Mechanotransduction in bone—role of the lacunocanalicular network

TLDR

The capacity of bone tissue to remodel in response to mechanical demands is well known, yet the cellular mechanisms remain poorly understood. The authors aim to summarize recent advances in bone mechanotransduction. Osteocytes sense mechanical strain through fluid flow in the lacuno‑canalicular network, which transmits signals and nutrients. This mechanosensing model explains bone remodeling in response to fatigue damage, linking osteocyte activity to local bone gain and loss.

Abstract

The capacity of bone tissue to alter its mass and structure in response to mechanical demands has long been recognized but the cellular mechanisms involved remained poorly understood. Over the last several years significant progress has been made in this field, which we will try to summarize. These studies emphasize the role of osteocytes as the professional mechanosensory cells of bone, and the lacuno-canalicular porosity as the structure that mediates mechanosensing. Strain-derived flow of interstitial fluid through this porosity seems to mechanically activate the osteocytes, as well as ensuring transport of cell signaling molecules and nutrients and waste products. This concept allows an explanation of local bone gain and loss, as well as remodeling in response to fatigue damage, as processes supervised by mechanosensitive osteocytes.