bims-ecemfi Biomed News
on ECM and fibroblasts
Issue of 2025–07–13
six papers selected by
Badri Narayanan Narasimhan, University of California, San Diego
  1. Confinement in fibrous environments positions and orients mitotic spindles.
  2. Suppression of cofilin-1 promotes invasion in 3D hyaluronic acid matrices by promoting actin-based protrusions.
  3. LATS1/2-Integrin Axis Confers Tumor-Generated Forces That Activate Neighboring Fibroblasts.
  4. Gel-Gel Interface Engineering for the Synthesis of Anisotropic Hydrogels with Designable Polymer Orientations.
  5. Genetic Manipulation of Mammalian Cells in Microphysiological Hydrogels.
  6. Integrin Tension Represents the Directed Differentiation of Mesenchymal Stem Cells via Mechanoadaptation.
  1. PNAS Nexus. 2025 Jul;4(7): pgaf201
    Confinement in fibrous environments positions and orients mitotic spindles.
    Apurba Sarkar, Aniket Jana, Atharva Agashe, Ji Wang, Rakesh Kapania, Nir S Gov, Jennifer G DeLuca, Raja Paul, Amrinder S Nain.
      Accurate positioning of the mitotic spindle within the rounded cell body is critical to physiological maintenance. Mitotic cells encounter confinement from neighboring cells or the extracellular matrix (ECM), which can cause rotation of mitotic spindles and tilting of the metaphase plate (MP). To understand the effect of confinement on mitosis by fibers (ECM confinement), we use flexible ECM-mimicking nanofibers that allow natural rounding of the cell body while confining it to differing levels. Rounded mitotic bodies are anchored in place by actin retraction fibers (RFs) originating from adhesions on fibers. We discover that the extent of confinement influences RF organization in 3D, forming triangular and band-like patterns on the cell cortex under low and high confinement, respectively. Our mechanistic analysis reveals that the patterning of RFs on the cell cortex is the primary driver of the MP rotation. A stochastic Monte Carlo simulation of the centrosome, chromosome, membrane interactions, and 3D arrangement of RFs recovers MP tilting trends observed experimentally. Under high ECM confinement, the fibers can mechanically pinch the cortex, causing the MP to have localized deformations at contact sites with fibers. Interestingly, high ECM confinement leads to low and high MP tilts, which we mechanistically show to depend upon the extent of cortical deformation, RF patterning, and MP position. We identify that cortical deformation and RFs work in tandem to limit MP tilt, while asymmetric positioning of MP leads to high tilts. Overall, we provide fundamental insights into how mitosis may proceed in ECM-confining microenvironments in vivo.
    DOI:  https://doi.org/10.1093/pnasnexus/pgaf201
  2. Mol Biol Cell. 2025 Jul 09. mbcE24080384
    Suppression of cofilin-1 promotes invasion in 3D hyaluronic acid matrices by promoting actin-based protrusions.
    Vivien D Tran, Kwasi Y Amofa, Lu Ling, Miles Duong, Sanjay Kumar.
      Contributions of the actin turnover machinery to cell motility have been extensively studied in traditional 2D culture paradigms. However, much remains unknown about how these proteins contribute to 3D motility, particularly in matrices lacking strong contact guidance cues. Here we explore this question in the context of glioblastoma (GBM) cell invasion through 3D hyaluronic acid (HA) hydrogels. We begin with a CRISPR screen to identify contributions of core actin turnover proteins to migration speed in 2D and 3D. While suppression of most proteins reduced motility in both 2D and 3D, suppression of cofilin-1 (CFL) increased migration speed in 3D. CFL knockout cells uniquely formed longer and more protrusions in 3D compared to non-targeting control cells. Consistent with the screen, targeted CFL shRNA-mediated knockdown (KD) decreased motility on 2D HA but increased motility in 3D HA. This effect appears HA-specific, as CFL KD did not increase motility in 3D collagen or in a transwell assay. Myosin X, CD44, and hyaluronidase-2 all localized to a subset of protrusions irrespective of cellular CFL status, implying that CFL suppression promotes filopodia and microtentacle extension. We propose that loss of CFL promotes the actin filaments in these protrusions, enabling GBM cells to penetrate 3D HA matrices.
    DOI:  https://doi.org/10.1091/mbc.E24-08-0384
  3. Cancer Sci. 2025 Jul 07.
    LATS1/2-Integrin Axis Confers Tumor-Generated Forces That Activate Neighboring Fibroblasts.
    Yanliang Liu, Saisai Liu, Yasuhisa Sakamoto, Paweenapon Chunthaboon, Chanida Thinyakul, Ryunosuke Mori, Shuran Li, Takahiro Watanabe-Nakayama, Seiji Omata, Yasuyuki Morita, Toshiro Moroishi.
      Tumors generate various forces during growth and progression, which in turn promote tumor development. Although fibroblasts are considered the primary force generators in the tumor microenvironment, recent studies have shown that cancer cells also generate considerable tensile forces. However, the roles that these forces play in the tumor microenvironment and the pathways regulating this process remain largely unknown. Here, we demonstrated that the Hippo pathway-associated kinases, LATS1/2, in cancer cells are essential for collective force generation and fibroblast activation via extracellular matrix-mediated cell-cell interactions. In murine breast cancer 4 T1 spheroids, the deletion of LATS1/2 dampened force generation and disrupted reorganization of the surrounding collagen matrix. LATS1/2-mediated mechanical forces of tumors are required for fibroblast activation and differentiation into mechanoresponsive fibroblasts. Mechanistically, LATS1/2 regulate tumor force generation through the expression of collagen receptor integrins. Our findings not only identify the Hippo pathway as a critical regulator of tumor force generation but also suggest potential strategies for targeting it in cancer therapy from a mechanobiological perspective, offering new avenues in the fight against cancer.
    Keywords:  cancer‐associated fibroblast; hippo pathway; integrins; mechanobiology; tumor microenvironment
    DOI:  https://doi.org/10.1111/cas.70137
  4. Adv Mater. 2025 Jul 09. e2505268
    Gel-Gel Interface Engineering for the Synthesis of Anisotropic Hydrogels with Designable Polymer Orientations.
    Tomohiro Takahashi, Naoya Karasawa, Koki Sano.
      Anisotropic hydrogels with designable structural complexity can exhibit sophisticated properties reminiscent of those found in living organisms. However, conventional synthetic methods typically require specific anisotropic additives and complicated processes, limiting design flexibility. Here, a simple and versatile strategy to synthesize anisotropic hydrogels with photo-designable orientations of polymer networks is developed by harnessing a "gel-gel interface," which can be generated through the intentional adhesion between hydrogels. This strategy originates from the serendipitous discovery: when a gel-gel interface is intentionally introduced into a hydrogel through a two-step polymerization, the polymer networks near the interface are spontaneously aligned perpendicular to the interface, as a result of the simultaneous swelling and fixation process during gel-to-gel adhesion. By employing a photo-initiator system to control the gel-gel interface, anisotropic hydrogels with both 2D and 3D designed polymer orientations, as well as anisotropic hydrogels with thermally switchable polymer orientations, are successfully synthesized. The gel-gel interface has long been regarded as merely an undesirable byproduct of gel adhesion, while the complementary bulk region of hydrogels has been the primary focus in constructing anisotropic hydrogels. In contrast, this work demonstrates the utility of the gel-gel interface, expanding design possibilities for next-generation hydrogels with designable structural complexity.
    Keywords:  anisotropic hydrogels; gel adhesion; gel‐gel interfaces; photo‐patterning; polymer orientation
    DOI:  https://doi.org/10.1002/adma.202505268
  5. Adv Sci (Weinh). 2025 Jul 09. e05474
    Genetic Manipulation of Mammalian Cells in Microphysiological Hydrogels.
    Anna C Jäkel, Dong-Jiunn Jeffery Truong, Friedrich C Simmel.
      Engineering functional 3D tissue constructs is essential for developing advanced organ-like systems, with applications ranging from fundamental biological research to drug testing. The generation of complex multicellular structures requires the integration of external geometric and mechanical cues with the ability to activate genetic programs that regulate and stimulate cellular self-organization. Here, it is demonstrated that gelatin methacryloyl (GelMA) hydrogels serve as effective matrices for 3D cell culture, supporting both in situ genetic manipulation and cell growth. HEK293T cells embedded in GelMA remained viable and proliferated over 16 days, forming clusters within the matrix. Efficient gene delivery is achieved in the 3D hydrogel environment using both plasmid DNA and mRNA as gene vectors. Furthermore, in situ prime editing is applied to induce permanent genetic modifications in embedded cells. To achieve spatially confined gene expression, gel-embedded channels are introduced that allowed localized stimulation via doxycycline perfusion through a Tet-On system. These findings demonstrate the feasibility of integrating gene delivery, inducible expression, and spatial control within GelMA-based hydrogels, establishing a versatile framework for engineered 3D cell systems with programmable genetic activity.
    Keywords:  3D cell culture; genome editing; hydrogels; tissue engineering; transfection; vascular channels
    DOI:  https://doi.org/10.1002/advs.202505474
  6. ACS Nano. 2025 Jul 07.
    Integrin Tension Represents the Directed Differentiation of Mesenchymal Stem Cells via Mechanoadaptation.
    Dawei Tian, Danyang Yue, Jingchen Zhu, Xiaoyu Zhang, Mingliang Gong, Mian Long, Yan Zhang, Jun Pan.
      The mechanism controlling the differentiation of mesenchymal stromal cells (MSCs) to the target cell is vital for their tissue repair. While integrins, physically connected focal adhesion proteins (FAs), cytoskeleton elements, and lamin A are involved, the quantitative roles of integrin tension and mechanoadaptation remain unknown. Here, we applied reversible shearing DNA-based tension probes (RSDTPs) to assess MSCs' integrin tension during spreading after biochemical induction to osteogenesis and chondrogenesis. The mechanical transmitters of paxillin, F-actin, and lamin A to transduce mechanical stress from integrin to the nucleus as well as differentiation of MSCs were assayed to reveal the mechanical adaptation of integrin tension. Integrin tensions of 44 and 5-18 pN were identified as the critical force for osteogenic and chondrogenic differentiations, respectively. To fit this tension difference, MSCs possessed FAs' orientation to align radially along the cell's normal axis in osteogenesis vs tangentially in chondrogenesis. Cytoskeleton F-actin was found to regulate the osteogenesis through altering the upstream integrin tension and FAs' orientation and the downstream lamin A expression but yield less influences on chondrogenesis. In turn, F-actin tended to be less modulated by lamin A and its accompanying changes in FAs and integrin tension than by biochemical induction. Lamin A favored the regulation of osteogenesis through altering the upstream integrin tension and orientations of FAs and F-actin but might play an inhibitory role in chondrogenic differentiation. This work contributes to the understanding of how integrins generate and transmit different magnitudes of forces to jointly regulate cell morphology and mechanical adaptability and to fit the differentiation fate of MSCs.
    Keywords:  F-actin; integrin; lamin A; mechanical signaling; tension probe
    DOI:  https://doi.org/10.1021/acsnano.5c03069
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