ABSTRACT
Energy metabolism is highly interdependent with adaptive cell migration in vivo. Mechanical confinement is a critical physical cue that induces switchable migration modes of the mesenchymal-to-amoeboid transition (MAT). However, the energy states in distinct migration modes, especially amoeboid-like stable bleb (A2) movement, remain unclear. In this report, we developed multivalent DNA framework-based nanomachines to explore strategical mitochondrial trafficking and differential ATP levels during cell migration in mechanically heterogeneous microenvironments. Through single-particle tracking and metabolomic analysis, we revealed that fast A2-moving cells driven by biomimetic confinement recruited back-end positioning of mitochondria for powering highly polarized cytoskeletal networks, preferentially adopting an energy-saving mode compared with a mesenchymal mode of cell migration. We present a versatile DNA nanotool for cellular energy exploration and highlight that adaptive energy strategies coordinately support switchable migration modes for facilitating efficient metastatic escape, offering a unique perspective for therapeutic interventions in cancer metastasis.
Subject(s)
Amoeba , Cell Line, Tumor , Cell Movement , Physical PhenomenaABSTRACT
The emerging outbreak of monkeypox is closely associated with the viral infection and spreading, threatening global public health. Virus-induced cell migration facilitates viral transmission. However, the mechanism underlying this type of cell migration remains unclear. Here we investigate the motility of cells infected by vaccinia virus (VACV), a close relative of monkeypox, through combining multi-omics analyses and high-resolution live-cell imaging. We find that, upon VACV infection, the epithelial cells undergo epithelial-mesenchymal transition-like transformation, during which they lose intercellular junctions and acquire the migratory capacity to promote viral spreading. After transformation, VACV-hijacked RhoA signaling significantly alters cellular morphology and rearranges the actin cytoskeleton involving the depolymerization of robust actin stress fibers, leading-edge protrusion formation, and the rear-edge recontraction, which coordinates VACV-induced cell migration. Our study reveals how poxviruses alter the epithelial phenotype and regulate RhoA signaling to induce fast migration, providing a unique perspective to understand the pathogenesis of poxviruses.
Subject(s)
Mpox (monkeypox) , Vaccinia virus , Humans , Cell Movement , Disease Outbreaks , Epithelial CellsABSTRACT
Electroporation techniques have emerged as attractive tools for intracellular delivery, rendering promising prospects towards clinical therapies. Transient disruption of membrane permeability is the critical process for efficient electroporation-based cargo delivery. However, smart nanotools for precise characterization of transient membrane changes induced by strong electric pulses are extremely limited. Herein, multivalent membrane-anchored fluorescent nanoprobes (MMFNPs) that take advantages of flexible functionalization and spatial arrangement of DNA frameworks are developed for in situ evaluation of electric field-induced membrane permeability during reversible electroporation . Single-molecule fluorescence imaging techniques are adopted to precisely verify the excellent analytical performance of the engineered MMFNPs. Benefited from tight membrane anchoring and sensitive adenosine triphosphate (ATP) profiling, varying degrees of membrane disturbances are visually exhibited under different intensities of the microsecond pulse electric field (µsPEF). Significantly, the dynamic process of membrane repair during reversible electroporation is well demonstrated via ATP fluctuations monitored by the designed MMFNPs. Furthermore, molecular dynamics (MD) simulations are performed for accurate verification of electroporation-driven dynamic cargo entry via membrane nanopores. This work provides an avenue for effectively capturing transient fluctuations of membrane permeability under external stimuli, offering valuable guidance for developing efficient and safe electroporation-driven delivery strategies for clinical diagnosis and therapeutics.
Subject(s)
Adenosine Triphosphate , Cell Membrane Permeability , DNA , Electroporation , Molecular Dynamics Simulation , Electroporation/methods , DNA/chemistry , DNA/administration & dosage , Adenosine Triphosphate/metabolism , Humans , Fluorescent Dyes/chemistry , Cell Membrane/metabolism , Cell Membrane/chemistry , NanoporesABSTRACT
The cell membrane separates the intracellular compartment from the extracellular environment, constraining exogenous molecules to enter the cell. Conventional electroporation typically employs high-voltage and short-duration pulses to facilitate the transmembrane transport of molecules impermeable to the membrane under natural conditions by creating temporary hydrophilic pores on the membrane. Electroporation not only enables the entry of exogenous molecules but also directs the intracellular distribution of the electric field. Recent advancements have markedly enhanced the efficiency of intracellular molecule delivery, achieved through the utilization of microstructures, microelectrodes, and surface modifications. However, little attention is paid to regulating the motion of molecules during and after passing through the membrane to improve delivery efficiency, resulting in an unsatisfactory delivery efficiency and high dose demand. Here, we proposed the strategy of regulating the motion of charged molecules during the delivery process by progressive electroporation (PEP), utilizing modulated electric fields. Efficient delivery of charged molecules with an expanded distribution and increased accumulation by PEP was demonstrated through numerical simulations and experimental results. The dose demand can be reduced by 10-40% depending on the size and charge of the molecules. We confirmed the safety of PEP for intracellular delivery in both short and long terms through cytotoxicity assays and transcriptome analysis. Overall, this work not only reveals the mechanism and effectiveness of PEP-enhanced intracellular delivery of charged molecules but also suggests the potential integration of field manipulation of molecular motion with surface modification techniques for biomedical applications such as cell engineering and sensitive cellular monitoring.
Subject(s)
Electroporation , Electroporation/methods , Humans , Cell Membrane/metabolismABSTRACT
Background: Steroid-induced Osteonecrosis of the Femoral Head (SIONFH) is a skeletal disease with a high incidence and a poor prognosis. Whole body vibration therapy (WBVT), a new type of physical training, is known to promote bone formation. However, it remains unclear whether WBVT has a therapeutic effect on SIONFH. Materials and methods: Thirty adult male and female Sprague-Dawley (SD) rats were selected and randomly assigned to three experimental groups: the control group, the model group, and the mechanical vibration group, respectively. SIONFH induction was achieved through the combined administration of lipopolysaccharides (LPS) and methylprednisolone sodium succinate for injection (MPS). The femoral head samples underwent hematoxylin and eosin (H&E) staining to visualize tissue structures. Structural parameters of the region of interest (ROI) were compared using Micro-CT analysis. Immunohistochemistry was employed to assess the expression levels of Piezo1, BMP2, RUNX2, HIF-1, VEGF, CD31, while immunofluorescence was used to examine CD31 and Emcn expression levels. Results: The H&E staining results revealed a notable improvement in the ratio of empty lacuna in various groups following WBVT intervention. Immunohistochemical analysis showed that the expression levels of Piezo1, BMP2, RUNX2, HIF-1, VEGF, and CD31 in the WBVT group exhibited significant differences when compared to the Model group (p < 0.05). Additionally, immunofluorescence analysis demonstrated statistically significant differences in CD31 and Emcn expression levels between the WBVT group and the Model group (p < 0.05). Conclusion: WBVT upregulates Piezo1 to promote osteogenic differentiation, potentially by enhancing the HIF-1α/VEGF axis and regulating H-vessel angiogenesis through the activation of the Piezo1 ion channel. This mechanism may lead to improved blood flow supply and enhanced osteogenic differentiation within the femoral head.
ABSTRACT
The tumor-treating fields (TTFields) technology has revolutionized the management of recurrent and newly diagnosed glioblastoma (GBM) cases. To ameliorate this treatment modality for GBM and other oncological conditions, it is necessary to understand the biophysical principles of TTFields better. In this study, we further analyzed the mechanism of the electromagnetic exposure with varying frequencies and electric field strengths on cells in mitosis, specifically in telophase. In reference to previous studies, an intuitive finite element model of the mitotic cell was built for electromagnetic simulations, predicting a local increase in the cleavage furrow region, which may help explain TTFields' anti-proliferative effects. Cell experiments confirmed that the reduction in proliferation and migration of glioma cell by TTFields was in a frequency- and field-strength-dependent manner. This work provides unique insights into the selection of frequencies in the anti-proliferative effect of TTFields on tumors, which could improve the application of TTFields.