Project description:<p>Mechanical force is critical for the development and remodeling of bone. Here we report that mechanical force regulates the production of the metabolite asymmetric dimethylarginine (ADMA) via regulating the hydrolytic enzyme dimethylarginine dimethylaminohydrolase 1 (Ddah1) expression in osteoblasts. The presence of -394 4N del/ins polymorphism of Ddah1 and higher serum ADMA concentration are negatively associated with bone mineral density. Global or osteoblast-specific deletion of Ddah1 leads to increased ADMA level but reduced bone formation. Further molecular study unveils that mechanical stimulation enhances TAZ/SMAD4-induced Ddah1 transcription. Deletion of Ddah1 in osteoblast-lineage cells fails to respond to mechanical stimulus-associated bone formation. Taken together, the study reveals mechanical force is capable of down-regulating ADMA to enhance bone formation.</p>
Project description:The ability of the skin to expand in response to stretching has, for decades, been exploited in reconstructive surgery. Several studies have investigated the response of stretching epidermal cells in vitro. However, it remains unclear how mechanical forces affect epidermal stem cell behaviour in vivo. Here, we develop a mouse model in which the temporal consequences of the stretching the skin epidermis can be studied. Using a multidisciplinary approach that combines clonal analysis and mathematical modelling, we show that mechanical force induces skin expansion by promoting the renewal of epidermal stem cells. This occurs through a structured response in which cell fates are coordinated locally by stem cells that switch between states primed for renewal or differentiation. Transcriptional and chromatin profiling identifies the gene regulatory networks modulated by mechanical force. Using a combination of pharmacological inhibition and several conditional gene loss-of-function mouse mutants, we dissect the signalling pathways that control force-mediated tissue expansion.
Project description:To assess the transcriptomic response to Klotho deficiency in the renal distal convolution (DC), we isolated DC cells from control and DC-specific Klotho KO mice using COPAS (Complex Object Parametric Analyzer and Sorter). Further comprehensive and unbiased RNA-seq identified altered transcripts associated with canonical MAPK pathway, as well as many novel targets of Klotho.
2023-12-15 | GSE247008 | GEO
Project description:Mechanical force and urinary bladder fibrosis
Project description:Macrophages play a pivotal role in mechanical force-induced inflammatory bone remodeling. Yet, how macrophages perceive mechanical stimuli and thereby modulate biological behaviors remain elusive. The orthodontic tooth movement (OTM) model was established to access the role of Piezo1 in modulating macrophage response upon mechanical stimuli. The potential functions and molecule mechanisms of Piezo1 were explored by bone marrow-derived macrophages (BMDMs) using mechanical stretch system, western blotting, immunofluorescence, flow cytometry and RNA sequencing. We first found macrophage proliferative phenotype enhanced at the later stage of force application. The biological variation mediated by mechanical force could be suppressed by Piezo1 inhibition. Furthermore, Piezo1 activated PI3K-AKT signaling was closely associated with macrophage proliferation upon mechanical stimuli. Additionally, Ccnd1 was authenticated as a critical downstream factor of PI3K-AKT signaling and conditional ablation of Ccnd1 in macrophages inhibited macrophage proliferation in mechanical force-induced bone remodeling procedure.
Project description:The ability of the skin to expand in response to stretching has, for decades, been exploited in reconstructive surgery. Several studies have investigated the response of stretching epidermal cells in vitro. However, it remains unclear how mechanical forces affect epidermal stem cell behaviour in vivo. Here, we develop a mouse model in which the temporal consequences of the stretching the skin epidermis can be studied. Using a multidisciplinary approach that combines clonal analysis and mathematical modelling, we show that mechanical force induces skin expansion by promoting the renewal of epidermal stem cells. This occurs through a structured response in which cell fates are coordinated locally by stem cells that switch between states primed for renewal or differentiation. Transcriptional and chromatin profiling identifies the gene regulatory networks modulated by mechanical force. Using a combination of pharmacological inhibition and several conditional gene loss-of-function mouse mutants, we dissect the signalling pathways that control force-mediated tissue expansion. We used microarray to molecularly profile basal cells isolated from the interfolliular epidermis during force-mediated tissue expansion and after 12-O-Tetradecanoylphorbol-13-acetate (TPA) tretment.
Project description:Despite the ubiquitous mechanical cues at both spatial and temporal dimensions, cell identities and functions are largely immune to the everchanging mechanical stimuli. To understand the molecular basis of this epigenetic stability, we interrogated compressive force elicited transcriptomic changes in mesenchymal stem cells purified from human periodontal ligament (PDLSCs), and identified H3K27me3 and E2F signatures populated within up- and weakly down-regulated genes respectively. Consistently, expressions of several E2F family transcription factors and EZH2, as core methyltransferase for H3K27me3, decreased in response to mechanical stress, which were attributed to force induced redistribution of RB from nucleoplasm to lamina. Importantly, although epigenomic analysis on H3K27me3 landscape only demonstrated correlating changes at one group of mechanoresponsive genes, we observed a genome-wide destabilization of super-enhancers along with aberrant EZH2 retention. These super-enhancers were tightly bounded by H3K27me3 domain on one side and exhibited attenuating H3K27ac deposition and flattening H3K27ac peaks after force exposure, analogous to increased H3K27ac entropy or decreased H3K27ac polarization. Interference of force induced EZH2 reduction could drive nuclear actin filaments dependent collision between EZH2 and super-enhancers and functionally compromise the multipotency of PDLSC following mechanical stress. These findings together unveil a specific contribution of EZH2 reduction for maintenance of super-enhancer stability and cell identity in mechanoresponse.
Project description:Mechanical force is a crucial external stimulus that plays a significant role in regulating bone structure and remodeling. Excessive loading of the bone and joint can lead to increased catabolism, chondrocyte necrosis, apoptosis and damage to the collagen network of bone(3–5). Osteoarthritis (OA), a degenerative osteoarticular disease, is associated with abnormal mechanical force stimulation, which can occur in various joints such as knee, temporomandibular joint [TMJ], shoulder and hip(6). Conversely, the absence of mechanical loading, such as prolonged bed rest or exposure to a microgravity environment in space, can result in a rapid decrease in bone mass and strength. Understanding how mechanical stimuli regulate bone homeostasis is crucial for exploring therapeutic strategies for bone metabolic diseases.Mesechymal stem cells (MSCs) act as the external force sensoring and compression-bearing elements.What we want to explore is how mechanical stimulation affects the genome changes of mesenchymal stem cells.
Project description:Mechanical force is critical for lung development. In this study we identified specific EV-miRNAs released from the mouse epithelial cell line in response to mechanical stretch involve in lung development. In utero fetal lung experiences significant continuous transpulmonary pressure as a result of epithelial secretion in to the airway lumen, and periodic fetal breathing movement that move the fluid along the developing airway. Mechanical force is important factors for fetal lung development. However, the effect of mechanical force on the functions of lung cells is not known precisely. Extracellular vesicles –microRNAs (EV-miRNA) are increasingly recognized as a new mode of cell-to-cell communication. miRNA is well known as a regulator of physio-pathological process. In this study, we used oligonucleotide microarray technology to investigate miRNA expression in EV-released from mouse lung epithelial cell MLE12 after exposed to 10% cyclic or 5% continuous stretch. Analysis of microarray data identified 9 and 33 miRNAs significantly differentially expressed by the cyclic and continuous stretch respectively. Several differentially expressed miRNAs were reported dynamically expressed in mouse developing lung. miRNAs associated with important transcription factors for cell function and key signaling pathways for fetal lung development also identified in this study. We conclude that mechanical signals differentially regulate the expression of specific EV/miRNAs in MLE12 are important for intercellular communication during lung fetal development.