bims-ecemfi 2025-11-30 papers

bims-ecemfi

Biomed News

on ECM and fibroblasts

Issue of 2025–11–30
eight papers selected by
Badri Narayanan Narasimhan, University of California, San Diego

Rigidity Sensing of Inclusions Directs Differentiated Cell Elongation and Force Generation across Phenotypes.
Adipose-mimetic granular hydrogels uncover biophysical cues driving breast cancer invasion.
Mechanical Cues Regulate Estrogen and Progesterone-Induced Nascent ECM Deposition by Human Endometrial Stromal Cells.
Measurement of cellular traction forces during confined migration.
Tuning Scaffold Degradation with Non-Natural Peptidomimetics to Control Human Umbilical Vein Endothelial Cell Morphology and Vessel Formation.
Amoeboid-Mesenchymal Transition and the Proteolytic Control of Cancer Invasion Plasticity.
Soft Matter Physics Meets Cell Biology: Transitions of Collective Cell Migration in 3D Environments.
Design and Synthesis of Peptide-Polyester Conjugates for Cell-Mediated Scaffold Degradation.

ACS Biomater Sci Eng. 2025 Nov 27.

Rigidity Sensing of Inclusions Directs Differentiated Cell Elongation and Force Generation across Phenotypes.

Yuxin Luo, Yimin Luo.

  Fibrosis is driven in part by the transition of healthy fibroblasts to a contractile phenotype called myofibroblasts. The mechanics of the extracellular matrix play a crucial role in regulating cell fates and behaviors during this transition. However, most studies to date focus on cells grown on 2D surfaces and matrices with homogeneous properties. This leaves open how local rigidity differentially regulates the behaviors of both phenotypes in 3D environments, including polarization, contraction, and maintenance of phenotypes, during remodeling. Here, we engineer 3D microgel-in-collagen composites by embedding low-volume fractions of cell-scale microgels with two levels of rigidity, mimicking healthy and pathological tissues that are stiffer than the surrounding collagen but do not significantly change the bulk modulus. We find that microgels serve as mechanical centers: both phenotypes polarize toward microgel inclusions. The polarization response decays as a power-law with distance ∼r-n, decreasing more slowly for myofibroblasts (n ≈ 0.35) than fibroblasts (n ≈ 0.81), indicating that myofibroblasts are more sensitive to small mechanical variations. In situ measurements finds that forces are highest for myofibroblasts near stiff microgels and lowest for fibroblasts near soft microgels. Local rigidity also stabilizes the myofibroblast phenotype: Both the ordering of the proinflammatory marker α-smooth muscle actin and nuclear Yes-associated protein localization persist for cells cultured with stiff microgels over several days but diminish quickly for those cultured with soft microgels and in pure collagen. Together, these results reveal a rigidity- and phenotype-dependent feedback loop: stiff inclusions induce cell polarization and collagen remodeling via a contractile force, which in turn maintain the myofibroblast phenotype. Our study positions mechanical heterogeneity as a useful and sensitive handle to probe and potentially modulate early fibrotic progressions.

Keywords:  biomaterials; hydrogels; mechanotransduction; myofibroblasts; polarization; remodeling

DOI:  https://doi.org/10.1021/acsbiomaterials.5c01611
bioRxiv. 2025 Oct 24. pii: 2025.10.23.684224. [Epub ahead of print]

Adipose-mimetic granular hydrogels uncover biophysical cues driving breast cancer invasion.

Brianna K Knode, Garrett Farrell Beeghly, Brittany E Schutrum, Dong Wang, Yitong Zheng, Alice Battistella, Ruchi Goswami, Chi-Yong Eom, Aline Bozec, Jochen Guck, Nozomi Nishimura, Salvatore Girardo, Corey O'Hern, Claudia Fischbach.

Breast cancer cells invade mammary adipose tissue during initial stages of metastasis but how the physical properties of adipose tissue regulate this process remains unclear. Here, we combined single cell mechanical characterization of primary adipocytes with microfluidic hydrogel fabrication, quantitative multiparametric imaging, Discrete Element Method (DEM) simulations, and in vivo experiments to elucidate these connections. First, we quantified the heterogeneous size and stiffness of primary adipocytes, and replicated these properties by fabricating adipocyte-sized polyacrylamide (PAAm) beads with tunable elasticity. Subsequently, we embedded these beads into type I collagen, the primary fibrillar extracellular matrix (ECM) component of breast adipose tissue, to form 3D granular hydrogels mimicking aspects of native adipose tissue architecture. Granular hydrogels embedded with beads demonstrated increased breast cancer cell invasion relative to bead-free controls, an effect that was more pronounced with soft versus stiff beads and correlated with increased collagen fiber alignment and hierarchical organization. In addition, live cell imaging and DEM simulations revealed that soft beads promoted invasion relative to stiff beads by deforming in response to confined cancer cell migration. Fiber alignment and adipocyte deformation trends were validated in vivo via intravital imaging of cancer cell migration in mammary fat pads of mice, and suggest that adipocyte mechanics regulate breast cancer invasion by coordinating both ECM architecture and cellular confinement. Ultimately, this work highlights the utility of tunable PAAm bead-collagen composites as micromechanical models to study the effect of adipose tissue structure on cancer cell invasion.

DOI: https://doi.org/10.1101/2025.10.23.684224
bioRxiv. 2025 Oct 14. pii: 2025.10.14.682403. [Epub ahead of print]

Mechanical Cues Regulate Estrogen and Progesterone-Induced Nascent ECM Deposition by Human Endometrial Stromal Cells.

Grace K Hinds, Arina Velieva, Yu-Chung Liu, Avinava Roy, Rima Chavali, Claudia Loebel.

The endometrium, the mucosal lining of the uterus, is a highly regenerative tissue that undergoes cyclic remodeling guided by tightly regulated levels of estrogen and progesterone. Stromal cells are embedded within the connective tissue of the endometrium and contribute to the rapidly changing extracellular matrix (ECM). With hormone exposure, endometrial stromal cells undergo decidualization, which alters their morphology and protein secretion. While an increase in tissue modulus is associated with gynecological diseases, the relationship between mechanical properties, hormone exposure, and ECM deposition remains poorly understood. Here, we investigated how both stiffness and hormones regulate ECM deposition by human endometrial stromal cells during decidualization. Using metabolic labeling with sugar analogs and click chemistry, we measure newly secreted ECM proteins deposited by endometrial stromal cells during decidualization. Additionally, we study the nascent ECM in response to different mechanical properties using hyaluronic acid hydrogels. To increase throughput and reproducibility, we designed an automated ImageJ-based workflow for unbiased quantification of nascent ECM deposition. Our results demonstrate that hormones induce decidualization, characterized by F-actin stress fiber formation and prolactin secretion. In addition, we show that decidualization on hydrogels is characterized by an increase in nascent ECM deposition which depends on the initial hydrogel modulus. In contrast, endometrial stromal cells on glass show little change in nascent ECM deposition during hormone exposure. Collectively, these findings demonstrate that both mechanical and biochemical cues regulate ECM deposition during endometrial remodeling. These observations may provide new insights towards future studies addressing the mechanisms of ECM remodeling in gynecological diseases.

DOI: https://doi.org/10.1101/2025.10.14.682403
Proc Natl Acad Sci U S A. 2025 Dec 02. 122(48): e2509535122

Measurement of cellular traction forces during confined migration.

Max A Hockenberry, Andrew J Ulmer, Johann L Rapp, Harrison H Truscott, Frank A Leibfarth, James E Bear, Wesley R Legant.

  To migrate efficiently through tissues, cells must transit through small constrictions within the extracellular matrix. However, in vivo environments are geometrically, mechanically, and chemically complex, and it has been difficult to understand how each of these parameters contribute to the propulsive strategy utilized by cells in different confining environments. To address this, we employed a sacrificial micromolding approach to generate polymer substrates with tunable stiffness, controlled adhesivity, and user-defined microscale geometries. We combined this together with live-cell imaging and three-dimensional traction force microscopy to quantify the forces that cells use to transit through constricting channels. Surprisingly, rather than enlarging the constriction via pushing forces, we observe that mesenchymal cells migrating through compliant constrictions generate inwardly directed contractile forces that decrease the size of the opening and pull the channel walls closed around the nucleus. This had the effect of increasing nuclear deformation compared to cells migrating through comparably sized rigid confinements. Additionally, the nucleus took longer to transit through compliant constrictions compared to similarly sized rigid constrictions. These findings show that nuclear deformation during confined migration can be accomplished by internal cytoskeletal machinery rather than by reactive forces from the substrate, and our approach provides a mechanism to test between different models for how cells translocate their nucleus through narrow constrictions. The methods, analysis, and results presented here will be useful to understand how cells choose between propulsive strategies in different physical environments.

Keywords:  cell migration; cytoskeleton; mechanotransduction; microfabrication; traction force microscopy

DOI:  https://doi.org/10.1073/pnas.2509535122
bioRxiv. 2025 Oct 28. pii: 2025.10.27.684851. [Epub ahead of print]

Tuning Scaffold Degradation with Non-Natural Peptidomimetics to Control Human Umbilical Vein Endothelial Cell Morphology and Vessel Formation.

Kathleen N Halwachs, Carolyn M Watkins, Morgan J Valdivieso, Janet Zoldan, Adrianne Rosales.

The in vitro vascularization of 3D tissue constructs, such as hydrogels, remains a paramount challenge in tissue engineering. Extracellular matrix degradation and remodeling are key parts of the vascularization process; however, it is difficult to isolate the effects of degradability in both natural and synthetic matrix models. Naturally-derived matrices typically couple degradability to other material properties, whereas synthetic matrices rely on short peptide sequences to impart degradability, which typically exhibit substrate overlap to many proteases. Here, we present a method to independently and broadly tune 3D hydrogel degradation using crosslinkers with non-natural peptoid (N-substituted glycine) substitutions. Increased peptoid substitutions reduced hydrogel degradability to collagenases without altering hydrogel modulus, swelling ratio, or crosslinker length. Using this approach, human umbilical vein endothelial cells (HUVECs) encapsulated in more degradable hydrogels proliferated more, formed more vessels, exhibited higher metabolic activity, and secreted more extracellular matrix than HUVECs encapsulated in less degradable or non-degradable hydrogels. Interestingly, HUVECs encapsulated in the least degradable hydrogels secreted significantly higher matrix metalloproteinase-2 (MMP-2) and matrix metalloproteinase-9 (MMP-9) than HUVECs encapsulated in the most degradable hydrogels, suggesting higher MMP secretion to compensate for the reduced matrix degradability. Overall, this work highlights the importance of protease-mediated remodeling on vascularization and suggests that peptoid substitutions are effective for tuning hydrogel degradability for a variety of 3D cell applications.

DOI: https://doi.org/10.1101/2025.10.27.684851
bioRxiv. 2025 Oct 24. pii: 2025.10.24.684403. [Epub ahead of print]

Amoeboid-Mesenchymal Transition and the Proteolytic Control of Cancer Invasion Plasticity.

Adam W Olson, Jonathan Li, Xiao-Yan Li, Lana King, Kalins Banerjee, Atticus J McCoy, Mahnoor N Gondal, Arul M Chinnaiyan, Dorraya El-Ashry, Evan T Keller, Andrew J Putnam, Stephen J Weiss.

Invasion plasticity allows malignant cells to toggle between collective, mesenchymal and amoeboid phenotypes while traversing extracellular matrix (ECM) barriers. Current dogma holds that collective and mesenchymal invasion programs trigger the mobilization of proteinases that digest structural barriers dominated by type I collagen, while amoeboid activity allows cancer cells to marshal mechanical forces to traverse tissues independently of ECM proteolysis. Here, we use cancer spheroid-3-dimensional matrix models, single-cell RNA sequencing, and human tissue explants to identify the mechanisms controlling mesenchymal versus amoeboid invasion. Unexpectedly, collective/mesenchymal- and amoeboid-type invasion programs - though distinct - are each characterized by active tunneling through ECM barriers, with expression of matrix-degradative metalloproteinases. CRISPR/Cas9-mediated targeting of a single membrane-anchored collagenase, MMP14/MT1-MMP, ablates tissue-invasive activity while co-regulating cancer cell transcriptional programs. Though changes in matrix architecture, nuclear rigidity, and metabolic stress as well as the presence of cancer-associated fibroblasts are proposed to support amoeboid activity, none of these changes restore invasive activity of MMP14-targeted cancer cells. While a requirement for MMP14 is bypassed in low-density collagen hydrogels, invasion by the proteinase-deleted cells is associated with nuclear envelope and DNA damage, highlighting a proteolytic requirement for maintaining nuclear integrity. Nevertheless, when cancer cells confront explants of live human breast tissue, MMP14 is again required to support invasive activity. Corroborating these results, spatial transcriptomic and immunohistological analyses of invasive human breast cancers identified clear expression of MMP14 in invasive cells that were further associated with degraded collagen, underlining the pathophysiologic importance of this proteinase in directing invasive activity in vivo .

DOI: https://doi.org/10.1101/2025.10.24.684403
Cold Spring Harb Perspect Biol. 2025 Nov 24. pii: a041794. [Epub ahead of print]

Soft Matter Physics Meets Cell Biology: Transitions of Collective Cell Migration in 3D Environments.

Mirjam M Zegers, Pablo Gottheil, Josef Käs, Peter Friedl.

Plasticity of cell migration is a hallmark of cell movement during morphogenesis, tissue repair, and cancer metastasis. Interconversions of migration modes are tissue context-dependent and range from (1) collective migration of cohesive cells, migrating as epithelial sheets and strands; (2) multicellular networks of individualized cells moving while maintaining short-lived interactions; and (3) fully individualized cells moving by mesenchymal or amoeboid migration. Modes of cell migration, which are controlled by cell-cell adhesion, cell density, and active forces, can also be represented by physics-derived parameters, including temperature, applied stress, and volume fraction in classical passive jamming phase diagrams. Cell-packing density, cell-cell adhesion strength, and intrinsic migratory capacity have been defined as the key parameters driving jamming transitions in 2D sheet models, where extracellular matrix (ECM) is typically not considered. Here, we review how plasticity of cell migration programs intersects with jamming/unjamming principles and specifically focus on the impact of ECM architectures. In three-dimensional (3D) tissues, additional spatial parameters determine cell density and cell-cell interactions, including the degree of confinement forcing cells together versus the availability of free space. Integrating mechanisms of jamming/unjamming with actin-based active movement of cells in a 3D environment, similar to the motion of active nematic droplets in a passive nematic matrix, will enable building realistic models to predict cell behaviors in physiological and pathological contexts, including cancer metastasis.

DOI: https://doi.org/10.1101/cshperspect.a041794
bioRxiv. 2025 Oct 06. pii: 2025.10.06.680674. [Epub ahead of print]

Design and Synthesis of Peptide-Polyester Conjugates for Cell-Mediated Scaffold Degradation.

Korina Vida G Sinad, Natasha K Hunt, Srujan Singh, Kelly B Seims, Yingjie Wu, E Thomas Pashuck, Warren L Grayson, Lesley W Chow.

  Biodegradable thermoplastic polyesters are promising biomaterials for tissue engineering due to their processability and mechanical properties. Polycaprolactone (PCL) is particularly attractive for load-bearing applications but does not degrade at the same rate as new tissue formation, which may compromise functional regeneration. This study presents a strategy for cell-mediated scaffold remodeling by incorporating a protease-cleavable peptide directly into the PCL backbone. Linear peptide-PCL conjugates were synthesized with poly(ethylene glycol) (PEG) spacers flanking the peptide to enhance protease access. A functional proteomics approach was used to identify a fast-degrading peptide sequence (Fast) selectively cleaved by multiple cell types. Conjugates containing Fast or its scrambled control (ScrFast) were combined with an RGDS-PCL conjugate and fabricated into scaffolds. Including Fast and ScrFast peptides did not impair cell adhesion to the scaffolds. Cy3 labeling enabled real-time quantification of scaffold degradation in the presence of collagenase or human mesenchymal stromal cells (hMSCs). Fast-PCL scaffolds degraded significantly faster than ScrFast-PCL in both conditions, demonstrating sequence-dependent and cell-directed resorption. Integrating protease-sensitive peptides into the polymer backbone is therefore an effective approach to fabricate solid scaffolds that degrade in response to cells. This platform can be adapted to couple cellular processes to scaffold remodeling to enhance tissue regeneration.

Keywords:  biodegradable polymers; biomaterials; cell-mediated degradation; peptides; proteases; tissue engineering

DOI:  https://doi.org/10.1101/2025.10.06.680674