2026-04-13T06:39:25Zhttps://recercat.cat/oai/request

oai:recercat.cat:2445/258532025-12-05T09:20:46Zcom_2072_1057col_2072_478799col_2072_478917

00925njm 22002777a 4500 dc Trepat Guixer, Xavier author Grabulosa Descals, Mireia author Buscemi Estefanell, Lara author Rico Camps, Félix author Farré Ventura, Ramon author Navajas Navarro, Daniel author 2012-05-16T10:52:34Z 2012-05-16T10:52:34Z 2005 The mechanical properties of alveolar epithelial cells play a central role in maintaining the physical integrity of the alveolar epithelium. We studied the viscoelastic properties of alveolar epithelial cells (A549) in response to thrombin and histamine with optical magnetic twisting cytometry. Ferrimagnetic beads coated with Arg-Gly-Asp (RGD)-peptide or acetylated low-density lipoprotein were bound to cell surface receptors and subsequently twisted in an oscillatory magnetic field (0.1–100 Hz). The cell storage (G′) and loss (G″) moduli were computed from twisting torque and bead displacement. In measurements with RGD-coated beads, thrombin (0.5 U/ml) induced a rapid and sustained threefold increase in G′ and G″ at ∼100 s after challenge. Histamine (100 μM) induced a rapid but transient twofold increase in G′ and G″ with maximum values 60 s after challenge. Posttreatment with cytochalasin D abolished thrombin-induced cell stiffening. G′ increased with frequency following a power law with exponent 0.214. G″ increased proportionally to G′ up to 10 Hz but showed a steeper rise at higher frequencies. Thrombin caused a fall in the power-law exponent (0.164). In measurements with acetylated low-density lipoprotein-coated beads, minor changes (<20%) were observed in G′ and G″ after the addition of thrombin and histamine. F-actin staining revealed that thrombin and histamine induced a profound reorganization of the actin cytoskeleton at the cell periphery and formation of actin bundles. In the mechanically dynamic environment of the lung, cell stiffening induced by thrombin and histamine increases centripetal tension, which could contribute to alveolar barrier dysfunction. Cèl·lules epitelials Transducció de senyal cel·lular Bronquis Hidrolases Epithelial cells Cellular signal transduction Bronchi Hydrolases Thrombin and histamine induce stiffening of alveolar epithelial cells.