Mechanical remodeling of normally sized mammalian cells under a gravity vector

• Published in: The FASEB journal Vol. 31; no. 2; p. 802
• Main Authors: Zhang, Chen, Zhou, Lüwen, Zhang, Fan, Lü, Dongyuan, Li, Ning, Zheng, Lu, Xu, Yanhong, Li, Zhan, Sun, Shujin, Long, Mian
• Format: Journal Article
• Language: English
• Published: United States 01.02.2017
• Subjects: Animals; Biomechanical Phenomena; Cell Culture Techniques; Cell Line; Cell Nucleus; Gene Expression Regulation, Enzymologic; Gravitation; Mice; Osteoblasts - cytology; Osteoblasts - physiology; rho-Associated Kinases - genetics; rho-Associated Kinases - metabolism; mechanosensing; gravity-directed; cytoskeletal remodeling; FAC reorganization; nucleus translocation
• ISSN: 1530-6860
• DOI: 10.1096/fj.201600897RR

Translocation of the dense nucleus along a gravity vector initiates mechanical remodeling of a cell, but the underlying mechanisms of cytoskeletal network and focal adhesion complex (FAC) reorganization in a mammalian cell remain unclear. We quantified the remodeling of an MC3T3-E1 cell placed in upward-, downward-, or edge-on-orientated substrate. Nucleus longitudinal translocation presents a high value in downward orientation at 24 h or in edge-on orientation at 72 h, which is consistent with orientation-dependent distribution of perinuclear actin stress fibers and vimentin cords. Redistribution of total FAC area and fractionized super mature adhesion number coordinates this dependence at short duration. This orientation-dependent remodeling is associated with nucleus flattering and lamin A/C phosphorylation. Actin depolymerization or Rho-associated protein kinase signaling inhibition abolishes the orientation dependence of nucleus translocation, whereas tubulin polymerization inhibition or vimentin disruption reserves the dependence. A biomechanical model is therefore proposed for integrating the mechanosensing of nucleus translocation with cytoskeletal remodeling and FAC reorganization induced by a gravity vector.-Zhang, C., Zhou, L., Zhang, F., Lü, D., Li, N., Zheng, L., Xu, Y., Li, Z., Sun, S., Long, M. Mechanical remodeling of normally sized mammalian cells under a gravity vector.