Bone Functional Adaptation by Remodeling: In Silico Modeling and Experiment

Seminar | September 24 | 4-5 p.m. | 3110 Etcheverry Hall

 Professor Taiji Adachi, Institute for Frontier Life and Medical Sciences; Kyoto University, Japan

 Department of Mechanical Engineering (ME)

Abstract: Bone structure is maintained by mechanical adaptation by remodeling, in which osteoclastic bone resorption and osteoblastic bone formation are in harmony with each other under the regulation by mechanosensory network of osteocytes in bone matrix. An imbalance between bone resorption and formation due to disuse results in metabolic bone disorders such as osteoporosis. Cell and molecular biology studies have identified many signaling pathways that regulate these cellular activities; however, the physiological and pathological conditions of bone as a system remain difficult to understand because of the complexity of the signaling networks including mechano-biochemical couplings. We have developed a novel mathematical model of bone functional adaptation by remodeling that enables us to conduct in silico experiment by which the effects of perturbation of the biochemical and mechanical factors on the spatiotemporal dynamics of bone remodeling can be observed.

Using the proposed in silico experiment platform, effects of disruption of the signaling molecules were investigated through computational simulations for cancellous bone remodeling using image-based cancellous bone models. Mechano-adaptive behaviors of trabecular bone under mechanical loading were investigated by considering a mechano-sensory network of osteocytes in bone matrix, in which the pathological bone states due to low mechanical loadings and abnormal expression of signaling molecules were reproduced. The developed platform was applied to conduct in silico perturbation experiment to observe the effects of specific signaling molecules on bone remodeling dynamics over time including distribution of signaling molecules, cell behaviors, and trabecular microstructure.

Biography: Taiji Adachi PhD is Professor at the Laboratory of Biomechanics, Department of Biosystems Science, Institute for Frontier Life and Medical Sciences, Kyoto University. He received his BS (1990) in Mechanical Engineering at Kobe University, MS (1992) and PhD (1997) at Osaka University. He joined the Department of Mechanical Engineering as a Research Associate (1992) at Kobe University, worked as a Research Fellow at the Orthopaedic Research Laboratory at the University of Michigan (1997-99). He joined the Department of Mechanical Engineering as an Associate Professor (2004) at Kyoto University, and was promoted to Professor (2010-) at the Institute for Frontier Medical Sciences. He is working in the fields of cell and molecular biomechanics and mechanobiology, and has been a World Council Member of Biomechanics since 2011., 510-643-8165