bims-ecemfi 2024-09-15 papers

Am J Physiol Cell Physiol. 2024 Sep 09.

Physical effects of 3D microenvironments on confined cell behaviors.

Bao-Qiong Lan, Ya-Jun Wang, Sai-Xi Yu, Wei Liu, Yan-Jun Liu.

Cell migration is a fundamental and functional cellular process, influenced by complex microenvironment consisting of different cells and extracellular matrix (ECM). Recent research has highlighted that, besides biochemical cues from the microenvironment, physical cues can also greatly alter cellular behavior. However, due to the complexity of the microenvironment, little is known about how the physical interactions between migrating cells and surrounding microenvironment instruct cell movement. Here, we explore various examples of 3D microenvironment reconstruction models in vitro and describe how the physical interplay between migrating cells and the neighboring microenvironment controls cell behavior. Understanding this mechanical cooperation will provide key insights into organ development, regeneration, and tumor metastasis.

Keywords: cell migration; confinement; microfluidics; physical microenvironments

DOI: https://doi.org/10.1152/ajpcell.00288.2024

bioRxiv. 2024 Aug 26. pii: 2024.08.26.609529. [Epub ahead of print]

Substrate stress relaxation regulates monolayer fluidity and leader cell formation for collectively migrating epithelia.

Frank Charbonier, Junqin Zhu, Raleigh Slyman, Cole Allan, Ovijit Chaudhuri.

Collective migration of epithelial tissues is a critical feature of developmental morphogenesis and tissue homeostasis. Coherent motion of cell collectives requires large scale coordination of motion and force generation and is influenced by mechanical properties of the underlying substrate. While tissue viscoelasticity is a ubiquitous feature of biological tissues, its role in mediating collective cell migration is unclear. Here, we have investigated the impact of substrate stress relaxation on the migration of micropatterned epithelial monolayers. Epithelial monolayers exhibit faster collective migration on viscoelastic alginate substrates with slower relaxation timescales, which are more elastic, relative to substrates with faster stress relaxation, which exhibit more viscous loss. Faster migration on slow-relaxing substrates is associated with reduced substrate deformation, greater monolayer fluidity, and enhanced leader cell formation. In contrast, monolayers on fast-relaxing substrates generate substantial substrate deformations and are more jammed within the bulk, with reduced formation of transient lamellipodial protrusions past the monolayer edge leading to slower overall expansion. This work reveals features of collective epithelial dynamics on soft, viscoelastic materials and adds to our understanding of cell-substrate interactions at the tissue scale.
Significance Statement: Groups of cells must coordinate their movements in order to sculpt organs during development and maintain tissues. The mechanical properties of the underlying substrate on which cells reside are known to influence key aspects of single and collective cell migration. Despite being a nearly universal feature of biological tissues, the role of viscoelasticity (i.e., fluid-like and solid-like behavior) in collective cell migration is unclear. Using tunable engineered biomaterials, we demonstrate that sheets of epithelial cells display enhanced migration on slower-relaxing (more elastic) substrates relative to faster-relaxing (more viscous) substrates. Building our understanding of tissue-substrate interactions and collective cell dynamics provides insights into approaches for tissue engineering and regenerative medicine, and therapeutic interventions to promote health and treat disease.

DOI: https://doi.org/10.1101/2024.08.26.609529

Adv Healthc Mater. 2024 Sep 09. e2401032

Tunable Hybrid Hydrogels of Alginate and Cell-Derived dECM to Study the Impact of Matrix Alterations on Epithelial-to-Mesenchymal Transition.

P Barros da Silva, Xiaoyu Zhao, Sílvia J Bidarra, Diana S Nascimento, Vernon LaLone, Bianca N Lourenço, Joana Paredes, Molly M Stevens, C C Barrias.

Epithelial-to-mesenchymal transition (EMT) is crucial for tumor progression, being linked to alterations in the extracellular matrix (ECM). Understanding the ECM's role in EMT can uncover new therapeutic targets, yet replicating these interactions in vitro remains challenging. It is shown that hybrid hydrogels of alginate (ALG) and cell-derived decellularized ECM (dECM), with independently tunable composition and stiffness, are useful 3D-models to explore the impact of the breast tumor matrix on EMT. Soft RGD-ALG hydrogels (200 Pa), used as neutral bulk material, supported mammary epithelial cells morphogenesis without spontaneous EMT, allowing to define the gene, protein, and biochemical profiles of cells at different TGFβ1-induced EMT states. To mimic the breast tumor composition, dECM from TGFβ1-activated fibroblasts (adECM) are generated, which shows upregulation of tumor-associated proteins compared to ndECM from normal fibroblasts. Using hybrid adECM-ALG hydrogels, it is shown that the presence of adECM induces partial EMT in normal epithelial cells, and amplifes TGF-β1 effects compared to ALG and ndECM-ALG. Increasing the hydrogel stiffness to tumor-like levels (2.5 kPa) have a synergistic effect, promoting a more evident EMT. These findings shed light on the complex interplay between matrix composition and stiffness in EMT, underscoring the utility of dECM-ALG hydrogels as a valuable in vitro platform for cancer research.

Keywords: cell‐derived decellularized ECM; defined hydrogel; tumor microenvironment; tunable hydrogel

DOI: https://doi.org/10.1002/adhm.202401032

iScience. 2024 Sep 20. 27(9): 110661

Divergent iron regulatory states contribute to heterogeneity in breast cancer aggressiveness.

William D Leineweber, Maya Z Rowell, Sural K Ranamukhaarachchi, Alyssa Walker, Yajuan Li, Jorge Villazon, Aida Mestre-Farrera, Zhimin Hu, Jing Yang, Lingyan Shi, Stephanie I Fraley.

Contact with dense collagen I (Col1) can induce collective invasion of triple negative breast cancer (TNBC) cells and transcriptional signatures linked to poor patient prognosis. However, this response is heterogeneous and not well understood. Using phenotype-guided sequencing analysis of invasive vs. noninvasive subpopulations, we show that these two phenotypes represent opposite sides of the iron response protein 1 (IRP1)-mediated response to cytoplasmic labile iron pool (cLIP) levels. Invasive cells upregulate iron uptake and utilization machinery characteristic of a low cLIP response, which includes contractility regulating genes that drive migration. Non-invasive cells upregulate iron sequestration machinery characteristic of a high cLIP response, which is accompanied by upregulation of actin sequestration genes. These divergent IRP1 responses result from Col1-induced transient expression of heme oxygenase I (HO-1), which cleaves heme and releases iron. These findings lend insight into the emerging theory that heme and iron fluxes regulate TNBC aggressiveness.

Keywords: Cancer; Cell biology; Molecular biology; Molecular physiology

DOI: https://doi.org/10.1016/j.isci.2024.110661

Nat Rev Cancer. 2024 Sep 09.

CAF-induced physical constraints controlling T cell state and localization in solid tumours.

Ludovica Arpinati, Giulia Carradori, Ruth Scherz-Shouval.

Solid tumours comprise cancer cells that engage in continuous interactions with non-malignant cells and with acellular components, forming the tumour microenvironment (TME). The TME has crucial and diverse roles in tumour progression and metastasis, and substantial efforts have been dedicated into understanding the functions of different cell types within the TME. These efforts highlighted the importance of non-cell-autonomous signalling in cancer, mediating interactions between the cancer cells, the immune microenvironment and the non-immune stroma. Much of this non-cell-autonomous signalling is mediated through acellular components of the TME, known as the extracellular matrix (ECM), and controlled by the cells that secrete and remodel the ECM - the cancer-associated fibroblasts (CAFs). In this Review, we delve into the complex crosstalk among cancer cells, CAFs and immune cells, highlighting the effects of CAF-induced ECM remodelling on T cell functions and offering insights into the potential of targeting ECM components to improve cancer therapies.

DOI: https://doi.org/10.1038/s41568-024-00740-4

ACS Appl Mater Interfaces. 2024 Sep 09.

A Facile Method to Quantify Synthetic Peptide Concentrations on Biomaterials.

Jonathan P Wojciechowski, Thomas Benge, Kaili Chen, Cécile Echalier, Ruoxiao Xie, Molly M Stevens.

While it is well understood that peptides can greatly improve cell-material interactions, it is often challenging to determine the concentration of the peptide which decorates a material. Herein, we describe a straightforward method using readily, synthetically accessible Fmoc peptides and commercially available reagents to measure the concentration of peptides on nanoparticles, surfaces, and hydrogels. To achieve this, the Fmoc protecting group from immobilized peptides is removed under optimized basic conditions. The dibenzofulvene released can be quantified by HPLC or UV-vis spectroscopy, enabling a direct experimental measurement of the concentration of the peptide. We show that we can measure the concentration of a BMP-2 peptide mimic on a hydrogel to determine the concentration required to stimulate osteogenesis of human mesenchymal stem cells. We envision that this methodology will enable a more thorough understanding of the concentration of synthetic peptides decorated on many biomaterials (e.g., nanoparticles, surfaces, hydrogels) to improve deconvolution of the interactions at the cell-material interface.

Keywords: biomaterials; hydrogels; nanoparticles; peptides; quantification; surfaces

DOI: https://doi.org/10.1021/acsami.4c07164