Beauty of science: Osteocyte lacuno-canalicular network

Reporter: Aviral Vatsa
A new study by Alexandra Pacureanu et al. of Creatis INSA Lyon & ESRF has been submitted for publication. It presents the 3D structure of human bone by using latest imaging techniques

Based on a sample from the femur of a 92-year-old female, it shows for the first time over a large field of view the 3D “osteocyte lacuno-canalicular network” – a complex mesh of holes and channels embedded in mineralised bone. By allowing the transport of signals, nutrients and waste, this cell network is what gives bone tissue the ability to locally alter its mass and structure in response to damage or mechanical stress. Until now, however, its 3D organisation and its implications for bone remodelling have remained out of reach. In this image, which represents a volume of around 0.02 mm³, several osteons (the primary functional units of compact bone) can be seen with a large number of cell dendrites emerging radially from the central canal (red). In addition to answering fundamental questions in biology, the technique is likely to be of interest for developing strategies to deal with bone diseases and provides new input for biomechanical modelling. The work was carried out by Alexandra Pacureanu et al. of Creatis INSA Lyon & ESRF and co-workers at the UPMC in Paris (submitted for publication).

Book Chapter - Mechanobiology of bone: From cell to organ

I am very pleased to post that the book containing a chapter authoured by myself and others has been released. This book entitled "Cell Mechanochemistry. Biological Systems and Factors Inducing Mechanical Stress, Such as Light, Pressure and Gravity " focuses on different aspects of cell mechanochemistry, mechanosensing and mechanotransduction.

Mechanobiology of bone: From cell to organ

Aviral Vatsa1, Theo H. Smit2 and Jenneke Klein-Nulend1

1Department of Oral Cell Biology, ACTA-University of Amsterdam and VU University Amsterdam Research Institute MOVE, Amsterdam, The Netherlands
2Department of Physics and Medical Technology, VU-University Medical Center, Vrije Universiteit, Research Institute MOVE, Amsterdam The Netherlands

Abstract. Bone is a dynamic tissue that adapts its mass and architecture in accordance with the external mechanical loads, which it experiences during daily life. Bones maintain a balance of toughness and light weight by a process of repeated turnover, wherein old and/or damaged bone is resorbed from the areas which are mechanically ‘unloaded’ and/or damaged, and deposited in the areas that experience increased mechanical loading. This precise phenomenon is achieved by the concerted activity of osteocytes, osteoblasts, and osteoclasts. Osteocytes sense the mechanical loads and transduce the mechanical signals into bio-molecules, which then orchestrate the activity of bone forming osteoblasts and/or bone resorbing osteoclasts. Recent years have seen a surge in the scientific efforts to better understand this intricate phenomenon of bone remodeling, both at the tissue level and at a single cell level. These new discoveries unravel the complexities involved in maintenance of bone physiology and hence pave a path in devising new therapeutic targets for bone repair and regeneration. In this chapter, we highlight the latest developments in bone remodeling and reflect on their connection with the historic perspective of bone adaptation to external mechanical loading.