Human embryonic stem cells (hESCs) can be maintained in a fully defined niche on extracellular matrix substrates, to which they attach through integrin receptors. However, the underlying integrin signaling mechanisms, and their contribution to hESC behavior, are largely unknown. Here, we show that focal adhesion kinase (FAK) transduces integrin activation and supports hESC survival, substrate adhesion, and maintenance of the undifferentiated state. After inhibiting FAK kinase activity we show that hESCs undergo cell detachment-dependent apoptosis or differentiation. We also report deactivation of FAK downstream targets, AKT and MDM2, and upregulation of p53, all key players in hESC regulatory networks. Loss of integrin activity or FAK also induces cell aggregation, revealing a role in the cell-cell interactions of hESCs. This study provides insight into the integrin signaling cascade activated in hESCs and reveals in FAK a key player in the maintenance of hESC survival and undifferentiated state.
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http://dx.doi.org/10.1016/j.stemcr.2016.07.006 | DOI Listing |
J Am Chem Soc
January 2025
Department of Chemistry, Colorado State University, Fort Collins, Colorado 80523-1872, United States.
Enthalpy is often the focal point when designing monomers for polymer circularity, but much less is explored on how entropy can be exploited to create polymers with synergistic circularity and properties. Here, we design a series of spiro-lactones (SLs) with closed-chain cycloalk(en)yl substituents at the α,α-position of δ-valerolactone (δVL), which, when combined with the parent δVL and -α,α-dialkyl-substituted δVL with open-chain alkyl groups, provide a desired platform for exploring the circular polymer design by focusing on the entropy change of polymerization. These SLs exhibit finely balanced (de)polymerizability that is regulated chiefly by entropy differentiation, allowing both the facile synthesis of polyester PSLs ( up to 1000 kg mol) in a living fashion and selective depolymerization of the PSLs to completely recover monomers under mild conditions (using a recyclable catalyst at 100 °C).
View Article and Find Full Text PDFMechanical forces are critical for virtually all fundamental biological processes, yet quantification of mechanical forces at the molecular scale remains challenging. Here, we present a new strategy using calibrated coiled-coils as genetically encoded, compact, tunable, and modular mechano-sensors to substantially simplify force measurement , via diverse readouts (luminescence, fluorescence and analytical biochemistry) and instrumentation readily available in biology labs. We demonstrate the broad applicability and ease-of-use of these coiled-coil mechano-sensors by measuring forces during cytokinesis (formin Cdc12) and endocytosis (epsin Ent1) in yeast, force distributions in nematode axons (β-spectrin UNC-70), and forces transmitted to the nucleus (mini-nesprin-2G) and within focal adhesions (vinculin) in mammalian cells.
View Article and Find Full Text PDFSci Rep
January 2025
Institute of Animal Reproduction and Food Research, Polish Academy of Sciences in Olsztyn, 10-748, Olsztyn, Poland.
Mares with endometrosis exhibit histological changes not only in the endometrium but also in the myometrium that suggest possible functional impairment. The molecular background of these changes is not well understood. We hypothesize that the transcriptomic profile of the mare myometrium varies depending on the degree of endometrosis in mares.
View Article and Find Full Text PDFProg Biophys Mol Biol
January 2025
Department of Vascular Surgery, The Affiliated Hospital of Southwest Medical University, Luzhou, 646000, China; Metabolic Vascular Disease Key Laboratory of Sichuan Province, The Affiliated Hospital of Southwest Medical University, 646000 Luzhou, China; Key Laboratory of Medical Electrophysiology, Ministry of Education & Medical Electrophysiological Key Laboratory of Sichuan Province, (Collaborative Innovation Center for Prevention of Cardiovascular Diseases) Institute of Cardiovascular Research, Southwest Medical University, Luzhou, 646000, China; Department of General Surgery, The Affiliated Hospital of Southwest Medical University, Luzhou, 646000, China. Electronic address:
Vinculin, a crucial adhesion plaque protein, plays a significant role in cell morphology and tissue development. Dysregulation of focal adhesion proteins has been linked to numerous diseases, including cardiovascular conditions, gastrointestinal disorders, and cancer. Recent studies increasingly highlight vinculin's involvement in the progression of these diseases; however, a comprehensive review remains lacking.
View Article and Find Full Text PDFPolymers (Basel)
January 2025
Center for Micro-Electro Mechanical Systems (CMEMS), Campus Azurém, University of Minho, 4800-058 Guimarães, Portugal.
Indwelling medical devices, such as urinary catheters, often experience bacterial colonization, forming biofilms that resist antibiotics and the host's immune defenses through quorum sensing (QS), a chemical communication system. This study explores the development of antimicrobial coatings by immobilizing acylase, a quorum-quenching enzyme, on sandblasted polydimethylsiloxane (PDMS) surfaces. PDMS, commonly used in medical devices, was sandblasted to increase its surface roughness, enhancing acylase attachment.
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