http://ukpmc.ac.uk – 1. We have used a cascade bioassay system and isolated arterial ring preparations to investigate the contribution of the endothelial microfilament and microtubule cytoskeleton to EDRF release evoked by time-averaged shear stress and by acetylcholine in rabbit abdominal aorta. 2. Cytochalasin B (1 microM) and phalloidin (100 nM) were used to depolymerize and stabilize, respectively, F-actin microfilaments. Colchicine (500 nM) was used to inhibit tubulin dimerization and thus disrupt the microtubule network. Read more »

http://www.springerlink.com – Focal adhesion proteins link cell surface integrins and intracellular actin stress fibers and therefore play an important role in mechanotransduction and cell motility. When endothelial cells are subjected to cyclic mechanical strain, time-lapse imaging revealed that cells underwent significant morphological changes with their resultant long axes aligned away from the strain direction. To explore how this response is regulated by focal adhesion-associated proteins the expression levels of paxillin, focal adhesion kinase (FAK), and zyxin were knocked down using gene silencing techniques. Read more »

http://www.sciencedirect.com – Recent developments in modeling the relationship between bone microstructure and mechanotransduction are reviewed. The focus is on the relationship between the bone microstructure and the mechanosensation mechanism by which osteocytes sense the bone fluid motion propelled by the mechanical loading of the whole bone. Read more »

http://arjournals.annualreviews.org – Mechanical forces play an important role in the organization, growth, maturation, and function of living tissues. At the cellular level, many of the biological responses to external forces originate at two types of specialized microscale structures: focal adhesions that link cells to their surrounding extracellular matrix and adherens junctions that link adjacent cells. Read more »

http://www.ncbi.nlm.nih.gov – Spermatogenesis is a highly complicated process in which functional spermatozoa (haploid, 1n) are generated from primitive mitotic spermatogonia (diploid, 2n). This process involves the differentiation and transformation of several types of germ cells as spermatocytes and spermatids undergo meiosis and differentiation. Due to its sophistication and complexity, testis possesses intrinsic mechanisms to modulate and regulate different stages of germ cell development under the intimate and indirect cooperation with Sertoli and Leydig cells, respectively. Read more »

http://www.ncbi.nlm.nih.gov – Cyclic stretching is pivotal to maintenance of the ligaments. However, it is still not clear when ligament fibroblasts switch on expression of genes related to the mechanotransduction pathway in response to cyclic stretching. This in vitro study investigated, using ligament fibroblasts, the time-dependent changes in distribution and gene expression of β1 integrin, the cytoskeleton, and collagens after the application of 6% cyclic stretching at a frequency of 0.1 Hz for 3 hr on silicon membranes. Read more »

http://www.ncbi.nlm.nih.gov – Actin stress fiber (SF), focal adhesion (FA) and adherens junction (AJ) are known structures whose formation and development are mechanical force-dependent. At these structures, actin is actively polymerized, which in turn contributes the development of these structures. Recently, we reported that actin polymerization at FAs is facilitated by mechanical forces, which was critically dependent on the force-induced recruitment of the LIM protein zyxin to FAs. Zyxin enhances actin polymerization with the aid of Ena/VASP proteins. Read more »

http://www3.interscience.wiley.com – The process of chondrocyte mechanotransduction is poorly understood. However, recent studies suggest the involvement of a purinergic calcium signaling pathway although the mechanism of ATP release has not been identified. The present study tests the hypothesis that cyclic compression opens hemichannels thereby triggering the release of ATP into the extracellular milieu activating P2 receptors. The well-established chondrocyte-agarose model was utilized enabling chondrocytes to be subjected to a 40-min period of cyclic compression at 0-15% strain and 1 Hz. Read more »

http://www.springerlink.com – Transient receptor potential (TRP) ion channel superfamily is involved in sensing and transmission of a broad variety of external or internal stimuli, including but not limited to mechanical stress. Based on homology analysis, genetic and molecular studies have recently identified TRP channels in different tissues, comprising blood vessels. In invertebrates, many TRP channels including five TRPV channels identified in Caenorhabditis elegans and two in Drosophila have been implicated in mechanosensory behaviors as molecular basis of volume regulation, hearing and touch sensitivity. Read more »

http://dx.doi.org – Mechanical properties of living cells are important for cell shape, motility, and cellular responses to biochemical and biophysical signals. Although these properties are predominantly determined by the cytoskeleton, relatively little is known about the mechanical organization of cells at a subcellular level. We have studied the cell cortex of bovine pulmonary artery endothelial cells (BPAECs) using atomic force microscopy (AFM) and confocal fluorescence microscopy (CFM). Read more »