Molecular & Cellular Biomechanics, Vol.15, No.1, pp. 21-36, 2018, DOI:10.3970/mcb.2018.015.021

Abstract Dendritic cells (DCs) are the most potent professional antigen presenting cells as now known, which play critical roles in the initiation, programming and regulation of the immune response. Transforming growth factor-β₁ (TGF-β₁), one of the major suppressive cytokines in tumor microenvironment, can deteriorate the biomechanical characteristics and motility of mature dendritic cells (mDCs)，but the underlying molecular mechanisms are not well defined. In this study, the effects of TGF-β₁ on the motilities and T cell priming capabilities of mDCs as well as the molecular regulatory mechanisms were investigated. The results showed that the cytoskeleton (F-actin) organizations of mDCs were abnormally remodeled… More >

Mingzhi Luo^1,2, Peili Yu¹, Yang Jin³, Zhili Qian¹, Yue Wang¹, Jingjing Li¹, Peng Shang^2*, Linhong Deng^1*

Molecular & Cellular Biomechanics, Vol.13, No.2, pp. 137-157, 2016, DOI:10.3970/mcb.2016.013.155

Abstract Random positioning machine (RPM) and diamagnetic levitation are two essential ground-based methods used to stimulate the effect of microgravity in space life science research. However, the force fields generated by these two methods are fundamentally different, as RPM generates a dynamic force field acting on the surface in contact with supporting substrate, whereas diamagnetic levitation generates a static force field acting on the whole body volume of the object (e.g. cell). Surprisingly, it is hardly studied whether these two fundamentally different force fields would cause different responses in mammalian cells. Thus we exposed cultured MC3T3-E1 osteoblasts to either dynamically stimulated… More >

Tong Li^∗, Prasad KDV Yarlagadda^∗, Adekunle Oloyede^∗, Namal Thibbotuwawa^∗, YuanTong Gu^∗,†

Molecular & Cellular Biomechanics, Vol.12, No.1, pp. 17-35, 2015, DOI:10.3970/mcb.2015.012.017

Abstract Living cells are the functional unit of organs that controls reactions to their exterior. However, the mechanics of living cells can be difficult to characterize due to the crypticity of their microscale structures and associated dynamic cellular processes. Fortunately, multiscale modelling provides a powerful simulation tool that can be used to study the mechanical properties of these soft hierarchical, biological systems. This paper reviews recent developments in hierarchical multiscale modeling technique that aimed at understanding cytoskeleton mechanics. Discussions are expanded with respects to cytoskeletal components including: intermediate filaments, microtubules and microfilament networks. The mechanical performance of difference cytoskeleton components are… More >

Syed A Jamal^*

Molecular & Cellular Biomechanics, Vol.10, No.4, pp. 267-273, 2013, DOI:10.3970/mcb.2013.010.267

Abstract Human Umbilical Cord Mesenchymal Stem Cells (hUCMSCs) were subjected to in vitro osteogenic differentiation using a novel combination of signaling molecules including BMP-2 and purmorphamine. Differentiation outcomes were assessed by calcein staining and by microscopic examination of the cytoskeleton. Calcein staining showed appreciable degree of calcium mineralization in cell culture, and changes in the morphological attributes of differentiating cells were observed vis-a-vis the actin cytoskeleton. Finally, positive calcein staining, altered cytoskeletal profile, and stress fiber formation in treated cells demonstrated, for the first time, a potentially synergistic interplay between BMP-2 and the hedgehog agonist, purmorphamine. This study lends support to… More >

Hana Chang^*, Melissa L. Knothe Tate^∗,†,‡

Molecular & Cellular Biomechanics, Vol.8, No.4, pp. 297-318, 2011, DOI:10.3970/mcb.2011.008.297

Abstract In the preceding study (Part A), we showed that prescribed seeding conditions as well as seeding density can be used to subject multipotent stem cells (MSCs) to volume changing stresses and that changes in volume of the cell are associated with changes in shape, but not volume, of the cell nucleus. In the current study, we aim to control the mechanical milieu of live cells using these prescribed seeding conditions concomitant to delivery of shape changing stresses via fluid flow, while observing adaptation of the cytoskeleton, a major cellular transducer that modulates cell shape, stiffness and remodeling. We hypothesize that… More >

Wangping Duan^∗, Lei Wei^†, Juntao Zhang^∗, Yongzhuang Hao^∗, Chunjiang Li^∗, Hao Li^∗, Qi Li^∗, Quanyou Zhang^‡, Weiyi Chen^‡, Xiaochun Wei^∗,§

Molecular & Cellular Biomechanics, Vol.8, No.4, pp. 253-274, 2011, DOI:10.3970/mcb.2011.008.253

Abstract The cytoskeleton network is believed to play an important role in the biomechanical properties of the chondrocyte. Ours and other laboratories have demonstrated that chondrocytes exhibit a viscoelastic solid creep behavior in vitro and that viscoelastic properties decrease in osteoarthritic chondrocytes. In this study, we aimed to understand whether the alteration of viscoelastic properties is associated with changes in cytoskeleton components of ageing chondrocytes from rabbit knee articular cartilage. Three age groups were used for this study: young (2-months-old, N=23), adult (8-months-old, N=23), and old (31-months-old, N=23) rabbit groups. Cartilage structure and proteoglycan and type II collagen content were determined… More >

K. Y. Volokh^*

Molecular & Cellular Biomechanics, Vol.8, No.3, pp. 195-214, 2011, DOI:10.3970/mcb.2011.008.195

Abstract All models are wrong, but some are useful. This famous saying mirrors the situation in cell mechanics as well. It looks like no particular model of the cell deformability can be unconditionally preferred over others and different models reveal different aspects of the mechanical behavior of living cells. The purpose of the present work is to discuss the so-called tensegrity models of the cell cytoskeleton. It seems that the role of the cytoskeleton in the overall mechanical response of the cell was not appreciated until Donald Ingber put a strong emphasis on it. It was fortunate that Ingber linked the… More >

T. Zhang^*

Molecular & Cellular Biomechanics, Vol.8, No.3, pp. 169-194, 2011, DOI:10.3970/mcb.2011.008.169

Abstract Cytoplasmic motion assumed as a steady state laminar flow induced by cytoskeleton stretching in a cell is determined and its effect on the mechanical behavior of the cell under externally applied forces is demonstrated. Non-Newtonian fluid is assumed for the multiphase cytoplasmic fluid and the analytical velocity field around the macromolecular chain is obtained by solving the reduced nonlinear momentum equation using homotopy technique. The entropy generation by the fluid internal friction is calculated and incorporated into the entropic elasticity based 8-chain constitutive relations. Numerical examples showed strengthening behavior of cells in response to externally applied mechanical stimuli. The spatial… More >

Ning Wang^*

Molecular & Cellular Biomechanics, Vol.7, No.1, pp. 33-44, 2010, DOI:10.3970/mcb.2010.007.033

Abstract Professor Y.C. Fung has shown that living tissues remodel extensively in response to mechanical forces such as blood pressure variations. At the cellular level, those mechanical perturbations must be perceived by individual cells. However, mechanisms of mechanochemical transduction in living cells remain a central challenge to cell biologists. Contrary to predictions by existing models of living cells, we reported previously that a local stress, applied via integrin receptors, is propagated to remote sites in the cytoplasm and is concentrated at discrete foci. Here we report that these foci of strains and stresses in the cytoplasm correspond to local peak deformation… More >

Siva A. Vanapalli^∗,†, Yixuan Li^†, Frieder Mugele^†, Michel H. G. Duits^†

Molecular & Cellular Biomechanics, Vol.6, No.4, pp. 191-202, 2009, DOI:10.3970/mcb.2009.006.191

Abstract Endogenous granules (EGs) that consist of lipid droplets and mitochondria have been commonly used to assess intracellular mechanical properties via multiple particle tracking microrheology (MPTM). Despite their widespread use, the nature of interaction of EGs with the cytoskeletal network and the type of forces driving their dynamics - both of which are crucial for the interpretation of the results from MPTM technique - are yet to be resolved. In this report, we study the dynamics of endogenous granules in mammalian cells using particle tracking methods. We find that the ensemble dynamics of EGs is diffusive in three types of mammalian… More >