title: Actin-myosin network influences morphological response of neuronal cells to altered osmolarity.
abstract: Acute osmotic fluctuations in the brain occur during a number of clinical conditions and can result in a variety of adverse neurological symptoms. Osmotic perturbation can cause changes in the volumes of intra- and extracellular fluid and, due to the rigidity of the skull, can alter intracranial pressure thus making it difficult to analyze purely osmotic effects in vivo. The present study aims to determine the effects of changes in osmolarity on SH-SY5Y human neuroblastoma cells in vitro, and the role of the actin-myosin network in regulating this response. Cells were exposed to hyper- or hypoosmotic media and morphological and cytoskeletal responses were recorded. Hyperosmotic shock resulted in a drop in cell body volume and planar area, a persisting shape deformation, and increases in cellular translocation. Hypoosmotic shock did not significantly alter planar area, but caused a transient increase in cell body volume and an increase in cellular translocation via the development of small protrusions rich in actin. Disruption of the actin-myosin network with latrunculin and blebbistatin resulted in changes to volume and shape regulation, and a decrease in cellular translocation. In both osmotic perturbations, no apparent disruptions to cytoskeletal integrity were observed by light microscopy. Overall, because osmotically induced changes persisted even after volume regulation occurred, it is possible that osmotic stress may play a larger role in neurological dysfunction than currently believed.
authors: Department of Bioengineering, University of California, San Diego, La Jolla, California.
authors: Brian G
authors: BG
authors: Bober
authors: Fischell Department of Bioengineering, University of Maryland, College Park, Maryland.
authors: James M
authors: JM
authors: Love
authors: Department of Orthopaedic Surgery, University of California, San Diego, La Jolla, California.
authors: Steven M
authors: SM
authors: Horton
authors: Fischell Department of Bioengineering, University of Maryland, College Park, Maryland.
authors: Mariya
authors: M
authors: Sitnova
authors: Fischell Department of Bioengineering, University of Maryland, College Park, Maryland.
authors: Sina
authors: S
authors: Shahamatdar
authors: Fischell Department of Bioengineering, University of Maryland, College Park, Maryland.
authors: Ajay
authors: A
authors: Kannan
authors: Department of Bioengineering, University of California, San Diego, La Jolla, California.|Fischell Department of Bioengineering, University of Maryland, College Park, Maryland.|Department of Orthopaedic Surgery, University of California, San Diego, La Jolla, California.
authors: Sameer B
authors: SB
authors: Shah
mesh_terms: D000199:Actins / Q000378:metabolism*; D045744:Cell Line, Tumor; D048430:Cell Shape / Q000187:drug effects / Q000502:physiology*; D003599:Cytoskeleton / Q000378:metabolism*; D006576:Heterocyclic Compounds, 4 or More Rings / Q000494:pharmacology; D006801:Humans; D009218:Myosins / Q000378:metabolism*; D009474:Neurons / Q000378:metabolism*; D009997:Osmotic Pressure / Q000187:drug effects / Q000502:physiology*
chemical_list: D000199:Actins; D006576:Heterocyclic Compounds, 4 or More Rings; C472645:blebbistatin; D009218:Myosins
keywords: SY5Y; cell shape; cytoskeleton; neuron; osmotic stress; pressure