Fibroblast spreading was studied using immunofluorescent method that provided visualization of actin structures and adhesion contacts in the same cell. Four stages of actin system formation were observed. 1. Actin concentration in ruffles at the cell periphery. Formation of numerous dot-like contacts along the whole perimeter of the cell. 2. Formation of a circumferential actin bundle. Focal contacts are located at the outer edge of the bundle. 3. Gradual transformation of the circumferential bundle into actin network with triangular meshes. Peripheral (rather than internal) filaments of the network are associated with the focal contacts. 4. Appearance of the system of long straight actin bundles (stress fibers) associated with dash-like focal contacts. The stress fibers are supposed to arise from the triangular actin network which in its turn arises from the circumferential bundle. It is suggested that the formation of actin cytoskeleton is a process driven by the development of tensions in actin structures attached to the focal contacts at the cell periphery.
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Cell Signal
January 2025
Division of Bioengineering, Graduate School of Engineering Science, University of Osaka, Japan; R(3) Institute for Newly-Emerging Science Design, University of Osaka, Japan; Global Center for Medical Engineering and Informatics, University of Osaka, Japan. Electronic address:
Aging proceeds with the accumulation of senescent cells in multiple organs. These cells exhibit increased size compared to young cells, which promotes further senescence and age-related diseases. Currently, the molecular mechanism behind the maintenance of such huge cell architecture undergoing senescence remains poorly understood.
View Article and Find Full Text PDFACS Biomater Sci Eng
January 2025
Department of Materials Science and Engineering, School of Materials and Chemical Technology, Institute of Science Tokyo, 2-12-1 Ookayama, Meguro-ku, Tokyo 152-8550, Japan.
The structure of many native tissues consists of aligned collagen (Col) fibrils, some of which are further composited with dispersed hydroxyapatite (HAp) nanocrystals. Accurately mimicking this inherent structure is a promising approach to enhance scaffold biocompatibility in tissue engineering. In this study, biomimetic sheets composed of highly aligned Col fibrils were fabricated using a plastic compression and tension method, followed by the deposition of HAp nanocrystals on the surface via an alternate soaking method.
View Article and Find Full Text PDFWorld J Biol Psychiatry
January 2025
School of Medicine, IMPACT, Institute for Innovation in Physical and Mental Health and Clinical Translation, Deakin University, Geelong, Australia.
Unlabelled: Focal adhesions and their dynamic nature are essential for various physiological processes, including the formation of neurites, synaptic function and plasticity. Alterations in these processes have been associated with schizophrenia and bipolar disorder.
Objectives: This study aimed to explore the impact of pharmacological treatments used for bipolar disorder and schizophrenia on the expression of genes involved in the focal adhesion pathway, addressing a gap in understanding the interaction between medication effects and disease pathophysiology.
Bioorg Chem
January 2025
Institute for Advanced Study, Department of Chemistry, School of Natural Sciences and Bavarian NMR Center (BNMRZ), Technical University Munich, Ernst-Otto-Fischer-Str. 2, 85748 Garching, Germany. Electronic address:
Integrins are well-characterized receptors involved in cell adhesion and signaling. With six approved drugs, they are recognized as valuable therapeutic targets. Here, we explore potential activation mechanisms that may clarify the agonist versus antagonist behavior of integrin ligands.
View Article and Find Full Text PDFJ Cell Physiol
January 2025
Department of Biosciences & Bioengineering, IIT Bombay, Mumbai, India.
In addition to proteins such as collagen (Col) and fibronectin, the extracellular matrix (ECM) is enriched with bulky proteoglycan molecules such as hyaluronic acid (HA). However, how ECM proteins and proteoglycans collectively regulate cellular processes has not been adequately explored. Here, we address this question by studying cytoskeletal and focal adhesion organization and dynamics on cells cultured on polyacrylamide hydrogels functionalized with Col, HA and a combination of Col and HA (Col/HA).
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