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Introduction: Tissue fibrosis is characterized by progressive extracellular matrix (ECM) stiffening and loss of viscoelasticity that ultimately impairs organ functionality. Cells bind to the ECM through integrins, where integrin engagement in particular has been correlated with fibroblast activation into contractile myofibroblasts that drive fibrosis progression. There is a significant unmet need for hydrogel systems that deconstruct the complexity of native tissues to better understand the individual and combined effects of stiffness, viscoelasticity, and integrin engagement on fibroblast behavior.
Methods: We developed hyaluronic acid hydrogels with independently tunable cell-instructive properties (stiffness, viscoelasticity, ligand presentation) to address this challenge. Hydrogels with mechanics matching normal or fibrotic lung tissue were synthesized using a combination of covalent crosslinks and supramolecular interactions to tune viscoelasticity. Cell adhesion was mediated through incorporation of either RGD peptide or engineered fibronectin fragments promoting preferential integrin engagement via 3 or 51.
Results: On fibrosis-mimicking stiff elastic hydrogels, preferential 3 engagement promoted increased spreading, actin stress fiber organization, and focal adhesion maturation as indicated by paxillin organization in human lung fibroblasts. In contrast, preferential 51 binding suppressed these metrics. Viscoelasticity, mimicking the mechanics of healthy tissue, largely curtailed fibroblast spreading and focal adhesion organization independent of adhesive ligand type, highlighting its role in reducing fibroblast-activating behaviors.
Conclusions: Together, these results provide new insights into how mechanical and adhesive cues collectively guide disease-relevant cell behaviors.
Supplementary Information: The online version contains supplementary material available at 10.1007/s12195-021-00672-1.
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http://dx.doi.org/10.1007/s12195-021-00672-1 | DOI Listing |
Mol Biol Cell
September 2025
Department of Cell and Developmental Biology, Vanderbilt University School of Medicine Basic Sciences, Nashville, TN, USA.
Cardiac sarcomere assembly is a highly orchestrated process requiring integration between intracellular contractile machinery and extracellular adhesions. While α-actinin-2 (ACTN2) is well known for its structural role at the cardiac Z-disc, the sarcomere border, the function of the "non-muscle" paralog α-actinin-1 (ACTN1) in cardiac myocytes remains unclear. Using human induced pluripotent stem cell-derived cardiac myocytes (hiCMs), we demonstrate that siRNA-mediated depletion of ACTN1 disrupts sarcomere assembly, and that exogenous re-introduction of ACTN1 but not ACTN2 restores assembly, revealing non-redundant functions.
View Article and Find Full Text PDFNat Cell Biol
September 2025
Department of Medicine, Division of Pulmonary and Critical Care Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA.
Durotaxis, cell migration along stiffness gradients, is linked to embryonic development, tissue repair and disease. Despite solid in vitro evidence, its role in vivo remains largely speculative. Here we demonstrate that durotaxis actively drives disease progression in vivo in mouse models of lung fibrosis and metastatic pancreatic cancer.
View Article and Find Full Text PDFSignal Transduct Target Ther
September 2025
State Key Laboratory of Molecular Oncology & Department of Medical Oncology & Department of Pathology, National Cancer Center/National Clinical Research Center for Cancer/Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China.
Small-cell lung cancer (SCLC), an aggressive neuroendocrine tumor strongly associated with exposure to tobacco carcinogens, is characterized by early dissemination and dismal prognosis with a five-year overall survival of less than 7%. High-frequency gain-of-function mutations in oncogenes are rarely reported, and intratumor heterogeneity (ITH) remains to be determined in SCLC. Here, via multiomics analyses of 314 SCLCs, we found that the ASCL1/MKI67 and ASCL1/CRIP2 clusters accounted for 74.
View Article and Find Full Text PDFMedicine (Baltimore)
September 2025
Department of Orthopedic Surgery, Wenzhou TCM Hospital of Zhejiang Chinese Medical University, Wenzhou, China.
The purpose of this study was to investigate potential therapeutic targets for osteosarcoma (OS) and offer hints regarding genetic factors for OS treatment using a bioinformatics method. This study processed 3 OS datasets from the gene expression omnibus database using R software, screening for differentially expressed genes (DEGs). After enrichment analysis, based on expression quantitative trait loci data and the genome-wide association study data of OS, Mendelian randomization analysis was used to screen the genes closely related to OS disease, which intersect with DEGs to obtain co-expressed genes, validation datasets were employed to verify the results.
View Article and Find Full Text PDFInt J Implant Dent
September 2025
Department of Periodontology, Center for Biomedical Education and Research (ZBAF), School of Dentistry, Faculty of Health, Witten/Herdecke University, Witten, Germany.
Background: Guided bone regeneration (GBR) relies on biocompatible membranes to support osteogenesis. 1,4-butanediol diglycidyl ether (BDDE)-crosslinked hyaluronic acid (xHyA) has shown promise in enhancing bone regeneration, yet its mechanisms remain unclear.
Objective: This study evaluates the osteogenic effects of xHyA-functionalized native pericardium collagen membrane (NPCM) and ribose-crosslinked collagen membrane (RCCM) using an airlift culture model with SaOS-2 cells.