title: Longterm conditions of mimicked weightlessness influences the cytoskeleton in thyroid cells.
abstract: Weightlessness influences the human immune and hormone system, reduces bone mass, leads to muscle atrophy and cardiac atrophy. Effects on control mechanisms for proliferation, programmed cell death and differentiation are well documented. The principal aim of this study was to investigate changes of the cytoskeleton in thyroid cells cultured in vector-averaged gravity under clinostat rotation. After 12 hours the formation of multicellular spheroids started. An increase of extracellular matrix proteins and beta 1-integrin was observed. Laser scanning confocal microscopy of ML-1 follicular thyroid carcinoma cells and normal thyroid HTU-5 cells immunostained with anti-cytokeratin to demonstrate these intermediate filaments revealed that cytokeratin filaments extended from centers, were thickened, coalesced and shortened as compared to control cells. Moreover, vimentin was highly disorganized. The vimentin network formed a coiled aggregate closely associated with the nucleus. Western blot analyses of talin, alpha- and beta-tubulin showed a clear increase of these proteins in cells cultured under simulated 0 g. Our data suggest that the effects of microgravity on cultured human thyroid cells are accompanied by noticeable functional cellular changes. Future studies to clarify the pathway that regulate the observed integrin activation and the mechanisms by which they function have to be performed.
authors.affiliation: Department of Trauma and Reconstructive Surgery, Charité University Medicine, Berlin, Germany. manfred.infanger@charite.de
authors.forename: Manfred
authors.initials: M
authors.lastname: Infanger
authors.forename: Peter
authors.initials: P
authors.lastname: Kossmehl
authors.forename: Mehdi
authors.initials: M
authors.lastname: Shakibaei
authors.forename: Gundula
authors.initials: G
authors.lastname: Schulze-Tanzil
authors.forename: Augusto
authors.initials: A
authors.lastname: Cogoli
authors.forename: Shideh
authors.initials: S
authors.lastname: Faramarzi
authors.forename: Johann
authors.initials: J
authors.lastname: Bauer
authors.forename: Francesco
authors.initials: F
authors.lastname: Curcio
authors.forename: Martin
authors.initials: M
authors.lastname: Paul
authors.forename: Daniela
authors.initials: D
authors.lastname: Grimm
mesh_terms: D002454:Cell Differentiation; D002460:Cell Line; D003599:Cytoskeleton / Q000378:metabolism*; D006801:Humans; D019012:Integrin beta1 / Q000378:metabolism; D007633:Keratins / Q000378:metabolism; D012399:Rotation; D016608:Talin / Q000378:metabolism; D013961:Thyroid Gland / Q000166:cytology* / Q000378:metabolism; D013964:Thyroid Neoplasms / Q000378:metabolism* / Q000648:ultrastructure; D014404:Tubulin / Q000378:metabolism; D014407:Tumor Cells, Cultured / Q000166:cytology / Q000378:metabolism; D014746:Vimentin / Q000378:metabolism; D018474:Weightlessness Simulation
chemical_list: D019012:Integrin beta1; D016608:Talin; D014404:Tubulin; D014746:Vimentin; D007633:Keratins