Transient receptor potential vanilloid 4 (TRPV4) is a calcium-permeable cation channel that has been associated with several types of cancer. However, its biological significance, as well as its ...related mechanism in endometrial cancer (EC) still remains elusive. In this study, we examined the function of calcium in EC, with a specific focus on TRPV4 and its downstream pathway. We reported here on the findings that a high level of serum ionized calcium was significantly correlated with advanced EC progression, and among all the calcium channels, TRPV4 played an essential role, with high levels of TRPV4 expression associated with cancer progression both in vitro and in vivo. Proteomic and bioinformatics analysis revealed that TRPV4 was involved in cytoskeleton regulation and Rho protein pathway, which regulated EC cell migration. Mechanistic investigation demonstrated that TRPV4 and calcium influx acted on the cytoskeleton via the RhoA/ROCK1 pathway, ending with LIMK/cofilin activation, which had an impact on F-actin and paxillin (PXN) levels. Overall, our findings indicated that ionized serum calcium level was significantly associated with poor outcomes and calcium channel TRPV4 should be targeted to improve therapeutic and preventive strategies in EC.
Mechanical phenotypes of cells are found to hold vital clues to reveal cellular functions and behaviors, which not only has great physiological significance but also is crucial for disease diagnosis. ...To this end, we developed a set of electrodeformation-based biomechanical microchip assays to quantify mechanical phenotypes on the single-cell level. By investigating the spatiotemporal dynamics of cancer cells driven by dielectrophoresis forces, we captured the key global viscoelastic indexes including cellular elasticity, viscosity, and transition time that was defined as the ratio of the transient viscosity and elasticity, simultaneously, and thus explored their intrinsic correlation with cell cycle progression. Our results showed that both global elasticity and viscosity have a significant periodic variation with cell cycle progression, but the transition time remained unchanged in the process, indicating that it might be an intrinsic property of cancer cells that is independent of the cell cycle and the type of cell in the experiments. Further, we investigated the molecular mechanism regulating cellular viscoelastic phenotypes on the biomechanical chips through intracellular cytoskeletal perturbation assays. These findings, together with the electrodeformation-based microchip technique, not only reveal the relation between mechanical phenotypes of cancer cells and cell cycle progression but also provide a platform for implementing multi-index mechanical phenotype assays associated with cancer cell cycles in the clinic.
Cell therapeutics hold tremendous regenerative potential and the therapeutic effect depends on the effective delivery of cells. However, current cell delivery carriers with unsuitable ...cytocompatibility and topological structure demonstrate poor cell viability during injection. Therefore, porous shape‐memory cryogel microspheres (CMS) are prepared from methacrylated gelatin (GelMA) by combining an emulsion technique with gradient‐cooling cryogelation. Pore sizes of the CMS are adjusted via the gradient‐cooling procedure, with the optimized pore size (15.5 ± 6.0 µm) being achieved on the 30‐min gradient‐cooled variant (CMS‐30). Unlike hydrogel microspheres (HMS), CMS promotes human bone marrow stromal cell (hBMSC) and human umbilical vein endothelial cell (HUVEC) adhesion, proliferated with high levels of stemness for 7 d, and protects cells during the injection process using a 26G syringe needle. Moreover, CMS‐30 enhances the osteogenic differentiation of hBMSCs in osteoinductive media. CMS can serve as building blocks for delivering multiple cell types. Here, hBMSC‐loaded and HUVEC‐loaded CMS‐30, mixed at a 1:1 ratio, are injected subcutaneously into nude mice for 2 months. Results show the development of vascularized bone‐like tissue with high levels of OCN and CD31. These findings indicate that GelMA CMS of a certain pore size can effectively deliver multiple cells to achieve functional tissue regeneration.
Injectable methacrylated gelatin (GelMA)‐based cryogel microspheres (CMS) with tunable pore size and shape‐memory performance having the ability to deliver cells are presented here. The microspheres show strong capacities in promoting cell adhesion and proliferation, and protecting cells during the injection. Owing to their flexibility in application as building blocks, CMS present a feasible approach for multiple cell delivery and functional tissue regeneration.
As a biocompatible material, soft silicone gels like CY52-276 have been applied to many engineering fields associated with interactions between mammalian cells and extracellular matrices/substrates, ...due to its nontoxicity, ease of preparation, optical transparency and tunable mechanical properties. Precise quantification of mechanical properties of silicone gels is crucial for quantitatively investigating mechanical responses of cells to microenvironments. Addressing the material with high surface energy, we design a new strategy for the nanoindentation technique to reduce or even eliminate the effect of interfacial adhesions with the aid of some specified buffers. Next, we dissect the dependence of its Young’s modulus on the ratios of monomers and crosslinkers and curing conditions, and therefore identify a dose–response relationship between its moduli and the corresponding prepolymer compositions. With the non-linear large deformation nanoindentation tests, we further showed that the two-parameter Mooney–Rivlin model may well characterize the hyperelastic deformations of the materials with different composition ratios. These pave the way for more precise exploration of the interaction between cells and extracellular matrix and the underlying mechanotransduction pathways in mechanobiology.
Graphic Abstract
Precise quantification of mechanical properties of silicone gels is crucial for quantitatively investigating mechanical responses of cells to microenvironments. Addressing the material with high surface energy, we design a new strategy for the nanoindentation technique to reduce or even eliminate the effect of interfacial adhesions with the aid of some specified buffers. Next, we dissect the dependence of its Young’s modulus on the ratios of monomers and crosslinkers and curing conditions. These pave the way for more precise exploration of the interaction between cells and extracellular matrix and the underlying mechanotransduction pathways in mechanobiology.
•An electrodeformation-based microchip is fabricated for mechanical characterization of cells undergoing EMT.•The correlation is revealed between the TGF-β1-induced EMT of cells and their mechanical ...deformability.•This technique presents an alternative biophysical way to detect EMT induced by TGF-β1.•This method provides a novel insight for designing biochips to clinically diagnose cancer.
Cancer development and progression associated with epithelial-mesenchymal transition (EMT) not only results in biological and functional abnormalities but also leads to changes in mechanical and structural characteristics of cells. Mechanical characterization has been considered as a promising, label-free, alternative way to cancer diagnosis. In this paper, we fabricate a microchip to quantify mechanical deformability of cancer cells during EMT in an electrodeformation-based way. For three typical cancer cells, i.e., MCF-7, MDA-MB-231 and A549 cells, our experimental outcome manifests that there exists significant difference in the deformability before and after EMT induced by TGF-β1. Both MCF-7 and MDA-MB-231 cells after EMT show more than 40% reduction in elasticity and viscosity, whereas A549 cells appear to have a ∼25% decrease in elasticity and ∼35% in viscosity, respectively. These findings imply it is feasible to monitor the EMT process by means of mechanical clue of cells involved. It is expected that the present electrodeformation-based technique can be developed into a label-free, high-throughput method to evaluate metastatic potential of cancer cells, which is crucial to early detection and diagnosis of cancer.
Cells respond to and actively remodel the extracellular matrix (ECM). The dynamic and bidirectional interaction between cells and ECM, especially their mechanical interactions, has been found to play ...an essential role in triggering a series of complex biochemical and biomechanical signal pathways and in regulating cellular functions and behaviours. The collagen gel contraction assay (CGCA) is a widely used method to investigate cell–ECM interactions in 3D environments and provides a mechanically associated readout reflecting 3D cellular contractility. In this review, we summarize various versions of CGCA, with an emphasis on recent high-throughput and low-consumption CGCA techniques. More importantly, we focus on the technique of force monitoring during the contraction of collagen gel, which provides a quantitative characterization of the overall forces generated by all the resident cells in the collagen hydrogel. Accordingly, we present recent biological applications of the CGCA, which have expanded from the initial wound healing model to other studies concerning cell–ECM interactions, including fibrosis, cancer, tissue repair and the preparation of biomimetic microtissues.
•Collagen gel contraction assay reflects the dynamical cell-ECM interactions and the 3D cellular contractility.•Various techniques have been proposed to improve the throughput of collagen gel contraction assay.•Monitoring the contractile force of collagen gel provides a readout for the overall force generated by resident cells.•Various mathematical models have been proposed to simulate the collagen hydrogel contraction.•Collagen gel contraction assay has been widely used in various biological researches involving cell-ECM interactions.
Zinc oxide nanoparticles (ZnO-NPs) have been widely used in engineering and biomedicine. However, their adverse pathological effects and mechanisms, especially the biomechanical effects on ...respiratory system where airway smooth muscle cell (ASMC) contractility regulates the airway response and lung function, are not fully understood. Herein, we used traction force microscopy (TFM) method to investigate whether ZnO-NPs of different concentrations (0.1–10
μ
g/mL) can alter ASMC contractility (basal and agonist-stimulated) after a short-term exposure and the potential mechanisms. We found that ZnO-NPs exposure led to a decrease of ASMC viability in a dose-dependent manner. Notably, basal contractility was enhanced when the concentration of ZnO-NPs was less than 0.1
μ
g/mL and decreased afterwards, while KCl-stimulated contractility was reduced in all cases of ZnO-NPs treated groups. Cytoskeleton structure was also found to be significantly altered in ASMC with the stimulation of ZnO-NPs. More importantly, it seems that ZnO-NPs with low concentration (< 0.1
μ
g/mL) would change ASMC contractility without any apparent cytotoxicity through disruption of the microtubule assembly. Moreover, our results also emerged that ASMC contractility responses were regulated by clathrin-mediated endocytosis and cytoskeleton remodeling. Together, these findings indicate the susceptibility of cell mechanics to NPs exposure, suggesting that cell mechanical testing will contribute to uncover the pathological mechanisms of NPs in respiratory diseases.
In recent years, dental implants have become the preferred approach for the restoration of missing teeth. At present, most dental implants are made of pure titanium, and are affected by ...peri-implantitis and bone resorption, which usually start from the implant neck, due to the complex environment in this region. To address these issues, in this study we modified the surface of titanium (Ti) implants to exploit the antibacterial and osteoinductive effects of single-layer graphene sheets. Chemical vapor deposition (CVD)-grown single-layer graphene sheets were transferred to titanium discs, and a method for improving the adhesion strength of graphene on Ti was developed due to compromised adhesion strength between graphene and titanium surface. A thermal treatment of 2 h at 160 °C was found to enhance the adhesion strength of graphene on Ti to facilitate clinical transformation. Graphene coatings of Ti enhanced cell adhesion and osteogenic differentiation, and imparted antibacterial activity to Ti substrate; these favorable effects were not affected by the thermal treatment. In summary, the present study elucidated the effects of a thermal treatment on the adhesion strength and osteoinductive activity of single-layer graphene sheets on titanium substrates.
Exosomes derived from mesenchymal stem cells (MSCs) have demonstrated regenerative potential for cell-free bone tissue engineering, nevertheless, certain challenges, including the confined ...therapeutic potency of exosomes and ineffective delivery method, are still persisted. Here, we confirmed that hypoxic precondition could induce enhanced secretion of exosomes from stem cells from human exfoliated deciduous teeth (SHEDs) via comprehensive proteomics analysis, and the corresponding hypoxic exosomes (H-Exo) exhibited superior potential in promoting cellular angiogenesis and osteogenesis via the significant up-regulation in focal adhesion, VEGF signaling pathway, and thyroid hormone synthesis. Then, we developed a platform technology enabling the effective delivery of hypoxic exosomes with sustained release kinetics to irregular-shaped bone defects via injection. This platform is based on a simple adsorbing technique, where exosomes are adsorbed onto the surface of injectable porous poly(lactide-co-glycolide) (PLGA) microspheres with bioinspired polydopamine (PDA) coating (PMS-PDA microspheres). The PMS-PDA microspheres could effectively adsorb exosomes, show sustained release of H-Exo for 21 days with high bioactivity, and induce vascularized bone regeneration in 5-mm rat calvarial defect. These findings indicate that the hypoxic precondition and PMS-PDA porous microsphere-based exosome delivery are efficient in inducing tissue regeneration, hence facilitating the clinical translation of exosome-based therapy.
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•Hypoxic precondition regulates the transcriptomics of SHEDs derived exosomes.•H-Exo exhibits enhanced angiogenesis and osteogenesis capacity.•PMS-PDA microspheres can effectively adsorb exosomes, and show sustained release of exosomes for 21 days.•PMS-PDA + H-Exo promotes vascularized bone regeneration in 5-mm rat calvarial defects.
The mechanosensing ability of lymphocytes regulates their activation in response to antigen stimulation, but the underlying mechanism remains unexplored. Here, we report that B cell ...mechanosensing-governed activation requires BCR signaling molecules. PMA-induced activation of PKCβ can bypass the Btk and PLC-γ2 signaling molecules that are usually required for B cells to discriminate substrate stiffness. Instead, PKCβ-dependent activation of FAK is required, leading to FAK-mediated potentiation of B cell spreading and adhesion responses. FAK inactivation or deficiency impaired B cell discrimination of substrate stiffness. Conversely, adhesion molecules greatly enhanced this capability of B cells. Lastly, B cells derived from rheumatoid arthritis (RA) patients exhibited an altered BCR response to substrate stiffness in comparison with healthy controls. These results provide a molecular explanation of how initiation of B cell activation discriminates substrate stiffness through a PKCβ-mediated FAK activation dependent manner.
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