisms that retain proper adipose tissue plasticity required for metabolic fitness are unclear. Here, we comprehensively showed that adipocyte-specific DNA methylation, manifested in enhancers and CTCF sites, directs distal enhancer-mediated transcriptomic features required to conserve metabolic functions of white adipocytes. Particularly, genetic ablation of adipocyte Dnmt1, the major methylation writer, led to increased adiposity characterized by increased adipocyte hypertrophy along with reduced expansion of adipocyte precursors (APs). These effects of Dnmt1 deficiency provoked systemic hyperlipidemia and impaired energy metabolism both in lean and obese mice. Mechanistically, Dnmt1 deficiency abrogated mitochondrial bioenergetics by inhibiting mitochondrial fission and promoted aberrant lipid metabolism in adipocytes, rendering adipocyte hypertrophy and WAT dysfunction. Dnmt1-dependent DNA methylation prevented aberrant CTCF binding and, in turn, sustained the proper chromosome architecture to permit interactions between enhancer and dynamin-related protein gene Drp1 in adipocytes. Also, adipose DNMT1 expression inversely correlated with adiposity and markers of metabolic health, but positively correlated with AP-specific markers in obese human subjects. Thus, these findings support strategies utilizing Dnmt1 action on mitochondrial bioenergetics in adipocytes to combat obesity and related metabolic pathology.
Project description:Preservation of cell identity is necessary for homeostasis of most adult tissues. This process is challenged every time a tissue undergoes regeneration after stress or injury. In the lethal Duchenne muscular Dystrophy (DMD), skeletal muscle regenerative capacity declines gradually as fibrosis increases. Using genetically engineered-tracing mice, we demonstrate that in dystrophic muscle, specialized cells of muscular, endothelial and hematopoietic origins gain plasticity towards a fibrogenic fate via a TGFβ-mediated pathway. This results in loss of cellular identity and normal function, with deleterious consequences for regeneration. Furthermore, this fibrogenic process involves acquisition of a mesenchymal progenitor multipotent status, illustrating a link between fibrogenesis and gain of progenitor cell functions. As this plasticity was also observed in DMD patients, we propose that mesenchymal transitions impair regeneration and worsen diseases with a fibrotic component. TGFb exposure induced gene expression was measured after 4 days of treatment compared to untreated cells. Three independent experiments were performed both for the treatment and for the control
Project description:A high degree of cell plasticity seems to promote malignant tumour progression, and an epithelial-mesenchymal transition (EMT) is suspected to provide cancer cells with increased cell plasticity for the development of metastasis and therapy resistance. Here, we have tested whether the EMT-induced cancer cell plasticity can be therapeutically exploited and we report the efficient conversion of breast cancer cells, which have undergone an EMT, into post-mitotic adipocytes. Delineation of the molecular pathways underlying such transdifferentiation has motivated a combination therapy with a MEK inhibitor and Rosiglitazone to demonstrate the conversion of invasive cancer cells into adipocytes and the repression of primary tumor invasion and metastasis formation in mouse models of breast cancer. The results indicate the high potential to utilize the increased cell plasticity of invasive cancer cells for differentiation therapy and they raise the possibility to employ pharmacological treatments to interfere with tumor invasion and metastasis.
Project description:Energy-storing white adipocytes maintain their identity by suppressing the gene program defining energy-burning thermogenic brown/beige adipocytes. Here, we reveal that the protein-protein interaction between the transcriptional co-regulator ZFP423 and brown/beige cell determination factor, EBF2, is essential for restraining the thermogenic phenotype of white adipose tissue (WAT). Disruption of the ZFP423-EBF2 protein interaction through CRISPR-Cas9 gene editing triggers widespread “browning” of WAT in adult mice. Mechanistically, adipocyte Zfp423 deficiency induces an EBF2 NuRD-to-BAF co-regulator switch and a shift in PPARgamma occupancy to thermogenic genes. This shift in PPARgamma occupancy increases the anti-diabetic efficacy of the PPARgamma agonist rosiglitazone in obesity while diminishing the unwanted weight-gaining effect of the drug. These data indicate that ZFP423 controls EBF2 co-activator recruitment and PPARgamma occupancy to determine the thermogenic plasticity of adipocytes and raise the concept of targeting transcriptional brakes in adipocyte gene expression as a therapeutic strategy to induce thermogenic adipocyte biogenesis in obesity.
Project description:Energy-storing white adipocytes maintain their identity by suppressing the gene program defining energy-burning thermogenic brown/beige adipocytes. Here, we reveal that the protein-protein interaction between the transcriptional co-regulator ZFP423 and brown/beige cell determination factor, EBF2, is essential for restraining the thermogenic phenotype of white adipose tissue (WAT). Disruption of the ZFP423-EBF2 protein interaction through CRISPR-Cas9 gene editing triggers widespread “browning” of WAT in adult mice. Mechanistically, adipocyte Zfp423 deficiency induces an EBF2 NuRD-to-BAF co-regulator switch and a shift in PPARgamma occupancy to thermogenic genes. This shift in PPARgamma occupancy increases the anti-diabetic efficacy of the PPARgamma agonist rosiglitazone in obesity while diminishing the unwanted weight-gaining effect of the drug. These data indicate that ZFP423 controls EBF2 co-activator recruitment and PPARgamma occupancy to determine the thermogenic plasticity of adipocytes and raise the concept of targeting transcriptional brakes in adipocyte gene expression as a therapeutic strategy to induce thermogenic adipocyte biogenesis in obesity.