An official website of the United States government
Abstract Mechanical interactions between cells have been shown to play critical roles in regulating cell signaling and communications. However, the precise measurement of intercellular forces is still quite challenging, especially considering the complex environment at cell–cell junctions. In this study, we report a fluorescence lifetime‐based approach to image and quantify intercellular molecular tensions. Using this method, tensile forces among multiple ligand–receptor pairs can be measured simultaneously. We first validated our approach and developed lifetime measurement‐based DNA tension probes to image E‐cadherin‐mediated tension on epithelial cells. These probes were then further applied to quantify the correlations between E‐cadherin and N‐cadherin tensions during an epithelial–mesenchymal transition process. The modular design of these probes can potentially be used to study the mechanical features of various physiological and pathological processes.
more »
« less
This content will become publicly available on May 13, 2026
E-cadherin mechanotransduction activates EGFR-ERK signaling in epithelial monolayers by inducing ADAM-mediated ligand shedding
The behavior of cells is governed by signals originating from their local environment, including mechanical forces exerted on the cells. Forces are transduced by mechanosensitive proteins, which can impinge on signaling cascades that are also activated by growth factors. We investigated the cross-talk between mechanical and biochemical signals in the regulation of intracellular signaling networks in epithelial monolayers. Phosphoproteomic and transcriptomic analyses on epithelial monolayers subjected to mechanical strain revealed the activation of extracellular signal–regulated kinase (ERK) downstream of the epidermal growth factor receptor (EGFR) as a predominant strain-induced signaling event. Strain-induced EGFR-ERK signaling depended on mechanosensitive E-cadherin adhesions. Proximity labeling showed that the metalloproteinase ADAM17, an enzyme that mediates shedding of soluble EGFR ligands, was closely associated with E-cadherin. A probe that we developed to monitor ADAM-mediated shedding demonstrated that mechanical strain induced ADAM activation. Mechanically induced ADAM activation was essential for mechanosensitive, E-cadherin–dependent EGFR-ERK signaling. Together, our data demonstrate that mechanical strain transduced by E-cadherin adhesion triggers the shedding of EGFR ligands that stimulate downstream ERK activity. Our findings illustrate how mechanical signals and biochemical ligands can operate within a linear signaling cascade.
more »
« less
- PAR ID:
- 10657365
- Publisher / Repository:
- Science
- Date Published:
- Journal Name:
- Science Signaling
- Volume:
- 18
- Issue:
- 886
- ISSN:
- 1945-0877
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
More Like this
-
-
Green, Kathleen (Ed.)ABSTRACT This study investigated possible mechanisms underlying differences between heterophilic and homophilic cadherin adhesions that influence intercellular mechanics and multicellular organization. Results suggest that homophilic cadherin ligation selectively activates force transduction, such that resulting signaling and mechano-transduction amplitudes are independent of cadherin-binding affinities. Epithelial (E-) and neural (N-)cadherin cooperate with distinct growth factors to mechanically activate force transduction cascades. Prior results have demonstrated that E-cadherin and epidermal growth factor receptor form force-sensitive complexes at intercellular junctions. Here, we show that the reconstitution of N-cadherin force transduction requires the co-expression of N-cadherin and fibroblast growth factor receptor. Mechanical measurements further demonstrated that homophilic ligation initiates receptor tyrosine kinase-dependent force transduction cascades, but heterophilic cadherin ligands fail to activate signaling or generate stereotypical mechano-transduction signatures. The all-or-nothing contrast between mechano-transduction by heterophilic versus homophilic cadherin adhesions supersedes differences in cadherin adhesion strength. This mechano-selectivity impacts cell spreading and traction generation on cadherin substrates. Homophilic ligation appears to be a key that selectively unlocks cadherin mechano-transduction. These findings might reconcile the roles of cadherin recognition and cell mechanics in the organization of multicellular assemblies.more » « less
-
ABSTRACT Many developmental processes rely on the localized activation of receptor tyrosine kinases and their canonical downstream effectors Erk and Akt, yet the specific roles played by each of these signals is still poorly understood. Gastruloids, 3D cell culture models of mammalian gastrulation and axial elongation, enable quantitative dissection of signaling patterns and cell responses in a simplified, experimentally accessible context. We find that mouse gastruloids contain posterior-to-anterior gradients of Erk and Akt phosphorylation induced by distinct receptor tyrosine kinases, with features of the Erk pattern and expression of its downstream target Snail exhibiting hallmarks of size-invariant scaling. Both Erk and Akt signaling contribute to cell proliferation, whereas Erk activation is also sufficient to induce Snail expression and precipitate profound tissue shape changes. We further uncover that Erk signaling is sufficient to convert the entire gastruloid to one of two mesodermal fates depending on position along the anteroposterior axis. In all, these data demonstrate functional roles for two core signaling gradients in mammalian development and suggest how these modules might be harnessed to engineer user-defined tissues with predictable shapes and cell fates.more » « less
-
Crosstalk between ERK and MRTF‐A signaling regulates TGFβ1‐induced epithelial‐mesenchymal transitionAbstract Epithelial‐mesenchymal transition (EMT) is a physiological process that is essential during embryogenesis and wound healing and also contributes to pathologies including fibrosis and cancer. EMT is characterized by marked gene expression changes, loss of cell–cell contacts, remodeling of the cytoskeleton, and acquisition of enhanced motility. In the late stages of EMT, cells can exhibit myofibroblast‐like properties with enhanced expression of the mesenchymal protein marker α‐smooth muscle actin and contractile activity. Transforming growth factor (TGF)‐β1 is a well‐known inducer of EMT and it activates a plethora of signaling cascades including extracellular signal‐regulated kinase (ERK). Previous reports have demonstrated a role for ERK signaling in the early stages of EMT, but the molecular impacts of ERK signaling on the late stages of EMT are still unknown. Here, we found that inhibition of the phosphorylation of ERK enhances focal adhesions, stress fiber formation, cell contractility, and gene expression changes associated with TGFβ1‐induced EMT in mammary epithelial cells. These effects are mediated in part by the phosphorylation state and subcellular localization of myocardin‐related transcription factor‐A. These findings indicate that the intricate crosstalk between signaling cascades plays an important role in regulating the progression of EMT and suggests new approaches to control EMT processes.more » « less
-
Shear forces between cells occur during global changes in multicellular organization during morphogenesis and tissue growth, yet how cells sense shear forces and propagate a response across a tissue is unknown. We found that applying exogenous shear at the midline of an epithelium induced a local, short-term deformation near the shear plane, and a long-term collective oscillatory movement across the epithelium that spread from the shear-plane and gradually dampened. Inhibiting actomyosin contraction or E-cadherin trans-cell adhesion blocked oscillations, whereas stabilizing actin filaments prolonged oscillations. Combining these data with a model of epithelium mechanics supports a mechanism involving the generation of a shear-induced mechanical event at the shear plane which is then relayed across the epithelium by actomyosin contraction linked through E-cadherin. This causes an imbalance of forces in the epithelium, which is gradually dissipated through oscillatory cell movements and actin filament turnover to restore the force balance across the epithelium.more » « less
