Short Abstract
The capacity of bone tissue to adapt to changing mechanical demands is well documented, but how the cells of bone perform this task remains poorly understood. Over the last decade significant progress has been made in understanding how bone cells may sense and transduce mechanical signals derived from bone loading. These studies emphasize the role of osteocytes as the “professional” mechanosensory cells of bone, and the lacuno-canalicular network as the structure that mediates mechanosensing. The regulatory process of mechanical adaptation produces flow of interstitial fluid in the bone lacunar-canalicular network along the surface of osteocytes, which is likely the physiological signal for bone cell adaptive responses in vivo. As a result, the maintenance of a mechanically efficient architecture is likely to depend on a balance between the intensity and spatial distribution of the mechanical stimulus and the responsiveness of the bone cells. In addition, the alignment of secondary osteons along the dominant loading direction suggests that bone remodeling is guided by mechanical strain. This means that adaptation (Wolff’s Law) takes place throughout life at each remodelling cycle. We propose that alignment during remodelling occurs as a result of different canalicular flow patterns around cutting cone and reversal zone during loading. This knowledge may lead to new strategies for combating disuse-related osteoporosis, and may also be of use in understanding and predicting the long-term integration of bone-replacing implants.
Biography
Jenneke Klein-Nulend (1957) is full Professor of Oral Cell Biology at ACTA-VU University Amsterdam. She has an extensive international reputation in the area of growth, mechanical adaptation, and regeneration of bone. She was postdoc at the University of Connecticut Health Center, and Fellow of the Royal Netherlands Academy of Arts & Sciences at Massachusetts General Hospital and Harvard Medical School, and at ACTA-VU University Amsterdam. She published >200 papers (peer-reviewed). She was Founding Member of the Micro-mechanical Tissue Repair Society, Board member of the Dutch Society for Calcium and Bone Metabolism, Chair of the Dutch Society of Biomaterials and Tissue Engineering, Editorial Staff Member of the Dutch Journal of Calcium and Bone Metabolism, and is currently Editorial Board member of 4 other international journals, and Directorate Board member of the Research Institute MOVE.