Journal of Bone and Mineral Research

Abstract

The use of hydrostatic pressure to apply mechanical stress to bone organ cultures is reviewed. Ossifying long bones and calvarial rudiments are sensitive to this type of stress. Intermittent hydrostatic compression of near physiologic magnitude (ICF) has anabolic effects on mineral metabolism in such rudiments, and continuous hydrostatic stress of high magnitude (CCP) has catabolic effects. The effects of ICF may be ascribed to shear stress generated at tissue interphases of different chemical and mechanical properties. Local factors, such as prostaglandins and growth factors, seem to be involved in the tissue response to mechanical stress.

Signaling by mechanical strain involves transcriptional regulation of proinflammatory genes in human periodontal ligament cells in vitro

“…Ample evidence exists to suggest that mechanical forces of high magnitude (12.5%-18%) evoke inflammatory responses in PDL cells that are characterized not only by the induction of IL-1β in the periodontal tissue, but also by the presence of PGE 2 . 10,22,24,25 For example, the application of mechanical forces on teeth induces PGE 2 production in vivo, 4,12 and IL-1β and PGE 2 production in PDL cells in vitro. 15,18,22,24,25 In vivo, PGE 2 production in response to mechanical stress has been shown to be associated with bone resorption, whereas the application of exogenous PGE 2 was shown to enhance matrix degradation and osteoclastic differentiation in response to applied mechanical forces.…”

“…On the other hand, nonphysiologic higher magnitudes of TENS provoke proinflammatory signals, which may consequently induce bone resorption, frequently observed at the tension sites in response to a higher magnitude of applied mechanical forces. 4,6,23,29 In both of these processes, molecules of the proinflammatory signal transduction pathways may act as intermediaries for the mechanotransduction pathways to induce synthesis of bone. Whether TENS specifically inhibits IL-1β actions or whether it can counteract actions of other inflammatory mediators like TNF-α, PGE 2 , or endotoxins found in inflamed PDL, has yet to be determined.…”

“…9,14,16,23 It is well documented that compressive forces induce expression of proinflammatory mediators, and interleukin-β (IL-1β) has been implicated as one of the major cytokines synthesized in response to compressive forces exerted on the PDL. 4,13,14,16,23 IL-1β stimulates prostaglandin estradiol (PGE 2 ) synthesis, 9,16,19,[23][24][25]30 Nitric oxide (NO) production, 9,28,30 and secretion of proteases. 7,10,19 Simultaneously, IL-1β induces synthesis of matrix metalloproteinases (MMPs) to augment matrix degradation, 2,12,18 and also inhibits synthesis of tissue inhibitor of metalloprotease-II (TIMP-II), a potent suppressor of MMP activity.…”

The effect of mechanical loading on osteogenesis of human dental pulp stromal cells in a novel in vitro model

“…In fact, Individual cells experience different combinations of substrate strain (e.g. tensile, compression, and shear); strain induced fluid flow depending on loading-related deformation of scaffold; and the hydrostatic compression from the environment (Burger et al 1992;Hsieh and Turner 2001;van der Linden et al 2001).The aim of this study was to mimic chewing force and to investigate the optimum mechanical force which could accelerate hDPSCs osteogenesis.…”

An Interleukin-1 Loop Is Induced in Human Skin Fibroblasts upon Stress Relaxation in a Three-dimensional Collagen Gel but Is Not Involved in the Up-regulation of Matrix Metalloproteinase 1

“…Much less is known about the messages that the cells receive and the signaling that is triggered when stress is released. This event is relevant to investigate since it participates in physiological and pathological processes observed during extracellular matrix degradation in remodeling, cancer and inflammatory diseases, mammary epithelium differentiation (3), and osteoporosis induced by suppression of muscular activity or in weightlessness conditions (4). Furthermore, reduced mechanical tension is actually regarded as a signal inducing programmed cell death (5,6) The culture of cells within a free floating gel of collagen polymers offers a model of integrin-mediated stress relaxation.…”