Shouqin Lü¹, Mian Long^1,2

Molecular & Cellular Biomechanics, Vol.2, No.4, pp. 161-178, 2005, DOI:10.3970/mcb.2005.002.161

Abstract Selectin-ligand interactions are crucial to such biological processes as inflammatory cascade or tumor metastasis. How transient formation and dissociation of selectin-ligand bonds in blood flow are coupled to molecular conformation at atomic level, however, has not been well understood. In this study, steered molecular dynamics (SMD) simulations were used to elucidate the intramolecular and intermolecular conformational evolutions involved in forced dissociation of three selectin-ligand systems: the construct consisting of P-selectin lectin (Lec) and epidermal growth factor (EGF)-like domains (P-LE) interacting with synthesized sulfoglycopeptide or SGP-3, P-LE with sialyl Lewis X (sLe^X), and E-LE with sLe^X. SMD… More >

Cheng Dong^1,2,3, Margaret J. Slattery^2,3, Shile Liang³, Hsin-Hsin Peng²

Molecular & Cellular Biomechanics, Vol.2, No.3, pp. 145-160, 2005, DOI:10.3970/mcb.2005.002.145

Abstract Attachment of tumor cells to the endothelium (EC) under flow conditions is critical for the migration of tumor cells out of the vascular system to establish metastases. Innate immune system processes can potentially promote tumor progression through inflammation dependant mechanisms.\nobreakspace {} White blood cells, neutrophils (PMN) in particular, are being studied to better understand how the host immune system affects cancer cell adhesion and subsequent migration and metastasis. Melanoma cell interaction with the EC is distinct from PMN-EC adhesion in the circulation. We found PMN increased melanoma cell extravasation, which involved initial PMN tethering on… More >

A.L. Brock, D.E. Ingber¹

Molecular & Cellular Biomechanics, Vol.2, No.3, pp. 135-144, 2005, DOI:10.3970/mcb.2005.002.135

Abstract The direction in which cells extend new motile processes, such as lamellipodia and filopodia, can be controlled by altering the geometry of extracellular matrix adhesive islands on which individual cells are cultured, thereby altering mechanical interactions between cells and the adhesive substrate [Parker (2002)]. Here we specifically investigate the intracellular molecular signals that mediate the mechanism by which cells selectively extend these processes from the corners of polygonal-shaped adhesive islands. Constitutive activation of the small GTPase Rac within cells cultured on square-shaped islands of fibronectin resulted in the elimination of preferential extension from corners. This… More >

S. Deguchi^1,2, T. Ohashi², M. Sato²

Molecular & Cellular Biomechanics, Vol.2, No.3, pp. 125-134, 2005, DOI:10.3970/mcb.2005.002.125

Abstract Actin bundles in vascular endothelial cells (ECs) play a critical role in transmitting intracellular forces between separate focal adhesion sites. However, quantitative descriptions of tension level in single actin bundles in a physiological condition are still poorly studied. Here, we evaluated magnitude of preexisting tension in a single actin bundle of ECs on the basis of measurements of its preexisting stretching strain and tensile properties. Cultured ECs expressing fluorescently-labeled actin were treated with detergents to extract acin bundles. One end of an actin bundle was then dislodged from the substrate by using a microneedle, resulting… More >

S.R.K. Vedula¹, T.S. Lim², P.J. Kausalya³, W. Hunziker³, G. Rajagopal², C.T. Lim^1,4

Molecular & Cellular Biomechanics, Vol.2, No.3, pp. 105-124, 2005, DOI:10.3970/mcb.2005.002.105

Abstract Cell-cell adhesion is an extremely important phenomenon as it influences several biologically important processes such as inflammation, cell migration, proliferation, differentiation and even cancer metastasis. Furthermore, proteins involved in cell-cell adhesion are also important from the perspective of facilitating better drug delivery across epithelia. The adhesion forces imparted by proteins involved in cell-cell adhesion have been the focus of research for sometime. However, with the advent of nanotechnological techniques such as the atomic force microscopy (AFM), we can now quantitatively probe these adhesion forces not only at the cellular but also molecular level. Here, we More >

Cheng Zhu¹, Rodger P. McEver²

Molecular & Cellular Biomechanics, Vol.2, No.3, pp. 91-104, 2005, DOI:10.3970/mcb.2005.002.091

Abstract Force can shorten the lifetimes of receptor-ligand bonds by accelerating their dissociation. Perhaps paradoxical at first glance, bond lifetimes can also be prolonged by force. This counterintuitive behavior was named catch bonds, which is in contrast to the ordinary slip bonds that describe the intuitive behavior of lifetimes being shortened by force. Fifteen years after their theoretical proposal, catch bonds have finally been observed. In this article we review recently published data that have demonstrated catch bonds in the selectin system and suggested catch bonds in other systems, the theoretical models for their explanations, and More >

X. Edward Guo¹, Gang Bao¹

Molecular & Cellular Biomechanics, Vol.2, No.3, pp. 89-90, 2005, DOI:10.3970/mcb.2005.002.089

Abstract This article has no abstract. More >

X. Edward Guo¹, Gang Bao¹

Molecular & Cellular Biomechanics, Vol.2, No.3, pp. 87-88, 2005, DOI:10.3970/mcb.2005.002.087

Abstract This article has no abstract. More >

Muhammad H. Zaman¹, Mohammad R. Kaazempur-Mofrad²

Molecular & Cellular Biomechanics, Vol.1, No.4, pp. 291-302, 2004, DOI:10.3970/mcb.2004.001.291

Abstract α-actinin, an actin binding protein, plays a key role in cell migration, cross-links actin filaments in the Z-disk, and is a major component of contractile muscle apparatus. The flexibility of the molecule is critical to its function. The flexibility of various regions of the molecule, including the linker connecting central subunits is studied using constant force steered molecular dynamics simulations. The linker, whose structure has been a subject of debate, is predicted to be semi-flexible. The flexibility of the linker is compared to all possible segments of equal length throughout the molecule. The stretching profile More >

A. Shukla^1,1, A.R. Dunn^2,2, M.A. Moses^3,3, K.J. Van Vliet^4,4

Molecular & Cellular Biomechanics, Vol.1, No.4, pp. 279-290, 2004, DOI:10.3970/mcb.2004.001.279

Abstract Although it is established that endothelial cells can respond to external mechanical cues (e.g., alignment in the direction of fluid shear stress), the extent to which mechanical stress and strain applied via the endothelial cell substrate impact biomolecular and cellular processes is not well-understood. This issue is particularly important in the context of inflammation, vascular remodeling, and cancer progression, as each of these processes occurs concurrently with localized increases in strain and marked changes in molecules secreted by adjacent cells. Here, we systematically vary the level and duration of cyclic tensile strain applied to human… More >