Abstract: Cytoskeleton is a multiscale dynamicnetworks in mechanics-chemistry-biology, and plays an essential role in manybiological process, such as cell spreading, migration and cellularmechanotransduction. In addition, the polymorphism of its microstructure anddynamic reorganization determine the mechanical behaviours and stability of acell.
Hence, exploring the micro-mechanism of these dynamic behaviours is achallenging problem. In this paper, the latest development of experimental andtheoretical studies on the reorganization and mechanical behaviours ofcytoskeleton is reviewed. Future development and challenges are alsoprospected.
Key Words: Cytoskeleton; Micro-structure; Reorganization;Mechanotransduction IntroductionThe cytoskeleton was found very late until the use of glutaraldehyde at room temperature in 1960s, whichmake it observable with the electron microscope. It consists of a structuralsystem called cytoskeletal system, and it is named three intracellular systemstogether with intracellular genetic systems and cell membranes system. In most mammals, three kinds of filaments in cells make up thecytoskeleton system: Microtubules, Microfilaments and Intermediate filaments (Figure1). Then dimension of microtubules is normally 25nm, the largest one, whichtakes longest time to growth and it is comparatively steady than the others.And microtubules build the main structure of cytoskeleton, supporting themicrofilaments and intermediate filaments.
Microfilaments have the smallestdimension (about 7nm) among them, and mainly make up from actin, so are namedactin filaments sometimes. The active actin filaments are formed with a complexcycle, including many cooperation of various types of actin proteins. Theformation is assisted by a wild range of actin-binding different proteins andsometimes overlapping activities (Jockusch, 2017). The diameter ofintermediate filaments is between microtubules and intermediate filaments,commonly 10nm. The cytoskeleton’s varied functions depend on the behaviour ofthree families of filaments, such as transformation, motility, growth anddifferentiation (Alberts, 2008).Fig.
1.Diagrams of the cytoskeleton systemThe cytoskeleton supports the cell structure anddetermine the shape. It not only determines the mechanical behaviours and stabilityof cells, but also controls the motility and deformation of cells and helpcells to perform various biological functions such as transport of biologicalmolecules.Recently, many important events about cell indifferent time and space scales have been discovered, including the cellularmechanotransduction. Briefly, thecellular mechanotransduction is a big discovery in the biology, and analysis ofthis subject need to understand Stretch-activated ion channels, caveolae,integrins, cadherins, growth factor receptors, myosin motors, cytoskeletalfilaments, nuclei, extracellular matrix, and numerous other structures andsignaling molecules (Ingber, 2006).
And it is a process that outside signal transmits to intracellular while cellcontacts the environment, which influences the growth/depolymerisation andcross-linking/unbinding of cytoskeleton. This process consists of a range of dynamicresponse. In contrast, this dynamic response will make an effect on theenvironment and both of them achieve a dynamic balance eventually.
Cellular mechanotransductionhas a deep influence on cell and biodiversity, and exploring and discovering cellularmechanotransduction not only promote the development of biomedicine, but also likethe goal scientists want to achieve. The study in cellular mechanotransductionstill has numbers of problems to be solved, but the important role cytoskeletonplays in the cellular mechanotransduction is widely recognised.Besides that, cytoskeletonnetwork is a kind of spatial flexible structure that can be simulated bymechanical model.
Cytoskeleton is an extremely complexbiomolecular system in which molecular-scale components form a mesoscopic scalestructure together, and mesoscopic scale structure couples with each other toform a continuous network. Some researchers use fractal dimension method to describethis continuous and inhomogeneous structure and this method will be talkedlater. From the viewpoint of bionics, thecytoskeleton network has certain reference value for the study of spatialstructure. Scientists can find more effective method to support a structurewith limited materials by simulating the cytoskeleton network directly insteadof using computers to explore.Researchers carried out a large number of experimentalstudies to approach the truth of cytoskeleton gradually, and this article isaimed at review and summarize some results.
Due to the limited background andlevel of author, this essay only talks about some experiments and simplytheoretical models.Some Dynamic Characteristics about Cytoskeleton and Experiments