title: Calcium signaling in live cells on elastic gels under mechanical vibration at subcellular levels.
abstract: A new device was designed to generate a localized mechanical vibration of flexible gels where human umbilical vein endothelial cells (HUVECs) were cultured to mechanically stimulate these cells at subcellular locations. A Fluorescence Resonance Energy Transfer (FRET)-based calcium biosensor (an improved Cameleon) was used to monitor the spatiotemporal distribution of intracellular calcium concentrations in the cells upon this mechanical stimulation. A clear increase in intracellular calcium concentrations over the whole cell body (global) can be observed in the majority of cells under mechanical stimulation. The chelation of extracellular calcium with EGTA or the blockage of stretch-activated calcium channels on the plasma membrane with streptomycin or gadolinium chloride significantly inhibited the calcium responses upon mechanical stimulation. Thapsigargin, an endoplasmic reticulum (ER) calcium pump inhibitor, or U73122, a phospholipase C (PLC) inhibitor, resulted in mainly local calcium responses occurring at regions close to the stimulation site. The disruption of actin filaments with cytochalasin D or inhibition of actomyosin contractility with ML-7 also inhibited the global calcium responses. Therefore, the global calcium response in HUVEC depends on the influx of calcium through membrane stretch-activated channels, followed by the release of inositol trisphosphate (IP3) via PLC activation to trigger the ER calcium release. Our newly developed mechanical stimulation device can also provide a powerful tool for the study of molecular mechanism by which cells perceive the mechanical cues at subcellular levels.
authors: Department of Bioengineering and Beckman Institute for Advanced Science and Technology, University of Illinois, Urbana-Champaign, Urbana, Illinois, United States of America.
authors: Wagner Shin
authors: WS
authors: Nishitani
authors: Taher A
authors: TA
authors: Saif
authors: Yingxiao
authors: Y
authors: Wang
mesh_terms: D008841:Actin Cytoskeleton / Q000378:metabolism; D000205:Actomyosin / Q000378:metabolism; D020013:Calcium Signaling; D002462:Cell Membrane / Q000378:metabolism; D002470:Cell Survival; D004548:Elasticity; D004721:Endoplasmic Reticulum / Q000378:metabolism; D005110:Extracellular Space / Q000378:metabolism; D005782:Gels / Q000378:metabolism*; D061307:Human Umbilical Vein Endothelial Cells / Q000166:cytology / Q000201:enzymology / Q000378:metabolism*; D006801:Humans; D013314:Stress, Mechanical; D013347:Subcellular Fractions / Q000378:metabolism; D010738:Type C Phospholipases / Q000378:metabolism; D014732:Vibration
chemical_list: D005782:Gels; D000205:Actomyosin; D010738:Type C Phospholipases