Project description:Impaired wound healing and tissue regeneration have severe consequences on the patient’s life quality. Micrograft therapies are emerging as promising and affordable alternatives to improve skin regeneration by enhancing the endogenous wound repair processes. However, the molecular mechanisms underpinning the beneficial effects of the micrograft treatments remain largely unknown. In this study, we identified the active protein-1 (AP-1) member Fos-related antigen-1 (Fra-1) to play a central role in the extracellular-signal-regulated kinase (ERK)-mediated enhanced cell migratory capacity of micrograft-treated mouse adult fibroblasts and in the human keratinocyte (HaCaT) cell model. Accordingly, we show that increased micrograft-dependent in vitro cell migration and matrix metalloprotease activity is abolished upon inhibition of AP-1. Furthermore, micrograft treatment leads to increased expression and post-translational phosphorylation of Fra-1 and c-Jun, resulting in the upregulation of wound healing associated genes mainly involved in the regulation of cell migration. Collectively, our work provides insights into the molecular mechanisms behind micrograft treatments, which might contribute to future advances in wound repair therapies.
Project description:Migratory macrophages play critical roles in tissue development, homeostasis and disease so it is important to understand how their migration machinery is regulated. Whole-transcriptome sequencing revealed that CSF-1-stimulated differentiation of bone marrow derived precursors into mature macrophages is accompanied by widespread, profound changes in the expression of genes regulating adhesion, actin cytoskeletal remodeling and extracellular matrix degradation. Significantly altered expression of almost 40% of adhesion genes, 60–86% of Rho family GTPases, their regulators and effectors and over 70% of extracellular proteases occurred. The gene expression changes were mirrored by changes in macrophage adhesion associated with increases in motility and matrix-degrading capacity. IL-4 further increased motility and matrix-degrading capacity in mature macrophages, with additional changes in migration machinery gene expression. Finally, siRNA-induced reductions in the expression of core adhesion proteins, paxillin and leupaxin, decreased macrophage spreading and adhesion numbers with distinct effects on adhesion numbers and their distribution and on matrix degradation. Together, the datasets provide an important resource to increase our understanding of the regulation of migration in macrophages and to develop therapies targeting disease enhancing macrophages.
Project description:Ribonucleotide reductase (RNR) is the rate limiting enzyme in the synthesis of deoxyribonucleotides and the target of multiple chemotherapy drugs, including gemcitabine and hydroxyurea. In previous work, we identified that inhibition of RNR in Ewing sarcoma tumors upregulates the expression levels of multiple members of the activator protein-1 (AP-1) transcription factor family, including c-Jun and c-Fos, and downregulates the expression of c-Myc. However, the broader functions and downstream targets of AP-1, which are highly context- and cell-dependent, are unknown in Ewing sarcoma tumors. Consequently, in this work, we used genetically defined models, transcriptome profiling, and gene set enrichment analysis to identify that AP-1 and EWS-FLI1, the driver oncogene in most Ewing sarcoma tumors, reciprocally regulate the expression of multiple extracellular matrix proteins, including fibronectins, integrins, and collagens. AP-1 expression in Ewing sarcoma cells also drives, coincident with these perturbations in gene and protein expression, changes in cell morphology and phenotype. Furthermore, we also identified that the EWS-FLI1 oncoprotein dysregulates the expression of multiple AP-1 proteins, aligning with previous reports demonstrating genetic and physical interactions between EWS-FLI1 and AP-1. Overall, these results provide novel insight into the distinct, EWS-FLI1-dependent features of Ewing sarcoma tumors and identify a novel, reciprocal regulation of extracellular matrix components by EWS-FLI1 and AP-1.
Project description:The increased stiffness of the extracellular matrix is a key driver of liver fibrosis. The activated hepatic stellate cell (HSC) is the major producer of extracellular matrix (ECM) components. While little is known about the epigenomic changes that underlie the fibrogenic impact of ECM mechanics. In this study, we utilized a reliable in vitro system to mimic liver cirrhosis and integrated multi-omics analysis, which includes time-series RNA-seq and ATAC-seq as well as histone modification Cut&Tag, with imaging and biochemical essays to study the mechanism underlying the biomechanics function on fibrotic phenotype. We found that cells cultured in stiff matrix displayed more accessible chromatin sites, consisting of amount regions became accessible before stable fibrotic phenotype. We defined these regions as primed chromatin that chromatin accessibility foreshadows changes in gene expression. This kind of chromatin enriched in cytoskeleton organization and responding to mechanical stimulus biological process. Here, we depicted the AP-1 transcription factor family as being responsible for driving the construction of primed chromatin. Among AP-1 transcription factors, we confirmed JUN was critical to reconstruct chromatin accessibility to promote fibrogenic genotype. In addition, we described ERK contribute to the activation of JUN resulting in its binding on chromatin. Our results profiled a dynamic landscape of chromatin accessibility and defined the primed chromatin that contribute to fibrosis during responding to stiff matrix. We identified that AP-1 was capable of reorganizing the chromatin accessibility in mechanotransduction.
Project description:The increased stiffness of the extracellular matrix is a key driver of liver fibrosis. The activated hepatic stellate cell (HSC) is the major producer of extracellular matrix (ECM) components. While little is known about the epigenomic changes that underlie the fibrogenic impact of ECM mechanics. In this study, we utilized a reliable in vitro system to mimic liver cirrhosis and integrated multi-omics analysis, which includes time-series RNA-seq and ATAC-seq as well as histone modification Cut&Tag, with imaging and biochemical essays to study the mechanism underlying the biomechanics function on fibrotic phenotype. We found that cells cultured in stiff matrix displayed more accessible chromatin sites, consisting of amount regions became accessible before stable fibrotic phenotype. We defined these regions as primed chromatin that chromatin accessibility foreshadows changes in gene expression. This kind of chromatin enriched in cytoskeleton organization and responding to mechanical stimulus biological process. Here, we depicted the AP-1 transcription factor family as being responsible for driving the construction of primed chromatin. Among AP-1 transcription factors, we confirmed JUN was critical to reconstruct chromatin accessibility to promote fibrogenic genotype. In addition, we described ERK contribute to the activation of JUN resulting in its binding on chromatin. Our results profiled a dynamic landscape of chromatin accessibility and defined the primed chromatin that contribute to fibrosis during responding to stiff matrix. We identified that AP-1 was capable of reorganizing the chromatin accessibility in mechanotransduction.
Project description:The increased stiffness of the extracellular matrix is a key driver of liver fibrosis. The activated hepatic stellate cell (HSC) is the major producer of extracellular matrix (ECM) components. While little is known about the epigenomic changes that underlie the fibrogenic impact of ECM mechanics. In this study, we utilized a reliable in vitro system to mimic liver cirrhosis and integrated multi-omics analysis, which includes time-series RNA-seq and ATAC-seq as well as histone modification Cut&Tag, with imaging and biochemical essays to study the mechanism underlying the biomechanics function on fibrotic phenotype. We found that cells cultured in stiff matrix displayed more accessible chromatin sites, consisting of amount regions became accessible before stable fibrotic phenotype. We defined these regions as primed chromatin that chromatin accessibility foreshadows changes in gene expression. This kind of chromatin enriched in cytoskeleton organization and responding to mechanical stimulus biological process. Here, we depicted the AP-1 transcription factor family as being responsible for driving the construction of primed chromatin. Among AP-1 transcription factors, we confirmed JUN was critical to reconstruct chromatin accessibility to promote fibrogenic genotype. In addition, we described ERK contribute to the activation of JUN resulting in its binding on chromatin. Our results profiled a dynamic landscape of chromatin accessibility and defined the primed chromatin that contribute to fibrosis during responding to stiff matrix. We identified that AP-1 was capable of reorganizing the chromatin accessibility in mechanotransduction.
Project description:The metabolic state of a cell is influenced by cell-extrinsic factors, including nutrient availability and growth factor signaling. Here, we present extracellular matrix (ECM) remodeling as another fundamental node of cell-extrinsic metabolic regulation. Unbiased analysis of glycolytic drivers identified the hyaluronan-mediated motility receptor as among the most highly correlated with glycolysis in cancer. Confirming a mechanistic link between the ECM glycosaminoglycan hyaluronan and metabolism, treatment of both cells and xenograft tumors with hyaluronidase (HAase) triggers a robust increase in glycolysis. This is largely achieved through rapid receptor tyrosine kinase-mediated induction of mRNA decay factor ZFP36, which targets TXNIP transcripts for degradation. Since TXNIP promotes internalization of the glucose transporter GLUT1, its acute decline enriches GLUT1 at the plasma membrane. Functionally, induction of glycolysis by HAase is required for concomitant acceleration of cell migration. This interconnection between ECM remodeling and metabolism is exhibited in dynamic tissues states including tumorigenesis and embryogenesis.
Project description:The increased stiffness of the extracellular matrix is a key driver of liver fibrosis. The activated hepatic stellate cell (HSC) is the major producer of extracellular matrix (ECM) components. While little is known about the epigenomic changes that underlie the fibrogenic impact of ECM mechanics. In this study, we utilized a reliable in vitro system to mimic liver cirrhosis and integrated multi-omics analysis, which includes time-series RNA-seq and ATAC-seq as well as histone modification Cut&Tag, with imaging and biochemical essays to study the mechanism underlying the biomechanics function on fibrotic phenotype. We found that cells cultured in stiff matrix displayed more accessible chromatin sites, consisting of amount regions became accessible before stable fibrotic phenotype. We defined these regions as primed chromatin that chromatin accessibility foreshadows changes in gene expression. This kind of chromatin enriched in cytoskeleton organization and responding to mechanical stimulus biological process. Here, we depicted the AP-1 transcription factor family as being responsible for driving the construction of primed chromatin. Among AP-1 transcription factors, we confirmed JUN was critical to reconstruct chromatin accessibility to promote fibrogenic genotype. In addition, we described ERK contribute to the activation of JUN resulting in its binding on chromatin. Our results profiled a dynamic landscape of chromatin accessibility and defined the primed chromatin that contribute to fibrosis during responding to stiff matrix. We identified that AP-1 was capable of reorganizing the chromatin accessibility in mechanotransduction.