Project description:To gain further insight into ageing-related changes in the superficial cervical lymphatics, we performed scRNA-seq on cells isolated from the superficial cervical lymphatic system.
Project description:Cyclic mechanical loads applied to the skeleton increase bone formation. Dynamic fluid flow is a potent anabolic stimulus for cultured osteoblasts. In this study, gene profiles involved in mediating the anabolic response of MC3T3 osteoblasts to dynamic fluid flow are investigated. MC3T3 osteoblast RNA was harvested 30-minutes and 1-hour post-stimulation respectively as experimental samples for comparison to the control group without dynamic fluid flow.
Project description:Meningeal lymphatics serve as the primary outlet for cerebrospinal fluid, and their dysfunction is associated with various neurodegenerative conditions. Previous studies have demonstrated that dysfunctional meningeal lymphatics evoke behavioral deficits, but the neural mechanisms underlying those behavioral changes remained elusive. Here, we show that prolonged impairment of meningeal lymphatics alters the balance of cortical excitatory and inhibitory synaptic inputs by reducing inhibitory synapses, accompanied by deficits in novelty recognition tasks. These synaptic and behavioral alterations are mediated by microglia, which exhibit transcriptomic, morphological, and functional alterations as a result of lymphatic dysfunction. Notably, microglial expression of Il6 increases, thereby mediating the reduction in inhibitory synapses via neuronal signaling. Interestingly, improving the function of meningeal lymphatics in aged mice restores the numbers of functional inhibitory synapses and cortical network activity. Our findings suggest that dysfunctional meningeal lymphatics adversely impact cortical circuitry through a microglia−IL-6-dependent mechanism, providing a potential target for the treatment of aging-associated cognitive decline.
Project description:Meningeal lymphatics serve as the primary outlet for cerebrospinal fluid, and their dysfunction is associated with various neurodegenerative conditions. Previous studies have demonstrated that dysfunctional meningeal lymphatics evoke behavioral deficits, but the neural mechanisms underlying those behavioral changes remained elusive. Here, we show that prolonged impairment of meningeal lymphatics alters the balance of cortical excitatory and inhibitory synaptic inputs by reducing inhibitory synapses, accompanied by deficits in novelty recognition tasks. These synaptic and behavioral alterations are mediated by microglia, which exhibit transcriptomic, morphological, and functional alterations as a result of lymphatic dysfunction. Notably, microglial expression of Il6 increases, thereby mediating the reduction in inhibitory synapses via neuronal signaling. Interestingly, improving the function of meningeal lymphatics in aged mice restores the numbers of functional inhibitory synapses and cortical network activity. Our findings suggest that dysfunctional meningeal lymphatics adversely impact cortical circuitry through a microglia−IL-6-dependent mechanism, providing a potential target for the treatment of aging-associated cognitive decline.
Project description:Background: Mechanical forces play a crucial role in regulating cellular communication during tissue repair, yet how mechanical stimulation modulates endothelial exosome secretion and their effects on fibroblast activation remains unclear. Methods: In this study, endothelial cells were incorporated into 3D bioprinted tissue-engineered dermal constructs and cultured under static or mechanically stretched conditions. Exosomes were isolated, characterized, and applied to human dermal fibroblasts to assess their influence on proliferation, migration, and extracellular matrix formation. Data-independent acquisition proteomics was performed to analyze exosomal protein cargo and associated signaling pathways. Results: Mechanical loading increased exosome secretion by approximately 2.5-fold without altering vesicle morphology. Functionally, mechanically stimulated exosomes significantly enhanced fibroblast migration and type I collagen synthesis compared with controls. Proteomic profiling identified 4,476 proteins, of which 677 were differentially expressed. Enrichment analysis revealed activation of VEGF, HIF-1, Relaxin, and AGE–RAGE pathways, implicating roles in angiogenesis, metabolic regulation, and extracellular matrix remodeling. Conclusion: These findings demonstrate that 3D mechanical stimulation not only augments the quantity of endothelial exosomes but also reshapes their molecular cargo, thereby enhancing biomechanical communication between endothelial cells and fibroblasts. Together with prior evidence of fibroblast-derived exosomes promoting endothelial angiogenesis, this study proposes a bidirectional “mechanical stimulation–exosome–communication–tissue reconstruction” loop, providing a theoretical foundation for optimizing exosome-based strategies in skin tissue engineering.
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:Major depressive disorder is one of the most common mental health conditions. Meningeal lymphatics are essential for drainage of molecules in the cerebrospinal fluid to the peripheral immune system. Their potential role in depression-like behaviour has not been investigated. Here, we show in mice, sub-chronic variable stress as a model of depression-like behaviour impairs meningeal lymphatics in females but not in males. Manipulations of meningeal lymphatics regulate the sex difference in the susceptibility to stress-induced depression- and anxiety-like behaviors in mice, as well as alterations of the medial prefrontal cortex and the ventral tegmental area, brain regions critical for emotional regulation. Together, our findings suggest meningeal lymphatic impairment contributes to susceptibility to stress in mice, and that restoration of the meningeal lymphatics might have potential for modulation of depression-like behaviour.
Project description:The glymphatic movement of fluid through the brain powerfully clears metabolic waste. We observed multisensory 40 Hz stimulation promotes the influx of cerebrospinal fluid and the efflux of interstitial fluid in the cortex of the 5XFAD mouse model of Alzheimer’s disease, which was associated with increased aquaporin-4 polarization along astrocytic endfeet, dilated meningeal lymphatic vessels, and amyloid accumulation in cervical lymph nodes. Inhibiting glymphatic clearance abolished the removal of amyloid by multisensory 40 Hz stimulation. Using chemogenetic manipulation and a genetically encoded sensor for neuropeptide signaling, we found VIP+ interneurons facilitate glymphatic clearance by regulating arterial pulsatility. Our findings establish novel mechanisms to recruit the glymphatic system to remove brain amyloid.
Project description:This study presents a first step towards identifying soluble mediators of keratinocyte-sensory neuron communication by evaluating the potential for top down mass spectrometry to identify proteoforms secreted during one minute of mechanical stimulation of mouse skin from na�ve animals. Overall, this study identified 47 proteoforms in the secretome of mouse hindpaw skin, of which 14 were deferentially secreted during mechanical stimulation, and includes proteins with known and previously unknown relevance to mechanotransduction. Finally, this study outlines a bioinformatic workflow that merges output from two complementary analysis platforms for top down data and demonstrates the utility of this workflow for integrating quantitative and qualitative data.