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CME/CE Test

Mechanosensation by Endothelial PIEZO1 Is Required for Leukocyte Diapedesis

  1. Based on the in vitro and mouse model study by Wang and colleagues, which of the following statements about how low flow and leukocyte-induced intercellular adhesion molecule 1 (ICAM-1) clustering interact to mechanically activate endothelial PIEZO1 is correct?
    Low flow and leukocyte-induced ICAM-1 clustering have opposing effects on mechanical activation of endothelial PIEZO1, a mechanosensitive cation channel
    Downstream signaling through ICAM-1 requires coactivation of PIEZO1 by fluid shear stress and ICAM-1-induced reorganization of the cortical cytoskeleton
    Changes in actomyosin cortical tension are unlikely to directly affect plasma membrane tension
    Small interfering RNA (siRNA)–mediated knockdown of α-actinin-4 and cortactin had no effect on ICAM-1–mediated increases in membrane tension
  2. Based on the in vitro and mouse model study by Wang and colleagues, which of the following statements about the role of PIEZO1 activation in signaling processes leading to opening of the endothelial barrier and leukocyte extravasation is correct?
    Activation of PIEZO1 initiates signaling processes that block opening of the endothelial barrier
    PIEZO1 activation leads to decreases in [Ca2+]i
    PIEZO1 activation leads to activation of downstream signaling events, including phosphorylation of SRC, PYK2, and myosin light chain
    The study showed involvement of PIEZO1 in transendothelial migration of leukocytes in vitro but not in vivo
  3. Based on the in vitro and mouse model study by Wang and colleagues, which of the following statements about pathophysiologic and clinical implications of how molecular mechanisms underlying the initial interactions between leukocytes and endothelial cells are linked to opening of the endothelial barrier is correct?
    Findings from this study are likely applicable only to hematologic disorders
    Mice with endothelium-specific Piezo1 deficiency show increased leukocyte extravasation in different inflammation models
    Inflammation does not require leukocyte extravasation
    Leukocytes and the hemodynamic microenvironment synergize to mechanically activate endothelial PIEZO1 and subsequent downstream signaling to initiate leukocyte diapedesis